Sample records for taxol-resistant cancer cells

  1. Insulin-Like Growth Factor 2 Silencing Restores Taxol Sensitivity in Drug Resistant Ovarian Cancer

    PubMed Central

    Brouwer-Visser, Jurriaan; Lee, Jiyeon; McCullagh, KellyAnne; Cossio, Maria J.; Wang, Yanhua; Huang, Gloria S.

    2014-01-01

    Drug resistance is an obstacle to the effective treatment of ovarian cancer. We and others have shown that the insulin-like growth factor (IGF) signaling pathway is a novel potential target to overcome drug resistance. The purpose of this study was to validate IGF2 as a potential therapeutic target in drug resistant ovarian cancer and to determine the efficacy of targeting IGF2 in vivo. An analysis of The Cancer Genome Atlas (TCGA) data in the serous ovarian cancer cohort showed that high IGF2 mRNA expression is significantly associated with shortened interval to disease progression and death, clinical indicators of drug resistance. In a genetically diverse panel of ovarian cancer cell lines, the IGF2 mRNA levels measured in cell lines resistant to various microtubule-stabilizing agents including Taxol were found to be significantly elevated compared to the drug sensitive cell lines. The effect of IGF2 knockdown on Taxol resistance was investigated in vitro and in vivo. Transient IGF2 knockdown significantly sensitized drug resistant cells to Taxol treatment. A Taxol-resistant ovarian cancer xenograft model, developed from HEY-T30 cells, exhibited extreme drug resistance, wherein the maximal tolerated dose of Taxol did not delay tumor growth in mice. Blocking the IGF1R (a transmembrane receptor that transmits signals from IGF1 and IGF2) using a monoclonal antibody did not alter the response to Taxol. However, stable IGF2 knockdown using short-hairpin RNA in HEY-T30 effectively restored Taxol sensitivity. These findings validate IGF2 as a potential therapeutic target in drug resistant ovarian cancer and show that directly targeting IGF2 may be a preferable strategy compared with targeting IGF1R alone. PMID:24932685

  2. Association between Twist and multidrug resistance gene-associated proteins in Taxol®-resistant MCF-7 cells and a 293 cell model of Twist overexpression.

    PubMed

    Wang, Li; Tan, Rui-Zhi; Zhang, Zhi-Xia; Yin, Rui; Zhang, Yong-Liang; Cui, Wei-Jia; He, Tao

    2018-01-01

    Multidrug resistance (MDR) severely limits the effectiveness of chemotherapy. Previous studies have identified Twist as a key factor of acquired MDR in breast, gastric and prostate cancer. However, the underlying mechanisms of action of Twist in MDR remain unclear. In the present study, the expression levels of MDR-associated proteins, including lung resistance-related protein (LRP), topoisomerase IIα (TOPO IIα), MDR-associated protein (MRP) and P-glycoprotein (P-gp), and the expression of Twist in cancerous tissues and pericancerous tissues of human breast cancer, were examined. In order to simulate Taxol ® resistance in cells, a Taxol ® -resistant human mammary adenocarcinoma cell subline (MCF-7/Taxol ® ) was established by repeatedly exposing MCF-7 cells to high concentrations of Taxol ® (up to 15 µg/ml). Twist was also overexpressed in 293 cells by transfecting this cell line with pcDNA5/FRT/TO vector containing full-length hTwist cDNA to explore the dynamic association between Twist and MDR gene-associated proteins. It was identified that the expression levels of Twist, TOPO IIα, MRP and P-gp were upregulated and LRP was downregulated in human breast cancer tissues, which was consistent with the expression of these proteins in the Taxol ® -resistant MCF-7 cell model. Notably, the overexpression of Twist in 293 cells increased the resistance to Taxol ® , Trichostatin A and 5-fluorouracil, and also upregulated the expression of MRP and P-gp. Taken together, these data demonstrated that Twist may promote drug resistance in cells and cancer tissues through regulating the expression of MDR gene-associated proteins, which may assist in understanding the mechanisms of action of Twist in drug resistance.

  3. Activation of acetyl-coenzyme A carboxylase is involved in Taxol-induced ovarian cancer cell death

    PubMed Central

    WU, JIANG; JI, FANG; DI, WEN; CHEN, HONGDUO; WAN, YINSHENG

    2011-01-01

    Acetyl-coenzyme A carboxylase (ACC) is an attractive target for research into the treatment of a variety of human diseases, including diabetes, obesity and cancer. Mounting evidence suggests that the inhibition of ACC induced of cancer cell apoptosis. However, whether the inhibition of ACC regulates apoptosis in CaOV3 cancer cells has yet to be addressed. This study investigated the cytotoxic mechanism of action of ACC inhibition. Results showed that 5-(tetradecyloxy)-2-furoic acid (TOFA), an ACC inhibitor, enhanced Taxol-induced CaOV3 human ovarian cancer cell apoptosis. Notably, when TOFA was administered as a monotherapy, it induced CaOV3 cell apoptosis. Pre-treatment with the EGFR inhibitor PD153035 was found to markedly enhance ACC phosphorylation, whereas AMP-activated protein kinase (AMPK) activator AICAR was found to marginally enhance ACC phosphorylation. Taken together, the data showed ACC is a potential novel molecular target of Taxol. Additionally, ACC inhibition partially contributed to the cytotoxic effect of Taxol in ovarian cancer cells. PMID:22866118

  4. Activation of acetyl-coenzyme A carboxylase is involved in Taxol-induced ovarian cancer cell death.

    PubMed

    Wu, Jiang; Ji, Fang; DI, Wen; Chen, Hongduo; Wan, Yinsheng

    2011-05-01

    Acetyl-coenzyme A carboxylase (ACC) is an attractive target for research into the treatment of a variety of human diseases, including diabetes, obesity and cancer. Mounting evidence suggests that the inhibition of ACC induced of cancer cell apoptosis. However, whether the inhibition of ACC regulates apoptosis in CaOV3 cancer cells has yet to be addressed. This study investigated the cytotoxic mechanism of action of ACC inhibition. Results showed that 5-(tetradecyloxy)-2-furoic acid (TOFA), an ACC inhibitor, enhanced Taxol-induced CaOV3 human ovarian cancer cell apoptosis. Notably, when TOFA was administered as a monotherapy, it induced CaOV3 cell apoptosis. Pre-treatment with the EGFR inhibitor PD153035 was found to markedly enhance ACC phosphorylation, whereas AMP-activated protein kinase (AMPK) activator AICAR was found to marginally enhance ACC phosphorylation. Taken together, the data showed ACC is a potential novel molecular target of Taxol. Additionally, ACC inhibition partially contributed to the cytotoxic effect of Taxol in ovarian cancer cells.

  5. Circumvention of Taxol-Resistance in Human Breast Cancers by Improved Water Soluble Taxanes

    DTIC Science & Technology

    2001-10-01

    possible roles of interferon alpha, tumor necrosis factor alpha and transforming growth factor beta in Mn-SOD induction by polysaccharide K. Cancer ...chemoembolization in combination with local hyperthermia. Japanese Journal of Cancer & Chemotherapy. 16:2957-2960 61. Kidd P. (2000) The use of mushroom glucans ...Circumvention of Taxol-Resistance in Human Breast Cancers by Improved Water Soluble Taxanes PRINCIPAL INVESTIGATOR: Li-Xi Yang, M.D., Ph.D. CONTRACTING

  6. Androgen and taxol cause cell type-specific alterations of centrosome and DNA organization in androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cells

    NASA Technical Reports Server (NTRS)

    Schatten, H.; Ripple, M.; Balczon, R.; Weindruch, R.; Chakrabarti, A.; Taylor, M.; Hueser, C. N.

    2000-01-01

    We investigated the effects of androgen and taxol on the androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cell lines. Cells were treated for 48 and 72 h with 0.05-1 nM of the synthetic androgen R1881 and with 100 nM taxol. Treatment of LNCaP cells with 0.05 nM R1881 led to increased cell proliferation, whereas treatment with 1 nM R1881 resulted in inhibited cell division, DNA cycle arrest, and altered centrosome organization. After treatment with 1 nM R1881, chromatin became clustered, nuclear envelopes convoluted, and mitochondria accumulated around the nucleus. Immunofluorescence microscopy with antibodies to centrosomes showed altered centrosome structure. Although centrosomes were closely associated with the nucleus in untreated cells, they dispersed into the cytoplasm after treatment with 1 nM R1881. Microtubules were only faintly detected in 1 nM R1881-treated LNCaP cells. The effects of taxol included microtubule bundling and altered mitochondria morphology, but not DNA organization. As expected, the androgen-independent prostate cancer cell line DU145 was not affected by R1881. Treatment with taxol resulted in bundling of microtubules in both cell lines. Additional taxol effects were seen in DU145 cells with micronucleation of DNA, an indication of apoptosis. Simultaneous treatment with R1881 and taxol had no additional effects on LNCaP or DU145 cells. These results suggest that LNCaP and DU145 prostate cancer cells show differences not only in androgen responsiveness but in sensitivity to taxol as well. Copyright 2000 Wiley-Liss, Inc.

  7. Live morphological analysis of taxol-induced cytoplasmic vacuolization [corrected] in human lung adenocarcinoma cells.

    PubMed

    Wang, Xiao-Ping; Chen, Tong-Sheng; Sun, Lei; Cai, Ji-Ye; Wu, Ming-Qian; Mok, Martin

    2008-12-01

    Taxol (paclitaxel), one of the most active cancer chemotherapeutic agents, can cause programmed cell death (PCD) and cytoplasmic vacuolization. The objective of this study was to analyze the morphological characteristics induced by taxol. Human lung adenocarcinoma (ASTC-a-1) cells were exposed to various concentration of taxol. CCK-8 was used to assay the cell viability. Atomic force microscopy (AFM), plasmid transfection and confocal fluorescence microscopy were performed to image the cells morphological change induced by taxol. Fluorescence resonance energy transfer (FRET) was used to monitor the caspase-3 activation in living cells during taxol-induced cell death. Cells treated with taxol exhibited significant swelling and cytoplasmic vacuolization which may be due to endoplasmic reticulum (ER) vacuolization. Caspase-3 was not activated during taxol-induced cytoplasmic vacuolization and cell death. These findings suggest that taxol induces caspase-3-independent cytoplasmic vacuolization, cell swelling and cell death through ER vacuolization.

  8. Anti-proliferative effect of fungal taxol extracted from Cladosporium oxysporum against human pathogenic bacteria and human colon cancer cell line HCT 15

    NASA Astrophysics Data System (ADS)

    Gokul Raj, K.; Manikandan, R.; Arulvasu, C.; Pandi, M.

    2015-03-01

    Cladosporium oxysporum a new taxol producing endophytic fungus was identified and production of taxol were characterized using UV-visible spectroscopy (UV-vis), high-performance liquid chromatography (HPLC), infrared (IR) nuclear magnetic resonance spectroscopy (NMR (13C and 1H)) and liquid chromatography-mass spectrometry (LC-MS). The taxol biosynthetic gene (dbat) was evaluated for new taxol producing fungus. Antibacterial activity against six different human pathogenic bacteria was done by agar well diffusion method. The anticancer efficacy of isolated fungal taxol were also evaluated in human colon cancer cell HCT 15 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cytotoxicity and nuclear morphology analysis. The isolated fungal taxol showed positive towards biosynthetic gene (dbat) and effective against both Gram positive as well as Gram negative. The fungal taxol suppress growth of cancer cell line HCT 15 with an IC50 value of 3.5 μM concentration by 24 h treatment. Thus, the result reveals that C. oxysporum could be a potential alternative source for production of taxol and have antibacterial as well as anticancer properties with possible clinical applications.

  9. Fluorescence imaging analysis of taxol-induced ASTC-a-1 cell death with cell swelling and cytoplasmic vacuolization

    NASA Astrophysics Data System (ADS)

    Chen, Tong-sheng; Sun, Lei; Wang, Longxiang; Wang, Huiying

    2008-02-01

    Taxol (Paclitaxel), an isolated component from the bark of the Pacific yew Taxus brevifolia, exhibits a broad spectrum of clinical activity against human cancers. Taxol can promote microtubule (MT) assembly, inhibit depolymerization, and change MT dynamics, resulting in disruption of the normal reorganization of the microtubule network required for mitosis and cell proliferation. However, the molecular mechanism of taxol-induced cell death is still unclear. In this report, CCK-8 was used to assay the inhibition of taxol on the human lung adenocarcinoma (ASTC-a-1) cells viability, confocal fluorescence microscope was used to monitor the morphology changes of cells with taxol treatment. We for the first time describe the characteristics of taxol-induced cells swelling, cytoplasmic vacuolization and cell death. Taxol induced swelling, cytoplasmatic vacuolization and cell death without cell shrinkage and membrane rupture. These features differ from those of apoptosis and resemble the paraptosis, a novel nonapoptotic PCD.

  10. Effect of taxol from Pestalotiopsis mangiferae on A549 cells-In vitro study.

    PubMed

    Kathiravan, Govindarajan; Sureban, Sripathi M

    2009-12-01

    Pestalotiopsis mangiferae Coelomycete fungi were used to examine the production of taxol. The taxol isolated from this fungus is biologically active against cancer cell lines were investigated for its antiproliferative activity in human Non Small Cell Lung Cancer A549 cells. The results showed that the methylene chloride extraction of Pestalotiopsis mangiferae inhibited the proliferation of A 549 cells as measured by MTT and Trypan blue assay. Flow cytometric analysis showed that methylene chloride extraction of Pestalotiopsis mangiferae blocked cell cycle progression in G0/G1 phase. In addition fungal taxol induced A549 cell apoptosis as determined by propidium iodide staining. Further the percentage of LDH release was increased at increasing concentrations which is a measure of cell death. The levels of sialic acid levels and DNA, RNA and protein levels were decreased after treatment with methylene chloride extraction of Pestalotiopsis mangiferae. We suggests that methylene chloride extraction of Pestalotiopsis mangiferae might be considered for future therapeutic application with further studies against lung cancer.

  11. Effect of taxol from Pestalotiopsis mangiferae on A549 cells-In vitro study

    PubMed Central

    Kathiravan, Govindarajan; Sureban, Sripathi M.

    2009-01-01

    Pestalotiopsis mangiferae Coelomycete fungi were used to examine the production of taxol. The taxol isolated from this fungus is biologically active against cancer cell lines were investigated for its antiproliferative activity in human Non Small Cell Lung Cancer A549 cells. The results showed that the methylene chloride extraction of Pestalotiopsis mangiferae inhibited the proliferation of A 549 cells as measured by MTT and Trypan blue assay. Flow cytometric analysis showed that methylene chloride extraction of Pestalotiopsis mangiferae blocked cell cycle progression in G0/G1 phase. In addition fungal taxol induced A549 cell apoptosis as determined by propidium iodide staining. Further the percentage of LDH release was increased at increasing concentrations which is a measure of cell death. The levels of sialic acid levels and DNA, RNA and protein levels were decreased after treatment with methylene chloride extraction of Pestalotiopsis mangiferae. We suggests that methylene chloride extraction of Pestalotiopsis mangiferae might be considered for future therapeutic application with further studies against lung cancer. PMID:25206246

  12. The flavonoid quercetin transiently inhibits the activity of taxol and nocodazole through interference with the cell cycle

    PubMed Central

    Samuel, Temesgen; Fadlalla, Khalda; Turner, Timothy; Yehualaeshet, Teshome E.

    2010-01-01

    Quercetin is a flavonoid with anticancer properties. In this study, we examined the effects of quercetin on cell cycle, viability and proliferation of cancer cells, either singly or in combination with the microtubule-targeting drugs taxol and nocodazole. Although quercetin induced cell death in a dose dependent manner, 12.5-50μM quercetin inhibited the activity of both taxol and nocodazole to induce G2/M arrest in various cell lines. Quercetin also partially restored drug-induced loss in viability of treated cells for up to 72 hours. This antagonism of microtubule-targeting drugs was accompanied by a delay in cell cycle progression and inhibition of the buildup of cyclin-B1 at the microtubule organizing center of treated cells. However, quercetin did not inhibit the microtubule targeting of taxol or nocodazole. Despite the short-term protection of cells by quercetin, colony formation and clonogenicity of HCT116 cells were still suppressed by quercetin or quercetin-taxol combination. The status of cell adherence to growth matrix was critical in determining the sensitivity of HCT116 cells to quercetin. We conclude that while long-term exposure of cancer cells to quercetin may prevent cell proliferation and survival, the interference of quercetin with cell cycle progression diminishes the efficacy of microtubule-targeting drugs to arrest cells at G2/M. PMID:21058190

  13. Taxol induces concentration-dependent phosphatidylserine (PS) externalization and cell cycle arrest in ASTC-a-1 cells

    NASA Astrophysics Data System (ADS)

    Guo, Wen-jing; Chen, Tong-sheng

    2010-02-01

    Taxol (Paclitaxel) is an important natural product for the treatment of solid tumors. Different concentrations of taxol can trigger distinct effects on both the cellular microtubule network and biochemical pathways. Apoptosis induced by low concentrations (5-30 nM) of taxol was associated with mitotic arrest, alteration of microtubule dynamics and/or G2/M cell cycle arrest, whereas high concentrations of this drug (0.2-30 μM) caused significant microtubule damage, and was found recently to induce cytoplasm vacuolization in human lung adenocarcinoma (ASTC-a-1) cells. In present study, cell counting kit (CCK-8) assay, confocal microscope, and flow cytometry analysis were used to analyze the cell death form induced by 35 nM and 70 μM of taxol respectively in human lung adenocarcinoma (ASTC-a-1) cells. After treatment of 35 nM taxol for 48 h, the OD450 value was 0.80, and 35 nM taxol was found to induce dominantly cell death in apoptotic pathway such as phosphatidylserine (PS) externalization, G2/M phase arrest after treatment for 24 h, and nuclear fragmentation after treatment for 48 h. After 70 μM taxol treated the cell for 24 h, the OD450 value was 1.01, and 70 μM taxol induced cytoplasm vacuolization programmed cell death (PCD) and G2/M phase as well as the polyploidy phase arrest in paraptotic-like cell death. These findings imply that the regulated signaling pathway of cell death induced by taxol is dependent on taxol concentration in ASTC-a-1 cells.

  14. [Apoptosis mechanism of taxol combined with resveratrol on human laryngeal carcinoma Hep-2 cells].

    PubMed

    Lu, Chen-Xin; Sun, Jing-Hui; Wu, Chun-Lian

    2016-02-01

    Laryngeal cancer is one of the most common malignant tumors in the respiratory tumors, and its incidence ranks second highest in the respiratory tumors. Resveratrol (Res) is a kind of polyphenols, which can inhibit nucleotides can inhibit the growth of liver cancer cells, gastric cancer cells, pancreatic cells and other tumor cells by inhibiting ribonucleotide reductase in the cells. Taxol (Tax) is a kind of secondary metabolites of Taxus chinensis, which has anti-tumor activity for breast cancer, cervical cancer, ovarian cancer and other tumors by inhibiting cellular microtubule depolymerization. But at present the effects of resveratrol combined with taxol on human laryngeal carcinoma cell strain Hep-2 and their underlying molecular mechanisms are rarely reported. After human laryngeal cancer cell Hep-2 cells were processed with resveratrol (Res) and taxol (Tax), CCK-8 assay was used to evaluate the effect of these two herbs on the proliferation of cancer cells; AO/PI staining and JC-1 were used to detect Hep-1 cells apoptosis; the expression of Bax, Bcl-2, PARP, TRIB3, and XIAP genes was detected by real time quantitative PCR; the activity of caspase-3 and caspase-8 was determined with quantitative fluorescence method. The experimental results showed that compared with Tax, Res medication alone, joint group significantly enhanced inhibition of Hep-2 cells activity, decreased the dosage of Tax, increased the expression of Bax and PARP, TRIB3, reduced the expression of the Bcl-2 and XIAP, and promoted the activity of caspase-3 and caspase-8. The test results showed that compared with the single medication, combined group could significantly increase the inhibitory effect on Hep-2 cells, significantly reduce Tax dosage, increase expressions of Bax, PARP, TRIB3, reduce expressions of Bcl-2, XIAP, and promote activity of caspase-3, caspase-8. This indicated apoptosis of human laryngeal carcinoma cell strain Hep-2 may be induced with Res, Tax, and the combination of

  15. Regulation of drug resistance by human pregnane X receptor in breast cancer

    PubMed Central

    Chen, Yakun; Tang, Yong; Chen, Shuqing; Nie, Daotai

    2012-01-01

    Drug resistance is a significant barrier to an effective treatment of breast cancer. Human pregnane X receptor (hPXR), an orphan nuclear receptor known for its activation by many important clinical drugs, is a major transcription factor of drug metabolism enzymes (DMEs), such as cytochrome P450 3A4 (CYP3A4), and efflux transporters such as multi-drug resistance gene (MDR1). hPXR has been detected in human breast cancers but its role in responses of cancers toward drugs remains unknown. In this study, hPXR expression was confirmed in breast cancer cell lines and in normal and cancerous human breast specimens. Preactivation of hPXR by SR12813 in MDA-MB-231 cells led to an increased resistance to Taxol at concentrations of 20 and 50 nmol/L. A significant increase in resistance toward tamoxifen was also observed in MCF-7 with hPXR preactivation. Activation of hPXR led to an increased expression of CYP3A4 and MDR1, two possible mediators for hPXR-mediated drug resistance in breast cancers. Furthermore, knockdown of hPXR via small hairpin RNA (shRNA) sensitized MDA-MB-231 and MCF-7 cells to the treatment of Taxol, vinblastine or tamoxifen. The reduction in resistance of hPXR knockdown cells was further confirmed by reduced colony formation under the pressure of cancer treatment drugs. Taken together, our data suggest a potential role of hPXR in breast cancer resistance to drug treatments. PMID:19746521

  16. A novel paclitaxel-loaded poly(d,l-lactide-co-glycolide)-Tween 80 copolymer nanoparticle overcoming multidrug resistance for lung cancer treatment

    PubMed Central

    Yuan, Xun; Ji, Wenxiang; Chen, Si; Bao, Yuling; Tan, Songwei; Lu, Shun; Wu, Kongming; Chu, Qian

    2016-01-01

    Drug resistance has become a main obstacle for the effective treatment of lung cancer. To address this problem, a novel biocompatible nanoscale package, poly(d,l-lactide-co-glycolide)-Tween 80, was designed and synthesized to overcome paclitaxel (PTX) resistance in a PTX-resistant human lung cancer cell line. The poly(d,l-lactide-co-glycolide) (PLGA)-Tween 80 nanoparticles (NPs) could efficiently load PTX and release the drug gradually. There was an increased level of uptake of PLGA-Tween 80 in PTX-resistant lung cancer cell line A549/T, which achieved a significantly higher level of cytotoxicity than both PLGA NP formulation and Taxol®. The in vivo antitumor efficacy also showed that PLGA-Tween 80 NP was more effective than Taxol®, indicating that PLGA-Tween 80 copolymer was a promising carrier for PTX in resistant lung cancer. PMID:27307727

  17. Montelukast is a potent and durable inhibitor of multidrug resistance protein 2 (MRP2)-mediated efflux of taxol and saquinavir

    PubMed Central

    Roy, Upal; Chakravarty, Geetika; Honer Zu Bentrup, Kerstin; Mondal, Debasis

    2009-01-01

    The ATP binding cassette (ABC)-transporters are energy dependent efflux pumps which regulate the pharmacokinetics of both anti-cancer chemotherapeutic agents, e.g. taxol, and of HIV-1 protease inhibitors (HPIs), e.g. saquinavir. Increased expression of several ABC-transporters, especially P-gp and MRP2, are observed in multidrug resistant (MDR) tumor cells and on HIV-1 infected lymphocytes. In addition, due to their apical expression on vascular endothelial barriers, both P-gp and MRP2 are of crucial importance towards dictating drug access into sequestered tissues. However, although a number of P-gp inhibitors are currently in clinical trials, possible inhibitors of MRP2 are not being thoroughly investigated. The experimental leukotriene receptor antagonist (LTRA), MK-571 is known to be a potent inhibitor of MRP transporters. Using the MRP2 over-expressing cell line, MDCKII-MRP2, we evaluated whether the clinically approved LTRAs, e.g. montelukast (Singulair™) and zafirlukast (Accolate™), can similarly suppress MRP2-mediated efflux. We compared the efficacy of increasing concentrations (20-100 μM) of MK-571, montelukast, and zafirlukast, in suppressing the efflux of calcein-AM, a fluorescent MRP substrate, and the radiolabeled [3H-] drugs, taxol and saquinavir. Montelukast was the most potent inhibitor (p<0.01) of MRP2-mediated efflux of all three substrates. Montelukast also increased (p<0.01) the duration of intracellular retention of both taxol and saquinavir. More than 50% of the drugs were retained in cells even after 90 mins post removal of montelukast from the medium. Our findings implicate that montelukast, a relatively safe anti-asthmatic agent, may be used as an adjunct therapy to suppress the efflux of taxol and saquinavir from MRP2 overexpressing cells. PMID:19952419

  18. Investigation of genotoxic effect of taxol plus radiation on mice bone marrow cells.

    PubMed

    Ozkan, Lütfi; Egeli, Unal; Tunca, Berrin; Aydemir, Nilüfer; Ceçener, Gülşah; Akpinar, Gürler; Ergül, Emel; Cimen, Ciğdem; Ozuysal, Sema; Kahraman-Cetintaş, Sibel; Engin, Kayihan; Ahmed, Mansoor M

    2002-01-01

    In this study, we investigated the genotoxic effect of taxol, radiation, or taxol plus radiation on highly proliferative normal tissue-bone marrow cells of Swiss albino mice. Swiss-albino mice, 3-4 months old, were used in this study. Taxol was administered bolus intravenously through the tail vein. Radiation was given by using a linear accelerator. There were four treatment categories, which had a total of 34 groups. Each group consisted of five animals. The first was the control category that had one group (n = 5). The second treatment category was taxol alone, which had three groups as per taxol dose alone (n = 15). The third treatment category was radiation alone, which had three groups as per the radiation dose (n = 15). The fourth treatment category was taxol plus radiation, which had 27 groups as per combined radiation dose plus taxol dose concentration and as per pre-treatment timing sequence of taxol before radiation (n = 135). Mice were sacrificed 24 h after taxol or radiation or combined administration using ether anesthesia. The cells were then dropped on two labeled slides, flamed, air dried, and stained in 7% Giemsa; 20-30 well-spread mitotic metaphases were analyzed for each animal; the cells with chromosome breaks, acentric fragments, and rearrangements were evaluated on x1,000 magnification with light microscope (Zeiss axioplan). The mitotic index was determined by counting the number of mitotic cells among 1,000 cells per animal. Differences between groups were evaluated with Student's t-test statistically. Taxol caused a dose-dependent increase in chromosomal aberrations (P = 0.027). Similarly, radiation caused a dose-dependent increase in chromosomal aberrations (P = 0.003) and decreased mitotic index (P = 0.002). In combination, there were a small enhancements at the 40 mg/kg taxol dose level and at 0.25 and 0.5 Gy radiation doses in the 48 h group. However, an increase in chromosomal aberrations was observed after 48 hours of taxol exposure

  19. Paclitaxel-resistant HeLa cells have up-regulated levels of reactive oxygen species and increased expression of taxol resistance gene 1.

    PubMed

    Bi, Wenxiang; Wang, Yuxia; Sun, Gaoying; Zhang, Xiaojin; Wei, Yongqing; Li, Lu; Wang, Xiaoyuan

    2014-07-01

    This study is to establish a paclitaxel (PTX)-resistant human cervical carcinoma HeLa cell line (HeLa/PTX) and to investigate its redox characteristics and the expression of taxol resistance gene 1 (Txr1). HeLa cells were treated with PTX and effects of PTX on cell proliferation were detected through cell counting and the MTT assay. Levels of cellular reactive oxygen species (ROS), reduced glutathione (GSH), and oxidized glutathione (GSSG) as well as the ratio of GSH to GSSG were measured by the 2,7-difluorescein diacetate (DCFH-DA) method and the 5,5'dithiobis(2-nitrobenzoic acid) (DTNB) method. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined by the nitrite formation method, the molybdate colorimetric method, and the DTNB colorimetric method, respectively. The level of Txr1 mRNA was determined by real-time PCR. Compared with the regular HeLa cells, HeLa/PTX cells were larger in size and had more cytoplasmic granules. The population doubling time for HeLa/PTX cells was 1.32 times of that of HeLa cells (P<0.01). HeLa/PTX cells showed stronger resistance to PTX than HeLa cells with a resistance index of 122.69. HeLa/PTX cells had higher levels of ROS (P<0.01) and Txr1 mRNA (P<0.01), lower level of GSH (P < 0.05), and lower activities of SOD (P<0.01) and GPx (P < 0.05) than HeLa cells. HeLa/PTX cells, with higher levels of ROS and Txr1 mRNA expression, are more resistant to PTX than HeLa cells.

  20. Design and synthesis of new hybrids from 2-cyano-3,12-dioxooleana- 9-dien-28-oic acid and O2-(2,4-dinitrophenyl) diazeniumdiolate for intervention of drug-resistant lung cancer.

    PubMed

    Kang, Fenghua; Ai, Yong; Zhang, Yihua; Huang, Zhangjian

    2018-04-10

    To search for new drugs for intervention of drug-resistant lung cancer, a series of hybrids 4-15 from 2-cyano-3,12-dioxooleana-9-dien-28-oic acid (CDDO) and O 2 -(2,4-dinitrophenyl) diazeniumdiolate were designed, synthesized and biologically evaluated. The most active compound 7 produced relatively high levels of nitric oxide (NO) and reactive oxygen species (ROS) in drug-resistant lung cancer A549/Taxol cells which over-express glutathione S-transferase π (GSTπ), and significantly inhibited the cells' proliferation (IC 50  = 0.349 ± 0.051 μM), superior to the positive controls CDDO-Me, JS-K and Taxol. The inhibitory activity of 7 could be attenuated by an NO scavenger, ROS scavenger or GSTπ inhibitor. In addition, 7 suppressed the Lon protease expression as well as induced cell apoptosis and cycle arrest in A549/Taxol cells more strongly than CDDO-Me or JS-K. Together, our findings suggest that 7 may be worth studying further for intervention of drug-resistant lung cancer. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  1. Taxol-producing [corrected] fungal endophyte, Pestalotiopsis species isolated from Taxus cuspidata.

    PubMed

    Kumaran, Rangarajulu Senthil; Kim, Hyung Joo; Hur, Byung-Ki

    2010-11-01

    The endophytic fungi, Pestalotiopsis versicolor and Pestalotiopsis neglecta, were isolated from the healthy leaves and bark of the Japanese Yew tree, Taxus cuspidata. The fungal species were identified by their characteristic culture morphology and molecular analysis. For the first time, the test fungi were screened for the production of taxol in modified liquid medium. The presence of taxol was confirmed by HPLC, (1)H NMR, and LC-MS methods of analysis. The maximum amount of taxol production in P. versicolor was recorded as 478 μg/l. The production rate was increased to 9560-fold than that found in the culture broth of earlier reported fungus, Taxomyces andreanae. The extracted fungal taxol showed a strong cytotoxic activity in the in vitro culture of tested human cancer cells by apoptotic assay indicating that the increase in taxol concentration induces increased cell death. A PCR-based screening for ts, a unique gene in the formation of the taxane skeleton, confirmed the molecular blueprint for taxol biosynthesis. The results designate that the fungal endophyte, P. versicolor, is an excellent candidate for an alternate source of taxol supply and can also serve as a potential species for genetic engineering to enhance the production of taxol to a higher level. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. In vitro cell cultures obtained from different explants of Corylus avellana produce Taxol and taxanes

    PubMed Central

    Bestoso, Federica; Ottaggio, Laura; Armirotti, Andrea; Balbi, Alessandro; Damonte, Gianluca; Degan, Paolo; Mazzei, Mauro; Cavalli, Francesca; Ledda, Bernardetta; Miele, Mariangela

    2006-01-01

    Background Taxol is an effective antineoplastic agent, originally extracted from the bark of Taxus brevifolia with a low yield. Many attempts have been made to produce Taxol by chemical synthesis, semi-synthesis and plant tissue cultures. However, to date, the availability of this compound is not sufficient to satisfy the commercial requirements. The aim of the present work was to produce suspension cell cultures from plants not belonging to Taxus genus and to verify whether they produced Taxol and taxanes. For this purpose different explants of hazel (Corylus avellana species) were used to optimize the protocol for inducing in vitro callus, an undifferentiated tissue from which suspension cell cultures were established. Results Calli were successfully induced from stems, leaves and seeds grown in various hormone concentrations and combinations. The most suitable callus to establish suspension cell cultures was obtained from seeds. Media recovered from suspension cell cultures contained taxanes, and showed antiproliferative activity on human tumour cells. Taxol, 10-deacetyltaxol and 10-deacetylbaccatin III were the main taxanes identified. The level of Taxol recovered from the media of hazel cultures was similar to that found in yew cultures. Moreover, the production of taxanes in hazel cell cultures increased when elicitors were used. Conclusion Here we show that hazel cell cultures produce Taxol and taxanes under controlled conditions. This result suggests that hazel possesses the enzymes for Taxol production, which until now was considered to be a pathway particular to Taxus genus. The main benefit of producing taxanes through hazel cell cultures is that hazel is widely available, grows at a much faster rate in vivo, and is easier to cultivate in vitro than yew. In addition, the production of callus directly from hazel seeds shortens the culture time and minimizes the probability of contamination. Therefore, hazel could become a commercial source of Taxol and

  3. Growth-inhibiting effects of taxol on human liver cancer in vitro and in nude mice

    PubMed Central

    Yuan, Jin Hui; Zhang, Ru Ping; Zhang, Ru Gang; Guo, Li Xia; Wang, Xing Wang; Luo, Dan; Xie, Yong; Xie, Hong

    2000-01-01

    AIM: To investigate the effects of taxol on SMMC-7721 human hepatoma and its mechanisms. METHODS: In vitro cell growth was assessed by trypan blue exclusion method. Experimental hepatoma model was established by seeding SMMC-7721 cells subcutaneously into Balb/c (nu/nu) nude mice. In vivo tumor growth was determined by measurement of tumor diameter with Vernier calipers. The syntheses of DNA, RNA and protein were analyzed by incorporation of 3H-thymidine, 3H-uridine and 3H-leucine respectively. Using light and electron microscopes to observe the morphological changes of cells including mitosis and apoptosis. RESULTS: Taxol was effective against SMMC-7721 human hepatoma cell growth in the ranges of 2.5 nmol/L-10 nmol/L- with mitotic arrest and apoptosis in vitro. DNA, RNA and protein syntheses in cells were also obviously suppressed by in vitro treatment of taxol for 72 h. Taxol at 2.5 nmol/L reduced 3H-thymidine uptake to about 34% of the control value (P < 0.05). Increasing the dose of taxol to 20 nmol/L resulted in a greater decrease in 3H-thymidine incorporation to 60% of the control value (P < 0.01). At a concentration of 20 nmol/L, the 3H-uridine and 3H-leucine uptakes were reduced to 52% (P < 0.05) and 63% (P < 0.01), respectively. In vivo, taxol significantly inhibited SMMC-7721 tumor growth at 10 mg/kg, i.p. once daily for 10 d. A more than 90% decrease in tumor volume was observed by day 11 (P < 0.01) similarly with mitotic arrest and cell apoptosis. CONCLUSION: Taxol has a marked anticancer activity in SMMC-7721 human hepatoma both in vitro and in nude mice. Its mechanisms might be associated with mitotic arrest, subsequently, apoptosis of the hepatoma cells. No obvious toxicity was observed with in vivo administration of taxol. PMID:11819558

  4. Effects of Taxol plus radiation on the apoptotic and mitotic indices of mouse intestinal crypt cells.

    PubMed

    Ozkan, L; Ozuysal, S; Egeli, U; Adim, S B; Tunca, B; Aydemir, N; Ceçener, G; Ergül, E; Akpinar, G; Cimen, C; Engin, K; Ahmed, M M

    2001-07-01

    In this study we investigated the effect of Taxol, radiation, or Taxol plus radiation on highly proliferative normal tissue--the intestinal crypt cells of Swiss albino mice. Swiss-albino mice, 3-4 months old, were used in this study. Taxol was administered by bolus intravenously through the tail vein. Radiation was given using a linear accelerator. There were four treatment categories, which comprised a total of 34 groups. Each group consisted of five animals. The first category was a control category which comprised one group (n = 5). The second treatment category was Taxol alone which comprised three groups (n = 15). The third treatment category was radiation alone which comprised three groups (n = 15). The fourth treatment category was Taxol plus radiation which comprised 27 groups (n = 135). Mice were killed 24 h after Taxol or radiation or combined administration using ether anesthesia. Using a light microscope, apoptotic and mitotic indices were counted on jejunal crypt cells of mice that were stained with hematoxylin-eosin. Differences between groups were statistically evaluated with Student's t-test. Taxol caused a dose-dependent increase in apoptosis (P = 0.045) and decreased the mitotic index (P = 0.006) at high doses. Similarly, radiation caused a dose-dependent increase in apoptosis (P = 0.046) and decreased the mitotic index (P = 0.299) at higher radiation doses. Compared to radiation alone, Taxol caused a significant induction of apoptosis (P = 0.010). In combination, no significant radiosensitizing effect of Taxol was observed (enhancement ratio < 1), when compared to radiation alone. However, an increase in apoptosis was observed after 24 h of Taxol exposure when compared to 12 or 48 h of Taxol exposure (P = 0.0001 and P = 0.0001). These findings suggest that Taxol did not cause a radiosensitizing effect in intestinal crypt cells. However, a 24-hour pretreatment of Taxol exposure followed by radiation caused significant induction of apoptosis and

  5. A novel paclitaxel-loaded poly(epsilon-caprolactone)/Poloxamer 188 blend nanoparticle overcoming multidrug resistance for cancer treatment.

    PubMed

    Zhang, Yangqing; Tang, Lina; Sun, Leilei; Bao, Junbo; Song, Cunxian; Huang, Laiqiang; Liu, Kexin; Tian, Yan; Tian, Ge; Li, Zhen; Sun, Hongfan; Mei, Lin

    2010-06-01

    Multidrug resistance (MDR) of tumor cells is a major obstacle to the success of cancer chemotherapy. Poloxamers have been used in cancer therapy to overcome MDR. The objective of this research is to test the feasibility of paclitaxel-loaded poly(epsilon-caprolactone)/Poloxamer 188 (PCL/Poloxamer 188) nanoparticles to overcome MDR in a paclitaxel-resistant human breast cancer cell line. Paclitaxel-loaded nanoparticles were prepared by a water-acetone solvent displacement method using commercial PCL and self-synthesized PCL/Poloxamer 188 compound, respectively. PCL/Poloxamer 188 nanoparticles were found to be of spherical shape and tended to have a rough and porous surface. The nanoparticles had an average size of around 220nm, with a narrow size distribution. The in vitro drug release profile of both nanoparticle formulations showed a clear biphasic release pattern. There was an increased level of uptake of PCL/Poloxamer 188 nanoparticles (PPNP) in the paclitaxel-resistant human breast cancer cell line MCF-7/TAX, in comparison with PCL nanoparticles. The cytotoxicity of PCL nanoparticles was higher than commercial Taxol in the MCF-7/TAX cell culture, but the differences were not significant. However, the PCL/Poloxamer 188 nanoparticles achieved a significantly higher level of cytotoxicity than both of PCL nanoparticle formulation and Taxol(R), indicating that paclitaxel-loaded PCL/Poloxamer 188 nanoparticles could overcome MDR in human breast cancer cells and therefore could have considerable therapeutic potential for breast cancer. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. New perspectives of cobalt tris(bipyridine) system: anti-cancer effect and its collateral sensitivity towards multidrug-resistant (MDR) cancers

    PubMed Central

    Mok, Simon Wing Fai; Liu, Hauwei; Zeng, Wu; Han, Yu; Gordillo-Martinez, Flora; Chan, Wai-Kit; Wong, Keith Man-Chung; Wong, Vincent Kam Wai

    2017-01-01

    Platinating compounds including cisplatin, carboplatin, and oxaliplatin are common chemotherapeutic agents, however, patients developed resistance to these clinical agents after initial therapeutic treatments. Therefore, different approaches have been applied to identify novel therapeutic agents, molecular mechanisms, and targets for overcoming drug resistance. In this study, we have identified a panel of cobalt complexes that were able to specifically induce collateral sensitivity in taxol-resistant and p53-deficient cancer cells. Consistently, our reported anti-cancer functions of cobalt complexes 1–6 towards multidrug-resistant cancers have suggested the protective and non-toxic properties of cobalt metal-ions based compounds in anti-cancer therapies. As demonstrated in xenograft mouse model, our results also confirmed the identified cobalt complex 2 was able to suppress tumor growth in vivo. The anti-cancer effect of the cobalt complex 2 was further demonstrated to be exerted via the induction of autophagy, cell cycle arrest, and inhibition of cell invasion and P-glycoprotein (P-gp) activity. These data have provided alternative metal ion compounds for targeting drug resistance cancers in chemotherapies. PMID:28903398

  7. Polysaccharide-based Noncovalent Assembly for Targeted Delivery of Taxol

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Zhang, Ying-Ming; Chen, Yong; Chen, Jia-Tong; Liu, Yu

    2016-01-01

    The construction of synthetic straightforward, biocompatible and biodegradable targeted drug delivery system with fluorescent tracking abilities, high anticancer activities and low side effects is still a challenge in the field of biochemistry and material chemistry. In this work, we constructed targeted paclitaxel (Taxol) delivery nanoparticles composed of permethyl-β-cyclodextrin modified hyaluronic acid (HApCD) and porphyrin modified paclitaxel prodrug (PorTaxol), through host-guest and amphiphilic interactions. The obtained nanoparticles (HATXP) were biocompatible and enzymatic biodegradable due to their hydrophilic hyaluronic acid (HA) shell and hydrophobic Taxol core, and exhibited specific targeting internalization into cancer cells via HA receptor mediated endocytosis effects. The cytotoxicity experiments showed that the HATXP exhibited similar anticancer activities to, but much lower side effects than commercial anticancer drug Taxol. The present work would provide a platform for targeted paclitaxel drug delivery and a general protocol for the design of advanced multifunctional nanoscale biomaterials for targeted drug/gene delivery.

  8. Analysis of Breast Cell-Lineage Response Differences to Taxol Using a Novel Co-Culture System

    DTIC Science & Technology

    2005-06-01

    as the Hayflick limit [159], is thought to be a "mitotic clock" preventing cumulative cell damage from progressing to tumorigenesis [164-166] and...TERMS Breast cancer, co-culture, gene expression profiles, Taxol, transport mechanisms 16. SECURITY CLASSIFICATION OF: 17. LIMITATION 18. NUMBER 19a...proteins have been shown to bind and inactivate p53 and pRb respectively [25]. While the mortal cells have limited replicative potential in culture and

  9. Occurrence of taxol and related taxanes in the wood of Pacific yew

    Treesearch

    John R. Obst

    1993-01-01

    Maximizing the yield of taxol per tree is important for the best management of the yew resource. Therefore, the possibility of obtaining additional taxol from the wood was explored. Initial reports form our laboratory, in cooperation with the National Cancer Institute, indicated relatively high concentrations of taxol in Pacific yew heartwood. Although these taxol...

  10. Cordyceps sinensis health supplement enhances recovery from taxol-induced leukopenia.

    PubMed

    Liu, Wei-Chung; Chuang, Wei-Ling; Tsai, Min-Lung; Hong, Ji-Hong; McBride, William H; Chiang, Chi-Shiun

    2008-04-01

    This study aimed to evaluate the ability of the health food supplement Cordyceps sinensis (CS) to ameliorate suppressive effects of chemotherapy on bone marrow function as a model for cancer treatment. Mice were treated with Taxol (17 mg/kg body wt) one day before oral administration of a hot-water extract of CS (50 mg/kg daily) that was given daily for 3 weeks. White blood cell counts in peripheral blood of mice receiving Taxol were at 50% of normal levels on day 28 but had recovered completely in mice treated with CS. In vitro assays showed that CS enhanced the colony-forming ability of both granulocyte macrophage colony forming unit (GM-CFU) and osteogenic cells from bone marrow preparations and promoted the differentiation of bone marrow mesenchymal stromal cells into adipocytes, alkaline phosphatase-positive osteoblasts, and bone tissue. This result could be attributed to enhanced expression of Cbfa1 (core binding factor a) and BMP-2 (bone morphogenetic protein) with concurrent suppression of ODF (osteoclast differentiation factor/RANK [receptor activator of NF-kappaB]) ligand. In summary, CS enhances recovery of mice from leukopenia caused by Taxol treatment. It appears to do so by protecting both hematopoietic progenitor cells directly and the bone marrow stem cell niche through its effects on osteoblast differentiation.

  11. Brain Tumor Genetic Modification Yields Increased Resistance to Paclitaxel in Physical Confinement

    PubMed Central

    Bui, Loan; Hendricks, Alissa; Wright, Jamie; Chuong, Cheng-Jen; Davé, Digant; Bachoo, Robert; Kim, Young-tae

    2016-01-01

    Brain tumor cells remain highly resistant to radiation and chemotherapy, particularly malignant and secondary cancers. In this study, we utilized microchannel devices to examine the effect of a confined environment on the viability and drug resistance of the following brain cancer cell lines: primary cancers (glioblastoma multiforme and neuroblastoma), human brain cancer cell lines (D54 and D54-EGFRvIII), and genetically modified mouse astrocytes (wild type, p53−/−, p53−/− PTEN−/−, p53−/− Braf, and p53−/− PTEN−/− Braf). We found that loss of PTEN combined with Braf activation resulted in higher viability in narrow microchannels. In addition, Braf conferred increased resistance to the microtubule-stabilizing drug Taxol in narrow confinement. Similarly, survival of D54-EGFRvIII cells was unaffected following treatment with Taxol, whereas the viability of D54 cells was reduced by 75% under these conditions. Taken together, our data suggests key targets for anticancer drugs based on cellular genotypes and their specific survival phenotypes during confined migration. PMID:27184621

  12. Tectorigenin sensitizes paclitaxel-resistant human ovarian cancer cells through downregulation of the Akt and NFκB pathway.

    PubMed

    Yang, Yeong-In; Lee, Kyung-Tae; Park, Hee-Juhn; Kim, Tae Jin; Choi, Youn Seok; Shih, Ie-Ming; Choi, Jung-Hye

    2012-12-01

    Paclitaxel (Taxol) is currently used as the front-line chemotherapeutic agent for several cancers including ovarian carcinoma; however, the drug frequently induces drug resistance through multiple mechanisms. The new strategy of using natural compounds in combination therapies is highly attractive because those compounds may enhance the efficacy of chemotherapy. In this study, we found that tectorigenin, an isoflavonoid isolated from flower of Pueraria thunbergiana, enhanced the growth-inhibitory effect of paclitaxel in paclitaxel-resistant ovarian cancer cells (MPSC1(TR), A2780(TR) and SKOV3(TR)) as well as their naive counterparts. The combination of tectorigenin with paclitaxel resulted in a synergistic apoptosis compared with either agent alone through activation of caspases-3, -8 and -9. Treatment with tectorigenin inhibited the nuclear translocation of NFκB and the expression of NFκB-dependent genes such as FLIP, XIAP, Bcl-2, Bcl-xL and COX-2, which are known to be associated with chemoresistance. In addition, the tectorigenin-paclitaxel combination inhibited the phosphorylation of IκB and IKK and the activation of Akt in paclitaxel-resistant cancer cells. Moreover, tectorigenin-paclitaxel-induced cell growth inhibition was enhanced by pretreatment with the Akt inhibitor LY294002 or overexpression of the dominant negative Akt (Akt-DN), but reduced by overexpression of constitutively activated Akt (Akt-Myr). Furthermore, we found that Akt-Myr, at least in part, reversed tectorigenin-paclitaxel-induced nuclear translocation of NFκB and the phosphorylation of IκB and IKK. These data suggest that tectorigenin could sensitize paclitaxel-resistant human ovarian cancer cells through inactivation of the Akt/IKK/IκB/NFκB signaling pathway, and promise a new intervention to chemosensitize paclitaxel-induced cytotoxicity in ovarian cancer.

  13. Alterations in Taxol production in plant cell culture via manipulation of the phenylalanine ammonia lyase pathway.

    PubMed

    Brincat, Michelle C; Gibson, Donna M; Shuler, Michael L

    2002-01-01

    One approach to increasing secondary metabolite production in plant cell culture is to manipulate metabolic pathways to utilize more resources toward production of one desired compound or class of compounds, such as diverting carbon flux from competing secondary pathways. Since phenylalanine provides both the phenylisoserine side chain and the benzoyl moiety at C-2 of Taxol, we speculated that blockage of the phenylpropanoid pathway might divert phenylalanine into Taxol biosynthesis. We used specific enzyme inhibitors to target the first enzyme in the phenylpropanoid pathway, phenylalanine ammonia lyase (PAL), the critical control point for conversion of L-phenylalanine to trans-cinnamic acid. Cinnamic acid acted quickly in reducing PAL activity by 40-50%, without affecting total protein levels, but it generally inhibited the taxane pathway, reducing Taxol by 90% of control levels. Of the taxanes produced, 13-acetyl-9-dihydro-baccatin III and 9-dihydrobaccatin III doubled as a percentage of total taxanes in C93AD and CO93P cells treated with 0.20 and 0.25 mM cinnamic acid, when all other taxanes were lowered. The PAL inhibitor alpha-aminooxyacetic acid (AOA) almost entirely shut down Taxol production at both 0.5 and 1.5 mM, whereas L-alpha-aminooxy-beta-phenylpropionic acid (AOPP) had the opposite effect, slightly enhancing Taxol production at 1 microM but having no effect at 10 microM. The discrepancy in the effectiveness of AOA and AOPP and the lack of effect with addition of phenylalanine or benzoic acid derivatives further indicates that the impact of cinnamic acid on Taxol is related not to its effect on PAL but rather to a specific effect on the taxane pathway. On the basis of these results, a less direct route for inhibiting the phenylpropanoid pathway may be required to avoid unwanted side effects and potentially enhance Taxol production.

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tang, Xiao-han; Deng, Suo; Li, Meng

    Highlights: Black-Right-Pointing-Pointer HB-EGF over-expression in A2780/Taxol, A2780/CDDP cells and the matched xenografts. Black-Right-Pointing-Pointer CRM197 induces enhanced apoptosis in A2780/Taxol and A2780/CDDP cells. Black-Right-Pointing-Pointer CRM197 arrests A2780/Taxol and A2780/CDDP cells at G0/G1 phase. Black-Right-Pointing-Pointer CRM197 suppressed the A2780/Taxol and A2780/CDDP growth of xenografts. -- Abstract: Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a promising target for ovarian cancer therapy. Cross-reacting material 197 (CRM197), a specific HB-EGF inhibitor, has been proven to represent possible chemotherapeutic agent for ovarian cancer. However, the effect of CRM197 on the resistant ovarian carcinoma cells has not been sufficiently elucidated. Here, we found that HB-EGF wasmore » over-expressed in a paclitaxel-resistant human ovarian carcinoma cell line (A2780/Taxol) and a cisplatin-resistant cell line (A2780/CDDP), as well as the xenograft mouse tissue samples with these cells. To investigate the possible significance of the HB-EGF over-expression in A2780/Taxol and A2780/CDDP cells, we inhibited HB-EGF expression by CRM197 to investigate the effect of CRM197 treatment on these cells. We observed that CRM197 significantly induced anti-proliferative activity in a dose-dependent manner with the cell-cycle arrest at the G0/G1 phase and enhanced apoptosis in A2780/Taxol and A2780/CDDP cells. The sensitive ovarian carcinoma parental cell line (A2780), A2780/Taxol and A2780/CDDP cells formed tumors in nude mice, and enhanced tumorigenicity was observed in drug-resistant tumors. Furthermore, we observed that CRM197 significantly suppressed the growth of drug-resistant ovarian cancer xenografts in vivo (p < 0.001). These results suggest that CRM197 as an HB-EGF-targeted agent has potent anti-tumor activity in paclitaxel- and cisplatin-resistant ovarian cancer which over-express HB-EGF.« less

  15. MicroRNA-133b targets glutathione S-transferase π expression to increase ovarian cancer cell sensitivity to chemotherapy drugs.

    PubMed

    Chen, Shuo; Jiao, Jin-Wen; Sun, Kai-Xuan; Zong, Zhi-Hong; Zhao, Yang

    2015-01-01

    Accumulating studies reveal that aberrant microRNA (miRNA) expression can affect the development of chemotherapy drug resistance by modulating the expression of relevant target proteins. The aim of this study was to investigate the role of miR-133b in the development of drug resistance in ovarian cancer cells. We examined the levels of miR-133b expression in ovarian carcinoma tissues and the human ovarian carcinoma cell lines (A2780, A2780/DDP and A2780/Taxol, respectively). We determined the cell viability of these cell lines treated with cisplatin or paclitaxel in the presence or absence of miR-133b or anti-miR-133b transfection using the MTT assay. Reverse transcription polymerase chain reaction and Western blotting were used to assess the mRNA and protein expression levels of two drug-resistance-related genes: glutathione S-transferase (GST)-π and multidrug resistance protein 1 (MDR1). The dual-luciferase reporter assay was used to detect the promoter activity of GST-π in the presence and absence of miR-133b. The expression of miR-133b was significantly lower in primary resistant ovarian carcinomas than in the chemotherapy-sensitive carcinomas (P<0.05), and the same results were found in primary resistant ovarian cell lines (A2780/Taxol and A2780/DDP) compared to the chemotherapy-sensitive cell line (A2780; P<0.05). Following miR-133b transfection, four cell lines showed increased sensitivity to paclitaxel and cisplatin, while anti-miR-133b transfection reduced cell sensitivity to paclitaxel and cisplatin. Dual-luciferase reporter assay showed that miR-133b interacted with the 3'-untranslated region of GST-π. Compared to controls, the mRNA and protein levels of MDR1 and GST-π were downregulated after miR-133b transfection and upregulated after anti-miR-133b transfection. MicroRNA-133b may reduce ovarian cancer drug resistance by silencing the expression of the drug-resistance-related proteins, GST-π and MDR1. In future, the combination of miR-133b with

  16. Overcoming cisplatin resistance of ovarian cancer cells by targeting HIF-1-regulated cancer metabolism

    PubMed Central

    Ai, Zhihong; Lu, Yang; Qiu, Songbo; Fan, Zhen

    2016-01-01

    Cisplatin is currently one of the most effective chemotherapeutic drugs used for treating ovarian cancer; however, resistance to cisplatin is common. In this study, we explored an experimental strategy for overcoming cisplatin resistance of human ovarian cancer from the new perspective of cancer cell metabolism. By using two pairs of genetically matched cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines, we tested the hypothesis that downregulating hypoxia-inducible factor-1 (HIF-1), which regulates metabolic enzymes involved in glycolysis, is a promising strategy for overcoming cisplatin resistance of human ovarian cancer cells. We found that cisplatin downregulated the level of the regulatable α subunit of HIF-1, HIF-1α, in cisplatin-sensitive ovarian cancer cells through enhancing HIF-1α degradation but did not downregulate HIF-1α in their cisplatin-resistant counterparts. Overexpression of a degradation-resistant HIF-1α (HIF-1α ΔODD) reduced cisplatin-induced apoptosis in cisplatin-sensitive cells, whereas genetic knockdown of HIF-1α or pharmacological promotion of HIF-1α degradation enhanced response to cisplatin in both cisplatin-sensitive and cisplatin-resistant ovarian cancer cells. We further demonstrated that knockdown of HIF-1α improved the response of cisplatin-resistant ovarian cancer cells to cisplatin by redirecting the aerobic glycolysis in the resistant cancer cells towards mitochondrial oxidative phosphorylation, leading to cell death through overproduction of reactive oxygen species. Our findings suggest that the HIF-1α-regulated cancer metabolism pathway could be a novel target for overcoming cisplatin resistance in ovarian cancer. PMID:26801746

  17. Isolation, Purification, and Identification of Taxol and Related Taxanes from Taxol-Producing Fungus Aspergillus niger subsp. taxi.

    PubMed

    Li, Dan; Fu, Dongwei; Zhang, Yue; Ma, Xueling; Gao, Liguo; Wang, Xioahua; Zhou, Dongpo; Zhao, Kai

    2017-08-28

    The content of taxol in the bark of yews is very low, and this is not affordable from the environmental point of view. Thus, it is a necessity to look for alternative sources of taxol production to solve its supply. Currently, a large portion of the taxol in the market comes from chemical semi-synthesis, but the semi-synthetic precursors such as baccatin III and 10-deacetyl-baccatin III are extracted from needles and twigs of yew trees. Taxol-producing fungi as a renewable resource is a very promising way to increase the scale of taxol production. Our group has obtained a taxol-producing endophytic fungus, Aspergillus niger subsp. taxi HD86-9, to examine if A. niger can produce the taxanes. Six compounds from the fermentation broth of strain HD86-9 were isolated and identified by 1 H NMR, 13 C NMR, and ESI-MS. The results showed that the six compounds included four taxane diterpenoids (taxol, cephalomannine, baccatin III, and 10-deacetyl-baccatin III) and two non-taxane compounds (β-sitosterol and flavonoid isovitexin). The study verified that the taxanes can be produced by the A. niger , which is very important to taxol production via chemical semi-synthesis. Additionally, the finding is potentially very significant to solve the taxol semi-synthetic precursors extracted from needles and twigs of yew trees, and the precursor production can be easily increased through the culture condition optimization, genetic breeding, and metabolic engineering of the A. niger .

  18. Direct effect of Taxol on free radical formation and mitochondrial permeability transition.

    PubMed

    Varbiro, G; Veres, B; Gallyas, F; Sumegi, B

    2001-08-15

    To elucidate the potential role of mitochondria in Taxol-induced cytotoxicity, we studied its direct mitochondrial effects. In Percoll-gradient purified liver mitochondria, Taxol induced large amplitude swelling in a concentration-dependent manner in the microM range. Opening of the permeability pore was also confirmed by the access of mitochondrial matrix enzymes for membrane impermeable substrates in Taxol-treated mitochondria. Taxol induced the dissipation of mitochondrial membrane potential (DeltaPsi) determined by Rhodamine123 release and induced the release of cytochrome c from the intermembrane space. All these effects were inhibited by 2.5 microM cyclosporine A. Taxol significantly increased the formation of reactive oxygen species (ROS) in both the aqueous and the lipid phase as determined by dihydrorhodamine123 and resorufin derivative. Cytochrome oxidase inhibitor CN(-), azide, and NO abrogated the Taxol-induced mitochondrial ROS formation while inhibitors of the other respiratory complexes and cyclosporine A had no effect. We confirmed that the Taxol-induced collapse of DeltaPsi and the induction of ROS production occurs in BRL-3A cells. In conclusion, Taxol-induced adenine nucleotide translocase-cyclophilin complex mediated permeability transition, and cytochrome oxidase mediated ROS production. Because both cytochrome c release and mitochondrial ROS production can induce suicide pathways, the direct mitochondrial effects of Taxol may contribute to its cytotoxicity.

  19. Sox2 promotes tamoxifen resistance in breast cancer cells

    PubMed Central

    Piva, Marco; Domenici, Giacomo; Iriondo, Oihana; Rábano, Miriam; Simões, Bruno M; Comaills, Valentine; Barredo, Inmaculada; López-Ruiz, Jose A; Zabalza, Ignacio; Kypta, Robert; Vivanco, Maria d M

    2014-01-01

    Development of resistance to therapy continues to be a serious clinical problem in breast cancer management. Cancer stem/progenitor cells have been shown to play roles in resistance to chemo- and radiotherapy. Here, we examined their role in the development of resistance to the oestrogen receptor antagonist tamoxifen. Tamoxifen-resistant cells were enriched for stem/progenitors and expressed high levels of the stem cell marker Sox2. Silencing of the SOX2 gene reduced the size of the stem/progenitor cell population and restored sensitivity to tamoxifen. Conversely, ectopic expression of Sox2 reduced tamoxifen sensitivity in vitro and in vivo. Gene expression profiling revealed activation of the Wnt signalling pathway in Sox2-expressing cells, and inhibition of Wnt signalling sensitized resistant cells to tamoxifen. Examination of patient tumours indicated that Sox2 levels are higher in patients after endocrine therapy failure, and also in the primary tumours of these patients, compared to those of responders. Together, these results suggest that development of tamoxifen resistance is driven by Sox2-dependent activation of Wnt signalling in cancer stem/progenitor cells. PMID:24178749

  20. Properties of resistant cells generated from lung cancer cell lines treated with EGFR inhibitors.

    PubMed

    Ghosh, Gargi; Lian, Xiaojun; Kron, Stephen J; Palecek, Sean P

    2012-03-20

    Epidermal growth factor receptor (EGFR) signaling plays an important role in non-small cell lung cancer (NSCLC) and therapeutics targeted against EGFR have been effective in treating a subset of patients bearing somatic EFGR mutations. However, the cancer eventually progresses during treatment with EGFR inhibitors, even in the patients who respond to these drugs initially. Recent studies have identified that the acquisition of resistance in approximately 50% of cases is due to generation of a secondary mutation (T790M) in the EGFR kinase domain. In about 20% of the cases, resistance is associated with the amplification of MET kinase. In the remaining 30-40% of the cases, the mechanism underpinning the therapeutic resistance is unknown. An erlotinib resistant subline (H1650-ER1) was generated upon continuous exposure of NSCLC cell line NCI-H1650 to erlotinib. Cancer stem cell like traits including expression of stem cell markers, enhanced ability to self-renew and differentiate, and increased tumorigenicity in vitro were assessed in erlotinib resistant H1650-ER1 cells. The erlotinib resistant subline contained a population of cells with properties similar to cancer stem cells. These cells were found to be less sensitive towards erlotinib treatment as measured by cell proliferation and generation of tumor spheres in the presence of erlotinib. Our findings suggest that in cases of NSCLC accompanied by mutant EGFR, treatment targeting inhibition of EGFR kinase activity in differentiated cancer cells may generate a population of cancer cells with stem cell properties.

  1. Collateral Sensitivity of Multidrug-Resistant Cells to the Orphan Drug Tiopronin

    PubMed Central

    Goldsborough, Andrew S.; Handley, Misty D.; Dulcey, Andrés E.; Pluchino, Kristen M.; Kannan, Pavitra; Brimacombe, Kyle R.; Hall, Matthew D.; Griffiths, Gary; Gottesman, Michael M.

    2011-01-01

    A major challenge in the treatment of cancer is multidrug resistance (MDR) that develops during chemotherapy. Here we demonstrate that tiopronin (1), a thiol-substituted N-propanoylglycine derivative, was selectively toxic to a series of cell lines expressing the drug efflux pump P-glycoprotein (P-gp, ABCB1) and MRP1 (ABCC1). Treatment of MDR cells with 1 led to instability of the ABCB1 mRNA and consequently a reduction in P-gp protein, despite functional assays demonstrating that tiopronin does not interact with P-gp. Long-term exposure of P-gp-expressing cells to 1 sensitized them to doxorubicin and taxol, both P-gp substrates. Treatment of MRP1-overexpressing cells with tiopronin led to a significant reduction in MRP1 protein. Synthesis and screening of analogs of tiopronin demonstrated that the thiol functional group was essential for collateral sensitivity, while substitution of the amino acid backbone altered but did not destroy specificity, pointing to future development of targeted analogs. PMID:21657271

  2. Novel Compounds Line up to Combat Drug Resistance in Cancer Cells | Center for Cancer Research

    Cancer.gov

    As the war on cancer has intensified and new molecular attacks on cancer cells have been developed, cancer cells have devised innovative ways of defending themselves. Many drugs have been designed or discovered and used to kill cancer cells; in response, these cells are staging new mechanisms to resist the effects of a variety of drugs, a phenomenon called multidrug resistance

  3. Nanodrug delivery in reversing multidrug resistance in cancer cells

    PubMed Central

    Kapse-Mistry, Sonali; Govender, Thirumala; Srivastava, Rohit; Yergeri, Mayur

    2014-01-01

    Different mechanisms in cancer cells become resistant to one or more chemotherapeutics is known as multidrug resistance (MDR) which hinders chemotherapy efficacy. Potential factors for MDR includes enhanced drug detoxification, decreased drug uptake, increased intracellular nucleophiles levels, enhanced repair of drug induced DNA damage, overexpression of drug transporter such as P-glycoprotein(P-gp), multidrug resistance-associated proteins (MRP1, MRP2), and breast cancer resistance protein (BCRP). Currently nanoassemblies such as polymeric/solid lipid/inorganic/metal nanoparticles, quantum dots, dendrimers, liposomes, micelles has emerged as an innovative, effective, and promising platforms for treatment of drug resistant cancer cells. Nanocarriers have potential to improve drug therapeutic index, ability for multifunctionality, divert ABC-transporter mediated drug efflux mechanism and selective targeting to tumor cells, cancer stem cells, tumor initiating cells, or cancer microenvironment. Selective nanocarrier targeting to tumor overcomes dose-limiting side effects, lack of selectivity, tissue toxicity, limited drug access to tumor tissues, high drug doses, and emergence of multiple drug resistance with conventional or combination chemotherapy. Current review highlights various nanodrug delivery systems to overcome mechanism of MDR by neutralizing, evading, or exploiting the drug efflux pumps and those independent of drug efflux pump mechanism by silencing Bcl-2 and HIF1α gene expressions by siRNA and miRNA, modulating ceramide levels and targeting NF-κB. “Theragnostics” combining a cytotoxic agent, targeting moiety, chemosensitizing agent, and diagnostic imaging aid are highlighted as effective and innovative systems for tumor localization and overcoming MDR. Physical approaches such as combination of drug with thermal/ultrasound/photodynamic therapies to overcome MDR are focused. The review focuses on newer drug delivery systems developed to overcome

  4. Novel Compounds Line up to Combat Drug Resistance in Cancer Cells | Center for Cancer Research

    Cancer.gov

    As the war on cancer has intensified and new molecular attacks on cancer cells have been developed, cancer cells have devised innovative ways of defending themselves. Many drugs have been designed or discovered and used to kill cancer cells; in response, these cells are staging new mechanisms to resist the effects of a variety of drugs, a phenomenon called multidrug resistance (MDR). One way cancer cells accomplish this is by catching the intruding drug and throwing it out of the cell before it can act. The arsenal that the cancer cell uses to accomplish this task is a collection of specialized proteins on its membrane called ATP-binding cassette (ABC) transporters.

  5. Cancer Stem Cells (CSCs) in Drug Resistance and their Therapeutic Implications in Cancer Treatment.

    PubMed

    Phi, Lan Thi Hanh; Sari, Ita Novita; Yang, Ying-Gui; Lee, Sang-Hyun; Jun, Nayoung; Kim, Kwang Seock; Lee, Yun Kyung; Kwon, Hyog Young

    2018-01-01

    Cancer stem cells (CSCs), also known as tumor-initiating cells (TICs), are suggested to be responsible for drug resistance and cancer relapse due in part to their ability to self-renew themselves and differentiate into heterogeneous lineages of cancer cells. Thus, it is important to understand the characteristics and mechanisms by which CSCs display resistance to therapeutic agents. In this review, we highlight the key features and mechanisms that regulate CSC function in drug resistance as well as recent breakthroughs of therapeutic approaches for targeting CSCs. This promises new insights of CSCs in drug resistance and provides better therapeutic rationales to accompany novel anticancer therapeutics.

  6. Isolation of anticancer drug TAXOL from Pestalotiopsis breviseta with apoptosis and B-Cell lymphoma protein docking studies.

    PubMed

    Kathiravan, G; Sureban, Sripathi M; Sree, Harsha N; Bhuvaneshwari, V; Kramony, Evelin

    2012-12-01

    Extraction and investigation of TAXOL from Pestalotiopsis breviseta (Sacc.) using protein docking, which is a computational technique that samples conformations of small molecules in protein-binding sites. Scoring functions are used to assess which of these conformations best complements the protein binding site and active site prediction. Coelomycetous fungi P. breviseta (Sacc.) Steyaert was screened for the production of TAXOL, an anticancer drug. TAXOL PRODUCTION WAS CONFIRMED BY THE FOLLOWING METHODS: Ultraviolet (UV) spectroscopic analysis, Infrared analysis, High performance liquid chromatography analysis (HPLC), and Liquid chromatography mass spectrum (LC-MASS). TAXOL produced by the fungi was compared with authentic TAXOL, and protein docking studies were performed. The BCL2 protein of human origin showed a higher affinity toward the compound paclitaxel. It has the binding energy value of -13.0061 (KJ/Mol) with four hydrogen bonds.

  7. Inhibition of the MUC1-C oncoprotein is synergistic with cytotoxic agents in the treatment of breast cancer cells

    PubMed Central

    Uchida, Yasumitsu; Raina, Deepak; Kharbanda, Surender; Kufe, Donald

    2013-01-01

    Mucin 1 (MUC1) is a heterodimeric glycoprotein that is aberrantly overexpressed in most human breast cancers. The oncogenic MUC1-C subunit promotes survival and blocks the apoptotic response to genotoxic anticancer agents. In the present studies, human MCF-7 and ZR-75-1 breast cancer cells were treated with the MUC1-C inhibitor, GO-203, a cell-penetrating peptide that blocks MUC1-C homodimerization and thereby its oncogenic function. Treatment with GO-203 was found to promote the apoptotic response of MCF-7 and ZR-75-1 cells to the therapeutic drugs taxol and doxorubicin (DOX). This effect was (1) attenuated by a pan-caspase inhibitor, and (2) mediated, at least in part, by activation of the effector caspase-7 and cleavage of the downstream substrate PARP. Further analysis of the interaction between GO-203 and taxol using isobolograms, which evaluate the nature of the interaction of two drugs, demonstrated that the combination is highly synergistic. These results were supported by combination index (CI) analysis with values of less than 1. GO-203 was also highly synergistic with DOX in studies of both MCF-7 and ZR-75-1 breast cancer cells. These findings indicate that blocking MUC1-C function could be effective in combination with taxol and DOX for the treatment of breast cancer. PMID:23114713

  8. Isolation of anticancer drug TAXOL from Pestalotiopsis breviseta with apoptosis and B-Cell lymphoma protein docking studies

    PubMed Central

    Kathiravan, G.; Sureban, Sripathi M.; Sree, Harsha N.; Bhuvaneshwari, V.; Kramony, Evelin

    2012-01-01

    Background: Extraction and investigation of TAXOL from Pestalotiopsis breviseta (Sacc.) using protein docking, which is a computational technique that samples conformations of small molecules in protein-binding sites. Scoring functions are used to assess which of these conformations best complements the protein binding site and active site prediction. Materials and Methods: Coelomycetous fungi P. breviseta (Sacc.) Steyaert was screened for the production of TAXOL, an anticancer drug. Results: TAXOL production was confirmed by the following methods: Ultraviolet (UV) spectroscopic analysis, Infrared analysis, High performance liquid chromatography analysis (HPLC), and Liquid chromatography mass spectrum (LC-MASS). TAXOL produced by the fungi was compared with authentic TAXOL, and protein docking studies were performed. Conclusion: The BCL2 protein of human origin showed a higher affinity toward the compound paclitaxel. It has the binding energy value of −13.0061 (KJ/Mol) with four hydrogen bonds. PMID:24808664

  9. Nuclear respiratory factor-1 and bioenergetics in tamoxifen-resistant breast cancer cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Radde, Brandie N.; Ivanova, Margarita M.; Mai, Huy Xuan

    Acquired tamoxifen (TAM) resistance is a significant clinical problem in treating patients with estrogen receptor α (ERα)+ breast cancer. We reported that ERα increases nuclear respiratory factor-1 (NRF-1), which regulates nuclear-encoded mitochondrial gene transcription, in MCF-7 breast cancer cells and NRF-1 knockdown stimulates apoptosis. Whether NRF-1 and target gene expression is altered in endocrine resistant breast cancer cells is unknown. We measured NRF-1and metabolic features in a cell model of progressive TAM-resistance. NRF-1 and its target mitochondrial transcription factor A (TFAM) were higher in TAM-resistant LCC2 and LCC9 cells than TAM-sensitive MCF-7 cells. Using extracellular flux assays we observed thatmore » LCC1, LCC2, and LCC9 cells showed similar oxygen consumption rate (OCR), but lower mitochondrial reserve capacity which was correlated with lower Succinate Dehydrogenase Complex, Subunit B in LCC1 and LCC2 cells. Complex III activity was lower in LCC9 than MCF-7 cells. LCC1, LCC2, and LCC9 cells had higher basal extracellular acidification (ECAR), indicating higher aerobic glycolysis, relative to MCF-7 cells. Mitochondrial bioenergetic responses to estradiol and 4-hydroxytamoxifen were reduced in the endocrine-resistant cells compared to MCF-7 cells. These results suggest the acquisition of altered metabolic phenotypes in response to long term antiestrogen treatment may increase vulnerability to metabolic stress. - Highlights: • NRF-1 and TFAM expression are higher in endocrine-resistant breast cancer cells. • Oxygen consumption rate is similar in endocrine-sensitive and resistant cells. • Mitochondrial reserve capacity is lower in endocrine-resistant cells. • Endocrine-resistant breast cancer cells have increased glycolysis. • Bioenergetic responses to E2 and tamoxifen are lower in endocrine-resistant cells.« less

  10. Resistance to Cell Death and Its Modulation in Cancer Stem Cells

    PubMed Central

    Safa, Ahmad R.

    2017-01-01

    Accumulating evidence has demonstrated that human cancers arise from various tissues of origin that initiate from cancer stem cells (CSCs) or cancer-initiating cells. The extrinsic and intrinsic apoptotic pathways are dysregulated in CSCs, and these cells play crucial roles in tumor initiation, progression, cell death resistance, chemo- and radiotherapy resistance, and tumor recurrence. Understanding CSC-specific signaling proteins and pathways is necessary to identify specific therapeutic targets that may lead to the development of more efficient therapies selectively targeting CSCs. Several signaling pathways—including the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), maternal embryonic leucine zipper kinase (MELK), NOTCH1, and Wnt/β-catenin—and expression of the CSC markers CD133, CD24, CD44, Oct4, Sox2, Nanog, and ALDH1A1 maintain CSC properties. Studying such pathways may help to understand CSC biology and lead to the development of potential therapeutic interventions to render CSCs more sensitive to cell death triggered by chemotherapy and radiation therapy. Moreover, recent demonstrations of dedifferentiation of differentiated cancer cells into CSC-like cells have created significant complexity in the CSCs hypothesis. Therefore, any successful therapeutic agent or combination of drugs for cancer therapy must eliminate not only CSCs but differentiated cancer cells and the entire bulk of tumor cells. This review article expands on the CSC hypothesis and paradigm with respect to major signaling pathways and effectors that regulate CSC apoptosis resistance. Moreover, selective CSC apoptotic modulators and their therapeutic potential for making tumors more responsive to therapy are discussed. The use of novel therapies, including small-molecule inhibitors of specific proteins in signaling pathways that regulate stemness, proliferation and migration of CSCs, immunotherapy, and noncoding microRNAs may provide better means of

  11. Rethinking production of Taxol® (paclitaxel) using endophyte biotechnology.

    PubMed

    Kusari, Souvik; Singh, Satpal; Jayabaskaran, Chelliah

    2014-06-01

    Taxol® (generic name paclitaxel) represents one of the most clinically valuable natural products known to mankind in the recent past. More than two decades have elapsed since the notable discovery of the first Taxol®-producing endophytic fungus, which was followed by a plethora of reports on other endophytes possessing similar biosynthetic potential. However, industrial-scale Taxol® production using fungal endophytes, although seemingly promising, has not seen the light of the day. In this opinion article, we embark on the current state of knowledge on Taxol® biosynthesis focusing on the chemical ecology of its producers, and ask whether it is actually possible to produce Taxol® using endophyte biotechnology. The key problems that have prevented the exploitation of potent endophytic fungi by industrial bioprocesses for sustained production of Taxol® are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Reprogramming mediated radio-resistance of 3D-grown cancer cells.

    PubMed

    Xue, Gang; Ren, Zhenxin; Grabham, Peter W; Chen, Yaxiong; Zhu, Jiayun; Du, Yarong; Pan, Dong; Li, Xiaoman; Hu, Burong

    2015-07-01

    In vitro 3D growth of tumors is a new cell culture model that more closely mimics the features of the in vivo environment and is being used increasingly in the field of biological and medical research. It has been demonstrated that cancer cells cultured in 3D matrices are more radio-resistant compared with cells in monolayers. However, the mechanisms causing this difference remain unclear. Here we show that cancer cells cultured in a 3D microenvironment demonstrated an increase in cells with stem cell properties. This was confirmed by the finding that cells in 3D cultures upregulated the gene and protein expression of the stem cell reprogramming factors such as OCT4, SOX2, NANOG, LIN28 and miR-302a, compared with cells in monolayers. Moreover, the expression of β-catenin, a regulating molecule of reprogramming factors, also increased in 3D-grown cancer cells. These findings suggest that cancer cells were reprogrammed to become stem cell-like cancer cells in a 3D growth culture microenvironment. Since cancer stem cell-like cells demonstrate an increased radio-resistance and chemo-resistance, our results offer a new perspective as to why. Our findings shed new light on understanding the features of the 3D growth cell model and its application in basic research into clinical radiotherapy and medicine. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  13. Reverse of non-small cell lung cancer drug resistance induced by cancer-associated fibroblasts via a paracrine pathway.

    PubMed

    Zhang, Quanhui; Yang, Junping; Bai, Jie; Ren, Jianzhuang

    2018-04-01

    The tumor microenvironment orchestrates the sustained growth, metastasis and recurrence of cancer. As an indispensable component of the tumor microenvironment, cancer-associated fibroblasts (CAF) are considered as an essential synthetic machine producing various tumor components, leading to cancer sustained stemness, drug resistance and tumor recurrence. Here, we developed a sustainable primary culture of lung cancer cells fed with lung cancer-associated fibroblasts, resulting in enrichment and acquisition of drug resistance in cancer cells. Moreover, IGF2/AKT/Sox2/ABCB1 signaling activation in cancer cells was observed in the presence of CAF, which induces upregulation of P-glycoprotein expression and the drug resistance of non-small cell lung cancer cells. Our results demonstrated that CAF cells constitute a mechanism for cancer drug resistance. Thus, traditional chemotherapy combined with insulin-like growth factor 2 (IGF2) signaling inhibitor may present an innovative therapeutic strategy for non-small cell lung cancer therapy. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  14. Cisplatin-resistant lung cancer cell-derived exosomes increase cisplatin resistance of recipient cells in exosomal miR-100-5p-dependent manner.

    PubMed

    Qin, Xiaobing; Yu, Shaorong; Zhou, Leilei; Shi, Meiqi; Hu, Yong; Xu, Xiaoyue; Shen, Bo; Liu, Siwen; Yan, Dali; Feng, Jifeng

    2017-01-01

    Exosomes derived from lung cancer cells confer cisplatin (DDP) resistance to other cancer cells. However, the underlying mechanism is still unknown. A549 resistance to DDP (A549/DDP) was established. Microarray was used to analyze microRNA (miRNA) expression profiles of A549 cells, A549/DDP cells, A549 exosomes, and A549/DDP exosomes. There was a strong correlation of miRNA profiles between exosomes and their maternal cells. A total of 11 miRNAs were significantly upregulated both in A549/DDP cells compared with A549 cells and in exosomes derived from A549/DDP cells in contrast to exosomes from A549 cells. A total of 31 downregulated miRNAs were also observed. miR-100-5p was the most prominent decreased miRNA in DDP-resistant exosomes compared with the corresponding sensitive ones. Downregulated miR-100-5p was proved to be involved in DDP resistance in A549 cells, and mammalian target of rapamycin (mTOR) expression was reverse regulated by miR-100-5p. Exosomes confer recipient cells' resistance to DDP in an exosomal miR-100-5p-dependent manner with mTOR as its potential target both in vitro and in vivo. Exosomes from DDP-resistant lung cancer cells A549 can alter other lung cancer cells' sensitivity to DDP in exosomal miR-100-5p-dependent manner. Our study provides new insights into the molecular mechanism of DDP resistance in lung cancer.

  15. Drug-resistant colon cancer cells produce high carcinoembryonic antigen and might not be cancer-initiating cells

    PubMed Central

    Lee, Hsin-chung; Ling, Qing-Dong; Yu, Wan-Chun; Hung, Chunh-Ming; Kao, Ta-Chun; Huang, Yi-Wei; Higuchi, Akon

    2013-01-01

    Purpose We evaluated the higher levels of carcinoembryonic antigen (CEA) secreted by the LoVo human colon carcinoma cells in a medium containing anticancer drugs. Drug-resistant LoVo cells were analyzed by subcutaneously xenotransplanting them into mice. The aim of this study was to evaluate whether the drug-resistant cells isolated in this study were cancer-initiating cells, known also as cancer stem cells (CSCs). Methods The production of CEA was investigated in LoVo cells that were cultured with 0–10 mM of anticancer drugs, and we evaluated the increase in CEA production by the LoVo cells that were stimulated by anticancer drug treatment. The expression of several CSC markers in LoVo cells treated with anticancer drugs was also evaluated. Following anticancer drug treatment, LoVo cells were injected subcutaneously into the flanks of severe combined immunodeficiency mice in order to evaluate the CSC fraction. Results Production of CEA by LoVo cells was stimulated by the addition of anticancer drugs. Drug-resistant LoVo cells expressed lower levels of CSC markers, and LoVo cells treated with any of the anticancer drugs tested did not generate tumors within 8 weeks from when the cells were injected subcutaneously into severe combined immunodeficiency mice. These results suggest that the drug-resistant LoVo cells have a smaller population of CSCs than the untreated LoVo cells. Conclusion Production of CEA by LoVo cells can be stimulated by the addition of anticancer drugs. The drug-resistant subpopulation of LoVo colon cancer cells could stimulate the production of CEA, but these cells did not act as CSCs in in vivo tumor generation experiments. PMID:23818760

  16. Ulinastatin Reduces the Resistance of Liver Cancer Cells to Epirubicin by Inhibiting Autophagy

    PubMed Central

    Shao, Cheng Hao; Li, Gang; Liu, An An; Jing, Wei; Liu, Rui; Zhang, Yi-Jie; Zhou, Ying-Qi; Hu, Xian-Gui; Jin, Gang

    2015-01-01

    During chemotherapy, drug resistance caused by autophagy remains a major challenge to successful treatment of cancer patients. The purpose of this study is to show that ulinastatin (UTI), a trypsin inhibitor, could reduce the resistance of liver cancer cells to chemotherapeutic agent epirubicin (EPI). We achieved this conclusion by analyzing the effect of EPI alone or UTI plus EPI on SMMC-7721 and MHCC-LM3 liver cancer cells. We also generated an EPI-resistant liver cancer cell line (MHCC-LM3er cells), and found that UTI could sensitize the LM3er cells to EPI. Autophagy usually functions to protect cancer cells during chemotherapy. Our study showed that UTI inhibited the autophagy induced by EPI in liver cancer cells, which promoted apoptosis, and therefore, reduced the resistance of the cancer cells to EPI. Further studies showed that the UTI-mediated inhibition on autophagy was achieved by inhibiting transcriptional factor nuclear factor-κB (NF-κB) signaling pathway. To verify our results in vivo, we injected MHCC-LM3 liver cancer cells or EPI-resistant LM3er cells into mice, and found that EPI could only effectively inhibit the growth of tumor in MHCC-LM3 cell-injected mice, but not in LM3er cell-injected mice. However, when UTI was also administered, the growth of tumor was inhibited in the MHCC-LM3er cell-injected mice as well. Our results suggest that UTI may be used in combination with anti-cancer drugs, such as EPI, to improve the outcome of cancer therapy. PMID:25815885

  17. Blockade of epidermal growth factor receptor signaling in tumor cells and tumor-associated endothelial cells for therapy of androgen-independent human prostate cancer growing in the bone of nude mice.

    PubMed

    Kim, Sun-Jin; Uehara, Hisanori; Karashima, Takashi; Shepherd, David L; Killion, Jerald J; Fidler, Isaiah J

    2003-03-01

    We determined whether blockade of the epidermal growth factor receptor (EGF-R) signaling pathway by oral administration of the EGF-R tyrosine kinase inhibitor (PKI 166) alone or in combination with injectable Taxol inhibits the growth of PC-3MM2 human prostate cancer cells in the bone of nude mice. Male nude mice implanted with PC-3MM2 cells in the tibia were treated with oral administrations of PKI 166 or PKI 166 plus injectable Taxol beginning 3 days after implantation. The incidence and size of bone tumors and destruction of bone were determined by digitalized radiography. Expression of epidermal growth factor (EGF), EGF-R, and activated EGF-R in tumor cells and tumor-associated endothelial cells was determined by immunohistochemistry. Oral administration of PKI 166 or PKI 166 plus injectable Taxol reduced the incidence and size of bone tumors and destruction of bone. Immunohistochemical analysis revealed that PC-3MM2 cells growing adjacent to the bone expressed high levels of EGF and activated EGF-R, whereas tumor cells in the adjacent musculature did not. Moreover, endothelial cells within the bone tumor lesions, but not in uninvolved bone or tumors in the muscle, expressed high levels of activated EGF-R. Treatment with PKI 166 and more so with PKI 166 plus Taxol significantly inhibited phosphorylation of EGF-R on tumor and endothelial cells and induced significant apoptosis and endothelial cells within tumor lesions. These data indicate that endothelial cells exposed to EGF produced by tumor cells express activated EGF-R and that targeting EGF-R can produce significant therapeutic effects against prostate cancer bone metastasis.

  18. Exosomes derived from human mesenchymal stem cells confer drug resistance in gastric cancer

    PubMed Central

    Ji, Runbi; Zhang, Bin; Zhang, Xu; Xue, Jianguo; Yuan, Xiao; Yan, Yongmin; Wang, Mei; Zhu, Wei; Qian, Hui; Xu, Wenrong

    2015-01-01

    Mesenchymal stem cells (MSCs) play an important role in chemoresistance. Exosomes have been reported to modify cellular phenotype and function by mediating cell-cell communication. In this study, we aimed to investigate whether exosomes derived from MSCs (MSC-exosomes) are involved in mediating the resistance to chemotherapy in gastric cancer and to explore the underlying molecular mechanism. We found that MSC-exosomes significantly induced the resistance of gastric cancer cells to 5-fluorouracil both in vivo and ex vivo. MSC-exosomes antagonized 5-fluorouracil-induced apoptosis and enhanced the expression of multi-drug resistance associated proteins, including MDR, MRP and LRP. Mechanistically, MSC-exosomes triggered the activation of calcium/calmodulin-dependent protein kinases (CaM-Ks) and Raf/MEK/ERK kinase cascade in gastric cancer cells. Blocking the CaM-Ks/Raf/MEK/ERK pathway inhibited the promoting role of MSC-exosomes in chemoresistance. Collectively, MSC-exosomes could induce drug resistance in gastric cancer cells by activating CaM-Ks/Raf/MEK/ERK pathway. Our findings suggest that MSC-exosomes have profound effects on modifying gastric cancer cells in the development of drug resistance. Targeting the interaction between MSC-exosomes and cancer cells may help improve the efficacy of chemotherapy in gastric cancer. PMID:26091251

  19. Exosomes derived from human mesenchymal stem cells confer drug resistance in gastric cancer.

    PubMed

    Ji, Runbi; Zhang, Bin; Zhang, Xu; Xue, Jianguo; Yuan, Xiao; Yan, Yongmin; Wang, Mei; Zhu, Wei; Qian, Hui; Xu, Wenrong

    2015-08-03

    Mesenchymal stem cells (MSCs) play an important role in chemoresistance. Exosomes have been reported to modify cellular phenotype and function by mediating cell-cell communication. In this study, we aimed to investigate whether exosomes derived from MSCs (MSC-exosomes) are involved in mediating the resistance to chemotherapy in gastric cancer and to explore the underlying molecular mechanism. We found that MSC-exosomes significantly induced the resistance of gastric cancer cells to 5-fluorouracil both in vivo and ex vivo. MSC-exosomes antagonized 5-fluorouracil-induced apoptosis and enhanced the expression of multi-drug resistance associated proteins, including MDR, MRP and LRP. Mechanistically, MSC-exosomes triggered the activation of calcium/calmodulin-dependent protein kinases (CaM-Ks) and Raf/MEK/ERK kinase cascade in gastric cancer cells. Blocking the CaM-Ks/Raf/MEK/ERK pathway inhibited the promoting role of MSC-exosomes in chemoresistance. Collectively, MSC-exosomes could induce drug resistance in gastric cancer cells by activating CaM-Ks/Raf/MEK/ERK pathway. Our findings suggest that MSC-exosomes have profound effects on modifying gastric cancer cells in the development of drug resistance. Targeting the interaction between MSC-exosomes and cancer cells may help improve the efficacy of chemotherapy in gastric cancer.

  20. Danshen extract circumvents drug resistance and represses cell growth in human oral cancer cells.

    PubMed

    Yang, Cheng-Yu; Hsieh, Cheng-Chih; Lin, Chih-Kung; Lin, Chun-Shu; Peng, Bo; Lin, Gu-Jiun; Sytwu, Huey-Kang; Chang, Wen-Liang; Chen, Yuan-Wu

    2017-12-29

    Danshen is a common traditional Chinese medicine used to treat neoplastic and chronic inflammatory diseases in China. However, the effects of Danshen on human oral cancer cells remain relatively unknown. This study investigated the antiproliferative effects of a Danshen extract on human oral cancer SAS, SCC25, OEC-M1, and KB drug-resistant cell lines and elucidated the possible underlying mechanism. We investigated the anticancer potential of the Danshen extract in human oral cancer cell lines and an in vivo oral cancer xenograft mouse model. The expression of apoptosis-related molecules was evaluated through Western blotting, and the concentration of in vivo apoptotic markers was measured using immunohistochemical staining. The antitumor effects of 5-fluorouracil and the Danshen extract were compared. Cell proliferation assays revealed that the Danshen extract strongly inhibited oral cancer cell proliferation. Cell morphology studies revealed that the Danshen extract inhibited the growth of SAS, SCC25, and OEC-M1 cells by inducing apoptosis. The Flow cytometric analysis indicated that the Danshen extract induced cell cycle G0/G1 arrest. Immunoblotting analysis for the expression of active caspase-3 and X-linked inhibitor of apoptosis protein indicated that Danshen extract-induced apoptosis in human oral cancer SAS cells was mediated through the caspase pathway. Moreover, the Danshen extract significantly inhibited growth in the SAS xenograft mouse model. Furthermore, the Danshen extract circumvented drug resistance in KB drug-resistant oral cancer cells. The study results suggest that the Danshen extract could be a potential anticancer agent in oral cancer treatment.

  1. Sortilin regulates progranulin action in castration-resistant prostate cancer cells.

    PubMed

    Tanimoto, Ryuta; Morcavallo, Alaide; Terracciano, Mario; Xu, Shi-Qiong; Stefanello, Manuela; Buraschi, Simone; Lu, Kuojung G; Bagley, Demetrius H; Gomella, Leonard G; Scotlandi, Katia; Belfiore, Antonino; Iozzo, Renato V; Morrione, Andrea

    2015-01-01

    The growth factor progranulin is as an important regulator of transformation in several cellular systems. We have previously demonstrated that progranulin acts as an autocrine growth factor and stimulates motility, proliferation, and anchorage-independent growth of castration-resistant prostate cancer cells, supporting the hypothesis that progranulin may play a critical role in prostate cancer progression. However, the mechanisms regulating progranulin action in castration-resistant prostate cancer cells have not been characterized. Sortilin, a single-pass type I transmembrane protein of the vacuolar protein sorting 10 family, binds progranulin in neurons and negatively regulates progranulin signaling by mediating progranulin targeting for lysosomal degradation. However, whether sortilin is expressed in prostate cancer cells and plays any role in regulating progranulin action has not been established. Here, we show that sortilin is expressed at very low levels in castration-resistant PC3 and DU145 cells. Significantly, enhancing sortilin expression in PC3 and DU145 cells severely diminishes progranulin levels and inhibits motility, invasion, proliferation, and anchorage-independent growth. In addition, sortilin overexpression negatively modulates Akt (protein kinase B, PKB) stability. These results are recapitulated by depleting endogenous progranulin in PC3 and DU145 cells. On the contrary, targeting sortilin by short hairpin RNA approaches enhances progranulin levels and promotes motility, invasion, and anchorage-independent growth. We dissected the mechanisms of sortilin action and demonstrated that sortilin promotes progranulin endocytosis through a clathrin-dependent pathway, sorting into early endosomes and subsequent lysosomal degradation. Collectively, these results point out a critical role for sortilin in regulating progranulin action in castration-resistant prostate cancer cells, suggesting that sortilin loss may contribute to prostate cancer progression.

  2. Sortilin Regulates Progranulin Action in Castration-Resistant Prostate Cancer Cells

    PubMed Central

    Tanimoto, Ryuta; Morcavallo, Alaide; Terracciano, Mario; Xu, Shi-Qiong; Stefanello, Manuela; Buraschi, Simone; Lu, Kuojung G.; Bagley, Demetrius H.; Gomella, Leonard G.; Scotlandi, Katia; Belfiore, Antonino; Iozzo, Renato V.

    2015-01-01

    The growth factor progranulin is as an important regulator of transformation in several cellular systems. We have previously demonstrated that progranulin acts as an autocrine growth factor and stimulates motility, proliferation, and anchorage-independent growth of castration-resistant prostate cancer cells, supporting the hypothesis that progranulin may play a critical role in prostate cancer progression. However, the mechanisms regulating progranulin action in castration-resistant prostate cancer cells have not been characterized. Sortilin, a single-pass type I transmembrane protein of the vacuolar protein sorting 10 family, binds progranulin in neurons and negatively regulates progranulin signaling by mediating progranulin targeting for lysosomal degradation. However, whether sortilin is expressed in prostate cancer cells and plays any role in regulating progranulin action has not been established. Here, we show that sortilin is expressed at very low levels in castration-resistant PC3 and DU145 cells. Significantly, enhancing sortilin expression in PC3 and DU145 cells severely diminishes progranulin levels and inhibits motility, invasion, proliferation, and anchorage-independent growth. In addition, sortilin overexpression negatively modulates Akt (protein kinase B, PKB) stability. These results are recapitulated by depleting endogenous progranulin in PC3 and DU145 cells. On the contrary, targeting sortilin by short hairpin RNA approaches enhances progranulin levels and promotes motility, invasion, and anchorage-independent growth. We dissected the mechanisms of sortilin action and demonstrated that sortilin promotes progranulin endocytosis through a clathrin-dependent pathway, sorting into early endosomes and subsequent lysosomal degradation. Collectively, these results point out a critical role for sortilin in regulating progranulin action in castration-resistant prostate cancer cells, suggesting that sortilin loss may contribute to prostate cancer progression

  3. In vitro TAXOL production, by Pestalotiopsis breviseta--a first report.

    PubMed

    Kathiravan, Govindarajan; Sri Raman, Vithiyanathan

    2010-09-01

    Coelomycetous fungi were screened for the production of TAXOL. TAXOL production of Pestalotiopsis breviseta fungi is confirmed by Ultra Violet (UV) spectroscopic analysis, Infra Red (IR) analysis, high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) and LC-MASS spectroscopy. TAXOL isolated from the P. breviseta fungus was identical with authentic TAXOL and produces 0.064 mg/L (0.128% dry weight of fungal mat). Copyright (c) 2010 Elsevier B.V. All rights reserved.

  4. Doxorubicin-induced mitophagy contributes to drug resistance in cancer stem cells from HCT8 human colorectal cancer cells.

    PubMed

    Yan, Chen; Luo, Lan; Guo, Chang-Ying; Goto, Shinji; Urata, Yoshishige; Shao, Jiang-Hua; Li, Tao-Sheng

    2017-03-01

    Cancer stem cells (CSCs) are known to be drug resistant. Mitophagy selectively degrades unnecessary or damaged mitochondria by autophagy during cellular stress. To investigate the potential role of mitophagy in drug resistance in CSCs, we purified CD133 + /CD44 + CSCs from HCT8 human colorectal cancer cells and then exposed to doxorubicin (DXR). Compared with parental cells, CSCs were more resistant to DXR treatment. Although DXR treatment enhanced autophagy levels in both cell types, the inhibition of autophagy by ATG7 silencing significantly increased the toxicity of DXR only in parental cells, not in CSCs. Interestingly, the level of mitochondrial superoxide was detected to be significantly lower in CSCs than in parental cells after DXR treatment. Furthermore, the mitophagy level and expression of BNIP3L, a mitophagy regulator, were significantly higher in CSCs than in parental cells after DXR treatment. Silencing BNIP3L significantly halted mitophagy and enhanced the sensitivity to DXR in CSCs. Our data suggested that mitophagy, but not non-selective autophagy, likely contributes to drug resistance in CSCs isolated from HCT8 cells. Further studies in other cancer cell lines will be needed to confirm our findings. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Microvesicle removal of anticancer drugs contributes to drug resistance in human pancreatic cancer cells

    PubMed Central

    Muralidharan-Chari, Vandhana; Kohan, Hamed Gilzad; Asimakopoulos, Alexandros G.; Sudha, Thangirala; Sell, Stewart; Kannan, Kurunthachalam; Boroujerdi, Mehdi; Davis, Paul J.; Mousa, Shaker A.

    2016-01-01

    High mortality in pancreatic cancer patients is partly due to resistance to chemotherapy. We describe that human pancreatic cancer cells acquire drug resistance by a novel mechanism in which they expel and remove chemotherapeutic drugs from the microenvironment via microvesicles (MVs). Using human pancreatic cancer cells that exhibit varied sensitivity to gemcitabine (GEM), we show that GEM exposure triggers the cancer cells to release MVs in an amount that correlates with that cell line's sensitivity to GEM. The importance of MV-release in gaining drug resistance in GEM-resistant pancreatic cancer cells was confirmed when the inhibition of MV-release sensitized the cells to GEM treatment, both in vitro and in vivo. Mechanistically, MVs remove drugs that are internalized into the cells and that are in the microenvironment. The differences between the drug-resistant and drug-sensitive pancreatic cancer cell lines tested here are explained based on the variable content of influx/efflux proteins present on MVs, which directly dictates the ability of MVs either to trap GEM or to allow GEM to flow back to the microenvironment. PMID:27391262

  6. Identifying clinically relevant drug resistance genes in drug-induced resistant cancer cell lines and post-chemotherapy tissues.

    PubMed

    Tong, Mengsha; Zheng, Weicheng; Lu, Xingrong; Ao, Lu; Li, Xiangyu; Guan, Qingzhou; Cai, Hao; Li, Mengyao; Yan, Haidan; Guo, You; Chi, Pan; Guo, Zheng

    2015-12-01

    Until recently, few molecular signatures of drug resistance identified in drug-induced resistant cancer cell models can be translated into clinical practice. Here, we defined differentially expressed genes (DEGs) between pre-chemotherapy colorectal cancer (CRC) tissue samples of non-responders and responders for 5-fluorouracil and oxaliplatin-based therapy as clinically relevant drug resistance genes (CRG5-FU/L-OHP). Taking CRG5-FU/L-OHP as reference, we evaluated the clinical relevance of several types of genes derived from HCT116 CRC cells with resistance to 5-fluorouracil and oxaliplatin, respectively. The results revealed that DEGs between parental and resistant cells, when both were treated with the corresponding drug for a certain time, were significantly consistent with the CRG5-FU/L-OHP as well as the DEGs between the post-chemotherapy CRC specimens of responders and non-responders. This study suggests a novel strategy to extract clinically relevant drug resistance genes from both drug-induced resistant cell models and post-chemotherapy cancer tissue specimens.

  7. In vitro Flow Adhesion Assay for Analyzing Shear-resistant Adhesion of Metastatic Cancer Cells to Endothelial Cells.

    PubMed

    Kang, Shin-Ae; Bajana, Sandra; Tanaka, Takemi

    2016-02-20

    Hematogenous metastasis is a primary cause of mortality from metastatic cancer. The shear-resistant adhesion of circulating tumor cells to the vascular endothelial cell surface under blood flow is an essential step in cell extravasation and further tissue invasion. This is similar to a process exploited by leukocytes for adhesion to inflamed blood vessels (leukocyte mimicry). The shear resistant adhesion is mediated by high affinity interactions between endothelial adhesion molecules and their counter receptor ligand expressed on circulating cells. Thus, weak interaction results in a rapid detachment of circulating cells from endothelium. Despite the critical role of vascular adhesion of cancer cells in hematogenous metastasis, our knowledge regarding this process has been limited due to the difficulty of mimicking dynamic flow conditions in vitro . In order to gain better insight into the shear-resistant adhesion of cancer cells to the endothelium, we developed a protocol for measuring the shear resistant adhesion of circulating tumor cells to endothelial cells under physiologic flow conditions by adapting a well established flow adhesion assay for inflammatory cells. This technique is useful to evaluate 1) the shear resistant adhesion competency of cancer cells and 2) the endothelial adhesion molecules necessary to support cancer cell adhesion (Kang et al. , 2015).

  8. Pancreatic cancer cells resistance to gemcitabine: the role of MUC4 mucin.

    PubMed

    Bafna, S; Kaur, S; Momi, N; Batra, S K

    2009-10-06

    A major obstacle to the successful management of pancreatic cancer is to acquire resistance to the existing chemotherapeutic agents. Resistance to gemcitabine, the standard first-line chemotherapeutic agent for advanced and metastatic pancreatic cancer, is mainly attributed to an altered apoptotic threshold in the pancreatic cancer. The MUC4 transmembrane glycoprotein is aberrantly overexpressed in the pancreatic cancer and recently, has been shown to increase pancreatic tumour cell growth by the inhibition of apoptosis. Effect of MUC4 on pancreatic cancer cells resistance to gemcitabine was studied in MUC4-expressing and MUC4-knocked down pancreatic cancer cell lines after treatment with gemcitabine by Annexin-V staining, DNA fragmentation assay, assessment of mitochondrial cytochrome c release, immunoblotting and co-immunoprecipitation techniques. Annexin-V staining and DNA fragmentation experiment demonstrated that MUC4 protects CD18/HPAF pancreatic cancer cells from gemcitabine-induced apoptosis. In concert with these results, MUC4 also attenuated mitochondrial cytochrome c release and the activation of caspase-9. Further, our results showed that MUC4 exerts anti-apoptotic function through HER2/extracellular signal-regulated kinase-dependent phosphorylation and inactivation of the pro-apoptotic protein Bad. Our results elucidate the function of MUC4 in imparting resistance to pancreatic cancer cells against gemcitabine through the activation of anti-apoptotic pathways and, thereby, promoting cell survival.

  9. Overexpression of CYP3A4 in a COLO 205 Colon Cancer Stem Cell Model in vitro

    PubMed Central

    Olszewski, Ulrike; Liedauer, Richard; Ausch, Christoph; Thalhammer, Theresia; Hamilton, Gerhard

    2011-01-01

    Cancer stem cells (CSCs) seem to constitute a subpopulation of tumor cells that escape from chemotherapy and cause recurrent disease. Low proliferation rates, protection in a stem cell niche and overexpression of drug resistance proteins are considered to confer chemoresistance. We established an in vitro colon CSC-like model using the COLO 205 cell line, which revealed transiently increased expression of CD133 when transferred to serum-free stem cell culture medium. Assessment of global gene expression of COLO 205 cells under these conditions identified a set of upregulated genes including cytochrome P450 3A4 (CYP3A4) and aldehyde dehydrogenase 1A1 (ALDH1A1), as confirmed by real-time qPCR. ALDH1A1 is a CSC marker for certain tumor entities and confers resistance to cyclophosphamide. CYP3A4 is expressed in liver and colon and its overexpression seems particularly relevant in colon cancer, since it inactivates irinotecan and other xenobiotics, such as taxols and vinca alkaloids. In conclusion, this COLO 205 model provides evidence for CD133 induction concomitant with overexpression of CYP3A4, which, together with ATP-binding cassette, subfamily G, member 2 (ABCG2) and others, may have a role in chemoresistant colon CSCs and a negative impact on disease-free survival in colon cancer patients. PMID:24212669

  10. Systemic mesenchymal stem cells reduce growth rate of cisplatin-resistant ovarian cancer.

    PubMed

    Zhu, Pengfei; Chen, Mo; Wang, Li; Ning, Yanxia; Liang, Jie; Zhang, Hao; Xu, Congjian; Chen, Sifeng; Yao, Liangqing

    2013-01-01

    Epithelial ovarian cancer is one of the most malignant cancers in women and resistant to chemotherapy is the major obstacle for the five-year survival rate. Cisplatin is one of the effective anticancer drug used in the ovarian cancer. To find a good strategy to cure the tumors which is resistant to cisplatin, the cisplatin-resistant 3SKOV3 cells were selected from SKOV-3 ovarian cancer cells. Furthermore, the isolated mesenchymal stem cells were infused systemically to try to cure the transplanted tumor induced by 3SKOV3 cells in nude mice. The morphology and cell membrane CD44 expression were investigated by microscope and flow cytometry. The biological behaviors of resistant 3SKOV3 and its parental SKOV3 cells, including proliferation, adhesion, and cell cycle were determined by CCK8, absorbance assay and FCM methods. The transplanted tumors were set up in nude mice with 3SKOV3 cells injection. The growth rate of transplanted tumors was detected following with MSCs injection. The 3SKOV3 cells have different morphologic manifestation and expressed high level of CD44 molecule. At the same time, 3SKOV3 cells have less adhesion ability and less S-phase ratio. The isolated MSCs from bone marrow could inhibit the growth of transplanted tumor via systemic injection. The cisplatin-resistant 3SKOV3 cells have the different biological behaviors as its parental SKOV3 cells. The present study indicated that systemic MSCs have the therapeutic role on ovarian cancer. However, further investigations are in progress to elucidate the underlying mechanism.

  11. COUP-TFII inhibits NFkappaB activation in endocrine-resistant breast cancer cells

    PubMed Central

    Litchfield, Lacey M.; Appana, Savitri N.; Datta, Susmita; Klinge, Carolyn M.

    2016-01-01

    Reduced COUP-TFII expression contributes to endocrine resistance in breast cancer cells. Endocrine-resistant breast cancer cells have higher NFkappa B (NFκB) activity and target gene expression. The goal of this study was to determine if COUP-TFII modulates NFκB activity. Endocrine-resistant LCC9 cells with low endogenous COUP-TFII displayed ~5-fold higher basal NFκB activity than parental endocrine-sensitive MCF-7 breast cancer cells. Transient transfection of LCC9 cells with COUP-TFII inhibited NFκB activation and reduced NFκB target gene expression. COUP-TFII and NFκB were inversely correlated in breast cancer patient samples. Endogenous COUP-TFII coimmunoprecipitated with NFκB subunits RelB and NFκB1 in MCF-7 cells. COUP-TFII inhibited NFκB-DNA binding in vitro and impaired coactivator induced NFκB transactivation. LCC9 cells were growth-inhibited by an NFκB inhibitor and 4-hydroxytamoxifen compared to MCF-7 cells. Together these data indicate a novel role for COUP-TFII in suppression of NFκB activity and explain, in part, why decreased COUP-TFII expression results in an endocrine-resistant phenotype. PMID:24141032

  12. Bimetallic redox nanoprobe enhances the therapeutic efficacy of hyperthermia in drug-resistant cancer cells

    NASA Astrophysics Data System (ADS)

    Vishwakarma, Sandeep Kumar; Lakkireddy, Chandrakala; Marjan, Tuba; Fatima, Anjum; Bardia, Avinash; Paspala, Syed Ameer Basha; Habeeb, Md. Aejaz; Khan, Aleem Ahmed

    2018-05-01

    Cancer nanotheranostics has emerged as one of the most promising fields of medicine wherein nano-sized molecules/agents are used for combined diagnosis and treatment of cancer. Despite promises of novel cancer therapeutic approaches, several crucial challenges have remained to be overcome for successful clinical translation of such agents. Hence, the present study has been aimed to investigate the therapeutic efficacy of bimetallic gadolinium super-paramagnetic iron oxide nanoformulation of ascorbic acid in synergism with hyperthermia on ascorbic acid-resistant breast cancer cells. This particular strategy provides real-time MRI-based non-invasive imaging of drug loading in resistant cancer cells along with highly enhanced therapeutic efficacy. This unique redox nanoprobe is capable of reversing drug-resistance mechanism in cancer cells and offers better therapeutic possibilities in targeted and effective destruction of drug-resistant cancer cells.

  13. Lapatinib sensitivities of two novel trastuzumab-resistant HER2 gene-amplified gastric cancer cell lines.

    PubMed

    Oshima, Yukiko; Tanaka, Harunari; Murakami, Hiroki; Ito, Yuichi; Furuya, Tomomi; Kondo, Eisaku; Kodera, Yasuhiro; Nakanishi, Hayao

    2014-01-01

    Trastuzumab (Tmab) resistance is a major clinical problem to be resolved in patients with HER2-positive gastric cancers. However, in contrast to the situation for HER2-positive breast cancer lines, the Tmab-resistant gastric cancer preclinical models that are needed to develop a new therapy to overcome this problem are not yet available. We developed three new cell lines from HER2 gene-amplified gastric cancer cell lines (GLM-1, GLM-4, NCI N-87) by a new in vivo selection method consisting of the repeated culture of small residual peritoneal metastasis but not subcutaneous tumor after Tmab treatment. We then evaluated the anti-tumor efficacy of lapatinib for these Tmab-resistant cells. We successfully isolated two Tmab-resistant cell lines (GLM1-HerR2(3), GLM4-HerR2) among the three tested cell lines. These resistant cells differed from the parental cells in their flat morphology and rapid growth in vitro, but HER2, P95HER2 expression, and Tmab binding were essentially the same for the parental and resistant cells. MUC4 expression was up- or downregulated depending on the cell line. These resistant cells were still sensitive to lapatinib, similar to the parental cells, in vitro. This growth inhibition of the Tmab-resistant cells by lapatinib was due to both G1 cell-cycle arrest and apoptosis induction via effective blockade of the PI3K/Akt and MAPK pathways. A preclinical study confirmed that the Tmab-resistant tumors are significantly susceptible to lapatinib. These results suggest that lapatinib has antitumor activity against the Tmab-resistant gastric cancer cell lines, and that these cell lines are useful for understanding the mechanism of Tmab resistance and for developing a new molecular therapy for Tmab-resistant HER2-positive gastric cancers.

  14. Engineered reversal of drug resistance in cancer cells--metastases suppressor factors as change agents.

    PubMed

    Yadav, Vinod Kumar; Kumar, Akinchan; Mann, Anita; Aggarwal, Suruchi; Kumar, Maneesh; Roy, Sumitabho Deb; Pore, Subrata Kumar; Banerjee, Rajkumar; Mahesh Kumar, Jerald; Thakur, Ram Krishna; Chowdhury, Shantanu

    2014-01-01

    Building molecular correlates of drug resistance in cancer and exploiting them for therapeutic intervention remains a pressing clinical need. To identify factors that impact drug resistance herein we built a model that couples inherent cell-based response toward drugs with transcriptomes of resistant/sensitive cells. To test this model, we focused on a group of genes called metastasis suppressor genes (MSGs) that influence aggressiveness and metastatic potential of cancers. Interestingly, modeling of 84 000 drug response transcriptome combinations predicted multiple MSGs to be associated with resistance of different cell types and drugs. As a case study, on inducing MSG levels in a drug resistant breast cancer line resistance to anticancer drugs caerulomycin, camptothecin and topotecan decreased by more than 50-60%, in both culture conditions and also in tumors generated in mice, in contrast to control un-induced cells. To our knowledge, this is the first demonstration of engineered reversal of drug resistance in cancer cells based on a model that exploits inherent cellular response profiles.

  15. Exosomes from adriamycin-resistant breast cancer cells transmit drug resistance partly by delivering miR-222.

    PubMed

    Yu, Dan-Dan; Wu, Ying; Zhang, Xiao-Hui; Lv, Meng-Meng; Chen, Wei-Xian; Chen, Xiu; Yang, Su-Jin; Shen, Hongyu; Zhong, Shan-Liang; Tang, Jin-Hai; Zhao, Jian-Hua

    2016-03-01

    Breast cancer (BCa) is one of the major deadly cancers in women. However, treatment of BCa is still hindered by the acquired-drug resistance. It is increasingly reported that exosomes take part in the development, metastasis, and drug resistance of BCa. However, the specific role of exosomes in drug resistance of BCa is poorly understood. In this study, we investigate whether exosomes transmit drug resistance through delivering miR-222. We established an adriamycin-resistant variant of Michigan Cancer Foundation-7 (MCF-7) breast cancer cell line (MCF-7/Adr) from a drug-sensitive variant (MCF-7/S). Exosomes were isolated from cell supernatant by ultracentrifugation. Cell viability was assessed by MTT assay and apoptosis assay. Individual miR-222 molecules in BCa cells were detected by fluorescence in situ hybridization (FISH). Then, FISH was combined with locked nucleic acid probes and enzyme-labeled fluorescence (LNA-ELF-FISH). Individual miR-222 could be detected as bright photostable fluorescent spots and then the quantity of miR-222 per cell could be counted. Stained exosomes were taken in by the receipt cells. MCF-7/S acquired drug resistance after co-culture with exosomes from MCF-7/Adr (A/exo) but did not after co-culture with exosomes from MCF-7/S (S/exo). The quantity of miR-222 in A/exo-treated MCF-7/S was significantly greater than in S/exo-treated MCF-7/S. MCF-7/S transfected with miR-222 mimics acquired adriamycin resistance while MCF-7/S transfected with miR-222 inhibitors lost resistance. In conclusion, exosomes are effective in transmitting drug resistance and the delivery of miR-222 via exosomes may be a mechanism.

  16. Identifying clinically relevant drug resistance genes in drug-induced resistant cancer cell lines and post- chemotherapy tissues

    PubMed Central

    Tong, Mengsha; Zheng, Weicheng; Lu, Xingrong; Ao, Lu; Li, Xiangyu; Guan, Qingzhou; Cai, Hao; Li, Mengyao; Yan, Haidan; Guo, You; Chi, Pan; Guo, Zheng

    2015-01-01

    Until recently, few molecular signatures of drug resistance identified in drug-induced resistant cancer cell models can be translated into clinical practice. Here, we defined differentially expressed genes (DEGs) between pre-chemotherapy colorectal cancer (CRC) tissue samples of non-responders and responders for 5-fluorouracil and oxaliplatin-based therapy as clinically relevant drug resistance genes (CRG5-FU/L-OHP). Taking CRG5-FU/L-OHP as reference, we evaluated the clinical relevance of several types of genes derived from HCT116 CRC cells with resistance to 5-fluorouracil and oxaliplatin, respectively. The results revealed that DEGs between parental and resistant cells, when both were treated with the corresponding drug for a certain time, were significantly consistent with the CRG5-FU/L-OHP as well as the DEGs between the post-chemotherapy CRC specimens of responders and non-responders. This study suggests a novel strategy to extract clinically relevant drug resistance genes from both drug-induced resistant cell models and post-chemotherapy cancer tissue specimens. PMID:26515599

  17. Isolation and characterization of endophytic taxol-producing fungi from Taxus chinensis.

    PubMed

    Liu, Kaihui; Ding, Xiaowei; Deng, Baiwan; Chen, Wenqiang

    2009-09-01

    This study investigated the endophytic fungi diversity of Taxus chinensis and screened the taxol-producing fungi in the host. A total of 115 endophytic fungi isolates obtained from bark segments of T. chinensis were grouped into 23 genera based on the morphological traits and sequence analysis of the internal transcribed spacers (ITS1-5.8S-ITS2), indicating endophytic fungi in T. chinensis are diverse and abundant. Diaporthe, Phomopsis (anamorph of Diaporthe), Acremonium, and Pezicula were the dominant genera, whereas the remaining genera were infrequent groups. The 13 representative species of the distinct genera were capable of producing taxol verified by reverse-phase high performance liquid chromatography (HPLC). Among the taxol-producing fungi, the yield of taxol produced by the Metarhizium anisopliae, H-27 was 846.1 microg l(-1) in reformative potato dextrose liquid medium, and the fungal taxol was further validated by mass spectrometry (MS). The taxol-producing fungi (92.3%) were infrequent communities, suggesting that infrequent fungi associated with T. chinensis might be a fascinating reservoir of taxol-generating fungi.

  18. Reduced Autophagy in 5-Fluorouracil Resistant Colon Cancer Cells

    PubMed Central

    Yao, Cheng Wen; Kang, Kyoung Ah; Piao, Mei Jing; Ryu, Yea Seong; Fernando, Pattage Madushan Dilhara Jayatissa; Oh, Min Chang; Park, Jeong Eon; Shilnikova, Kristina; Na, Soo-Young; Jeong, Seung Uk; Boo, Sun-Jin; Hyun, Jin Won

    2017-01-01

    We investigated the role of autophagy in SNUC5/5-FUR, 5-fluorouracil (5-FU) resistant SNUC5 colon cancer cells. SNUC5/5-FUR cells exhibited low level of autophagy, as determined by light microscopy, confocal microscopy, and flow cytometry following acridine orange staining, and the decreased level of GFP-LC3 puncta. In addition, expression of critical autophagic proteins such as Atg5, Beclin-1 and LC3-II and autophagic flux was diminished in SNUC5/5-FUR cells. Whereas production of reactive oxygen species (ROS) was significantly elevated in SNUC5/5-FUR cells, treatment with the ROS inhibitor N-acetyl cysteine further reduced the level of autophagy. Taken together, these results indicate that decreased autophagy is linked to 5-FU resistance in SNUC5 colon cancer cells. PMID:27737524

  19. In vitro synergistic efficacy of conjugated linoleic acid, oleic acid, safflower oil and taxol cytotoxicity on PC3 cells.

    PubMed

    Kızılşahin, Sadi; Nalbantsoy, Ayşe; Yavaşoğlu, N Ülkü Karabay

    2015-01-01

    The aim of this study was to determine in vitro synergistic efficacy of conjugated linoleic acid (CLA), oleic acid (OLA), safflower oil and taxol (Tax) cytotoxicity on human prostate cancer (PC3) cell line. To determine synergistic efficacy of oil combinations, PC3 treated with different doses of compounds alone and combined with 10 μg/mL Tax. The MTT results indicated that OLA-Tax combinations exhibited cytotoxicity against PC3 at doses of 30 nM+10 μg-Tax, 15 nM+5 μg-Tax and 7.5 nM+2.5 μg-Tax. The treatment of OLA or Tax did not show significant inhibition on PC3, while OLA-Tax combinations showed effective cytotoxicity at treated doses. CLA-Tax combinations demonstrated the same effect on PC3 as combined form with 45.72% versus the alone form as 74.51% viability. Cytotoxic synergy between Tax, OLA and CLA shows enhanced cytotoxicity on PC3 which might be used in the therapy of prostate cancer.

  20. Optical imaging of radiation-induced metabolic changes in radiation-sensitive and resistant cancer cells

    NASA Astrophysics Data System (ADS)

    Alhallak, Kinan; Jenkins, Samir V.; Lee, David E.; Greene, Nicholas P.; Quinn, Kyle P.; Griffin, Robert J.; Dings, Ruud P. M.; Rajaram, Narasimhan

    2017-06-01

    Radiation resistance remains a significant problem for cancer patients, especially due to the time required to definitively determine treatment outcome. For fractionated radiation therapy, nearly 7 to 8 weeks can elapse before a tumor is deemed to be radiation-resistant. We used the optical redox ratio of FAD/(FAD+NADH) to identify early metabolic changes in radiation-resistant lung cancer cells. These radiation-resistant human A549 lung cancer cells were developed by exposing the parental A549 cells to repeated doses of radiation (2 Gy). Although there were no significant differences in the optical redox ratio between the parental and resistant cell lines prior to radiation, there was a significant decrease in the optical redox ratio of the radiation-resistant cells 24 h after a single radiation exposure (p=0.01). This change in the redox ratio was indicative of increased catabolism of glucose in the resistant cells after radiation and was associated with significantly greater protein content of hypoxia-inducible factor 1 (HIF-1α), a key promoter of glycolytic metabolism. Our results demonstrate that the optical redox ratio could provide a rapid method of determining radiation resistance status based on early metabolic changes in cancer cells.

  1. Dependency of a therapy-resistant state of cancer cells on a lipid peroxidase pathway* | Office of Cancer Genomics

    Cancer.gov

    Plasticity of the cell state has been proposed to drive resistance to multiple classes of cancer therapies, thereby limiting their effectiveness. A high-mesenchymal cell state observed in human tumors and cancer cell lines has been associated with resistance to multiple treatment modalities across diverse cancer lineages, but the mechanistic underpinning for this state has remained incompletely understood.

  2. Ell3 stimulates proliferation, drug resistance, and cancer stem cell properties of breast cancer cells via a MEK/ERK-dependent signaling pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ahn, Hee-Jin; Kim, Gwangil; Park, Kyung-Soon, E-mail: kspark@cha.ac.kr

    2013-08-09

    Highlights: •Ell3 enhances proliferation and drug resistance of breast cancer cell lines. •Ell3 is related to the cancer stem cell characteristics of breast cancer cell lines. •Ell3 enhances oncogenicity of breast cancer through the ERK1/2 signaling pathway. -- Abstract: Ell3 is a RNA polymerase II transcription elongation factor that is enriched in testis. The C-terminal domain of Ell3 shows strong similarities to that of Ell (eleven−nineteen lysine-rich leukemia gene), which acts as a negative regulator of p53 and regulates cell proliferation and survival. Recent studies in our laboratory showed that Ell3 induces the differentiation of mouse embryonic stem cells bymore » protecting differentiating cells from apoptosis via the promotion of p53 degradation. In this study, we evaluated the function of Ell3 in breast cancer cell lines. MCF-7 cell lines overexpressing Ell3 were used to examine cell proliferation and cancer stem cell properties. Ectopic expression of Ell3 in breast cancer cell lines induces proliferation and 5-FU resistance. In addition, Ell3 expression increases the cancer stem cell population, which is characterized by CD44 (+) or ALDH1 (+) cells. Mammosphere-forming potential and migration ability were also increased upon Ell3 expression in breast cancer cell lines. Through biochemical and molecular biological analyses, we showed that Ell3 regulates proliferation, cancer stem cell properties and drug resistance in breast cancer cell lines partly through the MEK−extracellular signal-regulated kinase signaling pathway. Murine xenograft experiments showed that Ell3 expression promotes tumorigenesis in vivo. These results suggest that Ell3 may play a critical role in promoting oncogenesis in breast cancer by regulating cell proliferation and cancer stem cell properties via the ERK1/2 signaling pathway.« less

  3. Tcf3 and cell cycle factors contribute to butyrate resistance in colorectal cancer cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chiaro, Christopher, E-mail: cchiaro@tcmedc.org; Lazarova, Darina L., E-mail: dlazarova@tcmedc.org; Bordonaro, Michael, E-mail: mbordonaro@tcmedc.org

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer We investigate mechanisms responsible for butyrate resistance in colon cancer cells. Black-Right-Pointing-Pointer Tcf3 modulates butyrate's effects on Wnt activity and cell growth in resistant cells. Black-Right-Pointing-Pointer Tcf3 modulation of butyrate's effects differ by cell context. Black-Right-Pointing-Pointer Cell cycle factors are overexpressed in the resistant cells. Black-Right-Pointing-Pointer Reversal of altered gene expression can enhance the anti-cancer effects of butyrate. -- Abstract: Butyrate, a fermentation product of dietary fiber, inhibits clonal growth in colorectal cancer (CRC) cells dependent upon the fold induction of Wnt activity. We have developed a CRC cell line (HCT-R) that, unlike its parental cell line, HCT-116,more » does not respond to butyrate exposure with hyperactivation of Wnt signaling and suppressed clonal growth. PCR array analyses revealed Wnt pathway-related genes, the expression of which differs between butyrate-sensitive HCT-116 CRC cells and their butyrate-resistant HCT-R cell counterparts. We identified overexpression of Tcf3 as being partially responsible for the butyrate-resistant phenotype, as this DNA-binding protein suppresses the hyperinduction of Wnt activity by butyrate. Consequently, Tcf3 knockdown in HCT-R cells restores their sensitivity to the effects of butyrate on Wnt activity and clonal cell growth. Interestingly, the effects of overexpressed Tcf3 differ between HCT-116 and HCT-R cells; thus, in HCT-116 cells Tcf3 suppresses proliferation without rendering the cells resistant to butyrate. In HCT-R cells, however, the overexpression of Tcf3 inhibits Wnt activity, and the cells are still able to proliferate due to the higher expression levels of cell cycle factors, particularly those driving the G{sub 1} to S transition. Knowledge of the molecular mechanisms determining the variable sensitivity of CRC cells to butyrate may assist in developing approaches that

  4. Interactions between Co-Habitating fungi Elicit Synthesis of Taxol from an Endophytic Fungus in Host Taxus Plants

    PubMed Central

    Soliman, Sameh S. M.; Raizada, Manish N.

    2012-01-01

    Within a plant, there can exist an ecosystem of pathogens and endophytes, the latter described as bacterial and fungal inhabitants that thrive without causing disease to the host. Interactions between microbial inhabitants represent a novel area of study for natural products research. Here we analyzed the interactions between the fungal endophytes of Taxus (yew) trees. Fungal endophytes of Taxus have been proposed to produce the terpenoid secondary metabolite, Taxol, an anti-cancer drug. It is widely reported that plant extracts stimulate endophytic fungal Taxol production, but the underlying mechanism is not understood. Here, Taxus bark extracts stimulated fungal Taxol production 30-fold compared to a 10-fold induction with wood extracts. However, candidate plant-derived defense compounds (i.e., salicylic acid, benzoic acid) were found to act only as modest elicitors of fungal Taxol production from the endophytic fungus Paraconiothyrium SSM001, consistent with previous studies. We hypothesized the Taxus plant extracts may contain elicitors derived from other microbes inhabiting these tissues. We investigated the effects of co-culturing SSM001 with other fungi observed to inhabit Taxus bark, but not wood. Surprisingly, co-culture of SSM001 with a bark fungus (Alternaria) caused a ∼threefold increase in Taxol production. When SSM001 was pyramided with both the Alternaria endophyte along with another fungus (Phomopsis) observed to inhabit Taxus, there was an ∼eightfold increase in fungal Taxol production from SSM001. These results suggest that resident fungi within a host plant interact with one another to stimulate Taxol biosynthesis, either directly or through their metabolites. More generally, our results suggest that endophyte secondary metabolism should be studied in the context of its native ecosystem. PMID:23346084

  5. A new large-scale process for taxol and related taxanes from Taxus brevifolia.

    PubMed

    Rao, K V; Hanuman, J B; Alvarez, C; Stoy, M; Juchum, J; Davies, R M; Baxley, R

    1995-07-01

    In view of the demonstrated antitumor activity of taxol, ready availability of the drug is important. The current isolation methods starting from the bark of Taxus brevifolia involve multiple manipulations, leading to only taxol and in a yield of 0.01%. A new process consisting of a single reverse phase column is introduced here, and the present purpose is to determine its large scale applicability. The chloroform extractable fraction of the bark of T. brevifolia is applied directly on to a C-18 bonded silica column in 25% acetonitrile/water, with elution using a step gradient: 30-50% acetonitrile/water. On standing, eight different taxanes, including taxol, crystallize out directly from different fractions. The crystals are filtered and purified further by recrystallization. Taxol and four other taxanes are purified this way. The other three require a short silica column. Taxol is freed from cephalomannine by selective ozonolysis. The large scale process gave taxol (0.04%), 10-deacetylbaccatin III (0.02%), 10-deacetyl taxol-7-xyloside (0.1%), 10-deacetyl taxol-C-7-xyloside (0.04%), 10-deacetyl cephalomannine-7-xyloside (0.006%), taxol-7-xyloside (0.008%), 10-deacetyl taxol (0.008%) and cephalomannine (0.004%). Processing of the needles of T. brevifolia gave brevifoliol (0.17%), and that of the wood, 10-deacetyl taxol-C-7-xyloside (0.01%) and 10-deacetyl taxol-C. The reverse phase column process is simpler (one column, direct crystallization), more efficient (eight taxanes obtained simultaneously) and also gives higher yields.

  6. Enzalutamide inhibits proliferation of gemcitabine-resistant bladder cancer cells with increased androgen receptor expression.

    PubMed

    Kameyama, Koji; Horie, Kengo; Mizutani, Kosuke; Kato, Taku; Fujita, Yasunori; Kawakami, Kyojiro; Kojima, Toshio; Miyazaki, Tatsuhiko; Deguchi, Takashi; Ito, Masafumi

    2017-01-01

    Advanced bladder cancer is treated mainly with gemcitabine and cisplatin, but most patients eventually become resistance. Androgen receptor (AR) signaling has been implicated in bladder cancer as well as other types of cancer including prostate cancer. In this study, we investigated the expression and role of AR in gemcitabine-resistant bladder cancer cells and also the potential of enzalutamide, an AR inhibitor, as a therapeutic for the chemoresistance. First of all, we established gemcitabine-resistant T24 cells (T24GR) from T24 bladder cancer cells and performed gene expression profiling. Microarray analysis revealed upregulation of AR expression in T24GR cells compared with T24 cells. AR mRNA and protein expression was confirmed to be increased in T24GR cells, respectively, by quantitative RT-PCR and western blot analysis, which was associated with more potent AR transcriptional activity as measured by luciferase reporter assay. The copy number of AR gene in T24GR cells determined by PCR was twice as many as that of T24 cells. AR silencing by siRNA transfection resulted in inhibition of proliferation of T24GR cells. Cell culture in charcoal-stripped serum and treatment with enzalutamide inhibited growth of T24GR cells, which was accompanied by cell cycle arrest. AR transcriptional activity was found to be reduced in T24GR cells by enzalutamide treatment. Lastly, enzalutamide also inhibited cell proliferation of HTB5 bladder cancer cells that express AR and possess intrinsic resistance to gemcitabine. Our results suggest that enzalutamide may have the potential to treat patients with advanced gemcitabine-resistant bladder cancer with increased AR expression.

  7. Myricetin inhibits proliferation of cisplatin-resistant cancer cells through a p53-dependent apoptotic pathway

    PubMed Central

    HUANG, HAIZHI; CHEN, ALLEN Y.; YE, XINGQIAN; LI, BINGYUN; ROJANASAKUL, YON; RANKIN, GARY O.; CHEN, YI CHARLIE

    2015-01-01

    Cisplatin is a commonly used drug for cancer treatment by crosslinking DNA, leading to apoptosis of cancer cells, resistance to cisplatin treatment often occurs, leading to relapse. Therefore, there is a need for the development of more effective treatment strategies that can overcome chemoresistance. Myricetin is a flavonoid from fruits and vegetables, showing anticancer activity in various cancer cells. In this study, we found myricetin exhibited greater cytotoxicity than cisplatin in two cisplatin-resistant ovarian cancer cell lines, OVCAR-3 and A2780/CP70, and it was less cytotoxic to the normal ovarian cell line IOSE-364. Myricetin selectively induced apoptosis in both cisplatin-resistant cancer cell lines, but did not induce apoptosis in the normal ovarian cell line. It induced both Bcl-2 family-dependent intrinsic and DR5 dependent extrinsic apoptosis in OVCAR-3 cells. P53, a multifunctional tumor suppressor, regulated apoptosis in OVCAR-3 cells through a Bcl-2 family protein-dependent pathway. Myricetin did not induce cell cycle arrest in either ovarian cancer cell line. Because of its potency and selectivity against cisplatin-resistant cancer cells, myricetin could potentially be used to overcome cancer chemoresistance against platinum-based therapy. PMID:26315556

  8. Lipid-laden macrophage infiltration of human adenocarcinoma in vivo associated with taxol and GCSF treatment.

    PubMed

    Abramson, N; Castro, S; Goldstein, J D

    1997-01-01

    This brief report illustrates the presence of lipid-laden macrophages in proximity to metastatic adenocarcinoma cells within the bone marrow of a patient receiving taxol and GCSF therapy. The pathophysiological mechanism is uncertain. Taxol, which is associated with macrophage function in vitro, may have been responsible for the recruitment of macrophages in this patient. GCSF could have contributed as well; however, GCSF usually has little effect on monocytes and macrophages.

  9. Pristimerin overcomes adriamycin resistance in breast cancer cells through suppressing Akt signaling

    PubMed Central

    XIE, GUI'E; YU, XINPEI; LIANG, HUICHAO; CHEN, JINGSONG; TANG, XUEWEI; WU, SHAOQING; LIAO, CAN

    2016-01-01

    Breast cancer remains a major public health problem worldwide. Chemotherapy serves an important role in the treatment of breast cancer. However, resistance to chemotherapeutic agents, in particular, multi-drug resistance (MDR), is a major cause of treatment failure in cancer. Agents that can either enhance the effects of chemotherapeutics or overcome chemoresistance are urgently needed for the treatment of breast cancer. Pristimerin, a quinonemethide triterpenoid compound isolated from Celastraceae and Hippocrateaceae, has been shown to possess antitumor, anti-inflammatory, antioxidant and insecticidal properties. The aim of the present study was to investigate whether pristimerin can override chemoresistance in MCF-7/adriamycin (ADR)-resistant human breast cancer cells. The results demonstrated that pristimerin indeed displayed potent cytocidal effect on multidrug-resistant MCF-7/ADR breast cancer cells, and that these effects occurred through the suppression of Akt signaling, which in turn led to the downregulation of antiapoptotic effectors and increased apoptosis. These findings indicate that use of pristimerin may represent a potentially promising approach for the treatment of ADR-resistant breast cancer. PMID:27123073

  10. Exosomes promote cetuximab resistance via the PTEN/Akt pathway in colon cancer cells.

    PubMed

    Zhang, S; Zhang, Y; Qu, J; Che, X; Fan, Y; Hou, K; Guo, T; Deng, G; Song, N; Li, C; Wan, X; Qu, X; Liu, Y

    2017-11-13

    Cetuximab is widely used in patients with metastatic colon cancer expressing wildtype KRAS. However, acquired drug resistance limits its clinical efficacy. Exosomes are nanosized vesicles secreted by various cell types. Tumor cell-derived exosomes participate in many biological processes, including tumor invasion, metastasis, and drug resistance. In this study, exosomes derived from cetuximab-resistant RKO colon cancer cells induced cetuximab resistance in cetuximab-sensitive Caco-2 cells. Meanwhile, exosomes from RKO and Caco-2 cells showed different levels of phosphatase and tensin homolog (PTEN) and phosphor-Akt. Furthermore, reduced PTEN and increased phosphorylated Akt levels were found in Caco-2 cells after exposure to RKO cell-derived exosomes. Moreover, an Akt inhibitor prevented RKO cell-derived exosome-induced drug resistance in Caco-2 cells. These findings provide novel evidence that exosomes derived from cetuximab-resistant cells could induce cetuximab resistance in cetuximab-sensitive cells, by downregulating PTEN and increasing phosphorylated Akt levels.

  11. Dependency of a therapy-resistant state of cancer cells on a lipid peroxidase pathway.

    PubMed

    Viswanathan, Vasanthi S; Ryan, Matthew J; Dhruv, Harshil D; Gill, Shubhroz; Eichhoff, Ossia M; Seashore-Ludlow, Brinton; Kaffenberger, Samuel D; Eaton, John K; Shimada, Kenichi; Aguirre, Andrew J; Viswanathan, Srinivas R; Chattopadhyay, Shrikanta; Tamayo, Pablo; Yang, Wan Seok; Rees, Matthew G; Chen, Sixun; Boskovic, Zarko V; Javaid, Sarah; Huang, Cherrie; Wu, Xiaoyun; Tseng, Yuen-Yi; Roider, Elisabeth M; Gao, Dong; Cleary, James M; Wolpin, Brian M; Mesirov, Jill P; Haber, Daniel A; Engelman, Jeffrey A; Boehm, Jesse S; Kotz, Joanne D; Hon, Cindy S; Chen, Yu; Hahn, William C; Levesque, Mitchell P; Doench, John G; Berens, Michael E; Shamji, Alykhan F; Clemons, Paul A; Stockwell, Brent R; Schreiber, Stuart L

    2017-07-27

    Plasticity of the cell state has been proposed to drive resistance to multiple classes of cancer therapies, thereby limiting their effectiveness. A high-mesenchymal cell state observed in human tumours and cancer cell lines has been associated with resistance to multiple treatment modalities across diverse cancer lineages, but the mechanistic underpinning for this state has remained incompletely understood. Here we molecularly characterize this therapy-resistant high-mesenchymal cell state in human cancer cell lines and organoids and show that it depends on a druggable lipid-peroxidase pathway that protects against ferroptosis, a non-apoptotic form of cell death induced by the build-up of toxic lipid peroxides. We show that this cell state is characterized by activity of enzymes that promote the synthesis of polyunsaturated lipids. These lipids are the substrates for lipid peroxidation by lipoxygenase enzymes. This lipid metabolism creates a dependency on pathways converging on the phospholipid glutathione peroxidase (GPX4), a selenocysteine-containing enzyme that dissipates lipid peroxides and thereby prevents the iron-mediated reactions of peroxides that induce ferroptotic cell death. Dependency on GPX4 was found to exist across diverse therapy-resistant states characterized by high expression of ZEB1, including epithelial-mesenchymal transition in epithelial-derived carcinomas, TGFβ-mediated therapy-resistance in melanoma, treatment-induced neuroendocrine transdifferentiation in prostate cancer, and sarcomas, which are fixed in a mesenchymal state owing to their cells of origin. We identify vulnerability to ferroptic cell death induced by inhibition of a lipid peroxidase pathway as a feature of therapy-resistant cancer cells across diverse mesenchymal cell-state contexts.

  12. Multi-omics analysis reveals that ornithine decarboxylase contributes to erlotinib resistance in pancreatic cancer cells

    PubMed Central

    Song, Sang-Hoon; Lee, Naeun; Kim, Dong-Joon; Lee, Sooyeun; Jeong, Chul-Ho

    2017-01-01

    Molecular and metabolic alterations in cancer cells are one of the leading causes of acquired resistance to chemotherapeutics. In this study, we explored an experimental strategy to identify which of these alterations can induce erlotinib resistance in human pancreatic cancer. Using genetically matched erlotinib-sensitive (BxPC-3) and erlotinib-resistant (BxPC-3ER) pancreatic cancer cells, we conducted a multi-omics analysis of metabolomes and transcriptomes in these cells. Untargeted and targeted metabolomic analyses revealed significant changes in metabolic pathways involved in the regulation of polyamines, amino acids, and fatty acids. Further transcriptomic analysis identified that ornithine decarboxylase (ODC) and its major metabolite, putrescine, contribute to the acquisition of erlotinib resistance in BxPC-3ER cells. Notably, either pharmacological or genetic blockage of ODC was able to restore erlotinib sensitivity, and this could be rescued by treatment with exogenous putrescine in erlotinib-resistant BxPC-3ER cells. Moreover, using a panel of cancer cells we demonstrated that ODC expression levels in cancer cells are inversely correlated with sensitivity to chemotherapeutics. Taken together, our findings will begin to uncover mechanisms of acquired drug resistance and ultimately help to identify potential therapeutic markers in cancer. PMID:29190951

  13. Silibinin sensitizes chemo-resistant breast cancer cells to chemotherapy.

    PubMed

    Molavi, Ommoleila; Narimani, Farzaneh; Asiaee, Farshid; Sharifi, Simin; Tarhriz, Vahideh; Shayanfar, Ali; Hejazi, Mohammadsaied; Lai, Raymond

    2017-12-01

    Multiple drug resistance is the major obstacle to conventional chemotherapy. Silibinin, a nontoxic naturally occurring compound, has anticancer activity and can increase the cytotoxic effects of chemotherapy in various cancer models. To evaluate the effects of silibinin on enhancing the sensitivity of chemo-resistant human breast cell lines to doxorubicin (DOX) and paclitaxel (PAC). The cells were treated with silibinin (at 50 to 600 μM concentrations) and/or chemo drugs for 24 and 48 h, then cell viability and changes in oncogenic proteins were determined by MTT assay and Western blotting/RT-PCR, respectively. Flow cytometry was used to study apoptosis in the cells receiving different treatments. The antitumorigenic effects of silibinin (at 200 to 400 μM concentration) were evaluated by mammosphere assay. Silibinin exerted significant growth inhibitory effects with IC 50 ranging from 200 to 570 μM in different cell lines. Treatment of DOX-resistant MDA-MB-435 cells with silibinin at 200 μM reduced DOX IC 50 from 71 to 10 μg/mL and significantly suppressed the key oncogenic pathways including STAT3, AKT, and ERK in these cells. Interestingly treatment of DOX-resistant MDA-MB-435 cells with silibinin at 400 μM concentration for 48 h induced a 50% decrease in the numbers of colonies as compared with DMSO-treated cells. Treatment of PAC-resistant MCF-7 cells with silibinin at 400 μM concentration generated synergistic effects when it was used in combination with PAC at 250 nM concentration (CI = 0.81). Silibinin sensitizes chemo-resistant cells to chemotherapeutic agents and can be useful in treating breast cancers.

  14. Ginger Phytochemicals Inhibit Cell Growth and Modulate Drug Resistance Factors in Docetaxel Resistant Prostate Cancer Cell.

    PubMed

    Liu, Chi-Ming; Kao, Chiu-Li; Tseng, Yu-Ting; Lo, Yi-Ching; Chen, Chung-Yi

    2017-09-05

    Ginger has many bioactive compounds with pharmacological activities. However, few studies are known about these bioactive compounds activity in chemoresistant cells. The aim of the present study was to investigate the anticancer properties of ginger phytochemicals in docetaxel-resistant human prostate cancer cells in vitro. In this study, we isolated 6-gingerol, 10-gingerol, 4-shogaol, 6-shogaol, 10-shogaol, and 6-dehydrogingerdione from ginger. Further, the antiproliferation activity of these compounds was examined in docetaxel-resistant (PC3R) and sensitive (PC3) human prostate cancer cell lines. 6-gingerol, 10-gingerol, 6-shogaol, and 10-shogaol at the concentration of 100 μM significantly inhibited the proliferation in PC3R but 6-gingerol, 6-shogaol, and 10-shogaol displayed similar activity in PC3. The protein expression of multidrug resistance associated protein 1 (MRP1) and glutathione-S-transferase (GSTπ) is higher in PC3R than in PC3. In summary, we isolated the bioactive compounds from ginger. Our results showed that 6-gingerol, 10-gingerol, 6-shogaol, and 10-shogaol inhibit the proliferation of PC3R cells through the downregulation of MRP1 and GSTπ protein expression.

  15. Dragon (RGMb) induces oxaliplatin resistance in colon cancer cells.

    PubMed

    Shi, Ying; Huang, Xiao-Xiao; Chen, Guo-Bin; Wang, Ying; Zhi, Qiang; Liu, Yuan-Sheng; Wu, Xiao-Ling; Wang, Li-Fen; Yang, Bing; Xiao, Chuan-Xing; Xing, Hui-Qin; Ren, Jian-Lin; Xia, Yin; Guleng, Bayasi

    2016-07-26

    Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and a major cause of cancer mortality. Chemotherapy resistance remains a major challenge for treating advanced CRC. Therefore, the identification of targets that induce drug resistance is a priority for the development of novel agents to overcome resistance. Dragon (also known as RGMb) is a member of the repulsive guidance molecule (RGM) family. We previously showed that Dragon expression increases with CRC progression in human patients. In the present study, we found that Dragon inhibited apoptosis and increased viability of CMT93 and HCT116 cells in the presence of oxaliplatin. Dragon induced resistance of xenograft tumor to oxaliplatinin treatment in mice. Mechanistically, Dragon inhibited oxaliplatin-induced JNK and p38 MAPK activation, and caspase-3 and PARP cleavages. Our results indicate that Dragon may be a novel target that induces drug resistance in CRC.

  16. Dragon (RGMb) induces oxaliplatin resistance in colon cancer cells

    PubMed Central

    Wang, Ying; Zhi, Qiang; Liu, Yuan-Sheng; Wu, Xiao-Ling; Wang, Li-Fen; Yang, Bing; Xiao, Chuan-Xing; Xing, Hui-Qin; Ren, Jian-Lin; Xia, Yin; Guleng, Bayasi

    2016-01-01

    Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and a major cause of cancer mortality. Chemotherapy resistance remains a major challenge for treating advanced CRC. Therefore, the identification of targets that induce drug resistance is a priority for the development of novel agents to overcome resistance. Dragon (also known as RGMb) is a member of the repulsive guidance molecule (RGM) family. We previously showed that Dragon expression increases with CRC progression in human patients. In the present study, we found that Dragon inhibited apoptosis and increased viability of CMT93 and HCT116 cells in the presence of oxaliplatin. Dragon induced resistance of xenograft tumor to oxaliplatinin treatment in mice. Mechanistically, Dragon inhibited oxaliplatin-induced JNK and p38 MAPK activation, and caspase-3 and PARP cleavages. Our results indicate that Dragon may be a novel target that induces drug resistance in CRC. PMID:27384995

  17. Networking of differentially expressed genes in human cancer cells resistant to methotrexate

    PubMed Central

    2009-01-01

    Background The need for an integrated view of data obtained from high-throughput technologies gave rise to network analyses. These are especially useful to rationalize how external perturbations propagate through the expression of genes. To address this issue in the case of drug resistance, we constructed biological association networks of genes differentially expressed in cell lines resistant to methotrexate (MTX). Methods Seven cell lines representative of different types of cancer, including colon cancer (HT29 and Caco2), breast cancer (MCF-7 and MDA-MB-468), pancreatic cancer (MIA PaCa-2), erythroblastic leukemia (K562) and osteosarcoma (Saos-2), were used. The differential expression pattern between sensitive and MTX-resistant cells was determined by whole human genome microarrays and analyzed with the GeneSpring GX software package. Genes deregulated in common between the different cancer cell lines served to generate biological association networks using the Pathway Architect software. Results Dikkopf homolog-1 (DKK1) is a highly interconnected node in the network generated with genes in common between the two colon cancer cell lines, and functional validations of this target using small interfering RNAs (siRNAs) showed a chemosensitization toward MTX. Members of the UDP-glucuronosyltransferase 1A (UGT1A) family formed a network of genes differentially expressed in the two breast cancer cell lines. siRNA treatment against UGT1A also showed an increase in MTX sensitivity. Eukaryotic translation elongation factor 1 alpha 1 (EEF1A1) was overexpressed among the pancreatic cancer, leukemia and osteosarcoma cell lines, and siRNA treatment against EEF1A1 produced a chemosensitization toward MTX. Conclusions Biological association networks identified DKK1, UGT1As and EEF1A1 as important gene nodes in MTX-resistance. Treatments using siRNA technology against these three genes showed chemosensitization toward MTX. PMID:19732436

  18. Sulfur amino acid metabolism in doxorubicin-resistant breast cancer cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ryu, Chang Seon; Kwak, Hui Chan; Lee, Kye Sook

    2011-08-15

    Although methionine dependency is a phenotypic characteristic of tumor cells, it remains to be determined whether changes in sulfur amino acid metabolism occur in cancer cells resistant to chemotherapeutic medications. We compared expression/activity of sulfur amino acid metabolizing enzymes and cellular levels of sulfur amino acids and their metabolites between normal MCF-7 cells and doxorubicin-resistant MCF-7 (MCF-7/Adr) cells. The S-adenosylmethionine/S-adenosylhomocysteine ratio, an index of transmethylation potential, in MCF-7/Adr cells decreased to {approx} 10% relative to that in MCF-7 cells, which may have resulted from down-regulation of S-adenosylhomocysteine hydrolase. Expression of homocysteine-clearing enzymes, such as cystathionine beta-synthase, methionine synthase/methylene tetrahydrofolate reductase,more » and betaine homocysteine methyltransferase, was up-regulated in MCF-7/Adr cells, suggesting that acquiring doxorubicin resistance attenuated methionine-dependence and activated transsulfuration from methionine to cysteine. Homocysteine was similar, which is associated with a balance between the increased expressions of homocysteine-clearing enzymes and decreased extracellular homocysteine. Despite an elevation in cysteine, cellular GSH decreased in MCF-7/Adr cells, which was attributed to over-efflux of GSH into the medium and down-regulation of the GSH synthesis enzyme. Consequently, MCF-7/Adr cells were more sensitive to the oxidative stress induced by bleomycin and menadione than MCF-7 cells. In conclusion, our results suggest that regulating sulfur amino acid metabolism may be a possible therapeutic target for chemoresistant cancer cells. These results warrant further investigations to determine the role of sulfur amino acid metabolism in acquiring anticancer drug resistance in cancer cells using chemical and biological regulators involved in sulfur amino acid metabolism. - Research Highlights: > MCF-7/Adr cells showed decreases in

  19. MUC1 extracellular domain confers resistance of epithelial cancer cells to anoikis

    PubMed Central

    Zhao, Q; Piyush, T; Chen, C; Hollingsworth, M A; Hilkens, J; Rhodes, J M; Yu, L-G

    2014-01-01

    Anoikis, a special apoptotic process occurring in response to loss of cell adhesion to the extracellular matrix, is a fundamental surveillance process for maintaining tissue homeostasis. Resistance to anoikis characterises cancer cells and is a pre-requisite for metastasis. This study shows that overexpression of the transmembrane mucin protein MUC1 prevents initiation of anoikis in epithelial cancer cells in response to loss of adhesion. We show that this effect is largely attributed to the elongated and heavily glycosylated extracellular domain of MUC1 that protrudes high above the cell membrane and hence prevents activation of the cell surface anoikis-initiating molecules such as integrins and death receptors by providing them a mechanically ‘homing' microenvironment. As overexpression of MUC1 is a common feature of epithelial cancers and as resistance to anoikis is a hallmark of both oncogenic epithelial–mesenchymal transition and metastasis, MUC1-mediated cell resistance to anoikis may represent one of the fundamental regulatory mechanisms in tumourigenesis and metastasis. PMID:25275599

  20. A novel HDAC inhibitor, CG200745, inhibits pancreatic cancer cell growth and overcomes gemcitabine resistance.

    PubMed

    Lee, Hee Seung; Park, Soo Been; Kim, Sun A; Kwon, Sool Ki; Cha, Hyunju; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Song, Si Young

    2017-01-30

    Pancreatic cancer is predominantly lethal, and is primarily treated using gemcitabine, with increasing resistance. Therefore, novel agents that increase tumor sensitivity to gemcitabine are needed. Histone deacetylase (HDAC) inhibitors are emerging therapeutic agents, since HDAC plays an important role in cancer initiation and progression. We evaluated the antitumor effect of a novel HDAC inhibitor, CG200745, combined with gemcitabine/erlotinib on pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells. Three pancreatic cancer-cell lines were used to evaluate the antitumor effect of CG200745 combined with gemcitabine/erlotinib. CG200745 induced the expression of apoptotic proteins (PARP and caspase-3) and increased the levels of acetylated histone H3. CG200745 with gemcitabine/erlotinib showed significant growth inhibition and synergistic antitumor effects in vitro. In vivo, gemcitabine/erlotinib and CG200745 reduced tumor size up to 50%. CG200745 enhanced the sensitivity of gemcitabine-resistant pancreatic cancer cells to gemcitabine, and decreased the level of ATP-binding cassette-transporter genes, especially multidrug resistance protein 3 (MRP3) and MRP4. The novel HDAC inhibitor, CG200745, with gemcitabine/erlotinib had a synergistic anti-tumor effect on pancreatic cancer cells. CG200745 significantly improved pancreatic cancer sensitivity to gemcitabine, with a prominent antitumor effect on gemcitabine-resistant pancreatic cancer cells. Therefore, improved clinical outcome is expected in the future.

  1. A novel HDAC inhibitor, CG200745, inhibits pancreatic cancer cell growth and overcomes gemcitabine resistance

    PubMed Central

    Lee, Hee Seung; Park, Soo Been; Kim, Sun A; Kwon, Sool Ki; Cha, Hyunju; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Song, Si Young

    2017-01-01

    Pancreatic cancer is predominantly lethal, and is primarily treated using gemcitabine, with increasing resistance. Therefore, novel agents that increase tumor sensitivity to gemcitabine are needed. Histone deacetylase (HDAC) inhibitors are emerging therapeutic agents, since HDAC plays an important role in cancer initiation and progression. We evaluated the antitumor effect of a novel HDAC inhibitor, CG200745, combined with gemcitabine/erlotinib on pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells. Three pancreatic cancer-cell lines were used to evaluate the antitumor effect of CG200745 combined with gemcitabine/erlotinib. CG200745 induced the expression of apoptotic proteins (PARP and caspase-3) and increased the levels of acetylated histone H3. CG200745 with gemcitabine/erlotinib showed significant growth inhibition and synergistic antitumor effects in vitro. In vivo, gemcitabine/erlotinib and CG200745 reduced tumor size up to 50%. CG200745 enhanced the sensitivity of gemcitabine-resistant pancreatic cancer cells to gemcitabine, and decreased the level of ATP-binding cassette-transporter genes, especially multidrug resistance protein 3 (MRP3) and MRP4. The novel HDAC inhibitor, CG200745, with gemcitabine/erlotinib had a synergistic anti-tumor effect on pancreatic cancer cells. CG200745 significantly improved pancreatic cancer sensitivity to gemcitabine, with a prominent antitumor effect on gemcitabine-resistant pancreatic cancer cells. Therefore, improved clinical outcome is expected in the future. PMID:28134290

  2. Evolution of Cancer Stem-like Cells in Endocrine-Resistant Metastatic Breast Cancers Is Mediated by Stromal Microvesicles.

    PubMed

    Sansone, Pasquale; Berishaj, Marjan; Rajasekhar, Vinagolu K; Ceccarelli, Claudio; Chang, Qing; Strillacci, Antonio; Savini, Claudia; Shapiro, Lauren; Bowman, Robert L; Mastroleo, Chiara; De Carolis, Sabrina; Daly, Laura; Benito-Martin, Alberto; Perna, Fabiana; Fabbri, Nicola; Healey, John H; Spisni, Enzo; Cricca, Monica; Lyden, David; Bonafé, Massimiliano; Bromberg, Jacqueline

    2017-04-15

    The hypothesis that microvesicle-mediated miRNA transfer converts noncancer stem cells into cancer stem cells (CSC) leading to therapy resistance remains poorly investigated. Here we provide direct evidence supporting this hypothesis, by demonstrating how microvesicles derived from cancer-associated fibroblasts (CAF) transfer miR-221 to promote hormonal therapy resistance (HTR) in models of luminal breast cancer. We determined that CAF-derived microvesicles horizontally transferred miR-221 to tumor cells and, in combination with hormone therapy, activated an ER lo /Notch hi feed-forward loop responsible for the generation of CD133 hi CSCs. Importantly, microvesicles from patients with HTR metastatic disease expressed high levels of miR-221. We further determined that the IL6-pStat3 pathway promoted the biogenesis of onco-miR-221 hi CAF microvesicles and established stromal CSC niches in experimental and patient-derived breast cancer models. Coinjection of patient-derived CAFs from bone metastases led to de novo HTR tumors, which was reversed with IL6R blockade. Finally, we generated patient-derived xenograft (PDX) models from patient-derived HTR bone metastases and analyzed tumor cells, stroma, and microvesicles. Murine and human CAFs were enriched in HTR tumors expressing high levels of CD133 hi cells. Depletion of murine CAFs from PDX restored sensitivity to HT, with a concurrent reduction of CD133 hi CSCs. Conversely, in models of CD133 neg , HT-sensitive cancer cells, both murine and human CAFs promoted de novo HT resistance via the generation of CD133 hi CSCs that expressed low levels of estrogen receptor alpha. Overall, our results illuminate how microvesicle-mediated horizontal transfer of genetic material from host stromal cells to cancer cells triggers the evolution of therapy-resistant metastases, with potentially broad implications for their control. Cancer Res; 77(8); 1927-41. ©2017 AACR . ©2017 American Association for Cancer Research.

  3. GP88 (PC-Cell Derived Growth Factor, progranulin) stimulates proliferation and confers letrozole resistance to aromatase overexpressing breast cancer cells

    PubMed Central

    2011-01-01

    Background Aromatase inhibitors (AI) that inhibit breast cancer cell growth by blocking estrogen synthesis have become the treatment of choice for post-menopausal women with estrogen receptor positive (ER+) breast cancer. However, some patients display de novo or acquired resistance to AI. Interactions between estrogen and growth factor signaling pathways have been identified in estrogen-responsive cells as one possible reason for acquisition of resistance. Our laboratory has characterized an autocrine growth factor overexpressed in invasive ductal carcinoma named PC-Cell Derived Growth Factor (GP88), also known as progranulin. In the present study, we investigated the role GP88 on the acquisition of resistance to letrozole in ER+ breast cancer cells Methods We used two aromatase overexpressing human breast cancer cell lines MCF-7-CA cells and AC1 cells and their letrozole resistant counterparts as study models. Effect of stimulating or inhibiting GP88 expression on proliferation, anchorage-independent growth, survival and letrozole responsiveness was examined. Results GP88 induced cell proliferation and conferred letrozole resistance in a time- and dose-dependent fashion. Conversely, naturally letrozole resistant breast cancer cells displayed a 10-fold increase in GP88 expression when compared to letrozole sensitive cells. GP88 overexpression, or exogenous addition blocked the inhibitory effect of letrozole on proliferation, and stimulated survival and soft agar colony formation. In letrozole resistant cells, silencing GP88 by siRNA inhibited cell proliferation and restored their sensitivity to letrozole. Conclusion Our findings provide information on the role of an alternate growth and survival factor on the acquisition of aromatase inhibitor resistance in ER+ breast cancer. PMID:21658239

  4. Combining targeted drugs to overcome and prevent resistance of solid cancers with some stem-like cell features

    PubMed Central

    Koivunen, Peppi; Koivunen, Jussi P.

    2014-01-01

    Treatment resistance significantly inhibits the efficiency of targeted cancer therapies in drug-sensitive genotypes. In the current work, we studied mechanisms for rapidly occurring, adaptive resistance in targeted therapy-sensitive lung, breast, and melanoma cancer cell lines. The results show that in ALK translocated lung cancer lines H3122 and H2228, cells with cancer stem-like cell features characterized by high expression of cancer stem cell markers and/or in vivo tumorigenesis can mediate adaptive resistance to oncogene ablative therapy. When pharmacological ablation of ALK oncogene was accompanied with PI3K inhibitor or salinomycin therapy, cancer stem-like cell features were reversed which was accompanied with decreased colony formation. Furthermore, co-targeting was able to block the formation of acquired resistance in H3122 line. The results suggest that cells with cancer stem-like cell features can mediate adaptive resistance to targeted therapies. Since these cells follow the stochastic model, concurrent therapy with an oncogene ablating agent and a stem-like cell-targeting drug is needed for maximal therapeutic efficiency. PMID:25238228

  5. Chemosensitizing effects of metformin on cisplatin- and paclitaxel-resistant ovarian cancer cell lines.

    PubMed

    Dos Santos Guimarães, Isabella; Ladislau-Magescky, Taciane; Tessarollo, Nayara Gusmão; Dos Santos, Diandra Zipinotti; Gimba, Etel Rodrigues Pereira; Sternberg, Cinthya; Silva, Ian Victor; Rangel, Leticia Batista Azevedo

    2017-11-21

    Epithelial ovarian cancer (EOC) remains the most lethal gynecologic malignancy. Primary cytoreductive surgery with adjuvant taxane-platinum chemotherapy is the standard treatment to fight ovarian cancer, however, their side effects are severe, and chemoresistance emerges at high rates. Therefore, EOC clinic urges for novel treatment strategies to reverse chemoresistance and to improve the survival rates. Metformin has been shown to act in synergy with certain anti-cancer agents, overcoming chemoresistance in various types of tumors. This paper aims to investigate the use of metformin as a new treatment option for cisplatin- and paclitaxel-resistant ovarian cancer. The effects of metformin alone or in combination with conventional drugs on resistant EOC cell lines were investigated using the MTT assay for cell proliferation; Flow Cytometry analysis for cell cycle and the mRNA expression was analyzed using the real-time PCR technique. We found that metformin exhibited antiproliferative effects in paclitaxel-resistant A2780-PR, and in cisplatin-resistant ACRP cell lines. The combined therapy containing conventional drugs and metformin improved the effect of the treatment in cell proliferation rate, especially in the resistant cells. We found that metformin, in clinical relevant doses, could significantly reduce the mRNA expression of inflammatory cytokines and NF-κB signaling pathway. Taken together, our observations suggest that metformin inhibits the inflammatory pathway induced by paclitaxel and cisplatin treatment. Furthermore, metformin in combination with paclitaxel or cisplatin improved the sensitivity in drug-resistant ovarian cancer cells. Therefore, metformin may be beneficial treatment strategy, particularly in patients with tumors refractory to platinum and taxanes. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  6. Establishment of paclitaxel-resistant breast cancer cell line and nude mice models, and underlying multidrug resistance mechanisms in vitro and in vivo.

    PubMed

    Chen, Si-Ying; Hu, Sa-Sa; Dong, Qian; Cai, Jiang-Xia; Zhang, Wei-Peng; Sun, Jin-Yao; Wang, Tao-Tao; Xie, Jiao; He, Hai-Rong; Xing, Jian-Feng; Lu, Jun; Dong, Ya-Lin

    2013-01-01

    Breast cancer is a common malignant tumor which affects health of women and multidrug resistance (MDR) is one of the main factors leading to failure of chemotherapy. This study was conducted to establish paclitaxel-resistant breast cancer cell line and nude mice models to explore underlying mechanisms of MDR. The breast cancer drug-sensitive cell line MCF-7 (MCF-7/S) was exposed in stepwise escalating paclitaxel (TAX) to induce a resistant cell line MCF-7/TAX. Cell sensitivity to drugs and growth curves were measured by MTT assay. Changes of cell morphology and ultrastructure were examined by optical and electron microscopy. The cell cycle distribution was determined by flow cytometry. Furthermore, expression of proteins related to breast cancer occurrence and MDR was tested by immunocytochemistry. In Vivo, nude mice were injected with MCF-7/S and MCF-7/TAX cells and weights and tumor sizes were observed after paclitaxel treatment. In addition, proteins involved breast cancer and MDR were detected by immunohistochemistry. Compared to MCF-7/S, MCF-7/TAX cells had a higher resistance to paclitaxel, cross-resistance and prolonged doubling time. Moreover, MCF-7/TAX showed obvious alterations of ultrastructure. Estrogen receptor (ER) expression was low in drug resistant cells and tumors while expression of human epidermal growth factor receptor 2 (HER2) and Ki-67 was up-regulated. P-glycoprotein (P-gp), lung resistance-related protein (LRP) and glutathione-S-transferase-π (GST-π) involved in the MDR phenotype of resistant cells and tumors were all overexpressed. The underlying MDR mechanism of breast cancer may involve increased expression of P-gp, LRP and GST-π.

  7. Cancer stem cells and drug resistance: the potential of nanomedicine

    PubMed Central

    Vinogradov, Serguei; Wei, Xin

    2012-01-01

    Properties of the small group of cancer cells called tumor-initiating or cancer stem cells (CSCs) involved in drug resistance, metastasis and relapse of cancers can significantly affect tumor therapy. Importantly, tumor drug resistance seems to be closely related to many intrinsic or acquired properties of CSCs, such as quiescence, specific morphology, DNA repair ability and overexpression of antiapoptotic proteins, drug efflux transporters and detoxifying enzymes. The specific microenvironment (niche) and hypoxic stability provide additional protection against anticancer therapy for CSCs. Thus, CSC-focused therapy is destined to form the core of any effective anticancer strategy. Nanomedicine has great potential in the development of CSC-targeting drugs, controlled drug delivery and release, and the design of novel gene-specific drugs and diagnostic modalities. This review is focused on tumor drug resistance-related properties of CSCs and describes current nanomedicine approaches, which could form the basis of novel combination therapies for eliminating metastatic and CSCs. PMID:22471722

  8. Natural killer cells inhibit oxaliplatin-resistant colorectal cancer by repressing WBSCR22 via upregulating microRNA-146b-5p.

    PubMed

    Zhao, Haiyan; Su, Wuyun; Kang, Qingmei; Xing, Ze; Lin, Xue; Wu, Zhongjun

    2018-01-01

    Natural killer (NK) cells have exhibited promising efficacy in inhibiting cancer growth. We aimed to explorer the effect of NK cells on oxaliplatin-resistant colorectal cancer and the underlying molecular mechanism. Oxaliplatin-resistant colorectal cancer cell lines were co-cultured with NK cells to evaluate the effect on viability, proliferation, migration and invasion in vitro . Oxaliplatin-resistant colorectal cancer cells were also co-injected with NK cells into mice to establish xenograft tumor model, to assess the in vivo effect of NK cells on tumorigenesis of the oxaliplatin-resistant colorectal cancer cells. Expression of WBSCR22 gene was assessed in the oxaliplatin-resistant colorectal cancer cells following NK cell treatment to elucidate the mechanism. NK cell treatment significantly reduces growth of oxaliplatin-resistant colorectal cancer cells both in vitro and in vivo , as well as reduced WBSCR22 expression. MicroRNAs potentially targeting WBSCR22 were analyzed, and microRNA-146b-5p was found to be significantly upregulated following NK cell treatment. MicroRNA-146b-5p directly targeted WBSCR22 mRNA 3'-UTR to inhibit its expression, which was required for NK cell-induced inhibition of oxaliplatin-resistant colorectal cancer cell lines. NK cells inhibit oxaliplatin-resistant colorectal cancer by repressing WBSCR22 via upregulating microRNA-146b-5p, both of which could serve as candidates for targeted therapy against oxaliplatin-resistant colorectal cancer.

  9. Distinct apoptotic blocks mediate resistance to panHER inhibitors in HER2+ breast cancer cells.

    PubMed

    Karakas, Bahriye; Ozmay, Yeliz; Basaga, Huveyda; Gul, Ozgur; Kutuk, Ozgur

    2018-05-04

    Despite the development of novel targeted therapies, de novo or acquired chemoresistance remains a significant factor for treatment failure in breast cancer therapeutics. Neratinib and dacomitinib are irreversible panHER inhibitors, which block their autophosphorylation and downstream signaling. Moreover, neratinib and dacomitinib have been shown to activate cell death in HER2-overexpressing cell lines. Here we showed that increased MCL1 and decreased BIM and PUMA mediated resistance to neratinib in ZR-75-30 and SKBR3 cells while increased BCL-XL and BCL-2 and decreased BIM and PUMA promoted neratinib resistance in BT474 cells. Cells were also cross-resistant to dacomitinib. BH3 profiles of HER2+ breast cancer cells efficiently predicted antiapoptotic protein dependence and development of resistance to panHER inhibitors. Reactivation of ERK1/2 was primarily responsible for acquired resistance in SKBR3 and ZR-75-30 cells. Adding specific ERK1/2 inhibitor SCH772984 to neratinib or dacomitinib led to increased apoptotic response in neratinib-resistant SKBR3 and ZR-75-30 cells, but we did not detect a similar response in neratinib-resistant BT474 cells. Accordingly, suppression of BCL-2/BCL-XL by ABT-737 was required in addition to ERK1/2 inhibition for neratinib- or dacomitinib-induced apoptosis in neratinib-resistant BT474 cells. Our results showed that different mitochondrial apoptotic blocks mediated acquired panHER inhibitor resistance in HER2+ breast cancer cell lines as well as highlighted the potential of BH3 profiling assay in prediction of panHER inhibitor resistance in breast cancer cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. The lipid content of cisplatin- and doxorubicin-resistant MCF-7 human breast cancer cells.

    PubMed

    Todor, I N; Lukyanova, N Yu; Chekhun, V F

    2012-07-01

    To perform the comparative study both of qualitative and quantitative content of lipids in parental and drug resistant breast cancer cells. Parental (MCF-7/S) and resistant to cisplatin (MCF-7/CP) and doxorubicin (MCF-7/Dox) human breast cancer cells were used in the study. Cholesterol, total lipids and phospholipids content were determined by means of thin-layer chromatography. It was found that cholesterol as well as cholesterol ethers content are significantly higher but diacylglycerols, triacyl-glycerols content are significantly lower in resistant cell strains than in parental (sensitive) cells. Moreover the analysis of individual phospholipids showed the increase of sphingomyelin, phosphatidylserine, cardiolipin, phosphatidic acid and the decrease of phosphatidy-lethanolamine, phosphatidylcholine in MCF-7/CP and MCF-7/Dox cells. Obtained results allow to suggest that the lipid profile changes can mediate the modulation of membrane fluidity in drug resistant MCF-7 breast cancer cells.

  11. Inhibiting the cytoplasmic location of HMGB1 reverses cisplatin resistance in human cervical cancer cells.

    PubMed

    Xia, Jiyi; Yu, Xiaolan; Song, Xueqin; Li, Gang; Mao, Xiguang; Zhang, Yujiao

    2017-01-01

    Cervical cancer is the fourth most common malignancy in women worldwide, and resistance to chemotherapy drugs is the biggest obstacle in the treatment of cervical cancers. In the present study, the molecular mechanisms underlying cisplatin resistance in human cervical cancer cells were investigated. When human cervical cancer cells were treated with 10 µg/ml of cisplatin for 24 and 48 h, high mobility group box 1 (HMGB1) protein expression levels significantly increased in a time‑dependent manner. Comparisons between cisplatin‑sensitive HeLa cells and cisplatin‑resistant HeLa/DDP cells revealed higher levels of HMGB1 in HeLa/DDP cells than in HeLa cells. Additionally, the half maximal inhibitory concentration (IC50) value for cisplatin in HeLa/DDP cells was 5.3‑fold that in HeLa cells. Analysis of the distribution of cellular components revealed that HMGB1 translocation from the nucleus to cytoplasm contributed to cisplatin resistance. This was further confirmed by demonstration that ethyl pyruvate treatment suppressed the cytoplasmic translocation of HMGB1, resulting in inhibition of HeLa cell proliferation. Furthermore, endogenous HMGB1 was inhibited with HMGB1‑specific short hairpin (sh)RNA, and MTT assay results showed that interference with HMGB1 expression reduced cell viability and potentially reversed cisplatin resistance in HeLa cells. Transfection with HMGB1 shRNA was demonstrated to induce cell apoptosis in HeLa cells, as detected by FACS analysis. In addition, administration of recombinant HMGB1 protein in HeLa cells promoted cell autophagy, mediated by the phosphorylation of extracellular signal‑regulated kinase 1/2. Thus, cytoplasmic HMGB1 translocation and HMGB1‑induced cell autophagy are proposed to contribute to cisplatin resistance by inhibiting apoptosis of cervical cancer cells. HMGB1 could, therefore, represent a novel therapeutic target for, and a diagnostic marker of, chemotherapy resistant cervical cancers.

  12. CancerDR: cancer drug resistance database.

    PubMed

    Kumar, Rahul; Chaudhary, Kumardeep; Gupta, Sudheer; Singh, Harinder; Kumar, Shailesh; Gautam, Ankur; Kapoor, Pallavi; Raghava, Gajendra P S

    2013-01-01

    Cancer therapies are limited by the development of drug resistance, and mutations in drug targets is one of the main reasons for developing acquired resistance. The adequate knowledge of these mutations in drug targets would help to design effective personalized therapies. Keeping this in mind, we have developed a database "CancerDR", which provides information of 148 anti-cancer drugs, and their pharmacological profiling across 952 cancer cell lines. CancerDR provides comprehensive information about each drug target that includes; (i) sequence of natural variants, (ii) mutations, (iii) tertiary structure, and (iv) alignment profile of mutants/variants. A number of web-based tools have been integrated in CancerDR. This database will be very useful for identification of genetic alterations in genes encoding drug targets, and in turn the residues responsible for drug resistance. CancerDR allows user to identify promiscuous drug molecules that can kill wide range of cancer cells. CancerDR is freely accessible at http://crdd.osdd.net/raghava/cancerdr/

  13. Hyperactive ERK and persistent mTOR signaling characterize vemurafenib resistance in papillary thyroid cancer cells.

    PubMed

    Hanly, Elyse K; Tuli, Neha Y; Bednarczyk, Robert B; Suriano, Robert; Geliebter, Jan; Moscatello, Augustine L; Darzynkiewicz, Zbigniew; Tiwari, Raj K

    2016-02-23

    Clinical studies evaluating targeted BRAFV600E inhibitors in advanced thyroid cancer patients are currently underway. Vemurafenib (BRAFV600E inhibitor) monotherapy has shown promising results thus far, although development of resistance is a clinical challenge. The objective of this study was to characterize development of resistance to BRAFV600E inhibition and to identify targets for effective combination therapy. We created a line of BCPAP papillary thyroid cancer cells resistant to vemurafenib by treating with increasing concentrations of the drug. The resistant BCPAP line was characterized and compared to its sensitive counterpart with respect to signaling molecules thought to be directly related to resistance. Expression and phosphorylation of several critical proteins were analyzed by Western blotting and dimerization was evaluated by immunoprecipitation. Resistance to vemurafenib in BCPAP appeared to be mediated by constitutive overexpression of phospho-ERK and by resistance to inhibition of both phospho-mTOR and phospho-S6 ribosomal protein after vemurafenib treatment. Expression of potential alternative signaling molecule, CRAF, was not increased in the resistant line, although formation of CRAF dimers appeared increased. Expression of membrane receptors HER2 and HER3 was greatly amplified in the resistant cancer cells. Papillary thyroid cancer cells were capable of overcoming targeted BRAFV600E inhibition by rewiring of cell signal pathways in response to prolonged vemurafenib therapy. Our study suggests that in vitro culture of cancer cells may be useful in assessing molecular resistance pathways. Potential therapies in advanced thyroid cancer patients may combine vemurafenib with inhibitors of CRAF, HER2/HER3, ERK, and/or mTOR to delay or abort development of resistance.

  14. Greater taxol yield of fungus Pestalotiopsis hainanensis from dermatitic scurf of the giant panda (Ailuropoda melanoleuca).

    PubMed

    Gu, Yu; Wang, Yanlin; Ma, Xiaoping; Wang, Chengdong; Yue, Guizhou; Zhang, Yuetian; Zhang, Yunyan; Li, Shanshan; Ling, Shanshan; Liu, Xiaomin; Wen, Xintian; Cao, Sanjie; Huang, Xiaobo; Deng, Junliang; Zuo, Zhicai; Yu, Shumin; Shen, Liuhong; Wu, Rui

    2015-01-01

    While taxol yields of fungi from non-animal sources are still low, whether Pestalotiopsis hainanensis isolated from the scurf of a dermatitic giant panda, Ailuropoda melanoleuca, provides a greater taxol yield remains unknown. The objective of the study was to determine the corresponding taxol yield. The structure of the taxol produced by the fungus was evaluated by thin layer chromatography (TLC), ultraviolet (UV) spectroscopy, high-performance liquid chromatography (HPLC), (1)H and (13)C nuclear magnetic resonance spectroscopy ((1)H-NMR and (13)C-NMR), and time-of-flight mass spectrometry (TOF-MS), with standard taxol as a control. The results demonstrated that the P. hainanensis fungus produced taxol, which had the same structure as the standard taxol and yield of 1,466.87 μg/L. This fungal taxol yield from the dermatitic giant panda was significantly greater than those of fungus from non-animal sources. The taxol-producing fungus may be a potential candidate for the production of taxol on an industrial scale.

  15. ABCF2, an Nrf2 target gene, contributes to cisplatin resistance in ovarian cancer cells.

    PubMed

    Bao, Lingjie; Wu, Jianfa; Dodson, Matthew; Rojo de la Vega, Elisa Montserrat; Ning, Yan; Zhang, Zhenbo; Yao, Ming; Zhang, Donna D; Xu, Congjian; Yi, Xiaofang

    2017-06-01

    Previously, we have demonstrated that NRF2 plays a key role in mediating cisplatin resistance in ovarian cancer. To further explore the mechanism underlying NRF2-dependent cisplatin resistance, we stably overexpressed or knocked down NRF2 in parental and cisplatin-resistant human ovarian cancer cells, respectively. These two pairs of stable cell lines were then subjected to microarray analysis, where we identified 18 putative NRF2 target genes. Among these genes, ABCF2, a cytosolic member of the ABC superfamily of transporters, has previously been reported to contribute to chemoresistance in clear cell ovarian cancer. A detailed analysis on ABCF2 revealed a functional antioxidant response element (ARE) in its promoter region, establishing ABCF2 as an NRF2 target gene. Next, we investigated the contribution of ABCF2 in NRF2-mediated cisplatin resistance using our stable ovarian cancer cell lines. The NRF2-overexpressing cell line, containing high levels of ABCF2, was more resistant to cisplatin-induced apoptosis compared to its control cell line; whereas the NRF2 knockdown cell line with low levels of ABCF2, was more sensitive to cisplatin treatment than its control cell line. Furthermore, transient overexpression of ABCF2 in the parental cells decreased apoptosis and increased cell viability following cisplatin treatment. Conversely, knockdown of ABCF2 using specific siRNA notably increased apoptosis and decreased cell viability in cisplatin-resistant cells treated with cisplatin. This data indicate that the novel NRF2 target gene, ABCF2, plays a critical role in cisplatin resistance in ovarian cancer, and that targeting ABCF2 may be a new strategy to improve chemotherapeutic efficiency. © 2017 Wiley Periodicals, Inc.

  16. Oncogenic drivers, targeted therapies, and acquired resistance in non-small-cell lung cancer.

    PubMed

    Gower, Arjan; Wang, Yisong; Giaccone, Giuseppe

    2014-07-01

    In the past decade, a shift toward targeted therapies in non-small-cell lung cancer following molecular profiling has dramatically changed the way advanced adenocarcinoma is treated. However, tumor cells inevitably acquire resistance to such therapies, circumventing any sustained clinical benefit. As the genomic classification of lung cancer continues to evolve and as the mechanisms of acquired resistance to targeted therapies become elucidated and more improved target-specific drugs come into sight, the future will see more promising results from the clinic through the development of new therapeutic strategies to overcome, or prevent the development of, resistance for lung cancer patients.

  17. Rational design of cancer-targeted selenium nanoparticles to antagonize multidrug resistance in cancer cells.

    PubMed

    Liu, Ting; Zeng, Lilan; Jiang, Wenting; Fu, Yuanting; Zheng, Wenjie; Chen, Tianfeng

    2015-05-01

    Multidrug resistance is one of the greatest challenges in cancer therapy. Herein we described the synthesis of folate (FA)-conjugated selenium nanoparticles (SeNPs) as cancer-targeted nano-drug delivery system for ruthenium polypyridyl (RuPOP) exhibits strong fluorescence, which allows the direct imaging of the cellular trafficking of the nanosystem. This nanosystem could effectively antagonize against multidrug resistance in liver cancer. FA surface conjugation significantly enhanced the cellular uptake of SeNPs by FA receptor-mediated endocytosis through nystain-dependent lipid raft-mediated and clathrin-mediated pathways. The nanomaterials overcame the multidrug resistance in R-HepG2 cells through inhibition of ABC family proteins expression. Internalized nanoparticles triggered ROS overproduction and induced apoptosis by activating p53 and MAPKs pathways. Moreover, FA-SeNPs exhibited low in vivo acute toxicity, which verified the safety and application potential of FA-SeNPs as nanodrugs. This study provides an effective strategy for the design of cancer-targeted nanodrugs against multidrug resistant cancers. In the combat against hepatocellular carcinoma, multidrug resistance remains one of the obstacles to be overcome. The authors designed and synthesized folate (FA)-conjugated selenium nanoparticles (SeNPs) with enhanced cancer-targeting capability. This system carried ruthenium polypyridyl (RuPOP), an efficient metal-based anti-cancer drug with strong fluorescence. It was shown that this combination was effective in antagonizing against multidrug resistance in vitro. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Multi-nucleated cells use ROS to induce breast cancer chemo-resistance in vitro and in vivo.

    PubMed

    Parekh, Aditya; Das, Subhayan; Parida, Sheetal; Das, Chandan Kanta; Dutta, Debabrata; Mallick, Sanjaya K; Wu, Pei-Hsun; Kumar, B N Prashanth; Bharti, Rashmi; Dey, Goutam; Banerjee, Kacoli; Rajput, Shashi; Bharadwaj, Deblina; Pal, Ipsita; Dey, Kaushik Kumar; Rajesh, Yetirajam; Jena, Bikash Chandra; Biswas, Angana; Banik, Payel; Pradhan, Anjan K; Das, Swadesh K; Das, Amit Kumar; Dhara, Santanu; Fisher, Paul B; Wirtz, Denis; Mills, Gordon B; Mandal, Mahitosh

    2018-05-10

    Although there is a strong correlation between multinucleated cells (MNCs) and cancer chemo-resistance in variety of cancers, our understanding of how multinucleated cells modulate the tumor micro-environment is limited. We captured multinucleated cells from triple-negative chemo-resistant breast cancers cells in a time frame, where they do not proliferate but rather significantly regulate their micro-environment. We show that oxidatively stressed MNCs induce chemo-resistance in vitro and in vivo by secreting VEGF and MIF. These factors act through the RAS/MAPK pathway to induce chemo-resistance by upregulating anti-apoptotic proteins. In MNCs, elevated reactive oxygen species (ROS) stabilizes HIF-1α contributing to increase production of VEGF and MIF. Together the data indicate, that the ROS-HIF-1α signaling axis is very crucial in regulation of chemo-resistance by MNCs. Targeting ROS-HIF-1α in future may help to abrogate drug resistance in breast cancer.

  19. Prevention effect of rare ginsenosides against stress-hormone induced MTOC amplification

    PubMed Central

    Lee, Jee-Hyun; Cheong, Kyu Jin; Jung, Youn-Sang; Woo, Tae-Gyun; Yoon, Min-Ho; Oh, Ah-Young; Kang, So-Mi; Lee, Chunghui; Sun, Hokeun; Hwang, Jihwan; Song, Gyu-Yong; Park, Bum-Joon

    2016-01-01

    Stress has been suggested as one of important cause of human cancer without molecular biological evidence. Thus, we test the effect of stress-related hormones on cell viability and mitotic fidelity. Similarly to estrogen, stress hormone cortisol and its relative cortisone increase microtubule organizing center (MTOC) number through elevated expression of γ-tubulin and provide the Taxol resistance to human cancer cell lines. However, these effects are achieved by glucocorticoid hormone receptor (GR) but not by estrogen receptor (ER). Since ginsenosides possess steroid-like structure, we hypothesized that it would block the stress or estrogen-induced MTOC amplification and Taxol resistance. Among tested chemicals, rare ginsenoside, CSH1 (Rg6) shows obvious effect on inhibition of MTOC amplification, γ-tubulin induction and Taxol resistance. Comparing to Fulvestant (FST), ER-α specific inhibitor, this chemical can block the cortisol/cortisone-induced MTOC deregulation as well as ER-α signaling. Our results suggest that stress hormone induced tumorigenesis would be achieved by MTOC amplification, and CSH1 would be useful for prevention of stress-hormone or steroid hormone-induced chromosomal instability. PMID:27147573

  20. Differential effect of EGFR inhibitors on tamoxifen-resistant breast cancer cells.

    PubMed

    Kim, Sangmin; Lee, Jeongmin; Oh, Soo Jin; Nam, Seok Jin; Lee, Jeong Eon

    2015-09-01

    Although tamoxifen is the most common and effective therapy for treatment of estrogen receptor-α (ER-α) breast cancer patients, resistance of endocrine therapy occurs, either de novo or acquired during therapy. Here, we investigated the clinical value of epidermal growth factor receptor (EGFR) in tamoxifen-resistant (TamR) patients and the differential effect of EGFR inhibitors, neratinib and gefitinib, on TamR breast cancer cell model. The morphology of TamR MCF7 cells showed mesenchymal phenotypes and did not induce cell death by tamoxifen treatment compared with tamoxifen‑sensitive (TamS) MCF7 cells. In addition, mesenchymal marker proteins, including N-cadherin (N-cad), fibronectin (FN), and Slug, significantly increased in TamR cells. In contrast, ER-α and E-cadherin (E-cad) were greatly decreased. We also found that the levels of EGFR and HER2 expression were increased in TamR cells. Furthermore, we observed that EGFR expression was directly involved with poor prognosis of tamoxifen-treated breast cancer patients using the GSE1378 date set. Thus, we treated TamR and TamS cells with EGFR inhibitors, neratinib and gefitinib, respectively. Interestingly, neratinib induced apoptotic cell death of TamR but not gefitinib. Cleaved PARP-1 expression was also increased by neratinib treatment in TamR cells. Therefore, we suggest that neratinib may be a potential therapeutic drug for treating TamR breast cancer.

  1. Molecular Biomarkers of Cancer Stem/Progenitor Cells Associated with Progression, Metastases, and Treatment Resistance of Aggressive Cancers

    PubMed Central

    Mimeault, Murielle; Batra, Surinder K.

    2014-01-01

    The validation of novel diagnostic, prognostic, and predictive biomarkers and therapeutic targets in tumor cells is of critical importance for optimizing the choice and efficacy of personalized therapies. Importantly, recent advances have led to the identification of gene-expression signatures in cancer cells, including cancer stem/progenitor cells, in the primary tumors, exosomes, circulating tumor cells (CTC), and disseminated cancer cells at distant metastatic sites. The gene-expression signatures may help to improve the accuracy of diagnosis and predict the therapeutic responses and overall survival of patients with cancer. Potential biomarkers in cancer cells include stem cell–like markers [CD133, aldehyde dehydrogenase (ALDH), CD44, and CD24], growth factors, and their cognate receptors [epidermal growth factor receptor (EGFR), EGFRvIII, and HER2], molecules associated with epithelial–mesenchymal transition (EMT; vimentin, N-cadherin, snail, twist, and Zeb1), regulators of altered metabolism (phosphatidylinositol-3′ kinase/Akt/mTOR), and drug resistance (multidrug transporters and macrophage inhibitory cytokine-1). Moreover, different pluripotency-associated transcription factors (Oct3/4, Nanog, Sox2, and Myc) and microRNAs that are involved in the epigenetic reprogramming and acquisition of stem cell–like properties by cancer cells during cancer progression may also be exploited as molecular biomarkers to predict the risk of metastases, systemic treatment resistance, and disease relapse of patients with cancer. PMID:24273063

  2. Bioreactor engineering as an enabling technology to tap biodiversity. The case of taxol.

    PubMed

    Shuler, M L

    1994-11-30

    One barrier to exploiting the chemical and genetic diversity in nature is the difficulty of cultivating many organisms in a controlled manner. In some cases it is difficult to achieve growth. In many others, good growth is achieved, but the expression of the organism's genetic potential to make a desired product is not realized. The thesis of this paper is that a coupling of an understanding of reactor engineering principles with the basic knowledge of the biology is often necessary to circumvent these barriers. In many cases the construction of appropriate cultivation systems is a necessary step to better understanding of cellular physiology. In some cases the chemical of interest is of high social utility and comes from a natural source that is uncommon and difficult to secure. In these cases a method of controlled cultivation becomes a prerequisite for commercial exploitation. These points were illustrated using a taxol. Taxol is an important new anticancer drug whose development has been greatly impeded by supply problems. Taxol has been derived from the park of the pacific yew tree, a process that kills the tree. The pacific yew is a relatively uncommon tree and very slow growing. One alternative to the natural source is plant cell culture. Such cultures can produce significant levels of taxol with substantial release into the medium. Taxane products not observed in typical extracts from field-grown plants can be found in cell cultures, indicating the potential unmasking of pathways. These cultures are quite responsive to changes in their environments as illustrated by the summary of initial observations. With regard to natural compounds, biochemical engineers can play a major role in the capture and preservation of producing systems, in the discovery of useful compounds, and in providing the basis for commercial production of natural compounds.

  3. Cranberry Proanthocyanidins are Cytotoxic to Human Cancer Cells and Sensitize Platinum-Resistant Ovarian Cancer Cells to Paraplatin

    PubMed Central

    Singh, Ajay P.; Singh, Rakesh K.; Kim, Kyu Kwang; Satyan, K. S.; Nussbaum, Roger; Torres, Monica; Brard, Laurent; Vorsa, Nicholi

    2010-01-01

    Polyphenolic extracts of the principal flavonoid classes present in cranberry were screened in vitro for cytotoxicity against solid tumor cells lines, identifying two fractions composed principally of proanthocyanidins (PACs) with potential anticancer activity. Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) analysis of the proanthocyanidins (PACs) fractions indicated the presence of A-type PACs with 1–4 linkages containing between 2–8 epicatechin units with a maximum of 1 epigallocatechin unit. PACs exhibited in vitro cytotoxicity against platinum-resistant human ovarian, neuroblastoma and prostate cancer cell lines (IC50 = 79–479 μg/mL) but were non-cytotoxic to lung fibroblast cells (IC50 > 1000 μg/ml). SKOV-3 ovarian cancer cells treated with PACs exhibited classic apoptotic changes. PACs acted synergistically with paraplatin in SKOV-3 cells. Pretreatment of SKOV-3 cells with PACs (106 μg/ ml) resulted in a significant reduction of the paraplatin IC50 value. Similarly, in a BrdU incorporation assay, co-treatment of SKOV-3 cells with PACs and paraplatin revealed reduced cell proliferation at lower concentrations than with either individually. In SKOV-3 cell cultures co-treated with PAC-1 and paraplatin, an HPLC analysis indicated differential quantitative presence of various PAC oligomers such as DP-8, -9, -11 and -14 indicating either selective binding or uptake. Cranberry proanthocyanidins exhibit cell-line specific cytotoxicity, induce apoptotic markers and augment cytotoxicity of paraplatin in platinum-resistant SKOV-3 ovarian cancer cells. PMID:19172579

  4. Generation and Characterisation of Cisplatin-Resistant Non-Small Cell Lung Cancer Cell Lines Displaying a Stem-Like Signature

    PubMed Central

    Barr, Martin P.; Gray, Steven G.; Hoffmann, Andreas C.; Hilger, Ralf A.; Thomale, Juergen; O’Flaherty, John D.; Fennell, Dean A.; Richard, Derek; O’Leary, John J.; O’Byrne, Kenneth J.

    2013-01-01

    Introduction Inherent and acquired cisplatin resistance reduces the effectiveness of this agent in the management of non-small cell lung cancer (NSCLC). Understanding the molecular mechanisms underlying this process may result in the development of novel agents to enhance the sensitivity of cisplatin. Methods An isogenic model of cisplatin resistance was generated in a panel of NSCLC cell lines (A549, SKMES-1, MOR, H460). Over a period of twelve months, cisplatin resistant (CisR) cell lines were derived from original, age-matched parent cells (PT) and subsequently characterized. Proliferation (MTT) and clonogenic survival assays (crystal violet) were carried out between PT and CisR cells. Cellular response to cisplatin-induced apoptosis and cell cycle distribution were examined by FACS analysis. A panel of cancer stem cell and pluripotent markers was examined in addition to the EMT proteins, c-Met and β-catenin. Cisplatin-DNA adduct formation, DNA damage (γH2AX) and cellular platinum uptake (ICP-MS) was also assessed. Results Characterisation studies demonstrated a decreased proliferative capacity of lung tumour cells in response to cisplatin, increased resistance to cisplatin-induced cell death, accumulation of resistant cells in the G0/G1 phase of the cell cycle and enhanced clonogenic survival ability. Moreover, resistant cells displayed a putative stem-like signature with increased expression of CD133+/CD44+cells and increased ALDH activity relative to their corresponding parental cells. The stem cell markers, Nanog, Oct-4 and SOX-2, were significantly upregulated as were the EMT markers, c-Met and β-catenin. While resistant sublines demonstrated decreased uptake of cisplatin in response to treatment, reduced cisplatin-GpG DNA adduct formation and significantly decreased γH2AX foci were observed compared to parental cell lines. Conclusion Our results identified cisplatin resistant subpopulations of NSCLC cells with a putative stem-like signature, providing

  5. Melatonin Promotes Apoptosis of Oxaliplatin-resistant Colorectal Cancer Cells Through Inhibition of Cellular Prion Protein.

    PubMed

    Lee, Jun Hee; Yoon, Yeo Min; Han, Yong-Seok; Yun, Chul Won; Lee, Sang Hun

    2018-04-01

    Drug resistance restricts the efficacy of chemotherapy in colorectal cancer. However, the detailed molecular mechanism of drug resistance in colorectal cancer cells remains unclear. The level of cellular prion protein (PrP C ) in oxaliplatin-resistant colorectal cancer (SNU-C5/Oxal-R) cells was assessed. PrP C level in SNU-C5/Oxal-R cells was significantly increased compared to that in wild-type (SNU-C5) cells. Superoxide dismutase and catalase activities were higher in SNU-C5/Oxal-R cells than in SNU-C5 cells. Treatment of SNU-C5/Oxal-R cells with oxaliplatin and melatonin reduced PrP C expression, while suppressing antioxidant enzyme activity and increasing superoxide anion generation. In SNU-C5/Oxal-R cells, endoplasmic reticulum stress and apoptosis were significantly increased following co-treatment with oxaliplatin and melatonin compared to treatment with oxaliplatin alone. Co-treatment with oxaliplatin and melatonin increased endoplasmic reticulum stress in and apoptosis of SNU-C5/Oxal-R cells through inhibition of PrP C , suggesting that PrP C could be a key molecule in oxaliplatin resistance of colorectal cancer cells. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  6. MicroRNA-181a promotes docetaxel resistance in prostate cancer cells.

    PubMed

    Armstrong, Cameron M; Liu, Chengfei; Lou, Wei; Lombard, Alan P; Evans, Christopher P; Gao, Allen C

    2017-06-01

    Docetaxel is one of the primary drugs used for treating castration resistant prostate cancer (CRPC). Unfortunately, over time patients invariably develop resistance to docetaxel therapy and their disease will continue to progress. The mechanisms by which resistance develops are still incompletely understood. This study seeks to determine the involvement of miRNAs, specifically miR-181a, in docetaxel resistance in CRPC. Real-time PCR was used to measure miR-181a expression in parental and docetaxel resistant C4-2B and DU145 cells (TaxR and DU145-DTXR). miR-181a expression was modulated in parental or docetaxel resistant cells by transfecting them with miR-181a mimics or antisense, respectively. Following transfection, cell number was determined after 48 h with or without docetaxel. Cross resistance to cabazitaxel induced by miR-181a was also determined. Western blots were used to determine ABCB1 protein expression and rhodamine assays used to assess activity. Phospho-p53 expression was assessed by Western blot and apoptosis was measured by ELISA in C4-2B TaxR and PC3 cells with inhibited or overexpressed miR-181a expression with or without docetaxel. miR-181a is significantly overexpressed in TaxR and DU145-DTXR cells compared to parental cells. Overexpression of miR-181a in parental cells confers docetaxel and cabazitaxel resistance and knockdown of miR-181a in TaxR cells re-sensitizes them to treatment with both docetaxel and cabazitaxel. miR-181a was not observed to impact ABCB1 expression or activity, a protein which was previously demonstrated to be highly involved in docetaxel resistance. Knockdown of miR-181a in TaxR cells induced phospho-p53 expression. Furthermore, miR-181a knockdown alone induced apoptosis in TaxR cells which could be further enhanced by the addition of DTX. Overexpression of mir-181a in prostate cancer cells contributes to their resistance to docetaxel and cabazitaxel and inhibition of mir-181a expression can restore treatment response

  7. Side population cells of pancreatic cancer show characteristics of cancer stem cells responsible for resistance and metastasis.

    PubMed

    Niess, Hanno; Camaj, Peter; Renner, Andrea; Ischenko, Ivan; Zhao, Yue; Krebs, Stefan; Mysliwietz, Josef; Jäckel, Carsten; Nelson, Peter J; Blum, Helmut; Jauch, Karl-Walter; Ellwart, Joachim W; Bruns, Christiane J

    2015-06-01

    Cancer stem cells (CSCs) have been proposed to underlie the initiation and maintenance of tumor growth and the development of chemoresistance in solid tumors. The identification and role of these important cells in pancreatic cancer remains controversial. Here, we isolate side population (SP) cells from the highly aggressive and metastatic human pancreatic cancer cell line L3.6pl and evaluate their potential role as models for CSCs. SP cells were isolated following Hoechst 33342 staining of L3.6pl cells. SP, non-SP, and unsorted L3.6pl cells were orthotopically xenografted into the pancreas of nude mice and tumor growth observed. RNA was analyzed by whole genome array and pathway mapping was performed. Drug resistant variants of L3.6pl were developed and examined for SP proportions and evaluated for surface expression of known CSC markers. A distinct SP with the ability to self-renew and differentiate into non-SP cells was isolated from L3.6pl (0.9 % ± 0.22). SP cells showed highly tumorigenic and metastatic characteristics after orthotopic injection. Transcriptomic analysis identified modulation of gene networks linked to tumorigenesis, differentiation, and metastasization in SP cells relative to non-SP cells. Wnt, NOTCH, and EGFR signaling pathways associated with tumor stem cells were altered in SP cells. When cultured with increasing concentrations of gemcitabine, the proportion of SP cells, ABCG2(+), and CD24(+) cells were significantly enriched, whereas 5-fluorouracil (5-FU) treatment lowered the percentage of SP cells. SP cells were distinct from cells positive for previously postulated pancreatic CSC markers. The Hoechst-induced side population in L3.6pl cells comprises a subset of tumor cells displaying aggressive growth and metastasization, increased gemcitabine-, but not 5-FU resistance. The cells may act as a partial model for CSC biology.

  8. Controlled Breast Cancer Microarrays for the Deconvolution of Cellular Multilayering and Density Effects upon Drug Responses

    PubMed Central

    Håkanson, Maria; Kobel, Stefan; Lutolf, Matthias P.; Textor, Marcus; Cukierman, Edna; Charnley, Mirren

    2012-01-01

    Background Increasing evidence shows that the cancer microenvironment affects both tumorigenesis and the response of cancer to drug treatment. Therefore in vitro models that selectively reflect characteristics of the in vivo environment are greatly needed. Current methods allow us to screen the effect of extrinsic parameters such as matrix composition and to model the complex and three-dimensional (3D) cancer environment. However, 3D models that reflect characteristics of the in vivo environment are typically too complex and do not allow the separation of discrete extrinsic parameters. Methodology/Principal Findings In this study we used a poly(ethylene glycol) (PEG) hydrogel-based microwell array to model breast cancer cell behavior in multilayer cell clusters that allows a rigorous control of the environment. The innovative array fabrication enables different matrix proteins to be integrated into the bottom surface of microwells. Thereby, extrinsic parameters including dimensionality, type of matrix coating and the extent of cell-cell adhesion could be independently studied. Our results suggest that cell to matrix interactions and increased cell-cell adhesion, at high cell density, induce independent effects on the response to Taxol in multilayer breast cancer cell clusters. In addition, comparing the levels of apoptosis and proliferation revealed that drug resistance mediated by cell-cell adhesion can be related to altered cell cycle regulation. Conversely, the matrix-dependent response to Taxol did not correlate with proliferation changes suggesting that cell death inhibition may be responsible for this effect. Conclusions/Significance The application of the PEG hydrogel platform provided novel insight into the independent role of extrinsic parameters controlling drug response. The presented platform may not only become a useful tool for basic research related to the role of the cancer microenvironment but could also serve as a complementary platform for in

  9. Cytotoxicity of compounds from Xylopia aethiopica towards multi-factorial drug-resistant cancer cells.

    PubMed

    Kuete, Victor; Sandjo, Louis P; Mbaveng, Armelle T; Zeino, Maen; Efferth, Thomas

    2015-12-15

    Multidrug resistance (MDR) in cancer represent a major hurdle in chemotherapy. Previously, the methanol extract of the medicinal spice Xylopia aethiopica displayed considerable cytotoxicity against multidrug resistant (MDR) cancer cell lines. The present study was designed to assess the cytotoxicity of compounds, 16α-hydroxy-ent-kauran-19-oic acid (2), 3,4',5-trihydroxy-6″,6″-dimethylpyrano[2,3-g]flavone (3), isotetrandrine (5) and trans-tiliroside (6) derived from the methanol crude extract of Xylopia aethiopica against 9 drug-sensitive and -resistant cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these compounds, whilst caspase-Glo assay was used to detect caspase activation. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species (ROS) were all analyzed via flow cytometry. Flavonoid 3 and alkaloid 5 also displayed IC50 values ranging from 2.61 µM (towards leukemia CCRF-CEM cells) to 18.60 µM (towards gliobastoma multiforme U87MG.ΔEGFR cells) and from 1.45 µM (towards HepG2 cells) to 7.28 µM (towards MDA-MB-231-pcDNA cells), respectively. IC50 values ranged from 0.20 µM (against CCRF-CEM cells) to 195.12 µM (against CEM/ADR5000 cells) for doxorubicin. Compound 3 induced apoptosis in leukemia CCRF-CEM cells mediated by the disruption of the MMP, whilst 5 induced apoptosis mediated by ROS production. Compounds 2 and 5 represent potential cytotoxic phytochemicals that deserve more investigations to develop novel antineoplastic drugs against multifactorial drug-resistant cancers. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. Metabolic vulnerability of cisplatin-resistant cancers.

    PubMed

    Obrist, Florine; Michels, Judith; Durand, Sylvere; Chery, Alexis; Pol, Jonathan; Levesque, Sarah; Joseph, Adrien; Astesana, Valentina; Pietrocola, Federico; Wu, Gen Sheng; Castedo, Maria; Kroemer, Guido

    2018-06-06

    Cisplatin is the most widely used chemotherapeutic agent, and resistance of neoplastic cells against this cytoxicant poses a major problem in clinical oncology. Here, we explored potential metabolic vulnerabilities of cisplatin-resistant non-small human cell lung cancer and ovarian cancer cell lines. Cisplatin-resistant clones were more sensitive to killing by nutrient deprivation in vitro and in vivo than their parental cisplatin-sensitive controls. The susceptibility of cisplatin-resistant cells to starvation could be explained by a particularly strong dependence on glutamine. Glutamine depletion was sufficient to restore cisplatin responses of initially cisplatin-resistant clones, and glutamine supplementation rescued cisplatin-resistant clones from starvation-induced death. Mass spectrometric metabolomics and specific interventions on glutamine metabolism revealed that, in cisplatin-resistant cells, glutamine is mostly required for nucleotide biosynthesis rather than for anaplerotic, bioenergetic or redox reactions. As a result, cisplatin-resistant cancers became exquisitely sensitive to treatment with antimetabolites that target nucleoside metabolism. © 2018 The Authors.

  11. Characterization of acquired paclitaxel resistance of breast cancer cells and involvement of ABC transporters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Němcová-Fürstová, Vlasta, E-mail: vlasta.furstova@

    Development of taxane resistance has become clinically very important issue. The molecular mechanisms underlying the resistance are still unclear. To address this issue, we established paclitaxel-resistant sublines of the SK-BR-3 and MCF-7 breast cancer cell lines that are capable of long-term proliferation in 100 nM and 300 nM paclitaxel, respectively. Application of these concentrations leads to cell death in the original counterpart cells. Both sublines are cross-resistant to doxorubicin, indicating the presence of the MDR phenotype. Interestingly, resistance in both paclitaxel-resistant sublines is circumvented by the second-generation taxane SB-T-1216. Moreover, we demonstrated that it was not possible to establish sublinesmore » of SK-BR-3 and MCF-7 cells resistant to this taxane. It means that at least the tested breast cancer cells are unable to develop resistance to some taxanes. Employing mRNA expression profiling of all known human ABC transporters and subsequent Western blot analysis of the expression of selected transporters, we demonstrated that only the ABCB1/PgP and ABCC3/MRP3 proteins were up-regulated in both paclitaxel-resistant sublines. We found up-regulation of ABCG2/BCRP and ABCC4 proteins only in paclitaxel-resistant SK-BR-3 cells. In paclitaxel-resistant MCF-7 cells, ABCB4/MDR3 and ABCC2/MRP2 proteins were up-regulated. Silencing of ABCB1 expression using specific siRNA increased significantly, but did not completely restore full sensitivity to both paclitaxel and doxorubicin. Thus we showed a key, but not exclusive, role for ABCB1 in mechanisms of paclitaxel resistance. It suggests the involvement of multiple mechanisms in paclitaxel resistance in tested breast cancer cells. - Highlights: • Expression of all ABC transporters in paclitaxel-resistant sublines of SK-BR-3 and MCF-7 cells was analyzed. • SK-BR-3 and MCF-7 cells are unable to develop resistance to some taxanes. • Some taxanes are able to overcome developed resistance to

  12. Cell population heterogeneity and evolution towards drug resistance in cancer: Biological and mathematical assessment, theoretical treatment optimisation.

    PubMed

    Chisholm, Rebecca H; Lorenzi, Tommaso; Clairambault, Jean

    2016-11-01

    Drug-induced drug resistance in cancer has been attributed to diverse biological mechanisms at the individual cell or cell population scale, relying on stochastically or epigenetically varying expression of phenotypes at the single cell level, and on the adaptability of tumours at the cell population level. We focus on intra-tumour heterogeneity, namely between-cell variability within cancer cell populations, to account for drug resistance. To shed light on such heterogeneity, we review evolutionary mechanisms that encompass the great evolution that has designed multicellular organisms, as well as smaller windows of evolution on the time scale of human disease. We also present mathematical models used to predict drug resistance in cancer and optimal control methods that can circumvent it in combined therapeutic strategies. Plasticity in cancer cells, i.e., partial reversal to a stem-like status in individual cells and resulting adaptability of cancer cell populations, may be viewed as backward evolution making cancer cell populations resistant to drug insult. This reversible plasticity is captured by mathematical models that incorporate between-cell heterogeneity through continuous phenotypic variables. Such models have the benefit of being compatible with optimal control methods for the design of optimised therapeutic protocols involving combinations of cytotoxic and cytostatic treatments with epigenetic drugs and immunotherapies. Gathering knowledge from cancer and evolutionary biology with physiologically based mathematical models of cell population dynamics should provide oncologists with a rationale to design optimised therapeutic strategies to circumvent drug resistance, that still remains a major pitfall of cancer therapeutics. This article is part of a Special Issue entitled "System Genetics" Guest Editor: Dr. Yudong Cai and Dr. Tao Huang. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. A Novel Polyphenol Conjugate Sensitizes Cisplatin-Resistant Head and Neck Cancer Cells to Cisplatin via Nrf2 Inhibition.

    PubMed

    Kim, Eun Hye; Jang, Hyejin; Roh, Jong-Lyel

    2016-11-01

    Many cancer cells show acquired resistance to chemotherapeutic agents, such as cisplatin. This is a major cause of cancer treatment failure, and novel agents to overcome resistance are thus urgently required. A novel synthetic polyphenol conjugate, (E)-3-(3,5-dimethoxyphenyl)-1-(2-methoxyphenyl)prop-2-en-1-one (DPP-23), selectively kills tumor cells via the reactive oxygen species (ROS)-mediated unfolded protein response. We investigated the ability of DPP-23 to overcome cisplatin resistance in head and neck cancer (HNC) cells and further clarified its molecular mechanisms of action. Cisplatin-resistant HNC cell lines and their parental and other HNC cell lines were used. The effects of cisplatin and DPP-23 were assessed alone and in combination in HNC and normal cells using cell viability, cell cycle, and cell death assays, by measuring glutathione (GSH), ROS, and protein levels, and via preclinical mouse studies. DPP-23 induced selective cell death in HNC cells, including cisplatin-resistant HNC cells, but spared normal cells, via cellular GSH depletion and ROS accumulation. The effect was blocked by the antioxidant N-acetyl-L-cysteine. DPP-23 activated p53 and its related cell death pathways via a robust accumulation of cellular ROS that involved inhibition of nuclear factor erythroid 2-related factor 2 antioxidant defense mechanisms. Thus, DPP-23 significantly overcame cisplatin resistance in HNC cells in vitro and in vivo As a promising anticancer strategy, ROS generation and subsequent selective cancer cell killing by DPP-23 might help to overcome cisplatin resistance in HNC. Mol Cancer Ther; 15(11); 2620-9. ©2016 AACR. ©2016 American Association for Cancer Research.

  14. Cytotoxicity of South-African medicinal plants towards sensitive and multidrug-resistant cancer cells.

    PubMed

    Saeed, Mohamed E M; Meyer, Marion; Hussein, Ahmed; Efferth, Thomas

    2016-06-20

    Traditional medicine plays a major role for primary health care worldwide. Cancer belongs to the leading disease burden in industrialized and developing countries. Successful cancer therapy is hampered by the development of resistance towards established anticancer drugs. In the present study, we investigated the cytotoxicity of 29 extracts from 26 medicinal plants of South-Africa against leukemia cell lines, most of which are used traditionally to treat cancer and related symptoms. We have investigated the plant extracts for their cytotoxic activity towards drug-sensitive parental CCRF-CEM leukemia cells and their multidrug-resistant P-glycoprotein-overexpressing subline, CEM/ADR5000 by means of the resazurin assay. A panel of 60 NCI tumor cell lines have been investigated for correlations between selected phytochemicals from medicinal plants and the expression of resistance-conferring genes (ABC-transporters, oncogenes, tumor suppressor genes). Seven extracts inhibited both cell lines (Acokanthera oppositifolia, Hypoestes aristata, Laurus nobilis, Leonotis leonurus, Plectranthus barbatus, Plectranthus ciliates, Salvia apiana). CEM/ADR5000 cells exhibited a low degree of cross-resistance (3.35-fold) towards the L. leonurus extract, while no cross-resistance was observed to other plant extracts, although CEM/ADR5000 cells were highly resistant to clinically established drugs. The log10IC50 values for two out of 14 selected phytochemicals from these plants (acovenoside A and ouabain) of 60 tumor cell lines were correlated to the expression of ABC-transporters (ABCB1, ABCB5, ABCC1, ABCG2), oncogenes (EGFR, RAS) and tumor suppressors (TP53). Sensitivity or resistance of the cell lines were not statistically associated with the expression of these genes, indicating that multidrug-resistant, refractory tumors expressing these genes may still respond to acovenoside A and ouabain. The bioactivity of South African medicinal plants may represent a basis for the development

  15. FGFR signaling regulates resistance of head and neck cancer stem cells to cisplatin.

    PubMed

    McDermott, Sarah C; Rodriguez-Ramirez, Christie; McDermott, Sean P; Wicha, Max S; Nör, Jacques E

    2018-05-18

    Patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) have poor prognosis with less than 1-year median survival. Platinum-based chemotherapy remains the first-line treatment for HNSCC. The cancer stem cell (CSC) hypothesis postulates that tumors are maintained by a self-renewing CSC population that is also capable of differentiating into non-self renewing cell populations that constitute the bulk of the tumor. A small population of CSC exists within HNSCC that are relatively resistant to chemotherapy and clinically predicted to contribute to tumor recurrence. These head and neck CSCs (HNCSC) are identified by high cell-surface expression of CD44 and high intracellular activity of aldehyde dehydrogenase (ALDH) and termed ALDH high CD44 high . Here, we performed microarray analysis in two HNSCC cell lines (UM-SCC-1, UM-SCC-22B) to investigate molecular pathways active in untreated and cisplatin-resistant ALDH high CD44 high cells. Gene set enrichment analysis and iPathway analysis identified signaling pathways with major implications to the pathobiology of cancer (e.g. TNFα, IFN, IL6/STAT, NF-κB) that are enriched in cisplatin-resistant ALDH high CD44 high cells, when compared to control cells. FGF2 was also enriched in cisplatin-resistant ALDH high CD44 high , which was confirmed by ELISA analysis. Inhibition of FGF signaling using BGJ398, a pan-FGF receptor (FGFR) small-molecule inhibitor, decreased ALDH high CD44 high alone in UM-SCC-1 and preferentially targeted cisplatin-resistant ALDH high CD44 high cells in UM-SCC-22B. These findings suggest that FGFR signaling might play an important role in the resistance of head and neck CSC to cisplatin. Collectively, this work suggests that some head and neck cancer patients might benefit from the combination of cisplatin and a FGFR inhibitor.

  16. BMI-1 Promotes Self-Renewal of Radio- and Temozolomide (TMZ)-Resistant Breast Cancer Cells.

    PubMed

    Yan, Yanfang; Wang, Ying; Zhao, Pengxin; Ma, Weiyuan; Hu, Zhigang; Zhang, Kaili

    2017-12-01

    Breast cancer is a hormone-dependent malignancy and is the most prevalent cause of cancer-related mortality among females. Radiation therapy and chemotherapy are common treatments of breast cancer. However, tumor relapse and metastasis following therapy are major clinical challenges. The importance of B-lymphoma Moloney murine leukemia virus insertion region-1 (BMI-1) was implicated in cell proliferation, stem cell maintenance, and tumor initiation. We established radio- and temozolomide (TMZ)-resistant (IRC-R) MCF-7 and MDA-MB-231 cell lines to investigate the mechanism involved in therapeutic resistance. Cell proliferation and sphere number were dramatically elevated, and BMI-1 was remarkably upregulated, in IRC-R cells compared to parental cells. Silencing BMI-1 by RNA interference only affected the cell proliferation of IRC-R but not parental cells, suggesting the critical role of BMI-1 in radio- and TMZ resistance. We used a xenograft mice model to elucidate that BMI-1 was necessary in tumor development by assessing tumor volume and Ki67 expression. We found that Hedgehog (Hhg) signaling exerted synergized functions together with BMI-1, implicating the importance of BMI-1 in Hhg signaling. Downregulation of BMI-1 could be an effective strategy to suppress tumor growth, which supports the potential clinical use of targeting BMI-1 in breast cancer treatment.

  17. Notch3-specific inhibition using siRNA knockdown or GSI sensitizes paclitaxel-resistant ovarian cancer cells.

    PubMed

    Kang, Haeyoun; Jeong, Ju-Yeon; Song, Ji-Ye; Kim, Tae Heon; Kim, Gwangil; Huh, Jin Hyung; Kwon, Ah-Young; Jung, Sang Geun; An, Hee Jung

    2016-07-01

    Notch signaling plays an important role in ovarian cancer chemoresistance, which is responsible for recurrence. Gamma-secretase inhibitor (GSI) is a broad-spectrum Notch inhibitor, but it has serious side effects. The efficacy of Notch3-specific inhibition in paclitaxel-resistant ovarian cancers was assessed in this study, which has not yet been evaluated relative to GSI. To analyze the effect of Notch3-specific inhibition on paclitaxel-resistant ovarian cancers, we compared cell viability, apoptosis, cell migration, angiogenesis, cell cycle, and spheroid formation after treatment with either Notch3 siRNA or GSI in paclitaxel-resistant SKpac cells and parental SKOV3 cells. Expression levels of survival, cell cycle, and apoptosis-related proteins were measured and compared between groups. Notch3 was significantly overexpressed in chemoresistant cancer tissues and cell lines relative to chemosensitive group. In paclitaxel-resistant cancer cells, Notch inhibition significantly reduced viability, migration, and angiogenesis and increased apoptosis, thereby boosting sensitivity to paclitaxel. Spheroid formation was also significantly reduced. Both Notch3 siRNA-treated cells and GSI-treated cells arrested in the G2/M phase of the cell cycle. Proteins of cell survival, cyclin D1 and cyclin D3 were reduced, whereas p21 and p27 were elevated. Both GSI and Notch3 siRNA treatment reduced expression of anti-apoptotic proteins (BCL-W, BCL2, and BCL-XL) and increased expression of pro-apoptotic proteins (Bad, Bak, Bim, Bid, and Bax). These results indicate that Notch3-specific inhibition sensitizes paclitaxel-resistant cancer cells to paclitaxel treatment, with an efficacy comparable to that of GSI. This approach would be likely to avoid the side effects of broad-spectrum GSI treatment. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  18. Phenotypic Plasticity Determines Cancer Stem Cell Therapeutic Resistance in Oral Squamous Cell Carcinoma.

    PubMed

    Biddle, Adrian; Gammon, Luke; Liang, Xiao; Costea, Daniela Elena; Mackenzie, Ian C

    2016-02-01

    Cancer stem cells (CSCs) drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC), we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44(high)EpCAM(low/-) CD24(+) cell surface marker profile. Treatment with TGFβ and retinoic acid (RA) enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER) stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs.

  19. Phenotypic Plasticity Determines Cancer Stem Cell Therapeutic Resistance in Oral Squamous Cell Carcinoma

    PubMed Central

    Biddle, Adrian; Gammon, Luke; Liang, Xiao; Costea, Daniela Elena; Mackenzie, Ian C.

    2016-01-01

    Cancer stem cells (CSCs) drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC), we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44highEpCAMlow/− CD24+ cell surface marker profile. Treatment with TGFβ and retinoic acid (RA) enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER) stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs. PMID:26981578

  20. Induction of taxol metabolism in the rat by dexamethasone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anderson, C.D.; Gondi, K.N.; Walle, T.

    1994-12-31

    The antitumor drug taxol was metabolized to two major metabolites (RM1 and RM2) in adult male and female rat liver microsomes. The male rats produced RM1 2.6 fold faster than the females, and they produced RM2 3 fold faster than the females. This correlated well with the sex differences noticed in liver microsomal cytochrome P450 (CYP) 3A content (4.4 fold greater in male) and 6{beta}-hydroxylation of testosterone (2.4 fold greater in male). Taxol was metabolized to three major metabolites (RM1, RM2, and RM3) in adult male and female rat liver microsomes from rats pretreated with dexamethasone. Production of RM1 andmore » RM2 was increased in these rats (2.3 and 3.3 fold respectively in males; 6.5 and 8.7 fold respectively in females) as compared to the untreated rats. These results compared well with the induction of CYP 3A proteins (3.5 fold in male, 10 fold in female) and induction of 6{beta}-hydroxylation (1.9 fold in males, 3.8 fold in females). RM3, which was produced only by the rats pretreated with dexamethasone, had a retention time of 0.58 relative to taxol which corresponds to 6{alpha}- hydroxytaxol, the major human metabolite of taxol. This study indicates that taxol metabolism in the rat is likely due to CYP 3A enzymes. Although the evidence points toward CYP 3A1 as the major isoform involved, it does not rule out others. The findings also suggest that CYP 3A1 is responsible for the induced metabolite, RM3.« less

  1. Trastuzumab-Resistant Luminal B Breast Cancer Cells Show Basal-Like Cell Growth Features Through NF-κB-Activation

    PubMed Central

    Kanzaki, Hirotaka; Mukhopadhya, Nishit K.; Cui, Xiaojiang; Ramanujan, V. Krishnan

    2016-01-01

    A major clinical problem in the treatment of breast cancer is mortality due to metastasis. Understanding the molecular mechanisms associated with metastasis should aid in designing new therapeutic approaches for breast cancer. Trastuzumab is the main therapeutic option for HER2+ breast cancer patients; however, the molecular basis for trastuzumab resistance (TZR) and subsequent metastasis is not known. Earlier, we found expression of basal-like molecular markers in TZR tissues from patients with invasive breast cancer.(1) The basal-like phenotype is a particularly aggressive form of breast cancer. This observation suggests that TZR might contribute to an aggressive phenotype. To understand if resistance to TZR can lead to basal-like phenotype, we generated a trastuzumab-resistant human breast cancer cell line (BT-474-R) that maintained human epidermal growth factor receptor 2 (HER2) overexpression and HER2 mediated signaling. Analysis showed that nuclear factor-kappa B (NF-κB) was constitutively activated in the BT-474-R cells, a feature similar to the basal-like tumor phenotype. Pharmacologic inhibition of NF-κB improved sensitivity of BT-474-R cells to trastuzumab. Interestingly, activation of HER2 independent NF-κB is not shown in luminal B breast cancer cells. Our study suggests that by activating the NF-κB pathway, luminal B cells may acquire a HER2+ basal-like phenotype in which NF-κB is constitutively activated; this notion is consistent with the recently proposed “progression through grade” or “evolution of resistance” hypothesis. Furthermore, we identified IKK-α/IKK-β and nuclear accumulation of RelA/p65 as the major determinants in the resistant cells. Thus our study additionally suggests that the nuclear accumulation of p65 may be a useful marker for identifying metastasis-initiating tumor cells and targeting RelA/p65 may limit metastasis of breast and other cancers associated with NF-κB activation. PMID:26871511

  2. Fibrocytes: A Novel Stromal Cells to Regulate Resistance to Anti-Angiogenic Therapy and Cancer Progression.

    PubMed

    Goto, Hisatsugu; Nishioka, Yasuhiko

    2017-12-29

    An adequate blood supply is essential for cancer cells to survive and grow; thus, the concept of inhibiting tumor angiogenesis has been applied to cancer therapy, and several drugs are already in clinical use. It has been shown that treatment with those anti-angiogenic drugs improved the response rate and prolonged the survival of patients with various types of cancer; however, it is also true that the effect was mostly limited. Currently, the disappointing clinical results are explained by the existence of intrinsic or acquired resistance to the therapy mediated by both tumor cells and stromal cells. This article reviews the mechanisms of resistance mediated by stromal cells such as endothelial cells, pericytes, fibroblasts and myeloid cells, with an emphasis on fibrocytes, which were recently identified as the cell type responsible for regulating acquired resistance to anti-angiogenic therapy. In addition, the other emerging role of fibrocytes as mediator-producing cells in tumor progression is discussed.

  3. Furanodiene Induces Extrinsic and Intrinsic Apoptosis in Doxorubicin-Resistant MCF-7 Breast Cancer Cells via NF-κB-Independent Mechanism.

    PubMed

    Zhong, Zhang-Feng; Yu, Hai-Bing; Wang, Chun-Ming; Qiang, Wen-An; Wang, Sheng-Peng; Zhang, Jin-Ming; Yu, Hua; Cui, Liao; Wu, Tie; Li, De-Qiang; Wang, Yi-Tao

    2017-01-01

    Chemotherapy is used as a primary approach in cancer treatment after routine surgery. However, chemo-resistance tends to occur when chemotherapy is used clinically, resulting in poor prognosis and recurrence. Currently, Chinese medicine may provide insight into the design of new therapies to overcome chemo-resistance. Furanodiene, as a heat-sensitive sesquiterpene, is isolated from the essential oil of Rhizoma Curcumae . Even though mounting evidence claiming that furanodiene possesses anti-cancer activities in various types of cancers, the underlying mechanisms against chemo-resistant cancer are not fully clear. Our study found that furanodiene could display anti-cancer effects by inhibiting cell viability, inducing cell cytotoxicity, and suppressing cell proliferation in doxorubicin-resistant MCF-7 breast cancer cells. Furthermore, furanodiene preferentially causes apoptosis by interfering with intrinsic/extrinsic-dependent and NF-κB-independent pathways in doxorubicin-resistant MCF-7 cells. These observations also prompt that furanodiene may be developed as a promising natural product for multidrug-resistant cancer therapy in the future.

  4. Role of long non-coding RNA in drug resistance in non-small cell lung cancer.

    PubMed

    Wang, Leirong; Ma, Leina; Xu, Fei; Zhai, Wenxin; Dong, Shenghua; Yin, Ling; Liu, Jia; Yu, Zhuang

    2018-05-03

    Lung cancer is the leading cause of cancer-associated death, and non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancer cases. Many drugs have been used to treat NSCLC in order to improve patient prognosis. Platinum-based chemotherapy is the first-line treatment for locally advanced or metastatic patients. For patients with activating EGFR mutations, tyrosine kinase inhibitors are the best treatment choice. NSCLC initially exhibits an excellent response to treatment; however, acquired resistance has been observed in many patients, leading to ineffective treatment. Clinical resistance is an impediment in the treatment of patients with advanced NSCLC. Many sequencing technologies have shown that long non-coding RNA (lncRNA) is expressed differently between drug-resistant and drug-sensitive lung cancer cells. We review the literature on lncRNA in drug resistance of NSCLC. The aim of this review is to gain insight into the molecular mechanisms of drug resistance, mainly focusing on the role of lncRNA in NSCLC. © 2018 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  5. Transformation of taxol-producing endophytic fungi by restriction enzyme-mediated integration (REMI).

    PubMed

    Wang, Yechun; Guo, Binhui; Miao, Zhiqi; Tang, Kexuan

    2007-08-01

    The REMI method was used to introduce the plasmid pV2 harboring the hygromycin B phosphotransferase (hph) gene controlled by the Aspergillus nidulans trpC promoter and the trpC terminator into a taxol-producing endophytic fungus BT2. REMI transformation yielded stable transformants capable of continuing to grow on PDA medium containing 125 mug mL(-1) hygromycin B. The transformation efficiency was about 5-6 transformants mug(-1) plasmid DNA. The presence of hph gene in transformants was confirmed by PCR and Southern blot analyses. To the authors' knowledge, this is the first report on the transformation of taxol-producing endophytic fungi by the REMI technique. This study provides an effective approach for improving taxol production of endophytic fungi by the genetic engineering of taxol biosynthetic pathway genes in the future.

  6. Red Maca (Lepidium meyenii) did not affect cell viability despite increased androgen receptor and prostate-specific antigen gene expression in the human prostate cancer cell line LNCaP.

    PubMed

    Díaz, P; Cardenas, H; Orihuela, P A

    2016-10-01

    We examined whether aqueous extract of Lepidium meyenii (red Maca) could inhibit growth, potentiate apoptotic activity of two anticancer drugs Taxol and 2-methoxyestradiol (2ME) or change mRNA expression for the androgen target genes, androgen receptor (Ar) and prostate-specific antigen (Psa) in the human prostate cancer cell line LNCaP. Red Maca aqueous extract at 0, 10, 20, 40 or 80 μg/ml was added to LNCaP cells, and viability was evaluated by the MTS assay at 24 or 48 hr after treatment. Furthermore, LNCaP cells were treated with 80 μg/ml of red Maca plus Taxol or 2ME 5 μM and viability was assessed 48 hr later. Finally, LNCaP cells were treated with red Maca 0, 20, 40 or 80 μg/ml, and 12 hr later, mRNA level for Ar or Psa was assessed by real-time PCR. Treatment with red Maca did not affect viability of LNCaP cells. Apoptotic activity induced by Taxol and 2ME in LNCaP cells was not altered with red Maca treatment. Relative expression of the mRNA for Ar and Psa increased with red Maca 20 and 40 μg/ml, but not at 80 μg/ml. We conclude that red Maca aqueous extract does not have toxic effects, but stimulates androgen signalling in LNCaP cells. © 2016 Blackwell Verlag GmbH.

  7. Droplet-based microtumor model to assess cell-ECM interactions and drug resistance of gastric cancer cells.

    PubMed

    Jang, Minjeong; Koh, Ilkyoo; Lee, Seok Jae; Cheong, Jae-Ho; Kim, Pilnam

    2017-01-27

    Gastric cancer (GC) is a common aggressive malignant tumor with high incidence and mortality worldwide. GC is classified into intestinal and diffuse types according to the histo-morphological features. Because of distinctly different clinico-pathological features, new cancer therapy strategies and in vitro preclinical models for the two pathological variants of GC is necessary. Since extracellular matrix (ECM) influence the biological behavior of tumor cells, we hypothesized that GC might be more similarly modeled in 3D with matrix rather than in 2D. Herein, we developed a microfluidic-based a three-dimensional (3D) in vitro gastric cancer model, with subsequent drug resistance assay. AGS (intestinal type) and Hs746T (diffuse type) gastric cancer cell lines were encapsulated in collagen beads with high cellular viability. AGS exhibited an aggregation pattern with expansive growth, whereas Hs746T showed single-cell-level infiltration. Importantly, in microtumor models, epithelial-mesenchymal transition (EMT) and metastatic genes were upregulated, whereas E-cadherin was downregulated. Expression of ß-catenin was decreased in drug-resistant cells, and chemosensitivity toward the anticancer drug (5-FU) was observed in microtumors. These results suggest that in vitro microtumor models may represent a biologically relevant platform for studying gastric cancer cell biology and tumorigenesis, and for accelerating the development of novel therapeutic targets.

  8. TXNL1-XRCC1 pathway regulates cisplatin-induced cell death and contributes to resistance in human gastric cancer

    PubMed Central

    Xu, W; Wang, S; Chen, Q; Zhang, Y; Ni, P; Wu, X; Zhang, J; Qiang, F; Li, A; Røe, O D; Xu, S; Wang, M; Zhang, R; Zhou, J

    2014-01-01

    Cisplatin is a cytotoxic platinum compound that triggers DNA crosslinking induced cell death, and is one of the reference drugs used in the treatment of several types of human cancers including gastric cancer. However, intrinsic or acquired drug resistance to cisplatin is very common, and leading to treatment failure. We have recently shown that reduced expression of base excision repair protein XRCC1 (X-ray repair cross complementing group1) in gastric cancerous tissues correlates with a significant survival benefit from adjuvant first-line platinum-based chemotherapy. In this study, we demonstrated the role of XRCC1 in repair of cisplatin-induced DNA lesions and acquired cisplatin resistance in gastric cancer by using cisplatin-sensitive gastric cancer cell lines BGC823 and the cisplatin-resistant gastric cancer cell lines BGC823/cis-diamminedichloridoplatinum(II) (DDP). Our results indicated that the protein expression of XRCC1 was significantly increased in cisplatin-resistant cells and independently contributed to cisplatin resistance. Irinotecan, another chemotherapeutic agent to induce DNA damaging used to treat patients with advanced gastric cancer that progressed on cisplatin, was found to inhibit the expression of XRCC1 effectively, and leading to an increase in the sensitivity of resistant cells to cisplatin. Our proteomic studies further identified a cofactor of 26S proteasome, the thioredoxin-like protein 1 (TXNL1) that downregulated XRCC1 in BGC823/DDP cells via the ubiquitin-proteasome pathway. In conclusion, the TXNL1-XRCC1 is a novel regulatory pathway that has an independent role in cisplatin resistance, indicating a putative drug target for reversing cisplatin resistance in gastric cancer. PMID:24525731

  9. Targeting cancer stem cell-specific markers and/or associated signaling pathways for overcoming cancer drug resistance.

    PubMed

    Ranji, Peyman; Salmani Kesejini, Tayyebali; Saeedikhoo, Sara; Alizadeh, Ali Mohammad

    2016-10-01

    Cancer stem cells (CSCs) are a small subpopulation of tumor cells with capabilities of self-renewal, dedifferentiation, tumorigenicity, and inherent chemo-and-radio therapy resistance. Tumor resistance is believed to be caused by CSCs that are intrinsically challenging to common treatments. A number of CSC markers including CD44, CD133, receptor tyrosine kinase, aldehyde dehydrogenases, epithelial cell adhesion molecule/epithelial specific antigen, and ATP-binding cassette subfamily G member 2 have been proved as the useful targets for defining CSC population in solid tumors. Furthermore, targeting CSC markers through new therapeutic strategies will ultimately improve treatments and overcome cancer drug resistance. Therefore, the identification of novel strategies to increase sensitivity of CSC markers has major clinical implications. This review will focus on the innovative treatment methods such as nano-, immuno-, gene-, and chemotherapy approaches for targeting CSC-specific markers and/or their associated signaling pathways.

  10. MicroRNA expressions associated with progression of prostate cancer cells to antiandrogen therapy resistance

    PubMed Central

    2014-01-01

    Background Development of resistance to androgen deprivation therapy (ADT) is a major obstacle for the management of advanced prostate cancer. Therapies with androgen receptor (AR) antagonists and androgen withdrawal initially regress tumors but development of compensatory mechanisms including AR bypass signaling leads to re-growth of tumors. MicroRNAs (miRNAs) are small regulatory RNAs that are involved in maintenance of cell homeostasis but are often altered in tumor cells. Results In this study, we determined the association of genome wide miRNA expression (1113 unique miRNAs) with development of resistance to ADT. We used androgen sensitive prostate cancer cells that progressed to ADT and AR antagonist Casodex (CDX) resistance upon androgen withdrawal and treatment with CDX. Validation of expression of a subset of 100 miRNAs led to identification of 43 miRNAs that are significantly altered during progression of cells to treatment resistance. We also show a correlation of altered expression of 10 proteins targeted by some of these miRNAs in these cells. Conclusions We conclude that dynamic alterations in miRNA expression occur early on during androgen deprivation therapy, and androgen receptor blockade. The cumulative effect of these altered miRNA expression profiles is the temporal modulation of multiple signaling pathways promoting survival and acquisition of resistance. These early events are driving the transition to castration resistance and cannot be studied in already developed CRPC cell lines or tissues. Furthermore our results can be used a prognostic marker of cancers with a potential to be resistant to ADT. PMID:24387052

  11. ERK/p38 MAPK inhibition reduces radio-resistance to a pulsed proton beam in breast cancer stem cells

    NASA Astrophysics Data System (ADS)

    Jung, Myung-Hwan; Park, Jeong Chan

    2015-10-01

    Recent studies have identified highly tumorigenic cells with stem cell-like characteristics, termed cancer stem cells (CSCs) in human cancers. CSCs are resistant to conventional radiotherapy and chemotherapy owing to their high DNA repair ability and oncogene overexpression. However, the mechanisms regulating CSC radio-resistance, particularly proton beam resistance, remain unclear. We isolated CSCs from the breast cancer cell lines MCF-7 and MDA-MB-231, which expressed the characteristic breast CSC membrane protein markers CD44+/CD24-/ low , and irradiated the CSCs with pulsed proton beams. We confirmed that CSCs were resistant to pulsed proton beams and showed that treatment with p38 and ERK inhibitors reduced CSC radio-resistance. Based on these results, BCSC radio-resistance can be reduced during proton beam therapy by co-treatment with ERK1/2 or p38 inhibitors, a novel approach to breast cancer therapy.

  12. Bypass Mechanisms of the Androgen Receptor Pathway in Therapy-Resistant Prostate Cancer Cell Models

    PubMed Central

    Marques, Rute B.; Dits, Natasja F.; Erkens-Schulze, Sigrun; van Weerden, Wytske M.; Jenster, Guido

    2010-01-01

    Background Prostate cancer is initially dependent on androgens for survival and growth, making hormonal therapy the cornerstone treatment for late-stage tumors. However, despite initial remission, the cancer will inevitably recur. The present study was designed to investigate how androgen-dependent prostate cancer cells eventually survive and resume growth under androgen-deprived and antiandrogen supplemented conditions. As model system, we used the androgen-responsive PC346C cell line and its therapy-resistant sublines: PC346DCC, PC346Flu1 and PC346Flu2. Methodology/Principal Findings Microarray technology was used to analyze differences in gene expression between the androgen-responsive and therapy-resistant PC346 cell lines. Microarray analysis revealed 487 transcripts differentially-expressed between the androgen-responsive and the therapy-resistant cell lines. Most of these genes were common to all three therapy-resistant sublines and only a minority (∼5%) was androgen-regulated. Pathway analysis revealed enrichment in functions involving cellular movement, cell growth and cell death, as well as association with cancer and reproductive system disease. PC346DCC expressed residual levels of androgen receptor (AR) and showed significant down-regulation of androgen-regulated genes (p-value = 10−7). Up-regulation of VAV3 and TWIST1 oncogenes and repression of the DKK3 tumor-suppressor was observed in PC346DCC, suggesting a potential AR bypass mechanism. Subsequent validation of these three genes in patient samples confirmed that expression was deregulated during prostate cancer progression. Conclusions/Significance Therapy-resistant growth may result from adaptations in the AR pathway, but androgen-independence may also be achieved by alternative survival mechanisms. Here we identified TWIST1, VAV3 and DKK3 as potential players in the bypassing of the AR pathway, making them good candidates as biomarkers and novel therapeutical targets. PMID:20976069

  13. Anti-cancer Effects of Polyphenolic Compounds in Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor-resistant Non-small Cell Lung Cancer

    PubMed Central

    Jeong, Hyungmin; Phan, Ai N. H.; Choi, Jong-Whan

    2017-01-01

    Background: Polyphenolic phytochemicals are natural compounds, easily found in fruits and vegetables. Importantly, polyphenols have been intensively studied as excellent antioxidant activity which contributes to anticancer function of the natural compounds. Lung cancer has been reported to mainly account for cancer-related deaths in the world. Moreover, epidermal growth factor receptor tyrosine kinase inhibitor (TKI) resistance is one of the biggest issues in cancer treatment, especially in nonsmall cell lung cancer (NSCLC). Even though several studies both in preclinical and clinical trials have showed promising therapeutic effects of polyphenolic compounds in anticancer therapy, the function of the natural compounds in TKI-resistant (TKIR) lung cancer remains poorly studied. Objective: The aim of this study is to screen polyphenolic compounds as potential anticancer adjuvants which suppress TKIR lung cancer. Materials and Methods: Colony formation and thiazolyl blue tetrazolium blue assay were performed in the pair-matched TKI-sensitive (TKIS) versus TKIR tumor cell lines to investigate the therapeutic effect of polyphenolic compounds in TKIR NSCLC. Results: Our data show that equol, kaempferol, resveratrol, and ellagic acid exhibit strong anticancer effect in HCC827 panel. Moreover, the inhibitory effect of most of tested polyphenolic compounds was highly selective for TKIR lung cancer cell line H1993 while sparing the TKIS one H2073. Conclusion: This study provides an important screening of potential polyphenolic compounds for drug development to overcome TKI resistance in advanced lung cancer. SUMMARY The study provides an important screening of potential polyphenolic compounds for drug development to overcome tyrosine kinase inhibitor (TKI) resistance in advance lung cancerEquol, kaempferol, resveratrol, and ellagic acid show strong anticancer effect in HCC827 panel, including TKI-sensitive (TKIS) and TKI-resistant clonesThe inhibitory effect of polyphenolic

  14. Evaluation of Radiation Response and Gold Nanoparticle Enhancement in Drug-Resistant Pancreatic Cancer Cells

    NASA Astrophysics Data System (ADS)

    Abourabia, Assya

    Pancreatic cancer is a major cause of cancer-related death worldwide after lung cancer and colorectal cancer Pancreatic treatment modalities consist of surgery, chemotherapy, and radiation therapy or combination of these therapies. These modalities are good to some extents but they do have some limitations. For example, during the chemotherapy, tumor cells can develop some escape mechanisms and become chemoresistant to protect themselves against the chemo drugs and pass on theses escape mechanisms to their offspring, despite the treatment given. Cancer Cells can become chemoresistant by many mechanisms, for example, decreased drug influx mechanisms, decreased of drug transport molecules, decreased drug activation, altered drug metabolism that diminishes the capacity of cytotoxic drugs, and enhanced repair of DNA damage. Given that some of these chemoresistance mechanisms may impact sensitivity to radiation. Therefore, there is a strong need for a new alternative treatment option to amplify the therapeutic efficacy of radiotherapy and eventually increase the overall efficacy of cancer treatment. Nano-radiation therapy is an emerging and promising modality aims to enhance the therapeutic efficacy of radiotherapy through the use of radiosensitizing nanoparticles. The primary goal of using GNP-enhanced radiation is that GNPs are potent radiosensitizer agents that sensitize the tumor cells to radiation, and these agents promote generation of the free radicals produced by Photo- and Auger- electrons emission at the molecular level which can enhance the effectiveness of radiation-induced cancer cell death. The main aim of this research is to analyze and compare the response to radiation of pancreatic cancer cells, PANC-1, and PANC-1 cells that are resistant to oxaliplatin, PANC-1/OR, and investigate the radiation dose enhancement effect attributable to GNP when irradiating the cells with low-energy (220 kVp) beam at various doses. Based on evidence from the existing

  15. Multivalent Peptoid Conjugates Which Overcome Enzalutamide Resistance in Prostate Cancer Cells.

    PubMed

    Wang, Yu; Dehigaspitiya, Dilani C; Levine, Paul M; Profit, Adam A; Haugbro, Michael; Imberg-Kazdan, Keren; Logan, Susan K; Kirshenbaum, Kent; Garabedian, Michael J

    2016-09-01

    Development of resistance to antiandrogens for treating advanced prostate cancer is a growing concern and extends to recently developed therapeutics, including enzalutamide. Therefore, new strategies to block androgen receptor (AR) function in prostate cancer are required. Here, we report the characterization of a multivalent conjugate presenting two bioactive ethisterone ligands arrayed as spatially defined pendant groups on a peptoid oligomer. The conjugate, named Multivalent Peptoid Conjugate 6 (MPC6), suppressed the proliferation of multiple AR-expressing prostate cancer cell lines including those that failed to respond to enzalutamide and ARN509. The structure-activity relationships of MPC6 variants were evaluated, revealing that increased spacing between ethisterone moieties and changes in peptoid topology eliminated its antiproliferative effect, suggesting that both ethisterone ligand presentation and scaffold characteristics contribute to MPC6 activity. Mechanistically, MPC6 blocked AR coactivator-peptide interaction and prevented AR intermolecular interactions. Protease sensitivity assays suggested that the MPC6-bound AR induced a receptor conformation distinct from that of dihydrotestosterone- or enzalutamide-bound AR. Pharmacologic studies revealed that MPC6 was metabolically stable and displayed a low plasma clearance rate. Notably, MPC6 treatment reduced tumor growth and decreased Ki67 and AR expression in mouse xenograft models of enzalutamide-resistant LNCaP-abl cells. Thus, MPC6 represents a new class of compounds with the potential to combat treatment-resistant prostate cancer. Cancer Res; 76(17); 5124-32. ©2016 AACR. ©2016 American Association for Cancer Research.

  16. Requirement of T-lymphokine-activated killer cell-originated protein kinase for TRAIL resistance of human HeLa cervical cancer cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kwon, Hyeok-Ran; Lee, Ki Won; Dong, Zigang

    2010-01-01

    T-lymphokine-activated killer cell-originated protein kinase (TOPK) appears to be highly expressed in various cancer cells and to play an important role in maintaining proliferation of cancer cells. However, the underlying mechanism by which TOPK regulates growth of cancer cells remains elusive. Here we report that upregulated endogenous TOPK augments resistance of cancer cells to apoptosis induced by tumor necrosis factor-related apoptosis inducing ligand (TRAIL). Stable knocking down of TOPK markedly increased TRAIL-mediated apoptosis of human HeLa cervical cancer cells, as compared with control cells. Caspase 8 or caspase 3 activities in response to TRAIL were greatly incremented in TOPK-depleted cells.more » Ablation of TOPK negatively regulated TRAIL-mediated NF-{kappa}B activity. Furthermore, expression of NF-{kappa}B-dependent genes, FLICE-inhibitory protein (FLIP), inhibitor of apoptosis protein 1 (c-IAP1), or X-linked inhibitor of apoptosis protein (XIAP) was reduced in TOPK-depleted cells. Collectively, these findings demonstrated that TOPK contributed to TRAIL resistance of cancer cells via NF-{kappa}B activity, suggesting that TOPK might be a potential molecular target for successful cancer therapy using TRAIL.« less

  17. URI promotes gastric cancer cell motility, survival, and resistance to adriamycin in vitro.

    PubMed

    Hu, Xiaoxia; Zhang, Fei; Luo, Dongwei; Li, Na; Wang, Qian; Xu, Zhonghai; Bian, Huiqin; Liang, Yuting; Lu, Yaojuan; Zheng, Qiping; Gu, Junxia

    2016-01-01

    Unconventional prefoldin RPB5 interactor (URI), a RNA polymerase II Subunit 5-Interacting protein, is known to participate in the regulation of nutrient-sensitive mTOR-dependent transcription programs. Multiple studies have recently demonstrated that URI functions as an oncoprotein, possibly through the mTOR pathway, and regulates tumor cell motility, invasion, and metastasis. However, whether and how URI plays a role in gastric oncogenesis has not been elucidated. Due to drug resistance, recurrence and metastasis, the prognosis of gastric cancer remains poor. This study aims to explore the effects of URI on gastric cancer cells by focusing on their migratory ability and resistance to adriamycin. URI was over-expressed or knocked-down in MGC-803 and HGC-27 gastric cancer cells using URI plasmid or siRNA transfection approach. The cell viability, apoptosis, and migration ability were then examined by the CCK-8 assay, flow cytometer Annexin V/PI staining, and the Transwell cell migration assay respectively. The protein levels of apoptosis and EMT related genes were detected by western blot. The results showed that overexpression of URI promoted while knock-down of URI inhibited gastric cancer cell proliferation. URI overexpression resulted in increased Bcl-2 expression but decreased levels of Bax, cleaved PARP-1 and cleaved caspase-3. Conversely, cells treated with URI siRNA showed increased adriamycin induced apoptosis, along with reduced Bcl-2, but increased Bax, cleaved PARP-1 and cleaved caspase-3 expression. We have also shown that overexpression of URI enhanced cancer cell proliferation and migration with higher levels of Snail and Vimentin, whereas knockdown of URI in MGC-803 and HGC-27 cells inhibited proliferation and migration with decreased Snail and Vimentin expression. Together, our results support that URI promotes cell survival and mobility and acts as a chemotherapeutics resistant protein in MGC-803 and HGC-27 cells. URI might be a potential biomarker

  18. Curcumin reverses irinotecan resistance in colon cancer cell by regulation of epithelial-mesenchymal transition.

    PubMed

    Zhang, Chunhong; Xu, Yangjie; Wang, Haowen; Li, Gang; Yan, Han; Fei, Zhenghua; Xu, Yunsheng; Li, Wenfeng

    2018-04-01

    The objective of this study was to investigate the effect and the mechanism by which curcumin reverses irinotecan-induced chemotherapy resistance in colon cancer. Construction of irinotecan-resistant colon cancer model LoVo/CPT-11R cells was performed by increasing drug concentration. The Cell Counting Kit-8 assay was used to detect inhibition of proliferation; cell morphology was observed by an optical microscope. Quantitative RT-PCR and western blotting were performed to detect molecular marker expressions during epithelial-mesenchymal transition (EMT); drug-resistant cells were treated with curcumin at different concentrations and Cell Counting Kit-8 was reperformed to detect cell proliferation after treatments. Drug-resistant cells were then divided into four groups: control group, irinotecan group, curcumin group, and irinotecan+curcumin group; quantitative RT-PCR and western blotting were performed to detect molecular marker expressions during epithelial-mesenchymal transition. Flow cytometry was used to detect cell apoptosis after grouping, and apoptosis-related protein was detected by western blotting. LoVo/CPT-11R cells could survive in culture medium containing irinotecan at 60 μg/ml and the drug-resistance index was 5.69; the drug-resistant cells had a larger volume than normal cells and were poorly connected to each other. E-cadherin expression was downregulated, whereas vimentin and N-cadherin expressions were upregulated. After curcumin treatment, drug-resistant cell proliferation was significantly inhibited; in the curcumin+irinotecan treatment group, E-cadherin expression was upregulated, whereas vimentin and N-cadherin expressions were downregulated. Curcumin could significantly increase cell apoptosis. EMT is involved in the development of irinotecan resistance and curcumin can reverse this drug resistance through reversion of the EMT process.

  19. Cytokeratin 5 positive cells represent a therapy resistant subpopulation in epithelial ovarian cancer

    PubMed Central

    Corr, Bradley R.; Finlay-Schultz, Jessica; Rosen, Rachel B.; Qamar, Lubna; Post, Miriam D.; Behbakht, Kian; Spillman, Monique A.; Sartorius, Carol A.

    2015-01-01

    Objective Cytokeratin 5 (CK5) is an epithelial cell marker implicated in stem and progenitor cell activity in glandular reproductive tissues and endocrine and chemotherapy resistance in estrogen receptor (ER)+ breast cancer. The goal of this study was to determine the prevalence of CK5 expression in ovarian cancer and the response of CK5+ cell populations to cisplatin therapy. Materials and Methods CK5 expression was evaluated in two ovarian tissue microarrays, representing 137 neoplasms, and six ovarian cancer cell lines. Cell lines were treated with IC50 cisplatin and the prevalence of CK5+ cells pre- and post-treatment determined. Proliferation of CK5+ vs. CK5− cell populations was determined using bromodeoxyuridine (BrdU) incorporation. Chemotherapy induced apoptosis in CK5+ vs. CK5− cells was measured using immunohistochemical staining for cleaved caspase-3. Results CK5 was expressed in 39.3% (42/107) of epithelial ovarian cancers with a range of 1-80% positive cells. Serous and endometrioid histologic subtypes had the highest percentage of CK5+ specimens. CK5 expression correlated with ER positivity (38/42 CK5+ tumors were also ER+). CK5 was expressed in 5/6 overall and 4/4 ER+ epithelial ovarian cancer cell lines ranging from 2.4-52.7% positive cells. CK5+ compared to CK5− cells were slower proliferating. The prevalence of CK5+ cells increased following 48 hour cisplatin treatment in 4/5 cell lines tested. CK5+ compared to CK5− ovarian cancer cells were more resistant to cisplatin induced apoptosis. Conclusions CK5 is expressed in a significant proportion of epithelial ovarian cancers and represents a slower proliferating, chemoresistant subpopulation that may warrant co-targeting in combination therapy. PMID:26495758

  20. β-D-glucan inhibits endocrine-resistant breast cancer cell proliferation and alters gene expression

    PubMed Central

    JAFAAR, ZAINAB M.T.; LITCHFIELD, LACEY M.; IVANOVA, MARGARITA M.; RADDE, BRANDIE N.; AL-RAYYAN, NUMAN; KLINGE, CAROLYN M.

    2014-01-01

    Endocrine therapies have been successfully used for breast cancer patients with estrogen receptor α (ERα) positive tumors, but ∼40% of patients relapse due to endocrine resistance. β-glucans are components of plant cell walls that have immunomodulatory and anticancer activity. The objective of this study was to examine the activity of β-D-glucan, purified from barley, in endocrine-sensitive MCF-7 versus endocrine-resistant LCC9 and LY2 breast cancer cells. β-D-glucan dissolved in DMSO but not water inhibited MCF-7 cell proliferation in a concentration-dependent manner as measured by BrdU incorporation with an IC50 of ∼164±12 μg/ml. β-D-glucan dissolved in DMSO inhibited tamoxifen/endocrine-resistant LCC9 and LY2 cell proliferation with IC50 values of 4.6±0.3 and 24.2±1.4 μg/ml, respectively. MCF-10A normal breast epithelial cells showed a higher IC50 ∼464 μg/ml and the proliferation of MDA-MB-231 triple negative breast cancer cells was not inhibited by β-D-glucan. Concentration-dependent increases in the BAX/BCL2 ratio and cell death with β-D-glucan were observed in MCF-7 and LCC9 cells. PCR array analysis revealed changes in gene expression in response to 24-h treatment with 10 or 50 μg/ml β-D-glucan that were different between MCF-7 and LCC9 cells as well as differences in basal gene expression between the two cell lines. Select results were confirmed by quantitative real-time PCR demonstrating that β-D-glucan increased RASSF1 expression in MCF-7 cells and IGFBP3, CTNNB1 and ERβ transcript expression in LCC9 cells. Our data indicate that β-D-glucan regulates breast cancer-relevant gene expression and may be useful for inhibiting endocrine-resistant breast cancer cell proliferation. PMID:24534923

  1. Amino Acid Profiling of Zinc Resistant Prostate Cancer Cell Lines: Associations With Cancer Progression.

    PubMed

    Kratochvilova, Monika; Raudenska, Martina; Heger, Zbynek; Richtera, Lukas; Cernei, Natalia; Adam, Vojtech; Babula, Petr; Novakova, Marie; Masarik, Michal; Gumulec, Jaromir

    2017-05-01

    Failure in intracellular zinc accumulation is a key process in prostate carcinogenesis. Nevertheless, epidemiological studies of zinc administration have provided contradicting results. In order to examine the impact of the artificial intracellular increase of zinc(II) ions on prostate cancer metabolism, PNT1A, 22Rv1, and PC-3 prostatic cell lines-depicting different stages of cancer progression-and their zinc-resistant counterparts were used. To determine "benign" and "malignant" metabolic profiles, amino acid patterns, gene expression, and antioxidant capacity of these cell lines were assessed. Amino acid profiles were examined using an ion-exchange liquid chromatography. Intracellular zinc content was measured by atomic absorption spectrometry. Metallothionein was quantified using differential pulse voltammetry. The content of reduced glutathione was determined using high performance liquid chromatography coupled with an electrochemical detector. Cellular antioxidant capacity was determined by the ABTS test and gene expression analysis was performed by qRT-PCR. Long-term zinc treatment was shown to reroute cell metabolism from benign to more malignant type. Long-term application of high concentration of zinc(II) significantly enhanced cisplatin resistance, invasiveness, cellular antioxidant capacity, synthesis of glutathione, and expression of treatment resistance- and stemness-associated genes (SOX2, POU5F1, BIRC5). Tumorous cell lines universally displayed high accumulation of aspartate and sarcosine and depletion of essential amino acids. Increased aspartate/threonine, aspartate/methionine, and sarcosine/serine ratios were associated with cancer phenotype with high levels of sensitivity and specificity. Prostate 77: 604-616, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Metabolomics Analysis of Hormone-Responsive and Triple-Negative Breast Cancer Cell Responses to Paclitaxel Identify Key Metabolic Differences.

    PubMed

    Stewart, Delisha A; Winnike, Jason H; McRitchie, Susan L; Clark, Robert F; Pathmasiri, Wimal W; Sumner, Susan J

    2016-09-02

    To date, no targeted therapies are available to treat triple negative breast cancer (TNBC), while other breast cancer subtypes are responsive to current therapeutic treatment. Metabolomics was conducted to reveal differences in two hormone receptor-negative TNBC cell lines and two hormone receptor-positive Luminal A cell lines. Studies were conducted in the presence and absence of paclitaxel (Taxol). TNBC cell lines had higher levels of amino acids, branched-chain amino acids, nucleotides, and nucleotide sugars and lower levels of proliferation-related metabolites like choline compared with Luminal A cell lines. In the presence of paclitaxel, each cell line showed unique metabolic responses, with some similarities by type. For example, in the Luminal A cell lines, levels of lactate and creatine decreased while certain choline metabolites and myo-inositol increased with paclitaxel. In the TNBC cell lines levels of glutamine, glutamate, and glutathione increased, whereas lysine, proline, and valine decreased in the presence of drug. Profiling secreted inflammatory cytokines in the conditioned media demonstrated a greater response to paclitaxel in the hormone-positive Luminal cells compared with a secretion profile that suggested greater drug resistance in the TNBC cells. The most significant differences distinguishing the cell types based on pathway enrichment analyses were related to amino acid, lipid and carbohydrate metabolism pathways, whereas several biological pathways were differentiated between the cell lines following treatment.

  3. Involvement of RhoGDI2 in the resistance of colon cancer cells to 5-fluorouracil.

    PubMed

    Zheng, Zhong; Li, Jianfang; He, Xiangyi; Chen, Xuehua; Yu, Beiqin; Ji, Jun; Zhang, Jianian; Wang, Tingfeng; Gu, Qinlong; Zhu, Zhenggang; Liu, Bingya

    2010-01-01

    The acquisition of resistance to 5-FU is one of the most prominent obstacles to successful chemotherapy, and the mechanisms underlying the resistance are not fully understood. The aim of this study is to identify novel mediators of 5-FU resistance in colon cancer cells. LoVo colon cancer cells were induced to 5-FU resistance in vitro. The global protein profiles between LoVo and its 5-FU resistant derivative cell line LoVo/5-FU were analyzed by two dimensional gel electrophoresis-based comparative proteomics. The identified proteins expression was confirmed by Western blot analysis. The cytotoxicity of 5-FU was measured in LoVo/5-FU after knockdown of RhoGDI2 (one of the identified protien). Three differentially expressed proteins were identified. RhoGDI2 and CapG were upregulated, whereas proapoptotic protein Maspin was down-regulated in LoVo/5-FU and validated by Western blotting. Furthermore, knockdown of RhoGDI2 expression by transfection with the RhoGDI2-specific siRNA significantly reduced the resistance to 5-FU in LoVo/5-FU (p < 0.05). These novel data suggest that these differentially expressed proteins may contribute to the development of 5-FU resistance in colon cancer cells.

  4. Bcl-xL mediates therapeutic resistance of a mesenchymal breast cancer cell subpopulation

    PubMed Central

    Keitel, Ulrike; Scheel, Andreas; Thomale, Jürgen; Halpape, Rovena; Kaulfuß, Silke; Scheel, Christina; Dobbelstein, Matthias

    2014-01-01

    The transition from an epithelial to a mesenchymal phenotype (EMT) confers increased invasiveness and clonogenic potential to tumor cells. We used a breast epithelium-derived cell culture model to evaluate the impact of EMT on the cellular sensitivity towards chemotherapeutics and apoptotic stimuli. Cells that had passed through an EMT acquired resistance towards chemotherapeutics and death ligands. Mechanistically, we found that the levels of the apoptosis inhibitor Bcl-xL were strongly enhanced in mesenchymal versus epithelial cells, whereas the pro-apoptotic proteins Bim and Puma were diminished. Clinical samples from breast cancer showed enhanced Bcl-xL staining in cells that had dispersed into the desmoplastic stroma, as compared to cells that were part of large tumor cell aggregates, suggesting increased Bcl-xL expression when cells invade the stroma. Bcl-xL was necessary for apoptotic resistance in mesenchymal cells, and its expression was sufficient to confer such resistance to epithelial cells. To antagonize Bcl-xL, BH3-mimetics were used. They successfully interfered with the proliferation and survival of mesenchymal cells, and also inhibited the growth of xenograft tumors raised from the mesenchymal subpopulation. We conclude that enhanced Bcl-xL levels confer resistance to cells upon EMT, and that Bcl-xL represents a promising target for therapy directed against invasive cancer cells. PMID:25473892

  5. EphA2 affects the sensitivity of oxaliplatin by inducing EMT in oxaliplatin-resistant gastric cancer cells.

    PubMed

    Wen, Qiaocheng; Chen, Zihua; Chen, Zhikang; Chen, Jinxiang; Wang, Ran; Huang, Changhao; Yuan, Weijie

    2017-07-18

    Erythropoietin-producing hepatocellular receptor A2 (EphA2) is upregulated in gastric cancer tissues and cells, which is accompanied by epithelial-mesenchymal transition (EMT). The current study was designed to establish the oxaliplatin-resistant human gastric cancer cell line SGC-7901/L-OHP, to determine if EMT in these cells could be reversed, and to determine if the susceptibility of these cells to oxaliplatin was affected by silencing EphA2 expression. We found that EphA2 expression levels were upregulated in gastric cancer and associated with chemotherapy sensitivity. EphA2 and the EMT molecular markers N-cadherin and Snail were upregulated in SGC-7901/L-OHP cells, while silencing of EphA2 using small interfering RNA had the opposite effect. Moreover, silencing of EphA2 inhibited cell migration and invasion, and significantly enhanced the sensitivity of oxaliplatin-resistant gastric cancer cells to oxaliplatin. These observations demonstrate that EphA2 affects the sensitivity to oxaliplatin by inducing EMT in oxaliplatin-resistant gastric cancer cells.

  6. Elevated STAT3 Signaling-Mediated Upregulation of MMP-2/9 Confers Enhanced Invasion Ability in Multidrug-Resistant Breast Cancer Cells

    PubMed Central

    Zhang, Fei; Wang, Zhiyong; Fan, Yanling; Xu, Qiao; Ji, Wei; Tian, Ran; Niu, Ruifang

    2015-01-01

    The development of multidrug resistance greatly impedes effective cancer therapy. Recent advances in cancer research have demonstrated that acquisition of multidrug resistance by cancer cells is usually accompanied by enhanced cell invasiveness. Several lines of evidence indicated that cross activation of other signaling pathways during development of drug resistance may increase invasive potential of multidrug-resistant (MDR) cancer cells. However, the accurate mechanism of this process is largely undefined. In this study, to better understand the associated molecular pathways responsible for cancer progression induced by drug resistance, a MDR human breast cancer cell line SK-BR-3/EPR with P-glycoprotein overexpression was established using stepwise long-term exposure to increasing concentration of epirubicin. The SK-BR-3/EPR cell line exhibited decreased cell proliferative activity, but enhanced cell invasive capacity. We showed that the expression of metastasis-related matrix metalloproteinase (MMP)-2/9 was elevated in SK-BR-3/EPR cells. Moreover, SK-BR-3/EPR cells showed elevated activation of STAT3. Activation of STAT3 signaling is responsible for enhanced invasiveness of SK-BR-3/EPR cells through upregulation of MMP-2/9. STAT3 is a well-known oncogene and is frequently implicated in tumorigenesis and chemotherapeutic resistance. Our findings augment insight into the mechanism underlying the functional association between MDR and cancer invasiveness. PMID:26501276

  7. Role of Insulin-Like Growth Factor-1 Signaling Pathway in Cisplatin-Resistant Lung Cancer Cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sun Yunguang; Zheng Siyuan; Torossian, Artour

    2012-03-01

    Purpose: The development of drug-resistant phenotypes has been a major obstacle to cisplatin use in non-small-cell lung cancer. We aimed to identify some of the molecular mechanisms that underlie cisplatin resistance using microarray expression analysis. Methods and Materials: H460 cells were treated with cisplatin. The differences between cisplatin-resistant lung cancer cells and parental H460 cells were studied using Western blot, MTS, and clonogenic assays, in vivo tumor implantation, and microarray analysis. The cisplatin-R cells were treated with human recombinant insulin-like growth factor (IGF) binding protein-3 and siRNA targeting IGF-1 receptor. Results: Cisplatin-R cells illustrated greater expression of the markers CD133more » and aldehyde dehydrogenase, more rapid in vivo tumor growth, more resistance to cisplatin- and etoposide-induced apoptosis, and greater survival after treatment with cisplatin or radiation than the parental H460 cells. Also, cisplatin-R demonstrated decreased expression of insulin-like growth factor binding protein-3 and increased activation of IGF-1 receptor signaling compared with parental H460 cells in the presence of IGF-1. Human recombinant IGF binding protein-3 reversed cisplatin resistance in cisplatin-R cells and targeting of IGF-1 receptor using siRNA resulted in sensitization of cisplatin-R-cells to cisplatin and radiation. Conclusions: The IGF-1 signaling pathway contributes to cisplatin-R to cisplatin and radiation. Thus, this pathway represents a potential target for improved lung cancer response to treatment.« less

  8. Novel anticancer activity of phloroglucinol against breast cancer stem-like cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Rae-Kwon; Uddin, Nizam; Hyun, Jin-Won

    Poor prognosis of breast cancer patients is closely associated with metastasis and relapse. There is substantial evidence supporting that cancer stem-like cells (CSCs) are primarily responsible for relapse in breast cancer after anticancer treatment. However, there is a lack of suitable drugs that target breast cancer stem-like cells (BCSCs). Here, we report that phloroglucinol (PG), a natural phlorotannin component of brown algae, suppresses sphere formation, anchorage-independent colony formation and in vivo tumorigenicity. In line with these observations, treatment with PG also decreased CD44{sup +} cancer cell population as well as expression of CSC regulators such as Sox2, CD44, Oct4, Notch2more » and β-catenin. Also, treatment with PG sensitized breast cancer cells to anticancer drugs such as cisplatin, etoposide, and taxol as well as to ionizing radiation. Importantly, PG inhibited KRAS and its downstream PI3K/AKT and RAF-1/ERK signaling pathways that regulate the maintenance of CSCs. Taken together, our findings implicate PG as a good candidate to target BCSCs and to prevent the disease relapse. - Highlights: • Phloroglucinol suppresses in vivo tumor formation. • Phloroglucinol sensitizes breast cancer cells to anticancer agents. • Phloroglucinol inhibits breast cancer stem-like cells. • Phloroglucinol inhibits PI3K/AKT and KRAS/RAF/ERK signaling pathways.« less

  9. Broad targeting of resistance to apoptosis in cancer

    PubMed Central

    Mohammad, Ramzi M.; Muqbil, Irfana; Lowe, Leroy; Yedjou, Clement; Hsu, Hsue-Yin; Lin, Liang-Tzung; Siegelin, Markus David; Fimognari, Carmela; Kumar, Nagi B.; Dou, Q. Ping; Yang, Huanjie; Samadi, Abbas K.; Russo, Gian Luigi; Spagnuolo, Carmela; Ray, Swapan K.; Chakrabarti, Mrinmay; Morre, James D.; Coley, Helen M.; Honoki, Kanya; Fujii, Hiromasa; Georgakilas, Alexandros G.; Amedei, Amedeo; Niccolai, Elena; Amin, Amr; Ashraf, S. Salman; Helferich, William G.; Yang, Xujuan; Boosani, Chandra S.; Guha, Gunjan; Bhakta, Dipita; Ciriolo, Maria Rosa; Aquilano, Katia; Chen, Sophie; Mohammed, Sulma I.; Keith, W. Nicol; Bilsland, Alan; Halicka, Dorota; Nowsheen, Somaira; Azmi, Asfar S.

    2015-01-01

    Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer. PMID:25936818

  10. MicroRNA-128 suppresses paclitaxel-resistant lung cancer by inhibiting MUC1-C and BMI-1 in cancer stem cells.

    PubMed

    Koh, Hyebin; Park, Hyeri; Chandimali, Nisansala; Huynh, Do Luong; Zhang, Jiao Jiao; Ghosh, Mrinmoy; Gera, Meeta; Kim, Nameun; Bak, Yesol; Yoon, Do-Young; Park, Yang Ho; Kwon, Taeho; Jeong, Dong Kee

    2017-12-15

    The existence of cancer stem cells (CSCs) is the main reason for failure of cancer treatment caused by drug resistance. Therefore, eradicating cancers by targeting CSCs remains a significant challenge. In the present study, because of the important role of BMI-1 proto-oncogene, polycomb ring finger (BMI-1) and C-terminal Mucin1 (MUC1-C) in tumor growth and maintenance of CSCs, we aimed to confirm that microRNA miR-128, as an inhibitor of BMI-1 and MUC1-C, could effectively suppress paclitaxel (PTX)-resistant lung cancer stem cells. We showed that CSCs have significantly higher expression levels of BMI-1, MUC1-C, stemness proteins, signaling factors, and higher malignancy compared with normal tumor cells. After transfection with miR-128, the BMI-1 and MUC1-C levels in CSCs were suppressed. When miR-128 was stably expressed in PTX-resistant lung cancer stem cells, the cells showed decreased proliferation, metastasis, self-renewal, migration, invasive ability, clonogenicity, and tumorigenicity in vitro and in vivo and increased apoptosis compared with miR-NC (negative control) CSCs. Furthermore, miR-128 effectively decreased the levels of β-catenin and intracellular signaling pathway-related factors in CSCs. MiR-128 also decreased the luciferase activity of MUC1 reporter constructs and reduced the levels of transmembrane MUC1-C and BMI-1. These results suggested miR-128 as an attractive therapeutic strategy for PTX-resistant lung cancer via inhibition of BMI-1 and MUC1-C.

  11. miR-130a activates apoptotic signaling through activation of caspase-8 in taxane-resistant prostate cancer cells.

    PubMed

    Fujita, Yasunori; Kojima, Toshio; Kawakami, Kyojiro; Mizutani, Kosuke; Kato, Taku; Deguchi, Takashi; Ito, Masafumi

    2015-10-01

    The acquisition of drug resistance is one of the most malignant phenotypes of cancer and identification of its therapeutic target is a prerequisite for the development of novel therapy. MicroRNAs (miRNAs) have been implicated in various types of cancer and proposed as potential therapeutic targets for patients. In the present study, we aimed to identify miRNA that could serve as a therapeutic target for taxane-resistant prostate cancer. In order to identify miRNAs related to taxane-resistance, miRNA profiling was performed using prostate cancer PC-3 cells and paclitaxel-resistant PC-3 cell lines established from PC-3 cells. Microarray analysis of mRNA expression was also conducted to search for potential target genes of miRNA. Luciferase reporter assay was performed to examine miRNA binding to the 3'-UTR of target genes. The effects of ectopic expression of miRNA on cell growth, tubulin polymerization, drug sensitivity, and apoptotic signaling pathway were investigated in a paclitaxel-resistant PC-3 cell line. The expression of miR-130a was down-regulated in all paclitaxel-resistant cell lines compared with parental PC-3 cells. Based on mRNA microarray analysis and luciferase reporter assay, we identified SLAIN1 as a direct target gene for miR-130a. Transfection of a miR-130a precursor into a paclitaxel-resistant cell line suppressed cell growth and increased the sensitivity to paclitaxel. Lastly, ectopic expression of miR-130a did not affect the polymerized tubulin level, but activated apoptotic signaling through activation of caspase-8. Our results suggested that reduced expression of miR-130a may be involved in the paclitaxel-resistance and that miR-130a could be a therapeutic target for taxane-resistant prostate cancer patients. © 2015 Wiley Periodicals, Inc.

  12. Extracellular biosynthesis of gadolinium oxide (Gd2O3) nanoparticles, their biodistribution and bioconjugation with the chemically modified anticancer drug taxol

    PubMed Central

    Khan, Shadab Ali; Gambhir, Sanjay

    2014-01-01

    Summary As a part of our programme to develop nanobioconjugates for the treatment of cancer, we first synthesized extracellular, protein-capped, highly stable and well-dispersed gadolinium oxide (Gd2O3) nanoparticles by using thermophilic fungus Humicola sp. The biodistribution of the nanoparticles in rats was checked by radiolabelling with Tc-99m. Finally, these nanoparticles were bioconjugated with the chemically modified anticancer drug taxol with the aim of characterizing the role of this bioconjugate in the treatment of cancer. The biosynthesized Gd2O3 nanoparticles were characterized by UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS). The Gd2O3–taxol bioconjugate was confirmed by UV–vis spectroscopy and fluorescence microscopy and was purified by using high performance liquid chromatography (HPLC). PMID:24778946

  13. PTK6 inhibition promotes apoptosis of Lapatinib-resistant Her2(+) breast cancer cells by inducing Bim.

    PubMed

    Park, Sun Hee; Ito, Koichi; Olcott, William; Katsyv, Igor; Halstead-Nussloch, Gwyneth; Irie, Hanna Y

    2015-06-19

    Protein tyrosine kinase 6 (PTK6) is a non-receptor tyrosine kinase that is highly expressed in Human Epidermal Growth Factor 2(+) (Her2(+)) breast cancers. Overexpression of PTK6 enhances anchorage-independent survival, proliferation, and migration of breast cancer cells. We hypothesized that PTK6 inhibition is an effective strategy to inhibit growth and survival of Her2(+) breast cancer cells, including those that are relatively resistant to Lapatinib, a targeted therapy for Her2(+) breast cancer, either intrinsically or acquired after continuous drug exposure. To determine the effects of PTK6 inhibition on Lapatinib-resistant Her2(+) breast cancer cell lines (UACC893R1 and MDA-MB-453), we used short hairpin ribonucleic acid (shRNA) vectors to downregulate PTK6 expression. We determined the effects of PTK6 downregulation on growth and survival in vitro and in vivo, as well as the mechanisms responsible for these effects. Lapatinib treatment of "sensitive" Her2(+) cells induces apoptotic cell death and enhances transcript and protein levels of Bim, a pro-apoptotic Bcl2 family member. In contrast, treatment of relatively "resistant" Her2(+) cells fails to induce Bim or enhance levels of cleaved, poly-ADP ribose polymerase (PARP). Downregulation of PTK6 expression in these "resistant" cells enhances Bim expression, resulting in apoptotic cell death. PTK6 downregulation impairs growth of these cells in in vitro 3-D Matrigel(TM) cultures, and also inhibits growth of Her2(+) primary tumor xenografts. Bim expression is critical for apoptosis induced by PTK6 downregulation, as co-expression of Bim shRNA rescued these cells from PTK6 shRNA-induced death. The regulation of Bim by PTK6 is not via changes in Erk/MAPK or Akt signaling, two pathways known to regulate Bim expression. Rather, PTK6 downregulation activates p38, and pharmacological inhibition of p38 activity prevents PTK6 shRNA-induced Bim expression and partially rescues cells from apoptosis. PTK6 downregulation

  14. Deactivation of cisplatin-resistant human lung/ovary cancer cells with pyropheophorbide-α methyl ester-photodynamic therapy.

    PubMed

    Qian, Guanhua; Wang, Li; Zheng, Xueling; Yu, Tinghe

    2017-12-02

    The aim of this study was to determine whether photodynamic therapy (PDT) alone or combined with cisplatin (DDP), can deactivate cisplatin-resistant cancer cells. Human cancer cell lines A549 and SKOV3, and chemoresistant sublines A549/DDP and SKOV3/DDP, were subjected to PDT, DDP, or PDT combined with DDP. Cell viability and apoptosis were analyzed, and then intracellular reactive oxygen species (ROS) and proteins related to apoptosis were determined. PDT caused cell death, and PDT combined with DDP led to the highest percentage of dead cells in 4 cell lines; similar results were detected in ROS; a quantification evaluation manifested that the combined effect was addition. DDP increased the percentage of apoptotic cells, and the ROS level in A549 and SKOV3 cells, which was not observed in A549/DDP and SKOV3/DDP cells. Western blot revealed an increase of caspase 3 and Bax, and a decrease of Bcl-2, demonstrating the occurrence of apoptosis. The data suggest that PDT can efficiently deactivate resistant cells and enhance the action of DDP against resistant cancer cells.

  15. Prostate Cancer Stem-Like Cells | Center for Cancer Research

    Cancer.gov

    Prostate cancer is the third leading cause of cancer-related death among men, killing an estimated 27,000 men each year in the United States. Men with advanced prostate cancer often become resistant to conventional therapies. Many researchers speculate that the emergence of resistance is due to the presence of cancer stem cells, which are believed to be a small subpopulation of tumor cells that can self-renew and give rise to more differentiated tumor cells. It is thought that these stem cells survive initial therapies (such as chemotherapy and hormone therapy) and then generate new tumor cells that are resistant to these standard treatments. If prostate cancer stem cells could be identified and characterized, it might be possible to design treatments that prevent resistance.

  16. Multivalent peptoid conjugates which overcome enzalutamide resistance in prostate cancer cells

    PubMed Central

    Wang, Yu; Dehigaspitiya, Dilani C.; Levine, Paul M.; Profit, Adam A.; Haugbro, Michael; Imberg-Kazdan, Keren; Logan, Susan K.; Kirshenbaum, Kent; Garabedian, Michael J.

    2016-01-01

    Development of resistance to anti-androgens for treating advanced prostate cancer is a growing concern, and extends to recently developed therapeutics, including enzalutamide. Therefore, new strategies to block androgen receptor (AR) function in prostate cancer are required. Here we report the characterization of a multivalent conjugate presenting two bioactive ethisterone ligands arrayed as spatially defined pendant groups on a peptoid oligomer. The conjugate, named Multivalent Peptoid Conjugate 6 (MPC6), suppressed the proliferation of multiple AR-expressing prostate cancer cell lines including those that failed to respond to enzalutamide and ARN509. The structure-activity relationships of MPC6 variants were evaluated, revealing that increased spacing between ethisterone moieties and changes in peptoid topology eliminated its anti-proliferative effect, suggesting that both ethisterone ligand presentation and scaffold characteristics contribute to MPC6 activity. Mechanistically, MPC6 blocked AR coactivator-peptide interaction, and prevented AR intermolecular interactions. Protease sensitivity assays suggested that the MPC6-bound AR induced a receptor conformation distinct from that of dihydrotestosterone- or enzalutamide-bound AR. Pharmacological studies revealed that MPC6 was metabolically stable and displayed a low plasma clearance rate. Notably, MPC6 treatment reduced tumor growth and decreased Ki67 and AR expression in mouse xenograft models of enzalutamide-resistant LNCaP-abl cells. Thus, MPC6 represents a new class of compounds with the potential to combat treatment-resistant prostate cancer. PMID:27488525

  17. Antrodia cinnamomea extract inhibits the proliferation of tamoxifen-resistant breast cancer cells through apoptosis and skp2/microRNAs pathway.

    PubMed

    Lin, Yu-Shih; Lin, Yin-Yin; Yang, Yao-Hsu; Lin, Chun-Liang; Kuan, Feng-Che; Lu, Cheng-Nan; Chang, Geng-He; Tsai, Ming-Shao; Hsu, Cheng-Ming; Yeh, Reming-Albert; Yang, Pei-Rung; Lee, I-Yun; Shu, Li-Hsin; Cheng, Yu-Ching; Liu, Hung-Te; Lee, Kuan-Der; Chang, De-Ching; Wu, Ching-Yuan

    2018-05-09

    Breast cancer is the most common cancer in women and affects 1.38 million women worldwide per year. Antiestrogens such as tamoxifen, a selective estrogen receptor (ER) modulator, are widely used in clinics to treat ER-positive breast tumors. However, remissions of breast cancer are often followed by resistance to tamoxifen and disease relapse. Despite the increasing understanding of the resistance mechanisms, effective regimens for treating tamoxifen-resistant breast cancer are limited. Antrodia cinnamomea is a traditional medicinal mushroom native only to Taiwan. In this study, we aimed to examine in vitro effect of antrodia cinnamomea in the tamoxifen-resistant cancer. Antrodia cinnamomea was studied for its biological activity against proliferation of tamoxifen-resistant breast cancer by XTT assay. Next, the underlying mechanism was studied by flow cytometry, qPCR and Western's blotting assay. Our results revealed that the ethanol extract of antrodia cinnamomea (AC) can inhibit the growth of breast cancer cells, including MCF-7 cell and tamoxifen-resistant MCF-7 cell lines. Combination treatment with AC and 10 - 6  M tamoxifen have the better inhibitory effect on the proliferation of tamoxifen-resistant MCF-7 cells than only AC did. AC can induce apoptosis in these breast cancer cells. Moreover, it can suppress the mRNA expression of skp2 (S-phase kinase-associated protein 2) by increasing the expressions of miR-21-5p, miR-26-5p, and miR-30-5p in MCF-7 and tamoxifen-resistant MCF-7 cells. These results suggest that the ethanol extract of antrodia cinnamomea could be a novel anticancer agent in the armamentarium of tamoxifen-resistant breast cancer management. Moreover, we hope to identify additional pure compounds that could serve as promising anti-breast cancer candidates for further clinical trials.

  18. Tumor heterogeneity and resistance to EGFR-targeted therapy in advanced nonsmall cell lung cancer: challenges and perspectives

    PubMed Central

    Cheng, Xinghua; Chen, Haiquan

    2014-01-01

    Lung cancer, mostly nonsmall cell lung cancer, continues to be the leading cause of cancer-related death worldwide. With the development of tyrosine kinase inhibitors that selectively target lung cancer-related epidermal growth factor receptor mutations, management of advanced nonsmall cell lung cancer has been greatly transformed. Improvements in progression-free survival and life quality of the patients were observed in numerous clinical studies. However, overall survival is not prolonged because of later-acquired drug resistance. Recent studies reveal a heterogeneous subclonal architecture of lung cancer, so it is speculated that the tumor may rapidly adapt to environmental changes via a Darwinian selection mechanism. In this review, we aim to provide an overview of both spatial and temporal tumor heterogeneity as potential mechanisms underlying epidermal growth factor receptor tyrosine kinase inhibitor resistance in nonsmall cell lung cancer and summarize the possible origins of tumor heterogeneity covering theories of cancer stem cells and clonal evolution, as well as genomic instability and epigenetic aberrations in lung cancer. Moreover, investigational measures that overcome heterogeneity-associated drug resistance and new assays to improve tumor assessment are also discussed. PMID:25285017

  19. Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hofman, Jakub; Malcekova, Beata; Skarka, Adam

    2014-08-01

    Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantlymore » contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of

  20. Genomic and Molecular Screenings Identify Different Mechanisms for Acquired Resistance to MET Inhibitors in Lung Cancer Cells.

    PubMed

    Gimenez-Xavier, Pol; Pros, Eva; Bonastre, Ester; Moran, Sebastian; Aza, Ana; Graña, Osvaldo; Gomez-Lopez, Gonzalo; Derdak, Sophia; Dabad, Marc; Esteve-Codina, Anna; Hernandez Mora, Jose R; Salinas-Chaparro, Diana; Esteller, Manel; Pisano, David; Sanchez-Cespedes, Montse

    2017-07-01

    The development of resistance to tyrosine kinase inhibitors (TKI) limits the long-term efficacy of cancer treatments involving them. We aimed to understand the mechanisms that underlie acquired resistance (AR) to MET inhibitors in lung cancer. EBC1 cells, which have MET amplification and are sensitive to TKIs against MET, were used to generate multiple clones with AR to a MET-TKI. Whole-exome sequencing, RNA sequencing, and global DNA methylation analysis were used to scrutinize the genetic and molecular characteristics of the resistant cells. AR to the MET-TKI involved changes common to all resistant cells, that is, phenotypic modifications, specific changes in gene expression, and reactivation of AKT, ERK, and mTOR. The gene expression, global DNA methylation, and mutational profiles distinguished at least two groups of resistant cells. In one of these, the cells have acquired sensitivity to erlotinib, concomitantly with mutations of the KIRREL, HDAC11, HIATL1 , and MAPK1IP1L genes, among others. In the other group, some cells have acquired inactivation of neurofibromatosis type 2 ( NF2 ) concomitantly with strong overexpression of NRG1 and a mutational profile that includes changes in LMLN and TOMM34 Multiple independent and simultaneous strategies lead to AR to the MET-TKIs in lung cancer cells. The acquired sensitivity to erlotinib supports the known crosstalk between MET and the HER family of receptors. For the first time, we show inactivation of NF2 during acquisition of resistance to MET-TKI that may explain the refractoriness to erlotinib in these cells. Mol Cancer Ther; 16(7); 1366-76. ©2017 AACR . ©2017 American Association for Cancer Research.

  1. Tangeretin sensitizes cisplatin-resistant human ovarian cancer cells through downregulation of phosphoinositide 3-kinase/Akt signaling pathway.

    PubMed

    Arafa, El-Shaimaa A; Zhu, Qianzheng; Barakat, Bassant M; Wani, Gulzar; Zhao, Qun; El-Mahdy, Mohamed A; Wani, Altaf A

    2009-12-01

    Combination of innocuous dietary components with anticancer drugs is an emerging new strategy for cancer chemotherapy to increase antitumor responses. Tangeretin is a citrus flavonoid known to inhibit cancer cell proliferation. Here, we show an enhanced response of A2780/CP70 and 2008/C13 cisplatin-resistant human ovarian cancer cells to various combination treatments of cisplatin and tangeretin. Pretreatment of cells with tangeretin before cisplatin treatment synergistically inhibited cancer cell proliferation. This combination was effective in activating apoptosis via caspase cascade as well as arresting cell cycle at G(2)-M phase. Moreover, phospho-Akt and its downstream substrates, e.g., NF-kappaB, phospho-GSK-3beta, and phospho-BAD, were downregulated upon tangeretin-cisplatin treatment. The tangeretin-cisplatin-induced apoptosis in A2780/CP70 cells was increased by phosphoinositide-3 kinase (PI3K) inhibition and siRNA-mediated Akt silencing, but reduced by overexpression of constitutively activated Akt and GSK-3beta inhibition. The overall results indicated that tangeretin exposure preconditions cisplatin-resistant human ovarian cancer cells for a conventional response to low-dose cisplatin-induced cell death occurring through downregulation of PI3K/Akt signaling pathway. Thus, effectiveness of tangeretin combinations, as a promising modality in the treatment of resistant cancers, warrants systematic clinical studies.

  2. Non-Small Cell Lung Cancer Cells Acquire Resistance to the ALK Inhibitor Alectinib by Activating Alternative Receptor Tyrosine Kinases.

    PubMed

    Isozaki, Hideko; Ichihara, Eiki; Takigawa, Nagio; Ohashi, Kadoaki; Ochi, Nobuaki; Yasugi, Masayuki; Ninomiya, Takashi; Yamane, Hiromichi; Hotta, Katsuyuki; Sakai, Katsuya; Matsumoto, Kunio; Hosokawa, Shinobu; Bessho, Akihiro; Sendo, Toshiaki; Tanimoto, Mitsune; Kiura, Katsuyuki

    2016-03-15

    Crizotinib is the standard of care for advanced non-small cell lung cancer (NSCLC) patients harboring the anaplastic lymphoma kinase (ALK) fusion gene, but resistance invariably develops. Unlike crizotinib, alectinib is a selective ALK tyrosine kinase inhibitor (TKI) with more potent antitumor effects and a favorable toxicity profile, even in crizotinib-resistant cases. However, acquired resistance to alectinib, as for other TKIs, remains a limitation of its efficacy. Therefore, we investigated the mechanisms by which human NSCLC cells acquire resistance to alectinib. We established two alectinib-resistant cell lines that did not harbor the secondary ALK mutations frequently occurring in crizotinib-resistant cells. One cell line lost the EML4-ALK fusion gene, but exhibited increased activation of insulin-like growth factor-1 receptor (IGF1R) and human epidermal growth factor receptor 3 (HER3), and overexpressed the HER3 ligand neuregulin 1. Accordingly, pharmacologic inhibition of IGF1R and HER3 signaling overcame resistance to alectinib in this cell line. The second alectinib-resistant cell line displayed stimulated HGF autocrine signaling that promoted MET activation and remained sensitive to crizotinib treatment. Taken together, our findings reveal two novel mechanisms underlying alectinib resistance that are caused by the activation of alternative tyrosine kinase receptors rather than by secondary ALK mutations. These studies may guide the development of comprehensive treatment strategies that take into consideration the various approaches ALK-positive lung tumors use to withstand therapeutic insult. ©2015 American Association for Cancer Research.

  3. Src Drives Growth of Antiestrogen Resistant Breast Cancer Cell Lines and Is a Marker for Reduced Benefit of Tamoxifen Treatment

    PubMed Central

    Larsen, Sarah L.; Laenkholm, Anne-Vibeke; Duun-Henriksen, Anne Katrine; Bak, Martin; Lykkesfeldt, Anne E.; Kirkegaard, Tove

    2015-01-01

    The underlying mechanisms leading to antiestrogen resistance in estrogen-receptor α (ER)-positive breast cancer is still poorly understood. The aim of this study was therefore to identify biomarkers and novel treatments for antiestrogen resistant breast cancer. We performed a kinase inhibitor screen on antiestrogen responsive T47D breast cancer cells and T47D-derived tamoxifen and fulvestrant resistant cell lines. We found that dasatinib, a broad-spectrum kinase inhibitor, inhibited growth of the antiestrogen resistant cells compared to parental T47D cells. Furthermore western blot analysis showed increased expression and phosphorylation of Src in the resistant cells and that dasatinib inhibited phosphorylation of Src and also signaling via Akt and Erk in all cell lines. Immunoprecipitation revealed Src: ER complexes only in the parental T47D cells. In fulvestrant resistant cells, Src formed complexes with the Human Epidermal growth factor Receptor (HER)1 and HER2. Neither HER receptors nor ER were co-precipitated with Src in the tamoxifen resistant cell lines. Compared to treatment with dasatinib alone, combined treatment with dasatinib and fulvestrant had a stronger inhibitory effect on tamoxifen resistant cell growth, whereas dasatinib in combination with tamoxifen had no additive inhibitory effect on fulvestrant resistant growth. When performing immunohistochemical staining on 268 primary tumors from breast cancer patients who had received tamoxifen as first line endocrine treatment, we found that membrane expression of Src in the tumor cells was significant associated with reduced disease-free and overall survival. In conclusion, Src was identified as target for treatment of antiestrogen resistant T47D breast cancer cells. For tamoxifen resistant T47D cells, combined treatment with dasatinib and fulvestrant was superior to treatment with dasatinib alone. Src located at the membrane has potential as a new biomarker for reduced benefit of tamoxifen. PMID

  4. UCHL1 Is a Putative Tumor Suppressor in Ovarian Cancer Cells and Contributes to Cisplatin Resistance

    PubMed Central

    Jin, Chengmeng; Yu, Wei; Lou, Xiaoyan; Zhou, Fan; Han, Xu; Zhao, Na; Lin, Biaoyang

    2013-01-01

    Ubiquitin carboxyl terminal hydrolase 1 (UCHL1) catalyzes the hydrolysis of COOH-terminal ubiquityl esters and amides. It has been reported as either an oncogene or a tumor suppressor in cancers. However, UCHL1's role in ovarian cancer is still unclear. Therefore, we conducted an analysis to understand the role of UCHL1 in ovarian cancer. Firstly, we detected UCHL1 promoter methylation status in 7 ovarian cancer cell lines. 4 of them with UCHL1 silencing showed heavy promoter methylation while the other 3 with relative high UCHL1 expression showed little promoter methylation. Then we reduced UCHL1 expression in ovarian cancer cell line A2780 and IGROV1 and found that inhibition of UCHL1 promoted cell proliferation by increasing cells in S phases of cell cycle. Knockdown of UCHL1 also reduced cell apoptosis and contributed to cisplatin resistance. Furthermore, the expression level of UCHL1 in several ovarian cancer cell lines correlated negatively with their cisplatin resistance levels. Microarray data revealed that UCHL1 related genes are enriched in apoptosis and cell death gene ontology (GO) terms. Several apoptosis related genes were increased after UCHL1 knockdown, including apoptosis regulator BCL2, BCL11A, AEN and XIAP. Furthermore, we identified up-regulation of Bcl-2 and pAKT as well as down-regulation of Bax in UCHL1 knockdown cells, while no significant alteration of p53 and AKT1 was found. This study provides a new and promising strategy to overcome cisplatin resistance in ovarian cancer via UCHL1 mediated pathways. PMID:24155778

  5. Resistance-modifying Activity in Vinblastine-resistant Human Breast Cancer Cells by Oligosaccharides Obtained from Mucilage of Chia Seeds (Salvia hispanica).

    PubMed

    Rosas-Ramírez, Daniel G; Fragoso-Serrano, Mabel; Escandón-Rivera, Sonia; Vargas-Ramírez, Alba L; Reyes-Grajeda, Juan P; Soriano-García, Manuel

    2017-06-01

    The multidrug resistance (MDR) phenotype is considered as a major cause of the failure in cancer chemotherapy. The acquisition of MDR is usually mediated by the overexpression of drug efflux pumps of a P-glycoprotein. The development of compounds that mitigate the MDR phenotype by modulating the activity of these transport proteins is an important yet elusive target. Here, we screened the saponification and enzymatic degradation products from Salvia hispanica seed's mucilage to discover modulating compounds of the acquired resistance to chemotherapeutic in breast cancer cells. Preparative-scale recycling HPLC was used to purify the hydrolysis degradation products. All compounds were tested in eight different cancer cell lines and Vero cells. All compounds were noncytotoxic at the concentration tested against the drug-sensitive and multidrug-resistant cells (IC 50  > 29.2 μM). For the all products, a moderate vinblastine-enhancing activity from 4.55-fold to 6.82-fold was observed. That could be significant from a therapeutic perspective. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Ionic-Liquid-Based Paclitaxel Preparation: A New Potential Formulation for Cancer Treatment.

    PubMed

    Chowdhury, Md Raihan; Moshikur, Rahman Md; Wakabayashi, Rie; Tahara, Yoshiro; Kamiya, Noriho; Moniruzzaman, Muhammad; Goto, Masahiro

    2018-06-04

    Paclitaxel (PTX) injection (i.e., Taxol) has been used as an effective chemotherapeutic treatment for various cancers. However, the current Taxol formulation contains Cremophor EL, which causes hypersensitivity reactions during intravenous administration and precipitation by aqueous dilution. This communication reports the preliminary results on the ionic liquid (IL)-based PTX formulations developed to address the aforementioned issues. The formulations were composed of PTX/cholinium amino acid ILs/ethanol/Tween-80/water. A significant enhancement in the solubility of PTX was observed with considerable correlation with the density and viscosity of the ILs, and with the side chain of the amino acids used as anions in the ILs. Moreover, the formulations were stable for up to 3 months. The driving force for the stability of the formulation was hypothesized to be the involvement of different types of interactions between the IL and PTX. In vitro cytotoxicity and antitumor activity of the IL-based formulations were evaluated on HeLa cells. The IL vehicles without PTX were found to be less cytotoxic than Taxol, while both the IL-based PTX formulation and Taxol exhibited similar antitumor activity. Finally, in vitro hypersensitivity reactions were evaluated on THP-1 cells and found to be significantly lower with the IL-based formulation than Taxol. This study demonstrated that specially designed ILs could provide a potentially safer alternative to Cremophor EL as an effective PTX formulation for cancer treatment giving fewer hypersensitivity reactions.

  7. [A novel chemo-resistant gene MSX2 discovered by establishment of two pancreatic cancer drug resistant cell lines JF305/CDDP and PANC-1/GEM].

    PubMed

    Yuan, W; Sui, C G; Ma, X; Ma, J

    2018-05-23

    Objective: To explore new multidrug resistant genes of pancreatic cancer by establishment and characterization of chemo-resistant cell lines. Methods: The cisplatin-resistant cell line JF305/CDDP and the gemcitabine-resistant cell line PANC-1/GEM were induced by high-dose intermittent treatment. CCK-8 assay was used to detect the 50% inhibiting concentration (IC(50)), drug resistance index (R), cross-resistance, and growth difference of different cells. The changes of cell cycle and migration ability of drug-resistant cells were determined by flow cytometry and transwell assay, respectively. And then real-time fluorescence quantitative PCR was used to detect the expression of multidrug resistance-related genes. Results: The drug resistance indexes of JF305/CDDP and PANC-1/GEM were 15.3 and 27.31, respectively, and there was cross-resistance. Compared with the parental cells, the proliferation rate of JF305/CDDP was decreased by 40% on the fourth day ( P <0.05); the proportion of S phase was decreased from (45±2)% to (30±2)% ( P <0.05), and the migration ability was enhanced from (32 ±1) cells per field to (158±5) cells per field ( P <0.01). The expression of multidrug resistance-related genes MRP2, MDR1, LRP and MSX2 was increased in JF305/CDDP cells ( P <0.05). Knockdown of MSX2 in JF305 cells reduced the expression of MRP2, whereas overexpression of MSX2 in PANC-1 cells upregulated MRP2 level ( P <0.05). Conclusions: Two stable multidrug resistant cell lines of pancreatic cancer, JF305/CDDP and PANC-1/GEM, were successfully established. MSX2 might be a new drug resistance related gene in pancreatic cancer cells by up-regulation of MRP2 expression.

  8. Inhibition of disheveled-2 resensitizes cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling.

    PubMed

    Luo, Ke; Gu, Xiuhui; Liu, Jing; Zeng, Guodan; Peng, Liaotian; Huang, Houyi; Jiang, Mengju; Yang, Ping; Li, Minhui; Yang, Yuhan; Wang, Yuanyuan; Peng, Quekun; Zhu, Li; Zhang, Kun

    2016-09-10

    Cisplatin (CDDP) is currently recommended as the front-line chemotherapeutic agent for lung cancer. However, the resistance to cisplatin is widespread in patients with advanced lung cancer, and the molecular mechanism of such resistance remains incompletely understood. Disheveled (DVL), a key mediator of Wnt/β-catenin, has been linked to cancer progression, while the role of DVL in cancer drug resistance is not clear. Here, we found that DVL2 was over-expressed in cisplatin-resistant human lung cancer cells A549/CDDP compared to the parental A549 cells. Inhibition of DVL2 by its inhibitor (3289-8625) or shDVL2 resensitized A549/CDDP cells to cisplatin. In addition, over-expression of DVL2 in A549 cells increased the protein levels of BCRP, MRP4, and Survivin, which are known to be associated with chemoresistance, while inhibition of DVL2 in A549/CDDP cells decreased these protein levels, and reduced the accumulation and nuclear translocation of β-catenin. In addition, shβ-catenin abolished the DVL2-induced the expression of BCRP, MRP4, and Survivin. Furthermore, our data showed that GSK3β/β-catenin signals were aberrantly activated by DVL2, and inactivation of GSK3β reversed the shDVL2-induced down-regulation of β-catenin. Taken together, these results suggested that inhibition of DVL2 can sensitize cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling and inhibiting BCRP, MRP4, and Survivin expression. It promises a new strategy to chemosensitize cisplatin-induced cytotoxicity in lung cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. PAK4 confers the malignance of cervical cancers and contributes to the cisplatin-resistance in cervical cancer cells via PI3K/AKT pathway.

    PubMed

    Shu, Xiang-Rong; Wu, Jing; Sun, He; Chi, Li-Qun; Wang, Jin-Huan

    2015-09-28

    Multiple protein or microRNA markers have been recognized to contribute to the progression and recurrence of cervical cancers. Particular those, which are associated with the chemo- or radio-resistance of cervical cancers, have been proposed to be promising and to facilitate the definition for cervical cancer treatment options. This study was designed to explore the potential prognosis value of p21-activated kinase (PAK)-4 in cervical cancer, via the Kaplan-Meier analysis, log-rank test and Cox regression analysis, and then to investigate the regulatory role of PAK4 in the cisplatin resistance in cervical cancer cells, via the strategies of both PAK4 overexpression and PAK4 knockout. It was demonstrated that PAK4 was upregulated in cervical cancer tissues, in an association with the cancer's malignance variables such as FIGO stage, lymph node or distant metastasis and the poor histological grade. The high PAK4 expression was also independently associated with poor prognosis to cervical cancer patients. Moreover, PAK4 confers cisplatin resistance in cervical cancer Hela or Caski cells. In addition, the PI3K/Akt pathway has been implicated in the PAK4-confered cisplatin resistance. And the PI3K/Akt inhibitor, LY294002, markedly deteriorated the cisplatin-mediated viability reduction of Hela or Caski cells, indicating the involvement of PI3K/Akt pathway in the cisplatin resistance in cervical cancer cells. This study has confirmed the significant prognostic role of PAK4 level in cervical cancer patients and has recognized the regulatory role in cervical cancer progression. Moreover, our study has indicated that PAK4 also confers the chemoresistance of cervical cancer cells in a PI3K/Akt-dependent way. Thus, our study indicates PAK4 as a promising marker for cervical cancer treatment.

  10. MicroRNA expression profiles of drug-resistance breast cancer cells and their exosomes.

    PubMed

    Zhong, Shanliang; Chen, Xiu; Wang, Dandan; Zhang, Xiaohui; Shen, Hongyu; Yang, Sujin; Lv, Mengmeng; Tang, Jinhai; Zhao, Jianhua

    2016-04-12

    Exosomes have been shown to transmit drug resistance through delivering miRNAs. We aimed to explore their roles in breast cancer. Three resistant sublines were established by exposing parental MDA-MB-231 cell line to docetaxel, epirubicin and vinorelbine, respectively. Preneoadjuvant chemotherapy biopsies and paired surgically-resected specimens embedded in paraffin from 23 breast cancer patients were collected. MiRNA expression profiles of the cell lines and their exosomes were evaluated using microarray. The result showed that most miRNAs in exosomes had a lower expression level than that in cells, however, some miRNAs expressed higher in exosomes than in cells, suggesting a number of miRNAs is concentrated in exosomes. Among the dysregulated miRNAs, 22 miRNAs were consistently up-regulated in exosomes and their cells of origin. We further found that 12 of the 22 miRNAs were significantly up-regulated after preneoadjuvant chemotherapy. Further study of the role of these 12 miRNAs in acquisition of drug resistance is needed to clarify their contribution to chemoresistance.

  11. Nuclear EGFR-PKM2 axis induces cancer stem cell-like characteristics in irradiation-resistant cells.

    PubMed

    Shi, Ying; Liu, Na; Lai, Weiwei; Yan, Bin; Chen, Ling; Liu, Shouping; Liu, Shuang; Wang, Xiang; Xiao, Desheng; Liu, Xiaoli; Mao, Chao; Jiang, Yiqun; Jia, Jiantao; Liu, Yating; Yang, Rui; Cao, Ya; Tao, Yongguang

    2018-05-28

    Radiation therapy has become an important tool in the treatment of cancer patients, but most patients relapse within 5 years. Relapse is due to the presence of cancer stem cells (CSCs), but the molecular mechanism of radioresistance in CSCs remains largely elusive. Here, we found that irradiation-resistant (IR) cells exhibited increased stem cell-like properties together with elevated anchorage-independent growth and metastasis ability. EGFR not only leads to increased acquisition of endometrial cancer stem cell markers in radioresistant sublines but is critical for the cancer stem-cell phenotype and tumorigenicity. Moreover, PKM2 functions as an interacting partner of EGFR, which induces the EMT phenotype and stem cell-like properties in IR cells. Finally, we found that the regulatory function of the EGFR-PKM2 axis is dependent on nuclear EGFR. In sum, our study indicated that EGFR and PKM2 directly interact and bind with each other to regulate the transcription of stemness-related genes and promote the stem-like phenotype, thus promoting invasion and metastasis. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. C-Cbl reverses HER2-mediated tamoxifen resistance in human breast cancer cells.

    PubMed

    Li, Wei; Xu, Ling; Che, Xiaofang; Li, Haizhou; Zhang, Ye; Song, Na; Wen, Ti; Hou, Kezuo; Yang, Yi; Zhou, Lu; Xin, Xing; Xu, Lu; Zeng, Xue; Shi, Sha; Liu, Yunpeng; Qu, Xiujuan; Teng, Yuee

    2018-05-02

    Tamoxifen is a frontline therapy for estrogen receptor (ER)-positive breast cancer in premenopausal women. However, many patients develop resistance to tamoxifen, and the mechanism underlying tamoxifen resistance is not well understood. Here we examined whether ER-c-Src-HER2 complex formation is involved in tamoxifen resistance. MTT and colony formation assays were used to measure cell viability and proliferation. Western blot was used to detect protein expression and protein complex formations were detected by immunoprecipitation and immunofluorescence. SiRNA was used to examine the function of HER2 in of BT474 cells. An in vivo xenograft animal model was established to examine the role of c-Cbl in tumor growth. MTT and colony formation assay showed that BT474 cells are resistant to tamoxifen and T47D cells are sensitive to tamoxifen. Immunoprecipitation experiments revealed ER-c-Src-HER2 complex formation in BT474 cells but not in T47D cells. However, ER-c-Src-HER2 complex formation was detected after overexpressing HER2 in T47D cells and these cells were more resistant to tamoxifen. HER2 knockdown by siRNA in BT474 cells reduced ER-c-Src-HER2 complex formation and reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was also disrupted and tamoxifen resistance was reversed in BT474 cells by the c-Src inhibitor PP2 and HER2 antibody trastuzumab. Nystatin, a lipid raft inhibitor, reduced ER-c-Src-HER2 complex formation and partially reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was disrupted by overexpression of c-Cbl but not by the c-Cbl ubiquitin ligase mutant. In addition, c-Cbl could reverse tamoxifen resistance in BT474 cells, but the ubiquitin ligase mutant had no effect. The effect of c-Cbl was validated in BT474 tumor-bearing nude mice in vivo. Immunofluorescence also revealed ER-c-Src-HER2 complex formation was reduced in tumor tissues of nude mice with c-Cbl overexpression. Our results suggested that c-Cbl can reverse tamoxifen

  13. CD117/c-kit in Cancer Stem Cell-Mediated Progression and Therapeutic Resistance

    PubMed Central

    Young, Tyler R.; Mobley, Mary E.

    2018-01-01

    Metastasis is the primary cause of cancer patient morbidity and mortality, but due to persisting gaps in our knowledge, it remains untreatable. Metastases often occur as patient tumors progress or recur after initial therapy. Tumor recurrence at the primary site may be driven by a cancer stem-like cell or tumor progenitor cell, while recurrence at a secondary site is driven by metastatic cancer stem cells or metastasis-initiating cells. Ongoing efforts are aimed at identifying and characterizing these stem-like cells driving recurrence and metastasis. One potential marker for the cancer stem-like cell subpopulation is CD117/c-kit, a tyrosine kinase receptor associated with cancer progression and normal stem cell maintenance. Further, activation of CD117 by its ligand stem cell factor (SCF; kit ligand) in the progenitor cell niche stimulates several signaling pathways driving proliferation, survival, and migration. This review examines evidence that the SCF/CD117 signaling axis may contribute to the control of cancer progression through the regulation of stemness and resistance to tyrosine kinase inhibitors. PMID:29518044

  14. Cellular glutathione level does not predict ovarian cancer cells' resistance after initial or repeated exposure to cisplatin.

    PubMed

    Nikounezhad, Nastaran; Nakhjavani, Maryam; Shirazi, Farshad H

    2017-05-01

    Cisplatin resistance development is a major obstacle in ovarian cancer treatment. One of the most important mechanisms underlying cisplatin resistance is drug detoxification by glutathione. In the present study, the importance of initial or repeated exposure to cisplatin in glutathione dependent resistance was investigated. To this purpose, some cisplatin sensitive and resistant variants of human ovarian cancer cell lines providing an appropriate range of cisplatin sensitivity were selected. Clonogenic survival assay was performed to evaluate cisplatin resistance and intracellular contents of reduced (GSH) and oxidized (GSSG) glutathione were analyzed using an HPLC method. Our results indicated that the intracellular GSH and GSSG concentrations were nearly equal in A2780 and A2780CP cells, while the A2780CP cells showed 14 times more resistance than the A2780 cells after initial exposure to cisplatin. A2780-R1 and A2780-R3 cells which have been repeatedly exposed to cisplatin also showed no significant difference in glutathione content, even though A2780-R3 was about two times more resistant than A2780-R1. Moreover, intracellular GSH/GSSG ratio decreased in the resistant cells, reflecting a shift towards a more oxidizing intracellular environment indicative of oxidative stress. As a conclusion, it seems that although the intracellular glutathione concentration increases after repeated exposure to cisplatin, there is no clear correlation between the intracellular GSH content in ovarian cancer cells and their resistance to cisplatin neither after initial nor after repeated exposure to this drug.

  15. Bone stroma-derived cells change coregulators recruitment to androgen receptor and decrease cell proliferation in androgen-sensitive and castration-resistant prostate cancer cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Villagran, Marcelo A.; Gutierrez-Castro, Francisco A.; Pantoja, Diego F.

    Prostate cancer (CaP) bone metastasis is an early event that remains inactive until later-stage progression. Reduced levels of circulating androgens, due to andropause or androgen deprivation therapies, alter androgen receptor (AR) coactivator expression. Coactivators shift the balance towards enhanced AR-mediated gene transcription that promotes progression to androgen-resistance. Disruptions in coregulators may represent a molecular switch that reactivates latent bone metastasis. Changes in AR-mediated transcription in androgen-sensitive LNCaP and androgen-resistant C4-2 cells were analyzed for AR coregulator recruitment in co-culture with Saos-2 and THP-1. The Saos-2 cell line derived from human osteosarcoma and THP-1 cell line representing human monocytes were usedmore » to display osteoblast and osteoclast activity. Increased AR activity in androgen-resistant C4-2 was due to increased AR expression and SRC1/TIF2 recruitment and decreased SMRT/NCoR expression. AR activity in both cell types was decreased over 90% when co-cultured with Saos-2 or THP-1 due to dissociation of AR from the SRC1/TIF2 and SMRT/NCoR coregulators complex, in a ligand-dependent and cell-type specific manner. In the absence of androgens, Saos-2 decreased while THP-1 increased proliferation of LNCaP cells. In contrast, both Saos-2 and THP-1 decreased proliferation of C4-2 in absence and presence of androgens. Global changes in gene expression from both CaP cell lines identified potential cell cycle and androgen regulated genes as mechanisms for changes in cell proliferation and AR-mediated transactivation in the context of bone marrow stroma cells. - Highlights: • Decreased corepressor expression change AR in androgen-resistance prostate cancer. • Bone stroma-derived cells change AR coregulator recruitment in prostate cancer. • Bone stroma cells change cell proliferation in androgen-resistant cancer cells. • Global gene expression in CaP cells is modified by bone stroma cells in

  16. Telomerase and drug resistance in cancer.

    PubMed

    Lipinska, Natalia; Romaniuk, Aleksandra; Paszel-Jaworska, Anna; Toton, Ewa; Kopczynski, Przemyslaw; Rubis, Blazej

    2017-11-01

    It is well known that a decreased expression or inhibited activity of telomerase in cancer cells is accompanied by an increased sensitivity to some drugs (e.g., doxorubicin, cisplatin, or 5-fluorouracil). However, the mechanism of the resistance resulting from telomerase alteration remains elusive. There are theories claiming that it might be associated with telomere shortening, genome instability, hTERT translocation, mitochondria functioning modulation, or even alterations in ABC family gene expression. However, association of those mechanisms, i.e., drug resistance and telomerase alterations, is not fully understood yet. We review the current theories on the aspect of the role of telomerase in cancer cells resistance to therapy. We believe that revealing/unravelling this correlation might significantly contribute to an increased efficiency of cancer cells elimination, especially the most difficult ones, i.e., drug resistant.

  17. New HSP27 inhibitors efficiently suppress drug resistance development in cancer cells.

    PubMed

    Heinrich, Jörg C; Donakonda, Sainitin; Haupt, V Joachim; Lennig, Petra; Zhang, Yixin; Schroeder, Michael

    2016-10-18

    Drug resistance is an important open problem in cancer treatment. In recent years, the heat shock protein HSP27 (HSPB1) was identified as a key player driving resistance development. HSP27 is overexpressed in many cancer types and influences cellular processes such as apoptosis, DNA repair, recombination, and formation of metastases. As a result cancer cells are able to suppress apoptosis and develop resistance to cytostatic drugs. To identify HSP27 inhibitors we follow a novel computational drug repositioning approach. We exploit a similarity between a predicted HSP27 binding site to a viral thymidine kinase to generate lead inhibitors for HSP27. Six of these leads were verified experimentally. They bind HSP27 and down-regulate its chaperone activity. Most importantly, all six compounds inhibit development of drug resistance in cellular assays. One of the leads - chlorpromazine - is an antipsychotic, which has a positive effect on survival time in human breast cancer. In summary, we make two important contributions: First, we put forward six novel leads, which inhibit HSP27 and tackle drug resistance. Second, we demonstrate the power of computational drug repositioning.

  18. New HSP27 inhibitors efficiently suppress drug resistance development in cancer cells

    PubMed Central

    Lennig, Petra; Zhang, Yixin; Schroeder, Michael

    2016-01-01

    Drug resistance is an important open problem in cancer treatment. In recent years, the heat shock protein HSP27 (HSPB1) was identified as a key player driving resistance development. HSP27 is overexpressed in many cancer types and influences cellular processes such as apoptosis, DNA repair, recombination, and formation of metastases. As a result cancer cells are able to suppress apoptosis and develop resistance to cytostatic drugs. To identify HSP27 inhibitors we follow a novel computational drug repositioning approach. We exploit a similarity between a predicted HSP27 binding site to a viral thymidine kinase to generate lead inhibitors for HSP27. Six of these leads were verified experimentally. They bind HSP27 and down-regulate its chaperone activity. Most importantly, all six compounds inhibit development of drug resistance in cellular assays. One of the leads – chlorpromazine – is an antipsychotic, which has a positive effect on survival time in human breast cancer. In summary, we make two important contributions: First, we put forward six novel leads, which inhibit HSP27 and tackle drug resistance. Second, we demonstrate the power of computational drug repositioning. PMID:27626687

  19. Inhibition of disheveled-2 resensitizes cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luo, Ke; Gu, Xiuhui; Liu, Jing

    Cisplatin (CDDP) is currently recommended as the front-line chemotherapeutic agent for lung cancer. However, the resistance to cisplatin is widespread in patients with advanced lung cancer, and the molecular mechanism of such resistance remains incompletely understood. Disheveled (DVL), a key mediator of Wnt/β-catenin, has been linked to cancer progression, while the role of DVL in cancer drug resistance is not clear. Here, we found that DVL2 was over-expressed in cisplatin-resistant human lung cancer cells A549/CDDP compared to the parental A549 cells. Inhibition of DVL2 by its inhibitor (3289-8625) or shDVL2 resensitized A549/CDDP cells to cisplatin. In addition, over-expression of DVL2more » in A549 cells increased the protein levels of BCRP, MRP4, and Survivin, which are known to be associated with chemoresistance, while inhibition of DVL2 in A549/CDDP cells decreased these protein levels, and reduced the accumulation and nuclear translocation of β-catenin. In addition, shβ-catenin abolished the DVL2-induced the expression of BCRP, MRP4, and Survivin. Furthermore, our data showed that GSK3β/β-catenin signals were aberrantly activated by DVL2, and inactivation of GSK3β reversed the shDVL2-induced down-regulation of β-catenin. Taken together, these results suggested that inhibition of DVL2 can sensitize cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling and inhibiting BCRP, MRP4, and Survivin expression. It promises a new strategy to chemosensitize cisplatin-induced cytotoxicity in lung cancer. - Highlights: • Inhibition of DVL2 chemosensitizes resistant lung cancer to cisplatin. • DVL2 positively regulated the expression of BCRP, MRP4 and Survivin. • β-catenin mediated the DVL2-induced expression. • DVL2 increased the accumulation and nuclear translocation of β-catenin. • DVL2 up-regulated β-catenin via inhibiting GSK3β.« less

  20. MicroRNA-873 mediates multidrug resistance in ovarian cancer cells by targeting ABCB1.

    PubMed

    Wu, Di-di; Li, Xue-Song; Meng, Xiao-Na; Yan, Jing; Zong, Zhi-Hong

    2016-08-01

    Ovarian cancer is commonly treated with cisplatin and paclitaxel combination chemotherapy; however, ovarian cancer cells often develop resistance to these drugs. Increasingly, microRNAs (miRNAs) including miR-873 have been implicated in drug resistance in many cancers, but the role of miR-873 in ovarian cancer remains unknown. MTT cell viability assays revealed that the sensitivities of ovarian cancer lines to cisplatin and paclitaxel increased following transfection with miR-873 (P < 0.05). After predicting the miR-873 binding region in the 3'-untranslated region of ABCB1, dual-luciferase reporter assay confirmed this prediction. RT-PCR and Western blotting revealed that MDR1 expression was significantly downregulated after transfection with miR-873 and upregulated after transfection with anti-miR-873 at both mRNA and protein levels compared to negative controls (P < 0.05). Experiments in a mouse xenograft model confirmed that intratumoral administration of miR-873 could enhance the efficacy of cisplatin in inhibiting tumor growth in ovarian cancer in vivo (P < 0.05). ABCB1 overexpression reduced sensitivities of ovarian cancer lines OVCAR3 and A2780 to cisplatin and paclitaxel, which can be reversed by miR-873 mimic transfection (P < 0.05). In summary, we demonstrated that overexpression of miR-873 increased the sensitivity of ovarian cancer cells to cisplatin and paclitaxel by targeting MDR1 expression. Our findings suggest that combination therapies with chemotherapy agents and miR-873 may suppress drug resistance in ovarian cancer.

  1. Effects of HSP27 downregulation on PDT resistance through PDT-induced autophagy in head and neck cancer cells.

    PubMed

    Kim, Jisun; Lim, Haesoon; Kim, Sangwoo; Cho, Hyejung; Kim, Yong; Li, Xiaojie; Choi, Hongran; Kim, Okjoon

    2016-04-01

    We previously reported that photodynamic therapy (PDT) induces cell death in head and neck cancer through both autophagy and apoptosis. Regulation of cell death by autophagy and apoptosis is important to enhance the effects of PDT. Autophagy maintains a balance between cell death and PDT resistance. Downregulation of heat shock protein 27 (HSP27) induces PDT resistance in head and neck cancer cells. Furthermore, HSP70 regulates apoptosis during oxidative stress. However, the role of HSPs in PDT-induced cell death through autophagy and apoptosis is unclear. Therefore, in the present study, we investigated the effects of HSP27 and HSP70 on PDT-induced cell death of oral cancer cells through autophagy and apoptosis. Cancer cells were treated with hematoporphyrin at varying doses, followed by irradiation at 635 nm with an energy density of 5 mW/cm2. We determined the changes in HSP expression by determining the levels of PARP-1 and LC3II in PDT-resistant cells. Furthermore, we assessed cell death signaling after downregulating HSPs by transfecting specific siRNAs. We observed that PDT decreased HSP27 expression but increased HSP70 expression in the head and neck cancer cells. Treatment of cells with LC3II and PARP-1 inhibitors resulted in upregulation of HSP70 and HSP27 expression, respectively. Downregulation of HSP27 and HSP70 induced cell death and PDT resistance through autophagy and apoptosis. Moreover, downregulation of HSP27 in PDT-resistant cells resulted in enhanced survival. These results indicate that the regulation of HSP27 and HSP70 plays a principal role in increasing the effects of PDT by inducing autophagic and apoptotic cell death.

  2. Targeting Taxanes to Castration-Resistant Prostate Cancer Cells by Nanobubbles and Extracorporeal Shock Waves.

    PubMed

    Marano, Francesca; Rinella, Letizia; Argenziano, Monica; Cavalli, Roberta; Sassi, Francesca; D'Amelio, Patrizia; Battaglia, Antonino; Gontero, Paolo; Bosco, Ornella; Peluso, Rossella; Fortunati, Nicoletta; Frairia, Roberto; Catalano, Maria Graziella

    2016-01-01

    To target taxanes to castration-resistant prostate cancer cells, glycol-chitosan nanobubbles loaded with paclitaxel and docetaxel were constructed. The loaded nanobubbles were then combined with Extracorporeal Shock Waves, acoustic waves widely used in urology and orthopedics, with no side effects. Nanobubbles, with an average diameter of 353.3 ± 15.5 nm, entered two different castration-resistant prostate cancer cells (PC3 and DU145) as demonstrated by flow cytometry and immunofluorescence. The shock waves applied increased the amount of intracellular nanobubbles. Loading nanobubbles with paclitaxel and docetaxel and combining them with shock waves generated the highest cytotoxic effects, resulting in a paclitaxel GI50 reduction of about 55% and in a docetaxel GI50 reduction of about 45% respectively. Combined treatment also affected cell migration. Paclitaxel-loaded nanobubbles and shock waves reduced cell migration by more than 85% with respect to paclitaxel alone; whereas docetaxel-loaded nanobubbles and shock waves reduced cell migration by more than 82% with respect to docetaxel alone. The present data suggest that nanobubbles can act as a stable taxane reservoir in castration-resistant prostate cancer cells and shock waves can further increase drug release from nanobubbles leading to higher cytotoxic and anti-migration effect.

  3. Targeting Taxanes to Castration-Resistant Prostate Cancer Cells by Nanobubbles and Extracorporeal Shock Waves

    PubMed Central

    Argenziano, Monica; Cavalli, Roberta; Sassi, Francesca; D’Amelio, Patrizia; Battaglia, Antonino; Gontero, Paolo; Bosco, Ornella; Peluso, Rossella; Fortunati, Nicoletta; Frairia, Roberto; Catalano, Maria Graziella

    2016-01-01

    To target taxanes to castration-resistant prostate cancer cells, glycol-chitosan nanobubbles loaded with paclitaxel and docetaxel were constructed. The loaded nanobubbles were then combined with Extracorporeal Shock Waves, acoustic waves widely used in urology and orthopedics, with no side effects. Nanobubbles, with an average diameter of 353.3 ± 15.5 nm, entered two different castration-resistant prostate cancer cells (PC3 and DU145) as demonstrated by flow cytometry and immunofluorescence. The shock waves applied increased the amount of intracellular nanobubbles. Loading nanobubbles with paclitaxel and docetaxel and combining them with shock waves generated the highest cytotoxic effects, resulting in a paclitaxel GI50 reduction of about 55% and in a docetaxel GI50 reduction of about 45% respectively. Combined treatment also affected cell migration. Paclitaxel-loaded nanobubbles and shock waves reduced cell migration by more than 85% with respect to paclitaxel alone; whereas docetaxel-loaded nanobubbles and shock waves reduced cell migration by more than 82% with respect to docetaxel alone. The present data suggest that nanobubbles can act as a stable taxane reservoir in castration-resistant prostate cancer cells and shock waves can further increase drug release from nanobubbles leading to higher cytotoxic and anti-migration effect. PMID:28002459

  4. The role of exosomes and miRNAs in drug-resistance of cancer cells.

    PubMed

    Bach, Duc-Hiep; Hong, Ji-Young; Park, Hyen Joo; Lee, Sang Kook

    2017-07-15

    Chemotherapy, one of the principal approaches for cancer patients, plays a crucial role in controlling tumor progression. Clinically, tumors reveal a satisfactory response following the first exposure to the chemotherapeutic drugs in treatment. However, most tumors sooner or later become resistant to even chemically unrelated anticancer agents after repeated treatment. The reduced drug accumulation in tumor cells is considered one of the significant mechanisms by decreasing drug permeability and/or increasing active efflux (pumping out) of the drugs across the cell membrane. The mechanisms of treatment failure of chemotherapeutic drugs have been investigated, including drug efflux, which is mediated by extracellular vesicles (EVs). Exosomes, a subset of EVs with a size range of 40-150 nm and a lipid bilayer membrane, can be released by all cell types. They mediate specific cell-to-cell interactions and activate signaling pathways in cells they either fuse with or interact with, including cancer cells. Exosomal RNAs are heterogeneous in size but enriched in small RNAs, such as miRNAs. In the primary tumor microenvironment, cancer-secreted exosomes and miRNAs can be internalized by other cell types. MiRNAs loaded in these exosomes might be transferred to recipient niche cells to exert genome-wide regulation of gene expression. How exosomal miRNAs contribute to the development of drug resistance in the context of the tumor microenvironment has not been fully described. In this review, we will highlight recent studies regarding EV-mediated microRNA delivery in formatting drug resistance. We also suggest the use of EVs as an advancing method in antiresistance treatment. © 2017 UICC.

  5. In vitro Development of Chemotherapy and Targeted Therapy Drug-Resistant Cancer Cell Lines: A Practical Guide with Case Studies

    PubMed Central

    McDermott, Martina; Eustace, Alex J.; Busschots, Steven; Breen, Laura; Crown, John; Clynes, Martin; O’Donovan, Norma; Stordal, Britta

    2014-01-01

    The development of a drug-resistant cell line can take from 3 to 18 months. However, little is published on the methodology of this development process. This article will discuss key decisions to be made prior to starting resistant cell line development; the choice of parent cell line, dose of selecting agent, treatment interval, and optimizing the dose of drug for the parent cell line. Clinically relevant drug-resistant cell lines are developed by mimicking the conditions cancer patients experience during chemotherapy and cell lines display between two- and eight-fold resistance compared to their parental cell line. Doses of drug administered are low, and a pulsed treatment strategy is often used where the cells recover in drug-free media. High-level laboratory models are developed with the aim of understanding potential mechanisms of resistance to chemotherapy agents. Doses of drug are higher and escalated over time. It is common to have difficulty developing stable clinically relevant drug-resistant cell lines. A comparative selection strategy of multiple cell lines or multiple chemotherapeutic agents mitigates this risk and gives insight into which agents or type of cell line develops resistance easily. Successful selection strategies from our research are presented. Pulsed-selection produced platinum or taxane-resistant large cell lung cancer (H1299 and H460) and temozolomide-resistant melanoma (Malme-3M and HT144) cell lines. Continuous selection produced a lapatinib-resistant breast cancer cell line (HCC1954). Techniques for maintaining drug-resistant cell lines are outlined including; maintaining cells with chemotherapy, pulse treating with chemotherapy, or returning to master drug-resistant stocks. The heterogeneity of drug-resistant models produced from the same parent cell line with the same chemotherapy agent is explored with reference to P-glycoprotein. Heterogeneity in drug-resistant cell lines reflects the heterogeneity that can occur in clinical

  6. Bcl-XL small interfering RNA suppresses the proliferation of 5-fluorouracil-resistant human colon cancer cells.

    PubMed

    Zhu, Hongbo; Guo, Wei; Zhang, Lidong; Davis, John J; Teraishi, Fuminori; Wu, Shuhong; Cao, Xiaobo; Daniel, Jonathan; Smythe, W Roy; Fang, Bingliang

    2005-03-01

    5-Fluorouracil (5-FU) is commonly used to treat human colon cancers but resistance to this compound is frequently observed in clinics. To characterize mechanisms of resistance to 5-FU and to develop new strategies for overcoming it, we established two cell lines that were resistant to 5-FU but not other chemotherapeutic agents from parental 5-FU-sensitive cell lines. Western blot analysis revealed that these resistant cells overexpressed the proteins Bcl-XL, Bcl-Xs, and Bik, and further data showed that the cells were resistant to 5-FU-induced DNA damage and cell cycle disorder. However, in parental cells, enforced expression of Bcl-XL protein provided only limited protection from 5-FU-induced apoptosis and overexpression of Bcl-XL protein did not affect 5-FU-induced DNA damage or cell cycle changes; these findings suggested that overexpression of Bcl-XL protein was not the major contributor to 5-FU resistance in any of our cells lines. Even so, knockdown of Bcl-XL protein expression by Bcl-XL-specific small interfering RNA could inhibit proliferation more effectively in 5-FU-resistant cells than in 5-FU-sensitive cells, and the combination of Bcl-XL-specific small interfering RNA and 5-FU had additive effect on the inhibition of 5-FU-resistant cells. These results suggest that down-regulation of Bcl-XL protein expression might provide a new treatment strategy for human 5-FU-resistant colon cancer therapy.

  7. Up-regulation of HOXB cluster genes are epigenetically regulated in tamoxifen-resistant MCF7 breast cancer cells.

    PubMed

    Yang, Seoyeon; Lee, Ji-Yeon; Hur, Ho; Oh, Ji Hoon; Kim, Myoung Hee

    2018-05-28

    Tamoxifen (TAM) is commonly used to treat estrogen receptor (ER)-positive breast cancer. Despite the remarkable benefits, resistance to TAM presents a serious therapeutic challenge. Since several HOX transcription factors have been proposed as strong candidates in the development of resistance to TAM therapy in breast cancer, we generated an in vitro model of acquired TAM resistance using ER-positive MCF7 breast cancer cells (MCF7-TAMR), and analyzed the expression pattern and epigenetic states of HOX genes. HOXB cluster genes were uniquely up-regulated in MCF7-TAMR cells. Survival analysis of in slico data showed the correlation of high expression of HOXB genes with poor response to TAM in ER-positive breast cancer patients treated with TAM. Gain- and loss-of-function experiments showed that the overexpression of multi HOXB genes in MCF7 renders cancer cells more resistant to TAM, whereas the knockdown restores TAM sensitivity. Furthermore, activation of HOXB genes in MCF7-TAMR was associated with histone modifications, particularly the gain of H3K9ac. These findings imply that the activation of HOXB genes mediate the development of TAM resistance, and represent a target for development of new strategies to prevent or reverse TAM resistance.

  8. Berberine reverses lapatinib resistance of HER2-positive breast cancer cells by increasing the level of ROS

    PubMed Central

    Zhang, Ruohan; Qiao, Hongyu; Chen, Suning; Chen, Xu; Dou, Kefeng; Wei, Li; Zhang, Jian

    2016-01-01

    ABSTRACT Lapatinib, a novel tyrosine kinase inhibitor of HER2/EGFR, is used to treat HER2-positive breast cancer. However, acquired drug resistance has limited the clinical therapeutic efficacy of lapatinib. Our previous study found that inhibition of autophagy can reduce the proliferation, DNA synthesis, and colony-forming capacity of lapatinib-resistant cells. Berberine has attracted extensive attention due to its wide range of biochemical and pharmacological effects in breast cancer treatment. It has been reported that berberine can induce oxidative stress and the mitochondrial-related apoptotic pathway in human breast cancer cells. In our current study, we found that a new combination therapy of berberine with lapatinib overcame lapatinib resistance. Furthermore, we found that berberine induced apoptosis of lapatinib-resistant cells through upregulating the level of ROS. Specially, lapatinib activated both the c-Myc/pro-Nrf2 pathway and GSK-3β signaling to stabilize Nrf2 and maintain a low level of ROS in resistant cells. However, berberine can upset the ROS balance by downregulating c-Myc to reverse the lapatinib resistance. Our finding provides a novel strategy of using berberine to overcome lapatinib resistance. PMID:27416292

  9. Berberine reverses lapatinib resistance of HER2-positive breast cancer cells by increasing the level of ROS.

    PubMed

    Zhang, Ruohan; Qiao, Hongyu; Chen, Suning; Chen, Xu; Dou, Kefeng; Wei, Li; Zhang, Jian

    2016-09-01

    Lapatinib, a novel tyrosine kinase inhibitor of HER2/EGFR, is used to treat HER2-positive breast cancer. However, acquired drug resistance has limited the clinical therapeutic efficacy of lapatinib. Our previous study found that inhibition of autophagy can reduce the proliferation, DNA synthesis, and colony-forming capacity of lapatinib-resistant cells. Berberine has attracted extensive attention due to its wide range of biochemical and pharmacological effects in breast cancer treatment. It has been reported that berberine can induce oxidative stress and the mitochondrial-related apoptotic pathway in human breast cancer cells. In our current study, we found that a new combination therapy of berberine with lapatinib overcame lapatinib resistance. Furthermore, we found that berberine induced apoptosis of lapatinib-resistant cells through upregulating the level of ROS. Specially, lapatinib activated both the c-Myc/pro-Nrf2 pathway and GSK-3β signaling to stabilize Nrf2 and maintain a low level of ROS in resistant cells. However, berberine can upset the ROS balance by downregulating c-Myc to reverse the lapatinib resistance. Our finding provides a novel strategy of using berberine to overcome lapatinib resistance.

  10. Development and Characterization of a Differentiated Thyroid Cancer Cell Line Resistant to VEGFR-Targeted Kinase Inhibitors

    PubMed Central

    Isham, Crescent R.; Netzel, Brian C.; Bossou, Ayoko R.; Milosevic, Dragana; Cradic, Kendall W.; Grebe, Stefan K.

    2014-01-01

    Background: Vascular endothelial growth factor-targeted kinase inhibitors have emerged as highly promising therapies for radioiodine-refractory metastatic differentiated thyroid cancer. Unfortunately, drug resistance uniformly develops, limiting their therapeutic efficacies and thereby constituting a major clinical problem. Approach and Methods: To study acquired drug resistance and elucidate underlying mechanisms in this setting, BHP2–7 human differentiated thyroid cancer cells were subjected to prolonged continuous in vitro selection with 18 μM pazopanib, a clinically relevant concentration; acquisition of pazopanib resistance was serially assessed, with the resulting resistant cells thereafter subcloned and characterized to assess potential mechanisms of acquired pazopanib resistance. Results: Stable 2- to 4-fold in vitro pazopanib resistance emerged in response to pazopanib selection associated with similar in vitro growth characteristics but with markedly more aggressive in vivo xenograft growth. Selected cells were cross-resistant to sunitinib and to a lesser extent sorafenib but not to MAPK kinase (MEK1/2) inhibition by GSK1120212. Genotyping demonstrated acquisition of a novel activating KRAS codon 13 GGC to GTT (glycine to valine) mutation, consistent with the observed resistance to upstream vascular endothelial growth factor receptor inhibition yet sensitivity to downstream MAPK kinase (MEK1/2) inhibition. Conclusions: Selection of thyroid cancer cells with clinically utilized therapeutics can lead to acquired drug resistance and altered in vivo xenograft behavior that can recapitulate analogous drug resistance observed in patients. This approach has the potential to lead to insights into acquired treatment-related drug resistance in thyroid cancers that can be subjected to subsequent validation in serially collected patient samples and that has the potential to yield preemptive and responsive approaches to dealing with this important clinical problem

  11. Elevated β-catenin activity contributes to carboplatin resistance in A2780cp ovarian cancer cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barghout, Samir H.; Zepeda, Nubia; Xu, Zhihua

    Ovarian cancer is the fifth leading cause of cancer-related mortalities in women. Epithelial ovarian cancer (EOC) represents approximately 90% of all ovarian malignancies. Most EOC patients are diagnosed at advanced stages and current chemotherapy regimens are ineffective against advanced EOC due to the development of chemoresistance. It is important to better understand the molecular mechanisms underlying acquired resistance to effectively manage this disease. In this study, we examined the expression of the Wnt/β-catenin signaling components in the paired cisplatin-sensitive (A2780s) and cisplatin-resistant (A2780cp) EOC cell lines. Our results showed that several negative regulators of Wnt signaling are downregulated, whereas amore » few Wnt ligands and known Wnt/β-catenin target genes are upregulated in A2780cp cells compared to A2780s cells, suggesting that Wnt/β-catenin signaling is more active in A2780cp cells. Further analysis revealed nuclear localization of β-catenin and higher β-catenin transcriptional activity in A2780cp cells compared to A2780s cells. Finally, we demonstrated that chemical inhibition of β-catenin transcriptional activity by its inhibitor CCT036477 sensitized A2780cp cells to carboplatin, supporting a role for β-catenin in carboplatin resistance in A2780cp cells. In conclusion, our data suggest that increased Wnt/β-catenin signaling activity contributes to carboplatin resistance in A2780cp cells. - Highlights: • Wnt ligands and target genes are upregulated in cisplatin resistant A2780cp cells. • Negative regulators of Wnt signaling are down-regulated in A2780cp cells. • β-catenin transcriptional activity is higher in A2780cp cells compared to A2780s cells. • Inhibition of β-catenin activity increases carboplatin cytotoxicity in A2780cp cells.« less

  12. Calotropin from Asclepias curasavica induces cell cycle arrest and apoptosis in cisplatin-resistant lung cancer cells.

    PubMed

    Mo, En-Pan; Zhang, Rong-Rong; Xu, Jun; Zhang, Huan; Wang, Xiao-Xiong; Tan, Qiu-Tong; Liu, Fang-Lan; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-09-16

    Calotropin (M11), an active compound isolated from Asclepias curasavica L., was found to exert strong inhibitory and pro-apoptotic activity specifically against cisplatin-induced resistant non-small cell lung cancer (NSCLC) cells (A549/CDDP). Molecular mechanism study revealed that M11 induced cell cycle arrest at the G2/M phase through down-regulating cyclins, CDK1, CDK2 and up-regulating p53 and p21. Furthermore, M11 accelerated apoptosis through the mitochondrial apoptotic pathway which was accompanied by increase Bax/Bcl-2 ratio, decrease in mitochondrial membrane potential, increase in reactive oxygen species production, activations of caspases 3 and 9 as well as cleavage of poly ADP-ribose polymerase (PARP). The activation and phosphorylation of JNK was also found to be involved in M11-induced apoptosis, and SP610025 (specific JNK inhibitor) partially prevented apoptosis induced by M11. In contrast, all of the effects that M11 induce cell cycle arrest and apoptosis in A549/CDDP cells were not significant in A549 cells. Drugs with higher sensitivity against resistant tumor cells than the parent cells are rather rare. Results of this study supported the potential application of M11 on the non-small lung cancer (NSCLC) with cisplatin resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Mass spectrometry-based metabolic profiling of gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cells.

    PubMed

    Fujimura, Yoshinori; Ikenaga, Naoki; Ohuchida, Kenoki; Setoyama, Daiki; Irie, Miho; Miura, Daisuke; Wariishi, Hiroyuki; Murata, Masaharu; Mizumoto, Kazuhiro; Hashizume, Makoto; Tanaka, Masao

    2014-03-01

    Gemcitabine resistance (GR) is one of the critical issues for therapy for pancreatic cancer, but the mechanism still remains unclear. Our aim was to increase the understanding of GR by metabolic profiling approach. To establish GR cells, 2 human pancreatic cancer cell lines, SUIT-2 and CAPAN-1, were exposed to increasing concentration of gemcitabine. Both parental and chemoresistant cells obtained by this treatment were subjected to metabolic profiling based on liquid chromatography-mass spectrometry. Multivariate statistical analyses, both principal component analysis and orthogonal partial least squares discriminant analysis, distinguished metabolic signature of responsiveness and resistance to gemcitabine in both SUIT-2 and CAPAN-1 cells. Among significantly different (P < 0.005) metabolite peaks between parental and GR cells, we identified metabolites related to several metabolic pathways such as amino acid, nucleotide, energy, cofactor, and vitamin pathways. Decreases in glutamine and proline levels as well as increases in aspartate, hydroxyproline, creatine, and creatinine levels were observed in chemoresistant cells from both cell lines. These results suggest that metabolic profiling can isolate distinct features of pancreatic cancer in the metabolome of gemcitabine-sensitive and GR cells. These findings may contribute to the biomarker discovery and an enhanced understanding of GR in pancreatic cancer.

  14. The influence of the combined treatment with Vadimezan (ASA404) and taxol on the growth of U251 glioblastoma xenografts

    PubMed Central

    2012-01-01

    Background One of the most important biological characteristics of Glioblastoma multiforme (GBM) is high vascular density. Vadimezan (ASA404, DMXAA) belongs to the class of small molecule vascular disrupting agents (VDA) that cause disruption of established tumor vessels and subsequent tumor hemorrhagic necrosis. Its selective antivascular effect is mediated by intratumoral induction of several cytokines including tumor necrosis factor-α (TNF-α), granulocyte-colony-stimulating factor (G-CSF), interleukin 6 (IL-6) and macrophage inflammatory protein 1α (MIP-1α). Preclinical studies have demonstrated that ASA404 acts synergistically with taxanes. In this study, we investigated if treatment of mice bearing U251 human glioblastoma xenografts with ASA404 and taxol may be synergistic. Therapy response was evaluated by measuring changes in tumor size and metabolic activity using 18F-FDG PET (Fluorodeoxyglucose - positron emision tomography) imaging. Methods U251 cells were inoculated s.c. in the right hind limb of NMRI-Foxn1nu athymic female nude mice. Animals were randomly assigned into 4 groups (7–9 animals/group) for treatment: control, taxol, ASA404, and ASA404 plus taxol. The animals received either a single dose of taxol (10 mg/kg), ASA404 (27.5 mg/kg), or taxol (10 mg/kg) plus ASA404 (27.5 mg/kg) administered i.p.; ASA404 was administred 24 h after the treatment with taxol. 4 and 24 h after treatment with ASA404 (28 and 48 h hours after treatment with taxol) 18 F-FDG PET scans were performed. Results The treatment with taxol did not affect the tumor growth in comparison to untreated controls. The treatment of animals with single dose ASA404 alone or in combination with taxol caused a significant delay in tumor growth. The combined treatment did not decrease the growth of the xenografts significantly more than ASA404 alone, but early changes in tumor 18 F-FDG uptake preceded subsequent growth inhibition. The tumor weights, which were

  15. RNA interference of argininosuccinate synthetase restores sensitivity to recombinant arginine deiminase (rADI) in resistant cancer cells

    PubMed Central

    2011-01-01

    Background Sensitivity of cancer cells to recombinant arginine deiminase (rADI) depends on expression of argininosuccinate synthetase (AS), a rate-limiting enzyme in synthesis of arginine from citrulline. To understand the efficiency of RNA interfering of AS in sensitizing the resistant cancer cells to rADI, the down regulation of AS transiently and permanently were performed in vitro, respectively. Methods We studied the use of down-regulation of this enzyme by RNA interference in three human cancer cell lines (A375, HeLa, and MCF-7) as a way to restore sensitivity to rADI in resistant cells. The expression of AS at levels of mRNA and protein was determined to understand the effect of RNA interference. Cell viability, cell cycle, and possible mechanism of the restore sensitivity of AS RNA interference in rADI treated cancer cells were evaluated. Results AS DNA was present in all cancer cell lines studied, however, the expression of this enzyme at the mRNA and protein level was different. In two rADI-resistant cell lines, one with endogenous AS expression (MCF-7 cells) and one with induced AS expression (HeLa cells), AS small interference RNA (siRNA) inhibited 37-46% of the expression of AS in MCF-7 cells. ASsiRNA did not affect cell viability in MCF-7 which may be due to the certain amount of residual AS protein. In contrast, ASsiRNA down-regulated almost all AS expression in HeLa cells and caused cell death after rADI treatment. Permanently down-regulated AS expression by short hairpin RNA (shRNA) made MCF-7 cells become sensitive to rADI via the inhibition of 4E-BP1-regulated mTOR signaling pathway. Conclusions Our results demonstrate that rADI-resistance can be altered via AS RNA interference. Although transient enzyme down-regulation (siRNA) did not affect cell viability in MCF-7 cells, permanent down-regulation (shRNA) overcame the problem of rADI-resistance due to the more efficiency in AS silencing. PMID:21453546

  16. Role of Breast Cancer Resistance Protein (BCRP/ABCG2) in Cancer Drug Resistance

    PubMed Central

    Natarajan, Karthika; Xie, Yi; Baer, Maria R.; Ross, Douglas D.

    2012-01-01

    Since cloning of the ATP-binding cassette (ABC) family member breast cancer resistance protein (BCRP/ABCG2) and its characterization as a multidrug resistance efflux transporter in 1998, BCRP has been the subject of more than two thousand scholarly articles. In normal tissues, BCRP functions as a defense mechanism against toxins and xenobiotics, with expression in the gut, bile canaliculi, placenta, blood-testis and blood-brain barriers facilitating excretion and limiting absorption of potentially toxic substrate molecules, including many cancer chemotherapeutic drugs. BCRP also plays a key role in heme and folate homeostasis, which may help normal cells survive under conditions of hypoxia. BCRP expression appears to be a characteristic of certain normal tissue stem cells termed “side population cells,” which are identified on flow cytometric analysis by their ability to exclude Hoechst 33342, a BCRP substrate fluorescent dye. Hence, BCRP expression may contribute to the natural resistance and longevity of these normal stem cells. Malignant tissues can exploit the properties of BCRP to survive hypoxia and to evade exposure to chemotherapeutic drugs. Evidence is mounting that many cancers display subpopulations of stem cells that are responsible for tumor self-renewal. Such stem cells frequently manifest the “side population” phenotype characterized by expression of BCRP and other ABC transporters. Along with other factors, these transporters may contribute to the inherent resistance of these neoplasms and their failure to be cured. PMID:22248732

  17. Targeting Epithelial-Mesenchymal Transition (EMT) to Overcome Drug Resistance in Cancer.

    PubMed

    Du, Bowen; Shim, Joong Sup

    2016-07-22

    Epithelial-mesenchymal transition (EMT) is known to play an important role in cancer progression, metastasis and drug resistance. Although there are controversies surrounding the causal relationship between EMT and cancer metastasis, the role of EMT in cancer drug resistance has been increasingly recognized. Numerous EMT-related signaling pathways are involved in drug resistance in cancer cells. Cells undergoing EMT show a feature similar to cancer stem cells (CSCs), such as an increase in drug efflux pumps and anti-apoptotic effects. Therefore, targeting EMT has been considered a novel opportunity to overcome cancer drug resistance. This review describes the mechanism by which EMT contributes to drug resistance in cancer cells and summarizes new advances in research in EMT-associated drug resistance.

  18. Mechanism of c-Met and EGFR tyrosine kinase inhibitor resistance through epithelial mesenchymal transition in non-small cell lung cancer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rastogi, Ichwaku; Rajanna, Supriya; Webb, Andrew

    According to currently available estimates from Cancer Research UK, 14.1 million new lung cancer cases were diagnosed and a staggering 8.2 million people worldwide died from lung cancer in 2012. EGFR and c-Met are two tyrosine kinase receptors most commonly overexpressed or mutated in Non-small Cell Lung Cancer (NSCLC) resulting in increased proliferation and survival of lung cancer cells. Tyrosine kinase inhibitors (TKIs), such as erlotinib, approved by the FDA as first/second line therapy for NSCLC patients have limited clinical efficacy due to acquired resistance. In this manuscript, we investigate and discuss the role of epithelial mesenchymal transition (EMT) inmore » the development of resistance against EGFR and c-Met TKIs in NSCLC. Our findings show that Zeb-1, a transcriptional repressor of E-Cadherin, is upregulated in TKI-resistant cells causing EMT. We observed that TKI-resistant cells have increased gene and protein expression of EMT related proteins such as Vimentin, N-Cadherin, β-Catenin and Zeb-1, while expression of E-Cadherin, an important cell adhesion molecule, was suppressed. We also confirmed that TKI-resistant cells display mesenchymal cell type morphology, and have upregulation of β-Catenin which may regulate expression of Zeb-1, a transcriptional repressor of E-Cadherin in TKI-resistant NSCLC cells. Finally, we show that down-regulating Zeb-1 by inducing miR-200a or β-Catenin siRNA can increase drug sensitivity of TKI-resistant cells. - Highlights: • Resistance to TKIs in NSCLC cells is mediated via modulation in EMT related proteins. • EMT may induce c-Met mediated TKI resistance, similar to EGFR TKI resistance. • Role of β-catenin and cadherins in TKI resistance was validated by FACS and qPCR. • Knockdown of β-catenin or Zeb-1 can increase TKI sensitivity in TKI-resistant cells. • Targeting key EMT related proteins may overcome TKI resistance in NSCLC.« less

  19. Characterization of osimertinib (AZD9291)-resistant non-small cell lung cancer NCI-H1975/OSIR cell line

    PubMed Central

    Guo, Xia; Fong, Chi Man Vivienne; Chen, Xiuping; Lu, Jin-Jian

    2016-01-01

    Osimertinib (OSI, also known as AZD9291) is the newest FDA-approved epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor for non-small cell lung cancer (NSCLC) patients with EGFR T790M mutation. However, resistance to OSI is likely to progress and the study of potential OSI-resistant mechanisms in advanced is necessary. Here, the OSI-resistant NCI-H1975/OSIR cells were established. After cells developed resistance to OSI, cell proliferation was decreased while cell migration and invasion were increased. The NCI-H1975/OSIR cells exhibited more resistance to gefitinib, erlotinib, afatinib, rociletinib, doxorubicin, and fluorouracil, meanwhile showing higher sensitivity to paclitaxel, when compared with NCI-H1975 cells. In addition, the NCI-H1975/OSIR cells did not display multidrug resistance phenotype. The activation and expression of EGFR were decreased after cells exhibited resistance. Compared with NCI-H1975 cells, the activation of ERK and AKT in NCI-H1975/OSIR cells could not be significantly inhibited by OSI treatment. Navitoclax (ABT-263)-induced cell viability inhibition and apoptosis were more significant in NCI-H1975/OSIR cells than that in NCI-H1975 cells. Moreover, these effects of navitoclax in NCI-H1975/OSIR cells could be reversed by pretreatment of Z-VAD-FMK. Collectively, loss of EGFR could pose as one of the OSI-resistant mechanisms and navitoclax might be the candidate drug for OSI-resistant NSCLC patients. PMID:27835594

  20. Reversion of apoptotic resistance of TP53-mutated Burkitt lymphoma B-cells to spindle poisons by exogenous activation of JNK and p38 MAP kinases.

    PubMed

    Farhat, M; Poissonnier, A; Hamze, A; Ouk-Martin, C; Brion, J-D; Alami, M; Feuillard, J; Jayat-Vignoles, C

    2014-05-01

    Defects in apoptosis are frequently the cause of cancer emergence, as well as cellular resistance to chemotherapy. These phenotypes may be due to mutations of the tumor suppressor TP53 gene. In this study, we examined the effect of various mitotic spindle poisons, including the new isocombretastatin derivative isoNH2CA-4 (a tubulin-destabilizing molecule, considered to bind to the colchicine site by analogy with combretastatin A-4), on BL (Burkitt lymphoma) cells. We found that resistance to spindle poison-induced apoptosis could be reverted in tumor protein p53 (TP53)-mutated cells by EBV (Epstein Barr virus) infection. This reversion was due to restoration of the intrinsic apoptotic pathway, as assessed by relocation of the pro-apoptotic molecule Bax to mitochondria, loss of mitochondrial integrity and activation of the caspase cascade with PARP (poly ADP ribose polymerase) cleavage. EBV sensitized TP53-mutated BL cells to all spindle poisons tested, including vincristine and taxol, an effect that was systematically downmodulated by pretreatment of cells with inhibitors of p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases. Exogenous activation of p38 and JNK pathways by dihydrosphingosine reverted resistance of TP53-mutated BL cells to spindle poisons. Dihydrosphingosine treatment of TP53-deficient Jurkat and K562 cell lines was also able to induce cell death. We conclude that activation of p38 and JNK pathways may revert resistance of TP53-mutated cells to spindle poisons. This opens new perspectives for developing alternative therapeutic strategies when the TP53 gene is inactivated.

  1. Fisetin mediated apoptotic cell death in parental and Oxaliplatin/irinotecan resistant colorectal cancer cells in vitro and in vivo.

    PubMed

    Jeng, Long-Bin; Kumar Velmurugan, Bharath; Chen, Ming-Cheng; Hsu, Hsi-Hsien; Ho, Tsung-Jung; Day, Cecilia-Hsuan; Lin, Yueh-Min; Padma, V Vijaya; Tu, Chuan-Chou; Huang, Chih-Yang

    2018-09-01

    Irinotecan (CPT11) and Oxaliplatin have been used in combination with fluorouracil and leucovorin for treating colorectal cancer. However, the efficacy of these drugs is reduced due to various side effects and drug resistance. Fisetin, a hydroxyflavone possess anti-proliferative, anti-cancer, anti-inflammatory, and antioxidant activity against various types of cancers. Apart from that, fisetin has been shown to induce cytotoxic effects when combined with other known chemotherapeutic drugs. In this study, we aimed to investigate whether Fisetin was capable of sensitizing both Irinotecan and Oxaliplatin resistance colon cancer cells and explored the possible signaling pathways involved using In vitro and In vivo models. The results showed that Fisetin treatment effectively inhibited cell viability and apoptosis of CPT11-LoVo cells than Oxaliplatin (OR) and parental LoVo cancer cells. Western blot assays suggested that apoptosis was induced by fisetin administration, promoting Caspase-8, and Cytochrome-C expressions possibly by inhibiting aberrant activation of IGF1R and AKT proteins. Furthermore, fisetin inhibited tumor growth in athymic nude mouse xenograft model. Overall, our results provided a basis for Fisetin as a promising agent to treat parental as well as chemoresistance colon cancer. © 2018 Wiley Periodicals, Inc.

  2. Proteomic Signatures of Acquired Letrozole Resistance in Breast Cancer: Suppressed Estrogen Signaling and Increased Cell Motility and Invasiveness*

    PubMed Central

    Tilghman, Syreeta L.; Townley, Ian; Zhong, Qiu; Carriere, Patrick P.; Zou, Jin; Llopis, Shawn D.; Preyan, Lynez C.; Williams, Christopher C.; Skripnikova, Elena; Bratton, Melyssa R.; Zhang, Qiang; Wang, Guangdi

    2013-01-01

    Aromatase inhibitors, such as letrozole, have become the first-line treatment for postmenopausal women with estrogen-dependent breast cancer. However, acquired resistance remains a major clinical obstacle. Previous studies demonstrated constitutive activation of the MAPK signaling, overexpression of HER2, and down-regulation of aromatase and ERα in letrozole-resistant breast cancer cells. Given the complex signaling network involved in letrozole-refractory breast cancer and the lack of effective treatment for hormone resistance, further investigation of aromatase inhibitor resistance by a novel systems biology approach may reveal previously unconsidered molecular changes that could be utilized as therapeutic targets. This study was undertaken to characterize for the first time global proteomic alterations occurring in a letrozole-resistant cell line. A quantitative proteomic analysis of the whole cell lysates of LTLT-Ca (resistant) versus AC-1 cells (sensitive) was performed to identify significant protein expression changes. A total of 1743 proteins were identified and quantified, of which 411 were significantly up-regulated and 452 significantly down-regulated (p < 0.05, fold change > 1.20). Bioinformatics analysis revealed that acquired letrozole resistance is associated with a hormone-independent, more aggressive phenotype. LTLT-Ca cells exhibited 84% and 138% increase in migration and invasion compared with the control cells. The ROCK inhibitor partially abrogated the enhanced migration and invasion of the letrozole-resistant cells. Flow cytometric analyses also demonstrated an increase in vimentin and twist expression in letrozole-resistance cells, suggesting an onset of epithelial to mesenchymal transition (EMT). Moreover, targeted gene expression arrays confirmed a 28-fold and sixfold up-regulation of EGFR and HER2, respectively, whereas ERα and pS2 were dramatically reduced by 28-fold and 1100-fold, respectively. Taken together, our study revealed global

  3. Expression of NK Cell Surface Receptors in Breast Cancer Tissue as Predictors of Resistance to Antineoplastic Treatment

    PubMed Central

    Mariel, Garcia-Chagollan; Edith, Carranza-Torres Irma; Pilar, Carranza-Rosales; Elena, Guzmán-Delgado Nancy; Humberto, Ramírez-Montoya; Guadalupe, Martínez-Silva María; Ignacio, Mariscal-Ramirez; Alfredo, Barrón-Gallardo Carlos; Laura, Pereira-Suárez Ana; Adriana, Aguilar-Lemarroy; Felipe, Jave-Suárez Luis

    2018-01-01

    Background: Currently, one of the most used strategies for the treatment of newly diagnosed patients with breast cancer is neoadjuvant chemotherapy based on the application of taxanes and anthracyclines. However, despite the high number of patients who develop a complete pathological clinical response, resistance and relapse following this therapy continue to be a clinical challenge. As a component of the innate immune system, the cytotoxic function of Natural Killer (NK) cells plays an important role in the elimination of tumor cells. However, the role of NK cells in resistance to systemic therapy in breast cancer remains unclear. The present project aims to evaluate the gene expression profile of human NK cells in breast cancer tissue resistant to treatment with taxanes–anthracyclines. Methods: Biopsies from tumor tissues were obtained from patients with breast cancer without prior treatment. Histopathological analysis and ex vivo exposure to antineoplastic chemotherapeutics were carried out. Alamar blue and lactate dehydrogenase release assays were performed for quantitative analysis of tumor viability. Gene expression profiles from tumor tissues without prior exposure to therapeutic drugs were analyzed by gene expression microarrays and verified by polymerase chain reaction. Results: A significant decrease in gene expression of cell-surface receptors related to NK cells was observed in tumor samples resistant to antineoplastic treatment compared with those that were sensitive to treatment. Conclusion: A decrease in NK cell infiltration into tumor tissue might be a predictive marker for failure of chemotherapeutic treatment in breast cancer. PMID:29558872

  4. Expression of NK Cell Surface Receptors in Breast Cancer Tissue as Predictors of Resistance to Antineoplastic Treatment.

    PubMed

    Mariel, Garcia-Chagollan; Edith, Carranza-Torres Irma; Pilar, Carranza-Rosales; Elena, Guzmán-Delgado Nancy; Humberto, Ramírez-Montoya; Guadalupe, Martínez-Silva María; Ignacio, Mariscal-Ramirez; Alfredo, Barrón-Gallardo Carlos; Laura, Pereira-Suárez Ana; Adriana, Aguilar-Lemarroy; Felipe, Jave-Suárez Luis

    2018-01-01

    Currently, one of the most used strategies for the treatment of newly diagnosed patients with breast cancer is neoadjuvant chemotherapy based on the application of taxanes and anthracyclines. However, despite the high number of patients who develop a complete pathological clinical response, resistance and relapse following this therapy continue to be a clinical challenge. As a component of the innate immune system, the cytotoxic function of Natural Killer (NK) cells plays an important role in the elimination of tumor cells. However, the role of NK cells in resistance to systemic therapy in breast cancer remains unclear. The present project aims to evaluate the gene expression profile of human NK cells in breast cancer tissue resistant to treatment with taxanes-anthracyclines. Biopsies from tumor tissues were obtained from patients with breast cancer without prior treatment. Histopathological analysis and ex vivo exposure to antineoplastic chemotherapeutics were carried out. Alamar blue and lactate dehydrogenase release assays were performed for quantitative analysis of tumor viability. Gene expression profiles from tumor tissues without prior exposure to therapeutic drugs were analyzed by gene expression microarrays and verified by polymerase chain reaction. A significant decrease in gene expression of cell-surface receptors related to NK cells was observed in tumor samples resistant to antineoplastic treatment compared with those that were sensitive to treatment. A decrease in NK cell infiltration into tumor tissue might be a predictive marker for failure of chemotherapeutic treatment in breast cancer.

  5. Omega 3 fatty acids chemosensitize multidrug resistant colon cancer cells by down-regulating cholesterol synthesis and altering detergent resistant membranes composition

    PubMed Central

    2013-01-01

    Background The activity of P-glycoprotein (Pgp) and multidrug resistance related protein 1 (MRP1), two membrane transporters involved in multidrug resistance of colon cancer, is increased by high amounts of cholesterol in plasma membrane and detergent resistant membranes (DRMs). It has never been investigated whether omega 3 polyunsatured fatty acids (PUFAs), which modulate cholesterol homeostasis in dyslipidemic syndromes and have chemopreventive effects in colon cancer, may affect the response to chemotherapy in multidrug resistant (MDR) tumors. Methods We studied the effect of omega 3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in human chemosensitive colon cancer HT29 cells and in their MDR counterpart, HT29-dx cells. Results MDR cells, which overexpressed Pgp and MRP1, had a dysregulated cholesterol metabolism, due to the lower expression of ubiquitin E3 ligase Trc8: this produced lower ubiquitination rate of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCoAR), higher cholesterol synthesis, higher cholesterol content in MDR cells. We found that DHA and EPA re-activated Trc8 E3 ligase in MDR cells, restored the ubiquitination rate of HMGCoAR to levels comparable with chemosensitive cells, reduced the cholesterol synthesis and incorporation in DRMs. Omega 3 PUFAs were incorporated in whole lipids as well as in DRMs of MDR cells, and altered the lipid composition of these compartments. They reduced the amount of Pgp and MRP1 contained in DRMs, decreased the transporters activity, restored the antitumor effects of different chemotherapeutic drugs, restored a proper tumor-immune system recognition in response to chemotherapy in MDR cells. Conclusions Our work describes a new biochemical effect of omega 3 PUFAs, which can be useful to overcome chemoresistance in MDR colon cancer cells. PMID:24225025

  6. Multidrug resistance characterization in multicellular tumour spheroids from two human lung cancer cell lines.

    PubMed

    Barrera-Rodríguez, Raúl; Fuentes, Jorge Morales

    2015-01-01

    Most of the knowledge about the mechanisms of multidrug resistance in lung cancer has been achieved through the use of cell lines isolated from tumours cultivated either in suspensions of isolated cells or in monolayers and following exposition to different cytostatic agents. However, tumour cell lines growing as multicellular tumour spheroids (MTS) frequently develop multicellular resistance in a drug-independent form. The aim of this study was to characterize the phenotypic and functional differences between two human NSCLC cell lines (INER-37 and INER-51) grown as traditional monolayer cultures versus as MTS. After 72 hours treatment with anticancer drugs, chemosensitivity in monolayers and tumour spheroids cultures was assessed using MTT assay. Reverse transcription-polymerase chain reaction was employed to detect the mRNAs of multidrug resistance-related genes. The expression of P-gp was analyzed by immunohistochemical staining and cell cycle profiles were analyzed using FACS. The results indicate that when grown as MTS each lung cancer cell line had different morphologies as well as and abrogation of cell proliferation with decrease of the G2/M phase. Also, MTS acquired multicellular resistance to several chemotherapeutic agents in only a few days of culture which were accomplished by significant changes in the expression of MDR-related genes. Overall, the MTS culture changed the cellular response to drugs nevertheless each of the cell lines studied seems to implement different mechanisms to acquire multicellular resistance.

  7. The relationship between cisplatin resistance and histone deacetylase isoform overexpression in epithelial ovarian cancer cell lines

    PubMed Central

    Kim, Min-Gyun; Pak, Jhang Ho; Choi, Won Ho; Park, Jeong-Yeol; Nam, Joo-Hyun

    2012-01-01

    Objective To investigate the relationship between cisplatin resistance and histone deacetylase (HDAC) isoform overexpression in ovarian cancer cell lines. Methods Expression of four HDAC isoforms (HDAC 1, 2, 3, and 4) in two ovarian cancer cell lines, SKOV3 and OVCAR3, exposed to various concentrations of cisplatin was examined by western blot analyses. Cells were transfected with plasmid DNA of each HDAC. The overexpression of protein and mRNA of each HDAC was confirmed by western blot and reverse transcriptase-polymerase chain reaction analyses, respectively. The cell viability of the SKOV3 and OVCAR3 cells transfected with HDAC plasmid DNA was measured using the cell counting kit-8 assay after treatment with cisplatin. Results The 50% inhibitory concentration of the SKOV3 and OVCAR3 cells can be determined 15-24 hours after treatment with 15 µg/mL cisplatin. The expression level of acetylated histone 3 protein in SKOV3 cells increased after exposure to cisplatin. Compared with control cells at 24 hours after cisplatin exposure, the viability of SKOV3 cells overexpressing HDAC 1 and 3 increased by 15% and 13% (p<0.05), respectively. On the other hand, OVCAR3 cells that overexpressed HDAC 2 and 4 exhibited increased cell viability by 23% and 20% (p<0.05), respectively, compared with control cells 24 hours after exposure to cisplatin. Conclusion In SKOV3 and OVCAR3 epithelial ovarian cancer cell lines, the correlation between HDAC overexpression and cisplatin resistance was confirmed. However, the specific HDAC isoform associated with resistance to cisplatin varied depending on the ovarian cancer cell line. These results may suggest that each HDAC isoform conveys cisplatin resistance via different mechanisms. PMID:22808361

  8. Cisplatin resistance in non-small cell lung cancer cells is associated with an abrogation of cisplatin-induced G2/M cell cycle arrest

    PubMed Central

    Kalayda, Ganna V.; Mannewitz, Mareike; Cinatl, Jindrich; Rothweiler, Florian; Michaelis, Martin; Saafan, Hisham; Ritter, Christoph A.; Jaehde, Ulrich

    2017-01-01

    The efficacy of cisplatin-based chemotherapy in cancer is limited by the occurrence of innate and acquired drug resistance. In order to better understand the mechanisms underlying acquired cisplatin resistance, we have compared the adenocarcinoma-derived non-small cell lung cancer (NSCLC) cell line A549 and its cisplatin-resistant sub-line A549rCDDP2000 with regard to cisplatin resistance mechanisms including cellular platinum accumulation, DNA-adduct formation, cell cycle alterations, apoptosis induction and activation of key players of DNA damage response. In A549rCDDP2000 cells, a cisplatin-induced G2/M cell cycle arrest was lacking and apoptosis was reduced compared to A549 cells, although equitoxic cisplatin concentrations resulted in comparable platinum-DNA adduct levels. These differences were accompanied by changes in the expression of proteins involved in DNA damage response. In A549 cells, cisplatin exposure led to a significantly higher expression of genes coding for proteins mediating G2/M arrest and apoptosis (mouse double minute 2 homolog (MDM2), xeroderma pigmentosum complementation group C (XPC), stress inducible protein (SIP) and p21) compared to resistant cells. This was underlined by significantly higher protein levels of phosphorylated Ataxia telangiectasia mutated (pAtm) and p53 in A549 cells compared to their respective untreated control. The results were compiled in a preliminary model of resistance-associated signaling alterations. In conclusion, these findings suggest that acquired resistance of NSCLC cells against cisplatin is the consequence of altered signaling leading to reduced G2/M cell cycle arrest and apoptosis. PMID:28746345

  9. Oxidative phosphorylation-dependent regulation of cancer cell apoptosis in response to anticancer agents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yadav, N.; Kumar, S.; Marlowe, T.

    Cancer cells tend to develop resistance to various types of anticancer agents, whether they adopt similar or distinct mechanisms to evade cell death in response to a broad spectrum of cancer therapeutics is not fully defined. Current study concludes that DNA-damaging agents (etoposide and doxorubicin), ER stressor (thapsigargin), and histone deacetylase inhibitor (apicidin) target oxidative phosphorylation (OXPHOS) for apoptosis induction, whereas other anticancer agents including staurosporine, taxol, and sorafenib induce apoptosis in an OXPHOS-independent manner. DNA-damaging agents promoted mitochondrial biogenesis accompanied by increased accumulation of cellular and mitochondrial ROS, mitochondrial protein-folding machinery, and mitochondrial unfolded protein response. Induction of mitochondrialmore » biogenesis occurred in a caspase activation-independent mechanism but was reduced by autophagy inhibition and p53-deficiency. Abrogation of complex-I blocked DNA-damage-induced caspase activation and apoptosis, whereas inhibition of complex-II or a combined deficiency of OXPHOS complexes I, III, IV, and V due to impaired mitochondrial protein synthesis did not modulate caspase activity. Mechanistic analysis revealed that inhibition of caspase activation in response to anticancer agents associates with decreased release of mitochondrial cytochrome c in complex-I-deficient cells compared with wild type (WT) cells. Gross OXPHOS deficiencies promoted increased release of apoptosis-inducing factor from mitochondria compared with WT or complex-I-deficient cells, suggesting that cells harboring defective OXPHOS trigger caspase-dependent as well as caspase-independent apoptosis in response to anticancer agents. Interestingly, DNA-damaging agent doxorubicin showed strong binding to mitochondria, which was disrupted by complex-I-deficiency but not by complex-II-deficiency. Thapsigargin-induced caspase activation was reduced upon abrogation of complex-I or gross OXPHOS

  10. Oxidative phosphorylation-dependent regulation of cancer cell apoptosis in response to anticancer agents.

    PubMed

    Yadav, N; Kumar, S; Marlowe, T; Chaudhary, A K; Kumar, R; Wang, J; O'Malley, J; Boland, P M; Jayanthi, S; Kumar, T K S; Yadava, N; Chandra, D

    2015-11-05

    Cancer cells tend to develop resistance to various types of anticancer agents, whether they adopt similar or distinct mechanisms to evade cell death in response to a broad spectrum of cancer therapeutics is not fully defined. Current study concludes that DNA-damaging agents (etoposide and doxorubicin), ER stressor (thapsigargin), and histone deacetylase inhibitor (apicidin) target oxidative phosphorylation (OXPHOS) for apoptosis induction, whereas other anticancer agents including staurosporine, taxol, and sorafenib induce apoptosis in an OXPHOS-independent manner. DNA-damaging agents promoted mitochondrial biogenesis accompanied by increased accumulation of cellular and mitochondrial ROS, mitochondrial protein-folding machinery, and mitochondrial unfolded protein response. Induction of mitochondrial biogenesis occurred in a caspase activation-independent mechanism but was reduced by autophagy inhibition and p53-deficiency. Abrogation of complex-I blocked DNA-damage-induced caspase activation and apoptosis, whereas inhibition of complex-II or a combined deficiency of OXPHOS complexes I, III, IV, and V due to impaired mitochondrial protein synthesis did not modulate caspase activity. Mechanistic analysis revealed that inhibition of caspase activation in response to anticancer agents associates with decreased release of mitochondrial cytochrome c in complex-I-deficient cells compared with wild type (WT) cells. Gross OXPHOS deficiencies promoted increased release of apoptosis-inducing factor from mitochondria compared with WT or complex-I-deficient cells, suggesting that cells harboring defective OXPHOS trigger caspase-dependent as well as caspase-independent apoptosis in response to anticancer agents. Interestingly, DNA-damaging agent doxorubicin showed strong binding to mitochondria, which was disrupted by complex-I-deficiency but not by complex-II-deficiency. Thapsigargin-induced caspase activation was reduced upon abrogation of complex-I or gross OXPHOS deficiency

  11. Oxidative phosphorylation-dependent regulation of cancer cell apoptosis in response to anticancer agents

    DOE PAGES

    Yadav, N.; Kumar, S.; Marlowe, T.; ...

    2015-11-05

    Cancer cells tend to develop resistance to various types of anticancer agents, whether they adopt similar or distinct mechanisms to evade cell death in response to a broad spectrum of cancer therapeutics is not fully defined. Current study concludes that DNA-damaging agents (etoposide and doxorubicin), ER stressor (thapsigargin), and histone deacetylase inhibitor (apicidin) target oxidative phosphorylation (OXPHOS) for apoptosis induction, whereas other anticancer agents including staurosporine, taxol, and sorafenib induce apoptosis in an OXPHOS-independent manner. DNA-damaging agents promoted mitochondrial biogenesis accompanied by increased accumulation of cellular and mitochondrial ROS, mitochondrial protein-folding machinery, and mitochondrial unfolded protein response. Induction of mitochondrialmore » biogenesis occurred in a caspase activation-independent mechanism but was reduced by autophagy inhibition and p53-deficiency. Abrogation of complex-I blocked DNA-damage-induced caspase activation and apoptosis, whereas inhibition of complex-II or a combined deficiency of OXPHOS complexes I, III, IV, and V due to impaired mitochondrial protein synthesis did not modulate caspase activity. Mechanistic analysis revealed that inhibition of caspase activation in response to anticancer agents associates with decreased release of mitochondrial cytochrome c in complex-I-deficient cells compared with wild type (WT) cells. Gross OXPHOS deficiencies promoted increased release of apoptosis-inducing factor from mitochondria compared with WT or complex-I-deficient cells, suggesting that cells harboring defective OXPHOS trigger caspase-dependent as well as caspase-independent apoptosis in response to anticancer agents. Interestingly, DNA-damaging agent doxorubicin showed strong binding to mitochondria, which was disrupted by complex-I-deficiency but not by complex-II-deficiency. Thapsigargin-induced caspase activation was reduced upon abrogation of complex-I or gross OXPHOS

  12. CD24 negative lung cancer cells, possessing partial cancer stem cell properties, cannot be considered as cancer stem cells.

    PubMed

    Xu, Haineng; Mu, Jiasheng; Xiao, Jing; Wu, Xiangsong; Li, Maolan; Liu, Tianrun; Liu, Xinyuan

    2016-01-01

    Cancer stem cells (CSCs) play vital role in lung cancer progression, resistance, metastasis and relapse. Identifying lung CSCs makers for lung CSCs targeting researches are critical for lung cancer therapy. In this study, utilizing previous identified lung CSCs as model, we compared the expression of CD24, CD133 and CD44 between CSCs and non-stem cancer cells. Increased ratio of CD24- cells were found in CSCs. CD24- cells were then sorted by flow cytometry and their proliferative ability, chemo-resistance property and in vivo tumor formation abilities were detected. A549 CD24- cells formed smaller colonies, slower proliferated in comparison to A549 CD24+ cells. Besides, A549 CD24- exhibited stronger resistance to chemotherapy drug. However, A549 CD24- didn't exert any stronger tumor formation ability in vivo, which is the gold standard of CSCs. These results showed that CD24- A549 cells showed some properties of CSCs but not actually CSCs. This study provides evidence that CD24 cannot be considered as lung CSCs marker.

  13. Methotrexate diethyl ester-loaded lipid-core nanocapsules in aqueous solution increased antineoplastic effects in resistant breast cancer cell line.

    PubMed

    Yurgel, Virginia C; Oliveira, Catiuscia P; Begnini, Karine R; Schultze, Eduarda; Thurow, Helena S; Leon, Priscila M M; Dellagostin, Odir A; Campos, Vinicius F; Beck, Ruy C R; Guterres, Silvia S; Collares, Tiago; Pohlmann, Adriana R; Seixas, Fabiana K

    2014-01-01

    Breast cancer is the most frequent cancer affecting women. Methotrexate (MTX) is an antimetabolic drug that remains important in the treatment of breast cancer. Its efficacy is compromised by resistance in cancer cells that occurs through a variety of mechanisms. This study evaluated apoptotic cell death and cell cycle arrest induced by an MTX derivative (MTX diethyl ester [MTX(OEt)2]) and MTX(OEt)2-loaded lipid-core nanocapsules in two MTX-resistant breast adenocarcinoma cell lines, MCF-7 and MDA-MB-231. The formulations prepared presented adequate granulometric profile. The treatment responses were evaluated through flow cytometry. Relying on the mechanism of resistance, we observed different responses between cell lines. For MCF-7 cells, MTX(OEt)2 solution and MTX(OEt)2-loaded lipid-core nanocapsules presented significantly higher apoptotic rates than untreated cells and cells incubated with unloaded lipid-core nanocapsules. For MDA-MB-231 cells, MTX(OEt)2-loaded lipid-core nanocapsules were significantly more efficient in inducing apoptosis than the solution of the free drug. S-phase cell cycle arrest was induced only by MTX(OEt)2 solution. The drug nanoencapsulation improved apoptosis induction for the cell line that presents MTX resistance by lack of transport receptors.

  14. Methotrexate diethyl ester-loaded lipid-core nanocapsules in aqueous solution increased antineoplastic effects in resistant breast cancer cell line

    PubMed Central

    Yurgel, Virginia C; Oliveira, Catiuscia P; Begnini, Karine R; Schultze, Eduarda; Thurow, Helena S; Leon, Priscila MM; Dellagostin, Odir A; Campos, Vinicius F; Beck, Ruy CR; Guterres, Silvia S; Collares, Tiago; Pohlmann, Adriana R; Seixas, Fabiana K

    2014-01-01

    Breast cancer is the most frequent cancer affecting women. Methotrexate (MTX) is an antimetabolic drug that remains important in the treatment of breast cancer. Its efficacy is compromised by resistance in cancer cells that occurs through a variety of mechanisms. This study evaluated apoptotic cell death and cell cycle arrest induced by an MTX derivative (MTX diethyl ester [MTX(OEt)2]) and MTX(OEt)2-loaded lipid-core nanocapsules in two MTX-resistant breast adenocarcinoma cell lines, MCF-7 and MDA-MB-231. The formulations prepared presented adequate granulometric profile. The treatment responses were evaluated through flow cytometry. Relying on the mechanism of resistance, we observed different responses between cell lines. For MCF-7 cells, MTX(OEt)2 solution and MTX(OEt)2-loaded lipid-core nanocapsules presented significantly higher apoptotic rates than untreated cells and cells incubated with unloaded lipid-core nanocapsules. For MDA-MB-231 cells, MTX(OEt)2-loaded lipid-core nanocapsules were significantly more efficient in inducing apoptosis than the solution of the free drug. S-phase cell cycle arrest was induced only by MTX(OEt)2 solution. The drug nanoencapsulation improved apoptosis induction for the cell line that presents MTX resistance by lack of transport receptors. PMID:24741306

  15. Intercellular transfer of P-glycoprotein from the drug resistant human bladder cancer cell line BIU-87 does not require cell-to-cell contact.

    PubMed

    Zhou, Hui-liang; Zheng, Yong-jun; Cheng, Xiao-zhi; Lv, Yi-song; Gao, Rui; Mao, Hou-ping; Chen, Qin

    2013-09-01

    The efflux activity of transmembrane P-glycoprotein prevents various therapeutic drugs from reaching lethal concentrations in cancer cells, resulting in multidrug resistance. We investigated whether drug resistant bladder cancer cells could transfer functional P-glycoprotein to sensitive parental cells. Drug sensitive BIU-87 bladder cancer cells were co-cultured for 48 hours with BIU-87/ADM, a doxorubicin resistant derivative of the same cell line, in a Transwell® system that prevented cell-to-cell contact. The presence of P-glycoprotein in recipient cell membranes was established using fluorescein isothiocyanate, laser scanning confocal microscopy and Western blot. P-glycoprotein mRNA levels were compared between cell types. Rhodamine 123 efflux assay was done to confirm that P-glycoprotein was biologically active. The amount of P-glycoprotein protein in BIU-87 cells co-cultured with BIU-87/ADM was significantly higher than in BIU-87 cells (0.44 vs 0.25) and BIU-87/H33342 cells (0.44 vs 0.26, each p <0.001), indicating P-glycoprotein transfer. P-glycoprotein mRNA expression was significantly higher in BIU-87/ADM cells than in co-cultured BIU-87 cells (1.28 vs 0.30), BIU-87/H33342 (0.28) and BIU-87 cells (0.25, each p <0.001), ruling out a genetic mechanism. After 30 minutes of efflux, rhodamine 123 fluorescence intensity was significantly lower in BIU-87/ADM cells (5.55 vs 51.45, p = 0.004) and co-cultured BIU-87 cells than in BIU-87 cells (14.22 vs 51.45, p <0.001), indicating that P-glycoprotein was functional. Bladder cancer cells can acquire functional P-glycoprotein through a nongenetic mechanism that does not require direct cell contact. This mechanism is consistent with a microparticle mediated process. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  16. Targeting the Golgi apparatus to overcome acquired resistance of non-small cell lung cancer cells to EGFR tyrosine kinase inhibitors

    PubMed Central

    Katayama, Ryohei; Fang, Siyang; Tsutsui, Saki; Akatsuka, Akinobu; Shan, Mingde; Choi, Hyeong-Wook; Fujita, Naoya; Yoshimatsu, Kentaro; Shiina, Isamu; Yamori, Takao; Dan, Shingo

    2018-01-01

    Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (EGFR-TKIs) were demonstrated to provide survival benefit in patients with non-small cell lung cancer (NSCLC) harboring activating mutations of EGFR; however, emergence of acquired resistance to EGFR-TKIs has been shown to cause poor outcome. To overcome the TKI resistance, drugs with different mode of action are required. We previously reported that M-COPA (2-methylcoprophilinamide), a Golgi disruptor, suppressed the growth of gastric cancers overexpressing receptor tyrosine kinases (RTKs) such as hepatocyte growth factor receptor (MET) via downregulating their cell surface expression. In this study, we examined the antitumor effect of M-COPA on NSCLC cells with TKI resistance. As a result, M-COPA effectively downregulated cell surface EGFR and its downstream signals, and finally exerted in vivo antitumor effect in NSCLC cells harboring secondary (T790M/del19) and tertiary (C797S/T790M/del19) mutated EGFR, which exhibit acquired resistance to first- and third generation EGFR-TKIs, respectively. M-COPA also downregulated MET expression potentially involved in the acquired resistance to EGFR-TKIs via bypassing the EGFR pathway blockade. These results provide the first evidence that targeting the Golgi apparatus might be a promising therapeutic strategy to overcome the vicious cycle of TKI resistance in EGFR-mutated NSCLC cells via downregulating cell surface RTK expression. PMID:29416720

  17. Downstream reactions and engineering in the microbially reconstituted pathway for Taxol.

    PubMed

    Jiang, Ming; Stephanopoulos, Gregory; Pfeifer, Blaine A

    2012-05-01

    Taxol (a trademarked product of Bristol-Myers Squibb) is a complex isoprenoid natural product which has displayed potent anticancer activity. Originally isolated from the Pacific yew tree (Taxus brevifolia), Taxol has been mass-produced through processes reliant on plant-derived biosynthesis. Recently, there have been alternative efforts to reconstitute the biosynthetic process through technically convenient microbial hosts, which offer unmatched growth kinetics and engineering potential. Such an approach is made challenging by the need to successfully introduce the significantly foreign enzymatic steps responsible for eventual biosynthesis. Doing so, however, offers the potential to engineer more efficient and economical production processes and the opportunity to design and produce tailored analog compounds with enhanced properties. This mini review will specifically focus on heterologous biosynthesis as it applies to Taxol with an emphasis on the challenges associated with introducing and reconstituting the downstream reaction steps needed for final bioactivity.

  18. [Screening and identification of anoikis-resistant gene UBCH7 in esophageal cancer cells].

    PubMed

    Yang, Yang; Wang, Bo-Shi; Wang, Xiao-Min; Zhang, Yu; Wang, Ming-Rong; Jia, Xue-Mei

    2012-02-01

    Anoikis is a kind of programmed cell death induced by loss of extracellular matrix (ECM) adhesion, which is one of key factors for homestasis. Resistance to anoikis is required for tumor cell metastasis. We have previously shown several anoikis-resistance genes in esophageal squamous cell carcinoma (ESCC). In order to find novel anoikis-resistant genes in ESCC, we constructed retroviral cDNA library using total RNA from ESCC cell lines. NIH 3T3 cells, which are sensitive to anoikis, were infected with the library constructed. The cells were cultured in soft agar, and the clones which can survive in detached states were selected. The cDNAs inserted into the anoikis-resistant NIH3T3 clones were amplified using retroviral specific primers. Sequencing analysis showed that a cDNA fragment inserted into the anoikis-resistant clone contains full coding sequence (ORF) of human UBCH7/UBE2L3 gene. By infection with retrovirus encoding UBCH7 ORF (pMSCV-UBCH7), forced expression of UBCH7 increased the anoikis-resistance of NIH3T3 cells. More importantly, knockdown of UBCH7 expression by siRNA transfection reduced the anoikis-resistant ability of esophageal cancer MLuC1 cells. The data suggest that UBCH7/UBE2L3 gene would be involved in anoikis-resistance in ESCC.

  19. DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells.

    PubMed

    Hu, Hao; Gu, Yuanlong; Qian, Yi; Hu, Benshun; Zhu, Congyuan; Wang, Gaohe; Li, Jianping

    2014-09-12

    Pancreatic cancer is one of the most aggressive human malignancies with extremely poor prognosis. The moderate activity of the current standard gemcitabine and gemcitabine-based regimens was due to pre-existing or acquired chemo-resistance of pancreatic cancer cells. In this study, we explored the potential role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in gemcitabine resistance, and studied the underlying mechanisms. We found that NU-7026 and NU-7441, two DNA-PKcs inhibitors, enhanced gemcitabine-induced cytotoxicity and apoptosis in PANC-1 pancreatic cancer cells. Meanwhile, PANC-1 cells with siRNA-knockdown of DNA-PKcs were more sensitive to gemcitabine than control PANC-1 cells. Through the co-immunoprecipitation (Co-IP) assay, we found that DNA-PKcs formed a complex with SIN1, the latter is an indispensable component of mammalian target of rapamycin (mTOR) complex 2 (mTORC2). DNA-PKcs-SIN1 complexation was required for Akt activation in PANC-1 cells, while inhibition of this complex by siRNA knockdown of DNA-PKcs/SIN1, or by DNA-PKcs inhibitors, prevented Akt phosphorylation in PANC-1 cells. Further, SIN1 siRNA-knockdown also facilitated gemcitabine-induced apoptosis in PANC-1 cells. Finally, DNA-PKcs and p-Akt expression was significantly higher in human pancreatic cancer tissues than surrounding normal tissues. Together, these results show that DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. BAG3 Overexpression and Cytoprotective Autophagy Mediate Apoptosis Resistance in Chemoresistant Breast Cancer Cells.

    PubMed

    Das, Chandan Kanta; Linder, Benedikt; Bonn, Florian; Rothweiler, Florian; Dikic, Ivan; Michaelis, Martin; Cinatl, Jindrich; Mandal, Mahitosh; Kögel, Donat

    2018-03-01

    Target-specific treatment modalities are currently not available for triple-negative breast cancer (TNBC), and acquired chemotherapy resistance is a primary obstacle for the treatment of these tumors. Here we employed derivatives of BT-549 and MDA-MB-468 TNBC cell lines that were adapted to grow in the presence of either 5-Fluorouracil, Doxorubicin or Docetaxel in an aim to identify molecular pathways involved in the adaptation to drug-induced cell killing. All six drug-adapted BT-549 and MDA-MB-468 cell lines displayed cross resistance to chemotherapy and decreased apoptosis sensitivity. Expression of the anti-apoptotic co-chaperone BAG3 was notably enhanced in two thirds (4/6) of the six resistant lines simultaneously with higher expression of HSP70 in comparison to parental controls. Doxorubicin-resistant BT-549 (BT-549 r DOX 20 ) and 5-Fluorouracil-resistant MDA-MB-468 (MDA-MB-468 r 5-FU 2000 ) cells were chosen for further analysis with the autophagy inhibitor Bafilomycin A1 and lentiviral depletion of ATG5, indicating that enhanced cytoprotective autophagy partially contributes to increased drug resistance and cell survival. Stable lentiviral BAG3 depletion was associated with a robust down-regulation of Mcl-1, Bcl-2 and Bcl-xL, restoration of drug-induced apoptosis and reduced cell adhesion in these cells, and these death-sensitizing effects could be mimicked with the BAG3/Hsp70 interaction inhibitor YM-1 and by KRIBB11, a selective transcriptional inhibitor of HSF-1. Furthermore, BAG3 depletion was able to revert the EMT-like transcriptional changes observed in BT-549 r DOX 20 and MDA-MB-468 r 5-FU 2000 cells. In summary, genetic and pharmacological interference with BAG3 is capable to resensitize TNBC cells to treatment, underscoring its relevance for cell death resistance and as a target to overcome therapy resistance of breast cancer. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Anti-tumour activity of two novel compounds in cisplatin-resistant testicular germ cell cancer.

    PubMed

    Nitzsche, B; Gloesenkamp, C; Schrader, M; Hoffmann, B; Zengerling, F; Balabanov, S; Honecker, F; Höpfner, M

    2012-11-20

    Resistance to cisplatin-based chemotherapy is associated with poor prognosis in testicular germ cell cancer, emphasising the need for new therapeutic approaches. In this respect, the therapeutic concept of anti-angiogenesis is of particular interest. In a previous study, we presented two novel anti-angiogenic compounds, HP-2 and HP-14, blocking the tyrosine kinase activity of angiogenic growth factor receptors, such as vascular endothelial growth factor receptor-2 (VEGFR-2), and related signalling pathways in testicular cancer. In this study, we investigated the efficacy of these new compounds in platinum-resistant testicular germ cell tumours (TGCTs), in vitro and in vivo. Drug-induced changes in cell proliferation of the cisplatin-sensitive TGCT cell line 2102EP and its cisplatin-resistant counterpart 2102EP-R, both expressing the VEGFR-2, were evaluated by crystal violet staining. Both compounds inhibited the growth of cisplatin-resistant TGCT cells in a dose-dependent manner. In combination experiments with cisplatin, HP-14 revealed additive growth-inhibitory effects in TGCT cells, irrespective of the level of cisplatin resistance. Anti-angiogenic effects of HP compounds were confirmed by tube formation assays with freshly isolated human umbilical vein endothelial cells. Using TGCT cells inoculated onto the chorioallantoic membrane of fertilised chicken eggs (chicken chorioallantoic membrane assay), the anti-angiogenic and anti-proliferative potency of the novel compounds was also demonstrated in vivo. Gene expression profiling revealed changes in the expression pattern of genes related to DNA damage detection and repair, as well as in chaperone function after treatment with both cisplatin and HP-14, alone or in combination. This suggests that HP-14 can revert the lost effectiveness of cisplatin in the resistant cells by altering the expression of critical genes. The novel compound HP-14 effectively inhibits the growth of cisplatin-resistant TGCT cells and

  2. Human NK cells activated by EBV+ lymphoblastoid cells overcome anti-apoptotic mechanisms of drug resistance in haematological cancer cells

    PubMed Central

    Sánchez-Martínez, Diego; Azaceta, Gemma; Muntasell, Aura; Aguiló, Nacho; Núñez, David; Gálvez, Eva M; Naval, Javier; Anel, Alberto; Palomera, Luis; Vilches, Carlos; Marzo, Isabel; Villalba, Martín; Pardo, Julián

    2015-01-01

    Natural killer (NK) cells recognize and eliminate transformed or infected cells that have downregulated MHC class-I and express specific activating ligands. Recent evidence indicates that allogeneic NK cells are useful to eliminate haematological cancer cells independently of MHC-I expression. However, it is unclear if transformed cells expressing mutations that confer anti-apoptotic properties and chemoresistance will be susceptible to NK cells. Allogeneic primary human NK cells were activated using different protocols and prospectively tested for their ability to eliminate diverse mutant haematological and apoptotic-resistant cancer cell lines as well as patient-derived B-cell chronic lymphocytic leukemia cells with chemotherapy multiresistance. Here, we show that human NK cells from healthy donors activated in vitro with Epstein Barr virus positive (EBV+)-lymphoblastoid cells display an enhanced cytotoxic and proliferative potential in comparison to other protocols of activation such a K562 cells plus interleukin (IL)2. This enhancement enables them to kill more efficiently a variety of haematological cancer cell lines, including a panel of transfectants that mimic natural mutations leading to oncogenic transformation and chemoresistance (e.g., overexpression of Bcl-2, Bcl-XL and Mcl-1 or downregulation of p53, Bak/Bax or caspase activity). The effect was also observed against blasts from B-cell chronic lymphocytic leukemia patients showing multi-resistance to chemotherapy. Our findings demonstrate that particular in vitro activated NK cells may overcome anti-apoptotic mechanisms and oncogenic alterations frequently occurring in transformed cells, pointing toward the use of EBV+-lymphoblastoid cells as a desirable strategy to activate NK cells in vitro for the purpose of treating haematological neoplasia with poor prognosis. PMID:25949911

  3. Magnetic fluid hyperthermia enhances cytotoxicity of bortezomib in sensitive and resistant cancer cell lines.

    PubMed

    Alvarez-Berríos, Merlis P; Castillo, Amalchi; Rinaldi, Carlos; Torres-Lugo, Madeline

    2014-01-01

    The proteasome inhibitor bortezomib (BZ) has shown promising results in some types of cancer, but in others it has had minimal activity. Recent studies have reported enhanced efficacy of BZ when combined with hyperthermia. However, the use of magnetic nanoparticles to induce hyperthermia in combination with BZ has not been reported. This novel hyperthermia modality has shown better potentiation of chemotherapeutics over other types of hyperthermia. We hypothesized that inducing hyperthermia via magnetic nanoparticles (MFH) would enhance the cytotoxicity of BZ in BZ-sensitive and BZ-resistant cancer cells more effectively than hyperthermia using a hot water bath (HWH). Studies were conducted using BZ in combination with MFH in two BZ-sensitive cell lines (MDA-MB-468, Caco-2), and one BZ-resistant cell line (A2780) at two different conditions, ie, 43°C for 30 minutes and 45°C for 30 minutes. These experiments were compared with combined application of HWH and BZ. The results indicate enhanced potentiation between hyperthermic treatment and BZ. MFH combined with BZ induced cytotoxicity in sensitive and resistant cell lines to a greater extent than HWH under the same treatment conditions. The observation that MFH sensitizes BZ-resistant cell lines makes this approach a potentially effective anticancer therapy platform.

  4. GPER promotes tamoxifen-resistance in ER+ breast cancer cells by reduced Bim proteins through MAPK/Erk-TRIM2 signaling axis.

    PubMed

    Yin, Heng; Zhu, Qing; Liu, Manran; Tu, Gang; Li, Qing; Yuan, Jie; Wen, Siyang; Yang, Guanglun

    2017-10-01

    Tamoxifen resistance is a major clinical challenge in breast cancer treatment. Our previous studies find that GPER and its down-stream signaling play a pivotal role in the development of tamoxifen (TAM) resistance. cDNA array analysis indicated a set of genes associated with cell apoptosis are aberrant in GPER activated and TAM-resistant MCF-7R cells compared with TAM-sensitive MCF-7 cells. Among these genes, Bim (also named BCL2-L11), a member of the BH3-only pro-apoptotic protein family is significantly decreased, and TRIM RING finger protein TRIM2 (a ubiquitin ligase) is highly expressed in MCF-7R. To understand the mechanism of TAM-resistance in GPER activated ER+ breast cancer, the function of TRIM2 and Bim inducing cell apoptosis was studied. By using immunohistochemical and western blot analysis, there is an adverse correlation between TRIM2 and Bim in TAM-resistant breast tumor tissues and MCF-7R cells. Knockdown Bim in TAM-sensitive MCF-7 cells or overexpression of Bim in TAM-resistant MCF-7 cells significantly changed its sensibility to TAM through altering the levels of cleaved PARP and caspase-3. Activation of GPER and its downstream signaling MAPK/ERK, not PI3K/AKT, led to enhanced TRIM2 protein levels and affected the binding between TRIM2 and Bim which resulted in a reduced Bim in TAM-resistant breast cancer cells. Thus, the present study provides a novel insight to TAM-resistance in ER-positive breast cancer cells.

  5. CD133(+)/CD44(+)/Oct4(+)/Nestin(+) stem-like cells isolated from Panc-1 cell line may contribute to multi-resistance and metastasis of pancreatic cancer.

    PubMed

    Wang, Dongqing; Zhu, Haitao; Zhu, Ying; Liu, Yanfang; Shen, Huiling; Yin, Ruigen; Zhang, Zhijian; Su, Zhaoliang

    2013-05-01

    Pancreatic cancer is an aggressive malignant disease. Owing to the lack of early symptoms, accompanied by extensive metastasis and high resistance to chemotherapy, pancreatic adenocarcinoma becomes the fourth leading cause of cancer-related deaths. In this study, we identified a subpopulation of cells isolated from the Panc-1 cell line and named pancreatic cancer stem-like cells. These Panc-1 stem-like cells expressed high levels of CD133/CD44/Oct4/Nestin. Compared to Panc-1 cells, Panc-1 stem-like cells were resistant to gemcitabine and expressed high levels of MDR1; furthermore, Panc-1 stem-like cells have high anti-apoptotic, but weak proliferative potential. These results indicated that Panc-1 stem-like cells, as a novel group, may be a potential major cause of pancreatic cancer multidrug resistance and extensive metastasis. Copyright © 2012 Elsevier GmbH. All rights reserved.

  6. Preclinical Evaluation of Genexol-PM, a Nanoparticle Formulation of Paclitaxel, as a Novel Radiosensitizer for the Treatment of Non-Small Cell Lung Cancer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Werner, Michael E.; Cummings, Natalie D.; Sethi, Manish

    2013-07-01

    Purpose: A key research objective in radiation oncology is to identify agents that can improve chemoradiation therapy. Nanoparticle (NP) chemotherapeutics possess several properties, such as preferential accumulation in tumors, that are uniquely suited for chemoradiation therapy. To facilitate the clinical translation of NP chemotherapeutics in chemoradiation therapy, we conducted preclinical evaluation of Genexol-PM, the only clinically approved NP chemotherapeutic with a controlled drug release profile, as a radiosensitizer using non-small cell lung cancer (NSCLC) as a model disease. Methods and Materials: The physical characteristics and drug release profile of Genexol-PM were characterized. Genexol-PM's efficacy as a radiosensitizer was evaluated inmore » vitro using NSCLC cell lines and in vivo using mouse xenograft models of NSCLC. Paclitaxel dose to normal lung and liver after Genexol-PM administration were quantified and compared with that after Taxol administration. Results: Genexol-PM has a size of 23.91 ± 0.41 nm and surface charge of −8.1 ± 3.1 mV. It releases paclitaxel in a controlled release profile. In vitro evaluation of Genexol-PM as a radiosensitizer showed it is an effective radiosensitizer and is more effective than Taxol, its small molecule counterpart, at the half maximal inhibitory concentration. In vivo study of Genexol-PM as a radiosensitizer demonstrated that it is more effective as a radiosensitizer than Taxol. We also found that Genexol-PM leads to lower paclitaxel exposure to normal lung tissue than Taxol at 6 hours postadministration. Conclusions: We have demonstrated that Genexol-PM is more effective than Taxol as a radiosensitizer in the preclinical setting and holds high potential for clinical translation. Our data support the clinical evaluation of Genexol-PM in chemoradiation therapy for NSCLC.« less

  7. The role of Her2-Nrf2 axis in induction of oxaliplatin resistance in colon cancer cells.

    PubMed

    Pirpour Tazehkand, Abbas; Akbarzadeh, Maryam; Velaie, Kobra; Sadeghi, Mohammad Reza; Samadi, Nasser

    2018-04-20

    Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a pivotal role in promoting chemoresistance by regulation of antioxidants and detoxification enzymes. Her2 is a member of tyrosine kinase receptor family with a key function in resistance of cancer cells to chemotherapeutics. The aim of this study was to investigate the possible cross talk between Nrf2 and Her2 mediated signaling pathways in development of oxaliplatin resistance in colon cancer cells. We first generated oxaliplatin-resistant LS174T and SW480 colon cancer cells with different Her2 expression levels by employing IC50 concentrations followed by a resting period. We evaluated the viability and apoptosis of the cells by MTT and flow cytometry assays, respectively. Nrf2 and Her2 gene expression levels were examined by qRT-PCR. The morphology analysis and combination index calculation were performed using the ImagJ and CompuSyn softwares, respectively. Development of resistant cells revealed a marked increase in half maximal inhibitory concentration (IC50) value from 3.95 ± 0.92 μM to 29.27 ± 3.13 μM in SW480 cells and 377 ± 46 nM to 9.59 ± 0.76 μM in LS174T cells with a significant change in morphology of the cells from elongated to small round shape (p < 0.05). Her2 expression level was increased in both types of resistant cells, but the Nrf2 expression was increased in LS174T resistant (LS174T/Res) cells and decreased in SW480/Res cells which were consistent with the level of resistance in these cells (25 fold increase in IC50 value in LS174T/Res cells versus 7 fold increase in this value in SW480/Res cells). Inhibition of either Nrf2 or Her2 alone and in combination caused a significant increase in oxaliplatin-induced cytotoxicity and apoptosis with maximum effects in SW480/Res cells with low Her2 and Nrf2 expression levels. Altogether, our results suggest that inhibition of Nrf2 signaling in colon cancer patients with Her2 overexpression can be considered as

  8. Oxidative stress contributes to the tamoxifen-induced killing of breast cancer cells: implications for tamoxifen therapy and resistance

    PubMed Central

    Bekele, Raie T.; Venkatraman, Ganesh; Liu, Rong-Zong; Tang, Xiaoyun; Mi, Si; Benesch, Matthew G. K.; Mackey, John R.; Godbout, Roseline; Curtis, Jonathan M.; McMullen, Todd P. W.; Brindley, David N.

    2016-01-01

    Tamoxifen is the accepted therapy for patients with estrogen receptor-α (ERα)-positive breast cancer. However, clinical resistance to tamoxifen, as demonstrated by recurrence or progression on therapy, is frequent and precedes death from metastases. To improve breast cancer treatment it is vital to understand the mechanisms that result in tamoxifen resistance. This study shows that concentrations of tamoxifen and its metabolites, which accumulate in tumors of patients, killed both ERα-positive and ERα-negative breast cancer cells. This depended on oxidative damage and anti-oxidants rescued the cancer cells from tamoxifen-induced apoptosis. Breast cancer cells responded to tamoxifen-induced oxidation by increasing Nrf2 expression and subsequent activation of the anti-oxidant response element (ARE). This increased the transcription of anti-oxidant genes and multidrug resistance transporters. As a result, breast cancer cells are able to destroy or export toxic oxidation products leading to increased survival from tamoxifen-induced oxidative damage. These responses in cancer cells also occur in breast tumors of tamoxifen-treated mice. Additionally, high levels of expression of Nrf2, ABCC1, ABCC3 plus NAD(P)H dehydrogenase quinone-1 in breast tumors of patients at the time of diagnosis were prognostic of poor survival after tamoxifen therapy. Therefore, overcoming tamoxifen-induced activation of the ARE could increase the efficacy of tamoxifen in treating breast cancer. PMID:26883574

  9. Overcoming Drug Resistance in Pancreatic Cancer

    PubMed Central

    Long, Jiang; Zhang, Yuqing; Yu, Xianjun; Yang, Jingxuan; LeBrun, Drake; Chen, Changyi; Yao, Qizhi; Li, Min

    2011-01-01

    Introduction Pancreatic cancer has the worst survival rate of all cancers. The current standard care for metastatic pancreatic cancer is gemcitabine, however, the success of this treatment is poor and overall survival has not improved for decades. Drug resistance (both intrinsic and acquired) is thought to be a major reason for the limited benefit of most pancreatic cancer therapies. Areas covered Previous studies have indicated various mechanisms of drug resistance in pancreatic cancer, including changes in individual genes or signaling pathways, the influence of the tumor microenvironment, and the presence of highly resistant stem cells. This review summarizes recent advances in the mechanisms of drug resistance in pancreatic cancer, and potential strategies to overcome this. Expert Opinion Increasing drug delivery efficiency and decreasing drug resistance is the current aim in pancreatic cancer treatment, and will also benefit the treatment of other cancers. Understanding the molecular and cellular basis of drug resistance in pancreatic cancer will lead to the development of novel therapeutic strategies with the potential to sensitize pancreatic cancer to chemotherapy, and to increase the efficacy of current treatments in a wide variety of human cancers. PMID:21391891

  10. Neutral evolution of drug resistant colorectal cancer cell populations is independent of their KRAS status

    PubMed Central

    Blagoev, Krastan B.; Wilkerson, Julia; Burotto, Mauricio; Kim, Chul; Espinal-Domínguez, Edward; García-Alfonso, Pilar; Alimchandani, Meghna; Miettinen, Markku; Blanco-Codesido, Montserrat

    2017-01-01

    Emergence of tumor resistance to an anti-cancer therapy directed against a putative target raises several questions including: (1) do mutations in the target/pathway confer resistance? (2) Are these mutations pre-existing? (3) What is the relative fitness of cells with/without the mutation? We addressed these questions in patients with metastatic colorectal cancer (mCRC). We conducted an exhaustive review of published data to establish a median doubling time for CRCs and stained a cohort of CRCs to document mitotic indices. We analyzed published data and our own data to calculate rates of growth (g) and regression (d, decay) of tumors in patients with CRC correlating these results with the detection of circulating MT-KRAS DNA. Additionally we estimated mathematically the caloric burden of such tumors using data on mitotic and apoptotic indices. We conclude outgrowth of cells harboring intrinsic or acquired MT-KRAS cannot explain resistance to anti-EGFR (epidermal growth factor receptor) antibodies. Rates of tumor growth with panitumumab are unaffected by presence/absence of MT-KRAS. While MT-KRAS cells may be resistant to anti-EGFR antibodies, WT-KRAS cells also rapidly bypass this blockade suggesting inherent resistance mechanisms are responsible and a neutral evolution model is most appropriate. Using the above clinical data on tumor doubling times and mitotic and apoptotic indices we estimated the caloric intake required to support tumor growth and suggest it may explain in part cancer-associated cachexia. PMID:28981524

  11. Neutral evolution of drug resistant colorectal cancer cell populations is independent of their KRAS status.

    PubMed

    Blagoev, Krastan B; Wilkerson, Julia; Burotto, Mauricio; Kim, Chul; Espinal-Domínguez, Edward; García-Alfonso, Pilar; Alimchandani, Meghna; Miettinen, Markku; Blanco-Codesido, Montserrat; Fojo, Tito

    2017-01-01

    Emergence of tumor resistance to an anti-cancer therapy directed against a putative target raises several questions including: (1) do mutations in the target/pathway confer resistance? (2) Are these mutations pre-existing? (3) What is the relative fitness of cells with/without the mutation? We addressed these questions in patients with metastatic colorectal cancer (mCRC). We conducted an exhaustive review of published data to establish a median doubling time for CRCs and stained a cohort of CRCs to document mitotic indices. We analyzed published data and our own data to calculate rates of growth (g) and regression (d, decay) of tumors in patients with CRC correlating these results with the detection of circulating MT-KRAS DNA. Additionally we estimated mathematically the caloric burden of such tumors using data on mitotic and apoptotic indices. We conclude outgrowth of cells harboring intrinsic or acquired MT-KRAS cannot explain resistance to anti-EGFR (epidermal growth factor receptor) antibodies. Rates of tumor growth with panitumumab are unaffected by presence/absence of MT-KRAS. While MT-KRAS cells may be resistant to anti-EGFR antibodies, WT-KRAS cells also rapidly bypass this blockade suggesting inherent resistance mechanisms are responsible and a neutral evolution model is most appropriate. Using the above clinical data on tumor doubling times and mitotic and apoptotic indices we estimated the caloric intake required to support tumor growth and suggest it may explain in part cancer-associated cachexia.

  12. Mechanistic Exploration of Cancer Stem Cell Marker Voltage-Dependent Calcium Channel α2δ1 Subunit-mediated Chemotherapy Resistance in Small-Cell Lung Cancer.

    PubMed

    Yu, Jiangyong; Wang, Shuhang; Zhao, Wei; Duan, Jianchun; Wang, Zhijie; Chen, Hanxiao; Tian, Yanhua; Wang, Di; Zhao, Jun; An, Tongtong; Bai, Hua; Wu, Meina; Wang, Jie

    2018-05-01

    Purpose: Chemoresistance in small-cell lung cancer (SCLC) is reportedly attributed to the existence of resistant cancer stem cells (CSC). Studies involving CSC-specific markers and related mechanisms in SCLC remain limited. This study explored the role of the voltage-dependent calcium channel α2δ1 subunit as a CSC marker in chemoresistance of SCLC, and explored the potential mechanisms of α2δ1-mediated chemoresistance and strategies of overcoming the resistance. Experimental Design: α2δ1-positive cells were identified and isolated from SCLC cell lines and patient-derived xenograft (PDX) models, and CSC-like properties were subsequently verified. Transcriptome sequencing and Western blotting were carried out to identify pathways involved in α2δ1-mediated chemoresistance in SCLC. In addition, possible interventions to overcome α2δ1-mediated chemoresistance were examined. Results: Different proportions of α2δ1 + cells were identified in SCLC cell lines and PDX models. α2δ1 + cells exhibited CSC-like properties (self-renewal, tumorigenic, differentiation potential, and high expression of genes related to CSCs and drug resistance). Chemotherapy induced the enrichment of α2δ1 + cells instead of CD133 + cells in PDXs, and an increased proportion of α2δ1 + cells corresponded to increased chemoresistance. Activation and overexpression of ERK in the α2δ1-positive H1048 cell line was identified at the protein level. mAb 1B50-1 was observed to improve the efficacy of chemotherapy and delay relapse as maintenance therapy in PDX models. Conclusions: SCLC cells expressing α2δ1 demonstrated CSC-like properties, and may contribute to chemoresistance. ERK may play a key role in α2δ1-mediated chemoresistance. mAb 1B50-1 may serve as a potential anti-SCLC drug. Clin Cancer Res; 24(9); 2148-58. ©2018 AACR . ©2018 American Association for Cancer Research.

  13. Multidrug resistance reversal and apoptosis induction in human colon cancer cells by some flavonoids present in citrus plants.

    PubMed

    Wesołowska, Olga; Wiśniewski, Jerzy; Sroda-Pomianek, Kamila; Bielawska-Pohl, Aleksandra; Paprocka, Maria; Duś, Danuta; Duarte, Noélia; Ferreira, Maria-José U; Michalak, Krystyna

    2012-11-26

    Multidrug resistance (MDR) of cancer cells constitutes one of the main reasons for chemotherapy failure. The search for nontoxic modulators that reduce MDR is a task of great importance. An ability to enhance apoptosis of resistant cells would also be beneficial. In the present study, the MDR reversal and apoptosis-inducing potency of three flavonoids produced by Citrus plants, namely, naringenin (1a), aromadendrin (2), and tangeretin (3), and the methylated naringenin derivatives (1b, 1c), have been studied in sensitive (LoVo) and multidrug-resistant (LoVo/Dx) human colon adenocarcinoma cells. Cytotoxicity of methoxylated flavonoids was higher as compared to hydroxylated analogues. Only 3 turned out to inhibit P-glycoprotein, as demonstrated by a rhodamine 123 accumulation assay. It also increased doxorubicin accumulation in LoVo/Dx cells and enabled doxorubicin to enter cellular nuclei. In addition, 3 was found to be an effective MDR modulator in resistant cells by sensitizing them to doxorubicin. Tangeretin-induced caspase-3 activation and elevated surface phosphatidylserine exposure demonstrated its apoptosis-inducing activity in LoVo/Dx cells, while the other flavonoids evaluated were not active. Additionally, 3 was more toxic to resistant rather than to sensitive cancer cells. Its apoptosis-inducing activity was also higher in LoVo/Dx than in LoVo cells. It was concluded that the activity of 3 against multidrug-resistant cancer cells may be enhanced by its apoptosis-inducing activity.

  14. Salvianolic acid B reverses multidrug resistance in nude mice bearing human colon cancer stem cells.

    PubMed

    Guo, Piaoting; Wang, Jianchao; Gao, Wencang; Liu, Xia; Wu, Shaofei; Wan, Boshun; Xu, Lei; Li, Yanhua

    2018-05-29

    Salvianolic acid B (SalB) is a water‑soluble phenolic compound, extractable from Salvia miltiorrhiza, and has previously been demonstrated to reverse tumor multidrug resistance (MDR) in colon cancer cells. Cancer stem cells (CSCs) are closely associated with drug resistance. Therefore, establishing a nude mouse model bearing human colon CSCs is important for the study of the mechanisms underlying colon cancer drug resistance as well as the reversal of drug resistance. The present study aimed to establish a nude mouse model bearing human colon CSCs and to investigate the effects of SalB on the drug resistance exhibited by the nude mouse model as well as determine its underlying mechanism. Cells from two colon cancer cell lines (LoVo and HCT‑116) were cultured in serum‑free medium to obtain CSCs‑enriched spheroid cells. Following this, nude mice were transplanted with LoVo and HCT‑116 colon CSCs to establish the CSC nude mouse model, which was subsequently demonstrated to exhibit MDR. The results of the present study revealed that following treatment with SalB, the chemotherapeutic drug resistance of xenografts was reversed to a certain extent. Western blot analysis was performed to investigate the expression levels of cluster of differentiation (CD)44, CD133, transcription factor sox‑2 (SOX2) and ATP‑binding cassette sub‑family G member 2 (ABCG2) proteins, and the results demonstrated that treatment with SalB downregulated the expression of CD44, SOX2 and ABCG2 proteins in both LoVo and HCT‑116 colon CSCs xenografts. In conclusion, the results of the present study revealed that a serum‑free suspension method can be performed to successfully isolate colon CSCs. In addition, a nude mice bearing colon CSCs animal model was successfully established, and associated tumors were confirmed to exhibit MDR. Furthermore, SalB was demonstrated to successfully reverse MDR in nude mice bearing LoVo and HCT‑116 colon CSCs, as well as suppress the expression

  15. Bypassing multidrug resistance in human breast cancer cells with lipid/polymer particle assemblies

    PubMed Central

    Li, Bo; Xu, Hui; Li, Zhen; Yao, Mingfei; Xie, Meng; Shen, Haijun; Shen, Song; Wang, Xinshi; Jin, Yi

    2012-01-01

    Background Multidrug resistance (MDR) mediated by the overexpression of adenosine triphosphate (ATP)-binding cassette (ABC) transporters, such as P-glycoprotein (P-gp), remains one of the major obstacles to effective cancer chemotherapy. In this study, lipid/particle assemblies named LipoParticles (LNPs), consisting of a dimethyldidodecylammonium bromide (DMAB)-modified poly(lactic-co-glycolic acid) (PLGA) nanoparticle core surrounded by a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) shell, were specially designed for anticancer drugs to bypass MDR in human breast cancer cells that overexpress P-gp. Methods Doxorubicin (DOX), a chemotherapy drug that is a P-gp substrate, was conjugated to PLGA and encapsulated in the self-assembled LNP structure. Physiochemical properties of the DOX-loaded LNPs were characterized in vitro. Cellular uptake, intracellular accumulation, and cytotoxicity were compared in parental Michigan Cancer Foundation (MCF)-7 cells and P-gp-overexpressing, resistant MCF-7/adriamycin (MCF-7/ADR) cells. Results This study found that the DOX formulated in LNPs showed a significantly increased accumulation in the nuclei of drug-resistant cells relative to the free drug, indicating that LNPs could alter intracellular traffic and bypass drug efflux. The cytotoxicity of DOX loaded-LNPs had a 30-fold lower half maximal inhibitory concentration (IC50) value than free DOX in MCF-7/ADR, measured by the colorimetric cell viability (MTT) assay, correlated with the strong nuclear retention of the drug. Conclusion The results show that this core-shell lipid/particle structure could be a promising strategy to bypass MDR. PMID:22275834

  16. Overcoming acquired drug resistance in colorectal cancer cells by targeted delivery of 5-FU with EGF grafted hollow mesoporous silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Lijue; She, Xiaodong; Wang, Tao; He, Li; Shigdar, Sarah; Duan, Wei; Kong, Lingxue

    2015-08-01

    Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The effect and mechanism of 5-FU loaded EGF grafted HMSNs (EGF-HMSNs-5-FU) in overcoming acquired drug resistance in SW480/ADR cells were studied. The EGF-HMSNs were demonstrated to be specifically internalized in EGFR overexpressed SW480/ADR cells via a receptor-mediated endocytosis and can escape from endo-lysosomes. The EGF-HMSNs-5-FU exhibited much higher cytotoxicity on SW480/ADR cells than HMSNs-5-FU and free 5-FU while the plain HMSNs did not show significant cytotoxicity. The mechanism of EGF-HMSNs-5-FU in overcoming drug resistance in SW480/ADR cells could be attributed to the specific internalization of EGF-HMSNs-5-FU in EGFR overexpressed cells which can lead to high intracellular drug accumulation and cause cell death through S phase arrest.Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The

  17. Lectin array and glycogene expression analyses of ovarian cancer cell line A2780 and its cisplatin-resistant derivate cell line A2780-cp.

    PubMed

    Zhao, Ran; Qin, Wenjun; Qin, Ruihuan; Han, Jing; Li, Can; Wang, Yisheng; Xu, Congjian

    2017-01-01

    Ovarian cancer is one of the most lethal gynecological malignancies, in which platinum resistance is a common cause of its relapse and death. Glycosylation has been reported to be involved in drug resistance, and glycomic analyses of ovarian cancer may improve our understanding of the mechanisms underlying cancer cell drug resistance and provide potential biomarkers and therapeutic targets. The serous ovarian cancer cell line A2780 and its platinum-resistant counterpart A2780-cp were used in this study. We performed a lectin array analysis to compare the glycosylation patterns of the two cell lines, a gene expression array was employed to probe the differences in glycogenes. Furthermore, the results were verified by lectin blots. A2780-cp cell exhibited stronger intensities of Lens culinaris (LCA) Canavalia ensiformis (ConA), and Lycopersicon esculentum (LEL) and weaker intensities of Sambucus nigra (SNA) lectins. The gene expression array analysis revealed increased expression of Fut8, B3gnt4, B3gnt5, B4galt2 and decreased expression of Fut1 and ST6GalNAc 6 expression were evident in the A2780-cp cells. The lectin blot confirmed the differences in LCA, ConA, SNA and LEL between the A2780 and A2780-cp cells. The combination of the lectin and gene expression analyses showed that the levels of core fucosylation and poly-LacNAc were increased in the A2780-cp cells and the levels of Fuc α1-2(gal β1-4) GlcNAc and α2-6-linked sialic structures were decreased in the A2780-cp cells. These glycans represent potential biomarkers and might be involved in the mechanism of drug resistance in ovarian cancer.

  18. Low-dose naltrexone suppresses ovarian cancer and exhibits enhanced inhibition in combination with cisplatin.

    PubMed

    Donahue, Renee N; McLaughlin, Patricia J; Zagon, Ian S

    2011-07-01

    Ovarian cancer is the leading cause of death from gynecological malignancies. Although initial therapeutic modalities are successful, 65% of these women relapse with only palliative treatments available thereafter. Endogenous opioids repress the proliferation of human ovarian cancer cells in vitro, and do so in a receptor-mediated manner. The present study examined whether modulation of opioid systems by the opioid antagonist naltrexone (NTX), alone or in combination with standard of care therapies (taxol/paclitaxel, cisplatin), alters human ovarian cancer cell proliferation in tissue culture and tumor progression in mice. Administration of NTX for six hours every two days, but not continuously, reduced DNA synthesis and cell replication from vehicle-treated controls in tissue culture. Moreover, brief exposure to NTX in combination with taxol or cisplatin had an enhanced anticancer action. Mice with established ovarian tumors and treated with a low dosage of NTX (LDN), which invokes a short period of opioid receptor blockade, repressed tumor progression in a non-toxic fashion by reducing DNA synthesis and angiogenesis but not altering cell survival. The combination of LDN with cisplatin, but not taxol, resulted in an additive inhibitory effect on tumorigenesis with enhanced depression of DNA synthesis and angiogenesis. LDN combined with cisplatin alleviated the toxicity (e.g. weight loss) associated with cisplatin. LDN treatment upregulated the expression of the opioid growth factor (OGF, chemical term ([Met(5)]-enkephalin) and its receptor, OGFr. Previous tissue culture studies have reported that OGF is the only opioid peptide with antiproliferative activity on ovarian cancer cells, with OGF action mediated by OGFr. Thus, the common denominator of intermittent opioid receptor blockade by short-term NTX or LDN on ovarian cancer proliferation and tumorigenesis recorded herein appears to be related to the OGF-OGFr axis. These preclinical data may offer a non

  19. A cell-targeted, size-photocontrollable, nuclear-uptake nanodrug delivery system for drug-resistant cancer therapy.

    PubMed

    Qiu, Liping; Chen, Tao; Öçsoy, Ismail; Yasun, Emir; Wu, Cuichen; Zhu, Guizhi; You, Mingxu; Han, Da; Jiang, Jianhui; Yu, Ruqin; Tan, Weihong

    2015-01-14

    The development of multidrug resistance (MDR) has become an increasingly serious problem in cancer therapy. The cell-membrane overexpression of P-glycoprotein (P-gp), which can actively efflux various anticancer drugs from the cell, is a major mechanism of MDR. Nuclear-uptake nanodrug delivery systems, which enable intranuclear release of anticancer drugs, are expected to address this challenge by bypassing P-gp. However, before entering the nucleus, the nanocarrier must pass through the cell membrane, necessitating coordination between intracellular and intranuclear delivery. To accommodate this requirement, we have used DNA self-assembly to develop a nuclear-uptake nanodrug system carried by a cell-targeted near-infrared (NIR)-responsive nanotruck for drug-resistant cancer therapy. Via DNA hybridization, small drug-loaded gold nanoparticles (termed nanodrugs) can self-assemble onto the side face of a silver-gold nanorod (NR, termed nanotruck) whose end faces were modified with a cell type-specific internalizing aptamer. By using this size-photocontrollable nanodrug delivery system, anticancer drugs can be efficiently accumulated in the nuclei to effectively kill the cancer cells.

  20. Regulation of voltage-gated potassium channels attenuates resistance of side-population cells to gefitinib in the human lung cancer cell line NCI-H460.

    PubMed

    Choi, Seon Young; Kim, Hang-Rae; Ryu, Pan Dong; Lee, So Yeong

    2017-02-21

    Side-population (SP) cells that exclude anti-cancer drugs have been found in various tumor cell lines. Moreover, SP cells have a higher proliferative potential and drug resistance than main population cells (Non-SP cells). Also, several ion channels are responsible for the drug resistance and proliferation of SP cells in cancer. To confirm the expression and function of voltage-gated potassium (Kv) channels of SP cells, these cells, as well as highly expressed ATP-binding cassette (ABC) transporters and stemness genes, were isolated from a gefitinib-resistant human lung adenocarcinoma cell line (NCI-H460), using Hoechst 33342 efflux. In the present study, we found that mRNA expression of Kv channels in SP cells was different compared to Non-SP cells, and the resistance of SP cells to gefitinib was weakened with a combination treatment of gefitinib and Kv channel blockers or a Kv7 opener, compared to single-treatment gefitinib, through inhibition of the Ras-Raf signaling pathway. The findings indicate that Kv channels in SP cells could be new targets for reducing the resistance to gefitinib.

  1. Scriptaid overcomes hypoxia-induced cisplatin resistance in both wild-type and mutant p53 lung cancer cells

    PubMed Central

    Pradhan, Shrikant; Mahajan, Divyank; Kaur, Prabhjot; Pandey, Namita; Sharma, Chandresh; Srivastava, Tapasya

    2016-01-01

    Non-small cell lung cancer (NSCLC), comprising 85% of lung cancer cases, has been associated with resistance to chemo/radiotherapy. The hypoxic tumor micro-environment, where insufficient vasculature results in poor drug penetrance and sub-optimal chemotherapy in the tumor interiors contributes heavily to this resistance. Additionally, epigenetic changes in tumorigenic cells also change their response to different forms of therapy. In our study, we have investigated the effectiveness of a combination of cisplatin with scriptaid [a pan-Histone Deacetylase inhibitor (HDACi)] in a model that mimics the tumor microenvironment of hypoxia and sub-lethal chemotherapy. Scriptaid synergistically increases the efficacy of cisplatin in normoxia as well as hypoxia, accompanied with reduced metastasis and enhanced DNA damage. Addition of scriptaid also overcomes the cisplatin resistance exhibited in lung cancer cells with stabilized hypoxia inducible factor 1 (HIF1)-α (mutant) and mutant p53. Molecular studies showed that the combination treatment increased apoptotic cell death in both normoxia and hypoxia with a dual role of p38MAPK. Together, our results suggest that the combination of low dose cisplatin and scriptaid is cytotoxic to NSCLC lines, can overcome hypoxia induced resistance and mutant p53- induced instability often associated with this cancer, and has the potential to be an effective therapeutic modality. PMID:27708247

  2. Mitochondrial Delivery of Doxorubicin Using MITO-Porter Kills Drug-Resistant Renal Cancer Cells via Mitochondrial Toxicity.

    PubMed

    Yamada, Yuma; Munechika, Reina; Kawamura, Eriko; Sakurai, Yu; Sato, Yusuke; Harashima, Hideyoshi

    2017-09-01

    Most anticancer drugs are intended to function in the nuclei of cancer cells. If an anticancer drug could be delivered to mitochondria, the source of cellular energy, this organelle would be destroyed, resulting in the arrest of the energy supply and the killing of the cancer cells. To achieve such an innovative strategy, a mitochondrial drug delivery system targeted to cancer cells will be required. We recently reported on the development of a MITO-Porter, a liposome for mitochondrial delivery. In this study, we validated the utility of such a cancer therapeutic strategy by delivering anticancer drugs directly to mitochondria. We succeeded in packaging doxorubicin (DOX) as a model cargo in MITO-Porter to produce a DOX-MITO-Porter. We evaluated cellular toxicity of OS-RC-2 cell, a type of DOX-resistant cancer cell, after delivering DOX to mitochondria using the MITO-Porter system. Cell viability was decreased by the DOX-MITO-Porter treatment, while cell viability was not decreased in the case of naked DOX and a conventional DOX liposomal formulation. We also found a relationship between cellular toxicity and mitochondrial toxicity. The use of a MITO-Porter system for mitochondrial delivery of a toxic agent represents a possible therapeutic strategy for treating drug-resistant cancers. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  3. Microenvironmental Modulation of Decorin and Lumican in Temozolomide-Resistant Glioblastoma and Neuroblastoma Cancer Stem-Like Cells.

    PubMed

    Farace, Cristiano; Oliver, Jaime Antonio; Melguizo, Consolacion; Alvarez, Pablo; Bandiera, Pasquale; Rama, Ana Rosa; Malaguarnera, Giulia; Ortiz, Raul; Madeddu, Roberto; Prados, Jose

    2015-01-01

    The presence of cancer stem cells (CSCs) or tumor-initiating cells can lead to cancer recurrence in a permissive cell-microenvironment interplay, promoting invasion in glioblastoma (GBM) and neuroblastoma (NB). Extracellular matrix (ECM) small leucine-rich proteoglycans (SLRPs) play multiple roles in tissue homeostasis by remodeling the extracellular matrix (ECM) components and modulating intracellular signaling pathways. Due to their pan-inhibitory properties against receptor tyrosine kinases (RTKs), SLRPs are reported to exert anticancer effects in vitro and in vivo. However, their roles seem to be tissue-specific and they are also involved in cancer cell migration and drug resistance, paving the way to complex different scenarios. The aim of this study was to determine whether the SLRPs decorin (DCN) and lumican (LUM) are recruited in cell plasticity and microenvironmental adaptation of differentiated cancer cells induced towards stem-like phenotype. Floating neurospheres were generated by applying CSC enrichment medium (neural stem cell serum-free medium, NSC SFM) to the established SF-268 and SK-N-SH cancer cell lines, cellular models of GBM and NB, respectively. In both models, the time-dependent synergistic activation of DCN and LUM was observed. The highest DCN and LUM mRNA/protein expression was detected after cell exposure to NSC SFM for 8/12 days, considering these cells as SLRP-expressing (SLRP+) CSC-like. Ultrastructural imaging showed the cellular heterogeneity of both the GBM and NB neurospheres and identified the inner living cells. Parental cell lines of both GBM and NB grew only in soft agar + NSC SFM, whereas the secondary neurospheres (originated from SLRP+ t8 CSC-like) showed lower proliferation rates than primary neurospheres. Interestingly, the SLRP+ CSC-like from the GBM and NB neurospheres were resistant to temozolomide (TMZ) at concentrations >750 μM. Our results suggest that GBM and NB CSC-like promote the activation of huge quantities

  4. Cytoplasmic RAP1 mediates cisplatin resistance of non-small cell lung cancer.

    PubMed

    Xiao, Lu; Lan, Xiaoying; Shi, Xianping; Zhao, Kai; Wang, Dongrui; Wang, Xuejun; Li, Faqian; Huang, Hongbiao; Liu, Jinbao

    2017-05-18

    Cytotoxic chemotherapy agents (e.g., cisplatin) are the first-line drugs to treat non-small cell lung cancer (NSCLC) but NSCLC develops resistance to the agent, limiting therapeutic efficacy. Despite many approaches to identifying the underlying mechanism for cisplatin resistance, there remains a lack of effective targets in the population that resist cisplatin treatment. In this study, we sought to investigate the role of cytoplasmic RAP1, a previously identified positive regulator of NF-κB signaling, in the development of cisplatin resistance in NSCLC cells. We found that the expression of cytoplasmic RAP1 was significantly higher in high-grade NSCLC tissues than in low-grade NSCLC; compared with a normal pulmonary epithelial cell line, the A549 NSCLC cells exhibited more cytoplasmic RAP1 expression as well as increased NF-κB activity; cisplatin treatment resulted in a further increase of cytoplasmic RAP1 in A549 cells; overexpression of RAP1 desensitized the A549 cells to cisplatin, and conversely, RAP1 depletion in the NSCLC cells reduced their proliferation and increased their sensitivity to cisplatin, indicating that RAP1 is required for cell growth and has a key mediating role in the development of cisplatin resistance in NSCLC cells. The RAP1-mediated cisplatin resistance was associated with the activation of NF-κB signaling and the upregulation of the antiapoptosis factor BCL-2. Intriguingly, in the small portion of RAP1-depleted cells that survived cisplatin treatment, no induction of NF-κB activity and BCL-2 expression was observed. Furthermore, in established cisplatin-resistant A549 cells, RAP1 depletion caused BCL2 depletion, caspase activation and dramatic lethality to the cells. Hence, our results demonstrate that the cytoplasmic RAP1-NF-κB-BCL2 axis represents a key pathway to cisplatin resistance in NSCLC cells, identifying RAP1 as a marker and a potential therapeutic target for cisplatin resistance of NSCLC.

  5. Microenvironmental Modulation of Decorin and Lumican in Temozolomide-Resistant Glioblastoma and Neuroblastoma Cancer Stem-Like Cells

    PubMed Central

    Melguizo, Consolacion; Alvarez, Pablo; Bandiera, Pasquale; Rama, Ana Rosa; Malaguarnera, Giulia; Ortiz, Raul; Madeddu, Roberto; Prados, Jose

    2015-01-01

    The presence of cancer stem cells (CSCs) or tumor-initiating cells can lead to cancer recurrence in a permissive cell–microenvironment interplay, promoting invasion in glioblastoma (GBM) and neuroblastoma (NB). Extracellular matrix (ECM) small leucine-rich proteoglycans (SLRPs) play multiple roles in tissue homeostasis by remodeling the extracellular matrix (ECM) components and modulating intracellular signaling pathways. Due to their pan-inhibitory properties against receptor tyrosine kinases (RTKs), SLRPs are reported to exert anticancer effects in vitro and in vivo. However, their roles seem to be tissue-specific and they are also involved in cancer cell migration and drug resistance, paving the way to complex different scenarios. The aim of this study was to determine whether the SLRPs decorin (DCN) and lumican (LUM) are recruited in cell plasticity and microenvironmental adaptation of differentiated cancer cells induced towards stem-like phenotype. Floating neurospheres were generated by applying CSC enrichment medium (neural stem cell serum-free medium, NSC SFM) to the established SF-268 and SK-N-SH cancer cell lines, cellular models of GBM and NB, respectively. In both models, the time-dependent synergistic activation of DCN and LUM was observed. The highest DCN and LUM mRNA/protein expression was detected after cell exposure to NSC SFM for 8/12 days, considering these cells as SLRP-expressing (SLRP+) CSC-like. Ultrastructural imaging showed the cellular heterogeneity of both the GBM and NB neurospheres and identified the inner living cells. Parental cell lines of both GBM and NB grew only in soft agar + NSC SFM, whereas the secondary neurospheres (originated from SLRP+ t8 CSC-like) showed lower proliferation rates than primary neurospheres. Interestingly, the SLRP+ CSC-like from the GBM and NB neurospheres were resistant to temozolomide (TMZ) at concentrations >750 μM. Our results suggest that GBM and NB CSC-like promote the activation of huge quantities

  6. Expression of P-gp, MRP, LRP, GST-π and TopoIIα and intrinsic resistance in human lung cancer cell lines.

    PubMed

    Wang, Jiarui; Zhang, Jinhui; Zhang, Lichuan; Zhao, Long; Fan, Sufang; Yang, Zhonghai; Gao, Fei; Kong, Ying; Xiao, Gary Guishan; Wang, Qi

    2011-11-01

    This study aimed to determine the relationship between the endogenous levels of P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), lung resistance-related protein (LRP), glutathione-s-transferase-π (GST‑π) and topoisomerase IIα (TopoIIα) and intrinsic drug resistance in four human lung cancer cell lines, SK-MES-1, SPCA-1, NCI-H-460 and NCI-H-446, of different histological types. The expression of P-gp, MRP, LRP, GST-π and TopoIIα was measured by immunofluorescence, Western blotting and RT-PCR. Drug resistance to cisplatin, doxorubicin and VP-16 was determined using MTT assays. The correlation between expression of the resistance-related proteins and their roles in the resistance to drugs in these cancer cell lines was analyzed. We found that the endogenous levels of P-gp, MRP, LRP, GST-π and TopoIIα in the four cell lines varied. The level of GST-π in the SK-MES-1 cells was the highest, whereas the level of P-gp in the SPCA-1 cells was the lowest. The chemoresistance to cisplatin, doxorubicin and VP-16 in the four cell lines was different. The SPCA-1 cell line was most resistance to cisplatin; SK-MES-1 was most resistance to VP-16; whereas SK-MES-1 was most sensitive to doxorubicin. There was a positive correlation between GST-π expression and resistance to cisplatin, between TopoIIα expression and resistance to VP-16; and a negative correlation was noted between TopoIIα expression and resistance to doxorubicin. In summary, the endogenous expression of P-gp, MRP, LRP, GST-π and TopoIIα was different in the four human lung cancer cell lines of different histological types, and this variance may be associated with the variation in chemosensitivity to cisplatin, doxorubicin and VP-16. Among the related proteins, GST-π may be useful for the prediction of the intrinsic resistance to cisplatin, whereas TopoIIα may be useful to predict resistance to doxorubicin and VP-16 in human lung cancer cell lines.

  7. Genipin-induced inhibition of uncoupling protein-2 sensitizes drug-resistant cancer cells to cytotoxic agents.

    PubMed

    Mailloux, Ryan J; Adjeitey, Cyril Nii-Klu; Harper, Mary-Ellen

    2010-10-13

    Uncoupling protein-2 (UCP2) is known to suppress mitochondrial reactive oxygen species (ROS) production and is employed by drug-resistant cancer cells to mitigate oxidative stress. Using the drug-sensitive HL-60 cells and the drug-resistant MX2 subline as model systems, we show that genipin, a UCP2 inhibitor, sensitizes drug-resistant cells to cytotoxic agents. Increased MX2 cell death was observed upon co-treatment with genipin and different doses of menadione, doxorubicin, and epirubicin. DCFH-DA fluorimetry revealed that the increase in MX2 cell death was accompanied by enhanced cellular ROS levels. The drug-induced increase in ROS was linked to genipin-mediated inhibition of mitochondrial proton leak. State 4 and resting cellular respiratory rates were higher in the MX2 cells in comparison to the HL-60 cells, and the increased respiration was readily suppressed by genipin in the MX2 cells. UCP2 accounted for a remarkable 37% of the resting cellular oxygen consumption indicating that the MX2 cells are functionally reliant on this protein. Higher amounts of UCP2 protein were detected in the MX2 versus the HL-60 mitochondria. The observed effects of genipin were absent in the HL-60 cells pointing to the selectivity of this natural product for drug-resistant cells. The specificity of genipin for UCP2 was confirmed using CHO cells stably expressing UCP2 in which genipin induced an ∼22% decrease in state 4 respiration. These effects were absent in empty vector CHO cells expressing no UCP2. Thus, the chemical inhibition of UCP2 with genipin sensitizes multidrug-resistant cancer cells to cytotoxic agents.

  8. Tenascin-C induces resistance to apoptosis in pancreatic cancer cell through activation of ERK/NF-κB pathway.

    PubMed

    Shi, Meiyan; He, Xiaodan; Wei, Wei; Wang, Juan; Zhang, Ti; Shen, Xiaohong

    2015-06-01

    As a glycol-protein located in extracellular matrix (ECM), tenascin-C (TNC) is absent in most normal adult tissues but is highly expressed in the majority of malignant solid tumors. Pancreatic cancer is characterized by an abundant fibrous tissue rich in TNC. Although it was reported that TNC's expression increased in the progression from low-grade precursor lesions to invasive cancer and was associated with tumor differentiation in human pancreatic cancer, studies on the relations between TNC and tumor progression in pancreatic cancer were rare. In this study, we performed an analysis to determine the effects of TNC on modulating cell apoptosis and chemo-resistance and explored its mechanisms involving activation in pancreatic cancer cell. The expressions of TNC, ERK1/2/p-ERK1/2, Bcl-xL and Bcl-2 were detected by immunohistochemistry and western blotting. Then the effects of exogenous and endogenous TNC on the regulation of tumor proliferation, apoptosis and gemcitabine cytotoxicity were investigated. The associations among the TNC knockdown, TNC stimulation and expressions of ERK1/2/NF-κB/p65 and apoptotic regulatory proteins were also analyzed in cell lines. The mechanism of TNC on modulating cancer cell apoptosis and drug resistant through activation of ERK1/2/NF-κB/p65 signals was evaluated. The effect of TNC on regulating cell cycle distribution was also tested. TNC, ERK1/2/p-ERK1/2, and apoptotic regulatory proteins Bcl-xL and Bcl-2 were highly expressed in human pancreatic cancer tissues. In vitro, exogenous TNC promoted pancreatic cancer cell growth also mediates basal as well as starved and drug-induced apoptosis in pancreatic cancer cells. The effects of TNC on anti-apoptosis were induced by the activation state of ERK1/2/NF-κB/p65 signals in pancreatic cell. TNC phosphorylate ERK1/2 to induce NF-κB/p65 nucleus translocation. The latter contributes to promote Bcl-xL, Bcl-2 protein expressions and reduce caspase activity, which inhibit cell apoptotic

  9. Therapeutic strategies to overcome crizotinib resistance in non-small cell lung cancers harboring the fusion oncogene EML4-ALK

    PubMed Central

    Katayama, Ryohei; Khan, Tahsin M.; Benes, Cyril; Lifshits, Eugene; Ebi, Hiromichi; Rivera, Victor M.; Shakespeare, William C.; Iafrate, A. John; Engelman, Jeffrey A.; Shaw, Alice T.

    2011-01-01

    The echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion oncogene represents a molecular target in a small subset of non-small cell lung cancers (NSCLCs). This fusion leads to constitutive ALK activation with potent transforming activity. In a pivotal phase 1 clinical trial, the ALK tyrosine kinase inhibitor (TKI) crizotinib (PF-02341066) demonstrated impressive antitumor activity in the majority of patients with NSCLC harboring ALK fusions. However, despite these remarkable initial responses, cancers eventually develop resistance to crizotinib, usually within 1 y, thereby limiting the potential clinical benefit. To determine how cancers acquire resistance to ALK inhibitors, we established a model of acquired resistance to crizotinib by exposing a highly sensitive EML4-ALK–positive NSCLC cell line to increasing doses of crizotinib until resistance emerged. We found that cells resistant to intermediate doses of crizotinib developed amplification of the EML4-ALK gene. Cells resistant to higher doses (1 μM) also developed a gatekeeper mutation, L1196M, within the kinase domain, rendering EML4-ALK insensitive to crizotinib. This gatekeeper mutation was readily detected using a unique and highly sensitive allele-specific PCR assay. Although crizotinib was ineffectual against EML4-ALK harboring the gatekeeper mutation, we observed that two structurally different ALK inhibitors, NVP-TAE684 and AP26113, were highly active against the resistant cancer cells in vitro and in vivo. Furthermore, these resistant cells remained highly sensitive to the Hsp90 inhibitor 17-AAG. Thus, we have developed a model of acquired resistance to ALK inhibitors and have shown that second-generation ALK TKIs or Hsp90 inhibitors are effective in treating crizotinib-resistant tumors harboring secondary gatekeeper mutations. PMID:21502504

  10. The cellular uptake mechanism, intracellular transportation, and exocytosis of polyamidoamine dendrimers in multidrug-resistant breast cancer cells.

    PubMed

    Zhang, Jie; Liu, Dan; Zhang, Mengjun; Sun, Yuqi; Zhang, Xiaojun; Guan, Guannan; Zhao, Xiuli; Qiao, Mingxi; Chen, Dawei; Hu, Haiyang

    2016-01-01

    Polyamidoamine dendrimers, which can deliver drugs and genetic materials to resistant cells, are attracting increased research attention, but their transportation behavior in resistant cells remains unclear. In this paper, we performed a systematic analysis of the cellular uptake, intracellular transportation, and efflux of PAMAM-NH2 dendrimers in multidrug-resistant breast cancer cells (MCF-7/ADR cells) using sensitive breast cancer cells (MCF-7 cells) as the control. We found that the uptake rate of PAMAM-NH2 was much lower and exocytosis of PAMAM-NH2 was much greater in MCF-7/ADR cells than in MCF-7 cells due to the elimination of PAMAM-NH2 from P-glycoprotein and the multidrug resistance-associated protein in MCF-7/ADR cells. Macropinocytosis played a more important role in its uptake in MCF-7/ADR cells than in MCF-7 cells. PAMAM-NH2 aggregated and became more degraded in the lysosomal vesicles of the MCF-7/ADR cells than in those of the MCF-7 cells. The endoplasmic reticulum and Golgi complex were found to participate in the exocytosis rather than endocytosis process of PAMAM-NH2 in both types of cells. Our findings clearly showed the intracellular transportation process of PAMAM-NH2 in MCF-7/ADR cells and provided a guide of using PAMAM-NH2 as a drug and gene vector in resistant cells.

  11. Targeting the Warburg effect with a novel glucose transporter inhibitor to overcome gemcitabine resistance in pancreatic cancer cells

    PubMed Central

    Lai, I-Lu; Chou, Chih-Chien; Lai, Po-Ting; Fang, Chun-Sheng; Shirley, Lawrence A.; Yan, Ribai; Mo, Xiaokui; Bloomston, Mark; Kulp, Samuel K.; Bekaii-Saab, Tanios; Chen, Ching-Shih

    2014-01-01

    Gemcitabine resistance remains a significant clinical challenge. Here, we used a novel glucose transporter (Glut) inhibitor, CG-5, as a proof-of-concept compound to investigate the therapeutic utility of targeting the Warburg effect to overcome gemcitabine resistance in pancreatic cancer. The effects of gemcitabine and/or CG-5 on viability, survival, glucose uptake and DNA damage were evaluated in gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cell lines. Mechanistic studies were conducted to determine the molecular basis of gemcitabine resistance and the mechanism of CG-5-induced sensitization to gemcitabine. The effects of CG-5 on gemcitabine sensitivity were investigated in a xenograft tumor model of gemcitabine-resistant pancreatic cancer. In contrast to gemcitabine-sensitive pancreatic cancer cells, the resistant Panc-1 and Panc-1GemR cells responded to gemcitabine by increasing the expression of ribonucleotide reductase M2 catalytic subunit (RRM2) through E2F1-mediated transcriptional activation. Acting as a pan-Glut inhibitor, CG-5 abrogated this gemcitabine-induced upregulation of RRM2 through decreased E2F1 expression, thereby enhancing gemcitabine-induced DNA damage and inhibition of cell survival. This CG-5-induced inhibition of E2F1 expression was mediated by the induction of a previously unreported E2F1-targeted microRNA, miR-520f. The addition of oral CG-5 to gemcitabine therapy caused greater suppression of Panc-1GemR xenograft tumor growth in vivo than either drug alone. Glut inhibition may be an effective strategy to enhance gemcitabine activity for the treatment of pancreatic cancer. PMID:24879635

  12. 53BP1 depletion causes PARP inhibitor resistance in ATM-deficient breast cancer cells.

    PubMed

    Hong, Ruoxi; Ma, Fei; Zhang, Weimin; Yu, Xiying; Li, Qing; Luo, Yang; Zhu, Changjun; Jiang, Wei; Xu, Binghe

    2016-09-09

    Mutations in DNA damage response factors BRCA1 and BRCA2 confer sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors in breast and ovarian cancers. BRCA1/BRCA2-defective tumors can exhibit resistance to PARP inhibitors via multiple mechanisms, one of which involves loss of 53BP1. Deficiency in the DNA damage response factor ataxia-telangiectasia mutated (ATM) can also sensitize tumors to PARP inhibitors, raising the question of whether the presence or absence of 53BP1 can predict sensitivity of ATM-deficient breast cancer to these inhibitors. Cytotoxicity of PARP inhibitor and ATM inhibitor in breast cancer cell lines was assessed by MTS, colony formation and apoptosis assays. ShRNA lentiviral vectors were used to knockdown 53BP1 expression in breast cancer cell lines. Phospho-ATM and 53BP1 protein expressions were determined in human breast cancer tissues by immunohistochemistry (IHC). We show that inhibiting ATM increased cytotoxicity of PARP inhibitor in triple-negative and non-triple-negative breast cancer cell lines, and depleting the cells of 53BP1 reduced this cytotoxicity. Inhibiting ATM abrogated homologous recombination induced by PARP inhibitor, and down-regulating 53BP1 partially reversed this effect. Further, overall survival was significantly better in triple-negative breast cancer patients with lower levels of phospho-ATM and tended to be better in patients with negative 53BP1. These results suggest that 53BP1 may be a predictor of PARP inhibitor resistance in patients with ATM-deficient tumors.

  13. Anticancer Effects of the Nitric Oxide-Modified Saquinavir Derivative Saquinavir-NO against Multidrug-Resistant Cancer Cells12

    PubMed Central

    Rothweiler, Florian; Michaelis, Martin; Brauer, Peter; Otte, Jürgen; Weber, Kristoffer; Fehse, Boris; Doerr, Hans Wilhelm; Wiese, Michael; Kreuter, Jörg; Al-Abed, Yousef; Nicoletti, Ferdinando; Cinatl, Jindrich

    2010-01-01

    The human immunodeficiency virus (HIV) protease inhibitor saquinavir shows anticancer activity. Although its nitric oxide-modified derivative saquinavir-NO (saq-NO) was less toxic to normal cells, it exerted stronger inhibition of B16 melanoma growth in syngeneic C57BL/6 mice than saquinavir did. Saq-NO has been shown to block proliferation, upregulate p53 expression, and promote differentiation of C6 glioma and B16 cells. The anticancer activity of substances is frequently hampered by cancer cell chemoresistance mechanisms. Therefore, we here investigated the roles of p53 and the ATP-binding cassette (ABC) transporters P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), and breast cancer resistance protein 1 (BCRP1) in cancer cell sensitivity to saq-NO to get more information about the potential of saq-NO as anticancer drug. Saq-NO exerted anticancer effects in lower concentrations than saquinavir in a panel of human cancer cell lines. Neither p53 mutation or depletion nor expression of P-gp, MRP1, or BCRP1 affected anticancer activity of saq-NO or saquinavir. Moreover, saq-NO sensitized P-gp-, MRP1-, or BCRP1-expressing cancer cells to chemotherapy. Saq-NO induced enhanced sensitization of P-gp- or MRP1-expressing cancer cells to chemotherapy compared with saquinavir, whereas both substances similarly sensitized BCRP1-expressing cells. Washout kinetics and ABC transporter ATPase activities demonstrated that saq-NO is a substrate of P-gp as well as of MRP1. These data support the further investigation of saq-NO as an anticancer drug, especially in multidrug-resistant tumors. PMID:21170266

  14. Reactive oxygen species-mediated synergistic and preferential induction of cell death and reduction of clonogenic resistance in breast cancer cells by combined cisplatin and FK228.

    PubMed

    Pluchino, Lenora Ann; Choudhary, Shambhunath; Wang, Hwa-Chain Robert

    2016-10-10

    Safe and effective combination chemotherapy regimens against breast cancer are lacking. We used our cellular system, consisting of the non-cancerous human breast epithelial MCF10A cell line and its derived tumorigenic, oncogenic H-Ras-expressing, MCF10A-Ras cell line, to investigate the effectiveness of a combination chemotherapy regimen in treating breast cancer cells using two FDA-approved agents, cisplatin and FK228. Cisplatin and FK228 significantly, synergistically, and preferentially induced death and reduced drug resistance of MCF10A-Ras versus MCF10A cells. The ERK-Nox-ROS pathway played a major role in both synergistic cell death induction and GSH-level reduction, which contributed to the synergistic suppression of drug resistance in cells. Enhancement of the Ras-ERK-Nox pathway by combined cisplatin and FK228 significantly increased ROS levels, leading to induction of death, reduction of drug resistance, and induction of DNA damage and oxidation in cancerous MCF10A-Ras cells. Furthermore, synergistic induction of cell death and reduction of drug resistance by combined cisplatin and FK228 in breast cells is independent of their estrogen receptor status. Our study suggests that combined cisplatin and FK228 should be considered in clinical trials as a new regimen for therapeutic control of breast cancers. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. CD10-/ALDH- cells are the sole cisplatin-resistant component of a novel ovarian cancer stem cell hierarchy.

    PubMed

    Ffrench, Brendan; Gasch, Claudia; Hokamp, Karsten; Spillane, Cathy; Blackshields, Gordon; Mahgoub, Thamir Mahmoud; Bates, Mark; Kehoe, Louise; Mooney, Aoibhinn; Doyle, Ronan; Doyle, Brendan; O'Donnell, Dearbhaile; Gleeson, Noreen; Hennessy, Bryan T; Stordal, Britta; O'Riain, Ciaran; Lambkin, Helen; O'Toole, Sharon; O'Leary, John J; Gallagher, Michael F

    2017-10-19

    It is long established that tumour-initiating cancer stem cells (CSCs) possess chemoresistant properties. However, little is known of the mechanisms involved, particularly with respect to the organisation of CSCs as stem-progenitor-differentiated cell hierarchies. Here we aimed to elucidate the relationship between CSC hierarchies and chemoresistance in an ovarian cancer model. Using a single cell-based approach to CSC discovery and validation, we report a novel, four-component CSC hierarchy based around the markers cluster of differentiation 10 (CD10) and aldehyde dehydrogenase (ALDH). In a change to our understanding of CSC biology, resistance to chemotherapy drug cisplatin was found to be the sole property of CD10 - /ALDH - CSCs, while all four CSC types were sensitive to chemotherapy drug paclitaxel. Cisplatin treatment quickly altered the hierarchy, resulting in a three-component hierarchy dominated by the cisplatin-resistant CD10 - /ALDH - CSC. This organisation was found to be hard-wired in a long-term cisplatin-adapted model, where again CD10 - /ALDH - CSCs were the sole cisplatin-resistant component, and all CSC types remained paclitaxel-sensitive. Molecular analysis indicated that cisplatin resistance is associated with inherent- and adaptive-specific drug efflux and DNA-damage repair mechanisms. Clinically, low CD10 expression was consistent with a specific set of ovarian cancer patient samples. Collectively, these data advance our understanding of the relationship between CSC hierarchies and chemoresistance, which was shown to be CSC- and drug-type specific, and facilitated by specific and synergistic inherent and adaptive mechanisms. Furthermore, our data indicate that primary stage targeting of CD10 - /ALDH - CSCs in specific ovarian cancer patients in future may facilitate targeting of recurrent disease, before it ever develops.

  16. [Cell cycle and apoptosis mechanisms implicated in intravesical chemotherapy resistances in superficial bladder cancer].

    PubMed

    Burgués Gasión, J P; Pontones Moreno, J L; Vera Donoso, C D; Jiménez Cruz, J F; Ozonas Moragues, M

    2005-10-01

    It is well documented the effectiveness of intravesical chemotherapy following transurethral resection to prevent recurrences of superficial bladder cancer. But it is also known that efficacy may be limited by tumour cell resistance to one or several of the drugs available for instillation. In addition to the genetically determined unicellular mechanisms classically described in the literature such as glycoprotein P-170 expression (mdr-1), overexpression of Bcl-2 or glutation S-transferase activity, it has been recently shown that multicellular mechanisms may also be involved in drug resistance. Multicellular resistance can only be demonstrated in three-dimensional cultures and fails to be shown in monolayers or cell suspensions. This is explained by the fact that cell-to-cell and cell-to-stroma adhesion limits drug penetration and by the variable susceptibility to cytotoxicity determined by oxygen and tissue proliferation gradients. A better understanding of the molecular mechanisms involved in drug resistance is necessary to increase intravesical chemotherapy effectiveness. Current research includes improving drug penetration, searching resistance reversing agents and developing in vitro chemosensitivity tests to identify drug resistance.

  17. Cytokinetic study of MCF-7 cells treated with commercial and recombinant bromelain.

    PubMed

    Fouz, Nour; Amid, Azura; Hashim, Yumi Zuhanis Has-Yun

    2014-01-01

    Breast cancer is a leading cause of death in women. The available chemotherapy drugs have been associated with many side effects. Bromelain has novel medicinal qualities including anti-inflammatory, anti-thrombotic, fibrinolytic and anti-cancer functions. Commercially available bromelain is obtained through tedious methods; therefore, recombinant bromelain may provide a cheaper and simpler choice with similar quality. This study aimed to assess the effects of commercial and recombinant bromelain on the cytokinetic behavior of MCF-7 breast cancer cells and their potential as therapeutic alternatives in cancer treatment. Cytotoxic activities of commercial and recombinant bromelain were determined using (sulforhodamine) SRB assay. Next, cell viability assays were conducted to determine effects of commercial and recombinant bromelain on MCF-7 cell cytokinetic behavior. Finally, the established growth kinetic data were used to modify a model that predicts the effects of commercial and recombinant bromelain on MCF-7 cells. Commercial and recombinant bromelain exerted strong effects towards decreasing the cell viability of MCF-7 cells with IC50 values of 5.13 μg/mL and 6.25 μg/mL, respectively, compared to taxol with an IC50 value of 0.063 μg/mL. The present results indicate that commercial and recombinant bromelain both have anti-proliferative activity, reduced the number of cell generations from 3.92 to 2.81 for commercial bromelain and to 2.86 for recombinant bromelain, while with taxol reduction was to 3.12. Microscopic observation of bromelain-treated MCF-7 cells demonstrated detachment. Inhibition activity was verified with growth rates decreased dynamically from 0.009 h-1 to 0.0059 h-1 for commercial bromelain and to 0.0063 h-1 for recombinant bromelain. Commercial and recombinant bromelain both affect cytokinetics of MCF-7 cells by decreasing cell viability, demonstrating similar strength to taxol.

  18. Increasing the cytotoxicity of doxorubicin in breast cancer MCF-7 cells with multidrug resistance using a mesoporous silica nanoparticle drug delivery system.

    PubMed

    Wang, Xin; Teng, Zhaogang; Wang, Haiyan; Wang, Chunyan; Liu, Ying; Tang, Yuxia; Wu, Jiang; Sun, Jin; Wang, Hai; Wang, Jiandong; Lu, Guangming

    2014-01-01

    Resistance to cytotoxic chemotherapy is the main cause of therapeutic failure and death in women with breast cancer. Overexpression of various members of the superfamily of adenosine triphosphate binding cassette (ABC)-transporters has been shown to be associated with multidrug resistance (MDR) phenotype in breast cancer cells. MDR1 protein promotes the intracellular efflux of drugs. A novel approach to address cancer drug resistance is to take advantage of the ability of nanocarriers to sidestep drug resistance mechanisms by endosomal delivery of chemotherapeutic agents. Doxorubicin (DOX) is an anthracycline antibiotic commonly used in breast cancer chemotherapy and a substrate for ABC-mediated drug efflux. In the present study, we developed breast cancer MCF-7 cells with overexpression of MDR1 and designed mesoporous silica nanoparticles (MSNs) which were used as a drug delivery system. We tested the efficacy of DOX in the breast cancer cell line MCF-7/MDR1 and in a MCF-7/MDR1 xenograft nude mouse model using the MSNs drug delivery system. Our data show that drug resistance in the human breast cancer cell line MCF-7/MDR1 can be overcome by treatment with DOX encapsulated within mesoporous silica nanoparticles.

  19. Ursodeoxycholic acid effectively kills drug-resistant gastric cancer cells through induction of autophagic death.

    PubMed

    Lim, Sung-Chul; Han, Song Iy

    2015-09-01

    Carcinoma cells that have acquired drug resistance often exhibit cross-resistance to various other cytotoxic stimuli. Here, we investigated the effects of ursodeoxycholic acid (UDCA), a gastrointestinal tumor-suppressor, on a cisplatin‑resistant SNU601 gastric cancer subline (SNU601/R). While other anticancer drugs, including L-OHP, etoposide, and death ligand TRAIL, had minimal effects on the viability of these resistant cells, they were sensitive to UDCA. The UDCA‑induced reduction in the viability of the SNU601/R cells was accomplished through autophagy while the primary means of cell death in the parental SNU601 cells (SNU601/WT) was apoptosis. Previously, we demonstrated that the UDCA-triggered apoptosis of gastric cancer cells was regulated by a cell surface death receptor, TRAIL-R2/DR5, which was upregulated and re-distributed on lipid rafts. The UDCA stimulation of TRAIL-R2/DR5 also occurred in the SNU601/R cells despite the lack of apoptosis. In the present study, we found that CD95/Fas, another cell surface death receptor, was also translocated into lipid rafts in response to UDCA although it was not involved in the decrease in cell viability. Specifically, raft relocalization of CD95/Fas was triggered by UDCA in the SNU601/WT cells in which apoptosis occurred, but not in the SNU601/R cells where autophagic death occurred. Notably, UDCA reduced ATG5 levels, an essential component of autophagy, in the SNU601/WT, but not in the SNU601/R cell line. Moreover, in CD95/Fas-silenced SNU601/WT cells, UDCA did not decrease ATG5 levels and induced autophagic cell death rather than apoptosis. These results imply that raft‑distributed CD95/Fas may support UDCA-induced apoptosis via downregulation of ATG5 levels, preventing the autophagic pathway. Taken together, these results suggest that UDCA induces both apoptotic and autophagic cell death depending on the intracellular signaling environment, thereby conferring the advantage to overcome drug resistance

  20. Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells

    PubMed Central

    Muniyan, Sakthivel; D’Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G.; Bu, Xiu R.; Batra, Surinder K.; Lin, Ming-Fong

    2015-01-01

    Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents. PMID:26121643

  1. Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells.

    PubMed

    Ingersoll, Matthew A; Lyons, Anastesia S; Muniyan, Sakthivel; D'Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G; Bu, Xiu R; Batra, Surinder K; Lin, Ming-Fong

    2015-01-01

    Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents.

  2. Cancer stem cell-targeted therapeutics and delivery strategies.

    PubMed

    Ahmad, Gulzar; Amiji, Mansoor M

    2017-08-01

    Cancer initiating or stem cells (CSCs) are a small population of cells in the tumor mass, which have been reported to be present in different types of cancers. CSCs usually reside within the tumor and are responsible for reoccurrence of cancer. The imprecise, inaccessible nature and increased efflux of conventional therapeutic drugs make these cells resistant to drugs. We discuss the specific markers for identification of these cells, role of CSCs in chemotherapy resistance and use of different therapeutic means to target them, including elucidation of specific cell markers, exploitation of different signaling pathways and use of nanotechnology. Area covered: This review covers cancer stem cell signaling which are used by these cells to maintain their quiescence, stemness and resistant phenotype, distinct cell surface markers, contribution of these cells in drug resistance, inevitability to cure cancer and use of nanotechnology to overcome this hurdle. Expert opinion: Cancer stem cells are the main culprit of our failure to cure cancer. In order to cure cancer along with other cells types in cancer, cancer stem cells need to be targeted in the tumor bed. Nanotechnology solutions can facilitate clinical translation of the therapeutics along with other emerging technologies to cure cancer.

  3. Sphaeropsidin A shows promising activity against drug-resistant cancer cells by targeting regulatory volume increase.

    PubMed

    Mathieu, Véronique; Chantôme, Aurélie; Lefranc, Florence; Cimmino, Alessio; Miklos, Walter; Paulitschke, Verena; Mohr, Thomas; Maddau, Lucia; Kornienko, Alexander; Berger, Walter; Vandier, Christophe; Evidente, Antonio; Delpire, Eric; Kiss, Robert

    2015-10-01

    Despite the recent advances in the treatment of tumors with intrinsic chemotherapy resistance, such as melanoma and renal cancers, their prognosis remains poor and new chemical agents with promising activity against these cancers are urgently needed. Sphaeropsidin A, a fungal metabolite whose anticancer potential had previously received little attention, was isolated from Diplodia cupressi and found to display specific anticancer activity in vitro against melanoma and kidney cancer subpanels in the National Cancer Institute (NCI) 60-cell line screen. The NCI data revealed a mean LC50 of ca. 10 µM and a cellular sensitivity profile that did not match that of any other agent in the 765,000 compound database. Subsequent mechanistic studies in melanoma and other multidrug-resistant in vitro cancer models showed that sphaeropsidin A can overcome apoptosis as well as multidrug resistance by inducing a marked and rapid cellular shrinkage related to the loss of intracellular Cl(-) and the decreased HCO3 (-) concentration in the culture supernatant. These changes in ion homeostasis and the absence of effects on the plasma membrane potential were attributed to the sphaeropsidin A-induced impairment of regulatory volume increase (RVI). Preliminary results also indicate that depending on the type of cancer, the sphaeropsidin A effects on RVI could be related to Na-K-2Cl electroneutral cotransporter or Cl(-)/HCO3 (-) anion exchanger(s) targeting. This study underscores the modulation of ion-transporter activity as a promising therapeutic strategy to combat drug-resistant cancers and identifies the fungal metabolite, sphaeropsidin A, as a lead to develop anticancer agents targeting RVI in cancer cells.

  4. Acquisition of epithelial-mesenchymal transition phenotype in the tamoxifen-resistant breast cancer cell: a new role for G protein-coupled estrogen receptor in mediating tamoxifen resistance through cancer-associated fibroblast-derived fibronectin and β1-integrin signaling pathway in tumor cells.

    PubMed

    Yuan, Jie; Liu, Manran; Yang, Li; Tu, Gang; Zhu, Qing; Chen, Maoshan; Cheng, Hong; Luo, Haojun; Fu, Weijie; Li, Zhenhua; Yang, Guanglun

    2015-05-21

    Acquired tamoxifen resistance remains the major obstacle to breast cancer endocrine therapy. β1-integrin was identified as one of the target genes of G protein-coupled estrogen receptor (GPER), a novel estrogen receptor recognized as an initiator of tamoxifen resistance. Here, we investigated the role of β1-integrin in GPER-mediated tamoxifen resistance in breast cancer. The expression of β1-integrin and biomarkers of epithelial-mesenchymal transition were evaluated immunohistochemically in 53 specimens of metastases and paired primary tumors. The function of β1-integrin was investigated in tamoxifen-resistant (MCF-7R) subclones, derived from parental MCF-7 cells, and MCF-7R β1-integrin-silenced subclones in MTT and Transwell assays. Involved signaling pathways were identified using specific inhibitors and Western blotting analysis. GPER, β1-integrin and mesenchymal biomarkers (vimentin and fibronectin) expression in metastases increased compared to the corresponding primary tumors; a close expression pattern of β1-integrin and GPER were in metastases. Increased β1-integrin expression was also confirmed in MCF-7R cells compared with MCF-7 cells. This upregulation of β1-integrin was induced by agonists of GPER and blocked by both antagonist and knockdown of it in MCF-7R cells. Moreover, the epidermal growth factor receptor/extracellular regulated protein kinase (EGFR/ERK) signaling pathway was involved in this transcriptional regulation since specific inhibitors of these kinases also reduced the GPER-induced upregulation of β1-integrin. Interestingly, silencing of β1-integrin partially rescued the sensitivity of MCF-7R cells to tamoxifen and the α5β1-integrin subunit is probably responsible for this phenomenon. Importantly, the cell migration and epithelial-mesenchymal transition induced by cancer-associated fibroblasts, or the product of cancer-associated fibroblasts, fibronectin, were reduced by knockdown of β1-integrin in MCF-7R cells. In addition

  5. Long Non-Coding RNAs: Key Regulators of Epithelial-Mesenchymal Transition, Tumour Drug Resistance and Cancer Stem Cells

    PubMed Central

    Heery, Richard; Finn, Stephen P.; Cuffe, Sinead; Gray, Steven G.

    2017-01-01

    Epithelial mesenchymal transition (EMT), the adoption by epithelial cells of a mesenchymal-like phenotype, is a process co-opted by carcinoma cells in order to initiate invasion and metastasis. In addition, it is becoming clear that is instrumental to both the development of drug resistance by tumour cells and in the generation and maintenance of cancer stem cells. EMT is thus a pivotal process during tumour progression and poses a major barrier to the successful treatment of cancer. Non-coding RNAs (ncRNA) often utilize epigenetic programs to regulate both gene expression and chromatin structure. One type of ncRNA, called long non-coding RNAs (lncRNAs), has become increasingly recognized as being both highly dysregulated in cancer and to play a variety of different roles in tumourigenesis. Indeed, over the last few years, lncRNAs have rapidly emerged as key regulators of EMT in cancer. In this review, we discuss the lncRNAs that have been associated with the EMT process in cancer and the variety of molecular mechanisms and signalling pathways through which they regulate EMT, and finally discuss how these EMT-regulating lncRNAs impact on both anti-cancer drug resistance and the cancer stem cell phenotype. PMID:28430163

  6. Nanomedicine to Deal With Cancer Cell Biology in Multi-Drug Resistance.

    PubMed

    Tekchandani, Pawan; Kurmi, Balak Das; Paliwal, Shivani Rai

    2017-01-01

    Today Cancer still remains a major cause of mortality and death worldwide, in humans. Chemotherapy, a key treatment strategy in cancer, has significant hurdles such as the occurrence of chemoresistance in cancer, which is inherent unresponsiveness or acquired upon exposure to chemotherapeutics. The resistance of cancer cells to an antineoplastic agent accompanied to other chemotherapeutic drugs with different structures and mechanisms of action called multi-drug resistance (MDR) plays an important role in the failure of chemo- therapeutics. MDR is primarily based on the overexpression of drug efflux pumps in the cellular membrane, which belongs to the ATP-binding cassette (ABC) superfamily of proteins, are P-gp (P-glycoprotein) and multidrug resistance-associated protein (MRP). Over the years, various strategies have been evaluated to overcome MDR, based not only on the use of MDR modulators but also on the implementation an innovative approach and advanced nanosized drug delivery systems. Nanomedicine is an emerging tool of chemotherapy that focuses on alternative drug delivery for improvement of the treatment efficacy and reducing side effects to normal tissues. This review aims to focus on the details biology, reversal strategies option with the limitation of MDR and various advantages of the present medical science nanotechnology with intracellular delivery aspects for overcoming the significant potential for improving the treatment of MDR malignancies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Proteomic differential display analysis for TS-1-resistant and -sensitive pancreatic cancer cells using two-dimensional gel electrophoresis and mass spectrometry.

    PubMed

    Yoshida, Kanako; Kuramitsu, Yasuhiro; Murakami, Kohei; Ryozawa, Shomei; Taba, Kumiko; Kaino, Seiji; Zhang, Xiulian; Sakaida, Isao; Nakamura, Kazuyuki

    2011-06-01

    TS-1 is an oral anticancer agent containing two biochemical modulators for 5-fluorouracil (5-FU) and tegafur (FT), a metabolically activated prodrug of 5-FU. TS-1 has been recognized as an effective anticancer drug using standard therapies for patients with advanced pancreatic cancer along with gemcitabine. However, a high level of inherent and acquired tumor resistance to TS-1 induces difficulty in the treatment. To identify proteins linked to the TS-1-resistance of pancreatic cancer, we profiled protein expression levels in samples of TS-1-resistant and -sensitive pancreatic cancer cell lines by using two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The cytotoxicity of a 5-FU/5-chloro-2,4-dihydroxypyridine (CDHP) combination towards pancreatic cancer cell lines was evaluated by MTS assay. Panc-1, BxPC-3, MiaPaCa-2 and PK59 showed high sensitivity to the 5-FU/CDHP combination (TS-1-sensitive), whereas PK45p and KLM-1 were much less sensitive (TS-1-resistant). Proteomic analysis showed that eleven spots, including T-complex protein 1 subunit beta, ribonuclease inhibitor, elongation factor 1-delta, peroxiredoxin-2 and superoxide dismutase (Cu-Zn), appeared to be down-regulated, and 29 spots, including hypoxia up-regulated protein 1, lamin-A/C, endoplasmin, fascin and annexin A1, appeared to be up-regulated in TS-1-resistant cells compared with -sensitive cells. These results suggest that the identified proteins showing different expression between TS-1-sensitive and -resistant pancreatic cancer cells possibly relate to TS-1-sensitivity. These findings could be useful to overcome the TS-1-resistance of pancreatic cancer cells.

  8. BAG3-dependent expression of Mcl-1 confers resistance of mutant KRAS colon cancer cells to the HSP90 inhibitor AUY922.

    PubMed

    Wang, Chun Yan; Guo, Su Tang; Croft, Amanda; Yan, Xu Guang; Jin, Lei; Zhang, Xu Dong; Jiang, Chen Chen

    2018-02-01

    Past studies have shown that mutant KRAS colon cancer cells are susceptible to apoptosis induced by the HSP90 inhibitor AUY922. Nevertheless, intrinsic and acquired resistance remains an obstacle for the potential application of the inhibitor in the treatment of the disease. Here we report that Mcl-1 is important for survival of colon cancer cells in the presence of AUY922. Mcl-1 was upregulated in mutant KRAS colon cancer cells selected for resistance to AUY922-induced apoptosis. This was due to its increased stability mediated by Bcl-2-associated athanogene domain 3 (BAG3), which was also increased in resistant colon cancer cells by heat shock factor 1 (HSF1) as a result of chronic endoplasmic reticulum (ER) stress. Functional investigations demonstrated that inhibition of Mcl-1, BAG3, or HSF1 triggered apoptosis in resistant colon cancer cells, and rendered AUY922-naïve colon cancer cells more sensitive to the inhibitor. Together, these results identify that the HSF1-BAG3-Mcl-1 signal axis is critical for protection of mutant KRAS colon cancer cells from AUY922-induced apoptosis, with potential implications for targeting HSF1/BAG3/Mcl-1 to improve the efficacy of AUY922 in the treatment of colon cancer. © 2017 Wiley Periodicals, Inc.

  9. A Combination of Immune Checkpoint Inhibition with Metronomic Chemotherapy as a Way of Targeting Therapy-Resistant Cancer Cells.

    PubMed

    Kareva, Irina

    2017-10-13

    Therapeutic resistance remains a major obstacle in treating many cancers, particularly in advanced stages. It is likely that cytotoxic lymphocytes (CTLs) have the potential to eliminate therapy-resistant cancer cells. However, their effectiveness may be limited either by the immunosuppressive tumor microenvironment, or by immune cell death induced by cytotoxic treatments. High-frequency low-dose (also known as metronomic) chemotherapy can help improve the activity of CTLs by providing sufficient stimulation for cytotoxic immune cells without excessive depletion. Additionally, therapy-induced removal of tumor cells that compete for shared nutrients may also facilitate tumor infiltration by CTLs, further improving prognosis. Metronomic chemotherapy can also decrease the number of immunosuppressive cells in the tumor microenvironment, including regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Immune checkpoint inhibition can further augment anti-tumor immune responses by maintaining T cells in an activated state. Combining immune checkpoint inhibition with metronomic administration of chemotherapeutic drugs may create a synergistic effect that augments anti-tumor immune responses and clears metabolic competition. This would allow immune-mediated elimination of therapy-resistant cancer cells, an effect that may be unattainable by using either therapeutic modality alone.

  10. CIP-36, a novel topoisomerase II-targeting agent, induces the apoptosis of multidrug-resistant cancer cells in vitro.

    PubMed

    Cao, Bo; Chen, Hong; Gao, Ying; Niu, Cong; Zhang, Yuan; Li, Ling

    2015-03-01

    The need to overcome cancer multidrug resistance (MDR) has fueled considerable interest in the development of novel synthetic antitumor agents with cytotoxicity against cancer cell lines with MDR. In this study, we aimed to investigate CIP-36, a novel podophyllotoxin derivative, for its inhibitory effects on human cancer cells from multiple sources, particularly cells with MDR in vitro. The human leukemia cell line, K562, and the adriamycin-resistant subline, K562/A02, were exposed to CIP-36 or anticancer agents, and various morphological and biochemical properties were assessed by Hoechst 33342 staining under a fluorescence microscope. Subsequently, cytotoxicity, cell growth curves and the cell cycle were analyzed. Finally, the effects of CIP-36 on topoisomerase IIα (Topo IIα) activity were determined. Treatment with CIP-36 significantly inhibited the growth of the K562 and MDR K562/A02 cells. Our data demonstrated that CIP-36 induced apoptosis, inhibited cell cycle progression and inhibited Topo IIα activity. These findings suggest that CIP-36 has the potential to overcome the multidrug resistance of K562/A02 cells by mediating Topo IIα activity.

  11. Dual-targeting Wnt and uPA receptors using peptide conjugated ultra-small nanoparticle drug carriers inhibited cancer stem-cell phenotype in chemo-resistant breast cancer.

    PubMed

    Miller-Kleinhenz, Jasmine; Guo, Xiangxue; Qian, Weiping; Zhou, Hongyu; Bozeman, Erica N; Zhu, Lei; Ji, Xin; Wang, Y Andrew; Styblo, Toncred; O'Regan, Ruth; Mao, Hui; Yang, Lily

    2018-01-01

    Heterogeneous tumor cells, high incidence of tumor recurrence, and decrease in overall survival are the major challenges for the treatment of chemo-resistant breast cancer. Results of our study showed differential chemotherapeutic responses among breast cancer patient derived xenograft (PDX) tumors established from the same patients. All doxorubicin (Dox)-resistant tumors expressed higher levels of cancer stem-like cell biomarkers, including CD44, Wnt and its receptor LRP5/6, relative to Dox-sensitive tumors. To effectively treat resistant tumors, we developed an ultra-small magnetic iron oxide nanoparticle (IONP) drug carrier conjugated with peptides that are dually targeted to Wnt/LRP5/6 and urokinase plasminogen activator receptor (uPAR). Our results showed that simultaneous binding to LRP5/6 and uPAR by the dual receptor targeted IONPs was required to inhibit breast cancer cell invasion. Molecular analysis revealed that the dual receptor targeted IONPs significantly inhibited Wnt/β-catenin signaling and cancer stem-like phenotype of tumor cells, with marked reduction of Wnt ligand, CD44 and uPAR. Systemic administration of the dual targeted IONPs led to nanoparticle-drug delivery into PDX tumors, resulting in stronger tumor growth inhibition compared to non-targeted or single-targeted IONP-Dox in a human breast cancer PDX model. Therefore, co-targeting Wnt/LRP and uPAR using IONP drug carriers is a promising therapeutic approach for effective drug delivery to chemo-resistant breast cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. TARGETING THE MUC1-C ONCOPROTEIN DOWNREGULATES HER2 ACTIVATION AND ABROGATES TRASTUZUMAB RESISTANCE IN BREAST CANCER CELLS

    PubMed Central

    Raina, Deepak; Uchida, Yasumitsu; Kharbanda, Akriti; Rajabi, Hasan; Panchamoorthy, Govind; Jin, Caining; Kharbanda, Surender; Scaltriti, Maurizio; Baselga, Jose; Kufe, Donald

    2014-01-01

    Patients with HER2 positive breast cancer often exhibit intrinsic or acquired resistance to trastuzumab treatment. The transmembrane MUC1-C oncoprotein is aberrantly overexpressed in breast cancer cells and associates with HER2. The present studies demonstrate that silencing MUC1-C in HER2-overexpressing SKBR3 and BT474 breast cancer cells results in downregulation of constitutive HER2 activation. Moreover, treatment with the MUC1-C inhibitor, GO-203, was associated with disruption of MUC1-C/HER2 complexes and decreases in tyrosine phosphorylated HER2 (p-HER2) levels. In studies of trastuzumab-resistant SKBR3R and BT474R cells, we found that the association between MUC1-C and HER2 is markedly increased (~20-fold) as compared to that in sensitive cells. Additionally, silencing MUC1-C in the trastuzumab-resistant cells or treatment with GO-203 decreased p-HER2 and AKT activation. Moreover, targeting MUC1-C was associated with downregulation of phospho-p27 and cyclin E, which confer trastuzumab resistance. Consistent with these results, targeting MUC1-C inhibited the growth and clonogenic survival of both trastuzumab-resistant cells. Our results further demonstrate that silencing MUC1-C reverses resistance to trastuzumab and that the combination of GO-203 and trastuzumab is highly synergistic. These findings indicate that MUC1-C contributes to constitutive activation of the HER2 pathway and that targeting MUC1-C represents a potential approach to abrogate trastuzumab resistance. PMID:23912457

  13. Supermolecular drug challenge to overcome drug resistance in cancer cells.

    PubMed

    Onishi, Yasuhiko; Eshita, Yuki; Ji, Rui-Cheng; Kobayashi, Takashi; Onishi, Masayasu; Mizuno, Masaaki; Yoshida, Jun; Kubota, Naoji

    2018-06-04

    Overcoming multidrug resistance (MDR) of cancer cells can be accomplished using drug delivery systems in large-molecular-weight ATP-binding cassette transporters before entry into phagolysosomes and by particle-cell-surface interactions. However, these hypotheses do not address the intratumoral heterogeneity in cancer. Anti-MDR must be related to alterations of drug targets, expression of detoxification, as well as altered proliferation. In this study, it is shown that the excellent efficacy and sustainability of anti-MDR is due to a stable ES complex because of the allosteric facilities of artificial enzymes when they are used as supramolecular complexes. The allosteric effect of supermolecular drugs can be explained by the induced-fit model and can provide stable feedback control systems through the loop transfer function of the Hill equation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Molecular chess? Hallmarks of anti-cancer drug resistance.

    PubMed

    Cree, Ian A; Charlton, Peter

    2017-01-05

    The development of resistance is a problem shared by both classical chemotherapy and targeted therapy. Patients may respond well at first, but relapse is inevitable for many cancer patients, despite many improvements in drugs and their use over the last 40 years. Resistance to anti-cancer drugs can be acquired by several mechanisms within neoplastic cells, defined as (1) alteration of drug targets, (2) expression of drug pumps, (3) expression of detoxification mechanisms, (4) reduced susceptibility to apoptosis, (5) increased ability to repair DNA damage, and (6) altered proliferation. It is clear, however, that changes in stroma and tumour microenvironment, and local immunity can also contribute to the development of resistance. Cancer cells can and do use several of these mechanisms at one time, and there is considerable heterogeneity between tumours, necessitating an individualised approach to cancer treatment. As tumours are heterogeneous, positive selection of a drug-resistant population could help drive resistance, although acquired resistance cannot simply be viewed as overgrowth of a resistant cancer cell population. The development of such resistance mechanisms can be predicted from pre-existing genomic and proteomic profiles, and there are increasingly sophisticated methods to measure and then tackle these mechanisms in patients. The oncologist is now required to be at least one step ahead of the cancer, a process that can be likened to 'molecular chess'. Thus, as well as an increasing role for predictive biomarkers to clinically stratify patients, it is becoming clear that personalised strategies are required to obtain best results.

  15. Colon cancer stem cells dictate tumor growth and resist cell death by production of interleukin-4.

    PubMed

    Todaro, Matilde; Alea, Mileidys Perez; Di Stefano, Anna B; Cammareri, Patrizia; Vermeulen, Louis; Iovino, Flora; Tripodo, Claudio; Russo, Antonio; Gulotta, Gaspare; Medema, Jan Paul; Stassi, Giorgio

    2007-10-11

    A novel paradigm in tumor biology suggests that cancer growth is driven by stem-like cells within a tumor. Here, we describe the identification and characterization of such cells from colon carcinomas using the stem cell marker CD133 that accounts around 2% of the cells in human colon cancer. The CD133(+) cells grow in vitro as undifferentiated tumor spheroids, and they are both necessary and sufficient to initiate tumor growth in immunodeficient mice. Xenografts resemble the original human tumor maintaining the rare subpopulation of tumorigenic CD133(+) cells. Further analysis revealed that the CD133(+) cells produce and utilize IL-4 to protect themselves from apoptosis. Consistently, treatment with IL-4Ralpha antagonist or anti-IL-4 neutralizing antibody strongly enhances the antitumor efficacy of standard chemotherapeutic drugs through selective sensitization of CD133(+) cells. Our data suggest that colon tumor growth is dictated by stem-like cells that are treatment resistant due to the autocrine production of IL-4.

  16. Epigenetic Mechanisms of Tamoxifen Resistance in Luminal Breast Cancer.

    PubMed

    Abdel-Hafiz, Hany A

    2017-07-06

    Breast cancer is one of the most common cancers and the second leading cause of cancer death in the United States. Estrogen receptor (ER)-positive cancer is the most frequent subtype representing more than 70% of breast cancers. These tumors respond to endocrine therapy targeting the ER pathway including selective ER modulators (SERMs), selective ER downregulators (SERDs) and aromatase inhibitors (AIs). However, resistance to endocrine therapy associated with disease progression remains a significant therapeutic challenge. The precise mechanisms of endocrine resistance remain unclear. This is partly due to the complexity of the signaling pathways that influence the estrogen-mediated regulation in breast cancer. Mechanisms include ER modifications, alteration of coregulatory function and modification of growth factor signaling pathways. In this review, we provide an overview of epigenetic mechanisms of tamoxifen resistance in ER-positive luminal breast cancer. We highlight the effect of epigenetic changes on some of the key mechanisms involved in tamoxifen resistance, such as tumor-cell heterogeneity, ER signaling pathway and cancer stem cells (CSCs). It became increasingly recognized that CSCs are playing an important role in driving metastasis and tamoxifen resistance. Understanding the mechanism of tamoxifen resistance will provide insight into the design of novel strategies to overcome the resistance and make further improvements in breast cancer therapeutics.

  17. Therapeutic Implications for Overcoming Radiation Resistance in Cancer Therapy

    PubMed Central

    Kim, Byeong Mo; Hong, Yunkyung; Lee, Seunghoon; Liu, Pengda; Lim, Ji Hong; Lee, Yong Heon; Lee, Tae Ho; Chang, Kyu Tae; Hong, Yonggeun

    2015-01-01

    Ionizing radiation (IR), such as X-rays and gamma (γ)-rays, mediates various forms of cancer cell death such as apoptosis, necrosis, autophagy, mitotic catastrophe, and senescence. Among them, apoptosis and mitotic catastrophe are the main mechanisms of IR action. DNA damage and genomic instability contribute to IR-induced cancer cell death. Although IR therapy may be curative in a number of cancer types, the resistance of cancer cells to radiation remains a major therapeutic problem. In this review, we describe the morphological and molecular aspects of various IR-induced types of cell death. We also discuss cytogenetic variations representative of IR-induced DNA damage and genomic instability. Most importantly, we focus on several pathways and their associated marker proteins responsible for cancer resistance and its therapeutic implications in terms of cancer cell death of various types and characteristics. Finally, we propose radiation-sensitization strategies, such as the modification of fractionation, inflammation, and hypoxia and the combined treatment, that can counteract the resistance of tumors to IR. PMID:26569225

  18. The relationship of thioredoxin-1 and cisplatin resistance: its impact on ROS and oxidative metabolism in lung cancer cells.

    PubMed

    Wangpaichitr, Medhi; Sullivan, Elizabeth J; Theodoropoulos, George; Wu, Chunjing; You, Min; Feun, Lynn G; Lampidis, Theodore J; Kuo, Macus T; Savaraj, Niramol

    2012-03-01

    Elimination of cisplatin-resistant lung cancer cells remains a major obstacle. We have shown that cisplatin-resistant tumors have higher reactive oxygen species (ROS) levels and can be exploited for targeted therapy. Here, we show that increased secretion of the antioxidant thioredoxin-1 (TRX1) resulted in lowered intracellular TRX1 and contributed to higher ROS in cisplatin-resistant tumors in vivo and in vitro. By reconstituting TRX1 protein in cisplatin-resistant cells, we increased sensitivity to cisplatin but decreased sensitivity to elesclomol (ROS inducer). Conversely, decreased TRX1 protein in parental cells reduced the sensitivity to cisplatin but increased sensitivity to elesclomol. Cisplatin-resistant cells had increased endogenous oxygen consumption and mitochondrial activity but decreased lactic acid production. They also exhibited higher levels of argininosuccinate synthetase (ASS) and fumarase mRNA, which contributed to oxidative metabolism (OXMET) when compared with parental cells. Restoring intracellular TRX1 protein in cisplatin-resistant cells resulted in lowering ASS and fumarase mRNAs, which in turn sensitized them to arginine deprivation. Interestingly, cisplatin-resistant cells also had significantly higher basal levels of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). Overexpressing TRX1 lowered ACC and FAS proteins expressions in cisplatin-resistant cells. Chemical inhibition and short interfering RNA of ACC resulted in significant cell death in cisplatin-resistant compared with parental cells. Conversely, TRX1 overexpressed cisplatin-resistant cells resisted 5-(tetradecyloxy)-2-furoic acid (TOFA)-induced death. Collectively, lowering TRX1 expression through increased secretion leads cisplatin-resistant cells to higher ROS production and increased dependency on OXMET. These changes raise an intriguing therapeutic potential for future therapy in cisplatin-resistant lung cancer.

  19. Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong

    2015-04-03

    Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2more » and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells.« less

  20. The Emerging Role of Extracellular Vesicle-Mediated Drug Resistance in Cancers: Implications in Advanced Prostate Cancer.

    PubMed

    Soekmadji, Carolina; Nelson, Colleen C

    2015-01-01

    Emerging evidence has shown that the extracellular vesicles (EVs) regulate various biological processes and can control cell proliferation and survival, as well as being involved in normal cell development and diseases such as cancers. In cancer treatment, development of acquired drug resistance phenotype is a serious issue. Recently it has been shown that the presence of multidrug resistance proteins such as Pgp-1 and enrichment of the lipid ceramide in EVs could have a role in mediating drug resistance. EVs could also mediate multidrug resistance through uptake of drugs in vesicles and thus limit the bioavailability of drugs to treat cancer cells. In this review, we discussed the emerging evidence of the role EVs play in mediating drug resistance in cancers and in particular the role of EVs mediating drug resistance in advanced prostate cancer. The role of EV-associated multidrug resistance proteins, miRNA, mRNA, and lipid as well as the potential interaction(s) among these factors was probed. Lastly, we provide an overview of the current available treatments for advanced prostate cancer, considering where EVs may mediate the development of resistance against these drugs.

  1. Encapsulation in lipid-core nanocapsules overcomes lung cancer cell resistance to tretinoin.

    PubMed

    Schultze, Eduarda; Ourique, Aline; Yurgel, Virginia Campello; Begnini, Karine Rech; Thurow, Helena; de Leon, Priscila Marques Moura; Campos, Vinicius Farias; Dellagostin, Odir Antônio; Guterres, Silvia R; Pohlmann, Adriana R; Seixas, Fabiana Kömmling; Beck, Ruy Carlos Ruver; Collares, Tiago

    2014-05-01

    Tretinoin is a retinoid derivative that has an antiproliferative effect on several kinds of tumours. Human lung adenocarcinoma epithelial cell lines (A549) exhibit a profound resistance to the effects of tretinoin. Nanocarriers seem to be a good alternative to overcomecellular resistance to drugs. The aim of this study was to test whether tretinoin-loaded lipid-core nanocapsules exert anantitumor effect on A549 cells. A549 cells were incubated with free tretinoin (TTN), blank nanocapsules (LNC) and tretinoin-loaded lipid-core nanocapsules (TTN-LNC). Data from evaluation of DNA content and Annexin V binding assay by flow cytometry showed that TTN-LNC induced apoptosis and cell cycle arrest at the G1-phase while TTN did not. TTN-LNC showed higher cytotoxic effects than TTN on A549 cells evaluated by MTT and LIVE/DEAD cell viability assay. Gene expression profiling identified up-regulated expression of gene p21 by TTN-LNC, supporting the cell cycle arrest effect. These results showed for the first time that TTN-LNC are able to overcome the resistance of adenocarcinoma cell line A549 to treatment with TTN by inducing apoptosis and cell cycle arrest, providing support for their use in applications in lung cancer therapy. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Cancer stem cells and differentiation therapy.

    PubMed

    Jin, Xiong; Jin, Xun; Kim, Hyunggee

    2017-10-01

    Cancer stem cells can generate tumors from only a small number of cells, whereas differentiated cancer cells cannot. The prominent feature of cancer stem cells is its ability to self-renew and differentiate into multiple types of cancer cells. Cancer stem cells have several distinct tumorigenic abilities, including stem cell signal transduction, tumorigenicity, metastasis, and resistance to anticancer drugs, which are regulated by genetic or epigenetic changes. Like normal adult stem cells involved in various developmental processes and tissue homeostasis, cancer stem cells maintain their self-renewal capacity by activating multiple stem cell signaling pathways and inhibiting differentiation signaling pathways during cancer initiation and progression. Recently, many studies have focused on targeting cancer stem cells to eradicate malignancies by regulating stem cell signaling pathways, and products of some of these strategies are in preclinical and clinical trials. In this review, we describe the crucial features of cancer stem cells related to tumor relapse and drug resistance, as well as the new therapeutic strategy to target cancer stem cells named "differentiation therapy."

  3. Ratio of phosphorylated HSP27 to nonphosphorylated HSP27 biphasically acts as a determinant of cellular fate in gemcitabine-resistant pancreatic cancer cells.

    PubMed

    Kang, Dongxu; Choi, Hye Jin; Kang, Sujin; Kim, So Young; Hwang, Yong-Sic; Je, Suyeon; Han, Zhezhu; Kim, Joo-Hang; Song, Jae J

    2015-04-01

    Gemcitabine has been used most commonly as an anticancer drug to treat advanced pancreatic cancer patients. However, intrinsic or acquired resistance of pancreatic cancer to gemcitabine was also developed, which leads to very low five-year survival rates. Here, we investigated whether cellular levels of HSP27 phosphorylation act as a determinant of cellular fate with gemcitabine. In addition we have demonstrated whether HSP27 downregulation effectively could overcome the acquisition of gemcitabine resistance by using transcriptomic analysis. We observed that gemcitabine induced p38/HSP27 phosphorylation and caused acquired resistance. After acquisition of gemcitabine resistance, cancer cells showed higher activity of NF-κB. NF-κB activity, as well as colony formation in gemcitabine-resistant pancreatic cancer cells, was significantly decreased by HSP27 downregulation and subsequent TRAIL treatment, showing that HSP27 was a common network mediator of gemcitabine/TRAIL-induced cell death. After transcriptomic analysis, gene fluctuation after HSP27 downregulation was very similar to that of pancreatic cancer cells susceptible to gemcitabine, and then in opposite position to that of acquired gemcitabine resistance, which makes it possible to downregulate HSP27 to overcome the acquired gemcitabine resistance to function as an overall survival network inhibitor. Most importantly, we demonstrated that the ratio of phosphorylated HSP27 to nonphosphorylated HSP27 rather than the cellular level of HSP27 itself acts biphasically as a determinant of cellular fate in gemcitabine-resistant pancreatic cancer cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. [Clinical efficacy and adverse effects of taxol plus carboplatin or gemcitabine plus carboplatin in patients with advanced non-small-cell lung carcinoma].

    PubMed

    Wang, Xiao-Yun; Zhao, Yu-Liang

    2010-12-21

    To observe the clinical efficacy and adverse effects of taxol plus carboplatin (TP) or gemcitabine plus carboplatin (GP) in patients with advanced non-small-cell lung carcinoma. A total of 86 patients with advanced non-small-cell lung carcinoma with a histologically confirmed diagnosis at our department were treated with at least two cycles of drug therapy according to the WHO standard. There were 43 cases in TP group and 43 cases in GP group. TP group: taxol 150 mg/m(2), d1, carboplatin 300 mg/m(2) in d1; GP group: gemcitabine 1000 mg/m(2), 30 min, d1, 8, carboplatin 300 mg/m(2) in d1, 3 weeks a cycle. The efficacy and side effects were analyzed after two cycles of chemotherapy. When TP and GP groups were compared, the effective rate was 44.2% vs 39.5%; disease control rate (CR + PR + SD): 81.4% vs 74.4%; median time to progress (TTP): 4.6 vs 4.5 months; medium survivals: 8.6 vs 8.8 months; 1-year survival rates: 17.2% vs 18.1%; 2-year survival rates: 8% vs 10%. The statistic analysis showed that the two groups had no significant difference. The main cytotoxicities of GP and TP groups were predominantly thrombocytopenia and leucopenia respectively. The two groups had no significant statistical difference. The incidences of allergen, alopecia and peripheral neurotoxicity were higher in the TP group. The two groups had statistical difference. Tolerance was excellent in both groups. The therapeutic effect and tolerance are excellent for advanced non-small cell lung carcinoma. The efficacy and survival rate of two groups show no statistical difference.

  5. Single cell sequencing reveals heterogeneity within ovarian cancer epithelium and cancer associated stromal cells.

    PubMed

    Winterhoff, Boris J; Maile, Makayla; Mitra, Amit Kumar; Sebe, Attila; Bazzaro, Martina; Geller, Melissa A; Abrahante, Juan E; Klein, Molly; Hellweg, Raffaele; Mullany, Sally A; Beckman, Kenneth; Daniel, Jerry; Starr, Timothy K

    2017-03-01

    The purpose of this study was to determine the level of heterogeneity in high grade serous ovarian cancer (HGSOC) by analyzing RNA expression in single epithelial and cancer associated stromal cells. In addition, we explored the possibility of identifying subgroups based on pathway activation and pre-defined signatures from cancer stem cells and chemo-resistant cells. A fresh, HGSOC tumor specimen derived from ovary was enzymatically digested and depleted of immune infiltrating cells. RNA sequencing was performed on 92 single cells and 66 of these single cell datasets passed quality control checks. Sequences were analyzed using multiple bioinformatics tools, including clustering, principle components analysis, and geneset enrichment analysis to identify subgroups and activated pathways. Immunohistochemistry for ovarian cancer, stem cell and stromal markers was performed on adjacent tumor sections. Analysis of the gene expression patterns identified two major subsets of cells characterized by epithelial and stromal gene expression patterns. The epithelial group was characterized by proliferative genes including genes associated with oxidative phosphorylation and MYC activity, while the stromal group was characterized by increased expression of extracellular matrix (ECM) genes and genes associated with epithelial-to-mesenchymal transition (EMT). Neither group expressed a signature correlating with published chemo-resistant gene signatures, but many cells, predominantly in the stromal subgroup, expressed markers associated with cancer stem cells. Single cell sequencing provides a means of identifying subpopulations of cancer cells within a single patient. Single cell sequence analysis may prove to be critical for understanding the etiology, progression and drug resistance in ovarian cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Krüppel-like factor 4 promotes c-Met amplification-mediated gefitinib resistance in non-small-cell lung cancer.

    PubMed

    Feng, Wei; Xie, Qianyi; Liu, Suo; Ji, Ying; Li, Chunyun; Wang, Chunle; Jin, Longyu

    2018-06-01

    Gefitinib has been widely used in the first-line treatment of advanced EGFR-mutated non-small-cell lung cancer (NSCLC). However, many NSCLC patients will acquire resistance to gefitinib after 9-14 months of treatment. This study revealed that Krüppel-like factor 4 (KLF4) contributes to the formation of gefitinib resistance in c-Met-overexpressing NSCLC cells. We observed that KLF4 was overexpressed in c-Met-overexpressing NSCLC cells and tissues. Knockdown of KLF4 increased tumorigenic properties in gefitinib-resistant NSCLC cell lines without c-Met overexpression, but it reduced tumorigenic properties and increased gefitinib sensitivity in gefitinib-resistant NSCLC cells with c-Met overexpression, whereas overexpression of KLF4 reduced gefitinib sensitivity in gefitinib-sensitive NSCLC cells. Furthermore, Western blot analysis revealed that KLF4 contributed to the formation of gefitinib resistance in c-Met-overexpressing NSCLC cells by inhibiting the expression of apoptosis-related proteins under gefitinib treatment and activating the c-Met/Akt signaling pathway by decreasing the inhibition of β-catenin on phosphorylation of c-Met to prevent blockade by gefitinib. In summary, this study's results suggest that KLF4 is a promising candidate molecular target for both prevention and therapy of NSCLC with c-Met overexpression. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  7. Activation of EGFR Bypass Signaling by TGFα Overexpression Induces Acquired Resistance to Alectinib in ALK-Translocated Lung Cancer Cells.

    PubMed

    Tani, Tetsuo; Yasuda, Hiroyuki; Hamamoto, Junko; Kuroda, Aoi; Arai, Daisuke; Ishioka, Kota; Ohgino, Keiko; Miyawaki, Masayoshi; Kawada, Ichiro; Naoki, Katsuhiko; Hayashi, Yuichiro; Betsuyaku, Tomoko; Soejima, Kenzo

    2016-01-01

    Alectinib is a highly selective ALK inhibitor and shows promising efficacy in non-small cell lung cancers (NSCLC) harboring the EML4-ALK gene rearrangement. The precise mechanism of acquired resistance to alectinib is not well defined. The purpose of this study was to clarify the mechanism of acquired resistance to alectinib in ALK-translocated lung cancer cells. We established alectinib-resistant cells (H3122-AR) from the H3122 NSCLC cell line, harboring the EML4-ALK gene rearrangement, by long-term exposure to alectinib. The mechanism of acquired resistance to alectinib in H3122-AR cells was evaluated by phospho-receptor tyrosine kinase (phospho-RTK) array screening and Western blotting. No mutation of the ALK-TK domain was found. Phospho-RTK array analysis revealed that the phosphorylation level of EGFR was increased in H3122-AR cells compared with H3122. Expression of TGFα, one of the EGFR ligands, was significantly increased and knockdown of TGFα restored the sensitivity to alectinib in H3122-AR cells. We found combination therapy targeting ALK and EGFR with alectinib and afatinib showed efficacy both in vitro and in a mouse xenograft model. We propose a preclinical rationale to use the combination therapy with alectinib and afatinib in NSCLC that acquired resistance to alectinib by the activation of EGFR bypass signaling. ©2015 American Association for Cancer Research.

  8. The PSA−/lo prostate cancer cell population harbors self-renewing long-term tumor-propagating cells that resist castration

    PubMed Central

    Qin, Jichao; Liu, Xin; Laffin, Brian; Chen, Xin; Choy, Grace; Jeter, Collene; Calhoun-Davis, Tammy; Li, Hangwen; Palapattu, Ganesh S.; Pang, Shen; Lin, Kevin; Huang, Jiaoti; Ivanov, Ivan; Li, Wei; Suraneni, Mahipal V.; Tang, Dean G.

    2012-01-01

    SUMMARY Prostate cancer (PCa) is heterogeneous and contains both differentiated and undifferentiated tumor cells, but the relative functional contribution of these two cell populations remains unclear. Here we report distinct molecular, cellular, and tumor-propagating properties of PCa cells that express high (PSA+) and low (PSA−/lo) levels of the differentiation marker PSA. PSA−/lo PCa cells are quiescent and refractory to stresses including androgen deprivation, exhibit high clonogenic potential, and possess long-term tumor-propagating capacity. They preferentially express stem cell genes and can undergo asymmetric cell division generating PSA+ cells. Importantly, PSA−/lo PCa cells can initiate robust tumor development and resist androgen ablation in castrated hosts, and harbor highly tumorigenic castration-resistant PCa cells that can be prospectively enriched using ALDH+CD44+α2β1+ phenotype. In contrast, PSA+ PCa cells possess more limited tumor-propagating capacity, undergo symmetric division and are sensitive to castration. Together, our study suggests PSA−/lo cells may represent a critical source of castration-resistant PCa cells. PMID:22560078

  9. Collagen type I induces EGFR-TKI resistance in EGFR-mutated cancer cells by mTOR activation through Akt-independent pathway.

    PubMed

    Yamazaki, Shota; Higuchi, Youichi; Ishibashi, Masayuki; Hashimoto, Hiroko; Yasunaga, Masahiro; Matsumura, Yasuhiro; Tsuchihara, Katsuya; Tsuboi, Masahiro; Goto, Koichi; Ochiai, Atsushi; Ishii, Genichiro

    2018-06-01

    Primary resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is a serious problem in lung adenocarcinoma patients harboring EGFR mutations. The aim of this study was to examine whether and how collagen type I (Col I), the most abundantly deposited matrix in tumor stroma, affects EGFR-TKI sensitivity in EGFR-mutant cells. We evaluated the EGFR-TKI sensitivity of EGFR-mutated cancer cells cultured with Col I. Changes in the activation of downstream signaling molecules of EGFR were analyzed. We also examined the association between the Col I expression in tumor stroma in surgical specimens and EGFR-TKI response of postoperative recurrence patients with EGFR mutations. Compared to cancer cells without Col I, the survival rate of cancer cells cultured with Col I was significantly higher after EGFR-TKI treatment. In cancer cells cultured with and without Col I, EGFR-TKI suppressed the levels of phosphorylated (p-)EGFR, p-ERK1/2, and p-Akt. When compared to cancer cells without Col I, expression of p-P70S6K, a hallmark of mTOR activation, was dramatically upregulated in cancer cells with Col I. This activation was maintained even after EGFR-TKI treatment. Simultaneous treatment with EGFR-TKI and mTOR inhibitor abrogated Col I-induced resistance to EGFR-TKI. Patients with Col I-rich stroma had a significantly shorter progression-free survival time after EGFR-TKI therapy (238 days vs 404 days; P < .05). Collagen type I induces mTOR activation through an Akt-independent pathway, which results in EGFR-TKI resistance. Combination therapy using EGFR-TKI and mTOR inhibitor could be a possible strategy to combat this resistance. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  10. Cell-cycle-dependent drug-resistant quiescent cancer cells induce tumor angiogenesis after chemotherapy as visualized by real-time FUCCI imaging.

    PubMed

    Yano, Shuya; Takehara, Kiyoto; Tazawa, Hiroshi; Kishimoto, Hiroyuki; Urata, Yasuo; Kagawa, Shunsuke; Fujiwara, Toshiyoshi; Hoffman, Robert M

    2017-03-04

    We previously demonstrated that quiescent cancer cells in a tumor are resistant to conventional chemotherapy as visualized with a fluorescence ubiquitination cell cycle indicator (FUCCI). We also showed that proliferating cancer cells exist in a tumor only near nascent vessels or on the tumor surface as visualized with FUCCI and green fluorescent protein (GFP)-expressing tumor vessels. In the present study, we show the relationship between cell-cycle phase and chemotherapy-induced tumor angiogenesis using in vivo FUCCI real-time imaging of the cell cycle and nestin-driven GFP to detect nascent blood vessels. We observed that chemotherapy-treated tumors, consisting of mostly of quiescent cancer cells after treatment, had much more and deeper tumor vessels than untreated tumors. These newly-vascularized cancer cells regrew rapidly after chemotherapy. In contrast, formerly quiescent cancer cells decoyed to S/G 2 phase by a telomerase-dependent adenovirus did not induce tumor angiogenesis. The present results further demonstrate the importance of the cancer-cell position in the cell cycle in order that chemotherapy be effective and not have the opposite effect of stimulating tumor angiogenesis and progression.

  11. Cell-cycle-dependent drug-resistant quiescent cancer cells induce tumor angiogenesis after chemotherapy as visualized by real-time FUCCI imaging

    PubMed Central

    Yano, Shuya; Takehara, Kiyoto; Tazawa, Hiroshi; Kishimoto, Hiroyuki; Urata, Yasuo; Kagawa, Shunsuke; Fujiwara, Toshiyoshi; Hoffman, Robert M.

    2017-01-01

    ABSTRACT We previously demonstrated that quiescent cancer cells in a tumor are resistant to conventional chemotherapy as visualized with a fluorescence ubiquitination cell cycle indicator (FUCCI). We also showed that proliferating cancer cells exist in a tumor only near nascent vessels or on the tumor surface as visualized with FUCCI and green fluorescent protein (GFP)-expressing tumor vessels. In the present study, we show the relationship between cell-cycle phase and chemotherapy-induced tumor angiogenesis using in vivo FUCCI real-time imaging of the cell cycle and nestin-driven GFP to detect nascent blood vessels. We observed that chemotherapy-treated tumors, consisting of mostly of quiescent cancer cells after treatment, had much more and deeper tumor vessels than untreated tumors. These newly-vascularized cancer cells regrew rapidly after chemotherapy. In contrast, formerly quiescent cancer cells decoyed to S/G2 phase by a telomerase-dependent adenovirus did not induce tumor angiogenesis. The present results further demonstrate the importance of the cancer-cell position in the cell cycle in order that chemotherapy be effective and not have the opposite effect of stimulating tumor angiogenesis and progression. PMID:27715464

  12. Cancer-associated fibroblasts promote epithelial-mesenchymal transition and EGFR-TKI resistance of non-small cell lung cancers via HGF/IGF-1/ANXA2 signaling.

    PubMed

    Yi, Yanmei; Zeng, Shanshan; Wang, Zhaotong; Wu, Minhua; Ma, Yuanhuan; Ye, Xiaoxia; Zhang, Biao; Liu, Hao

    2018-03-01

    The involvement of the tumor stromal cells in acquired resistance of non-small cell lung cancers (NSCLCs) to tyrosine kinase inhibitors (TKIs) has previously been reported, but the precise mechanism remains unclear. In the present study, we investigated the role and mechanism underlying Cancer-associated fibroblasts (CAFs) in TKI resistance of NSCLCs. In vitro and in vivo experiments showed that HCC827 and PC9 cells, non-small cell lung cancer cells with EGFR-activating mutations, became resistant to the EGFR-TKI gefitinib when cultured with CAFs isolated from NSCLC tissues. Moreover, we showed that CAFs could induce epithelial-mesenchymal transition (EMT) phenotype of HCC827 and PC9 cells, with an associated change in the expression of epithelial to mesenchymal transition markers. Using proteomics-based method, we identified that CAFs significantly increased the expression of the Annexin A2 (ANXA2). More importantly, knockdown of ANXA2 completely reversed EMT phenotype and gefitinib resistance induced by CAFs. Furthermore, we found that CAFs increased the expression and phosphorylation of ANXA2 by secretion of growth factors HGF and IGF-1 and by activation of the corresponding receptors c-met and IGF-1R. Dual inhibition of HGF/c-met and IGF-1/IGF-1R pathways could significantly suppress ANXA2, and markedly reduced CAFs-induced EMT and gefitinib resistance. Taken together, these findings indicate that CAFs promote EGFR-TKIs resistance through HGF/IGF-1/ANXA2/EMT signaling and may be an ideal therapeutic target in NSCLCs with EGFR-activating mutations. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Wound Healing and Cancer Stem Cells: Inflammation as a Driver of Treatment Resistance in Breast Cancer

    PubMed Central

    Arnold, Kimberly M; Opdenaker, Lynn M; Flynn, Daniel; Sims-Mourtada, Jennifer

    2015-01-01

    The relationship between wound healing and cancer has long been recognized. The mechanisms that regulate wound healing have been shown to promote transformation and growth of malignant cells. In addition, chronic inflammation has been associated with malignant transformation in many tissues. Recently, pathways involved in inflammation and wound healing have been reported to enhance cancer stem cell (CSC) populations. These cells, which are highly resistant to current treatments, are capable of repopulating the tumor after treatment, causing local and systemic recurrences. In this review, we highlight proinflammatory cytokines and developmental pathways involved in tissue repair, whose deregulation in the tumor microenvironment may promote growth and survival of CSCs. We propose that the addition of anti-inflammatory agents to current treatment regimens may slow the growth of CSCs and improve therapeutic outcomes. PMID:25674014

  14. Curcumin Induces G2/M Arrest and Apoptosis in Cisplatin-Resistant Human Ovarian Cancer Cells by Modulating Akt and p38 MAPK

    PubMed Central

    Weir, Nathan M.; Selvendiran, Karuppaiyah; Kutala, Vijay Kumar; Tong, Liyue; Vishwanath, Shilpa; Rajaram, Murugesan; Tridandapani, Susheela; Anant, Shrikant; Kuppusamy, Periannan

    2007-01-01

    Curcumin, a major active component of turmeric, is known to induce apoptosis in several types of cancer cells, but little is known about its activity in chemoresistant cells. Hence, the aim of the present study was to investigate the anticancer properties of curcumin in cisplatin-resistant human ovarian cancer cells in vitro. The results indicated that curcumin inhibited the proliferation of both cisplatin-resistant (CR) and sensitive (CS) human ovarian cancer cells almost equally. Enhanced superoxide generation was observed in both CR and CS cells treated with curcumin. Curcumin induced G2/M phase cell-cycle arrest in CR cells by enhancing the p53 phosphorylation and apoptosis through the activation of caspase-3 followed by PARP degradation. Curcumin also inhibited the phosphorylation of Akt while the phosphorylation of p38 MAPK was enhanced. In summary, our results showed that curcumin inhibits the proliferation of cisplatin-resistant ovarian cancer cells through the induction of superoxide generation, G2/M arrest, and apoptosis. PMID:17218783

  15. The Stress Protein BAG3 Stabilizes Mcl-1 Protein and Promotes Survival of Cancer Cells and Resistance to Antagonist ABT-737*

    PubMed Central

    Boiani, Mariana; Daniel, Cristina; Liu, Xueyuan; Hogarty, Michael D.; Marnett, Lawrence J.

    2013-01-01

    Members of the Bcl-2 family of proteins are important inhibitors of apoptosis in human cancer and are targets for novel anticancer agents such as the Bcl-2 antagonists, ABT-263 (Navitoclax), and its analog ABT-737. Unlike Bcl-2, Mcl-1 is not antagonized by ABT-263 or ABT-737 and is considered to be a major factor in resistance. Also, Mcl-1 exhibits differential regulation when compared with other Bcl-2 family members and is a target for anticancer drug discovery. Here, we demonstrate that BAG3, an Hsp70 co-chaperone, protects Mcl-1 from proteasomal degradation, thereby promoting its antiapoptotic activity. Using neuroblastoma cell lines, with a defined Bcl-2 family dependence, we found that BAG3 expression correlated with Mcl-1 dependence and ABT-737 resistance. RNA silencing of BAG3 led to a marked reduction in Mcl-1 protein levels and overcame ABT-737 resistance in Mcl-1-dependent cells. In ABT-737-resistant cells, Mcl-1 co-immunoprecipitated with BAG3, and loss of Mcl-1 after BAG3 silencing was prevented by proteasome inhibition. BAG3 and Mcl-1 were co-expressed in a panel of diverse cancer cell lines resistant to ABT-737. Silencing BAG3 reduced Mcl-1 protein levels and overcame ABT-737 resistance in several of the cell lines, including triple-negative breast cancer (MDA-MB231) and androgen receptor-negative prostate cancer (PC3) cells. These studies identify BAG3-mediated Mcl-1 stabilization as a potential target for cancer drug discovery. PMID:23341456

  16. The stress protein BAG3 stabilizes Mcl-1 protein and promotes survival of cancer cells and resistance to antagonist ABT-737.

    PubMed

    Boiani, Mariana; Daniel, Cristina; Liu, Xueyuan; Hogarty, Michael D; Marnett, Lawrence J

    2013-03-08

    Members of the Bcl-2 family of proteins are important inhibitors of apoptosis in human cancer and are targets for novel anticancer agents such as the Bcl-2 antagonists, ABT-263 (Navitoclax), and its analog ABT-737. Unlike Bcl-2, Mcl-1 is not antagonized by ABT-263 or ABT-737 and is considered to be a major factor in resistance. Also, Mcl-1 exhibits differential regulation when compared with other Bcl-2 family members and is a target for anticancer drug discovery. Here, we demonstrate that BAG3, an Hsp70 co-chaperone, protects Mcl-1 from proteasomal degradation, thereby promoting its antiapoptotic activity. Using neuroblastoma cell lines, with a defined Bcl-2 family dependence, we found that BAG3 expression correlated with Mcl-1 dependence and ABT-737 resistance. RNA silencing of BAG3 led to a marked reduction in Mcl-1 protein levels and overcame ABT-737 resistance in Mcl-1-dependent cells. In ABT-737-resistant cells, Mcl-1 co-immunoprecipitated with BAG3, and loss of Mcl-1 after BAG3 silencing was prevented by proteasome inhibition. BAG3 and Mcl-1 were co-expressed in a panel of diverse cancer cell lines resistant to ABT-737. Silencing BAG3 reduced Mcl-1 protein levels and overcame ABT-737 resistance in several of the cell lines, including triple-negative breast cancer (MDA-MB231) and androgen receptor-negative prostate cancer (PC3) cells. These studies identify BAG3-mediated Mcl-1 stabilization as a potential target for cancer drug discovery.

  17. Management of Resistance to Crizotinib in Anaplastic Lymphoma Kinase-Positive Non-Small-cell Lung Cancer.

    PubMed

    Matikas, Alexios; Kentepozidis, Nikolaos; Georgoulias, Vassilis; Kotsakis, Athanasios

    2016-11-01

    During the past decade, the recognition of an ever-expanding list of driver oncogenic mutations in non-small-cell lung cancer has resulted in rapid therapeutic advances. Since the first description of the echinoderm microtubule-associated protein-like 4 anaplastic lymphoma kinase (EML4-ALK) rearrangement in 4% of cases of non-small-cell lung cancer in 2007, a highly potent and selective ALK inhibitor, crizotinib, was developed and approved in record time. However, it soon became apparent that although the responses can be dramatic and durable and primary intrinsic resistance to crizotinib is uncommon, the emergence of secondary resistance is inevitable. Efforts to elucidate the specific mechanisms that confer acquired resistance to crizotinib are underway. These have led to the recognition of the role of secondary resistance mutations, of ALK amplification, and of activation of bypass signaling, all of which contribute to resistance to crizotinib. Moreover, the rapid preclinical and clinical development of multiple second-generation ALK inhibitors that exhibit significant clinical activity against crizotinib-resistant disease has provided multiple options to treating physicians, with the ultimate goal the delivery of tailored medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Cytokines in cancer drug resistance: Cues to new therapeutic strategies.

    PubMed

    Jones, Valerie Sloane; Huang, Ren-Yu; Chen, Li-Pai; Chen, Zhe-Sheng; Fu, Liwu; Huang, Ruo-Pan

    2016-04-01

    The development of oncoprotein-targeted anticancer drugs is an invaluable weapon in the war against cancer. However, cancers do not give up without a fight. They may develop multiple mechanisms of drug resistance, including apoptosis inhibition, drug expulsion, and increased proliferation that reduce the effectiveness of the drug. The collective work of researchers has highlighted the role of cytokines in the mechanisms of cancer drug resistance, as well as in cancer cell progression. Furthermore, recent studies have described how specific cytokines secreted by cancer stromal cells confer resistance to chemotherapeutic treatments. In order to gain a better understanding of mechanism of cancer drug resistance and a prediction of treatment outcome, it is imperative that correlations are established between global cytokine profiles and cancer drug resistance. Here we discuss the recent discoveries in this field of research and discuss their implications for the future development of effective anti-cancer medicines. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. ATP11B mediates platinum resistance in ovarian cancer

    PubMed Central

    Moreno-Smith, Myrthala; Halder, J.B.; Meltzer, Paul S.; Gonda, Tamas A.; Mangala, Lingegowda S.; Rupaimoole, Rajesha; Lu, Chunhua; Nagaraja, Archana S.; Gharpure, Kshipra M.; Kang, Yu; Rodriguez-Aguayo, Cristian; Vivas-Mejia, Pablo E.; Zand, Behrouz; Schmandt, Rosemarie; Wang, Hua; Langley, Robert R.; Jennings, Nicholas B.; Ivan, Cristina; Coffin, Jeremy E.; Armaiz, Guillermo N.; Bottsford-Miller, Justin; Kim, Sang Bae; Halleck, Margaret S.; Hendrix, Mary J.C.; Bornman, William; Bar-Eli, Menashe; Lee, Ju-Seog; Siddik, Zahid H.; Lopez-Berestein, Gabriel; Sood, Anil K.

    2013-01-01

    Platinum compounds display clinical activity against a wide variety of solid tumors; however, resistance to these agents is a major limitation in cancer therapy. Reduced platinum uptake and increased platinum export are examples of resistance mechanisms that limit the extent of DNA damage. Here, we report the discovery and characterization of the role of ATP11B, a P-type ATPase membrane protein, in cisplatin resistance. We found that ATP11B expression was correlated with higher tumor grade in human ovarian cancer samples and with cisplatin resistance in human ovarian cancer cell lines. ATP11B gene silencing restored the sensitivity of ovarian cancer cell lines to cisplatin in vitro. Combined therapy of cisplatin and ATP11B-targeted siRNA significantly decreased cancer growth in mice bearing ovarian tumors derived from cisplatin-sensitive and -resistant cells. In vitro mechanistic studies on cellular platinum content and cisplatin efflux kinetics indicated that ATP11B enhances the export of cisplatin from cells. The colocalization of ATP11B with fluorescent cisplatin and with vesicular trafficking proteins, such as syntaxin-6 (STX6) and vesicular-associated membrane protein 4 (VAMP4), strongly suggests that ATP11B contributes to secretory vesicular transport of cisplatin from Golgi to plasma membrane. In conclusion, inhibition of ATP11B expression could serve as a therapeutic strategy to overcome cisplatin resistance. PMID:23585472

  20. Two Novel Determinants of Etoposide Resistance in Small Cell Lung Cancer

    PubMed Central

    Lawson, Malcolm H; Cummings, Natalie M; Rassl, Doris M; Russell, Roslin; Brenton, James D; Rintoul, Robert C; Murphy, Gillian

    2011-01-01

    Patient survival in small cell lung cancer (SCLC) is limited by acquired chemoresistance. Here we report the use of a biologically relevant model to identify novel candidate genes mediating in vivo acquired resistance to etoposide. Candidate genes derived from a cDNA microarray analysis were cloned and transiently overexpressed to evaluate their potential functional roles. We identified two promising genes in the DNA repair enzyme DNA Polymerase β and in the neuroendocrine transcription factor NKX2.2. Specific inhibition of DNA Polymerase β reduced the numbers of cells surviving treatment with etoposide and increased the amount of DNA damage in cells. Conversely, stable overexpression of NKX2.2 increased cell survival in response to etoposide in SCLC cell lines. Consistent with these findings, we found that an absence of nuclear staining for NKX2.2 in SCLC primary tumors was an independent predictor of improved outcomes in chemotherapy-treated patients. Taken together, our findings justify future prospective studies to confirm the roles of these molecules in mediating chemotherapy resistance in SCLC. PMID:21642373

  1. Role of GPR30 in the mechanisms of tamoxifen resistance in breast cancer MCF-7 cells.

    PubMed

    Ignatov, Atanas; Ignatov, Tanja; Roessner, Albert; Costa, Serban Dan; Kalinski, Thomas

    2010-08-01

    Tamoxifen is the most frequently used anti-hormonal drug for treatment of women with hormone-dependent breast cancer. The aim of this study is to investigate the mechanism of tamoxifen resistance and the impact of the new estrogen G-protein coupled receptor (GPR30). MCF-7 cells were continuously exposed to tamoxifen for 6 months to induce resistance to the inhibitory effect of tamoxifen. These tamoxifen-resistant cells (TAM-R) exhibited enhanced sensitivity to 17-ss-estradiol and GPR30 agonist, G1, when compared to the parental cells. In TAM-R cells, tamoxifen was able to stimulate the cell growth and MAPK phosphorylation. These effects were abolished by EGFR inhibitor AG1478, GPR30 anti-sense oligonucleotide, and the selective c-Src inhibitor PP2. Only EGFR basal expression was slightly elevated in the TAM-R cells, whereas GPR30 expression and the basal phosphorylation of Akt and MAPK remained unchanged when compared to the parental cells. Interestingly, estrogen treatment significantly increased GPR30 translocation to the cell surface, which was stronger in TAM-R cells. Continuous treatment of MCF-7 cells with GPR30 agonist G1 mimics the long-term treatment with tamoxifen and increases drastically its agonistic activity. This data suggests the important role of GPR30/EGFR receptor signaling in the development of tamoxifen resistance. The inhibition of this pathway is a valid option to improve anti-hormone response in breast cancer.

  2. Bitter melon juice targets molecular mechanisms underlying gemcitabine resistance in pancreatic cancer cells.

    PubMed

    Somasagara, Ranganatha R; Deep, Gagan; Shrotriya, Sangeeta; Patel, Manisha; Agarwal, Chapla; Agarwal, Rajesh

    2015-04-01

    Pancreatic cancer (PanC) is one of the most lethal malignancies, and resistance towards gemcitabine, the front-line chemotherapy, is the main cause for dismal rate of survival in PanC patients; overcoming this resistance remains a major challenge to treat this deadly malignancy. Whereas several molecular mechanisms are known for gemcitabine resistance in PanC cells, altered metabolism and bioenergetics are not yet studied. Here, we compared metabolic and bioenergetic functions between gemcitabine-resistant (GR) and gemcitabine-sensitive (GS) PanC cells and underlying molecular mechanisms, together with efficacy of a natural agent bitter melon juice (BMJ). GR PanC cells showed distinct morphological features including spindle-shaped morphology and a decrease in E-cadherin expression. GR cells also showed higher ATP production with an increase in oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). Molecular studies showed higher expression of glucose transporters (GLUT1 and 4) suggesting an increase in glucose uptake by GR cells. Importantly, GR cells showed a significant increase in Akt and ERK1/2 phosphorylation and their inhibition decreased cell viability, suggesting their role in survival and drug resistance of these cells. Recently, we reported strong efficacy of BMJ against a panel of GS cells in culture and nude mice, which we expanded here and found that BMJ was also effective in decreasing both Akt and ERK1/2 phosphorylation and viability of GR PanC cells. Overall, we have identified novel mechanisms of gemcitabine resistance in PanC cells which are targeted by BMJ. Considering the short survival in PanC patients, our findings could have high translational potential in controlling this deadly malignancy.

  3. Aspirin counteracts cancer stem cell features, desmoplasia and gemcitabine resistance in pancreatic cancer

    PubMed Central

    Zhang, Yiyao; Liu, Li; Fan, Pei; Bauer, Nathalie; Gladkich, Jury; Ryschich, Eduard; Bazhin, Alexandr V.; Giese, Nathalia A.; Strobel, Oliver; Hackert, Thilo; Hinz, Ulf; Gross, Wolfgang; Fortunato, Franco; Herr, Ingrid

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDA) is characterized by an extremely poor prognosis. An inflammatory microenvironment triggers the pronounced desmoplasia, the selection of cancer stem-like cells (CSCs) and therapy resistance. The anti-inflammatory drug aspirin is suggested to lower the risk for PDA and to improve the treatment, although available results are conflicting and the effect of aspirin to CSC characteristics and desmoplasia in PDA has not yet been investigated. We characterized the influence of aspirin on CSC features, stromal reactions and gemcitabine resistance. Four established and 3 primary PDA cell lines, non-malignant cells, 3 patient tumor-derived CSC-enriched spheroidal cultures and tissues from patients who did or did not receive aspirin before surgery were analyzed using MTT assays, flow cytometry, colony and spheroid formation assays, Western blot analysis, antibody protein arrays, electrophoretic mobility shift assays (EMSAs), immunohistochemistry and in vivo xenotransplantation. Aspirin significantly induced apoptosis and reduced the viability, self-renewal potential, and expression of proteins involved in inflammation and stem cell signaling. Aspirin also reduced the growth and invasion of tumors in vivo, and it significantly prolonged the survival of mice with orthotopic pancreatic xenografts in combination with gemcitabine. This was associated with a decreased expression of markers for progression, inflammation and desmoplasia. These findings were confirmed in tissue samples obtained from patients who had or had not taken aspirin before surgery. Importantly, aspirin sensitized cells that were resistant to gemcitabine and thereby enhanced the therapeutic efficacy. Aspirin showed no obvious toxic effects on normal cells, chick embryos or mice. These results highlight aspirin as an effective, inexpensive and well-tolerated co-treatment to target inflammation, desmoplasia and CSC features PDA. PMID:25846752

  4. Protein and chemotherapy profiling of extracellular vesicles harvested from therapeutic induced senescent triple negative breast cancer cells

    PubMed Central

    Kavanagh, E L; Lindsay, S; Halasz, M; Gubbins, L C; Weiner-Gorzel, K; Guang, M H Z; McGoldrick, A; Collins, E; Henry, M; Blanco-Fernández, A; Gorman, P O'; Fitzpatrick, P; Higgins, M J; Dowling, P; McCann, A

    2017-01-01

    Triple negative breast cancer (TNBC) is an aggressive subtype with relatively poor clinical outcomes and limited treatment options. Chemotherapy, while killing cancer cells, can result in the generation of highly chemoresistant therapeutic induced senescent (TIS) cells that potentially form stem cell niches resulting in metastases. Intriguingly, senescent cells release significantly more extracellular vesicles (EVs) than non-senescent cells. Our aim was to profile EVs harvested from TIS TNBC cells compared with control cells to identify a potential mechanism by which TIS TNBC cells maintain survival in the face of chemotherapy. TIS was induced and confirmed in Cal51 TNBC cells using the chemotherapeutic paclitaxel (PTX) (Taxol). Mass spectrometry (MS) analysis of EVs harvested from TIS compared with control Cal51 cells was performed using Ingenuity Pathway Analysis and InnateDB programs. We demonstrate that TIS Cal51 cells treated with 75 nM PTX for 7 days became senescent (senescence-associated β-galactosidase (SA-β-Gal) positive, Ki67-negative, increased p21 and p16, G2/M cell cycle arrest) and released significantly more EVs (P=0.0002) and exosomes (P=0.0007) than non-senescent control cells. Moreover, TIS cells displayed an increased expression of the multidrug resistance protein 1/p-glycoprotein. MS analysis demonstrated that EVs derived from senescent Cal51 cells contained 142 proteins with a significant increased fold change compared with control EVs. Key proteins included ATPases, annexins, tubulins, integrins, Rabs and insoluble senescence-associated secretory phenotype (SASP) factors. A fluorescent analogue of PTX (Flutax-2) allowed appreciation of the removal of chemotherapy in EVs from senescent cells. Treatment of TIS cells with the exosome biogenesis inhibitor GW4869 resulted in reduced SA-β-Gal staining (P=0.04). In summary, this study demonstrates that TIS cells release significantly more EVs compared with control cells, containing chemotherapy

  5. Aspirin plus sorafenib potentiates cisplatin cytotoxicity in resistant head and neck cancer cells through xCT inhibition.

    PubMed

    Roh, Jong-Lyel; Kim, Eun Hye; Jang, Hyejin; Shin, Daiha

    2017-03-01

    The nonsteroidal anti-inflammatory drug aspirin and the multikinase inhibitor sorafenib have both shown experimental and clinical anticancer activities. The present study investigated whether aspirin and sorafenib synergize to potentiate cisplatin treatment in resistant head and neck cancer (HNC) cells. The effects of aspirin, sorafenib and cisplatin, and combinations thereof were assessed by measuring cell viability, death, glutathione (GSH) and reactive oxygen species (ROS) levels, protein and mRNA expression, genetic inhibition and overexpression of cystine-glutamate antiporter (xCT) and tumor xenograft mouse models. Even at low concentrations, aspirin plus sorafenib synergized to induce cell death of cisplatin-resistant HNC cells. The combination of aspirin and sorafenib induced xCT inhibition, GSH depletion, and ROS accumulation in cancer cells. Genetic and pharmacological inhibition of xCT potentiated the cytotoxic effects of aspirin plus sorafenib; this effect was diminished by xCT overexpression. Low-dose aspirin plus sorafenib enhanced the cytotoxicity of cisplatin in resistant HNC cells through xCT inhibition and oxidant and DNA damage. The in vivo effects of aspirin plus sorafenib on cisplatin therapy were also confirmed in resistant HNC xenograft models, in terms of growth inhibition, GSH depletion, and increased γH2AX formation and apoptosis in tumors. Aspirin and sorafenib synergize to potentiate the cytotoxicity of cisplatin in resistant HNC cells. This therapeutic strategy may help to eliminate resistant HNC. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. miR-25-3p reverses epithelial-mesenchymal transition via targeting Sema4C in cisplatin-resistance cervical cancer cells.

    PubMed

    Song, Jing; Li, Yue

    2017-01-01

    Acquisition of epithelial-mesenchymal transition (EMT) has recently been proposed as an important contributor of drug resistance in cervical cancer cells. However, the underlying mechanisms are still unclear. MicroRNAs play a crucial role in regulating EMT. The aim of this study was to explore the potential role of miR-25-3p in regulating EMT in cisplatin-resistant (CR) cervical cancer cells. To this end, we established stable CR cervical cancer cells, HeLa-CR and CaSki-CR, and investigated the function of miR-25-3p in regulating EMT. It is found that CR cervical cancer cells possessed more EMT characteristics and demonstrated higher migratory abilities and invasiveness. miR-25-3p downregulation was also seen in HeLa-CR and CaSki-CR cells. Of note, ectopic expression of miR-25-3p reversed the EMT phenotype and sensitized CR cells to cisplatin via targeting Sema4C. Furthermore, stable overexpression of miR-25-3p in HeLa-CR cells suppressed tumor growth in mice, downregulated Sema4C and Snail, and upregulated E-cadherin compared with the control group. These results suggest that miR-25-3p is an important regulator of cervical cancer EMT and chemoresistance. Thus, upregulation of miR-25-3p could be a novel approach to treat cervical cancers that are resistant to chemotherapy. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  7. Adaptation of cancer cells from different entities to the MDM2 inhibitor nutlin-3 results in the emergence of p53-mutated multi-drug-resistant cancer cells

    PubMed Central

    Michaelis, M; Rothweiler, F; Barth, S; Cinatl, J; van Rikxoort, M; Löschmann, N; Voges, Y; Breitling, R; von Deimling, A; Rödel, F; Weber, K; Fehse, B; Mack, E; Stiewe, T; Doerr, H W; Speidel, D; Cinatl, J

    2011-01-01

    Six p53 wild-type cancer cell lines from infrequently p53-mutated entities (neuroblastoma, rhabdomyosarcoma, and melanoma) were continuously exposed to increasing concentrations of the murine double minute 2 inhibitor nutlin-3, resulting in the emergence of nutlin-3-resistant, p53-mutated sublines displaying a multi-drug resistance phenotype. Only 2 out of 28 sublines adapted to various cytotoxic drugs harboured p53 mutations. Nutlin-3-adapted UKF-NB-3 cells (UKF-NB-3rNutlin10 μM, harbouring a G245C mutation) were also radiation resistant. Analysis of UKF-NB-3 and UKF-NB-3rNutlin10 μM cells by RNA interference experiments and lentiviral transduction of wild-type p53 into p53-mutated UKF-NB-3rNutlin10 μM cells revealed that the loss of p53 function contributes to the multi-drug resistance of UKF-NB-3rNutlin10 μM cells. Bioinformatics PANTHER pathway analysis based on microarray measurements of mRNA abundance indicated a substantial overlap in the signalling pathways differentially regulated between UKF-NB-3rNutlin10 μM and UKF-NB-3 and between UKF-NB-3 and its cisplatin-, doxorubicin-, or vincristine-resistant sublines. Repeated nutlin-3 adaptation of neuroblastoma cells resulted in sublines harbouring various p53 mutations with high frequency. A p53 wild-type single cell-derived UKF-NB-3 clone was adapted to nutlin-3 in independent experiments. Eight out of ten resulting sublines were p53-mutated harbouring six different p53 mutations. This indicates that nutlin-3 induces de novo p53 mutations not initially present in the original cell population. Therefore, nutlin-3-treated cancer patients should be carefully monitored for the emergence of p53-mutated, multi-drug-resistant cells. PMID:22170099

  8. Fyn is an important molecule in cancer pathogenesis and drug resistance.

    PubMed

    Elias, Daniel; Ditzel, Henrik J

    2015-10-01

    Fyn is a non-receptor tyrosine kinase that belongs to the Src family kinases (SFKs) which under normal physiological conditions is involved in signal transduction pathways in the nervous system, as well as the development and activation of T lymphocytes. In cancer, Fyn contributes to the development and progression of several cancer types through its involvement in the control of cell growth, death, morphogenic transformation and cellular motility. Enhanced expression and/or activation of Fyn is observed in various cancers, including melanoma, glioblastoma, squamous cell carcinoma, prostate and breast cancers. Recent studies have demonstrated the importance of Fyn in the resistance or susceptibility of cancer cells to some anti-cancer treatments. We have recently shown that Fyn is upregulated in tamoxifen-resistant breast cancer cell lines and demonstrated that it plays a key role in the resistance mechanism. Further, we found that the cellular localization of Fyn within cancer cells of primary ER+ breast tumor tissue may serve as a prognostic marker. Understanding the role of Fyn in initiation and progression of cancer and its contribution to resistance against anti-cancer therapeutic agents may facilitate the development and use of novel drugs targeting Fyn for better management of malignancies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Induction of autophagy contributes to crizotinib resistance in ALK-positive lung cancer.

    PubMed

    Ji, Cheng; Zhang, Li; Cheng, Yan; Patel, Raj; Wu, Hao; Zhang, Yi; Wang, Mian; Ji, Shundong; Belani, Chandra P; Yang, Jin-Ming; Ren, Xingcong

    2014-05-01

    Use of the inhibitor of ALK fusion onco-protein, crizotinib (PF02341066), has achieved impressive clinical efficacy in patients with ALK-positive non-small cell lung cancer. Nevertheless, acquired resistance to this drug occurs inevitably in approximately a year, limiting the therapeutic benefits of this novel targeted therapy. In this study, we found that autophagy was induced in crizonitib-resistant lung cancer cells and contributed to drug resistance. We observed that ALK was downregulated in the crizotinib-resistant lung cancer cell line, H3122CR-1, and this was causally associated with autophagy induction. The degree of crizotinib resistance correlated with autophagic activity. Activation of autophagy in crizotinib-resistant H3122CR-1 cells involved alteration of the Akt/mTOR signaling pathway. Furthermore, we demonstrated that chloroquine, an inhibitor of autophagy, could restore sensitivity of H3122CR-1 to crizotinib and enhance its efficacy against drug-resistant lung cancer. Thus, modulating autophagy may be worth exploring as a new strategy to overcome acquired crizonitib resistance in ALK-positive lung cancer.

  10. EDD enhances cell survival and cisplatin resistance and is a therapeutic target for epithelial ovarian cancer

    PubMed Central

    Bradley, Amber; Zheng, Hui; Eblen, Scott T.

    2014-01-01

    The E3 ubiquitin ligase EDD is overexpressed in recurrent, platinum-resistant ovarian cancers, suggesting a role in tumor survival and/or platinum resistance. EDD knockdown by small interfering RNA (siRNA) induced apoptosis in A2780ip2, OVCAR5 and ES-2 ovarian cancer cells, correlating with loss of the prosurvival protein myeloid cell leukemia sequence 1 (Mcl-1) through a glycogen synthase kinase 3 beta-independent mechanism. SiRNA to EDD or Mcl-1 induced comparable levels of apoptosis in A2780ip2 and ES-2 cells. Stable overexpression of Mcl-1 protected cells from apoptosis following EDD knockdown, accompanied by a loss of endogenous, but not exogenous, Mcl-1 protein, suggesting that EDD regulated Mcl-1 synthesis. Indeed, EDD knockdown induced a 1.87-fold decrease in Mcl-1 messenger RNA and EDD transfection enhanced murine Mcl-1 promoter-driven luciferase expression 5-fold. To separate EDD survival and potential cisplatin resistance functions, we generated EDD shRNA stable cell lines that could survive initial EDD knockdown and showed that these cells were 4- to 21-fold more sensitive to cisplatin. Moreover, transient EDD overexpression in COS-7 cells was sufficient to promote cisplatin resistance 2.4-fold, dependent upon its E3 ligase activity. In vivo, mouse intraperitoneal ES-2 and A2780ip2 xenograft experiments showed that mice treated with EDD siRNA by nanoliposomal delivery [1,2-dioleoyl-sn-glycero-3-phophatidylcholine (DOPC)] and cisplatin had significantly less tumor burden than those treated with control siRNA/DOPC alone (ES-2, 77.9% reduction, P = 0.004; A2780ip2, 75.9% reduction, P = 0.042) or control siRNA/DOPC with cisplatin in ES-2 (64.4% reduction, P = 0.035), with a trend in A2780ip2 (60.3% reduction, P = 0.168). These results identify EDD as a dual regulator of cell survival and cisplatin resistance and suggest that EDD is a therapeutic target for ovarian cancer. PMID:24379240

  11. mTOR Signaling Confers Resistance to Targeted Cancer Drugs.

    PubMed

    Guri, Yakir; Hall, Michael N

    2016-11-01

    Cancer is a complex disease and a leading cause of death worldwide. Extensive research over decades has led to the development of therapies that target cancer-specific signaling pathways. However, the clinical benefits of such drugs are at best transient due to tumors displaying intrinsic or adaptive resistance. The underlying compensatory pathways that allow cancer cells to circumvent a drug blockade are poorly understood. We review here recent studies suggesting that mammalian TOR (mTOR) signaling is a major compensatory pathway conferring resistance to many cancer drugs. mTOR-mediated resistance can be cell-autonomous or non-cell-autonomous. These findings suggest that mTOR signaling should be monitored routinely in tumors and that an mTOR inhibitor should be considered as a co-therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Cisplatin induces expression of drug resistance-related genes through c-jun N-terminal kinase pathway in human lung cancer cells.

    PubMed

    Xu, Li; Fu, Yingya; Li, Youlun; Han, Xiaoli

    2017-08-01

    Change of multidrug resistance-related genes (e.g., lung resistance protein, LRP) and overexpression of anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are responsible for cisplatin resistance. In our study, we investigated the mechanism by which cisplatin induces LRP, Bcl-2, Bcl-xL, XIAP, and Survivin expression in human lung adenocarcinoma A549 cells and human H446 small cell lung cancer cells at mRNA and protein levels. In our study, cell proliferation was assessed with CCK-8 assays, and cell apoptosis was assessed with flow cytometric analysis and Annexin-V/PI staining. qPCR was used to complete RNA experiments. Protein expression was assessed with Western blotting. Cisplatin increased Bcl-2, LRP, and Survivin expression, but decreased Bcl-xL and XIAP expression in a dose-dependent manner. Preincubation with JNK-specific inhibitor, SP600125, significantly inhibited these genes' expression at mRNA and protein levels, enhanced chemosensitivity of lung cancer cells to cisplatin, and promoted cisplatin-induced apoptosis. Our data suggest that the JNK signaling pathway plays an important role in cisplatin resistance. Lung resistance protein (LRP) and anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are involved in the process. The results reminded us of a novel therapy target for lung cancer treatment.

  13. Bortezomib sensitises TRAIL-resistant HPV-positive head and neck cancer cells to TRAIL through a caspase-dependent, E6-independent mechanism.

    PubMed

    Bullenkamp, J; Raulf, N; Ayaz, B; Walczak, H; Kulms, D; Odell, E; Thavaraj, S; Tavassoli, M

    2014-10-23

    Human papillomavirus (HPV) is causative for a new and increasing form of head and neck squamous cell carcinomas (HNSCCs). Although localised HPV-positive cancers have a favourable response to radio-chemotherapy (RT/CT), the impact of HPV in advanced or metastatic HNSCC remains to be defined and targeted therapeutics need to be tested for cancers resistant to RT/CT. To this end, we investigated the sensitivity of HPV-positive and -negative HNSCC cell lines to TRAIL (tumour necrosis factor-related apoptosis-inducing ligand), which induces tumour cell-specific apoptosis in various cancer types. A clear correlation was observed between HPV positivity and resistance to TRAIL compared with HPV-negative head and neck cancer cell lines. All TRAIL-resistant HPV-positive cell lines tested were sensitised to TRAIL-induced cell death by treatment with bortezomib, a clinically approved proteasome inhibitor. Bortezomib-mediated sensitisation to TRAIL was associated with enhanced activation of caspase-8, -9 and -3, elevated membrane expression levels of TRAIL-R2, cytochrome c release and G2/M arrest. Knockdown of caspase-8 significantly blocked cell death induced by the combination therapy, whereas the BH3-only protein Bid was not required for induction of apoptosis. XIAP depletion increased the sensitivity of both HPV-positive and -negative cells to TRAIL alone or in combination with bortezomib. In contrast, restoration of p53 following E6 knockdown in HPV-positive cells had no effect on their sensitivity to either single or combination therapy, suggesting a p53-independent pathway for the observed response. In summary, bortezomib-mediated proteasome inhibition sensitises previously resistant HPV-positive HNSCC cells to TRAIL-induced cell death through a mechanism involving both the extrinsic and intrinsic pathways of apoptosis. The cooperative effect of these two targeted anticancer agents therefore represents a promising treatment strategy for RT/CT-resistant HPV

  14. MENA Confers Resistance to Paclitaxel in Triple-Negative Breast Cancer.

    PubMed

    Oudin, Madeleine J; Barbier, Lucie; Schäfer, Claudia; Kosciuk, Tatsiana; Miller, Miles A; Han, Sangyoon; Jonas, Oliver; Lauffenburger, Douglas A; Gertler, Frank B

    2017-01-01

    Taxane therapy remains the standard of care for triple-negative breast cancer. However, high frequencies of recurrence and progression in treated patients indicate that metastatic breast cancer cells can acquire resistance to this drug. The actin regulatory protein MENA and particularly its invasive isoform, MENA INV , are established drivers of metastasis. MENA INV expression is significantly correlated with metastasis and poor outcome in human patients with breast cancer. We investigated whether MENA isoforms might play a role in driving resistance to chemotherapeutics. We find that both MENA and MENA INV confer resistance to the taxane paclitaxel, but not to the widely used DNA-damaging agents doxorubicin or cisplatin. Furthermore, paclitaxel treatment does not attenuate growth of MENA INV -driven metastatic lesions. Mechanistically, MENA isoform expression alters the ratio of dynamic and stable microtubule populations in paclitaxel-treated cells. MENA expression also increases MAPK signaling in response to paclitaxel treatment. Decreasing ERK phosphorylation by co-treatment with MEK inhibitor restored paclitaxel sensitivity by driving microtubule stabilization in MENA isoform-expressing cells. Our results reveal a novel mechanism of taxane resistance in highly metastatic breast cancer cells and identify a combination therapy to overcome such resistance. Mol Cancer Ther; 16(1); 143-55. ©2016 AACR. ©2016 American Association for Cancer Research.

  15. Loss of Activating EGFR Mutant Gene Contributes to Acquired Resistance to EGFR Tyrosine Kinase Inhibitors in Lung Cancer Cells

    PubMed Central

    Kubo, Takuya; Murakami, Yuichi; Kawahara, Akihiko; Azuma, Koichi; Abe, Hideyuki; Kage, Masayoshi; Yoshinaga, Aki; Tahira, Tomoko; Hayashi, Kenshi; Arao, Tokuzo; Nishio, Kazuto; Rosell, Rafael; Kuwano, Michihiko; Ono, Mayumi

    2012-01-01

    Non-small-cell lung cancer harboring epidermal growth factor receptor (EGFR) mutations attains a meaningful response to EGFR-tyrosine kinase inhibitors (TKIs). However, acquired resistance to EGFR-TKIs could affect long-term outcome in almost all patients. To identify the potential mechanisms of resistance, we established cell lines resistant to EGFR-TKIs from the human lung cancer cell lines PC9 and11–18, which harbored activating EGFR mutations. One erlotinib-resistant cell line from PC9 and two erlotinib-resistant cell lines and two gefitinib-resistant cell lines from 11–18 were independently established. Almost complete loss of mutant delE746-A750 EGFR gene was observed in the erlotinib-resistant cells isolated from PC9, and partial loss of the mutant L858R EGFR gene copy was specifically observed in the erlotinib- and gefitinib-resistant cells from 11–18. However, constitutive activation of EGFR downstream signaling, PI3K/Akt, was observed even after loss of the mutated EGFR gene in all resistant cell lines even in the presence of the drug. In the erlotinib-resistant cells from PC9, constitutive PI3K/Akt activation was effectively inhibited by lapatinib (a dual TKI of EGFR and HER2) or BIBW2992 (pan-TKI of EGFR family proteins). Furthermore, erlotinib with either HER2 or HER3 knockdown by their cognate siRNAs also inhibited PI3K/Akt activation. Transfection of activating mutant EGFR complementary DNA restored drug sensitivity in the erlotinib-resistant cell line. Our study indicates that loss of addiction to mutant EGFR resulted in gain of addiction to both HER2/HER3 and PI3K/Akt signaling to acquire EGFR-TKI resistance. PMID:22815900

  16. MiR-20a-5p promotes radio-resistance by targeting Rab27B in nasopharyngeal cancer cells.

    PubMed

    Huang, Dabing; Bian, Geng; Pan, Yueyin; Han, Xinghua; Sun, Yubei; Wang, Yong; Shen, Guodong; Cheng, Min; Fang, Xiang; Hu, Shilian

    2017-01-01

    MicroRNAs (miRNAs) was reported to be involved in cancer radio-resistance, which remains a major obstacle for effective cancer therapy. The differently expressed miRNAs were detected by RNA-seq experiment in nasopharyngeal cancer (NPC) cells. MiR-20a-5p was selected as our target, which was subject to finding its target gene Rab27B via bioinformatics analysis. The qRT-PCR, western blot and the luciferase reporter assays were performed to confirm Rab27B as the target of miR-20a-5p. In addition, the roles of miR-20a-5p in NPC radio-resistance were detected by transfection of either miR-20a-5p-mimic or miR-20a-5p-antagomiR. The involvement of Rab27B with NPC radio-resistance was also detected by the experiments with siRNA-mediated repression of Rab27B or over-expression of GFP-Rab27B. Wound healing and invasion assays were performed to detect the roles of both miR-20a-5p and Rab27B. MiR-20a-5p promotes NPC radio-resistance. We identified that its target gene Rab27B negatively correlates with miR-20a-5p-mediated NPC radio-resistance by systematic studies of a radio-sensitive (CNE-2) and resistant (CNE-1) NPC cell lines. Repression of Rab27B by siRNA suppresses cell apoptosis and passivates CNE-2 cells, whereas over-expression of Rab27B triggered cell apoptosis and sensitizes CNE-1 cells. MiR-20a-5p and its target gene Rab27B might be involved in the NPC radio-resistance. Thus the key players and regulators involved in this pathway might be the potential targets for developing effective therapeutic strategies against NPC.

  17. Alteration of gene expression and DNA methylation in drug-resistant gastric cancer.

    PubMed

    Maeda, Osamu; Ando, Takafumi; Ohmiya, Naoki; Ishiguro, Kazuhiro; Watanabe, Osamu; Miyahara, Ryoji; Hibi, Yoko; Nagai, Taku; Yamada, Kiyofumi; Goto, Hidemi

    2014-04-01

    The mechanisms of drug resistance in cancer are not fully elucidated. To study the drug resistance of gastric cancer, we analyzed gene expression and DNA methylation profiles of 5-fluorouracil (5-FU)- and cisplatin (CDDP)-resistant gastric cancer cells and biopsy specimens. Drug-resistant gastric cancer cells were established with culture for >10 months in a medium containing 5-FU or CDDP. Endoscopic biopsy specimens were obtained from gastric cancer patients who underwent chemotherapy with oral fluoropyrimidine S-1 and CDDP. Gene expression and DNA methylation analyses were performed using microarray, and validated using real-time PCR and pyrosequencing, respectively. Out of 17,933 genes, 541 genes commonly increased and 569 genes decreased in both 5-FU- and CDDP-resistant AGS cells. Genes with expression changed by drugs were related to GO term 'extracellular region' and 'p53 signaling pathway' in both 5-FU- and CDDP-treated cells. Expression of 15 genes including KLK13 increased and 12 genes including ETV7 decreased, in both drug-resistant cells and biopsy specimens of two patients after chemotherapy. Out of 10,365 genes evaluated with both expression microarray and methylation microarray, 74 genes were hypermethylated and downregulated, or hypomethylated and upregulated in either 5-FU-resistant or CDDP-resistant cells. Of these genes, expression of 21 genes including FSCN1, CPT1C and NOTCH3, increased from treatment with a demethylating agent. There are alterations of gene expression and DNA methylation in drug-resistant gastric cancer; they may be related to mechanisms of drug resistance and may be useful as biomarkers of gastric cancer drug sensitivity.

  18. miR-125b Functions as a Key Mediator for Snail-induced Stem Cell Propagation and Chemoresistance*

    PubMed Central

    Liu, Zixing; Liu, Hao; Desai, Shruti; Schmitt, David C.; Zhou, Ming; Khong, Hung T.; Klos, Kristine S.; McClellan, Steven; Fodstad, Oystein; Tan, Ming

    2013-01-01

    Chemoresistance is a major obstacle in cancer treatment. Our previous studies have shown that miR-125b plays an important role in chemoresistance. Here we report a novel mechanism that up-regulation of miR-125b through Wnt signaling by Snail enriches cancer stem cells. Overexpression of Snail dramatically increases the expression of miR-125b through the Snail-activated Wnt/β-catenin/TCF4 axis. Snail confers chemoresistance by repressing Bak1 through up-regulation of miR-125b. Restoring the expression of Bak1 or depleting miR-125b re-sensitizes Snail-expressing cancer cells to Taxol, indicating that miR-125b is critical in Snail-induced chemoresistance. Moreover, overexpression of miR-125b significantly increases the cancer stem cell population (CD24-CD44+), while depletion of miR-125b or rescue of the expression of Bak1 increases the non-stem cell population (CD24+CD44+) in Snail-overexpressing cells. These findings strongly support that miR-125b functions as a key mediator in Snail-induced cancer stem cell enrichment and chemoresistance. This novel mechanism for Snail-induced stem cell propagation and chemoresistance may have important implications in the development of strategies for overcoming cancer cell resistance to chemotherapy. PMID:23255607

  19. The Effects of HSP27 on Gemcitabine-Resistant Pancreatic Cancer Cell Line Through Snail.

    PubMed

    Zhang, Song; Zhang, Xiao-qi; Huang, Shu-ling; Chen, Min; Shen, Shan-shan; Ding, Xi-wei; Lv, Ying; Zou, Xiao-ping

    2015-10-01

    To evaluate the regulation mechanism of heat shock protein 27 (HSP27) on gemcitabine (GEM) resistance of pancreatic cancer cell. The expression vectors pEGFP-C1-HSP27 and the vectors of MicroRNA targeting Snail were introduced into GEM-sensitive pancreatic cancer SW1990 cells, and the vectors of small hairpin RNA targeting HSP27 were transfected into SW1990 and GEM-resistant SW1990/GEM cells. The expressions of HSP27, p-HSP27 (Ser82), Snail, ERCC1, and E-cadherin were evaluated by Western blotting. The sensitivity of transfected cells to GEM was detected by CCK-8 assay and Annexin V-FITC apoptosis assay. As compared to SW1990, SW1990/GEM showed significantly increased expressions of HSP27, p-HSP27, Snail and ERCC1 with decreased expression of E-cadherin. By increasing HSP27 expression, we found increase of Snail and ERCC1 with reduction of E-cadherin expressions, while reduction of HSP27 expression caused reduction of Snail and ERCC1 but increase of E-cadherin expressions. Downregulation of Snail resulted in the reduction of ERCC1 expression and increase of E-cadherin. Furthermore, downregulation of HSP27 or snail caused increased GEM sensitivity of pancreatic cancer cells, and upregulation of HSP27 showed the opposite results. There is an inverse correlation between HSP27 expression and GEM sensitivity of SW1990 cells, which might be realized by regulating E-cadherin and ERCC1 expressions through Snail.

  20. An outline of main factors of drug resistance influencing cancer therapy.

    PubMed

    Frączek, Natalia; Bronisz, Iwona; Pietryka, Magdalena; Kępińska, Dorota; Strzała, Patrycja; Mielnicka, Kamila; Korga, Agnieszka; Dudka, Jaroslaw

    2016-12-01

    Drug resistance in cancer therapy is a multifactorial phenomenon that determines remission or progression. It is known that resistance to used anticancer drugs may be the consequence of drug transport to the cell or intracellular distribution. It may also be the result of its molecular target structural change, apoptosis inhibition or increase in some enzymes activity, e.g. pentose phosphate pathway enzymes. Intrinsic (pre-existed) drug resistance is related to the phenotype of cancer as well as normal cells. Acquired, after partial administration of chemotherapy, type of drug resistance in addition to the starting phenotype is closely linked to the development of new more aggressive clones and adaptive processes. In both, the intrinsic and acquired resistance, role play also mutations. These may be partially spontaneous, but in terms of acquired resistance, they are mostly induced by the exposure to the drugs. The article mentions some traditional mechanisms related to the acquisition of resistance by cancer cells during therapy, through the protein transporters, apoptosis deregulation, angiogenesis and the impact of the tumour microenvironment. We focused however on some more alternative ways of therapy resistance, such as, hypoxia and tumour acidification, cancer stem cells (CSCs), exosomes and radiotherapy resistance. A concise summary of the drug resistance presented in the paper may be an important aspect in studies to increase the effectiveness of cancer therapies.

  1. Molecular Dissection of Induced Platinum Resistance through Functional and Gene Expression Analysis in a Cell Culture Model of Bladder Cancer

    DOE PAGES

    Wang, Sisi; Zhang, Hongyong; Scharadin, Tiffany M.; ...

    2016-01-22

    Here, we report the development, functional and molecular characterization of an isogenic, paired bladder cancer cell culture model system for studying platinum drug resistance. The 5637 human bladder cancer cell line was cultured over ten months with stepwise increases in oxaliplatin concentration to generate a drug resistant 5637R sub cell line. The MTT assay was used to measure the cytotoxicity of several bladder cancer drugs. Liquid scintillation counting allowed quantification of cellular drug uptake and efflux of radiolabeled oxaliplatin and carboplatin. The impact of intracellular drug inactivation was assessed by chemical modulation of glutathione levels. Oxaliplatin- and carboplatin-DNA adduct formationmore » and repair was measured using accelerator mass spectrometry. Resistance factors including apoptosis, growth factor signaling and others were assessed with RNAseq of both cell lines and included confirmation of selected transcripts by RT-PCR. Oxaliplatin, carboplatin, cisplatin and gemcitabine were significantly less cytotoxic to 5637R cells compared to the 5637 cells. In contrast, doxorubicin, methotrexate and vinblastine had no cell line dependent difference in cytotoxicity. Upon exposure to therapeutically relevant doses of oxaliplatin, 5637R cells had lower drug-DNA adduct levels than 5637 cells. This difference was partially accounted for by pre-DNA damage mechanisms such as drug uptake and intracellular inactivation by glutathione, as well as faster oxaliplatin-DNA adduct repair. In contrast, both cell lines had no significant differences in carboplatin cell uptake, efflux and drug-DNA adduct formation and repair, suggesting distinct resistance mechanisms for these two closely related drugs. The functional studies were augmented by RNAseq analysis, which demonstrated a significant change in expression of 83 transcripts, including 50 known genes and 22 novel transcripts. Most of the transcripts were not previously associated with bladder cancer

  2. Molecular Dissection of Induced Platinum Resistance through Functional and Gene Expression Analysis in a Cell Culture Model of Bladder Cancer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Sisi; Zhang, Hongyong; Scharadin, Tiffany M.

    Here, we report the development, functional and molecular characterization of an isogenic, paired bladder cancer cell culture model system for studying platinum drug resistance. The 5637 human bladder cancer cell line was cultured over ten months with stepwise increases in oxaliplatin concentration to generate a drug resistant 5637R sub cell line. The MTT assay was used to measure the cytotoxicity of several bladder cancer drugs. Liquid scintillation counting allowed quantification of cellular drug uptake and efflux of radiolabeled oxaliplatin and carboplatin. The impact of intracellular drug inactivation was assessed by chemical modulation of glutathione levels. Oxaliplatin- and carboplatin-DNA adduct formationmore » and repair was measured using accelerator mass spectrometry. Resistance factors including apoptosis, growth factor signaling and others were assessed with RNAseq of both cell lines and included confirmation of selected transcripts by RT-PCR. Oxaliplatin, carboplatin, cisplatin and gemcitabine were significantly less cytotoxic to 5637R cells compared to the 5637 cells. In contrast, doxorubicin, methotrexate and vinblastine had no cell line dependent difference in cytotoxicity. Upon exposure to therapeutically relevant doses of oxaliplatin, 5637R cells had lower drug-DNA adduct levels than 5637 cells. This difference was partially accounted for by pre-DNA damage mechanisms such as drug uptake and intracellular inactivation by glutathione, as well as faster oxaliplatin-DNA adduct repair. In contrast, both cell lines had no significant differences in carboplatin cell uptake, efflux and drug-DNA adduct formation and repair, suggesting distinct resistance mechanisms for these two closely related drugs. The functional studies were augmented by RNAseq analysis, which demonstrated a significant change in expression of 83 transcripts, including 50 known genes and 22 novel transcripts. Most of the transcripts were not previously associated with bladder cancer

  3. ABCC3 as a marker for multidrug resistance in non-small cell lung cancer

    PubMed Central

    Zhao, Yanbin; Lu, Hailing; Yan, An; Yang, Yanmei; Meng, Qingwei; Sun, Lichun; Pang, Hui; Li, Chunhong; Dong, Xiaoqun; Cai, Li

    2013-01-01

    Multidrug resistance (MDR) contributes to the failure of chemotherapy and high mortality in non-small cell lung cancer (NSCLC). We aim to identify MDR genes that predict tumor response to chemotherapy. 199 NSCLC fresh tissue samples were tested for chemosensitivity by MTT assay. cDNA microarray was done with 5 samples with highest resistance and 6 samples with highest sensitivity. Expression of ABCC3 mRNA and protein was detected by real-time PCR and immunohistochemisty, respectively. The association between gene expression and overall survival (OS) was examined using Cox proportional hazard regression. 44 genes were upregulated and 168 downregulated in the chemotherapy-resistant group. ABCC3 was one of the most up-regulated genes in the resistant group. ABCC3-positive expression correlated with lymph node involvement, advanced TNM stage, more malignant histological type, multiple-resistance to anti-cancer drugs, and reduced OS. ABCC3 expression may serve as a marker for MDR and predictor for poor clinical outcome of NSCLC. PMID:24176985

  4. Phenethyl Isothiocyanate Induces Apoptotic Cell Death Through the Mitochondria-dependent Pathway in Gefitinib-resistant NCI-H460 Human Lung Cancer Cells In Vitro.

    PubMed

    Hsia, Te-Chun; Huang, Yi-Ping; Jiang, Yi-Wen; Chen, Hsin-Yu; Cheng, Zheng-Yu; Hsiao, Yung-Ting; Chen, Cheng-Yen; Peng, Shu-Fen; Chueh, Fu-Shin; Chou, Yu-Cheng; Chung, Jing-Gung

    2018-04-01

    Some lung cancer patients treated with gefitinib develop resistance to this drug resulting in unsatisfactory treatment outcomes. Phenethyl isothiocyanate (PEITC), present in our common cruciferous vegetables, exhibits anticancer activities in many human cancer cell lines. Currently, there is no available information on the possible modification of gefitinib resistance of lung cancer in vitro by PEITC. Thus, the effects of PEITC on gefitinib resistant lung cancer NCI-H460 cells were investigated in vitro. The total cell viability, apoptotic cell death, production of reactive oxygen species (ROS) and Ca 2+ , levels of mitochondria membrane potential (ΔΨ m ) and caspase-3, -8 and -9 activities were measured by flow cytometry assay. PEITC induced chromatin condensation was examined by DAPI staining. PEITC-induced cell morphological changes, decreased total viable cell number and induced apoptotic cell death in NCI-H460 and NCI-H460/G cells. PEITC decreased ROS production in NCI-H460 cells, but increased production in NCI-H460/G cells. PEITC increased Ca 2+ production, decreased the levels of ΔΨ m and increased caspase-3, -8 and -9 activities in both NCI-H460 and NCI-H460/G cells. Western blotting was used to examine the effect of apoptotic cell death associated protein expression in NCI-H460 NCI-H460/G cells after exposure to PEITC. Results showed that PEITC increased expression of cleaved caspase-3, PARP, GADD153, Endo G and pro-apoptotic protein Bax in NCI-H460/G cells. Based on these results, we suggest that PEITC induces apoptotic cell death via the caspase- and mitochondria-dependent pathway in NCI-H460/G cells. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  5. Cancer drug resistance: redox resetting renders a way

    PubMed Central

    Xie, Na; Nice, Edouard C.; Zhang, Haiyuan; Huang, Canhua; Lei, Yunlong

    2016-01-01

    Disruption of redox homeostasis is a crucial factor in the development of drug resistance, which is a major problem facing current cancer treatment. Compared with normal cells, tumor cells generally exhibit higher levels of reactive oxygen species (ROS), which can promote tumor progression and development. Upon drug treatment, some tumor cells can undergo a process of ‘Redox Resetting’ to acquire a new redox balance with higher levels of ROS accumulation and stronger antioxidant systems. Evidence has accumulated showing that the ‘Redox Resetting’ enables cancer cells to become resistant to anticancer drugs by multiple mechanisms, including increased rates of drug efflux, altered drug metabolism and drug targets, activated prosurvival pathways and inefficient induction of cell death. In this article, we provide insight into the role of ‘Redox Resetting’ on the emergence of drug resistance that may contribute to pharmacological modulation of resistance. PMID:27057637

  6. Drug-tolerant persister cancer cells are vulnerable to GPX4 inhibition* | Office of Cancer Genomics

    Cancer.gov

    Acquired drug resistance prevents cancer therapies from achieving stable and complete responses. Emerging evidence implicates a key role for non-mutational drug resistance mechanisms underlying the survival of residual cancer 'persister' cells. The persister cell pool constitutes a reservoir from which drug-resistant tumours may emerge. Targeting persister cells therefore presents a therapeutic opportunity to impede tumour relapse. We previously found that cancer cells in a high mesenchymal therapy-resistant cell state are dependent on the lipid hydroperoxidase GPX4 for survival.

  7. Anti-mitotic potential of 7-diethylamino-3(2 Prime -benzoxazolyl)-coumarin in 5-fluorouracil-resistant human gastric cancer cell line SNU620/5-FU

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Nam Hyun; Kim, Su-Nam; Oh, Joa Sub

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer DBC exerts antiproliferative potential against 5FU-resistant human gastric cancer cells. Black-Right-Pointing-Pointer This effect is mediated by destabilization of microtubules and subsequent mitotic arrest. Black-Right-Pointing-Pointer DBC enhances apoptosis via caspase activation and downregulation of antiapoptotic genes. -- Abstract: In this study, we investigate an anti-mitotic potential of the novel synthetic coumarin-based compound, 7-diethylamino-3(2 Prime -benzoxazolyl)-coumarin, in 5-fluorouracil-resistant human gastric cancer cell line SNU-620-5FU and its parental cell SNU-620. It exerts the anti-proliferative effects with similar potencies against both cancer cells, which is mediated by destabilization of microtubules and subsequent mitotic arrest. Furthermore, this compound enhances caspase-dependent apoptotic cell deathmore » via decreased expression of anti-apoptotic genes. Taken together, our data strongly support anti-mitotic potential of 7-diethylamino-3(2 Prime -benzoxazolyl)-coumarin against drug-resistant cancer cells which will prompt us to further develop as a novel microtubule inhibitor for drug-resistant cancer chemotherapy.« less

  8. Neratinib overcomes trastuzumab resistance in HER2 amplified breast cancer

    PubMed Central

    Mullooly, Maeve; Bennett, Ruth; Bouguern, Noujoude; Pedersen, Kasper; O'Brien, Neil A; Roxanis, Ioannis; Li, Ji-Liang; Bridge, Esther; Finn, Richard; Slamon, Dennis; McGowan, Patricia; Duffy, Michael J.

    2013-01-01

    Trastuzumab has been shown to improve the survival outcomes of HER2 positive breast cancer patients. However, a significant proportion of HER2-positive patients are either inherently resistant or develop resistance to trastuzumab. We assessed the effects of neratinib, an irreversible panHER inhibitor, in a panel of 36 breast cancer cell lines. We further assessed its effects with or without trastuzumab in several sensitive and resistant breast cancer cells as well as a BT474 xenograft model. We confirmed that neratinib was significantly more active in HER2-amplified than HER2 non-amplified cell lines. Neratinib decreased the activation of the 4 HER receptors and inhibited downstream pathways. However, HER3 and Akt were reactivated at 24 hours, which was prevented by the combination of trastuzumab and neratinib. Neratinib also decreased pHER2 and pHER3 in acquired trastuzumab resistant cells. Neratinib in combination with trastuzumab had a greater growth inhibitory effect than either drug alone in 4 HER2 positive cell lines. Furthermore, trastuzumab in combination with neratinib was growth inhibitory in SKBR3 and BT474 cells which had acquired resistance to trastuzumab as well as in a BT474 xenograft model. Innately trastuzumab resistant cell lines showed sensitivity to neratinib, but the combination did not enhance response compared to neratinib alone. Levels of HER2 and phospho-HER2 showed a direct correlation with sensitivity to neratinib. Our data indicate that neratinib is an effective anti-HER2 therapy and counteracted both innate and acquired trastuzumab resistance in HER2 positive breast cancer. Our results suggest that combined treatment with trastuzumab and neratinib is likely to be more effective than either treatment alone for both trastuzumab-sensitive breast cancer as well as HER2-positive tumors with acquired resistance to trastuzumab. PMID:24009064

  9. Neratinib overcomes trastuzumab resistance in HER2 amplified breast cancer.

    PubMed

    Canonici, Alexandra; Gijsen, Merel; Mullooly, Maeve; Bennett, Ruth; Bouguern, Noujoude; Pedersen, Kasper; O'Brien, Neil A; Roxanis, Ioannis; Li, Ji-Liang; Bridge, Esther; Finn, Richard; Siamon, Dennis; McGowan, Patricia; Duffy, Michael J; O'Donovan, Norma; Crown, John; Kong, Anthony

    2013-10-01

    Trastuzumab has been shown to improve the survival outcomes of HER2 positive breast cancer patients. However, a significant proportion of HER2-positive patients are either inherently resistant or develop resistance to trastuzumab. We assessed the effects of neratinib, an irreversible panHER inhibitor, in a panel of 36 breast cancer cell lines. We further assessed its effects with or without trastuzumab in several sensitive and resistant breast cancer cells as well as a BT474 xenograft model. We confirmed that neratinib was significantly more active in HER2-amplified than HER2 non-amplified cell lines. Neratinib decreased the activation of the 4 HER receptors and inhibited downstream pathways. However, HER3 and Akt were reactivated at 24 hours, which was prevented by the combination of trastuzumab and neratinib. Neratinib also decreased pHER2 and pHER3 in acquired trastuzumab resistant cells. Neratinib in combination with trastuzumab had a greater growth inhibitory effect than either drug alone in 4 HER2 positive cell lines. Furthermore, trastuzumab in combination with neratinib was growth inhibitory in SKBR3 and BT474 cells which had acquired resistance to trastuzumab as well as in a BT474 xenograft model. Innately trastuzumab resistant cell lines showed sensitivity to neratinib, but the combination did not enhance response compared to neratinib alone. Levels of HER2 and phospho-HER2 showed a direct correlation with sensitivity to neratinib. Our data indicate that neratinib is an effective anti-HER2 therapy and counteracted both innate and acquired trastuzumab resistance in HER2 positive breast cancer. Our results suggest that combined treatment with trastuzumab and neratinib is likely to be more effective than either treatment alone for both trastuzumab-sensitive breast cancer as well as HER2-positive tumors with acquired resistance to trastuzumab.

  10. Doxorubicin resistance mediated by cytoplasmic macrophage colony-stimulating factor is associated with switch from apoptosis to autophagic cell death in MCF-7 breast cancer cells

    PubMed Central

    Zhang, Mengxia; Zhang, Hailiang; Tang, Fan; Wang, Yuhua; Mo, Zhongcheng; Lei, Xiaoyong

    2016-01-01

    Macrophage colony-stimulating factor is a vital factor in maintaining the biological function of monocyte–macrophage lineage. It is expressed in many tumor tissues and cancer cells. Recent findings indicate that macrophage colony-stimulating factor might contribute to chemoresistance, but the precise mechanisms are unclear. This study was to explore the effect of macrophage colony-stimulating factor on doxorubicin resistance in MCF-7 breast cancer cells and the possible mechanism. In the study, the human breast cancer cells, MCF-7, were transfected with macrophage colony-stimulating factor. We document that cytoplasmic macrophage colony-stimulating factor induces doxorubicin resistance and inhibits apoptosis in MCF-7 cells. Further studies demonstrated that cytoplasmic macrophage colony-stimulating factor-mediated apoptosis inhibition was dependent on the activation of PI3K/Akt/Survivin pathway. More importantly, we found that macrophage colony-stimulating factor-induced autophagic cell death in doxorubicin-treated MCF-7 cells. Taken together, we show for the first time that macrophage colony-stimulating factor-induced doxorubicin resistance is associated with the changes in cell death response with defective apoptosis and promotion of autophagic cell death. PMID:27439542

  11. Secondary Metabolites from Plants Inhibiting ABC Transporters and Reversing Resistance of Cancer Cells and Microbes to Cytotoxic and Antimicrobial Agents

    PubMed Central

    Wink, Michael; Ashour, Mohamed L.; El-Readi, Mahmoud Zaki

    2012-01-01

    Fungal, bacterial, and cancer cells can develop resistance against antifungal, antibacterial, or anticancer agents. Mechanisms of resistance are complex and often multifactorial. Mechanisms include: (1) Activation of ATP-binding cassette (ABC) transporters, such as P-gp, which pump out lipophilic compounds that have entered a cell, (2) Activation of cytochrome p450 oxidases which can oxidize lipophilic agents to make them more hydrophilic and accessible for conjugation reaction with glucuronic acid, sulfate, or amino acids, and (3) Activation of glutathione transferase, which can conjugate xenobiotics. This review summarizes the evidence that secondary metabolites (SM) of plants, such as alkaloids, phenolics, and terpenoids can interfere with ABC transporters in cancer cells, parasites, bacteria, and fungi. Among the active natural products several lipophilic terpenoids [monoterpenes, diterpenes, triterpenes (including saponins), steroids (including cardiac glycosides), and tetraterpenes] but also some alkaloids (isoquinoline, protoberberine, quinoline, indole, monoterpene indole, and steroidal alkaloids) function probably as competitive inhibitors of P-gp, multiple resistance-associated protein 1, and Breast cancer resistance protein in cancer cells, or efflux pumps in bacteria (NorA) and fungi. More polar phenolics (phenolic acids, flavonoids, catechins, chalcones, xanthones, stilbenes, anthocyanins, tannins, anthraquinones, and naphthoquinones) directly inhibit proteins forming several hydrogen and ionic bonds and thus disturbing the 3D structure of the transporters. The natural products may be interesting in medicine or agriculture as they can enhance the activity of active chemotherapeutics or pesticides or even reverse multidrug resistance, at least partially, of adapted and resistant cells. If these SM are applied in combination with a cytotoxic or antimicrobial agent, they may reverse resistance in a synergistic fashion. PMID:22536197

  12. MicroRNAs Change the Landscape of Cancer Resistance.

    PubMed

    Zhu, Jun; Zhu, Wei; Wu, Wei

    2018-01-01

    One of the major challenges in the cancer treatment is the development of drug resistance. It represents a major obstacle to curing cancer with constrained efficacy of both conventional chemotherapy and targeted therapies, even recent immune checkpoint blockade therapy. Deciphering the mechanisms of resistance is critical to further understanding the multifactorial pathways involved, and developing more specific targeted treatments. To date, numerous studies have reported the potential role of microRNAs (miRNAs) in the resistance to various cancer treatments. MicroRNAs are a family of small noncoding RNAs that regulate gene expression by sequence-specific targeting of mRNAs causing translational repression or mRNA degradation. More than 1200 validated human miRNAs have been identified in human genome. While one miRNA can regulate hundreds of targets, a single target can also be affected by multiple miRNAs. Evidence suggests that dysregulation of specific miRNAs may be involved in the acquisition of resistance, thereby modulating the sensitivity of cancer cells to treatment. Therefore, manipulation of miRNAs may be an attractive strategy for more effective individualized therapies through reprograming resistant network in cancer cells.

  13. TAM Receptor Tyrosine Kinases in Cancer Drug Resistance.

    PubMed

    Vouri, Mikaella; Hafizi, Sassan

    2017-06-01

    Receptor tyrosine kinases (RTK) are major regulators of key biological processes, including cell growth, survival, and differentiation, and were established early on as proto-oncogenes, with aberrant expression linked to tumor progression in many cancers. Therefore, RTKs have emerged as major targets for selective therapy with small-molecule inhibitors. However, despite improvements in survival rates, it is now apparent that the targeting of RTKs with selective inhibitors is only transiently effective, as the majority of patients eventually become resistant to therapy. As chemoresistance is the leading cause of cancer spread, progression, and mortality, there is an increasing need for understanding the mechanisms by which cancer cells can evade therapy-induced cell death. The TAM (Tyro3, Axl, Mer) subfamily of RTKs in particular feature in a variety of cancer types that have developed resistance to a broad range of therapeutic agents, including both targeted as well as conventional chemotherapeutics. This article reviews the roles of TAMs as tumor drivers and as mediators of chemoresistance, and the potential effectiveness of targeting them as part of therapeutic strategies to delay or combat resistance. Cancer Res; 77(11); 2775-8. ©2017 AACR . ©2017 American Association for Cancer Research.

  14. Tumor Suppression and Sensitization to Taxol Induces Apoptosis of EIA in Breast Cancer Cells

    DTIC Science & Technology

    2005-06-01

    participated in the regulation of apoptosis induced by ceramide, mistletoe lectin, and 4-hydroxynonenal, an aldehyde product of mem- brane lipid peroxidation... Mistletoe lectin induces apoptosis and telomerase inhibition in hu- man A253 cancer cells through dephosphorylation of Akt. Arch Pharm Res 2004; 27:68-76...participated subunit of protein phosphatase 2A [PP2A (PP2A/C)l enhanced the activity in the regulation of apoptosis induced by ceramide, mistletoe lectin, of

  15. Systematic drug screening reveals specific vulnerabilities and co-resistance patterns in endocrine-resistant breast cancer.

    PubMed

    Kangaspeska, Sara; Hultsch, Susanne; Jaiswal, Alok; Edgren, Henrik; Mpindi, John-Patrick; Eldfors, Samuli; Brück, Oscar; Aittokallio, Tero; Kallioniemi, Olli

    2016-07-04

    The estrogen receptor (ER) inhibitor tamoxifen reduces breast cancer mortality by 31 % and has served as the standard treatment for ER-positive breast cancers for decades. However, 50 % of advanced ER-positive cancers display de novo resistance to tamoxifen, and acquired resistance evolves in 40 % of patients who initially respond. Mechanisms underlying resistance development remain poorly understood and new therapeutic opportunities are urgently needed. Here, we report the generation and characterization of seven tamoxifen-resistant breast cancer cell lines from four parental strains. Using high throughput drug sensitivity and resistance testing (DSRT) with 279 approved and investigational oncology drugs, exome-sequencing and network analysis, we for the first time, systematically determine the drug response profiles specific to tamoxifen resistance. We discovered emerging vulnerabilities towards specific drugs, such as ERK1/2-, proteasome- and BCL-family inhibitors as the cells became tamoxifen-resistant. Co-resistance to other drugs such as the survivin inhibitor YM155 and the chemotherapeutic agent paclitaxel also occurred. This study indicates that multiple molecular mechanisms dictate endocrine resistance, resulting in unexpected vulnerabilities to initially ineffective drugs, as well as in emerging co-resistances. Thus, combatting drug-resistant tumors will require patient-tailored strategies in order to identify new drug vulnerabilities, and to understand the associated co-resistance patterns.

  16. Aberrantly regulated dysadherin and B-cell lymphoma 2/B-cell lymphoma 2-associated X enhances tumorigenesis and DNA targeting drug resistance of liver cancer stem cells

    PubMed Central

    JIANG, NAN; CHEN, WEI; ZHANG, JIAN-WEN; LI, YANG; ZENG, XIAN-CHENG; ZHANG, TONG; FU, BIN-SHENG; YI, HUI-MIN; ZHANG, QI

    2015-01-01

    Cancer stem cells (CSCs) in hepatocellular carcinoma (HCC) are frequently resistant to current therapeutic regimens and therefore responsible for tumor recurrence. Previous studies have reported that expression levels of dysadherin in CSCs may be used as a prognostic indicator, which is also responsible for treatment failure and poor survival rates. The present study analyzed the association of enhanced dysadherin levels with drug resistance and evasion of apoptosis in human HCC SP cells. An SP of 3.7% was isolated from human HCC cells using fluorescence-activated cell sorting. These SP cells displayed elevated levels of dysadherin and stemness proteins as well as high resistance to chemotherapeutic drugs and apoptosis. In order to reveal the possible link between dysadherin levels and tumorigenesis of SP cells, small interfering RNA technology was used to knockdown the expression of dysadherin in SP cells. Of note, the siRNA-transfected SP cells showed significantly reduced levels of stemness proteins, and were more sensitive to DNA-targeting drugs and apoptotic cell death as compared to non-transfected cells. Furthermore, in vivo experiments in NON/SCID mice indicated that dysadherin-expressing SP cells were highly tumorigenic, as they were able to induce tumor growth. The SP cell-derived tumor tissues in turn showed elevated dysadherin levels. The results of the present study therefore suggested that knockdown of dysadherin suppressed the tumorigenic properties of cancer stem-like SP cells. Hence, dysadherin is a valuable potential target for the development of novel anti-cancer drugs. PMID:26458963

  17. Dinaciclib Induces Anaphase Catastrophe in Lung Cancer Cells via Inhibition of Cyclin-Dependent Kinases 1 and 2.

    PubMed

    Danilov, Alexey V; Hu, Shanhu; Orr, Bernardo; Godek, Kristina; Mustachio, Lisa Maria; Sekula, David; Liu, Xi; Kawakami, Masanori; Johnson, Faye M; Compton, Duane A; Freemantle, Sarah J; Dmitrovsky, Ethan

    2016-11-01

    Despite advances in targeted therapy, lung cancer remains the most common cause of cancer-related mortality in the United States. Chromosomal instability is a prominent feature in lung cancer and, because it rarely occurs in normal cells, it represents a potential therapeutic target. Our prior work discovered that lung cancer cells undergo anaphase catastrophe in response to inhibition of cyclin-dependent kinase 2 (CDK2), followed by apoptosis and reduced growth. In this study, the effects and mechanisms of the multi-CDK inhibitor dinaciclib on lung cancer cells were investigated. We sought to determine the specificity of CDK-dependent induction of anaphase catastrophe. Live cell imaging provided direct evidence that dinaciclib caused multipolar cell divisions resulting in extensive chromosome missegregation. Genetic knockdown of dinaciclib CDK targets revealed that repression of CDK2 and CDK1, but not CDK5 or CDK9, triggered anaphase catastrophe in lung cancer cells. Overexpression of CP110, which is a mediator of CDK2 inhibitor-induced anaphase catastrophe (and a CDK1 and 2 phosphorylation substrate), antagonized anaphase catastrophe and apoptosis following dinaciclib treatment. Consistent with our previous findings, acquisition of activated KRAS sensitized lung cancer cells to dinaciclib-mediated anaphase catastrophe and cell death. Combining dinaciclib with the mitotic inhibitor taxol augmented anaphase catastrophe induction and reduced cell viability of lung cancer cells. Thus, the multi-CDK inhibitor dinaciclib causes anaphase catastrophe in lung cancer cells and should be investigated as a potential therapeutic for wild-type and KRAS-mutant lung cancer, individually or in combination with taxanes. Mol Cancer Ther; 15(11); 2758-66. ©2016 AACR. ©2016 American Association for Cancer Research.

  18. Hyaluronic Acid-Modified Multifunctional Q-Graphene for Targeted Killing of Drug-Resistant Lung Cancer Cells.

    PubMed

    Luo, Yanan; Cai, Xiaoli; Li, He; Lin, Yuehe; Du, Dan

    2016-02-17

    Considering the urgent need to explore multifunctional drug delivery system for overcoming multidrug resistance, we prepared a new nanocarbon material Q-Graphene as a nanocarrier for killing drug-resistant lung cancer cells. Attributing to the introduction of hyaluronic acid and rhodamine B isothiocyanate (RBITC), the Q-Graphene-based drug delivery system was endowed with dual function of targeted drug delivery and fluorescence imaging. Additionally, doxorubicin (DOX) as a model drug was loaded on the surface of Q-Graphene via π-π stacking. Interestingly, the fluorescence of DOX was quenched by Q-Graphene due to its strong electron-accepting capability, and a significant recovery of fluorescence was observed, while DOX was released from Q-Graphene. Because of the RBITC labeling and the effect of fluorescence quenching/restoring of Q-Graphene, the uptake of nanoparticles and intracellular DOX release can be tracked. Overall, a highly promising multifunctional nanoplatform was developed for tracking and monitoring targeted drug delivery for efficiently killing drug-resistant cancer cells.

  19. Dihydroartemisinin potentiates the anticancer effect of cisplatin via mTOR inhibition in cisplatin-resistant ovarian cancer cells: involvement of apoptosis and autophagy.

    PubMed

    Feng, Xue; Li, Ling; Jiang, Hong; Jiang, Keping; Jin, Ye; Zheng, Jianhua

    2014-02-14

    Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistant human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Identification and Characterization of Cells with Cancer Stem Cell Properties in Human Primary Lung Cancer Cell Lines

    PubMed Central

    Suo, Zhenhe; Munthe, Else; Solberg, Steinar; Ma, Liwei; Wang, Mengyu; Westerdaal, Nomdo Anton Christiaan; Kvalheim, Gunnar; Gaudernack, Gustav

    2013-01-01

    Lung cancer (LC) with its different subtypes is generally known as a therapy resistant cancer with the highest morbidity rate worldwide. Therapy resistance of a tumor is thought to be related to cancer stem cells (CSCs) within the tumors. There have been indications that the lung cancer is propagated and maintained by a small population of CSCs. To study this question we established a panel of 15 primary lung cancer cell lines (PLCCLs) from 20 fresh primary tumors using a robust serum-free culture system. We subsequently focused on identification of lung CSCs by studying these cell lines derived from 4 representative lung cancer subtypes such as small cell lung cancer (SCLC), large cell carcinoma (LCC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). We identified a small population of cells strongly positive for CD44 (CD44high) and a main population which was either weakly positive or negative for CD44 (CD44low/−). Co-expression of CD90 further narrowed down the putative stem cell population in PLCCLs from SCLC and LCC as spheroid-forming cells were mainly found within the CD44highCD90+ sub-population. Moreover, these CD44highCD90+ cells revealed mesenchymal morphology, increased expression of mesenchymal markers N-Cadherin and Vimentin, increased mRNA levels of the embryonic stem cell related genes Nanog and Oct4 and increased resistance to irradiation compared to other sub-populations studied, suggesting the CD44highCD90+ population a good candidate for the lung CSCs. Both CD44highCD90+ and CD44highCD90− cells in the PLCCL derived from SCC formed spheroids, whereas the CD44low/− cells were lacking this potential. These results indicate that CD44highCD90+ sub-population may represent CSCs in SCLC and LCC, whereas in SCC lung cancer subtype, CSC potentials were found within the CD44high sub-population. PMID:23469181

  1. MicroRNA-29a contributes to drug-resistance of breast cancer cells to adriamycin through PTEN/AKT/GSK3β signaling pathway.

    PubMed

    Shen, Hongyu; Li, Liangpeng; Yang, Sujin; Wang, Dandan; Zhong, Shanliang; Zhao, Jianhua; Tang, Jinhai

    2016-11-15

    Acquisition of resistance to adriamycin (ADR) during the treatment of breast cancer is still a major clinical obstacle. MicroRNAs (miRNAs) are a class of short noncoding RNAs which associate with cancer chemoresistance through regulating gene expression by targeting mRNAs. Our previous microarray found that miR-29a may strongly confer the ADR resistance of breast cancer cells. Here, we aim to explore the possible mechanism by which miR-29a affects sensitivity to ADR. ADR-resistant MCF-7 breast cancer cell subline (MCF-7/ADR) was successfully established in vitro through a stepwise increase of ADR concentrations in the culture based on parental MCF-7 cell lines (MCF-7/S). We used TargetScan (a wide use of target prediction algorithms) in conjunction with pathway enrichment analyses to predict the mRNAs that were most likely to involve in miR-29a-mediated drug resistance in cancers. We confirmed the effects of miR-29a-mediated ADR resistance through MTT and apoptosis assays, and further investigated the activities of two target genes, PTEN and GSK3β, by RT-qPCR analyses and western blot assays. The expression level of miR-29a in MCF-7/ADR cells was remarkablely higher than in MCF-7/S cells. Further MTT and apoptosis assays revealed that transfection of miR-29a inhibitors into MCF-7/ADR cells resulted in prominent reduction of the drug resistance, in contrast, transfection of miR-29a mimics into MCF-7/S cells obviously increased their drug resistance. Through pathway enrichment analyses for miR-29a, we found that PTEN/AKT/GSK3β signaling pathway may be of importance. RT-qPCR and Western blot results showed that downregulation of miR-29a expression in MCF-7/ADR cells increased PTEN expression levels, resulting in decreased phospho-Akt (p-Akt) and phospho-GSK3β (p-GSK3β) expression. Conversely, upregulation of miR-29a expression in MCF-7/S cells is associated with decreasing PTEN expression and increasing p-Akt and p-GSK3β expression. PTEN and GSK3β are targeted

  2. Cancer cell-selective killing polymer/copper combination.

    PubMed

    He, Huacheng; Altomare, Diego; Ozer, Ufuk; Xu, Hanwen; Creek, Kim; Chen, Hexin; Xu, Peisheng

    2016-01-01

    Chemotherapy has been adopted for cancer treatment for decades. However, its efficacy and safety are frequently compromised by the multidrug-resistance of cancer cells and the poor cancer cell selectivity of anticancer drugs. Hereby, we report a combination of a pyridine-2-thiol containing polymer and copper which can effectively kill a wide spectrum of cancer cells, including drug resistant cancer cells, while sparing normal cells. The polymer nanoparticle enters cells via an exofacial thiol facilitated route, and releases active pyridine-2-thiol with the help of intracellularly elevated glutathione (GSH). Due to their high GSH level, cancer cells are more vulnerable to the polymer/copper combination. In addition, RNA microarray analysis revealed that the treatment can reverse cancer cells' upregulated oncogenes (CIRBP and STMN1) and downregulated tumor suppressor genes (CDKN1C and GADD45B) to further enhance the selectivity for cancer cells.

  3. Enrichment of putative prostate cancer stem cells after androgen deprivation: upregulation of pluripotency transactivators concurs with resistance to androgen deprivation in LNCaP cell lines.

    PubMed

    Seiler, Daniel; Zheng, Junying; Liu, Gentao; Wang, Shunyou; Yamashiro, Joyce; Reiter, Robert E; Huang, Jiaoti; Zeng, Gang

    2013-09-01

    Prostate cancer stem cells (PCSC) offer theoretical explanations to many clinical and biological behaviors of the disease in human. In contrast to approaches of using side populations and cell-surface markers to isolate and characterize the putative PCSC, we hypothesize that androgen deprivation leads to functional enrichment of putative PCSC. Human prostate cancer lines LNCaP, LAPC4 and LAPC9 were depleted of androgen in cell cultures and in castrated SCID mice. The resultant androgen deprivation-resistant or castration-resistant populations, in particular in LNCaP and its derivative cell lines, displayed increased expression of pluripotency transactivators and significantly higher tumorigenicity. Individual tumor cell clones were isolated from castration-resistant bulk cultures of LNCaP (CR-LNCaP) and tested for tumorigenicity in male SCID mice under limiting dilution conditions. As few as 200 cells were able to form spheres in vitro, and generate tumors with similar growth kinetics as 10(6) LNCaP or 10(4) CR-LNCaP cells in vivo. These putative PCSC were CD44(+) /CD24(-) and lack the expression of prostate lineage proteins. When transplanted into the prostate of an intact male SCID mouse, these putative PCSC seemed to show limited differentiation into Ck5(+) , Ck8(+) , Ck5(+) /Ck8(+) , and AR(+) cells. On the other hand, stable transduction of LNCaP with retrovirus encoding Sox2 led to androgen-deprivation resistant growth and down-regulation of major prostate lineage gene products in vitro. Concurrence of overexpression of pluripotency transactivators and resistance to androgen deprivation supported the role of putative PCSC in the emergence of prostate cancer resistant to androgen deprivation. © 2013 Wiley Periodicals, Inc.

  4. Apigenin overcomes drug resistance by blocking the signal transducer and activator of transcription 3 signaling in breast cancer cells

    PubMed Central

    Seo, Hye-Sook; Ku, Jin Mo; Choi, Hyeong Sim; Woo, Jong-Kyu; Lee, Byung Hoon; Kim, Doh Sun; Song, Hyun Jong; Jang, Bo-Hyoung; Shin, Yong Cheol; Ko, Seong-Gyu

    2017-01-01

    Drug resistance in chemotherapy is a serious obstacle for the successful treatment of cancer. Drug resistance is caused by various factors, including the overexpression of P-glycoprotein (P-gp, MDR1). The development of new, useful compounds that overcome drug resistance is urgent. Apigenin, a dietary flavonoid, has been reported as an anticancer drug in vivo and in vitro. In the present study, we investigated whether apigenin is able to reverse drug resistance using adriamycin-resistant breast cancer cells (MCF-7/ADR). In our experiments, apigenin significantly decreased cell growth and colony formation in MCF-7/ADR cells and parental MCF-7 cells. This growth inhibition was related to the accumulation of cells in the sub-G0/G1 apoptotic population and an increase in the number of apoptotic cells. Apigenin reduced the mRNA expression of multidrug resistance 1 (MDR1) and multidrug resistance-associated proteins (MRPs) in MCF-7/ADR cells. Apigenin also downregulated the expression of P-gp. Apigenin reversed drug efflux from MCF-7/ADR cells, resulting in rhodamine 123 (Rho123) accumulation. Inhibition of drug resistance by apigenin is related to the suppression of the signal transducer and activator of transcription 3 (STAT3) signaling pathway. Apigenin decreased STAT3 activation (p-STAT3) and its nuclear translocation and inhibited the secretion of VEGF and MMP-9, which are STAT3 target genes. A STAT3 inhibitor, JAK inhibitor I and an HIF-1α inhibitor decreased cell growth in MCF-7 and MCF-7/ADR cells. Taken together, these results demonstrate that apigenin can overcome drug resistance. PMID:28656316

  5. Long non‑coding RNA AK001796 contributes to cisplatin resistance of non‑small cell lung cancer.

    PubMed

    Liu, Bin; Pan, Chun-Feng; Ma, Teng; Wang, Jun; Yao, Guo-Liang; Wei, Ke; Chen, Yi-Jiang

    2017-10-01

    Cisplatin (DDP)‑based chemotherapy is the most widely used therapy for non‑small cell lung cancer (NSCLC). However, the existence of chemoresistance has become a major limitation in its efficacy. Long non‑coding RNAs (lncRNAs) have been shown to be involved in chemotherapy drug resistance. The aim of the present study was to investigate the biological role of lncRNA AK001796 in cisplatin‑resistant NSCLC A549/DDP cells. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis was performed to monitor the differences in the expression of AK001796 in cisplatin-resistant (A549/DDP) cells and parental A549 cells. Cellular sensitivity to cisplatin and cell viability were examined using an MTT assay. Cell apoptosis and cell cycle distribution were measured using flow cytometry. The expression levels of cell cycle proteins cyclin C (CCNC), baculoviral IAP repeat containing 5 (BIRC5), cyclin‑dependent kinase 1 (CDK1) and G2 and S phase‑expressed 1 (GTSE1) were assessed using RT‑qPCR and western blot analyses. It was found that the expression of AK001796 was increased in A549/DDP cells, compared with that in A549 cells. The knockdown of AK001796 by small interfering RNA reduced cellular cisplatin resistance and cell viability, and resulted in cell‑cycle arrest, with a marked increase in the proportion of A549/DDP cells in the G0/G1 phase. By contrast, the knockdown of AK001796 increased the number of apoptotic cancer cells during cisplatin treatment. It was also shown that the knockdown of AK001796 positively induced the expression of cell apoptosis‑associated factors, CCNC and BIRC5, and suppressed the expression of cell cycle‑associated factors, CDK1 and GTSE5. Taken together, these findings indicated that lncRNA AK001796 increased the resistance of NSCLC cells to cisplatin through regulating cell apoptosis and cell proliferation, and thus provides an attractive therapeutic target for NSCLC.

  6. Hederagenin Induces Apoptosis in Cisplatin-Resistant Head and Neck Cancer Cells by Inhibiting the Nrf2-ARE Antioxidant Pathway.

    PubMed

    Kim, Eun Hye; Baek, Seungho; Shin, Daiha; Lee, Jaewang; Roh, Jong-Lyel

    2017-01-01

    Acquired resistance to cisplatin is the most common reason for the failure of cisplatin chemotherapy. Hederagenin, triterpenoids extracted from ivy leaves, exhibits antitumor activity in various types of cancer. However, the therapeutic potential of hederagenin in head and neck cancer (HNC) has remained unclear. Therefore, we examined the effects of hederagenin in cisplatin-resistant HNC cells and characterized its molecular mechanisms of action in this context. We evaluated the effects of hederagenin treatment on cell viability, apoptosis, reactive oxygen species (ROS) production, glutathione levels, mitochondrial membrane potential (Δ Ψ m), and protein and mRNA expression in HNC cells. The antitumor effect of hederagenin in mouse tumor xenograft models was also analyzed. Hederagenin selectively induced cell death in both cisplatin-sensitive and cisplatin-resistant HNC cells by promoting changes in Δ Ψ m and inducing apoptosis. Hederagenin inhibited the Nrf2-antioxidant response element (ARE) pathway and activated p53 in HNC cells, thereby enhancing ROS production and promoting glutathione depletion. These effects were reversed by the antioxidant trolox. Hederagenin activated intrinsic apoptotic pathways via cleaved PARP, cleaved caspase-3, and Bax. The selective inhibitory effects of hederagenin were confirmed in cisplatin-resistant HNC xenograft models. These data suggest that hederagenin induces cell death in resistant HNC cells via the Nrf2-ARE antioxidant pathway.

  7. AIB1 is required for the acquisition of epithelial growth factor receptor-mediated tamoxifen resistance in breast cancer cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhao Wenhui; Zhang Qingyuan; Kang Xinmei

    2009-03-13

    Acquired resistance to tamoxifen has become a serious obstacle in breast cancer treatment. The underlying mechanism responsible for this condition has not been completely elucidated. In this study, a tamoxifen-resistant (Tam-R) MCF-7 breast cancer cell line was developed to mimic the occurrence of acquired tamoxifen resistance as seen in clinical practice. Increased expression levels of HER1, HER2 and the estrogen receptor (ER)-AIB1 complex were found in tamoxifen-resistant cells. EGF stimulation and gefitinib inhibition experiments further demonstrated that HER1/HER2 signaling and AIB1 were involved in the proliferation of cells that had acquired Tam resistance. However, when AIB1 was silenced with AIB1-siRNAmore » in Tam-R cells, the cell growth stimulated by the HER1/HER2 signaling pathway was significantly reduced, and the cells were again found to be inhibited by tamoxifen. These results suggest that the AIB1 protein could be a limiting factor in the HER1/HER2-mediated hormone-independent growth of Tam-R cells. Thus, AIB1 may be a new therapeutic target, and the removal of AIB1 may decrease the crosstalk between ER and the HER1/HER2 pathway, resulting in the restoration of tamoxifen sensitivity in tamoxifen-resistant cells.« less

  8. Prostate Cancer Stem-Like Cells | Center for Cancer Research

    Cancer.gov

    Prostate cancer is the third leading cause of cancer-related death among men, killing an estimated 27,000 men each year in the United States. Men with advanced prostate cancer often become resistant to conventional therapies. Many researchers speculate that the emergence of resistance is due to the presence of cancer stem cells, which are believed to be a small subpopulation

  9. IAP Antagonists Enhance Apoptotic Response to Enzalutamide in Castration-Resistant Prostate Cancer Cells via Autocrine TNF-α Signaling.

    PubMed

    Pilling, Amanda B; Hwang, Ok; Boudreault, Alain; Laurent, Alain; Hwang, Clara

    2017-06-01

    Castration-resistant prostate cancer (CRPC) remains incurable and identifying effective treatments continues to present a clinical challenge. Although treatment with enzalutamide, a second generation androgen receptor (AR) antagonist, prolongs survival in prostate cancer patients, responses can be limited by intrinsic resistance or acquired resistance. A potential mechanism of resistance to androgen axis inhibition is evasion of apoptosis. Inhibitor of apoptosis proteins (IAPs) are found to be overexpressed in prostate cancer and function to block apoptosis and promote survival signaling. Novel, small-molecule IAP antagonists, such as AEG40995, are emerging as a strategy to induce apoptosis and increase therapeutic response in cancer. Human prostate cancer cell lines LNCaP and C4-2 were treated with enzalutamide with or without addition of IAP antagonist AEG40995 and proliferation and survival were determined by MTS and clonogenic assay. Western blot was used to evaluate IAP protein expression changes and PARP-1 cleavage was assessed as indication of apoptosis. Flow cytometry was performed to analyze apoptosis in treated cells. Caspase activity was determined by luminescence assay. Quantitative real-time PCR and immunometric ELISA was used to assess TNF-α (transcript and protein levels, respectively) in response to treatment. In this study, we demonstrate that IAP antagonist AEG40995 exhibits minimal effects on prostate cancer cell proliferation or survival, but rapidly degrades cIAP1 protein. Combination treatment with enzalutamide demonstrates that AEG40995 increases apoptosis and reduces proliferation and clonogenic survival in cell line models of prostate cancer. Mechanistically, we demonstrate that apoptosis in response to enzalutamide and IAP antagonist requires activation of caspase-8, suggesting extrinsic/death receptor apoptosis signaling. Assessment of TNF-α in response to combination treatment with enzalutamide and AEG40995 reveals increased m

  10. Tamoxifen resistance and metastasis of human breast cancer cells were mediated by the membrane-associated estrogen receptor ER-α36 signaling in vitro.

    PubMed

    Gu, Wenwen; Dong, Nian; Wang, Peng; Shi, Changgen; Yang, Jun; Wang, Jian

    2017-04-01

    The drug resistance and tumor metastasis have been the main obstacles for the longer-term therapeutic effects of tamoxifen (TAM) on estrogen receptor-positive (ER + ) breast cancer, but the mechanisms underlying the TAM resistance are still unclear. Here, we demonstrated that the membrane-associated estrogen receptor ER-α36 signaling, but not the G protein-coupled estrogen receptor 1 (GPER1) signaling, might be involved in the TAM resistance and metastasis of breast cancer cells. In this study, a model of ER + breast cancer cell MCF-7 that involves the up-regulated expression of ER-α36 and unchanged expression of ER-α66 and GPER1 was established via the removal of insulin from the cell culture medium. The mechanism of TAM resistance in the ER + breast cancer cell line MCF-7 was investigated, and the results showed that the stimulating effect of insulin on susceptibility of MCF-7 to TAM was mediated by ER-α36 and that the expression level of ER-α36 in TAM-resistant MCF-7 cells was also significantly increased. Both TAM and estradiol (E2) could promote the migration of triple negative (ER-α66 - /PR - /HER2 - ) and ER-α36 + /GPER1 + breast cancer cells MDA-MB-231. The migration of MDA-MB-231 cells was inhibited by the down-regulated intracellular expression of ER-α36 by transient transfection of specific small interfering RNA, whereas no effect of GPER1 down-regulation was observed. Meanwhile, the effect of TAM on the migration of ER-α36-down-regulated MDA-MB-231 cells was also reduced. Furthermore, it was found that TAM enhanced the distribution of integrin β1 on the cell surface but did not affect the expression of integrin β1 in MDA-MB-231 cells. Collectively, these data suggested that ER-α36 signaling might play critical roles in acquired and de novo TAM resistance and metastasis of breast cancer, and ER-α36 might present a potential biomarker of TAM resistance in the clinical diagnosis and treatment of ER + breast cancer.

  11. 4-Nitroquinoline-1-oxide effects human lung adenocarcinoma A549 cells by regulating the expression of POLD4

    PubMed Central

    HUANG, QIN-MIAO; ZENG, YI-MING; ZHANG, HUA-PING; LV, LIANG-CHAO; YANG, DONG-YONG; LIN, HUI-HUANG

    2016-01-01

    The aim of the present study was to explore the expression of POLD4 in human lung adenocarcinoma A549 cells under 4-nitroquinoline-1-oxide (4NQO) stimulation to investigate the role of POLD4 in smoking-induced lung cancer. The lung cancer A549 cell line was treated with 4NQO, with or without MG132 (an inhibitor of proteasome activity), and subsequently the POLD4 level was determined by western blot analysis. Secondly, the cell sensitivity to 4NQO and Taxol was determined when the POLD4 expression level was downregulated by siRNA. The POLD4 protein levels in the A549 cells decreased following treatment with 4NQO; however, MG132 could reverse this phenotype. Downregulation of the POLD4 expression by siRNA enhanced A549 cell sensitivity to 4NQO, but not to Taxol. In conclusion, 4NQO affects human lung adenocarcinoma A549 cells by regulating the expression of POLD4. PMID:26998273

  12. Quercetin-3-methyl ether inhibits lapatinib-sensitive and -resistant breast cancer cell growth by inducing G2/M arrest and apoptosis

    PubMed Central

    Li, Jixia; Zhu, Feng; Lubet, Ronald A.; De Luca, Antonella; Grubbs, Clinton; Ericson, Marna E.; D’Alessio, Amelia; Normano, Nicola; Dong, Zigang; Bode, Ann M.

    2012-01-01

    Lapatinib, an oral, small-molecule, reversible inhibitor of both EGFR and HER2, is highly active in HER2 positive breast cancer as a single agent and in combination with other therapeutics. However, resistance against lapatinib is an unresolved problem in clinical oncology. Recently, interest in the use of natural compounds to prevent or treat cancers has gained increasing interest because of presumed low toxicity. Quercetin-3-methyl ether, a naturally occurring compound present in various plants, has potent anticancer activity. Here, we found that quercetin-3-methyl ether caused in a significant growth inhibition of lapatinib-sensitive and -resistant breast cancer cells. Western blot data showed that quercetin-3-methyl ether had no effect on Akt or ERKs signaling in resistant cells. However, quercetin-3-methyl ether caused a pronounced G2/M block mainly through the Chk1-Cdc25c-cyclin B1/Cdk1 pathway in lapatinib-sensitive and -resistant cells. In contrast, lapatinib produced an accumulation of cells in the G1 phase mediated through cyclin D1, but only in lapatinib-sensitive cells. Moreover, quercetin-3-methyl ether induced significant apoptosis, accompanied with increased levels of cleaved caspase 3, caspase 7 and poly (ADP-ribose) polymerase (PARP) in both cell lines. Overall, these results suggested that quercetin-3-methyl ether might be a novel and promising therapeutic agent in lapatinib-sensitive or -resistant breast cancer patients. PMID:22086611

  13. Photochemical internalisation of chemotherapy potentiates killing of multidrug-resistant breast and bladder cancer cells.

    PubMed

    Adigbli, D K; Wilson, D G G; Farooqui, N; Sousi, E; Risley, P; Taylor, I; Macrobert, A J; Loizidou, M

    2007-08-20

    Multidrug resistance (MDR) is the major confounding factor in adjuvant solid tumour chemotherapy. Increasing intracellular amounts of chemotherapeutics to circumvent MDR may be achieved by a novel delivery method, photochemical internalisation (PCI). PCI consists of the co-administration of drug and photosensitiser; upon light activation the latter induces intracellular release of organelle-bound drug. We investigated whether co-administration of hypericin (photosensitiser) with mitoxantrone (MTZ, chemotherapeutic) plus illumination potentiates cytotoxicity in MDR cancer cells. We mapped the extent of intracellular co-localisation of drug/photosensitiser. We determined whether PCI altered drug-excreting efflux pump P-glycoprotein (Pgp) expression or function in MDR cells. Bladder and breast cancer cells and their Pgp-overexpressing MDR subclones (MGHU1, MGHU1/R, MCF-7, MCF-7/R) were given hypericin/MTZ combinations, with/without blue-light illumination. Pilot experiments determined appropriate sublethal doses for each. Viability was determined by the 3-[4,5-dimethylthiazolyl]-2,5-diphenyltetrazolium bromide assay. Intracellular localisation was mapped by confocal microscopy. Pgp expression was detected by immunofluorescence and Pgp function investigated by Rhodamine123 efflux on confocal microscopy. MTZ alone (0.1-0.2 microg ml(-1)) killed up to 89% of drug-sensitive cells; MDR cells exhibited less cytotoxicity (6-28%). Hypericin (0.1-0.2 microM) effects were similar for all cells; light illumination caused none or minimal toxicity. In combination, MTZ /hypericin plus illumination, potentiated MDR cell killing, vs hypericin or MTZ alone. (MGHU1/R: 38.65 and 36.63% increase, P<0.05; MCF-7/R: 80.2 and 46.1% increase, P<0.001). Illumination of combined MTZ/hypericin increased killing by 28.15% (P<0.05 MGHU1/R) compared to dark controls. Intracytoplasmic vesicular co-localisation of MTZ/hypericin was evident before illumination and at serial times post

  14. Effective photodynamic therapy in drug-resistant prostate cancer cells utilizing a non-viral antitumor vector (a secondary publication).

    PubMed

    Yamauchi, Masaya; Honda, Norihiro; Hazama, Hisanao; Tachikawa, Shoji; Nakamura, Hiroyuki; Kaneda, Yasufumi; Awazu, Kunio

    2016-03-31

    There is an urgent need to develop an efficient strategy for the treatment of drug-resistant prostate cancer. Photodynamic therapy (PDT), in which low incident levels of laser energy are used to activate a photosensitizer taken up by tumor cells, is expected as a novel therapy for the treatment of prostate cancer because of the minimal invasive nature of PDT. The present study was designed to assess the efficacy of a novel vector approach combined with a conventional porphyrin-based photosensitizer. Our group focused on a non-viral vector (hemagglutinating virus of Japan envelope; HVJ-E) combined with protoporphyrin IX (PpIX) lipid, termed the porphyrus envelope (PE). It has been previously confirmed that HVJ-E has drug-delivering properties and can induce cancer-specific cell death. The PE (HVJ-E contained in PpIX lipid) was developed as a novel photosensitizer. In this study, the antitumor and PDT efficacy of the PE against hormone-antagonistic human prostate cancer cells (PC-3) were evaluated. Our results demonstrated that, under specific circumstances, PDT using the PE was very effective against PC-3 cells. A novel therapy for drug-resistant prostate cancer based on this vector approach is eagerly anticipated.

  15. Surfactant-based drug delivery systems for treating drug-resistant lung cancer.

    PubMed

    Kaur, Prabhjot; Garg, Tarun; Rath, Goutam; Murthy, R S R; Goyal, Amit K

    2016-01-01

    Among all cancers, lung cancer is the major cause of deaths. Lung cancer can be categorized into two classes for prognostic and treatment purposes: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Both categories of cancer are resistant to certain drugs. Various mechanisms behind drug resistance are over-expression of superficial membrane proteins [glycoprotein (P-gp)], lung resistance-associated proteins, aberration of the intracellular enzyme system, enhancement of the cell repair system and deregulation of cell apoptosis. Structure-performance relationships and chemical compatibility are consequently major fundamentals in surfactant-based formulations, with the intention that a great deal investigation is committed to this region. With the purpose to understand the potential of P-gp in transportation of anti-tumor drugs to cancer cells with much effectiveness and specificity, several surfactant-based delivery systems have been developed which may include microspheres, nanosized drug carriers (nanoparticles, nanoemulsions, stealth liposomes, nanogels, polymer-drug conjugates), novel powders, hydrogels and mixed micellar systems intended for systemic and/or localized delivery.

  16. Expression of CD147 in advanced non-small cell lung cancer correlated with cisplatin-based chemotherapy resistance.

    PubMed

    Zeng, H Z; Qu, Y Q; Liang, A B; Deng, A M; Zhang, W J; Xiu, B; Wang, H; Wang, H

    2011-01-01

    CD147, a widely expressed cell surface glycoprotein in cancer, is associated with tumor invasiveness and chemotherapy resistance. Recently, CD147 is also regarded as a potential therapeutic target for cancer therapy. The aim of the study was to investigate CD147 expression in non-small cell lung cancer (NSCLC), and evaluate its correlation with cisplatin-based chemotherapy resistance. In this study, we examined immunohistochemically the expression of CD147 in 118 advanced NSCLC cases treated with cisplatin-based chemotherapy, and then the association of CD147 expression with clinicopathological characteristics was analyzed. Furthermore, RNA interference approach was used to silence CD147 expression in a cisplatin-resistant human lung cancer cell line A549/DDP, and the inhibition effect of cisplatin on tumor cells was assayed by MTT. In the overall series, positive CD147 expression was observed in 101/118 (85.6%) cases. A membranous CD147 pattern was identified in 76/101 (75.2%) of CD147 positive tumors. CD147 membranous expression,but not the overall CD147 expression, was associated with poor response to cisplatin-based chemotherapies and a poor prognosis in advanced NSCLC patients. In vitro results showed that silencing CD147 increased the proliferation inhibitory effect of cisplatin to A549/DDP cells. In conclusion, our study indicated that membranous CD147 expression is a predictive factor of the response to cisplatin-based chemotherapies, and the use of CD147-targeted therapeutic adjuvants might be considered in the treatment of advanced NSCLC patients.

  17. Reversing drug resistance of soft tumor-repopulating cells by tumor cell-derived chemotherapeutic microparticles

    PubMed Central

    Ma, Jingwei; Zhang, Yi; Tang, Ke; Zhang, Huafeng; Yin, Xiaonan; Li, Yong; Xu, Pingwei; Sun, Yanling; Ma, Ruihua; Ji, Tiantian; Chen, Junwei; Zhang, Shuang; Zhang, Tianzhen; Luo, Shunqun; Jin, Yang; Luo, Xiuli; Li, Chengyin; Gong, Hongwei; Long, Zhixiong; Lu, Jinzhi; Hu, Zhuowei; Cao, Xuetao; Wang, Ning; Yang, Xiangliang; Huang, Bo

    2016-01-01

    Developing novel approaches to reverse the drug resistance of tumor-repopulating cells (TRCs) or stem cell-like cancer cells is an urgent clinical need to improve outcomes of cancer patients. Here we show an innovative approach that reverses drug resistance of TRCs using tumor cell-derived microparticles (T-MPs) containing anti-tumor drugs. TRCs, by virtue of being more deformable than differentiated cancer cells, preferentially take up T-MPs that release anti-tumor drugs after entering cells, which in turn lead to death of TRCs. The underlying mechanisms include interfering with drug efflux and promoting nuclear entry of the drugs. Our findings demonstrate the importance of tumor cell softness in uptake of T-MPs and effectiveness of a novel approach in reversing drug resistance of TRCs with promising clinical applications. PMID:27167569

  18. Super-Penetrant Androgen Receptor: Overcoming Enzalutamide Sensitivity in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2016-07-01

    Prostate Cancer Research Symposium- Prostate Cancer Epigenetic Reprogramming of the Androgen Receptor in Castration Resistant Prostate Cancer , May19... cancer cells rely critically on the androgen receptor (AR) for initiation, growth and progression to castration resistant prostate cancer (CRPC...Androgen receptor, castration resistant prostate cancer , Enzalutamide , kinases. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER

  19. Investigating Novel Resistance Mechanisms to Third-Generation EGFR Tyrosine Kinase Inhibitor Osimertinib in Non-Small Cell Lung Cancer Patients.

    PubMed

    Yang, Zhe; Yang, Nong; Ou, Qiuxiang; Xiang, Yi; Jiang, Tao; Wu, Xue; Bao, Hua; Tong, Xiaoling; Wang, Xiaonan; Shao, Yang W; Liu, Yunpeng; Wang, Yan; Zhou, Caicun

    2018-03-05

    Background: The third-generation EGFR tyrosine kinase inhibitor osimertinib is approved to treat patients with EGFR T790M-positive non-small cell lung cancer (NSCLC) who have developed resistance to earlier-generation drugs. Acquired EGFR C797S mutation has been reported to mediate osimertinib resistance in some patients. However, the remaining resistance mechanisms are largely unknown. Methods: We performed mutation profiling using targeted next-generation sequencing (NGS) for 416 cancer-relevant genes on 93 osimertinib-resistant lung cancer patients' samples, mainly cell-free DNAs (cfDNAs), and matched pretreatment samples of 12 patients. In vitro experiments were conducted to functionally study the secondary EGFR mutations identified. Results: EGFR G796/C797, L792, and L718/G719 mutations were identified in 24.7%, 10.8%, and 9.7% of the cases, respectively, with certain mutations coexisting in one patient with different prevalence. L792 and L718 mutants markedly increased the half inhibitory concentration (IC 50 ) of osimertinib in vitro , among which the L718Q mutation conferred the greatest resistance to osimertinib, as well as gefitinib resistance when not coexisting with T790M. Further analysis of the 12 matched pretreatment samples confirmed that these EGFR mutations were acquired during osimertinib treatment. Alterations in parallel or downstream oncogenes such as MET, KRAS , and PIK3CA were also discovered, potentially contributing to the osimertinib-resistance in patients without EGFR secondary mutations. Conclusions: We present comprehensive mutation profiles of a large cohort of osimertinib-resistance lung cancer patients using mainly cfDNA. Besides C797 mutations, novel secondary mutations of EGFR L718 and L792 residues confer osimertinib resistance, both in vitro and in vivo , and are of great clinical and pharmaceutical relevance. Clin Cancer Res; 1-11. ©2018 AACR. ©2018 American Association for Cancer Research.

  20. Ovarian cancer stem cells.

    PubMed

    Zeimet, A G; Reimer, D; Sopper, S; Boesch, M; Martowicz, A; Roessler, J; Wiedemair, A M; Rumpold, H; Untergasser, G; Concin, N; Hofstetter, G; Muller-Holzner, E; Fiegl, H; Marth, C; Wolf, D; Pesta, M; Hatina, J

    2012-01-01

    Because of its semi-solid character in dissemination and growth, advanced ovarian cancer with its hundreds of peritoneal tumor nodules and plaques appears to be an excellent in vivo model for studying the cancer stem cell hypothesis. The most important obstacle, however, is to adequately define and isolate these tumor-initiating cells endowed with the properties of anoikis-resistance and unlimited self-renewal. Until now, no universal single marker or marker constellation has been found to faithfully isolate (ovarian) cancer stem cells. As these multipotent cells are known to possess highly elaborated efflux systems for cytotoxic agents, these pump systems have been exploited to outline putative stem cells as a side-population (SP) via dye exclusion analysis. Furthermore, the cells in question have been isolated via flow cytometry on the basis of cell surface markers thought to be characteristic for stem cells.In the Vienna variant of the ovarian cancer cell line A2780 a proof-of-principle model with both a stable SP and a stable ALDH1A1+ cell population was established. Double staining clearly revealed that both cell fractions were not identical. Of note, A2780V cells were negative for expression of surface markers CD44 and CD117 (c-kit). When cultured on monolayers of healthy human mesothelial cells, green-fluorescence-protein (GFP)-transfected SP of A2780V exhibited spheroid-formation, whereas non-side-population (NSP) developed a spare monolayer growing over the healthy mesothelium. Furthermore, A2780V SP was found to be partially resistant to platinum. However, this resistance could not be explained by over-expression of the "excision repair cross-complementation group 1" (ERCC1) gene, which is essentially involved in the repair of platinated DNA damage. ERCC1 was, nonetheless, over-expressed in A2780V cells grown as spheres under stem cell-selective conditions as compared to adherent monolayers cultured under differentiating conditions. The same was true for

  1. Label free quantitative proteomics analysis on the cisplatin resistance in ovarian cancer cells.

    PubMed

    Wang, F; Zhu, Y; Fang, S; Li, S; Liu, S

    2017-05-20

    Quantitative proteomics has been made great progress in recent years. Label free quantitative proteomics analysis based on the mass spectrometry is widely used. Using this technique, we determined the differentially expressed proteins in the cisplatin-sensitive ovarian cancer cells COC1 and cisplatin-resistant cells COC1/DDP before and after the application of cisplatin. Using the GO analysis, we classified those proteins into different subgroups bases on their cellular component, biological process, and molecular function. We also used KEGG pathway analysis to determine the key signal pathways that those proteins were involved in. There are 710 differential proteins between COC1 and COC1/DDP cells, 783 between COC1 and COC1/DDP cells treated with cisplatin, 917 between the COC1/DDP cells and COC1/DDP cells treated with LaCl3, 775 between COC1/DDP cells treated with cisplatin and COC1/DDP cells treated with cisplatin and LaCl3. Among the same 411 differentially expressed proteins in cisplatin-sensitive COC1 cells and cisplain-resistant COC1/DDP cells before and after cisplatin treatment, 14% of them were localized on the cell membrane. According to the KEGG results, differentially expressed proteins were classified into 21 groups. The most abundant proteins were involved in spliceosome. This study lays a foundation for deciphering the mechanism for drug resistance in ovarian tumor.

  2. The role of DNA repair pathways in cisplatin resistant lung cancer.

    PubMed

    O'Grady, Shane; Finn, Stephen P; Cuffe, Sinead; Richard, Derek J; O'Byrne, Kenneth J; Barr, Martin P

    2014-12-01

    Platinum chemotherapeutic agents such as cisplatin are currently used in the treatment of various malignancies such as lung cancer. However, their efficacy is significantly hindered by the development of resistance during treatment. While a number of factors have been reported that contribute to the onset of this resistance phenotype, alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating this phenomenon. The mode of action of cisplatin has been linked to its ability to crosslink purine bases on the DNA, thereby interfering with DNA repair mechanisms and inducing DNA damage. Following DNA damage, cells respond by activating a DNA-damage response that either leads to repair of the lesion by the cell thereby promoting resistance to the drug, or cell death via activation of the apoptotic response. Therefore, DNA repair is a vital target to improving cancer therapy and reduce the resistance of tumour cells to DNA damaging agents currently used in the treatment of cancer patients. To date, despite the numerous findings that differential expression of components of the various DNA repair pathways correlate with response to cisplatin, translation of such findings in the clinical setting are still warranted. The identification of alterations in specific proteins and pathways that contribute to these unique DNA repair pathways in cisplatin resistant cancer cells may potentially lead to a renewed interest in the development of rational novel therapies for cisplatin resistant cancers, in particular, lung cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. MENA confers resistance to paclitaxel in triple-negative breast cancer

    PubMed Central

    Oudin, Madeleine J.; Barbier, Lucie; Schäfer, Claudia; Kosciuk, Tatsiana; Miller, Miles A.; Han, Sangyoon; Jonas, Oliver; Lauffenburger, Douglas A.; Gertler, Frank B.

    2017-01-01

    Taxane therapy remains the standard of care for triple-negative breast cancer. However, high frequencies of recurrence and progression in treated patients indicate that metastatic breast cancer cells can acquire resistance to this drug. The actin regulatory protein MENA, particularly its invasive isoform, MENAINV, are established drivers of metastasis. MENAINV expression is significantly correlated with metastasis and poor outcome in human breast cancer patients. We investigated whether MENA isoforms might play a role in driving resistance to chemotherapeutics. We find that both MENA and MENAINV confer resistance to the taxane paclitaxel, but not to the widely used DNA damaging agents doxorubicin or cisplatin. Furthermore, paclitaxel treatment does not attenuate growth of MENAINV-driven metastatic lesions. Mechanistically, MENA isoform expression alters the ratio of dynamic and stable microtubule populations in paclitaxel-treated cells. MENA expression also increases MAPK signaling in response to paclitaxel treatment. Decreasing ERK phosphorylation by co-treatment with MEK inhibitor restored paclitaxel sensitivity by driving microtubule stabilization in MENA isoform-expressing cells. Our results reveal a novel mechanism of taxane resistance in highly metastatic breast cancer cells and identify a combination therapy to overcome such resistance. PMID:27811011

  4. Selective inhibition of tumor cell associated Vacuolar-ATPase 'a2' isoform overcomes cisplatin resistance in ovarian cancer cells.

    PubMed

    Kulshrestha, Arpita; Katara, Gajendra K; Ginter, Jordyn; Pamarthy, Sahithi; Ibrahim, Safaa A; Jaiswal, Mukesh K; Sandulescu, Corina; Periakaruppan, Ramayee; Dolan, James; Gilman-Sachs, Alice; Beaman, Kenneth D

    2016-06-01

    Development of resistance to platinum compounds significantly hinders successful ovarian cancer (OVCA) treatment. In tumor cells, dysregulated pH gradient across cell membranes is a key physiological mechanism of metastasis/chemo-resistance. These pH alterations are mediated by aberrant activation of key multi-subunit proton pumps, Vacuolar-ATPases (V-ATPases). In tumor cells, its 'a2' isoform (V-ATPase-V0a2) is a component of functional plasma-membrane complex and promotes tumor invasion through tumor-acidification and immuno-modulation. Its involvement in chemo-resistance has not been studied. Here, we show that V-ATPase-V0a2 is over-expressed in acquired-cisplatin resistant OVCA cells (cis-A2780/cis-TOV112D). Of all the 'a' subunit isoforms, V-ATPase-V0a2 exhibited an elevated expression on plasma membrane of cisplatin-resistant cells compared to sensitive counterparts. Immuno-histochemistry revealed V-ATPase-V0a2 expression in both low grade (highly drug-resistant) and high grade (highly recurrent) human OVCA tissues indicating its role in a centralized mechanism of tumor resistance. In cisplatin resistant cells, shRNA mediated inhibition of V-ATPase-V0a2 enhanced sensitivity towards both cisplatin and carboplatin. This improved cytotoxicity was mediated by enhanced cisplatin-DNA-adduct formation and suppressed DNA-repair pathway, leading to enhanced apoptosis. Suppression of V0a2 activity strongly reduced cytosolic pH in resistant tumor cells, which is known to enhance platinum-associated DNA-damage. As an indicator of reduced metastasis and chemo-resistance, in contrast to plasma membrane localization, a diffused cytoplasmic localization of acidic vacuoles was observed in V0a2-knockdown resistant cells. Interestingly, pre-treatment with monoclonal V0a2-inhibitory antibody enhanced cisplatin cytotoxicity in resistant cells. Taken together, our findings suggest that the isoform specific inhibition of V-ATPase-V0a2 could serve as a therapeutic strategy for chemo-resistant

  5. Marine actinomycete crude extracts with potent TRAIL-resistance overcoming activity against breast cancer cells.

    PubMed

    Elmallah, Mohammed I Y; Micheau, Olivier; Eid, Mennat Allah G; Hebishy, Ali M S; Abdelfattah, Mohamed S

    2017-06-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent, as it can kill tumor cells selectively. In our search of bioactive natural products to overcome TRAIL-resistance, we isolated 47 actinomycete strains from different sediments and seawater samples collected from the Red Sea coast in Egypt and found four crude extracts (EGY1, EGY3, EGY24 and EGY34) displaying TRAIL sensitizing activity in the resistant breast cancer cell line MDA-MB-231. None of these crude extracts exhibited cytotoxic effect on normal mouse embryonic fibroblasts (MEF), with the exception of EGY34. Analysis of the signaling pathways underlying the sensitization of MDA-MB-231 cells to TRAIL-induced apoptosis, by western blotting, revealed that all crude extracts facilitated initiator caspase‑8/-10 activation upon TRAIL stimulation, but that in addition, EGY3 and EGY34, alone, induced strong ER-stress activation, with the appearance of BiP in the cytosolic extracts. Our results pave the way to the discovery and the development of marine-derived drugs for cancer therapy.

  6. 20(S)-Protopanaxadiol (PPD) analogues chemosensitize multidrug-resistant cancer cells to clinical anticancer drugs.

    PubMed

    Liu, Junhua; Wang, Xu; Liu, Peng; Deng, Rongxin; Lei, Min; Chen, Wantao; Hu, Lihong

    2013-07-15

    Novel 20(S)-protopanoxadiol (PPD) analogues were designed, synthesized, and evaluated for the chemosensitizing activity against a multidrug resistant (MDR) cell line (KBvcr) overexpressing P-glycoprotein (P-gp). Structure-activity relationship analysis showed that aromatic substituted aliphatic amine at the 24-positions (groups V) effectively and significantly sensitized P-gp overexpressing multidrug resistant (MDR) cells to anticancer drugs, such as docetaxel (DOC), vincristine (VCR), and adriamycin (ADM). PPD derivatives 12 and 18 showed 1.3-2.6 times more effective reversal ability than verapamil (VER) for DOC and VCR. Importantly, no cytotoxicity was observed by the active PPD analogues (5μM) against both non-MDR and MDR cells, suggesting that PPD analogues serve as novel lead compounds toward a potent and safe resistance modulator. Moreover, a preliminary mechanism study demonstrated that the chemosensitizing activity of PPD analogues results from inhibition of P-glycoprotein (P-gp) overexpressed in MDR cancer cells. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Apigenin overcomes drug resistance by blocking the signal transducer and activator of transcription 3 signaling in breast cancer cells.

    PubMed

    Seo, Hye-Sook; Ku, Jin Mo; Choi, Hyeong Sim; Woo, Jong-Kyu; Lee, Byung Hoon; Kim, Doh Sun; Song, Hyun Jong; Jang, Bo-Hyoung; Shin, Yong Cheol; Ko, Seong-Gyu

    2017-08-01

    Drug resistance in chemotherapy is a serious obstacle for the successful treatment of cancer. Drug resistance is caused by various factors, including the overexpression of P‑glycoprotein (P‑gp, MDR1). The development of new, useful compounds that overcome drug resistance is urgent. Apigenin, a dietary flavonoid, has been reported as an anticancer drug in vivo and in vitro. In the present study, we investigated whether apigenin is able to reverse drug resistance using adriamycin‑resistant breast cancer cells (MCF‑7/ADR). In our experiments, apigenin significantly decreased cell growth and colony formation in MCF‑7/ADR cells and parental MCF‑7 cells. This growth inhibition was related to the accumulation of cells in the sub‑G0/G1 apoptotic population and an increase in the number of apoptotic cells. Apigenin reduced the mRNA expression of multidrug resistance 1 (MDR1) and multidrug resistance‑associated proteins (MRPs) in MCF‑7/ADR cells. Apigenin also downregulated the expression of P‑gp. Apigenin reversed drug efflux from MCF‑7/ADR cells, resulting in rhodamine 123 (Rho123) accumulation. Inhibition of drug resistance by apigenin is related to the suppression of the signal transducer and activator of transcription 3 (STAT3) signaling pathway. Apigenin decreased STAT3 activation (p‑STAT3) and its nuclear translocation and inhibited the secretion of VEGF and MMP‑9, which are STAT3 target genes. A STAT3 inhibitor, JAK inhibitor I and an HIF‑1α inhibitor decreased cell growth in MCF‑7 and MCF‑7/ADR cells. Taken together, these results demonstrate that apigenin can overcome drug resistance.

  8. BIM-Mediated AKT Phosphorylation Is a Key Modulator of Arsenic Trioxide-Induced Apoptosis in Cisplatin-Sensitive and -Resistant Ovarian Cancer Cells

    PubMed Central

    Yuan, Zhu; Wang, Fang; Zhao, Zhiwei; Zhao, Xinyu; Qiu, Ji; Nie, Chunlai; Wei, Yuquan

    2011-01-01

    Background Chemo-resistance to cisplatin-centered cancer therapy is a major obstacle to the effective treatment of human ovarian cancer. Previous reports indicated that arsenic trioxide (ATO) induces cell apoptosis in both drug-sensitive and -resistant ovarian cancer cells. Principal Findings In this study, we determined the molecular mechanism of ATO-induced apoptosis in ovarian cancer cells. Our data demonstrated that ATO induced cell apoptosis by decreasing levels of phosphorylated AKT (p-AKT) and activating caspase-3 and caspase-9. Importantly, BIM played a critical role in ATO-induced apoptosis. The inhibition of BIM expression prevented AKT dephosphorylation and inhibited caspase-3 activation during cell apoptosis. However, surprisingly, gene silencing of AKT or FOXO3A had little effect on BIM expression and phosphorylation. Moreover, the activation of caspase-3 by ATO treatment improved AKT dephosphorylation, not only by cleaving the regulatory A subunit of protein phosphatase 2A (PP2A), but also by increasing its activation. Furthermore, our data indicated that the c-Jun N-terminal kinases (JNK) pathway is involved in the regulation of BIM expression. Conclusions We demonstrated the roles of BIM in ATO-induced apoptosis and the molecular mechanisms of BIM expression regulated by ATO during ovarian cancer cell apoptosis. Our findings suggest that BIM plays an important role in regulating p-AKT by activating caspase-3 and that BIM mediates the level of AKT phosphorylation to determine the threshold for overcoming cisplatin resistance in ovarian cancer cells. PMID:21655183

  9. Taxol: a review

    Treesearch

    Walter C. Shortle; Rakesh Minocha

    1999-01-01

    Cancer is one of the most feared diseases. It involves the rapid and uncontrolled proliferation of "abnormal" cells in the body. The cancerous cell mass disrupts normal functioning of the organ or tissue in which it is found. Current treatments involve surgery, radiotherapy, and chemotherapy often applied in some combination. Naturally occurring...

  10. Cancer Stem-Like Cells Enriched in Panc-1 Spheres Possess Increased Migration Ability and Resistance to Gemcitabine

    PubMed Central

    Yin, Tao; Wei, Hongji; Gou, Shanmiao; Shi, Pengfei; Yang, Zhiyong; Zhao, Gang; Wang, Chunyou

    2011-01-01

    Pancreatic cancer is one of the most lethal malignancies with poor prognosis. Previously, we found that a subpopulation of cancer stem cells (CSCs) in the Panc-1 pancreatic cancer cell line could propagate to form spheres. Here we characterized the malignant phenotypes of the pancreatic cancer stem CD44+/CD24+ cells, which were enriched under sphere forming conditions as analyzed by flow cytometry. These cells demonstrated increased resistance to gemcitabine and increased migration ability. Moreover, these cells exhibited epithelial to mesenchymal transition characterized by a decreased level of the epithelial marker E-cadherin and an increased level of the mesenchymal marker vimentin. Notably, abnormal expression of Bmi-1, ABCG2, Cyclin D1 and p16 were found in Panc-1 CSCs. Our results suggest that targeted inhibition of CSCs represents a novel therapeutic approach to overcome chemoresistance and metastasis of pancreatic cancer. PMID:21673909

  11. Aspirin regulation of c-myc and cyclinD1 proteins to overcome tamoxifen resistance in estrogen receptor-positive breast cancer cells.

    PubMed

    Cheng, Ran; Liu, Ya-Jing; Cui, Jun-Wei; Yang, Man; Liu, Xiao-Ling; Li, Peng; Wang, Zhan; Zhu, Li-Zhang; Lu, Si-Yi; Zou, Li; Wu, Xiao-Qin; Li, Yu-Xia; Zhou, You; Fang, Zheng-Yu; Wei, Wei

    2017-05-02

    Tamoxifen is still the most commonly used endocrine therapy drug for estrogen receptor (ER)-positive breast cancer patients and has an excellent outcome, but tamoxifen resistance remains a great impediment to successful treatment. Recent studies have prompted an anti-tumor effect of aspirin. Here, we demonstrated that aspirin not only inhibits the growth of ER-positive breast cancer cell line MCF-7, especially when combined with tamoxifen, but also has a potential function to overcome tamoxifen resistance in MCF-7/TAM. Aspirin combined with tamoxifen can down regulate cyclinD1 and block cell cycle in G0/G1 phase. Besides, tamoxifen alone represses c-myc, progesterone receptor (PR) and cyclinD1 in MCF-7 cell line but not in MCF-7/TAM, while aspirin combined with tamoxifen can inhibit the expression of these proteins in the resistant cell line. When knocking down c-myc in MCF-7/TAM, cells become more sensitive to tamoxifen, cell cycle is blocked as well, indicating that aspirin can regulate c-myc and cyclinD1 proteins to overcome tamoxifen resistance. Our study discovered a novel role of aspirin based on its anti-tumor effect, and put forward some kinds of possible mechanisms of tamoxifen resistance in ER-positive breast cancer cells, providing a new strategy for the treatment of ER-positive breast carcinoma.

  12. Inhibition of Aerobic Glycolysis Represses Akt/mTOR/HIF-1α Axis and Restores Tamoxifen Sensitivity in Antiestrogen-Resistant Breast Cancer Cells

    PubMed Central

    Woo, Yu Mi; Shin, Yubin; Lee, Eun Ji; Lee, Sunyoung; Jeong, Seung Hun; Kong, Hyun Kyung; Park, Eun Young; Kim, Hyoung Kyu; Han, Jin; Chang, Minsun; Park, Jong-Hoon

    2015-01-01

    Tamoxifen resistance is often observed in the majority of estrogen receptor–positive breast cancers and it remains as a serious clinical problem in breast cancer management. Increased aerobic glycolysis has been proposed as one of the mechanisms for acquired resistance to chemotherapeutic agents in breast cancer cells such as adriamycin. Herein, we report that the glycolysis rates in LCC2 and LCC9—tamoxifen-resistant human breast cancer cell lines derived from MCF7— are higher than those in MCF7S, which is the parent MCF7 subline. Inhibition of key glycolytic enzyme such as hexokinase-2 resulted in cell growth retardation at higher degree in LCC2 and LCC9 than that in MCF7S. This implies that increased aerobic glycolysis even under O2-rich conditions, a phenomenon known as the Warburg effect, is closely associated with tamoxifen resistance. We found that HIF-1α is activated via an Akt/mTOR signaling pathway in LCC2 and LCC9 cells without hypoxic condition. Importantly, specific inhibition of hexokinase-2 suppressed the activity of Akt/mTOR/HIF-1α axis in LCC2 and LCC9 cells. In addition, the phosphorylated AMPK which is a negative regulator of mTOR was decreased in LCC2 and LCC9 cells compared to MCF7S. Interestingly, either the inhibition of mTOR activity or increase in AMPK activity induced a reduction in lactate accumulation and cell survival in the LCC2 and LCC9 cells. Taken together, our data provide evidence that development of tamoxifen resistance may be driven by HIF-1α hyperactivation via modulation of Akt/mTOR and/or AMPK signaling pathways. Therefore, we suggest that the HIF-1α hyperactivation is a critical marker of increased aerobic glycolysis in accordance with tamoxifen resistance and thus restoration of aerobic glycolysis may be novel therapeutic target for treatment of tamoxifen-resistant breast cancer. PMID:26158266

  13. Multidrug Resistance and Cancer Stem Cells in Neuroblastoma and Hepatoblastoma

    PubMed Central

    Alisi, Anna; Cho, William C.; Locatelli, Franco; Fruci, Doriana

    2013-01-01

    Chemotherapy is one of the major modalities in treating cancers. However, its effectiveness is limited by the acquisition of multidrug resistance (MDR). Several mechanisms could explain the up-regulation of MDR genes/proteins in cancer after chemotherapy. It is known that cancer stem cells (CSCs) play a role as master regulators. Therefore, understanding the mechanisms that regulate some traits of CSCs may help design efficient strategies to overcome chemoresistance. Different CSC phenotypes have been identified, including those found in some pediatric malignancies. As solid tumors in children significantly differ from those observed in adults, this review aims at providing an overview of the mechanistic relationship between MDR and CSCs in common solid tumors, and, in particular, focuses on clinical as well as experimental evidence of the relations between CSCs and MDR in neuroblastoma and hepatoblastoma. Finally, some novel approaches, such as concomitant targeting of multiple key transcription factors governing the stemness of CSCs, as well as nanoparticle-based approaches will also be briefly addressed. PMID:24351843

  14. Elucidation of Resistance Mechanisms to Second-Generation ALK Inhibitors Alectinib and Ceritinib in Non-Small Cell Lung Cancer Cells.

    PubMed

    Dong, Xuyuan; Fernandez-Salas, Ester; Li, Enxiao; Wang, Shaomeng

    2016-03-01

    Crizotinib is the first anaplastic lymphoma kinase (ALK) inhibitor to have been approved for the treatment of non-small cell lung cancer (NSCLC) harboring an ALK fusion gene, but it has been found that, in the clinic, patients develop resistance to it. Alectinib and ceritinib are second-generation ALK inhibitors which show remarkable clinical responses in both crizotinib-naive and crizotinib-resistant NSCLC patients harboring an ALK fusion gene. Despite their impressive activity, clinical resistance to alectinib and ceritinib has also emerged. In the current study, we elucidated the resistance mechanisms to these second-generation ALK inhibitors in the H3122 NSCLC cell line harboring the EML4-ALK variant 1 fusion in vitro. Prolonged treatment of the parental H3122 cells with alectinib and ceritinib led to two cell lines which are 10 times less sensitive to alectinib and ceritinib than the parental H3122 cell line. Although mutations of ALK in its kinase domain are a common resistance mechanism for crizotinib, we did not detect any ALK mutation in these resistant cell lines. Rather, overexpression of phospho-ALK and alternative receptor tyrosine kinases such as phospho-EGFR, phospho-HER3, and phospho-IGFR-1R was observed in both resistant cell lines. Additionally, NRG1, a ligand for HER3, is upregulated and responsible for resistance by activating the EGFR family pathways through the NRG1-HER3-EGFR axis. Combination treatment with EGFR inhibitors, in particular afatinib, was shown to be effective at overcoming resistance. Our study provides new mechanistic insights into adaptive resistance to second-generation ALK inhibitors and suggests a potential clinical strategy to combat resistance to these second-generation ALK inhibitors in NSCLC. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Elucidation of Resistance Mechanisms to Second-Generation ALK Inhibitors Alectinib and Ceritinib in Non–Small Cell Lung Cancer Cells

    PubMed Central

    Dong, Xuyuan; Fernandez-Salas, Ester; Li, Enxiao; Wang, Shaomeng

    2016-01-01

    Crizotinib is the first anaplastic lymphoma kinase (ALK) inhibitor to have been approved for the treatment of non–small cell lung cancer (NSCLC) harboring an ALK fusion gene, but it has been found that, in the clinic, patients develop resistance to it. Alectinib and ceritinib are second-generation ALK inhibitors which show remarkable clinical responses in both crizotinib-naive and crizotinib-resistant NSCLC patients harboring an ALK fusion gene. Despite their impressive activity, clinical resistance to alectinib and ceritinib has also emerged. In the current study, we elucidated the resistance mechanisms to these second-generation ALK inhibitors in the H3122 NSCLC cell line harboring the EML4-ALK variant 1 fusion in vitro. Prolonged treatment of the parental H3122 cells with alectinib and ceritinib led to two cell lines which are 10 times less sensitive to alectinib and ceritinib than the parental H3122 cell line. Although mutations of ALK in its kinase domain are a common resistance mechanism for crizotinib, we did not detect any ALK mutation in these resistant cell lines. Rather, overexpression of phospho-ALK and alternative receptor tyrosine kinases such as phospho-EGFR, phospho-HER3, and phospho-IGFR-1R was observed in both resistant cell lines. Additionally, NRG1, a ligand for HER3, is upregulated and responsible for resistance by activating the EGFR family pathways through the NRG1-HER3-EGFR axis. Combination treatment with EGFR inhibitors, in particular afatinib, was shown to be effective at overcoming resistance. Our study provides new mechanistic insights into adaptive resistance to second-generation ALK inhibitors and suggests a potential clinical strategy to combat resistance to these second-generation ALK inhibitors in NSCLC. PMID:26992917

  16. Natural Killer Cell Immunotherapy Targeting Cancer Stem Cells

    PubMed Central

    Luna, Jesus I; Grossenbacher, Steven K.; Murphy, William J; Canter, Robert J

    2017-01-01

    Introduction Standard cytoreductive cancer therapy, such as chemotherapy and radiotherapy, are frequently resisted by a small portion of cancer cells with “stem-cell” like properties including quiescence and repopulation. Immunotherapy represents a breakthrough modality for improving oncologic outcomes in cancer patients. Since the success of immunotherapy is not contingent on target cell proliferation, it may also be uniquely suited to address the problem of resistance and repopulation exerted by cancer stem cells (CSCs). Areas covered Natural killer (NK) cells have long been known for their ability to reject allogeneic hematopoietic stem cells, and there are increasing data demonstrating that NK cells can selectively identify and lyse CSCs. In this report, we review the current knowledge of CSCs and NK cells and highlight recent studies that support the concept that NK cells are capable of targeting CSC in solid tumors, especially in the context of combination therapy simultaneously targeting non-CSCs and CSCs. Expert Opinion Unlike cytotoxic cancer treatments, NK cells are able to target and eliminate quiescent/non-proliferating cells such as CSCs, and these enigmatic cells are an important source of relapse and metastasis. NK targeting of CSCs represents a novel and potentially high impact method to capitalize on the intrinsic therapeutic potential of NK cells. PMID:27960589

  17. HOXC10 Expression Supports the Development of Chemotherapy Resistance by Fine Tuning DNA Repair in Breast Cancer Cells.

    PubMed

    Sadik, Helen; Korangath, Preethi; Nguyen, Nguyen K; Gyorffy, Balazs; Kumar, Rakesh; Hedayati, Mohammad; Teo, Wei Wen; Park, Sunju; Panday, Hardik; Munoz, Teresa Gonzalez; Menyhart, Otilia; Shah, Nilay; Pandita, Raj K; Chang, Jenny C; DeWeese, Theodore; Chang, Howard Y; Pandita, Tej K; Sukumar, Saraswati

    2016-08-01

    Development of drug resistance is a major factor limiting the continued success of cancer chemotherapy. To overcome drug resistance, understanding the underlying mechanism(s) is essential. We found that HOXC10 is overexpressed in primary carcinomas of the breast, and even more significantly in distant metastasis arising after failed chemotherapy. High HOXC10 expression correlates with shorter recurrence-free and overall survival in patients with estrogen receptor-negative breast cancer undergoing chemotherapy. We found that HOXC10 promotes survival in cells treated with doxorubicin, paclitaxel, or carboplatin by suppressing apoptosis and upregulating NF-κB Overexpressed HOXC10 increases S-phase-specific DNA damage repair by homologous recombination (HR) and checkpoint recovery in cells at three important phases. For double-strand break repair, HOXC10 recruits HR proteins at sites of DNA damage. It enhances resection and lastly, it resolves stalled replication forks, leading to initiation of DNA replication following DNA damage. We show that HOXC10 facilitates, but is not directly involved in DNA damage repair mediated by HR. HOXC10 achieves integration of these functions by binding to, and activating cyclin-dependent kinase, CDK7, which regulates transcription by phosphorylating the carboxy-terminal domain of RNA polymerase II. Consistent with these findings, inhibitors of CDK7 reverse HOXC10-mediated drug resistance in cultured cells. Blocking HOXC10 function, therefore, presents a promising new strategy to overcome chemotherapy resistance in breast cancer. Cancer Res; 76(15); 4443-56. ©2016 AACR. ©2016 American Association for Cancer Research.

  18. Nanoparticle-mediated inhibition of survivin to overcome drug resistance in cancer therapy.

    PubMed

    Wang, Shengpeng; Xu, Yingqi; Chan, Hon Fai; Kim, Hae-Won; Wang, Yitao; Leong, Kam W; Chen, Meiwan

    2016-10-28

    The acquired resistance of human cancer cells to apoptosis is one of the defining hallmarks of cancer. Upregulated expression of inhibitors of apoptosis proteins (IAP) has been implicated in drug resistance in several cancers. Survivin (encoded by BIRC5), the smallest member of the IAP family, has been correlated with both the control of cell apoptosis and regulation of cell mitosis in cancer. Owing to its critical role in regulation of cell survival and development of cancer resistance, as well as its distinguishingly high level of expression in many types of cancer, survivin has long been regarded as a promising therapeutic target for cancer therapy. This review first presents an overview of the mechanism by which survivin regulates cell function, followed by a discussion of the current state of survivin-targeted therapies. We focus on the application of nanoparticulate systems to deliver survivin inhibitors, co-delivery of survivin inhibitors with chemotherapeutic agents, synchronous targeting of survivin, other drug resistant molecules, and survivin regulators. We conclude by highlighting the current limitations associated with survivin-targeted therapies and speculating on the future strategies to surmount these impediments. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Novel quinolone chalcones targeting colchicine-binding pocket kill multidrug-resistant cancer cells by inhibiting tubulin activity and MRP1 function.

    PubMed

    Lindamulage, I Kalhari; Vu, Hai-Yen; Karthikeyan, Chandrabose; Knockleby, James; Lee, Yi-Fang; Trivedi, Piyush; Lee, Hoyun

    2017-08-31

    Agents targeting colchicine-binding pocket usually show a minimal drug-resistance issue, albeit often associated with high toxicity. Chalcone-based compounds, which may bind to colchicine-binding site, are found in many edible fruits, suggesting that they can be effective drugs with less toxicity. Therefore, we synthesized and examined 24 quinolone chalcone compounds, from which we identified ((E)-3-(3-(2-Methoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one) (CTR-17) and ((E)-6-Methoxy-3-(3-(2-methoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one) (CTR-20) as promising leads. In particular, CTR-20 was effective against 65 different cancer cell lines originated from 12 different tissues, largely in a cancer cell-specific manner. We found that both CTR-17 and CTR-20 reversibly bind to the colchicine-binding pocket on β-tubulin. Interestingly however, both the CTRs were highly effective against multidrug-resistant cancer cells while colchicine, paclitaxel and vinblastine were not. Our study with CTR-20 showed that it overcomes multidrug-resistance through its ability to impede MRP1 function while maintaining strong inhibition against microtubule activity. Data from mice engrafted with the MDA-MB-231 triple-negative breast cancer cells showed that both CTR-17 and CTR-20 possess strong anticancer activity, alone or in combination with paclitaxel, without causing any notable side effects. Together, our data demonstrates that both the CTRs can be effective and safe drugs against many different cancers, especially against multidrug-resistant tumors.

  20. TET1 promotes cisplatin-resistance via demethylating the vimentin promoter in ovarian cancer.

    PubMed

    Han, Xi; Zhou, Yuanyuan; You, Yuanyi; Lu, Jiaojiao; Wang, Lijie; Hou, Huilian; Li, Jing; Chen, Wei; Zhao, Le; Li, Xu

    2017-04-01

    The development of chemo-resistance impairs the outcome of the first line platinum-based chemotherapies for ovarian cancer. Deregulation of DNA methylation/demethylation provides a critical mechanism for the occurrence of chemo-resistance. The ten-eleven translocation (TET) family of dioxygenases including TET1/2/3 plays an important part in DNA demethylation, but their roles in cisplatin resistance have not been elucidated. Using cisplatin-sensitive and cisplatin-resistant ovarian cancer cell models, we found that TET1 was significantly upregulated in cisplatin-resistant CP70 cells compared with that in cisplatin-sensitive A2780 cells. Ectopic expression of TET1 in A2780 cells promoted cisplatin resistance and decreased cytotoxicity induced by cisplatin, while inhibition of TET1 by siRNA transfection in CP70 cells attenuated cisplatin resistance and enhanced cytotoxicity of cisplatin. Increased TET1 induced re-expression of vimentin through active DNA demethylation, and cause partial epithelial-to-mesenchymal (EMT) in A2780 cells. Contrarily, knocking down of TET1 in CP70 cells reduced vimentin expression and reversed EMT process. Immunohistochemical analysis of TET1 in human ovarian cancer tissues revealed that TET1 existed in nucleus and cytoplasm in ovarian cancer tissues. And the expression of nuclear TET1 was positively correlated with residual tumor and chemotherapeutic response. Thus, TET1 expression causes resistance to cisplatin and one of the targets of TET1 action is vimentin in ovarian cancer. © 2017 International Federation for Cell Biology.

  1. Resistance to hypoxia-induced necroptosis is conferred by glycolytic pyruvate scavenging of mitochondrial superoxide in colorectal cancer cells.

    PubMed

    Huang, C-Y; Kuo, W-T; Huang, Y-C; Lee, T-C; Yu, L C H

    2013-05-02

    Cancer cells may survive under oxygen and nutrient deprivation by metabolic reprogramming for high levels of anaerobic glycolysis, which contributes to tumor growth and drug resistance. Abnormally expressed glucose transporters (GLUTs) are colocalized with hypoxia (Hx) inducible factor (HIF)1α in peri-necrotic regions in human colorectal carcinoma. However, the underlying mechanisms of anti-necrotic resistance conferred by glucose metabolism in hypoxic cancer cells remain poorly understood. Our aim was to investigate signaling pathways of Hx-induced necroptosis and explore the role of glucose pyruvate metabolite in mechanisms of death resistance. Human colorectal carcinoma cells were Hx exposed with or without glucose, and cell necroptosis was examined by receptor-interacting protein (RIP)1/3 kinase immunoprecipitation and (32)P kinase assays. Our results showed increased RIP1/3 complex formation and phosphorylation in hypoxic, but not normoxic cells in glucose-free media. Blocking RIP1 signaling, by necrostatin-1 or gene silencing, decreased lactodehydrogenase (LDH) leakage and plasma membrane disintegration. Generation of mitochondrial superoxide was noted after hypoxic challenge; its reduction by antioxidants inhibited RIP signaling and cell necrosis. Supplementation of glucose diminished the RIP-dependent LDH leakage and morphological damage in hypoxic cells, whereas non-metabolizable sugar analogs did not. Hypoxic cells given glucose showed nuclear translocation of HIF1α associated with upregulation of GLUT-1 and GLUT-4 expression, as well as increase of intracellular ATP, pyruvate and lactate levels. The glucose-mediated death resistance was ablated by iodoacetate (an inhibitor to glyceraldehyde-3-phosphate dehydrogenase), but not by UK5099 (an inhibitor to mitochondrial pyruvate carrier), suggesting that glycolytic pathway was involved in anti-necrotic mechanism. Lastly, replacing glucose with cell-permeable pyruvate derivative also led to decrease of Hx

  2. Cell-of-Origin of Cancer versus Cancer Stem Cells: Assays and Interpretations.

    PubMed

    Rycaj, Kiera; Tang, Dean G

    2015-10-01

    A tumor originates from a normal cell that has undergone tumorigenic transformation as a result of genetic mutations. This transformed cell is the cell-of-origin for the tumor. In contrast, an established clinical tumor is sustained by subpopulations of self-renewing cancer cells operationally called cancer stem cells (CSC) that can generate, intraclonally, both tumorigenic and nontumorigenic cells. Identifying and characterizing tumor cell-of-origin and CSCs should help elucidate tumor cell heterogeneity, which, in turn, should help understand tumor cell responses to clinical treatments, drug resistance, tumor relapse, and metastatic spread. Both tumor transplantation and lineage-tracing assays have been helpful in characterizing these cancer cell populations, although each system has its strengths and caveats. In this article, we briefly review and summarize advantages and limitations of both assays in support of a combinatorial approach to accurately define the roles of both cancer-initiating and cancer-propagating cells. As an aside, we also wish to clarify the definitions of cancer cell-of-origin and CSCs, which are often interchangeably used by mistake. ©2015 American Association for Cancer Research.

  3. Drug Resistance to EGFR Inhibitors in Lung Cancer | Office of Cancer Genomics

    Cancer.gov

    The discovery of mutations in epidermal growth factor receptor (EGFR) has dramatically changed the treatment of patients with non-small-cell lung cancer (NSCLC), the leading cause of cancer deaths worldwide. EGFR-targeted therapies show considerable promise, but drug resistance has become a substantial issue. We reviewed the literature to provide an overview of the drug resistance to EGFR tyrosine kinase inhibitors (TKIs) in NSCLC. The mechanisms causing primary, acquired and persistent drug resistance to TKIs vary.

  4. Plasmonic nanobubble-enhanced endosomal escape processes for selective and guided intracellular delivery of chemotherapy to drug-resistant cancer cells

    PubMed Central

    Lukianova-Hleb, Ekaterina Y.; Belyanin, Andrey; Kashinath, Shruti; Wu, Xiangwei; Lapotko, Dmitri O.

    2012-01-01

    Cancer chemotherapies suffer from multi drug resistance, high non-specific toxicity and heterogeneity of tumors. We report a method of plasmonic nanobubble-enhanced endosomal escape (PNBEE) for the selective, fast and guided intracellular delivery of drugs through a self-assembly by cancer cells of separately targeted gold nanoparticles and encapsulated drug (Doxil). The co-localized with Doxil plasmonic nanobubbles optically generated in cancer cells released the drug into the cytoplasm thus increasing the therapeutic efficacy against these drug-resistant cells by 31-fold, reducing drug dose by 20-fold, the treatment time by 3-fold and the non-specific toxicity by 10-fold compared to standard treatment. Thus the PNBEE mechanism provided selective, safe and efficient intracellular drug delivery in heterogeneous environment opening new opportunities for drug therapies. PMID:22137124

  5. Resistance to DNA-damaging treatment in non-small cell lung cancer tumor-initiating cells involves reduced DNA-PK/ATM activation and diminished cell cycle arrest

    PubMed Central

    Lundholm, L; Hååg, P; Zong, D; Juntti, T; Mörk, B; Lewensohn, R; Viktorsson, K

    2013-01-01

    Increasing evidence suggests that tumor-initiating cells (TICs), also called cancer stem cells, are partly responsible for resistance to DNA-damaging treatment. Here we addressed if such a phenotype may contribute to radio- and cisplatin resistance in non-small cell lung cancer (NSCLC). We showed that four out of eight NSCLC cell lines (H125, A549, H1299 and H23) possess sphere-forming capacity when cultured in stem cell media and three of these display elevated levels of CD133. Indeed, sphere-forming NSCLC cells, hereafter called TICs, showed a reduced apoptotic response and increased survival after irradiation (IR), as compared with the corresponding bulk cell population. Decreased cytotoxicity and apoptotic signaling manifested by diminished poly (ADP-ribose) polymerase (PARP) cleavage and caspase 3 activity was also evident in TICs after cisplatin treatment. Neither radiation nor cisplatin resistance was due to quiescence as H125 TICs proliferated at a rate comparable to bulk cells. However, TICs displayed less pronounced G2 cell cycle arrest and S/G2-phase block after IR and cisplatin, respectively. Additionally, we confirmed a cisplatin-refractory phenotype of H125 TICs in vivo in a mouse xenograft model. We further examined TICs for altered expression or activation of DNA damage repair proteins as a way to explain their increased radio- and/or chemotherapy resistance. Indeed, we found that TICs exhibited increased basal γH2AX (H2A histone family, member X) expression and diminished DNA damage-induced phosphorylation of DNA-dependent protein kinase (DNA-PK), ataxia telangiectasia-mutated (ATM), Krüppel-associated protein 1 (KAP1) and monoubiquitination of Fanconi anemia, complementation group D2 (FANCD2). As a proof of principle, ATM inhibition in bulk cells increased their cisplatin resistance, as demonstrated by reduced PARP cleavage. In conclusion, we show that reduced apoptotic response, altered DNA repair signaling and cell cycle perturbations in NSCLC

  6. Exosomes in development, metastasis and drug resistance of breast cancer

    PubMed Central

    Yu, Dan-dan; Wu, Ying; Shen, Hong-yu; Lv, Meng-meng; Chen, Wei-xian; Zhang, Xiao-hui; Zhong, Shan-liang; Tang, Jin-hai; Zhao, Jian-hua

    2015-01-01

    Transport through the cell membrane can be divided into active, passive and vesicular types (exosomes). Exosomes are nano-sized vesicles released by a variety of cells. Emerging evidence shows that exosomes play a critical role in cancers. Exosomes mediate communication between stroma and cancer cells through the transfer of nucleic acid and proteins. It is demonstrated that the contents and the quantity of exosomes will change after occurrence of cancers. Over the last decade, growing attention has been paid to the role of exosomes in the development of breast cancer, the most life-threatening cancer in women. Breast cancer could induce salivary glands to secret specific exosomes, which could be used as biomarkers in the diagnosis of early breast cancer. Exosome-delivered nucleic acid and proteins partly facilitate the tumorigenesis, metastasis and resistance of breast cancer. Exosomes could also transmit anti-cancer drugs outside breast cancer cells, therefore leading to drug resistance. However, exosomes are effective tools for transportation of anti-cancer drugs with lower immunogenicity and toxicity. This is a promising way to establish a drug delivery system. PMID:26052865

  7. Hepatocyte growth factor induces resistance to anti-epidermal growth factor receptor antibody in lung cancer.

    PubMed

    Yamada, Tadaaki; Takeuchi, Shinji; Kita, Kenji; Bando, Hideaki; Nakamura, Takahiro; Matsumoto, Kunio; Yano, Seiji

    2012-02-01

    Epidermal growth factor receptor (EGFR) is an attractive drug target in lung cancer, with several anti-EGFR antibodies and small-molecule inhibitors showing efficacy in lung cancer patients. Patients, however, may develop resistance to EGFR inhibitors. We demonstrated previously that hepatocyte growth factor (HGF) induced resistance to EGFR tyrosine kinase inhibitors in lung cancers harboring EGFR mutations. We therefore determined whether HGF could induce resistance to the anti-EGFR antibody (EGFR Ab) cetuximab in lung cancer cells, regardless of EGFR gene status. Cetuximab sensitivity and signal transduction in lung cancer cells were examined in the presence or absence of HGF, HGF-producing fibroblasts, and cells tranfected with the HGF gene in vitro and in vivo. HGF induced resistance to cetuximab in H292 (EGFR wild) and Ma-1(EGFR mutant) cells. Western blotting showed that HGF-induced resistance was mediated by the Met/Gab1/Akt signaling pathway. Resistance of H292 and Ma-1 cells to cetuximab was also induced by coculture with lung fibroblasts producing high levels of HGF and by cells stably transfected with the HGF gene. This resistance was abrogated by treatment with anti-HGF neutralizing antibody. HGF-mediated resistance is a novel mechanism of resistance to EGFR Ab in lung cancers, with fibroblast-derived HGF inducing cetuximab resistance in H292 tumors in vivo. The involvement of HGF-Met-mediated signaling should be assessed in acquired resistance to EGFR Ab in lung cancer, regardless of EGFR gene status.

  8. Natural products to prevent drug resistance in cancer chemotherapy: a review.

    PubMed

    Yuan, Renyikun; Hou, Ying; Sun, Wen; Yu, Jie; Liu, Xin; Niu, Yanan; Lu, Jin-Jian; Chen, Xiuping

    2017-08-01

    Chemotherapy is the standard internal medical treatment for cancer. However, the resistance of cancer cells to nearly all kinds of chemotherapeutic drugs and targeted drugs has become prevalent, and approximately 80-90% of deaths in cancer patients are directly or indirectly attributed to drug resistance. The progress of new drug research and development has also been impeded by the occurrence of drug resistance, which has emerged as a considerable challenge in cancer therapy. Fortunately, natural products with diverse chemical structures and pharmacological effects serve as effective substances against drug resistance. Since the discovery of a series of drug-resistant proteins, drug-efflux inhibition has been applied as the primary strategy to overcome drug resistance by maintaining the intracellular concentrations of chemotherapeutic drugs. Nonapoptotic cell death is considered an alternative strategy because most cases of drug resistance result in evasion and insensitivity to apoptosis. In this concise review, we summarize two strategies using natural products against drug resistance. © 2017 New York Academy of Sciences.

  9. Solitomab, an epithelial cell adhesion molecule/CD3 bispecific antibody (BiTE), is highly active against primary chemotherapy-resistant ovarian cancer cell lines in vitro and fresh tumor cells ex vivo.

    PubMed

    English, Diana P; Bellone, Stefania; Schwab, Carlton L; Roque, Dana M; Lopez, Salvatore; Bortolomai, Ileana; Cocco, Emiliano; Bonazzoli, Elena; Chatterjee, Sudeshna; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E; Rutherford, Thomas J; Santin, Alessandro D

    2015-02-01

    Solitomab is a novel, bispecific, single-chain antibody that targets epithelial cell adhesion molecule (EpCAM) on tumor cells and also contains a cluster of differentiation 3 (CD3) (T-cell coreceptor) binding region. The authors evaluated the in vitro activity of solitomab against primary chemotherapy-resistant epithelial ovarian carcinoma cell lines as well as malignant cells in ascites. EpCAM expression was evaluated by flow cytometry in 5 primary ovarian cancer cell lines and in 42 fresh ovarian tumor cell cultures in ascites from patients with mainly advanced or recurrent, chemotherapy-resistant disease. The potential activity of solitomab against EpCAM-positive tumor cells was evaluated by flow cytometry, proliferation, and 4-hour chromium-release, cell-mediated cytotoxicity assays. EpCAM expression was detected by flow cytometry in approximately 80% of the fresh ovarian tumors and primary ovarian tumor cell lines tested. EpCAM-positive, chemotherapy-resistant cell lines were identified as resistant to natural killer cell-mediated or T-cell-mediated killing after exposure to peripheral blood lymphocytes in 4-hour chromium-release assays (mean±standard error of the mean, 3.6%±0.7% of cells killed after incubation of EpCAM-positive cell lines with control bispecific antibody). In contrast, after incubation with solitomab, EpCAM-positive, chemotherapy-resistant cells became highly sensitive to T-cell cytotoxicity (mean±standard error of the mean, 28.2%±2.05% of cells killed; P<.0001) after exposure to peripheral blood lymphocytes. Ex vivo incubation of autologous tumor-associated lymphocytes with EpCAM-expressing malignant cells in ascites with solitomab resulted in a significant increase in T-cell activation markers and a reduction in the number of viable ovarian tumor cells in ascites (P<.001). Solitomab may represent a novel, potentially effective agent for the treatment of chemotherapy-resistant ovarian cancers that overexpress EpCAM. © 2014 American

  10. Overcoming chemotherapy resistance of ovarian cancer cells by liposomal cisplatin: molecular mechanisms unveiled by gene expression profiling.

    PubMed

    Koch, Martin; Krieger, Michaela L; Stölting, Daniel; Brenner, Norbert; Beier, Manfred; Jaehde, Ulrich; Wiese, Michael; Royer, Hans-Dieter; Bendas, Gerd

    2013-04-15

    Previously we reported that liposomal cisplatin (CDDP) overcomes CDDP resistance of ovarian A2780cis cancer cells (Krieger et al., Int. J. Pharm. 389, 2010, 10-17). Here we find that the cytotoxic activity of liposomal CDDP is not associated with detectable DNA platination in resistant ovarian cancer cells. This suggests that the mode of action of liposomal CDDP is different from the free drug. To gain insight into mechanisms of liposomal CDDP activity, we performed a transcriptome analysis of untreated A2780cis cells, and A2780cis cells in response to exposure with IC50 values of free or liposomal CDDP. A process network analysis of upregulated genes showed that liposomal CDDP induced a highly different gene expression profile in comparison to the free drug. p53 was identified as a key player directing transcriptional responses to free or liposomal CDDP. The free drug induced expression of essential genes of the intrinsic (mitochondrial) apoptosis pathway (BAX, BID, CASP9) most likely through p38MAPK activation. In contrast, liposomal CDDP induced expression of genes from DNA damage pathways and several genes of the extrinsic pathway of apoptosis (TNFRSF10B-DR5, CD70-TNFSF7). It thus appears that liposomal CDDP overcomes CDDP resistance by inducing DNA damage and in consequence programmed cell death by the extrinsic pathway. Predictions from gene expression data with respect to apoptosis activation were confirmed at the protein level by an apoptosis antibody array. This sheds new light on liposomal drug carrier approaches in cancer and suggests liposomal CDDP as promising strategy for the treatment of CDDP resistant ovarian carcinomas. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. EPHA2 Blockade Overcomes Acquired Resistance to EGFR Kinase Inhibitors in Lung Cancer.

    PubMed

    Amato, Katherine R; Wang, Shan; Tan, Li; Hastings, Andrew K; Song, Wenqiang; Lovly, Christine M; Meador, Catherine B; Ye, Fei; Lu, Pengcheng; Balko, Justin M; Colvin, Daniel C; Cates, Justin M; Pao, William; Gray, Nathanael S; Chen, Jin

    2016-01-15

    Despite the success of treating EGFR-mutant lung cancer patients with EGFR tyrosine kinase inhibitors (TKI), all patients eventually acquire resistance to these therapies. Although various resistance mechanisms have been described, there are currently no FDA-approved therapies that target alternative mechanisms to treat lung tumors with acquired resistance to first-line EGFR TKI agents. Here we found that EPHA2 is overexpressed in EGFR TKI-resistant tumor cells. Loss of EPHA2 reduced the viability of erlotinib-resistant tumor cells harboring EGFR(T790M) mutations in vitro and inhibited tumor growth and progression in an inducible EGFR(L858R+T790M)-mutant lung cancer model in vivo. Targeting EPHA2 in erlotinib-resistant cells decreased S6K1-mediated phosphorylation of cell death agonist BAD, resulting in reduced tumor cell proliferation and increased apoptosis. Furthermore, pharmacologic inhibition of EPHA2 by the small-molecule inhibitor ALW-II-41-27 decreased both survival and proliferation of erlotinib-resistant tumor cells and inhibited tumor growth in vivo. ALW-II-41-27 was also effective in decreasing viability of cells with acquired resistance to the third-generation EGFR TKI AZD9291. Collectively, these data define a role for EPHA2 in the maintenance of cell survival of TKI-resistant, EGFR-mutant lung cancer and indicate that EPHA2 may serve as a useful therapeutic target in TKI-resistant tumors. ©2016 American Association for Cancer Research.

  12. Isolation and Characterization of Cancer Stem Cells of the Non-Small-Cell Lung Cancer (A549) Cell Line.

    PubMed

    Halim, Noor Hanis Abu; Zakaria, Norashikin; Satar, Nazilah Abdul; Yahaya, Badrul Hisham

    2016-01-01

    Cancer is a major health problem worldwide. The failure of current treatments to completely eradicate cancer cells often leads to cancer recurrence and dissemination. Studies have suggested that tumor growth and spread are driven by a minority of cancer cells that exhibit characteristics similar to those of normal stem cells, thus these cells are called cancer stem cells (CSCs). CSCs are believed to play an important role in initiating and promoting cancer. CSCs are resistant to currently available cancer therapies, and understanding the mechanisms that control the growth of CSCs might have great implications for cancer therapy. Cancer cells are consist of heterogeneous population of cells, thus methods of identification, isolation, and characterisation of CSCs are fundamental to obtain a pure CSC populations. Therefore, this chapter describes in detail a method for isolating and characterizing a pure population of CSCs from heterogeneous population of cancer cells and CSCs based on specific cell surface markers.

  13. miR-338-3p confers 5-fluorouracil resistance in p53 mutant colon cancer cells by targeting the mammalian target of rapamycin.

    PubMed

    Han, Jia; Li, Jie; Tang, Kaijie; Zhang, Huahua; Guo, Bo; Hou, Ni; Huang, Chen

    2017-11-15

    Evidence demonstrate that p53 mutations and microRNAs (miRs) are important components of 5-FU resistance in colorectal cancer (CRC). miR-338-3p has been reported associated with cancer prognosis. However whether or not it influences chemotherapy sensitivity and the underlying mechanisms have not been elucidated. Here, three types of human colon cancer cell lines, HT29 (mutant p53), HCT116 (wild-type p53), and HCT116 p53 -/- (deficient p53), were treated with 5-FU. We showed that expression of miR-338-3p was correlated with apoptosis and 5-FU resistance in colon cancer cells. Ectopic expression of miR-338-3p conferred resistance to 5-FU in HCT116 cells. Further experiments indicated that miR-338-3p mediated 5-FU resistance through down-regulation of mTOR expression. Moreover, inhibition of miR-338-3p in HT29 and HCT116 p53 -/- cells increased their sensitivity to 5-FU treatment. Furthermore, we detected autophagy changes in our experiment because mTOR was known prominently regulating autophagy and the competition between autophagy and apoptosis in response to 5-FU was a mechanism influencing 5-FU sensitivity. Our results reveal a critical and novel role of miR-338-3p in the correlation of 5-FU resistance with p53 status. Moreover, the miR-338-3p inhibitor has the potential to overcome 5-FU resistance in p53 mutant colon cancer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Long Non-Coding RNA (lncRNA) Urothelial Carcinoma-Associated 1 (UCA1) Enhances Tamoxifen Resistance in Breast Cancer Cells via Inhibiting mTOR Signaling Pathway.

    PubMed

    Wu, Chihua; Luo, Jing

    2016-10-21

    BACKGROUND Long non-coding RNA (lncRNA) UCA1 is an oncogene in breast cancer. The purpose of this study was to investigate the role of UCA1 in tamoxifen resistance of estrogen receptor positive breast cancer cells. MATERIAL AND METHODS Tamoxifen sensitive MCF-7 cells were transfected for UCA1 overexpression, while tamoxifen resistant LCC2 and LCC9 cells were transfected with UCA siRNA for UCA1 knockdown. qRT-PCR was performed to analyze UCA1 expression. CCK-8 assay, immunofluorescence staining of cleaved caspase-9, and flow cytometric analysis of Annexin V/PI staining were used to assess tamoxifen sensitivity. Western blot analysis was performed to detect p-AKT and p-mTOR expression. RESULTS LncRNA UCA1 was significantly upregulated in tamoxifen resistant breast cancer cells compared to tamoxifen sensitive cells. LCC2 and LCC9 cells transfected with UCA1 siRNA had significantly higher ratio of apoptosis after tamoxifen treatment. UCA1 siRNA significantly decreased the protein levels of p-AKT and p-mTOR in LCC2 and LCC9 cells. Enforced UCA1 expression substantially reduced tamoxifen induced apoptosis in MCF-7 cells, while rapamycin treatment abrogated the protective effect of UCA1. CONCLUSIONS UCA1 upregulation was associated with tamoxifen resistance in breast cancer. Mechanistically, UCA1 confers tamoxifen resistance to breast cancer cells partly via activating the mTOR signaling pathway.

  15. The usefulness of three-dimensional cell culture in induction of cancer stem cells from esophageal squamous cell carcinoma cell lines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fujiwara, Daisuke; Kato, Kazunori, E-mail: kzkatou@juntendo.ac.jp; Department of Atopy Research Center, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421

    2013-05-17

    Highlights: •Spheroids were created from esophageal carcinoma cells using NanoCulture® Plates. •The proportion of strongly ALDH-positive cells increased in 3-D culture. •Expression of cancer stem cell-related genes was enhanced in 3-D culture. •CA-9 expression was enhanced, suggesting hypoxia had been induced in 3-D culture. •Drug resistance was increased. 3-D culture is useful for inducing cancer stem cells. -- Abstract: In recent years, research on resistance to chemotherapy and radiotherapy in cancer treatment has come under the spotlight, and researchers have also begun investigating the relationship between resistance and cancer stem cells. Cancer stem cells are assumed to be present inmore » esophageal cancer, but experimental methods for identification and culture of these cells have not yet been established. To solve this problem, we created spheroids using a NanoCulture® Plate (NCP) for 3-dimensional (3-D) cell culture, which was designed as a means for experimentally reproducing the 3-D structures found in the body. We investigated the potential for induction of cancer stem cells from esophageal cancer cells. Using flow cytometry we analyzed the expression of surface antigen markers CD44, CD133, CD338 (ABCG2), CD318 (CDCP1), and CD326 (EpCAM), which are known cancer stem cell markers. None of these surface antigen markers showed enhanced expression in 3-D cultured cells. We then analyzed aldehyde dehydrogenase (ALDH) enzymatic activity using the ALDEFLUOR reagent, which can identify immature cells such as stem cells and precursor cells. 3-D-cultured cells were strongly positive for ALDH enzyme activity. We also analyzed the expression of the stem cell-related genes Sox-2, Nanog, Oct3/4, and Lin28 using RT-PCR. Expression of Sox-2, Nanog, and Lin28 was enhanced. Analysis of expression of the hypoxic surface antigen marker carbonic anhydrase-9 (CA-9), which is an indicator of cancer stem cell induction and maintenance, revealed that CA-9

  16. H19 mediates methotrexate resistance in colorectal cancer through activating Wnt/β-catenin pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Ke-feng; Liang, Wei-Cheng; Feng, Lu

    Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. As one of the earliest cytotoxic drugs, methotrexate (MTX) serves as an anti-metabolite and anti-folate chemotherapy for various cancers. Unfortunately, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the therapeutic efficacy of MTX in clinics. Long noncoding RNAs (lncRNAs) have gained widespread attention in recent years. More and more emerging evidences have demonstrated that they play important regulatory roles in various biological activities and disease progression including drug resistance. In the present study, amore » MTX-resistant colorectal cell line HT-29 (HT-29-R) was developed, which displayed the active proliferation and shortened cell cycle. LncRNA H19 was found to be significantly upregulated in this resistant cell line. Further investigation showed that H19 knockdown sensitized the MTX resistance in HT-29-R cells while its overexpression improved the MTX resistance in the parental cells, suggesting that H19 mediate MTX resistance. The Wnt/β-catenin signaling was activated in HT-29-R cells, and H19 knockdown suppressed this signaling in the parental cells. In conclusion, H19 mediated MTX resistance via activating Wnt/β-catenin signaling, which help to develop H19 as a promising therapeutic target for MTX resistant CRC. - Highlights: • A methotrexate (MTX) -resistant colorectal cancer cell line HT-29 (HT-29-R) has been developed. • H19 was upregulated in HT-29-R cells. • H19 mediated MTX resistance in colorectal cancer (CRC). • Wnt/β-catenin pathway was involved in the H19-mediated MTX resistance in CRC cells.« less

  17. Harnessing Drug Resistance: Using ABC Transporter Proteins To Target Cancer Cells

    PubMed Central

    Leitner, Heather M.; Kachadourian, Remy; Day, Brian J.

    2007-01-01

    The ATP-binding cassette (ABC) class of proteins is one of the most functionally diverse transporter families found in biological systems. Although the abundance of ABC proteins varies between species, they are highly conserved in sequence and often demonstrate similar functions across prokaryotic and eukaryotic organisms. Beginning with a brief summary of the events leading to our present day knowledge of ABC transporters, the purpose of this review is to discuss the potential for utilizing ABC transporters as a means for cellular glutathione (GSH) modulation. GSH is one of the most abundant thiol antioxidants in cells. It is involved in cellular division, protein and DNA synthesis, maintenance of cellular redox status and xenobiotic metabolism. Cellular GSH levels are often altered in many disease states including cancer. Over the past two decades there has been considerable emphasis on methods to sensitize cancer cells to chemotherapeutics and ionization radiation therapy by GSH depletion. We contend that ABC transporters, particularly multi-drug resistant proteins (MRPs), may be used as therapeutic targets for applications aimed at modulation of GSH levels. This review will emphasize MRP-mediated modulation of intracellular GSH levels as a potential alternative and adjunctive approach for cancer therapy. PMID:17585883

  18. Wnt5a Increases Properties of Lung Cancer Stem Cells and Resistance to Cisplatin through Activation of Wnt5a/PKC Signaling Pathway

    PubMed Central

    Yang, Jiali; Zhang, Kangjian; Wu, Jing; Shi, Juan; Xue, Jing; Li, Jing; Zhu, Yongzhao; Wei, Jun

    2016-01-01

    The development of chemoresistance to cisplatin regimens causes a poor prognosis in patients with advanced NSCLC. The role of noncanonical Wnt signaling in the regulation of properties of lung cancer stem cells and chemoresistance was interrogated, by accessing capacities of cell proliferation, migration, invasion, and clonogenicity as well as the apoptosis in A549 cell lines and cisplatin-resistant A549 cells treated with Wnt5a conditional medium or protein kinase C (PKC) inhibitor GF109203X. Results showed that the noncanonical Wnt signaling ligand, Wnt5a, could promote the proliferation, migration, invasion, and colony formation in A549 lung adenocarcinoma cells and cisplatin-resistant A549/DDP cells and increase the fraction of ALDH-positive cell in A549/DDP cells. An exposure of cells to Wnt5a led to a significant reduction of A549/DDP cell apoptosis but not A549 cells. An addition of GF109203X could both strikingly increase the baseline apoptosis and resensitize the Wnt5a-inhibited cell apoptosis. Interestingly, an inhibition of Wnt/PKC signaling pathway could reduce properties of lung cancer stem cells, promote cell apoptosis, and resensitize cisplatin-resistant cells to cisplatin via a caspase/AIF-dependent pathway. These data thus suggested that the Wnt5a could promote lung cancer cell mobility and cisplatin-resistance through a Wnt/PKC signaling pathway and a blockage of this signaling may be an alternative therapeutic strategy for NSCLC patients with resistance to chemotherapies. PMID:27895670

  19. Activation of HER family signaling as a mechanism of acquired resistance to ALK inhibitors in EML4-ALK-positive non-small cell lung cancer.

    PubMed

    Tanizaki, Junko; Okamoto, Isamu; Okabe, Takafumi; Sakai, Kazuko; Tanaka, Kaoru; Hayashi, Hidetoshi; Kaneda, Hiroyasu; Takezawa, Ken; Kuwata, Kiyoko; Yamaguchi, Haruka; Hatashita, Erina; Nishio, Kazuto; Nakagawa, Kazuhiko

    2012-11-15

    Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKI) such as crizotinib show marked efficacy in patients with non-small cell lung cancer positive for the echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion protein. However, acquired resistance to these agents has already been described in treated patients, and the mechanisms of such resistance remain largely unknown. We established lines of EML4-ALK-positive H3122 lung cancer cells that are resistant to the ALK inhibitor TAE684 (H3122/TR cells) and investigated their resistance mechanism with the use of immunoblot analysis, ELISA, reverse transcription and real-time PCR analysis, and an annexin V binding assay. We isolated EML4-ALK-positive lung cancer cells (K-3) from a patient who developed resistance to crizotinib and investigated their characteristics. The expression of EML4-ALK was reduced at the transcriptional level, whereas phosphorylation of epidermal growth factor receptor (EGFR), HER2, and HER3 was upregulated, in H3122/TR cells compared with those in H3122 cells. This activation of HER family proteins was accompanied by increased secretion of EGF. Treatment with an EGFR-TKI induced apoptosis in H3122/TR cells, but not in H3122 cells. The TAE684-induced inhibition of extracellular signal-regulated kinase (ERK) and STAT3 phosphorylation observed in parental cells was prevented by exposure of these cells to exogenous EGF, resulting in a reduced sensitivity of cell growth to TAE684. K-3 cells also manifested HER family activation accompanied by increased EGF secretion. EGF-mediated activation of HER family signaling is associated with ALK-TKI resistance in lung cancer positive for EML4-ALK. ©2012 AACR.

  20. JAK1/STAT3 Activation through a Proinflammatory Cytokine Pathway Leads to Resistance to Molecularly Targeted Therapy in Non-Small Cell Lung Cancer.

    PubMed

    Shien, Kazuhiko; Papadimitrakopoulou, Vassiliki A; Ruder, Dennis; Behrens, Carmen; Shen, Li; Kalhor, Neda; Song, Juhee; Lee, J Jack; Wang, Jing; Tang, Ximing; Herbst, Roy S; Toyooka, Shinichi; Girard, Luc; Minna, John D; Kurie, Jonathan M; Wistuba, Ignacio I; Izzo, Julie G

    2017-10-01

    Molecularly targeted drugs have yielded significant therapeutic advances in oncogene-driven non-small cell lung cancer (NSCLC), but a majority of patients eventually develop acquired resistance. Recently, the relation between proinflammatory cytokine IL6 and resistance to targeted drugs has been reported. We investigated the functional contribution of IL6 and the other members of IL6 family proinflammatory cytokine pathway to resistance to targeted drugs in NSCLC cells. In addition, we examined the production of these cytokines by cancer cells and cancer-associated fibroblasts (CAF). We also analyzed the prognostic significance of these molecule expressions in clinical NSCLC samples. In NSCLC cells with acquired resistance to targeted drugs, we observed activation of the IL6-cytokine pathway and STAT3 along with epithelial-to-mesenchymal transition (EMT) features. In particular, IL6 family cytokine oncostatin-M (OSM) induced a switch to the EMT phenotype and protected cells from targeted drug-induced apoptosis in OSM receptors (OSMRs)/JAK1/STAT3-dependent manner. The cross-talk between NSCLC cells and CAFs also preferentially activated the OSM/STAT3 pathway via a paracrine mechanism and decreased sensitivity to targeted drugs. The selective JAK1 inhibitor filgotinib effectively suppressed STAT3 activation and OSMR expression, and cotargeting inhibition of the oncogenic pathway and JAK1 reversed resistance to targeted drugs. In the analysis of clinical samples, OSMR gene expression appeared to be associated with worse prognosis in patients with surgically resected lung adenocarcinoma. Our data suggest that the OSMRs/JAK1/STAT3 axis contributes to resistance to targeted drugs in oncogene-driven NSCLC cells, implying that this pathway could be a therapeutic target. Mol Cancer Ther; 16(10); 2234-45. ©2017 AACR . ©2017 American Association for Cancer Research.

  1. YC-1 induces G0/G1 phase arrest and mitochondria-dependent apoptosis in cisplatin-resistant human oral cancer CAR cells.

    PubMed

    Lee, Miau-Rong; Lin, Chingju; Lu, Chi-Cheng; Kuo, Sheng-Chu; Tsao, Je-Wei; Juan, Yu-Ning; Chiu, Hong-Yi; Lee, Fang-Yu; Yang, Jai-Sing; Tsai, Fuu-Jen

    2017-06-01

    Oral cancer is a serious and fatal disease. Cisplatin is the first line of chemotherapeutic agent for oral cancer therapy. However, the development of drug resistance and severe side effects cause tremendous problems clinically. In this study, we investigated the pharmacologic mechanisms of YC-1 on cisplatin-resistant human oral cancer cell line, CAR. Our results indicated that YC-1 induced a concentration-dependent and time-dependent decrease in viability of CAR cells analyzed by MTT assay. Real-time image analysis of CAR cells by IncuCyte™ Kinetic Live Cell Imaging System demonstrated that YC-1 inhibited cell proliferation and reduced cell confluence in a time-dependent manner. Results from flow cytometric analysis revealed that YC-1 promoted G 0 /G 1 phase arrest and provoked apoptosis in CAR cells. The effects of cell cycle arrest by YC-1 were further supported by up-regulation of p21 and down-regulation of cyclin A, D, E and CDK2 protein levels. TUNEL staining showed that YC-1 caused DNA fragmentation, a late stage feature of apoptosis. In addition, YC-1 increased the activities of caspase-9 and caspase-3, disrupted the mitochondrial membrane potential (AYm) and stimulated ROS production in CAR cells. The protein levels of cytochrome c, Bax and Bak were elevated while Bcl-2 protein expression was attenuated in YC-1-treated CAR cells. In summary, YC-1 suppressed the viability of cisplatin-resistant CAR cells through inhibiting cell proliferation, arresting cell cycle at G 0 /G 1 phase and triggering mitochondria-mediated apoptosis. Our results provide evidences to support the potentially therapeutic application of YC-1 on fighting against drug resistant oral cancer in the future. © Author(s) 2017. This article is published with open access by China Medical University.

  2. Exosomes in development, metastasis and drug resistance of breast cancer.

    PubMed

    Yu, Dan-dan; Wu, Ying; Shen, Hong-yu; Lv, Meng-meng; Chen, Wei-xian; Zhang, Xiao-hui; Zhong, Shan-liang; Tang, Jin-hai; Zhao, Jian-hua

    2015-08-01

    Transport through the cell membrane can be divided into active, passive and vesicular types (exosomes). Exosomes are nano-sized vesicles released by a variety of cells. Emerging evidence shows that exosomes play a critical role in cancers. Exosomes mediate communication between stroma and cancer cells through the transfer of nucleic acid and proteins. It is demonstrated that the contents and the quantity of exosomes will change after occurrence of cancers. Over the last decade, growing attention has been paid to the role of exosomes in the development of breast cancer, the most life-threatening cancer in women. Breast cancer could induce salivary glands to secret specific exosomes, which could be used as biomarkers in the diagnosis of early breast cancer. Exosome-delivered nucleic acid and proteins partly facilitate the tumorigenesis, metastasis and resistance of breast cancer. Exosomes could also transmit anti-cancer drugs outside breast cancer cells, therefore leading to drug resistance. However, exosomes are effective tools for transportation of anti-cancer drugs with lower immunogenicity and toxicity. This is a promising way to establish a drug delivery system. © 2015 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  3. PLGA nanoparticles codeliver paclitaxel and Stat3 siRNA to overcome cellular resistance in lung cancer cells

    PubMed Central

    Su, Wen-Pin; Cheng, Fong-Yu; Shieh, Dar-Bin; Yeh, Chen-Sheng; Su, Wu-Chou

    2012-01-01

    Background: Effective cancer chemotherapy remains an important issue in cancer treatment, and signal transducer and activator of transcription-3 (Stat3) activation leads to cellular resistance of anticancer agents. Polymers are ideal vectors to carry both chemotherapeutics and small interfering ribonucleic acid (siRNA) to enhance antitumor efficacy. In this paper, poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with paclitaxel and Stat3 siRNA were successfully synthesized, and their applications in cancer cells were investigated. Methods: Firstly, paclitaxel was enclosed by PLGA nanoparticles through solvent evaporation. They were then coated with cationic polyethylenimine polymer (PLGA-PEI-TAX), enabling it to carry Stat3 siRNA on its surface through electrostatic interactions (PLGA-PEI-TAX-S3SI). The size, zeta potential, deliver efficacy, and release profile of the PLGA nanocomplexes were characterized in vitro. The cellular uptake, intracellular nanoparticle trajectory, and subsequent cellular events were evaluated after treatment with various PLGA nanocomplexes in human lung cancer A549 cells and A549-derived paclitaxel-resistant A549/T12 cell lines with α-tubulin mutation. Results: A549 and A549/T12 cells contain constitutively activated Stat3, and silencing Stat3 by siRNA made both cancer cells more sensitive to paclitaxel. Therefore, PLGA-PEI-TAX-S3SI was synthesized to test its therapeutic role in A549 and A549/T12 cells. Transmission electron microscopy showed the size of PLGA-PEI-TAX-S3SI to be around 250 nm. PLGA-PEI nanoparticles were nontoxic. PLGA-PEI-TAX was taken up by A549 and A549/T12 cells more than free paclitaxel, and they induced more condensed microtubule bundles and had higher cytotoxicity in these cancer cells. Moreover, the yellowish fluorescence observed in the cytoplasm of the cancer cells indicates that the PLGA-PEI nanoparticles were still simultaneously delivering Oregon Green paclitaxel and cyanine-5-labeled Stat3 siRNA 3

  4. Photochemical internalisation of chemotherapy potentiates killing of multidrug-resistant breast and bladder cancer cells

    PubMed Central

    Adigbli, D K; Wilson, D G G; Farooqui, N; Sousi, E; Risley, P; Taylor, I; MacRobert, A J; Loizidou, M

    2007-01-01

    Multidrug resistance (MDR) is the major confounding factor in adjuvant solid tumour chemotherapy. Increasing intracellular amounts of chemotherapeutics to circumvent MDR may be achieved by a novel delivery method, photochemical internalisation (PCI). PCI consists of the co-administration of drug and photosensitiser; upon light activation the latter induces intracellular release of organelle-bound drug. We investigated whether co-administration of hypericin (photosensitiser) with mitoxantrone (MTZ, chemotherapeutic) plus illumination potentiates cytotoxicity in MDR cancer cells. We mapped the extent of intracellular co-localisation of drug/photosensitiser. We determined whether PCI altered drug-excreting efflux pump P-glycoprotein (Pgp) expression or function in MDR cells. Bladder and breast cancer cells and their Pgp-overexpressing MDR subclones (MGHU1, MGHU1/R, MCF-7, MCF-7/R) were given hypericin/MTZ combinations, with/without blue-light illumination. Pilot experiments determined appropriate sublethal doses for each. Viability was determined by the 3-[4,5-dimethylthiazolyl]-2,5-diphenyltetrazolium bromide assay. Intracellular localisation was mapped by confocal microscopy. Pgp expression was detected by immunofluorescence and Pgp function investigated by Rhodamine123 efflux on confocal microscopy. MTZ alone (0.1–0.2 μg ml−1) killed up to 89% of drug-sensitive cells; MDR cells exhibited less cytotoxicity (6–28%). Hypericin (0.1–0.2 μM) effects were similar for all cells; light illumination caused none or minimal toxicity. In combination, MTZ /hypericin plus illumination, potentiated MDR cell killing, vs hypericin or MTZ alone. (MGHU1/R: 38.65 and 36.63% increase, P<0.05; MCF-7/R: 80.2 and 46.1% increase, P<0.001). Illumination of combined MTZ/hypericin increased killing by 28.15% (P<0.05 MGHU1/R) compared to dark controls. Intracytoplasmic vesicular co-localisation of MTZ/hypericin was evident before illumination and at serial times post

  5. MCAK and Stathmin Upregulation in Breast Cancer Cells: Etiology and Response to Pharmacologic Reagents

    DTIC Science & Technology

    2004-07-01

    and the affinity for MTs are cells (Maney et al., 2001). Finally, the neck domain is not molecular refinements that adapt motile kinesins for specific...1,500 nM taxol-stabilized MTs in 80 p.I of BRB80 (80 mM molecular motor. Nature. 389:93-96. Pipes, pH 6.8, 1 mM EGTA, and 1 mM MgCI2), 12.5 p.M taxol, 1...summarizes the biological functions and examines the possible molecular the r egio immeiatel iete mt core mechanisms of Kin C and Kin I unconventional

  6. Plasmonic nanobubble-enhanced endosomal escape processes for selective and guided intracellular delivery of chemotherapy to drug-resistant cancer cells.

    PubMed

    Lukianova-Hleb, Ekaterina Y; Belyanin, Andrey; Kashinath, Shruti; Wu, Xiangwei; Lapotko, Dmitri O

    2012-02-01

    Cancer chemotherapies suffer from multi drug resistance, high non-specific toxicity and heterogeneity of tumors. We report a method of plasmonic nanobubble-enhanced endosomal escape (PNBEE) for the selective, fast and guided intracellular delivery of drugs through a self-assembly by cancer cells of separately targeted gold nanoparticles and encapsulated drug (Doxil). The co-localized with Doxil plasmonic nanobubbles optically generated in cancer cells released the drug into the cytoplasm thus increasing the therapeutic efficacy against these drug-resistant cells by 31-fold, reducing drug dose by 20-fold, the treatment time by 3-fold and the non-specific toxicity by 10-fold compared to standard treatment. Thus the PNBEE mechanism provided selective, safe and efficient intracellular drug delivery in heterogeneous environment opening new opportunities for drug therapies. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Triptolide Inhibits the AR Signaling Pathway to Suppress the Proliferation of Enzalutamide Resistant Prostate Cancer Cells.

    PubMed

    Han, Yangyang; Huang, Weiwei; Liu, Jiakuan; Liu, Dandan; Cui, Yangyan; Huang, Ruimin; Yan, Jun; Lei, Ming

    2017-01-01

    Enzalutamide is a second-generation androgen receptor (AR) antagonist for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Unfortunately, AR dysfunction means that resistance to enzalutamide will eventually develop. Thus, novel agents are urgently needed to treat this devastating disease. Triptolide (TPL), a key active compound extracted from the Chinese herb Thunder God Vine ( Tripterygium wilfordii Hook F.), possesses anti-cancer activity in human prostate cancer cells. However, the effects of TPL against CRPC cells and the underlying mechanism of any such effect are unknown. In this study, we found that TPL at low dose inhibits the transactivation activity of both full-length and truncated AR without changing their protein levels. Interestingly, TPL inhibits phosphorylation of AR and its CRPC-associated variant AR-V7 at Ser515 through XPB/CDK7. As a result, TPL suppresses the binding of AR to promoter regions in AR target genes along with reduced TFIIH and RNA Pol II recruitment. Moreover, TPL at low dose reduces the viability of prostate cancer cells expressing AR or AR-Vs. Low-dose TPL also shows a synergistic effect with enzalutamide to inhibit CRPC cell survival in vitro , and enhances the anti-cancer effect of enzalutamide on CRPC xenografts with minimal side effects. Taken together, our data demonstrate that TPL targets the transactivation activity of both full-length and truncated ARs. Our results also suggest that TPL is a potential drug for CRPC, and can be used in combination with enzalutamide to treat CRPC.

  8. Triptolide Inhibits the AR Signaling Pathway to Suppress the Proliferation of Enzalutamide Resistant Prostate Cancer Cells

    PubMed Central

    Han, Yangyang; Huang, Weiwei; Liu, Jiakuan; Liu, Dandan; Cui, Yangyan; Huang, Ruimin; Yan, Jun; Lei, Ming

    2017-01-01

    Enzalutamide is a second-generation androgen receptor (AR) antagonist for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Unfortunately, AR dysfunction means that resistance to enzalutamide will eventually develop. Thus, novel agents are urgently needed to treat this devastating disease. Triptolide (TPL), a key active compound extracted from the Chinese herb Thunder God Vine (Tripterygium wilfordii Hook F.), possesses anti-cancer activity in human prostate cancer cells. However, the effects of TPL against CRPC cells and the underlying mechanism of any such effect are unknown. In this study, we found that TPL at low dose inhibits the transactivation activity of both full-length and truncated AR without changing their protein levels. Interestingly, TPL inhibits phosphorylation of AR and its CRPC-associated variant AR-V7 at Ser515 through XPB/CDK7. As a result, TPL suppresses the binding of AR to promoter regions in AR target genes along with reduced TFIIH and RNA Pol II recruitment. Moreover, TPL at low dose reduces the viability of prostate cancer cells expressing AR or AR-Vs. Low-dose TPL also shows a synergistic effect with enzalutamide to inhibit CRPC cell survival in vitro, and enhances the anti-cancer effect of enzalutamide on CRPC xenografts with minimal side effects. Taken together, our data demonstrate that TPL targets the transactivation activity of both full-length and truncated ARs. Our results also suggest that TPL is a potential drug for CRPC, and can be used in combination with enzalutamide to treat CRPC. PMID:28638477

  9. Integrative molecular network analysis identifies emergent enzalutamide resistance mechanisms in prostate cancer

    PubMed Central

    King, Carly J.; Woodward, Josha; Schwartzman, Jacob; Coleman, Daniel J.; Lisac, Robert; Wang, Nicholas J.; Van Hook, Kathryn; Gao, Lina; Urrutia, Joshua; Dane, Mark A.; Heiser, Laura M.; Alumkal, Joshi J.

    2017-01-01

    Recent work demonstrates that castration-resistant prostate cancer (CRPC) tumors harbor countless genomic aberrations that control many hallmarks of cancer. While some specific mutations in CRPC may be actionable, many others are not. We hypothesized that genomic aberrations in cancer may operate in concert to promote drug resistance and tumor progression, and that organization of these genomic aberrations into therapeutically targetable pathways may improve our ability to treat CRPC. To identify the molecular underpinnings of enzalutamide-resistant CRPC, we performed transcriptional and copy number profiling studies using paired enzalutamide-sensitive and resistant LNCaP prostate cancer cell lines. Gene networks associated with enzalutamide resistance were revealed by performing an integrative genomic analysis with the PAthway Representation and Analysis by Direct Reference on Graphical Models (PARADIGM) tool. Amongst the pathways enriched in the enzalutamide-resistant cells were those associated with MEK, EGFR, RAS, and NFKB. Functional validation studies of 64 genes identified 10 candidate genes whose suppression led to greater effects on cell viability in enzalutamide-resistant cells as compared to sensitive parental cells. Examination of a patient cohort demonstrated that several of our functionally-validated gene hits are deregulated in metastatic CRPC tumor samples, suggesting that they may be clinically relevant therapeutic targets for patients with enzalutamide-resistant CRPC. Altogether, our approach demonstrates the potential of integrative genomic analyses to clarify determinants of drug resistance and rational co-targeting strategies to overcome resistance. PMID:29340039

  10. CD44-engineered mesoporous silica nanoparticles for overcoming multidrug resistance in breast cancer

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Liu, Ying; Wang, Shouju; Shi, Donghong; Zhou, Xianguang; Wang, Chunyan; Wu, Jiang; Zeng, Zhiyong; Li, Yanjun; Sun, Jing; Wang, Jiandong; Zhang, Longjiang; Teng, Zhaogang; Lu, Guangming

    2015-03-01

    Multidrug resistance is a major impediment for the successful chemotherapy in breast cancer. CD44 is over-expressed in multidrug resistant human breast cancer cells. CD44 monoclonal antibody exhibits anticancer potential by inhibiting proliferation and regulating P-glycoprotein-mediated drug efflux activity in multidrug resistant cells. Thereby, CD44 monoclonal antibody in combination with chemotherapeutic drug might be result in enhancing chemosensitivity and overcoming multidrug resistance. The purpose of this study is to investigate the effects of the CD44 monoclonal antibody functionalized mesoporous silica nanoparticles containing doxorubicin on human breast resistant cancer MCF-7 cells. The data showed that CD44-modified mesoporous silica nanoparticles increased cytotoxicity and enhanced the downregulation of P-glycoprotein in comparison to CD44 antibody. Moreover, CD44-engineered mesoporous silica nanoparticles provided active target, which promoted more cellular uptake of DOX in the resistant cells and more retention of DOX in tumor tissues than unengineered counterpart. Animal studies of the resistant breast cancer xenografts demonstrated that CD44-engineered drug delivery system remarkably induced apoptosis and inhibited the tumor growth. Our results indicated that the CD44-engineered mesoporous silica nanoparticle-based drug delivery system offers an effective approach to overcome multidrug resistance in human breast cancer.

  11. Basal expression of insulin-like growth factor 1 receptor determines intrinsic resistance of cancer cells to a phosphatidylinositol 3-kinase inhibitor ZSTK474

    PubMed Central

    Isoyama, Sho; Kajiwara, Gensei; Tamaki, Naomi; Okamura, Mutsumi; Yoshimi, Hisashi; Nakamura, Naoki; Kawamura, Kento; Nishimura, Yumiko; Namatame, Nachi; Yamori, Takao; Dan, Shingo

    2015-01-01

    Drug resistance often critically limits the efficacy of molecular targeted drugs. Although pharmacological inhibition of phosphatidylinositol 3-kinase (PI3K) is an attractive therapeutic strategy for cancer therapy, molecular determinants for efficacy of PI3K inhibitors (PI3Kis) remain unclear. We previously identified that overexpression of insulin-like growth factor 1 receptor (IGF1R) contributed to the development of drug resistance after long-term exposure to PI3Kis. In this study, we examined the involvement of basal IGF1R expression in intrinsic resistance of drug-naïve cancer cells to PI3Kis and whether inhibition of IGF1R overcomes the resistance. We found that cancer cells highly expressing IGF1R showed resistance to dephosphorylation of Akt and subsequent antitumor effect by ZSTK474 treatment. Knockdown of IGF1R by siRNAs facilitated the dephosphorylation and enhanced the drug efficacy. These cells expressed tyrosine-phosphorylated insulin receptor substrate 1 at high levels, which was dependent on basal IGF1R expression. In these cells, the efficacy of ZSTK474 in vitro and in vivo was improved by its combination with the IGF1R inhibitor OSI-906. Finally, we found a significant correlation between the basal expression level of IGF1R and the inefficacy of ZSTK474 in an in vivo human cancer panel, as well as in vitro. These results suggest that basal IGF1R expression affects intrinsic resistance of cancer cells to ZSTK474, and IGF1R is a promising target to improve the therapeutic efficacy. The current results provide evidence of combination therapy of PI3Kis with IGF1R inhibitors for treating IGF1R-positive human cancers. PMID:25483727

  12. Androgen Receptor Antagonism By Divalent Ethisterone Conjugates In Castrate-Resistant Prostate Cancer Cells

    PubMed Central

    Levine, Paul M.; Lee, Eugine; Greenfield, Alex; Bonneau, Richard; Logan, Susan K.; Garabedian, Michael J.; Kirshenbaum, Kent

    2013-01-01

    Sustained treatment of prostate cancer with Androgen Receptor (AR) antagonists can evoke drug resistance, leading to castrate-resistant disease. Elevated activity of the AR is often associated with this highly aggressive disease state. Therefore, new therapeutic regimens that target and modulate AR activity could prove beneficial. We previously introduced a versatile chemical platform to generate competitive and non-competitive multivalent peptoid oligomer conjugates that modulate AR activity. In particular, we identified a linear and a cyclic divalent ethisterone conjugate that exhibit potent anti-proliferative properties in LNCaP-abl cells, a model of castrate-resistant prostate cancer. Here, we characterize the mechanism of action of these compounds utilizing confocal microscopy, time-resolved fluorescence resonance energy transfer, chromatin immunoprecipitation, flow cytometry, and microarray analysis. The linear conjugate competitively blocks AR action by inhibiting DNA binding. In addition, the linear conjugate does not promote AR nuclear localization or co-activator binding. In contrast, the cyclic conjugate promotes AR nuclear localization and induces cell-cycle arrest, despite its inability to compete against endogenous ligand for binding to AR in vitro. Genome-wide expression analysis reveals that gene transcripts are differentially affected by treatment with the linear or cyclic conjugate. Although the divalent ethisterone conjugates share extensive chemical similarities, we illustrate that they can antagonize the AR via distinct mechanisms of action, establishing new therapeutic strategies for potential applications in AR pharmacology. PMID:22871957

  13. NHERF1 Enhances Cisplatin Sensitivity in Human Cervical Cancer Cells.

    PubMed

    Tao, Tao; Yang, Xiaomei; Qin, Qiong; Shi, Wen; Wang, Qiqi; Yang, Ying; He, Junqi

    2017-01-12

    Cervical cancer is one of the most common female malignancies, and cisplatin-based chemotherapy is routinely utilized in locally advanced cervical cancer patients. However, resistance has been the major limitation. In this study, we found that Na⁺/H⁺ Exchanger Regulatory Factor 1 (NHERF1) was downregulated in cisplatin-resistant cells. Analysis based on a cervical cancer dataset from The Cancer Genome Atlas (TCGA) showed association of NHERF1 expression with disease-free survival of patients received cisplatin treatment. NHERF1 overexpression inhibited proliferation and enhanced apoptosis in cisplatin-resistant HeLa cells, whereas NHERF1 knockdown had inverse effects. While parental HeLa cells were more resistant to cisplatin after NHERF1 knockdown, NHERF1 overexpression in CaSki cells promoted cisplatin sensitivity. Overexpression and knockdown studies also showed that NHERF1 significantly inhibited AKT and extracellular signal-regulated kinase (ERK) signaling pathways in cisplatin-resistant cells. Taken together, our results provide the first evidence that NHERF1 can sensitize cisplatin-refractory cervical cancer cells. This study may help to increase understanding of the molecular mechanisms underlying cisplatin resistance in tumors.

  14. NHERF1 Enhances Cisplatin Sensitivity in Human Cervical Cancer Cells

    PubMed Central

    Tao, Tao; Yang, Xiaomei; Qin, Qiong; Shi, Wen; Wang, Qiqi; Yang, Ying; He, Junqi

    2017-01-01

    Cervical cancer is one of the most common female malignancies, and cisplatin-based chemotherapy is routinely utilized in locally advanced cervical cancer patients. However, resistance has been the major limitation. In this study, we found that Na+/H+ Exchanger Regulatory Factor 1 (NHERF1) was downregulated in cisplatin-resistant cells. Analysis based on a cervical cancer dataset from The Cancer Genome Atlas (TCGA) showed association of NHERF1 expression with disease-free survival of patients received cisplatin treatment. NHERF1 overexpression inhibited proliferation and enhanced apoptosis in cisplatin-resistant HeLa cells, whereas NHERF1 knockdown had inverse effects. While parental HeLa cells were more resistant to cisplatin after NHERF1 knockdown, NHERF1 overexpression in CaSki cells promoted cisplatin sensitivity. Overexpression and knockdown studies also showed that NHERF1 significantly inhibited AKT and extracellular signal–regulated kinase (ERK) signaling pathways in cisplatin-resistant cells. Taken together, our results provide the first evidence that NHERF1 can sensitize cisplatin-refractory cervical cancer cells. This study may help to increase understanding of the molecular mechanisms underlying cisplatin resistance in tumors. PMID:28085111

  15. Pancreatic cancer cells express CD44 variant 9 and multidrug resistance protein 1 during mitosis.

    PubMed

    Kiuchi, Shizuka; Ikeshita, Shunji; Miyatake, Yukiko; Kasahara, Masanori

    2015-02-01

    Pancreatic cancer is one of the most lethal cancers with high metastatic potential and strong chemoresistance. Its intractable natures are attributed to high robustness in tumor cells for their survival. We demonstrate here that pancreatic cancer cells (PCCs) with an epithelial phenotype upregulate cell surface expression of CD44 variant 9 (CD44v9), an important cancer stem cell marker, during the mitotic phases of the cell cycle. Of five human CD44(+) PCC lines examined, three cell lines, PCI-24, PCI-43 and PCI-55, expressed E-cadherin and CD44 variants, suggesting that they have an epithelial phenotype. By contrast, PANC-1 and MIA PaCa-2 cells expressed vimentin and ZEB1, suggesting that they have a mesenchymal phenotype. PCCs with an epithelial phenotype upregulated cell surface expression of CD44v9 in prophase, metaphase, anaphase and telophase and downregulated CD44v9 expression in late-telophase, cytokinesis and interphase. Sorted CD44v9-negative PCI-55 cells resumed CD44v9 expression when they re-entered the mitotic stage. Interestingly, CD44v9(bright) mitotic cells expressed multidrug resistance protein 1 (MDR1) intracellularly. Upregulated expression of CD44v9 and MDR1 might contribute to the intractable nature of PCCs with high proliferative activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Isolation and characterization of an IGROV-1 human ovarian cancer cell line made resistant to Ecteinascidin-743 (ET-743)

    PubMed Central

    Erba, E; Bergamaschi, D; Bassano, L; Ronzoni, S; Liberti, G Di; Muradore, I; Vignati, S; Faircloth, G; Jimeno, J; D'Incalci, M

    2000-01-01

    By exposing Igrov-1 human ovarian cancer cells to increasing concentrations of Ecteinascidin-743 (ET-743), either for a short or prolonged time, we obtained sublines resistant to ET-743 which overexpress Pgp. The most resistant clone (Igrov-1/25 ET) was evaluated for biological and pharmacological characterizations. The increased Pgp levels of Igrov-1/25 ET were not due to amplification of the mdr-1 gene but to increased mRNA levels. No increase in other multidrug resistance-related proteins such as MRP or LRP was observed in Igrov-1/25 ET. The IC50values of ET-743 against Igrov-1/25 ET was approximately 50 times higher than the parental cell line. Resistance was not reversed while maintaining the cell line in drug-free medium for at least 24 months. Igrov-1/25 ET was cross-resistant to Doxorubicin and VP16 while it was equally sensitive to L-PAM, MNNG, CPT and only marginally less sensitive to Cis-DDP and Oxaliplatin compared to the parental cell line. Igrov-1/25 ET exposed to Doxorubicin retained this drug much less, mainly because of a more efficient drug efflux. The cyclosporine analogue SDZ PSC-833 reversed the resistance of Igrov-1/25 ET to ET-743, without any enhancement of the drug activity against the parental Igrov-1 cell line. Igrov-1/25 ET exhibits typical features of cell lines overexpressing the mdr-1 gene and can be a potentially useful tool in selecting ET-743 non-cross-resistant analogues as well as to investigate methods to counteract resistance to this drug. © 2000 Cancer Research Campaign PMID:10817511

  17. Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

    PubMed Central

    Kuo, Han-Peng; Hsu, Shih-Chung; Li, Jhy-Wei; Tseng, Hsiu-Hsueh; Chuang, Tzu-Chao; Liu, Jah-Yao; Chen, Shih-Jung; Su, Muh-Hwan; Cheng, Yung-Chi; Chou, Wei-Yuan; Kao, Ming-Ching

    2013-01-01

    Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT), one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE) inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin) in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2. PMID:23662119

  18. URI expression in cervical cancer cells is associated with higher invasion capacity and resistance to cisplatin

    PubMed Central

    Gu, Junxia; Liang, Yuting; Qiao, Longwei; Lu, Yaojuan; Hu, Xiaoxia; Luo, Dongwei; Li, Na; Zhang, Leilei; Chen, Yiyang; Du, Jialu; Zheng, Qiping

    2015-01-01

    Cervical cancer is a common and devastating female cancer worldwide. The etiology of cervical cancer has been largely attributed to human papillomavirus (HPV) infection and activation of the P13K/AKT/mTOR (mammalian target of rapamycin) pathway. However, the limited HPV-directed therapy, as well as therapeutic approach targeting P13K/AKT/mTOR pathway, has not yet been established or effective. A deeper understanding of cervical carcinogenesis and finding of novel candidate molecules for cervical cancer therapeutics is largely warranted. The unconventional prefoldin RPB5 interactor (URI or URI1), a known transcription factor involving the TOR signaling pathway, has recently been implicated a role in multiple tumorigenesis. We recently reported significant upregulation of URI in precancerous cervical intra-epithelial neoplasia (CIN) and invasive cervical cancer, suggesting its role in cervical carcinogenesis. However, the effect and underlying mechanism of URI in cervical cancer development have never been elucidated. Here, we aimed to investigate the in vitro effect of URI on cervical cancer using two cervical cancer cell lines CaSki and C33A, which are HPV-positive and HPV-negative respectively. We have shown that forced over-expression of URI in C33A and CaSki cells markedly promoted cell growth, while down-regulation of URI mediated by siRNA inhibited cell proliferation. We have found that URI over-expression enhanced resistance of cervical cancer cells to cisplatin. In contrast, knockdown of URI promoted apoptosis by influencing cell response to cisplatin, supporting URI as an oncogenic protein for cervical cancer cells. We have also shown that URI promoted the migration and invasive capacity of cervical cancer cells by up-regulation of Vimentin, a mesenchymal cell migration marker relating to the epithelial-mesenchymal transition (EMT) program. Our data support an important function of URI in the biological behavior of cervical cancer cells and provide novel

  19. Biotin-targeted Pluronic(®) P123/F127 mixed micelles delivering niclosamide: A repositioning strategy to treat drug-resistant lung cancer cells.

    PubMed

    Russo, Annapina; Pellosi, Diogo Silva; Pagliara, Valentina; Milone, Maria Rita; Pucci, Biagio; Caetano, Wilker; Hioka, Noboru; Budillon, Alfredo; Ungaro, Francesca; Russo, Giulia; Quaglia, Fabiana

    2016-09-10

    With the aim to develop alternative therapeutic tools for the treatment of resistant cancers, here we propose targeted Pluronic(®) P123/F127 mixed micelles (PMM) delivering niclosamide (NCL) as a repositioning strategy to treat multidrug resistant non-small lung cancer cell lines. To build multifunctional PMM for targeting and imaging, Pluronic(®) F127 was conjugated with biotin, while Pluronic(®) P123 was fluorescently tagged with rhodamine B, in both cases at one of the two hydroxyl end groups. This design intended to avoid any interference of rhodamine B on biotin exposition on PMM surface, which is a key fundamental for cell trafficking studies. Biotin-decorated PMM were internalized more efficiently than non-targeted PMM in A549 lung cancer cells, while very low internalization was found in NHI3T3 normal fibroblasts. Biotin-decorated PMM entrapped NCL with good efficiency, displayed sustained drug release in protein-rich media and improved cytotoxicity in A549 cells as compared to free NCL (P<0.01). To go in depth into the actual therapeutic potential of NCL-loaded PMM, a cisplatin-resistant A549 lung cancer cell line (CPr-A549) was developed and its multidrug resistance tested against common chemotherapeutics. Free NCL was able to overcome chemoresistance showing cytotoxic effects in this cell line ascribable to nucleolar stress, which was associated to a significant increase of the ribosomal protein rpL3 and consequent up-regulation of p21. It is noteworthy that biotin-decorated PMM carrying NCL at low doses demonstrated a significantly higher cytotoxicity than free NCL in CPr-A549. These results point at NCL-based regimen with targeted PMM as a possible second-line chemotherapy for lung cancer showing cisplatin or multidrug resistance. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. p110α Inhibition Overcomes Stromal Cell-Mediated Ibrutinib Resistance in Mantle Cell Lymphoma.

    PubMed

    Guan, Jiyu; Huang, Dan; Yakimchuk, Konstantin; Okret, Sam

    2018-05-01

    Acquired resistance to cancer drugs is common, also for modern targeted drugs like the Bruton tyrosine kinase (BTK) inhibitor ibrutinib, a new drug approved for the treatment of the highly aggressive and relapsing mantle cell lymphoma (MCL). The tumor microenvironment often impacts negatively on drug response. Here, we demonstrate that stromal cells protect MCL cells from ibrutinib-induced apoptosis and support MCL cell regrowth after drug removal by impairing ibrutinib-mediated downregulation of PI3K/AKT signaling. Importantly, the stromal cell-mediated ibrutinib resistance was overcome in vitro by inhibiting AKT activity using the PI3K catalytic p110α subunit-specific inhibitor BYL719. This was seen both for MCL cell lines and primary MCL cells. Furthermore, inhibition of p110α activity by BYL719 potentiated the ability of ibrutinib to inhibit MCL tumor growth in vivo in a mouse xenograft model. The stromal cell-mediated ibrutinib resistance was found to be due to a direct interaction with MCL cells and involves the integrin VLA-4, as disrupting stromal cell-MCL cell interaction using a VLA-4 blocking antibody abrogated the ibrutinib resistance. This suggests that combined treatment with ibrutinib and a p110α inhibitor, alternatively by disrupting stromal cell-MCL cell interaction, may be a promising therapeutic strategy to overcome stromal cell-mediated ibrutinib resistance in MCL. Mol Cancer Ther; 17(5); 1090-100. ©2018 AACR . ©2018 American Association for Cancer Research.

  1. Biomimetic RNA-silencing nanocomplexes: overcoming multidrug resistance in cancer cells.

    PubMed

    Wang, Zhongliang; Wang, Zhe; Liu, Dingbin; Yan, Xuefeng; Wang, Fu; Niu, Gang; Yang, Min; Chen, Xiaoyuan

    2014-02-10

    RNA interference (RNAi) is an RNA-dependent gene silencing approach controlled by an RNA-induced silencing complex (RISC). Herein, we present a synthetic RISC-mimic nanocomplex, which can actively cleave its target RNA in a sequence-specific manner. With high enzymatic stability and efficient self-delivery to target cells, the designed nanocomplex can selectively and potently induce gene silencing without cytokine activation. These nanocomplexes, which target multidrug resistance, are not only able to bypass the P-glycoprotein (Pgp) transporter, due to their nano-size effect, but also effectively suppress Pgp expression, thus resulting in successful restoration of drug sensitivity of OVCAR8/ADR cells to Pgp-transportable cytotoxic agents. This nanocomplex approach has the potential for both functional genomics and cancer therapy. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. The role of hERG1 ion channels in epithelial-mesenchymal transition and the capacity of riluzole to reduce cisplatin resistance in colorectal cancer cells.

    PubMed

    Fortunato, Angelo

    2017-08-01

    The transition of cells from the epithelial to the mesenchymal state (EMT) plays an important role in tumor progression. EMT allows cells to acquire mobility, stem-like behavior and resistance to apoptosis and drug treatment. These features turn EMT into a central process in tumor biology. Ion channels are attractive targets for the treatment of cancer since they play critical roles in controlling a wide range of physiological processes that are frequently deregulated in cancer. Here, we investigated the role of ether-a-go-go-related 1 (hERG1) ion channels in the EMT of colorectal cancer cells. We studied the epithelial-mesenchymal profile of different colorectal cancer-derived cell lines and the expression of hERG1 potassium channels in these cell lines using real-time PCR. Next, we knocked down hERG1 expression in HCT116 cells using lentivirus mediated RNA interference and characterized the hERG1 silenced cells in vitro and in vivo. Finally, we investigated the capacity of riluzole, an ion channel-modulating drug used in humans to treat amyotrophic lateral sclerosis, to reduce the resistance of the respective colorectal cancer cells to the chemotherapeutic drug cisplatin. We found that of the colorectal cancer-derived cell lines tested, HCT116 showed the highest mesenchymal profile and a high hERG1 expression. Subsequent hERG1 expression knockdown induced a change in cell morphology, which was accompanied by a reduction in the proliferative and tumorigenic capacities of the cells. Notably, we found that hERG1expression knockdown elicited a reversion of the EMT profile in HCT116 cells with a reacquisition of the epithelial-like profile. We also found that riluzole increased the sensitivity of HCT116 cisplatin-resistant cells to cisplatin. Our data indicate that hERG1 plays a role in the EMT of colorectal cancer cells and that its knockdown reduces the proliferative and tumorigenic capacities of these cells. In addition, we conclude that riluzole may be used in

  3. Estrogen related receptor alpha in castration-resistant prostate cancer cells promotes tumor progression in bone

    PubMed Central

    Delliaux, Carine; Gervais, Manon; Kan, Casina; Benetollo, Claire; Pantano, Francesco; Vargas, Geoffrey; Bouazza, Lamia; Croset, Martine; Bala, Yohann; Leroy, Xavier; Rosol, Thomas J; Rieusset, Jennifer; Bellahcène, Akeila; Castronovo, Vincent; Aubin, Jane E; Clézardin, Philippe; Duterque-Coquillaud, Martine; Bonnelye, Edith

    2016-01-01

    Bone metastases are one of the main complications of prostate cancer and they are incurable. We investigated whether and how estrogen receptor-related receptor alpha (ERRα) is involved in bone tumor progression associated with advanced prostate cancer. By meta-analysis, we first found that ERRα expression is correlated with castration-resistant prostate cancer (CRPC), the hallmark of progressive disease. We then analyzed tumor cell progression and the associated signaling pathways in gain-of-function/loss-of-function CRPC models in vivo and in vitro. Increased levels of ERRα in tumor cells led to rapid tumor progression, with both bone destruction and formation, and direct impacts on osteoclasts and osteoblasts. VEGF-A, WNT5A and TGFβ1 were upregulated by ERRα in tumor cells and all of these factors also significantly and positively correlated with ERRα expression in CRPC patient specimens. Finally, high levels of ERRα in tumor cells stimulated the pro-metastatic factor periostin expression in the stroma, suggesting that ERRα regulates the tumor stromal cell microenvironment to enhance tumor progression. Taken together, our data demonstrate that ERRα is a regulator of CRPC cell progression in bone. Therefore, inhibiting ERRα may constitute a new therapeutic strategy for prostate cancer skeletal-related events. PMID:27776343

  4. TUG1 mediates methotrexate resistance in colorectal cancer via miR-186/CPEB2 axis.

    PubMed

    Li, Changfeng; Gao, Yongjian; Li, Yongchao; Ding, Dayong

    2017-09-16

    Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. Methotrexate (MTX) is one of the earliest cytotoxic drugs and serves as an anti-metabolite and anti-folate chemotherapy for various types of cancer. However, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the efficacy of MTX therapies in clinics. Long non-coding RNAs (lncRNAs) have gained widespread attention in recent years. More and more evidences have shown that lncRNAs play regulatory roles in various biological activities and disease progression including drug resistance in cancer cells. Here, we observed lncRNA TUG1 was associated to the MTX resistant in colorectal cancer cells. Firstly, quantitative analysis indicated that TUG1 was significantly increased in tumors which were resistant to MTX treatment. TUG1 knockdown re-sensitized the MTX resistance in colorectal cancer cells, which were MTX-resistant colorectal cell line. Furthermore, bioinformatics analysis showed that miR-186 could directly bind to TUG1, suggesting TUG1 might worked as a ceRNA to sponge miR-186. Extensively, our study also showed that CPEB2 was the direct target of miR-186 in colorectal cancer cells. Taken together, our study suggests that lncRNA TUG1 mediates MTX resistance in colorectal cancer via miR-186/CPEB2 axis. Copyright © 2017. Published by Elsevier Inc.

  5. Sox2 Is an Androgen Receptor-Repressed Gene That Promotes Castration-Resistant Prostate Cancer

    PubMed Central

    Kregel, Steven; Kiriluk, Kyle J.; Rosen, Alex M.; Cai, Yi; Reyes, Edwin E.; Otto, Kristen B.; Tom, Westin; Paner, Gladell P.; Szmulewitz, Russell Z.; Vander Griend, Donald J.

    2013-01-01

    Despite advances in detection and therapy, castration-resistant prostate cancer continues to be a major clinical problem. The aberrant activity of stem cell pathways, and their regulation by the Androgen Receptor (AR), has the potential to provide insight into novel mechanisms and pathways to prevent and treat advanced, castrate-resistant prostate cancers. To this end, we investigated the role of the embryonic stem cell regulator Sox2 [SRY (sex determining region Y)-box 2] in normal and malignant prostate epithelial cells. In the normal prostate, Sox2 is expressed in a portion of basal epithelial cells. Prostate tumors were either Sox2-positive or Sox2-negative, with the percentage of Sox2-positive tumors increasing with Gleason Score and metastases. In the castration-resistant prostate cancer cell line CWR-R1, endogenous expression of Sox2 was repressed by AR signaling, and AR chromatin-IP shows that AR binds the enhancer element within the Sox2 promoter. Likewise, in normal prostate epithelial cells and human embryonic stem cells, increased AR signaling also decreases Sox2 expression. Resistance to the anti-androgen MDV3100 results in a marked increase in Sox2 expression within three prostate cancer cell lines, and in the castration-sensitive LAPC-4 prostate cancer cell line ectopic expression of Sox2 was sufficient to promote castration-resistant tumor formation. Loss of Sox2 expression in the castration-resistant CWR-R1 prostate cancer cell line inhibited cell growth. Up-regulation of Sox2 was not associated with increased CD133 expression but was associated with increased FGF5 (Fibroblast Growth Factor 5) expression. These data propose a model of elevated Sox2 expression due to loss of AR-mediated repression during castration, and consequent castration-resistance via mechanisms not involving induction of canonical embryonic stem cell pathways. PMID:23326489

  6. A conversation with Susan Band Horwitz.

    PubMed

    Horwitz, Susan Band; Goldman, I David

    2015-01-01

    Susan Band Horwitz is a Distinguished Professor and holds the Falkenstein Chair in Cancer Research at Albert Einstein College of Medicine in New York. She is co-chair of the Department of Molecular Pharmacology and associate director for therapeutics at the Albert Einstein Cancer Center. After graduating from Bryn Mawr College, Dr. Horwitz received her PhD in biochemistry from Brandeis University. She has had a continuing interest in natural products as a source of new drugs for the treatment of cancer. Her most seminal research contribution has been in the development of Taxol(®). Dr. Horwitz and her colleagues made the discovery that Taxol had a unique mechanism of action and suggested that it was a prototype for a new class of antitumor drugs. Although Taxol was an antimitotic agent blocking cells in the metaphase stage of the cell cycle, Dr. Horwitz recognized that Taxol was blocking mitosis in a way different from that of other known agents. Her group demonstrated that the binding site for Taxol was on the β-tubulin subunit. The interaction of Taxol with the β-tubulin subunit resulted in stabilized microtubules, essentially paralyzing the cytoskeleton, thereby preventing cell division. Dr. Horwitz served as president (2002-2003) of the American Association for Cancer Research (AACR). She is a member of the National Academy of Sciences, the Institute of Medicine, the American Academy of Arts and Sciences, and the American Philosophical Society. She has received numerous honors and awards, including the C. Chester Stock Award from Memorial Sloan Kettering Cancer Center, the Warren Alpert Foundation Prize from Harvard Medical School, the Bristol-Myers Squibb Award for Distinguished Achievement in Cancer Research, the American Cancer Society's Medal of Honor, and the AACR Award for Lifetime Achievement in Cancer Research. The following interview was conducted on January 23, 2014.

  7. EPHA2 blockade overcomes acquired resistance to EGFR kinase inhibitors in lung cancer

    PubMed Central

    Amato, Katherine R.; Wang, Shan; Tan, Li; Hastings, Andrew K.; Song, Wenqiang; Lovly, Christine M.; Meador, Catherine B.; Ye, Fei; Lu, Pengcheng; Balko, Justin M.; Colvin, Daniel C.; Cates, Justin M.; Pao, William; Gray, Nathanael S.; Chen, Jin

    2015-01-01

    Despite the success of treating EGFR mutant lung cancer patients with EGFR tyrosine kinase inhibitors (TKIs), all patients eventually acquire resistance to these therapies. Although various resistance mechanisms have been described, there are currently no FDA-approved therapies that target alternative mechanisms to treat lung tumors with acquired resistance to first-line EGFR TKI agents. Here we found that EPHA2 is overexpressed in EGFR TKI resistant tumor cells. Loss of EPHA2 reduced the viability of erlotinib resistant tumor cells harboring EGFRT790M mutations in vitro and inhibited tumor growth and progression in an inducible EGFRL858R+T790M mutant lung cancer model in vivo. Targeting EPHA2 in erlotinib resistant cells decreased S6K1-mediated phosphorylation of cell death agonist BAD, resulting in reduced tumor cell proliferation and increased apoptosis. Furthermore, pharmacologic inhibition of EPHA2 by the small molecule inhibitor, ALW-II-41-27, decreased both survival and proliferation of erlotinib resistant tumor cells and inhibited tumor growth in vivo. ALW-II-41-27 was also effective in decreasing viability of cells with acquired resistance to the third generation EGFR TKI, AZD9291. Collectively, these data define a role for EPHA2 in the maintenance of cell survival of TKI resistant, EGFR mutant lung cancer and indicate that EPHA2 may serve as a useful therapeutic target in TKI resistant tumors. PMID:26744526

  8. The enriched fraction of Vernonia cinerea L. induces apoptosis and inhibits multi-drug resistance transporters in human epithelial cancer cells.

    PubMed

    Appadath Beeran, Asmy; Maliyakkal, Naseer; Rao, Chamallamudi Mallikarjuna; Udupa, Nayanabhirama

    2014-12-02

    Vernonia cinerea Less. (VC) of the family Asteraceaes is considered as the sacred plant; 'Dasapushpam' which is ethnopharmacologically significant to the people of Kerala in India. In fact, VC has been used in the traditional system of medicine (Ayurveda) for the treatment of various ailments including cancer. Cytotoxicity of the ethanolic extract of VC (VC-ET), petroleum ether fraction (VC-PET), dichloromethane fraction (VC-DCM), n-butyl alcohol fraction (VC-BT), and rest fraction (VC-R) was evaluated in cervical carcinoma (HeLa), lung adenocarcinoma (A549), breast cancer (MCF-7), and colon carcinoma (Caco-2) cells using Sulforhodamine B (SRB) assay. The apoptotic effects of VC-DCM were assessed in cancer cells using Annexin V assay. The effects of VC-DCM on multi-drug resistance (MDR) transporters in HeLa, A549, MCF-7, and Caco-2 cells were evaluated using flow cytometry based functional assays. Similarly, drug uptake in cancer cells and sensitization of cancer cells towards chemotherapeutic drugs in the presence of VC-DCM were studied using Daunorubicin (DNR) accumulation assay and SRB assay, respectively. Cytotoxicity assay revealed that the enriched fraction of VC (VC-DCM) possessed dose-dependent cytotoxic effects in human epithelial cancer cells (HeLa, A549, MCF-7, and Caco-2). Further, treatment of cancer cells (HeLa, A549, MCF-7, and Caco-2) with VC-DCM led to a significant increase in both early and late apoptosis, indicating the induction of apoptosis. Interestingly, VC-DCM significantly inhibited functional activity of MDR transporters (ABC-B1 and ABC-G2), enhanced DNR-uptake in cancer cells, and sensitized cancer cells towards chemotherapeutic drug-mediated cytotoxicity, thus indicating the ability of VC-DCM to reverse MDR in cancer and enhance the cytotoxic effects of anticancer drugs. A methodological investigation on the anti-cancer properties of Vernonia cinerea Less. (VC) revealed that an enriched fraction of VC (VC-DCM) possessed cytotoxic

  9. Lapatinib-resistant cancer cells possessing epithelial cancer stem cell properties develop sensitivity during sphere formation by activation of the ErbB/AKT/cyclin D2 pathway.

    PubMed

    Ohnishi, Yuichi; Yasui, Hiroki; Kakudo, Kenji; Nozaki, Masami

    2016-11-01

    Lapatinib, a dual inhibitor of epidermal growth factor receptor (EGFR)/ErbB2, has antiproliferative effects and is used to treat patients with ErbB2-positive metastatic breast cancer. In the present study, we examined the effects of lapatinib on growth of oral and prostate cancer cells. Oral squamous cell carcinoma (OSCC) cell lines HSC3, HSC4 and Ca9-22 were sensitive to the antiproliferative effects of lapatinib in anchorage-dependent culture, but the OSCC cell lines KB and SAS and the prostate cancer cell line DU145 were resistant to lapatinib. Phosphorylation levels of EGFR in all cell lines decreased during lapatinib treatment in anchorage‑dependent culture. Furthermore, the phosphorylation levels of ErbB2, ErbB3 and Akt and the protein levels of cyclin D1 were decreased by lapatinib treatment of HSC3, HSC4 and Ca9-22 cells. ErbB3 was not expressed and cyclin D1 protein levels were not altered by lapatinib treatment in KB, DU145 and SAS cells. The phosphorylation of ErbB2 and AKT was not affected by lapatinib in SAS cells and was not detected in KB and DU145 cells. Lapatinib-resistant cell lines exhibited sphere-forming ability, and SAS cells developed sensitivity to lapatinib during sphere formation. The phosphorylation levels of ErbB2 and AKT and protein levels of cyclin D2 increased during sphere formation of SAS cells and decreased with lapatinib treatment. In addition, sphere formation of SAS cells was inhibited by the AKT inhibitor MK2206. AKT phosphorylation and cyclin D2 levels in SAS spheres were decreased by MK2206 treatment. SAS cells expressed E-cadherin, but not vimentin and KB cells expressed vimentin, but not E-cadherin. DU145 cells expressed vimentin and E-cadherin. These results suggested that phosphorylation of EGFR and ErbB2 by cell detachment from the substratum induces the AKT pathway/cyclin D2-dependent sphere growth in SAS epithelial cancer stem-like cells, thereby rendering SAS spheres sensitive to lapatinib treatment.

  10. A drug-delivery strategy for overcoming drug resistance in breast cancer through targeting of oncofetal fibronectin.

    PubMed

    Saw, Phei Er; Park, Jinho; Jon, Sangyong; Farokhzad, Omid C

    2017-02-01

    A major problem with cancer chemotherapy begins when cells acquire resistance. Drug-resistant cancer cells typically upregulate multi-drug resistance proteins such as P-glycoprotein (P-gp). However, the lack of overexpressed surface biomarkers has limited the targeted therapy of drug-resistant cancers. Here we report a drug-delivery carrier decorated with a targeting ligand for a surface marker protein extra-domain B(EDB) specific to drug-resistant breast cancer cells as a new therapeutic option for the aggressive cancers. We constructed EDB-specific aptide (APT EDB )-conjugated liposome to simultaneously deliver siRNA(siMDR1) and Dox to drug-resistant breast cancer cells. APT EDB -LS(Dox,siMDR1) led to enhanced delivery of payloads into MCF7/ADR cells and showed significantly higher accumulation and retention in the tumors. While either APT EDB -LS(Dox) or APT EDB -LS(siMDR1) did not lead to appreciable tumor retardation in MCF7/ADR orthotropic model, APT EDB -LS(Dox,siMDR1) treatment resulted in significant reduction of the drug-resistant breast tumor. Taken together, this study provides a new strategy of drug delivery for drug-resistant cancer therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. A POX on Renal Cancer Cells | Center for Cancer Research

    Cancer.gov

    Proline oxidase, or POX, is an enzyme responsible for metabolizing the amino acid proline. POX contributes to the regulation of cell death that occurs when cellular systems malfunction, a process called apoptosis. Previous studies have determined that levels of POX are reduced in several types of human cancer. Likewise, many cancer cells become resistant to apoptosis, suggesting a link between POX and cancer cell survival.

  12. Receptor Interactive Protein Kinase 3 Promotes Cisplatin-Triggered Necrosis in Apoptosis-Resistant Esophageal Squamous Cell Carcinoma Cells

    PubMed Central

    Zhao, Nan; Zhou, Lanping; Liu, Fang; Cichacz, Zbigniew; Zhang, Lin; Zhan, Qimin; Zhao, Xiaohang

    2014-01-01

    Cisplatin-based chemotherapy is currently the standard treatment for locally advanced esophageal cancer. Cisplatin has been shown to induce both apoptosis and necrosis in cancer cells, but the mechanism by which programmed necrosis is induced remains unknown. In this study, we provide evidence that cisplatin induces necrotic cell death in apoptosis-resistant esophageal cancer cells. This cell death is dependent on RIPK3 and on necrosome formation via autocrine production of TNFα. More importantly, we demonstrate that RIPK3 is necessary for cisplatin-induced killing of esophageal cancer cells because inhibition of RIPK1 activity by necrostatin or knockdown of RIPK3 significantly attenuates necrosis and leads to cisplatin resistance. Moreover, microarray analysis confirmed an anti-apoptotic molecular expression pattern in esophageal cancer cells in response to cisplatin. Taken together, our data indicate that RIPK3 and autocrine production of TNFα contribute to cisplatin sensitivity by initiating necrosis when the apoptotic pathway is suppressed or absent in esophageal cancer cells. These data provide new insight into the molecular mechanisms underlying cisplatin-induced necrosis and suggest that RIPK3 is a potential marker for predicting cisplatin sensitivity in apoptosis-resistant and advanced esophageal cancer. PMID:24959694

  13. Up-regulation of antioxidant enzymes and coenzyme Q(10) in a human oral cancer cell line with acquired bleomycin resistance.

    PubMed

    Yen, Hsiu-Chuan; Li, Sin-Hua; Majima, Hideyuki J; Huang, Yu-Hsiang; Chen, Chiu-Ping; Liu, Chia-Chi; Tu, Ya-Chi; Chen, Chih-Wei

    2011-06-01

    Bleomycin (BLM) is an anti-cancer drug that can induce formation of reactive oxygen species (ROS). To investigate the association between up-regulation of antioxidant enzymes and coenzyme Q(10) (CoQ(10)) in acquired BLM resistance, one BLM-resistant clone, SBLM24 clone, was selected from a human oral cancer cell line, SCC61 clone. The BLM resistance of SBLM24 clone relative to a sub-clone of SCC61b cells was confirmed by analysis of clonogenic ability and cell cycle arrest. CoQ(10) levels and levels of Mn superoxide dismutase, glutathione peroxidase 1, catalase and thioredoxin reductase 1 were augmented in SBLM24 clone although there was also a mild increase in the expression of BLM hydrolase. Suppression of CoQ(10) levels by 4-aminobenzoate sensitized BLM-induced cytotoxicity. The results of suppression on enhanced ROS production by BLM and the cross-resistance to hydrogen peroxide in SBLM24 clone further demonstrated the development of adaptation to oxidative stress during the formation of acquired BLM resistance.

  14. Cdc20/p55 mediates the resistance to docetaxel in castration-resistant prostate cancer in a Bim-dependent manner.

    PubMed

    Wu, Fei; Lin, Yun; Cui, Peng; Li, Hongyun; Zhang, Lechao; Sun, Zeqiang; Huang, Shengliang; Li, Shun; Huang, Shiming; Zhao, Qingli; Liu, Qingyong

    2018-06-01

    At least to date, no effective treatment for advanced castration-resistant prostate cancer (CRPC) has been established. Recent studies indicated that cell division cycle 20 homolog (Cdc20) overexpression is associated with poor prognosis in patients with castration-resistant prostate cancer. However, the mechanism of Cdc20 in the development of docetaxel resistance in CRPC remains elusive. In this study, the transcription of Cdc20 was confirmed in three independent CRPC cell lines derived from different tissues, including LNCaP, PC3, and DU145. Docetaxel resistant (DR) cell lines were generated within the background of DU145 and PC3. The protein levels of Cdc20 and the biological phenotype were detected in both wild-type and DR cell lines. To further explore the mechanism of Cdc20 overexpression, stable cell lines with Cdc20 or Bcl-2 interacting mediator of cell death (Bim) deprivation were generated and examined for biological parameters. In addition, a specific Cdc20 inhibitor was used in DR cell lines to explore the potential solution for docetaxel resistant CRPC. Here, we identified Cdc20 is overexpressed in docetaxel resistant CRPC cell lines, including LNCaP, PC3, and DU145. We also reported that DR cell lines, which mimic the recurrent prostate cancer cells after docetaxel treatment, have higher levels of Cdc20 protein compared with the CRPC cell lines. Interestingly, the protein levels of Bim, an E3 ligase substrate of Cdc20, were decreased in DR cell lines compared with the wild-type, while the mRNA levels were similar. More importantly, in DR cell lines, the biological phenotype induced by Cdc20 deletion could be significantly reversed by the additional knockdown of Bim. As a result, docetaxel resistant prostate cancer cells treated with the pharmacological Cdc20 inhibitor became sensitive to docetaxel treatment. In conclusion, our data collectively demonstrated that Cdc20 overexpression facilitates the docetaxel resistant of the CRPC cell lines in a Bim

  15. Tumourigenicity and radiation resistance of mesenchymal stem cells.

    PubMed

    D'Andrea, Filippo P; Horsman, Michael R; Kassem, Moustapha; Overgaard, Jens; Safwat, Akmal

    2012-05-01

    Cancer stem cells are believed to be more radiation resistant than differentiated tumour cells of the same origin. It is not known, however, whether normal nontransformed adult stem cells share the same radioresistance as their cancerous counterpart. Nontumourigenic (TERT4) and tumourigenic (TRET20) cell lines, from an immortalised mesenchymal stem cell line, were grown in culture prior to irradiation and gene expression analysis. Radiation resistance was measured using a clonogenic assay. Differences in gene expression between the two cell lines, both under nontreated and irradiated conditions, were assessed with microarrays (Affymetrix Human Exon 1.0 ST array). The cellular functions affected by the altered gene expressions were assessed through gene pathway mapping (Ingenuity Pathway Analysis). Based on the clonogenic assay the nontumourigenic cell line was found to be more sensitive to radiation than the tumourigenic cell line. Using the exon chips, 297 genes were found altered between untreated samples of the cell lines whereas only 16 genes responded to radiation treatment. Among the genes with altered expression between the untreated samples were PLAU, PLAUR, TIMP3, MMP1 and LOX. The pathway analysis based on the alteration between the untreated samples indicated cancer and connective tissue disorders. This study has shown possible common genetic events linking tumourigenicity and radiation response. The PLAU and PLAUR genes are involved in apoptosis evasion while the genes TIMP3, MMP1 and LOX are involved in regulation of the surrounding matrix. The first group may contribute to the difference in radiation resistance observed and the latter could be a major contributor to the tumourigenic capabilities by degrading the intercellular matrix. These results also indicate that cancer stem cells are more radiation resistant than stem cells of the same origin.

  16. Research Advances in Resistance to Platinum-based Chemotherapy in Lung Cancer.

    PubMed

    Zhang, Yajuan; Chang, De; Zhang, Jianpeng

    2017-02-20

    Platinum-based chemotherapy is the the cornerstone of treatment of many cancers. Combinations of platinum drugs with other agents are still the mainstream therapies for non-small cell lung cancer,showing significant effectiveness in an early phase. Along with the treatment,the tumor cells can become resistant to chemotherapy drugs,which affect the efficacy and prognosis. The mechanisms of drug resistance are complicated,including abnormal expressions of membrane proteins,enhanced DNA repair functions,abnormal regulation mechanisms of apoptosis,and enhanced cellular detoxification function. In this article we summarize some of the main mechanisms of platinum resistance in lung cancer cells,with an attempt to identify new potential target analogues or inhibitors and improve the efficacies of the combined use of platinum-based drugs.

  17. Single-cell imaging of the heat-shock response in colon cancer cells suggests that magnitude and length rather than time of onset determines resistance to apoptosis.

    PubMed

    Ramapathiran, Lavanya; Bernas, Tytus; Walter, Franziska; Williams, Linda; Düssmann, Heiko; Concannon, Caoimhín G; Prehn, Jochen H M

    2014-02-01

    Targeting the proteasome is a valuable approach for cancer therapy, potentially limited by pro-survival pathways that are induced in parallel to cell death. Whether these pro-survival pathways are activated in all cells, show different activation kinetics in sensitive versus resistant cells or interact functionally with cell death pathways is unknown. We monitored activation of the heat-shock response (HSR), a key survival pathway induced by proteasome inhibition, relative to apoptosis activation in HCT116 colon cancer cells expressing enhanced green fluorescent protein (EGFP) under the control of the HSP70 promoter. Single-cell and high-content time-lapse imaging of epoxomicin treatment revealed that neither basal activity nor the time of onset of the HSR differed between resistant and sensitive populations. However, resistant cells had significantly higher and prolonged reporter activity than those that succumbed to cell death. p53 deficiency protected against cell death but failed to modulate the HSR. By contrast, inhibition of the HSR significantly increased the cytotoxicity of epoxomicin. Our data provide novel insights into the kinetics and heterogeneity of the HSR during proteasome inhibition, suggesting that the HSR modulates cell death signalling unidirectionally.

  18. Platelet-camouflaged nanococktail: Simultaneous inhibition of drug-resistant tumor growth and metastasis via a cancer cells and tumor vasculature dual-targeting strategy.

    PubMed

    Jing, Lijia; Qu, Haijing; Wu, Dongqi; Zhu, Chaojian; Yang, Yongbo; Jin, Xing; Zheng, Jian; Shi, Xiangsheng; Yan, Xiufeng; Wang, Yang

    2018-01-01

    Multidrug resistance (MDR) poses a great challenge to cancer therapy. It is difficult to inhibit the growth of MDR cancer due to its chemoresistance. Furthermore, MDR cancers are more likely to metastasize, causing a high mortality among cancer patients. In this study, a nanomedicine RGD-NPVs@MNPs/DOX was developed by encapsulating melanin nanoparticles (MNPs) and doxorubicin (DOX) inside RGD peptide (c(RGDyC))-modified nanoscale platelet vesicles (RGD-NPVs) to efficiently inhibit the growth and metastasis of drug-resistant tumors via a cancer cells and tumor vasculature dual-targeting strategy. Methods: The in vitro immune evasion potential and the targeting performance of RGD-NPVs@MNPs/DOX were examined using RAW264.7, HUVECs, MDA-MB-231 and MDA-MB-231/ADR cells lines. We also evaluated the pharmacokinetic behavior and the in vivo therapeutic performance of RGD-NPVs@MNPs/DOX using a MDA-MB-231/ADR tumor-bearing nude mouse model. Results: By taking advantage of the self-recognizing property of the platelet membrane and the conjugated RGD peptides, RGD-NPVs@MNPs/DOX was found to evade immune clearance and target the αvβ3 integrin on tumor vasculature and resistant breast tumor cells. Under irradiation with a NIR laser, RGD-NPVs@MNPs/DOX produced a multipronged effect, including reversal of cancer MDR, efficient killing of resistant cells by chemo-photothermal therapy, elimination of tumor vasculature for blocking metastasis, and long-lasting inhibition of the expressions of VEGF, MMP2 and MMP9 within the tumor. Conclusion: This versatile nanomedicine of RGD-NPVs@MNPs/DOX integrating unique biomimetic properties, excellent targeting performance, and comprehensive therapeutic strategies in one formulation might bring opportunities to MDR cancer therapy.

  19. Epigenetics in cancer stem cells.

    PubMed

    Toh, Tan Boon; Lim, Jhin Jieh; Chow, Edward Kai-Hua

    2017-02-01

    Compelling evidence have demonstrated that bulk tumors can arise from a unique subset of cells commonly termed "cancer stem cells" that has been proposed to be a strong driving force of tumorigenesis and a key mechanism of therapeutic resistance. Recent advances in epigenomics have illuminated key mechanisms by which epigenetic regulation contribute to cancer progression. In this review, we present a discussion of how deregulation of various epigenetic pathways can contribute to cancer initiation and tumorigenesis, particularly with respect to maintenance and survival of cancer stem cells. This information, together with several promising clinical and preclinical trials of epigenetic modulating drugs, offer new possibilities for targeting cancer stem cells as well as improving cancer therapy overall.

  20. Novel Holistic Approaches for Overcoming Therapy Resistance in Pancreatic and Colon Cancers.

    PubMed

    Sarkar, Fazlul H

    2016-01-01

    Gastrointestinal (GI) cancers, such as of the colon and pancreas, are highly resistant to both standard and targeted therapeutics. Therapy-resistant and heterogeneous GI cancers harbor highly complex signaling networks (the resistome) that resist apoptotic programming. Commonly used gemcitabine or platinum-based regimens fail to induce meaningful (i.e. disease-reversing) perturbations in the resistome, resulting in high rates of treatment failure. The GI cancer resistance networks are, in part, due to interactions between parallel signaling and aberrantly expressed microRNAs (miRNAs) that collectively promote the development and survival of drug-resistant cancer stem cells with epithelial-to-mesenchymal transition (EMT) characteristics. The lack of understanding of the resistance networks associated with this subpopulation of cells as well as reductionist, single protein-/pathway-targeted approaches have made 'effective drug design' a difficult task. We propose that the successful design of novel therapeutic regimens to target drug-resistant GI tumors is only possible if network-based drug avenues and agents, in particular 'natural agents' with no known toxicity, are correctly identified. Natural agents (dietary agents or their synthetic derivatives) can individually alter miRNA profiles, suppress EMT pathways and eliminate cancer stem-like cells that derive from pancreatic cancer and colon cancer, by partially targeting multiple yet meaningful networks within the GI cancer resistome. However, the efficacy of these agents as combinations (e.g. consumed in the diet) against this resistome has never been studied. This short review article provides an overview of the different challenges involved in the understanding of the GI resistome, and how novel computational biology can help in the design of effective therapies to overcome resistance. © 2015 S. Karger AG, Basel.

  1. Epigenetic modification of α-N-acetylgalactosaminidase enhances cisplatin resistance in ovarian cancer

    PubMed Central

    Ha, Ye-Na; Sung, Hye Youn; Yang, San-Duk; Chae, Yun Ju

    2018-01-01

    Although cisplatin is one of the most effective antitumor drugs for ovarian cancer, the emergence of chemoresistance to cisplatin in over 80% of initially responsive patients is a major barrier to successful therapy. The precise mechanisms underlying the development of cisplatin resistance are not fully understood, but alteration of DNA methylation associated with aberrant gene silencing may play a role. To identify epigenetically regulated genes directly associated with ovarian cancer cisplatin resistance, we compared the expression and methylation profiles of cisplatin-sensitive and -resistant human ovarian cancer cell lines. We identified α-Nacetylgalactosaminidase (NAGA) as one of the key candidate genes for cisplatin drug response. Interestingly, in cisplatin-resistant cell lines, NAGA was significantly downregulated and hypermethylated at a promoter CpG site at position +251 relative to the transcriptional start site. Low NAGA expression in cisplatin-resistant cell lines was restored by treatment with a DNA demethylation agent, indicating transcriptional silencing by hyper-DNA methylation. Furthermore, overexpression of NAGA in cisplatin-resistant lines induced cytotoxicity in response to cisplatin, whereas depletion of NAGA expression increased cisplatin chemoresistance, suggesting an essential role of NAGA in sensitizing ovarian cells to cisplatin. These findings indicate that NAGA acts as a cisplatin sensitizer and its gene silencing by hypermethylation confers resistance to cisplatin in ovarian cancer. Therefore, we suggest NAGA may be a promising potential therapeutic target for improvement of sensitivity to cisplatin in ovarian cancer. PMID:29302211

  2. Epigenetic modification of α-N-acetylgalactosaminidase enhances cisplatin resistance in ovarian cancer.

    PubMed

    Ha, Ye-Na; Sung, Hye Youn; Yang, San-Duk; Chae, Yun Ju; Ju, Woong; Ahn, Jung-Hyuck

    2018-01-01

    Although cisplatin is one of the most effective antitumor drugs for ovarian cancer, the emergence of chemoresistance to cisplatin in over 80% of initially responsive patients is a major barrier to successful therapy. The precise mechanisms underlying the development of cisplatin resistance are not fully understood, but alteration of DNA methylation associated with aberrant gene silencing may play a role. To identify epigenetically regulated genes directly associated with ovarian cancer cisplatin resistance, we compared the expression and methylation profiles of cisplatin-sensitive and -resistant human ovarian cancer cell lines. We identified α- N acetylgalactosaminidase ( NAGA ) as one of the key candidate genes for cisplatin drug response. Interestingly, in cisplatin-resistant cell lines, NAGA was significantly downregulated and hypermethylated at a promoter CpG site at position +251 relative to the transcriptional start site. Low NAGA expression in cisplatin-resistant cell lines was restored by treatment with a DNA demethylation agent, indicating transcriptional silencing by hyper-DNA methylation. Furthermore, overexpression of NAGA in cisplatin-resistant lines induced cytotoxicity in response to cisplatin, whereas depletion of NAGA expression increased cisplatin chemoresistance, suggesting an essential role of NAGA in sensitizing ovarian cells to cisplatin. These findings indicate that NAGA acts as a cisplatin sensitizer and its gene silencing by hypermethylation confers resistance to cisplatin in ovarian cancer. Therefore, we suggest NAGA may be a promising potential therapeutic target for improvement of sensitivity to cisplatin in ovarian cancer.

  3. The spectrum of resistance in SR/CR mice: the critical role of chemoattraction in the cancer/leukocyte interaction.

    PubMed

    Riedlinger, Gregory; Adams, Jonathan; Stehle, John R; Blanks, Michael J; Sanders, Anne M; Hicks, Amy M; Willingham, Mark C; Cui, Zheng

    2010-05-03

    Spontaneous regression/complete resistance (SR/CR) mice are a unique colony of mice that possess an inheritable, natural cancer resistance mediated primarily by innate cellular immunity. This resistance is effective against sarcoma 180 (S180) at exceptionally high doses and these mice remain healthy. In this study, we challenged SR/CR mice with additional lethal transplantable mouse cancer cell lines to determine their resistance spectrum. The ability of these transplantable cancer cell lines to induce leukocyte infiltration was quantified and the percentage of different populations of responding immune cells was determined using flow cytometry. In comparison to wild type (WT) mice, SR/CR mice showed significantly higher resistance to all cancer cell lines tested. However, SR/CR mice were more sensitive to MethA sarcoma (MethA), B16 melanoma (B16), LL/2 lung carcinoma (LL/2) and J774 lymphoma (J774) than to sarcoma 180 (S180) and EL-4 lymphoma (EL-4). Further mechanistic studies revealed that this lower resistance to MethA and LL/2 was due to the inability of these cancer cells to attract SR/CR leukocytes, leading to tumor cell escape from resistance mechanism. This escape mechanism was overcome by co-injection with S180, which could attract SR/CR leukocytes allowing the mice to resist higher doses of MethA and LL/2. S180-induced cell-free ascites fluid (CFAF) co-injection recapitulated the results obtained with live S180 cells, suggesting that this chemoattraction by cancer cells is mediated by diffusible molecules. We also tested for the first time whether SR/CR mice were able to resist additional cancer cell lines prior to S180 exposure. We found that SR/CR mice had an innate resistance against EL-4 and J774. Our results suggest that the cancer resistance in SR/CR mice is based on at least two separate processes: leukocyte migration/infiltration to the site of cancer cells and recognition of common surface properties on cancer cells. The infiltration of SR

  4. MicroRNAs and cancer resistance: A new molecular plot.

    PubMed

    Fanini, F; Fabbri, M

    2016-05-01

    The most common cause of cancer relapse is drug resistance, acquired or intrinsic, which strongly limits the efficacy of both conventional and new targeted chemotherapy. MicroRNAs (miRNAs) are a growing, large family of short noncoding RNAs frequently dysregulated in malignancies. Although the mechanism of miRNA-mediated drug resistance is not fully understood, an increasing amount of evidence suggests their involvement in the acquisition of tumor cell drug resistance, pointing towards the need for novel and more innovative therapeutic approaches. Use of antagomiRs or mimics can modulate specific miRNAs in order to restore gene networks and signaling pathways, perhaps optimizing chemotherapies by increasing cancer cell sensitivity to drugs. The aim of this review is to provide a state-of-the-art scenario with regard to the most recent discoveries in the field of miRNAs involved in the process of resistance to cancer therapy. © 2016 The American Society for Clinical Pharmacology and Therapeutics.

  5. 5-FU resistant EMT-like pancreatic cancer cells are hypersensitive to photochemical internalization of the novel endoglin-targeting immunotoxin CD105-saporin.

    PubMed

    Lund, Kaja; Olsen, Cathrine Elisabeth; Wong, Judith Jing Wen; Olsen, Petter Angell; Solberg, Nina Therese; Høgset, Anders; Krauss, Stefan; Selbo, Pål Kristian

    2017-12-19

    Development of resistance to 5-fluorouracil (5-FU) is a major problem in treatment of various cancers including pancreatic cancer. In this study, we reveal important resistance mechanisms and photochemical strategies to overcome 5-FU resistance in pancreatic adenocarcinoma. 5-FU resistant (5-FUR), epithelial-to-mesenchymal-like sub-clones of the wild type pancreatic cancer cell line Panc03.27 were previously generated in our lab. We investigated the cytotoxic effect of the endosomal/lysosomal-localizing photosensitizer TPCS 2a (fimaporfin) combined with light (photochemical treatment, PCT) using MTS viability assay, and used fluorescence microscopy to show localization of TPCS 2a and to investigate the effect of photodamage of lysosomes. Flow cytometric analysis was performed to investigate uptake of photosensitizer and to assess intracellular ROS levels. Expression and localization of LAMP1 was assessed using RT-qPCR, western blotting, and structured illumination microscopy. MTS viability assay was used to assess the effect of combinations of 5-FU, chloroquine (CQ), and photochemical treatment. Expression of CD105 was investigated using RT-qPCR, western blotting, flow cytometry, and fluorescence microscopy, and co-localization of TPCS 2a and anti-CD105-saporin was assessed using microscopy. Lastly, the MTS assay was used to investigate cytotoxic effects of photochemical internalization (PCI) of the anti-CD105-immunotoxin. The 5-FUR cell lines display hypersensitivity to PCT, which was linked to increased uptake of TPCS 2a , altered lysosomal distribution, lysosomal photodamage and increased expression of the lysosomal marker LAMP-1 in the 5-FUR cells. We show that inhibition of autophagy induced by either chloroquine or lysosomal photodamage increases the sensitivity to 5-FU in the resistant cells. The three 5-FUR sub-clones overexpress Endoglin (CD105). Treatment with the immunotoxin anti-CD105-saporin alone significantly reduced the viability of the CD105

  6. Repression of ESR1 transcription by MYOD potentiates letrozole-resistance in ERα-positive breast cancer cells.

    PubMed

    Zhang, Qiang; Liu, Xiao-Yan; Li, Shuang; Zhao, Zhao; Li, Juan; Cui, Ming-Ke; Wang, En-Hua

    2017-10-21

    Transcriptional silencing of estrogen receptor α (ERα) expression is an important etiology contributing to the letrozole-resistance in ERα-positive breast cancer (BCa) cells, but the transcription factors responsible for this transcriptional repression remain largely unidentified. Here we report that the expression of the basic helix-loop-helix myogenic regulatory factor MYOD was abnormally up-regulated in letrozole-resistant BCa tissues and in experimentally-induced letrozole-resistant BCa cells. Overexpression of the exogenous MYOD impaired ERα expression and potentiated letrozole-resistance in letrozole-sensitive MCF7 cells, whereas MYOD knockdown could effectively restore ERα expression and thereby promote letrozole-sensitivity in letrozole-resistant MCF-7/LR cells. Mechanistically, MYOD was shown to be a potent corepressor of ESR1 transcription, and this transcriptional repression was significantly enhanced in the presence of letrozole treatment. Thus, targeted inhibition of MYOD may restore ERα level and lead to resensitization to letrozole-based hormone therapy, providing a novel therapeutic strategy for relapsed ERα-positive BCa patients. Our data also underscore an unexpected chemotherapeutic facet of MYOD, which may operate as a novel regulator of BCa biology. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Microparticles shed from multidrug resistant breast cancer cells provide a parallel survival pathway through immune evasion.

    PubMed

    Jaiswal, Ritu; Johnson, Michael S; Pokharel, Deep; Krishnan, S Rajeev; Bebawy, Mary

    2017-02-06

    Breast cancer is the most frequently diagnosed cancer in women. Resident macrophages at distant sites provide a highly responsive and immunologically dynamic innate immune response against foreign infiltrates. Despite extensive characterization of the role of macrophages and other immune cells in malignant tissues, there is very little known about the mechanisms which facilitate metastatic breast cancer spread to distant sites of immunological integrity. The mechanisms by which a key healthy defense mechanism fails to protect distant sites from infiltration by metastatic cells in cancer patients remain undefined. Breast tumors, typical of many tumor types, shed membrane vesicles called microparticles (MPs), ranging in size from 0.1-1 μm in diameter. MPs serve as vectors in the intercellular transfer of functional proteins and nucleic acids and in drug sequestration. In addition, MPs are also emerging to be important players in the evasion of cancer cell immune surveillance. A comparative analysis of effects of MPs isolated from human breast cancer cells and non-malignant human brain endothelial cells were examined on THP-1 derived macrophages in vitro. MP-mediated effects on cell phenotype and functionality was assessed by cytokine analysis, cell chemotaxis and phagocytosis, immunolabelling, flow cytometry and confocal imaging. Student's t-test or a one-way analysis of variance (ANOVA) was used for comparison and statistical analysis. In this paper we report on the discovery of a new cellular basis for immune evasion, which is mediated by breast cancer derived MPs. MPs shed from multidrug resistant (MDR) cells were shown to selectively polarize macrophage cells to a functionally incapacitated state and facilitate their engulfment by foreign cells. We propose this mechanism may serve to physically disrupt the inherent immune response prior to cancer cell colonization whilst releasing mediators required for the recruitment of distant immune cells. These findings

  8. Antiproliferative activity of novel imidazopyridine derivatives on castration-resistant human prostate cancer cells

    PubMed Central

    Muniyan, Sakthivel; Chou, Yu-Wei; Ingersoll, Matthew A.; Devine, Alexus; Morris, Marisha; Odero-Marah, Valerie A.; Khan, Shafiq A.; Chaney, William G.; Bu, Xiu R.; Lin, Ming-Fong

    2014-01-01

    Metastatic prostate cancer (mPCa) relapses after a short period of androgen deprivation therapy and becomes the castration-resistant prostate cancer (CR PCa); to which the treatment is limited. Hence, it is imperative to identify novel therapeutic agents towards this patient population. In the present study, antiproliferative activities of novel imidazopyridines were compared. Among three derivatives, PHE, AMD and AMN, examined, AMD showed the highest inhibitory activity on LNCaP C-81 cell proliferation, following dose- and time-dependent manner. Additionally, AMD exhibited significant antiproliferative effect against a panel of PCa cells, but not normal prostate epithelial cells. Further, when compared to AMD, its derivative DME showed higher inhibitory activities on PCa cell proliferation, clonogenic potential and in vitro tumorigenicity. The inhibitory activity was apparently in part due to the induction of apoptosis. Mechanistic studies indicate that AMD and DME treatments inhibited both AR and PI3K/Akt signaling. The results suggest that better understanding of inhibitory mechanisms of AMD and DME could help design novel therapeutic agents for improving the treatment of CR PCa. PMID:25050738

  9. Cancer stem cells and personalized cancer nanomedicine.

    PubMed

    Gener, Petra; Rafael, Diana Fernandes de Sousa; Fernández, Yolanda; Ortega, Joan Sayós; Arango, Diego; Abasolo, Ibane; Videira, Mafalda; Schwartz, Simo

    2016-02-01

    Despite the progress in cancer treatment over the past years advanced cancer is still an incurable disease. Special attention is pointed toward cancer stem cell (CSC)-targeted therapies, because this minor cell population is responsible for the treatment resistance, metastatic growth and tumor recurrence. The recently described CSC dynamic phenotype and interconversion model of cancer growth hamper even more the possible success of current cancer treatments in advanced cancer stages. Accordingly, CSCs can be generated through dedifferentiation processes from non-CSCs, in particular, when CSC populations are depleted after treatment. In this context, the use of targeted CSC nanomedicines should be considered as a promising tool to increase CSC sensitivity and efficacy of specific anti-CSC therapies.

  10. Quercetin-Based Modified Porous Silicon Nanoparticles for Enhanced Inhibition of Doxorubicin-Resistant Cancer Cells.

    PubMed

    Liu, Zehua; Balasubramanian, Vimalkumar; Bhat, Chinmay; Vahermo, Mikko; Mäkilä, Ermei; Kemell, Marianna; Fontana, Flavia; Janoniene, Agne; Petrikaite, Vilma; Salonen, Jarno; Yli-Kauhaluoma, Jari; Hirvonen, Jouni; Zhang, Hongbo; Santos, Hélder A

    2017-02-01

    One of the most challenging obstacles in nanoparticle's surface modification is to achieve the concept that one ligand can accomplish multiple purposes. Upon such consideration, 3-aminopropoxy-linked quercetin (AmQu), a derivative of a natural flavonoid inspired by the structure of dopamine, is designed and subsequently used to modify the surface of thermally hydrocarbonized porous silicon (PSi) nanoparticles. This nanosystem inherits several advanced properties in a single carrier, including promoted anticancer efficiency, multiple drug resistance (MDR) reversing, stimuli-responsive drug release, drug release monitoring, and enhanced particle-cell interactions. The anticancer drug doxorubicin (DOX) is efficiently loaded into this nanosystem and released in a pH-dependent manner. AmQu also effectively quenches the fluorescence of the loaded DOX, thereby allowing the use of the nanosystem for monitoring the intracellular drug release. Furthermore, a synergistic effect with the presence of AmQu is observed in both normal MCF-7 and DOX-resistant MCF-7 breast cancer cells. Due to the similar structure as dopamine, AmQu may facilitate both the interaction and internalization of PSi into the cells. Overall, this PSi-based platform exhibits remarkable superiority in both multifunctionality and anticancer efficiency, making this nanovector a promising system for anti-MDR cancer treatment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. BRAF associated autophagy exploitation: BRAF and autophagy inhibitors synergise to efficiently overcome resistance of BRAF mutant colorectal cancer cells.

    PubMed

    Goulielmaki, Maria; Koustas, Evangelos; Moysidou, Eirini; Vlassi, Margarita; Sasazuki, Takehiko; Shirasawa, Senji; Zografos, George; Oikonomou, Eftychia; Pintzas, Alexander

    2016-02-23

    Autophagy is the basic catabolic mechanism that involves cell degradation of unnecessary or dysfunctional cellular components. Autophagy has a controversial role in cancer--both in protecting against tumor progression by isolation of damaged organelles, or by potentially contributing to cancer growth. The impact of autophagy in RAS induced transformation still remains to be further analyzed based on the differential effect of RAS isoforms and tumor cell context. In the present study, the effect of KRAS/BRAF/PIK3CA oncogenic pathways on the autophagic cell properties and on main components of the autophagic machinery like p62 (SQSTM1), Beclin-1 (BECN1) and MAP1LC3 (LC3) in colon cancer cells was investigated. This study provides evidence that BRAF oncogene induces the expression of key autophagic markers, like LC3 and BECN1 in colorectal tumor cells. Herein, PI3K/AKT/MTOR inhibitors induce autophagic tumor properties, whereas RAF/MEK/ERK signalling inhibitors reduce expression of autophagic markers. Based on the ineffectiveness of BRAFV600E inhibitors in BRAFV600E bearing colorectal tumors, the BRAF related autophagic properties in colorectal cancer cells are further exploited, by novel combinatorial anti-cancer protocols. Strong evidence is provided here that pre-treatment of autophagy inhibitor 3-MA followed by its combination with BRAFV600E targeting drug PLX4720 can synergistically sensitize resistant colorectal tumors. Notably, colorectal cancer cells are very sensitive to mono-treatments of another autophagy inhibitor, Bafilomycin A1. The findings of this study are expected to provide novel efficient protocols for treatment of otherwise resistant colorectal tumors bearing BRAFV600E, by exploiting the autophagic properties induced by BRAF oncogene.

  12. Primary cultures of human colon cancer as a model to study cancer stem cells.

    PubMed

    Koshkin, Sergey; Danilova, Anna; Raskin, Grigory; Petrov, Nikolai; Bajenova, Olga; O'Brien, Stephen J; Tomilin, Alexey; Tolkunova, Elena

    2016-09-01

    The principal cause of death in cancer involves tumor progression and metastasis. Since only a small proportion of the primary tumor cells, cancer stem cells (CSCs), which are the most aggressive, have the capacity to metastasize and display properties of stem cells, it is imperative to characterize the gene expression of diagnostic markers and to evaluate the drug sensitivity in the CSCs themselves. Here, we have examined the key genes that are involved in the progression of colorectal cancer and are expressed in cancer stem cells. Primary cultures of colorectal cancer cells from a patient's tumors were studied using the flow cytometry and cytological methods. We have evaluated the clinical and stem cell marker expression in these cells, their resistance to 5-fluorouracil and irinotecan, and the ability of cells to form tumors in mice. The data shows the role of stem cell marker Oct4 in the resistance of primary colorectal cancer tumor cells to 5-fluorouracil.

  13. Curcumin Chemosensitizes 5-Fluorouracil Resistant MMR-Deficient Human Colon Cancer Cells in High Density Cultures

    PubMed Central

    Shakibaei, Mehdi; Buhrmann, Constanze; Kraehe, Patricia; Shayan, Parviz; Lueders, Cora; Goel, Ajay

    2014-01-01

    Objective Treatment of colorectal cancer (CRC) remains a clinical challenge, as more than 15% of patients are resistant to 5-Fluorouracil (5-FU)-based chemotherapeutic regimens, and tumor recurrence rates can be as high as 50–60%. Cancer stem cells (CSC) are capable of surviving conventional chemotherapies that permits regeneration of original tumors. Therefore, we investigated the effectiveness of 5-FU and plant polyphenol (curcumin) in context of DNA mismatch repair (MMR) status and CSC activity in 3D cultures of CRC cells. Methods High density 3D cultures of CRC cell lines HCT116, HCT116+ch3 (complemented with chromosome 3) and their corresponding isogenic 5-FU-chemo-resistant derivative clones (HCT116R, HCT116+ch3R) were treated with 5-FU either without or with curcumin in time- and dose-dependent assays. Results Pre-treatment with curcumin significantly enhanced the effect of 5-FU on HCT116R and HCR116+ch3R cells, in contrast to 5-FU alone as evidenced by increased disintegration of colonospheres, enhanced apoptosis and by inhibiting their growth. Curcumin and/or 5-FU strongly affected MMR-deficient CRC cells in high density cultures, however MMR-proficient CRC cells were more sensitive. These effects of curcumin in enhancing chemosensitivity to 5-FU were further supported by its ability to effectively suppress CSC pools as evidenced by decreased number of CSC marker positive cells, highlighting the suitability of this 3D culture model for evaluating CSC marker expression in a close to vivo setting. Conclusion Our results illustrate novel and previously unrecognized effects of curcumin in enhancing chemosensitization to 5-FU-based chemotherapy on DNA MMR-deficient and their chemo-resistant counterparts by targeting the CSC sub-population. (246 words in abstract). PMID:24404205

  14. Curcumin chemosensitizes 5-fluorouracil resistant MMR-deficient human colon cancer cells in high density cultures.

    PubMed

    Shakibaei, Mehdi; Buhrmann, Constanze; Kraehe, Patricia; Shayan, Parviz; Lueders, Cora; Goel, Ajay

    2014-01-01

    Treatment of colorectal cancer (CRC) remains a clinical challenge, as more than 15% of patients are resistant to 5-Fluorouracil (5-FU)-based chemotherapeutic regimens, and tumor recurrence rates can be as high as 50-60%. Cancer stem cells (CSC) are capable of surviving conventional chemotherapies that permits regeneration of original tumors. Therefore, we investigated the effectiveness of 5-FU and plant polyphenol (curcumin) in context of DNA mismatch repair (MMR) status and CSC activity in 3D cultures of CRC cells. High density 3D cultures of CRC cell lines HCT116, HCT116+ch3 (complemented with chromosome 3) and their corresponding isogenic 5-FU-chemo-resistant derivative clones (HCT116R, HCT116+ch3R) were treated with 5-FU either without or with curcumin in time- and dose-dependent assays. Pre-treatment with curcumin significantly enhanced the effect of 5-FU on HCT116R and HCR116+ch3R cells, in contrast to 5-FU alone as evidenced by increased disintegration of colonospheres, enhanced apoptosis and by inhibiting their growth. Curcumin and/or 5-FU strongly affected MMR-deficient CRC cells in high density cultures, however MMR-proficient CRC cells were more sensitive. These effects of curcumin in enhancing chemosensitivity to 5-FU were further supported by its ability to effectively suppress CSC pools as evidenced by decreased number of CSC marker positive cells, highlighting the suitability of this 3D culture model for evaluating CSC marker expression in a close to vivo setting. Our results illustrate novel and previously unrecognized effects of curcumin in enhancing chemosensitization to 5-FU-based chemotherapy on DNA MMR-deficient and their chemo-resistant counterparts by targeting the CSC sub-population. (246 words in abstract).

  15. Decreased glutathione biosynthesis contributes to EGFR T790M-driven erlotinib resistance in non-small cell lung cancer.

    PubMed

    Li, Hongde; Stokes, William; Chater, Emily; Roy, Rajat; de Bruin, Elza; Hu, Yili; Liu, Zhigang; Smit, Egbert F; Heynen, Guus Jje; Downward, Julian; Seckl, Michael J; Wang, Yulan; Tang, Huiru; Pardo, Olivier E

    2016-01-01

    Epidermal growth factor receptor (EGFR) inhibitors such as erlotinib are novel effective agents in the treatment of EGFR-driven lung cancer, but their clinical impact is often impaired by acquired drug resistance through the secondary T790M EGFR mutation. To overcome this problem, we analysed the metabonomic differences between two independent pairs of erlotinib-sensitive/resistant cells and discovered that glutathione (GSH) levels were significantly reduced in T790M EGFR cells. We also found that increasing GSH levels in erlotinib-resistant cells re-sensitised them, whereas reducing GSH levels in erlotinib-sensitive cells made them resistant. Decreased transcription of the GSH-synthesising enzymes (GCLC and GSS) due to the inhibition of NRF2 was responsible for low GSH levels in resistant cells that was directly linked to the T790M mutation. T790M EGFR clinical samples also showed decreased expression of these key enzymes; increasing intra-tumoural GSH levels with a small-molecule GST inhibitor re-sensitised resistant tumours to erlotinib in mice. Thus, we identified a new resistance pathway controlled by EGFR T790M and a therapeutic strategy to tackle this problem in the clinic.

  16. miR-204 reverses temozolomide resistance and inhibits cancer initiating cells phenotypes by degrading FAP-α in glioblastoma.

    PubMed

    Yang, Yun-Na; Zhang, Xiang-Hua; Wang, Yan-Ming; Zhang, Xi; Gu, Zheng

    2018-05-01

    Malignant gliomas are treated with temozolomide (TMZ) at present, but often exhibit resistance to this agent. Cancer-initiating cells (CICs) have been suggested to lead to TMZ resistance. The mechanisms underlying CICs-based TMZ resistance are not fully understood. MicroRNAs (miRNAs) have been demonstrated to serve important roles in tumorigenesis and TMZ resistance. In the present study, a sphere forming assay and western blot analysis were performed to detect the formation of CICs and fibroblast activation protein α (FAP-α) protein expression. It was revealed that TMZ resistance promoted the formation of CICs and upregulated FAP-α expression in glioblastoma cells. Over-expressing FAP-α was also demonstrated to promote TMZ resistance and induce the formation of CICs in U251MG cells. In addition, using a reverse transcription-quantitative polymerase chain reaction, it was observed that miR-204 was downregulated in U251MG-resistant (-R) cells. miR-204 expression negatively correlated with the FAP-α levels in human glioblastoma tissues, and it may inhibit the formation of CICs and reverse TMZ resistance in U251MG-R cells. Therefore, it was concluded that miR-204 reversed temozolomide resistance and inhibited CICs phenotypes by degrading FAP-α in glioblastoma.

  17. miR-204 reverses temozolomide resistance and inhibits cancer initiating cells phenotypes by degrading FAP-α in glioblastoma

    PubMed Central

    Yang, Yun-Na; Zhang, Xiang-Hua; Wang, Yan-Ming; Zhang, Xi; Gu, Zheng

    2018-01-01

    Malignant gliomas are treated with temozolomide (TMZ) at present, but often exhibit resistance to this agent. Cancer-initiating cells (CICs) have been suggested to lead to TMZ resistance. The mechanisms underlying CICs-based TMZ resistance are not fully understood. MicroRNAs (miRNAs) have been demonstrated to serve important roles in tumorigenesis and TMZ resistance. In the present study, a sphere forming assay and western blot analysis were performed to detect the formation of CICs and fibroblast activation protein α (FAP-α) protein expression. It was revealed that TMZ resistance promoted the formation of CICs and upregulated FAP-α expression in glioblastoma cells. Over-expressing FAP-α was also demonstrated to promote TMZ resistance and induce the formation of CICs in U251MG cells. In addition, using a reverse transcription-quantitative polymerase chain reaction, it was observed that miR-204 was downregulated in U251MG-resistant (-R) cells. miR-204 expression negatively correlated with the FAP-α levels in human glioblastoma tissues, and it may inhibit the formation of CICs and reverse TMZ resistance in U251MG-R cells. Therefore, it was concluded that miR-204 reversed temozolomide resistance and inhibited CICs phenotypes by degrading FAP-α in glioblastoma. PMID:29725461

  18. TNFα-Induced Mucin 4 Expression Elicits Trastuzumab Resistance in HER2-Positive Breast Cancer.

    PubMed

    Mercogliano, María F; De Martino, Mara; Venturutti, Leandro; Rivas, Martín A; Proietti, Cecilia J; Inurrigarro, Gloria; Frahm, Isabel; Allemand, Daniel H; Deza, Ernesto Gil; Ares, Sandra; Gercovich, Felipe G; Guzmán, Pablo; Roa, Juan C; Elizalde, Patricia V; Schillaci, Roxana

    2017-02-01

    Although trastuzumab administration improved the outcome of HER2-positive breast cancer patients, resistance events hamper its clinical benefits. We demonstrated that TNFα stimulation in vitro induces trastuzumab resistance in HER2-positive breast cancer cell lines. Here, we explored the mechanism of TNFα-induced trastuzumab resistance and the therapeutic strategies to overcome it. Trastuzumab-sensitive breast cancer cells, genetically engineered to stably overexpress TNFα, and de novo trastuzumab-resistant tumors, were used to evaluate trastuzumab response and TNFα-blocking antibodies effectiveness respectively. Immunohistochemistry and antibody-dependent cell cytotoxicity (ADCC), together with siRNA strategy, were used to explore TNFα influence on the expression and function of its downstream target, mucin 4 (MUC4). The clinical relevance of MUC4 expression was studied in a cohort of 78 HER2-positive breast cancer patients treated with adjuvant trastuzumab. TNFα overexpression turned trastuzumab-sensitive cells and tumors into resistant ones. Histopathologic findings revealed mucin foci in TNFα-producing tumors. TNFα induced upregulation of MUC4 that reduced trastuzumab binding to its epitope and impaired ADCC. Silencing MUC4 enhanced trastuzumab binding, increased ADCC, and overcame trastuzumab and trastuzumab-emtansine antiproliferative effects in TNFα-overexpressing cells. Accordingly, administration of TNFα-blocking antibodies downregulated MUC4 and sensitized de novo trastuzumab-resistant breast cancer cells and tumors to trastuzumab. In HER2-positive breast cancer samples, MUC4 expression was found to be an independent predictor of poor disease-free survival (P = 0.008). We identified TNFα-induced MUC4 expression as a novel trastuzumab resistance mechanism. We propose MUC4 expression as a predictive biomarker of trastuzumab efficacy and a guide to combination therapy of TNFα-blocking antibodies with trastuzumab. Clin Cancer Res; 23(3); 636-48.

  19. UCH-L1-containing exosomes mediate chemotherapeutic resistance transfer in breast cancer.

    PubMed

    Ning, Kuan; Wang, Teng; Sun, Xu; Zhang, Pengfei; Chen, Yun; Jin, Jian; Hua, Dong

    2017-06-01

    Chemotherapy resistance has become a serious challenge in the treatment of breast cancer. Previous studies showed cells can transfer proteins, including those responsible for drug resistance to adjacent cells via exosomes. The switches of drug resistance via exosomes transfer were assessed by CellTiter-Blue Viability assay, flow cytometry, and immunostaining analysis. Relative protein levels of Ubiquitin carboxyl terminal hydrolase-L1 (UCH-L1), P-glycoprotein (P-gp), extracellular-signal regulated protein kinase1/2 (ERK1/2), and phospho-extracellular-signal regulated protein kinase1/2 (p-ERK1/2) were measured by Western blot. Immunohistochemistry was performed on 93 breast cancer samples to assess the associations of UCH-L1 levels with immunofluorescence value of UCH-L1 in circulating exosomes. The Adriamycin-resistant human breast cancer cells (MCF7/ADM) secreted exosomes carrying UCH-L1 and P-gp proteins into the extracellular microenvironment then integrated into Adriamycin-sensitive human breast cancer cells (MCF7/WT) in a time-dependent manner, transferring the chemoresistance phenotype. Notably, in blood samples from patients with breast cancer, the level of exosomes carrying UCH-L1 before chemotherapy was significantly negatively correlated with prognosis. Our study demonstrated that UCH-L1-containing exosomes can transfer chemoresistance to recipient cells and these exosomes may be useful as non-invasive diagnostic biomarkers for detection of chemoresitance in breast cancer patients, achieving more effective and individualized chemotherapy. © 2017 Wiley Periodicals, Inc.

  20. Discovery of potent cytotoxic ortho-aryl chalcones as new scaffold targeting tubulin and mitosis with affinity-based fluorescence.

    PubMed

    Zhu, Cuige; Zuo, Yinglin; Wang, Ruimin; Liang, Baoxia; Yue, Xin; Wen, Gesi; Shang, Nana; Huang, Lei; Chen, Yu; Du, Jun; Bu, Xianzhang

    2014-08-14

    A series of new ortho-aryl chalcones have been designed and synthesized. Many of these compounds were found to exhibit significant antiproliferation activity toward a panel of cancer cell lines. Selected compounds show potent cytotoxicity against several drug resistant cell lines including paclitaxel (Taxol) resistant human ovarian carcinoma cells, vincristine resistant human ileocecum carcinoma cells, and doxorubicin resistant human breast carcinoma cells. Further investigation revealed that active analogues could inhibit the microtubule polymerization by binding to colchicine site and thus induce multipolar mitosis, G2/M phase arrest, and apoptosis of cancer cells. Furthermore, affinity-based fluorescence enhancement was observed during the binding of active compounds with tubulin, which greatly facilitated the determination of tubulin binding site of the compounds. Finally, selected compound 26 was found to exhibit obvious in vivo antitumor activity in A549 tumor xenografts model. Our systematic studies implied a new scaffold targeting tubulin and mitosis for novel antitumor drug discovery.

  1. Induction of oxidative stress by Taxol® vehicle Cremophor-EL triggers production of interleukin-8 by peripheral blood mononuclear cells through the mechanism not requiring de novo synthesis of mRNA.

    PubMed

    Ilinskaya, Anna N; Clogston, Jeffrey D; McNeil, Scott E; Dobrovolskaia, Marina A

    2015-11-01

    Understanding the ability of cytotoxic oncology drugs, and their carriers and formulation excipients, to induce pro-inflammatory responses is important for establishing safe and efficacious formulations. Literature data about cytokine response induction by the traditional formulation of paclitaxel, Taxol®, are controversial, and no data are available about the pro-inflammatory profile of the nano-albumin formulation of this drug, Abraxane®. Herein, we demonstrate and explain the difference in the cytokine induction profile between Taxol® and Abraxane®, and describe a novel mechanism of cytokine induction by a nanosized excipient, Cremophor EL, which is not unique to Taxol® and is commonly used in the pharmaceutical industry for delivery of a wide variety of small molecular drugs. Advances in nanotechnology have enabled the production of many nano-formulation drugs. The cellular response to drugs has been reported to be different between traditional and nano-formulations. In this article, the authors investigated and compared cytokine response induction profiles between Taxol® and Abraxane®. The findings here provided further understanding to create drugs with better safety profiles. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Phenotype heterogeneity in cancer cell populations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Almeida, Luis; Chisholm, Rebecca; Clairambault, Jean

    2016-06-08

    Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a fewmore » results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as “bet hedging” of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms

  3. Phenotype heterogeneity in cancer cell populations

    NASA Astrophysics Data System (ADS)

    Almeida, Luis; Chisholm, Rebecca; Clairambault, Jean; Escargueil, Alexandre; Lorenzi, Tommaso; Lorz, Alexander; Trélat, Emmanuel

    2016-06-01

    Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as "bet hedging" of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to

  4. Cytoplasmic GPER translocation in cancer-associated fibroblasts mediates cAMP/PKA/CREB/glycolytic axis to confer tumor cells with multidrug resistance.

    PubMed

    Yu, T; Yang, G; Hou, Y; Tang, X; Wu, C; Wu, X-A; Guo, L; Zhu, Q; Luo, H; Du, Y-E; Wen, S; Xu, L; Yin, J; Tu, G; Liu, M

    2017-04-01

    Multiple drug resistance is a challenging issue in the clinic. There is growing evidence that the G-protein-coupled estrogen receptor (GPER) is a novel mediator in the development of multidrug resistance in both estrogen receptor (ER)-positive and -negative breast cancers, and that cancer-associated fibroblasts (CAFs) in the tumor microenvironment may be a new agent that promotes drug resistance in tumor cells. However, the role of cytoplasmic GPER of CAFs on tumor therapy remains unclear. Here we first show that the breast tumor cell-activated PI3K/AKT (phosphoinositide 3-kinase/AKT) signaling pathway induces the cytoplasmic GPER translocation of CAFs in a CRM1-dependent pattern, and leads to the activation of a novel estrogen/GPER/cAMP/PKA/CREB signaling axis that triggers the aerobic glycolysis switch in CAFs. The glycolytic CAFs feed the extra pyruvate and lactate to tumor cells for augmentation of mitochondrial activity, and this energy metabolically coupled in a 'host-parasite relationship' between catabolic CAFs and anabolic cancer cells confers the tumor cells with multiple drug resistance to several conventional clinical treatments including endocrine therapy (tamoxifen), Her-2-targeted therapy (herceptin) and chemotherapy (epirubicin). Moreover, the clinical data from 18 F-fluorodeoxyglucose positron emission tomography/computed tomography further present a strong association between the GPER/cAMP/PKA/CREB pathway of stromal fibroblasts with tumor metabolic activity and clinical treatment, suggesting that targeting cytoplasmic GPER in CAFs may rescue the drug sensitivity in patients with breast cancer. Thus, our data define novel insights into the stromal GPER-mediated multiple drug resistance from the point of reprogramming of tumor energy metabolism and provide the rationale for CAFs as a promising target for clinical therapy.

  5. Coffee induces breast cancer resistance protein expression in Caco-2 cells.

    PubMed

    Isshiki, Marina; Umezawa, Kazuo; Tamura, Hiroomi

    2011-01-01

    Coffee is a beverage that is consumed world-wide on a daily basis and is known to induce a series of metabolic and pharmacological effects, especially in the digestive tract. However, little is known concerning the effects of coffee on transporters in the gastrointestinal tract. To elucidate the effect of coffee on intestinal transporters, we investigated its effect on expression of the breast cancer resistance protein (BCRP/ABCG2) in a human colorectal cancer cell line, Caco-2. Coffee induced BCRP gene expression in Caco-2 cells in a coffee-dose dependent manner. Coffee treatment of Caco-2 cells also increased the level of BCRP protein, which corresponded to induction of gene expression, and also increased cellular efflux activity, as judged by Hoechst33342 accumulation. None of the major constituents of coffee tested could induce BCRP gene expression. The constituent of coffee that mediated this induction was extractable with ethyl acetate and was produced during the roasting process. Dehydromethylepoxyquinomicin (DHMEQ), an inhibitor of nuclear factor (NF)-κB, inhibited coffee-mediated induction of BCRP gene expression, suggesting involvement of NF-κB in this induction. Our data suggest that daily consumption of coffee might induce BCRP expression in the gastrointestinal tract and may affect the bioavailability of BCRP substrates.

  6. Binding of galectin-1 to integrin β1 potentiates drug resistance by promoting survivin expression in breast cancer cells.

    PubMed

    Nam, KeeSoo; Son, Seog-Ho; Oh, Sunhwa; Jeon, Donghwan; Kim, Hyungjoo; Noh, Dong-Young; Kim, Sangmin; Shin, Incheol

    2017-05-30

    Galectin-1 is a β-galactoside binding protein secreted by many types of aggressive cancer cells. Although many studies have focused on the role of galectin-1 in cancer progression, relatively little attention has been paid to galectin-1 as an extracellular therapeutic target. To elucidate the molecular mechanisms underlying galectin-1-mediated cancer progression, we established galectin-1 knock-down cells via retroviral delivery of short hairpin RNA (shRNA) against galectin-1 in two triple-negative breast cancer (TNBC) cell lines, MDA-MB-231 and Hs578T. Ablation of galectin-1 expression decreased cell proliferation, migration, invasion, and doxorubicin resistance. We found that these effects were caused by decreased galectin-1-integrin β1 interactions and suppression of the downstream focal adhesion kinase (FAK)/c-Src pathway. We also found that silencing of galectin-1 inhibited extracellular signal-regulated kinase (ERK)/signal transducer and activator of transcription 3 (STAT3) signaling, thereby down-regulating survivin expression. This finding implicates STAT3 as a transcription factor for survivin. Finally, rescue of endogenous galectin-1 knock-down and recombinant galectin-1 treatment both recovered signaling through the FAK/c-Src/ERK/STAT3/survivin pathway. Taken together, these results suggest that extracellular galectin-1 contributes to cancer progression and doxorubicin resistance in TNBC cells. These effects appear to be mediated by galectin-1-induced up-regulation of the integrin β1/FAK/c-Src/ERK/STAT3/survivin pathway. Our results imply that extracellular galectin-1 has potential as a therapeutic target for triple-negative breast cancer.

  7. Simultaneous targeting of ATM and Mcl-1 increases cisplatin sensitivity of cisplatin-resistant non-small cell lung cancer.

    PubMed

    Zhang, Fuquan; Shen, Mingjing; Yang, Li; Yang, Xiaodong; Tsai, Ying; Keng, Peter C; Chen, Yongbing; Lee, Soo Ok; Chen, Yuhchyau

    2017-08-03

    Development of cisplatin-resistance is an obstacle in non-small cell lung cancer (NSCLC) therapeutics. To investigate which molecules are associated with cisplatin-resistance, we analyzed expression profiles of several DNA repair and anti-apoptosis associated molecules in parental (A549P and H157P) and cisplatin-resistant (A549CisR and H157CisR) NSCLC cells. We detected constitutively upregulated nuclear ATM and cytosolic Mcl-1 molcules in cisplatin-resistant cells compared with parental cells. Increased levels of phosphorylated ATM (p-ATM) and its downstream molecules, CHK2, p-CHK2, p-53, and p-p53 were also detected in cisplatin-resistant cells, suggesting an activation of ATM signaling in these cells. Upon inhibition of ATM and Mcl-1 expression/activity using specific inhibitors of ATM and/or Mcl-1, we found significantly enhanced cisplatin-cytotoxicity and increased apoptosis of A549CisR cells after cisplatin treatment. Several A549CisR-derived cell lines, including ATM knocked down (A549CisR-siATM), Mcl-1 knocked down (A549CisR-shMcl1), ATM/Mcl-1 double knocked down (A549CisR-siATM/shMcl1) as well as scramble control (A549CisR-sc), were then developed. Higher cisplatin-cytotoxicity and increased apoptosis were observed in A549CisR-siATM, A549CisR-shMcl1, and A549CisR-siATM/shMcl1 cells compared with A549CisR-sc cells, and the most significant effect was shown in A549CisR-siATM/shMcl1 cells. In in vivo mice studies using subcutaneous xenograft mouse models developed with A549CisR-sc and A549CisR-siATM/shMcl1 cells, significant tumor regression in A549CisR-siATM/shMcl1 cells-derived xenografts was observed after cisplatin injection, but not in A549CisR-sc cells-derived xenografts. Finally, inhibitor studies revealed activation of Erk signaling pathway was most important in upregulation of ATM and Mcl-1 molcules in cisplatin-resistant cells. These studies suggest that simultaneous blocking of ATM/Mcl-1 molcules or downstream Erk signaling may recover the

  8. Trial of Cisplatin Plus Radiation Followed by Carbo and Taxol Vs. Sandwich Therapy of Carbo and Taxol Followed Radiation Then Further Carbo and Taxol

    ClinicalTrials.gov

    2017-10-30

    Endometrial Clear Cell Adenocarcinoma; Endometrial Serous Adenocarcinoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer

  9. Interference with endogenous EZH2 reverses the chemotherapy drug resistance in cervical cancer cells partly by up-regulating Dicer expression.

    PubMed

    Cai, Liqiong; Wang, Zehua; Liu, Denghua

    2016-05-01

    Cervical cancer is one of the most common female malignancies in the world, and chemotherapeutic drug resistance is a major obstacle to cancer therapy. Enhancer of zeste homolog 2 (EZH2) is an enzymatic subunit of polycomb repressive complex 2 (PRC2) and catalyzes the repressive histone H3 lysine 27 trimethylation (H3K27me3). However, the role of EZH2 on the chemotherapy drug resistance in cervical cancers remains unclear. In the present study, the cervical carcinoma specimens and paired normal tissue specimens were obtained and the expression of EZH2 was detected by western blotting. The results showed that high levels of EZH2 were detected in cervical carcinoma tissues, compared with paired control tissues (**p < 0.01). Next, three pairs of shRNA specific to EZH2 were designed and used to interfere with endogenous EZH2 expression. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays following treatment with various concentrations of cisplatin in HeLa and HeLa/DDP cells. The MTT assay results showed that knockdown of EZH2 in HeLa/DDP cells caused a 2.29- or 1.83-fold decrease in the cisplatin IC50 values (for shRNA1-EZH2, 34.88 vs. 15.21 μg/mL; p < 0.01; for shRNA3-EZH2, 34.88 vs. 19.09 μg/mL; p < 0.01). The EZH2 activity was also suppressed by 3-deazaneplanocin A (DZNep), EZH2 inhibitor, and the results demonstrated that, meanwhile, DZNep potently inhibited cell viability of HeLa/DDP cells, partly by suppression the levels of EZH2 and H3K27me3, but not H3K27me2, which was detected by western blotting analysis. Moreover, cell migration assay results showed that knockdown of EZH2 decreased cell metastasis of cervical cancer cells. Furthermore, cell cycle was detected by fluorescence-activated cell sorting (FACS) assay and the results demonstrated that interference with EZH2 expression increased the percentage of cells at G0/G1 phase and the HeLa/DDP cells were blocked at G0/G1 phase. Interestingly

  10. Patent Survey of Resveratrol, Taxol, Podophyllotoxin, Withanolides and Their Derivatives Used in Anticancer Therapy.

    PubMed

    Routh, Shreya; Nandagopal, Krishnadas

    2017-01-01

    Resveratrol, taxol, podophyllotoxin, withanolides and their derivatives find applications in anti-cancer therapy. They are plant-derived compounds whose chemical structures and synthesis limit their natural availability and restrict a large-scale industrial production. Hence, their production by various biotechnological approaches may hold promise for a continuous and reliable mode of supply. We review process and product patents in this regard. Accordingly, we provide a general outline to search the freely accessible WIPO, EPO, USPTO and Cambia databases with several keywords and patent codes. We have tabulated both granted and filed patents from the said databases. We retrieved ~40 patents from these databases. Novel biotechnological processes for production of these anticancer compounds include Agrobacterium rhizogenes-mediated hairy root culture, suspension culture, cell culture with elicitors, use of recombinant microorganisms, and bioreactors among others. The results are indicative of being both database-specific as well as queryspecific. A ten-year search window yielded 33 patents. The utility of the search strategy is discussed in the light of biotechnological developments in the field. Those who examine patent literature using similar search strategies may complement their knowledge obtained from perusal of mainstream journal resources. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. The relevance of using 3D cell cultures, in addition to 2D monolayer cultures, when evaluating breast cancer drug sensitivity and resistance

    PubMed Central

    Breslin, Susan; O'Driscoll, Lorraine

    2016-01-01

    Solid tumours naturally grow in 3D wherein the spatial arrangement of cells affects how they interact with each other. This suggests that 3D cell culture may mimic the natural in vivo setting better than traditional monolayer (2D) cell culture, where cells are grown attached to plastic. Here, using HER2-positive breast cancer cell lines as models (BT474, HCC1954, EFM192A), the effects of culturing cells in 3D using the poly-HEMA method compared to 2D cultures were assessed in terms of cellular viability, response/resistance to anti-cancer drugs, protein expression and enzyme activity. Scanning electron microscopy showed the morphology of cells in 3D to be substantially different to those cultured in 2D. Cell viability in 3D cells was substantially lower than that of cells in 2D cultures, while 3D cultures were more resistant to the effects of HER-targeted (neratinib) and classical chemotherapy (docetaxel) drugs. Expression of proteins involved in cell survival, transporters associated with drug resistance and drug targets were increased in 3D cultures. Finally, activity of drug metabolising enzyme CYP3A4 was substantially increased in 3D compared to 2D cultures. Together this data indicates that the biological information represented by 3D and 2D cell cultures is substantially different i.e. 3D cell cultures demonstrate higher innate resistance to anti-cancer drugs compared to 2D cultures, which may be facilitated by the altered receptor proteins, drug transporters and metabolising enzyme activity. This highlights the importance of considering 3D in addition to 2D culture methods in pre-clinical studies of both newer targeted and more traditional anti-cancer drugs. PMID:27304190

  12. Emodin enhances the chemosensitivity of endometrial cancer by inhibiting ROS-mediated Cisplatin-resistance.

    PubMed

    Ding, Ning; Zhang, Hong; Su, Shan; Ding, Yumei; Yu, Xiaohui; Tang, Yujie; Wang, Qingfang; Liu, Peishu

    2017-12-18

    Background Endometrial cancer is a common cause of death in gynecological malignancies. Cisplatin is a clinically chemotherapeutic agent. However, drug-resistance is the primary cause of treatment failure. Objective Emodin is commonly used clinically to increase the sensitivity of chemotherapeutic agents, yet whether Emodin promotes the role of Cisplatin in the treatment of endometrial cancer has not been studied. Method CCK-8 kit was utilized to determine the growth of two endometrial cancer cell lines, Ishikawa and HEC-IB. The apoptosis level of Ishikawa and HEC-IB cells was detected by Annexin V / propidium iodide double-staining assay. ROS level was detected by DCFH-DA and NADPH oxidase expression. Expressions of drug-resistant genes were examined by real-time PCR and Western blotting. Results Emodin combined with Cisplatin reduced cell growth and increased the apoptosis of endometrial cancer cells. Co-treatment of Emodin and Cisplatin increased chemosensitivity by inhibiting the expression of drug-resistant genes through reducing the ROS levels in endometrial cancer cells. In an endometrial cancer xenograft murine model, the tumor size was reduced and animal survival time was increased by co-treatment of Emodin and Cisplatin. Conclusion This study demonstrates that Emodin enhances the chemosensitivity of Cisplatin on endometrial cancer by inhibiting ROS-mediated expression of drug-resistance genes. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Reversion of the P-glycoprotein-mediated multidrug resistance of cancer cells by FK-506 derivatives.

    PubMed

    Jachez, B; Boesch, D; Grassberger, M A; Loor, F

    1993-04-01

    FK-506 is a resistance-modulating agent (RMA) for tumor cells whose multidrug resistance (MDR) involves a P-glycoprotein (Pgp)-mediated anti-cancer drug efflux. The family of FK-506 relatives and derivatives includes analogs which display a whole range of chemosensitizing strengths, from no detectable RMA activity to a complete reversion of the MDR phenotype. Similarly, FK-506 analogs display a whole range of immunosuppressive activities, including inactive ones. FK-506 was compared for RMA activity with 11 FK-506 analogs which were at least 20-fold less active than FK-506 for the inhibition of the bi-directional mixed lymphocyte reaction displayed the whole range of RMA activity. One such strong RMA derivative of FK-506 (SDZ 280-629) was further shown able to restore completely daunomycin retention by highly resistant MDR P388 tumor cells.

  14. The MUC4 mucin mediates gemcitabine resistance of human pancreatic cancer cells via the Concentrative Nucleoside Transporter family

    PubMed Central

    Skrypek, Nicolas; Duchêne, Bélinda; Hebbar, Mohamed; Leteurtre, Emmanuelle; Van Seuningen, Isabelle; Jonckheere, Nicolas

    2013-01-01

    The fluorinated analog of deoxycytidine, Gemcitabine (Gemzar®), is the main chemotherapy in pancreatic cancer, but survival remains weak mainly because of the high resistance of tumors to the drug. Recent works have shown that the mucin MUC4 may confer an advantage to pancreatic tumor cells by modifying their susceptibility to drugs. However, the cellular mechanism(s) responsible for this MUC4-mediated resistance is unknown. The aim of this work was to identify the cellular mechanisms responsible for gemcitabine resistance linked to MUC4 expression. CAPAN-2 and CAPAN-1 adenocarcinomatous pancreatic cancer cell lines were used to establish stable MUC4-deficient clones (MUC4-KD) by shRNA interference. Measurement of the IC50 index using tetrazolium salt test indicated that MUC4-deficient cells were more sensitive to gemcitabine. This was correlated with increased Bax/BclXL ratio and apoptotic cell number. Expression of Equilibrative/Concentrative Nucleoside Transporter (hENT1, hCNT1/3), deoxycytidine kinase (dCK), ribonucleotide reductase (RRM1/2) and Multidrug-resistance Protein (MRP3/4/5) was evaluated by quantitative RT-PCR (qRT-PCR) and Western-blotting. Alteration of MRP3, MRP4, hCNT1 and hCNT3 expression was observed in MUC4-KD cells but only hCNT1 alteration was correlated to MUC4 expression and sensitivity to gemcitabine. Decreased activation of MAPK, JNK and NF-κB pathways was observed in MUC4-deficient cells in which NF-κB pathway was found to play an important role both in sensitivity to gemcitabine and in hCNT1 regulation. Finally and accordingly to our in vitro data, we found that MUC4 expression was conversely correlated to that of hCNT1 in tissues from patients with pancreatic adenocarcinoma. This work describes a new mechanism of pancreatic cancer cell resistance to gemcitabine in which the MUC4 mucin negatively regulates the hCNT1 transporter expression via the NF-κB pathway. Altogether, these data point out to MUC4 and hCNT1 as potential targets

  15. Evolution of platinum resistance in high-grade serous ovarian cancer.

    PubMed

    Cooke, Susanna L; Brenton, James D

    2011-11-01

    High-grade serous ovarian cancers account for most ovarian-cancer mortality. Although this disease initially responds well to platinum-based chemotherapy, relapse and progression to chemotherapy resistance are frequently seen. Time to relapse after first-line therapy is a predictor of response to secondary platinum treatment: more than 12 months is associated with high chance of a secondary response, whereas relapses within 6 months generally indicate platinum resistance. In this Personal View we discuss whether patterns of response, relapse, and the development of drug resistance in high-grade serous ovarian cancers are related to distinct underlying molecular and cellular biological characteristics. In particular, we propose that rapid relapse with platinum-resistant disease is due to minor subpopulations of intrinsically resistant cancer cells at presentation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Quantification of sensitivity and resistance of breast cancer cell lines to anti-cancer drugs using GR metrics

    PubMed Central

    Hafner, Marc; Heiser, Laura M.; Williams, Elizabeth H.; Niepel, Mario; Wang, Nicholas J.; Korkola, James E.; Gray, Joe W.; Sorger, Peter K.

    2017-01-01

    Traditional means for scoring the effects of anti-cancer drugs on the growth and survival of cell lines is based on relative cell number in drug-treated and control samples and is seriously confounded by unequal division rates arising from natural biological variation and differences in culture conditions. This problem can be overcome by computing drug sensitivity on a per-division basis. The normalized growth rate inhibition (GR) approach yields per-division metrics for drug potency (GR50) and efficacy (GRmax) that are analogous to the more familiar IC50 and Emax values. In this work, we report GR-based, proliferation-corrected, drug sensitivity metrics for ~4,700 pairs of breast cancer cell lines and perturbagens. Such data are broadly useful in understanding the molecular basis of therapeutic response and resistance. Here, we use them to investigate the relationship between different measures of drug sensitivity and conclude that drug potency and efficacy exhibit high variation that is only weakly correlated. To facilitate further use of these data, computed GR curves and metrics can be browsed interactively at http://www.GRbrowser.org/. PMID:29112189

  17. Cell cycle arrest or survival signaling through αv integrins, activation of PKC and ERK1/2 lead to anoikis resistance of ovarian cancer spheroids.

    PubMed

    Carduner, Ludovic; Picot, Cédric R; Leroy-Dudal, Johanne; Blay, Lyvia; Kellouche, Sabrina; Carreiras, Franck

    2014-01-15

    Ovarian cancer is the most lethal gynecologic cancer mainly due to spheroids organization of cancer cells that disseminate within the peritoneal cavity. We have investigated the molecular mechanisms by which ovarian cancer spheroids resist anoikis, choosing as models the 2 well-characterized human ovarian cancer cell lines IGROV1 and SKOV3. These cell lines have the propensity to float as clusters, and were isolated from tumor tissue and ascites, respectively. To form spheroids, IGROV1 and SKOV3 ovarian adenocarcinoma cells were maintained under anchorage-independent culture conditions, in which both lines survive at least a week. A short apoptotic period prior to a survival signaling commitment was observed for IGROV1 cells whereas SKOV3 cells entered G0/G1 phase of the cell cycle. This difference in behavior was due to different signals. With regard to SKOV3 cells, activation of p38 and an increase in p130/Rb occurred once anchorage-independent culture was established. Analyses of the survival signaling pathway switched on by IGROV1 cells showed that activation of ERK1/2 was required to evade apoptosis, an effect partly dependent on PKC activation and αv integrins. αv-integrin expression is essential for survival through activation of ERK1/2 phosphorylation. The above data indicate that ovarian cancer cells can resist anoikis in the spheroid state by arrest in the cell cycle or through activation of αv-integrin-ERK-mediated survival signals. Such signaling might result in the selection of resistant cells within disseminating spheroids, favoring further relapse in ovarian cancers. © 2013 Elsevier Inc. All rights reserved.

  18. Targeting Nrf2 with wogonin overcomes cisplatin resistance in head and neck cancer.

    PubMed

    Kim, Eun Hye; Jang, Hyejin; Shin, Daiha; Baek, Seung Ho; Roh, Jong-Lyel

    2016-11-01

    A principal limitation to the clinical use of cisplatin is the high incidence of chemoresistance to this drug. Combination treatments with other drugs may help to circumvent this problem. Wogonin, one of the major natural flavonoids, is known to reverse multidrug resistance in several types of cancers. We investigated the ability of wogonin to overcome cisplatin resistance in head and neck cancer (HNC) cells and further clarified its molecular mechanisms of action. Two cisplatin-resistant HNC cell lines (AMC-HN4R and -HN9R) and their parental and other human HNC cell lines were used. The effects of wogonin, either alone or in combination with cisplatin, were assessed in HNC cells and normal cells using cell cycle and death assays and by measuring cell viability, reactive oxygen species (ROS) production, and protein expression, and in tumor xenograft mouse models. Wogonin selectively killed HNC cells but spared normal cells. It inhibited nuclear factor erythroid 2-related factor 2 and glutathione S-transferase P in cisplatin-resistant HNC cells, resulting in increased ROS accumulation in HNC cells, an effect that could be blocked by the antioxidant N-acetyl-L-cysteine. Wogonin also induced selective cell death by targeting the antioxidant defense mechanisms enhanced in the resistant HNC cells and activating cell death pathways involving PUMA and PARP. Hence, wogonin significantly sensitized resistant HNC cells to cisplatin both in vitro and in vivo. Wogonin is a promising anticancer candidate that induces ROS accumulation and selective cytotoxicity in HNC cells and can help to overcome cisplatin-resistance in this cancer.

  19. Resistance to cisplatin and paclitaxel does not affect the sensitivity of human ovarian cancer cells to antiprogestin-induced cytotoxicity.

    PubMed

    Gamarra-Luques, Carlos D; Hapon, Maria B; Goyeneche, Alicia A; Telleria, Carlos M

    2014-01-01

    Antiprogestin compounds have been shown to be effective in blocking the growth of ovarian cancer cells of different genetic backgrounds. Herein we studied the anti-ovarian cancer effect of a series of antiprogestins sharing the chemical backbone of the most characterized antiprogestin, mifepristone, but with unique modifications in position C-17 of the steroid ring. We assessed the effect of mifepristone-like antiprogestins on the growth of ovarian cancer cells sensitive to the standard combination therapy cisplatin-paclitaxel or made double-resistant upon six cycles of pulse-selection with the drugs used at clinically relevant concentrations and exposure times. IGROV-1 and SKOV-3 cells were pulsed with 20 μM cisplatin for 1 h followed by 100 nM paclitaxel for 3 h once a week for six weeks. The cells that did not die and repopulate the culture after the chemotherapies were termed Platinum-Taxane-EScape cells (PTES). Parental cells were compared against their PTES derivatives in their responses to further platinum-taxane treatments. Moreover, both ovarian cancer cells and their PTES siblings were exposed to escalating doses of the various antiprogestin derivatives. We assessed cell growth, viability and sub-G1 DNA content using microcapillary cytometry. Cyclin-dependent kinase inhibitors p21(cip1) and p27(kip1) and cleavage of downstream caspase-3 substrate PARP were used to assess whether cell fate, as a consequence of treatment, was limited to cytostasis or progressed to lethality. Cells subjected to six pulse-selection cycles of cisplatin-paclitaxel gave rise to sibling derivatives that displayed ~2-7 fold reduction in their sensitivities to further chemotherapy. However, regardless of the sensitivity the cells developed to the combination cisplatin-paclitaxel, they displayed similar sensitivity to the antiprogestins, which blocked their growth in a dose-related manner, with lower concentrations causing cytostasis, and higher concentrations causing lethality

  20. Resistance to cisplatin and paclitaxel does not affect the sensitivity of human ovarian cancer cells to antiprogestin-induced cytotoxicity

    PubMed Central

    2014-01-01

    Background Antiprogestin compounds have been shown to be effective in blocking the growth of ovarian cancer cells of different genetic backgrounds. Herein we studied the anti-ovarian cancer effect of a series of antiprogestins sharing the chemical backbone of the most characterized antiprogestin, mifepristone, but with unique modifications in position C-17 of the steroid ring. We assessed the effect of mifepristone-like antiprogestins on the growth of ovarian cancer cells sensitive to the standard combination therapy cisplatin-paclitaxel or made double-resistant upon six cycles of pulse-selection with the drugs used at clinically relevant concentrations and exposure times. Methods IGROV-1 and SKOV-3 cells were pulsed with 20 μM cisplatin for 1 h followed by 100 nM paclitaxel for 3 h once a week for six weeks. The cells that did not die and repopulate the culture after the chemotherapies were termed Platinum-Taxane-EScape cells (PTES). Parental cells were compared against their PTES derivatives in their responses to further platinum-taxane treatments. Moreover, both ovarian cancer cells and their PTES siblings were exposed to escalating doses of the various antiprogestin derivatives. We assessed cell growth, viability and sub-G1 DNA content using microcapillary cytometry. Cyclin-dependent kinase inhibitors p21cip1 and p27kip1 and cleavage of downstream caspase-3 substrate PARP were used to assess whether cell fate, as a consequence of treatment, was limited to cytostasis or progressed to lethality. Results Cells subjected to six pulse-selection cycles of cisplatin-paclitaxel gave rise to sibling derivatives that displayed ~2-7 fold reduction in their sensitivities to further chemotherapy. However, regardless of the sensitivity the cells developed to the combination cisplatin-paclitaxel, they displayed similar sensitivity to the antiprogestins, which blocked their growth in a dose-related manner, with lower concentrations causing cytostasis, and higher