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Sample records for multidrug-resistant tumor cells

  1. Reversal of multidrug resistance by 7-O-benzoylpyripyropene A in multidrug-resistant tumor cells.

    PubMed

    Rho, M C; Hayashi, M; Fukami, A; Obata, R; Sunazuka, T; Tomoda, H; Komiyama, K; Omura, S

    2000-10-01

    7-O-Benzoylpyripyropene A (7-O-BzP), a semi-synthetic analog of pyripyropene, was investigated for its reversing effect on multidrug-resistant (MDR) tumor cells. 7-O-BzP (6.25 microg/ml) completely reversed resistance against vincristine and adriamycin in vincristine-resistant KB cells (VJ-300) and adriamycin-resistant P388 cells (P388/ADR), respectively. 7-O-BzP alone had no effect on the growth of drug sensitive and drug-resistant cells. 7-O-BzP (6.25 microg/ml) significantly enhanced accumulation of [3H]vincristine in VJ-300 cells and completely inhibited the binding of [3H]azidopine to the P-glycoprotein in VJ-300 cells and P388/ADR cells. The result suggests that 7-O-BzP effectively reverses P-glycoprotein-related MDR by interacting directly with P-glycoprotein in drug resistant VJ-300 and P388/ADR cells. PMID:11132967

  2. Cell Biological Mechanisms of Multidrug Resistance in Tumors

    NASA Astrophysics Data System (ADS)

    Simon, Sanford M.; Schindler, Melvin

    1994-04-01

    Multidrug resistance (MDR) is a generic term for the variety of strategies tumor cells use to evade the cytotoxic effects of anticancer drugs. MDR is characterized by a decreased sensitivity of tumor cells not only to the drug employed for chemotherapy but also to a broad spectrum of drugs with neither obvious structural homology nor common targets. This pleotropic resistance is one of the major obstacles to the successful treatment of tumors. MDR may result from structural or functional changes at the plasma membrane or within the cytoplasm, cellular compartments, or nucleus. Molecular mechanisms of MDR are discussed in terms of modifications in detoxification and DNA repair pathways, changes in cellular sites of drug sequestration, decreases in drug-target affinity, synthesis of specific drug inhibitors within cells, altered or inappropriate targeting of proteins, and accelerated removal or secretion of drugs.

  3. Cell biological mechanisms of multidrug resistance in tumors.

    PubMed Central

    Simon, S M; Schindler, M

    1994-01-01

    Multidrug resistance (MDR) is a generic term for the variety of strategies tumor cells use to evade the cytotoxic effects of anticancer drugs. MDR is characterized by a decreased sensitivity of tumor cells not only to the drug employed for chemotherapy but also to a broad spectrum of drugs with neither obvious structural homology nor common targets. This pleiotropic resistance is one of the major obstacles to the successful treatment of tumors. MDR may result from structural or functional changes at the plasma membrane or within the cytoplasm, cellular compartments, or nucleus. Molecular mechanisms of MDR are discussed in terms of modifications in detoxification and DNA repair pathways, changes in cellular sites of drug sequestration, decreases in drug-target affinity, synthesis of specific drug inhibitors within cells, altered or inappropriate targeting of proteins, and accelerated removal or secretion of drugs. PMID:7909602

  4. Bioengineering approaches to study multidrug resistance in tumor cells

    PubMed Central

    Fallica, Brian; Makin, Guy

    2015-01-01

    The ability of cancer cells to become resistant to chemotherapeutic agents is a major challenge for the treatment of malignant tumors. Several strategies have emerged to attempt to inhibit chemoresistance, but the fact remains that resistance is a problem for every effective anticancer drug. The first part of this review will focus on the mechanisms of chemoresistance. It is important to understand the environmental cues, transport limitations and the cellular signaling pathways associated with chemoresistance before we can hope to effectively combat it. The second part of this review focuses on the work that needs to be done moving forward. Specifically, this section focuses on the necessity of translational research and interdisciplinary directives. It is critical that the expertise of oncologists, biologists, and engineers be brought together to attempt to tackle the problem. This discussion is from an engineering perspective, as the dialogue between engineers and other cancer researchers is the most challenging due to non-overlapping background knowledge. Chemoresistance is a complex and devastating process, meaning that we urgently need sophisticated methods to study the process of how cells become resistant. PMID:21387035

  5. Bisbenzylisoquinolines as modulators of chloroquine resistance in Plasmodium falciparum and multidrug resistance in tumor cells.

    PubMed

    Frappier, F; Jossang, A; Soudon, J; Calvo, F; Rasoanaivo, P; Ratsimamanga-Urverg, S; Saez, J; Schrevel, J; Grellier, P

    1996-06-01

    Ten naturally occurring bisbenzylisoquinolines (BBIQ) and two dihydro derivatives belonging to five BBIQ subgroups were evaluated in vitro for their ability to inhibit Plasmodium falciparum growth and, in drug combination, to reverse the resistance to chloroquine of strain FcB1. The same alkaloids were also assessed in vitro for their potentiating activity against vinblastine with the multidrug-resistant clone CCRF-CEM/VLB, established from lymphoblastic acute leukemia. Three of the BBIQ tested had 50% inhibitory concentrations of less than 1 microM. The most potent antimalarial agent was cocsoline (50% inhibitory concentration, 0.22 microM). Regarding the chloroquine-potentiating effect, fangchinoline exhibited the highest biological activity whereas the remaining compounds displayed either antagonistic or slight synergistic effects. Against the multidrug-resistant cancer cell line, fangchinoline was also by far the most active compound. Although there were clear differences between the activities of tested alkaloids, no relevant structure-activity relationship could be established. Nevertheless, fangchinoline appears to be a new biochemical tool able to help in the comprehension of the mechanism of both chloroquine resistance in P. falciparum and multidrug resistance in tumor cells. PMID:8726022

  6. Bisbenzylisoquinolines as modulators of chloroquine resistance in Plasmodium falciparum and multidrug resistance in tumor cells.

    PubMed Central

    Frappier, F; Jossang, A; Soudon, J; Calvo, F; Rasoanaivo, P; Ratsimamanga-Urverg, S; Saez, J; Schrevel, J; Grellier, P

    1996-01-01

    Ten naturally occurring bisbenzylisoquinolines (BBIQ) and two dihydro derivatives belonging to five BBIQ subgroups were evaluated in vitro for their ability to inhibit Plasmodium falciparum growth and, in drug combination, to reverse the resistance to chloroquine of strain FcB1. The same alkaloids were also assessed in vitro for their potentiating activity against vinblastine with the multidrug-resistant clone CCRF-CEM/VLB, established from lymphoblastic acute leukemia. Three of the BBIQ tested had 50% inhibitory concentrations of less than 1 microM. The most potent antimalarial agent was cocsoline (50% inhibitory concentration, 0.22 microM). Regarding the chloroquine-potentiating effect, fangchinoline exhibited the highest biological activity whereas the remaining compounds displayed either antagonistic or slight synergistic effects. Against the multidrug-resistant cancer cell line, fangchinoline was also by far the most active compound. Although there were clear differences between the activities of tested alkaloids, no relevant structure-activity relationship could be established. Nevertheless, fangchinoline appears to be a new biochemical tool able to help in the comprehension of the mechanism of both chloroquine resistance in P. falciparum and multidrug resistance in tumor cells. PMID:8726022

  7. Inhibition of tumor cells multidrug resistance by cucumarioside A2-2, frondoside A and their complexes with cholesterol.

    PubMed

    Menchinskaya, Ekaterina S; Aminin, Dmitry L; Avilov, Sergey A; Silchenko, Aleksandra S; Andryjashchenko, Pelageya V; Kalinin, Vladimir I; Stonik, Valentin A

    2013-10-01

    In non-cytotoxic concentrations, frondoside A (1) from the sea cucumber Cucumaria okhotensis and cucumarioside A2-2 (2) from C. japonica, as well as their complexes with cholesterol block the activity of membrane transport P-glycoprotein in cells of the ascite form of mouse Ehrlich carcinoma. They prevent in this way an efflux of fluorescent probe Calcein from the cells. Since the blocking of P-glycoprotein activity results in decrease of multidrug resistance, these glycosides and their complexes with cholesterol may be considered as potential inhibitors of multidrug resistance of tumor cells. PMID:24354179

  8. Pharmacogenomic and molecular docking studies on the cytotoxicity of the natural steroid wortmannin against multidrug-resistant tumor cells.

    PubMed

    Kuete, Victor; Saeed, Mohamed E M; Kadioglu, Onat; Börtzler, Jonas; Khalid, Hassan; Greten, Henry Johannes; Efferth, Thomas

    2015-01-15

    Wortmannin is a cytotoxic compound derived from the endophytic fungi Fusarium oxysporum, Penicillium wortmannii and Penicillium funiculosum that occurs in many plants, including medicinal herbs. The rationale to develop novel anticancer drugs is the frequent development of tumor resistance to the existing antineoplasic agents. Therefore, it is mandatory to analyze resistance mechanisms of novel drug candidates such as wortmannin as well to bring effective drugs into the clinic that have the potential to bypass or overcome resistance to established drugs and to substantially increase life span of cancer patients. In the present project, we found that P-glycoprotein-overexpressing tumor cells displaying the classical multidrug resistance phenotype toward standard anticancer drugs were not cross-resistant to wortmannin. Furthermore, three point-mutated PIK3CA protein structures revealed similar binding energies to wortmannin than wild-type PIK3CA. This protein is the primary target of wortmannin and part of the PI3K/AKT/mTOR signaling pathway. PIK3CA mutations are known to be associated with worse response to therapy and shortened its activity toward wild-type and mutant PIK3CA with similar efficacy. PMID:25636880

  9. BRCA2-deficient sarcomatoid mammary tumors exhibit multidrug resistance.

    PubMed

    Jaspers, Janneke E; Sol, Wendy; Kersbergen, Ariena; Schlicker, Andreas; Guyader, Charlotte; Xu, Guotai; Wessels, Lodewyk; Borst, Piet; Jonkers, Jos; Rottenberg, Sven

    2015-02-15

    Pan- or multidrug resistance is a central problem in clinical oncology. Here, we use a genetically engineered mouse model of BRCA2-associated hereditary breast cancer to study drug resistance to several types of chemotherapy and PARP inhibition. We found that multidrug resistance was strongly associated with an EMT-like sarcomatoid phenotype and high expression of the Abcb1b gene, which encodes the drug efflux transporter P-glycoprotein. Inhibition of P-glycoprotein could partly resensitize sarcomatoid tumors to the PARP inhibitor olaparib, docetaxel, and doxorubicin. We propose that multidrug resistance is a multifactorial process and that mouse models are useful to unravel this. PMID:25511378

  10. Activation of the mouse mdr3 gene by insertion of retroviruses in multidrug-resistant P388 tumor cells.

    PubMed Central

    Lepage, P; Devault, A; Gros, P

    1993-01-01

    In multidrug-resistant (MDR) derivatives of the mouse lymphoid tumor P388, the emergence of MDR is associated with overexpression and transcriptional activation of the mdr3 gene, either in the absence of (P388/VCR-10) or concomitant with (P388/ADM-2) gene amplification. In both instances, Northern (RNA) blotting analyses have suggested the presence of altered mdr3 transcripts in these cells, possibly originating from novel transcription initiation sites. The mechanisms underlying mdr3 overexpression in these cells have been investigated. In P388/VCR-10 cells, Southern blotting analyses together with genomic DNA cloning and nucleotide sequencing have demonstrated the presence of an intact mouse mammary tumor virus (MMTV) within the boundaries of intron 1 of mdr3. cDNA cloning and nucleotide sequencing indicated that this integration event results in the synthesis and overexpression of a hybrid MMTV-mdr3 mRNA which initiates within the U3 region of the 5' long terminal repeat (LTR) of the provirus. Consequently, this mRNA lacks the normal exon 1 of mdr3 but contains (i) MMTV LTR-derived sequences at its 5' end, (ii) a novel mdr3 exon, mapping within the boundaries of intron 1 downstream of the MMTV integration site and generated by alternative splicing, and (iii) an otherwise intact 3' portion of mdr3 starting at exon 2. A similar type of analysis of P388/ADM-2 cells revealed that mdr3 overexpression in these cells is associated with the integration of an intracisternal A particle (IAP) within an L1Md repetitive element, immediately upstream of mdr3. The IAP insertion results in the overexpression of hybrid IAP-mdr3 mRNA transcripts that initiate within the 3' LTR of the IAP and which contain IAP LTR-derived sequences at the 5' end spliced 14 nucleotides upstream of the normal exon 1 of mdr3. Taken together, these results indicate that independent retroviral insertions were the initial mutagenic event responsible for mdr3 overexpression and survival during drug

  11. Investigations on the cell metabolomics basis of multidrug resistance from tumor cells by ultra-performance liquid chromatography-mass spectrometry.

    PubMed

    Zhang, Ruixing; Zhuang, Xiaoyu; Zong, Li; Liu, Shu; Liu, Zhiqiang; Song, Fengrui

    2016-08-01

    Although anticancer drug resistance has been linked to high expression of P-glycoprotein and the enhanced DNA repair ability, the biochemical process and the underlying mechanisms of drug resistance are not clear. In order to clarify the biochemical mechanisms of drug resistance during anticancer drug treatment, we studied the metabolomics of MCF-7/S and MCF-7/Adr cell lines, the COC1 and COC1/DDP cell lines, including the metabolic pathways of multidrug-resistant tumor cells and the changes of endogenous substances in cells. The intracellular metabolites were profiled using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). In this study, 24 biomarkers in MCF-7/Adr cells and 15 biomarkers in COC1/DDP cells that are involved in some important metabolic pathways were putatively identified. Several metabolic pathways are changed in tumor cells showing drug resistance, such as protein synthesis pathways, cysteine synthesis, the glutamine metabolic pathway, and the ammonia cycle; the first of these are involved in the synthesis of some important proteins including membrane proteins, multidrug resistance-associated proteins, and P-glycoprotein (P-gp). Proteins related to drug resistance were overexpressed in multidrug-resistant tumor cells. These proteins depended on energy and play important roles in the emergence of drug resistance. The changes in glutathione and cysteine metabolic pathways showed that the cells can activate related metabolic pathways and reduce the cell apoptosis when they encounter oxidative damage. These findings indicate that drug resistance is likely associated with increased P-gp synthesis and reduced apoptosis of tumor cells. Graphical Abstract Drug resistance was charactered in the changing of genomics and proteomics. Like enhancing DNA repair, reducing uptake, high P-g protein expression. Here, we studied the changes of metabolite pathway which could be also play an imported role in drug resistance. PMID

  12. Four ardeemin analogs from endophytic Aspergillus fumigatus SPS-02 and their reversal effects on multidrug-resistant tumor cells.

    PubMed

    Zhang, Hua-Wei; Ying, Chen; Tang, Yi-Fei

    2014-01-01

    Four ardeemin derivatives, 5-N-acetylardeemin (1), 5-N-acetyl-15bβ-hydroxyardeemin (2), 5-N-acetyl-15b-didehydroardeemin (3), and 5-N-acetyl-16α-hydroxyardeemin (4), were isolated from the fermentation broth of an endophytic Aspergillus fumigatus SPS-02 associated with Artemisia annua L. The structures of these metabolites were elucidated by a combination of spectroscopic data, including 1D-, 2D-NMR and MS. In vitro chemosensitization assay indicated that these ardeemins had different activities of reversing the multidrug-resistant (MDR) phenotype in three cancer cell lines, leukemia doxorubicin resistant cell K562/DOX, human lung adenocarcinoma cis-platin-resistant cell A549/DDP, and ovarian cancer cisplatin-resistant cell SK-OV-S/DDP. Compound 4 exhibited the strongest MDR reversing effect at 5 μM concentration in K562/DOX and A549/DDP cell lines 5.2±0.18-fold, 8.2±0.23-fold, respectively, while compound 2 had the highest reversal capacity in SK-OV-S/DDP cell line with 10.8±0.28 fold. Preliminary investigation of their structureactivity relationship suggested that a OH group at C(15b) or C(16) in ardeemin plays a key role in reversing the MDR effect. It is the first report on ardeemin analogs from endophytic A. fumigatus with reversal effects on MDR cancer cell lines K562/DOX, A549/DDP and SK-OV-S/DDP. PMID:24443428

  13. Triptolide Induces Cell Killing in Multidrug-Resistant Tumor Cells via CDK7/RPB1 Rather than XPB or p44.

    PubMed

    Yi, Jun-Mei; Huan, Xia-Juan; Song, Shan-Shan; Zhou, Hu; Wang, Ying-Qing; Miao, Ze-Hong

    2016-07-01

    Multidrug resistance (MDR) is a major cause of tumor treatment failure; therefore, drugs that can avoid this outcome are urgently needed. We studied triptolide, which directly kills MDR tumor cells with a high potency and a broad spectrum of cell death. Triptolide did not inhibit P-glycoprotein (P-gp) drug efflux and reduced P-gp and MDR1 mRNA resulting from transcription inhibition. Transcription factors including c-MYC, SOX-2, OCT-4, and NANOG were not correlated with triptolide-induced cell killing, but RPB1, the largest subunit of RNA polymerase II, was critical in mediating triptolide's inhibition of MDR cells. Triptolide elicited antitumor and anti-MDR activity through a universal mechanism: by activating CDK7 by phosphorylating Thr170 in both parental and MDR cell lines and in SK-OV-3 cells. The CDK7-selective inhibitor BS-181 partially rescued cell killing induced by 72-hour treatment of triptolide, which may be due to partial rescue of RPB1 degradation. We suggest that a precise phosphorylation site on RPB1 (Ser1878) was phosphorylated by CDK7 in response to triptolide. In addition, XPB and p44, two transcription factor TFIIH subunits, did not contribute to triptolide-driven RPB1 degradation and cell killing, although XPB was reported to covalently bind to triptolide. Several clinical trials are underway to test triptolide and its analogues for treating cancer and other diseases, so our data may help expand potential clinical uses of triptolide, as well as offer a compound that overcomes tumor MDR. Future investigations into the primary molecular target(s) of triptolide responsible for RPB1 degradation may suggest novel anti-MDR target(s) for therapeutic development. Mol Cancer Ther; 15(7); 1495-503. ©2016 AACR. PMID:27197304

  14. Identification of compounds selectively killing multidrug resistant cancer cells

    PubMed Central

    Türk, Dóra; Hall, Matthew D.; Chu, Benjamin F.; Ludwig, Joseph A.; Fales, Henry M.; Gottesman, Michael M.; Szakács, Gergely

    2009-01-01

    There is a great need for the development of novel chemotherapeutic agents that overcome the emergence of multidrug resistance in cancer. We catalogued the National Cancer Institute’s Developmental Therapeutics Program (DTP) drug repository in search of compounds showing increased toxicity in multidrug resistant (MDR) cells. By comparing the sensitivity of parental cell lines with multidrug resistant derivatives, we identified 22 compounds possessing MDR-selective activity. Analysis of structural congeners led to the identification of 15 additional drugs showing increased toxicity in Pgp-expressing cells. Analysis of MDR-selective compounds led to the formulation of structure activity relationships (SAR) and pharmacophore models. This data mining coupled with experimental data points to a possible mechanism of action linked to metal chelation. Taken together, the discovery of the MDR-selective compound set demonstrates the robustness of the developing field of MDR-targeting therapy as a new strategy for resolving Pgp-mediated multidrug resistance. PMID:19843850

  15. 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

  16. Nanodrug delivery in reversing multidrug resistance in cancer cells.

    PubMed

    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 MDR in

  17. Reversal effect of Dioscin on multidrug resistance in human hepatoma HepG2/adriamycin cells.

    PubMed

    Sun, Bu Tong; Zheng, Li Hua; Bao, Yong Li; Yu, Chun Lei; Wu, Yin; Meng, Xiang Ying; Li, Yu Xin

    2011-03-01

    Multidrug resistance is a serious obstacle encountered in cancer treatment. Since drug resistance in human cancer is mainly associated with overexpression of the multidrug resistance gene 1 (MDR1), the promoter of the human MDR1 gene may be a target for multidrug resistance reversion drug screening. In the present study, HEK293T cells were transfected with pGL3 reporter plasmids containing the 2kb of MDR1 promoter, and the transfected cells were used as models to screen for candidate multidrug resistance inhibitors from over 300 purified naturally occurring compounds extracted from plants and animals. Dioscin was found to have an inhibiting effect on MDR1 promoter activity. The resistant HepG2 cell line (HepG2/adriamycin) was used to validate the activity of multidrug resistance reversal by Dioscin. Results showed that Dioscin could decrease the resistance degree of HepG2/adriamycin cells, and significantly inhibit P-glycoprotein expression, as well as increase the accumulation of adriamycin in HepG2/adriamycin cells as measured by Flow Cytometric analysis. These results suggest that Dioscin is a potent multidrug resistance reversal agent and may be a potential adjunctive agent for tumor chemotherapy. PMID:21195709

  18. Phorbol esters induce multidrug resistance in human breast cancer cells

    SciTech Connect

    Fine, R.L.; Patel, J.; Chabner, B.A.

    1988-01-01

    Mechanisms responsible for broad-based resistance to antitumor drugs derived from natural products (multidrug resistance) are incompletely understood. Agents known to reverse the multidrug-resistant phenotype (verapamil and trifluoperazine) can also inhibit the activity of protein kinase C. When the authors assayed human breast cancer cell lines for protein kinase C activity, they found that enzyme activity was 7-fold higher in the multidrug-resistance cancer cells compared with the control, sensitive parent cells. Exposure of drug-sensitive cells to the phorbol ester phorbol 12,13-dibutyate (P(BtO)/sub 2/) led to an increase in protein kinase C activity and induced a drug-resistance phenotype, whereas exposure of drug-resistant cells to P(BtO)/sub 2/ further increased drug resistance. In sensitive cells, this increased resistance was accomplished by a 3.5-fold increased phosphorylation of a 20-kDa particulate protein and a 35-40% decreased intracellular accumulation of doxorubicin and vincristine. P(BtO)/sub 2/ induced resistance to agents involved in the multidrug-resistant phenotype (doxorubicin and vincristine) but did not affect sensitivity to an unrelated alkylating agent (melphalan). The increased resistance was partially or fully reversible by the calcium channel blocker verapamil and by the calmodulin-antagonist trifluoperazine. These data suggest that stimulation of protein kinase C playus a role in the drug-transport changes in multidrug-resistant cells. This may occur through modulation of an efflux pump by protein phosphorylation.

  19. Nanomedicinal strategies to treat multidrug-resistant tumors: current progress

    PubMed Central

    Dong, Xiaowei; Mumper, Russell J

    2010-01-01

    Multidrug resistance (MDR) is a major impediment to the success of cancer chemotherapy. P-glycoprotein is an important and the best-known membrane transporter involved in MDR. Several strategies have been used to address MDR, especially P-glycoprotein-mediated drug resistance in tumors. However, clinical success has been limited, largely due to issues regarding lack of efficacy and/or safety. Nanoparticles have shown the ability to target tumors based on their unique physical and biological properties. To date, nanoparticles have been investigated primarily to address P-glycoprotein and the observed improved anticancer efficacy suggests that nanomedicinal strategies provide a new opportunity to overcome MDR. This article focuses on nanotechnology-based formulations and current nanomedicine approaches to address MDR in tumors and discusses the proposed mechanisms of action. PMID:20528455

  20. Increased multi-drug resistance and reduced apoptosis in osteosarcoma side population cells are crucial factors for tumor recurrence

    PubMed Central

    WANG, YANG; TENG, JIA-SONG

    2016-01-01

    The present study investigated the characteristic features of cancer stem cells (CSCs) using an aggressive human osteosarcoma cell line OS-65. Hoechst 33342 dye exclusion was used to distinguish the cancer stem-like side population (SP) cells from OS-65 cells. Furthermore, the SP cells were characterized via chemoresistance and cell death assays, reverse transcription-quantitative polymerase chain reaction and immunofluorescence. The present study identified ~3.3% of cancer stem-like SP cells from OS-65 cells whose prevalence is reduced significantly (0.9%) following treatment with verapamil. It was demonstrated that osteosarcoma SP cells are highly efficient at generating additional sarcospheres as transcriptional regulation of stemness genes, including SOX2, OCT-4 and NANOG, is highly upregulated. Notably, these SP cells demonstrated high resistance against chemotherapeutic drugs and apoptosis via elevated transcriptional regulation of several ATPase binding cassette (ABC) transporter and anti-apoptotic proteins, including ABCG2, ABCB1/MDR1 ABCB5, B cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein, respectively. The results of the present study suggested that CSCs may be a novel therapeutic target for the prevention of tumor relapse. PMID:27347020

  1. An Autocrine Cytokine/JAK/STAT-Signaling Induces Kynurenine Synthesis in Multidrug Resistant Human Cancer Cells

    PubMed Central

    Campia, Ivana; Buondonno, Ilaria; Castella, Barbara; Rolando, Barbara; Kopecka, Joanna; Gazzano, Elena; Ghigo, Dario; Riganti, Chiara

    2015-01-01

    Background Multidrug resistant cancer cells are hard to eradicate for the inefficacy of conventional anticancer drugs. Besides escaping the cytotoxic effects of chemotherapy, they also bypass the pro-immunogenic effects induced by anticancer drugs: indeed they are not well recognized by host dendritic cells and do not elicit a durable anti-tumor immunity. It has not yet been investigated whether multidrug resistant cells have a different ability to induce immunosuppression than chemosensitive ones. We addressed this issue in human and murine chemosensitive and multidrug resistant cancer cells. Results We found that the activity and expression of indoleamine 2,3-dioxygenase 1 (IDO1), which catalyzes the conversion of tryptophan into the immunosuppressive metabolite kynurenine, was higher in all the multidrug resistant cells analyzed and that IDO1 inhibition reduced the growth of drug-resistant tumors in immunocompetent animals. In chemoresistant cells the basal activity of JAK1/STAT1 and JAK1/STAT3 signaling was higher, the STAT3 inhibitor PIAS3 was down-regulated, and the autocrine production of STAT3-target and IDO1-inducers cytokines IL-6, IL-4, IL-1β, IL-13, TNF-α and CD40L, was increased. The disruption of the JAK/STAT signaling lowered the IDO1 activity and reversed the kynurenine-induced pro-immunosuppressive effects, as revealed by the restored proliferation of T-lymphocytes in STAT-silenced chemoresistant cells. Conclusions Our work shows that multidrug resistant cells have a stronger immunosuppressive attitude than chemosensitive cells, due to the constitutive activation of the JAK/STAT/IDO1 axis, thus resulting chemo- and immune-evasive. Disrupting this axis may significantly improve the efficacy of chemo-immunotherapy protocols against resistant tumors. PMID:25955018

  2. Overcoming Multidrug Resistance in Cancer Stem Cells

    PubMed Central

    Moitra, Karobi

    2015-01-01

    The principle mechanism of protection of stem cells is through the expression of ATP-binding cassette (ABC) transporters. These transporters serve as the guardians of the stem cell population in the body. Unfortunately these very same ABC efflux pumps afford protection to cancer stem cells in tumors, shielding them from the adverse effects of chemotherapy. A number of strategies to circumvent the function of these transporters in cancer stem cells are currently under investigation. These strategies include the development of competitive and allosteric modulators, nanoparticle mediated delivery of inhibitors, targeted transcriptional regulation of ABC transporters, miRNA mediated inhibition, and targeting of signaling pathways that modulate ABC transporters. The role of ABC transporters in cancer stem cells will be explored in this paper and strategies aimed at overcoming drug resistance caused by these particular transporters will also be discussed. PMID:26649310

  3. A highly tumor-targeted nanoparticle of podophyllotoxin penetrated tumor core and regressed multidrug resistant tumors

    PubMed Central

    Roy, Aniruddha; Ernsting, Mark J.; Undzys, Elijus; Li, Shyh-Dar

    2015-01-01

    Podophyllotoxin (PPT) exhibited significant activity against P-glycoprotein mediated multidrug resistant (MDR) tumor cell lines; however, due to its poor solubility and high toxicity, PPT cannot be dosed systemically, preventing its clinical use for MDR cancer. We developed a nanoparticle dosage form of PPT by covalently conjugating PPT and polyethylene glycol (PEG) with acetylated carboxymethyl cellulose (CMC-Ac) using one-pot esterification chemistry. The polymer conjugates self-assembled into nanoparticles (NPs) of variable sizes (20–120 nm) depending on the PPT-to-PEG molar ratio (2–20). The conjugate with a low PPT/PEG molar ratio of 2 yielded NPs with a mean diameter of 20 nm and released PPT at ~5%/day in serum, while conjugates with increased PPT/PEG ratios (5 and 20) produced bigger particles (30 nm and 120 nm respectively) that displayed slower drug release (~2.5%/day and ~1%/day respectively). The 20 nm particles exhibited 2- to 5-fold enhanced cell killing potency and 5- to 20-fold increased tumor delivery compared to the larger NPs. The biodistribution of the 20 nm PPT-NPs was highly selective to the tumor with 8-fold higher accumulation than all other examined tissues, while the larger PPT-NPs (30 and 100 nm) exhibited increased liver uptake. Within the tumor, >90% of the 20 nm PPT-NPs penetrated to the hypovascular core, while the larger particles were largely restricted in the hypervascular periphery. The 20 nm PPT-NPs displayed significantly improved efficacy against MDR tumors in mice compared to the larger PPT-NPs, native PPT and the standard taxane chemotherapies, with minimal toxicity. PMID:25818440

  4. IF7-Conjugated Nanoparticles Target Annexin 1 of Tumor Vasculature against P-gp Mediated Multidrug Resistance.

    PubMed

    Yu, De-Hong; Liu, Ya-Rong; Luan, Xin; Liu, Hai-Jun; Gao, Yun-Ge; Wu, Hao; Fang, Chao; Chen, Hong-Zhuan

    2015-08-19

    Multidrug resistance is the main cause of clinical chemotherapeutic failure. Antiangiogenic cancer therapy with nanomedicine that allows the targeted delivery of antiangiogenic agents to tumor endothelial cells may contribute to innovative strategies for treating multidrug-resistant cancers. In this study, we developed a new nanodrug delivery system (nano-DDS), with improved antiangiogenic efficacy against multidrug resistant human breast cancer MCF-7/ADR cells. Here, the IF7 ligand was a peptide designed to bind the annexin 1 (Anxa 1), a highly specific marker of the tumor vasculature surface, with high affinity and specificity. IF7-conjugated Anxa 1-targeting nanoparticles containing paclitaxel (IF7-PTX-NP) allowed controlled drug release and displayed favorable prolonged circulation in vivo. IF7-PTX-NP was significantly internalized by human umbilical vein endothelial cells (HUVEC) through the IF7-Anxa 1 interaction, and this facilitated uptake enhanced the expected antiangiogenic activity of inhibiting HUVEC proliferation, migration, and tube formation in a Matrigel plug relative to those of Taxol and PTX-NP. As IF7-PTX-NP targeted the tumor vessels, more nanoparticles accumulated in MCF-7/ADR tumors, and more importantly, induced significant apoptosis of the tumor vascular endothelial cells and necrosis of the tumor tissues. Low dose paclitaxel (1 mg/kg) formulated in IF7-PTX-NP showed significant anticancer efficacy, delaying the growth of MCF-7/ADR tumors. The same efficacy was only obtained with an 8-fold dose of paclitaxel (8 mg/kg) as Taxol plus XR9576, a potent P-gp inhibitor. The anticancer efficacy of IF7-PTX-NP was strongly associated with the improved antiangiogenic effect, evident as a dramatic reduction in the tumor microvessel density and pronounced increase in apoptotic tumor cells, with no obvious toxicity to the mice. This nano-DDS, which targets the tumor neovasculature, offers a promising strategy for the treatment of multidrug-resistant

  5. Metformin reverses multidrug resistance in human hepatocellular carcinoma Bel-7402/5-fluorouracil cells

    PubMed Central

    LING, SUNBIN; TIAN, YU; ZHANG, HAIQUAN; JIA, KAIQI; FENG, TINGTING; SUN, DEGUANG; GAO, ZHENMING; XU, FEI; HOU, ZHAOYUAN; LI, YAN; WANG, LIMING

    2014-01-01

    Metformin exhibits anti-proliferative effects in tumor cells in vitro and in vivo. The present study investigated the ability of metformin to reverse multidrug resistance (MDR) in human hepatocellular carcinoma Bel-7402/5-fluorouracil (5-Fu; Bel/Fu) cells. The synergistic anti-proliferative effect of metformin combined with 5-Fu was evaluated using a Cell Counting kit-8 assay. The variation in apoptotic rates and cell cycle distribution were evaluated using a flow cytometric assay and variations in target gene and protein expression were monitored using reverse transcription-polymerase chain reaction and western blot analysis. The results demonstrated that metformin had a synergistic anti-proliferative effect with 5-Fu in the Bel/Fu cells. The variations in the number of apoptotic cells and distribution of the cell cycle were consistent with the variability in cell viability. Metformin targeted the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, suppressed the expression of hypoxia-inducible factor-1α (HIF-1α) and transcriptionally downregulated the expression of multidrug resistance protein 1/P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1). Collectively, these findings suggested that metformin may target the AMPK/mTOR/HIF-1α/P-gp and MRP1 pathways to reverse MDR in hepatocellular carcinoma. PMID:25310259

  6. Codelivery of Chemotherapeutics via Crosslinked Multilamellar Liposomal Vesicles to Overcome Multidrug Resistance in Tumor

    PubMed Central

    Joo, Kye-Il; Wong, Michael K.; Wang, Pin

    2014-01-01

    Multidrug resistance (MDR) is a significant challenge to effective cancer chemotherapy treatment. However, the development of a drug delivery system that allows for the sustained release of combined drugs with improved vesicle stability could overcome MDR in cancer cells. To achieve this, we have demonstrated codelivery of doxorubicin (Dox) and paclitaxel (PTX) via a crosslinked multilamellar vesicle (cMLV). This combinatorial delivery system achieves enhanced drug accumulation and retention, in turn resulting in improved cytotoxicity against tumor cells, including drug-resistant cells. Moreover, this delivery approach significantly overcomes MDR by reducing the expression of P-glycoprotein (P-gp) in cancer cells, thus improving antitumor activity in vivo. Thus, by enhancing drug delivery to tumors and lowering the apoptotic threshold of individual drugs, this combinatorial delivery system represents a potentially promising multimodal therapeutic strategy to overcome MDR in cancer therapy. PMID:25330237

  7. A peptide derived from phage display library exhibits anti-tumor activity by targeting GRP78 in gastric cancer multidrug resistance cells.

    PubMed

    Kang, Jianqin; Zhao, Guohong; Lin, Tao; Tang, Shanhong; Xu, Guanghui; Hu, Sijun; Bi, Qian; Guo, Changcun; Sun, Li; Han, Shuang; Xu, Qian; Nie, Yongzhan; Wang, Biaoluo; Liang, Shuhui; Ding, Jie; Wu, Kaichun

    2013-10-10

    Multidrug resistance (MDR) remains a significant challenge to the clinical treatment of gastric cancer (GC). In the present study, using a phage display approach combined with MTT assays, we screened a specific peptide GMBP1 (Gastric cancer MDR cell-specific binding peptide), ETAPLSTMLSPY, which could bind to the surface of GC MDR cells specifically and reverse their MDR phenotypes. Immunocytochemical staining showed that the potential receptor of GMBP1 was located at the membrane and cytoplasm of MDR cells. In vitro and in vivo drug sensitivity assays, FACS analysis and Western blotting confirmed that GMBP1 was able to re-sensitize MDR cells to chemical drugs. Western blotting and proteomic approaches were used to screen the receptor of GMBP1, and GRP78, a MDR-related protein, was identified as a receptor of GMBP1. This result was further supported by immunofluoresence microscopy and Western blot. Additionally, Western blotting demonstrated that pre-incubation of GMBP1 in MDR cells greatly diminished MDR1, Bcl-2 and GRP78 expression but increased the expression of Bax, whereas downregulation of GRP78, function as a receptor and directly target for GMBP1, only inhibited MDR1 expression. Our findings suggest that GMBP1 could re-sensitize GC MDR cells to a variety of chemotherapeutic agents and this role might be mediated partly through down-regulating GRP78 expression and then inhibiting MDR1 expression. These findings indicate that peptide GMBP1 likely recognizes a novel GRP78 receptor and mediates cellular activities associated with the MDR phenotype, which provides new insight into research on the management of MDR in gastric cancer cells. PMID:23792224

  8. Quantitative analysis of MDR1 (multidrug resistance) gene expression in human tumors by polymerase chain reaction

    SciTech Connect

    Noonan, K.E.; Beck, C.; Holzmayer, T.A.; Chin, J.E.; Roninson, I.B. ); Wunder, J.S.; Andrulis, I.L. ); Gazdar, A.F. ); Willman, C.L.; Griffith, B. ); Von Hoff, D.D. )

    1990-09-01

    The resistance of tumor cells ot chemotheraprutic drugs is a major obstacle to successful cancer chemotherapy. In human cells, expression of the MDR1 gene, encoding a transmembrane efflux pump (P-glycoprotein), leads to decreased intracellular accumulation and resistance to a variety of lipophilic drugs (multidrug resistance; MDR). The levels of MDR in cell lines selected in bitro have been shown to correlate with the steady-state levels of MDR1 mRNA and P-glycoprotein. In cells with a severalfold increase in cellular drug resistance, MDR1 expression levels are close to the limits of detection by conventional assays. MDR1 expression has been frequently observed in human tumors after chemotherapy and in some but not all types of clinically refactory tumors untreated with chemotherapeutic drugs. The authors have devised a highly sensitive, specific, and quantitative protocol for measuring the levels of MDR1 mRNA in clincal samples, based on the polymerase chain reaction. They have used this assay to measure MDR1 gene expression in MDR cell lines and >300 normal tissues, tumor-derived cell lines, and clinical specimens of untreated tumors of the types in which MDR1 expression was rarely observed by standard assays. Low levels of MDR1 expression were found by polymerase chain reaction in most solid tumors and leukemias tested. The frequency of samples without detectable MDR1 expression varied among different types of tumors; MDR1-negative samples were ost common among tumor types known to be relatively responsive to chemotherapy.

  9. Chinese hamster pleiotropic multidrug-resistant cells are not radioresistant

    SciTech Connect

    Mitchell, J.B.; Gamson, J.; Russo, A.; Friedman, N.; DeGraff, W.; Carmichael, J.; Glatstein, E.

    1988-01-01

    The inherent cellular radiosensitivity of a Chinese hamster ovary pleiotropic cell line that is multidrug resistant (CHRC5) was compared to that of its parental cell line (AuxB1). Radiation survival curve parameters n and D0 were 4.5 and 1.1 Gy, respectively, for the CHRC5 line and 5.0 and 1.2 Gy, respectively, for the parental line. Thus, the inherent radiosensitivity of the two lines was similar even though key intracellular free radical scavenging and detoxifying systems employing glutathione, glutathione transferase, and catalase produced enzyme levels that were 2.0-, 1.9-, and 1.9-fold higher, respectively, in the drug-resistant cell line. Glutathione depletion by buthionine sulfoximine resulted in the same extent of aerobic radiosensitization in both lines (approximately 10%). Incorporation of iododeoxyuridine into cellular DNA sensitized both cell lines to radiation. These studies indicate that pleiotropic drug resistance does not necessarily confer radiation resistance.

  10. Aliphatic acid-conjugated antimicrobial peptides--potential agents with anti-tumor, multidrug resistance-reversing activity and enhanced stability.

    PubMed

    Deng, Xin; Qiu, Qianqian; Ma, Ke; Wang, Xuekun; Huang, Wenlong; Qian, Hai

    2015-07-28

    Compared with traditional therapeutics, antimicrobial peptides as novel anti-tumor agents have prominent advantages of higher specificity and circumvention of multi-drug resistance. In a previous study, we found that B1, an antimicrobial peptide derived from Cathelicidin-BF15, presented specific anti-tumor activity against several tumor cells. Since aliphatic chain-conjugated peptides have shown ameliorative activity and stability, we conjugated aliphatic acids with different lengths to the amino terminal of B1. All the conjugated peptides exhibited improved anti-tumor activity over B1. Further investigations revealed that the peptides were capable of disrupting the cell membrane, stimulating cytochrome c release into the cytosol, which results in apoptosis. The peptides also acted against multidrug resistant cells and had multidrug resistance-reversing effects. Additionally, conjugation of aliphatic acid enhanced the peptide stability in plasma. In summary, aliphatic acid-modified peptides might be promising anti-tumor agents in the future. PMID:26083110

  11. Role of multidrug resistance in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Diddens, Heyke C.

    1992-06-01

    Multidrug resistance in cancer chemotherapy is a well established phenomenon. One of the most common phenotypical changes in acquired or intrinsic multidrug resistance in human tumor cells is the overexpression of the mdrl gene product P-glycoprotein, which acts as an active efflux pump. Increased levels of P-glycoprotein are associated with resistance to a variety of anticancer drugs commonly used in tumor chemotherapy like anthracyclins, vinca- alcaloids, epipodophyllotoxins or actinomycin D. We investigated the efficacy or photodynamic therapy in the treatment of tumor cells expressing the multidrug resistance phenotype. Our data show that multidrug resistant cells are highly cross resistant to the phototoxic stain rhodamine 123 but exhibit only low degrees of cross resistance (2 - 3 -folds) to the photosensitizers Photosan-3, Clorin-2, methylene blue and meso-tetra (4- sulfonatophenyl) porphine (TPPS4). Resistance is associated with a decrease in intracellular accumulation of the photosensitizer. Verapamil, a membrane active compound known to enhance drug sensitivity in multidrug resistant cells by inhibition of P-glycoprotein, also increases phototoxicity in multidrug resistant cells. Our results imply that tumors expressing the multidrug resistance phenotype might fail to respond to photochemotherapy with rhodamine 123. On the other hand, multidrug resistance may not play an important role in photodynamic therapy with Photosan-3, Chlorin-2, methylene blue or TPPS4.

  12. Ascites Increases Expression/Function of Multidrug Resistance Proteins in Ovarian Cancer Cells.

    PubMed

    Mo, Lihong; Pospichalova, Vendula; Huang, Zhiqing; Murphy, Susan K; Payne, Sturgis; Wang, Fang; Kennedy, Margaret; Cianciolo, George J; Bryja, Vitezslav; Pizzo, Salvatore V; Bachelder, Robin E

    2015-01-01

    Chemotherapy resistance is the major reason for the failure of ovarian cancer treatment. One mechanism behind chemo-resistance involves the upregulation of multidrug resistance (MDR) genes (ABC transporters) that effectively transport (efflux) drugs out of the tumor cells. As a common symptom in stage III/IV ovarian cancer patients, ascites is associated with cancer progression. However, whether ascites drives multidrug resistance in ovarian cancer cells awaits elucidation. Here, we demonstrate that when cultured with ascites derived from ovarian cancer-bearing mice, a murine ovarian cancer cell line became less sensitive to paclitaxel, a first line chemotherapeutic agent for ovarian cancer patients. Moreover, incubation of murine ovarian cancer cells in vitro with ascites drives efflux function in these cells. Functional studies show ascites-driven efflux is suppressible by specific inhibitors of either of two ABC transporters [Multidrug Related Protein (MRP1); Breast Cancer Related Protein (BCRP)]. To demonstrate relevance of our findings to ovarian cancer patients, we studied relative efflux in human ovarian cancer cells obtained from either patient ascites or from primary tumor. Immortalized cell lines developed from human ascites show increased susceptibility to efflux inhibitors (MRP1, BCRP) compared to a cell line derived from a primary ovarian cancer, suggesting an association between ascites and efflux function in human ovarian cancer. Efflux in ascites-derived human ovarian cancer cells is associated with increased expression of ABC transporters compared to that in primary tumor-derived human ovarian cancer cells. Collectively, our findings identify a novel activity for ascites in promoting ovarian cancer multidrug resistance. PMID:26148191

  13. Biomimetic RNA Silencing Nanocomplexes Overcome Multidrug Resistance in Cancer Cells**

    PubMed Central

    Wang, Zhongliang; Wang, Zhe; Liu, Dingbin; Yan, Xuefeng; Wang, Fu; Niu, Gang

    2015-01-01

    RNA interference (RNAi) is an RNA-dependent gene silencing approach controlled by RNA-induced silencing complex (RISC). Here we represent 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. The nanocomplexes targeting to multidrug resistance are able to not only bypass P-glycoprotein (Pgp) transporter due to their nano-size effect, but also effectively suppress the 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. PMID:24446433

  14. In vivo uptake of carbon-14-colchicine for identification of tumor multidrug resistance

    SciTech Connect

    Mehta, B.M.; Rosa, E.; Biedler, J.L.

    1994-07-01

    A major limitation in the treatment of cancer with natural product chemotherapeutic agents is the development of multidrug resistance (MDR). Multidrug resistance is attributed to enhanced expression of the multidrug resistance gene MDR1. Colchicine (CHC) is known to be one of the MDR drugs. The authors have previously demonstrated that it is possible to distinguish multidrug resistant tumors from the multidrug-sensitive tumors in vivo on the basis of tritium ({sup 3}H) uptake following injection of {sup 3}H-CHC. The present studies were carried out in xenografted animals using {sup 14}C-CHC which may be more indicative of {sup 11}C-labeled CHC distribution with regard to circulating metabolites, since metabolic processes following injection of (ring C, methoxy-{sup 11}C)-CHC may produce significant amounts of circulating 1l-carbon fragments (i.e., methanol and/or formaldehyde). Experiments were carried out at a dose of 2 mg/kg. Activity concentration per injected dose was approximately twice as great in sensitive as in resistant tumors (p < 0.05) at 60 min following intravenous injection of {sup 14}C-CHC. About 75% of total activity was CHC in the sensitive tumors. The findings are further confirmed by the quantitative autoradiographic evaluation of resistant and sensitive tumors. These studies confirm our previous observations that it is possible to noninvasively distinguish multidrug-resistant tumors from sensitive tumors in vivo based on uptake of an injected MDR drug using a{sup 14}C-labeled CHC at the same position and of comparable specific activity to a {sup 11}C-CHC tracer used for PET imaging. 16 refs., 5 figs., 2 tabs.

  15. Enhancing Activity of Anticancer Drugs in Multidrug Resistant Tumors by Modulating P-Glycoprotein through Dietary Nutraceuticals.

    PubMed

    Khan, Muhammad; Maryam, Amara; Mehmood, Tahir; Zhang, Yaofang; Ma, Tonghui

    2015-01-01

    Multidrug resistance is a principal mechanism by which tumors become resistant to structurally and functionally unrelated anticancer drugs. Resistance to chemotherapy has been correlated with overexpression of p-glycoprotein (p-gp), a member of the ATP-binding cassette (ABC) superfamily of membrane transporters. P-gp mediates resistance to a broad-spectrum of anticancer drugs including doxorubicin, taxol, and vinca alkaloids by actively expelling the drugs from cells. Use of specific inhibitors/blocker of p-gp in combination with clinically important anticancer drugs has emerged as a new paradigm for overcoming multidrug resistance. The aim of this paper is to review p-gp regulation by dietary nutraceuticals and to correlate this dietary nutraceutical induced-modulation of p-gp with activity of anticancer drugs. PMID:26514453

  16. Metformin reverses multidrug resistance in human hepatocellular carcinoma Bel‑7402/5‑fluorouracil cells.

    PubMed

    Ling, Sunbin; Tian, Yu; Zhang, Haiquan; Jia, Kaiqi; Feng, Tingting; Sun, Deguang; Gao, Zhenming; Xu, Fei; Hou, Zhaoyuan; Li, Yan; Wang, Liming

    2014-12-01

    Metformin exhibits anti‑proliferative effects in tumor cells in vitro and in vivo. The present study investigated the ability of metformin to reverse multidrug resistance (MDR) in human hepatocellular carcinoma Bel‑7402/5‑fluorouracil (5‑Fu; Bel/Fu) cells. The synergistic anti‑proliferative effect of metformin combined with 5‑Fu was evaluated using a Cell Counting kit‑8 assay. The variation in apoptotic rates and cell cycle distribution were evaluated using a flow cytometric assay and variations in target gene and protein expression were monitored using reverse transcription‑polymerase chain reaction and western blot analysis. The results demonstrated that metformin had a synergistic anti‑proliferative effect with 5‑Fu in the Bel/Fu cells. The variations in the number of apoptotic cells and distribution of the cell cycle were consistent with the variability in cell viability. Metformin targeted the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, suppressed the expression of hypoxia‑inducible factor‑1α (HIF‑1α) and transcriptionally downregulated the expression of multidrug resistance protein 1/P‑glycoprotein (P‑gp) and multidrug resistance‑associated protein 1 (MRP1). Collectively, these findings suggested that metformin may target the AMPK/mTOR/HIF‑1α/P‑gp and MRP1 pathways to reverse MDR in hepatocellular carcinoma. PMID:25310259

  17. Plasma membrane microorganization of LR73 multidrug-resistant cells revealed by FCS

    NASA Astrophysics Data System (ADS)

    Winckler, Pascale; Jaffiol, Rodolphe; Cailler, Aurélie; Morjani, Hamid; Jeannesson, Pierre; Deturche, Régis

    2011-03-01

    Tumoral cells could present a multidrug resistance (MDR) to chemotherapeutic treatments. This drug resistance would be associated to biomechanisms occurring at the plasma membrane level, involving modification of membrane fluidity, drug permeability, presence of microdomains (rafts, caveolae...), and membrane proteins overexpression such as Pglycoprotein. Fluorescence correlation spectroscopy (FCS) is the relevant method to investigate locally the fluidity of biological membranes through the lateral diffusion of a fluorescent membrane probe. Thus, we use FCS to monitor the plasma membrane local organization of LR73 carcinoma cells and three derived multidrug-resistant cancer cells lines. Measurements were conducted at the single cell level, which enabled us to get a detailed overview of the plasma membrane microviscosity distribution of each cell line studied. Moreover, we propose 2D diffusion simulation based on a Monte Carlo model to investigate the membrane organisation in terms of microdomains. This simulation allows us to relate the differences in the fluidity distributions with microorganization changes in plasma membrane of MDR cells.

  18. Reversal effect of vitamin D on different multidrug-resistant cells.

    PubMed

    Yan, M; Nuriding, H

    2014-01-01

    We investigated the reversal effect of vitamin D on the multidrug-resistant leukemic Jurkat/ADR and K562/ADR cell lines and conducted a preliminary investigation of its reversal mechanism. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to detect the reversal effect of vitamin D on multidrug-resistant cells. Real-time polymerase chain reaction was used to determine the effect of vitamin D on intracellular expression of mRNA of the multidrug-resistant gene (MDRI) and the multidrug-resistance-related gene (MRP1). A protein quantitative analysis method was used to determine the effect of vitamin D on intracellular glutathione content. After treatment of Jurkat/ADR and K562/ADR cells with vitamin D, multidrug resistance was reversed in a dose-dependent manner, which may have reduced mRNA expression of the MDR1 and MRP1 genes, the P-glycoprotein content on the cell surface, and the intracellular glutathione level. Different concentrations of vitamin D showed varying reversal effects on different multidrug-resistant cells. The resistance mechanism may be related to the inhibition of the expression of MDR1 and MRP1 genes. PMID:25158250

  19. PEITC reverse multi-drug resistance of human gastric cancer SGC7901/DDP cell line.

    PubMed

    Tang, Tao; Song, Xin; Liu, Yu-Fen; Wang, Wen-Yue

    2014-04-01

    Gastric cancer is one of the leading causes of cancer death in the world and nearly all patients who respond initially to cisplatin later develop drug resistance, indicating multi-drug resistance is an essential aspect of the failure of treatment. Phenethyl isothiocyanate (PEITC) has been implicated in inhibiting metastasis of several types of human cancer. However, the effect and potential mechanism of PEITC reversed multi-drug resistance of human gastric cancer is not fully clear. We have identified the role of PEITC in multi-drug resistance reversal of human gastric cancer SGC7901/DDP cell line. PEITC inhibited cisplatin-resistant human SGC7901/DDP cell growth in a dose-dependent manner, causing increased apoptosis, ROS generation, glutathione depletion, accumulation of Rhodamine-123, decreased expression of P-glycoprotein and cell cycle arrest. mRNA and protein expression of the multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), survivin, and Mad2 was decreased, and phosphorylation of Akt and transcriptional activation of NF-κB were suppressed. PEITC may be useful as the therapeutic strategy for overcoming multi-drug resistance through suppressing the PI3K-Akt pathway in human gastric cancer. PMID:23956061

  20. Role of mitochondrial translocation of telomerase in hepatocellular carcinoma cells with multidrug resistance.

    PubMed

    Ling, Xianlong; Wen, Lei; Zhou, Yuan

    2012-01-01

    Multidrug resistance (MDR) is a major obstacle of cancer chemotherapy. This study aimed to investigate the role of mitochondrial translocation of telomerase (hTERT) in MDR of human hepatocellular carcinoma (HCC) cells. In this study, three HCC cell lines (SK-Hep1/CDDP1 cells, SK-Hep1/CDDP2 cells and SK-Hep1/CDDP3 cells) with differential resistance index (RI) to cisplatin (CDDP) were induced by pulse treatment of SK-Hep1 (human hepatocellular cell line) with CDDP in vitro. The RI of SK-Hep1/CDDP1 cells, SK-Hep1/CDDP2 cells and SK-Hep1/CDDP3 cells was 5.14, 8.66, and 14.25, respectively, and all the cell lines showed cross-resistance to Doxorubicin (DOX) and 5-Fuorouracil (5-FU). The apoptosis rates in drug-resistant cells were significantly reduced. Cell cycle analysis revealed the ratio of drug-resistant cells in G2/M and S phases increased, while that in G1 phase decreased. Immunofluorescence staining and Western blot assay demonstrated, with the gradual elevation in RI, increasing hTERT translocated from the nuclei to the mitochondria, while real-time PCR indicated the shortening of telomere length in drug-resistant cells under the chemotherapeutic stress and the reduction of damaged mtDNA with the increase in RI. Furthermore, JC-1 staining also indicated the reduction of mitochondrial membrane potential in drug-resistant cells. The mitochondrial translocation of hTERT increases in multidrug-resistant cells and exerts protective effect on mitochondrial function. Drug-resistant tumor cells escape from apoptosis through hTERT-mediated mitochondrial protection. Mitochondrial translocation of hTERT may serve as an underlying mechanism of MDR. PMID:22991493

  1. Human SPF45, a splicing factor, has limited expression in normal tissues, is overexpressed in many tumors, and can confer a multidrug-resistant phenotype to cells.

    PubMed

    Sampath, Janardhan; Long, Pandy R; Shepard, Robert L; Xia, Xiaoling; Devanarayan, Viswanath; Sandusky, George E; Perry, William L; Dantzig, Anne H; Williamson, Mark; Rolfe, Mark; Moore, Robert E

    2003-11-01

    Our effort to identify novel drug-resistant genes in cyclophosphamide-resistant EMT6 mouse mammary tumors led us to the identification of SPF45. Simultaneously, other groups identified SPF45 as a component of the spliceosome that is involved in alternative splicing. We isolated the human homologue and examined the normal human tissue expression, tumor expression, and the phenotype caused by overexpression of human SPF45. Our analyses revealed that SPF45 is expressed in many, but not all, normal tissues tested with predominant expression in normal ductal epithelial cells of the breast, liver, pancreas, and prostate. Our analyses using tissue microarrays and sausages of tumors indicated that SPF45 is highly expressed in numerous carcinomas including bladder, breast, colon, lung, ovarian, pancreatic, and prostate. Interestingly, this study revealed that overexpression of SPF45 in HeLa, a cervical carcinoma cell line, resulted in drug resistance to doxorubicin and vincristine, two chemotherapeutic drugs commonly used in cancer. To our knowledge, this is the first study showing tumor overexpression of an alternate splicing factor resulting in drug resistance. PMID:14578179

  2. BIIB021, a synthetic Hsp90 inhibitor, has broad application against tumors with acquired multidrug resistance.

    PubMed

    Zhang, Hong; Neely, Laura; Lundgren, Karen; Yang, Yong-Ching; Lough, Rachel; Timple, Noel; Burrows, Francis

    2010-03-01

    17-AAG, the first-generation clinical Hsp90 inhibitor, exhibits promising antitumor activity in clinical studies, but is limited by poor solubility and hepatotoxicity. To pursue compounds with better biopharmaceutical properties, we have developed a series of fully synthetic orally bioavailable inhibitors of Hsp90. Here, we report that 17-AAG and other ansamycin derivatives are inactive in P-gp and/or MRP-1 expressing cell lines and sensitivity could be restored by coadministration of P-gp or MRP inhibitors. In contrast, the synthetic Hsp90 inhibitor, BIIB021 was active in these models. Accordingly, BIIB021 was considerably more active than 17-AAG against adrenocortical carcinoma, a tumor that naturally expresses P-gp, both in vitro and in vivo. This efflux pump-mediated resistance is manifested in both cytotoxicity assays and measurements of target inhibition, such as client protein degradation. Other than this, the cytotoxic activity of BIIB021 was also not influenced by loss of NQO1 or Bcl-2 overexpression, molecular lesions that do not prevent client loss but are nonetheless associated with reduced cell killing by 17-AAG. Our results indicate that the activity of 17-AAG and other ansamycins may be curtailed in tumors that have upregulated efflux pumps or antiapoptotic proteins or other genetic alterations. These data indicate that the new generation of synthetic anti-Hsp90 drugs, exemplified by BIIB021 that is currently undergoing Phase II testing, may have broader application against tumors with acquired multidrug resistance or tumors located in organs protected by MDR proteins, such as the adrenal glands, brain and testis. PMID:19676042

  3. ATP-dependent transport of vinblastine in vesicles from human multidrug-resistant cells

    SciTech Connect

    Horio, M.; Gottesman, M.M.; Pastan, I. )

    1988-05-01

    Resistance of human cancer cells to multiple cytotoxic hydrophobic agents (multidrug resistance) is due to overexpression of the MDR1 gene, whose product is the plasma membrane P-glycoprotein. Plasma membrane vesicles partially purified from multidrug-resistant human KB carcinoma cells, but not from drug-sensitive cells, accumulate ({sup 3}H)vinblastine in an ATP-dependent manner. This transport is osmotically sensitive, with an apparent K{sub m} of 38 {mu}M for ATP and of {approx} 2 {mu}M for vinblastine. The nonhydrolyzable analog adenosine 5{prime}-({beta},{gamma}-imido)triphosphate does not substitute for ATP but is a competitive inhibitor of ATP for the transport process. Vanadate, and ATPase inhibitor, is a potent noncompetitive inhibitor of transport. These results indicate that hydrolysis of ATP is probably required for active transport vinblastine. Several other drugs to which multidrug-resistant cell lines are resistant inhibit transport, with relative potencies as follows: vincristine > actinomycin D > daunomycin > colchicine = puromycin. Verapamil and quinidine, which reverse the multidrug-resistance phenotype, are good inhibitors of the transport process. These results confirm that multidrug-resistant cells express an energy-dependent plasma membrane transporter for hydrophobic drugs, and establish a system for the detailed biochemical analysis of this transport process.

  4. A safe, simple and efficient doxorubicin prodrug hybrid micelle for overcoming tumor multidrug resistance and targeting delivery.

    PubMed

    Bao, Yuling; Yin, Mingxing; Hu, Xiaomeng; Zhuang, Xiangting; Sun, Yu; Guo, Yuanyuan; Tan, Songwei; Zhang, Zhiping

    2016-08-10

    A pH-sensitive prodrug, TPGS-CHN-DOX, was introduced by conjugating anticancer drug, doxorubicin (DOX), onto d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) via a cleavable Schiff base linkage. The prodrug was mixed with a PEGylated lipid to form a simple but multifunctional hybrid micelle system, which can realize high drug loading capability and biocompatibility, extended blood circulation time, inhibited drug resistance in cancer cells, improved therapeutic response, reduced side effects, and easy functionalities for targeting delivery. The hybrid micelles exhibited in vitro pH-sensitive drug release, enhanced cellular uptake and strengthened cytotoxicity on both drug-sensitive human breast cancer MCF-7 and resistant MCF-7/ADR cells. P-glycoprotein functional inhibition and mitochondria-associated cell apoptosis induced by TPGS were thought to play an important role in overcoming the multidrug resistance. As a result, the hybrid micelles demonstrated good anticancer efficacy in MCF-7/ADR xenograft model. Additionally, after modifying with a tumor-specific targeting peptic ligand, cRGD, the tumor growth/metastasis inhibition was further evidenced in integrin receptor overexpressed melanoma cancer B16F10 and even murine hepatocarcinoma H22 models. This TPGS-based pH-sensitive prodrug provides a safe and "Molecular economical" way in the rational design of prodrugs for overcoming multidrug resistance and targeting delivery, which can improve the potency for clinical use. PMID:27264552

  5. Microbial transformation of ginsenoside-Rg₁ by Absidia coerulea and the reversal activity of the metabolites towards multi-drug resistant tumor cells.

    PubMed

    Liu, Xin; Qiao, Lirui; Xie, Dan; Zhang, Yi; Zou, Jianhua; Chen, Xiaoguang; Dai, Jungui

    2011-12-01

    Biotransformation of ginsenoside-Rg₁ (1) by the fungus Absidia coerulea AS 3.2462 yielded five metabolites (2-6). On the basis of spectroscopic data analyses, the metabolites were identified as ginsenoside-F₁ (2), 6α,12β-dihydroxydammar-3-one-20(S)-O-β-D-glucopyranoside (3), 3-oxo-20(S)-protopanaxatriol (4), 3-oxo-7β-hydroxy-20(S)-protopanaxatriol (5), and 3-oxo-7β,15α-dihydroxy-20(S)-protopanaxatriol (6), respectively. Among them, 5 and 6 are new compounds. These results indicated that Absidia coerulea AS 3.2462 could catalyze the specific C-3 dehydrogenation of derivatives of ginsenoside-Rg₁, as well as hydroxylation at the 7β and 15α positions. Metabolites 2, 4 and 5 exhibited moderate reversal activity towards A549/taxol MDR tumor cells in vitro. PMID:21946057

  6. The multidrug resistant modulator HZ08 reverses multidrug resistance via P-glycoprotein inhibition and apoptosis sensitization in human epidermoid carcinoma cell line KBV200.

    PubMed

    Zhu, Y-L; Cen, J; Zhang, Y-Y; Feng, Y-D; Yang, Y; Li, Y-M; Huang, W-L

    2012-05-01

    Previous studies have demonstrated that the multidrug resistance modulator HZ08 has a strong multidrug resistance reversal effect in vitro and in vivo by inhibiting P-glycoprotein and multidrug resistance-associated protein 1 in K562/A02 and MCF-7/ADM cells, respectively. However, there are many other mechanisms responsible for resistance. In this study, MTT assay was used to examine the cytotoxicity and multidrug resistance reversal of HZ08 in KBV200 cells. It was also used to detect Rh123 and adriamycin accumulation in the presence of HZ08 to assess the effect on P-glycoprotein. Caspase-3 activity was analyzed under the incubation of HZ08 per se and in combination with vincristine. Results showed that HZ08 could increase the activity of caspase-3 with P-glycoprotein inhibition. Further studies revealed that HZ08 increased vincristine-induced apoptosis, characterized as an intrinsic apoptosis pathway with enhanced G2/M phase arrest, since HZ08 had an effect on the intrinsic apoptotic regulator Bcl-2 and Bax. Therefore, the outstanding reversal effect of HZ08 occurs not only through suppressing the P-glycoprotein function but also through activating the intrinsic apoptosis pathway. PMID:22344570

  7. Expression of a multidrug-resistance gene in human tumors and tissues

    SciTech Connect

    Fojo, A.T.; Ueda, K.; Slamon, D.J.; Poplack, D.G.; Gottesman, M.M.; Pastan, I.

    1987-01-01

    The identification and cloning of a segment of a human multidrug resistance gene (mdr1) was reported recently. To examine, the molecular basis of one type of multidrug resistance, the authors have prepared RNA from human tumors and normal tissues and measured their content of mdr1 RNA. They find that the mdr1 gene is expressed at a very high level in the adrenal gland; at a high level in the kidney; at intermediate levels in the lung, liver, lower jejunum, colon, and rectum; and at low levels in many other tissues. The mdr1 gene is also expressed in several human tumors, including many but not all tumors derived from the adrenal gland and the colon. In addition, increased expression was detected in a few tumors at the time of relapse following initial chemotherapy. Although controlled clinical studies will be required, the results suggest that measurement of mdr1 RNA may prove to be a valuable tool in the design of chemotherapy protocols.

  8. A Multidrug-resistant Engineered CAR T Cell for Allogeneic Combination Immunotherapy

    PubMed Central

    Valton, Julien; Guyot, Valérie; Marechal, Alan; Filhol, Jean-Marie; Juillerat, Alexandre; Duclert, Aymeric; Duchateau, Philippe; Poirot, Laurent

    2015-01-01

    The adoptive transfer of chimeric antigen receptor (CAR) T cell represents a highly promising strategy to fight against multiple cancers. The clinical outcome of such therapies is intimately linked to the ability of effector cells to engraft, proliferate, and specifically kill tumor cells within patients. When allogeneic CAR T-cell infusion is considered, host versus graft and graft versus host reactions must be avoided to prevent rejection of adoptively transferred cells, host tissue damages and to elicit significant antitumoral outcome. This work proposes to address these three requirements through the development of multidrug-resistant T cell receptor αβ-deficient CAR T cells. We demonstrate that these engineered T cells displayed efficient antitumor activity and proliferated in the presence of purine and pyrimidine nucleoside analogues, currently used in clinic as preconditioning lymphodepleting regimens. The absence of TCRαβ at their cell surface along with their purine nucleotide analogues-resistance properties could prevent their alloreactivity and enable them to resist to lymphodepleting regimens that may be required to avoid their ablation via HvG reaction. By providing a basic framework to develop a universal T cell compatible with allogeneic adoptive transfer, this work is laying the foundation stone of the large-scale utilization of CAR T-cell immunotherapies. PMID:26061646

  9. Targeted multidrug-resistance reversal in tumor based on PEG-PLL-PLGA polymer nano drug delivery system

    PubMed Central

    Guo, Liting; Zhang, Haijun; Wang, Fei; Liu, Ping; Wang, Yonglu; Xia, Guohua; Liu, Ran; Li, Xueming; Yin, Haixiang; Jiang, Hulin; Chen, Baoan

    2015-01-01

    The study investigated the reversal of multidrug resistance (MDR) and the biodistribution of nanoparticles (NPs) that target leukemia cells in a nude mice model via a surface-bound transferrin (Tf). The cytotoxic cargo of daunorubicin (DNR) and tetrandrine (Tet) was protected in the NPs by an outer coat composed of polyethylene glycol (PEG)-poly-l-lysine (PLL)-poly(lactic-co-glycolic acid) (PLGA) NPs. Injection of DNR-Tet-Tf-PEG-PLL-PLGA NPs into nude mice bearing MDR leukemia cell K562/A02 xenografts was shown to inhibit tumor growth, and contemporaneous immunohistochemical analysis of tumor tissue showed the targeted NPs induced apoptosis in tumor cells. Targeted tumor cells exhibited a marked increase in Tf receptor expression, with noticeable decreases in P-glycoprotein, MDR protein, and nuclear factor κB, as assessed by quantitative real-time polymerase chain reaction and Western blot analysis. Moreover, the concentration of DNR was shown to increase in plasma, tumor tissue, and major organs. Flow cytometry analysis with a near-infrared fluorescent (NIRF) dye, NIR797, was used to study the effectiveness of Tf as a targeting group for leukemia cells, a finding that was supported by NIRF imaging in tumor-bearing nude mice. In summary, our studies show that DNR-Tet-Tf-PEG-PLL-PLGA NPs provide a specific and effective means to target cytotoxic drugs to MDR tumor cells. PMID:26213467

  10. Targeted multidrug-resistance reversal in tumor based on PEG-PLL-PLGA polymer nano drug delivery system.

    PubMed

    Guo, Liting; Zhang, Haijun; Wang, Fei; Liu, Ping; Wang, Yonglu; Xia, Guohua; Liu, Ran; Li, Xueming; Yin, Haixiang; Jiang, Hulin; Chen, Baoan

    2015-01-01

    The study investigated the reversal of multidrug resistance (MDR) and the biodistribution of nanoparticles (NPs) that target leukemia cells in a nude mice model via a surface-bound transferrin (Tf). The cytotoxic cargo of daunorubicin (DNR) and tetrandrine (Tet) was protected in the NPs by an outer coat composed of polyethylene glycol (PEG)-poly-L-lysine (PLL)-poly(lactic-co-glycolic acid) (PLGA) NPs. Injection of DNR-Tet-Tf-PEG-PLL-PLGA NPs into nude mice bearing MDR leukemia cell K562/A02 xenografts was shown to inhibit tumor growth, and contemporaneous immunohistochemical analysis of tumor tissue showed the targeted NPs induced apoptosis in tumor cells. Targeted tumor cells exhibited a marked increase in Tf receptor expression, with noticeable decreases in P-glycoprotein, MDR protein, and nuclear factor κB, as assessed by quantitative real-time polymerase chain reaction and Western blot analysis. Moreover, the concentration of DNR was shown to increase in plasma, tumor tissue, and major organs. Flow cytometry analysis with a near-infrared fluorescent (NIRF) dye, NIR797, was used to study the effectiveness of Tf as a targeting group for leukemia cells, a finding that was supported by NIRF imaging in tumor-bearing nude mice. In summary, our studies show that DNR-Tet-Tf-PEG-PLL-PLGA NPs provide a specific and effective means to target cytotoxic drugs to MDR tumor cells. PMID:26213467

  11. The involvement of sphingolipids in multidrug resistance.

    PubMed

    Sietsma, H; Veldman, R J; Kok, J W

    2001-06-01

    Administration of most chemotherapeutic agents eventually results in the onset of apoptosis, despite the agents' variety in structure and molecular targets. Ceramide, the central molecule in cellular glycosphingolipid metabolism, has recently been identified as an important mediator of this process. Indeed, one of the events elicited by application of many cytotoxic drugs is an accumulation of this lipid. Treatment failure in cancer chemotherapy is largely attributable to multidrug resistance, in which tumor cells are typically cross-resistant to multiple chemotherapeutic agents. Different cellular mechanisms underlying this phenomenon have been described. Of these the drug efflux pump activity of P-glycoprotein and the multidrug resistance-associated proteins are the most extensively studied examples. Recently, an increased cellular capacity for ceramide glycosylation has been recognized as a novel multidrug resistance mechanism. Indeed, virtually all multidrug-resistant cells exhibit a deviating sphingolipid composition, most typically, increased levels of glucosylceramide. On the other hand, several direct molecular interactions between sphingolipids and drug efflux proteins have been described. Therefore, in addition to a role in the multidrug resistance phenotype by which ceramide accumulation and, thus, the onset of apoptosis are prevented, an indirect role for sphingolipids might be envisaged, by which the activity of these efflux proteins is modulated. In this review, we present an overview of the current understanding of the interesting relations that exist between sphingolipid metabolism and multidrug resistance. PMID:11420602

  12. Meayamycin Inhibits pre-mRNA Splicing and Exhibits Picomolar Activity Against Multidrug Resistant Cells

    PubMed Central

    Albert, Brian J.; McPherson, Peter A.; O'Brien, Kristine; Czaicki, Nancy L.; DeStefino, Vincent; Osman, Sami; Li, Miaosheng; Day, Billy W.; Grabowski, Paula J.; Moore, Melissa J.; Vogt, Andreas; Koide, Kazunori

    2009-01-01

    FR901464 is a potent antitumor natural product that binds to the SF3b complex and inhibits pre-mRNA splicing. Its analogue, meayamycin, is two orders of magnitude more potent as an antiproliferative agent against human breast cancer MCF-7 cells. Here, we report the picomolar antiproliferative activity of meayamycin against various cancer cell lines and multidrug resistant cells. Time-dependence studies implied that meayamycin may form a covalent bond with its target protein(s). Meayamycin inhibited pre-mRNA splicing in HEK-293 cells but not alternative splicing in a neuronal system. Meayamycin exhibited specificity toward human lung cancer cells compared to non-tumorigenic human lung fibroblasts and retained picomolar growth inhibitory activity against multi-drug resistant cells. These data suggest that meayamycin is a useful chemical probe to study pre-mRNA splicing in live cells and is a promising lead as an anticancer agent. PMID:19671752

  13. 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. PMID:23683834

  14. Cytotoxicity of novel sulfanilamides towards sensitive and multidrug-resistant leukemia cells.

    PubMed

    AlSalim, T; Saeed, M E M; Hadi, J S; Zeino, M; Gany, R; Kadioglu, O; Titinchi, S J J; Abbo, H S; Efferth, T

    2014-01-01

    Novel sulfa Schiff bases were synthesized and characterized by a reaction between aromatic sulfonamides and aromatic aldehydes or heterocyclic ketones in equimolar ratios. Their cytotoxicity was evaluated by the resazurin assay towards human sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells. Three of the tested compounds viz., 4-(anthracen-9-ylmethyleneamino)-N-(pyrimidin-2-yl)benzenesulfonamide (4), 4-(anthracen-9- ylmethyleneamino)benzenesulfonamide, (5) and 4-((3-phenylallylidene)amino)benzene-sulfonamide, (6) were cytotoxic (IC50 values: 5.38-19.96 µM). CEM/ADR5000 cells were not cross-resistant to these compounds, indicating activity against otherwise drug-resistant tumors. Compound 6 inhibited P-glycoprotein by increasing doxorubicin accumulation and reducing expression of P-glycoprotein in CEM/ADR5000 cells. A human P-glycoprotein homology model was used for molecular docking studies. Compound 6 and verapamil (a well-known P-glycoprotein inhibitor) docked with similar binding energies to the same binding pocket. PMID:24438524

  15. Self-assembling nanoparticles encapsulating zoledronic acid revert multidrug resistance in cancer cells

    PubMed Central

    Gazzano, Elena; Salzano, Giuseppina; Giordano, Antonio; Desiderio, Vincenzo; Ghigo, Dario; Caraglia, Michele; De Rosa, Giuseppe; Riganti, Chiara

    2015-01-01

    The overexpression of ATP binding cassette (ABC) transporters makes tumor cells simultaneously resistant to several cytotoxic drugs. Impairing the energy metabolism of multidrug resistant (MDR) cells is a promising chemosensitizing strategy, but many metabolic modifiers are too toxic in vivo. We previously observed that the aminobisphosphonate zoledronic acid inhibits the activity of hypoxia inducible factor-1α (HIF-1α), a master regulator of cancer cell metabolism. Free zoledronic acid, however, reaches low intratumor concentration. We synthesized nanoparticle formulations of the aminobisphosphonate that allow a higher intratumor delivery of the drug. We investigated whether they are effective metabolic modifiers and chemosensitizing agents against human MDR cancer cells in vitro and in vivo. At not toxic dosage, nanoparticles carrying zoledronic acid chemosensitized MDR cells to a broad spectrum of cytotoxic drugs, independently of the type of ABC transporters expressed. The nanoparticles inhibited the isoprenoid synthesis and the Ras/ERK1/2-driven activation of HIF-1α, decreased the transcription and activity of glycolytic enzymes, the glucose flux through the glycolysis and tricarboxylic acid cycle, the electron flux through the mitochondrial respiratory chain, the synthesis of ATP. So doing, they lowered the ATP-dependent activity of ABC transporters, increasing the chemotherapy efficacy in vitro and in vivo. These effects were more pronounced in MDR cells than in chemosensitive ones and were due to the inhibition of farnesyl pyrophosphate synthase (FPPS), as demonstrated in FPPS-silenced tumors. Our work proposes nanoparticle formulations of zoledronic acid as the first not toxic metabolic modifiers, effective against MDR tumors. PMID:26372812

  16. High heterogeneity of plasma membrane microfluidity in multidrug-resistant cancer cells

    NASA Astrophysics Data System (ADS)

    Boutin, Céline; Roche, Yann; Millot, Christine; Deturche, Régis; Royer, Pascal; Manfait, Michel; Plain, Jérôme; Jeannesson, Pierre; Millot, Jean-Marc; Jaffiol, Rodolphe

    2009-05-01

    Diffusion-time distribution analysis (DDA) has been used to explore the plasma membrane fluidity of multidrug-resistant cancer cells (LR73 carcinoma cells) and also to characterize the influence of various membrane agents present in the extracellular medium. DDA is a recent single-molecule technique, based on fluorescence correlation spectroscopy (FCS), well suited to retrieve local organization of cell membrane. The method was conducted on a large number of living cells, which enabled us to get a detailed overview of plasma membrane microviscosity, and plasma membrane micro-organization, between the cells of the same line. Thus, we clearly reveal the higher heterogeneity of plasma membrane in multidrug-resistant cancer cells in comparison with the nonresistant ones (denoted sensitive cells). We also display distinct modifications related to a membrane fluidity modulator, benzyl alcohol, and two revertants of multidrug resistance, verapamil and cyclosporin-A. A relation between the distribution of the diffusion-time values and the modification of membrane lateral heterogeneities is proposed.

  17. Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy.

    PubMed

    Kuss, Sabine; Polcari, David; Geissler, Matthias; Brassard, Daniel; Mauzeroll, Janine

    2013-06-01

    The emergence of resistance to multiple unrelated chemotherapeutic drugs impedes the treatment of several cancers. Although the involvement of ATP-binding cassette transporters has long been known, there is no in situ method capable of tracking this transporter-related resistance at the single-cell level without interfering with the cell's environment or metabolism. Here, we demonstrate that scanning electrochemical microscopy (SECM) can quantitatively and noninvasively track multidrug resistance-related protein 1-dependent multidrug resistance in patterned adenocarcinoma cervical cancer cells. Nonresistant human cancer cells and their multidrug resistant variants are arranged in a side-by-side format using a stencil-based patterning scheme, allowing for precise positioning of target cells underneath the SECM sensor. SECM measurements of the patterned cells, performed with ferrocenemethanol and [Ru(NH3)6](3+) serving as electrochemical indicators, are used to establish a kinetic "map" of constant-height SECM scans, free of topography contributions. The concept underlying the work described herein may help evaluate the effectiveness of treatment administration strategies targeting reduced drug efflux. PMID:23686580

  18. Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy

    PubMed Central

    Kuss, Sabine; Polcari, David; Geissler, Matthias; Brassard, Daniel; Mauzeroll, Janine

    2013-01-01

    The emergence of resistance to multiple unrelated chemotherapeutic drugs impedes the treatment of several cancers. Although the involvement of ATP-binding cassette transporters has long been known, there is no in situ method capable of tracking this transporter-related resistance at the single-cell level without interfering with the cell’s environment or metabolism. Here, we demonstrate that scanning electrochemical microscopy (SECM) can quantitatively and noninvasively track multidrug resistance-related protein 1–dependent multidrug resistance in patterned adenocarcinoma cervical cancer cells. Nonresistant human cancer cells and their multidrug resistant variants are arranged in a side-by-side format using a stencil-based patterning scheme, allowing for precise positioning of target cells underneath the SECM sensor. SECM measurements of the patterned cells, performed with ferrocenemethanol and [Ru(NH3)6]3+ serving as electrochemical indicators, are used to establish a kinetic “map” of constant-height SECM scans, free of topography contributions. The concept underlying the work described herein may help evaluate the effectiveness of treatment administration strategies targeting reduced drug efflux. PMID:23686580

  19. Overexpression of CDX2 in gastric cancer cells promotes the development of multidrug resistance.

    PubMed

    Yan, Lin-Hai; Wei, Wei-Yuan; Cao, Wen-Long; Zhang, Xiao-Shi; Xie, Yu-Bo; Xiao, Qiang

    2015-01-01

    Modulator of multidrug resistance (MDR) gene is a direct transcriptional target of CDX2. However, we still speculate whether CDX2 affects MDR through other ways. In this study, a cisplatin-resistant (SGC7901/DDP) and a 5-fluoro-2, 4(1h,3h)pyrimidinedione-resistant (BGC823/5-FU) gastric cancer cell line with stable overexpression of CDX2 were established. The influence of overexpression of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP and BGC823/5-FU cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2-overexpression lentiviral vector (LV-CDX2-GFP) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. Results showed that LV-CDX2-GFP led to up-regulation of CDX2 mRNA and protein expression. It significantly inhibited the sensitivity of SGC7901/DDP and BGC823/5-FU cells to cisplatin, doxorubicin, and 5-fluorouracil. Flow cytometry confirmed that the percentage of apoptotic cells decreased after CDX2 up-regulation. This notion was further supported by the observation that up-regulation of CDX2 blocked entry into the M-phase of the cell cycle. Furthermore, up-regulation of CDX2 significantly decreased intracellular accumulation of doxorubicin. In molecular studies, quantitative reverse-transcriptase real-time polymerase chain reaction and western blotting revealed that CDX2 up-regulation could suppress expression of Caspase-3, Caspase-9 and PTEN, and increased the expression of MDR1, MRP, mTOR, HIF-1α. PMID:25628941

  20. Regulatory mechanism of ZNF139 in multi-drug resistance of gastric cancer cells.

    PubMed

    Li, Yong; Tan, Bi-bo; Zhao, Qun; Fan, Li-qiao; Liu, Yü; Wang, Dong

    2014-06-01

    Our previous study found increased zinc finger protein 139 (ZNF139) expression in gastric cancer (GC) cells. Purpose of the study is to further clarify the role and mechanism of ZNF139 in multi-drug resistance (MDR) of GC cells. MTT assay, RT-PCR, Western blotting were employed to detect susceptibility of GC cells to chemotherapeutic agents (5-FU, L-OHP) in vitro, and expressions of ZNF139 and MDR associated genes MDR1/P-gp, MRP1, Bcl-2, Bax were also detected. siRNA specific to ZNF139 was transfected into MKN28 cells, then chemosensitivity of GC cells as well as changes of ZNF139 and MDR associated genes were detected. It's found the inhibition rate of 5-FU, L-OHP to well-differentiated GC tissues and cell line was lower than that in the poorly differentiated tissues and cell line; expressions of ZNF139 and MDR1/P-gp, MRP1 and Bcl-2 in well-differentiated GC tissues and cell line MKN28 were higher, while Bax expression was lower. After ZNF139-siRNA was transfected into MKN28, ZNF139 expression in GC cells was inhibited by 90%; inhibition rate of 5-FU, L-OHP to tumor cells increased, and expressions of MDR1/P-gp, MRP1 and Bcl-2 were down-regulated, while Bax was up-regulated. ZNF139 was involved in GC MDR by promoting expressions of MDR1/P-gp, MRP1 and Bcl-2 and inhibiting Bax simultaneously. PMID:24515389

  1. Sweat but no gain: Inhibiting proliferation of multidrug resistant cancer cells with “Ersatzdroges”

    PubMed Central

    Kam, Yoonseok; Das, Tuhin; Tian, Haibin; Foroutan, Parastou; Ruiz, Epifanio; Martinez, Gary; Minton, Susan; Gillies, Robert J.; Gatenby, Robert A.

    2014-01-01

    ATP-binding cassette (ABC) drug transporters consuming ATPs for drug efflux is a common mechanism by which clinical cancers develop multidrug resistance (MDR). We hypothesized that MDR phenotypes could be suppressed by administration of “ersatzdroges”, non-chemotherapy drugs that are, nevertheless, ABC substrates. We reasoned that, through prolonged activation of the ABC pumps, ersatzdroges will force MDR cells to divert limited resources from proliferation and invasion thus delaying disease progression. We evaluated ABC substrates as ersatzdroge by comparing their effects on proliferation and survival of MDR cell lines (MCF-7/Dox and 8226/Dox40) with the effects on the drug-sensitive parental lines (MCF-7 and 8226/s, respectively) in glucose-limited condition. The changes in glucose and energy demands were also examined in vitro and in vivo. MCF-7/Dox showed higher ATP demand and susceptibility to glucose resource limitation. Ersatzdroges significantly decreased proliferation of MCF-7/Dox when the culture media contained physiological glucose concentrations (1.0 g/L) or less, but had no effect on MCF-7. Similar evidence was obtained from 8226/Dox40 and 8226/s comparison. In vivo 18F-FDG-PET imaging demonstrated that glucose uptake was increased by systemic administration of an ersatzdroge in tumors composed of MDR. These results suggest that administration of ersatzdroges, by increasing the metabolic cost of resistance, can suppress proliferation of drug-resistance phenotypes. This provides a novel and relatively simple application model of evolution-based strategy which can exploit the cost of resistance to delay proliferation of drug-resistant cancer phenotypes. Furthermore, suggested is the potential of ersatzdroges to identify tumors or regions of tumors that express the MDR phenotype. PMID:25156304

  2. Sweat but no gain: inhibiting proliferation of multidrug resistant cancer cells with "ersatzdroges".

    PubMed

    Kam, Yoonseok; Das, Tuhin; Tian, Haibin; Foroutan, Parastou; Ruiz, Epifanio; Martinez, Gary; Minton, Susan; Gillies, Robert J; Gatenby, Robert A

    2015-02-15

    ATP-binding cassette (ABC) drug transporters consuming ATPs for drug efflux is a common mechanism by which clinical cancers develop multidrug resistance (MDR). We hypothesized that MDR phenotypes could be suppressed by administration of "ersatzdroges," nonchemotherapy drugs that are, nevertheless, ABC substrates. We reasoned that, through prolonged activation of the ABC pumps, ersatzdroges will force MDR cells to divert limited resources from proliferation and invasion thus delaying disease progression. We evaluated ABC substrates as ersatzdroge by comparing their effects on proliferation and survival of MDR cell lines (MCF-7/Dox and 8226/Dox40) with the effects on the drug-sensitive parental lines (MCF-7 and 8226/s, respectively) in glucose-limited condition. The changes in glucose and energy demands were also examined in vitro and in vivo. MCF-7/Dox showed higher ATP demand and susceptibility to glucose resource limitation. Ersatzdroges significantly decreased proliferation of MCF-7/Dox when the culture media contained physiological glucose concentrations (1.0 g/L) or less, but had no effect on MCF-7. Similar evidence was obtained from 8226/Dox40 and 8226/s comparison. In vivo 18F-FDG-PET imaging demonstrated that glucose uptake was increased by systemic administration of an ersatzdroge in tumors composed of MDR. These results suggest that administration of ersatzdroges, by increasing the metabolic cost of resistance, can suppress proliferation of drug-resistance phenotypes. This provides a novel and relatively simple application model of evolution-based strategy, which can exploit the cost of resistance to delay proliferation of drug-resistant cancer phenotypes. Furthermore, suggested is the potential of ersatzdroges to identify tumors or regions of tumors that express the MDR phenotype. PMID:25156304

  3. Complexation study and anticellular activity enhancement by doxorubicin-cyclodextrin complexes on a multidrug-resistant adenocarcinoma cell line.

    PubMed

    Al-Omar, A; Abdou, S; De Robertis, L; Marsura, A; Finance, C

    1999-04-19

    Ability of molecular complexes of [Doxorubicin (DX)-cyclodextrin (Cd)] to enhance the anticellular activity of antineoplastic drug Doxorubicin and to reverse its multidrug resistance has been investigated. A spectroscopic study of the alpha, beta, and gamma-[DX-Cds] complexes has been investigated in relation to their biological effects on a multidrug resistant (MDR) human rectal adenocarcinoma cell line (HRT-18). A ten fold enhancement of DX anticellular activity in presence of beta-cyclodextrin alone was detected. PMID:10328296

  4. Phytochemical analysis and cytotoxicity towards multidrug-resistant leukemia cells of essential oils derived from Lebanese medicinal plants.

    PubMed

    Saab, Antoine M; Guerrini, Alessandra; Sacchetti, Gianni; Maietti, Silvia; Zeino, Maʼen; Arend, Joachim; Gambari, Roberto; Bernardi, Francesco; Efferth, Thomas

    2012-12-01

    Juniperus excelsa fruit essential oil as well as J. oxycedrus, Cedrus libani, and Pinus pinea wood essential oils have been obtained with yields between 2.2 ± 0.3 % to 3.4 ± 0.5 % and analyzed by gas chromatography. Sesquiterpenes mainly characterized C. libani and J. oxycedrus essential oils, while in P. pinea and J. excelsa, monoterpenes were the most abundant compounds. In J. oxycedrus, cis-calamenene (7.8 %), cuparene (3.8 %), and cis-thujopsenal (2.0 %) have been detected for the first time. The cytotoxic activity of these essential oils against drug-sensitive CCRF-CEM and multidrug-resistant P-glycoprotein-expressing CEM/ADR5000 leukemia cells has been investigated (IC₅₀ values: 29.46 to 61.54 µg/mL). Remarkably, multidrug-resistant CEM/ADR5000 cells did not reveal cross-resistance, indicating that these essential oils might be useful to treat otherwise drug-resistant and refractory tumors. PMID:23154840

  5. Preliminary studies on phenothiazine-mediated reversal of multidrug resistance in mouse lymphoma and COLO 320 cells.

    PubMed

    Pajak, Beata; Molnar, Joseph; Engi, Helga; Orzechowski, Arkadiusz

    2005-01-01

    The ability of phenothiazine derivatives to inhibit the transport activity of P-glycoprotein in resistant mouse lymphoma and MDR/COLO 320 cells was studied. A rhodamine 123 efflux from the above-mentioned neoplastic cells in the presence of tested compounds was examined by flow cytometry. Two of the phenothiazine derivatives, namely perphenazine and prochlorperazine dimaleate, proved to be effective inhibitors of the rhodamine efflux. Other tested phenothiazine derivatives (promethazine hydrochloride, oxomemazine, methotrimeprazine maleate, trifluoropromazine hydrochloride, trimeprazine) also modulated the intracellular drug accumulation in both resistant cell lines, however, they exerted additional cytotoxic effects. The differences observed between the effects of the test compounds on intracellular drug accumulation could be the outcome of differences in phenothiazine's chemical structure, which is crucial for drug-cell membrane interactions. The results of this study provide information about a new group of compounds that offer promise in multidrug resistance reversal in tumor cells. PMID:16277030

  6. Cytotoxicity of Salvia miltiorrhiza Against Multidrug-Resistant Cancer Cells.

    PubMed

    Wu, Ching-Fen; Bohnert, Stefan; Thines, Eckhard; Efferth, Thomas

    2016-01-01

    Salvia miltiorrhiza Bunge (Lamiaceae) is a well-known Chinese herb that possesses numerous therapeutic activities, including anticancer effects. In this study, the cytotoxicity and the biological mechanisms of S. miltiorrhiza (SM) root extract on diverse resistant and sensitive cancer cell lines were investigated. CEM/ADR5000 cells were 1.68-fold resistant to CCRF-CEM cells, while HCT116 (p53[Formula: see text] and U87.MG[Formula: see text]EGFR cells were hypersensitive (collateral sensitive) compared to their parental cells. SM root extract stimulated ROS generation, cell cycle S phase arrest and apoptosis. The induction of the intrinsic apoptotic pathway was validated by increased cleavage of caspase 3, 7, 9 and poly ADP-ribose polymerase (PARP). MAP kinases including JNK, ERK1/2 and p38 were obviously phosphorylated and nuclear P65 was downregulated upon SM treatment. Transcriptome-wide COMPARE analysis revealed that the expression of encoding genes with diverse functions were associated with the cellular response to cryptotanshinone, one of the main constituents of SM root extract. In conclusion, SM root extract exerted profound cytotoxicity towards various sensitive and resistant cancer cells and induced the intrinsic apoptotic pathway. PMID:27222067

  7. Involvement of EGFR in the promotion of malignant properties in multidrug resistant breast cancer cells.

    PubMed

    Xu, Jia-Wen; Li, Qing-Quan; Tao, Li-Li; Cheng, Yuan-Yuan; Yu, Juan; Chen, Qi; Liu, Xiu-Ping; Xu, Zu-De

    2011-12-01

    Multidrug resistance is the most predominant phenomenon leading to chemotherapy treatment failure in breast cancer patients. Despite many studies having suggested that overexpression of epidermal growth factor receptor (EGFR) is a potent predictor of malignancy in cancers, systematic research of EGFR in multidrug resistant (MDR) breast cancer cells is lacking. In order to clarify the role of EGFR in MDR breast cancer cells, MCF7/Adr expressing relatively higher EGFR, and its parental cell line MCF7 expressing relatively lower EGFR, were chosen for this study. Knockdown of EGFR by siRNA in MCF7/Adr cells showed that EGFR siRNA inhibits cell migration, invasion and proliferation in vitro; converse effects were observed in MCF7 cells transfected with pcDNA3.0-EGFR plasmid. Moreover, we found that EGFR upregulated migration and invasion via EMMPRIN, MMP2 and MMP9 in addition to promoting cell cycle passage via elevation of cyclin D1 and CDK4 in MDR breast cancer cells. Interestingly, MCF7/Adr cells not expressing EGFR showed significant decrease of P-glycoprotein (P-gp) and ABCG2 expression levels, and became more sensitive to treatment of adriamycin (ADR) and paclitaxel (Taxol); the above results indicated that MDR of cancer cells is related to S-phase arrest. In conclusion, EGFR is an important factor enhancing the malignancy of MDR breast cancer cells, partially, inducing MDR. Anti-EGFR therapy may improve outcome in chemorefractory breast cancer patients. PMID:21805028

  8. Multidrug Resistance in Bacteria

    PubMed Central

    Nikaido, Hiroshi

    2010-01-01

    Large amounts of antibiotics used for human therapy, as well as for farm animals and even for fish in aquaculture, resulted in the selection of pathogenic bacteria resistant to multiple drugs. Multidrug resistance in bacteria may be generated by one of two mechanisms. First, these bacteria may accumulate multiple genes, each coding for resistance to a single drug, within a single cell. This accumulation occurs typically on resistance (R) plasmids. Second, multidrug resistance may also occur by the increased expression of genes that code for multidrug efflux pumps, extruding a wide range of drugs. This review discusses our current knowledge on the molecular mechanisms involved in both types of resistance. PMID:19231985

  9. Effect of different agents onto multidrug resistant cells revealed by fluorescence correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Boutin, C.; Roche, Y.; Jaffiol, R.; Millot, J.-M.; Millot, C.; Plain, J.; Deturche, R.; Jeannesson, P.; Manfait, M.; Royer, P.

    Fluorescence correlation spectroscopy (FCS), which is a sensitive and non invasive technique, has been used to characterize the plasma membrane fluidity and heterogeneity of multidrug resistant living cells. At the single cell level, the effects of different membrane agents present in the extra-cellular medium have been analyzed. Firstly, we reveal a modification of plasma membrane microviscosity according to the addition of a fluidity modulator, benzyl alcohol. In the other hand, revertant such as verapamil and cyclosporin-A appears to act more specifically on the slow diffusion sites as microdomains.

  10. Tetrandrine and fangchinoline, bisbenzylisoquinoline alkaloids from Stephania tetrandra can reverse multidrug resistance by inhibiting P-glycoprotein activity in multidrug resistant human cancer cells.

    PubMed

    Sun, Yan Fang; Wink, Michael

    2014-01-01

    The overexpression of ABC transporters is a common reason for multidrug resistance (MDR) in cancer cells. In this study, we found that the isoquinoline alkaloids tetrandrine and fangchinoline from Stephania tetrandra showed a significant synergistic cytotoxic effect in MDR Caco-2 and CEM/ADR5000 cancer cells in combination with doxorubicin, a common cancer chemotherapeutic agent. Furthermore, tetrandrine and fangchinoline increased the intracellular accumulation of the fluorescent P-glycoprotein (P-gp) substrate rhodamine 123 (Rho123) and inhibited its efflux in Caco-2 and CEM/ADR5000 cells. In addition, tetrandrine and fangchinoline significantly reduced P-gp expression in a concentration-dependent manner. These results suggest that tetrandrine and fangchinoline can reverse MDR by increasing the intracellular concentration of anticancer drugs, and thus they could serve as a lead for developing new drugs to overcome P-gp mediated drug resistance in clinic cancer therapy. PMID:24856768

  11. Altered sphingolipid metabolism in multidrug-resistant ovarian cancer cells is due to uncoupling of glycolipid biosynthesis in the Golgi apparatus.

    PubMed

    Veldman, Robert Jan; Klappe, Karin; Hinrichs, John; Hummel, Ina; van der Schaaf, Gieta; Sietsma, Hannie; Kok, Jan Willem

    2002-07-01

    Multidrug-resistant tumor cells display enhanced levels of glucosylceramide. In this study, we investigated how this relates to the overall sphingolipid composition of multidrug-resistant ovarian carcinoma cells and which mechanisms are responsible for adapted sphingolipid metabolism. We found in multidrug-resistant cells substantially lower levels of lactosylceramide and gangliosides in sharp contrast to glucosylceramide, galactosylceramide, and sphingomyelin levels. This indicates a block in the glycolipid biosynthetic pathway at the level of lactosylceramide formation, with concomitant accumulation of glucosylceramide. A series of observations exclude regulation at the enzyme level as the underlying mechanism. First, reduced lactosylceramide formation occurred only in intact resistant cells whereas cell-free activity of lactosylceramide synthase was higher compared with the parental cells. Second, the level of lactosylceramide synthase gene expression was equal in both phenotypes. Third, glucosylceramide synthase (mRNA and protein) expression and activity were equal or lower in resistant cells. Based on the kinetics of sphingolipid metabolism, the observation that brefeldin A does not restore lactosylceramide synthesis, and altered localization of lactosylceramide synthase fused to green fluorescent protein, we conclude that lactosylceramide biosynthesis is highly uncoupled from glucosylceramide biosynthesis in the Golgi apparatus of resistant cells. PMID:12039850

  12. Reversal of P-glycoprotein-mediated multidrug resistance in human hepatoma cells by hedyotiscone A, a compound isolated from Hedyotis corymbosa.

    PubMed

    Yue, Grace Gar-Lee; Kin-Ming Lee, Julia; Cheng, Ling; Chung-Lap Chan, Ben; Jiang, Lei; Fung, Kwok-Pui; Leung, Ping-Chung; Bik-San Lau, Clara

    2012-06-01

    Multidrug resistance is a major problem in hepatocellular carcinoma. Hedyotiscone A, a compound isolated from Chinese herbal medicine Hedyotis corymbosa (HC, family Rubiaceae), was used as the chemical marker to distinguish between HC and an anticancer herb Hedyotis diffusa (HD) in our previous study. The present study aimed to investigate whether HA exhibited antiproliferative activities in multidrug-resistant hepatocellular carcinoma cells R-HepG2 and the parental cells HepG2 using MTT assay and [(3)H]-thymidine incorporation assay. Our results showed that HA could significantly inhibit cell proliferation in R-HepG2 and HepG2 (IC(50) = 43.7 and 56.3 µg/mL, respectively), but not in normal human liver cells WRL-68 (IC(50) > 100 µg/mL) cells, suggesting its selective cytotoxic effects. Besides, HA induced apoptosis in R-HepG2 cells, as confirmed by annexin-V & propidium iodide staining, and DNA fragmentation assay. The caspase cascade was activated as shown by a significant increase of cleaved caspases-3, -7 and -9 in HA-treated R-HepG2 cells. The activities and protein expression of P-glycoprotein as well as mRNA expression of MDR1 were also decreased in HA-treated R-HepG2 cells. Our study demonstrated for the first time the antiproliferative activities of hedyotiscone A in multidrug-resistant R-HepG2 cells. The findings revealed the potential of this compound in treating multidrug-resistant tumor. PMID:22352391

  13. Reversal of Multidrug Resistance in Mouse Lymphoma Cells by Extracts and Flavonoids from Pistacia integerrima.

    PubMed

    Rauf, Abdur; Uddin, Ghias; Raza, Muslim; Ahmad, Bashir; Jehan, Noor; Siddiqui, Bina S; Molnar, Joseph; Csonka, Akos; Szabo, Diana

    2016-01-01

    Phytochemical investigation of Pistacia integerrima has highlighted isolation of two known compounds naringenin (1) and dihydrokaempferol (2). A crude extract and these isolated compounds were here evaluated for their effects on reversion of multidrug resistance (MDR) mediated by P-glycoprotein (P-gp). The multidrug resistance P-glycoprotein is a target for chemotherapeutic drugs from cancer cells. In the present study rhodamine- 123 exclusion screening test on human mdr1 gene transfected mouse gene transfected L5178 and L5178Y mouse T-cell lymphoma cells showed excellent MDR reversing effects in a dose dependent manner. In-silico molecular docking investigations demonstrated a common binding site for Rhodamine123, and compounds naringenin and dihydrokaempferol. Our results showed that the relative docking energies estimated by docking softwares were in satisfactory correlation with the experimental activities. Preliminary interaction profile of P-gp docked complexes were also analysed in order to understand the nature of binding modes of these compounds. Our computational investigation suggested that the compounds interactions with the hydrophobic pocket of P-gp are mainly related to the inhibitory activity. Moreover this study s a platform for the discovery of novel natural compounds from herbal origin, as inhibitor molecules against the P-glycoprotein for the treatment of cancer. PMID:26838254

  14. Biochemical and genetic characterization of the multidrug resistance phenotype in murine macrophage-like J774.2 cells.

    PubMed

    Kirschner, L S; Greenberger, L M; Hsu, S I; Yang, C P; Cohen, D; Piekarz, R L; Castillo, G; Han, E K; Yu, L J; Horwitz, S B

    1992-01-01

    The development of multidrug resistance (MDR) in malignant tumors is a major obstacle to the treatment of many cancers. MDR sublines have been derived from the J774.2 mouse macrophage-like cell line and utilized to characterize the phenotype at the biochemical and genetic level. Two isoforms of the drug resistance-associated P-glycoprotein are present and distinguishable both electrophoretically and pharmacologically. Genetic analysis has revealed the presence of a three-member gene family; expression of two of these genes, mdr1a and mdr1b, is associated with MDR whereas the expression of the third, mdr2, is not. Studies of these three genes have revealed similarities and differences in the manner in which they are regulated at the transcriptional level, and have suggested that post-transcriptional effects may also be important. PMID:1346495

  15. In silico identified targeted inhibitors of P-glycoprotein overcome multidrug resistance in human cancer cells in culture

    PubMed Central

    Follit, Courtney A; Brewer, Frances K; Wise, John G; Vogel, Pia D

    2015-01-01

    Failure of cancer chemotherapies is often linked to the over expression of ABC efflux transporters like the multidrug resistance P-glycoprotein (P-gp). P-gp expression in cells leads to the elimination of a variety of chemically unrelated, mostly cytotoxic compounds. Administration of chemotherapeutics during therapy frequently selects for cells that over express P-gp and are therefore capable of robustly exporting diverse compounds, including chemotherapeutics, from the cells. P-gp thus confers multidrug resistance to a majority of drugs currently available for the treatment of cancers and diseases like HIV/AIDS. The search for P-gp inhibitors for use as co-therapeutics to combat multidrug resistances has had little success to date. In a previous study (Brewer et al., Mol Pharmacol 86: 716–726, 2014), we described how ultrahigh throughput computational searches led to the identification of four drug-like molecules that specifically interfere with the energy harvesting steps of substrate transport and inhibit P-gp catalyzed ATP hydrolysis in vitro. In the present study, we demonstrate that three of these compounds reversed P-gp-mediated multidrug resistance of cultured prostate cancer cells to restore sensitivity comparable to naïve prostate cancer cells to the chemotherapeutic drug, paclitaxel. Potentiation concentrations of the inhibitors were <3 μmol/L. The inhibitors did not exhibit significant toxicity to noncancerous cells at concentrations where they reversed multidrug resistance in cancerous cells. Our results indicate that these compounds with novel mechanisms of P-gp inhibition are excellent leads for the development of co-therapeutics for the treatment of multidrug resistances. PMID:26516582

  16. Broad distribution of the multidrug resistance-related vault lung resistance protein in normal human tissues and tumors.

    PubMed

    Izquierdo, M A; Scheffer, G L; Flens, M J; Giaccone, G; Broxterman, H J; Meijer, C J; van der Valk, P; Scheper, R J

    1996-03-01

    Multidrug resistance (MDR) to anticancer drugs is a major cause of treatment failure in cancer. The lung resistance protein LRP is a newly described protein related to MDR in several in vitro models. LRP has been shown to be a strong predictor of poor response to chemotherapy and prognosis in acute myeloid leukemia and in ovarian carcinoma patients. Recently, based on a 57% and 88% amino acid identity with major vault proteins from Dictyostelium discoideum and Rattus norvegicus, respectively, we identified LRP as the human major vault protein, the main component of highly conserved cellular organelles named vaults. We have studied the immunohistochemical expression of LRP in freshly frozen normal human tissues and 174 cancer specimens of 28 tumor types. LRP was broadly distributed in normal and malignant cells, but distinct patterns of expression were noticed. High LRP expression was seen in bronchus, digestive tract, renal proximal tubules, keratinocytes, macrophages, and adrenal cortex whereas varying ing levels were observed in other organs. LRP was detected in all tumor types examined, but its frequency varied, fairly reflecting the chemosensitivity of different cancers. For example, low rates of LRP positivity were seen in testicular cancer, neuroblastoma, and acute myeloid leukemia; intermediate in ovarian cancer; and high in colon, renal, and pancreatic carcinomas. The wide occurrence of LRP in normal and transformed cells in humans, its similar distribution to that of vaults in other species, as well as the high level of conservation among eukaryotic cells of both the amino acid sequence of the major vault protein and the composition and structure of vaults, suggest that vault function is important to eukaryotic cells. PMID:8774142

  17. Induction of multidrug resistance downregulates the expression of CFTR in colon epithelial cells.

    PubMed

    Breuer, W; Slotki, I N; Ausiello, D A; Cabantchik, I Z

    1993-12-01

    The epithelial cell line HT-29, which constitutively expresses the cystic fibrosis transmembrane conductance regulator (CFTR), was induced to become drug resistant by cultivation in the presence of colchicine. The gradual acquisition of drug resistance was associated with a corresponding increase in the expression of the multidrug resistance P-glycoprotein (P-gp) and a marked (> 80%) decrease in the constitutive levels of CFTR protein, as determined by immunoblotting. The reduction in CFTR content occurred at the onset of acquisition of drug resistance when P-gp expression was still relatively low. Reversal of drug resistance by removal of colchicine from the culture medium led to a 70% decrease in P-gp levels and a concomitant 40% increase in CFTR. The levels of other membrane proteins such as Na(+)-K(+)-ATPase and alkaline phosphatase remained relatively constant (< 26% variation). We propose that a selective downregulation of CFTR is elicited by acquisition of the multidrug resistance (MDR) phenotype and that induction of P-gp expression leads to a reversible repression of CFTR biosynthesis. These findings provide an experimental foundation for the complementary patterns of expression of the CFTR and MDR1 genes observed in vivo. PMID:7506492

  18. Meloxicam increases intracellular accumulation of doxorubicin via downregulation of multidrug resistance-associated protein 1 (MRP1) in A549 cells.

    PubMed

    Chen, S F; Zhang, Z Y; Zhang, J L

    2015-01-01

    It has been suggested that selected COX inhibitors can overcome multidrug resistance through the inhibition of ATP‑binding cassette-transporter proteins thereby enhancing the inhibitory effect of doxorubicin on human tumor growth and promoting the actions of cytostatics. However, their effect on lung cancer and the molecular mechanisms involved in the overcoming of multidrug resistance are unclear. In the present study, the ability of meloxicam, a COX-2-specific inhibitor to enhance doxorubicin‑mediated inhibition was investigated in human A549 lung cancer in vivo and in vitro. In order to unravel the molecular mechanisms involved in doxorubicin accumulation, we measured the levels of multidrug resistance-associated protein (MRP)-transporter protein activity and expression by western blotting, since this has been implicated in meloxicam action as well as in chemoresistance. We found that, in A549 cells, meloxicam could increase intracellular accumulation of doxorubicin, a substrate for MRP, through inhibition of cellular export. Western blot analysis indicated that meloxicam reduced the expression of MRP1 and MRP4. The results reported in the present study demonstrate for the first time that the specific COX-2 inhibitor meloxicam can increase the intracellular accumulation of doxorubicin and enhance doxorubicin-induced cytotoxicity in A549 cancer cells by reducing the expression of MRP1 and MRP4. PMID:26600514

  19. Modulation of P-glycoprotein function and multidrug resistance in cancer cells by Thai plant extracts.

    PubMed

    Takano, M; Kakizoe, S; Kawami, M; Nagai, J; Patanasethnont, D; Sripanidkulchai, B; Yumoto, R

    2014-11-01

    The effects of ethanol extracts from Thai plants belonging to the families of Annonaceae, Rutaceae, and Zingiberaceae on P-glycoprotein (P-gp) function and multidrug resistance were examined in paclitaxel-resistant HepG2 (PR-HepG2) cells. All the extracts tested, significantly increased the accumulation of [3H]paclitaxel, a P-gp substrate, in the cells. Among nine extracts, Z01 and Z02, extracts from Curcuma comosa and Kaempferia marginata (Zingiberaceae family), respectively, potently increased the accumulation. In addition, Z01 and Z02 increased the accumulation of other P-gp substrates, rhodamine 123 and doxorubicin, in PR-HepG2 cells in a concentration-dependent manner. Increased accumulation of rhodamine 123 and doxorubicin by Z01 and Z02 was also confirmed by confocal laser scanning microscopy. The effect of Z01 and Z02 pretreatment on the expression of MDR1 mRNA was also examined. The expression of MDR1 mRNA was not affected by the treatment of PR-HepG2 cells with these extracts for 48 hours. Cytotoxicity of paclitaxel was examined by XTT and protein assays in the absence and presence of Z02. Z02 potentiated the cytotoxicity of paclitaxel in PR-HepG2 cells. These results suggest that Curcuma comosa and Kaempferia marginata belonging to Zingiberaceae are useful sources to search for new P-gp modulator(s) that can be used to overcome multidrug resistance of cancer cells. PMID:25985578

  20. Circumvention of multi-drug resistance of cancer cells by Chinese herbal medicines

    PubMed Central

    2010-01-01

    Multi-drug resistance (MDR) of cancer cells severely limits therapeutic outcomes. A proposed mechanism for MDR involves the efflux of anti-cancer drugs from cancer cells, primarily mediated by ATP-binding cassette (ABC) membrane transporters including P-glycoprotein. This article reviews the recent progress of using active ingredients, extracts and formulae from Chinese medicine (CM) in circumventing ABC transporters-mediated MDR. Among the ABC transporters, Pgp is the most extensively studied for its role in MDR reversal effects. While other MDR reversal mechanisms remain unclear, Pgp inhibition is a criterion for further mechanistic study. More mechanistic studies are needed to fully establish the pharmacological effects of potential MDR reversing agents. PMID:20653978

  1. [Multidrug resistance (MDR) in oncology].

    PubMed

    Souvirón Rodríguez, A; Ruiz Gómez, M J; Morales Moreno, J A; Martínez Morillo, M

    1997-03-01

    Multidrug resistance or mdr is a frequent phenomenon for which tumor cells can develop, in only one step, cross-resistance to a different anticancer drugs such as antibiotics, vinca alkaloids and podophylotoxins. This is due to an extrusion of drugs out of the cells, since it is interrelated with the decrease of the intracellular concentration of the drug, compared to sensitive cells. This phenomeno of multidrug resistance (mdr) is considered one of the principal causes of failure in quimiotherapic treatment of cancer, and is associated in many cases to an hyperexpression of mdr-I gene, that codifies for a high molecular weight glycoprotein (p-170) (170-180 Kdaltons), also called p-glycoprotein (pgp). Locadet it in the cellular membrane extracts, like a pump, the quimiotherapic drugs with consumption of ATP. In humans, there are two principal genes that codify for pgp: mdr-I and mdr2/3; being the most important the mdr-I gene. The structure of p-glycoprotein consists in two symmetrical halves anchored in the cellular membrane that includes three extracellular dominances each one, and on intracellular portion with the ATP binding site. Also, has got an for extracellular carbohydrates chain. It is specially important to find drugs that reverse the multidrug resistance. Chemicals such as verapamil, nifedine, quinidine and calmodulin inhibitors are joined to pgp inhibiting it. A Cyclosporine and its non-immunosuppressors derivateds such as SDZ 280-125 and SDZ PSC 833 reverse mdr. At present it is being advancing in clinical trials, but the results are not satisfactory. Most useful chemicals are verapamil, better R-verapamil and A-cyclosporine or its non-immunosuppressors derivates. Futures possibilities are grateful. From diagnostic point of view the mains are: 1. Detection of mdr-I gene. 2. Recognition of the presence of mRNA for pgp. 3. Detection of pgp by flow cytometry or western blot. 4. Immunohistochemistry with monoclonal antibodies to pgp. 5. Rhodamine 123 to

  2. MRP1 and glucosylceramide are coordinately over expressed and enriched in rafts during multidrug resistance acquisition in colon cancer cells.

    PubMed

    Klappe, Karin; Hinrichs, John W J; Kroesen, Bart-Jan; Sietsma, Hannie; Kok, Jan Willem

    2004-07-01

    Previously we have described a novel multidrug-resistant cell line, HT29(col), which displayed over expression of the multidrug-resistance protein 1 (MRP1) and an altered sphingolipid composition, including enhanced levels of glucosylceramide (GlcCer; Kok JW, Veldman RJ, Klappe K, Koning H, Filipeanu C, Muller M. Int J Cancer 2000;87:172-8). In our study, long-term screening revealed that, during colchicine-induced acquisition of multidrug resistance in a new HT29(col) cell line, increases in GlcCer occurred concomitantly with upregulation of MRP1 expression. Both MRP1 and GlcCer were found enriched in Lubrol-insoluble membrane domains. The expression of MRP1 and GlcCer were tightly correlated, as indicated also by a reversal of both at the later stage of colchicine consolidation. Resistance to colchicine was determined by MRP1, while glucosylceramide synthase (GCS) did not contribute: 1). Resistance was fully inhibited by MK571. 2). GCS expression and activity were not upregulated in HT29(col) cells. 3). Inhibition of GCS did not affect MRP1-mediated efflux function or sensitivity to colchicine. Instead, overall sphingolipid metabolism was upregulated through an increased rate of ceramide biosynthesis. In conclusion, upregulation of MRP1 occurs in concert with upregulation of GlcCer during multidrug-resistance acquisition, and both are enriched in rafts. The increased GlcCer pool does not directly modulate MRP1 function and cell survival. PMID:15122583

  3. Modulation of multidrug resistance gene expression in human breast cancer cells by (-)-gossypol-enriched cottonseed oil.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    P-glycoprotein, the product of the multidrug resistance 1 gene, acts as an efflux pump and prevents sufficient intracellular accumulation of several anticancer agents. Thus, it plays a major role in multidrug cancer resistance. Using the non-radioactive cell proliferation MTS assay, none of three ...

  4. Biofunctionalized polymer-lipid supported mesoporous silica nanoparticles for release of chemotherapeutics in multidrug resistant cancer cells.

    PubMed

    Zhang, Xinxin; Li, Feifei; Guo, Shiyan; Chen, Xi; Wang, Xiaoli; Li, Juan; Gan, Yong

    2014-04-01

    Multidrug resistance (MDR) is a major impediment to the success of cancer chemotherapy. A polymer-lipid supported mesoporous silica nanoparticle (PLS-MSNs) is described here to facilitate intracellular delivery of anticancer drug and enhance the antitumor efficacy against MDR breast cancer cells. By coating MSNs with a synthetic dual-functional polymer-lipid material P123-DOPE, the supported membrane acted as an intact barrier against the escape of encapsulated drugs before reaching the target cells, leading to depolymerization and triggered storm release of loaded irinotecan (CPT-11) in acidic endosomal pH of tumor cells. In addition, P123-DOPE can inhibit breast cancer resistance protein (BCPR) mediated CPT-11 efflux in drug resistant MCF-7/BCRP breast cancer cells, thus acting as a "door blocker". Compared to free CPT-11, PLS-MSNs resulted in a maximum increase in the intracellular CPT-11 concentration (12.9-fold), had 7.1-fold higher cytotoxicity and processed a stronger cell cycle arrest in MCF-7/BCRP cells. Moreover, CPT-11 loaded PLS-MSNs showed high therapeutic performance and low toxicity in BALB/c nude mice bearing drug resistant breast tumors, with an inhibition rate of 81.2% compared to free CPT-11 treatment group. The reported PLS-MSNs provide promising applicability in future preclinical and clinical MDR cancer treatment. PMID:24462359

  5. Cytotoxicity of the Sesquiterpene Lactones Neoambrosin and Damsin from Ambrosia maritima Against Multidrug-Resistant Cancer Cells

    PubMed Central

    Saeed, Mohamed; Jacob, Stefan; Sandjo, Louis P.; Sugimoto, Yoshikazu; Khalid, Hassan E.; Opatz, Till; Thines, Eckhard; Efferth, Thomas

    2015-01-01

    Multidrug resistance is a prevailing phenomenon leading to chemotherapy treatment failure in cancer patients. In the current study two known cytotoxic pseudoguaianolide sesquiterpene lactones; neoambrosin (1) and damsin (2) that circumvent MDR were identified. The two cytotoxic compounds were isolated using column chromatography, characterized using 1D and 2D NMR, MS, and compared with literature values. The isolated compounds were investigated for their cytotoxic potential using resazurin assays and thereafter confirmed with immunoblotting and in silico studies. MDR cells overexpressing ABC transporters (P-glycoprotein, BCRP, ABCB5) did not confer cross-resistance toward (1) and (2), indicating that these compounds are not appropriate substrates for any of the three ABC transporters analyzed. Resistance mechanisms investigated also included; the loss of the functions of the TP53 and the mutated EGFR. The HCT116 p53-/- cells were sensitive to 1 but resistant to 2. It was interesting to note that resistant cells transfected with oncogenic ΔEGFR exhibited hypersensitivity CS toward (1) and (2) (degrees of resistances were 0.18 and 0.15 for (1) and (2), respectively). Immunoblotting and in silico analyses revealed that 1 and 2 silenced c-Src kinase activity. It was hypothesized that inhibition of c-Src kinase activity may explain CS in EGFR-transfected cells. In conclusion, the significant cytotoxicity of 1 and 2 against different drug-resistant tumor cell lines indicate that they may be promising candidates to treat refractory tumors. PMID:26617519

  6. Hepatocyte growth factor (HGF), heat shock proteins (HSPs) and multidrug resistance protein (MRP) expression in co-culture of colon tumor spheroids with normal cells after incubation with interleukin-1beta (IL-1beta) and/or camptothecin (CPT-11).

    PubMed

    Paduch, Roman; Jakubowicz-Gil, Joanna; Niedziela, Piotr

    2010-04-01

    Tumor chemoresistance and metastasis are some of the most important problems in colon cancer therapy. In the present study, co-cultures of human colon carcinoma cell spheroids, obtained from different grades of tumor, with human colon epithelium, myofibroblast and endothelial cell monolayers were performed. The purpose of these co-cultures was to reflect, in in vitro conditions, different stages of colon tumor development. In order to investigate the invasive capacities of the tumor cells and their resistance to chemotherapy, HGF, HSP27, HSP72 and MRP levels were analyzed after incubation of the co-cultures with IL-1beta and irinotecan (CPT-11) added as single agents or in combination. Myofibroblasts produced significantly higher amounts of HGF than epithelial cells. Tumor cells released trace amounts of this molecule. In cocultures, IL-1beta induced HGF release, while CPT-11 alone or combined with IL-1beta decreased HGF secretion. An immunoblotting analysis followed by densitometry revealed that the combination of IL-1beta plus CPT-11 added to the cocultures led to a decrease in HSPs and MRP levels. In conclusion, direct and paracrine interactions of colon tumor cell spheroids with normal cells and exogenously added CPT-11 change HSP27, HSP72 and MRP expression in comparison to monocultures. IL-1beta and CPT-11, dependent on whether they are added separately or jointly, differentially modulate HGF expression in monocultures of colon tumor spheroids or normal cells and their co-cultures. PMID:20726333

  7. The multidrug-resistance transporter Abcc3 protects NK cells from chemotherapy in a murine model of malignant glioma

    PubMed Central

    Pessina, Sara; Cantini, Gabriele; Kapetis, Dimos; Cazzato, Emanuela; Di Ianni, Natalia; Finocchiaro, Gaetano; Pellegatta, Serena

    2016-01-01

    ABSTRACT Abcc3, a member of the ATP-binding cassette transporter superfamily, plays a role in multidrug resistance. Here, we found that Abcc3 is highly expressed in blood-derived NK cells but not in CD8+ T cells. In GL261 glioma-bearing mice treated with the alkylating agent temozolomide (TMZ) for 5 d, an early increased frequency of NK cells was observed. We also found that Abcc3 is strongly upregulated and functionally active in NK cells from mice treated with TMZ compared to controls. We demonstrate that Abcc3 is critical for NK cell survival during TMZ administration; more importantly, Akt, involved in lymphocyte survival, is phosphorylated only in NK cells expressing Abcc3. The resistance of NK cells to chemotherapy was accompanied by increased migration and homing in the brain at early time points. Cytotoxicity, evaluated by IFNγ production and specific lytic activity against GL261 cells, increased peripherally in the later phases, after conclusion of TMZ treatment. Intra-tumor increase of the NK effector subset as well as in IFNγ, granzymes and perforin-1 expression, were found early and persisted over time, correlating with a profound modulation on glioma microenvironment induced by TMZ. Our findings reveal an important involvement of Abcc3 in NK cell resistance to chemotherapy and have important clinical implications for patients treated with chemo-immunotherapy. PMID:27467914

  8. Synergistic effect of a novel cyclic pentadepsipeptide, neoN-methylsansalvamide, and paclitaxel on human multidrug resistance cancer cell lines.

    PubMed

    Lee, Hee-Seok; Phat, Chanvorleak; Choi, Sang-Un; Lee, Chan

    2013-06-01

    NeoN-methylsansalvamide is a novel low-molecular-weight cyclic pentadepsipeptide that exerts cytotoxic effects on various human cancer cell lines. Its structural analysis using liquid chromatography mass/mass spectrometry showed the cyclic structure sequence -phenylalanine-leucine-valine-N-methylleucine-leucic acid-. The intrinsic cytotoxic and multidrug resistance reversal effects of neoN-methylsansalvamide were evaluated on the human cancer cell lines MES-SA and HCT15 as well as on their multidrug resistance sublines (MES-SA/DX5 and HCT15/CL05, respectively) using the sulforhodamine B assay. The EC50 values of paclitaxel for MES-SA, HCT15, and for the multidrug resistance sublines MES-SA/DX5 and HCT15/CL05 were 1.00±0.20, 0.85±0.63, 10.00±0.53, and >1000 nmol/l, respectively. However, the EC50 values for paclitaxel including 3 μmol/l neoN-methylsansalvamide for MES-SA/DX5, HCT15, and HCT15/CL02 were 1.58±0.12, 0.10±0.02, and 288.40±21.02 nmol/l, respectively. The in-vitro multidrug resistance reversal activity of neoN-methylsansalvamide was similar to that of the control verapamil. These finding suggests that a novel cyclic pentadepsipeptide, neoN-methylsansalvamide, is effective in reversing multidrug resistance in vitro, and this activity may be a major applicable biological function of this compound. PMID:23411682

  9. 1H nuclear magnetic resonance-based extracellular metabolomic analysis of multidrug resistant Tca8113 oral squamous carcinoma cells

    PubMed Central

    WANG, HUI; CHEN, JIAO; FENG, YUN; ZHOU, WENJIE; ZHANG, JIHUA; YU, YU; WANG, XIAOQIAN; ZHANG, PING

    2015-01-01

    A major obstacle of successful chemotherapy is the development of multidrug resistance (MDR) in the cancer cells, which is difficult to reverse. Metabolomic analysis, an emerging approach that has been increasingly applied in various fields, is able to reflect the unique chemical fingerprints of specific cellular processes in an organism. The assessment of such metabolite changes can be used to identify novel therapeutic biomarkers. In the present study, 1H nuclear magnetic resonance (NMR) spectroscopy was used to analyze the extracellular metabolomic spectrum of the Tca8113 oral squamous carcinoma cell line, in which MDR was induced using the carboplatin (CBP) and pingyangmycin (PYM) chemotherapy drugs in vitro. The data were analyzed using the principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) methods. The results demonstrated that the extracellular metabolomic spectrum of metabolites such as glutamate, glycerophosphoethanol amine, α-Glucose and β-Glucose for the drug-induced Tca8113 cells was significantly different from the parental Tca8113 cell line. A number of biochemicals were also significantly different between the groups based on their NMR spectra, with drug-resistant cells presenting relatively higher levels of acetate and lower levels of lactate. In addition, a significantly higher peak was observed at δ 3.35 ppm in the spectrum of the PYM-induced Tca8113 cells. Therefore, 1H NMR-based metabolomic analysis has a high potential for monitoring the formation of MDR during clinical tumor chemotherapy in the future. PMID:26137105

  10. A protein kinase Cβ inhibitor attenuates multidrug resistance of neuroblastoma cells

    PubMed Central

    Svensson, Karin; Larsson, Christer

    2003-01-01

    Background The acquisition of drug resistance is a major reason for poor outcome of neuroblastoma. Protein kinase C (PKC) has been suggested to influence drug resistance in cancer cells. The aim of this study was to elucidate whether inhibition of PKCβ isoforms influences drug-resistance of neuroblastoma cells. Methods The effect of the PKCβ inhibitor LY379196 on the growth-suppressing effects of different chemotherapeutics on neuroblastoma cells was analyzed with MTT assays. The effect of LY379196 on the accumulation of [3H]vincristine was also investigated Results The PKCβ inhibitor LY379196 suppressed the growth of three neuroblastoma cell lines. LY379196 also augmented the growth-suppressive effect of doxorubicin, etoposide, paclitaxel, and vincristine, but not of carboplatin. The effect was most marked for vincristine and for the cell-line (SK-N-BE(2)) that was least sensitive to vincristine. No effect was observed on the non-resistant IMR-32 cells. Two other PKC inhibitors, Gö6976 and GF109203X, also enhanced the vincristine effect. The PKC inhibitors caused an increased accumulation of [3H]vincristine in SK-N-BE(2) cells. Conclusions This indicates that inhibition of PKCβ could attenuate multidrug resistance in neuroblastoma cells by augmenting the levels of natural product anticancer drugs in resistant cells. PMID:12697075

  11. Simple avarone mimetics as selective agents against multidrug resistant cancer cells.

    PubMed

    Jeremić, Marko; Pešić, Milica; Dinić, Jelena; Banković, Jasna; Novaković, Irena; Šegan, Dejan; Sladić, Dušan

    2016-08-01

    In this work, synthesis of alkylamino and aralkylamino derivatives of sesquiterpene quinone avarone and its model compound tert-butylquinone was described. For all obtained derivatives biological activity was studied. Cytotoxic activity of the synthesized derivatives towards multidrug resistant MDR human non-small cell lung carcinoma NCI-H460/R cells, their sensitive counterpart NCI-H460 and human normal keratinocytes (HaCaT) as well as detection of cell death superoxide anion generation were investigated. Antimicrobial activity towards Gram positive and Gram negative bacteria and fungal cultures was determined. The results showed that strong cytotoxic activity toward cancer cells was improved with simple avarone mimetics. Some derivatives were selective towards MDR cancer cells. The most active derivatives induced apoptosis in both cancer cell lines, but not in normal cells. Superoxide production was induced by 2,6-disubstituted compounds in MDR cancer cells and not by less active 2,5-disubstituted compounds and was accompanied by the collapse of the mitochondrial transmembrane potential. Two tert-butylquinone derivatives were particularly selective towards MDR cancer cells. Some tert-butylquinone derivatives exhibited a strong antimicrobial activity. PMID:27128177

  12. Multidrug Resistance Protein-4 Influences Aspirin Toxicity in Human Cell Line.

    PubMed

    Massimi, Isabella; Ciuffetta, Ambra; Temperilli, Flavia; Ferrandino, Francesca; Zicari, Alessandra; Pulcinelli, Fabio M; Felli, Maria Pia

    2015-01-01

    Overexpression of efflux transporters, in human cells, is a mechanism of resistance to drug and also to chemotherapy. We found that multidrug resistance protein-4 (MRP4) overexpression has a role in reducing aspirin action in patients after bypass surgery and, very recently, we found that aspirin enhances platelet MRP4 levels through peroxisome proliferator activated receptor-α (PPARα). In the present paper, we verified whether exposure of human embryonic kidney-293 cells (Hek-293) to aspirin modifies MRP4 gene expression and its correlation with drug elimination and cell toxicity. We first investigated the effect of high-dose aspirin in Hek-293 and we showed that aspirin is able to increase cell toxicity dose-dependently. Furthermore, aspirin effects, induced at low dose, already enhance MRP4 gene expression. Based on these findings, we compared cell viability in Hek-293, after high-dose aspirin treatment, in MRP4 overexpressing cells, either after aspirin pretreatment or in MRP4 transfected cells; in both cases, a decrease of selective aspirin cell growth inhibition was observed, in comparison with the control cultures. Altogether, these data suggest that exposing cells to low nontoxic aspirin dosages can induce gene expression alterations that may lead to the efflux transporter protein overexpression, thus increasing cellular detoxification of aspirin. PMID:26491233

  13. Differential expression of sphingolipids in P-glycoprotein or multidrug resistance-related protein 1 expressing human neuroblastoma cell lines.

    PubMed

    Dijkhuis, Anne-Jan; Douwes, Jenny; Kamps, Willem; Sietsma, Hannie; Kok, Jan Willem

    2003-07-31

    The sphingolipid composition and multidrug resistance status of three human neuroblastoma cell lines were established. SK-N-FI cells displayed high expression and functional (efflux) activity of P-glycoprotein, while multidrug resistance-related protein 1 was relatively abundant and most active in SK-N-AS cells. These two cell lines exhibited higher sphingolipid levels, compared to SK-N-DZ, which had the lowest activity of either ATP-binding cassette transporter protein. SK-N-DZ cells also differed in ganglioside composition with predominant expression of b-series gangliosides. In conclusion, these three neuroblastoma cell lines offer a good model system to study sphingolipid metabolism in relation to ATP-binding cassette transporter protein function. PMID:12885402

  14. Inhibition of Glutathione Peroxidase Mediates the Collateral Sensitivity of Multidrug-resistant Cells to Tiopronin*

    PubMed Central

    Hall, Matthew D.; Marshall, Travis S.; Kwit, Alexandra D. T.; Miller Jenkins, Lisa M.; Dulcey, Andrés E.; Madigan, James P.; Pluchino, Kristen M.; Goldsborough, Andrew S.; Brimacombe, Kyle R.; Griffiths, Gary L.; Gottesman, Michael M.

    2014-01-01

    Multidrug resistance (MDR) is a major obstacle to the successful chemotherapy of cancer. MDR is often the result of overexpression of ATP-binding cassette transporters following chemotherapy. A common ATP-binding cassette transporter that is overexpressed in MDR cancer cells is P-glycoprotein, which actively effluxes drugs against a concentration gradient, producing an MDR phenotype. Collateral sensitivity (CS), a phenomenon of drug hypersensitivity, is defined as the ability of certain compounds to selectively target MDR cells, but not the drug-sensitive parent cells from which they were derived. The drug tiopronin has been previously shown to elicit CS. However, unlike other CS agents, the mechanism of action was not dependent on the expression of P-glycoprotein in MDR cells. We have determined that the CS activity of tiopronin is mediated by the generation of reactive oxygen species (ROS) and that CS can be reversed by a variety of ROS-scavenging compounds. Specifically, selective toxicity of tiopronin toward MDR cells is achieved by inhibition of glutathione peroxidase (GPx), and the mode of inhibition of GPx1 by tiopronin is shown in this report. Why MDR cells are particularly sensitive to ROS is discussed, as is the difficulty in exploiting this hypersensitivity to tiopronin in the clinic. PMID:24930045

  15. Natural lignans from Arctium lappa modulate P-glycoprotein efflux function in multidrug resistant cancer cells.

    PubMed

    Su, Shan; Cheng, Xinlai; Wink, Michael

    2015-02-15

    Arctium lappa is a well-known traditional medicinal plant in China (TCM) and Europe that has been used for thousands of years to treat arthritis, baldness or cancer. The plant produces lignans as secondary metabolites which have a wide range of bioactivities. Yet, their ability to reverse multidrug resistance (MDR) in cancer cells has not been explored. In this study, we isolated six lignans from A. lappa seeds, namely arctigenin, matairesinol, arctiin, (iso)lappaol A, lappaol C, and lappaol F. The MDR reversal potential of the isolated lignans and the underlying mechanism of action were studied using two MDR cancer cell lines, CaCo2 and CEM/ADR 5000 which overexpress P-gp and other ABC transporters. In two-drug combinations of lignans with the cytotoxic doxorubicin, all lignans exhibited synergistic effects in CaCo2 cells and matairesinol, arctiin, lappaol C and lappaol F display synergistic activity in CEM/ADR 5000 cells. Additionally, in three-drug combinations of lignans with the saponin digitonin and doxorubicin MDR reversal activity was even stronger enhanced. The lignans can increase the retention of the P-gp substrate rhodamine 123 in CEM/ADR 5000 cells, indicating that lignans can inhibit the activity of P-gp. Our study provides a first insight into the potential chemosensitizing activity of a series of natural lignans, which might be candidates for developing novel adjuvant anticancer agents. PMID:25765837

  16. Mixed Micelles for Targeted and Efficient Doxorubicin Delivery to Multidrug-Resistant Breast Cancer Cells.

    PubMed

    Jung, Heesun; Mok, Hyejung

    2016-05-01

    For efficient treatment of multidrug-resistance (MDR) breast cancer cells, design of biocompatible mixed micelles with diverse functional moieties and superior stability is needed for targeted delivery of chemical drugs. In this study, polypropylene glycol (PPG)-grafted hyaluronic acid (HA) copolymers (PPG-g-HA) are used to make mixed micelles with different amounts of pluronic L61, named PPG-g-HA/L61 micelles. Optimized PPG-g-HA/L61 micelles with 3% pluronic L61 exhibit great stability in aqueous solution, superior biocompatibility, and significantly increased uptake into MCF-7 MDR cells via HA-CD44-specific interactions when compared to free doxorubicin (DOX) and other types of micelles. In addition, DOX in PPG-g-HA/L61 micelles with 3% pluronic L61 have toxicity in MCF-7 MDR cells but significantly lower toxicity in fibroblast L929 cells compared to free DOX. Thus, PPG-g-HA/L61 micelles with 3% pluronic L61 content can be a promising nanocarrier to overcome MDR and release DOX in a hyaluronidase-sensitive manner without any toxicity to normal cells. PMID:26806493

  17. 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. PMID:23137376

  18. The phytoestrogen genistein enhances multidrug resistance in breast cancer cell lines by translational regulation of ABC transporters.

    PubMed

    Rigalli, Juan Pablo; Tocchetti, Guillermo Nicolás; Arana, Maite Rocío; Villanueva, Silvina Stella Maris; Catania, Viviana Alicia; Theile, Dirk; Ruiz, María Laura; Weiss, Johanna

    2016-06-28

    Breast cancer is the most frequent malignancy in women. Multidrug resistance due to overexpression of ABC drug transporters is a common cause of chemotherapy failure and disease recurrence. Genistein (GNT) is a phytoestrogen present in soybeans and hormone supplements. We investigated the effect of GNT on the expression and function of ABC transporters in MCF-7 and MDA-MB-231 breast cancer cell lines. Results demonstrated an induction at the protein level of ABCC1 and ABCG2 and of ABCC1 in MCF-7 and MDA-MB-231, respectively. MCF-7 cells showed a concomitant increase in doxorubicin and mitoxantrone efflux and resistance, dependent on ABCG2 activity. ABCC1 induction by GNT in MDA-MB-231 cells modified neither drug efflux nor chemoresistance due to simultaneous acute inhibition of the transporter activity by GNT. All inductions took place at the translational level, as no increment in mRNA was observed and protein increase was prevented by cycloheximide. miR-181a, already demonstrated to inhibit ABCG2 translation, was down-regulated by GNT, explaining translational induction. Effects were independent of classical estrogen receptors. Results suggest potential nutrient-drug interactions that could threaten chemotherapy efficacy, especially in ABCG2-expressing tumors treated with substrates of this transporter. PMID:27033456

  19. Reversion of p-glycoprotein-mediated multidrug resistance in human leukemic cell line by diallyl trisulfide.

    PubMed

    Xia, Qing; Wang, Zhi-Yong; Li, Hui-Qing; Diao, Yu-Tao; Li, Xiao-Li; Cui, Jia; Chen, Xue-Liang; Li, Hao

    2012-01-01

    Multidrug resistance (MDR) is the major obstacle in chemotherapy, which involves multiple signaling pathways. Diallyl trisulfide (DATS) is the main sulfuric compound in garlic. In the present study, we aimed to explore whether DATS could overcome P-glycoprotein-(P-gp-)mediated MDR in K562/A02 cells, and to investigate whether NF-κB suppression is involved in DATS-induced reversal of MDR. MTT assay revealed that cotreatment with DATS increased the response of K562/A02 cells to adriamycin (the resistance reversal fold was 3.79) without toxic side effects. DATS could enhance the intracellular concentration of adriamycin by inhibiting the function and expression of P-gp, as shown by flow cytometry, RT-PCR, and western blot. In addition, DATS resulted in more K562/A02 cell apoptosis, accompanied by increased expression of caspase-3. The expression of NF-κB/p65 (downregulation) was significantly linked to the drug-resistance mechanism of DATS, whereas the expression of IκBα was not affected by DATS. Our findings demonstrated that DATS can serve as a novel, nontoxic modulator of MDR, and can reverse the MDR of K562/A02 cells in vitro by increasing intracellular adriamycin concentration and inducing apoptosis. More importantly, we proved for the first time that the suppression of NF-κB possibly involves the molecular mechanism in the course of reversion by DATS. PMID:22919419

  20. The Effects and Mechanisms of Periplaneta americana Extract Reversal of Multi-Drug Resistance in BEL-7402/5-FU Cells.

    PubMed

    Yuan, Falu; Liu, Junyong; Qiao, Tingting; Li, Ting; Shen, Qi; Peng, Fang

    2016-01-01

    The present study reports the reversing effects of extracts from P. americana on multidrug resistance of BEL-7402/5-FU cells, as well as a preliminary investigation on their mechanism of action. A methylthiazolyl tetrazolium (MTT) method was applied to determine the multidrug resistance of BEL-7402/5-FU, while an intracellular drug accumulation assay was used to evaluate the effects of a column chromatography extract (PACC) and defatted extract (PADF) from P. americana on reversing multi-drug resistance. BEL-7402/5-FU reflected high resistance to 5-FU; PACC and PADF could promote drug accumulation in BEL-7402/5-FU cells, among which PADF was more effective than PACC. Moreover, results from the immunocytochemical method showed that PACC and PADF could downregulate the expression of drug resistance-associated proteins (P-gp, MRP, LRP); PACC and PADF had no effects on the expression of multidrug resistance-associated enzymes (GST-π), but PACC could increase the expression of multidrug resistance-associated enzymes (PKC). Results of real-time fluorescence quantitative PCR revealed that PACC and PADF were able to markedly inhibit the expression of multidrug resistance-associated genes (MDR1, LRP and MRP1); PACC presented a significant impact on the gene expression of multidrug resistance-associated enzymes, which increased the gene expression of GST-π and PKC. However, PADF had little impact on the expression of multidrug resistance-associated enzymes. These results demonstrated that PACC and PADF extracted from P. americana could effectively reverse MDR in BEL-7402/5-FU cells, whose mechanism was to inhibit the expression of P-gp, MRP, and LRP, and that PADF was more effective in the reversal of MDR than did PACC. In addition, some of extracts from P. americana altered (sometimes increasing) the expression of multidrug resistance-associated enzymes. PMID:27367657

  1. Enhanced chemosensitization in multidrug-resistant human breast cancer cells by inhibition of IL-6 and IL-8 production.

    PubMed

    Shi, Zhi; Yang, Wei-Min; Chen, Li-Pai; Yang, Dong-Hua; Zhou, Qi; Zhu, Jin; Chen, Jun-Jiang; Huang, Ruo-Chun; Chen, Zhe-Sheng; Huang, Ruo-Pan

    2012-10-01

    Drug resistance remains a major hurdle to successful cancer treatment. Many mechanisms such as overexpression of multidrug-resistance related proteins, increased drug metabolism, decreased apoptosis, and impairment of signal transduction pathway can contribute multidrug resistance (MDR). Recent studies strongly suggest a close link between cytokines and drug resistance. To identify new targets involved in drug resistance, we established a multidrug-resistant human breast cancer cell line MCF-7/R and examined the cytokine profile using cytokine antibody array technology. Among 120 cytokines/chemokines screened, IL-6, IL-8, and 13 other proteins were found to be markedly increased in drug-resistant MCF-7/R cell line as compared to sensitive MCF-7/S cell line, while 7 proteins were specifically reduced in drug-resistant MCF-7/R cells. Neutralizing antibodies against IL-6 and IL-8 partially reversed the drug resistance of MCF-7/R to paclitaxel and doxorubicin, while a neutralizing antibody against MCP-1 had no significant effect. Inhibition of endogenous IL-6 or IL-8 by siRNA technology significantly enhanced drug sensitivity of MCF-7/R cells. Furthermore, overexpression of IL-6 or IL-8 expression by transfection increased the ADM resistance in MCF-7/S cells. Our data suggest that increased expression levels of IL-6 and IL-8 may contribute to MDR in human breast cancer cells. PMID:22923236

  2. Reversal effects of traditional Chinese herbs on multidrug resistance in cancer cells.

    PubMed

    Yang, Lei; Wei, Dan-Dan; Chen, Zhong; Wang, Jun-Song; Kong, Ling-Yi

    2011-11-01

    Multidrug resistance (MDR) continues to be a major obstacle for successful anticancer therapy. In this work, fractions from 17 clinically used antitumour traditional Chinese medicinal herbs were tested for their potential to restore the sensitivity of MCF-7/ADR and A549/Taxol cells to a known antineoplastic agent. The effects of these fractions were evaluated by MTT method and an assay of the cellular accumulation of doxorubicin. Fractions from the PB group (herbs with the ability to promote blood circulation and remove blood stasis) showed more significant effects than fractions from the CH group (herbs with the ability to clear away heat and toxic materials). Fractions from CH₂Cl₂ extracts were more effective than fractions from EtOAc extracts. Five herbs (Curcuma wenyujin, Chrysanthemum indicum, Salvia chinensis, Ligusticum chuanxiong Hort. and Cassia tora L.) could sensitise these resistant cancer cells at a non-toxic concentration (10 µg mL⁻¹), and markedly increased doxorubicin accumulation in MCF-7/ADR cells, which necessitates further investigations on the active ingredients of these herbs and their underlying mechanisms. PMID:21848372

  3. Overcoming of multidrug resistance by introducing the apoptosis gene, bcl-Xs, into MRP-overexpressing drug resistant cells.

    PubMed

    Ohi, Y; Kim, R; Toge, T

    2000-05-01

    Multidrug resistance associated protein (MRP) is one of drug transport membranes that confer multidrug resistance in cancer cells. Multidrug resistance has been known to be associated with resistance to apoptosis. In this study, using MRP overexpressing multidrug resistant nasopharyngeal cancer cells, we examined the expression of apoptosis related genes including p53, p21WAF1, bax and bcl-Xs between drug sensitive KB and its resistant KB/7D cells. We also examined whether the introduction of apoptosis related gene could increase the sensitivity to anticancer drugs in association with apoptotic cell death. The relative resistances to anticancer drugs in KB/7D cells evaluated by IC50 values were 3.6, 61.3, 10.4 and 10.5 to adriamycin (ADM), etoposide (VP-16), vincristine (VCR) and vindesine (VDS), respectively. The resistance to anticancer drugs in KB/7D cells was associated with the attenuation of internucleosomal DNA ladder formation in apoptosis. Of important, the mRNA expression of bcl-Xs gene in KB/7D cells was decreased in one-fourth as compared to that of KB cells among the apoptosis genes. The mRNA expression of bcl-Xs gene in a bcl-Xs transfected clone (KB/7Dbcl-Xs) was increased about 2-fold compared to that of KB/7Dneo cells, while the mRNA expression of MRP gene was not significantly different in KB/7bcl-Xs and KB/7Dneo cells. The sensitivities to anticancer drugs including ADM, VCR and VDS except VP-16 were increased in KB/7Dbcl-Xs cells, in turn, the relative resistance in KB/7Dbcl-Xs cells was decreased to 1.4, 4.0, and 3.0 in ADM, VCR and VDS, respectively, as compared to those of KB/7Dneo cells. Of interest, the studies on the accumulation of [3H]VCR showed that the decrease of [3H]VCR accumulation in KB/7Dbcl-Xs was not significantly different from that of KB/7Dneo cells. Collectively, these results indicated that the mechanism(s) of drug resistance in KB/7D cells could be explained at least by two factors: a) reduced drug accumulation mediated by

  4. miR-1915 inhibits Bcl-2 to modulate multidrug resistance by increasing drug-sensitivity in human colorectal carcinoma cells.

    PubMed

    Xu, Ke; Liang, Xin; Cui, Daling; Wu, Yixin; Shi, Weibin; Liu, Jianwen

    2013-01-01

    Colorectal carcinoma is a frequent cause of cancer-related death in the world for men and women. microRNAs are endogenous small noncoding RNAs that regulate gene expression negatively at post-transcriptional level. Here, we investigated the possible role of microRNAs in the development of multidrug resistance (MDR) in colorectal carcinoma cells. We analyzed microRNA (miRNA) expression levels between multidrug resistant colorectal carcinoma cell line HCT116/L-OHP and its parent cell line HCT116 using a miRNA microarray. miR-1915 had the lowest expression of miRNA in HCT116/L-OHP cells compared to its parental cells. Overexpression of Bcl-2 is generally associated with tumor drug resistance, meanwhile Bcl-2 is a predicted target of miR-1915. We found that elevated levels of miR-1915 in the mimics-transfected HCT116/L-OHP cells reduced Bcl-2 protein level and the luciferase activity of a Bcl-2 3'-untranslated region-based reporter, and also sensitized these cells to some anticancer drugs. Taken together, our findings suggest that miR-1915 could play a role in the development of MDR in colorectal carcinoma cells at least in part by modulation of apoptosis via targeting Bcl-2. PMID:22121083

  5. Redox active copper chelate overcomes multidrug resistance in T-lymphoblastic leukemia cell by triggering apoptosis.

    PubMed

    Ganguly, Avishek; Basu, Soumya; Banerjee, Kaushik; Chakraborty, Paramita; Sarkar, Avijit; Chatterjee, Mitali; Chaudhuri, Soumitra Kumar

    2011-05-01

    Multidrug resistance (MDR) mediated by the over expression of drug efflux protein P-glycoprotein (P-gp) is one of the major impediments to successful treatment of cancer. P-gp acts as an energy-dependent drug efflux pump and reduces the intracellular concentration of structurally unrelated drugs inside the cells. Therefore, there is an urgent need for development of new molecules that are less toxic to normal cell and preferentially effective against drug resistant malignant cells. In this preclinical study we report the apoptotic potential of copper N-(2-hydroxyacetophenone) glycinate (CuNG) on doxorubicin resistant T lymphoblastic leukaemia cells (CEM/ADR5000). To evaluate the cytotoxic effect of CuNG, we used different normal cell lines (NIH 3T3, Chang liver and human PBMC) and cancerous cell lines (CEM/ADR5000, parental sensitive CCRF-CEM, SiHa and 3LL) and conclude that CuNG preferentially kills cancerous cells, especially both leukemic cell types irrespective of their MDR status, while leaving normal cell totally unaffected. Moreover, CuNG involves reactive oxygen species (ROS) for induction of apoptosis in CEM/ADR5000 cells through the intrinsic apoptotic pathway. This is substantiated by our observation that antioxidant N-acetyle-cysteine (NAC) and PEG catalase could completely block ROS generation and, subsequently, abrogates CuNG induced apoptosis. On the other hand, uncomplexed ligand N-(2-hydroxyacetophenone) glycinate (NG) fails to generate a significant amount of ROS and concomitant induction of apoptosis in CEM/ADR5000 cells. Therefore, CuNG induces drug resistant leukemia cells to undergo apoptosis and proves to be a molecule having therapeutic potential to overcome MDR in cancer. PMID:21409205

  6. Regulation of Multi-drug Resistance in hepatocellular carcinoma cells is TRPC6/Calcium Dependent

    PubMed Central

    Wen, Liang; Liang, Chao; Chen, Enjiang; Chen, Wei; Liang, Feng; Zhi, Xiao; Wei, Tao; Xue, Fei; Li, Guogang; Yang, Qi; Gong, Weihua; Feng, Xinhua; Bai, Xueli; Liang, Tingbo

    2016-01-01

    Hepatocellular carcinoma (HCC) is notoriously refractory to chemotherapy because of its tendency to develop multi-drug resistance (MDR), whose various underlying mechanisms make it difficult to target. The calcium signalling pathway is associated with many cellular biological activities, and is also a critical player in cancer. However, its role in modulating tumour MDR remains unclear. In this study, stimulation by doxorubicin, hypoxia and ionizing radiation was used to induce MDR in HCC cells. A sustained aggregation of intracellular calcium was observed upon these stimuli, while inhibition of calcium signalling enhanced the cells’ sensitivity to various drugs by attenuating epithelial-mesenchymal transition (EMT), Hif1-α signalling and DNA damage repair. The effect of calcium signalling is mediated via transient receptor potential canonical 6 (TRPC6), a subtype of calcium-permeable channel. An in vivo xenograft model of HCC further confirmed that inhibiting TRPC6 enhanced the efficacy of doxorubicin. In addition, we deduced that STAT3 activation is a downstream signalling pathway in MDR. Collectively, this study demonstrated that the various mechanisms regulating MDR in HCC cells are calcium dependent through the TRPC6/calcium/STAT3 pathway. We propose that targeting TRPC6 in HCC may be a novel antineoplastic strategy, especially combined with chemotherapy. PMID:27011063

  7. Chemotherapeutic activities of Carthami Flos and its reversal effect on multidrug resistance in cancer cells.

    PubMed

    Wu, Jimmy Yiu-Cheong; Yu, Zhi-Ling; Fong, Wang-Fun; Shi, Yi-Qian

    2013-01-01

    Multidrug-resistance (MDR) represents a major cause of failure in cancer chemotherapy. The need for a reduction in MDR by natural-product-based drugs of low toxicity led to the current investigation of applying medicinal herbs in future cancer adjuvant therapy. Carthami Flos (CF), the dried flower of safflower (Carthamus tinctorius L.), is one of the most popular traditional Chinese medicinal herbs used to alleviate pain, increase circulation, and reduce blood-stasis syndrome. The drug resistance index of the total extract of CF in MDR KB-V1 cells and its synergistic effects with other chemotherapeutic agents were studied. SRB cell viability assays were used to quantify growth inhibition after exposure to single drug and in combinations with other chemotherapeutic agents using the median effect principle. The combination indexes were then calculated according to the classic isobologram equation. The results revealed that CF showed a drug resistance index of 0.096. In combination with other chemotherapeutic agents, it enhanced their chemo-sensitivities by 2.8 to 4.0 folds and gave a general synergism in cytotoxic effect. These results indicate that CF could be a potential alternative adjuvant antitumour herbal medicine representing a promising approach to the treatment of some malignant and MDR cancers in the future. PMID:24146498

  8. Deficiency of multidrug resistance 2 contributes to cell transformation through oxidative stress

    PubMed Central

    Tebbi, Ali; Levillayer, Florence; Jouvion, Grégory; Fiette, Laurence; Soubigou, Guillaume; Varet, Hugo; Boudjadja, Nesrine; Cairo, Stefano; Hashimoto, Kosuke; Suzuki, Ana Maria; Carninci, Piero; Carissimo, Annamaria; di Bernardo, Diego; Wei, Yu

    2016-01-01

    Multidrug resistance 2 (Mdr2), also called adenosine triphosphate-binding cassette B4 (ABCB4), is the transporter of phosphatidylcholine (PC) at the canalicular membrane of mouse hepatocytes, which plays an essential role for bile formation. Mutations in human homologue MDR3 are associated with several liver diseases. Knockout of Mdr2 results in hepatic inflammation, liver fibrosis and hepatocellular carcinoma (HCC). Whereas the pathogenesis in Mdr2 −/− mice has been largely attributed to the toxicity of bile acids due to the absence of PC in the bile, the question of whether Mdr2 deficiency per se perturbs biological functions in the cell has been poorly addressed. As Mdr2 is expressed in many cell types, we used mouse embryonic fibroblasts (MEF) derived from Mdr2 −/− embryos to show that deficiency of Mdr2 increases reactive oxygen species accumulation, lipid peroxidation and DNA damage. We found that Mdr2 −/− MEFs undergo spontaneous transformation and that Mdr2 −/− mice are more susceptible to chemical carcinogen-induced intestinal tumorigenesis. Microarray analysis in Mdr2−/− MEFs and cap analysis of gene expression in Mdr2 −/− HCCs revealed extensively deregulated genes involved in oxidation reduction, fatty acid metabolism and lipid biosynthesis. Our findings imply a close link between Mdr2 −/−-associated tumorigenesis and perturbation of these biological processes and suggest potential extrahepatic functions of Mdr2/MDR3. PMID:26542370

  9. TRAIL Recombinant Adenovirus Triggers Robust Apoptosis in Multidrug-Resistant HL-60/Vinc Cells Preferentially Through Death Receptor DR5

    PubMed Central

    Wu, Ching-Huang; Kao, Ching-Hai

    2008-01-01

    Abstract Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising cancer therapeutic because of its highly selective apoptosis-inducing action on neoplastic versus normal cells. However, some cancer cells express resistance to recombinant soluble TRAIL. To overcome this problem, we used a TRAIL adenovirus (Ad5/35-TRAIL) to induce apoptosis in a drug-sensitive and multidrug-resistant variant of HL-60 leukemia cells and determined the molecular mechanisms of Ad5/35-TRAIL-induced apoptosis. Ad5/35-TRAIL did not induce apoptosis in normal human lymphocytes, but caused massive apoptosis in acute myelocytic leukemia cells. It triggered more efficient apoptosis in drug-resistant HL-60/Vinc cells than in HL-60 cells. Treating the cells with anti-DR4 and anti-DR5 neutralizing antibodies (particularly anti-DR5) reduced, whereas anti-DcR1 antibody enhanced, the apoptosis triggered by Ad5/35-TRAIL. Whereas Ad5/35-TRAIL induced apoptosis in both cell lines through activation of caspase-3 and caspase-10, known to link the cell death receptor pathway to the mitochondrial pathway, it triggered increased mitochondrial membrane potential change (Δψm) only in HL-60/Vinc cells. Ad5/35-TRAIL also increased the production of reactive oxygen species, which play an important role in apoptosis. Therefore, using Ad5/35-TRAIL may be an effective therapeutic strategy for eliminating TRAIL-resistant malignant cells and these studies may provide clues to treat and eradicate acute myelocytic leukemias. PMID:18476767

  10. Natural paniceins from mediterranean sponge inhibit the multidrug resistance activity of Patched and increase chemotherapy efficiency on melanoma cells.

    PubMed

    Fiorini, Laura; Tribalat, Marie-Aude; Sauvard, Lucy; Cazareth, Julie; Lalli, Enzo; Broutin, Isabelle; Thomas, Olivier P; Mus-Veteau, Isabelle

    2015-09-01

    Multidrug resistance has appeared to mitigate the efficiency of anticancer drugs and the possibility of successful cancer chemotherapy. The Hedgehog receptor Patched is a multidrug transporter expressed in several cancers and as such it represents a new target to circumvent chemotherapy resistance. We report herein that paniceins and especially panicein A hydroquinone, natural meroterpenoids produced by the Mediterranean sponge Haliclona (Soestella) mucosa, inhibit the doxorubicin efflux activity of Patched and enhance the cytotoxicity of this chemotherapeutic agent on melanoma cells in vitro. These results are supported by the molecular docking performed on the structure of the bacterial drug efflux pump AcrB and on the Patched model built from AcrB structure. Docking calculations show that panicein A hydroquinone interacts with AcrB and Patched model close to the doxorubicin binding site. This compound thus appears as the first antagonist of the doxorubicin efflux activity of Patched. The use of inhibitors of Patched drug efflux activity in combination with classical chemotherapy could represent a novel approach to reduce tumor drug resistance, recurrence and metastasis. PMID:26068979

  11. Natural paniceins from mediterranean sponge inhibit the multidrug resistance activity of Patched and increase chemotherapy efficiency on melanoma cells

    PubMed Central

    Fiorini, Laura; Tribalat, Marie-Aude; Sauvard, Lucy; Cazareth, Julie; Lalli, Enzo; Broutin, Isabelle; Thomas, Olivier P.; Mus-Veteau, Isabelle

    2015-01-01

    Multidrug resistance has appeared to mitigate the efficiency of anticancer drugs and the possibility of successful cancer chemotherapy. The Hedgehog receptor Patched is a multidrug transporter expressed in several cancers and as such it represents a new target to circumvent chemotherapy resistance. We report herein that paniceins and especially panicein A hydroquinone, natural meroterpenoids produced by the Mediterranean sponge Haliclona (Soestella) mucosa, inhibit the doxorubicin efflux activity of Patched and enhance the cytotoxicity of this chemotherapeutic agent on melanoma cells in vitro. These results are supported by the molecular docking performed on the structure of the bacterial drug efflux pump AcrB and on the Patched model built from AcrB structure. Docking calculations show that panicein A hydroquinone interacts with AcrB and Patched model close to the doxorubicin binding site. This compound thus appears as the first antagonist of the doxorubicin efflux activity of Patched. The use of inhibitors of Patched drug efflux activity in combination with classical chemotherapy could represent a novel approach to reduce tumor drug resistance, recurrence and metastasis. PMID:26068979

  12. Curcumin promotes apoptosis in A549/DDP multidrug-resistant human lung adenocarcinoma cells through an miRNA signaling pathway

    SciTech Connect

    Zhang, Jian; Zhang, Tao; Ti, Xinyu; Shi, Jieran; Wu, Changgui; Ren, Xinling; Yin, Hong

    2010-08-13

    Research highlights: {yields} Curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells {yields} Curcumin promotes apoptosis in A549/DDP cells through a miRNA signaling pathway {yields} Curcumin induces A549/DDP cell apoptosis by downregulating miR-186* {yields} miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin -- Abstract: Curcumin extracted from the rhizomes of Curcuma longa L. has been shown to have inhibitory effects on cancers through its anti-proliferative and pro-apoptotic activities. Emerging evidence demonstrates that curcumin can overcome drug resistance to classical chemotherapies. Thus, the mechanisms underlying the anti-tumor activities of curcumin require further study. In our study, we first demonstrated that curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells. Further studies showed that curcumin altered miRNA expression; in particular, significantly downregulated the expression of miR-186* in A549/DDP. In addition, transfection of cells with a miR-186* inhibitor promoted A549/DDP apoptosis, and overexpression of miR-186* significantly inhibited curcumin-induced apoptosis in A549/DDP cells. These observations suggest that miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin.

  13. An AS1411 aptamer-conjugated liposomal system containing a bubble-generating agent for tumor-specific chemotherapy that overcomes multidrug resistance.

    PubMed

    Liao, Zi-Xian; Chuang, Er-Yuan; Lin, Chia-Chen; Ho, Yi-Cheng; Lin, Kun-Ju; Cheng, Po-Yuan; Chen, Ko-Jie; Wei, Hao-Ji; Sung, Hsing-Wen

    2015-06-28

    Recent research in chemotherapy has prioritized overcoming the multidrug resistance (MDR) of cancer cells. In this work, liposomes that contain doxorubicin (DOX) and ammonium bicarbonate (ABC, a bubble-generating agent) are prepared and functionalized with an antinucleolin aptamer (AS1411 liposomes) to target DOX-resistant breast cancer cells (MCF-7/ADR), which overexpress nucleolin receptors. Free DOX and liposomes without functionalization with AS1411 (plain liposomes) were used as controls. The results of molecular dynamic simulations suggest that AS1411 functionalization may promote the affinity and specific binding of liposomes to the nucleolin receptors, enhancing their subsequent uptake by tumor cells, whereas plain liposomes enter cells with difficulty. Upon mild heating, the decomposition of ABC that is encapsulated in the liposomes enables the immediate activation of generation of CO2 bubbles, creating permeable defects in their lipid bilayers, and ultimately facilitating the swift intracellular release of DOX. In vivo studies in nude mice that bear tumors demonstrate that the active targeting of AS1411 liposomes can substantially increase the accumulation of DOX in the tumor tissues relative to free DOX or passively targeted plain liposomes, inhibiting tumor growth and reducing systemic side effects, including cardiotoxicity. The above findings indicate that liposomes that are functionalized with AS1411 represent an attractive therapeutic alternative for overcoming the MDR effect, and support a potentially effective strategy for cancer therapy. PMID:25637705

  14. Phospholipase D activation mediates cobalamin-induced downregulation of Multidrug Resistance-1 gene and increase in sensitivity to vinblastine in HepG2 cells.

    PubMed

    Marguerite, Véronique; Gkikopoulou, Effrosyni; Alberto, Jean-Marc; Guéant, Jean-Louis; Merten, Marc

    2013-02-01

    Failure of cancer chemotherapy due to multidrug resistance is often associated with altered Multidrug Resistance-1 gene expression. Cobalamin is the cofactor of methionine synthase, a key enzyme of the methionine cycle which synthesizes methionine, the precursor of cell S-adenosyl-methionine synthesis. We previously showed that cobalamin was able to down-regulate Multidrug Resistance-1 gene expression. Herein we report that this effect occurs through cobalamin-activation of phospholipase D activity in HepG2 cells. Cobalamin-induced down-regulation of Multidrug Resistance-1 gene expression was similar to that induced by the phospholipase D activator oleic acid and was negatively modulated by the phospholipase D inhibitor n-butanol. Cobalamin increased cell S-adenosyl-methionine content, which is the substrate for phosphatidylethanolamine-methyltransferase-dependent phosphatidylcholine production. We showed that cobalamin-induced increase in cell phosphatidylcholine production was phosphatidylethanolamine-methyltransferase-dependent. Oleic acid-dependent activation of phospholipase D was accompanied by an increased sensitivity to vinblastine of HepG2 cells while n-butanol enhanced the resistance of the cells to vinblastine. These data indicate that cobalamin mediates down-regulation of Multidrug Resistance-1 gene expression through increased S-adenosyl-methionine and phosphatidylcholine productions and phospholipase D activation. This points out phospholipase D as a potential target to down-regulate Multidrug Resistance-1 gene expression for improving chemotherapy efficacy. PMID:23032700

  15. Knockdown of HOXA10 reverses the multidrug resistance of human chronic mylogenous leukemia K562/ADM cells by downregulating P-gp and MRP-1.

    PubMed

    Yi, Ying-Jie; Jia, Xiu-Hong; Wang, Jian-Yong; Li, You-Jie; Wang, Hong; Xie, Shu-Yang

    2016-05-01

    Multidrug resistance (MDR) of leukemia cells is a major obstacle in chemotherapeutic treatment. The high expression and constitutive activation of P-glycoprotein (P-gp) and multidrug resistance protein-1 (MRP-1) have been reported to play a vital role in enhancing cell resistance to anticancer drugs in many tumors. The present study aimed to investigate the reversal of MDR by silencing homeobox A10 (HOXA10) in adriamycin (ADR)-resistant human chronic myelogenous leukemia (CML) K562/ADM cells by modulating the expression of P-gp and MRP-1. K562/ADM cells were stably transfected with HOXA10-targeted short hairpin RNA (shRNA). The results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis showed that the mRNA and protein expression of HOXA10 was markedly suppressed following transfection with a shRNA-containing vector. The sensitivity of the K562/ADM cells to ADR was enhanced by the silencing of HOXA10, due to the increased intracellular accumulation of ADR. The accumulation of ADR induced by the silencing of HOXA10 may be due to the downregulation of P-gp and MRP-1. Western blot analysis revealed that downregulating HOXA10 inhibited the protein expression of P-gp and MRP-1. Taken together, these results suggest that knockdown of HOXA10 combats resistance and that HOXA10 is a potential target for resistant human CML. PMID:27035504

  16. Arachidonic acid pathway activates multidrug resistance related protein in cultured human lung cells.

    PubMed

    Torky, Abdelrahman; Raemisch, Anja; Glahn, Felix; Foth, Heidi

    2008-05-01

    Primary cultures of human lung cells can serve as a model system to study the mechanisms underlying the effects of irritants in air and to get a deeper insight into the (patho)physiological roles of the xenobiotic detoxification systems. For 99 human lung cancer cases the culture duration for bronchial epithelium and peripheral lung cells (PLC) are given in term of generations and weeks. Using this system, we investigated whether and how prostaglandins (PG) modify multidrug resistance related protein (MRP) function in normal human lung cells. PGF2alpha had no effect on MRP function, whereas PGE2 induced MRP activity in cultured NHBECs. The transport activity study of MRP in NHBEC, PLC, and A549 under the effect of exogenously supplied PGF2alpha (10 microM, 1 day) using single cell fluorimetry revealed no alteration in transport activity of MRP. PG concentrations were within the physiological range. COX I and II inhibitors indomethacin (5, 10 microM) and celecoxib (5, 10 microM) could substantially decrease the transport activity of MRP in NHBEC, PLC, and A549 in 1- and 4-day trials. Prostaglandin E2 did not change cadmium-induced caspase 3/7 activation in NHBECs and had no own effect on caspase 3/7 activity. Cadmium chloride (5, 10 microM) was an effective inducer of caspase 3/7 activation in NHBECs with a fivefold and ninefold rise of activity. In primary human lung cells arachidonic acid activates MRP transport function only in primary epithelial lung cells by prostaglandin E2 but not by F2alpha mediated pathways and this effect needs some time to develop. PMID:17943274

  17. Chemosensitizing effects of synthetic curcumin analogs on human multi-drug resistance leukemic cells.

    PubMed

    Mapoung, Sariya; Pitchakarn, Pornsiri; Yodkeeree, Supachai; Ovatlarnporn, Chitchamai; Sakorn, Natee; Limtrakul, Pornngarm

    2016-01-25

    Curcumin analogs were synthesized and their multi-drug resistance (MDR) reversing properties were determined in human MDR leukemic (K562/Adr) cells. Four analogs, 1,7-bis-(3,4-dimethoxy-phenyl)-hepta-1,6-diene-3,5-dione (1J), 2,6-bis-(4-hydroxy-3-methoxy-benzylidene)-cyclohexanone (2A), 2,6-bis-(3,4-dihydroxy-benzylidene)-cyclohexanone (2F) and 2,6-bis-(3,4-dimethoxy-benzylidene)-cyclohexanone (2J) markedly increased the sensitivity of K562/Adr cells to paclitaxel (PTX) for 8-, 2-, 8- and 16- folds, respectively and vinblastine (Vin) for 5-, 3-, 12- and 30- folds, respectively. The accumulation of P-gp substrates, Calcein-AM, Rhodamine 123 and Doxorubicin, was significantly increased by 1J (up to 6-, 11- and 22- folds, respectively) and 2J (up to 7-, 12- and 17- folds, respectively). Besides 2A, 2F and 2J dramatically decreased P-gp expression in K562/Adr cells. These results could be summarized in the following way. Analog 1J inhibited only P-gp function, while 2A and 2F inhibited only P-gp expression. Interestingly, 2J exerts inhibition of both P-gp function and expression. The combination index (CI) of combination between 2J and PTX (0.09) or Vin (0.06) in K562/Adr cells indicated strong synergistic effects, which likely due to its MDR reversing activity. Moreover, these analogs showed less cytotoxicity to peripheral mononuclear cells (human) and red blood cells (human and rat) suggesting the safety of analogs for further animal and clinical studies. PMID:26689174

  18. Feroniellin A-induced autophagy causes apoptosis in multidrug-resistant human A549 lung cancer cells.

    PubMed

    Kaewpiboon, Chutima; Surapinit, Serm; Malilas, Waraporn; Moon, Jeong; Phuwapraisirisan, Preecha; Tip-Pyang, Santi; Johnston, Randal N; Koh, Sang Seok; Assavalapsakul, Wanchai; Chung, Young-Hwa

    2014-04-01

    During the screening of natural chemicals that can reverse multidrug resistance in human A549 lung cancer cells resistant to etoposide (A549RT-eto), we discovered that Feroniellin A (FERO), a novel furanocoumarin, shows toxicity toward A549RT-eto cells in a dose- and time-dependent manner. FERO reduced the expression of NF-κB, leading to downregulation of P-glycoprotein (P-gp), encoded by MDR1, which eventually sensitized A549RT-eto cells to apoptosis. FERO specifically diminished transcription and promoter activity of MDR1 but did not inhibit the expression of other multidrug resistance genes MRP2 and BCRP. Moreover, co-administration of FERO with Bay11-7802, an inhibitor of NF-κB, accelerated apoptosis of A549RT-eto cells through decreased expression of P-gp, indicating that NF-κB is involved in multidrug resistance. Conversely, addition of Z-VAD, a pan-caspase inhibitor, blocked FERO-induced apoptosis in A549RT-eto cells but did not block downregulation of P-gp, indicating that a decrease in P-gp expression is necessary but not sufficient for FERO-induced apoptosis. Interestingly, we found that FERO also induces autophagy, which is characterized by the conversion of LC3 I to LC3 II, induction of GFP-LC3 puncta, enhanced expression of Beclin-1 and ATG5, and inactivation of mTOR. Furthermore, suppression of Beclin-1 by siRNA reduced FERO-induced apoptosis in A549RT-eto cells and activation of autophagy by rapamycin accelerated FERO-induced apoptosis, suggesting that autophagy plays an active role in FERO-induced apoptosis. Herein, we report that FERO reverses multidrug resistance in A549RT-eto cells and exerts its cytotoxic effect by induction of both autophagy and apoptosis, which suggests that FERO can be a useful anticancer drug for multidrug-resistant lung cancer. PMID:24535083

  19. Cytotoxic and multidrug resistance reversal activities of novel 1,4-dihydropyridines against human cancer cells.

    PubMed

    Shekari, Farnaz; Sadeghpour, Hossein; Javidnia, Katayoun; Saso, Luciano; Nazari, Farhad; Firuzi, Omidreza; Miri, Ramin

    2015-01-01

    Multidrug resistance (MDR) caused by P-glycoprotein (P-gp, ABCB1, MDR-1) transporter over-expression in cancer cells substantially limits the effectiveness of chemotherapy. 1,4-Dihydropyridines (DHPs) derivatives possess several pharmacological activities. In this study, 18 novel asymmetrical DHPs bearing 3-pyridyl methyl carboxylate and alkyl carboxylate moieties at C₃ and C₅ positions, respectively, as well as nitrophenyl or hetero aromatic rings at C₄ were synthesized and tested for MDR reversal with the aim of establishing a structure-activity relationship (SAR) for these agents. Effect of these compounds on P-gp mediated MDR was assessed in P-gp over-expressing MES-SA/DX5 doxorubicin resistant cells by flow cytometric detection of rhodamine 123 efflux. MDR reversal was further examined as the alteration of doxorubicin׳s IC₅₀ in MES-SA/DX5 cells in the presence of DHPs by MTT assay and was compared to nonresistant MES-SA cells. Direct anticancer effect was examined against 4 human cancer cells including HL-60, K562, MCF-7 and LS180. Calcium channel blocking (CCB) activity was also measured as a potential side effect. Most DHPs, particularly compounds bearing 3-nitrophenyl (A2B2 and A3B2) and 4-nitrophenyl (A3B1 and A4B1) moieties at C₄ significantly inhibited rhodamine 123 efflux at 5-25 µM, showing that the mechanism of MDR reversal by these agents is P-gp transporter modulation. Same derivatives were also able to selectively lower the resistance of MES-SA/DX5 to doxorubicin. A2B2 bearing ethyl carboxylate at C₅ had also high direct antitumoral effect (IC₅₀ range: 3.77-15.60 μM). Our findings suggest that SAR studies of DHPs may lead to the discovery of novel MDR reversal agents. PMID:25445037

  20. A new method to induce multi-drug resistance to carboplatin in a mouse model of human tongue squamous cell carcinoma.

    PubMed

    Feng, G; Wang, D-Z; Chen, H-Q; Hu, J; He, J

    2008-12-01

    Multi-drug resistance (MDR) in human head and neck squamous cell carcinoma (HNSCC) constitutes a major obstacle to the effectiveness of chemotherapy. In previous studies, MDR was mainly induced in vitro. The authors report a novel in vivo method of inducing MDR in nude mice with xenotransplanted Tca8113 cells. Carboplatin, a chemotherapeutic agent used to treat HNSCC, was injected around the tumors for 10 weeks. A subsequent cell survival assay of dissociated tumor cells suggested that MDR had been induced successfully. Immunocytochemistry, reverse transcription polymerase chain reaction and Western blot analysis showed that the expression levels of MDR-related proteins, including topoisomerase II, MRP and glutathione transferase, were elevated in the induction group. The authors conclude that in vivo induction of MDR provides a useful method for establishing animal models of MDR. PMID:18715753

  1. Probenecid-resistant J774 cell expression of enhanced organic anion transport by a mechanism distinct from multidrug resistance.

    PubMed

    Cao, C; Steinberg, T H; Neu, H C; Cohen, D; Horwitz, S B; Hickman, S; Silverstein, S C

    1993-08-01

    Macrophages possess organic anion transporters that carry membrane-impermeant fluorescent dyes, such as lucifer yellow (LY) and carboxy-fluorescein, from the cytoplasm into endosomes and out of the cells. Probenecid, an organic anion transport inhibitor, blocks these processes. Prolonged incubation of J774 cells in medium containing 2.5 mM probenecid eventually kills most of these cells. To identify J774 variants that express increased organic anion transport activity, we selected probenecid-resistant (PBR) J774 cells by growing them in medium containing increasing concentrations of probenecid. When PBR and unselected J774 cells were loaded with LY by ATP4- permeabilization, the amount of LY accumulated by the PBR cells was about half that in the unselected cells. This difference was abolished by adding 10 mM probenecid to the medium in which the cells were loaded, suggesting that the diminished LY accumulation in PBR cells was due to enhanced LY secretion and that the PBR cells expressed increased organic anion transport activity. Direct comparison of LY efflux from J774 and PBR J774 cells showed a faster initial rate of secretion of LY from PBR J774 cells than from unselected J774 cells. To determine whether LY efflux is mediated by P-glycoprotein, we compared LY efflux in unselected J774 cells, PBR J774 cells, and multidrug-resistant J774 cells (J7.C1). LY efflux from J7.C1 cells was not sensitive to verapamil, which inhibits multidrug-resistance transporters, and reverses the multidrug-resistant phenotype of J7.C1 cells. The rates of LY efflux from unselected J774 and J7.C1 cells were virtually identical.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7909709

  2. Cucurbitacin B reverses multidrug resistance by targeting CIP2A to reactivate protein phosphatase 2A in MCF-7/adriamycin cells.

    PubMed

    Cai, Fen; Zhang, Liang; Xiao, Xiangling; Duan, Chao; Huang, Qiuyue; Fan, Chunsheng; Li, Jian; Liu, Xuewen; Li, Shan; Liu, Ying

    2016-08-01

    Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a human oncoprotein that is overexpressed in various tumors. A previous study found that CIP2A expression is associated with doxorubicin (Dox) resistance. In the present study, we investigated whether cucurbitacin B (CuB), a natural anticancer compound found in Cucurbitaceae, reversed multidrug resistance (MDR) and downregulated CIP2A expression in MCF-7/Adriamycin (MCF-7/Adr) cells, a human breast multidrug-resistant cancer cell line. CuB treatment significantly suppressed MCF-7/Adr cell proliferation, and reversed Dox resistance. CuB treatment also induced caspase-dependent apoptosis, decreased phosphorylation of Akt (pAkt). The suppression of pAkt was mediated through CuB-induced activation of protein phosphatase 2A (PP2A). Furthermore, CuB activated PP2A through the suppression of CIP2A. Silencing CIP2A enhanced CuB-induced growth inhibition, apoptosis and MDR inhibition in MCF-7/Adr cells. In conclusion, we found that enhancement of PP2A activity by inhibition of CIP2A promotes the reversal of MDR induced by CuB. PMID:27350399

  3. Effects of hypergravity on the expression of multidrug resistance proteins in human melanocytic cells

    NASA Astrophysics Data System (ADS)

    Lambers, B.; Stieber, C.; Grigorieva, O.; Block, I.; Bromeis, B.; Buravkova, L.; Gerzer, R.; Ivanova, K.

    In humans the skin serves as a barrier against potentially harmful effects of the environment Human melanocytes constitute the principal cells for skin pigmentation by synthesizing the pigment melanin Melanin acts as a scavenger for free radicals that may arise during metabolic stress The melanocytes are also able to secrete a wide range of signal molecules In previous studies we found that normal human melanocytes NHMs and non-metastatic melanoma cells respond to long-time exposure to hypergravity up to 5 g for 24 h with elevated efflux of guanosine 3 5 -cyclic monophosphate cGMP in the presence of phosphodiesterase PDE inhibitors e g 3-isobutyl-1-methylxanthine Cyclic GMP is known to play a signaling role in human melanocyte physiology It controls the signaling activities of nitric oxide NO in relation to melanogenesis as well as in melanocyte-extracellular matrix interactions that may be important for some pathological processes including metastasis The present study investigated the effects of hypergravity on the expression of the multidrug resistance proteins MRP 4 and 5 as highly selective cGMP exporters in non-stimulated and NO-stimulated NHMs and melanoma cells MCs on mRNA levels using semi-quantitative RT-PCR analysis Hypergravity up to 5 g for 24 h was produced by horizontal centrifugal acceleration The NONOate DETA-NO 0 1 mM was used as a direct NO donor for cell stimulation For 5-g experiments the mRNA levels for the highly specific cGMP transporter MRP5 appeared to be

  4. Fallopia japonica, a Natural Modulator, Can Overcome Multidrug Resistance in Cancer Cells.

    PubMed

    Eid, Safaa Yehia; El-Readi, Mahmoud Zaki; Ashour, Mohamed Lotfy; Wink, Michael

    2015-01-01

    Resistance of cancer cells to chemotherapy is controlled by the decrease of intracellular drug accumulation, increase of detoxification, and diminished propensity of cancer cells to undergo apoptosis. ATP-binding cassette (ABC) membrane transporters with intracellular metabolic enzymes contribute to the complex and unresolved phenomenon of multidrug resistance (MDR). Natural products as alternative medicine have great potential to discover new MDR inhibitors with diverse modes of action. In this study, we characterized several extracts of traditional Chinese medicine (TCM) plants (N = 16) for their interaction with ABC transporters, cytochrome P3A4 (CYP3A4), and glutathione-S-transferase (GST) activities and their cytotoxic effect on different cancer cell lines. Fallopia japonica (FJ) (Polygonaceae) shows potent inhibitory effect on CYP3A4 P-glycoprotein activity about 1.8-fold when compared to verapamil as positive control. FJ shows significant inhibitory effect (39.81%) compared with the known inhibitor ketoconazole and 100 μg/mL inhibited GST activity to 14 μmol/min/mL. FJ shows moderate cytotoxicity in human Caco-2, HepG-2, and HeLa cell lines; IC50 values were 630.98, 198.80, and 317.37 µg/mL, respectively. LC-ESI-MS were used to identify and quantify the most abundant compounds, emodin, polydatin, and resveratrol, in the most active extract of FJ. Here, we present the prospect of using Fallopia japonica as natural products to modulate the function of ABC drug transporters. We are conducting future study to evaluate the ability of the major active secondary metabolites of Fallopia japonica to modulate MDR and their impact in case of failure of chemotherapy. PMID:26346937

  5. Fallopia japonica, a Natural Modulator, Can Overcome Multidrug Resistance in Cancer Cells

    PubMed Central

    Eid, Safaa Yehia; El-Readi, Mahmoud Zaki; Ashour, Mohamed Lotfy; Wink, Michael

    2015-01-01

    Resistance of cancer cells to chemotherapy is controlled by the decrease of intracellular drug accumulation, increase of detoxification, and diminished propensity of cancer cells to undergo apoptosis. ATP-binding cassette (ABC) membrane transporters with intracellular metabolic enzymes contribute to the complex and unresolved phenomenon of multidrug resistance (MDR). Natural products as alternative medicine have great potential to discover new MDR inhibitors with diverse modes of action. In this study, we characterized several extracts of traditional Chinese medicine (TCM) plants (N = 16) for their interaction with ABC transporters, cytochrome P3A4 (CYP3A4), and glutathione-S-transferase (GST) activities and their cytotoxic effect on different cancer cell lines. Fallopia japonica (FJ) (Polygonaceae) shows potent inhibitory effect on CYP3A4 P-glycoprotein activity about 1.8-fold when compared to verapamil as positive control. FJ shows significant inhibitory effect (39.81%) compared with the known inhibitor ketoconazole and 100 μg/mL inhibited GST activity to 14 μmol/min/mL. FJ shows moderate cytotoxicity in human Caco-2, HepG-2, and HeLa cell lines; IC50 values were 630.98, 198.80, and 317.37 µg/mL, respectively. LC-ESI-MS were used to identify and quantify the most abundant compounds, emodin, polydatin, and resveratrol, in the most active extract of FJ. Here, we present the prospect of using Fallopia japonica as natural products to modulate the function of ABC drug transporters. We are conducting future study to evaluate the ability of the major active secondary metabolites of Fallopia japonica to modulate MDR and their impact in case of failure of chemotherapy. PMID:26346937

  6. Silencing of long non-coding RNA ANRIL inhibits the development of multidrug resistance in gastric cancer cells.

    PubMed

    Lan, Wei-Guang; Xu, Dian-Hong; Xu, Chen; Ding, Chang-Ling; Ning, Fang-Ling; Zhou, Yan-Li; Ma, Long-Bo; Liu, Chang-Min; Han, Xia

    2016-07-01

    The development of multidrug resistance (MDR) is a crucial cause of therapy failure in gastric cancer, which results in disease recurrence and metastasis. Long non-coding RNAs (lncRNAs) have been proven to be critical in carcinogenesis and metastasis of gastric cancer. However, little is known about the roles of ANRIL (antisense non-coding RNA in the INK4 locus) in gastric cancer MDR. The aim of our study is to identify the biological function of ANRIL in gastric cancer MDR. In our results, ANRIL was highly expressed in gastric cancer tissues of cisplatin-resistant and 5-fluorouracil (5-FU)-resistant patients, and the same upregulation trends were observed in cisplatin-resistant cells (BGC823/DDP) and 5-FU-resistant cells (BGC823/5-FU). In addition, BGC823/DDP and BGC823/5-FU cells transfected with ANRIL siRNA and treated with cisplatin or 5-FU, respectively, exhibited significant lower survival rate, decreased invasion capability, and high percentage of apoptotic tumor cells. The influence of ANRIL knockdown on MDR was assessed by measuring IC50 of BGC823/DDP and BGC823/5-FU cells to cisplatin and 5-FU, the result showed that silencing ANRIL decreased the IC50 values in gastric cancer cells. Moreover, qRT-PCR and western blotting revealed that ANRIL knockdown decreased the expression of MDR1 and MRP1, both of which are MDR related genes; regression analysis showed that the expression of ANRIL positively correlated with the expression of MDR1 and MRP1, resprectively In summary, knockdown of lncRNA ANRIL in gastric cancer cells inhibits the development of MDR, suggesting an efficacious target for reversing MDR in gastric cancer therapy. PMID:27121324

  7. Effect of Prostaglandin E2 on Multidrug Resistance Transporters In Human Placental Cells

    PubMed Central

    Lee, Gene T.; Dong, Yafeng; Zhou, Helen; He, Lily; Weiner, Carl P.

    2014-01-01

    Prostaglandin (PG) E2, a major product of cyclooxygenase (COX)-2, acts as an immunomodulator at the maternal-fetal interface during pregnancy. It exerts biologic function through interaction with E-prostanoid (EP) receptors localized to the placenta. The activation of the COX-2/PGE2/EP signal pathway can alter the expression of the ATP-binding cassette (ABC) transporters, multidrug resistance protein 1 [P-glycoprotein (Pgp); gene: ABCB1], and breast cancer resistance protein (BCRP; gene: ABCG2), which function to extrude drugs and xenobiotics from cells. In the placenta, PGE2-mediated changes in ABC transporter expression could impact fetal drug exposure. Furthermore, understanding the signaling cascades involved could lead to strategies for the control of Pgp and BCRP expression levels. We sought to determine the impact of PGE2 signaling mechanisms on Pgp and BCRP in human placental cells. The treatment of placental cells with PGE2 up-regulated BCRP expression and resulted in decreased cellular accumulation of the fluorescent substrate Hoechst 33342. Inhibiting the EP1 and EP3 receptors with specific antagonists attenuated the increase in BCRP. EP receptor signaling results in activation of transcription factors, which can affect BCRP expression. Although PGE2 decreased nuclear factor κ-light chain-enhancer of activated B activation and increased activator protein 1, chemical inhibition of these inflammatory transcription factors did not blunt BCRP up-regulation by PGE2. Though PGE2 decreased Pgp mRNA, Pgp expression and function were not significantly altered. Overall, these findings suggest a possible role for PGE2 in the up-regulation of placental BCRP expression via EP1 and EP3 receptor signaling cascades. PMID:25261564

  8. Effect of prostaglandin E2 on multidrug resistance transporters in human placental cells.

    PubMed

    Mason, Clifford W; Lee, Gene T; Dong, Yafeng; Zhou, Helen; He, Lily; Weiner, Carl P

    2014-12-01

    Prostaglandin (PG) E2, a major product of cyclooxygenase (COX)-2, acts as an immunomodulator at the maternal-fetal interface during pregnancy. It exerts biologic function through interaction with E-prostanoid (EP) receptors localized to the placenta. The activation of the COX-2/PGE2/EP signal pathway can alter the expression of the ATP-binding cassette (ABC) transporters, multidrug resistance protein 1 [P-glycoprotein (Pgp); gene: ABCB1], and breast cancer resistance protein (BCRP; gene: ABCG2), which function to extrude drugs and xenobiotics from cells. In the placenta, PGE2-mediated changes in ABC transporter expression could impact fetal drug exposure. Furthermore, understanding the signaling cascades involved could lead to strategies for the control of Pgp and BCRP expression levels. We sought to determine the impact of PGE2 signaling mechanisms on Pgp and BCRP in human placental cells. The treatment of placental cells with PGE2 up-regulated BCRP expression and resulted in decreased cellular accumulation of the fluorescent substrate Hoechst 33342. Inhibiting the EP1 and EP3 receptors with specific antagonists attenuated the increase in BCRP. EP receptor signaling results in activation of transcription factors, which can affect BCRP expression. Although PGE2 decreased nuclear factor κ-light chain-enhancer of activated B activation and increased activator protein 1, chemical inhibition of these inflammatory transcription factors did not blunt BCRP up-regulation by PGE2. Though PGE2 decreased Pgp mRNA, Pgp expression and function were not significantly altered. Overall, these findings suggest a possible role for PGE2 in the up-regulation of placental BCRP expression via EP1 and EP3 receptor signaling cascades. PMID:25261564

  9. [Cytological Study in vitro on Co-delivery of siRNA and Paclitaxel within Solid Lipid Nanoparticles to Overcome Multidrug Resistance in Tumors].

    PubMed

    Huang, Rui; Yao, Xinyu; Chen, Yuan; Sun, Xun; Lin, Yunzhu

    2016-02-01

    Multidrug resistance (MDR) remains the major obstacle to the success of clinical cancer chemotherapy. P-glycoprotein (P-gp), encoded by the MDR1, is an important part with complex mechanisms associated with the MDR. In order to overcome the MDR of tumors, we in the present experimental design incorporated small interfering RNA (siRNA) targeting MDR1 gene and anticancer drug paclitaxel (PTX) into the solid lipid nanoparticles (SLNs) to achieve the combinational therapeutic effects of genetherapy and chemotherapy. In this study, siRNA-PTX-SLNs were successfully prepared. The cytotoxicity of blank SLNs and siRNA-PTX-SLNs in MCF-7 cells and MCF-7/ADR cells were detected by MTT; and the uptake efficiency of PTX in MCF-7/ADR cells were detected via HPLC method; quantitative real-time PCR and flow cytometry were performed to investigate the silencing effect of siRNA-PTX- SLNs on MDR1 gene in MCF-7/ADR cells. The results showed that PTX loaded SLNs could significantly inhibit the growth of tumor cells, and more importantly, the MDR tumor cells treated with siRNA-PTX-SLNs showed the lowest viability. HPLC study showed that SLNs could enhance the cellular uptake for PTX. Meanwhile, siRNA delivered by SLNs significantly decreased the P-gp expression in MDR tumor cells, thus increased the cellular accumulation of rhodamine123 as a P-gp substrate. In conclusion, the MDR1 gene could be silenced by siRNA-PTX-SLNs, which could promote the growth inhibition efficiency of PTX on tumor cells, leading to synergetic effect on MDR tumor therapy. PMID:27382749

  10. Co-Silencing of PKM-2 and MDR-1 Sensitizes Multidrug Resistant Ovarian Cancer Cells to Paclitaxel in a Murine Model of Ovarian Cancer

    PubMed Central

    Talekar, Meghna; Ouyang, Qijun; Goldberg, Michael S.; Amiji, Mansoor M.

    2015-01-01

    Tumor multidrug resistance (MDR) is a serious clinical challenge that significantly limits the effectiveness of cytotoxic chemotherapy. As such, complementary therapeutic strategies are being explored to prevent relapse. The altered metabolic state of cancer cells, which perform aerobic glycolysis, represents an interesting target that can enable discrimination between healthy cells and cancer cells. We hypothesized that co-silencing of genes responsible for aerobic glycolysis and for MDR would have synergistic antitumor effect. In the current study, siRNA duplexes against pyruvate kinase M2 (siPKM-2) and multidrug resistance gene-1 (siMDR-1) were encapsulated in hyaluronic acid (HA)-based self-assembling nanoparticles. The particles were characterized for morphology, size, charge, encapsulation efficiency and transfection efficiency. In vivo studies included biodistribution assessment, gene knockdown confirmation, therapeutic efficacy, and safety analysis. The benefit of active targeting of cancer cells was confirmed by modifying the particles’ surface with a peptide targeted to epidermal growth factor receptor (EGFR), which is overexpressed on the membranes of the SKOV-3 cancer cells. To augment the studies involving transplantation of a PTX-resistant cell line, an in vivo paclitaxel (PTX) resistance model was developed by injecting repeated doses of PTX following tumor inoculation. The nanoparticles accumulated significantly in the tumors, hindering tumor volume doubling time (p<0.05) upon combination therapy in both the wild type (2-fold) and resistant (8-fold) xenograft models. Whereas previous studies indicated that silencing of MDR-1 alone sensitized MDR ovarian cancer to PTX only modestly, these data suggest that concurrent silencing of PKM-2 improves the efficacy of PTX against MDR ovarian cancer. PMID:25964202

  11. Cosilencing of PKM-2 and MDR-1 Sensitizes Multidrug-Resistant Ovarian Cancer Cells to Paclitaxel in a Murine Model of Ovarian Cancer.

    PubMed

    Talekar, Meghna; Ouyang, Qijun; Goldberg, Michael S; Amiji, Mansoor M

    2015-07-01

    Tumor multidrug resistance (MDR) is a serious clinical challenge that significantly limits the effectiveness of cytotoxic chemotherapy. As such, complementary therapeutic strategies are being explored to prevent relapse. The altered metabolic state of cancer cells, which perform aerobic glycolysis, represents an interesting target that can enable discrimination between healthy cells and cancer cells. We hypothesized that cosilencing of genes responsible for aerobic glycolysis and for MDR would have synergistic antitumor effect. In this study, siRNA duplexes against pyruvate kinase M2 and multidrug resistance gene-1 were encapsulated in hyaluronic acid-based self-assembling nanoparticles. The particles were characterized for morphology, size, charge, encapsulation efficiency, and transfection efficiency. In vivo studies included biodistribution assessment, gene knockdown confirmation, therapeutic efficacy, and safety analysis. The benefit of active targeting of cancer cells was confirmed by modifying the particles' surface with a peptide targeted to epidermal growth factor receptor, which is overexpressed on the membranes of the SKOV-3 cancer cells. To augment the studies involving transplantation of a paclitaxel-resistant cell line, an in vivo paclitaxel resistance model was developed by injecting repeated doses of paclitaxel following tumor inoculation. The nanoparticles accumulated significantly in the tumors, hindering tumor volume doubling time (P < 0.05) upon combination therapy in both the wild-type (2-fold) and resistant (8-fold) xenograft models. Although previous studies indicated that silencing of MDR-1 alone sensitized MDR ovarian cancer to paclitaxel only modestly, these data suggest that concurrent silencing of PKM-2 improves the efficacy of paclitaxel against MDR ovarian cancer. PMID:25964202

  12. Screening for phenotype selective activity in multidrug resistant cells identifies a novel tubulin active agent insensitive to common forms of cancer drug resistance

    PubMed Central

    2013-01-01

    Background Drug resistance is a common cause of treatment failure in cancer patients and encompasses a multitude of different mechanisms. The aim of the present study was to identify drugs effective on multidrug resistant cells. Methods The RPMI 8226 myeloma cell line and its multidrug resistant subline 8226/Dox40 was screened for cytotoxicity in response to 3,000 chemically diverse compounds using a fluorometric cytotoxicity assay (FMCA). Follow-up profiling was subsequently performed using various cellular and biochemical assays. Results One compound, designated VLX40, demonstrated a higher activity against 8226/Dox40 cells compared to its parental counterpart. VLX40 induced delayed cell death with apoptotic features. Mechanistic exploration was performed using gene expression analysis of drug exposed tumor cells to generate a drug-specific signature. Strong connections to tubulin inhibitors and microtubule cytoskeleton were retrieved. The mechanistic hypothesis of VLX40 acting as a tubulin inhibitor was confirmed by direct measurements of interaction with tubulin polymerization using a biochemical assay and supported by demonstration of G2/M cell cycle arrest. When tested against a broad panel of primary cultures of patient tumor cells (PCPTC) representing different forms of leukemia and solid tumors, VLX40 displayed high activity against both myeloid and lymphoid leukemias in contrast to the reference compound vincristine to which myeloid blast cells are often insensitive. Significant in vivo activity was confirmed in myeloid U-937 cells implanted subcutaneously in mice using the hollow fiber model. Conclusions The results indicate that VLX40 may be a useful prototype for development of novel tubulin active agents that are insensitive to common mechanisms of cancer drug resistance. PMID:23919498

  13. Regulation of Multidrug Resistance Proteins by Genistein in a Hepatocarcinoma Cell Line: Impact on Sorafenib Cytotoxicity

    PubMed Central

    Rigalli, Juan Pablo; Ciriaci, Nadia; Arias, Agostina; Ceballos, María Paula; Villanueva, Silvina Stella Maris; Luquita, Marcelo Gabriel; Mottino, Aldo Domingo; Ghanem, Carolina Inés; Catania, Viviana Alicia; Ruiz, María Laura

    2015-01-01

    Hepatocellular carcinoma (HCC) is the fifth most frequent cancer worldwide. Sorafenib is the only drug available that improves the overall survival of HCC patients. P-glycoprotein (P-gp), Multidrug resistance-associated proteins 2 and 3 (MRP2 and 3) and Breast cancer resistance protein (BCRP) are efflux pumps that play a key role in cancer chemoresistance. Their modulation by dietary compounds may affect the intracellular accumulation and therapeutic efficacy of drugs that are substrates of these transporters. Genistein (GNT) is a phytoestrogen abundant in soybean that exerts its genomic effects through Estrogen-Receptors and Pregnane-X-Receptor (PXR), which are involved in the regulation of the above-mentioned transporters. We evaluated the effect of GNT on the expression and activity of P-gp, MRP2, MRP3 and BCRP in HCC-derived HepG2 cells. GNT (at 1.0 and 10 μM) increased P-gp and MRP2 protein expression and activity, correlating well with an increased resistance to sorafenib cytotoxicity as detected by the methylthiazole tetrazolium (MTT) assay. GNT induced P-gp and MRP2 mRNA expression at 10 but not at 1.0 μM concentration suggesting a different pattern of regulation depending on the concentration. Induction of both transporters by 1.0 μM GNT was prevented by cycloheximide, suggesting translational regulation. Downregulation of expression of the miR-379 by GNT could be associated with translational regulation of MRP2. Silencing of PXR abolished P-gp induction by GNT (at 1.0 and 10 μM) and MRP2 induction by GNT (only at 10 μM), suggesting partial mediation of GNT effects by PXR. Taken together, the data suggest the possibility of nutrient-drug interactions leading to enhanced chemoresistance in HCC when GNT is ingested with soy rich diets or dietary supplements. PMID:25781341

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

    PubMed Central

    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. PMID:27536106

  15. 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. PMID:27536106

  16. Establishment and characterization of gemcitabine-resistant human cholangiocarcinoma cell lines with multidrug resistance and enhanced invasiveness.

    PubMed

    Wattanawongdon, Wareeporn; Hahnvajanawong, Chariya; Namwat, Nisana; Kanchanawat, Sirimas; Boonmars, Thidarut; Jearanaikoon, Patcharee; Leelayuwat, Chanwit; Techasen, Anchalee; Seubwai, Wunchana

    2015-07-01

    To establish and characterize the gemcitabine-resistant cholangiocarcinoma (CCA) cell lines, CCA KKU‑M139 and KKU‑M214 cell lines were exposed stepwisely to increasing gemcitabine (GEM). The resultant drug-resistant cell lines, KKU‑M139/GEM and KKU‑M214/GEM, retained the resistant phenotype in drug-free medium at least for 2 months. Sulforhodamine B assay demonstrated that KKU‑M139/GEM and KKU‑M214/GEM were 25.88- and 62.31-fold more resistant to gemcitabine than their parental cells. Both gemcitabine-resistant cell lines were cross-resistant to 5-fluorouracil (5-FU), doxorubicin and paclitaxel indicating their multidrug-resistant nature. Using reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR and western blot analyses, gemcitabine-resistant cells showed upregulation of RRM1 and downregulation of hENT1 and dCK. In relation to multidrug resistance, these cell lines showed upregulation of multidrug resistance protein 1 (MRP1) leading to an increase of drug efflux. Using cell adhesion and Boyden chamber transwell assays, these cell lines also showed higher cell adhesion, migration and invasion capabilities via the activations of protein kinase C (PKC), focal adhesion kinase (FAK), extracellular signal-regulated kinase-1/2 (ERK1/2) and nuclear factor-κB (NF-κB). Higher activity of matrix metalloproteinase-9 (MMP-9) and urokinase plasminogen activator (uPA) was also observed by a gelatin zymography assay and a casein-plasminogen zymography assay. Flow cytometry analysis indicated the G2/M arrest regulated by downregulation of cyclin B1 and cyclin-dependent kinase 1 (Cdk1) resulted in an extended population doubling time. Using Annexin V/propidium iodide staining, evasion of apoptosis via an intrinsic pathway was observed in both cell lines in association with upregulation of Bcl-2 and downregulation of Bax. Interestingly, Fas was additionally downregulated in KKU‑M214/GEM supporting the view of its higher GEM resistant

  17. Increased fucosylation has a pivotal role in multidrug resistance of breast cancer cells through miR-224-3p targeting FUT4.

    PubMed

    Feng, Xiaobin; Zhao, Lifen; Gao, Shuhang; Song, Xiaobo; Dong, Weijie; Zhao, Yongfu; Zhou, Huimin; Cheng, Lei; Miao, Xiaolong; Jia, Li

    2016-03-10

    Fucosylation is the final step in the glycosylation machinery, which produces glycans involved in tumor multidrug resistance development. MicroRNAs (miRNAs) are endogenous negative regulators of gene expression and have been implicated in most cellular processes of tumors, including drug resistance. This study was undertaken to determine the roles of fucosylation and miR-224-3p in multidrug resistance of human breast cancer cell lines. Comparative analysis revealed differential modification patterns of fucosylation of the fucosylated N-glycans in drug-resistant T47D/ADR cells and sensitive line T47D cells. The expressional profiles of fucosyltransferase genes in two pairs of parental and chemoresistant human breast cancer cell lines showed that FUT4 was up-regulated highly in MDR cell lines. Altered level of FUT4 affected the drug-resistant phenotype of T47D and T47D/ADR cells both in vitro and in vivo. By bioinformatics analysis, we identified FUT4 as one of the miR-224-3p-targeted genes. Further studies showed an inverse relationship between of FUT4 and miR-224-3p in parental and ADR-resistant breast cancer cells, wherein miR-224-3p was downregulated in resistant cells. 3'-UTR dual-luciferase reporter assay confirmed that miR-224-3p directly targeted 3'-untranslation region (3'-UTR) of FUT4 mRNA. In addition, miR-224-3p overexpression sensitized T47D/ADR cells to chemotherapeutics and reduced the growth rate of breast cancer xenografts in vivo. Our results indicate that FUT4 and miR-224-3p are crucial regulators of cancer response to chemotherapy, and may serve as therapeutic targets to reverse chemotherapy resistance in breast cancer. PMID:26701615

  18. Multidrug-resistant hela cells overexpressing MRP1 exhibit sensitivity to cell killing by hyperthermia: Interactions with etoposide

    SciTech Connect

    Souslova, Tatiana; Averill-Bates, Diana A. . E-mail: averill.diana@uqam.ca

    2004-12-01

    Purpose: Multidrug resistance (MDR) remains one of the primary obstacles in cancer chemotherapy and often involves overexpression of drug efflux transporters such as P-glycoprotein and multidrug resistance protein 1 (MRP1). Regional hyperthermia is undergoing clinical investigation in combination with chemotherapy or radiotherapy. This study evaluates whether hyperthermia can reverse MDR mediated by MRP1 in human cervical adenocarcinoma (HeLa) cells. Methods and materials: Cytotoxicity of hyperthermia and/or etoposide was evaluated using sulforhodamine-B in HeLa cells overexpressing MRP1 and their drug-sensitive counterparts. Glutathione, glutathione peroxidase (GPx), and glutathione S-transferase (GST) were quantified by spectrophotometry. GST isoenzymes were quantified by immunodetection. Caspase activation was evaluated by fluorometry and chromatin condensation by fluorescence microscopy using Hoechst 33258. Necrosis was determined using propidium iodide. Results: The major finding is that HeLa and HeLaMRP cells are both sensitive to cytotoxicity of hyperthermia (41-45 deg C). Hyperthermia induced activation of caspase 3 and chromatin condensation. Although total levels of cell killing were similar, there was a switch from apoptotic to necrotic cell death in MDR cells. This could be explained by decreased glutathione and GPx in MDR cells. MDR cells also contained very low levels of GST and were resistant to etoposide-induced apoptosis. Hyperthermia caused a modest increase in etoposide-induced apoptosis in HeLa and HeLaMRP cells, which required appropriate heat-drug scheduling. Conclusions: Hyperthermia could be useful in eliminating MDR cells that overexpress MRP1.

  19. Multifunctional polyamidoamine-modified selenium nanoparticles dual-delivering siRNA and cisplatin to A549/DDP cells for reversal multidrug resistance.

    PubMed

    Zheng, Wenjing; Cao, Chengwen; Liu, Yanan; Yu, Qianqian; Zheng, Chuping; Sun, Dongdong; Ren, Xiaofan; Liu, Jie

    2015-01-01

    Multidrug resistance (MDR) is a major barrier against effective cancer treatment. Dual-delivering a therapeutic small interfering RNA (siRNA) and chemotherapeutic agents has been developed to reverse drug resistance in tumor cells. In this study, amine-terminated generation 5 polyamidoamine (PAMAM) dendrimers (G5.NH2)-modified selenium nanoparticles (G5@Se NP) were synthesized for the systemic dual-delivery of mdr1 siRNA and cisplatin (cis-diamminedichloroplatinum-(II), DDP), which was demonstrated to enhance siRNA loading, releasing efficiency and gene-silencing efficacy. When the mdr1 siRNA was conjugated with G5@Se NP via electrostatic interaction, a significant down-regulation of P-glycoprotein and multidrug resistance-associated protein expression was observed; G5@Se-DDP-siRNA arrested A549/DDP cells at G1 phase and led to enhanced cytotoxicity in A549/DDP cells through induction of apoptosis involving the AKT and ERK signaling pathways. Interestingly, G5@Se-DDP NP were much less reactive than DDP in the reactions with both MT and GSH, indicating that loading of DDP in a nano-delivery system could effectively prevent cell detoxification. Furthermore, animal studies demonstrated that the new delivery system of G5@Se-DDP-siRNA significantly enhanced the anti-tumor effect on tumor-bearing nude mice, with no appreciable abnormality in the major organs. These results suggest that G5@Se NP could be a potential platform to combine chemotherapy and gene therapy technology in the treatment of human disease. PMID:25204523

  20. Silencing clusterin gene transcription on effects of multidrug resistance reversing of human hepatoma HepG2/ADM cells.

    PubMed

    Zheng, Wenjie; Sai, Wenli; Yao, Min; Gu, Hongbin; Yao, Yao; Qian, Qi; Yao, Dengfu

    2015-05-01

    Abnormal clusterin (CLU) expression is associated with multidrug resistance (MDR) of hepatocellular carcinoma (HCC). In the present study, the CLU expression was analyzed in human hepatoma cells and chemoresistant counterpart HepG2/ADM cells. Compared with L02 cells, the overexpression of cellular CLU was identified in HepG2, HepG2/ADM, SMMC7721, Hep3B ,and PLC cells and relatively lower expression in Bel-7404, SNU-739, and MHCC97H cells. Specific short hairpin RNAs (shRNAs) to silence CLU gene transcription were designed, and the most effective sequences were screened. After the HepG2/ADM cells transfected with shRNA-1, the inhibition of CLU expression was 73.68 % at messenger RNA (mRNA) level by real-time quantitative RT-PCR with obvious enhancement in cell chemosensitivity, increasing apoptosis induced by doxorubicin using fluorescence kit, and Rh-123 retention qualified with flow cytometry. Knockdown CLU also significantly decreased the drug efflux pump activity through the depression of MDR1/P-glycoprotein (q = 11.739, P < 0.001). Moreover, silencing CLU led to downregulation of β-catenin (q = 13.544, P = 0.001), suggesting that downregulation of CLU might be a key point to reverse multidrug resistance of HepG2/ADM cells. PMID:25600802

  1. Effect of CD38 on the multidrug resistance of human chronic myelogenous leukemia K562 cells to doxorubicin

    PubMed Central

    YALÇINTEPE, LEMAN; HALIS, EMRE; ULKU, SIBEL

    2016-01-01

    Drug resistance is a serious challenge in cancer chemotherapy. Alterations in the intracellular concentration and homeostasis of calcium (Ca2+) may contribute to the development of drug resistance. To investigate the mechanism of drug resistance in leukemia, the present study rendered human chronic myelogenous leukemia K562 cells resistant to the cytotoxic effect of doxorubicin by progressively adapting the sensitive parental K562 cells to doxorubicin. The resulting cells were termed K562/DOX. Subsequently, the expression of two multidrug resistance proteins, P-glycoprotein (P-gp) and multidrug resistance protein 1 (MRP1), was analyzed in K562/DOX cells. In addition to P-gp and MRP1, these cells also expressed cluster of differentiation (CD)38 and its active enzyme adenosine diphosphate (ADP)-ribosyl cyclase. The present study also demonstrated that K562/DOX cells responded to cyclic ADP-ribose-mediated increases in intracellular Ca2+. These data indicate that CD38 may participate in the development of drug resistance to doxorubicin in K562 cells. PMID:26998164

  2. Shugoshin1 enhances multidrug resistance of gastric cancer cells by regulating MRP1, Bcl-2, and Bax genes.

    PubMed

    Wang, Yafang; Liu, Lili; Liu, Xiangqiang; Zhang, Hui; Liu, Jiaming; Feng, Bin; Shang, Yulong; Zhou, Lin; Wu, Kaichun; Nie, Yongzhan; Zhang, Hongbo; Fan, Daiming

    2013-08-01

    Multidrug resistance (MDR) is a major clinical obstacle in treatment of gastric cancer (GC) and it accounts for the majority of cancer-related mortalities. Shugoshin1 (SGO1) is an important player in appropriate chromosome segregation and is involved in tumorigenesis. In this study, we found endogenous SGO1 overexpression in the multidrug-resistant GC cell lines SGC7901/VCR and SGC7901/ADR compared with their parental cell line SGC7901. By enhancing expression of SGO1, sensitivity of SGC7901 cells to vincristine (VCR), adriamycin, 5-fluorouracil (5-FU), and cisplatin (CDDP) was significantly diminished. Silencing its expression resulted in enhanced sensitivity of SGC7901/VCR and SGC7901/ADR cells to these antitumor drugs. Additionally, we confirmed that SGO1 increased capacity of cells to enable adriamycin (ADR) efflux and inhibit drug-induced apoptosis by regulating MRP 1, Bcl-2, and Bax genes so as to confer a MDR phenotype to GC cells. In brief, these findings suggest that SGO1 promotes MDR of GC cells and may be useful as a novel therapeutic target for preventing or reversing MDR. PMID:23564482

  3. Effects of the multidrug resistance modulator HZ08 on the apoptosis pathway in human chronic leukaemia cell line K562/A02.

    PubMed

    Cen, Juan; Zhu, Yi-Lin; Yang, Yu; Zhu, Jun-Rong; Fang, Wei-Rong; Huang, Wen-Long; Li, Yun-Man; Tao, Yi-Fu

    2011-01-01

    ōancer falls to respond to chemotherapy by acquiring multidrug resistance in over 90% of patients. A previous study revealed that multidrug resistance modulator HZ08 had great multidrug resistance reversal effect in vitro and in vivo. It could enhance adriamycin (doxorubicin) induced intrinsic apoptosis pathway and rectify cell cycle and some apoptosis related proteins in human breast resistant cancer MCF-7/ADM cells. This study detected Rh123 accumulation to assess the effect of HZ08 on P-glycoprotein function in human chronic leukaemia cell line K562/A02. Moreover, mitochondria membrane potential, cytochrome c release and caspase-3 activity were analyzed for HZ08 treatment with or without vincristine. Since pretreatment with HZ08 could also reverse the multidrug resistance to vincristine in K562/A02 cells, the individual influence of HZ08 was further detected on apoptotic regulator like Bcl-2, Bax, p53, cell cycle checkpoints and proliferation regulatory factors like survivin, hTERT, c-Myc, c-Fos, c-Jun. Finally, it revealed that HZ08 increased vincristine induced activation in intrinsic apoptosis pathway by inhibition of P-gp mediated efflux. In addition, the outstanding reversal effect of HZ08 should also attribute to its individual effect on apoptosis and proliferation related regulatory factors. It renders HZ08 possibility of application in pretreatment to reverse multidrug resistance while avoiding unexpected drug interactions and accumulative toxicity. PMID:22232851

  4. Sinomenine Sensitizes Multidrug-Resistant Colon Cancer Cells (Caco-2) to Doxorubicin by Downregulation of MDR-1 Expression

    PubMed Central

    Liu, Zhen; Duan, Zhi-Jun; Chang, Jiu-Yang; Zhang, Zhi-feng; Chu, Rui; Li, Yu-Ling; Dai, Ke-Hang; Mo, Guang-quan; Chang, Qing-Yong

    2014-01-01

    Chemoresistance in multidrug-resistant (MDR) cells over expressing P-glycoprotein (P-gp) encoded by the MDR1 gene, is a major obstacle to successful chemotherapy for colorectal cancer. Previous studies have indicated that sinomenine can enhance the absorption of various P-gp substrates. In the present study, we investigated the effect of sinomenine on the chemoresistance in colon cancer cells and explored the underlying mechanism. We developed multidrug-resistant Caco-2 (MDR-Caco-2) cells by exposure of Caco-2 cells to increasing concentrations of doxorubicin. We identified overexpression of COX-2 and MDR-1 genes as well as activation of the NF-κB signal pathway in MDR-Caco-2 cells. Importantly, we found that sinomenine enhances the sensitivity of MDR-Caco-2 cells towards doxorubicin by downregulating MDR-1 and COX-2 expression through inhibition of the NF-κB signaling pathway. These findings provide a new potential strategy for the reversal of P-gp-mediated anticancer drug resistance. PMID:24901713

  5. Retroviral transfer of a murine cDNA for multidrug resistance confers pleiotropic drug resistance to cells without prior drug selection

    SciTech Connect

    Guild, B.C.; Mulligan, R.C.; Gros, P.; Housman, D.E.

    1988-03-01

    The authors have constructed a retrovirus expression vector that carries the murine mdr cDNA transcribed under the control of the human H4 histone promoter to examine the feasibility of efficiently transferring a multidrug resistance phenotype to cells without requiring drug selection. This approach will facilitate the transfer of mdr cDNA to hematopoietic progenitor cells for the study of multidrug resistance in vivo. The retrovirus vector pHmdr has been used for transmission and expression of the mdr cDNA in initially drug-sensitive NIH 3T3 fibroblasts. Selection of pHmdr infectants in the cytotoxic agents colchicine or doxorubicin gave rise to highly multidrug-resistant colonies containing a single gene copy of the vector. Moreover, in the analysis of 12 cloned unselected NIH 3T3 cell infectants, a multidrug resistance phenotype was conferred by as few as two copies of the pHmdr vector. Overexpression of the mdr cDNA in drug-selected and unselected pHmdr infectants was directly related to cell survival in three cytotoxic agents tested. These results hold significant implications for the study of multidrug resistance in vivo.

  6. Reversal of multidrug resistance by cisplatin-loaded magnetic Fe3O4 nanoparticles in A549/DDP lung cancer cells in vitro and in vivo

    PubMed Central

    Li, Ke; Chen, Baoan; Xu, Lin; Feng, Jifeng; Xia, Guohua; Cheng, Jian; Wang, Jun; Gao, Feng; Wang, Xuemei

    2013-01-01

    The purpose of this study was to explore whether magnetic Fe3O4 nanoparticles (Fe3O4-MNP) loaded with cisplatin (Fe3O4-MNP-DDP) can reverse DDP resistance in lung cancer cells and to investigate mechanisms of multidrug resistance in vitro and in vivo. MTT assay showed that DDP inhibited both A549 cells and DDP-resistant A549 cells in a time-dependent and dose-dependent manner, and that this inhibition was enhanced by Fe3O4-MNP. An increased rate of apoptosis was detected in the Fe3O4-MNP-DDP group compared with a control group and the Fe3O4-MNP group by flow cytometry, and typical morphologic features of apoptosis were confirmed by confocal microscopy. Accumulation of intracellular DDP in the Fe3O4-MNP-DDP group was greater than that in the DDP group by inductively coupled plasma mass spectrometry. Further, lower levels of multidrug resistance-associated protein-1, lung resistance-related protein, Akt, and Bad, and higher levels of caspase-3 genes and proteins, were demonstrated by reverse transcriptase polymerase chain reaction and Western blotting in the presence of Fe3O4-MNP-DDP. We also demonstrated that Fe3O4-MNP enhanced the effect of DDP on tumor growth in BALB/c nude mice bearing DDP-resistant human A549 xenografts by decreasing localization of lung resistance-related protein and Ki-67 immunoreactivity in cells. There were no apparent signs of toxicity in the animals. Overall, these findings suggest potential clinical application of Fe3O4-MNP-DDP to increase cytotoxicity in lung tumor xenografts. PMID:23690684

  7. Purine Nucleoside Analog - Sulfinosine Modulates Diverse Mechanisms of Cancer Progression in Multi-Drug Resistant Cancer Cell Lines

    PubMed Central

    Dačević, Mirjana; Isaković, Aleksandra; Podolski-Renić, Ana; Isaković, Andelka M.; Stanković, Tijana; Milošević, Zorica; Rakić, Ljubisav; Ruždijić, Sabera; Pešić, Milica

    2013-01-01

    Achieving an effective treatment of cancer is difficult, particularly when resistance to conventional chemotherapy is developed. P-glycoprotein (P-gp) activity governs multi-drug resistance (MDR) development in different cancer cell types. Identification of anti-cancer agents with the potential to kill cancer cells and at the same time inhibit MDR is important to intensify the search for novel therapeutic approaches. We examined the effects of sulfinosine (SF), a quite unexplored purine nucleoside analog, in MDR (P-gp over-expressing) non-small cell lung carcinoma (NSCLC) and glioblastoma cell lines (NCI-H460/R and U87-TxR, respectively). SF showed the same efficacy against MDR cancer cell lines and their sensitive counterparts. However, it was non-toxic for normal human keratinocytes (HaCaT). SF induced caspase-dependent apoptotic cell death and autophagy in MDR cancer cells. After SF application, reactive oxygen species (ROS) were generated and glutathione (GSH) concentration was decreased. The expression of key enzyme for GSH synthesis, gamma Glutamyl-cysteine-synthetase (γGCS) was decreased as well as the expression of gst-π mRNA. Consequently, SF significantly decreased the expression of hif-1α, mdr1 and vegf mRNAs even in hypoxic conditions. SF caused the inhibition of P-gp (coded by mdr1) expression and activity. The accumulation of standard chemotherapeutic agent – doxorubicin (DOX) was induced by SF in concentration- and time-dependent manner. The best effect of SF was obtained after 72 h when it attained the effect of known P-gp inhibitors (Dex-verapamil and tariquidar). Accordingly, SF sensitized the resistant cancer cells to DOX in subsequent treatment. Furthermore, SF decreased the experssion of vascular endothelial growth factor (VEGF) on mRNA and protein level and modulated its secretion. In conclusion, the effects on P-gp (implicated in pharmacokinetics and MDR), GSH (implicated in detoxification) and VEGF (implicated in tumor-angiogenesis and

  8. Non-alkaloids extract from Stemona sessilifolia enhances the activity of chemotherapeutic agents through P-glycoprotein-mediated multidrug-resistant cancer cells.

    PubMed

    Han, Lu; Ma, Yang-Mei; An, Li; Zhang, Qiao; Wang, Chang-Li; Zhao, Qing-Chun

    2016-01-01

    One of the major impediments to the successful treatment of cancer is the development of resistant cancer cells, which could cause multidrug resistance (MDR), and overexpression of ABCB1/P-glycoprotein (P-gp) is one of the most common causes of MDR in cancer cells. Recently, natural products or plant-derived chemicals have been investigated more and more widely as potential multidrug-resistant (MDR) reversing agents. The current study demonstrated for the first time that non-alkaloids extract from Stemona sessilifolia significantly reversed the resistance of chemotherapeutic agents, adriamycin, paclitaxel and vincristine to MCF-7/ADR cells compared with MCF-7/S cells in a dose-dependent manner. The results obtained from these studies indicated that the non-alkaloids extract from S. sessilifolia plays an important role in reversing MDR of cancer as a P-gp modulator in vitro and may be effective in the treatment of multidrug-resistant cancers. PMID:26190165

  9. Rapid identification of the multidrug resistance in the human leukemic cells by near-infrared Fourier transform Raman microspectroscopy

    NASA Astrophysics Data System (ADS)

    Beljebbar, Abdelilah; Morjani, Hamid; Sockalingum, Ganesh D.; Manfait, Michel

    1998-04-01

    In this work, we have studied the cancer cell lines sharing a common feature: the multi-drug resistance where P- glycoprotein is responsible for the active efflux of the drug out of the cell. For this, we have used two types of cells, MDR-human leukemic K562 cells and non-MDR acute promyelocytic leukemic HL60 cells. The comparison between normalized micro FT-Raman spectra of resistant and sensitive K652 cells shows a decrease in the intensity of the amide I and III bands and a down shift of the amide I band. On the other hand, control experiments with HL60 cells do not show any remarkable changes. Analysis of micro-FT-Raman spectra by resolution enhancement methods and by chemometrics tools reveal further information concerning the conformational changes of the cell constituents involved in the expression of the MDR-phenotype.

  10. Synthesis of α,β-Unsaturated Carbonyl-Based Compounds, Oxime and Oxime Ether Analogs as Potential Anticancer Agents for Overcoming Cancer Multidrug Resistance by Modulation of Efflux Pumps in Tumor Cells.

    PubMed

    Qin, Hua-Li; Leng, Jing; Zhang, Cheng-Pan; Jantan, Ibrahim; Amjad, Muhammad Wahab; Sher, Muhammad; Naeem-Ul-Hassan, Muhammad; Hussain, Muhammad Ajaz; Bukhari, Syed Nasir Abbas

    2016-04-14

    Sixty-nine novel α,β-unsaturated carbonyl based compounds, including cyclohexanone, tetralone, oxime, and oxime ether analogs, were synthesized. The antiproliferative activity determined by using seven different human cancer cell lines provided a structure-activity relationship. Compound 8ag exhibited high antiproliferative activity against Panc-1, PaCa-2, A-549, and PC-3 cell lines, with IC50 value of 0.02 μM, comparable to the positive control Erlotinib. The ten most active antiproliferative compounds were assessed for mechanistic effects on BRAF(V600E), EGFR TK kinases, and tubulin polymerization, and were investigated in vitro to reverse efflux-mediated resistance developed by cancer cells. Compound 8af exhibited the most potent BRAF(V600E) inhibitory activity with an IC50 value of 0.9 μM. Oxime analog 7o displayed the most potent EGFR TK inhibitory activity with an IC50 of 0.07 μM, which was analogous to the positive control. Some analogs including 7f, 8af, and 8ag showed a dual role as anticancer and MDR reversal agents. PMID:27010345

  11. Reversal effect of bufalin on multidrug resistance in human hepatocellular carcinoma BEL-7402/5-FU cells.

    PubMed

    Gu, Wei; Liu, Long; Fang, Fan-Fu; Huang, Feng; Cheng, Bin-Bin; Li, Bai

    2014-01-01

    Multidrug resistance (MDR) is a major obstacle to chemotherapy in patients with hepatocellular carcinoma (HCC). To overcome MDR and improve chemotherapeutic efficacy, novel reversal agents with higher efficacy and lower toxicity are urgently needed for HCC. The present study was designed to examine the potential reversal activity of bufalin, a toxic ligand isolated from the traditional Chinese medicine 'Chansu' and to elucidate the possible related mechanisms. A multidrug-resistant HCC cell line, BEL-7402/5-FU, was used as the cell model. The working concentration of bufalin as an effective reversal agent, and the cell viability in the reversal experiments were determined by MTT assay. The effects of bufalin at a non-cytotoxic dose on cell cycle distribution, apoptosis and drug efflux pump activity were measured by flow cytometry. Qualitative observation of apoptosis was also carried out by confocal microscopy. Furthermore, the effects of bufalin on the expression of potential genes involved in MDR of BEL-7402/5-FU cells, including thymidylate synthase (TS), P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), B-cell lymphoma-extra large (Bcl-xL) and Bcl-2-associated X protein (Bax), were determined using real-time PCR and western blot analysis. The results showed that bufalin at a concentration of 1 nM enhanced the chemosensitivity of BEL-7402/5-FU cells to 5-FU with a reversal fold of 3.8 which was similar to that of 1 µM verapamil. Bufalin significantly arrested the cell cycle at the G₀/G₁ phase, induced apoptosis through an increase in the Bax/Bcl-xL ratio, inhibited drug efflux pump activity via downregulation of MRP1, and reduced the expression of TS in BEL-7402/5-FU cells. The present study revealed that bufalin effectively reversed MDR in BEL-7402/5-FU cells through multiple pathways. The combination of bufalin with cytotoxic drugs may serve as a promising strategy for the chemotherapy of HCC. PMID:24173654

  12. Combating P-glycoprotein-mediated multidrug resistance with 10-O-phenyl dihydroartemisinin ethers in MCF-7 cells.

    PubMed

    Zhong, Hang; Zhao, Xuan; Zuo, Zhizhong; Sun, Jingwei; Yao, Yao; Wang, Tao; Liu, Dan; Zhao, Linxiang

    2016-01-27

    A series of 10-β-phenyl ethers of dihydroartemisinin (DHA) with piperazine substitutions were synthesized with the goal of overcoming multidrug resistance in cancer therapy. These novel compounds exerted significant antiproliferative activities in breast cancer MCF-7 and MCF-7/Adr cell lines at the submicromolar level and were shown to be approximately 100- to 300-times more potent than the lead compound DHA. Remarkably, the P-gp-overexpressed MCF-7/Adr cell line showed collateral sensitivity towards these derivatives. Furthermore, compounds 3d and 5c, with the highest selectivity for MCF-7/Adr towards MCF-7 cells, were free from P-gp efflux in a MDCK-MDR1 assay. Flow cytometry and western blot assays suggested that the antiproliferative effects of 5c were associated with cell cycle arrest at G1 phase through the downregulation of Cyclin D1 and Cyclin B1. PMID:26741854

  13. miR-218 inhibits multidrug resistance (MDR) of gastric cancer cells by targeting Hedgehog/smoothened

    PubMed Central

    Zhang, Xiang-Liang; Shi, Hui-Juan; Wang, Ji-Ping; Tang, Hong-Sheng; Cui, Shu-Zhong

    2015-01-01

    Multidrug resistance (MDR) is the main obstacle to successful chemotherapy for patients with gastric cancer. The microRNA miR-218 influences various pathobiological processes in gastric cancer, and its down-regulation in this disease raises the question of whether it normally inhibits MDR. In this study we observed that two MDR gastric cancer cell lines showed lower expression of miR-218 compared with their chemosensitive parental cell line. Overexpressing miR-218 chemosensitizes gastric cancer cells, slowed efflux of adriamycin, and accelerated drug-induced apoptosis. We identified the smoothened (SMO) gene as a functional target of miR-218, and found that SMO overexpression counteracts the chemosensitizing effects of miR-218. These findings suggest that miR-218 inhibits MDR of gastric cancer cells by down-regulating SMO expression. PMID:26261515

  14. A Novel Nitrobenzoate Microtubule Inhibitor that Overcomes Multidrug Resistance Exhibits Antitumor Activity.

    PubMed

    Zheng, Yan-Bo; Gong, Jian-Hua; Liu, Xiu-Jun; Wu, Shu-Ying; Li, Yi; Xu, Xian-Dong; Shang, Bo-Yang; Zhou, Jin-Ming; Zhu, Zhi-Ling; Si, Shu-Yi; Zhen, Yong-Su

    2016-01-01

    Multidrug resistance is a major limitation for microtubule-binding agents in cancer treatment. Here we report a novel microtubule inhibitor (2-morpholin-4-yl-5-nitro-benzoic acid 4-methylsulfanyl-benzyl ester, IMB5046), its cytotoxicity against multidrug-resistant cell lines and its antitumor efficacy in animal models. IMB5046 disrupted microtubule structures in cells and inhibited purified tubulin polymerization in vitro. It bound to the colchicine pocket of tubulin. IMB5046 displayed potent cytotoxicity against multiple tumor cell lines with an IC50 range of 0.037-0.426 μM. Notably, several multidrug-resistant cell lines which were resistant to colchicine, vincristine and paclitaxel remained sensitive to IMB5046. IMB5046 was not a P-glycoprotein substrate. IMB5046 blocked cell cycle at G2/M phase and induced cell apoptosis. Microarray assay indicated that the differentially expressed genes after IMB5046 treatment were highly related to immune system, cell death and cancer. In a mouse xenograft model IMB5046 inhibited the growth of human lung tumor xenograft by 83% at a well-tolerated dose. It is concluded that IMB5046 is a tubulin polymerization inhibitor with novel chemical structure and can overcome multidrug resistance. It is a promising lead compound for cancer chemotherapy, especially for treatment of multidrug-resistant tumors. PMID:27510727

  15. A Novel Nitrobenzoate Microtubule Inhibitor that Overcomes Multidrug Resistance Exhibits Antitumor Activity

    PubMed Central

    Zheng, Yan-Bo; Gong, Jian-Hua; Liu, Xiu-Jun; Wu, Shu-Ying; Li, Yi; Xu, Xian-Dong; Shang, Bo-Yang; Zhou, Jin-Ming; Zhu, Zhi-Ling; Si, Shu-Yi; Zhen, Yong-Su

    2016-01-01

    Multidrug resistance is a major limitation for microtubule-binding agents in cancer treatment. Here we report a novel microtubule inhibitor (2-morpholin-4-yl-5-nitro-benzoic acid 4-methylsulfanyl-benzyl ester, IMB5046), its cytotoxicity against multidrug-resistant cell lines and its antitumor efficacy in animal models. IMB5046 disrupted microtubule structures in cells and inhibited purified tubulin polymerization in vitro. It bound to the colchicine pocket of tubulin. IMB5046 displayed potent cytotoxicity against multiple tumor cell lines with an IC50 range of 0.037–0.426 μM. Notably, several multidrug-resistant cell lines which were resistant to colchicine, vincristine and paclitaxel remained sensitive to IMB5046. IMB5046 was not a P-glycoprotein substrate. IMB5046 blocked cell cycle at G2/M phase and induced cell apoptosis. Microarray assay indicated that the differentially expressed genes after IMB5046 treatment were highly related to immune system, cell death and cancer. In a mouse xenograft model IMB5046 inhibited the growth of human lung tumor xenograft by 83% at a well-tolerated dose. It is concluded that IMB5046 is a tubulin polymerization inhibitor with novel chemical structure and can overcome multidrug resistance. It is a promising lead compound for cancer chemotherapy, especially for treatment of multidrug-resistant tumors. PMID:27510727

  16. Identification of microRNAs and mRNAs associated with multidrug resistance of human laryngeal cancer Hep-2 cells

    PubMed Central

    Yin, Wanzhong; Wang, Ping; Wang, Xin; Song, Wenzhi; Cui, Xiangyan; Yu, Hong; Zhu, Wei

    2013-01-01

    Multidrug resistance (MDR) poses a serious impediment to the success of chemotherapy for laryngeal cancer. To identify microRNAs and mRNAs associated with MDR of human laryngeal cancer Hep-2 cells, we developed a multidrug-resistant human laryngeal cancer subline, designated Hep-2/v, by exposing Hep-2 cells to stepwise increasing concentrations of vincristine (0.02-0.96'µM). Microarray assays were performed to compare the microRNA and mRNA expression profiles of Hep-2 and Hep-2/v cells. Compared to Hep-2 cells, Hep-2/v cells were more resistant to chemotherapy drugs (∼45-fold more resistant to vincristine, 5.1-fold more resistant to cisplatin, and 5.6-fold more resistant to 5-fluorouracil) and had a longer doubling time (42.33±1.76 vs 28.75±1.12'h, P<0.05), higher percentage of cells in G0/G1 phase (80.98±0.52 vs 69.14±0.89, P<0.05), increased efflux of rhodamine 123 (95.97±0.56 vs 12.40±0.44%, P<0.01), and up-regulated MDR1 expression. A total of 7 microRNAs and 605 mRNAs were differentially expressed between the two cell types. Of the differentially expressed mRNAs identified, regulator of G-protein signaling 10, high-temperature requirement protein A1, and nuclear protein 1 were found to be the putative targets of the differentially expressed microRNAs identified. These findings may open a new avenue for clarifying the mechanisms responsible for MDR in laryngeal cancer. PMID:23780424

  17. Label-free detection of multidrug resistance in K562 cells through isolated 3D-electrode dielectrophoresis.

    PubMed

    Demircan, Yağmur; Koyuncuoğlu, Aziz; Erdem, Murat; Özgür, Ebru; Gündüz, Ufuk; Külah, Haluk

    2015-05-01

    Dielectrophoresis (DEP), a technique used to separate particles based on different sizes and/or dielectric properties under nonuniform electric field, is a promising method to be applied in label-free, rapid, and effective cell manipulation and separation. In this study, a microelectromechanical systems-based, isolated 3D-electrode DEP device has been designed and implemented for the label-free detection of multidrug resistance in K562 leukemia cells, based on the differences in their cytoplasmic conductivities. Cells were hydrodynamically focused to the 3D-electrode arrays, placed on the side walls of the microchannel, through V-shaped parylene-C obstacles. 3D-electrodes extruded along the z-direction provide uniformly distributed DEP force through channel depth. Cell suspension containing resistant and sensitive cancer cells with 1:100 ratio was continuously flown through the channel at a rate of 10 μL/min. Detection was realized at 48.64 MHz, the cross-over frequency of sensitive K562 cells, at which sensitive cells flow with the fluid, while the resistant ones are trapped by positive DEP force. Device can be operated at considerably low voltages (<9 Vpp ). This is achieved by means of a very thin (0.5 μm) parylene coating on electrodes, providing the advantages offered by the isolation of electrodes from the sample, while the working voltage can still be kept low. Results prove that the presented DEP device can provide an efficient platform for the detection of multidrug resistance in leukemia, in a label-free manner. PMID:25781271

  18. Indomethacin Analogues that Enhance Doxorubicin Cytotoxicity in Multidrug Resistant Cells without Cox Inhibitory Activity.

    PubMed

    Arisawa, Mitsuhiro; Kasaya, Yayoi; Obata, Tohru; Sasaki, Takuma; Ito, Mika; Abe, Hiroshi; Ito, Yoshihiro; Yamano, Akihito; Shuto, Satoshi

    2011-05-12

    Conformationally restricted indomethacin analogues were designed and prepared from the corresponding 2-substituted indoles, which were synthesized by a one-pot isomerization/enamide-ene metathesis as the key reaction. Conformational analysis by calculations, NMR studies, and X-ray crystallography suggested that these analogues were conformationally restricted in the s-cis or the s-trans form due to the 2-substituent as expected. Their biological activities on cyclooxygenase-1 (COX-1) inhibition, cyclooxygenase-2 (COX-2) inhibition, and modulation of MRP-1-mediated multidrug resistance (MDR) are described. Some of these indomethacin analogues enhanced doxorubicin cytotoxicity, although they do not have any COX inhibitory activity, which suggests that the MDR-modulating effect of an NSAID can be unassociated with its COX-inhibitory activity. This may be an entry into the combination chemotherapy of doxorubicin with a MDR modulator. PMID:24900317

  19. Multidrug-resistance gene (P-glycoprotein) is expressed by endothelial cells at blood-brain barrier sites

    SciTech Connect

    Cordon-Cardo, C.; O'Brien, J.P.; Casals, D.; Biedler, J.L.; Melamed, M.R.; Bertino, J.R. ); Rittman-Grauer, L. )

    1989-01-01

    Endothelial cells of human capillary blood vessels at the blood-brain and other blood-tissue barrier sites express P-glycoprotein as detected by mouse monoclonal antibodies against the human multidrug-resistance gene product. This pattern of endothelial cell expression may indicate a physiological role for P-glycoprotein in regulating the entry of certain molecules into the central nervous system and other anatomic compartments, such as the testes. These tissues, which limit the access of systemic drugs, are known pharmacologic sanctuaries for metastatic cancer. P-glycoprotein expression in capillary endothelium of brain and testes and not other tissues (i.e., kidney and placenta) may in part explain this phenomenon and could have important implications in cancer chemotherapy.

  20. [The structure of cellular vaults, their role in the normal cell and in the multidrug resistance of cancer].

    PubMed

    Szaflarski, Witold; Nowicki, Michał; Zabel, Maciej

    2011-01-01

    The cellular vaults have been described for the first time in 1986 as ribonucleoprotein complexes composed of three proteins, MVP, TEP1 and vPARP and several vRNA strains. Biochemical and structural studies revealed their ubiquitous existence in the cytoplasm of many eukaryotic cells and their barrel-like structure indicating their engagement in the intracellular transport. Furthermore, the high homology between MVP and LRP which was already known to be involved in multidrug resistance mechanism opened a discussion about the role of vaults in both normal and cancer cells. The histopathology research demonstrated an increased amount of MVP/LRP proteins in the cancer as well as showed translocation possibility between cytoplasm and nuclear envelope, which can be of crucial point in the prevention of nucleus against anticancer drugs. PMID:22235652

  1. Membrane vesicles from multidrug-resistant human carcinoma cells contain a specific 150,000-170,000 dalton protein detected by photoaffinity labeling

    SciTech Connect

    Cornwell, M.M.; Safa, A.R.; Felsted, R.L.; Gottesman, M.M.; Pastan, I.

    1986-05-01

    The authors have selected multidrug-resistant human KB carcinoma cells in high levels of colchicine (KB-C4) or vinblastine (KB-V1) which are cross-resistant to many other structurally unrelated chemotheraputic agents. To determine the mechanism of reduced drug accumulation, they measured /sup 3/H-vinblastine (/sup 3/H-VBL) association with membrane vesicles made from parental drug sensitive, drug-resistant and revertant cells. Membrane vesicles from highly multidrug resistant cells exhibited increased specific and saturable binding of vinblastine, (Kd = 1 ..mu..M) that was temperature dependent and trypsin sensitive. To identify the molecules which bind vinblastine, membrane vesicles were exposed to two photo-activatable analogs of vinblastine, (N-P-(azido-3,5,-(/sup 3/H)-benzoyl)-N'-..beta..-aminoethylvindisine (/sup 3/H-NAB) and N-P-(azido-3-(/sup 125/I)-solicyl)-N'-..beta..-aminoethylvindesine (/sup 125/I-NASV). The specific labeling of a 150,000-170,000 dalton protein in membrane vesicles from multidrug-resistant KB-C4 and KB-V1 cells was found. /sup 125/I-NASV labeling was inhibited by vinblastine, vincrinstine and verapamil but not by colchicine or dexamethasone. The 150,000-170,000 dalton protein may have an important role in the multidrug resistance phenotype.

  2. Pirarubicin inhibits multidrug-resistant osteosarcoma cell proliferation through induction of G2/M phase cell cycle arrest

    PubMed Central

    Zheng, Shui-er; Xiong, Sang; Lin, Feng; Qiao, Guang-lei; Feng, Tao; Shen, Zan; Min, Da-liu; Zhang, Chun-ling; Yao, Yang

    2012-01-01

    Aim: Pirarubicin (THP) is recently found to be effective in treating patients with advanced, relapsed or recurrent high-grade osteosarcoma. In this study, the effects of THP on the multidrug-resistant (MDR) osteosarcoma cells were assessed, and the underlying mechanisms for the disruption of cell cycle kinetics by THP were explored. Methods: Human osteosarcoma cell line MG63 and human MDR osteosarcoma cell line MG63/DOX were tested. The cytotoxicity of drugs was examined using a cell proliferation assay with the Cell Counting Kit-8 (CCK-8). The distribution of cells across the cell cycle was determined with flow cytometry. The expression of cell cycle-regulated genes cyclin B1 and Cdc2 (CDK1), and the phosphorylated Cdc2 and Cdc25C was examined using Western blot analyses. Results: MG63/DOX cells were highly resistant to doxorubicin (ADM) and gemcitabine (GEM), but were sensitive or lowly resistant to THP, methotrexate (MTX) and cisplatin (DDP). Treatment of MG63/DOX cells with THP (200–1000 ng/mL) inhibited the cell proliferation in time- and concentration-dependent manners. THP (50–500 ng/mL) induced MG63/DOX cell cycle arrest at the G2/M phase in time- and concentration-dependent manners. Furthermore, the treatment of MG63/DOX cells with THP (200–1000 ng/mL) downregulated cyclin B1 expression, and decreased the phosphorylated Cdc2 at Thr161. Conversely, the treatment increased the phosphorylated Cdc2 at Thr14/Tyr15 and Cdc25C at Ser216, which led to a decrease in Cdc2-cyclin B1 activity. Conclusion: The cytotoxicity of THP to MG63/DOX cells may be in part due to its ability to arrest cell cycle progression at the G2/M phase, which supports the use of THP for managing patients with MDR osteosarcoma. PMID:22580740

  3. Screening for multidrug resistance in leukemia: cell reactivity to MRK-16 correlates with anthracycline retention and sensitivity of leukemic cells.

    PubMed

    Michieli, M; Damiani, D; Michelutti, A; Grimaz, S; Geromin, A; Fanin, R; Russo, D; Masolini, P; Baccarani, M

    1996-09-01

    The biologic and clinical importance of the multidrug resistance (MDR) that is related with the overexpression of the P170 glycoprotein (Pgp) is widely recognized. However, a major issue that has not yet been solved is the definition of the degree of Pgp expression which is associated with a significant decrease of the sensitivity of the cells to chemotherapy. For this reason we studied the leukemic cells from 83 cases of acute leukemia. Leukemic cells were fixed in PLP and treated with saponine. Pgp expression was assayed by flow cytometry, using the anti Pgp monoclonal antibody MRK-16. Results were expressed both as the number of positive cells and by the intensity of the reaction as defined by the mean fluorescence index (MFI), i.e. the ratio between the mean fluorescence intensity of the MRK-16 incubated cells and of the IgG2a incubated cells. Thus, Pgp expression was compared with the results of two in vitro tests of cell sensitivity to anthracyclines, daunorubicin (DNR) cell retention and DNR cytotoxicity. We found that it was not the number of MRK-16 positive cells, but the degree of the reaction with MRK-16 (MFI) that significantly related to the anthracycline toxicity tests. Therefore, we propose that for clinical purposes a quick and cheap determination of Pgp-related MDR in leukemic cells may be obtained by measuring the MFI with MRK-16 in a standard flow cytometry assay and that the assay may indeed be sufficient to estimate Pgp expression as well as the influence of Pgp on cell sensitivity to anthracyclines. PMID:9021691

  4. Chemotherapeutic efficacy of the protein-doxorubicin conjugates on multidrug resistant rat hepatoma cell line in vitro.

    PubMed Central

    Ohkawa, K.; Hatano, T.; Tsukada, Y.; Matsuda, M.

    1993-01-01

    In vitro studies were initiated to study the antitumour effect of protein-doxorubicin (DXR) conjugate on the growth of the multidrug resistant rat ascites hepatoma cell line, AH66DR. The 50% inhibitory concentration (IC50) for DXR in AH66DR cell line was 16 mumol l-1 (AH66 parental cell line, AH66P, IC50 was 0.08 mumol l-1). Treatment of AH66P and AH66DR cells with various concentrations of DXR or conjugates at equivalent concentrations of DXR was performed. The two types of conjugates used were bovine serum albumin (BSA)-DXR conjugate and immunoglobulin G (IgG)-DXR conjugate. Both of these conjugates showed potent dose-dependent inhibition of cell growth against AH66DR cells as compared with the cells treated with DXR or other controls. The IC50 for BSA-DXR and IgG-DXR conjugates in AH66DR cell line was 0.05 (equivalent DXR) mumol l-1 and 0.07 (equivalent DXR) mumol l-1, respectively. These values were similar to that of the AH66P treated with DXR. Cellular uptake and accumulation of DXR or BSA-DXR conjugate was also quantitated in both cell lines. The cellular concentration of DXR in AH66DR cells was 2-fold lower than that of AH66P cells throughout the experiment. In contrast, by the treatment of AH66DR cells with BSA-DXR conjugate, the intracellular drug concentration increased as a function of time up to 24 h (639.1 +/- 41.8, equivalent DXR, ng 10(-5) cells) and reached the same drug level as AH66P cells treated with DXR (617.9 +/- 17.3 ng-5 cells). Ammonium chloride treatment inhibited the effects of the conjugates but did not inhibit the free drugs. Intracellular DXR was effluxed rapidly from AH66DR cells, but BSA-DXR conjugate remained in the cells at relatively high concentration for a long time. These results indicate that by chemically modifying DXR, such as by conjugation of the drug with proteins, it may be possible to overcome multidrug resistance. Images Figure 2 PMID:8431358

  5. [Relevance of animal models in the development of compounds targeting multidrug resistant cancer].

    PubMed

    Füredi, András; Tóth, Szilárd; Hámori, Lilla; Nagy, Veronika; Tóvári, József; Szakács, Gergely

    2015-12-01

    Anticancer compounds are typically identified in in vitro screens. Unfortunately, the in vitro drug sensitivity of cell lines does not reflect treatment efficiency in animal models, and neither show acceptable correlation to clinical results. While cell lines and laboratory animals can be readily "cured", the treatment of malignancies remains hampered by the multidrug resistance (MDR) of tumors. Genetically engineered mouse models (GEMMs) giving rise to spontaneous tumors offer a new possibility to characterize the evolution of drug resistance mechanisms and to target multidrug resistant cancer. PMID:26665195

  6. Quaternized Chitosan/Alginate-Fe3O4 Magnetic Nanoparticles Enhance the Chemosensitization of Multidrug-Resistant Gastric Carcinoma by Regulating Cell Autophagy Activity in Mice.

    PubMed

    Li, Xiujuan; Feng, Jing; Zhang, Ran; Wang, Jinda; Su, Tao; Tian, Zuhong; Han, Dong; Zhao, Chuanxu; Fan, Miaomiao; Li, Congye; Liu, Bing; Feng, Xuyang; Nie, Yongzhan; Wu, Kaichun; Chen, Yundai; Deng, Hongbing; Cao, Feng

    2016-05-01

    Multidrug resistance (MDR) and targeted therapies present major challenges in tumor chemotherapy. Nanoparticles (NPs) hold promise for use in cancer theranostics due to their advantages in terms of tumor-targeted cytotoxicity and imaging. In this study, we developed N-((2-hydroxy-3-trimethylammonium) propyl) chitosan chloride (HTCC)/alginate-encapsulated Fe3O4 magnetic NPs (HTCC-MNPs) and applied them to MDR gastric cancer both in vivo and in vitro. HTCC-MNPs were fabricated from sodium alginate (ALG), Fe3O4 and HTCC using an ionic gelation method. The sizes and physical characteristics of the NPs were determined using dynamic light scattering, transmission electron microscopy (TEM) and zeta potential analysis. The HTCC-MNPs exhibited excellent water solubility and biocompatibility as well as significantly reduced cell viability in the drug-resistant cancer cell line SGC7901/ADR, but not in normal gastric cells (P < 0.05). An analysis of LC3 expression demonstrated the involvement of autophagy in HTCC-MNP cytotoxicity. Additionally, apoptosis was verified using a DNA content assay. HTCC-MNPs led to mitochondrial membrane potential loss, decreased ATP production and excessive reactive oxygen species (ROS) generation compared to a control group (P < 0.05). Magnetic resonance imaging showed enrichment of HTCC-MNPs in tumor-bearing mice. In vivo bioluminescence imaging and tumor volume measurements revealed that HTCC-MNPs markedly inhibited in vivo tumor growth (P < 0.05). In conclusion, HTCC-MNPs significantly inhibited MDR gastric tumor growth and reduced tumor volume via the induction of cellular autophagy and apoptosis, which was attributed to mitochondrial dysfunction and excessive ROS accumulation. PMID:27305817

  7. Multidrug Resistance-associated Protein-1 (MRP-1)-dependent Glutathione Disulfide (GSSG) Efflux as a Critical Survival Factor for Oxidant-enriched Tumorigenic Endothelial Cells.

    PubMed

    Gordillo, Gayle M; Biswas, Ayan; Khanna, Savita; Spieldenner, James M; Pan, Xueliang; Sen, Chandan K

    2016-05-01

    Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics. PMID:26961872

  8. 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.

  9. Chromosomal instability, tolerance of mitotic errors and multidrug resistance are promoted by tetraploidization in human cells

    PubMed Central

    Kuznetsova, Anastasia Y; Seget, Katarzyna; Moeller, Giuliana K; de Pagter, Mirjam S.; de Roos, Jeroen A D M; Dürrbaum, Milena; Kuffer, Christian; Müller, Stefan; Zaman, Guido J R; Kloosterman, Wigard P; Storchová, Zuzana

    2015-01-01

    Up to 80% of human cancers, in particular solid tumors, contain cells with abnormal chromosomal numbers, or aneuploidy, which is often linked with marked chromosomal instability. Whereas in some tumors the aneuploidy occurs by missegregation of one or a few chromosomes, aneuploidy can also arise during proliferation of inherently unstable tetraploid cells generated by whole genome doubling from diploid cells. Recent findings from cancer genome sequencing projects suggest that nearly 40% of tumors underwent whole genome doubling at some point of tumorigenesis, yet its contribution to cancer phenotypes and benefits for malignant growth remain unclear. Here, we investigated the consequences of a whole genome doubling in both cancerous and non-transformed p53 positive human cells. SNP array analysis and multicolor karyotyping revealed that induced whole-genome doubling led to variable aneuploidy. We found that chromosomal instability (CIN) is a frequent, but not a default outcome of whole genome doubling. The CIN phenotypes were accompanied by increased tolerance to mitotic errors that was mediated by suppression of the p53 signaling. Additionally, the expression of pro-apoptotic factors, such as iASPP and cIAP2, was downregulated. Furthermore, we found that whole genome doubling promotes resistance to a broad spectrum of chemotherapeutic drugs and stimulates anchorage-independent growth even in non-transformed p53-positive human cells. Taken together, whole genome doubling provides multifaceted benefits for malignant growth. Our findings provide new insight why genome-doubling promotes tumorigenesis and correlates with poor survival in cancer. PMID:26151317

  10. AB249. 15-oxospiramilactone reverses multidrug resistance in the Human Renal Cell Carcinoma by targeting ABCB1 through Inhibition of Wnt/β-catenin signaling

    PubMed Central

    Shen, Tianyi; Yi, Xiaoming; Zhou, Wenquan

    2016-01-01

    Background Multidrug resistance (MDR) is the main barrier to the success of chemotherapy for Human Renal Cell Carcinoma. P-glycoprotein ABCB1 plays a major role in MDR of malignant cells and is regulated by various transcription factors, including Wnt/β-catenin /TCF4. We previously reported 15-oxospiramilactone was a new Wnt molecule inhibiter. In this study, ABCB1 was found to be significantly down regulated in A498 and ACHN cells by using 15-oxospiramilactone, suggesting an important role for the Wnt/b-catenin/TCF4 signaling pathway in cancer drug resistance. Methods Here we demonstrated thatin the renal cancer cell lines A498and ACHN, the level of ABCB1 expression and function correlate with nuclear TCF7L2-luciferase reporter gene activity (A498>ACHN). We constructed TCF7L2 interference vector withLV-TCF7L2-GFPplasmid reduced the expression of TCF7L2 by shRNA-mediated partial depletion.15-oxospiramilactone was treated ACHN, A498 andTCF7L2 knock down RCC cell lines. Carcinogenesis and tumor development measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and clonogenic survival assays. The efflux function of P glycoprotein was assayed by ABCB1 efflux assay. Protein and mRNA expression were assayed by western blotting and quantitative real-time PCR (qPCR). The association between ABCB1 and TCF7L2 was assayed by luciferase reporter assay. Results 15-oxospiramilactone could cooperate with toxicity to suppress RCC cell lines proliferation while had no significant effect in shTCF7L2 groups. 15-oxospiramilactone could inhibit the efflux function of P glycoprotein and had no obvious effect in shTCF7L2 groups either. The association between ABCB1 and TCF7L2 was ensured by luciferase reporter assay. Protein and mRNA of ABCB1, TCF4 andβ-catenin expression were significant down regulated while MRP1 had no obvious change in 15-oxospiramilactone treated group, however, 15-oxospiramilactonehad no obvious effect in shTCF7L2 groups in RCC

  11. Reduced topoisomerase II activity in multidrug-resistant human non-small cell lung cancer cell lines.

    PubMed Central

    Eijdems, E. W.; de Haas, M.; Timmerman, A. J.; Van der Schans, G. P.; Kamst, E.; de Nooij, J.; Astaldi Ricotti, G. C.; Borst, P.; Baas, F.

    1995-01-01

    Multidrug-resistant (MDR) cell lines often have a compound phenotype, combining reduced drug accumulation with a decrease in topoisomerase II. We have analysed alterations in topoisomerase II in MDR derivatives of the human lung cancer cell line SW-1573. Selection with doxorubicin frequently resulted in reduced topo II alpha mRNA and protein levels, whereas clones selected with vincristine showed normal levels of topo II alpha. No alterations of topo II beta levels were detected. To determine the contribution of topo II alterations to drug resistance, topo II activity was analysed by the determination of DNA breaks induced by the topo II-inhibiting drug 4'-(9-acridinylamino)methane-sulphon-m-anisidide (m-AMSA) in living cells, as m-AMSA is not affected by the drug efflux mechanism in the SW-1573 cells. The number of m-AMSA-induced DNA breaks correlated well (r = 0.96) with in vitro m-AMSA sensitivity. Drug sensitivity, however, did not always correlate with reduced topo II mRNA or protein levels. In one of the five doxorubicin-selected clones m-AMSA resistance and a reduction in m-AMSA-induced DNA breaks were found in the absence of reduced topo II protein levels. Therefore, we assume that post-translational modifications of topo II also contribute to drug resistance in SW-1573 cells. These results suggest that methods that detect quantitative as well as qualitative alterations of topo II should be used to predict the responsiveness of tumours to cytotoxic agents. The assay we used, which measures DNA breaks as an end point of topo II activity, could be a good candidate. Images Figure 1 Figure 2 Figure 4 PMID:7819046

  12. EZH2 inhibition re-sensitizes multidrug resistant B-cell lymphomas to etoposide mediated apoptosis

    PubMed Central

    Smonskey, Matthew; Lasorsa, Elena; Rosario, Spencer; Kirk, Jason S.; Hernandez-Ilizaliturri, Francisco J.; Ellis, Leigh

    2016-01-01

    Reactivation of apoptotic pathways is an attractive strategy for patients with treatment-resistant B-cell lymphoma. The tumor suppressor, p53 is central for apoptotic response to multiple DNA damaging agents used to treat aggressive B-cell lymphomas, including etoposide. It has been demonstrated that etoposide induced DNA damage and therapeutic efficacy is enhanced by combination with inhibitors of the histone methyltransferase, enhancer of zeste homolog 2 (EZH2). Further, EZH2 was identified to regulate cell fate decisions in response to DNA damage. Using B-cell lymphoma cell lines resistant to etoposide induced cell death; we show that p53 is dramatically down regulated and MDMX, a negative regulator of p53, is significantly up regulated. However, these cell lines remain responsive to etoposide mediated DNA damage and exhibit cell cycle inhibition and induction of senescence. Furthermore, chemical inhibition of EZH2 directs DNA damage to a predominant p53 dependent apoptotic response associated with loss of MDMX and BCL-XL. These data provide confirmation of EZH2 in determining cell fate following DNA damage and propose a novel therapeutic strategy for patients with aggressive treatment-resistant B-cell lymphoma. PMID:26973857

  13. The multidrug resistance pumps are inhibited by silibinin and apoptosis induced in K562 and KCL22 leukemia cell lines.

    PubMed

    Noori-Daloii, Mohammad Reza; Saffari, Mojtaba; Raoofian, Reza; Yekaninejad, Mirsaeed; Dinehkabodi, Orkideh Saydi; Noori-Daloii, Ali Reza

    2014-05-01

    Silibinin have been introduced for several years as a potent antioxidant in the field of nutraceuticals. Based on wide persuasive effects of this drug, we have decided to investigate the effects of silibinin on chronic myelogenous leukemia (CML) in vitro models, K562 and KCL22 cell lines. Lactate dehydrogenase (LDH) release, microculture tetrazolium test (MTT assay) and real-time PCR were employed to evaluate the effects of silibinin on cell cytotoxicity, cell proliferation and expression of various multidrug resistance genes in these cell lines, respectively. Our results have shown that presence of silibinin has inhibitory effects on cell proliferation of K562 and KCL22 cell lines. Also, our data indicated that silibinin, in a dose-dependent manner with applying no cytotoxic effects, inhibited cell proliferation and reduced mRNA expression levels of some transporter genes e.g. MDR1, MRP3, MRP2, MRP1, MRP5, MRP4, ABCG2, ABCB11, MRP6 and MRP7. The multifarious in vitro inhibitory effects of silibinin are in agreement with growing body of evidence that silibinin would be an efficient anticancer agent in order to be used in multi-target therapy to prevail the therapeutic hold backs against CML. PMID:24522246

  14. Investigation of doxorubicin for multidrug resistance using a fluorescent cytometric imaging system integrated onto cell culture analog devices

    NASA Astrophysics Data System (ADS)

    Kim, Donghyun; Xu, Hui; Kim, Sung J.; Shuler, Michael L.

    2004-06-01

    An integrated cytometric fluorescent imaging system is developed for characterizing chemical concentration and cellular status in microscale cell culture analog (μCCA) devices. A μCCA is used to evaluate the potential toxicity and efficacy of proposed pharmaceutical treatment of animals or humans. The imaging system, based on discrete optical components, not only provides a robust and compact tool for real-time measurements, but the modularity of the system also offers flexibility to be applicable to various μCCA structures that may be appropriate to various animal or human models. We investigate the dynamics of doxorubicin, a chemotherapeutic agent, on cultured cells in a μCCA using the integrated cytometric fluorescent imaging system. This study incorporates two uteran cancer cell lines representing a sensitive cell type and a multi-drug resistant (MDR) derivative cell line. The ultimate goal is to test the effect of MDR modulators in combination with doxorubicin to kill cancer cells while not causing undue harm to normal cells.

  15. Progesterone interacts with P-glycoprotein in multidrug-resistant cells and in the endometrium of gravid uterus.

    PubMed

    Yang, C P; DePinho, S G; Greenberger, L M; Arceci, R J; Horwitz, S B

    1989-01-15

    P-Glycoprotein (P-GP) plays a pivotal role in maintaining the multidrug-resistant (MDR) phenotype. This membrane glycoprotein is overproduced in MDR cells and the endometrium of the mouse gravid uterus (Arceci, R.J., Croop, J.M., Horwitz, S.B., and Housman, D. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 4350-4354). This latter observation and an interest in endogenous substrates for P-GP led to a study of the interaction of steroids with P-GP found in the endometrium of the mouse gravid uterus and in MDR cells derived from the murine macrophage-like cell J774.2. [3H]Azidopine labeling of P-GP from these two sources was inhibited by various steroids, particularly progesterone. Progesterone also markedly inhibited [3H]vinblastine binding to membrane vesicles prepared from MDR cells, enhanced vinblastine accumulation in MDR cells, and increased the sensitivity of MDR cells to vinblastine. In addition, we have demonstrated that the hydrophobicity of a steroid is important in determining its effect on inhibition of drug binding to P-GP. It is concluded that progesterone, a relatively nontoxic endogenous steroid, interacts with P-GP and is capable of reversing drug resistance in MDR cells. PMID:2562956

  16. Biodegradable cationic polymeric nanocapsules for overcoming multidrug resistance and enabling drug-gene co-delivery to cancer cells

    NASA Astrophysics Data System (ADS)

    Chen, Chih-Kuang; Law, Wing-Cheung; Aalinkeel, Ravikumar; Yu, Yun; Nair, Bindukumar; Wu, Jincheng; Mahajan, Supriya; Reynolds, Jessica L.; Li, Yukun; Lai, Cheng Kee; Tzanakakis, Emmanuel S.; Schwartz, Stanley A.; Prasad, Paras N.; Cheng, Chong

    2014-01-01

    Having unique architectural features, cationic polymeric nanocapsules (NCs) with well-defined covalently stabilized biodegradable structures were generated as potentially universal and safe therapeutic nanocarriers. These NCs were synthesized from allyl-functionalized cationic polylactide (CPLA) by highly efficient UV-induced thiol-ene interfacial cross-linking in transparent miniemulsions. With tunable nanoscopic sizes, negligible cytotoxicity and remarkable degradability, they are able to encapsulate doxorubicin (Dox) with inner cavities and bind interleukin-8 (IL-8) small interfering RNA (siRNA) with cationic shells. The Dox-encapsulated NCs can effectively bypass the P-glycoprotein (Pgp)-mediated multidrug resistance of MCF7/ADR cancer cells, thereby resulting in increased intracellular drug concentration and reduced cell viability. In vitro studies also showed that the NCs loaded with Dox, IL-8 siRNA and both agents can be readily taken up by PC3 prostate cancer cells, resulting in a significant chemotherapeutic effect and/or IL-8 gene silencing.Having unique architectural features, cationic polymeric nanocapsules (NCs) with well-defined covalently stabilized biodegradable structures were generated as potentially universal and safe therapeutic nanocarriers. These NCs were synthesized from allyl-functionalized cationic polylactide (CPLA) by highly efficient UV-induced thiol-ene interfacial cross-linking in transparent miniemulsions. With tunable nanoscopic sizes, negligible cytotoxicity and remarkable degradability, they are able to encapsulate doxorubicin (Dox) with inner cavities and bind interleukin-8 (IL-8) small interfering RNA (siRNA) with cationic shells. The Dox-encapsulated NCs can effectively bypass the P-glycoprotein (Pgp)-mediated multidrug resistance of MCF7/ADR cancer cells, thereby resulting in increased intracellular drug concentration and reduced cell viability. In vitro studies also showed that the NCs loaded with Dox, IL-8 siRNA and both

  17. Cytotoxicity of spermine oxidation products to multidrug resistant melanoma M14 ADR2 cells: sensitization by the MDL 72527 lysosomotropic compound.

    PubMed

    Agostinelli, Enzo; Condello, Maria; Molinari, Agnese; Tempera, Giampiero; Viceconte, Nikenza; Arancia, Giuseppe

    2009-09-01

    It has been confirmed that multidrug resistant (MDR) human melanoma cells are more sensitive than their wild-type counterparts to H2O2 and aldehydes, the products of bovine serum amine oxidase (BSAO)-catalyzed oxidation of spermine. The metabolites formed by BSAO and spermine are more toxic than exogenous H2O2 and acrolein, even though their concentration is lower during the initial phase of incubation due to their more gradual release than the exogenous products. Both wild-type and MDR cells, after pre-treatment with MDL 72527, an inactivator of polyamine oxidase and a lysosomotropic compound, show to be sensitized to subsequent exposure to BSAO/spermine. Evidence of ultrastructural aberrations and acridine orange release from lysosomes is presented in this work that is in favor of the permeabilization of the lysosomal membrane as the major cause of sensitization by MDL 72527. Owing to its lysosomotropic effect, pre-treatment with MDL 72527 amplifies the ability of the metabolites formed from spermine by oxidative deamination to induce cell death. Since it is conceivable that combined treatment with a lysosomotropic compound and BSAO/spermine would be effective against tumor cells, it is of interest to search for such novel compounds, which might be promising for application in a therapeutic setting. PMID:19639169

  18. Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1.

    PubMed

    Kim, Hak-Bong; Lee, Su-Hoon; Um, Jee-Hyun; Oh, Won Keun; Kim, Dong-Wan; Kang, Chi-Dug; Kim, Sun-Hee

    2015-11-01

    The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp. PMID:26416354

  19. Multidrug resistance in chronic myeloid leukaemia: how much can we learn from MDR–CML cell lines?

    PubMed Central

    Rumjanek, Vivian M.; Vidal, Raphael S.; Maia, Raquel C.

    2013-01-01

    The hallmark of CML (chronic myeloid leukaemia) is the BCR (breakpoint cluster region)–ABL fusion gene. CML evolves through three phases, based on both clinical and pathological features: a chronic phase, an accelerated phase and blast crisis. TKI (tyrosine kinase inhibitors) are the treatment modality for patients with chronic phase CML. The therapeutic potential of the TKI imatinib is affected by BCR–ABL dependent an independent mechanisms. Development of MDR (multidrug resistance) contributes to the overall clinical resistance. MDR involves overexpression of ABC -transporters (ATP-binding-cassette transporter) among other features. MDR studies include the analysis of cancer cell lines selected for resistance. CML blast crisis is accompanied by increased resistance to apoptosis. This work reviews the role played by the influx transporter OCT1 (organic cation transporter 1), by efflux ABC transporters, molecules involved in the modulation of apoptosis (p53, Bcl-2 family, CD95, IAPs (inhibitors of apoptosis protein)], Hh and Wnt/β-catenin pathways, cytoskeleton abnormalities and other features described in leukaemic cells of clinical samples and CML cell lines. An MDR cell line, Lucena-1, generated from K562 by stepwise exposure to vincristine, was used as our model and some potential anticancer drugs effective against the MDR cell line and patients’ samples are presented. PMID:24070327

  20. Astragaloside IV reduces the expression level of P-glycoprotein in multidrug-resistant human hepatic cancer cell lines

    PubMed Central

    WANG, PEI-PEI; XU, DU-JUAN; HUANG, CAN; WANG, WEI-PING; XU, WEN-KE

    2014-01-01

    Astragaloside is a saponin widely used in traditional Chinese medicine and has been reported to be a potent multidrug resistance (MDR) reversal agent. The present study investigated the role of astragaloside IV (ASIV) in the regulation of P-glycoprotein (P-gp, encoded by the mdr1 gene) and its effect on the reversal of MDR. The activity of ASIV was evaluated using human hepatic cancer cells Bel-7402 and the corresponding 5-fluorouracil (5-FU) resistant cells Bel-7402/FU. ASIV (0.08 mg/ml) potentiated the cytotoxicity of 5-FU which was demonstrated using the MTT assay on Bel-7402/FU cells. ASIV reduced the expression of P-gp as was revealed by immunocytochemistry. Accumulation and efflux studies with the P-gp substrate, rhodamine 123 (Rh123), demonstrated that ASIV inhibited P-gp-mediated drug efflux. Furthermore, it was demonstrated that ASIV enhanced the drug accumulation of 5-FU using a high performance liquid chromatography (HPLC) assay for drug resistant cells. Furthermore, ASIV may downregulate the expression of P-gp, which was examined using western blot analysis and polymerase chain reaction. In conclusion, the results of the present study indicated that ASIV reverses the drug resistance of Bel-7402/FU cells by downregulating the expression of mdr1. ASIV may represent a potent modulator of P-gp-mediated MDR in hepatic cancer therapy. PMID:24676670

  1. Astragaloside Ⅳ reduces the expression level of P-glycoprotein in multidrug-resistant human hepatic cancer cell lines.

    PubMed

    Wang, Pei-Pei; Xu, Du-Juan; Huang, Can; Wang, Wei-Ping; Xu, Wen-Ke

    2014-06-01

    Astragaloside is a saponin widely used in traditional Chinese medicine and has been reported to be a potent multidrug resistance (MDR) reversal agent. The present study investigated the role of astragaloside Ⅳ (ASIV) in the regulation of P-glycoprotein (P-gp, encoded by the mdr1 gene) and its effect on the reversal of MDR. The activity of ASIV was evaluated using human hepatic cancer cells Bel-7402 and the corresponding 5-fluorouracil (5-FU) resistant cells Bel-7402/FU. ASIV (0.08 mg/ml) potentiated the cytotoxicity of 5-FU which was demonstrated using the MTT assay on Bel-7402/FU cells. ASIV reduced the expression of P-gp as was revealed by immunocytochemistry. Accumulation and efflux studies with the P-gp substrate, rhodamine 123 (Rh123), demonstrated that ASIV inhibited P-gp-mediated drug efflux. Furthermore, it was demonstrated that ASⅣ enhanced the drug accumulation of 5-FU using a high performance liquid chromatography (HPLC) assay for drug resistant cells. Furthermore, ASIV may downregulate the expression of P-gp, which was examined using western blot analysis and polymerase chain reaction. In conclusion, the results of the present study indicated that ASIV reverses the drug resistance of Bel-7402/FU cells by downregulating the expression of mdr1. ASIV may represent a potent modulator of P-gp-mediated MDR in hepatic cancer therapy. PMID:24676670

  2. Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1

    PubMed Central

    Kim, Hak-Bong; Lee, Su-Hoon; Um, Jee-Hyun; Oh, Won Keun; Kim, Dong-Wan; Kang, Chi-Dug; Kim, Sun-Hee

    2015-01-01

    The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp. PMID:26416354

  3. Chromosome breakage at a major fragile site associated with P-glycoprotein gene amplification in multidrug-resistant CHO cells.

    PubMed Central

    Kuo, M T; Vyas, R C; Jiang, L X; Hittelman, W N

    1994-01-01

    Recent studies of several drug-resistant Chinese hamster cell lines suggested that a breakage-fusion-bridge mechanism is frequently involved in the amplification of drug resistance genes. These observations underscore the importance of chromosome breakage in the initiation of DNA amplification in mammalian cells. However, the mechanism of this breakage is unknown. Here, we propose that the site of chromosome breakage consistent with the initial event of P-glycoprotein (P-gp) gene amplification via the breakage-fusion-bridge cycle in three independently established multidrug-resistant CHO cells was located at 1q31. This site is a major chromosome fragile site that can be induced by methotrexate and aphidicolin treatments. Pretreatments of CHO cells with methotrexate or aphidicolin enhanced the frequencies of resistance to vinca alkaloid and amplification of the P-gp gene. These observations suggest that chromosome fragile sites play a pivotal role in DNA amplification in mammalian cells. Our data are also consistent with the hypothesis that gene amplification can be initiated by stress-induced chromosome breakage that is independent of modes of action of cytotoxic agents. Drug-resistant variants may arise by their growth advantage due to overproduction of cellular target molecules via gene amplification. Images PMID:7913517

  4. Chromosome breakage at a major fragile site associated with P-glycoprotein gene amplification in multidrug-resistant CHO cells.

    PubMed

    Kuo, M T; Vyas, R C; Jiang, L X; Hittelman, W N

    1994-08-01

    Recent studies of several drug-resistant Chinese hamster cell lines suggested that a breakage-fusion-bridge mechanism is frequently involved in the amplification of drug resistance genes. These observations underscore the importance of chromosome breakage in the initiation of DNA amplification in mammalian cells. However, the mechanism of this breakage is unknown. Here, we propose that the site of chromosome breakage consistent with the initial event of P-glycoprotein (P-gp) gene amplification via the breakage-fusion-bridge cycle in three independently established multidrug-resistant CHO cells was located at 1q31. This site is a major chromosome fragile site that can be induced by methotrexate and aphidicolin treatments. Pretreatments of CHO cells with methotrexate or aphidicolin enhanced the frequencies of resistance to vinca alkaloid and amplification of the P-gp gene. These observations suggest that chromosome fragile sites play a pivotal role in DNA amplification in mammalian cells. Our data are also consistent with the hypothesis that gene amplification can be initiated by stress-induced chromosome breakage that is independent of modes of action of cytotoxic agents. Drug-resistant variants may arise by their growth advantage due to overproduction of cellular target molecules via gene amplification. PMID:7913517

  5. Overexpression of the cystic fibrosis transmembrane conductance regulator in NIH 3T3 cells lowers membrane potential and intracellular pH and confers a multidrug resistance phenotype.

    PubMed Central

    Wei, L Y; Stutts, M J; Hoffman, M M; Roepe, P D

    1995-01-01

    Because of the similarities between the cystic fibrosis transmembrane conductance regulator (CFTR) and multidrug resistance (MDR) proteins, recent observations of decreased plasma membrane electrical potential (delta psi) in cells overexpressing either MDR protein or the CFTR, and the effects of delta psi on passive diffusion of chemotherapeutic drugs, we have analyzed chemotherapeutic drug resistance for NIH 3T3 cells overexpressing different levels of functional CFTR. Three separate clones not previously exposed to chemotherapeutic drugs exhibit resistance to doxorubicin, vincristine, and colchicine that is similar to MDR transfectants not previously exposed to chemotherapeutic drugs. Two other clones expressing lower levels of CFTR are less resistant. As shown previously these clones exhibit decreased plasma membrane delta psi similar to MDR transfectants, but four of five exhibit mildly acidified intracellular pH in contrast to MDR transfectants, which are in general alkaline. Thus the MDR protein and CFTR-mediated MDR phenotypes are distinctly different. Selection of two separate CFTR clones on either doxorubicin or vincristine substantially increases the observed MDR and leads to increased CFTR (but not measurable MDR or MRP) mRNA expression. CFTR overexpressors also exhibit a decreased rate of 3H -vinblastine uptake. These data reveal a new and previously unrecognized consequence of CFTR expression, and are consistent with the hypothesis that membrane depolarization is an important determinant of tumor cell MDR. Images FIGURE 1 FIGURE 3 FIGURE 6 PMID:8519988

  6. Biodegradable cationic polymeric nanocapsules for overcoming multidrug resistance and enabling drug-gene co-delivery to cancer cells.

    PubMed

    Chen, Chih-Kuang; Law, Wing-Cheung; Aalinkeel, Ravikumar; Yu, Yun; Nair, Bindukumar; Wu, Jincheng; Mahajan, Supriya; Reynolds, Jessica L; Li, Yukun; Lai, Cheng Kee; Tzanakakis, Emmanuel S; Schwartz, Stanley A; Prasad, Paras N; Cheng, Chong

    2014-01-01

    Having unique architectural features, cationic polymeric nanocapsules (NCs) with well-defined covalently stabilized biodegradable structures were generated as potentially universal and safe therapeutic nanocarriers. These NCs were synthesized from allyl-functionalized cationic polylactide (CPLA) by highly efficient UV-induced thiol-ene interfacial cross-linking in transparent miniemulsions. With tunable nanoscopic sizes, negligible cytotoxicity and remarkable degradability, they are able to encapsulate doxorubicin (Dox) with inner cavities and bind interleukin-8 (IL-8) small interfering RNA (siRNA) with cationic shells. The Dox-encapsulated NCs can effectively bypass the P-glycoprotein (Pgp)-mediated multidrug resistance of MCF7/ADR cancer cells, thereby resulting in increased intracellular drug concentration and reduced cell viability. In vitro studies also showed that the NCs loaded with Dox, IL-8 siRNA and both agents can be readily taken up by PC3 prostate cancer cells, resulting in a significant chemotherapeutic effect and/or IL-8 gene silencing. PMID:24326457

  7. Silencing of ABCG2 by MicroRNA-3163 Inhibits Multidrug Resistance in Retinoblastoma Cancer Stem Cells.

    PubMed

    Jia, Ming; Wei, Zhenhua; Liu, Peng; Zhao, Xiaoli

    2016-06-01

    To investigate the function and regulation mechanism of ATP-binding cassette, subfamily G, member 2 (ABCG2) in retinoblastoma cancer stem cells (RCSCs), a long-term culture of RCSCs from WERI-Rb1 cell line was successfully established based on the high expression level of ABCG2 on the surface of RCSCs. To further explore the molecular mechanism of ABCG2 on RCSCs, a microRNA that specifically targets ABCG2 was predicted. Subsequently, miR-3163 was selected and confirmed as the ABCG2-regulating microRNA. Overexpression of miR-3163 led to a significant decrease in ABCG2 expression. Additionally, ABCG2 loss-of-function induced anti-proliferation and apoptosis-promoting functions in RCSCs, and multidrug resistance to cisplatin, carboplatin, vincristine, doxorubicin, and etoposide was greatly improved in these cells. Our data suggest that miR-3163 has a significant impact on ABCG2 expression and can influence proliferation, apoptosis, and drug resistance in RCSCs. This work may provide new therapeutic targets for retinoblastoma. PMID:27247490

  8. Silencing of ABCG2 by MicroRNA-3163 Inhibits Multidrug Resistance in Retinoblastoma Cancer Stem Cells

    PubMed Central

    Wei, Zhenhua; Liu, Peng; Zhao, Xiaoli

    2016-01-01

    To investigate the function and regulation mechanism of ATP-binding cassette, subfamily G, member 2 (ABCG2) in retinoblastoma cancer stem cells (RCSCs), a long-term culture of RCSCs from WERI-Rb1 cell line was successfully established based on the high expression level of ABCG2 on the surface of RCSCs. To further explore the molecular mechanism of ABCG2 on RCSCs, a microRNA that specifically targets ABCG2 was predicted. Subsequently, miR-3163 was selected and confirmed as the ABCG2-regulating microRNA. Overexpression of miR-3163 led to a significant decrease in ABCG2 expression. Additionally, ABCG2 loss-of-function induced anti-proliferation and apoptosis-promoting functions in RCSCs, and multidrug resistance to cisplatin, carboplatin, vincristine, doxorubicin, and etoposide was greatly improved in these cells. Our data suggest that miR-3163 has a significant impact on ABCG2 expression and can influence proliferation, apoptosis, and drug resistance in RCSCs. This work may provide new therapeutic targets for retinoblastoma. PMID:27247490

  9. New mouse xenograft model modulated by tumor-associated fibroblasts for human multi-drug resistance in cancer

    PubMed Central

    MA, YAN; LIN, ZHIQIANG; FALLON, JOHN K.; ZHAO, QIANG; LIU, DAN; WANG, YONGJUN; LIU, FENG

    2015-01-01

    We developed an MDR tumor model that is modulated by tumor-associated fibroblasts. Studies on proliferation of tumor cell lines including paclitaxel-sensitive and resistant cell lines were performed. The expressions of P-gp and α-smooth muscle actin (α-SMA) antigen were evaluated by immunohistochemistry and western blot analysis. Quantitative P-gp analyses of different cell lines were accomplished by nanoUPLC-MS/MS. Tumor cell colony formation assay and established xenograft model was used to investigate the relationship between P-gp expression, fibroblast levels and tumorigenesis. The mouse xenograft model was developed after co-inoculation with MDR tumor cells and NIH/3T3 fibroblast cells. There was no correlation between tumorigenesis in vivo and the growth rate of cells in vitro. The proliferation among different cell lines had no significant differences, but the P-gp expression and tumor growth in the xenograft model were fairly different. P-gp determination and α-SMA immunofluorescence staining clarified the relationship between P-gp expression, fibroblast levels and tumorigenesis. It was more difficult for tumor cells with higher P-gp levels to recruit fibroblasts in vivo, resulting in lower tumorigenesis due to the lack of structural and chemical support during tumor progression. In the established paclitaxel-resistant mouse xenograft model, no obvious antitumor effect was observed after Taxol treatment, but a significant decrease in tumor size for the group treated with gemcitabine sensitive to the model. The results show that the added fibroblasts do not disturb the applicability of the model in MDR. Therefore, this mouse xenograft MDR model could serve as an effective tool for MDR research. PMID:26352907

  10. [Proteins in cancer multidrug resistance].

    PubMed

    Popęda, Marta; Płuciennik, Elżbieta; Bednarek, Andrzej K

    2014-01-01

    Multidrug Resistance (MDR) is defined as insensitivity to administered medicines that are structurally unrelated and have different molecular targets. Cancers possess numerous mechanisms of drug resistance, involving various aspects of cell biology. A pivotal role in this phenomenon is played by proteins--enzymatic or structural parts of the cell. Membrane transporters, including the main members of ABC protein family--P-gp, MRP1 and BCRP, as well as LRP, which builds structure of vaults, determine the multidrug-resistant phenotype by decreasing drug concentration within the cell or modifying its distribution to intracellular compartments. The π isoform of protein enzyme--glutathione S-transferase (GSTP-1), is responsible for excessive intensity of detoxification of cytostatics. A common example of altered drug target site that does not respond to chemotherapy is topoisomerase II α (TopoIIa). Alterations of programmed cell death result from expression of metallothionein (MT)--inhibitor of the process, and cytokeratin 18 (CK18), which, if in high concentration, also prevents apoptosis of cells. Several methods of decreasing activity of these proteins have been developed, aiming to overcome MDR in cancer cells. However, for a variety of reasons, their clinical suitability is still very low, leading to continuous increase in death rate among patients. This paper presents current state of knowledge on the most important examples of proteins responsible for MDR of cancer cells and molecular mechanisms of their action. PMID:24864112

  11. A retrovirus carrying an MDR1 cDNA confers multidrug resistance and polarized expression of P-glycoprotein in MDCK cells.

    PubMed Central

    Pastan, I; Gottesman, M M; Ueda, K; Lovelace, E; Rutherford, A V; Willingham, M C

    1988-01-01

    A full-length cDNA for the human multidrug resistance gene 1 (MDR1) has been inserted into a retroviral vector containing a murine Harvey sarcoma virus from which the viral oncogene was deleted. Ecotropic and amphotropic virus was produced after transfection of this vector into psi-2 and PA-12 packaging cell lines. This virus conferred the full phenotype of multidrug resistance on mouse and human cell lines. Viral titers of up to 2 X 10(5) drug-resistant colonies per ml were observed. Infected cells became resistant to colchicine, vinblastine, doxorubicin, VP16 (etoposide), and puromycin, but not cisplatin, indicating that the presence of the human MDR1 gene is sufficient to cause multidrug resistance. When the dog kidney cell line MDCK was infected with the MDR1 virus, P-glycoprotein was expressed in a polarized manner on the upper surface of the cells, showing that the cloned cDNA also encodes information for polarized expression of P-glycoprotein. The MDR1 virus should be useful for introducing this drug resistance gene into a variety of cell types for biological experiments in vitro and in vivo. Images PMID:2898143

  12. Yeast ABC proteins involved in multidrug resistance.

    PubMed

    Piecuch, Agata; Obłąk, Ewa

    2014-03-01

    Pleiotropic drug resistance is a complex phenomenon that involves many proteins that together create a network. One of the common mechanisms of multidrug resistance in eukaryotic cells is the active efflux of a broad range of xenobiotics through ATP-binding cassette (ABC) transporters. Saccharomyces cerevisiae is often used as a model to study such activity because of the functional and structural similarities of its ABC transporters to mammalian ones. Numerous ABC transporters are found in humans and some are associated with the resistance of tumors to chemotherapeutics. Efflux pump modulators that change the activity of ABC proteins are the most promising candidate drugs to overcome such resistance. These modulators can be chemically synthesized or isolated from natural sources (e.g., plant alkaloids) and might also be used in the treatment of fungal infections. There are several generations of synthetic modulators that differ in specificity, toxicity and effectiveness, and are often used for other clinical effects. PMID:24297686

  13. Epoxylathyrol Derivatives: Modulation of ABCB1-Mediated Multidrug Resistance in Human Colon Adenocarcinoma and Mouse T-Lymphoma Cells.

    PubMed

    Matos, Ana M; Reis, Mariana; Duarte, Noélia; Spengler, Gabriella; Molnár, Joseph; Ferreira, Maria-José U

    2015-09-25

    Epoxyboetirane A (1), a macrocyclic diterpene that was found to be inactive as an ABCB1 modulator, was submitted to several chemical transformations, aimed at generating a series of compounds with improved multidrug resistance (MDR)-modifying activity. Overall, 23 new derivatives were prepared, in addition to the already reported epoxylathyrol (2) and methoxyboetirol (3). Their anti-MDR potential was assessed through both functional and chemosensitivity assays on resistant human colon adenocarcinoma and human ABCB1-gene transfected L5178Y mouse lymphoma cells. Structure-activity relationship analysis showed that different substitution patterns led to distinct ABCB1 inhibitory activities, although intrinsic cellular characteristics seemed to influence the modulatory behavior. A considerable enhancement in MDR-modifying activity was observed for aromatic compounds in both cell lines, particularly in 3,17-disubstituted esters derived from 3, a Payne-rearranged Michael adduct of 2. All compounds tested were revealed to interact synergistically with doxorubicin, and ATPase inhibition by three representative MDR-modifying compounds was also investigated. On account of its outstanding ABCB1 inhibitory activity at 0.2 μM and overall remarkable bioactive profile, methoxyboetirane B (22) was found to be a new promising lead for MDR-reversing anticancer drug development. PMID:26331763

  14. Reversal of multidrug resistance of hepatocellular carcinoma cells by metformin through inhibiting NF-κB gene transcription

    PubMed Central

    Wu, Wei; Yang, Jun-Ling; Wang, Yi-Lang; Wang, Han; Yao, Min; Wang, Li; Gu, Juan-Juan; Cai, Yin; Shi, Yun; Yao, Deng-Fu

    2016-01-01

    AIM To interfere with the activation of nuclear factor-κB (NF-κB) with metformin and explore its effect in reversing multidrug resistance (MDR) of hepatocellular carcinoma (HCC) cells. METHODS Expression of P-glycoprotein (P-gp) and NF-κB in human HepG2 or HepG2/adriamycin (ADM) cells treated with pCMV-NF-κB-small interference RNA (siRNA) with or without metformin, was analyzed by Western blot or fluorescence quantitative PCR. Cell viability was tested by CCK-8 assay. Cell cycle and apoptosis were measured by flow cytometry and Annexin-V-PE/7-AnnexinV apoptosis detection double staining assay, respectively. RESULTS P-gp overexpression in HepG2 and HepG2/ADM cells was closely related to mdr1 mRNA (3.310 ± 0.154) and NF-κB mRNA (2.580 ± 0.040) expression. NF-κB gene transcription was inhibited by specific siRNA with significant down-regulation of P-gp and enhanced HCC cell chemosensitivity to doxorubicin. After pretreatment with metformin, HepG2/ADM cells were sensitized to doxorubicin and P-gp was decreased through the NF-κB signaling pathway. The synergistic effect of metformin and NF-κB siRNA were found in HepG2/ADM cells with regard to proliferation inhibition, cell cycle arrest and inducing cell apoptosis. CONCLUSION Metformin via silencing NF-κB signaling could effectively reverse MDR of HCC cells by down-regulating MDR1/P-gp expression.

  15. Visual detection of multidrug resistance gene in living cell using the molecular beacon imaging

    NASA Astrophysics Data System (ADS)

    Zhou, Qiumei; Ma, Yi; Gu, Yueqing

    2014-09-01

    A major problem in cancer treatment is the development of resistance to chemotherapeutic agents in tumor cells. Detection of effective prognostic biomarkers and targets are of crucial importance to the management of individualized therapies. However, quantitative analysis of the drug resistance gene had been difficult because of technical limitations. In this study, we designed and used a special hairpin deoxyribonucleic acid (DNA), which served as a beacon for detecting human drug resistance indicater. Upon hybridizing with the target mRNA, the hairpin DNA modified gold nanoparticle beacons (hDAuNP beacons) release the fluorophores attached at 5'end of the oligonucleotide sequence. The fluorescence properties of the beacon before and after the hybridization with the complementary DNA were confirmed in vitro. The hDAuNP beacons could be taken up by living cells with low inherent cytotoxicity and higher stability. hDAuNP beacon imaged by confocal laser scanning microscopy to detect the resistance gene expression. The detected fluorescence in MCF7and MCF7/ADR cells correlates with the specific drug resistance gene expression, which is consistent with the result from Q-PCR. Thus, this approach overcame many of the challenges of previous techniques by creating highly sensitive and effective intracellular probes for monitoring gene expression.

  16. Cytotoxicity of Elaoephorbia drupifera and other Cameroonian medicinal plants against drug sensitive and multidrug resistant cancer cells

    PubMed Central

    2013-01-01

    Background Multidrug resistance (MDR) is a major hurdle for cancer treatment worldwide and accounts for chemotherapy failure in over 90% of patients with metastatic cancer. Evidence of the cytotoxicity of Cameroonian plants against cancer cell lines including MDR phenotypes is been intensively and progressively provided. The present work was therefore designed to evaluate the cytotoxicity of the methanol extracts of twenty-two Cameroonian medicinal plants against sensitive and MDR cancer cell lines. Methods The methanol maceration was used to obtain the crude plant extracts whilst the cytotoxicity of the studied extracts was determined using a resazurin reduction assay. Results A preliminary assay on leukemia CCRF-CEM cells at 40 μg/mL shows that six of the twenty plant extract were able to enhance less than 50% of the growth proliferation of CCRF-CEM cells. These include Crinum zeylanicum (32.22%), Entada abyssinica (34.67%), Elaoephorbia drupifera (35.05%), Dioscorea bulbifera (45.88%), Eremomastax speciosa (46.07%) and Polistigma thonningii (45.11%). Among these six plants, E. drupifera showed the best activity with IC50 values below or around 30 μg/mL against the nine tested cancer cell lines. The lowest IC50 value of 8.40 μg/mL was recorded with the extract of E. drupifera against MDA-MB231 breast cancer cell line. The IC50 values below 10 μg/mL were recorded with the extracts of E. drupifera against MDA-MB231 breast cancer cells, C. zeylanicum against HCT116 p53+/+ and HCT116p53-/- colon cancer cells and E. abyssinica against HCT116 p53+/+ cells. Conclusion The results of the present study provide evidence of the cytotoxic potential of some Cameroonian medicinal plants and a baseline information for the potential use of Elaoephorbia drupifera in the treatment of sensitive and drug-resistant cancer cell lines. PMID:24088184

  17. B4GALT family mediates the multidrug resistance of human leukemia cells by regulating the hedgehog pathway and the expression of p-glycoprotein and multidrug resistance-associated protein 1

    PubMed Central

    Zhou, H; Ma, H; Wei, W; Ji, D; Song, X; Sun, J; Zhang, J; Jia, L

    2013-01-01

    β-1, 4-Galactosyltransferase gene (B4GALT) family consists of seven members, which encode corresponding enzymes known as type II membrane-bound glycoproteins. These enzymes catalyze the biosynthesis of different glycoconjugates and saccharide structures, and have been recognized to be involved in various diseases. In this study, we sought to determine the expressional profiles of B4GALT family in four pairs of parental and chemoresistant human leukemia cell lines and in bone marrow mononuclear cells (BMMC) of leukemia patients with multidrug resistance (MDR). The results revealed that B4GALT1 and B4GALT5 were highly expressed in four MDR cells and patients, altered levels of B4GALT1 and B4GALT5 were responsible for changed drug-resistant phenotype of HL60 and HL60/adriamycin-resistant cells. Further data showed that manipulation of these two gene expression led to increased or decreased activity of hedgehog (Hh) signaling and proportionally mutative expression of p-glycoprotein (P-gp) and MDR-associated protein 1 (MRP1) that are both known to be related to MDR. Thus, we propose that B4GALT1 and B4GALT5, two members of B4GALT gene family, are involved in the development of MDR of human leukemia cells, probably by regulating the activity of Hh signaling and the expression of P-gp and MRP1. PMID:23744354

  18. P-glycoprotein antagonists confer synergistic sensitivity to short-chain ceramide in human multidrug resistant cancer cells

    PubMed Central

    Chapman, Jacqueline V.; Gouazé-Andersson, Valérie; Karimi, Ramin; Messner, Maria C; Cabot, Myles C.

    2011-01-01

    P-glycoprotein (P-gp) antagonists inhibit ceramide metabolism at the juncture of glycosylation. The purpose of this study was to test whether targeting P-gp would be a viable alternative to targeting glucosylceramide synthase (GCS) for enhancing ceramide cytotoxicity. A2780 wild-type, and multidrug resistant 2780AD and NCI/ADR-RES human ovarian cancer cell lines and the cell-permeable ceramide analog, C6-ceramide (C6-cer), were employed. Compared to P-gp-poor A2780 cells, P-gp-rich 2780AD cells converted 3.7-fold more C6-cer to nontoxic C6-glucosylceramide (C6-GC), whereas cell-free GCS activities were equal. 2780AD cells displayed resistance to C6-cer (10 μM) that was reversed by inclusion of the P-gp antagonist tamoxifen (5 μM) but not by inclusion of a GCS inhibitor. Co-administration of C6-cer and P-gp antagonists was also effective in NCI/ADR-RES cells. For example, C6-cer, VX-710 (Biricodar), and cyclosporin A (cyc A) exposure resulted in viabilities of ~90% of control; however, C6-cer/VX-710 and C6-cer/cyc A additions were synergistic and resulted in viabilities of 22 and 17%, respectively. Further, whereas C6-ceramide and cyc A imparted 1.5- and zero-fold increases in caspase 3/7 activity, the combination produced a 3.5-fold increase. Although the upstream elements of cell death have not been elucidated, the novel C6-ceramide/P-gp antagonist combination merits further study and assessment of clinical translational potential. PMID:21396934

  19. Nitrogen monoxide (NO)-mediated iron release from cells is linked to NO-induced glutathione efflux via multidrug resistance-associated protein 1

    PubMed Central

    Watts, Ralph N.; Hawkins, Clare; Ponka, Prem; Richardson, Des R.

    2006-01-01

    Nitrogen monoxide (NO) plays a role in the cytotoxic mechanisms of activated macrophages against tumor cells by inducing iron (Fe) release. We have shown that NO-mediated Fe efflux from cells required glutathione (GSH), and we have hypothesized that a GS–Fe–NO complex was released. Hence, we studied the role of the GSH-conjugate transporter multidrug resistance-associated protein 1 (MRP1) in NO-mediated Fe efflux. MCF7-VP cells overexpressing MRP1 exhibited a 3- to 4-fold increase in NO-mediated 59Fe and GSH efflux compared with WT cells (MCF7-WT) over 4 h. Similar results were found for other MRP1-overexpressing cell types but not those expressing another drug efflux pump, P-glycoprotein. NO-mediated 59Fe and GSH efflux were temperature- and energy-dependent and were significantly decreased by the GSH-depleting agent and MRP1 transport inhibitor l-buthionine-[S,R]-sulfoximine. Other MRP1 inhibitors, MK571, probenecid, and difloxacin, significantly inhibited NO-mediated 59Fe release. EPR spectroscopy demonstrated the dinitrosyl-dithiol-Fe complex (DNIC) peak in NO-treated cells was increased by MRP1 inhibitors, indicating inhibited DNIC transport from cells. The extent of DNIC accumulation correlated with the ability of MRP1 inhibitors to prevent NO-mediated 59Fe efflux. MCF7-VP cells were more sensitive than MCF7-WT cells to growth inhibition by effects of NO, which was potentiated by l-buthionine-[S,R]-sulfoximine. These data indicate the importance of GSH in NO-mediated inhibition of proliferation. Collectively, NO stimulates Fe and GSH efflux from cells via MRP1. Active transport of NO by MRP1 overcomes diffusion that is inefficient and nontargeted, which has broad ramifications for understanding NO biology. PMID:16679408

  20. Differential growth inhibition of isoquinolinesulfonamides H-8 and H-7 towards multidrug-resistant P388 murine leukaemia cells.

    PubMed Central

    Ido, M.; Nagao, Y.; Higashigawa, M.; Shibata, T.; Taniguchi, K.; Hamazaki, M.; Sakurai, M.

    1991-01-01

    The effects of N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide (H-8) and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) on the growth of P388 and its multidrug-resistant (MDR) variants were examined with the objective of assessing the possible changes in cyclic nucleotide-dependent protein kinases and protein kinase C-mediated pathways associated with MDR. H-8, an inhibitor of cyclic nucleotide-dependent protein kinases, inhibited the growth of the parental P388 murine leukaemic cells, but not that of MDR variants up to 200 microM. However the growth of both drug-sensitive and resistant cell lines were uniformly inhibited by H-7. Both the cytotoxic and cytokinetic results revealed that the growth-inhibition by H-8 of P388 cells is mainly due to a blockade of cell-cycle progression rather than due to a killing of cells. The degree of resistance to H-8 was directly proportional to their extent of resistance to vincristine, adriamycin, and 4'-demethylepipodophyllotoxin-9-(4,6-O-ethylidene)-beta-D-gluco pyr anoside (VP-16) and to that of the expression of P-glycoprotein. These findings raised the possibility that P-glycoprotein might play a role in the cross-resistance to H-8. To test the hypothesis, we examined the effect of H-8 on the binding of 3H-vincristine to membrane fraction isolated from P388/VCR-600 cells and on the enhancement of cytotoxicity to anticancer drugs in MDR cells. H-8 did not have any influences on these reactions. Thus, the cross-resistance to H-8 may be mediated through a mechanism different from an overexpression of P-glycoprotein.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 PMID:1684908

  1. Modulation of P-glycoprotein-mediated multidrug resistance in K562 leukemic cells by indole-3-carbinol

    SciTech Connect

    Arora, Annu; Seth, Kavita; Kalra, Neetu; Shukla, Yogeshwer . E-mail: yogeshwer_shukla@hotmail.com

    2005-02-01

    Resistance to chemotherapeutic drugs is one of the major problems in the treatment of cancer. P-glycoprotein (P-gp) encoded by the mdr gene is a highly conserved protein, acts as a multidrug transporter, and has a major role in multiple drug resistance (MDR). Targeting of P-gp by naturally occurring compounds is an effective strategy to overcome MDR. Indole-3-carbinol (I3C), a glucosinolates present in cruciferous vegetables, is a promising chemopreventive agent as it is reported to possess antimutagenic, antitumorigenic, and antiestrogenic properties in experimental studies. In the present investigation, the potential of I3C to modulate P-gp expression was evaluated in vinblastine (VBL)-resistant K562 human leukemic cells. The resistant K562 cells (K562/R10) were found to be cross-resistant to vincristine (VCR), doxorubicin (DXR), and other antineoplastic agents. I3C at a nontoxic dose (10 x 10{sup -3} M) enhanced the cytotoxic effects of VBL time dependently in VBL-resistant human leukemia (K562/R10) cells but had no effect on parent-sensitive cells (K562/S). The Western blot analysis of K 562/R 10 cells showed that I3C downregulates the induced levels of P-gp in resistant cells near to normal levels. The quantitation of immunocytochemically stained K562/R10 cells showed 24%, 48%, and 80% decrease in the levels of P-gp by I3C for 24, 48, and 72 h of incubation. The above features thus indicate that I3C could be used as a novel modulator of P-gp-mediated multidrug resistance in vitro and may be effective as a dietary adjuvant in the treatment of MDR cancers.

  2. Psoralen reverses the P-glycoprotein-mediated multidrug resistance in human breast cancer MCF-7/ADR cells.

    PubMed

    Jiang, Jingru; Wang, Xiaohong; Cheng, Kai; Zhao, Wanzhong; Hua, Yitong; Xu, Chengfeng; Yang, Zhenlin

    2016-06-01

    The resistance of cancer to chemotherapeutic agents is a major obstacle during chemotherapy. Clinical multidrug resistance (MDR) is commonly mediated by membrane drug efflux pumps, including ATP‑binding cassette subfamily B member 1, also termed P-glycoprotein (P-gp). P-gp is a membrane transporter encoded by the MDR1 gene. The current study aimed to investigate the impact of psoralen on the expression and function of P‑gp. The 10% inhibitory concentration (IC10) of psoralen, and its capacity to reduce MDR in adriamycin (ADR)‑resistant MCF‑7/ADR cells were determined using MTT assay. The ability of psoralen to modulate the transport activity of P‑gp in MCF‑7/ADR cells was evaluated by measuring the accumulation and efflux of rhodamine 123 (Rh 123) and adriamycin with flow cytometry. The present study evaluated the mRNA level of MDR1 in MCF‑7 and MCF‑7/ADR cells treated with psoralen using reverse transcription-quantitative polymerase chain reaction. The protein expression level of P‑gp was examined by western blot analysis. The current study demonstrated that the IC10 of psoralen in MCF‑7/ADR cells was 8 µg/ml. At 8 µg/ml, psoralen reduced MDR and the sensitivity of the MCF‑7/ADR cells to ADR compared with untreated cells. Additionally, psoralen significantly increased the intracellular accumulation of ADR and Rh 123. However, the IC10 of psoralen did not affect the protein expression levels of P‑gp or mRNA levels of MDR1 (P>0.05). Psoralen reduces MDR by inhibiting the efflux function of P‑gp, which may be important for increasing the efficiency of chemotherapy and improving the clinical protocols aiming to reverse P-gp-mediated MDR. PMID:27082231

  3. Effect of curcumin on human colon cancer multidrug resistance in vitro and in vivo

    PubMed Central

    Lu, Wei-Dong; Qin, Yong; Yang, Chuang; Li, Lei

    2013-01-01

    OBJECTIVE: To determine whether curcumin reverses the multidrug resistance of human colon cancer cells in vitro and in vivo. METHODS: In a vincristine-resistant cell line of human colon cancer, the cell viability of curcumin-treated cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Rhodamine123 efflux was evaluated to detect P-glycoprotein transporter activity, and expression of the multidrug resistance protein 1 and survivin genes was analyzed by reverse transcription polymerase chain reaction and western blotting. In addition, xenograft mouse tumors were grown and treated with curcumin. The morphology of the xenografts was investigated by hematoxylin-eosin staining. The in vivo expression of the multidrug resistance gene and P-glycoprotein and survivin genes and proteins was observed using reverse transcription-polymerase chain reaction and western blotting, respectively. RESULTS: Curcumin was not obviously toxic to the vincristine-resistant human colon cancer cells at concentrations less than 25 μM, but the growth of cells was significantly inhibited. At concentrations greater than 25 μM, curcumin was toxic in a concentration-dependent manner. The sensitivity of cells to vincristine, cisplatin, fluorouracil, and hydroxycamptothecin was enhanced, intracellular Rhodamine123 accumulation was increased (p<0.05), and the expression of the multidrug resistance gene and P-glycoprotein were significantly suppressed (p<0.05). The combination of curcumin and vincristine significantly inhibited xenograft growth. The expression of the multidrug resistance protein 1 and survivin genes was significantly reduced in xenografts of curcumin-treated mice and mice treated with both curcumin and vincristine relative to control mice. CONCLUSION: Curcumin has strong reversal effects on the multidrug resistance of human colon carcinoma in vitro and in vivo. PMID:23778405

  4. Molecular/cytogenetic alterations accompanying the development of multidrug resistance in the J774.2 murine cell line.

    PubMed

    Slovak, M L; Lothstein, L; Horwitz, S B; Trent, J M

    1988-07-01

    Mouse macrophage-like J774.2 cells were selected for resistance to colchicine and examined by molecular/cytogenetic analysis to determine whether the acquisition of the multidrug resistant (mdr) phenotype was associated with specific chromosomal rearrangements. Cytogenetic studies of the J774.2 parental and two colchicine-resistant (CLCR) sublines--J7.Cl-30 (770-fold CLCR) and J7.Cl-100 (2500-fold CLCR)--demonstrated specific numeric and structural karyotypic alterations accompanying the emergence of mdr. The parental cells demonstrated a modal chromosome number of 63, while the modal number of the J7.Cl-30 subline was 53. The most striking difference between the parental and J7.Cl-30 subline was the presence of an average of 60 double minutes (DMs) per cell in the CLCR cells. The 2500-fold resistant J7.Cl-100 subline displayed a modal number of 50, which included structural rearrangements involving chromosomes 2 and 7 and concomitant replacement of DMs by a homogeneously staining region (HSR). Southern blotting analysis demonstrated a approximately 35-fold amplification of P-glycoprotein homologous sequences in the J7.Cl-30 subline and approximately 70-fold amplification in the J7.Cl-100 subline. Chromosomal in situ hybridization localized the amplified P-glycoprotein sequences to DMs (J7.Cl-30) and the HSR (J7.Cl-100) in these CLCR sublines. Our results suggest that CLCR in J774.2 cells results from overexpression of P-glycoprotein via gene amplification which was accompanied by chromosomal evolution from DMs to an HSR. PMID:2899184

  5. Consequences of cell-to-cell P-glycoprotein transfer on acquired multidrug resistance in breast cancer: a cell population dynamics model

    PubMed Central

    2011-01-01

    Background Cancer is a proliferation disease affecting a genetically unstable cell population, in which molecular alterations can be somatically inherited by genetic, epigenetic or extragenetic transmission processes, leading to a cooperation of neoplastic cells within tumoural tissue. The efflux protein P-glycoprotein (P-gp) is overexpressed in many cancer cells and has known capacity to confer multidrug resistance to cytotoxic therapies. Recently, cell-to-cell P-gp transfers have been shown. Herein, we combine experimental evidence and a mathematical model to examine the consequences of an intercellular P-gp trafficking in the extragenetic transfer of multidrug resistance from resistant to sensitive cell subpopulations. Methodology and Principal Findings We report cell-to-cell transfers of functional P-gp in co-cultures of a P-gp overexpressing human breast cancer MCF-7 cell variant, selected for its resistance towards doxorubicin, with the parental sensitive cell line. We found that P-gp as well as efflux activity distribution are progressively reorganized over time in co-cultures analyzed by flow cytometry. A mathematical model based on a Boltzmann type integro-partial differential equation structured by a continuum variable corresponding to P-gp activity describes the cell populations in co-culture. The mathematical model elucidates the population elements in the experimental data, specifically, the initial proportions, the proliferative growth rates, and the transfer rates of P-gp in the sensitive and resistant subpopulations. Conclusions We confirmed cell-to-cell transfer of functional P-gp. The transfer process depends on the gradient of P-gp expression in the donor-recipient cell interactions, as they evolve over time. Extragenetically acquired drug resistance is an additional aptitude of neoplastic cells which has implications in the diagnostic value of P-gp expression and in the design of chemotherapy regimens. Reviewers This article was reviewed by

  6. pH-Responsive therapeutic solid lipid nanoparticles for reducing P-glycoprotein-mediated drug efflux of multidrug resistant cancer cells.

    PubMed

    Chen, Hsin-Hung; Huang, Wen-Chia; Chiang, Wen-Hsuan; Liu, Te-I; Shen, Ming-Yin; Hsu, Yuan-Hung; Lin, Sung-Chyr; Chiu, Hsin-Cheng

    2015-01-01

    In this study, a novel pH-responsive cholesterol-PEG adduct-coated solid lipid nanoparticles (C-PEG-SLNs) carrying doxorubicin (DOX) capable of overcoming multidrug resistance (MDR) breast cancer cells is presented. The DOX-loaded SLNs have a mean hydrodynamic diameter of ~100 nm and a low polydispersity index (under 0.20) with a high drug-loading efficiency ranging from 80.8% to 90.6%. The in vitro drug release profiles show that the DOX-loaded SLNs exhibit a pH-controlled drug release behavior with the maximum and minimum unloading percentages of 63.4% at pH 4.7 and 25.2% at pH 7.4, respectively. The DOX-loaded C-PEG-SLNs displayed a superior ability in inhibiting the proliferation of MCF-7/MDR cells. At a DOX concentration of 80 μM, the cell viabilities treated with C-PEG-SLNs were approximately one-third of the group treated with free DOX. The inhibition activity of C-PEG-SLNs could be attributed to the transport of C-PEG to cell membrane, leading to the change of the composition of the cell membrane and thus the inhibition of permeability glycoprotein activity. This hypothesis is supported by the confocal images showing the accumulation of DOX in the nuclei of cancer cells and the localization of C-PEG on the cell membranes. The results of in vivo study further demonstrated that the DOX delivered by the SLNs accumulates predominantly in tumor via enhanced permeability and retention effect, the enhanced passive tumor accumulation due to the loose intercellular junctions of endothelial cells lining inside blood vessels at tumor site, and the lack of lymphatic drainage. The growth of MCF-7/MDR xenografted tumor on Balb/c nude mice was inhibited to ~400 mm(3) in volume as compared with the free DOX treatment group, 1,140 mm(3), and the group treated with 1,2 distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)] solid lipid nanoparticles, 820 mm(3). Analysis of the body weight of nude mice and the histology of organs and tumor after the

  7. pH-Responsive therapeutic solid lipid nanoparticles for reducing P-glycoprotein-mediated drug efflux of multidrug resistant cancer cells

    PubMed Central

    Chen, Hsin-Hung; Huang, Wen-Chia; Chiang, Wen-Hsuan; Liu, Te-I; Shen, Ming-Yin; Hsu, Yuan-Hung; Lin, Sung-Chyr; Chiu, Hsin-Cheng

    2015-01-01

    In this study, a novel pH-responsive cholesterol-PEG adduct-coated solid lipid nanoparticles (C-PEG-SLNs) carrying doxorubicin (DOX) capable of overcoming multidrug resistance (MDR) breast cancer cells is presented. The DOX-loaded SLNs have a mean hydrodynamic diameter of ~100 nm and a low polydispersity index (under 0.20) with a high drug-loading efficiency ranging from 80.8% to 90.6%. The in vitro drug release profiles show that the DOX-loaded SLNs exhibit a pH-controlled drug release behavior with the maximum and minimum unloading percentages of 63.4% at pH 4.7 and 25.2% at pH 7.4, respectively. The DOX-loaded C-PEG-SLNs displayed a superior ability in inhibiting the proliferation of MCF-7/MDR cells. At a DOX concentration of 80 μM, the cell viabilities treated with C-PEG-SLNs were approximately one-third of the group treated with free DOX. The inhibition activity of C-PEG-SLNs could be attributed to the transport of C-PEG to cell membrane, leading to the change of the composition of the cell membrane and thus the inhibition of permeability glycoprotein activity. This hypothesis is supported by the confocal images showing the accumulation of DOX in the nuclei of cancer cells and the localization of C-PEG on the cell membranes. The results of in vivo study further demonstrated that the DOX delivered by the SLNs accumulates predominantly in tumor via enhanced permeability and retention effect, the enhanced passive tumor accumulation due to the loose intercellular junctions of endothelial cells lining inside blood vessels at tumor site, and the lack of lymphatic drainage. The growth of MCF-7/MDR xenografted tumor on Balb/c nude mice was inhibited to ~400 mm3 in volume as compared with the free DOX treatment group, 1,140 mm3, and the group treated with 1,2 distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)] solid lipid nanoparticles, 820 mm3. Analysis of the body weight of nude mice and the histology of organs and tumor after the

  8. An Inactivated Antibiotic-Exposed Whole-Cell Vaccine Enhances Bactericidal Activities Against Multidrug-Resistant Acinetobacter baumannii.

    PubMed

    Shu, Meng-Hooi; MatRahim, NorAziyah; NorAmdan, NurAsyura; Pang, Sui-Ping; Hashim, Sharina H; Phoon, Wai-Hong; AbuBakar, Sazaly

    2016-01-01

    Vaccination may be an alternative treatment for infection with multidrug-resistance (MDR) Acinetobacter baumannii. The study reported here evaluated the bactericidal antibody responses following immunization of mice using an inactivated whole-cell vaccine derived from antibiotic-exposed MDR A. baumannii (I-M28-47-114). Mice inoculated with I-M28-47 (non-antibiotic-exposed control) and I-M28-47-114 showed a high IgG antibody response by day 5 post-inoculation. Sera from mice inoculated with I-M28-47-114 collected on day 30 resulted in 80.7 ± 12.0% complement-mediated bacteriolysis in vitro of the test MDR A. baumannii treated with imipenem, which was a higher level of bacteriolysis over sera from mice inoculated with I-M28-47. Macrophage-like U937 cells eliminated 49.3 ± 11.6% of the test MDR A. baumannii treated with imipenem when opsonized with sera from mice inoculated with I-M28-47-114, which was a higher level of elimination than observed for test MDR A. baumannii opsonized with sera from mice inoculated with I-M28-47. These results suggest that vaccination with I-M28-47-114 stimulated antibody responses capable of mounting high bactericidal killing of MDR A. baumannii. Therefore, the inactivated antibiotic-exposed whole-cell vaccine (I-M28-47-114) has potential for development as a candidate vaccine for broad clearance and protection against MDR A. baumannii infections. PMID:26923424

  9. An Inactivated Antibiotic-Exposed Whole-Cell Vaccine Enhances Bactericidal Activities Against Multidrug-Resistant Acinetobacter baumannii

    PubMed Central

    Shu, Meng-Hooi; MatRahim, NorAziyah; NorAmdan, NurAsyura; Pang, Sui-Ping; Hashim, Sharina H.; Phoon, Wai-Hong; AbuBakar, Sazaly

    2016-01-01

    Vaccination may be an alternative treatment for infection with multidrug-resistance (MDR) Acinetobacter baumannii. The study reported here evaluated the bactericidal antibody responses following immunization of mice using an inactivated whole-cell vaccine derived from antibiotic-exposed MDR A. baumannii (I-M28-47-114). Mice inoculated with I-M28-47 (non-antibiotic-exposed control) and I-M28-47-114 showed a high IgG antibody response by day 5 post-inoculation. Sera from mice inoculated with I-M28-47-114 collected on day 30 resulted in 80.7 ± 12.0% complement-mediated bacteriolysis in vitro of the test MDR A. baumannii treated with imipenem, which was a higher level of bacteriolysis over sera from mice inoculated with I-M28-47. Macrophage-like U937 cells eliminated 49.3 ± 11.6% of the test MDR A. baumannii treated with imipenem when opsonized with sera from mice inoculated with I-M28-47-114, which was a higher level of elimination than observed for test MDR A. baumannii opsonized with sera from mice inoculated with I-M28-47. These results suggest that vaccination with I-M28-47-114 stimulated antibody responses capable of mounting high bactericidal killing of MDR A. baumannii. Therefore, the inactivated antibiotic-exposed whole-cell vaccine (I-M28-47-114) has potential for development as a candidate vaccine for broad clearance and protection against MDR A. baumannii infections. PMID:26923424

  10. Dielectrophoretic Microfluidic Chip Enables Single-Cell Measurements for Multidrug Resistance in Heterogeneous Acute Myeloid Leukemia Patient Samples.

    PubMed

    Khamenehfar, Avid; Gandhi, Maher K; Chen, Yuchun; Hogge, Donna E; Li, Paul C H

    2016-06-01

    The front-line treatment for adult acute myeloid leukemia (AML) is anthracycline-based combination chemotherapy. However, treatment outcomes remain suboptimal with relapses frequently observed. Among the mechanisms of treatment failure is multidrug resistance (MDR) mediated by the ABCB1, ABCC1, and ABCG2 drug-efflux transporters. Although genetic and phenotypic heterogeneity between leukemic blast cells is a well-recognized phenomenon, there remains minimal data on differences in MDR activity at the individual cell level. Specifically, functional assays that can distinguish the variability in MDR activity between individual leukemic blasts are lacking. Here, we outline a new dielectrophoretic (DEP) chip-based assay. This assay permits measurement of drug accumulation in single cells, termed same-single-cell analysis in the accumulation mode (SASCA-A). Initially, the assay was optimized in pretherapy samples from 20 adults with AML whose leukemic blasts had MDR activity against the anthracyline daunorubicin (DNR) tested using multiple MDR inhibitors. Parameters tested were initial drug accumulation, time to achieve signal saturation, fold-increase of DNR accumulation with MDR inhibition, ease of cell trapping, and ease of maintaining the trapped cells stationary. This enabled categorization into leukemic blast cells with MDR activity (MDR(+)) and leukemic blast cells without MDR activity (MDR(-ve)). Leukemic blasts could also be distinguished from benign white blood cells (notably these also lacked MDR activity). MDR(-ve) blasts were observed to be enriched in samples taken from patients who went on to enter complete remission (CR), whereas MDR(+) blasts were frequently observed in patients who failed to achieve CR following front-line chemotherapy. However, pronounced variability in functional MDR activity between leukemic blasts was observed, with MDR(+) cells not infrequently seen in some patients that went on to achieve CR. Next, we tested MDR activity in two

  11. Osthole shows the potential to overcome P-glycoprotein‑mediated multidrug resistance in human myelogenous leukemia K562/ADM cells by inhibiting the PI3K/Akt signaling pathway.

    PubMed

    Wang, Hong; Jia, Xiu-Hong; Chen, Jie-Ru; Wang, Jian-Yong; Li, You-Jie

    2016-06-01

    P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) has been reported to play a pivotal role in tumor chemotherapy failure. Study after study has illustrated that the phosphoinositide 3-kinase (PI3K)/Akt signaling cascade is involved in the MDR phenotype and is correlated with P-gp expression in many human malignancies. In the present study, osthole, an O-methylated coumarin, exhibited potent reversal capability of MDR in myelogenous leukemia K562/ADM cells. Simultaneously, the uptake and efflux of Rhodamine-123 (Rh-123) and the accumulation of doxorubicin assays combined with flow cytometric analysis suggested that osthole could increase intracellular drug accumulation. Furthermore, osthole decreased the expression of multidrug resistance gene 1 (MDR1) at both the mRNA and protein levels. Further experiments elucidated that osthole could suppress P-gp expression by inhibiting the PI3K/Akt signaling pathway which might be the main mechanism accounting for the reversal potential of osthole in the MDR in K562/ADM cells. In conclusion, osthole combats MDR and could be a promising candidate for the development of novel MDR reversal modulators. PMID:27109742

  12. Co-encapsulation of chrysophsin-1 and epirubicin in PEGylated liposomes circumvents multidrug resistance in HeLa cells.

    PubMed

    Lo, Yu-Li; Tu, Wei-Chen

    2015-12-01

    Chrysophsin-1, an amphipathic alpha-helical antimicrobial peptide, is isolated from the gills of the red sea bream and possesses different structure and mechanism(s) in comparison with traditional multidrug resistance (MDR) modulators. For the purpose of reducing off-target normal cell toxicity, it is rational to incorporate chrysophsin-1 and epirubicin in a PEGylated liposomal formulation. In the present study, we report a multifunctional liposomes with epirubicin as an antineoplastic agent and an apoptosis inducer, as well as chrysophsin-1 as a MDR transporter inhibitor and an apoptosis modulator in human cervical cancer HeLa cells. Co-incubation of HeLa cells with PEGylated liposomal formulation of epirubicin and chrysophsin-1 resulted in a significant increase in the cytotoxicity of epirubicin. The liposomal formulations of epirubicin and/or chrysophsin-1 were shown to considerably improve the intracellular H2O2 and O2(-) levels of HeLa cells. Furthermore, these treatments were found to extensively reduce mRNA expression levels of MDR1, MRP1, and MRP2. The addition of chrysophsin-1 in liposomes was demonstrated to substantially enhance the intracellular accumulation of epirubicin in HeLa cells. Moreover, the PEGylated liposomes of epirubicin and chrysophsin-1 were also found to significantly increase the mRNA expressions of p53, Bax, and Bcl-2. The ratio of Bax to Bcl-2 was noticeably amplified in the presence of these formulations. Apoptosis induction was also validated by chromatin condensation, a reduction in mitochondrial membrane potential, the increased sub-G1 phase of cell cycle, and more populations of apoptosis using annexin V/PI assay. These formulations were verified to increase the activity and mRNA expression levels of caspase-9 and caspases-3. Collectively, our findings provide the first evidence that cotreatment with free or liposomal chrysophsin-1 and epirubicin leads to cell death in human cervical cancer cells through the ROS

  13. Nuclear Multidrug Resistance-Related Protein 1 Is Highly Associated with Better Prognosis of Human Mucoepidermoid Carcinoma through the Suppression of Cell Proliferation, Migration and Invasion

    PubMed Central

    Shen, Liang-Liang; Zhao, Jin-Long; Liu, Yuan; Wu, Jun-Zheng; Liu, Yan-Pu; Yu, Bo

    2016-01-01

    Objectives Multidrug resistance-related protein 1 (MRP1) overexpression is a well acknowledged predictor of poor response to chemotherapy, but MRP1 also correlated to better prognosis in some reports, especially for patients not pretreated with chemotherapy. In our previous study, we found nuclear translocation of MRP1 in mucoepidermoid carcinoma (MEC) for the first time. The purpose of this study was to further investigate the function of nuclear MRP1 in MEC. Materials and Methods Human MEC tissue samples of 125 patients were selected and stained using immunohistochemistry. The expression level of total MRP1/nuclear MRP1 of each sample was evaluated by expression index (EI) which was scored using both qualitative and quantitative analysis. The correlations between the clinicopathologic parameters and the EI of nuclear MRP1 were analyzed using Spearman’s rank correlation analysis, respectively. The effects of RNAi-mediated downregulation of nuclear MRP1 on MEC cells were assessed using flow cytometric analysis, MTT assay, plate colony formation assay, transwell invasion assay and monolayer wound healing assay. Results In this study, we found the EI of nuclear MRP1 was negatively correlated to the pathologic grading (r = -0.498, P<0.01) / clinical staging (r = -0.41, P<0.01) / tumor stage (r = -0.28, P = 0.02) / nodal stage (r = -0.29, P<0.01) of MEC patients. The RNAi-mediated downregulation of nuclear MRP1 further proved that the downregulation of nuclear MRP1 could increase the cell replication, growth speed, colony formation efficiency, migration and invasion ability of MEC cells. Conclusion Our results suggested that nuclear MRP1 is highly associated with better prognosis of human mucoepidermoid carcinoma and further study of its function mechanism would provide clues in developing new treatment modalities of MEC. PMID:26829120

  14. Tumor hypoxia, the Warburg effect, and multidrug resistance: Modulation of hypoxia induced MDR using EGFR-targeted polymer blend nanocarriers for combination paclitaxel/lonidamine therapy

    NASA Astrophysics Data System (ADS)

    Jabr-Milane, Lara Scheherazade

    Multi-drug resistant (MDR) cancer is a significant clinical obstacle and is often implicated in cases of recurrent, non-responsive disease. The biological focus of this work is to explore the relationship between the hypoxic microenvironment of a tumor, the development of MDR, and the energetic profile characteristic of the Warburg effect (aerobic glycolysis). The therapeutic aim of this research is to develop an EGFR-targeted nanocarrier system for combination (paclitaxel/lonidamine) therapy for the treatment of MDR cancer. The stability of the nanocarrier formulation was validated in vitro and the system was characterized for drug release kinetics, size, surface modification, and EGFR-targeting ability. An orthotopic animal model of hypoxic, MDR breast cancer was developed for the pre-clinical evaluation of this system. The EGFR-targeted nanoparticles loaded with lonidamine and paclitaxel demonstrated superior pharmacokinetic parameters relative to non-targeted nanoparticles and drug solution. Combination therapy with lonidamine and paclitaxel, in solution and EGFR-targeted nanoparticle form, was more effective at suppressing tumor growth than single agent treatment. However, combination therapy with EGFR-targeted nanoparticles was less toxic than treatment with drug solution. Combination therapy did change the MDR and hypoxic character of the tumors as demonstrated by a decrease in marker proteins. This EGFR-targeted combination nanocarrier therapy has the potential to make the successful treatment of MDR a clinical reality.

  15. Deletions of multidrug resistance gene loci in breast cancer leads to the down-regulation of its expression and predict tumor response to neoadjuvant chemotherapy

    PubMed Central

    Litviakov, Nikolai V.; Cherdyntseva, Nadezhda V.; Tsyganov, Matvey M.; Slonimskaya, Elena M.; Ibragimova, Marina K.; Kazantseva, Polina V.; Kzhyshkowska, Julia; Choinzonov, Eugeniy L.

    2016-01-01

    Neoadjuvant chemotherapy (NAC) is intensively used for the treatment of primary breast cancer. In our previous studies, we reported that clinical tumor response to NAC is associated with the change of multidrug resistance (MDR) gene expression in tumors after chemotherapy. In this study we performed a combined analysis of MDR gene locus deletions in tumor DNA, MDR gene expression and clinical response to NAC in 73 BC patients. Copy number variations (CNVs) in biopsy specimens were tested using high-density microarray platform CytoScanTM HD Array (Affymetrix, USA). 75%–100% persons having deletions of MDR gene loci demonstrated the down-regulation of MDR gene expression. Expression of MDR genes was 2–8 times lower in patients with deletion than in patients having no deletion only in post-NAC tumors samples but not in tumor tissue before chemotherapy. All patients with deletions of ABCB1 ABCB 3 ABCC5 gene loci – 7q21.1, 6p21.32, 3q27 correspondingly, and most patients having deletions in ABCC1 (16p13.1), ABCC2 (10q24), ABCG1 (21q22.3), ABCG2 (4q22.1), responded favorably to NAC. The analysis of all CNVs, including both amplification and deletion showed that the frequency of 13q14.2 deletion was 85% among patients bearing tumor with the deletion at least in one MDR gene locus versus 9% in patients with no deletions. Differences in the frequency of 13q14.2 deletions between the two groups were statistically significant (p = 2.03 ×10−11, Fisher test, Bonferroni-adjusted p = 1.73 × 10−8). In conclusion, our study for the first time demonstrates that deletion MDR gene loci can be used as predictive marker for tumor response to NAC. PMID:26799285

  16. Constitutive expression of multidrug resistance in human colorectal tumours and cell lines.

    PubMed Central

    Kramer, R.; Weber, T. K.; Morse, B.; Arceci, R.; Staniunas, R.; Steele, G.; Summerhayes, I. C.

    1993-01-01

    In this study we report detection of mdr1 gene expression in the liver metastases of 7/11 patients with colon carcinoma and characterise the MDR phenotype associated with a panel of 19 human colon carcinoma cell lines. Within this panel, mdr1 mRNA biosynthesis and surface localisation of Pgp were assessed with respect to MDR functionality where the cell lines are representative of different clinical stages of tumour progression, metastatic potential and differentiation. The data indicates that constitutive levels of mdr1 mRNA/Pgp expression may not necessarily result in the functional expression of the MDR phenotype. While low levels of mdr1 mRNA/Pgp were detected in 5/8 well differentiated colon cell lines, only 2/8 were functionally MDR. In contrast, 10/11 moderate and poorly differentiated lines expressed mdr1 mRNA/Pgp and of these, 9/11 were functionally MDR. The phosphorylation status of the mature 170 kD P-glycoprotein and the surface localisation of this glycoprotein showed the strongest correlation with functionality. Analysis of cell lines for cross-resistance and chemosensitivity profiles against a battery of chemotherapeutic drugs suggests multiple mechanisms, in addition to Pgp, contribute to the overall resistance of colorectal cancer. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8098614

  17. Arsenite-loaded nanoparticles inhibit PARP-1 to overcome multidrug resistance in hepatocellular carcinoma cells

    PubMed Central

    Liu, Hanyu; Zhang, Zongjun; Chi, Xiaoqin; Zhao, Zhenghuan; Huang, Dengtong; Jin, Jianbin; Gao, Jinhao

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the highest incidences in cancers; however, traditional chemotherapy often suffers from low efficiency caused by drug resistance. Herein, we report an arsenite-loaded dual-drug (doxorubicin and arsenic trioxide, i.e., DOX and ATO) nanomedicine system (FeAsOx@SiO2-DOX, Combo NP) with significant drug synergy and pH-triggered drug release for effective treatment of DOX resistant HCC cells (HuH-7/ADM). This nano-formulation Combo NP exhibits the synergistic effect of DNA damage by DOX along with DNA repair interference by ATO, which results in unprecedented killing efficiency on DOX resistant cancer cells. More importantly, we explored the possible mechanism is that the activity of PARP-1 is inhibited by ATO during the treatment of Combo NP, which finally induces apoptosis of HuH-7/ADM cells by poly (ADP-ribosyl) ation suppression and DNA lesions accumulation. This study provides a smart drug delivery strategy to develop a novel synergistic combination therapy for effectively overcome drug- resistant cancer cells. PMID:27484730

  18. Arsenite-loaded nanoparticles inhibit PARP-1 to overcome multidrug resistance in hepatocellular carcinoma cells.

    PubMed

    Liu, Hanyu; Zhang, Zongjun; Chi, Xiaoqin; Zhao, Zhenghuan; Huang, Dengtong; Jin, Jianbin; Gao, Jinhao

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the highest incidences in cancers; however, traditional chemotherapy often suffers from low efficiency caused by drug resistance. Herein, we report an arsenite-loaded dual-drug (doxorubicin and arsenic trioxide, i.e., DOX and ATO) nanomedicine system (FeAsOx@SiO2-DOX, Combo NP) with significant drug synergy and pH-triggered drug release for effective treatment of DOX resistant HCC cells (HuH-7/ADM). This nano-formulation Combo NP exhibits the synergistic effect of DNA damage by DOX along with DNA repair interference by ATO, which results in unprecedented killing efficiency on DOX resistant cancer cells. More importantly, we explored the possible mechanism is that the activity of PARP-1 is inhibited by ATO during the treatment of Combo NP, which finally induces apoptosis of HuH-7/ADM cells by poly (ADP-ribosyl) ation suppression and DNA lesions accumulation. This study provides a smart drug delivery strategy to develop a novel synergistic combination therapy for effectively overcome drug- resistant cancer cells. PMID:27484730

  19. Molecular basis of preferential resistance to colchicine in multidrug-resistant human cells conferred by Gly-185 yields Val-185 substitution in P-glycoprotein

    SciTech Connect

    Safa, A.R.; Stern, R.K.; Choi, Kyunghee; Agresti, M.; Tamai, Ikumi; Mehta, N.D.; Roninson, I.B. )

    1990-09-01

    Expression of P-glycoprotein, encoded by the human MDR1 gene, results in cross-resistance to many lipophilic cytotoxic drugs (multidrug resistance). P-glycoprotein is believed to function as an energy-dependent efflux pump that is responsible for decreased drug accumulation in multidrug-resistant cells. Previous work showed that preferential resistance to colchicine in a colchicine-selected multidrug-resistant cell line was caused by spontaneous mutations in the MDR1 gene that resulted in a Gly-185 {yields} Val-185 substitution in P-glycoprotein. The authors have now compared transfectant cell lines expressing the wild-type Gly-185 or the mutant Val-185 P-glycoprotein with regard to their levels of resistance to and accumulation and binding of different drugs. In cells expressing the mutant protein, increased resistance to colchicine and decreased resistance to vinblastine correlated with a decreased accumulation of colchicine and increased accumulation of vinblastine. Expression of the mutant P-glycoprotein also resulted in significantly increased resistance to epipodophyllotoxin and decreased resistance to vincristine and actinomycin D; smaller changes in resistance were observed for several other drugs. Unexpectedly, the mutant P-glycoprotein showed increased binding of photoactive analogs of vinblastine and verapamil and the photoactive compound azidopine and decreased binding of a photoactive colchicine analog. These results suggest that the Gly-185 {yields} Val-185 substitution affects not the initial drug-binding site of P-glycoprotein but another site, associated with the release of P-glycoprotein-bound drugs to the outside of the cell.

  20. Synthesis and study of cytotoxic activity of 1,2,4-trioxane- and egonol-derived hybrid molecules against Plasmodium falciparum and multidrug-resistant human leukemia cells.

    PubMed

    Reiter, Christoph; Capcı Karagöz, Aysun; Fröhlich, Tony; Klein, Volker; Zeino, Maen; Viertel, Katrin; Held, Jana; Mordmüller, Benjamin; Emirdağ Öztürk, Safiye; Anıl, Hüseyin; Efferth, Thomas; Tsogoeva, Svetlana B

    2014-03-21

    Malaria and cancer cause the death of millions of people every year. To combat these two diseases, it is important that new pharmaceutically active compounds have the ability to overcome multidrug resistance in cancer and Plasmodium falciparum strains. In search of effective anti-cancer and anti-malaria hybrids that possess improved properties compared to their parent compounds, a series of novel 1,2,4-trioxane-based hybrids incorporating egonol and/or ferrocene fragments were synthesized and tested in vitro against P. falciparum strains, CCRF-CEM cells and the multidrug-resistant P-glycoprotein-over-expressing CEM/ADR5000 cells. The most active compounds against P. falciparum strains were artesunic acid homodimers 12 and 13 (IC50 of 0.32 and 0.30 nM, respectively), whereas novel hybrids 7 (1,2,4-trioxane-ferrocene-egonol), 9 (1,2,4-trioxane-ferrocene) and 11 (artesunic acid-egonol) showed a remarkable cytotoxicity toward CCRF-CEM cells (IC50 of 0.07, 0.25 and 0.18 μM, respectively). A cooperative and synergistic effect of the three moieties 1,2,4-trioxane, ferrocene and egonol in hybrid molecule 7 is significant and is obviously stronger than in hybrids 9 (1,2,4-trioxane-ferrocene) and 11 (artesunic acid-egonol), which comprises of only two of the three considered parent compounds. Interestingly, hybrid 9 containing a 1,2,4-trioxane and a ferrocene fragment has shown to be the most effective among the studied hybrids against the tested multidrug-resistant leukemia CEM/ADR5000 cells (IC50 of 0.57 μM) and possesses a degree of cross-resistance of 2.34. PMID:24561670

  1. MicroRNA-199a targets CD44 to suppress the tumorigenicity and multidrug resistance of ovarian cancer-initiating cells.

    PubMed

    Cheng, Weiwei; Liu, Te; Wan, Xiaoping; Gao, Yongtao; Wang, Hui

    2012-06-01

    In ovarian cancer, CD44(+) /CD117(+) stem cells, also known as cancer-initiating cells (CICs), are highly proliferative, have a low degree of differentiation, and are resistant to chemotherapeutics. Therefore, the CD44(+) /CD117(+) subpopulation is thought to be an important target for novel therapeutic strategies. In this study, we investigated the role of microRNA-199a (miR-199a) in ovarian cancer stem cells. Luciferase reporter gene assays confirmed that miR-199a targets CD44 via an miR-199a-binding site in the 3'-UTR. CD44(+) /CD117(+) ovarian CICs were enriched from human primary ovarian tumor tissues and confirmed by flow cytometric sorting. miR-199a was cloned and transfected into ovarian CICs. CD44 mRNA and protein expression was significantly decreased in miR-199a-transfected ovarian CICs as compared with miR-199a mutant-transfected and untransfected cells. Cell cycle analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide proliferation assays, the colony formation assay and the transwell migration assay indicated that miR-199a significantly affected cell cycle regulation and suppressed the proliferation and invasive capacity of ovarian CICs in vitro. miR-199a significantly increased the chemosensitivity of ovarian CICs to cisplatin, pacitaxel, and adriamycin, and reduced mRNA expression of the multidrug resistance gene ABCG2 as compared with miR-199a mutant-transfected and untransfected cells. The expression of stemness markers was also significantly reduced in miR-199a-transfected CICs as compared with miR-199a mutant-transfected and untransfected ovarian cells. Furthermore, xenograft experiments confirmed that miR-199a suppressed the growth of xenograft tumors formed by ovarian CICs in vivo. Thus, expression of endogenous mature miR-199a may prevent tumorigenesis in human ovarian cancer by regulating expression of its target gene CD44. PMID:22498306

  2. Zosuquidar and an albumin-binding prodrug of zosuquidar reverse multidrug resistance in breast cancer cells of doxorubicin and an albumin-binding prodrug of doxorubicin.

    PubMed

    Abu Ajaj, Khalid; Graeser, Ralph; Kratz, Felix

    2012-07-01

    The P-glycoprotein (P-gp) is a 170-kDa protein that acts as an energy dependent, transmembrane efflux pump and is encoded by the MDR1 gene. It has been shown to be responsible for multidrug resistance (MDR) in a defined subpopulation of breast cancer patients and thus represents a molecular target for circumventing MDR in this tumor indication. MDR modulators have been developed and demonstrated high selectivity for P-gp with inhibitory activities in the low nanomolar range. Although some objective responses were achieved in clinical trials, combination therapy with these MDR modulators, such as Ca2+ antagonists caused unacceptable toxicity. Targeting P-gp inhibitors to the tumor site is a mean to increase their therapeutic index, and in this context binding of tailor-made prodrugs to circulating albumin is an established technology to reduce the toxicity and enhance the efficacy of anticancer drugs. In this study, we consequently developed an acid-sensitive albumin-binding prodrug of the P-gp inhibitor zosuquidar (LY335979) in a two-step synthesis using a maleimide hydrazone linker system established in our laboratory that first introduces acetylbenzoic acid at the HO-group of zosuquidar followed by derivatization with 6-maleimidocaproyl hydrazide to form the acid-sensitive hydrazone bond. The maleimide group enables the prodrug to bind rapidly and selectively to the cysteine-34 position of endogenous albumin after intravenous administration. HPLC analysis demonstrated rapid albumin binding of the zosuquidar prodrug as well as the quantitative release of the acetylbenzoic ester derivative of zosuquidar at pH 5.0. Subsequently, its ability to circumvent MDR was tested in two doxorubicin-resistant breast carcinoma cell lines (MCF-7/ADR and MT-3/ADR). The MDR status of these cell lines can be reversed by zosuquidar which was confirmed in a rhodamine 123 assay using fluorescence microscopy and FACS analysis. Furthermore, zosuquidar as well its acid-sensitive albumin

  3. Clitocine Reversal of P-Glycoprotein Associated Multi-Drug Resistance through Down-Regulation of Transcription Factor NF-κB in R-HepG2 Cell Line

    PubMed Central

    Sun, Jianguo; Yeung, Chilam Au; Co, Ngai Na; Tsang, Tsun Yee; Yau, Esmond; Luo, Kewang; Wu, Ping; Wa, Judy Chan Yuet; Fung, Kwok-Pui; Kwok, Tim-Tak; Liu, Feiyan

    2012-01-01

    Multidrug resistance(MDR)is one of the major reasons for failure in cancer chemotherapy and its suppression may increase the efficacy of therapy. The human multidrug resistance 1 (MDR1) gene encodes the plasma membrane P-glycoprotein (P-gp) that pumps various anti-cancer agents out of the cancer cell. R-HepG2 and MES-SA/Dx5 cells are doxorubicin induced P-gp over-expressed MDR sublines of human hepatocellular carcinoma HepG2 cells and human uterine carcinoma MES-SA cells respectively. Herein, we observed that clitocine, a natural compound extracted from Leucopaxillus giganteus, presented similar cytotoxicity in multidrug resistant cell lines compared with their parental cell lines and significantly suppressed the expression of P-gp in R-HepG2 and MES-SA/Dx5 cells. Further study showed that the clitocine increased the sensitivity and intracellular accumulation of doxorubicin in R-HepG2 cells accompanying down-regulated MDR1 mRNA level and promoter activity, indicating the reversal effect of MDR by clitocine. A 5′-serial truncation analysis of the MDR1 promoter defined a region from position −450 to −193 to be critical for clitocine suppression of MDR1. Mutation of a consensus NF-κB binding site in the defined region and overexpression of NF-κB p65 could offset the suppression effect of clitocine on MDR1 promoter. By immunohistochemistry, clitocine was confirmed to suppress the protein levels of both P-gp and NF-κB p65 in R-HepG2 cells and tumors. Clitocine also inhibited the expression of NF-κB p65 in MES-SA/Dx5. More importantly, clitocine could suppress the NF-κB activation even in presence of doxorubicin. Taken together; our results suggested that clitocine could reverse P-gp associated MDR via down-regulation of NF-κB. PMID:22927901

  4. Reconstituted high density lipoprotein mediated targeted co-delivery of HZ08 and paclitaxel enhances the efficacy of paclitaxel in multidrug-resistant MCF-7 breast cancer cells.

    PubMed

    Zhang, Fangrong; Wang, Xiaoyi; Xu, Xiangting; Li, Min; Zhou, Jianping; Wang, Wei

    2016-09-20

    In the past decades, reconstituted high density lipoprotein (rHDL) has been successfully developed as a drug carrier since the enhanced HDL-lipids uptake is demonstrated in several human cancers. In this paper, rHDL, for the first time, was utilized to co-encapsulate two hydrophobic drugs: an anticancer drug, paclitaxel (PTX), and a new reversal agent for P-gp (P-glycoprotein)-mediated multidrug resistance (MDR) of cancer, N-cyano-1-[(3,4-dimethoxyphenyl)methyl]-3,4-dihydro-6,7-dimethoxy-N'-octyl-2(1H)-isoquinoline-carboximidamide (HZ08). We proposed this drug co-delivery strategy to reverse PTX resistance. The study aimed to develop a biomimetic nanovector, reconstituted high density lipoprotein (rHDL), mediating targeted PTX-HZ08 delivery for cancer therapy. Using sodium cholate dialysis method, we successfully formulated dual-agent co-delivering rHDL nanoparticles (PTX-HZ08-rHDL NPs) with a typical spherical morphology, well-distributed size (~100nm), high drug encapsulation efficiency (approximately 90%), sustained drug release properties and exceptional stability even after storage for 1month or incubation in 10% fetal bovine serum (FBS) DMEM for up to 2days. Results demonstrated that PTX-HZ08-rHDL NPs significantly enhanced anticancer efficacy in vitro, including higher cytotoxicity and better ability to induce cell apoptosis against both PTX-sensitive and -resistant MCF-7 human breast cancer cell lines (MCF-7 and MCF-7/PTX cells). Mechanism studies demonstrated that these improvements could be correlated with increased cellular uptake of PTX mediated by scavenger receptor class B type I (SR-BI) as well as prolonged intracellular retention of PTX due to the HZ08 mediated drug-efflux inhibition. In addition, in vivo investigation showed that the PTX-HZ08-rHDL NPs were substantially safer, have higher tumor-targeted capacity and have stronger antitumor activity than the corresponding dosage of paclitaxel injection. These findings suggested that rHDL NPs could

  5. Design, synthesis and evaluation of the multidrug resistance-reversing activity of pyridine acid esters of podophyllotoxin in human leukemia cells.

    PubMed

    Zhang, Lei; Chen, Fan; Zhang, Zeguo; Chen, Yongzheng; Lin, Ya; Wang, Jing

    2016-09-15

    Multidrug resistance (MDR) is the main cause for chemotherapeutic failure in cancer treatment. To overcome MDR, a serious of pyridine acid esters of podophyllotoxin was synthesized and their antiproliferation activities were evaluated against two human chronic myeloid leukemia cell lines in vitro. Most of them exhibited potent growth inhibition with IC50 values in the nanomolar range as well as markedly reduced resistance factors. The most potent compound, Y8 exhibited an IC50 of 0.046±0.003μM against resistance K562/ADR cells, showing more significant than that of adriamycin and etoposide, respectively. Furthermore, Y8 efficiently triggered cell cycle arrest at S phase and simultaneously induced apoptosis in K562/ADR cells. Meanwhile, Y8 also regulated the expression levels of cell cycle- and apoptosis-related proteins. Additionally, Y8 stimulated the ERK1/2 signalling and reduced the expression of Pgp protein. Finally, on the basis of results obtained using U0126, an ERK1/2 inhibitor, the ERK1/2 signalling pathway was proposed for the multidrug resistance-reversing effect of Y8 in K562/ADR cells. Together, Y8 could be a novel potential MDR reversal agent for the treatment of drug-resistant leukemia. PMID:27503681

  6. Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression.

    PubMed

    Yuan, Wei-Qi; Zhang, Rong-Rong; Wang, Jun; Ma, Yan; Li, Wen-Xue; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-05-24

    Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is a major cause of cancer therapy failure. In this study, we identified a novel C21 steroidal glycoside, asclepiasterol, capable of reversing P-gp-mediated MDR. Asclepiasterol (2.5 and 5.0μM) enhanced the cytotoxity of P-gp substrate anticancer drugs in MCF-7/ADR and HepG-2/ADM cells. MDR cells were more responsive to paclitaxel in the presence of asclepiasterol, and colony formation of MDR cells was only reduced upon treatment with a combination of asclepiasterol and doxorubicin. Consistent with these findings, asclepiasterol treatment increased the intracellular accumulation of doxorubicin and rhodamine 123 (Rh123) in MDR cells. Asclepiasterol decreased expression of P-gp protein without stimulating or suppressing MDR1 mRNA levels. Asclepiasterol-mediated P-gp suppression caused inhibition of ERK1/2 phosphorylation in two MDR cell types, and EGF, an activator of the MAPK/ERK pathway, reversed the P-gp down-regulation, implicating the MAPK/ERK pathway in asclepiasterol-mediated P-gp down-regulation. These results suggest that asclepiasterol could be developed as a modulator for reversing P-gp-mediated MDR in P-gp-overexpressing cancer variants. PMID:27129170

  7. The Effects and Molecular Mechanisms of MiR-106a in Multidrug Resistance Reversal in Human Glioma U87/DDP and U251/G Cell Lines.

    PubMed

    Wang, Qin; Wang, Zhenlian; Chu, LinYang; Li, Xu; Kan, Pengcheng; Xin, Xin; Zhu, Yu; Yang, Ping

    2015-01-01

    Chemotherapy resistance is one of the major obstacles to effective glioma therapy. Currently, the mechanism underlying chemotherapy resistance is unclear. A recent study showed that miR-106a is an important molecule involved in chemotherapy resistance. To explore the effects and mechanisms of miR-106a on multidrug resistance reversal in human glioma cells, we silenced miR-106a expression in the cisplatin-resistant U87 (U87/DDP) and the gefitinib-resistant U251 (U251/G) glioma cell lines and measured the resulting drug sensitivity, cell apoptosis rate and rhodamine 123 content. In addition, we detected decreased expression of P-glycoprotein, MDR1, MRP1, GST-π, CDX2, ERCC1, RhoE, Bcl-2, Survivin and Topo-II, as well as reduced production of IL-6, IL-8 and TGF-β in these cell lines. Furthermore, we found decreased expression of p-AKT and transcriptional activation of NF-κB, Twist, AP-1 and Snail in these cell lines. These results suggest that miR-106a is a promising therapeutic target for the treatment of human multidrug resistant glioma. PMID:25950430

  8. Modulation of Multidrug Resistance Protein 2 Efflux in the Cisplatin Resistance Human Ovarian Carcinoma Cells A2780/RCIS by Sesquiterpene Coumarins.

    PubMed

    Kasaian, Jamal; Mosaffa, Fatemeh; Behravan, Javad; Masullo, Milena; Piacente, Sonia; Iranshahi, Mehrdad

    2016-01-01

    Recent in vitro studies showed that sesquiterpene coumarins (SCs) can be used as chemosensitizers. In this study, 14 SCs were isolated and purified from roots of four Ferula species and their structures were elucidated by spectroscopic methods. The purified SCs were evaluated for multidrug resistance (MDR) reversal properties in A2780/RCIS cells (cisplatin-resistant derivatives of the human ovarian carcinoma cell line A2780P). Among the tested compounds, mogoltacin, mogoltadone, farnesiferol A, farnesiferol B, farnesiferol C, lehmferin, conferdione, and samarcandin showed significant MDR reversing effects. The combination of nontoxic concentrations of SCs (20 μM) with cisplatin enhanced cisplatin cytotoxicity on A2780/RCIS cells significantly. Flow cytometric efflux assay confirmed that the intracellular accumulation of 5-carboxyfluorescein diacetate (5-CFDA) was significantly increased in A2780/RCIS cells when treated with SCs. Our findings revealed that conferdione and samarcandin possessed the highest inhibitory effects on multidrug resistance-associated protein 2 pump efflux, and therefore, these compounds could be considered as lead scaffolds for further structure modifications. PMID:26503061

  9. Immunohistochemical detection of DNA topoisomerase IIalpha, P-glycoprotein and multidrug resistance protein (MRP) in small-cell and non-small-cell lung cancer.

    PubMed Central

    Kreisholt, J.; Sorensen, M.; Jensen, P. B.; Nielsen, B. S.; Andersen, C. B.; Sehested, M.

    1998-01-01

    Non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC) differ significantly in their clinical response to topoisomerase IIalpha (topo-IIalpha)-directed drugs, such as etoposide and teniposide, as NSCLC is virtually insensitive to single-agent therapy, while SCLC responds in two-thirds of cases. Preclinical studies have indicated that resistance to topo-IIalpha drugs depends on topo-IIalpha content and/or activity, the altered-topo-II multidrug resistance phenotype (at-MDR) and/or one of two different drug efflux pumps, P-glycoprotein (P-gp) and the multidrug resistance protein (MRP). Immunohistochemical analysis on paraffin-embedded tissue from 27 cases of untreated NSCLC and 29 cases of untreated SCLC (of which additional tumour biopsies after treatment with topo-IIalpha-directed drugs were available in ten cases) yielded the following results: NSCLC had significantly less topo-IIalpha than SCLC (P < 0.0001), as only 5 out of 27 NSCLC cases had > 5% positive cells compared with 28 out of 29 SCLC, and 0 out of 27 NSCLC had > 25% positive cells compared with 26 out of 29 SCLC. P-gp was detected in > 5% of cells in only 3 out of 27 NSCLC and in 6 out of 29 SCLC, and MRP in 5 out of 27 of NSCLC and 9 out of 29 SCLC. After treatment of patients with SCLC with either etoposide or teniposide, which are topo-IIalpha-directed drugs, there was an increase in MRP (P < 0.1) and P-gp (P < 0.05) positivity, while topo-IIalpha decreased (P < 0.05). In conclusion, the major difference between untreated NSCLC and SCLC was in topo-IIalpha content. In the small series of ten patients treated for SCLC, all three MDR phenotypes appeared to increase. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:9652763

  10. Multidrug Resistant Acinetobacter

    PubMed Central

    Manchanda, Vikas; Sanchaita, Sinha; Singh, NP

    2010-01-01

    Emergence and spread of Acinetobacter species, resistant to most of the available antimicrobial agents, is an area of great concern. It is now being frequently associated with healthcare associated infections. Literature was searched at PUBMED, Google Scholar, and Cochrane Library, using the terms ‘Acinetobacter Resistance, multidrug resistant (MDR), Antimicrobial Therapy, Outbreak, Colistin, Tigecycline, AmpC enzymes, and carbapenemases in various combinations. The terms such as MDR, Extensively Drug Resistant (XDR), and Pan Drug Resistant (PDR) have been used in published literature with varied definitions, leading to confusion in the correlation of data from various studies. In this review various mechanisms of resistance in the Acinetobacter species have been discussed. The review also probes upon the current therapeutic options, including combination therapies available to treat infections due to resistant Acinetobacter species in adults as well as children. There is an urgent need to enforce infection control measures and antimicrobial stewardship programs to prevent the further spread of these resistant Acinetobacter species and to delay the emergence of increased resistance in the bacteria. PMID:20927292

  11. Pluronic mixed micelles overcoming methotrexate multidrug resistance: in vitro and in vivo evaluation

    PubMed Central

    Chen, Yanzuo; Sha, Xianyi; Zhang, Wei; Zhong, Weitong; Fan, Zhuoyang; Ren, Qiuyue; Chen, Liangcen; Fang, Xiaoling

    2013-01-01

    A Pluronic polymeric mixed micelle delivery system was developed in this study by using Pluronic P105 and F127 block copolymers to encapsulate the antitumor compound, methotrexate (MTX). The MTX-loaded Pluronic P105/F127 mixed micelle exhibited the spherical shape with about 22 nm in diameter, high encapsulation efficiency (about 85%) and pH-dependent in vitro drug release. In this study, A-549 and KBv cell lines were selected as multidrug resistance tumor cell models, while H-460 and KB cell lines were chosen as sensitive tumor cells. The MTX-loaded Pluronic P105/F127 mixed micelle exhibited significant higher in vitro cytotoxicity in multidrug resistant tumor cells than that of control (MTX injection) mainly because of higher cellular uptake of MTX. The pharmacokinetic studies indicated that the Pluronic micelles significantly prolonged systemic circulation time of MTX compared to MTX injection. Moreover, a much stronger antitumor efficacy in KBv tumor xenografts nude mice was observed in the MTX-loaded Pluronic P105/F127 mixed micelle group, than MTX. Collectively, Pluronic P105/F127 mixed micelles could significantly enhance the antitumor activity of MTX and might be a promising drug delivery platform for multidrug resistance modulation. PMID:23620663

  12. Suppression of MAPK Signaling and Reversal of mTOR-Dependent MDR1-Associated Multidrug Resistance by 21α-Methylmelianodiol in Lung Cancer Cells

    PubMed Central

    Aldonza, Mark Borris Docdoc; Hong, Ji-Young; Bae, Song Yi; Song, Jayoung; Kim, Won Kyung; Oh, Jedo; Shin, Yoonho; Lee, Seung Ho; Lee, Sang Kook

    2015-01-01

    Lung cancer is the leading cause of cancer-related deaths worldwide and remains the most prevalent. Interplay between PI3K/AMPK/AKT and MAPK pathways is a crucial effector in lung cancer growth and progression. These signals transduction protein kinases serve as good therapeutic targets for non-small cell lung cancer (NSCLC) which comprises up to 90% of lung cancers. Here, we described whether 21α-Methylmelianodiol (21α-MMD), an active triterpenoid derivative of Poncirus trifoliate, can display anticancer properties by regulating these signals and modulate the occurrence of multidrug resistance in NSCLC cells. We found that 21α-MMD inhibited the growth and colony formation of lung cancer cells without affecting the normal lung cell phenotype. 21α-MMD also abrogated the metastatic activity of lung cancer cells through the inhibition of cell migration and invasion, and induced G0/G1 cell cycle arrest with increased intracellular ROS generation and loss of mitochondrial membrane integrity. 21α-MMD regulated the expressions of PI3K/AKT/AMPK and MAPK signaling which drove us to further evaluate its activity on multidrug resistance (MDR) in lung cancer cells by specifying on P-glycoprotein (P-gp)/MDR1-association. Employing the established paclitaxel-resistant A549 cells (A549-PacR), we further found that 21α-MMD induced a MDR reversal activity through the inhibition of P-gp/MDR1 expressions, function, and transcription with regained paclitaxel sensitivity which might dependently correlate to the regulation of PI3K/mTOR signaling pathway. Taken together, these findings demonstrate, for the first time, the mechanistic evaluation in vitro of 21α-MMD displaying growth-inhibiting potential with influence on MDR reversal in human lung cancer cells. PMID:26098947

  13. Fludarabine phosphate selectively inhibits growth and modifies the antigenic phenotype of human glioblastoma-multiforme cells expressing a multidrug resistance phenotype.

    PubMed

    Jiang, H; Su, Z; Datta, S; Guarini, L; Waxman, S; Fisher, P

    1992-07-01

    Fludarabine phosphate (FLU), the 2-fluro derivative of Ara-A, 9-beta-D-arabino-furanosyl-2-fluoroadenine, has been shown to display both in vitro and in vivo antiproliferative activity toward a variety of murine tumors and human lymphoid malignancies. In the present study, we have determined the effect of FLU, alone and in combination with recombinant human fibroblast interferon (IFN-B), on in vitro growth, gene expression and the antigenic phenotype of human glioblastoma multiforme (GBM) cells displaying a multidrug sensitive and a multidrug resistant (MDR) phenotype. FLU exhibited a marked differential toxicity toward GBM-MDR cells versus the multidrug sensitive GBM parental cell line. Growth of GBM-MDR cells for seven days in 2.5 to 7.5 muM FLU resulted in a dose-dependent reduction or elimination of growth which persisted after removal of this agent. In contrast, recovery from FLU-induced growth suppression was observed in parental multidrug sensitive GBM cells. Acquisition of increased FLU sensitivity in GBM-MDR cells did not appear to result from selection for a subset of sensitive cells or an artifact associated with the DNA-transfection process. This conclusion is supported by the similar pattern of FLU resistance in GBM-18 clones isolated after transfection with a cloned hygromycin resistance gene and selection for resistance to hygromycin. The antiproliferative and toxic effect of FLU was increased in GBM-MDR cells by simultaneous growth in IFN-B and the toxic effect of FLU could be blocked in a dose-dependent manner by the simultaneous addition of deoxycytidine. In contrast, the toxicity of FLU toward GBM-MDR cells was not altered when cells were grown in the presence or absence of colchicine or by the administration of verapamil, which can reverse the MDR phenotype in GBM-MDR cells. The selective toxicity of FLU toward GBM-MDR versus GBM-18 cells was not associated with a consistent differential change in all of the GBM-18 MDR clones in the steady

  14. Binding and inhibition of drug transport proteins by heparin: a potential drug transporter modulator capable of reducing multidrug resistance in human cancer cells.

    PubMed

    Chen, Yunliang; Scully, Michael; Petralia, Gloria; Kakkar, Ajay

    2014-01-01

    A major problem in cancer treatment is the development of resistance to chemotherapeutic agents, multidrug resistance (MDR), associated with increased activity of transmembrane drug transporter proteins which impair cytotoxic treatment by rapidly removing the drugs from the targeted cells. Previously, it has been shown that heparin treatment of cancer patients undergoing chemotherapy increases survival. In order to determine whether heparin is capable reducing MDR and increasing the potency of chemotherapeutic drugs, the cytoxicity of a number of agents toward four cancer cell lines (a human enriched breast cancer stem cell line, two human breast cancer cell lines, MCF-7 and MDA-MB-231, and a human lung cancer cell line A549) was tested in the presence or absence of heparin. Results demonstrated that heparin increased the cytotoxicity of a range of chemotherapeutic agents. This effect was associated with the ability of heparin to bind to several of the drug transport proteins of the ABC and non ABC transporter systems. Among the ABC system, heparin treatment caused significant inhibition of the ATPase activity of ABCG2 and ABCC1, and of the efflux function observed as enhanced intracellular accumulation of specific substrates. Doxorubicin cytoxicity, which was enhanced by heparin treatment of MCF-7 cells, was found to be under the control of one of the major non-ABC transporter proteins, lung resistance protein (LRP). LRP was also shown to be a heparin-binding protein. These findings indicate that heparin has a potential role in the clinic as a drug transporter modulator to reduce multidrug resistance in cancer patients. PMID:24253450

  15. RNA helicase A in the MEF1 transcription factor complex up-regulates the MDR1 gene in multidrug-resistant cancer cells.

    PubMed

    Zhong, Xiaoling; Safa, Ahmad R

    2004-04-23

    RNA helicase A (RHA) is a member of the DEAD/H family of RNA helicases and unwinds duplex RNA and DNA. Recent studies have shown that RHA regulates the activity of gene promoters. However, little information is available about the in vivo relevance of RHA in the regulation of natural genes. We previously characterized a nuclear protein (MEF1) that binds to the proximal promoter of the multidrug resistance gene (MDR1) and up-regulates the promoter activity. In the present study, we isolated and identified RHA as a component of the MEF1 complex by using DNA-affinity chromatography and mass spectrometry. The antibody against RHA specifically disrupted the complex formation in electrophoretic mobility shift assay, confirming the identity of RHA. Western blotting showed that RHA in drug-resistant cells had a higher molecular weight than that in drug-sensitive cells. Similar results were obtained when FLAG-tagged RHA was overexpressed in these cells. This size difference probably reflects posttranslational modification(s) of RHA in drug-resistant cells. Chromatin immunoprecipitation revealed that RHA occupies the MDR1 promoter in vivo. Overexpression of RHA enhanced expression of the MDR1 promoter/reporter construct and endogenous P-glycoprotein (P-gp), the MDR1 gene product, and increased drug resistance of drug-resistant cells but not the drug-sensitive counterpart. Introduction of short interfering RNA targeting the RHA gene sequence selectively knocked-down RHA expression and concomitantly reduced P-gp level. Thus, our study demonstrates, for the first time, the involvement of RHA in up-regulation of the MDR1 gene. Interactions of RHA with other protein factors in the MEF1 complex bound to the promoter element may contribute to P-gp overexpression and multidrug resistance phenotype in drug-resistant cancer cells. PMID:14769796

  16. Inhibition of P-glycoprotein-mediated transport by S-adenosylmethionine and cynarin in multidrug-resistant human uterine sarcoma MES-SA/Dx5 cells.

    PubMed

    Angelini, A; Di Pietro, R; Centurione, L; Castellani, M L; Conti, P; Porreca, E; Cuccurullo, F

    2012-01-01

    Multidrug resistance (MDR) to anticancer chemotherapy is often mediated by the overexpression of the plasma membrane drug transporter P-glycoprotein (Pgp) encoded by multidrug resistance gene (MDR1). Various chemosensitizing agents are able to inhibit Pgp activity but their clinical application is limited by their toxicity. Furthermore, hepatotoxicity related to chemotherapy causes delays of treatment in cancer patients and often requires supplementation of anti-tumour therapy with hepatoprotective agents. In this in vitro study, we investigated the effectiveness of an endogenous hepatoprotective agent, S-adenosylmethionine (SAMe), and a natural hepatoprotective compound, Cynarin (Cyn), to inhibit Pgp activity in order to evaluate their potential use as chemosensitizing agents. Human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx5) expressing high levels of Pgp were treated with two hepatoprotectors at various concentrations (1, 5 and 10 microM) that are clinically achievable, in the presence or absence of three different concentrations of doxo (2, 4 and 8 microM). In order to evaluate the effects of both hepatoprotectors, we measured the intracellular accumulation and cytotoxicity of doxo, the cellular GSH level, ROS production and catalase (CAT) activity. We found that treatment with 2, 4 and 8 microM doxo in the presence of SAMe or Cyn significantly increased the doxo accumulation and cytotoxicity on MES-SA/Dx5 cells, when compared to control cells receiving doxo alone. Moreover, treatment with SAMe or Cyn significantly increased GSH content, greater than 80 percent and 60 percent, respectively) and CAT activity greater than 60 and 150 percent, respectively) in resistant cancer cells, while ROS production was below the values of corresponding untreated control cells. Our in vitro findings provide a rationale for the potential clinical use of these hepatoprotectors both as chemosensitizing agents, to reverse Pgp-mediated MDR, and as antioxidants to

  17. Impaired NK cells' activity and increased numbers of CD4 + CD25+ regulatory T cells in multidrug-resistant Mycobacterium tuberculosis patients.

    PubMed

    Fan, Renhua; Xiang, Yangen; Yang, Li; Liu, Yanke; Chen, Pingsheng; Wang, Lei; Feng, Wenjun; Yin, Ke; Fu, Manjiao; Xu, Yixin; Wu, Jialin

    2016-05-01

    Multidrug-resistant tuberculosis (MDR-TB) often causes persistent infection and chemotherapy failure, which brings heavy burden of society and family. Many immune cell subsets and regulatory mechanisms may operate throughout the various stages of infection. The presence of regulatory T cells (Tregs) is thought to be an important mechanism that TB successfully evades the immune system. Tregs play a central role in the prevention of autoimmunity and in the control of immune responses. The role of Tregs in MDR-TB infection and persistence is inadequately documented. The current study was designed to determine whether CD4 + CD25+ regulatory T cells may modulate innate immunity (such as NK cells) against human tuberculosis. Our results indicated that the numbers of CD4 + CD25+ Treg cells increased in MDR-TB patients' blood, and the cytokine production of IL-10 increased from MDR-patients compared with healthy subjects, along with the lower activity and low CD69 expression of NK cells in patients. These results suggested that immunity to MDR-TB patients induced circulating CD4 + CD25+ T regulatory cells expansion, which may be related to the persistence of Mycobacterium tuberculosis (M. tb) infection, and to the balance between effectors immune responses and suppression immune responses. PMID:27156613

  18. Activating transcription factor 4 mediates a multidrug resistance phenotype of esophageal squamous cell carcinoma cells through transactivation of STAT3 expression.

    PubMed

    Zhu, Hongwu; Chen, Xiong; Chen, Bin; Chen, Bei; Fan, Jianyong; Song, Weibing; Xie, Ziying; Jiang, Dan; Li, Qiuqiong; Zhou, Meihua; Sun, Dayong; Zhao, Yagang

    2014-11-01

    Multidrug resistance (MDR) is a major challenge to the clinical treatment of esophageal cancer. The stress response gene activating transcription factor 4 (ATF4) is involved in homeostasis and cellular protection. However, relatively little is known about the expression and function of ATF4 in esophageal squamous cell carcinoma (ESCC) MDR. In this study, we investigate the potential role and mechanisms of ATF4 in ESCC MDR. We demonstrated that overexpression of ATF4 promotes the MDR phenotype in ESCC cells, while depletion of ATF4 in the MDR ESCC cell line induces drug re-sensitization. We also demonstrated that ATF4 transactivates STAT3 expression by directly binding to the signal transducers and activators of transcription 3 (STAT3) promoter, resulting in MDR in ESCC cells. Significantly, inhibition of STAT3 by small interfering RNA (siRNA) or a selective inhibitor (JSI-124) reintroduces therapeutic sensitivity. In addition, increased Bcl-2, survivin, and MRP1 expression levels were observed in ATF4-overexpressing cells. In conclusion, ATF4 may promote MDR in ESCC cells through the up-regulation of STAT3 expression, and thus is an attractive therapeutic target to combat therapeutic resistance in ESCC. PMID:25130172

  19. The involvement of a LINE-1 element in a DNA rearrangement upstream of the mdr1a gene in a taxol multidrug-resistant murine cell line.

    PubMed

    Cohen, D; Higman, S M; Hsu, S I; Horwitz, S B

    1992-10-01

    Two closely related but functionally distinct P-glycoprotein isoforms are encoded by the murine multidrug-resistance genes mdr1a and mdr1b. In a series of independently selected multidrug-resistant (MDR) J774.2 cell lines, mdr gene amplification and/or overexpression and overproduction of either the mdr1a or mdr1b products, or both gene products, correlates with the MDR phenotype. To investigate the possibility that mutations in the promoter regions of the mdr1a or mdr1b genes could influence their differential expression, mdr promoter-specific probes were used to detect and map potential structural alterations. An unusual structural rearrangement was found in the 5'-region of the amplified mdr1a allele in J7.T1, a cell line selected with taxol. To characterize this rearrangement, the regulatory regions of the mdr1a and mdr1b genes were analyzed. Whereas no gross structural alterations were detected by Southern blot hybridization using the mdr1b promoter probe, a novel amplified EcoRI fragment was detected by the mdr1a promoter probe. To determine the precise nature of this mutation, an mdr1a 5'-genomic clone was isolated from J7.T1 cells. Sequence analysis revealed an unusual DNA rearrangement consisting of the mdr1b gene, from its fourth intron toward its 3'-end, upstream of an intact mdr1a promoter on the amplified allele. We propose that this event occurred by an unequal sister chromatid exchange that was mediated by LINE-1 repetitive elements. PMID:1356977

  20. Adenovirus vector infection of non-small-cell lung cancer cells is a trigger for multi-drug resistance mediated by P-glycoprotein.

    PubMed

    Tomono, Takumi; Kajita, Masahiro; Yano, Kentaro; Ogihara, Takuo

    2016-08-01

    P-glycoprotein (P-gp) is an ATP-binding cassette protein involved in cancer multi-drug resistance (MDR). It has been reported that infection with some bacteria and viruses induces changes in the activities of various drug-metabolizing enzymes and transporters, including P-gp. Although human adenoviruses (Ad) cause the common cold, the effect of Ad infection on MDR in cancer has not been established. In this study, we investigated whether Ad infection is a cause of MDR in A549, H441 and HCC827 non-small-cell lung cancer (NSCLC) cell lines, using an Ad vector system. We found that Ad vector infection of NSCLC cell lines induced P-gp mRNA expression, and the extent of induction was dependent on the number of Ad vector virus particles and the infection time. Heat-treated Ad vector, which is not infectious, did not alter P-gp mRNA expression. Uptake experiments with doxorubicin (DOX), a P-gp substrate, revealed that DOX accumulation was significantly decreased in Ad vector-infected A549 cells. The decrease of DOX uptake was blocked by verapamil, a P-gp inhibitor. Our results indicated that Ad vector infection of NSCLC cells caused MDR mediated by P-gp overexpression. The Ad vector genome sequence is similar to that of human Ad, and therefore human Ad infection of lung cancer patients may lead to chemoresistance in the clinical environment. PMID:27286705

  1. Jalapinoside, a macrocyclic bisdesmoside from the resin glycosides of Ipomea purga, as a modulator of multidrug resistance in human cancer cells.

    PubMed

    Bautista, Elihú; Fragoso-Serrano, Mabel; Pereda-Miranda, Rogelio

    2015-01-23

    The first macrocyclic bisdesmoside resin glycoside, jalapinoside (4), was purified by preparative-scale recycling HPLC from the MeOH-soluble extracts of Ipomoea purga roots, the officinal jalap. Purgic acid C (3), a new glycosidic acid of ipurolic acid, was identified as 3-O-β-d-quinovopyranoside, 11-O-β-d-quinovopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→3)-O-[β-d-fucopyranosyl-(1→4)]-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-β-d-quinovopyranoside (3S,11S)-dihydroxytetradecanoic acid. The acylating residues of this core were acetic, (+)-(2S)-methylbutanoic, and dodecanoic acids. The site of lactonization was defined as C-3 of the second saccharide moiety. Reversal of multidrug resistance by this noncytotoxic compound was evaluated in vinblastine-resistant human breast carcinoma cells. PMID:25536852

  2. An antimitotic and antivascular agent BPR0L075 overcomes multidrug resistance and induces mitotic catastrophe in paclitaxel-resistant ovarian cancer cells.

    PubMed

    Wang, Xiaolei; Wu, Erxi; Wu, Jun; Wang, Tian-Li; Hsieh, Hsing-Pang; Liu, Xinli

    2013-01-01

    Paclitaxel plays a major role in the treatment of ovarian cancer; however, resistance to paclitaxel is frequently observed. Thus, new therapy that can overcome paclitaxel resistance will be of significant clinical importance. We evaluated antiproliferative effects of an antimitotic and antivascular agent BPR0L075 in paclitaxel-resistant ovarian cancer cells. BPR0L075 displays potent and broad-spectrum cytotoxicity at low nanomolar concentrations (IC50 = 2-7 nM) against both parental ovarian cancer cells (OVCAR-3, SKOV-3, and A2780-1A9) and paclitaxel-resistant sublines (OVCAR-3-TR, SKOV-3-TR, 1A9-PTX10), regardless of the expression levels of the multidrug resistance transporter P-gp and class III β-tubulin or mutation of β-tubulin. BPR0L075 blocks cell cycle at the G2/M phase in paclitaxel-resistant cells while equal concentration of paclitaxel treatment was ineffective. BPR0L075 induces cell death by a dual mechanism in parental and paclitaxel-resistant ovarian cancer cells. In the parental cells (OVCAR-3 and SKOV-3), BPR0L075 induced apoptosis, evidenced by poly(ADP-ribose) polymerase (PARP) cleavage and DNA ladder formation. BPR0L075 induced cell death in paclitaxel-resistant ovarian cancer cells (OVCAR-3-TR and SKOV-3-TR) is primarily due to mitotic catastrophe, evidenced by formation of giant, multinucleated cells and absence of PARP cleavage. Immunoblotting analysis shows that BPR0L075 treatment induced up-regulation of cyclin B1, BubR1, MPM-2, and survivin protein levels and Bcl-XL phosphorylation in parental cells; however, in resistant cells, the endogenous expressions of BubR1 and survivin were depleted, BPR0L075 treatment failed to induce MPM-2 expression and phosphorylation of Bcl-XL. BPR0L075 induced cell death in both parental and paclitaxel-resistant ovarian cancer cells proceed through caspase-3 independent mechanisms. In conclusion, BPR0L075 displays potent cytotoxic effects in ovarian cancer cells with a potential to overcome paclitaxel

  3. NANOPREPARATIONS TO OVERCOME MULTIDRUG RESISTANCE IN CANCER

    PubMed Central

    Patel, Niravkumar R.; Pattni, Bhushan S.; Abouzeid, Abraham H.; Torchilin, Vladimir P.

    2013-01-01

    Multidrug resistance is the most widely exploited phenomenon by which cancer eludes chemotherapy. Broad variety of factors, ranging from the cellular ones, such as over-expression of efflux transporters, defective apoptotic machineries, and altered molecular targets, to the physiological factors such as higher interstitial fluid pressure, low extracellular pH, and formation of irregular tumor vasculature are responsible for multidrug resistance. A combination of various undesirable factors associated with biological surroundings together with poor solubility and instability of many potential therapeutic small & large molecules within the biological systems and systemic toxicity of chemotherapeutic agents has necessitated the need for nano-preparations to optimize drug delivery. The physiology of solid tumors presents numerous challenges for successful therapy. However, it also offers unique opportunities for the use of nanotechnology. Nanoparticles, up to 400 nm in size, have shown great promise for carrying, protecting and delivering potential therapeutic molecules with diverse physiological properties. In this review, various factors responsible for the MDR and the use of nanotechnology to overcome the MDR, the use of spheroid culture as well as the current technique of producing micro tumor tissues in vitro are discussed in detail. PMID:23973912

  4. Regulation of MAPKs Signaling Contributes to the Growth Inhibition of 1,7-Dihydroxy-3,4-dimethoxyxanthone on Multidrug Resistance A549/Taxol Cells.

    PubMed

    Zuo, Jian; Jiang, Hui; Zhu, Yan-Hong; Wang, Ya-Qin; Zhang, Wen; Luan, Jia-Jie

    2016-01-01

    1,7-Dihydroxy-3,4-dimethoxyxanthone (XAN) is a bioactive compound isolated from Securidaca inappendiculata Hassk. and validated with antiproliferative activities on a panel of cancer cell lines. This study was designed to investigate its growth inhibitory effects on multidrug resistance (MDR) non-small cell lung carcinoma (NSCLC) cell line A549/Taxol and explore the possible linkage between modulation of MAPKs and the bioactivities. Its growth inhibitory potency on the cells was estimated by MTT assay, and flow cytometric analysis was employed to investigate its potential cell cycle arrest and proapoptosis effects. Expressions of hallmark proteins were assessed by Western-Blot method. The results showed A549/Taxol cells were sensitive to XAN. XAN inhibited the proliferation of A549/Taxol cells in the time and concentration dependent manners. It acted as a potent inducer of apoptosis and cell cycle arrest in the cells. Western-Blot investigation validated the proapoptosis and cell cycle arrest activities of XAN and the potential of MDR reversion. Upregulation of p38 by XAN, which accounted for the cell cycle arrest at G2 phase, and the downregulation of ERK associated with the proapoptosis activity were also revealed. Further analysis found p53 may be the central role mediated the bioactivities of MAPKs in A549/Taxol cells. Based on these evidences, a conclusion has been deduced that XAN could be a potential agent for MDR NSCLC therapy targeting specifically MAPKs. PMID:27403196

  5. Regulation of MAPKs Signaling Contributes to the Growth Inhibition of 1,7-Dihydroxy-3,4-dimethoxyxanthone on Multidrug Resistance A549/Taxol Cells

    PubMed Central

    Zuo, Jian; Jiang, Hui; Zhu, Yan-Hong; Wang, Ya-Qin; Zhang, Wen

    2016-01-01

    1,7-Dihydroxy-3,4-dimethoxyxanthone (XAN) is a bioactive compound isolated from Securidaca inappendiculata Hassk. and validated with antiproliferative activities on a panel of cancer cell lines. This study was designed to investigate its growth inhibitory effects on multidrug resistance (MDR) non-small cell lung carcinoma (NSCLC) cell line A549/Taxol and explore the possible linkage between modulation of MAPKs and the bioactivities. Its growth inhibitory potency on the cells was estimated by MTT assay, and flow cytometric analysis was employed to investigate its potential cell cycle arrest and proapoptosis effects. Expressions of hallmark proteins were assessed by Western-Blot method. The results showed A549/Taxol cells were sensitive to XAN. XAN inhibited the proliferation of A549/Taxol cells in the time and concentration dependent manners. It acted as a potent inducer of apoptosis and cell cycle arrest in the cells. Western-Blot investigation validated the proapoptosis and cell cycle arrest activities of XAN and the potential of MDR reversion. Upregulation of p38 by XAN, which accounted for the cell cycle arrest at G2 phase, and the downregulation of ERK associated with the proapoptosis activity were also revealed. Further analysis found p53 may be the central role mediated the bioactivities of MAPKs in A549/Taxol cells. Based on these evidences, a conclusion has been deduced that XAN could be a potential agent for MDR NSCLC therapy targeting specifically MAPKs. PMID:27403196

  6. Pyrazine, 2-ethylpyridine, and 3-ethylpyridine are cigarette smoke components that alter the growth of normal and malignant human lung cells, and play a role in multidrug resistance development.

    PubMed

    Liu, Min; Poo, Wak-Kim; Lin, Yu-Ling

    2015-02-01

    Lung cancer is one of the few human diseases for which the primary etiological agent, cigarette smoke (CS), has been described; however, the precise role of individual cigarette smoke toxicant in tumor development and progression remains to be elusive. The purpose of this study was to assess in vitro the effects of previously identified cigarette smoke components, pyrazine, 2-ethylpyridine, and 3-ethylpyridine, on non-tumorigenic (MRC5) and adenocarcinomic (A549) human lung cell lines. Our data showed that the administration of three cigarette smoke components in combination perturbed the proliferation of both normal and adenocarcinomic cells. Study of malignant cells revealed that CS components were cytotoxic at high concentration (10(-6) M) and stimulatory in a dose-dependent manner at lower concentrations (10(-8) M to 10(-10) M). This adverse effect was enhanced when adenocarcinomic cells were maintained in hypoxia resembling intratumoral environment. Furthermore, exposure to pyrazine, 2-ethylpyridine, and 3-ethylpyridine induced oxidative stress in both normal and malignant cells. Finally, assessment of P-gp activity revealed that multidrug resistance was induced in CS component exposed adenocarcinomic lung cells and the induction was augmented in hypoxia. Taken together, pyrazine, 2-ethylpyridine, and 3-ethylpyridine adversely altered both normal and diseased lung cells in vitro and data collected from this study may help lung cancer patients to understand the importance of quitting smoking during lung cancer treatment. PMID:25449333

  7. Reversal of multidrug resistance in MCF-7/Adr cells by codelivery of doxorubicin and BCL2 siRNA using a folic acid-conjugated polyethylenimine hydroxypropyl-β-cyclodextrin nanocarrier

    PubMed Central

    Li, Jin-Ming; Zhang, Wei; Su, Hua; Wang, Yuan-Yuan; Tan, Cai-Ping; Ji, Liang-Nian; Mao, Zong-Wan

    2015-01-01

    Systemic administration of chemotherapy for cancer often faces drug resistance, limiting its applications in cancer therapy. In this study, we developed a simple multifunctional nanocarrier based on polyethylenimine (PEI) to codeliver doxorubicin (DOX) and BCL2 small interfering RNA (siRNA) for overcoming multidrug resistance (MDR) and enhancing apoptosis in MCF-7/Adr cancer cells by combining chemotherapy and RNA interference (RNAi) therapy. The low-molecular-weight branch PEI was used to conjugate hydroxypropyl-β-cyclodextrin (HP-β-CD) and folic acid (FA), forming the codelivery nanocarrier (FA-HP-β-CD-PEI) to encapsulate DOX with the cavity HP-β-CD and bind siRNA with the positive charge of PEI for tumor-targeting codelivering drugs. The drug-loaded nanocomplexes (FA-HP-β-CD-PEI/DOX/siRNA) showed uniform size distribution, high cellular uptake, and significant gene suppression of BCL2, displaying the potential of overcoming MDR for enhancing the effect of anticancer drugs. Furthermore, the nanocomplexes achieved significant cell apoptosis through a mechanism of downregulating the antiapoptotic protein BCL2, resulted in improving therapeutic efficacy of the coadministered DOX by tumor targeting and RNA interference. Our study indicated that combined RNAi therapy and chemotherapy using our functional codelivery nanocarrier could overcome MDR and enhance apoptosis in MDR cancer cells for a potential application in treating MDR cancers. PMID:25960653

  8. Interrogation of multidrug resistance (MDR1) P-glycoprotein (ABCB1) expression in human pancreatic carcinoma cells: correlation of 99mTc-Sestamibi uptake with western blot analysis.

    PubMed

    Harpstrite, Scott E; Gu, Hannah; Natarajan, Radhika; Sharma, Vijay

    2014-10-01

    Histopathological studies indicate that ∼63% of pancreatic tumors express multidrug resistance (MDR1) P-glycoprotein (Pgp) and its polymorphic variants. However, Pgp expression detected at the mRNA or protein level does not always correlate with functional transport activity. Because Pgp transport activity is affected by specific mutations and the phosphorylation state of the protein, altered or less active forms of Pgp may also be detected by PCR or immunohistochemistry, which do not accurately reflect the status of tumor cell resistance. To interrogate the status of the functional expression of MDR1 Pgp in MiaPaCa-2 and PANC-1 cells, cellular transport studies using Tc-Sestamibi were performed and correlated with western blot analysis. Biochemical transport assays in human pancreatic carcinoma MiaPaCa-2 and PANC-1 cells, human epidermal carcinoma drug-sensitive KB-3-1 cells, and human breast carcinoma MCF-7 cells (negative controls), and human epidermal carcinoma drug-resistant KB-8-5 cells, human breast carcinoma stably transfected with Pgp MCF-7/MDR1Pgp cells, and liver carcinoma HepG2 cells (positive controls) were performed. Protein levels were determined using a monoclonal antibody C219. Tc-Sestamibi demonstrates accumulation in human pancreatic carcinoma MiaPaCa-2 and PANC-1 cells. Uptake profiles are not affected by treatment with LY335979, a Pgp inhibitor, and correlate with western blot analysis. These cellular transport studies indicate an absence of Pgp at a functional level in MiaPaCa-2 and PANC-1 cells. Because major pancreatic tumors originate from the pancreatic duct and Tc-Sestamibi undergoes a dominant hepatobiliary mode of excretion, it would not be a sensitive probe for imaging pancreatic adenocarcinomas. Following interrogation of the functional status of Pgp in other pancreatic carcinoma cells, chemotherapeutic drugs that are also MDR1 substrates could offer alternative therapeutics for treating pancreatic adenocarcinomas. PMID:25036383

  9. Vitamin E derivative-based multifunctional nanoemulsions for overcoming multidrug resistance in cancer.

    PubMed

    Zheng, Nannan; Gao, Yanan; Ji, Hongyu; Wu, Linhua; Qi, Xuejing; Liu, Xiaona; Tang, Jingling

    2016-08-01

    The multidrug resistance (MDR), including intrinsic and acquired multidrug resistance, is a major problem in tumor chemotherapy. Here, we proposed a strategy for modulating intrinsic and/or acquired multidrug resistance by altering the levels of Bax and Bcl-2 expression and inhibiting the transport function of P-gp, increasing the intracellular concentration of its substrate anticancer drugs. Vitamin E derivative-based nanoemulsions containing paclitaxel (MNEs-PTX) were fabricated in this study, and in vitro anticancer efficacy of the nanoemulsion system was evaluated in the paclitaxel-resistant human ovarian carcinoma cell line A2780/Taxol. The MNEs-PTX exhibited a remarkably enhanced antiproliferation effect on A2780/Taxol cells than free paclitaxel (PTX) (p < 0.01). Compared with that in the Taxol group, MNEs-PTX further decreased mitochondrial potential. Vitamin E derivative-based multifunctional nanoemulsion (MNEs) obviously increased intracellular accumulation of rhodamine 123 (P-gp substrate). Overexpression of Bcl-2 is generally associated with tumor drug resistance, we found that MNEs could reduce Bcl-2 protein level and increase Bax protein level. Taken together, our findings suggest that anticancer drugs associated with MNEs could play a role in the development of MDR in cancers. PMID:26710274

  10. Biosynthesis of heterogeneous forms of multidrug resistance-associated glycoproteins.

    PubMed

    Greenberger, L M; Williams, S S; Horwitz, S B

    1987-10-01

    Multidrug-resistant J774.2 mouse macrophage-like cells, selected for resistance to colchicine, vinblastine, or taxol, overexpress antigenically related glycoproteins with distinct electrophoretic mobilities. These plasma membrane glycoproteins are likely to play a pivotal role in the expression of the multidrug resistance phenotype. To determine how these multidrug resistance-associated glycoproteins differ, the biosynthesis and N-linked carbohydrate composition of these proteins were examined and compared. Vinblastineor colchicine-selected cells made a 125-kDa precursor that was rapidly processed (t1/2 approximately equal to 20 min) to mature forms of 135 and 140 kDa, respectively. Heterogeneity between the 135- and 140-kDa forms of the molecule can be attributed to N-linked carbohydrate. In contrast, taxol-selected cells made two precursors, 125 and 120 kDa, which appeared within 5 and 15 min after the onset of pulse labeling, respectively. They were processed to mature forms of 140 and 130 kDa. Since a single deglycosylated precursor or mature form was not observed after enzymatic removal of N-linked oligosaccharides, other differences, besides N-linked glycosylation, which occur in early processing compartments, are likely to account for the two multidrug resistance-associated glycoproteins in taxol-selected cells. These results demonstrate that a family of multidrug resistance-associated glycoproteins can be differentially expressed. PMID:2888763