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Sample records for multidrug-resistant tumor cells

  1. Cell biological mechanisms of multidrug resistance in tumors.

    PubMed

    Simon, S M; Schindler, M

    1994-04-26

    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.

  2. 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

  3. The Impact of Cell Density and Mutations in a Model of Multidrug Resistance in Solid Tumors

    PubMed Central

    Greene, James; Lavi, Orit; Gottesman, Michael M.; Levy, Doron

    2016-01-01

    In this paper we develop a mathematical framework for describing multidrug resistance in cancer. To reflect the complexity of the underlying interplay between cancer cells and the therapeutic agent, we assume that the resistance level is a continuous parameter. Our model is written as a system of integro-differential equations that are parametrized by the resistance level. This model incorporates the cell-density and mutation dependence. Analysis and simulations of the model demonstrate how the dynamics evolves to a selection of one or more traits corresponding to different levels of resistance. The emerging limit distribution with nonzero variance is the desirable modeling outcome as it represents tumor heterogeneity. PMID:24553772

  4. Reversal effect of Tween-20 on multidrug resistance in tumor cells in vitro.

    PubMed

    Yang, Shouhui; Liu, Jinjuan; Chen, Yongqiang; Jiang, Jihong

    2012-04-01

    Multidrug resistance (MDR) is a major barrier for chemotherapy of many cancers. Non-ionic surfactants have great potential to reverse the MDR by preventing onset or delay progression of the carcinogenic process. However, the role of Tween-20 in the development of MDR remains unknown. The aim of this study was to explore the reversal effect and potential mechanism of Tween-20 on tumor cells in vitro. Alamar Blue assay was used to examine the reversal index of Tween-20 to vincristine (VCR), doxorubicin (DOX) and 5-fluorouracil (5-FU) in KBv200, HepG2/R and Bel-7402/5-FU, respectively. Morphological change was determined by Gimsa and Hoechst 33258 staining. The acumulation of DOX was confirmed by spectrofluorimetric assay. Cell cycle analysis was performed using flow cytometry. The mRNA and protein expression levels of MDR were assessed by semiquantitative RT-PCR and dot blot, respectively. The results showed that Tween-20 at concentrations of 0.0025%, 0.005%, 0.01% had little cytotoxicity. When combined with the cancer drugs, it significantly promoted the sensitivity of MDR cells. Fluorescence staining confirmed that the percentage of apoptotic cell increased when combined with Tween-20. This notion was further supported by the observation that Tween-20 treatment potentiated VIN-induced G2/M arrest of the cell cycle. Furthermore, Tween-20 treatment increased significantly intracellular accumulation of DOX. RT-PCR and dot blot revealed that Tween-20 could downregulate the expression of MDR and P-glycoprotein. Low concentrations of Tween-20 can efficiently reverse the multidrug resistance phenotype by enhancing accumulation of the anticancer drugs. The potential mechanism may be via inhibiting the multidrug-resistant gene expression.

  5. Structure-activity relationships of diverse xanthones against multidrug resistant human tumor cells.

    PubMed

    Wang, Qiwen; Ma, Chenyao; Ma, Yun; Li, Xiang; Chen, Yong; Chen, Jianwei

    2017-02-01

    Thirteen xanthones were isolated naturally from the stem of Securidaca inappendiculata Hassk, and structure-activity relationships (SARs) of these compounds were comparatively predicted for their cytotoxic activity against three human multidrug resistant (MDR) cell lines MCF-7/ADR, SMMC-7721/Taxol, and A549/Taxol cells. The results showed that the selected xanthones exhibited different potent cytotoxic activity against the growth of different human tumor cell lines, and most of the xanthones exhibited selective cytotoxicity against SMMC-7721/Taxol cells. Furthermore, some tested xanthones showed stronger cytotoxicity than Cisplatin, which has been used in clinical application extensively. The SARs analysis revealed that the cytotoxic activities of diverse xanthones were affected mostly by the number and position of methoxyl and hydroxyl groups. Xanthones with more free hydroxyl and methoxyl groups increased the cytotoxic activity significantly, especially for those with the presence of C-3 hydroxyl and C-4 methoxyl groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Comparison of daunorubicin and Fluo-3 for detection of multidrug resistance in human tumor cells.

    PubMed

    Gheuens, E E; van der Heyden, S A; Elst, H E; Van Oosterom, A T; De Bruijn, E A

    1997-01-01

    The detection of multidrug resistance (MDR) in clinical samples is still a topic for discussion. One method, proven extremely useful for detection of membrane proteins in patients with hematological malignancies is the flow cytometrical analysis of individual tumor cells. Recently an assay was described based on the labeling of the P-glycoprotein (P-gp) with the monoclonal antibody MRK16, combined with detection of active daunorubicin (DNR) extrusion. In order to improve the specificity of the assay, on line with the results obtained by Wall et al., we exploited staining with Fluo-3. Both assays prove to be able to discriminate between drug-resistant and drug-sensitive cells. A major drawback of labeling with Fluo-3 in combination with the monoclonal antibody MRK16 is the important overlap of emission spectra of both fluorochromes. Moreover, using Fluo-3 for the detection of MDR might be complicated by the fact that differences in fluorescence intensities are not solely dependent on the presence of P-gp, but also on the activity of cytosolic esterases and the intracellular calcium concentration. Combination of the detection of structural and functional aspects of the MDR-associated protein may lead to a more precise detection of the MDR-positive patient.

  7. Laurus nobilis L. Seed Extract Reveals Collateral Sensitivity in Multidrug-Resistant P-Glycoprotein-Expressing Tumor Cells.

    PubMed

    Saab, Antoine M; Guerrini, Alessandra; Zeino, Maen; Wiench, Benjamin; Rossi, Damiano; Gambari, Roberto; Sacchetti, Gianni; Greten, Henry Johannes; Efferth, Thomas

    2015-01-01

    The frequent failure of standard cancer chemotherapy requires the development of novel drugs capable of killing otherwise drug-resistant tumors. Here, we have investigated a chloroform extract of Laurus nobilis seeds. Fatty acids and 23 constituents of the volatile fraction were identified by gas chromotography/flame ionization detection (GC/FID) and gas chromatography/mass spectrometry (GC/MS), in good agreement with (1)H NMR (nuclear magnetic resonance) spectrum. Multidrug-resistant P-glycoprotein-expressing CEM/ADR5000 leukemia cells were hypersensitive (collaterally sensitive) toward this extract compared to drug-sensitive CCRF-CEM cells, whereas CEM/ADR5000 cells were 2586-fold resistant to doxorubicin as control drug. Collateral sensitivity was verified by measurement of apoptotic cells by flow cytometry. The log10IC50 values of 3 compounds in the extract (limonene, eucalyptol, oleic acid) did not correlate with mRNA expression of the P-glycoprotein-coding ABCB1/MDR1 gene and accumulation of the P-glycoprotein substrate rhodamine in the NCI panel of tumor cell lines. A microarray-based profile of 20 genes predicted resistance to doxorubicin and 7 other anticancer drugs involved in the multidrug resistance phenotype but not to limonene, eucalyptol and oleic acid. In conclusion, our results show that Laurus nobilis seed extract is suitable to kill multidrug-resistant P-glycoprotein expressing tumor cells.

  8. Activity of the dietary flavonoid, apigenin, against multidrug-resistant tumor cells as determined by pharmacogenomics and molecular docking.

    PubMed

    Saeed, Mohamed; Kadioglu, Onat; Khalid, Hassan; Sugimoto, Yoshikazu; Efferth, Thomas

    2015-01-01

    Apigenin is a common dietary flavonoid with considerable cytotoxic activity in vitro and in vivo. Despite many mechanistic studies, less is known about resistance factors hampering apigenin's activity. We investigated the ATP-binding cassette (ABC) transporters BCRP/ABCG2, P-glycoprotein/ABCB1 and its close relative ABCB5. Multidrug-resistant cells overexpressing these ABC transporters were not cross-resistant toward apigenin. Moreover, apigenin inhibited not only P-glycoprotein but also BCRP by increasing cellular uptake of doxorubicin and synergistic inhibition of cell viability in combination with doxorubicin or docetaxel in multidrug-resistant cells. To perform in silico molecular docking studies, we first generated homology models for human P-glycoprotein and ABCB5 based on the crystal structure of murine P-glycoprotein. Their nucleotide binding domains (NDBs) revealed the highest degrees of sequence homologies (89%-100%), indicating that ATP binding and cleavage is of crucial importance for ABC transporters. Molecular docking of apigenin bound to the NDBs of P-glycoprotein and ABCB5 in molecular docking studies. Hence, apigenin may compete with ATP for NDB-binding leading to energy depletion to fuel the transport of ABC transporter substrates. Furthermore, we performed COMPARE and hierarchical cluster analyses of transcriptome-wide mRNA expression profiles of the National Cancer Institute tumor cell line panel. Microarray-based mRNA expressions of genes of diverse biological functions (signal transduction, transcriptional regulation, ubiquitination, autophagy, metabolic activity, xenobiotic detoxification and microtubule formation) significantly predicted responsiveness of tumor cells to apigenin. In conclusion, apigenin's activity is not hampered by classical mechanisms of multidrug resistance and the inhibition of ABC transporters by apigenin indicates that apigenin may overcome multidrug resistance in otherwise refractory tumors.

  9. Reversal effect and mechanism of Ginkgo biloba exocarp extracts in multidrug resistance of mice S180 tumor cells.

    PubMed

    Hu, Bi-Yuan; Gu, Yun-Hao; Cao, Chen-Jie; Wang, Jun; Han, Dong-Dong; Tang, Ying-Chao; Chen, Hua-Sheng; Xu, Aihua

    2016-10-01

    The aim of the present study was to investigate the reversal effect and its related mechanism of Ginkgo biloba exocarp extracts (GBEEs) in obtained multidrug resistance (MDR) of mice S180 tumor cells in vitro and in vivo. In order to simulate the clinical PFC [cis-dichlorodiamineplatinum, cisplatin (DDP) + fluorouracil (FU), FU+cyclophosphamide and cyclophosphamide] scheme, a gradually increasing dose was administered in a phased induction in order to induce S180 cells in vivo and to make them obtain multidrug resistance. The results in vitro demonstrated that GBEE could significantly increase the IC50 of DDP on S180 MDR cells, increase the accumulation of Adriamycin (ADR) and rhodamine 123 (Rho 123), and reduce the efflux of Rho 123 of S180 MDR cells. The results from the in vivo treatment with a combination of GBEE and DDP to S180 MDR ascites tumor in mice demonstrated that each dose of GBEE could effectively reverse the drug-resistance of S180 MDR cells to DDP in order to extend the survival time of mice with ascite tumors and inhibit tumor growth in solid tumor mice. In addition, GBEE effectively inhibited the expression of MDR-1 mRNA and multidrug resistance-associated protein-1 mRNA in S180 MDR cells of ascites tumor in mice and improved the expression levels of cytokines, including interleukin (IL)-3, IL-18 and interferon-γ in the blood serum of S180 MDR tumor-bearing mice. The present study showed that the mechanism of GBEE reversal of MDR may be associated with the inhibition of the functional activity of P-glycoprotein, the downregulation of drug resistance related gene expression of S180 MDR cells and the improvement of the production of related serum cytokines of S180 MDR tumor mice.

  10. Reversal effect and mechanism of Ginkgo biloba exocarp extracts in multidrug resistance of mice S180 tumor cells

    PubMed Central

    Hu, Bi-Yuan; Gu, Yun-Hao; Cao, Chen-Jie; Wang, Jun; Han, Dong-Dong; Tang, Ying-Chao; Chen, Hua-Sheng; Xu, Aihua

    2016-01-01

    The aim of the present study was to investigate the reversal effect and its related mechanism of Ginkgo biloba exocarp extracts (GBEEs) in obtained multidrug resistance (MDR) of mice S180 tumor cells in vitro and in vivo. In order to simulate the clinical PFC [cis-dichlorodiamineplatinum, cisplatin (DDP) + fluorouracil (FU), FU+cyclophosphamide and cyclophosphamide] scheme, a gradually increasing dose was administered in a phased induction in order to induce S180 cells in vivo and to make them obtain multidrug resistance. The results in vitro demonstrated that GBEE could significantly increase the IC50 of DDP on S180 MDR cells, increase the accumulation of Adriamycin (ADR) and rhodamine 123 (Rho 123), and reduce the efflux of Rho 123 of S180 MDR cells. The results from the in vivo treatment with a combination of GBEE and DDP to S180 MDR ascites tumor in mice demonstrated that each dose of GBEE could effectively reverse the drug-resistance of S180 MDR cells to DDP in order to extend the survival time of mice with ascite tumors and inhibit tumor growth in solid tumor mice. In addition, GBEE effectively inhibited the expression of MDR-1 mRNA and multidrug resistance-associated protein-1 mRNA in S180 MDR cells of ascites tumor in mice and improved the expression levels of cytokines, including interleukin (IL)-3, IL-18 and interferon-γ in the blood serum of S180 MDR tumor-bearing mice. The present study showed that the mechanism of GBEE reversal of MDR may be associated with the inhibition of the functional activity of P-glycoprotein, the downregulation of drug resistance related gene expression of S180 MDR cells and the improvement of the production of related serum cytokines of S180 MDR tumor mice. PMID:27698692

  11. Radioiodinated agents for imaging multidrug resistant tumors.

    PubMed

    Kortylewicz, Zbigniew P; Augustine, Ann M; Nearman, Jessica; McGarry, Jonathon; Baranowska-Kortylewicz, Janina

    2009-03-01

    Diagnostic agents enabling characterization of multidrug resistance (MDR) in tumors can aid in the selection of chemotherapy regimens. We report here synthesis and evaluation of radiopharmaceuticals based on the second-generation MDR-reversing drug MS-209. 5-[3-{4-(2-Phenyl-2-(4'-[(125)I]iodo-phenyl)acetyl)piperazin-1-yl}-2-hydroxypropoxy]quino-line (17) was prepared from the 4'-tributylstannyl precursor (16) in >95% radiochemical yield. (16) was synthesized in a six-step process with the overall yield of 25%. In vitro studies were conducted in MES-SA (drug-sensitive) and MES-SA/Dx5 (MDR) human uterine sarcoma cell lines. In vivo studies were performed in athymic mice bearing MES-SA and MES-SA/Dx5 xenografts. The uptake of (17) is higher in MES-SA than MES-SA/Dx5 cells. The uptake and efflux of (17) depend on temperature and concentration, and indicate active transport mechanism(s). Incubation of drug sensitive MES-SA cells with verapamil or (15), a nonradioactive analog of (17), alters the cellular retention of radioactivity only marginally. However, MES-SA/Dx5 cells retain approximately 12% more of (17) when incubated with 10 muM verapamil. The addition of (15) or high concentrations of (17) also increase the uptake of (17) in MES-SA/Dx5 up to 200%, depending on the concentration and temperature. The dependence of (17) uptake on the MDR status is also evident in the ex vivo binding studies. In vivo tests in mice xenografted simultaneously with both tumor cell lines indicate distinct pharmacokinetics for each tumor. The absorption half-life in MES-SA/Dx5 xenograft is approximately 10x shorter and the mean residence time approximately 50% shorter compared to MES-SA xenograft in the same mouse. Radioiodinated derivatives of MS-209 appear to be good indicators of multidrug resistance.

  12. A light in multidrug resistance: photodynamic treatment of multidrug-resistant tumors.

    PubMed

    Capella, Márcia Alves Marques; Capella, Luiz Sabbatini

    2003-01-01

    The major drawback of cancer chemotherapy is the development of multidrug-resistant (MDR) tumor cells, which are cross-resistant to a broad range of structurally and functionally unrelated agents, making it difficult to treat these tumors. In the last decade, a number of authors have studied the effects of photodynamic therapy (PDT), a combination of visible light with photosensitizing agents, on MDR cells. The results, although still inconclusive, have raised the possibility of treating MDR tumors by PDT. This review examines the growing literature concerning the responses of MDR cells to PDT, while stressing the need for the development of new photosensitizers that possess the necessary characteristics for the photodynamic treatment of this class of tumor. Copyright 2003 National Science Council, ROC and S. Karger AG, Basel

  13. Cytotoxicity and apoptosis induced by alfalfa (Medicago sativa) leaf extracts in sensitive and multidrug-resistant tumor cells.

    PubMed

    Gatouillat, Grégory; Magid, Abdulmagid Alabdul; Bertin, Eric; Okiemy-Akeli, Marie-Genevieve; Morjani, Hamid; Lavaud, Catherine; Madoulet, Claudie

    2014-01-01

    Alfalfa (Medicago sativa) has been used to cure a wide variety of ailments. However, only a few studies have reported its anticancer effects. In this study, extracts were obtained from alfalfa leaves and their cytotoxic effects were assessed on several sensitive and multidrug-resistant tumor cells lines. Using the mouse leukaemia P388 cell line and its doxorubicin-resistant counterpart (P388/DOX), we showed that the inhibition of cell growth induced by alfalfa leaf extracts was mediated through the induction of apoptosis, as evidenced by DNA fragmentation analysis. The execution of programmed cell death was achieved via the activation of caspase-3, leading to PARP cleavage. Fractionation of toluene extract (To-1), the most active extract obtained from crude extract, led to the identification of 3 terpene derivatives and 5 flavonoids. Among them, (-)-medicarpin, (-)-melilotocarpan E, millepurpan, tricin, and chrysoeriol showed cytotoxic effects in P388 as well as P388/DOX cells. These results demonstrate that alfalfa leaf extract may have interesting potential in cancer chemoprevention and therapy.

  14. 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.

  15. Overexpression of the multidrug resistance-associated protein (MRP1) in human heavy metal-selected tumor cells.

    PubMed

    Vernhet, L; Courtois, A; Allain, N; Payen, L; Anger, J P; Guillouzo, A; Fardel, O

    1999-01-29

    Cellular and molecular mechanisms involved in the resistance to cytotoxic heavy metals remain largely to be characterized in mammalian cells. To this end, we have analyzed a metal-resistant variant of the human lung cancer GLC4 cell line that we have selected by a step-wise procedure in potassium antimony tartrate. Antimony-selected cells, termed GLC4/Sb30 cells, poorly accumulated antimony through an enhanced cellular efflux of metal, thus suggesting up-regulation of a membrane export system in these cells. Indeed, GLC4/Sb30 cells were found to display a functional overexpression of the multidrug resistance-associated protein MRP1, a drug export pump, as demonstrated by Western blotting, reverse transcriptase-polymerase chain reaction and calcein accumulation assays. Moreover, MK571, a potent inhibitor of MRP1 activity, was found to markedly down-modulate resistance of GLC4/Sb30 cells to antimony and to decrease cellular export of the metal. Taken together, our data support the conclusion that overexpression of functional MRP1 likely represents one major mechanism by which human cells can escape the cytotoxic effects of heavy metals.

  16. Inhibitory effect of steroidal alkaloids on drug transport and multidrug resistance in human cancer cells.

    PubMed

    Lavie, Y; Harel-Orbital, T; Gaffield, W; Liscovitch, M

    2001-01-01

    Intrinsic or acquired resistance of tumor cells to multiple cytotoxic drugs (multidrug resistance MDR) is a major cause of failure of cancer chemotherapy. MDR is often caused by elevated expression of drug transporters such as P-glycoprotein (P-gp) or multidrug resistance protein (MRP). A number of compounds, termed chemosensitizers, have little or no cytotoxic action of their own, but inhibit (P-gp) or MRP-mediated drug export and are capable of sensitizing MDR cells to the cytotoxic effects of chemotherapeutic drugs. Here we examined the ability of steroidal alkaloids of plant origin, namely the Veratrum sp. alkaloid cyclopamine and the Lycopersicon sp. alkaloid tomatidine, to act as potent and effective chemosensitizers in multidrug resistant tumor cells. Drug uptake was determined by measuring accumulation of tetramethylrosamine in multidrug resistant NCI AdrR human adenocarcinoma cells. Resistance to adriamycin and vinblastine was determined by utilizing the MTT cell survival assay. Cyclopamine and tomatidine elevate tetramethylrosamine uptake by NCI AdrR cells and sensitize the cells to the cytotoxic action of adriamycin and vinblastine. In both cases these agents are comparable in patency and efficacy to verapamil, a reversal agent commonly used in MDR research. It is concluded that steroidal alkaloids of plant origin act as inhibitors of P-gp-mediated drug transport and multidrug resistance and therefore may serve as chemosensitizers in combination chemotherapy with conventional cytotoxic drugs for treating multidrug resistant cancer.

  17. 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

  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. Histone deacetylase inhibitor (HDACI) PCI-24781 enhances chemotherapy induced apoptosis in multidrug resistant sarcoma cell lines

    PubMed Central

    Yang, Cao; Choy, Edwin; Hornicek, Francis J.; Wood, Kirkham B; Schwab, Joseph H; Liu, Xianzhe; Mankin, Henry; Duan, Zhenfeng

    2013-01-01

    The anti-tumor activity of histone deacetylase inhibitors (HDACI) on multi-drug resistant sarcoma cell lines has never been previously described. Four multidrug resistant sarcoma cell lines treated with HDACI PCI-24781 resulted in dose-dependent accumulation of acetylated histones, p21 and PARP cleavage products. Growth of these cell lines was inhibited by PCI-24781 at IC50 of 0.43 to 2.7. When we looked for synergy of PCI-24781 with chemotherapeutic agents, we found that PCI-24781 reverses drug resistance in all four multidrug resistant sarcoma cell lines and synergizes with chemotherapeutic agents to enhance caspase-3/7 activity. Expression of RAD51 (a marker for DNA double-strand break repair) was inhibited and the expression of GADD45α (a marker for growth arrest and DNA-damage) was induced by PCI-24781 in multidrug resistant sarcoma cell lines. In conclusion, HDACI PCI-24781 synergizes with chemotherapeutic drugs to induce apoptosis and reverses drug resistance in multidrug resistant sarcoma cell lines. PMID:21508354

  1. Promoter methylation patterns of ABCB1, ABCC1 and ABCG2 in human cancer cell lines, multidrug-resistant cell models and tumor, tumor-adjacent and tumor-distant tissues from breast cancer patients

    PubMed Central

    Spitzwieser, Melanie; Pirker, Christine; Koblmüller, Bettina; Pfeiler, Georg; Hacker, Stefan; Berger, Walter; Heffeter, Petra; Cichna-Markl, Margit

    2016-01-01

    Overexpression of ABCB1, ABCC1 and ABCG2 in tumor tissues is considered a major cause of limited efficacy of anticancer drugs. Gene expression of ABC transporters is regulated by multiple mechanisms, including changes in the DNA methylation status. Most of the studies published so far only report promoter methylation levels for either ABCB1 or ABCG2, and data on the methylation status for ABCC1 are scarce. Thus, we determined the promoter methylation patterns of ABCB1, ABCC1 and ABCG2 in 19 human cancer cell lines. In order to contribute to the elucidation of the role of DNA methylation changes in acquisition of a multidrug resistant (MDR) phenotype, we also analyzed the promoter methylation patterns in drug-resistant sublines of the cancer cell lines GLC-4, SW1573, KB-3-1 and HL-60. In addition, we investigated if aberrant promoter methylation levels of ABCB1, ABCC1 and ABCG2 occur in tumor and tumor-surrounding tissues from breast cancer patients. Our data indicates that hypomethylation of the ABCC1 promoter is not cancer type-specific but occurs in cancer cell lines of different origins. Promoter methylation was found to be an important mechanism in gene regulation of ABCB1 in parental cancer cell lines and their drug-resistant sublines. Overexpression of ABCC1 in MDR cell models turned out to be mediated by gene amplification, not by changes in the promoter methylation status of ABCC1. In contrast to the promoters of ABCC1 and ABCG2, the promoter of ABCB1 was significantly higher methylated in tumor tissues than in tumor-adjacent and tumor-distant tissues from breast cancer patients. PMID:27689338

  2. Overcoming Multidrug Resistance in Cancer Stem Cells

    PubMed Central

    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. 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

  4. 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

  5. Inhibition of Snail Family Transcriptional Repressor 2 (SNAI2) Enhances Multidrug Resistance of Hepatocellular Carcinoma Cells

    PubMed Central

    Fu, Rong-Jie; Lv, Ya-Ping; Jin, Wei; Meng, Chao; Chen, Guo-Qiang; Huang, Lei

    2016-01-01

    China accounts for almost half of the total number of liver cancer cases and deaths worldwide, and hepatocellular carcinoma (HCC) is the most primary liver cancer. Snail family transcriptional repressor 2 (SNAI2) is known as an epithelial to mesenchymal transition-inducing transcription factor that drives neoplastic epithelial cells into mesenchymal phenotype. However, the roles of endogenous SNAI2 remain controversial in different types of malignant tumors. Herein, we surprisingly identify that anchorage-independent growth, including the formation of tumor sphere and soft agar colony, is significantly increased when SNAI2 expression is inhibited by shRNAs in HCC cells. Suppression of SNAI2 suffices to up-regulate several cancer stem genes. Although unrelated to the metastatic ability, SNAI2 inhibition does increase the efflux of Hoechst 33342 and enhance multidrug resistance in vitro and in vivo. In agreement with this data, we demonstrate for the first time that decreasing SNAI2 level can transcriptionally upregulate several ATP binding cassette (ABC) transporter genes such as ABCB1. Moreover, ABC transporters’ inhibitor verapamil can rescue the multidrug resistance induced by SNAI2 inhibition. Our results implicate that SNAI2 behaves as a tumor suppressor by inhibiting multidrug resistance via suppressing ABC transporter genes in HCC cells. PMID:27760172

  6. Dual Agent Loaded PLGA Nanoparticles Enhanced Antitumor Activity in a Multidrug-Resistant Breast Tumor Eenograft Model

    PubMed Central

    Chen, Yan; Zheng, Xue-Lian; Fang, Dai-Long; Yang, Yang; Zhang, Jin-Kun; Li, Hui-Li; Xu, Bei; Lei, Yi; Ren, Ke; Song, Xiang-Rong

    2014-01-01

    Multidrug-resistant breast cancers have limited and ineffective clinical treatment options. This study aimed to develop PLGA nanoparticles containing a synergistic combination of vincristine and verapamil to achieve less toxicity and enhanced efficacy on multidrug-resistant breast cancers. The 1:250 molar ratio of VCR/VRP showed strong synergism with the reversal index of approximately 130 in the multidrug-resistant MCF-7/ADR cells compared to drug-sensitive MCF-7 cells. The lyophilized nanoparticles could get dispersed quickly with the similar size distribution, zeta potential and encapsulation efficiency to the pre-lyophilized nanoparticles suspension, and maintain the synergistic in vitro release ratio of drugs. The co-encapsulated nanoparticle formulation had lower toxicity than free vincristine/verapamil combinations according to the acute-toxicity test. Furthermore, the most effective tumor growth inhibition in the MCF-7/ADR human breast tumor xenograft was observed in the co-delivery nanoparticle formulation group in comparison with saline control, free vincristine, free vincristine/verapamil combinations and single-drug nanoparticle combinations. All the data demonstrated that PLGANPs simultaneously loaded with chemotherapeutic drug and chemosensitizer might be one of the most potential formulations in the treatment of multidrug-resistant breast cancer in clinic. PMID:24552875

  7. Sorcin, a calcium binding protein involved in the multidrug resistance mechanisms in cancer cells.

    PubMed

    Colotti, Gianni; Poser, Elena; Fiorillo, Annarita; Genovese, Ilaria; Chiarini, Valerio; Ilari, Andrea

    2014-09-05

    Sorcin is a penta-EF hand calcium binding protein, which participates in the regulation of calcium homeostasis in cells. Sorcin regulates calcium channels and exchangers located at the plasma membrane and at the endo/sarcoplasmic reticulum (ER/SR), and allows high levels of calcium in the ER to be maintained, preventing ER stress and possibly, the unfolded protein response. Sorcin is highly expressed in the heart and in the brain, and overexpressed in many cancer cells. Sorcin gene is in the same amplicon as other genes involved in the resistance to chemotherapeutics in cancer cells (multi-drug resistance, MDR) such as ABCB4 and ABCB1; its overexpression results in increased drug resistance to a number of chemotherapeutic agents, and inhibition of sorcin expression by sorcin-targeting RNA interference leads to reversal of drug resistance. Sorcin is increasingly considered a useful marker of MDR and may represent a therapeutic target for reversing tumor multidrug resistance.

  8. Acquired multidrug resistance in human K562/ADM cells is associated with enhanced autophagy.

    PubMed

    Cheng, Juan; Chen, Jing; Xie, Bei; Wei, Hu-lai

    2013-11-01

    Autophagy, as a necessary process for survival in mammalian cells deprived of nutrients or growth factors, will be activated in many tumor cells while treated with chemotherapeutic drugs, but the role of autophagy in acquired multidrug resistance of human acute myelogenous leukemia to adriamycin-based chemotherapy remains to be clarified. Our aim was to address that question by surveying the autophagic activity in parental acute myelogenous leukemia cell line K562 and resistant sub cell line, K562/ADM, which were obtained by treating adriamycin with increasing concentrations. K562/ADM and K562 cells were exposed to PBS culture medium for 3 hours, then the stress-induced autophagy was measured. Real-time quantitative RT-PCR revealed the expression of LC3 mRNA was higher in K562/ADM than in K562 cells. LC3-II, as an autophagosomal marker, was more abundant in K562/ADM than in K562 cells measured by Western blotting. To determine the effect of 3-MA, a known specific inhibitor of autophagy, on overcoming acquired multidrug resistance induced by adriamycin, the MTT assay and flow cytometry were performed. We also found that 3-MA can enhance the growth inhibition and apoptotic effect of adriamycin in acquired resistant cells (K562/ADM). Collectively, our results provide evidence that the upregulation of autophagy plays a major role in multidrug resistance of K562/ADM cells induced by adriamycin.

  9. Novel nanostructured enoxaparin sodium-PLGA hybrid carriers overcome tumor multidrug resistance of doxorubicin hydrochloride.

    PubMed

    Wang, Jia; Wu, Lei; Kou, Longfa; Xu, Meng; Sun, Jin; Wang, Yongjun; Fu, Qiang; Zhang, Peng; He, Zhonggui

    2016-11-20

    Novel enoxaparin sodium-PLGA hybrid nanocarries (EPNs) were successfully designed for sustained delivery of hydrophilic cationic doxorubicin hydrochloride (DOX) and to overcome multidrug resistance (MDR). By incorporation of the negative polymer of enoxaparin sodium (ES), DOX was highly encapsulated into EPNs with an encapsulation efficiency of 92.49%, and ES effectively inhibited the proliferation of HUVEC cell lines. The in vivo pharmacokinetics study after intravenous injection indicated that DOX-loaded EPNs (DOX-EPNs) exhibited a higher area under the curve (AUC) and a longer half-life (t1/2) in comparison with DOX solution (DOX-Sol). The biodistribution study demonstrated that DOX-EPNs increased the DOX level in plasma and decreased the accumulation of DOX in liver and spleen. Compared with DOX-Sol, DOX-EPNs increased the cytotoxicity in P-gp over-expressing MCF-7/Adr cells, attributed to the higher intracellular efficiency of DOX produced by the EPNs. DOX-EPNs entered into resistant tumor cells by multiple endocytosis pathways, which resulted in overcoming the multidrug resistance of MCF-7/Adr cells by escaping the efflux induced by P-gp transporters. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. 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

  11. Development of EGFR-Targeted Polymer Blend Nanocarriers for Combination Paclitaxel/Lonidamine Delivery to Treat Multi-Drug Resistance in Human Breast and Ovarian Tumor Cells

    PubMed Central

    Milane, Lara; Duan, Zhenfeng; Amiji, Mansoor

    2013-01-01

    Multi-drug resistant (MDR) cancer is a significant clinical obstacle and is often implicated in cases of recurrent, non-responsive disease. Targeted nanoparticles were made by synthesizing a poly(D,L-lactide-co-glycolide)/poly(ethylene glycol)/epidermal growth factor receptor targeting peptide (PLGA/PEG/EGFR-peptide) construct for incorporation in poly(epsilon-caprolactone) (PCL) nanoparticles. MDR was induced in a panel of nine human breast and ovarian cancer cell lines using hypoxia. EGFR-targeted polymer blend nanoparticles were shown to actively target EGFR over-expressing cell lines, especially upon induction of hypoxia. The nanoparticles were capable of sustained drug release. Combination therapy with lonidamine and paclitaxel significantly improved the therapeutic index of both drugs. Treatment with a nanoparticle dose of 1 μM paclitaxel/10 μM lonidamine resulted in less than 10% cell viability for all hypoxic/MDR cell lines and less than 5% cell viability for all normoxic cell lines. Comparatively, treatment with 1 μM paclitaxel alone was the approximate IC50 value of the MDR cells while treatment with lonidamine alone had very little effect. PLGA/PEG/EGFR-peptide delivery system actively targets a MDR cell by exploiting the expression of EGFR. This system treats MDR by inhibiting the Warburg effect and promoting mitochondrial binding of pro-apoptotic Bcl-2 proteins (lonidamine), while hyperstabilizing microtubules (paclitaxel). This nanocarrier system actively targets a MDR associated phenotype (EGFR receptor over-expression), further enhancing the therapeutic index of both drugs and potentiating the use of lonidamine/paclitaxel combination therapy in the treatment of MDR cancer. PMID:20942457

  12. Biodegradable Nanocomplex from Hyaluronic acid and Arginine based Poly(ester amide)s as the Delivery Vehicles for Improved Photodynamic Therapy of Multidrug Resistant Tumor Cells: An In Vitro Study of the Performance of Chlorin e6 Photosensitizer.

    PubMed

    Ji, Ying; Zhao, Jihui; Chu, Chih-Chang

    2016-12-20

    Photodynamic therapy (PDT), which enables the localized therapeutic effect by light irradiation, provides an alternative and complementary modality for the treatment of tumor. However, the aggregation of photosensitizers in acidic microenvironment of tumor and the non-targeted distribution of photosensitizers in normal tissues significantly affect the PDT efficiency. In this study, we developed a biodegradable nanocomplex HA-Arg-PEA from hyaluronic acid (HA) and arginine based poly(ester amide)s (Arg-PEA) as the nano-carrier for chlorin e6 (Ce6). HA enhanced the tumor-specific endocytosis mediated by the overexpression of CD44 receptor. Arg-PEA not only provide electrostatic interaction with HA to form self-assembled nanostructure, but also improve the monomerization of Ce6 at physiological pH as well as mildly acidic pH. The biodegradable characteristic of HA-Arg-PEA nanocomplex enabled the intracellular delivery of Ce6, in which its release and generation of singlet oxygen can be accelerated by enzymatic degradation of the carrier. The in vitro PDT efficiency of Ce6-loaded HA-Arg-PEA nanocomplex was examined in CD44 positive MDA-MB-435/MDR multidrug resistant melanoma cells. CD44-mediated uptake of Ce6-loaded HA-Arg-PEA nanocomplex significantly improved Ce6 level in MDA-MB-435/MDR cells within short incubation time, and the PDT efficiency in inhibiting multidrug resistant tumor cells was also enhanced at higher Ce6 concentrations. This article is protected by copyright. All rights reserved.

  13. 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.

  14. Effects of standard chemotherapy on tumor growth and regulation of multidrug resistance genes and proteins in childhood rhabdomyosarcoma.

    PubMed

    Seitz, Guido; Warmann, Steven W; Vokuhl, Christian O; Heitmann, Heike; Treuner, Claudia; Leuschner, Ivo; Fuchs, Jörg

    2007-05-01

    The prognosis of rhabdomyosarcoma (RMS) in advanced stages is still sobering. Therapy is limited due to local tumor recurrence, development of metastases and multidrug resistance. The aim of this study was to investigate the development of multidrug resistance in cell lines and in xenografts of alveolar and embryonal RMS treated according to the German Soft Tissue Sarcoma Study (CWS). Alveolar and embryonal RMS cell lines were treated with Vincristine, Topotecan, Carboplatin, Actinomycin D, or Ifosfamide. Expression levels of resistance-associated genes were assessed using Real time-PCR. Nude mice (NMRI nu/nu, n = 10 per group) underwent xenotransplantation of human embryonal or alveolar RMS. Animals were treated with standard chemotherapeutic drugs Vincristine, Topotecan, Carboplatin, Actinomycin D, or Ifosfamide according to treatment schedules of the CWS-study. Tumor sizes were measured and relative tumor volumes were calculated. Animals were sacrificed after 20 days and standard histology, Real-time-PCR for MDR1-, MRP-, LRP- and MDM2-gene as well as immunohistochemistry for MDR1-, LRP-, and MRP-protein were performed. In the cell lines, an up-regulation of MDR-1 gene was found in alveolar rhabdomyosarcoma. In embryonal rhabdomyosarcoma, an up-regulation of LRP and MRP was found. Standard chemotherapy of alveolar rhabdomyosarcoma resulted in a significant reduction of tumor growth (P < 0.05) in all groups. In embryonal rhabdomyosarcoma strongest effects were found after treatment with Ifosfamide, Vincristine and Carboplatin (P < 0.05). RT-PCR revealed a MDR1-dependent mechanism in alveolar rhabdomyosarcoma. In embryonal rhabdomyosarcoma, MDR1 occurred to a lower degree. Immunohistochemistry revealed correlating expression levels of multidrug resistance-associated proteins. The use of established chemotherapy on human RMS in vivo had strong effects on xenografts compared to their controls. In all cases, there was only a reduction of tumor growth, but not a

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

    PubMed Central

    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

  16. 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.

  17. Effect of multidrug resistance 1/P-glycoprotein on the hypoxia-induced multidrug resistance of human laryngeal cancer cells.

    PubMed

    Li, Dawei; Zhou, Liang; Huang, Jiameng; Xiao, Xiyan

    2016-08-01

    In a previous study, it was demonstrated that hypoxia upregulated the multidrug resistance (MDR) of laryngeal cancer cells to chemotherapeutic drugs, with multidrug resistance 1 (MDR1)/P-glycoprotein (P-gp) expression also being upregulated. The present study aimed to investigate the role and mechanism of MDR1/P-gp on hypoxia-induced MDR in human laryngeal carcinoma cells. The sensitivity of laryngeal cancer cells to multiple drugs and cisplatin-induced apoptosis was determined by CCK-8 assay and Annexin-V/propidium iodide staining analysis, respectively. The accumulation of rhodamine 123 (Rh123) in the cells served as an estimate of drug accumulation and was evaluated by flow cytometry (FCM). MDR1/P-gp expression was inhibited using interference RNA, and the expression of the MDR1 gene was analyzed using reverse transcription-quantitative polymerase chain reaction and western blotting. As a result, the sensitivity to multiple chemotherapeutic agents and the apoptosis rate of the hypoxic laryngeal carcinoma cells increased following a decrease in MDR1/P-gp expression (P<0.05). Additionally, FCM analysis of fluorescence intensity indicated that the downregulated expression of MDR1/P-gp markedly increased intracellular Rh123 accumulation (P<0.05). Such results suggest that MDR1/P-gp serves an important role in regulating hypoxia-induced MDR in human laryngeal carcinoma cells through a decrease in intracellular drug accumulation.

  18. ROS-triggered and regenerating anticancer nanosystem: an effective strategy to subdue tumor's multidrug resistance.

    PubMed

    Su, Zhigui; Chen, Minglei; Xiao, Yanyu; Sun, Minjie; Zong, Li; Asghar, Sajid; Dong, Mei; Li, Huipeng; Ping, Qineng; Zhang, Can

    2014-12-28

    Drug delivery strategies utilizing tumor microenvironment are recognized as a critical doorway to overcome multidrug resistance (MDR). However, the variability of tumor microenvironment at different disease stages would definitely minimize stimuli generation and eventually the therapeutic effects of these stimuli sensitive systems. Herein, we report a unique reactive oxygen species (ROS) triggered nanosystem that can replenish the ROS upon disassembly to maintain its high level. This was accomplished by a new amphiphilic polymer (TBH) composed of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS), hyaluronic acid (HA) and arylboronic ester. As a linker of TPGS to HA, arylboronic ester could efficiently degrade in response to ROS resulting in dismantling of nanosystem followed by rapid release of TPGS. Owing to ROS inducing activity of TPGS with mitochondrial respiratory complex II, ROS regeneration was observed for TBH nanosystem both in MCF-7/ADR cells and tumor tissues xenografted with MCF-7/ADR cells. Furthermore, doxorubicin-loaded TBH nanosystem (DOX-TBH) revealed higher drug cytotoxicity due to enhanced retention effect on account of ROS triggered DOX release and P-gp inhibitory mechanism of TPGS. Moreover, HA significantly improved tumor targeting capability of DOX-TBH, while ROS based triggering and regenerating mechanism lead to marked inhibition of the tumor growth in the xenograft MCF-7/ADR tumor-bearing nude mice.

  19. The tumor microenvironment is a dominant force in multidrug resistance

    PubMed Central

    Correia, Ana Luísa; Bissell, Mina J.

    2013-01-01

    The emergence of clinical drug resistance is still one of the most challenging factors in cancer treatment effectiveness. Until more recently, the assumption has been that random genetic lesions are sufficient to explain the progression of malignancy and escape from chemotherapy. Here we propose an additional perspective, one in which the tumor cells despite the malignant genome could find a microenvironment either within the tumor or as a dormant cell to remain polar and blend into an organized context. Targeting this dynamic interplay could be considered a new avenue to prevent therapeutic resistance, and may even provide a promising effective cancer treatment. PMID:22335920

  20. The Role of Cell Density and Intratumoral Heterogeneity in Multidrug Resistance

    PubMed Central

    Lavi, Orit; Greene, James M.; Levy, Doron; Gottesman, Michael M.

    2016-01-01

    Recent data have demonstrated that cancer drug resistance reflects complex biological factors including tumor heterogeneity, varying growth, differentiation, apoptosis pathways, and cell density. As a result, there is a need to find new ways to incorporate these complexities in the mathematical modeling of multidrug resistance. Here, we derive a novel structured population model that describes the behavior of cancer cells under selection with cytotoxic drugs. Our model is designed to estimate intratumoral heterogeneity as a function of the resistance level and time. This updated model of the multidrug resistance problem integrates both genetic and epigenetic changes, density-dependence, and intratumoral heterogeneity. Our results suggest that treatment acts as a selection process, while genetic/epigenetic alterations rates act as a diffusion process. Application of our model to cancer treatment suggests that reducing alteration rates as a first step in treatment causes a reduction in tumor heterogeneity, and may improve targeted therapy. The new insight provided by this model could help to dramatically change the ability of clinical oncologists to design new treatment protocols and analyze the response of patients to therapy. Major Findings We suggest that chemotherapeutic treatment acts as a selection process in the effective drug concentrations range, while genetic/epigenetic alterations act as a diffusion process that results in trait spread based on different stress signals. Application of our model to cancer treatment suggests that reducing the alteration rate as a first step in treatment causes a reduction in tumor heterogeneity, and may improve targeted therapy. PMID:24163380

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

    PubMed

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

    2016-06-20

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

  2. Sinomenine reverses multidrug resistance in bladder cancer cells via P-glycoprotein-dependent and independent manners.

    PubMed

    Chen, Yule; Zhang, Linlin; Lu, Xinlan; Wu, Kaijie; Zeng, Jin; Gao, Yang; Shi, Qi; Wang, Xinyang; Chang, Luke S; He, Dalin

    2014-01-01

    P-Glycoprotein-mediated multidrug resistance is a frequent event during chemotherapy and a key obstacle for bladder cancer therapy. Search for strategies to reverse multidrug resistance is a promising approach to improve the management of bladder cancer. In the present study, we reported a novel P-glycoprotein-mediated multidrug resistant cell model 253J/DOX, which was generated from human bladder cancer 253J cell line. Furthermore, we found that the multidrug resistant phenotype of 253J/DOX cells could be overcome by sinomenine, an alkaloid derived from the stem of Sinomenium acutum. Mechanistically, the chemosensitive effect by sinomenine was mediated by down-regulating P-glycoprotein expression, as well as triggering apoptotic pathways. The chemosensitive effect of sinomenine may make it a prime candidate agent to target bladder cancer.

  3. Multidrug-resistance proteins are weak tumor associated antigens for colorectal carcinoma

    PubMed Central

    2011-01-01

    Background Multidrug resistance (MDR) is a clinically, highly relevant phenomenon. Under chemotherapy many tumors show an increasing resistance towards the applied substance(s) and to a certain extent also towards other agents. An important molecular cause of this phenomenon is an increased expression of transporter proteins. The functional relationship between high expression levels and chemotherapy resistance makes these MDR and MRP (MDR related protein) proteins to interesting therapeutic targets. We here wanted to systematically analyze, whether these proteins are tumor specific antigens which could be targeted immunologically. Results Using the reverse immunology approach, 30 HLA-A2.1 restricted MDR and MRP derived peptides (MDP) were selected. Stimulated T cell lines grew well and mainly contained activated CD8+ cells. Peptide specificity and HLA-A2.1 restriction were proven in IFN-γ-ELISpot analyses and in cytotoxicity tests against MDP loaded target cells for a total of twelve peptides derived from MDR-1, MDR-3, MRP-1, MRP-2, MRP-3 and MRP-5. Of note, two of these epitopes are shared between MDR-1 and MDR-3 as well as MRP-2 and MRP-3. However, comparably weak cytotoxic activities were additionally observed against HLA-A2.1+ tumor cells even after upregulation of MDR protein expression by in vitro chemotherapy. Conclusions Taken together, these data demonstrate that human T cells can be sensitised towards MDPs and hence, there is no absolute immunological tolerance. However, our data also hint towards rather low endogenous tumor cell processing and presentation of MDPs in the context of HLA-A2.1 molecules. Consequently, we conclude that MDR and MRP proteins must be considered as weak tumor specific antigens-at least for colorectal carcinoma. Their direct contribution to therapy-failure implies however, that it is worth to further pursue this approach. PMID:21740599

  4. Role of uL3 in Multidrug Resistance in p53-Mutated Lung Cancer Cells

    PubMed Central

    Russo, Annapina; Saide, Assunta; Smaldone, Silvia; Faraonio, Raffaella; Russo, Giulia

    2017-01-01

    Cancer is one of the most common causes of death among adults. Chemotherapy is crucial in determining patient survival and quality of life. However, the development of multidrug resistance (MDR) continues to pose a significant challenge in the management of cancer. In this study, we analyzed the role of human ribosomal protein uL3 (formerly rpL3) in multidrug resistance. Our studies revealed that uL3 is a key determinant of multidrug resistance in p53-mutated lung cancer cells by controlling the cell redox status. We established and characterized a multidrug resistant Calu-6 cell line. We found that uL3 down-regulation correlates positively with multidrug resistance. Restoration of the uL3 protein level re-sensitized the resistant cells to the drug by regulating the reactive oxygen species (ROS) levels, glutathione content, glutamate release, and cystine uptake. Chromatin immunoprecipitation experiments and luciferase assays demonstrated that uL3 coordinated the expression of stress-response genes acting as transcriptional repressors of solute carrier family 7 member 11 (xCT) and glutathione S-transferase α1 (GST-α1), independently of Nuclear factor erythroid 2-related factor 2 (Nrf2). Altogether our results describe a new function of uL3 as a regulator of oxidative stress response genes and advance our understanding of the molecular mechanisms underlying multidrug resistance in cancers. PMID:28273808

  5. Nanoparticle-mediated drug delivery to tumor neovasculature to combat P-gp expressing multidrug resistant cancer.

    PubMed

    Bai, Fan; Wang, Chao; Lu, Qin; Zhao, Mei; Ban, Fu-Qiang; Yu, De-Hong; Guan, Ying-Yun; Luan, Xin; Liu, Ya-Rong; Chen, Hong-Zhuan; Fang, Chao

    2013-08-01

    Anticancer drug resistance is a common intractable obstacle in clinical cancer chemotherapy. Here, we hypothesize that antiangiogenic cancer therapy through the targeted delivery of antiangiogenic agents to the tumor endothelial cells (EC), not the resistant cancer cells, may have the potential of combating multidrug resistant cancer. The K237 peptide-conjugated paclitaxel loaded nanoparticles (K237-PTX-NP), which can target KDR receptors highly expressed in the tumor vasculature, were fabricated for this investigation and the human colorectal adenocarcinoma HCT-15 with naturally expressed P-gp on the cell surface was adopted as the resistant tumor model. The human umbilical vein endothelial cells (HUVEC, a classical cell model mimicking tumor EC) were much more sensitive, in the cytotoxicity and apoptosis test, to K237-PTX-NP than Taxol and non-targeted PTX-NP. The enhanced antiangiogenic feature of K237-PTX-NP can be ascribed to the active internalization mediated by the interaction of K237 and KDR specifically highly expressed on the HUVEC, and the significantly extended intracellular drug retention. The tumor vessel targeting of K237-PTX-NP led to increased nanoparticle accumulation in HCT-15 tumors, and more importantly, induced significant apoptosis of tumor vascular EC and necrosis of tumor tissues. Low dose paclitaxel formulated in K237-PTX-NP (1 mg/kg) achieved significant anticancer efficacy of inhibiting the growth of HCT-15 tumors, but the same efficacy could be only obtained with 8 fold dose paclitaxel (8 mg/kg) in Taxol plus XR9576, a potent P-gp inhibitor. The anticancer efficacy of K237-PTX-NP was well related with the improved antiangiogenic effect shown in the dramatically decreased intratumoral microvessel density and pronouncedly increased apoptotic tumor cells, and such approach did not lead to obvious toxicity in the mice. These results suggest that the nanoparticles targeting drug to tumor neovasculature may be a promising strategy for the

  6. 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 Central

    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.

    2003-01-01

    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

  7. Establishment of a human hepatoma multidrug resistant cell line in vitro

    PubMed Central

    Zhou, Yuan; Ling, Xian-Long; Li, Shi-Wei; Li, Xin-Qiang; Yan, Bin

    2010-01-01

    AIM: To establish a multidrug-resistant hepatoma cell line (SK-Hep-1), and to investigate its biological characteristics. METHODS: A highly invasive SK-Hep-1 cell line of human hepatocellular carcinoma, also known as malignant hepatoma was incubated with a high concentration of cisplatin (CDDP) to establish a CDDP-resistant cell subline (SK-Hep-1/CDDP). The 50% inhibitory dose (IC50) values and the resistance indexes [(IC50 SK-Hep-1/CDDP)/(IC50 SK-Hep-1)] for other chemotherapeutic agents and the growth curve of cells were all evaluated using cell counting kit-8 assays. The distribution of the cell cycles were detected by flow cytometry. Expression of acquired multidrug resistance P-glycoprotein (MDR1, ABCB1) and multidrug resistance-associated protein 1 (MRP1, ABCC1) was compared with that in parent cells by Western blotting and immunofluorescence combined with laser scanning confocal microscopy. RESULTS: The SK-Hep-1/CDDP cells (IC50 = 70.61 ± 1.06 μg/mL) was 13.76 times more resistant to CDDP than the SK-Hep-1 cells (IC50 = 5.13 ± 0.09 μg/mL), and CDDP-resistant cells also demonstrated cross-resistance to many anti-tumor agents such as doxorubicin, 5-fluorouracil and vincristine. Similar morphologies were determined in both SK-Hep-1 and SK-Hep-1/CDDP groups. The cell cycle distribution of the SK-Hep-1/CDDP cell line exhibited a significantly increased percentage of cells in S (42.2% ± 2.65% vs 27.91% ± 2.16%, P < 0.01) and G2/M (20.67% ± 5.69% vs 12.14% ± 3.36%, P < 0.01) phases in comparison with SK-Hep-1 cells, while the percentage of cells in the G0/G1 phase decreased (37.5% ± 5.05% vs 59.83% ± 3.28%, P < 0.01). The levels of MDR1 and MRP1 were overexpressed in the SK-Hep-1/CDDP cells exhibiting the MDR phenotype. CONCLUSION: Multiple drug resistance of multiple drugs in the human hepatoma cell line SK-Hep-1/CDDP was closely related to the overexpression of MDR1 and MRP1. PMID:20458768

  8. Nrf2 pathway regulates multidrug-resistance-associated protein 1 in small cell lung cancer.

    PubMed

    Ji, Lili; Li, Hui; Gao, Pan; Shang, Guoguo; Zhang, Donna D; Zhang, Nong; Jiang, Tao

    2013-01-01

    Although multidrug-resistance-associated protein-1 (MRP1) is a major contributor to multi-drug resistance (MDR), the regulatory mechanism of Mrp1 still remains unclear. Nrf2 is a transcription factor that regulates cellular defense response through antioxidant response elements (AREs) in normal tissues. Recently, Nrf2 has emerged as an important contributor to chemo-resistance in tumor tissues. In the present study, the role of Nrf2-ARE pathway on regulation of Mrp1 was investigated. Compared with H69 lung cancer cells, H69AR cells with MDR showed significantly higher Nrf2-ARE pathway activity and expression of Mrp1 as well. When Nrf2 was knocked down in H69AR cells, MRP1's expression decreased accordingly. Moreover, those H69AR cells with reduced Nrf2 level restored sensitivity to chemo-drugs. To explore how Nrf2-ARE pathway regulates Mrp1, the promoter of Mrp1 gene was searched, and two putative AREs--ARE1 and ARE2--were found. Using reporter gene and ChIP assay, both ARE1 and ARE2 showed response to and interaction with Nrf2. In 40 cases of cancer tissues, the expression of Nrf2 and MRP1 was measured by immunohistochemistry (IHC). As the quantitive data of IHC indicated, both Nrf2 and MRP1 showed significantly higher expression in tumor tissue than adjacent non-tumor tissue. And more important, the correlation analysis of the two genes proved that their expression was correlative. Taken together, theses data suggested that Nrf2-ARE pathway is required for the regulatory expression of Mrp1 and implicated Nrf2 as a new therapeutic target for MDR.

  9. Reversion of P-glycoprotein-mediated multidrug resistance by guggulsterone in multidrug-resistant human cancer cell lines.

    PubMed

    Xu, Hong-Bin; Xu, Lu-Zhong; Li, Ling; Fu, Jun; Mao, Xia-Ping

    2012-11-05

    Multidrug resistance (MDR) presents a serious problem in cancer chemotherapy. Our previous studies have shown that guggulsterone could reverse MDR through inhibiting the function and expression of P-glycoprotein (P-gp). The present study is to further investigate the reversal effects of guggulsterone on MDR in drug-resistant cancer cell lines. The effects of guggulsterone on MDR1mRNA gene expression, intracellular pH, P-gp ATPase activity and glucosylceramide synthase (GCS) expression were assessed by RT-PCR, Laser Scanning Confocal Microscope using the pH-sensitive fluorescent probe BCECF-AM, Pgp-Glo assay system, and flow cytometric technology, respectively. The results showed that guggulsterone ranging from 2.5 to 80 μM significantly promoted the activity of P-gp ATPase in a dose-dependent manner. The intracellular pH of K562/DOX cells was found to be higher than K562 cells. After treatment with guggulsterone (1, 3, 10, 30, 100 μM), intracellular pH of K562/DOX cells decreased in a dose- and time-dependent manner. However, the present study revealed that guggulsterone ranging from 3 to 100 μM had little influence on MDR1 gene expression in K562/DOX cells. Further, the isogenic doxorubicin-resistant MCF-7/DOX cells exhibited a 4.9-fold increase in GCS level as compared with parental MCF-7 human breast cancer cells. After treatment with guggulsterone (0.1, 1, 10 μM) for 48 h, MCF-7/DOX cells were found to have no change of GCS protein expression amount. Guggulsterone might be a potent MDR reversal agent, and its mechanism on MDR needs more research. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. A Novel Submicron Emulsion System Loaded with Doxorubicin Overcome Multi-Drug Resistance in MCF-7/ADR Cells

    PubMed Central

    Zhou, W. P.; Hua, H. Y.; Sun, P. C.; Zhao, Y. X.

    2015-01-01

    The purpose of the present study was to develop the Solutol HS15-based doxorubicin submicron emulsion with good stability and overcoming multi-drug resistance. In this study, we prepared doxorubicin submicron emulsion, and examined the stability after autoclaving, the in vitro cytotoxic activity, the intracellular accumulation and apoptpsis of doxorubicin submicron emulsion in MCF-7/ADR cells. The physicochemical properties of doxorubicin submicron emulsion were not significantly affected after autoclaving. The doxorubicin submicron emulsion significantly increased the intracellular accumulation of doxorubicin submicron emulsion and enhanced cytotoxic activity and apoptotic effects of doxorubicin. These results may be correlated to doxorubicin submicron emulsion inhibitory effects on efflux pumps through the progressive release of intracellular free Solutol HS15 from doxorubicin submicron emulsion. Furthermore, these in vitro results suggest that the Solutol HS15-based submicron emulsion may be a potentially useful drug delivery system to circumvent multi-drug resistance of tumor cells. PMID:26664069

  11. Increased cellular internalization of amphiphiles in a multidrug-resistant CHO cell line.

    PubMed

    Boscoboinik, D; Epand, R M

    1989-10-30

    The uptake of labeled palmitoyl carnitine and palmitoyl lysophosphatidylcholine by CHO cells was studied by measuring the extractability of these amphiphiles by bovine serum albumin. A multidrug-resistant cell line, CHRC5, showed a more rapid uptake, compared with the parental line, of these amphiphiles into a pool that was no longer susceptible to extraction with bovine serum albumin. The more rapid uptake by the drug-resistant cell line was reversed back to the rates observed with the parental cell line in the presence of verapamil, quinacrine or cyclosporin A. These latter three drugs also reverse the multidrug-resistant phenotype. These results demonstrate a relationship between the rate of amphiphile uptake and multidrug resistance.

  12. 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.

  13. Mitochondria-mediated apoptosis operating irrespective of multidrug resistance in breast cancer cells by the anticancer agent prodigiosin.

    PubMed

    Soto-Cerrato, Vanessa; Llagostera, Esther; Montaner, Beatriz; Scheffer, George L; Perez-Tomas, Ricardo

    2004-10-01

    Prodigiosin (PG) is a red pigment produced by Serratia marcescens with pro-apoptotic activity in haematopoietic and gastrointestinal cancer cell lines, but no marked toxicity in non-malignant cells. Breast cancer is the most frequent malignancy among women in the European Union and better therapies are needed, especially for metastatic tumors. Moreover, multidrug resistance is a common phenomenon that appears during chemotherapy, necessitating more aggressive treatment as prognosis worsens. In this work, we extend our experiments on PG-induced apoptosis to breast cancer cells. PG was potently cytotoxic in both estrogen receptor positive (MCF-7) and negative (MDA-MB-231) breast cancer cell lines. Cytochrome c release, activation of caspases-9, -8 and -7 and cleavage of poly (ADP-ribose) polymerase protein typified the apoptotic event and caspase inhibition revealed that PG acts via the mitochondrial pathway. In a multidrug-resistant subline of MCF-7 cells that over-expresses the breast cancer resistance protein, the cytotoxic activity of PG was slightly reduced. However, flow-cytometry analysis of PG accumulation and efflux in MCF-7 sublines showed that PG is not a substrate for this resistance protein. These results suggest that PG is an interesting and potent new pro-apoptotic agent for the treatment of breast cancer even when multidrug resistance transporter molecules are present.

  14. Ganoderma lucidum derived ganoderenic acid B reverses ABCB1-mediated multidrug resistance in HepG2/ADM cells.

    PubMed

    Liu, Dao-Lu; Li, Ying-Jie; Yang, Dong-Hua; Wang, Chen-Ran; Xu, Jun; Yao, Nan; Zhang, Xiao-Qi; Chen, Zhe-Sheng; Ye, Wen-Cai; Zhang, Dong-Mei

    2015-05-01

    Chemotherapy is one of the most common therapeutic option for metastatic tumors and hematological malignancies. ABCB1-mediated multidrug resistance is the major obstacle for chemotherapy. Natural products with diversified structures are ideal source of ABCB1 modulators. Ganoderenic acid B, a lanostane-type triterpene isolated from Ganoderma lucidum, exhibited potent reversal effect on ABCB1-mediated multidrug resistance of HepG2/ADM cells to doxorubicin, vincristine and paclitaxel. Similarly, ganoderenic acid B could also significantly reverse the resistance of ABCB1-overexpressing MCF-7/ADR cells to doxorubicin. Furthermore, ganoderenic acid B notably enhanced intracellular accumulation of rhodamine-123 in HepG2/ADM cells through inhibition of its efflux. ABCB1 siRNA interference assay indicated that the reversal activity of ganoderenic acid B was dependent on ABCB1. Further mechanistic investigations found that ganoderenic acid B did not alter the expression level of ABCB1 and the activity of ABCB1 ATPase. Molecular docking model displayed that the positions of ganoderenic acid B binding to ABCB1 were different from the region of verapamil interacted with ABCB1. Collectively, ganoderenic acid B can enhance the cytotoxicity of chemotherapeutics towards ABCB1-mediated MDR cancer cells via inhibition of the transport function of ABCB1. These findings provide evidence that ganoderenic acid B has the potential to be developed into an ABCB1-mediated multidrug resistance reversal agent.

  15. Multidrug-Resistant Tuberculous Mediastinal Lymphadenitis, with an Esophagomediastinal Fistula, Mimicking an Esophageal Submucosal Tumor.

    PubMed

    Kim, Dongwuk; Kim, Juwon; Lee, Daegeun; Chang, Ha Sung; Joh, Hyunsung; Koh, Won-Jung; Lee, Jun Haeng

    2016-11-01

    Mediastinal tuberculous lymphadenitis rarely mimics esophageal submucosal tumor, particularly in the case of multidrug-resistant tuberculosis (MDR-TB). Herein, we report the case of a 61-year-old woman who visited a local hospital complaining of odynophagia. An initial esophagogastroduodenoscopy revealed an esophageal submucosal tumor, and subsequent chest computed tomography showed subcarinal lymphadenopathy with an esophagomediastinal fistula. The patient was then referred to Samsung Medical Center, and a second esophagogastroduodenoscopy showed deep central ulceration, as well as a suspicious fistula in the esophageal submucosal tumor-like lesion. A biopsy examination of the ulcerative lesion confirmed focal inflammation only. Next, an endobronchial, ultrasound-guided lymph node biopsy was performed, and TB was confirmed. The patient initially began a course of isoniazid, rifampicin, ethambutol, and pyrazinamide. However, after a drug sensitivity test, she was diagnosed with MDR-TB, and second-line anti-TB medications were prescribed. She recovered well subsequently.

  16. 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.

  17. Investigation of the relationship between altered intracellular pH and multidrug resistance in mammalian cells.

    PubMed Central

    Boscoboinik, D.; Gupta, R. S.; Epand, R. M.

    1990-01-01

    The intracellular pH of a number of multidrug resistant cell lines was compared with that of their parental lines using the fluorescent probe bis-carboxyethylcarboxyfluorescein. In four different cases, cells having 5-fold resistance or more exhibited an intracellular pH which was 0.10-0.17 units higher than that of the parental cell line. A CHO cell line, AB1, and its 180-fold resistant counterpart, CHRC5, were further investigated with regard to the role of Na+/H+ antiport. The Na+/H+ antiport activity was greater at any intracellular pH for the CHRC5 cells than the AB1 cells. To investigate the possible role of higher intracellular pH in multidrug resistance, the effect of several agents which are either known to reverse multidrug resistance or inhibit Na+/H+ antiport activity were examined. Verapamil was found to reverse multidrug resistance but had no effect on intracellular pH while amiloride, which acidifies the cytoxol by blocking Na+/H+ antiport activity, did not cause reversal of drug resistance. In contrast to verapamil, treatment of CHRC5 cells with cyclosporin A had a parallel effect on reversal of their drug resistant phenotype and a lowering of their intracellular pH to that of the sensitive cell level. However, cyclosporin was ineffective in either lowering the intracellular pH or reversing drug resistance in DC3F/ADX cells. Therefore, except for the effect of cyclosporin A on the CHRC5 line, the effects of other agents on reversal of multidrug resistance and intracellular pH did not correlate with each other. PMID:2158805

  18. Investigation of the relationship between altered intracellular pH and multidrug resistance in mammalian cells.

    PubMed

    Boscoboinik, D; Gupta, R S; Epand, R M

    1990-04-01

    The intracellular pH of a number of multidrug resistant cell lines was compared with that of their parental lines using the fluorescent probe bis-carboxyethylcarboxyfluorescein. In four different cases, cells having 5-fold resistance or more exhibited an intracellular pH which was 0.10-0.17 units higher than that of the parental cell line. A CHO cell line, AB1, and its 180-fold resistant counterpart, CHRC5, were further investigated with regard to the role of Na+/H+ antiport. The Na+/H+ antiport activity was greater at any intracellular pH for the CHRC5 cells than the AB1 cells. To investigate the possible role of higher intracellular pH in multidrug resistance, the effect of several agents which are either known to reverse multidrug resistance or inhibit Na+/H+ antiport activity were examined. Verapamil was found to reverse multidrug resistance but had no effect on intracellular pH while amiloride, which acidifies the cytoxol by blocking Na+/H+ antiport activity, did not cause reversal of drug resistance. In contrast to verapamil, treatment of CHRC5 cells with cyclosporin A had a parallel effect on reversal of their drug resistant phenotype and a lowering of their intracellular pH to that of the sensitive cell level. However, cyclosporin was ineffective in either lowering the intracellular pH or reversing drug resistance in DC3F/ADX cells. Therefore, except for the effect of cyclosporin A on the CHRC5 line, the effects of other agents on reversal of multidrug resistance and intracellular pH did not correlate with each other.

  19. 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

  20. Importance of inducible multidrug resistance 1 expression in HL-60 cells resistant to gemtuzumab ozogamicin.

    PubMed

    Matsumoto, Taichi; Jimi, Shiro; Hara, Shuuji; Takamatsu, Yasushi; Suzumiya, Junji; Tamura, Kazuo

    2012-07-01

    Resistance to gemtuzumab ozogamicin (GO) hampers the effective treatment of refractory acute myeloid leukemia (AML). To clarify the mechanism of resistance to GO, HL-60 cells were persistently exposed to GO in order to establish GO-resistant HL-60 (HL-60/GOR) cells. Multidrug resistance 1 (MDR-1) was strongly expressed in HL-60/GOR cells, but not in HL-60 cells. Although withdrawal of GO after the chronic exposure of HL-60/GOR cells to this compound gradually decreased MDR-1 expression to trace levels, reintroducing GO restored high MDR-1 expression in HL-60/GOR cells, but not in HL-60 cells. These results indicate that HL-60/GOR cells acquired the ability to induce MDR-1 expression in response to GO. U0126, a MEK1/2 inhibitor, prevented GO-inducible MDR-1 expression and abrogated GO resistance in HL-60/GOR cells. These results suggest that in the clinical use of GO, inducible MDR-1 expression in tumor cells should be investigated before treatment with GO. If the cells are positive then MEK1/2 inhibitors may be effective in overcoming resistance to GO.

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

    PubMed

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

    2015-09-01

    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.

  2. Ceramide toxicity and metabolism differ in wild-type and multidrug-resistant cancer cells.

    PubMed

    Lucci, A; Giuliano, A E; Han, T Y; Dinur, T; Liu, Y Y; Senchenkov, A; Cabot, M C

    1999-09-01

    Previously we demonstrated that multidrug-resistant (MDR) cancer cells have elevated levels of a glycosylated form of ceramide, glucosylceramide. Here we compared ceramide metabolism and ceramide toxicity in MCF-7 and in adriamycin-resistant (MCF-7-AdrR) human breast cancer cells. MCF-7-AdrR cells were resistant to C6-ceramide (1-10 microM); however, in MCF-7 cells treated with C6-ceramide, viability dropped sharply. Ceramide, when supplemented, was not metabolized by MCF-7 cells. In contrast, ceramide was efficiently converted to glucosylceramide by MCF-7-AdrR cells. Analysis of extracellular [3H]ceramide in radiolabeled cells showed that MCF-7-AdrR cells do not have an enhanced capacity to efflux ceramide compared with MCF-7 cells. Triphenylethylene anti-estrogens, known modulators of drug resistance, were effective inhibitors of ceramide conversion to glucosylceramide, suggesting that blocking ceramide metabolism plays a role in chemosensitization. The anti-progestine, RU486, also blocked glucosylceramide synthesis in cells; however, LY117018, a raloxifene analog, was without influence. We propose that an enhanced capacity to glycosylate ceramide as evidenced in MCF-7-AdrR cells, is a molecular determinant of drug resistance, particularly as regards resistance to ceramide-enhancing agents such as anthracyclines, ionizing radiation, and tumor necrosis factor-alpha.

  3. By inhibiting Src, verapamil and dasatinib overcome multidrug resistance via increased expression of Bim and decreased expressions of MDR1 and survivin in human multidrug-resistant myeloma cells.

    PubMed

    Tsubaki, Masanobu; Komai, Makiko; Itoh, Tatsuki; Imano, Motohiro; Sakamoto, Kotaro; Shimaoka, Hirotaka; Takeda, Tomoya; Ogawa, Naoki; Mashimo, Kenji; Fujiwara, Daiichiro; Mukai, Junji; Sakaguchi, Katsuhiko; Satou, Takao; Nishida, Shozo

    2014-01-01

    The calcium channel blocker verapamil inhibits the transport function of multidrug resistance protein 1 (MDR1). Although verapamil acts to reverse MDR in cancer cells, the underlying mechanism remains unclear. In the present study, we investigated the mechanism of reversing MDR by verapamil in anti-cancer drug-resistant multiple myeloma (MM) cell lines. We found that verapamil suppresses MDR1 and survivin expressions and increases Bim expression via suppression of Src activation. Furthermore, dasatinib reversed the drug-resistance of the drug-resistant cell lines. These findings suggest that Src inhibitors are potentially useful as an anti-MDR agent for the treatment of malignant tumor cells.

  4. Toxicity mechanisms of onion (Allium cepa) extracts and compounds in multidrug resistant erythroleukemic cell line.

    PubMed

    Votto, Ana P S; Domingues, Beatriz S; de Souza, Michele M; da Silva Júnior, Flavio M R; Caldas, Sergiane S; Filgueira, Daza M V B; Clementin, Rosilene M; Primel, Ednei G; Vallochi, Adriana L; Furlong, Eliana B; Trindade, Gilma S

    2010-01-01

    Onion (Allium cepa) is being studied as a potential anticancer agent, but little is known regarding its effect in multidrug resistance (MDR) cells. In this work, the cytotoxicity of crude onion extract (OE) and fractioned extract (aqueous, methanolic and ethyl acetate), as well as some onion compounds (quercetin and propyl disulfide) were evaluated in Lucena MDR human erythroleukemic and its K562 parental cell line. The capacity of OE to induce apoptosis and/or necrosis in these cells, the possible participation of oxidative stress and DNA damage were also assessed. Similar sensitivities were obtained for both tumoral cells, however only OE caused significant effects in the cells. In K562 cells, a significant increase of apoptosis was verified while the Lucena cells experienced a significant increase of necrosis. An antioxidant capacity was verified for OE discarding oxidative damage. However, OE provoked similar significant DNA damage in both cell lines. Thus, the OE capacity to overcome the MDR phenotype suggests anti-MDR action of OE.

  5. Regulation of multidrug resistance protein 1 by tumor necrosis factor alpha in cultured glial cells: involvement of nuclear factor-kappaB and c-Jun N-terminal kinase signaling pathways.

    PubMed

    Ronaldson, Patrick T; Ashraf, Tamima; Bendayan, Reina

    2010-04-01

    Pharmacotherapy of brain HIV-1 infection may be limited by ABC transporters [i.e., P-glycoprotein (P-gp), multidrug resistance protein 1 (Mrp1)] that export antiretroviral drugs from HIV-1 brain cellular targets (i.e., astrocytes, microglia). Using an in vitro astrocyte model of an HIV-1 associated inflammatory response, our laboratory has shown that cytokines [i.e., tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1 beta, IL-6], which are secreted in response to HIV-1 envelope glycoprotein gp120 exposure, can decrease P-gp functional expression; however, it is unknown whether these same cytokines can alter expression and/or activity of other ABC transporters (i.e., Mrp1). In primary cultures of rat astrocytes, Mrp1 expression was increased by TNF-alpha (2.7-fold) but was not altered by IL-1 beta or IL-6. Cellular retention of 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, an Mrp substrate, was reduced in TNF-alpha-treated astrocytes, suggesting increased Mrp-mediated transport. Pharmacologic inhibition of nuclear factor-kappaB (NF-kappaB) signaling with SN50 prevented both TNF-alpha release and Mrp1 expression changes in astrocytes triggered with gp120; however, SN50 did not attenuate Mrp1 expression in cells triggered with TNF-alpha. In contrast, Mrp1 functional expression was not altered in the presence of gp120 or TNF-alpha when astrocyte cultures were pretreated with 1,9-pyrazoloanthrone (SP600125), an established c-Jun N-terminal kinase (JNK) inhibitor. SP600125 did not affect TNF-alpha release from cultured astrocytes triggered with gp120. Mrp1 mRNA expression was increased after treatment with gp120 (1.6-fold) or TNF-alpha (1.7-fold), suggesting altered Mrp1 gene transcription. These data suggest that gp120 and TNF-alpha can up-regulate Mrp1 expression in cultured astrocytes. Furthermore, our results imply that both NF-kappaB and JNK signaling are involved in Mrp1 regulation during an HIV-1 associated inflammatory response.

  6. Reversal of intrinsic multidrug resistance in Chinese hamster ovary cells by amiloride analogs.

    PubMed Central

    Epand, R. F.; Epand, R. M.; Gupta, R. S.; Cragoe, E. J.

    1991-01-01

    A number of amiloride analogs can sensitise wild type Chinese Hamster ovary (CHO) cells to the cytotoxic action of vinblastine, daunomycin, puromycin or colchicine. Some of these analogs also have weak sensitising effects on the multidrug resistant CHO cell line, CHRC5. The unusual feature of most of the active amiloride analogs is that they are more potent in reversing the intrinsic multidrug resistance (MDR) phenotype of CHO cells than their acquired MDR characteristic. Human HeLa cells that do not exhibit intrinsic MDR are not affected by these agents. Several of the amiloride analogs have a greater effect in increasing adriamycin uptake in wild type CHO cells than they do with CHRC5 cells. The differential effect of amiloride analogs on intrinsic versus acquired MDR characteristics of Chinese hamster cells suggests some differences in the underlying resistance mechanisms. PMID:1671752

  7. Unaltered expression of multidrug resistance transporters in polycyclic aromatic hydrocarbon-resistant rat liver cells.

    PubMed

    Payen, L; Courtois, A; Langouët, S; Guillouzo, A; Fardel, O

    2001-01-02

    Rat liver epithelial cells resistant to the chemical carcinogen 3MC, termed F258/3MC cells and generated by long-term exposure of parental F258 cells to the PAH, were characterized, especially with respect to expression of multidrug resistance transporters such as P-glycoprotein, MRP1 and MRP2. F258/3MC cells were found to be cross-resistant to other PAHs such as BP and dimethylbenz(a)anthracene but remained sensitive to known substrates of multidrug resistance efflux pumps such as doxorubicin and vincristine. They did not display either decreased cellular PAH accumulation or increased PAH efflux. In addition, P-glycoprotein and MRP2 mRNA levels were not, or only barely detected, in F258/3MC cells and in their parental counterparts whereas these PAH-resistant and sensitive cells showed closed levels of MRP1 mRNAs and activity. Moreover, P-gp- and MRP1-overexpressing cells were shown to display similar accumulation and efflux of BP than those found in P-gp- and MRP1-negative control cells. These data therefore suggest that multidrug resistance transporters do not contribute to PAH resistance in PAH-selected liver cells.

  8. Effects of cyclosporin at various concentrations on dexamethasone intracellular uptake in multidrug resistant cells

    PubMed Central

    Maillefert, J; Duchamp, O; Solary, E; Genne, P; Tavernier, C

    2000-01-01

    BACKGROUND—The multidrug resistance phenomenon results from the expression of P-glycoprotein (P-gp), a drug-efflux pump. Corticosteroids are substrates for P-gp, whose function can be inhibited by cyclosporin. This study evaluates the ability of cyclosporin to modulate dexamethasone uptake in multidrug resistant cells.
METHODS—The K 562 cell line, which does not express P-gp and a P-gp expressing clone, K562/ADM, were used. Cells were incubated with H3-dexamethasone in the absence or presence of cyclosporin at various concentrations. Then, cells were washed, lysed, and radioactivity was measured.
RESULTS—The uptake of dexamethasone alone was higher in sensitive than in resistant cells. Addition of cyclosporin induced a dose dependent increase of dexamethasone uptake in resistant cells, whereas the drug did not influence dexamethasone uptake in parental cells.
CONCLUSION—Cyclosporin, at therapeutic concentrations induces a moderate, but significant increase in dexamethasone accumulation in multidrug resistant cells. Thus, cyclosporin might increase the intestinal absorption of corticosteroids or their accumulation in mononuclear cells, or both, thereby increasing their therapeutic efficacy.

 PMID:10666173

  9. 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.

  10. Reversal of ABC drug transporter-mediated multidrug resistance in cancer cells: Evaluation of current strategies

    PubMed Central

    Wu, Chung-Pu; Calcagno, Anna Maria; Ambudkar, Suresh V.

    2008-01-01

    Overexpression of ATP-binding cassette (ABC) drug transporters that actively efflux a variety of amphipathic compounds can cause multidrug resistance (MDR) in cancer cells, which is a major obstacle in the success of cancer chemotherapy. The development of synthetic small molecule compounds or the identification of natural products that block ABC transporter-mediated efflux has been the conventional approach used to combat MDR. The strategy of using chemosensitizers, however, has not been successful in clinical cancer chemotherapy. Therefore, alternative approaches to identify or to synthesize compounds that can induce selective toxicity in cancer cells overexpressing one or more ABC transporters have been undertaken. This review summarizes the recent advances in identifying strategies to restore sensitivity to chemotherapeutics in multidrug resistant cancer cells. PMID:19079736

  11. Inorganic nanoparticle-based drug codelivery nanosystems to overcome the multidrug resistance of cancer cells.

    PubMed

    Chen, Yu; Chen, Hangrong; Shi, Jianlin

    2014-08-04

    Biocompatible inorganic material-based nanosystems provide a novel choice to effectively circumvent the intrinsic drawbacks of traditional organic materials in biomedical applications, especially in overcoming the multidrug resistance (MDR) of cancer cells due to their unique structural and compositional characteristics, for example, high stability, large surface area, tunable compositions, abundant physicochemical multifunctionalities, and specific biological behaviors. In this review, we focus on the recent developments in the construction of inorganic nanoparticles-based drug codelivery nanosystems (mesoporous SiO2, Fe3O4, Au, Ag, quantum dots, carbon nanotubes, graphene oxide, LDH, etc.) to efficiently circumvent the MDR of cancer cells, including the well-known codelivery of small molecular anticancer drug/macromolecular therapeutic gene and codelivery of small molecular chemosensitizer/anticancer drug, and very recently explored codelivery of targeting ligands/anticancer drug, codelivery of energy/anticancer drug, and codelivery of contrast agent for diagnostic imaging and anticancer drug. The unsolved issues, future developments, and potential clinical translations of these codelivery nanosystems are also discussed. These elaborately designed biocompatible inorganic materials-based nanosystems offer an unprecedented opportunity and show the encouraging bright future for overcoming the MDR of tumors in clinic personalized medicine and the pharmaceutical industry.

  12. Induction of apoptotic cell death by betulin in multidrug-resistant human renal carcinoma cells.

    PubMed

    Yim, Nam-Hui; Jung, Young Pil; Kim, Aeyung; Kim, Taesoo; Ma, Jin Yeul

    2015-08-01

    Betulin, a triterpene from the bark of various species of birch tree, has various biological effects, including antiviral, antifungal and anticancer activities. The aim of the present study was to elucidate the mechanisms underlying the apoptotic effect of betulin in RCC4 multidrug-resistant human renal carcinoma cells. To evaluate anticancer activity, we performed cell viability and caspase activity assays, a proteome profiler array and western blot analysis in RCC4 cells. Betulin significantly decreased RCC4 cell viability in a time- and concentration-dependent manner. Betulin activated caspase family proteins, including caspase-3, -7, -8 and -9, and increased the expression of apoptosis-related proteins, including PARP and Bcl-2 family members. In an apoptosis array, betulin activated the tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors TRAIL R1/DR4 and R2/DR5, and tumour necrosis factor receptor 1 (TNFR1), suggesting that betulin treatment leads to induction of apoptosis through both intrinsic and extrinsic apoptosis pathways in RCC4 cells. Notably, betulin significantly enhanced cytotoxicity and PARP cleavage in etoposide-treated RCC4 cells, and downregulated the expression of multidrug resistance protein 1 (MDR1). Taken together, our findings suggest that the anticancer effects of betulin involve induction of apoptosis and sensitisation of RCC4 cells, providing potentially useful information applicable to the use of betulin in renal cancer treatment.

  13. Elevated expression of Nrf2 mediates multidrug resistance in CD133+ head and neck squamous cell carcinoma stem cells

    PubMed Central

    Lu, Bao-Cai; Li, Jing; Yu, Wen-Fa; Zhang, Guo-Zheng; Wang, Hui-Min; Ma, Hui-Min

    2016-01-01

    Enhanced expression of the ATP-binding cassette (ABC) transporter protein ABC sub-family G member 2 (ABCG2) in cancer stem cells (CSCs) plays a major role in chemotherapeutic drug efflux, which results in therapy failure and tumor relapse. In addition to downregulating apoptosis in CSCs, it has been reported that the transcriptional upregulation of the redox sensing factor Nrf2 is involved in the upregulation of ABCG2 expression and consequent chemoresistance. The current study investigated the presence of cancer stem-like side population (SP) cells from head and neck squamous cell carcinoma (HNSCC) samples, and evaluated the Nrf2 expression profile and multidrug resistance properties of HNSCC stem cells. Fluorescence-activated cell sorting was used for SP cells detection, while reverse transcription-polymerase chain reaction was used for the analysis of Nrf2 expression. The present study identified ~2.1% SP cells present in HNSCC specimens, which were positive for cluster of differentiation (CD)133 expression and displayed significantly elevated messenger RNA expression of Nrf2, compared with non-SP cells. These data suggest that the ABC transporter ABCG2 is highly upregulated in SP cells, and this results in multidrug resistance. In addition, these CD133+ cells underwent rapid proliferation and exhibited high self-renewal and tumorigenic properties. Taken together, the present findings suggest that elevated expression of Nrf2 mediated drug resistance in HNSCC CSCs, which may be one of the causative factors for cancer treatment failure. Therefore, novel anti-cancer drugs that downregulate the Nrf2 signaling pathway could effectively improve the treatment and survival rate of patients with HNSCC. PMID:28101198

  14. [The role of cell wall organization and active efflux pump systems in multidrug resistance of bacteria].

    PubMed

    Hasdemir, Ufuk

    2007-04-01

    Multiple antibiotic resistance of clinically important bacteria are of major concern worldwide. Alterations of drug targets or enzymatic inactivation of antimicrobial agents are the well known mechanisms of antimicrobial drug resistance. Besides these well known mechanisms, recent studies have shown that a further resistance mechanism, active drug efflux, has become increasingly important in the current threat of multidrug resistance. It involves certain bacterial transport proteins which pump out toxic antimicrobial compounds from the cell. Drug efflux pump proteins in bacteria fall into five distinct protein super families [ATP binding cassette super family (ABC), Major facilitator super family (MFS), Small multidrug resistance super family (SMR), Multidrug and toxic compound extrusion (MATE) super family, Resistance-nodulation-cell division (RND) super family] and are mostly encoded by chromosomal genes. Among them, the members of RND protein super family are widely distrubuted in Gram negative bacteria and play siginificant role in both, intrinsic and acquired multidrug resistance of these bacteria with very wide substrate specificity. RND type multidrug efflux proteins usually function together with an outer membrane canal protein (OMP) and a membrane fusion protein (MFP) to pump out drugs. AcrAB-TolC of Escherichia coli and MexAB-OprM of Pseudomonas aeruginosa are the typical examples of these tripartite systems. They are constitutively expressed in wild type cells and play significant role in intrinsic resistance of these bacteria. However, multidrug resistance which is of major clinical significance, rises as a result of overexpression of these pump systems due to mutations and elevated levels of resistance are recorded to structurally unrelated antimicrobial drugs such as fluoroquinolones, beta-lactams, tetracyclines, chloramphenicol, trimethoprim, aminoglycosides and toxic compunds. Synthesis of RND type pump proteins are regulated by complex genetic

  15. Jurkat/A4 cells with multidrug resistance exhibit reduced sensitivity to quercetin.

    PubMed

    Philchenkov, A; Zavelevich, M; Savinska, L; Blokhin, D

    2010-07-01

    While multidrug resistance of cancer cells is a well-known phenomenon, little is known on the cross resistance between cytotoxic chemotherapeutical agents and unrelated substances such as natural flavonoids. To compare the effects of cytotoxic drug, vepeside and natural flavonoid, quercetin in Jurkat cells and their multidrug-resistant subline Jurkat/A4, in particular to analyze the effector mechanisms of apoptosis and the profiles of several pro- and antiapoptotic proteins in these cells upon exposure to vepeside or quercetin. Apoptosis and poly (ADP-ribose) polymerase cleavage were assessed by flow cytometry. Expression of apoptosis-related proteins was analyzed by Western blotting. Jurkat/A4 cells are less sensitive to antiproliferative effects of quercetin as compared with the parental Jurkat cell line. While vepeside as well as quercetin initially induces apoptosis in both cell lines, the following survival of the exposed cells is essentially different. In resistant Jurkat/A4 cells, vepeside or quercetin treatment activates significantly less caspase-9 and -3 as compared with that in the parental cells. The expression of Bad and BNip1 proteins in Jurkat/A4 cells is lower than in the parental cell line. At the same time, XIAP and CAS levels in Jurkat/A4 cells increase. Upon apoptosis induction, XIAP and CAS levels in Jurkat cells decrease, this effect being negligible in resistant cells. Multidrug-resistant Jurkat/A4 cells exhibit reduced sensitivity to cytotoxic effects of quercetin. The expression profile of Jurkat/A4 cells is characterized by the increased levels of XIAP and CAS representing the endogenous inhibitors of apoptosis.

  16. Targeting ABCB1-mediated tumor multidrug resistance by CRISPR/Cas9-based genome editing

    PubMed Central

    Yang, Yang; Qiu, Jian-Ge; Li, Yong; Di, Jin-Ming; Zhang, Wen-Ji; Jiang, Qi-Wei; Zheng, Di-Wei; Chen, Yao; Wei, Meng-Ning; Huang, Jia-Rong; Wang, Kun; Shi, Zhi

    2016-01-01

    The RNA-guided clustered regularly interspaced short palindromic (CRISPR) in combination with a CRISPR-associated nuclease 9 (Cas9) nuclease system is a new rapid and precise technology for genome editing. In the present study, we applied the CRISPR/Cas9 system to target ABCB1 (also named MDR1) gene which encodes a 170 kDa transmembrane glycoprotein (P-glycoprotein/P-gp) transporting multiple types of chemotherapeutic drugs including taxanes, epipodophyllotoxins, vinca alkaloids and anthracyclines out of cells to contribute multidrug resistance (MDR) in cancer cells. Our data showed that knockout of ABCB1 by CRISPR/Cas9 system was succesfully archieved with two target sgRNAs in two MDR cancer cells due to the alteration of genome sequences. Knockout of ABCB1 by CRISPR/Cas9 system significantly enhances the sensitivity of ABCB1 substrate chemotherapeutic agents and the intracellular accumulation of rhodamine 123 and doxorubicin in MDR cancer cells. Although now there are lots of limitations to the application of CRISPR/Cas9 for editing cancer genes in human patients, our study provides valuable clues for the use of the CRISPR/Cas9 technology in the investigation and conquest of cancer MDR. PMID:27725879

  17. Ability of polymer-bound P-glycoprotein inhibitor ritonavir to overcome multidrug resistance in various resistant neuroblastoma cell lines.

    PubMed

    Koziolová, Eva; Chytil, Petr; Etrych, Tomáš; Janoušková, Olga

    2017-09-08

    Polymer prodrugs can considerably improve the treatment of tumors with multidrug resistance, often caused by overexpression of P-glycoprotein (P-gp). Here, we present the effect of the N-(2-hydroxypropyl) methacrylamide-based polymer conjugate with P-gp inhibitor ritonavir (RIT) on the increase of free doxorubicin (DOX) and polymer-bound DOX cytotoxicity in the human neuroblastoma 4 cell line and its resistant clones to different cytostatics. The increase in cytotoxicity after polymer-RIT conjugate pretreatment was higher for the lines overexpressing P-gp and less pronounced for those with decreased P-gp levels. Moreover, the effect of polymer conjugate containing inhibitor and DOX on the same polymer chain was lower than that of two individual polymer conjugates used sequentially. In conclusion, the polymer-RIT conjugate can significantly increase the cytotoxicity of free DOX and polymer-DOX conjugates in cells with various multidrug resistance origins and can thus be considered a suitable therapeutic enhancer of polymer prodrugs.

  18. 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. Georg Thieme Verlag KG Stuttgart · New York.

  19. Characteristics of human tumour cell lines after induction of multidrug resistance.

    PubMed

    Nouri, A; Sharghi, S; Symes, M; Paris, A; Oliver, R

    1996-06-01

    A colorimetric technique was used to investigate some aspects of multidrug resistant (MDR)-induced cell lines. Continuous contact of the inducing agent with cells was necessary for MDR induction and this was followed by a series of phases i.e., a selection phase (ESP) lasted up to 6 days, a conditioning phase (CP) lasted up to 14 days and an expansion phase (EP) lasted up to 7 days. Gene transfection to correct missing MHC class I antigens on the Fen cell line did not affect cell behaviour. Of particular interest was the finding that the withdrawal of the MDR inducing agent did not reverse MDR phenotype immediately.

  20. MEK inhibitor enhances sensitivity to chemotherapeutic drugs in multidrug resistant hepatocellular carcinoma cells.

    PubMed

    Meng, Qingliang; He, Xiaoqi; Xie, Guangwei; Tian, Qingzhong; Shu, Xiaogang; Li, Jin; Xiao, Yong

    2017-09-01

    The aim of the present study was to investigate the association between the mitogen-activated protein kinase (MAPK) signal transduction pathway and multidrug resistance in hepatocellular carcinoma cells. A Cell Counting Kit-8 assay was used to determine the drug sensitivity of HepG2 and HepG2/ADM hepatocellular carcinoma cell lines in combination with the MAPK/extracellular-signal-regulated kinase kinase (MEK) inhibitor U0126. Flow cytometry was used to analyze the rate of apoptosis. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to determine P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) mRNA expression following treatment with various concentrations of U0126. P-gp and MRP1 expression levels were measured using Western blot analysis. The half-maximal inhibitory concentration was markedly decreased in combination with U0126. RT-qPCR results demonstrated that the expression of multidrug resistance 1 (MDR1) and MRP1 in HepG2/ADM cells was increased 5.37- and 6-14-fold compared with that in HepG2 cells. Furthermore, the expression levels in HepG2/ADM cells were decreased following U0126 treatment in a dose-dependent manner. The expression of P-gp and MRP1 in HepG2/ADM cells was increased 2.68- and 2.76-fold compared with that in HepG2 cells. Furthermore, the expression levels in HepG/ADM cells were decreased following U0126 treatment in a dose-dependent manner. The results of the present study indicate that the MEK inhibitor U0126 enhances sensitivity to chemotherapeutic drugs by downregulating P-gp and MRP1 expression in resistant hepatocellular carcinoma cells. The combination of MEK inhibitor and conventional chemotherapeutic drugs may provide novel therapeutic prospects for the treatment of drug-resistant hepatocellular carcinoma.

  1. Microparticles shed from multidrug resistant breast cancer cells provide a parallel survival pathway through immune evasion.

    PubMed

    Jaiswal, Ritu; Johnson, Michael S; Pokharel, Deep; Krishnan, S Rajeev; Bebawy, Mary

    2017-02-06

    Breast cancer is the most frequently diagnosed cancer in women. Resident macrophages at distant sites provide a highly responsive and immunologically dynamic innate immune response against foreign infiltrates. Despite extensive characterization of the role of macrophages and other immune cells in malignant tissues, there is very little known about the mechanisms which facilitate metastatic breast cancer spread to distant sites of immunological integrity. The mechanisms by which a key healthy defense mechanism fails to protect distant sites from infiltration by metastatic cells in cancer patients remain undefined. Breast tumors, typical of many tumor types, shed membrane vesicles called microparticles (MPs), ranging in size from 0.1-1 μm in diameter. MPs serve as vectors in the intercellular transfer of functional proteins and nucleic acids and in drug sequestration. In addition, MPs are also emerging to be important players in the evasion of cancer cell immune surveillance. A comparative analysis of effects of MPs isolated from human breast cancer cells and non-malignant human brain endothelial cells were examined on THP-1 derived macrophages in vitro. MP-mediated effects on cell phenotype and functionality was assessed by cytokine analysis, cell chemotaxis and phagocytosis, immunolabelling, flow cytometry and confocal imaging. Student's t-test or a one-way analysis of variance (ANOVA) was used for comparison and statistical analysis. In this paper we report on the discovery of a new cellular basis for immune evasion, which is mediated by breast cancer derived MPs. MPs shed from multidrug resistant (MDR) cells were shown to selectively polarize macrophage cells to a functionally incapacitated state and facilitate their engulfment by foreign cells. We propose this mechanism may serve to physically disrupt the inherent immune response prior to cancer cell colonization whilst releasing mediators required for the recruitment of distant immune cells. These findings

  2. 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.

  3. Salvianolic acid B reverses multidrug resistance in HCT‑8/VCR human colorectal cancer cells by increasing ROS levels.

    PubMed

    Guo, Piaoting; Wang, Songpo; Liang, Wei; Wang, Wenjing; Wang, Huijun; Zhao, Miaomiao; Liu, Xiaowei

    2017-02-01

    Salvianolic acid B (SalB) a water‑soluble phenolic compound, extracted from Salvia miltiorrhiza, has previously been demonstrated to reverse tumor multidrug resistance (MDR), including in colorectal cancer. Reactive oxygen species (ROS) are oxygen radicals generated during aerobic metabolism (superoxide and hydroxyl radicals) and superoxide easily generating free radicals (H2O2). The concept that increased ROS levels can lead to augmented tumor cell‑sensitivity to chemotherapy drugs has become notable. The aim of the present study was to elucidate the role of ROS in mediating the effect of SalB on drug resistance and the correlation with drug resistance‑associated protein, P‑glycoprotein (P‑gp), and apoptosis‑associated proteins, B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X (Bax). In the current study, through utilizing the multidrug resistant colorectal cancer cell line, HCT‑8/VCR, it was demonstrate that SalB reversed MDR in HCT‑8/VCR. In addition, SalB significantly increased ROS levels, which may have accelerated the apoptosis of HCT‑8/VCR cells by downregulating Bcl‑2 and increasing Bax protein expression. Furthermore the increased intracellular ROS levels may have inhibited P‑gp expression at the gene and protein levels. In conclusion, the data of the current study demonstrate that SalB reversed MDR in HCT‑8/VCR cells, and the effect is associated with increased ROS levels, which may downregulate P‑gp expression and promote tumor cell apoptosis, which in turn increases the sensitivity of drug‑resistant cells to chemotherapy drugs.

  4. Sensitization of multidrug-resistant malignant cells by liposomes co-encapsulating doxorubicin and chloroquine through autophagic inhibition.

    PubMed

    Gao, Menghua; Xu, Yuzhen; Qiu, Liyan

    2017-06-01

    Adenosine triphosphate (ATP)-binding cassette (ABC) transporters play a key role in the development of multidrug resistance (MDR) in cancer cells. P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) are important proteins in this superfamily which are widely expressed on the membranes of multidrug resistance (MDR) cancer cells. Besides, upregulation of cellular autophagic responses is considered a contributing factor for MDR in cancer cells. We designed a liposome system co-encapsulating a chemotherapeutic drug (doxorubicin hydrochloride, DOX) and a typical autophagy inhibitior (chloroquine phosphate, CQ) at a weight ratio of 1:2 and investigated its drug resistance reversal mechanism. MTT assay showed that the IC50 of DOX/CQ co-encapsulated liposome in DOX-resistant human breast cancer cells (MCF7/ADR) was 4.7 ± 0.2 μM, 5.7-fold less than that of free DOX (26.9 ± 1.9  μM), whereas it was 19.5-fold in doxorubicin-resistant human acute myelocytic leukemia cancer cells (HL60/ADR) (DOX/CQ co-encapsulated liposome 1.2 ± 0.1 μM, free DOX 23.4 ± 2.8 μM). The cellular uptake of DOX increased upon addition of free CQ, indicating that CQ may interact with P-gp and MRP1; however, the expressions of P-gp and MRP1 remained unchanged. In contrast, the expression of the autophagy-related protein LC3-II increased remarkably. Therefore, the mechanism of MDR reversal may be closely related to autophagic inhibition. Evaluation of anti-tumor activity was achieved in an MCF-7/ADR multicellular tumor spheroid model and transgenic zebrafish model. DOX/CQ co-encapsulated liposome exerted a better anti-tumor effect in both models than that of liposomal DOX or DOX alone. These findings suggest that encapsulating CQ with DOX in liposomes significantly improves the sensitivity of DOX in DOX-resistant cancer cells.

  5. 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.

  6. [Reversal of mdrl gene-dependent multidrug resistance in multidrug resistance human leukemia cell line K562/ADM using short hairpin RNA expression vectors].

    PubMed

    Gan, Hui-zhu; Zhang, Gui-zhen; Lu, Zhen-xia; Pu, Li-sha; Yang, Shao-juan; Gao, Shen; Zheng, De-ming

    2007-06-01

    To explore the role of reversal multidrug resistance (MDR) using short hairpin RNA (shRNA) expression vectors in multidrug resistance human leukemia cell line K562/ADM. The oligonucleotides with 19-mer hairpin structure were synthesized. The shRNA expression vectors were constructed and introduced into K562/ADM cells. Expression of mdr1 mRNA was assessed by RT-PCR, and P-gp expression was determined by Western blot. The apoptosis and sensitivity of the K562/ADM cells to doxorubicin were quantified by flow cytometry and methyl thiazolyl tetrazolium (MTT) assays, respectively. Cellular daunorubicin accumulation was assayed by laser confocal scanning microscope (LCSM). In positive clones of K562/ADM cells stably transfected with pSilencer 3.1-HI neo mdr1-A and mdr1-B shRNA expression vectors, RT-PCR showed that mdr1 mRNA expression was significantly reduced to 35.9% (P < 0.05), 27.5% (P < 0.01), respectively. Western blot showed that P-gp expression was significantly and specifically inhibited. Resistance against doxorubicin was decreased from 79-fold to 38-fold (P < 0.05), 30-fold (P < 0.01) respectively. Furthermore, the fluorescence intensity of K562/ADM cells was increased significantly compared with the control. shRNA vectors significantly enhanced the cellular daunorubicin accumulation. The percent of the apoptosis cell was significantly enhanced to 18.1% (P < 0.05) , 54.4% (P < 0.01) respectively. shRNA expression vectors can effectively reverse MDR, and restore the sensitivity of drug-resistance K562/ADM cells to conventional chemotherapeutic agents.

  7. Polysaccharide-lecithin reverse micelles with enzyme-degradable triglyceride shell for overcoming tumor multidrug resistance.

    PubMed

    Su, Chia-Wei; Chen, San-Yuan; Liu, Dean-Mo

    2013-05-08

    A newly-designed drug carrier with enzyme-triggered release behavior and the ability to circumvent multidrug resistance was successfully developed. By optimizing the ratio of lecithin and polysaccharide in reverse micelles, encapsulation efficiency and encapsulation stability can be significantly improved.

  8. [Establishment and biological characteristics of a multi-drug resistant cell line A549/Gem.].

    PubMed

    Wang, Weixia; Liu, Xiaoqing; Liu, Guangxian; Lin, Li; Zheng, Xiaoling; Zhu, Yunfeng; Li, Xiaobing

    2008-02-20

    doubling time of A549/Gem was longer and figures in G0-G1 phase were decreased than A549/Gem'. It's expressions of P53, EGFR, PCNA and MDR-1 protein was same to that of A549/Gem'. A549/Gem achieved TIMP-1 and PTEN protein expression, Cerb-B-2, MMP-9, cmyc and bcl-2 protein expression enhanced, nm23 protein expression vanished, but the expression of VEGF and CD44v6 protein changed trivially. Furthermore, Compared with its parental cell, A549/Gem was mixed with giant cells of different sizes that were larger and more irregular. The multi-drug resistant non-small cell lung cancer cell line A549/Gem has multi-drug resistance and great change of biological character compared with its parental cell. And the change can participate in the formation of multidrug resistance.

  9. Multivalent Aptamer-RNA Conjugates for Simple and Efficient Delivery of Doxorubicin/siRNA into Multidrug-Resistant Cells.

    PubMed

    Jeong, Hyosook; Lee, Soo Hyeon; Hwang, Yeonju; Yoo, Hyundong; Jung, Heesun; Kim, Sun Hwa; Mok, Hyejung

    2017-04-01

    Multivalent aptamer-siRNA conjugates containing multiple mucin-1 aptamers and BCL2-specific siRNA are synthesized, and doxorubicin, an anthracycline anticancer drug, is loaded into these conjugates through intercalation with nucleic acids. These doxorubicin-incorporated multivalent aptamer-siRNA conjugates are transfected to mucin-1 overexpressing MCF-7 breast cancer cells and their multidrug-resistant cell lines. Doxorubicin-incorporated multivalent aptamer-siRNA conjugates exert promising anticancer effects, such as activation of caspase-3/7 and decrease of cell viability, on multidrug-resistant cancer cells because of their high intracellular uptake efficiency. Thus, this delivery system is an efficient tool for combination oncotherapy with chemotherapeutics and nucleic acid drugs to overcome multidrug resistance.

  10. 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.

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

    PubMed Central

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

    1996-01-01

    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. Images Figure 1 Figure 2 Figure 3 PMID:8774142

  12. Ceramide glycosylation potentiates cellular multidrug resistance.

    PubMed

    Liu, Y Y; Han, T Y; Giuliano, A E; Cabot, M C

    2001-03-01

    Ceramide glycosylation, through glucosylceramide synthase (GCS), allows cellular escape from ceramide-induced programmed cell death. This glycosylation event confers cancer cell resistance to cytotoxic anticancer agents [Liu, Y. Y., Han, T. Y., Giuliano, A. E., and M. C. Cabot. (1999) J. Biol. Chem. 274, 1140-1146]. We previously found that glucosylceramide, the glycosylated form of ceramide, accumulates in adriamycin-resistant breast carcinoma cells, in vinblastine-resistant epithelioid carcinoma cells, and in tumor specimens from patients showing poor response to chemotherapy. Here we show that multidrug resistance can be increased over baseline and then totally reversed in human breast cancer cells by GCS gene targeting. In adriamycin-resistant MCF-7-AdrR cells, transfection of GCS upgraded multidrug resistance, whereas transfection of GCS antisense markedly restored cellular sensitivity to anthracyclines, Vinca alkaloids, taxanes, and other anticancer drugs. Sensitivity to the various drugs by GCS antisense transfection increased 7- to 240-fold and was consistent with the resumption of ceramide-caspase-apoptotic signaling. GCS targeting had little influence on cellular sensitivity to either 5-FU or cisplatin, nor did it modify P-glycoprotein expression or rhodamine-123 efflux. GCS antisense transfection did enhance rhodamine-123 uptake compared with parent MCF-7-AdrR cells. This study reveals that GCS is a novel mechanism of multidrug resistance and positions GCS antisense as an innovative force to overcome multidrug resistance in cancer chemotherapy.

  13. High levels of the MDM2 oncogene in paediatric rhabdomyosarcoma cell lines may confer multidrug resistance

    PubMed Central

    Cocker, H A; Hobbs, S M; Tiffin, N; Pritchard-Jones, K; Pinkerton, C R; Kelland, L R

    2001-01-01

    The MDM2 protein is known to be overexpressed in some sarcomas including rhabdomyosarcoma. However, the extent to which the MDM2 protein influences sensitivity to chemotherapeutic drugs is unclear. We have analysed this further using stable transfection of the mdm2 gene into 4 well-characterised human paediatric rhabdomyosarcoma cell lines. Transfection with the mdm2 gene resulted in increased levels of the MDM2 protein in all the cell lines. In 2 of the lines, SCMC and RD, the mdm2 gene caused between 2-fold and 61-fold increase in resistance to vincristine, etoposide and doxorubicin but not to cisplatin. In these lines there was an increase in expression of the mdr-1 gene which encodes P-glycoprotein, but not the mrp1 gene which encodes the multidrug resistance protein (MRP). The resistance was reversible using the MDR modulator PSC833, confirming the presence of P-glycoprotein. We conclude that MDM2 overexpression may be a mechanism by which multidrug resistance is regulated in some rhabdomyosarcomas. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11742497

  14. Tolerance to drug-induced cell death favours the acquisition of multidrug resistance in Leishmania

    PubMed Central

    Moreira, W; Leprohon, P; Ouellette, M

    2011-01-01

    The control of the protozoan parasite Leishmania relies on few drugs with unknown cellular targets and unclear mode of action. Several antileishmanials, however, were shown to induce apoptosis in Leishmania and this death mechanism was further studied in drug-sensitive and drug-resistant Leishmania infantum. In sensitive parasites, antimonials (SbIII), miltefosine (MF) and amphotericin B (AMB), but not paromomycin (PARO), triggered apoptotic cell death associated with reactive oxygen species (ROS). In contrast, Leishmania mutants resistant to SbIII, MF or AMB not only failed to undergo apoptosis following exposure to their respective drugs, but also were more tolerant towards apoptosis induced by other antileishmanials, provided that these killed Leishmania via ROS production. Such tolerance favored the rapid acquisition of multidrug resistance. PARO killed Leishmania in a non-apoptotic manner and failed to produce ROS. PARO resistance neither protected against drug-induced apoptosis nor provided an increased rate of acquisition of resistance to other antileishmanials. However, the PARO-resistant mutant, but not SbIII-, MF- or AMB-resistant mutants, became rapidly cross-resistant to methotrexate, a model drug also not producing ROS. Our results therefore link the mode of killing of drugs to tolerance to cell death and to a facilitated emergence of multidrug resistance. These findings may have fundamental implications in the field of chemotherapeutic interventions. PMID:21881603

  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. Doxorubicin and siRNA Codelivery via Chitosan-Coated pH-Responsive Mixed Micellar Polyplexes for Enhanced Cancer Therapy in Multidrug-Resistant Tumors.

    PubMed

    Butt, Adeel Masood; Amin, Mohd Cairul Iqbal Mohd; Katas, Haliza; Abdul Murad, Nor Azian; Jamal, Rahman; Kesharwani, Prashant

    2016-12-05

    This study investigated the potential of chitosan-coated mixed micellar nanocarriers (polyplexes) for codelivery of siRNA and doxorubicin (DOX). DOX-loaded mixed micelles (serving as cores) were prepared by thin film hydration method and coated with chitosan (CS, serving as outer shell), and complexed with multidrug resistance (MDR) inhibiting siRNA. Selective targeting was achieved by folic acid conjugation. The polyplexes showed pH-responsive enhanced DOX release in acidic tumor pH, resulting in higher intracellular accumulation, which was further augmented by downregulation of mdr-1 gene after treatment with siRNA-complexed polyplexes. In vitro cytotoxicity assay demonstrated an enhanced cytotoxicity in native 4T1 and multidrug-resistant 4T1-mdr cell lines, compared to free DOX. Furthermore, in vivo, polyplexes codelivery resulted in highest DOX accumulation and significantly reduced the tumor volume in mice with 4T1 and 4T1-mdr tumors as compared to the free DOX groups, leading to improved survival times in mice. In conclusion, codelivery of siRNA and DOX via polyplexes has excellent potential as targeted drug nanocarriers for treatment of MDR cancers.

  17. MiR-30a Decreases Multidrug Resistance (MDR) of Gastric Cancer Cells

    PubMed Central

    Li, Chunying; Zou, Jinhai; Zheng, Guoqi; Chu, Jiankun

    2016-01-01

    Background The effectiveness of chemotherapy for gastric cancer is largely limited by either intrinsic or acquired drug resistance. In this study, we aimed to explore the association between miR-30a dysregulation and multidrug resistance (MDR) in gastric cancer cells. Material/Methods We recruited 20 patients with advanced gastric cancer. Chemosensitivity was assessed after completion of the chemotherapy. SGC-7901 and SGC-7901/DDP cells were transfected for miR-30a overexpression or knockdown. Then, MTT assay was performed to assess the IC50 of DPP and 5-FU in SGC-7901 and SGC-7901/DDP cells. Flow cytometry analysis was used to detect DPP- and 5-FU-induced cell apoptosis. Western blot analysis and immunofluorescence staining were used to assess EMT of the cells. Results MiR-30a was significantly downregulated in the chemoresistant tissues. In both SGC-7901 and SGC-7901/DDP cells, miR-30a overexpression decreased the expression of P-gp, a MDR-related protein. MTT assay and flow cytometry analysis showed that miR-30a inhibition increased chemoresistance, while miR-30a overexpression decreased chemoresistance in gastric cancer cells. Both Western blot analysis and immunofluorescence staining confirmed that miR-30a inhibition decreased E-cadherin but increased N-cadherin in SGC-7901 cells, while miR-30a overexpression increased E-cadherin but decreased N-cadherin in SGC-7901 cells. Conclusions MiR-30a can decrease multidrug resistance (MDR) of gastric cancer cells. It is also an important miRNA modulating EMT of the cancer cells.

  18. Association between DNA methylation and multidrug resistance in human glioma SHG-44 cells

    PubMed Central

    CHEN, JIN; XU, ZHONG-YE; WANG, FENG

    2015-01-01

    The aim of the present study was to evaluate the association between DNA methylation and multidrug resistance (MDR) in glioma and identify novel effectors responsible for MDR in human gliomas. An MDR glioma cell line, SGH-44/ADM, was developed using adriamycin (ADM) impulse treatment. Cryopreservation, recovery and withdrawal were performed to evaluate the stability of SGH-44/ADM cells. The adherence rate and cellular morphology were observed by microscopy, and the cell growth curve and doubling time were determined. DNA methylation was analyzed using a methylated DNA immunoprecipitation microarray chip (MeDIP-Chip). The cell cycle, Rh123 ingestion and exudation, and SGH-44/ADM apoptosis were analyzed by flow cytometry. SGH-44/ADM cells showed little difference as compared with parental cells, except that SGH-44/ADM cells were bigger in size with a wizened nucleus. Compared to SGH-44 cells, a larger proportion of SGH-44/ADM cells remained in G1 and S phase, as measured by flow cytometry. The MDR of SGH-44/ADM was associated with the upregulation of multi-drug resistance 1, prostaglandin-endoperoxide synthase 2 (COX-2); protein kinase C α (PKCα); however, the expression of these genes was not associated with DNA methylation. In the MeDIP-Chip analysis, 74 functions were markedly enhanced, and seven significant pathways were observed. Genes including SNAP47, ARRB2, PARD6B, TGFB1, VPS4B and CBLB were identified by gene ontology analysis. The predominant molecular mechanism of MDR in SGH-44/ADM cells was identified as exocytosis and efflux. The expression of COX-2, PKCα and P-glycoprotein (Pgp) was not found to be associated with DNA methylation. Genes including SNAP47, VAMP4 and VAMP3 may serve as the downstream effectors of Pgp, COX-2 or PKCα; however, further experiments are required to verify these observations. PMID:25333456

  19. Autophagy facilitates multidrug resistance development through inhibition of apoptosis in breast cancer cells.

    PubMed

    Sun, W L; Lan, D; Gan, T Q; Cai, Z W

    2015-01-01

    Acquired multidrug resistance (MDR) is the main mechanism of chemotherapeutic drugs resistance. Nevertheless, the mechanisms of MDR are complex and still not very clear. Recently, including our previous study, several studies have revealed that macroautophagy (here referred to as autophagy) induced by anti-cancer drugs in breast cancer cells may facilitate the development of resistance to epirubicin (EPI), paclitaxel (PTX), tamoxifen or herceptin. Whereas there are a few studies on the relationship between autophagy and MDR, especially the studies designed directly employing induced resistant breast cancer cells. Based on previous study, we explored the relationship between autophagy and MDR. The results showed that induced EPI-resistant MCF-7er and SK-BR-3er cells were simultaneously resistant to PTX and vinorelbine (NVB), which demonstrated that the cells obtained MDR phenotype. Furthermore, PTX and NVB could also induce autophagy in MCF-7er and SK-BR-3er cells, and the induced autophagy protected the cells from apoptosis, which facilitated the development of resistance to PTX and NVB. Thus, autophagy promoted the development of MDR in breast cancer cells through inhibition of apoptosis. In addition, we found that P-glycoprotein (Pgp) was overexpressed in MCF-7er and SK-Br-3er cells. And we preliminarily investigated the relationship between autophagy and P-glycoprotein (Pgp). The results showed that the expression of the protein did not obviously change despite the inhibition of autophagy. Therefore, the role of Pgp in the development of MDR might be independent of autophahy. Also this finding implies that autophagy might be a target to overcome MDR in breast cancer cells, and clinical use autophagy inhibitors might be one of the important strategies for overcoming MDR in breast cancer therapy. Autophagy, apoptosis, multidrug resistance, breast cancer, chemotherapy.

  20. Hyaluronan induces migration of multidrug-resistant lymphoma cell lines in vitro through Tiam1 activation by a PI3K-dependent mechanism.

    PubMed

    Cordo-Russo, Rosalía I; Alaniz, Laura D; Saccodossi, Natalia; Lompardía, Silvina; Blanco, Guillermo; Alvarez, Elida; García, Mariana G; Hajos, Silvia E

    2010-11-01

    Hyaluronan (HA) modulates multidrug resistance (MDR) as well as cell migration. Tiam1 is involved in cytoskeleton reorganization during tumor invasion. In this report we show the relationship among HA, Tiam1, migration and MDR in murine lymphoma cell lines. We observed that MDR cells presented higher migratory capacity towards HA in vitro as well as higher constitutive active Tiam1 expression than the sensitive cell line. Besides, HA treatment induced migration towards HA of MDR cell lines through Tiam1 activation by a PI3K-dependent mechanism, showing that disruption of HA signaling would be useful in treatment of MDR hematological malignancies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Cytoskeleton alteration in MCF7R cells, a multidrug resistant human breast cancer cell line.

    PubMed

    Bichat, F; Mouawad, R; Solis-Recendez, G; Khayat, D; Bastian, G

    1997-01-01

    Various cytoskeleton modifications are associated with malignant cell transformation and have been used as prognostic factors. A human breast cancer cell line (MCF7S) and its multidrug resistant (MDR) subline (MCF7R) were characterized here for their intermediate filaments (IFs) expression (cytokeratin 8, 18, 19 and vimentin) as a function of their resistance phenotype. Modifications of these cytoskeleton molecules were analyzed by flow cytometry, immunofluorescence, electrophoresis and immunoblotting techniques. Cytokeratins 8 and 18 were similarly expressed in the cell lines. Cytokeratin 19 was expressed in the MCF7S cell line and not in the MCF7R variant, while vimentin was highly expressed in MCF7R and slightly in MCF7S. Analysis of IFs after the addition of doxorubicin (Dox) in the culture medium of MCF7S, showed an increase in cytokeratin 8 filaments. Vimentin expression in MCF7R was not modified in the presence of these different MDR modulators. Acquisition of MDR was associated with an increase and a redistribution of vimentin filaments characterized by a perinuclear polarization. These drug resistance associated changes might derive from different biological processes triggered by chemotherapy. In conclusion, this suggests that this intermediate filament could be a marker associated with chemoresistance or a marker of malignancy in certain epithelial cancers.

  2. 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

  3. A cytotoxic ribonuclease reduces the expression level of P-glycoprotein in multidrug-resistant cell lines.

    PubMed

    Castro, Jessica; Ribó, Marc; Puig, Teresa; Colomer, Ramon; Vilanova, Maria; Benito, Antoni

    2012-06-01

    We have previously described a cytotoxic human pancreatic-ribonuclease variant, named PE5, which is able to cleave nuclear RNA, inducing the apoptosis of cancer cells. We have investigated whether PE5 could specifically inhibit the accumulation of P-glycoprotein in multidrug-resistant cells, since P-glycoprotein overexpression is one of the most important mechanisms contributing to the multiple drug resistance phenotype. We show that PE5 is able to reduce the amount of P-glycoprotein in two different multidrug-resistant cell lines, NCI/H460-R and NCI/ADR-RES, while glutathione S-transferase-л is not affected. We also show that onconase, an amphibian ribonuclease that is undergoing phase II/III clinical trials as an antitumor drug, does not affect the expression of these proteins. The reduction of P-glycoprotein accumulation, which has been functionally confirmed by flow cytometry analysis, may be caused by the previously reported underphosphorylation of JNK induced by PE5. We also show that PE5 has synergistic cytotoxicity with doxorubicin on the NCI/ADR-RES multidrug-resistant cell line. In conclusion, PE5 is a cytotoxic ribonuclease that cleaves nuclear RNA and decreases the expression of P-glycoprotein, showing anticancer activity in multidrug-resistant cell lines.

  4. Effects of iron deprivation on multidrug resistance of leukemic K562 cells.

    PubMed

    Fang, Dingzhu; Bao, Yixiao; Li, Xiaobin; Liu, Fang; Cai, Kang; Gao, Ju; Liao, Qingkui

    2010-01-01

    Multidrug resistance (MDR) compromises the efficacy of chemotherapy. Many approaches have been used to reduce MDR; however, the results are poor. It has been reported that iron deprivation downregulates MDR genes. To investigate the relationship of iron with MDR and early growth response gene-1 (EGR1), we investigated the effect of iron deprivation on expression and/or function of multidrug resistance-1 (MDR1), early growth response gene-1 (EGR1), ferritin heavy chain gene (H-Fn) and MDR1-encoded P-glycoprotein (P-gp) in the K562 leukemic cell line. The cells were stimulated with 12-O-tetradecanoylphorbol-13-acetate (TPA) and incubated with either FeCl(3) or the iron-chelating drug DFO. The mRNA levels of MDR1, EGR1 and H-Fn were detected by RT-PCR. The protein expression and function of P-gp were measured by immunohistochemical staining and flow cytometry, respectively. DFO significantly reduced the intracellular iron level, and led to approximately 70% reduction of MDR1 mRNA, approximately 50% of reduction of H-Fn mRNA and approximately 30% reduction of P-gp protein in TPA-differentiated K562 cells. The P-gp pump function, measured by daunorubicin exclusion, was also reduced by DFO treatment. These results suggest a close relationship between iron deprivation and reduced MDR1/P-gp expression and function. DFO may be used together with chemotherapeutic drugs to achieve better clinical efficacy. Copyright 2010 S. Karger AG, Basel.

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  6. 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.

  7. The plant alkaloid voacamine induces apoptosis-independent autophagic cell death on both sensitive and multidrug resistant human osteosarcoma cells.

    PubMed

    Meschini, Stefania; Condello, Maria; Calcabrini, Annarica; Marra, Manuela; Formisano, Giuseppe; Lista, Pasquale; De Milito, Angelo; Federici, Elena; Arancia, Giuseppe

    2008-11-01

    In our previous studies, the bisindolic alkaloid voacamine (VOA), isolated from the plant Peschiera fuchsiaefolia, proved to exert a chemosensitizing effect on cultured multidrug resistant (MDR) osteosarcoma cells exposed to doxorubicin (DOX). In particular, VOA was capable of inhibiting P-glycoprotein action in a competitive way, thus explaining the enhancement of the cytotoxic effect induced by DOX on MDR cells. Afterwards, preliminary observations suggested that such an enhancement did not involve the apoptotic process but was due instead to the induction of autophagic cell death. The results of the present investigation demonstrate that the plant alkaloid VOA is an autophagy inducer able to exert apoptosis-independent cytotoxic effect on both wild-type and MDR tumor cells. In fact, under treatment condition causing about 50 percent of cell death, no evidence of apoptosis could be revealed by microscopical observations, Annexin V-FITC labeling and analysis of PARP cleavage, whereas the same cells underwent apoptosis when treated with apoptosis inducers, such as doxorubicin and staurosporine. Conversely, VOA-induced autophagy was clearly evidentiated by electron microscopy observations, monodansylcadaverine staining, LC3 expression, and conversion. These results were confirmed by the analysis of the modulating effects of the pretreatment with autophagy inhibitors prior to VOA administration. In addition, transfection of osteosarcoma cells with siRNA against ATG genes reduced VOA cytotoxicity. In conclusion, considering the very debated dual role of autophagy in cancer cells (protective or lethal, pro- or anti- apoptotic) our findings seem to demonstrate, at least in vitro, that a natural product able to induce autophagy can be effective against drug resistant tumors, either used alone or in association with conventional chemotherapeutics.

  8. Multidrug resistance protein 1 (ABCC1) confers resistance to arsenic compounds in human myeloid leukemic HL-60 cells.

    PubMed

    Xu, Shi; Zhang, Yan Fang; Carew, Micheal W; Hao, Wen Hui; Loo, Jacky Fong Chuen; Naranmandura, Hua; Le, X Chris

    2013-06-01

    Arsenic trioxide (As(2)O(3)) is established as one of the most effective drugs for treatment of patients with acute promyelocytic leukemia, as well as other types of malignant tumors. However, HL-60 cells are resistant to As(2)O(3), and little is known about the underlying resistance mechanism for As(2)O(3) and its biomethylation products, namely, monomethylarsonous acid (MMA(III)) on the treatment of tumors. In the present study, we investigated the molecular mechanisms underlying iAs(III) and its intermediate metabolite MMA(III)-induced anticancer effects in the HL-60 cells. Here, we show that the HL-60 cells exhibit resistance to inorganic iAs(III) (IC(50) = 10 μM), but are relatively sensitive to its intermediate MMA(III) (IC(50) = 3.5 μM). Moreover, we found that the multidrug resistance protein 1 (MRP1), but not MRP2, is expressed in HL-60 cells, which reduced the intracellular arsenic accumulation, and conferred resistance to inorganic iAs(III) and MMA(III). Pretreatment of HL-60 with MK571, an inhibitor of MRP1, significantly increased iAs(III) and MMA(III)-induced cytotoxicity and arsenic accumulations, suggesting that the expression of MRP1/4 may lead to HL-60 cells resistance to trivalent arsenic compounds.

  9. 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

  10. Overcoming multidrug resistance of breast cancer cells by the micellar doxorubicin nanoparticles of mPEG-PCL-graft-cellulose.

    PubMed

    Chen, Chao-Hsuan; Cuong, Nguyen-Van; Chen, Yung-Tsung; So, Regina Cheng; Liau, Ian; Hsieh, Ming-Fa

    2011-01-01

    The amphiphilic block copolymer methoxy-poly(ethylene glycol)-poly(epsilon-caprolactone) (mPEG-PCL) was grafted to 2-hydroxyethyl cellulose (HEC) to produce nano-sized micellar nanoparticles. The nanoparticles were loaded with anti-tumor drug, doxorubicin (DOX) and the size of the DOX-loaded nanoparticles were determined by dynamic light scattering (DLS) in aqueous solution to be from 197.4 to 230 nm. The nanoparticles subjected to co-culture with macrophage cells showed that these nanoparticles used as drug carrier are not recognized as foreign bodies. Overexpression of P-glycoprotein (P-gp) is an important factor in the development of multidrug resistance (MDR) in many cancer cells. In this study, Western blot and Rhodamine 123 were used to monitor the relative P-glycoprotein expression in human breast cancer cell lines MCF-7/WT and MCF-7/ADR. The endocytosis of the DOX-loaded nanoparticles by breast cancer cells is more efficient observed under a confocal laser scanning microscopy (CLSM) and a flow cytometry in MCF7/ADR cells, compared to the diffusion of the free drug into the cytoplasm of cells. Based on these findings, we concluded that the nanoparticles made from mPEG-PCL-g-cellulose were effective in overcoming P-gp efflux in MDR breast cancer cells.

  11. [Mechanisms of Chansu Injection in reversing multidrug resistance of HL60/ADM cells].

    PubMed

    Xiong, Xin; Zhou, Yuan-da

    2012-03-01

    To investigate the mechanisms underlying the effect of Chansu Injection (CHS) in reversing multi-drug resistance (MDR) of HL60/ADM cells. MTT assay was used to investigate the effect of CHS on adramycin (ADM) sensitivity of HL-60/ADM cells. Flow cytometry was used to observe the effect of CHS on the cell cycle of HL60/ADM cell. The expressions of NF-κB, MRP, GST-π, and iNOS were detected by immunocytochemistry. Treatment with CHS lowered the IC(50) of ADM in HL60/ADM cells from 34.1971 µmol/L to 17.4393 µmol/L, and caused an increase in G(0)/G1 and G(2)/M phase cells with decreased S phase cells. CHS decreased the expressions of MRP mRNA and GST-π and MRP proteins but increased the expressions of iNOS and NF-κB proteins in the cells. CHS can partly reverse MDR in HL60/ADM cells possibly by down-regulating MRP and GST-π, up-regulating NF-κB and iNOS, and promoting cell apoptosis, thereby increase ADM sensitivity of HL-60/ADM cells.

  12. Sensitization of Cells Overexpressing Multidrug Resistant Proteins by Pluronic P85

    PubMed Central

    Batrakova, Elena V.; Li, Shu; Alakhov, Valery Yu.; Elmquist, William F.; Miller, Donald W.; Kabanov, Alexander V.

    2011-01-01

    Purpose This study evaluated the chemosensitizing effects of Pluronic P85 (P85) on the cells expressing multidrug resistance-associated proteins, MRP1 and MRP2. Methods Cell models included MRP1- and MRP2-transfected MDCKII cells, as well as doxorubicin-selected COR-L23/R cells overexpressing MRP1. Effects of P85 on cellular accumulation and cytotoxicity of vinblastine and doxorubicin were determined. Mechanistic studies characterized the effects of P85 on ATP and reduced glutathione (GSH) intracellular levels as well as MRPs ATPase and glutathione-S-transferase (GST) activities in these cells. Results Considerable increases of vinblastine and doxorubicin accumulation in the cells overexpressing MRP1 and MRP2 in the presence of P85 were observed, while no statistically significant changes in the drug accumulation in the parental cells were found. P85 treatment caused an inhibition of MRPs ATPase activity. Furthermore, P85 induced ATP depletion in these cells similar to that previously reported for Pgp-overexpressing cells. In addition, reduction of GSH intracellular levels and decrease of GST activity following P85 treatment were observed. Finally, significant enhancement of cytotoxicity of vinblastine and doxorubicin by P85 in MRPs -overexpressing cells was demonstrated. Conclusions This study suggests that P85 can sensitize cells overexpressing MRP1 and MRP2, which could be useful for chemotherapy of cancers that display these resistant mechanisms. PMID:14620511

  13. Salvianolic acid A shows selective cytotoxicity against multidrug-resistant MCF-7 breast cancer cells.

    PubMed

    Wang, Xin; Wang, Chunyan; Zhang, Longjiang; Li, Yanjun; Wang, Shouju; Wang, Jiandong; Yuan, Caiyun; Niu, Jia; Wang, Chengsheng; Lu, Guangming

    2015-02-01

    Multidrug resistance (MDR) is a major cause for incurable breast cancer. Salvianolic acid A (SAA), the hydrophilic polyphenolic derivative of Salvia miltiorrhiza Bunge (Danshen/Red Sage), was examined for cytotoxicities to MDR MCF-7 human breast cancer cells and their parental counterparts. We have shown that SAA inhibited proliferation, caused cell cycle arrest at the S phase, and induced apoptosis dose dependently to the two kinds of cancer cells. However, the resistant cells were significantly susceptible to the inhibition of SAA compared with the parental cells. SAA increased the level of reactive oxygen species (ROS) by 6.2-fold in the resistant cells, whereas the level of SAA-induced ROS changed only by 1.6-fold in their parental counterparts. Thus, the data showed that the selective cytotoxicity resulted from the hypersensitivity of the resistant cells to the strongly elevated ROS by SAA. In addition, SAA-triggered apoptosis was associated with increased caspase-3 activity, disrupted mitochondrial membrane potential, downregulated Bcl-2 expression, and upregulated Bax expression in the resistant cells. Moreover, SAA downregulated the level of P-glycoprotein, which was overexpressed in the resistant cells. This indicated that SAA modulated MDR. Furthermore, SAA showed higher antitumor activity than did doxorubicin in xenografts established from the resistant cells. The present work raised a possibility that SAA might be considered a potential choice to overcome MDR for the selective susceptibility of the resistant breast cancer cells to SAA treatment.

  14. 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.

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

    PubMed

    Wang, Hui; Chen, Jiao; Feng, Yun; Zhou, Wenjie; Zhang, Jihua; Yu, Y U; Wang, Xiaoqian; Zhang, Ping

    2015-06-01

    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, (1)H 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, (1)H NMR-based metabolomic analysis has a high potential for monitoring the formation of MDR during clinical tumor chemotherapy in the future.

  16. [Reversing effects of emodin on multidrug resistance in resistant HL-60/ADR cells].

    PubMed

    Chen, Ying-Yu; Li, Jing; Hu, Jian-Da; Zheng, Jing; Zheng, Zhi-Hong; Zhu, Liang-Fang; Chen, Xin-Ji; Lin, Zhen-Xing

    2013-12-01

    This study was aimed to investigate the reversing effects of emodin on multidrug resistance (MDR) in resistant HL-60/ADR cells, and to explore the underlying mechanisms. The MTT assay was used to assess the chemoresistance of HL-60/ADR cells to emodin and 8 chemotherapeutic agents commonly used in clinic. The reversal effects of emodin on MDR of HL-60/ADR cells were also evaluated by MTT method. DNA ploidy analysis and DNA Ladder assay were used to detect apoptosis-induced effects on HL-60/ADR cells via the adriamycin (ADR) and emodin combination. The expression changes of the drug resistance-associated genes and proteins were detected by RT-PCR and Western Blot respectively. The intracellular accumulation and subcellular distribution of ADR and DNR were measured by flow cytometry and confocal laser scanning microscopy. The results showed that emodin inhibited HL-60/ADR cell proliferation with an average IC50 value of 24.09 ± 1.72 µmol/L, which was similar to that of the parental HL-60 cells (average IC50 = 23.18 ± 0.87 µmol/L). HL-60/ADR cells were resistant to a variety of chemotherapeutic agents, such as ADR, DNR, VP16, VCR,Ara-C, HHT, MTZ and THP. The reversal multiple were between 1.58 and 4.12 after the treatment with low concentration of emodin combined with the above mentioned different agents. The combination of ADR with emodin showed the best reversal effects, and the typical hypodiploid peak (apoptotic peak) and DNA ladder could be detected after the co-treatment.In addition, emodin down-regulated the mRNA and protein expression levels of MRP1, TOPOIIβ, GST π and BCL-2. Furthermore, the addition of emodin enhanced ADR and DNR intracellular accumulation and subcellular distribution in HL-60/ADR cells in dose-dependent manner. It is concluded that the emodin shows reversing effects on the multidrug resistant HL-60/ADR cells, possibly via decreasing the expression levels of drug resistance-associated genes, increasing the intracellular accumulation of

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

    PubMed Central

    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

  18. Altered MRP is associated with multidrug resistance and reduced drug accumulation in human SW-1573 cells.

    PubMed Central

    Eijdems, E. W.; Zaman, G. J.; de Haas, M.; Versantvoort, C. H.; Flens, M. J.; Scheper, R. J.; Kamst, E.; Borst, P.; Baas, F.

    1995-01-01

    We have analysed the contribution of several parameters, e.g. drug accumulation, MDR1 P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP) and topoisomerase (topo) II, to drug resistance in a large set of drug-resistant variants of the human non-small-cell lung cancer cell line SW-1573 derived by selection with low concentrations of doxorubicin or vincristine. Selection with either drug nearly always resulted in MDR clones. The resistance of these clones could be explained by reduced drug accumulation and was associated with a decrease rather than an increase in the low MDR1 mRNA level. To test whether a decrease in MDR1 mRNA indirectly affected resistance in these cells, we introduced a MDR1-specific hammerhead ribozyme into wild-type SW-1573 cells. Although this led to a substantial reduction in MDR1 mRNA, it did not result in resistance. In all resistant clones we found an altered form of the multidrug resistance-associated protein (MRP), migrating slightly slower during SDS-polyacrylamide gel electrophoresis than MRP in parental cells. This altered MRP was also present in non-P-gp MDR somatic cell hybrids of the SW-1573 cells, demonstrating a clear linkage with the MDR phenotype. Treatment of crude cellular membrane fractions with N-glycanase, endoglycosidase H or neuraminidase showed that the altered migration of MRP on SDS-PAGE is due to a post-translational modification. There was no detectable difference in sialic acid content. In most but not all doxorubicin-selected clones, this MDR phenotype was accompanied by a reduction in topo II alpha mRNA level. No reduction was found in the clones selected with vincristine. We conclude from these results that selection of the SW-1573 cell line for low levels of doxorubicin or vincristine resistance, predominantly results in MDR with reduced drug accumulation associated with the presence of an altered MRP protein. This mechanism can be accompanied by other resistance mechanisms, such as reduced topo

  19. Long-Term Alteration of Reactive Oxygen Species Led to Multidrug Resistance in MCF-7 Cells

    PubMed Central

    Cen, Juan; Zhang, Li; Liu, Fangfang

    2016-01-01

    Reactive oxygen species (ROS) play an important role in multidrug resistance (MDR). This study aimed to investigate the effects of long-term ROS alteration on MDR in MCF-7 cells and to explore its underlying mechanism. Our study showed both long-term treatments of H2O2 and glutathione (GSH) led to MDR with suppressed iROS levels in MCF-7 cells. Moreover, the MDR cells induced by 0.1 μM H2O2 treatment for 20 weeks (MCF-7/ROS cells) had a higher viability and proliferative ability than the control MCF-7 cells. MCF-7/ROS cells also showed higher activity or content of intracellular antioxidants like glutathione peroxidase (GPx), GSH, superoxide dismutase (SOD), and catalase (CAT). Importantly, MCF-7/ROS cells were characterized by overexpression of MDR-related protein 1 (MRP1) and P-glycoprotein (P-gp), as well as their regulators NF-E2-related factor 2 (Nrf2), hypoxia-inducible factor 1 (HIF-1α), and the activation of PI3K/Akt pathway in upstream. Moreover, several typical MDR mediators, including glutathione S-transferase-π (GST-π) and c-Myc and Protein Kinase Cα (PKCα), were also found to be upregulated in MCF-7/ROS cells. Collectively, our results suggest that ROS may be critical in the generation of MDR, which may provide new insights into understanding of mechanisms of MDR. PMID:28058088

  20. MUC1 induces drug resistance in pancreatic cancer cells via upregulation of multidrug resistance genes.

    PubMed

    Nath, S; Daneshvar, K; Roy, L D; Grover, P; Kidiyoor, A; Mosley, L; Sahraei, M; Mukherjee, P

    2013-06-17

    MUC1 (CD227), a membrane tethered mucin glycoprotein, is overexpressed in >60% of human pancreatic cancers (PCs), and is associated with poor prognosis, enhanced metastasis and chemoresistance. The objective of this study was to delineate the mechanism by which MUC1 induces drug resistance in human (BxPC3 and Capan-1) and mouse (KCKO, KCM) PC cells. We report that PC cells that express high levels of MUC1 exhibit increased resistance to chemotherapeutic drugs (gemcitabine and etoposide) in comparison with cells that express low levels of MUC1. This chemo resistance was attributed to the enhanced expression of multidrug resistance (MDR) genes including ABCC1, ABCC3, ABCC5 and ABCB1. In particular, levels of MRP1 protein encoded by the ABCC1 gene were significantly higher in the MUC1-high PC cells. In BxPC3 and Capan-1 cells MUC1 upregulates MRP1 via an Akt-dependent pathway, whereas in KCM cells MUC1-mediated MRP1 upregulation is via an Akt-independent mechanism. In KCM, BxPC3 and Capan-1 cells, the cytoplasmic tail motif of MUC1 associates directly with the promoter region of the Abcc1/ABCC1 gene, indicating a possible role of MUC1 acting as a transcriptional regulator of this gene. This is the first report to show that MUC1 can directly regulate the expression of MDR genes in PC cells, and thus confer drug resistance.

  1. MUC1 induces drug resistance in pancreatic cancer cells via upregulation of multidrug resistance genes

    PubMed Central

    Nath, S; Daneshvar, K; Roy, L D; Grover, P; Kidiyoor, A; Mosley, L; Sahraei, M; Mukherjee, P

    2013-01-01

    MUC1 (CD227), a membrane tethered mucin glycoprotein, is overexpressed in >60% of human pancreatic cancers (PCs), and is associated with poor prognosis, enhanced metastasis and chemoresistance. The objective of this study was to delineate the mechanism by which MUC1 induces drug resistance in human (BxPC3 and Capan-1) and mouse (KCKO, KCM) PC cells. We report that PC cells that express high levels of MUC1 exhibit increased resistance to chemotherapeutic drugs (gemcitabine and etoposide) in comparison with cells that express low levels of MUC1. This chemo resistance was attributed to the enhanced expression of multidrug resistance (MDR) genes including ABCC1, ABCC3, ABCC5 and ABCB1. In particular, levels of MRP1 protein encoded by the ABCC1 gene were significantly higher in the MUC1-high PC cells. In BxPC3 and Capan-1 cells MUC1 upregulates MRP1 via an Akt-dependent pathway, whereas in KCM cells MUC1-mediated MRP1 upregulation is via an Akt-independent mechanism. In KCM, BxPC3 and Capan-1 cells, the cytoplasmic tail motif of MUC1 associates directly with the promoter region of the Abcc1/ABCC1 gene, indicating a possible role of MUC1 acting as a transcriptional regulator of this gene. This is the first report to show that MUC1 can directly regulate the expression of MDR genes in PC cells, and thus confer drug resistance. PMID:23774063

  2. miR-137 restoration sensitizes multidrug-resistant MCF-7/ADM cells to anticancer agents by targeting YB-1.

    PubMed

    Zhu, Xiaolan; Li, Yuefeng; Shen, Huiling; Li, Hao; Long, Lulu; Hui, Lulu; Xu, Wenlin

    2013-02-01

    Multidrug resistance (MDR) to chemotherapeutic agents is a major obstacle to successful treatment in breast cancer patients. The aims of this study were to investigate whether miR-137 was involved in the regulation of MDR, and to explore the mechanism of miR-137 on the sensitivity of MCF-7/ADM cells. miR-137 was downregulated in MCF-7/ADM cells, and its expression was found to inversely correlate with Y-box binding protein-1 (YB-1) and P-glycoprotein (P-gp) levels in breast cancer cells. Furthermore, YB-1 was confirmed as a target of miR-137 by luciferase reporter assay and western blot analysis. Moreover, elevated expression of miR-137 reduced the protein expression levels of YB-1 and P-gp, mimicking the effect of YB-1 knockdown in the sensitivity of MCF-7/ADM cells to anticancer agents, whereas restoration of YB-1 diminished this effect. In conclusion, our results demonstrated that miR-137 was involved in MDR in cancer through modulation of P-gp by targeting YB-1, suggesting that miR-137 might be a potential target for preventing and reversing MDR in tumor cells.

  3. Regulation of MDR1 gene expression in multidrug-resistant cancer cells is independent from YB-1.

    PubMed

    Kaszubiak, Alexander; Kupstat, Annette; Müller, Ursula; Hausmann, Romy; Holm, Per Sonne; Lage, Hermann

    2007-05-25

    The MDR1 gene encoded transmembrane ABC-transporter MDR1/P-glycoprotein can mediate the phenotype of multidrug resistance (MDR), a major obstacle in the clinical management of cancer patients. It was hypothesized that YB-1 is a fundamental regulatory factor of the MDR1 gene in tumor cells and can therewith enhance drug resistance. To analyze the potential impact of YB-1 in MDR cancer cells, two specific anti-YB-1 small interfering RNAs (siRNAs) were designed for transient triggering the gene-silencing RNA interference (RNAi) pathway in the MDR cell lines EPG85-257RDB and EPP85-181RDB as well as in their drug-sensitive counterparts EPG85-257P and EPP85-181P. Since both siRNAs showed biological activity, for stable inhibition of YB-1 corresponding tetracycline-inducible short hairpin RNA (shRNA)-encoding expression vectors were designed. By treatment of the cancer cells with these constructs, the expression of the targeted YB-1 encoding mRNA and protein was completely inhibited following tetracycline exposure. These gene-silencing effects were not accompanied by modulation of the MDR1 expression or by reversal of the drug-resistant phenotype. In conclusion, the data demonstrate the utility of the analyzed RNAs as powerful laboratory tools and indicate that YB-1 is not involved in the regulation of the MDR1 gene or the development of the drug-resistant phenotype in MDR cancer cells.

  4. Expression and activity of multidrug resistance proteins in mature endothelial cells and their precursors: A challenging correlation

    PubMed Central

    Bielawska-Pohl, Aleksandra; Wojtowicz, Karolina; Jura, Roksana; Paprocka, Maria; Wojdat, Elżbieta; Kozłowska, Urszula; Klimczak, Aleksandra; Grillon, Catherine; Kieda, Claudine; Duś, Danuta

    2017-01-01

    Active cellular transporters of harmful agents—multidrug resistance (mdr) proteins—are present in tumor, stem and endothelial cells, among others. While mdr proteins are broadly studied in tumor cells, their role in non-tumor cells and the significance of their action not connected with removal of harmful xenobiotics is less extensively documented. Proper assessment of mdr proteins expression is difficult. Mdr mRNA presence is most often evaluated but that does not necessarily correlate with the protein level. The protein expression itself is difficult to determine; usually cells with mdr overexpression are studied, not cells under physiological conditions, in which a low expression level of mdr protein is often insufficient for detection in vitro. Various methods are used to identify mdr mRNA and protein expression, together with functional tests demonstrating their biological drug transporting activities. Data comparing different methods of investigating expression of mdr mRNAs and their corresponding proteins are still scarce. In this article we present the results of a study concerning mdr mRNA and protein expression. Our goal was to search for the best method to investigate the expression level and functional activity of five selected mdr proteins—MDR1, BCRP, MRP1, MRP4 and MRP5—in established in vitro cell lines of human endothelial cells (ECs) and their progenitors. Endothelial cells demonstrated mdr presence at the mRNA level, which was not always confirmed at the protein level or in functional tests. Therefore, several different assays had to be applied for evaluation of mdr proteins expression and functions in endothelial cells. Among them functional tests seemed to be the most conclusive, although not very specific. PMID:28212450

  5. MDR1/P-gp and VEGF synergistically enhance the invasion of Hep-2 cells with multidrug resistance induced by taxol.

    PubMed

    Li, Li; Jiang, Alice C; Dong, Pin; Wang, Haibo; Xu, Wei; Xu, Chengzhi

    2009-05-01

    Tumor invasion/metastasis and multidrug resistance (MDR) are the main causes of treatment failure and high mortality in all kinds of cancer patients. The relationship between the two factors is still unclear. The aim of this study is to investigate the association between MDR and invasion, especially the role of multidrug resistance 1/P-glycoprotein (MDR1/P-gp) and vascular endothelial growth factor (VEGF) during the invasion. Multidrug resistance 1 (MDR1) and VEGF receptor 2 (VEGFR-2) were detected with real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) and Western blotting at the levels of messenger RNA (mRNA) and protein, respectively. RNA interference was applied to inhibit the expression of MDR1. The invasive assays were performed with the CHEMICON cell invasion assay kit. The MDR cell line induced by Taxol (Hep-2T cell) was more invasive than its parent cell line (Hep-2 cell), which was at least in part mediated through the overexpressed MDR1/P-pg. MDR1-targeted RNA interference could effectively inhibit the expression of MDR1 and obviously decrease the invasive ability. Synergistic enhancing effects existed between MDR1/P-gp and VEGF on the invasion of Hep-2T cells. The expression of VEGFR-2 was elevated in Hep-2T cells. SU1498 could significantly decrease the invasion of Hep-2T cells. MDR1-targeted RNA interference and SU1498 had synergistic decreasing effect on the invasion of Hep-2T cells. MDR1/P-pg may be a risk predictor for the invasion of laryngeal cancer. MDR1 knock down and VEGFR-2 inhibitor may be two promising treatment regiments for advanced laryngeal carcinoma patients with MDR and invasion/metastasis.

  6. 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. Copyright © 2015 Elsevier GmbH. All rights reserved.

  7. Resveratrol down-regulates survivin and induces apoptosis in human multidrug-resistant SPC-A-1/CDDP cells.

    PubMed

    Zhao, Weiguo; Bao, Pengtao; Qi, Haowen; You, Houcheng

    2010-01-01

    We studied the effect of resveratrol treatment on multidrug-resistant human non-small cell lung cancer cells. Human multidrug-resistant SPC-A-1/CDDP cells were treated with resveratrol at a concentration of 25, 50, or 100 microM in in vitro studies and nude mice were implanted with multidrug-resistant SPC-A-1/and fed a special diet that included resveratrol at a dose of either 1 g/kg/day or 3 g/kg/day in in vivo studies. No adverse toxicological effects of resveratrol treatment were observed. The rate of cell proliferation, apoptosis ratio, cell cycle phase distribution, IC50 values of cisplatin, gefitinib, and paclitaxel, implanted tumour volume, and expression of survivin in resveratrol-treated and control mice were then determined. Resveratrol significantly inhibited the proliferation of SPC-A-1/CDDP cells, induced apoptosis, arrested the cell cycle phase between G0-G1 and S phase or at the G2/M phase, decreased the IC50 values of multiple chemotherapeutic drugs, and showed anti-tumour effects in nude mice that had been implanted with SPC-A-1/CDDP cells. In additional, resveratrol affected the proliferation of SPC-A-1/CDDP cells in a dose- and time-dependent manner. Expression of survivin in SPC-A-1/CDDP cells decreased after they were treated with all concentrations of resveratrol and resveratrol was also found to have a dose-dependent effect on survivin expression. Resveratrol can induce apoptosis in multidrug-resistant human NSCLC SPC-A-1/CDDP cells by down-regulating the expression of survivin.

  8. Phospholipid-modified PEI-based nanocarriers for in vivo siRNA therapeutics against multi-drug resistant tumors

    PubMed Central

    Sabhachandani, Pooja; Chordia, Aabha; Trivedi, Malav; Movassaghian, Sara; Torchilin, Vladimir P.

    2014-01-01

    Multidrug resistance (MDR) mediated by P-glycoprotein overexpression in solid tumors is a major factor in the failure of many forms of chemotherapy. Here, we evaluated phospholipid-modified, low molecular weight polyethylenimine (DOPE-PEI) nanocarriers for intravenous delivery of anti-P-pg siRNA to tumors with the final goal of modulating MDR in breast cancer. First, we studied the biodistribution of DOPE-PEI nanocarriers and the effect of PEG coating in a s.c. breast tumor model. Four hours post-injection, PEGylated carriers showed an 8% injected dose (ID) accumulation in solid tumor via the enhanced permeability and retention effect and 22% ID in serum due to a prolonged, PEG-mediated circulation. Second, we established the therapeutic efficacy and safety of DOPE-PEI/siRNA-mediated P-gp down-regulation in combination with Doxorubicin (Dox) chemotherapy in MCF-7/MDR xenografts. Weekly injection of siRNA nanopreparations and Dox for up to 5 weeks sensitized the tumors to otherwise non-effective doses of Dox and decreased the tumor volume by 3-fold versus controls. This therapeutic improvement in response to Dox was attributed to the significant, sequence-specific P-gp down-regulation in excised tumors mediated by the DOPE-PEI formulations. PMID:25354685

  9. Phospholipid-modified PEI-based nanocarriers for in vivo siRNA therapeutics against multidrug-resistant tumors.

    PubMed

    Essex, S; Navarro, G; Sabhachandani, P; Chordia, A; Trivedi, M; Movassaghian, S; Torchilin, V P

    2015-03-01

    Multidrug resistance (MDR) mediated by P-glycoprotein overexpression in solid tumors is a major factor in the failure of many forms of chemotherapy. Here we evaluated phospholipid-modified, low-molecular-weight polyethylenimine (DOPE-PEI) nanocarriers for intravenous delivery of anti-P-pg siRNA to tumors with the final goal of modulating MDR in breast cancer. First, we studied the biodistribution of DOPE-PEI nanocarriers and the effect of PEG coating in a subcutaneous breast tumor model. Four hours postinjection, PEGylated carriers showed an 8% injected dose (ID) accumulation in solid tumor via the enhanced permeability and retention effect and 22% ID in serum due to a prolonged, PEG-mediated circulation. Second, we established the therapeutic efficacy and safety of DOPE-PEI/siRNA-mediated P-gp downregulation in combination with doxorubicin (Dox) chemotherapy in MCF-7/MDR xenografts. Weekly injection of siRNA nanopreparations and Dox for up to 5 weeks sensitized the tumors to otherwise non-effective doses of Dox and decreased the tumor volume by threefold vs controls. This therapeutic improvement in response to Dox was attributed to the significant, sequence-specific P-gp downregulation in excised tumors mediated by the DOPE-PEI formulations.

  10. Nonthermal Atmospheric Plasma Rapidly Disinfects Multidrug-Resistant Microbes by Inducing Cell Surface Damage

    PubMed Central

    Davis, Brian; Mondello, Frank; Garner, Allen L.

    2012-01-01

    Plasma, a unique state of matter with properties similar to those of ionized gas, is an effective biological disinfectant. However, the mechanism through which nonthermal or “cold” plasma inactivates microbes on surfaces is poorly understood, due in part to challenges associated with processing and analyzing live cells on surfaces rather than in aqueous solution. Here, we employ membrane adsorption techniques to visualize the cellular effects of plasma on representative clinical isolates of drug-resistant microbes. Through direct fluorescent imaging, we demonstrate that plasma rapidly inactivates planktonic cultures, with >5 log10 kill in 30 s by damaging the cell surface in a time-dependent manner, resulting in a loss of membrane integrity, leakage of intracellular components (nucleic acid, protein, ATP), and ultimately focal dissolution of the cell surface with longer exposure time. This occurred with similar kinetic rates among methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Candida albicans. We observed no correlative evidence that plasma induced widespread genomic damage or oxidative protein modification prior to the onset of membrane damage. Consistent with the notion that plasma is superficial, plasma-mediated sterilization was dramatically reduced when microbial cells were enveloped in aqueous buffer prior to treatment. These results support the use of nonthermal plasmas for disinfecting multidrug-resistant microbes in environmental settings and substantiate ongoing clinical applications for plasma devices. PMID:22232292

  11. Reversal effect of Ganoderma lucidum polysaccharide on multidrug resistance in K562/ADM cell line.

    PubMed

    Li, Wei-Dong; Zhang, Bo-di; Wei, Ran; Liu, Ji-Hong; Lin, Zhi-Bin

    2008-05-01

    To investigate the reversal effect of Ganoderma lucidum polysaccharides (Gl-PS) on multidrug resistance (MDR) in the adriamycin (ADM)-resistant leukemic cell line K562/ADM. Cytotoxicity was assayed by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide method; the ADM concentration in cells was determined by flow cytometry and confocal laser scanning microscopy techniques; the expression of P-glycoprotein was assayed by flow cytometry; and the mRNA expression levels of MDR-1 and MDR-associated protein (MRP)1 were determined by RT-PCR. Gl-PS reversed MDR in K562/ADM cells. Gl-PS obviously reversed the resistance of K562/ADM to doxorubicin. The reversing factors of Gl-PS at 10 and 20 mg/L were 6.46 and 6.80, respectively. MDR-1 and MRP1 transcription were downregulated by 10 and 50 mg/L Gl-PS. Gl-PS can reverse the MDR by downregulating the expression of MDR-1 and MRP1 in K562/ADM cells.

  12. Nonthermal atmospheric plasma rapidly disinfects multidrug-resistant microbes by inducing cell surface damage.

    PubMed

    Kvam, Erik; Davis, Brian; Mondello, Frank; Garner, Allen L

    2012-04-01

    Plasma, a unique state of matter with properties similar to those of ionized gas, is an effective biological disinfectant. However, the mechanism through which nonthermal or "cold" plasma inactivates microbes on surfaces is poorly understood, due in part to challenges associated with processing and analyzing live cells on surfaces rather than in aqueous solution. Here, we employ membrane adsorption techniques to visualize the cellular effects of plasma on representative clinical isolates of drug-resistant microbes. Through direct fluorescent imaging, we demonstrate that plasma rapidly inactivates planktonic cultures, with >5 log(10) kill in 30 s by damaging the cell surface in a time-dependent manner, resulting in a loss of membrane integrity, leakage of intracellular components (nucleic acid, protein, ATP), and ultimately focal dissolution of the cell surface with longer exposure time. This occurred with similar kinetic rates among methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Candida albicans. We observed no correlative evidence that plasma induced widespread genomic damage or oxidative protein modification prior to the onset of membrane damage. Consistent with the notion that plasma is superficial, plasma-mediated sterilization was dramatically reduced when microbial cells were enveloped in aqueous buffer prior to treatment. These results support the use of nonthermal plasmas for disinfecting multidrug-resistant microbes in environmental settings and substantiate ongoing clinical applications for plasma devices.

  13. Reversal of multidrug resistance by small interfering RNA (siRNA) in doxorubicin-resistant MCF-7 breast cancer cells.

    PubMed

    Dönmez, Yaprak; Gündüz, Ufuk

    2011-03-01

    Resistance to anticancer drugs is a serious obstacle to cancer chemotherapy. A common form of multidrug resistance (MDR) is caused by the overexpression of transmembrane transporter proteins P-glycoprotein (P-gp) and multidrug resistance-associated protein-1 (MRP1), encoded by MDR1 and MRP1 genes, respectively. These proteins lead to reduced intracellular drug concentration and decreased cytotoxicity by means of their ability to pump the drugs out of the cells. Breast cancer tumor resistance is mainly associated with overexpression of P-gp/MDR1. Although some chemical MDR modulators aim to overcome MDR by interfering functioning of P-gp, their toxicities limit their usage in clinics. Consequently, RNA interference mediated sequence specific inhibition of the expression of P-gp/MDR1 mRNA may be an efficient tool to reverse MDR phenotype and increase the success of chemotherapy. Aim of this study was resensitizing doxorubicin-resistant breast cancer cells to anticancer agent doxorubicin by selective downregulation of P-gp/MDR1 mRNA. The effect of the selected MDR1 siRNA, and MRP1 expression after MDR1 silencing was determined by qPCR analysis. Intracellular drug accumulation and localization was investigated by confocal laser scanning microscopy after treatment with MDR1 siRNA. XTT cell proliferation assay was performed to determine the effect of MDR1 silencing on doxorubicin sensitivity. The results demonstrated that approximately 90% gene silencing occurred by the selected siRNA targeting MDR1 mRNA. However, the level of MRP1 mRNA did not change after MDR1 downregulation. Silencing of P-gp encoding MDR1 gene resulted in almost complete restoration of the intracellular doxorubicin accumulation and relocalization of the drug in the nuclei. Introduction of siRNA resulted in about 70% resensitization to doxorubicin. Selected siRNA duplex was shown to effectively inhibit MDR1 gene expression, restore doxorubicin accumulation and localization, and enhance

  14. A novel curcumin derivative which inhibits P-glycoprotein, arrests cell cycle and induces apoptosis in multidrug resistance cells.

    PubMed

    Lopes-Rodrigues, Vanessa; Oliveira, Ana; Correia-da-Silva, Marta; Pinto, Madalena; Lima, Raquel T; Sousa, Emília; Vasconcelos, M Helena

    2017-01-15

    Cancer multidrug resistance (MDR) is a major limitation to the success of cancer treatment and is highly associated with the overexpression of drug efflux pumps such as P-glycoprotein (P-gp). In order to achieve more effective chemotherapeutic treatments, it is important to develop P-gp inhibitors to block/decrease its activity. Curcumin (1) is a secondary metabolite isolated from the turmeric of Curcuma longa L.. Diverse biological activities have been identified for this compound, particularly, MDR modulation in various cancer cell models. However, curcumin (1) has low chemical stability, which severely limits its application. In order to improve stability and P-gp inhibitory effect, two potential more stable curcumin derivatives were synthesized as building blocks, followed by several curcumin derivatives. These compounds were then analyzed in terms of antitumor and anti-P-gp activity, in two MDR and sensitive tumor lines (from chronic myeloid leukemia and non-small cell lung cancer). We identified from a series of curcumin derivatives a novel curcumin derivative (1,7-bis(3-methoxy-4-(prop-2-yn-1-yloxy)phenyl)hepta-1,6-diene-3,5-dione, 10) with more potent antitumor and anti-P-gp activity than curcumin (1). This compound (10) was shown to promote cell cycle arrest (at the G2/M phase) and induce apoptosis in the MDR chronic myeloid leukemia cell line. Therefore it is a really interesting P-gp inhibitor due to its ability to inhibit both P-gp function and expression.

  15. Cell Type Dependent Regulation of Multidrug Resistance-1 Gene Expression by AML1-ETO

    PubMed Central

    Hines, Robert; Boyapati, Anita; Zhang, Dong-Er

    2007-01-01

    The AML1-ETO fusion protein is generated from the 8;21 chromosome translocation that is commonly identified in acute myeloid leukemia. AML1-ETO is a DNA binding transcription factor and has been demonstrated to play a critical role in promoting leukemogenesis. Therefore, it is important to define the molecular mechanism of AML1-ETO in the regulation of gene expression. Here, we report that the effect of AML1-ETO on the promoter of multidrug resistance-1 (MDR1) gene, a known AML1-ETO target, is highly cell type specific. Besides observing repression of the MDR1 promoter in C33A and CV-1 cells as reported previously, AML1-ETO strongly activated the promoter in K562 and B210 cells. More importantly, this activation required both the AML1 and ETO portions of the fusion protein, but did not depend on the AML1 binding site in MDR1 promoter. Furthermore, results from promoter deletion analysis and chromatin immunoprecipitation assays suggested that this activation effect was likely through the influence of the general transcription machinery rather than promoter-specific factors. Based on these data, we propose that AML1-ETO may have opposing effects on gene expression depending on the various conditions of the cellular environment. PMID:17590361

  16. 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

    2016-06-28

    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.

  17. Psoralen reverses docetaxel-induced multidrug resistance in A549/D16 human lung cancer cells lines.

    PubMed

    Hsieh, Ming-Ju; Chen, Mu-Kuan; Yu, Ya-Yen; Sheu, Gwo-Tarng; Chiou, Hui-Ling

    2014-06-15

    Chemotherapy is the recommended treatment for advanced-stage cancers. However, the emergence of multidrug resistance (MDR), the ability of cancer cells to become simultaneously resistant to different drugs, limits the efficacy of chemotherapy. Previous studies have shown that herbal medicine or natural food may be feasible for various cancers as potent chemopreventive drug. This study aims to explore the capablility of reversing the multidrug resistance of docetaxel (DOC)-resistant A549 cells (A549/D16) of psoralen and the underlying mechanisms. In this study, results showed that the cell viability of A549/D16 subline is decreased when treated with psoralen plus DOC, while psoralen has no effect on the cell proliferation on A549 and A549/D16 cells. Furthermore, mRNA and proteins levels of ABCB1 were decreased in the presence of psoralen, while decreased ABCB1 activity was also revealed by flow cytometry. Based on these results, we believe that psoralen may be feasible for reversing the multidrug resistance by inhibiting ABCB1 gene and protein expression. Such inhibition will lead to a decrease in ABCB1 activity and anti-cancer drug efflux, which eventually result in drug resistance reversal and therefore, sensitizing drug-resistant cells to death in combination with chemotherapeutic drugs.

  18. Rack1 Mediates the Interaction of P-Glycoprotein with Anxa2 and Regulates Migration and Invasion of Multidrug-Resistant Breast Cancer Cells

    PubMed Central

    Yang, Yi; Wu, Na; Wang, Zhiyong; Zhang, Fei; Tian, Ran; Ji, Wei; Ren, Xiubao; Niu, Ruifang

    2016-01-01

    The emergence of multidrug resistance is always associated with more rapid tumor recurrence and metastasis. P-glycoprotein (P-gp), which is a well-known multidrug-efflux transporter, confers enhanced invasion ability in drug-resistant cells. Previous studies have shown that P-gp probably exerts its tumor-promoting function via protein-protein interaction. These interactions were implicated in the activation of intracellular signal transduction. We previously showed that P-gp binds to Anxa2 and promotes the invasiveness of multidrug-resistant (MDR) breast cancer cells through regulation of Anxa2 phosphorylation. However, the accurate mechanism remains unclear. In the present study, a co-immunoprecipitation coupled with liquid chromatography tandem mass spectrometry-based interactomic approach was performed to screen P-gp binding proteins. We identified Rack1 as a novel P-gp binding protein. Knockdown of Rack1 significantly inhibited proliferation and invasion of MDR cancer cells. Mechanistic studies demonstrated that Rack1 functioned as a scaffold protein that mediated the binding of P-gp to Anxa2 and Src. We showed that Rack1 regulated P-gp activity, which was necessary for adriamycin-induced P-gp-mediated phosphorylation of Anxa2 and Erk1/2. Overall, the findings in this study augment novel insights to the understanding of the mechanism employed by P-gp for promoting migration and invasion of MDR cancer cells. PMID:27754360

  19. Fulvestrant reverses doxorubicin resistance in multidrug-resistant breast cell lines independent of estrogen receptor expression.

    PubMed

    Huang, Yuan; Jiang, Donghai; Sui, Meihua; Wang, Xiaojia; Fan, Weimin

    2017-02-01

    Drug resistance, a major obstacle to successful cancer chemotherapy, frequently occurs in recurrent or metastatic breast cancer and results in poor clinical response. Fulvestrant is a new type of selective estrogen receptor (ER) downregulator and a promising endocrine therapy for breast cancer. In this study, we evaluated the combination treatment of fulvestrant and doxorubicin in ER-negative multidrug-resistant (MDR) breast cancer cell lines Bads‑200 and Bats‑72. Fulvestrant potentiated doxorubicin-induced cytotoxicity, apoptosis and G2/M arrest with upregulation of cyclin B1. It functioned as a substrate for P-glycoprotein (P-gp) without affecting its expression. Furthermore, fulvestrant not only restored the intracellular accumulation of doxorubicin but also relocalized it to the nuclei in Bats‑72 and Bads‑200 cells, which may be another potential mechanism of reversal of P-gp mediated doxorubicin resistance. These results indicated that the combination of fulvestrant and doxorubicin-based chemotherapy may be feasible and effective for patients with advanced breast cancer.

  20. A role for multidrug resistance protein 4 (MRP4; ABCC4) in human dendritic cell migration

    PubMed Central

    van de Ven, Rieneke; Scheffer, George L.; Reurs, Anneke W.; Lindenberg, Jelle J.; Oerlemans, Ruud; Jansen, Gerrit; Gillet, Jean-Pierre; Glasgow, Joel N.; Pereboev, Alexander; Curiel, David T.; Scheper, Rik J.

    2008-01-01

    The capacity of dendritic cells (DCs) to migrate from peripheral organs to lymph nodes (LNs) is important in the initiation of a T cell–mediated immune response. The ATP-binding cassette (ABC) transporters P-glycoprotein (P-gp; ABCB1) and the multidrug resistance protein 1 (MRP1; ABCC1) have been shown to play a role in both human and murine DC migration. Here we show that a more recently discovered family member, MRP4 (ABCC4), is expressed on both epidermal and dermal human skin DCs and contributes to the migratory capacity of DCs. Pharmacological inhibition of MRP4 activity or down-regulation through RNAi in DCs resulted in reduced migration of DCs from human skin explants and of in vitro generated Langerhans cells. The responsible MRP4 substrate remains to be identified as exogenous addition of MRP4's known substrates prostaglandin E2, leukotriene B4 and D4, or cyclic nucleotides (all previously implicated in DC migration) could not restore migration. This notwithstanding, our data show that MRP4 is an important protein, significantly contributing to human DC migration toward the draining lymph nodes, and therefore relevant for the initiation of an immune response and a possible target for immunotherapy. PMID:18625884

  1. Reversal of multidrug resistance in cancer cells by novel asymmetrical 1,4-dihydropyridines.

    PubMed

    Firuzi, Omidreza; Javidnia, Katayoun; Mansourabadi, Elham; Saso, Luciano; Mehdipour, Ahmad Reza; Miri, Ramin

    2013-11-01

    Multidrug resistance (MDR) is an important obstacle that limits the efficacy of chemotherapy in many types of cancer. In this study, 14 novel asymmetrical DHPs possessing pyridyl alkyl carboxylate substitutions at C3 and alkyl carboxylate groups at C5 in addition to a nitroimidazole or nitrophenyl moiety at C4 position were synthesized. Calcium channel blocking (CCB) activity was measured in guinea pig ileal longitudinal smooth muscle. Cytotoxicity was tested on 4 human cancer cell lines, while MDR reversal capacity was examined on P-glycoprotein overexpressing doxorubicin resistant MES-SA-DX5 and compared with non-resistant MES-SA cells. Compounds showed different CCB (IC50: 29.3 nM-4.75 μM) and cytotoxic activities (IC50: 6.4 to more than 100 μM). Several compounds having nitrophenyl moiety at C4, could significantly reverse resistance to doxorubicin at 0.5 and 1 μM. The most active ones were 7e and 7g containing ethyl carboxylate and isopropyl carboxylate at C5, respectively. CCB activity, which is considered an undesirable effect for these agents, of 7e and 7g were 33 and 20 times lower than nifedipine, respectively. In conclusion, the newly synthesized asymmetrical DHP compounds showed promising MDR reversal and antitumoral activities with low CCB effects and could be of therapeutic value in drug resistant cancer.

  2. Mycobacterium tuberculosis Multidrug Resistant Strain M Induces an Altered Activation of Cytotoxic CD8+ T Cells

    PubMed Central

    Geffner, Laura; Kviatcovsky, Denise; Sabio y García, Carmen; Ritacco, Viviana; López, Beatriz; Sasiain, María del Carmen; de la Barrera, Silvia

    2014-01-01

    In human tuberculosis (TB), CD8+ T cells contribute to host defense by the release of Th1 cytokines and the direct killing of Mycobacterium tuberculosis (Mtb)-infected macrophages via granule exocytosis pathway or the engagement of receptors on target cells. Previously we demonstrated that strain M, the most prevalent multidrug-resistant (MDR) Mtb strain in Argentine, is a weak inducer of IFN-γ and elicits a remarkably low CD8-dependent cytotoxic T cell activity (CTL). In contrast, the closely related strain 410, which caused a unique case of MDR-TB, elicits a CTL response similar to H37Rv. In this work we extend our previous study investigating some parameters that can account for this discrepancy. We evaluated the expressions of the lytic molecules perforin, granzyme B and granulysin and the chemokine CCL5 in CD8+ T cells as well as activation markers CD69 and CD25 and IL-2 expression in CD4+ and CD8+ T cells stimulated with strains H37Rv, M and 410. Our results demonstrate that M-stimulated CD8+ T cells from purified protein derivative positive healthy donors show low intracellular expression of perforin, granzyme B, granulysin and CCL5 together with an impaired ability to form conjugates with autologous M-pulsed macrophages. Besides, M induces low CD69 and IL-2 expression in CD4+ and CD8+ T cells, being CD69 and IL-2 expression closely associated. Furthermore, IL-2 addition enhanced perforin and granulysin expression as well as the degranulation marker CD107 in M-stimulated CD8+ T cells, making no differences with cells stimulated with strains H37Rv or 410. Thus, our results highlight the role of IL-2 in M-induced CTL activity that drives the proper activation of CD8+ T cells as well as CD4+ T cells collaboration. PMID:24836916

  3. Novel quinolone chalcones targeting colchicine-binding pocket kill multidrug-resistant cancer cells by inhibiting tubulin activity and MRP1 function.

    PubMed

    Lindamulage, I Kalhari; Vu, Hai-Yen; Karthikeyan, Chandrabose; Knockleby, James; Lee, Yi-Fang; Trivedi, Piyush; Lee, Hoyun

    2017-08-31

    Agents targeting colchicine-binding pocket usually show a minimal drug-resistance issue, albeit often associated with high toxicity. Chalcone-based compounds, which may bind to colchicine-binding site, are found in many edible fruits, suggesting that they can be effective drugs with less toxicity. Therefore, we synthesized and examined 24 quinolone chalcone compounds, from which we identified ((E)-3-(3-(2-Methoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one) (CTR-17) and ((E)-6-Methoxy-3-(3-(2-methoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one) (CTR-20) as promising leads. In particular, CTR-20 was effective against 65 different cancer cell lines originated from 12 different tissues, largely in a cancer cell-specific manner. We found that both CTR-17 and CTR-20 reversibly bind to the colchicine-binding pocket on β-tubulin. Interestingly however, both the CTRs were highly effective against multidrug-resistant cancer cells while colchicine, paclitaxel and vinblastine were not. Our study with CTR-20 showed that it overcomes multidrug-resistance through its ability to impede MRP1 function while maintaining strong inhibition against microtubule activity. Data from mice engrafted with the MDA-MB-231 triple-negative breast cancer cells showed that both CTR-17 and CTR-20 possess strong anticancer activity, alone or in combination with paclitaxel, without causing any notable side effects. Together, our data demonstrates that both the CTRs can be effective and safe drugs against many different cancers, especially against multidrug-resistant tumors.

  4. 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.

  5. 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

  6. 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.

  7. Detection of oligomeric and monomeric forms of P-glycoprotein in multidrug resistant cells.

    PubMed

    Poruchynsky, M S; Ling, V

    1994-04-12

    P-glycoprotein (P-gp) is thought to function as a drug efflux pump in multidrug resistant (MDR) cells. The functional form of P-gp in its native state is not known. Previous results from radiation target size analysis have suggested that P-gp occurs as dimers in MDR cell plasma membranes [Boscoboinik et al. (1990) Biochim. Biophys. Acta 1027, 225-228]. In this study, we used sucrose gradient velocity sedimentation to determine if P-gp oligomers could be retrieved from detergent extracts of hamster and human MDR cell lines. The proportion of P-gp recovered as higher order oligomers was dependent on the detergents used for solubilization of the cells. When a detergent such as CHAPS was used, 50% or more of the P-gp sedimented as higher order oligomers. In contrast, in the presence of SDS, only monomers were retrieved, but naturally occurring oligomers could be preserved if the cells were treated with a cross-linker prior to detergent solubilization. The oligomers and monomers were both able to bind the photoactive analog of ATP (8-azido[alpha-32P]ATP) or the drug [3H]azidopine in membrane preparations. P-gp is a phosphoprotein, and its phosphorylated state is thought to be important for function. When MDR cells were labeled with [32P]orthophosphate in vivo, we observed that the monomer and dimer were more highly phosphorylated than the larger oligomers, suggesting that these different forms of P-gp may be functionally distinct. The assembly of oligomers appears to occur in an early bisynthetic compartment, and asparagine-linked glycosylation is not required for their formation. Our findings indicate that oligomers of P-gp exist in MDR cells and raise the possibility that the dynamics of oligomer formation and dissociation may be important in the mechanism of action of P-gp.

  8. 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. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Genes amplified and overexpressed in human multidrug-resistant cell lines.

    PubMed

    Van der Bliek, A M; Baas, F; Van der Velde-Koerts, T; Biedler, J L; Meyers, M B; Ozols, R F; Hamilton, T C; Joenje, H; Borst, P

    1988-11-01

    Multidrug resistance (MDR) is associated with overproduction of Mr 170,000 membrane proteins (P-glycoproteins) caused by either gene amplification, transcriptional activation, or both. In rodents the amplified domain comprises genes that encode P-glycoproteins and at least five unrelated genes, one of which encodes the calcium-binding protein sorcin. The amplification and increased expression of these genes always includes one P-glycoprotein-encoding gene (pgp1 in hamsters, homologous to mdr1 in humans). In human MDR cells only elevated mdr1 expression has been shown thusfar, although another P-glycoprotein encoding gene (mdr3, homologous to hamster pgp3) is closely linked. Here we show that the human homolog of the hamster sorcin gene resides on chromosome 7 like the P-glycoprotein-encoding genes. Furthermore, gene classes designated 4, 5, and 6 are coamplified with mdr1 and mdr3 in the human ovarian carcinoma cell line 2780AD, which strongly suggests that the overall structure of the human MDR domain is the same as in rodents. Class 6 was moderately and mdr1 was highly overexpressed in this cell line. Four other human MDR cell lines also have much higher mdr1 overexpression than expected from the relatively low levels (2- to 30-fold) of gene amplification. This contrasts with the results of previous work with rodent MDR cells, in which the increase in P-glycoprotein mRNA levels usually parallels the increase in gene copy number. Although four of the five human MDR cell lines have coamplified mdr3, its expression was undetectable. Our results confirm the central role of the mdr1 (pgp1) gene in MDR and suggest that different cross-resistance patterns are not due to differential expression of different P-glycoprotein genes.

  10. Modulation of multidrug resistance in cancer cells by chelidonine and Chelidonium majus alkaloids.

    PubMed

    El-Readi, Mahmoud Zaki; Eid, SafaaYehia; Ashour, Mohamed Lotfy; Tahrani, Ahmad; Wink, Michael

    2013-02-15

    Cancer cells often develop multidrug resistance (MDR) which is a multidimensional problem involving several mechanisms and targets. This study demonstrates that chelidonine and an alkaloid extract from Chelidonium majus, which contains protoberberine and benzo[c]phenanthridine alkaloids, has the ability to overcome MDR of different cancer cell lines through interaction with ABC-transporters, CYP3A4 and GST, by induction of apoptosis, and cytotoxic effects. Chelidonine and the alkaloid extract inhibited P-gp/MDR1 activity in a concentration-dependent manner in Caco-2 and CEM/ADR5000 and reversed their doxorubicin resistance. In addition, chelidonine and the alkaloid extract inhibited the activity of the drug modifying enzymes CYP3A4 and GST in a dose-dependent manner. The alkaloids induced apoptosis in MDR cells which was accompanied by an activation of caspase-3, -8,-6/9, and phosphatidyl serine (PS) exposure. cDNA arrays were applied to identify differentially expressed genes after treatment with chelidonine and the alkaloid extract. The expression analysis identified a common set of regulated genes related to apoptosis, cell cycle, and drug metabolism. Treatment of Caco-2 cells with 50 μg/ml alkaloid extract and 50 μM chelidonine for up to 48 h resulted in a significant decrease in mRNA levels of P-gp/MDR1, MRP1, BCRP, CYP3A4, GST, and hPXR and in a significant increase in caspase-3 and caspase-8 mRNA. Thus, chelidonine is a promising model compound for overcoming MDR and for enhancing cytotoxicity of chemotherapeutics, especially against leukaemia cells. Its efficacy needs to be confirmed in animal models. Crown Copyright © 2012. Published by Elsevier GmbH. All rights reserved.

  11. 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.

  12. Amplicon structure in multidrug-resistant murine cells: a nonrearranged region of genomic DNA corresponding to large circular DNA.

    PubMed Central

    Ståhl, F; Wettergren, Y; Levan, G

    1992-01-01

    Multidrug resistance (MDR) in tumor cell lines is frequently correlated with amplification of one or more mdr genes. Usually the amplified domain also includes several neighboring genes. Using pulsed-field gel electrophoresis, we have established a restriction map covering approximately 2,200 kb in the drug-sensitive mouse tumor cell line TC13K. The mapped region is located on mouse chromosome 5 and includes the three mdr genes, the gene for the calcium-binding sorcin protein, and a gene with unknown function designated class 5. Long-range maps of the amplified DNA sequences in five of six MDR sublines that had been independently derived from TC13K generally displayed the same pattern as did the parental cell line. All six MDR sublines exhibited numerous double minutes, and one of them displayed a homogeneously staining region in a subpopulation. Large circular molecules, most likely identical to one chromatid of the double minutes, were detected in four of the sublines by linearization with gamma irradiation. The size of the circles was about 2,500 kb, which correlated to a single unit of the amplified domain. We therefore propose that in four independent instances of MDR development, a single unit of about 2,500 kb has been amplified in the form of circular DNA molecules. The restriction enzyme map of the amplified unit is unchanged compared with that of the parental cell line, whereas the joining sites of the circular DNA molecules are not identical but are in the same region. Images PMID:1545798

  13. Cell-Penetrating, Guanidinium-Rich Molecular Transporters for Overcoming Efflux-Mediated Multidrug Resistance

    PubMed Central

    2015-01-01

    Multidrug resistance (MDR) is a major cause of chemotherapy failure in the clinic. Drugs that were once effective against naïve disease subsequently prove ineffective against recurrent disease, which often exhibits an MDR phenotype. MDR can be attributed to many factors; often dominating among these is the ability of a cell to suppress or block drug entry through upregulation of membrane-bound drug efflux pumps. Efflux pumps exhibit polyspecificity, recognizing and exporting many different types of drugs, especially those whose lipophilic nature contributes to residence in the membrane. We have developed a general strategy to overcome efflux-based resistance. This strategy involves conjugating a known drug that succumbs to efflux-mediated resistance to a cell-penetrating molecular transporter, specifically, the cell-penetrating peptide (CPP), d-octaarginine. The resultant conjugates are discrete single entities (not particle mixtures) and highly water-soluble. They rapidly enter cells, are not substrates for efflux pumps, and release the free drug only after cellular entry at a rate controlled by linker design and favored by target cell chemistry. This general strategy can be applied to many classes of drugs and allows for an exceptionally rapid advance to clinical testing, especially of drugs that succumb to resistance. The efficacy of this strategy has been successfully demonstrated with Taxol in cellular and animal models of resistant cancer and with ex vivo samples from patients with ovarian cancer. Next generation efforts in this area will involve the extension of this strategy to other chemotherapeutics and other MDR-susceptible diseases. PMID:24798708

  14. Targeting the ABCG2-overexpressing multidrug resistant (MDR) cancer cells by PPARγ agonists

    PubMed Central

    To, Kenneth K W; Tomlinson, Brian

    2013-01-01

    Background and Purpose Multidrug resistance (MDR), usually mediated by overexpression of efflux transporters such as P-gp, ABCG2 and/or MRP1, remains a major obstacle hindering successful cancer chemotherapy. There has been great interest in the development of inhibitors towards these transporters to circumvent resistance. However, since the inhibition of transporter is not specific to cancer cells, a decrease in the cytotoxic drug dosing may be needed to prevent excess toxicity, thus undermining the potential benefit brought about by a drug efflux inhibitor. The design of potent MDR modulators specific towards resistant cancer cells and devoid of drug-drug interactions will be needed to effect MDR reversal. Experimental Approach Recent evidence suggests that the PTEN/PI3K/Akt pathway may be exploited to alter ABCG2 subcellular localization, thereby circumventing MDR. Three PPARγ agonists (telmisartan, pioglitazone and rosiglitazone) that have been used in the clinics were tested for their effect on the PTEN/PI3K/Akt pathway and possible reversal of ABCG2-mediated drug resistance. Key Results The PPARγ agonists were found to be weak ABCG2 inhibitors by drug efflux assay. They were also shown to elevate the reduced PTEN expression in a resistant and ABCG2-overexpressing cell model, which inhibit the PI3K-Akt pathway and lead to the relocalization of ABCG2 from the plasma membrane to the cytoplasma, thus apparently circumventing the ABCG2-mediated MDR. Conclusions and Implications Since this PPARγ/PTEN/PI3K/Akt pathway regulating ABCG2 is only functional in drug-resistant cancer cells with PTEN loss, the PPARγ agonists identified may represent promising agents targeting resistant cells for MDR reversal. PMID:24032744

  15. 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

    2015-01-05

    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.

  16. Multifunctional micelle delivery system for overcoming multidrug resistance of doxorubicin.

    PubMed

    Qin, Li; Wu, Lei; Jiang, Shanshan; Yang, Dandan; He, Huiyang; Zhang, Fang; Zhang, Peng

    2017-09-13

    Doxorubicin, as an anthracycline, plays an important role in chemotherapy. But multidrug resistance tremendously retards the anticancer effect of doxorubicin and results in the failure of chemotherapy. Multifunctional micelles emerge as a valid strategy to load doxorubicin by physical encapsulation or chemical binding to be delivered to cancer cells against multidrug resistance. In this review, mechanism of multidrug resistance of doxorubicin is simply described. Multifunctional co-delivery micelles of doxorubicin and main multidrug resistance modulators have been summarized in detail. Doxorubicin-loaded multifunctional polymeric micelles are also introduced to alleviate multidrug resistance of doxorubicin, in which polymers act as multidrug resistance modulators.

  17. Overcoming intrinsic multi-drug resistance in melanoma by blocking the mitochondrial respiratory chain of slow-cycling JARID1Bhigh cells

    PubMed Central

    Roesch, Alexander; Vultur, Adina; Bogeski, Ivan; Wang, Huan; Zimmermann, Katharina M.; Speicher, David; Körbel, Christina; Laschke, Matthias W.; Gimotty, Phyllis A.; Philipp, Stephan E.; Krause, Elmar; Pätzold, Sylvie; Villanueva, Jessie; Krepler, Clemens; Fukunaga-Kalabis, Mizuho; Hoth, Markus; Bastian, Boris; Vogt, Thomas; Herlyn, Meenhard

    2013-01-01

    Summary Despite success with BRAFV600E–inhibitors, therapeutic responses in patients with metastatic melanoma are short-lived because of the acquisition of drug resistance. We identified a mechanism of intrinsic multi-drug resistance based on the survival of a tumor cell subpopulation. Treatment with various drugs, including cisplatin and vemurafenib, uniformly leads to enrichment of slow-cycling, long-term tumor-maintaining melanoma cells expressing the H3K4-demethylase JARID1B/KDM5B/PLU-1. Proteome-profiling revealed an upregulation in enzymes of mitochondrial oxidative-ATP-synthesis (OXPHOS) in this subpopulation. Inhibition of mitochondrial respiration blocked the emergence of the JARID1Bhigh subpopulation and sensitized melanoma cells to therapy, independent of their genotype. Our findings support a two-tiered approach combining anti-cancer agents that eliminate rapidly proliferating melanoma cells with inhibitors of the drug-resistant slow-cycling subpopulation. PMID:23764003

  18. Overcoming intrinsic multidrug resistance in melanoma by blocking the mitochondrial respiratory chain of slow-cycling JARID1B(high) cells.

    PubMed

    Roesch, Alexander; Vultur, Adina; Bogeski, Ivan; Wang, Huan; Zimmermann, Katharina M; Speicher, David; Körbel, Christina; Laschke, Matthias W; Gimotty, Phyllis A; Philipp, Stephan E; Krause, Elmar; Pätzold, Sylvie; Villanueva, Jessie; Krepler, Clemens; Fukunaga-Kalabis, Mizuho; Hoth, Markus; Bastian, Boris C; Vogt, Thomas; Herlyn, Meenhard

    2013-06-10

    Despite success with BRAFV600E inhibitors, therapeutic responses in patients with metastatic melanoma are short-lived because of the acquisition of drug resistance. We identified a mechanism of intrinsic multidrug resistance based on the survival of a tumor cell subpopulation. Treatment with various drugs, including cisplatin and vemurafenib, uniformly leads to enrichment of slow-cycling, long-term tumor-maintaining melanoma cells expressing the H3K4-demethylase JARID1B/KDM5B/PLU-1. Proteome-profiling revealed an upregulation in enzymes of mitochondrial oxidative-ATP-synthesis (oxidative phosphorylation) in this subpopulation. Inhibition of mitochondrial respiration blocked the emergence of the JARID1B(high) subpopulation and sensitized melanoma cells to therapy, independent of their genotype. Our findings support a two-tiered approach combining anticancer agents that eliminate rapidly proliferating melanoma cells with inhibitors of the drug-resistant slow-cycling subpopulation. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. 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

  20. Removal of digoxin and doxorubicin by multidrug resistance protein-overexpressed cell culture in hollow fiber.

    PubMed

    Tsuruoka, S; Sugimoto, K I; Ueda, K; Suzuki, M; Imai, M; Fujimura, A

    1999-07-01

    Drug removal by hemoperfusion is not effective because of its lower capacity and nonspecificity. We invented a new hybrid type of hemodialysis system. An immortalized proximal tubular cell line (PCTL) overexpressing human multidrug resistance protein-1 (MDR-1) was cultured either on polus filter membranes or on hollow fiber modules. The modules were incubated in an incubator conditioned with 95% O2/5% CO2 that was kept at 37 degrees C. At 10 days on culture, the drug-transporting capacity of these systems was examined. MDR was successfully expressed in the PCTL as evaluated by Western blot. Basolateral to apical transport of 3H-digoxin, a substrate of MDR, was examined by using the cells cultured on a microporous membrane. PCTL-MDR showed a 10-fold increase in MDR protein and a 12-fold increase of 3H-digoxin transport through a cell layer on a microporous membrane. The increase of the transport was abolished by the addition of 5 microM verapamil, an inhibitor of MDR, to the apical side. When digoxin or doxorubicin was infused in the capillary side of the hollow fiber modules after 10 days on culture, the largest portion of the drugs was transported to the pericapillary side (P < 0.001). This transport was also abolished by an addition of verapamil to the pericapillary side. Transport of para-aminohippurate was not different between two cells, and inulin was not transported in this system. The hybrid hollow fiber system can selectively remove a significant amount of drugs that have an affinity to MDR from the medium, and perfuse them to the capillary side in vitro.

  1. 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

  2. Molecular evidence and functional expression of multidrug resistance associated protein (MRP) in rabbit corneal epithelial cells.

    PubMed

    Karla, Pradeep K; Pal, Dananjay; Mitra, Ashim K

    2007-01-01

    Multidrug resistance associated protein (MRP) is a major family of efflux transporters involved in drug efflux leading to drug resistance. The objective of this study was to explore physical barriers for ocular drug absorption and to verify if the role of efflux transporters. MRP-2 is a major homologue of MRP family and found to express on the apical side of cell membrane. Cultured Rabbit Corneal Epithelial Cells (rCEC) were selected as an in vitro model for corneal epithelium. [14C]-erythromycin which is a proven substrate for MRP-2 was selected as a model drug for functional expression studies. MK-571, a known specific and potent inhibitor for MRP-2 was added to inhibit MRP mediated efflux. Membrane fraction of rCEC was used for western blot analysis. Polarized transport of [14C]-erythromycin was observed in rCEC and transport from B-->A was significantly high than from A-->B. Permeability's increased significantly from A-->B in the presence of MK-571 and ketoconozole. Uptake of [14C]-erythromycin in the presence of MK-571 was significantly higher than control in rCEC. RT-PCR analysis indicated a unique and distinct band at approximately 498 bp corresponding to MRP-2 in rCEC and MDCK11-MRP-2 cells. Immunoprecipitation followed by Western Blot analysis indicated a specific band at approximately 190 kDa in membrane fraction of rCEC and MDCK11-MRP-2 cells. For the first time we have demonstrated high expression of MRP-2 in rabbit corneal epithelium and its functional activity causing drug efflux. RT-PCR, immunoprecipitation followed by Western blot analysis further confirms the result.

  3. Nigericin decreases the viability of multidrug-resistant cancer cells and lung tumorspheres and potentiates the effects of cardiac glycosides.

    PubMed

    Yakisich, Juan Sebastian; Azad, Neelam; Kaushik, Vivek; O'Doherty, George A; Iyer, Anand Krishnan V

    2017-03-01

    Multiple factors including tumor heterogeneity and intrinsic or acquired resistance have been associated with drug resistance in lung cancer. Increased stemness and the plasticity of cancer cells have been identified as important mechanisms of resistance; therefore, treatments targeting cancer cells independent of stemness phenotype would be much more effective in treating lung cancer. In this article, we have characterized the anticancer effects of the antibiotic Nigericin in cells displaying varying degrees of stemness and resistance to anticancer drugs, arising from (1) routine culture conditions, (2) prolonged periods of serum starvation. These cells are highly resistant to conventional anticancer drugs such as Paclitaxel, Hydroxyurea, Colchicine, Obatoclax, Wortmannin, and LY294002, and the multidrug-resistant phenotype of cells growing under prolonged periods of serum starvation is likely the result of extensive rewiring of signaling pathways, and (3) lung tumorspheres that are enriched for cancer stem-like cells. We found that Nigericin potently inhibited the viability of cells growing under routine culture conditions, prolonged periods of serum starvation, and lung tumorspheres. In addition, we found that Nigericin downregulated the expression of key proteins in the Wnt canonical signaling pathway such as LRP6, Wnt5a/b, and β-catenin, but promotes β-catenin translocation into the nucleus. The antitumor effects of Nigericin were potentiated by the Wnt activator HLY78 and by therapeutic levels of the US Food and Drug Administration-approved drug Digitoxin and its novel synthetic analog MonoD. We believe that Nigericin may be used in a co-therapy model in combination with other novel chemotherapeutic agents in order to achieve potent inhibition of cancers that display varying degrees of stemness, potentially leading to sustained anticancer effects.

  4. 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.

  5. Reversal of P-glycoprotein-mediated multidrug resistance is induced by saikosaponin D in breast cancer MCF-7/adriamycin cells.

    PubMed

    Li, Chun; Guan, Xingang; Xue, Haogang; Wang, Peng; Wang, Manli; Gai, Xiaodong

    2017-07-01

    Multidrug resistance (MDR) cells over expressing P-glycoprotein (P-gp) encoded by the MDR1 gene is major obstacles for successful cancer chemotherapy. P-gp could extrude anti-cancer drugs out of cancer cells and decrease effective intracellular drug concentrations. MDR reversal agents for P-gp can restore the sensitivity of MDR cells to such drugs. Saikosaponin D (SSd), one of the major triterpenoid saponins derived from Bupleurum chinense DC (BCDC), has been shown to possess anti-inflammatory, anti-infectious and anti-tumor properties. The aim of the present study was to investigate the reversal effect of SSd on MDR in MCF-7/adriamycin (ADR) human breast cancer cells and investigate the underlying mechanisms of SSd. The results demonstrated that SSd inhibited the proliferation of MCF-7/ADR and MCF-7 cells in a dose-dependent manner. Moreover, SSd increased the cytotoxicity of ADR on MCF-7/ADR cells and the resistance fold of SSd treatment was demonstrated to be significantly higher when compared with that of the group without SSd treatment. Additionally, the effects of the drug combination showed that SSd and ADR combination were synergistic. Accumulation and efflux studies with the P-gp substrate, rhodamine 123 (Rh123), demonstrated that SSd restored Rh123 accumulation and inhibited P-gp-mediated drug efflux. Importantly, we found that SSd could enhance the sensitivity of MCF-7/ADR cells towards ADR by down-regulating MDR1 and P-gp expression. In conclusion, the results of the present study indicated that SSd may represent a potent reversal agent for P-gp-mediated MDR in breast cancer therapy. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. 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

  7. 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. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

  8. [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.

  9. NF-κB decoy polyplexes decrease P-glycoprotein-mediated multidrug resistance in colorectal cancer cells.

    PubMed

    Abd Ellah, N H; Taylor, L; Ayres, N; Elmahdy, M M; Fetih, G N; Jones, H N; Ibrahim, E A; Pauletti, G M

    2016-05-01

    Multidrug resistance (MDR), a major cause for chemotherapy failure, has been linked to upregulation of ATP-dependent membrane efflux systems that limit intracellular accumulation of cytotoxic anticancer agents. P-glycoprotein (P-gp) encoded by the human ABCB1 gene was the first efflux transporter identified to contribute to MDR. ABCB1 gene expression is correlated with constitutive activation of the NF-κB signaling pathway in tumor cells. The objective of this research is to modulate P-gp activity in colon cancer cells using NF-κB decoy oligodeoxynucleotides (ODNs) that are effectively delivered into the nucleus of colorectal cancer cells by self-assembling nonviral nanoparticles comprising the novel poly[N-(2-hydroxypropyl)methacrylamide]-poly(N,N-dimethylaminoethylmethacrylate) diblock copolymer (pHPMA-b-pDMAEMA). Ethidium bromide intercalation and gel retardation assays demonstrated high DNA condensation capacity of pHPMA-b-pDMAEMA. Nanoparticles prepared with and without decoy ODNs did not significantly compromise cellular safety at N/P ratios ⩽4. Transfection efficiency of pHPMA-b-pDMAEMA polyplexes (N/P=4) in Caco-2 cells was comparable to TurboFect transfection standard, resulting in a 98% reduction in P-gp protein levels. As a pharmacodynamic consequence, intracellular accumulation of the P-gp substrate Rhodamine123 significantly increased by almost twofold. In conclusion, NF-κB ODN polyplexes fabricated with pHPMA-b-pDMAEMA polymer effectively reduced P-gp-mediated efflux activity in Caco-2 cells, suggesting successful interference with NF-κB-binding sites in the promoter region of the ABCB1 gene.

  10. Intracellular pH and multidrug resistance regulate complement-mediated cytotoxicity of nucleated human cells.

    PubMed

    Weisburg, J H; Roepe, P D; Dzekunov, S; Scheinberg, D A

    1999-04-16

    In previous work (Weisburg, J. H., Curcio, M., Caron, P. C., Raghi, G., Mechetner, E. B., Roepe, P. D., and Scheinberg, D. A. (1996) J. Exp. Med. 183, 2699-2704), we showed that multidrug resistance (MDR) cells created by continuous selection with the vinca alkaloid vincristine (HL60 RV+) or by retroviral infection (K562/human MDR 1 cells) exhibited significant resistance to complement-mediated cytotoxicity (CMC). This resistance was due to the presence of overexpressed P-glycoprotein (P-GP). In this paper, we probe the molecular mechanism of this phenomenon. We test whether the significant elevated intracellular pH (pHi) that accompanies P-GP overexpression is sufficient to confer resistance to CMC and whether this resistance is related to effects on complement function in the cell membrane. Control HL60 cells not expressing P-GP, but comparably elevated in cytosolic pHi by two independent methods (CO2 "conditioning" or isotonic Cl- substitution), are tested for CMC using two different antibody-antigen systems (human IgG and murine IgM; protein and carbohydrate) and two complement sources (rabbit and human). Elevation of pHi by either of these methods or by expression of P-GP confers resistance to CMC. Resistance is not observed when the alkalinization mediated by reverse Cl-/HCO3- exchange upon Cl- substitution is blocked by treatment with dihydro-4,4'-diisothiocyanostilbene-2,2'-disulfonate. Continuous photometric monitoring of 2',7'-bis(carboxyethyl)-5, 6-carboxyfluorescein (BCECF), to assess changes in pHi or efflux of the probe through MAC pores, in single cells or cell populations, respectively, verifies changes in pHi upon CO2 conditioning and Cl- substitution and release of BCECF upon formation of MAC pores. Antibody binding and internalization kinetics are similar in both the parental and resistant cell lines as measured by radioimmunoassay, but flow cytometric data showed that net complement deposition in the cell membrane is both delayed and reduced in

  11. Elevation of glucosylceramide in multidrug-resistant cancer cells and accumulation in cytoplasmic droplets.

    PubMed

    Morjani, H; Aouali, N; Belhoussine, R; Veldman, R J; Levade, T; Manfait, M

    2001-10-15

    Multidrug-resistant (MDR) cancer cells have been shown to have an accumulation of glucosylceramide (GlcCer). In this study, we aim at localizing, at subcellular level, where these lipids accumulate. Neutral lipids and phospholipid containing organelles have been identified using confocal fluorescence microscopy and microspectrofluorometry by monitoring the emission of the fluorescent probe Nile-red. Data from confocal fluorescence microscopy analysis shows accumulation of neutral lipids in cytoplasmic droplets of MDR human carcinoma MCF7R cells. Microspectrofluorometric measurements show an increase of the gold-yellow emission intensity in MCF7R cells, corresponding to neutral lipids. Similar observations were made in human MDR vincristine-HL60 and doxorubicin-KB selected cells. Total cellular glucosylceramide (GlcCer) measurements using [(3)H]-palmitic acid and thin layer chromatography show a significant increase of GlcCer in MCF7R cells. Moreover, MCF7R cells treated with fluorescent GlcCer-bodipy exhibit an accumulation of this lipid in cytoplasmic droplets. Treatment of MCF7R cells with 1-phenyl-2-palmitoylamino-3-morpholino-1-propanolol (PPMP), a potent inhibitor of GlcCer synthase, attenuates the Nile-red fluorescence emission emanating from these structures and reverses MDR. Moreover, Golgi compartments stained with fluorescent PPMP-bodipy, show an increase in the Golgi compartments density. Treatment of MCF7R cells with cyclosporine A (CSA), tamoxifen (TMX) and 3'-azido-3'deoxythymidine (AZT) leads to the same effect observed in the presence of PPMP. Treatment of MCF7 and MCF7R with the beta-glucosidase inhibitor conduritol beta-epoxide (CBE) significantly increases resistance to daunorubicin only in MCF7R cells. These data demonstrate also that: (i) CSA, an inhibitor of MDR, has an additional target in addition to P-glycoprotein; and (ii) TMX (used in breast cancer treatment and prevention) and AZT (used in the treatment of HIV) could have side effects by

  12. Novel cellular determinants for reversal of multidrug resistance in cells expressing P170-glycoprotein.

    PubMed

    Yin, M B; Guo, B; Voigt, W; Vanhoefer, U; Gibbs, J F; Skenderis, B S; Frank, C; Wrzosek, C; Rustum, Y M

    1998-03-05

    fragmentation and specific cell-cycle perturbation are potentially important molecular determinants for reversal of multidrug resistance in addition to restoration of intracellular drug retention.

  13. 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.

  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. miR-181b modulates multidrug resistance by targeting BCL2 in human cancer cell lines.

    PubMed

    Zhu, Wei; Shan, Xia; Wang, Tongshan; Shu, Yongqian; Liu, Ping

    2010-12-01

    MicroRNAs (miRNAs) are short noncoding RNA molecules, which posttranscriptionally regulate genes expression and play crucial roles in diverse biological processes, such as development, differentiation, apoptosis and proliferation. Here, we investigated the possible role of miRNAs in the development of multidrug resistance (MDR) in human gastric and lung cancer cell lines. We found that miR-181b was downregulated in both multidrug-resistant human gastric cancer cell line SGC7901/vincristine (VCR) and multidrug-resistant human lung cancer cell line A549/cisplatin (CDDP), and the downregulation of miR-181b in SGC7901/VCR and A549/CDDP cells was concurrent with the upregulation of BCL2 protein, compared with the parental SGC7901 and A549 cell lines, respectively. In vitro drug sensitivity assay demonstrated that overexpression of miR-181b sensitized SGC7901/VCR and A549/CDDP cells to anticancer drugs, respectively. The luciferase activity of a BCL2 3'-untranslated region-based reporter construct in SGC7901/VCR and A549/CDDP cells suggests that a new target site in the 3'UTR of BCL2 of the mature miR-181s (miR-181a, miR-181b, miR-181c and miR-181d) was found. Enforced miR-181b expression reduced BCL2 protein level and sensitized SGC7901/VCR and A549/CDDP cells to VCR-induced and CDDP-induced apoptosis, respectively. Taken together, our findings suggest that miR-181b could play a role in the development of MDR in both gastric and lung cancer cell lines, at least in part, by modulation of apoptosis via targeting BCL2.

  16. Cytotoxicity of 15 Cameroonian medicinal plants against drug sensitive and multi-drug resistant cancer cells.

    PubMed

    Kuete, Victor; Djeussi, Doriane E; Mbaveng, Armelle T; Zeino, Maen; Efferth, Thomas

    2016-06-20

    Cameroonian medicinal plants are traditionally used to treat many ailments, including cancer and related diseases. Cancer is characterized as a condition with complex signs and symptoms. It has been recommended that ethnopharmacological usages such as immune and skin disorders, inflammatory, infectious, parasitic and viral diseases should be taken into account when selecting plants for anticancer screenings, since these reflect disease states bearing relevance to cancer or cancer-like symptoms. The present study aims at investigating 20 methanol extracts from 15 Cameroonian medicinal plants on a panel of human cancer cell lines, including various drug-resistant phenotypes. Possible modes of action of the of the most active plant were analyzed. Methanol extracts from different plant parts (leaves, bark, roots, fruits or whole plant) were evaluated for their cytotoxicity using resazurin reduction assay on a panel of nine sensitive and multi-drug resistant (MDR) cancer cell lines. Cell cycle, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were measured by flow cytometry. Prescreening of extracts at 80µg/mL showed that 6 extracts out of 20 inhibited more than 50% proliferation of leukemia CCRF-CEM cells; these include extracts from Anthocleista schweinfurthii fruits (ASF; 48.28%), Morus mesozygia bark (MMB; 42.76%), Nauclea latifolia bark (NLB; 38.75%), Tridesmostemon omphalocarpoides bark (TOB; 38.53%), Nauclea latifolia leaves (NLL; 35.17%) and Erythrina sigmoidea bark (ESB; 33.77%). Subsequent investigations revealed IC50 values below or around 20µg/mL for extracts from MMB, NLB, NLL and ESB towards sensitive CCRF-CEM cells and its resistant P-glycoprotein over-expressing subline CEM/ADR5000. The best extract, ESB also displayed IC50 values below 20µg/mL colon carcinoma HCT116 (p53(+/+)) cells with an IC50 value of 19.63µg/mL and it resistant p53 knockout subline HCT116 (p53(-)(/-)) with an IC50 value of 16.22µg

  17. Cyclosporine diminishes multidrug resistance in K562/ADM cells and improves complete remission in patients with acute myeloid leukemia.

    PubMed

    Li, Guang-Yao; Liu, Ji-Zhu; Zhang, Bin; Wang, Le-Xin; Wang, Chun-Bo; Chen, Shou-Guo

    2009-09-01

    This study was designed to investigate the effects of cyclosporine A (CsA) on a multidrug resistance cultured cell line, and its effect on complete remission in patients with acute myeloid leukemia (AML). A multidrug resistant K562/ADM cell line and drug-sensitive K562 cell line was used. The intracellular concentration of daunorubicin and the accumulation of Rhodamine 123 (Rh123) in the K562/ADM and K562 cells were evaluated. Clinical effects of CsA were also studied in 65 patients with AML. In the K562/ADM cells, the 50% of inhibition concentration (IC50) of daunorubicin only group was 23.0+/-5.2 micromol/L, which was greater than in other groups co-administered with CsA (1.2+/-4.8 micromol/L), verapamil (1.5+/-5.4 micromol/L) or CsA+verapamil (1.4+/-4.3 micromol/L) (all P<0.01). The relative fluorescence intensity of Rh123 in the K562/ADM cells treated with CsA and daunorubicin was increased from 48.9% to 69.8% (P<0.05). CsA also improved the complete remission rate in the AML patients (72.7% vs 21.9%, P<0.01). We conclude that CsA can significantly diminish the multidrug resistance in K562/ADM cells. It also enhances the complete remission rates in patients with AML. CsA may be used as an integral part of the chemotherapy for AML.

  18. A fission yeast cell-based system for multidrug resistant HIV-1 proteases.

    PubMed

    Benko, Zsigmond; Liang, Dong; Li, Ge; Elder, Robert T; Sarkar, Anindya; Takayama, Jun; Ghosh, Arun K; Zhao, Richard Y

    2017-01-01

    HIV-1 protease (PR) is an essential enzyme for viral production. Thus, PR inhibitors (PIs) are the most effective class of anti-HIV drugs. However, the main challenge to the successful use of PI drugs in patient treatment is the emergence of multidrug resistant PRs (mdrPRs). This study aimed to develop a fission yeast cell-based system for rapid testing of new PIs that combat mdrPRs. Three mdrPRs were isolated from HIV-infected patients that carried seven (M7PR), ten (M10PR) and eleven (M11PR) PR gene mutations, respectively. They were cloned and expressed in fission yeast under an inducible promoter to allow the measurement of PR-specific proteolysis and drug resistance. The results showed that all three mdrPRs maintained their abilities to proteolyze HIV viral substrates (MA↓CA and p6) and to confer drug resistance. Production of these proteins in the fission yeast caused cell growth inhibition, oxidative stress and altered mitochondrial morphologies that led to cell death. Five investigational PIs were used to test the utility of the established yeast system with an FDA-approved PI drug Darunavir (DRV) as control. All six compounds suppressed the wildtype PR (wtPR) and the M7PR-mediated activities. However, none of them were able to suppress the M10PR or the M11PR. The three clinically isolated mdrPRs maintained their viral proteolytic activities and drug resistance in the fission yeast. Furthermore, those viral mdrPR activities were coupled with the induction of growth inhibition and cell death, which could be used to test the PI activities. Indeed, the five investigational PIs and DRV suppressed the wtPR in fission yeast as they did in mammalian cells. Significantly, two of the high level mdrPRs (M10PR and M11PR) were resistant to all of the existing PI drugs including DRV. This observation underscores the importance of continued searching for new PIs against mdrPRs.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. [Empirical study of reverse effect on mediated multidrug resistance of U-2OS/ADM cells with curcumin in vitro].

    PubMed

    Xiao, Yang; Wang, Wanchun

    2011-01-01

    To investigate the reversion of P-gp mediated multidrug resistance of U-2OS/ADM cells with curcumin in vitro. With doxorubicin as induction drugs, human osteosarcoma cell line U-2OS was induced object, multi-drug resistant of human osteosarcoma cell line model (U-2OS/ADM) were established by high-dose method, The before and after reversal efficacy of curcumin for U-2OS/ADM cells to chemotherapeutic drugs were measured by MTT assay. The effects of curcumin on Rh-123 uptake and efflux were analyzed by flow cytometer. (1) MTT demonstrates curcumin (20 micromol/L) can increase the cytotoxicity of Adriamycin to U-2OS/ADM cells. (2) The result of FCM shows that Curcumin can increase the accumulation of Rh-123 and increase the cytotoxicity of Adriamycin to U-2OS/ADM cells in a dose-dependent manner. The reversal mechanism of curcumin was blocked the function of P-gp in U-2OS/ADM cellular membrane.

  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. Sensitization to the cytotoxicity of melphalan by ethacrynic acid and hyperthermia in drug-sensitive and multidrug-resistant Chinese hamster ovary cells.

    PubMed

    Turcotte, S; Averill-Bates, D A

    2001-09-01

    The ability of physical and pharmacological modulators to increase the cytotoxicity of melphalan was investigated in Chinese hamster ovary cells using a clonogenic cell survival assay. Hyperthermia has potential for use in cancer treatment, particularly as an adjuvant to chemotherapy or radiotherapy. Ethacrynic acid is a glutathione S-transferase inhibitor and also undergoes conjugation with glutathione. Interactions between hyperthermia (41-43 degrees C), ethacrynic acid and melphalan were evaluated in multidrug-resistant (CH(R)C5) cells with overexpression of P-glycoprotein (33.69-fold), and in drug-sensitive (AuxB1) cells. GST alpha was expressed at a higher level (3.65-fold) in CH(R)C5 cells than in sensitive cells, whereas levels of isoforms pi and mu were the same. GST pi was the most highly expressed isoform in the two cell populations. Ethacrynic acid was cytotoxic at elevated temperatures, while it caused little or no cytotoxicity at 37 degrees C. This effect occurred in drug-resistant and drug-sensitive cells, and attributes thermosensitizing properties to ethacrynic acid. Ethacrynic acid (20 microM) alone did not alter the cytotoxicity of melphalan at 37 degrees C. Hyperthermia potentiated drug cytotoxicity in cells, both with and without ethacrynic acid treatment. Ethacrynic acid could be useful in cancer treatment by acting as a thermosensitizer when combined with heat and by enhancing the cytotoxicity of melphalan at elevated temperatures. A major advantage arising from the use of regional hyperthermia is the ability to target drug cytotoxicity to the tumor volume. A useful finding is that ethacrynic acid, heat and/or melphalan are also effective against multidrug-resistant cells with overexpression of P-glycoprotein.

  6. 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.

  7. Terminal functionalized thiourea-containing dipeptides as multidrug-resistance reversers that target 20S proteasome and cell proliferation.

    PubMed

    Qin, Jian-Mei; Huang, Ri-Zhen; Yao, Gui-Yang; Liao, Zhi-Xin; Pan, Ying-Ming; Wang, Heng-Shan

    2017-01-27

    A series of inhibitors of 20S proteasome based on terminal functionalized dipeptide derivatives containing the thiourea moiety were synthesized and evaluated for inhibition of 20S proteasome and the effects of multidrug-resistance reversers. These compounds exhibited significant selectivity to the β5-subunit of the human 20S proteasome with IC50 values at submicromolar concentrations. A docking study of the most active compound 6i revealed key interactions between 6i and the active site of the 20S proteasome in which the thiourea moiety and a nitro group were important for improving activity. In particular, compound 6i appeared to be the most potent compound against the NCI-H460 cell line, and displayed similar efficiency in drug-sensitive versus drug-resistant cancer cell lines, at least partly, by inhibition of the activity of 20S proteasome and induce apoptosis. In addition, 6i-induced apoptosis was significantly facilitated in NCI-H460/DOX cells that had been pretreated with inhibitors of P-gp. Mechanistically, compound 6i might trigger apoptotic signalling pathway. Thus, we conclude that dipeptide derivatives containing the thiourea moiety may be the potential inhibitors of proteasome with the ability to reverse multidrug resistance.

  8. Dihydropyridines and multidrug resistance: previous attempts, present state, and future trends.

    PubMed

    Zarrin, Abdolhossein; Mehdipour, Ahmad R; Miri, Ramin

    2010-11-01

    Multidrug resistance is defined as the resistance of a tumor cell to the cytotoxic action of divergent drugs used in chemotherapy. Dihydropyridines are a class of calcium channel antagonists that were discovered to have a multidrug resistance reversing effect and prompted investigations resulting in the synthesis of hundreds of new derivatives. Most of the investigators tried to achieve two goals: a decrease in Ca²(+) channel-blocking activity and an increase in the multidrug resistance reversing effect. Most of the synthesized compounds failed in the later stages of studies especially in clinical trials because of pharmacokinetic or pharmacodynamic limitations. Therefore, it will be necessary to include new methods, such as combinatorial synthesis, and, more importantly, to apply computational methods based on global structure-activity relationship models that consider all problems. Moreover, some compounds should be synthesized that are effective on several multidrug resistance targets.

  9. Overcoming of P-glycoprotein-mediated multidrug resistance in K562/A02 cells using riccardin F and pakyonol, bisbibenzyl derivatives from liverworts.

    PubMed

    Ji, Mei; Shi, Yanquiu; Lou, Hongxiang

    2011-01-01

    Riccardin F and pakyonol, macrocyclic bisbibenzyls from Plagiochasm intermedium, have been confirmed to possess antifungic activities against Candida albicans. Herein, we evaluated their anti-tumor activity in vitro by employing K562 and K562/A02 cells, the well-known adriamycin (ADR)-induced multidrug resistance (MDR) tumor cell lines over-expressing P-glycoprotein (P-gp). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assays showed that riccardin F and pakyonol ranging from 0 to 6 μg/mL exhibited no inhibitory effects on the growth of the two cell lines. However, in the presence of 3 μg/mL riccardin F or pakyonol (non-cytotoxic concentration), the IC50 of ADR against K562/A02 cells decreased by 2.51- and 4.78-fold, respectively. Flow cytometry showed that riccardin F and pakyonol significantly enhanced the accumulation of ADR in K562/A02 cells. Furthermore, fluorescence intensity detection revealed that the two natural products remarkably increased the retention of rhodamine-123 in K562/A02 cells rather than in K562 cells, indicating that the major cause for riccardin F and pakyonol to reverse P-gp-mediated MDR in K562/A02 cells is probably due to the constrained transport activity of P-gp. This study explores the potential application of bisbibenzyl type compounds as modulators of P-gp-mediated MDR in tumor cells.

  10. Analysis of the tangled relationships between P-glycoprotein-mediated multidrug resistance and the lipid phase of the cell membrane.

    PubMed

    Ferté, J

    2000-01-01

    P-glycoprotein (Pgp), the so-called multidrug transporter, is a plasma membrane glycoprotein often involved in the resistance of cancer cells towards multiple anticancer agents in the multidrug-resistant (MDR) phenotype. It has long been recognized that the lipid phase of the plasma membrane plays an important role with respect to multidrug resistance and Pgp because: the compounds involved in the MDR phenotype are hydrophobic and diffuse passively through the membrane; Pgp domains involved in drug binding are located within the putative transmembrane segments; Pgp activity is highly sensitive to its lipid environment; and Pgp may be involved in lipid trafficking and metabolism. Unraveling the different roles played by the membrane lipid phase in MDR is relevant, not only to the evaluation of the precise role of Pgp, but also to the understanding of the mechanism of action and function of Pgp. With this aim, I review the data from different fields (cancer research, medicinal chemistry, membrane biophysics, pharmaceutical research) concerning drug-membrane, as well as Pgp-membrane, interactions. It is emphasized that the lipid phase of the membrane cannot be overlooked while investigating the MDR phenotype. Taking into account these aspects should be useful in the search of ways to obviate MDR and could also be relevant to the study of other multidrug transporters.

  11. Modulation of mdr1 expression by cytokines in human colon carcinoma cells: an approach for reversal of multidrug resistance.

    PubMed Central

    Stein, U.; Walther, W.; Shoemaker, R. H.

    1996-01-01

    Reversal of multidrug resistance (MDR) may offer a means of increasing the effectiveness of tumour chemotherapy. A variety of recent evidence indicates that cytokines may be particularly useful in this endeavour. To investigate the molecular mechanism by which cytokines may sensitise multidrug-resistant colon carcinoma cells, HCT15 and HCT116, to treatment with MDR-related drugs, we evaluated the effects of the human cytokines tumour necrosis factor alpha (TNF alpha), interleukin 2 (IL-2) and interferon gamma (IFN gamma) on mdr1 gene expression at the mRNA level by reverse transcription-polymerase chain reaction (RT-PCR) and at the protein level with monoclonal antibodies by immuno flow cytometry. P-glycoprotein function was examined after accumulation of the fluorescent drug, doxorubicin, by flow cytometry. Chemosensitivity to doxorubicin and vincristine was analysed using the XTT assay. All three cytokines were found to modulate the MDR characteristics on mdr1 expression levels, P-glycoprotein function and measured chemosensitivity to MDR-associated anti-cancer drugs. This cytokine-induced reversal of MDR was strongly time dependent, with maximal effects after 48 and 72 h of cytokine treatment. If similar modulation of MDR phenotype can be obtained in in vivo models, it may be possible to verify the time course for modulation by cytokine treatment and to design appropriate clinical trials of this strategy for MDR reversal. Images Figure 1 PMID:8912533

  12. The anthracycline resistance-associated (ara) gene, a novel gene associated with multidrug resistance in a human leukaemia cell line.

    PubMed Central

    Longhurst, T. J.; O'Neill, G. M.; Harvie, R. M.; Davey, R. A.

    1996-01-01

    Multidrug resistance (MDR) in cancer cells is a major contributor to the failure of chemotherapy treatment. This paper describes a novel protein named the anthracycline resistance associated (ARA) protein. The ara gene is amplified in the MDR leukaemia line CCRF-CEM/E1000 and its mRNA is overexpressed. ARA belongs to the ATP binding cassette (ABC) family of proteins. Another ABC protein, the multidrug resistance-associated protein (MRP), has previously been reported to be overexpressed in the CEM/E1000 subline. The primary amino acid sequence of ARA indicates that it is 49.5 kDa without glycosylation, and that it has one potential glycosylation site. ARA has one ATP binding site and associated transmembrane regions. This is in contrast to MRP (190 kDa, 172 kDa deglycosylated) and most other higher eukaryote ABC proteins, which consist of two similar halves, each having one ATP binding site. In addition to ARA being coexpressed with MRP, comparison of amino acid sequences showed that, among known proteins, ARA is most similar to the C-terminal half of MRP. Images Figure 1 Figure 2 PMID:8912525

  13. Saikosaponin A, an active glycoside from Radix bupleuri, reverses P-glycoprotein-mediated multidrug resistance in MCF-7/ADR cells and HepG2/ADM cells.

    PubMed

    Ye, Rui-Ping; Chen, Zhen-Dong

    2017-02-01

    1. The expression and function of P-glycoprotein (P-gp) is associated with the phenotype of multidrug resistance (MDR). Saikosaponin A (SSA) is a triterpenoid saponin isolated from Radix Bupleuri. This study was mainly designed to understand effects of SSA on MDR in MCF-7/ADR and HepG2/ADM cells. 2. MDR reversal was examined as the alteration of cytotoxic drugs IC50 in resistant cells in the presence of SSA by MTT assay, and was compared with the non-resistant cells. Apoptosis and uptake of P-gp substrates in the tumor cells were detected by flow cytometry. Western blot was performed to assay the expression of P-gp. 3. Our results demonstrate SSA could increase the chemosensitivity of P-gp overexpressing HepG2/ADM and MCF-7/ADR cells to doxorubicin (DOX), vincristine (VCR) and paclitaxel. SSA promoted apoptosis of MCF-7/ADR cells in the presence of DOX. Moreover, it could also increase the retention of P-gp substrates DOX and rhodamine 123 in MCF-7/ADR cells, and decrease digoxin efflux ratio in Caco-2 cell monolayer. Finally, a mechanistic study showed that SSA reduced P-gp expression without affecting hydrolytic activity of P-gp. 4. In conclusion, our findings suggest that SSA could be further developed for sensitizing resistant cancer cells and used as an adjuvant therapy together with anticancer drugs to improve their therapeutic efficacies.

  14. Effect and mechanism of nociceptin/orphanin FQ reversing multi-drug resistance in K562/ADM cell.

    PubMed

    Li, Zhao; Zhou, Lan-Xia; Zhang, Bao-Hong; Yan, Xiang; Li, Juan; Peng, Ya-Li; Chang, Min; Dong, Shou-Liang; Wang, Rui

    2008-09-01

    To investigate the effect and mechanism of nociceptin/orphanin FQ (OFQ) reversing multi-drug resistance of K562/ADM cells in vitro. MTT assay, Wright staining, flow cytometry, transmission electron microscope and gel electrophoresis were used to evaluate the effect and mechanism of OFQ in reversing multi-drug resistance of K562/ADM cells. OFQ could time-dependently reverse the ADM resistance of K562/ADM cell. After treatment with OFQ (1 x 10(-7) mol x L(-1)), K562/ADM cells were cultured for 24, 48 and 72 h. The reversal index (RI) was 1.33, 1.42 and 1.53, respectively. Furthermore, OFQ significantly increased the intracellular accumulation of ADM in K562/ADM cells and percentage apoptosis in K562/ADM cells. OFQ down-regulated the level of P-gp time-dependently, while the level of Fas and FasL were up-regulated. There were evidently significant differences compared with the control (P < 0.01). After treating K562/ADM cells with OFQ (1 x 10(-7) mol x L(-1)) and ADM (20 microg x ml(-1)) for 48 hours, the cells showed apoptotic nuclear fragmentation, which was characterized by the appearance of a DNA ladder pattern in genomic DNA gel electrophoresis. OFQ can reverse the ADM resistance of K562/ADM cells. The mechanism involves OFQ up-regulating the expression of Fas/FasL, down-regulating the level of P-gp, and decreasing the intracellular level of calcium in K562/ADM cells.

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

    PubMed

    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.

  16. Comparison of the multi-drug resistant human hepatocellular carcinoma cell line Bel-7402/ADM model established by three methods

    PubMed Central

    2010-01-01

    Background To compare the biological characteristics of three types of human hepatocellular carcinoma multi-drug resistant cell sub-lines Bel-7402/ADM models established by three methods. Methods Established human hepatocellular carcinoma adriamycin (ADM) multi-drug resistant cell sub-lines models Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS by three methods of in vitro concentration gradient increased induction, nude mice liver-implanted induction and subcutaneous-implanted induction respectively. Phase contrast microscopy was used to observe the cells and the MTT (methyl thiazolyl tetrazolium) method was used to detect drug resistance of the three different sub-lines of cells. Results The three groups of drug resistant cells, Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS generated cross-resistance to ADM and CDDP (cis-Diaminedichloroplatinum), but showed a significant difference in resistance to Bel-7402 IC50 value (P < 0.01). The doubling times were significantly extended compared to the parent cell line (39 h) and were 65 h (Bel-7402/ADMV), 46 h (Bel-7402/ADML), and 45 h (Bel-7402/ADMS). The excretion rates of ADM were significantly increased compared with the parent cell (34.14%) line and were 81.06% (Bel-7402/ADMV), 66.56% (Bel-7402/ADML) and 61.56% (Bel-7402/ADMS). Expression of P-gp and MRP in the three groups of resistant cells was significantly enhanced (P < 0.01). There was no significant variation in the expression of GSH/GST (P > 0.05). Conclusions Stable resistance was involved in the resistant cell line model established by the above three methods. Liver implantation was a good simulation of human hepatocellular and proved to be an ideal model with characteristics similar to human hepatocellular biology and the pharmacokinetics of anticancer drugs. PMID:20727186

  17. Comparison of the multi-drug resistant human hepatocellular carcinoma cell line Bel-7402/ADM model established by three methods.

    PubMed

    Zhong, Xingguo; Xiong, Maoming; Meng, Xiangling; Gong, Renhua

    2010-08-20

    To compare the biological characteristics of three types of human hepatocellular carcinoma multi-drug resistant cell sub-lines Bel-7402/ADM models established by three methods. Established human hepatocellular carcinoma adriamycin (ADM) multi-drug resistant cell sub-lines models Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS by three methods of in vitro concentration gradient increased induction, nude mice liver-implanted induction and subcutaneous-implanted induction respectively. Phase contrast microscopy was used to observe the cells and the MTT (methyl thiazolyl tetrazolium) method was used to detect drug resistance of the three different sub-lines of cells. The three groups of drug resistant cells, Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS generated cross-resistance to ADM and CDDP (cis-Diaminedichloroplatinum), but showed a significant difference in resistance to Bel-7402 IC50 value (P < 0.01). The doubling times were significantly extended compared to the parent cell line (39 h) and were 65 h (Bel-7402/ADMV), 46 h (Bel-7402/ADML), and 45 h (Bel-7402/ADMS). The excretion rates of ADM were significantly increased compared with the parent cell (34.14%) line and were 81.06% (Bel-7402/ADMV), 66.56% (Bel-7402/ADML) and 61.56% (Bel-7402/ADMS). Expression of P-gp and MRP in the three groups of resistant cells was significantly enhanced (P < 0.01). There was no significant variation in the expression of GSH/GST (P > 0.05). Stable resistance was involved in the resistant cell line model established by the above three methods. Liver implantation was a good simulation of human hepatocellular and proved to be an ideal model with characteristics similar to human hepatocellular biology and the pharmacokinetics of anticancer drugs.

  18. Multidrug resistance-1 in T lymphocytes and natural killer cells of adults with idiopathic thrombocytopenic purpura: effect of prednisone treatment.

    PubMed

    López-Karpovitch, Xavier; Graue, Gerardo; Crespo-Solís, Erick; Piedras, Josefa

    2008-07-01

    High P-glycoprotein-mediated multidrug resistance-1 (P-gp/MDR1) activity in lymphocytes from idiopathic thrombocytopenic purpura (ITP) patients may affect disease outcome. ITP treatment includes glucocorticoids that are substrates of P-gp; hence, P-gp functional activity and antigenic expression were assessed by flow cytometry in T and natural killer (NK) cells from ITP patients before and after prednisone therapy. Herein, patients' T and NK cells did not show increased MDR1 functional activity, whereas P-gp antigenic expression was significantly enhanced in both therapy-free and prednisone-treated patients. Prednisone treatment did not significantly modify the function and expression of MDR1 in T and NK cells of ITP patients.

  19. The role of long noncoding RNA HOTAIR in the acquired multidrug resistance to imatinib in chronic myeloid leukemia cells.

    PubMed

    Wang, Haiying; Li, Qian; Tang, Shusen; Li, Meifang; Feng, Anhua; Qin, Lili; Liu, Zhiqiang; Wang, Xin

    2017-05-01

    Imatinib, a breakpoint cluster region-Abelson murine leukemia tyrosine kinase inhibitor, has revolutionized the treatment of chronic myelogenous leukemia (CML). However, the development of multidrug resistance (MDR) limits the clinical application of imatinib. In this study, we aimed to investigate the mechanisms of long noncoding RNA (lncRNA) HOTAIR in CML resistance to imatinib. Thirty-four CML patients were divided into multidrug resistance protein 1 (MRP1)-low and MRP1-high groups according to the median expression. Real-time PCR (qPCR) was used to detect the expression of lncRNA HOTAIR in CML patients, and MTT assay and flow cytometry assay were employed to detect the biological function of silencing lncRNA HOTAIR on the cell survival rate and apoptotic rate. An imatinib-resistant human CML cell line K562 (K562-R) was established, and western blot was used to detect the impact of lncRNA HOTAIR on the activation of PI3K/Akt signaling pathway. Our results showed that lncRNA HOTAIR was greatly upregulated in the MRP1-high patients as well as in the K562-imatinib-resistant cells compared with control. Knockdown of HOTAIR expression downregulated the MRP1 expression levels in the K562-imatinib cells and resulted in higher sensitivity to the imatinib treatment. In addition, the activation of PI3K/Akt was greatly attenuated when HOTAIR was knocked down in K562-imatinib cells. These data suggest that the knockdown of HOTAIR may play a crucial role in improving acquired resistance to imatinib in CML K562-R cells via PI3K/Akt pathway. LncRNA HOTAIR modulates CML cell MDR in a PI3K/Akt-dependent way.

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

    PubMed

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

    2013-06-01

    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.

  1. 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

  2. Role of XIAP in the malignant phenotype of transitional cell cancer (TCC) and therapeutic activity of XIAP antisense oligonucleotides against multidrug-resistant TCC in vitro.

    PubMed

    Bilim, Vladimir; Kasahara, Takashi; Hara, Noboru; Takahashi, Kota; Tomita, Yoshihiko

    2003-01-01

    XIAP directly inhibits executor caspases, making it the most downstream antiapoptotic molecule. Here, we examined the expression and function of XIAP in normal urothelium and TCC. We also examined the therapeutic effect of xiap AS PODN on the cell cycle and apoptosis of multidrug-resistant T24 bladder cancer cells. XIAP was moderately expressed in normal transitional epithelium with prominent expression on the superficial layer cells. Seventy-nine of 108 (73.15%) tumor samples were positive for XIAP protein, but XIAP positivity was not correlated with tumor stage or grade. Moreover, 4 bladder cancer cell lines (SCaBER, HT1376, T24 and RT4) expressed similar levels of XIAP. xiap AS PODN dose-dependently reduced the XIAP protein level and induced apoptosis, leading to decreased cell viability by 87%. Combined administration with doxorubicin resulted in marked cytotoxicity due to escalation of apoptosis. Overexpression of XIAP in T24 cells resulted in a modest but statistically significant (p < 0.01) survival advantage compared to parental cells. Thus, XIAP expression may be critical for maintaining the viability and drug resistance of TCC, and endogenous XIAP levels are sufficient to protect cells from apoptosis. Our results suggest that XIAP may play an important role early in human TCC carcinogenesis. xiap AS may be a candidate for use as a cancer therapy for overcoming drug resistance in highly malignant TCC.

  3. Constitutive AhR activation leads to concomitant ABCG2-mediated multidrug resistance in cisplatin-resistant esophageal carcinoma cells.

    PubMed

    To, Kenneth K W; Yu, Le; Liu, Shuwen; Fu, Jianhua; Cho, Chi Hin

    2012-06-01

    Esophageal squamous cell carcinoma (ESCC) is a highly malignant disease that is generally not responding to chemotherapy. It is particularly predominant in China. Although ESCC is significantly associated with cigarette smoking, the relationship between its molecular pathogenesis and responsiveness to chemotherapy and cigarette smoke remains elusive. This study reported the constitutive activation of aryl hydrocarbon receptor (AhR), leading to ABCG2 upregulation and the multidrug resistance (MDR) phenotype, in ESCC cell lines with acquired cisplatin resistance. Reporter gene assay, chromatin immunoprecipitation analysis and specific gene knockdown confirmed that the enhanced AhR binding to a xenobiotic response element (XRE) within the ABCG2 promoter is responsible for ABCG2 overexpression. A HSP90 inhibitor (17-AAG) and two AhR antagonists (kaempferol and salicylamide) were shown to inhibit ABCG2 upregulation, thereby reversing the ABCG2-mediated MDR. Our data therefore advocate the use of these inhibitors as novel chemosensitizers for the treatment of esophageal cancer.

  4. 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.

  5. 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

  6. Piperine, a piperidine alkaloid from Piper nigrum re-sensitizes P-gp, MRP1 and BCRP dependent multidrug resistant cancer cells.

    PubMed

    Li, Sen; Lei, Yu; Jia, Yingjie; Li, Na; Wink, Michael; Ma, Yonggang

    2011-12-15

    Over-expression of P-gp, MRP1 and BCRP in tumor cells is one of the important mechanisms leading to multidrug resistance (MDR), which impairs the efficacy of chemotherapy. P-gp, MRP1 and BCRP are ABC (ATP-Binding Cassette) transporters, which can expel a variety of lipophilic anti-cancer drugs and protect tumor cells. During a screening of MDR reversal agents among alkaloids of various structural types, a piperidine alkaloid, piperine (a main piperidine alkaloid in Piper nigurm) was identified as an inhibitor. Piperine can potentiate the cytotoxicity of anti-cancer drugs in resistant sublines, such as MCF-7/DOX and A-549/DDP, which were derived from MCF-7 and A-549 cell lines. At a concentration of 50 μM piperine could reverse the resistance to doxorubicin 32.16 and 14.14 folds, respectively. It also re-sensitized cells to mitoxantrone 6.98 folds. In addition, long-term treatment of cells by piperine inhibits transcription of the corresponding ABC transporter genes. These results suggest that piperine can reverse MDR by multiple mechanisms and it may be a promising lead compound for future studies.

  7. Multidrug resistance protein and topoisomerase 2 alpha expression in non-small cell lung cancer are related with brain metastasis postoperatively

    PubMed Central

    Huang, Huan; Liu, Jihong; Meng, Qinglian; Niu, Guozhong

    2015-01-01

    The aim of this study was to investigate association between expressions of multidrug resistance protein (MRP) and topoisomerase 2 alpha expression in non-small cell lung cancer (TOP2A) and brain metastasis operatively. The expression of MRP and TOP2A were performed using immunohistochemistry (IHC) staining, and the results were analyzed in correlation with clinicopathological data. A total of 286 NSCLC patients who underwent curative surgery between 2007 and 2013 were enrolled in this study. Positive expression of MRP and TOP2A were 62.2% and 37.8%. MRP positive expression in NSCLC was significantly correlated with tumor cell differentiation (P=0.028). TOP2A expression was significantly associated with patients’ smoking status, tumor histological type (P<0.05). The positive MRP group had significantly inferior survival rates for 2-year BMFS than did the negative MRP group (79.0% vs. 93.4%, P=0.003) by the Kaplan-Meier method and a log-rank test. Similarly, the positive TOP2A expression was inversely correlated with 2-year BMFS (84.2% vs. 93.4%, P=0.030). Multivariate analysis showed that gender, MRP expression and TOP2A expression were independent prognostic factors for BMFS (P<0.05). Positive expressions of MRP and TOP2A in the tumor tissue are associated with increased risk of developing brain metastases in NSCLC. PMID:26617887

  8. 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.

  9. Hepatocyte SLAMF3 reduced specifically the multidrugs resistance protein MRP-1 and increases HCC cells sensitization to anti-cancer drugs

    PubMed Central

    Eugenio, Mélanie Simoes; Demey, Baptiste; Singh, Amrathlal Rabbind; Ossart, Christèle; Bagami, Mohammed Al; Regimbeau, Jean-Marc; Nguyen-Khac, Eric; Naassila, Mickael

    2016-01-01

    Multidrug resistance MDR proteins (MRPs) are members of the C family of a group of proteins named ATP binding cassette (ABC) transporters. MRPs can transport drugs including anticancer drugs, nucleoside analogs, antimetabolites and tyrosine kinase inhibitors. Drugs used in HCC therapy, such as tyrosine kinase inhibitor sorafenib, are substrates of uptake and/or efflux transporters. Variable expression of MRPs at the plasma membrane of tumor cells may contribute to drug resistance and subsequent clinical response. Recently, we reported that the hepatocyte SLAMF3 expression (Signaling Lymphocytic Activation Molecule Family member 3) was reduced in tumor cells from hepatocellular carcinoma (HCC) compared to its high expression in adjacent tissues. In the present study, we make a strong correlation between induced SLAMF3 overexpression and the specific loss of MRP-1 expression and its functionalities as a drugs resistance transporter. No changes were observed on expression of ABCG2 and MDR. More importantly, we highlight a strong inverse correlation between MRP-1 and SLAMF3 expression in patients with HCC. We propose that the SLAMF3 overexpression in cancerous cells could represent a potential therapeutic strategy to improve the drugs sensibility of resistant cells and thus control the therapeutic failure in HCC patients. PMID:27081035

  10. Hepatocyte SLAMF3 reduced specifically the multidrugs resistance protein MRP-1 and increases HCC cells sensitization to anti-cancer drugs.

    PubMed

    Fouquet, Grégory; Debuysscher, Véronique; Ouled-Haddou, Hakim; Eugenio, Mélanie Simoes; Demey, Baptiste; Singh, Amrathlal Rabbind; Ossart, Christèle; Al Bagami, Mohammed; Regimbeau, Jean-Marc; Nguyen-Khac, Eric; Naassila, Mickael; Marcq, Ingrid; Bouhlal, Hicham

    2016-05-31

    Multidrug resistance MDR proteins (MRPs) are members of the C family of a group of proteins named ATP binding cassette (ABC) transporters. MRPs can transport drugs including anticancer drugs, nucleoside analogs, antimetabolites and tyrosine kinase inhibitors. Drugs used in HCC therapy, such as tyrosine kinase inhibitor sorafenib, are substrates of uptake and/or efflux transporters. Variable expression of MRPs at the plasma membrane of tumor cells may contribute to drug resistance and subsequent clinical response. Recently, we reported that the hepatocyte SLAMF3 expression (Signaling Lymphocytic Activation Molecule Family member 3) was reduced in tumor cells from hepatocellular carcinoma (HCC) compared to its high expression in adjacent tissues. In the present study, we make a strong correlation between induced SLAMF3 overexpression and the specific loss of MRP-1 expression and its functionalities as a drugs resistance transporter. No changes were observed on expression of ABCG2 and MDR. More importantly, we highlight a strong inverse correlation between MRP-1 and SLAMF3 expression in patients with HCC. We propose that the SLAMF3 overexpression in cancerous cells could represent a potential therapeutic strategy to improve the drugs sensibility of resistant cells and thus control the therapeutic failure in HCC patients.

  11. FZD1 activates protein kinase C delta-mediated drug-resistance in multidrug-resistant MES-SA/Dx5 cancer cells.

    PubMed

    Hung, Tsai-Hsien; Chen, Chuan-Mu; Tseng, Ching-Ping; Shen, Chih-Jie; Wang, Hui-Ling; Choo, Kong-Bung; Chong, Kowit Yu

    2014-08-01

    Multidrug-resistant (MDR) cancer is a major clinical problem in chemotherapy of cancer patients. We have noted inappropriate PKCδ hypomethylation and overexpression of genes in the PKCδ/AP-1 pathway in the human uterus sarcoma drug-resistant cell line, MES-SA/Dx5 cells, which also overexpress p-glycoprotein (ABCB1). Recent studies have indicated that FZD1 is overexpressed in both multidrug-resistant cancer cell lines and in clinical tumor samples. These data have led us to hypothesize that the FZD1-mediated PKCδ signal-transduction pathway may play an important role in drug resistance in MES-SA/Dx5 cells. In this work, the PKCδ inhibitor Rottlerin was found to reduce ABCB1 expression and to inhibit the MDR drug pumping ability in the MES-SA/Dx5 cells when compared with the doxorubicin-sensitive parental cell line, MES-SA. PKCδ was up-regulated with concurrent up-regulation of the mRNA levels of the AP-1-related factors, c-JUN and c-FOS. Activation of AP-1 also correlated with up-regulation of the AP-1 downstream genes HGF and EGR1. Furthermore, AP-1 activities were reduced and the AP-1 downstream genes were down-regulated in Rottlerin-treated or PKCδ shRNA-transfected cells. MES-SA/Dx5 cells were resensitized to doxorubicin-induced toxicity by co-treatment with doxorubicin and Rottlerin or PKCδ shRNA. In addition, cell viability and drug pump-out ability were significantly reduced in the FZD1 inhibitor curcumin-treated and FZD1 shRNA-knockdown MES-SA/Dx5 cells, indicating involvement of PKCδ in FZD1-modulated ABCB1 expression pathway. Taken together, our data demonstrate that FZD1 regulates PKCδ, and the PKCδ/AP-1 signalling transduction pathway plays an important role in drug resistance in MES-SA/Dx5 cells. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. 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

    2016-05-06

    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.

  13. IMD-0354 Targets Breast Cancer Stem Cells: A Novel Approach for an Adjuvant to Chemotherapy to Prevent Multidrug Resistance in a Murine Model

    PubMed Central

    Gomez-Cabrero, Azucena; Wrasidlo, Wolfgang; Reisfeld, Ralph A.

    2013-01-01

    Although early detection of breast cancer improved in recent years, prognosis of patients with late stage breast cancer remains poor, mostly due to development of multidrug resistance (MDR) followed by tumor recurrence. Cancer stem cells (CSCs), with higher drug efflux capability and other stem cell-like properties, are concentrated in a side population (SP) of cells, which were proposed to be responsible for MDR and tumor repopulation that cause patients to succumb to breast cancer. Therefore, targeting of CSCs as an adjuvant to chemotherapy should be able to provide a more effective treatment of this disease. Here, we used IMD-0354, an inhibitor of NF-κB, identified for targeting CSCs, in a combination therapy with doxorubicin encapsulated in targeted nanoparticles. IMD-0354 did target CSCs, evidenced by a decrease in the SP, demonstrated by the inhibition of the following: dye/drug efflux, reduction in ABC transporters as well as in colony formation in soft agar and low attachment plates. Decrease of stem-like gene expression of Oct4, Nanog and Sox2, and apoptosis resistance related to the Survivin gene also was observed after treatment with this compound. In addition, IMD-0354 targeted non-CSCs as indicated by reducing viability and increasing apoptosis. Targeted drug delivery, achieved with a legumain inhibitor, proved to enhance drug delivery under hypoxia, a hallmark of the tumor microenvironment, but not under normoxia. Together, this allowed a safe, non-toxic delivery of both anticancer agents to the tumor microenvironment of mice bearing syngeneic metastatic breast cancer. Targeting both bulk tumor cells with a chemotherapeutic agent and CSCs with IMD-0354 should be able to reduce MDR. This could eventually result in decreasing tumor recurrences and/or improve the outcome of metastatic disease. PMID:24014113

  14. A comparison of membrane properties and composition between cell lines selected and transfected for multi-drug resistance.

    PubMed Central

    Callaghan, R.; van Gorkom, L. C.; Epand, R. M.

    1992-01-01

    Cell lines selected (CHRC5) and transfected (LR-73-1A) for multi-drug resistance have total lipid compositions which are indistinguishable between resistant and parental cells. Lipid composition was evaluated by 1H NMR and the total fatty acid content by GLC. No change in surface hydrophobicity, as measured with the fluorescent probe dansyl-PE, was observed as a result of transfection of CHO cells with the mdr1 gene. However, the selected cell line, CHRC5, showed a decreased surface hydrophobicity. This decreased surface hydrophobicity was indicated by an 8 nm increase in the fluorescence emission of dansyl-PE in the CHRC5 cell line compared with the AB1. Both resistant cell lines showed an increase in the polarisation of the fluorescent probe, TMA-DPH in the plasma membranes corresponding to a 14% and a 24% change in fluorescence polarisation for the selected and transfected cell lines, respectively. This is indicative of reduced mobility of the acyl chains in the resistant cell lines. Both the CHRC5 and the transfected cell lines showed almost a 2-fold increase in the initial rate of membrane cycling. The membrane cycling could be inhibited by a known bilayer stabiliser, the N-carbobenzoxy-D-Phe-L-Phe-Gly. These results indicate that the properties of the plasma membrane from resistant cells are altered compared with their parental cell line. PMID:1358166

  15. 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.

  16. Isomahanine induces endoplasmic reticulum stress and simultaneously triggers p38 MAPK-mediated apoptosis and autophagy in multidrug-resistant human oral squamous cell carcinoma cells.

    PubMed

    Utaipan, Tanyarath; Athipornchai, Anan; Suksamrarn, Apichart; Chunsrivirot, Surasak; Chunglok, Warangkana

    2017-02-01

    Advanced oral squamous cell carcinoma (OSCC) is typically aggressive and closely correlated with disease recurrence and poor survival. Multidrug resistance (MDR) is the most critical problem leading to therapeutic failure. Investigation of novel anticancer candidates targeting multidrug-resistant OSCC cells may provide a basis for developing effective strategies for OSCC treatment. In the present study, we investigated the cytotoxic mechanism of a carbazole alkaloid, namely isomahanine, in a multidrug‑resistant OSCC cell line CLS-354/DX. We demonstrated that CLS-354/DX cells overexpressing multidrug resistance-associated protein 1 (MRP1) were resistant to anticancer drugs cisplatin and camptothecin. Isomahanine effectively induced cytotoxicity against CLS-354/DX cells regardless of resistance. Apoptosis as determined by FITC‑Annexin V/PI staining and western blot analysis of cleaved caspase-3 and cleaved poly(ADP‑ribose) polymerase (PARP) was significantly induced in a time-dependent manner upon isomahanine treatment. Isomahanine-induced caspase‑dependent apoptosis was determined using z-VAD‑fmk. The effects on autophagy in isomahanine-treated cells were investigated via conversion of LC3B and degradation of p62/SQSTM1 (p62). Isomahanine obviously induced autophagic flux as shown by an increase in punctate GFP-LC3B and the LC3B-II/LC3B-I ratio with a concomitant decrease in p62 levels. Autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) protected isomahanine-induced cell death, indicating the activation of autophagic cell death. Endoplasmic reticulum (ER) stress and MAPK activation were examined to elucidate the mechanism underlying cell death. The expression levels of PERK, CHOP and phosphorylated MAPK (p38, ERK1/2 and JNK1/2) were upregulated following isomahanine treatment. We found that p38 MAPK inhibitor (SB203580) significantly attenuated isomahanine-induced apoptosis and autophagic flux and this prevented cell death. Collectively

  17. Pseudolaric acid B circumvents multidrug resistance phenotype in human gastric cancer SGC7901/ADR cells by downregulating Cox-2 and P-gp expression.

    PubMed

    Yu, Fei; Li, Kai; Chen, Suning; Liu, Yunpeng; Li, Yan

    2015-01-01

    Multidrug resistance (MDR) is a challenging issue in the treatment of gastric cancer. Pseudolaric acid B is a new diterpene acid compound isolated from pseudolarix, which has been found to have anti-tumor activities in recent studies. The purpose of the present study was to evaluate the effects of pseudolaric acid B in an MDR gastric cancer cell line and elucidate the possible underlying mechanisms of action. SGC7901/ADR, a P-glycoprotein (P-gp)-overexpressing cell line, was used to evaluate the efficacy of pseudolaric acid B against MDR phenotypes. The effects of pseudolaric acid B and chemotherapeutic agents on cell proliferation and apoptosis were assessed using the MTT assay and flow cytometry, respectively. Immunocytochemistry and Western blot were used to detect the possible relevant molecules in order to elucidate the underlying mechanism of action. The results showed that pseudolaric acid B inhibited cell proliferation and induced apoptosis in SGC7901/ADR cells. A low dose of pseudolaric acid B (0.5 µmol/L) augmented the inhibitory effects of chemotherapeutic agents on proliferation (p < 0.05). The expression of P-gp and cyclooxygenase 2 (Cox-2) was downregulated with pseudolaric acid B treatment. The present results showed that pseudolaric acid B inhibited cell proliferation, induced apoptosis, circumvented MDR, and increased the sensitivity of chemotherapeutic agents in vitro by downregulating the expression of P-gp and Cox-2.

  18. Effect of phosphatase and tensin homology deleted on chromosome 10 (PTEN) gene transfection on reversal of multidrug resistance in K562/ADM cells.

    PubMed

    Cheng, Zhiyong; Yang, Ning; Liang, Wentong; Yan, Xiaoyan; Li, Lin; Pan, Ling

    2012-07-01

    The phosphatase and tensin homology deleted on chromosome 10 (PTEN) gene is a novel tumor suppressor gene of the phosphatase family. Studies have shown that the PTEN gene is probably involved in human malignant disease pathogenesis, multidrug resistance, angiogenesis and extramedullary infiltration. This study was designed to investigate the effect of wild-type PTEN gene transfection on drug resistance reversal in K562/ADM leukemia cells in vitro and the possible mechanism. A recombinant adenovirus containing green fluorescent protein gene and wild-type PTEN gene (Ad-PTEN-GFP) or a recombined adenovirus containing green fluorescent protein gene only (Ad-GFP) was transfected into K562/ADM cells. These cells were then treated with different concentrations of adriamycin, cytarabine or arsenic trioxide, respectively. The half-maximal inhibitory concentration (IC(50)) of each drug was detected by MTT assay and the drug resistance reversal factor (RF) was calculated. The proliferation inhibition rate of these K562/ADM cells treated with or without the above-mentioned drugs was determined by MTT assay and the apoptosis rate was evaluated by flow cytometry. PTEN, nuclear factor-κB (NF-κB), I-κB, p53, multidrug resistance genes MDR1 and MRP, and apoptosis related genes Bcl-2, Bcl-xL and Bax mRNA levels were detected by real-time fluorescence relative-quantification reverse transcription polymerase chain reaction (FQ-PCR). PTEN, Akt, p-Akt and NF-κB (p65) protein levels were detected by Western blot. Results showed that PTEN gene transfection could increase the sensitivity of K562/ADM cells to chemotherapeutic drugs. The drug resistance reversal index of adriamycin, cytarabine and arsenic trioxide was 3.8-fold, 2.65-fold and 2.64-fold, respectively, after PTEN gene transfection. NF-κB, MDR1, Bcl-2 and Bcl-xL mRNA levels as well as p-Akt and NF-κB (p65) protein levels were down-regulated, while p53 and Bax mRNA levels were up-regulated in K562/ADM cells after

  19. 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

  20. Differential levels of human leukocyte antigen-class I, multidrug-resistance 1 and androgen receptor expressions in untreated prostate cancer cells: the robustness of prostate cancer.

    PubMed

    Homma, Shigenori; Komohara, Yoshihiro; Harada, Mamoru; Saya, Hideyuki; Todo, Satoru; Itoh, Kyogo; Noguchi, Masanori

    2007-08-01

    Tumors are highly robust and maintain their proliferative potential against a wide range of both host-defense mechanisms and anticancer therapies. One of the approaches to overcome cancer robustness could be combined therapy in which each modality imposes independent selective pressures against the acquired mutation of cancer. To develop such a therapy, it is crucial to understand the magnitude of acquired mutations. In this study, we investigated the levels of human leukocyte antigen (HLA)-class I, multidrug-resistance 1 (MDR1), and androgen receptor (AR) expressions in untreated prostate cancers harvested by radical prostatectomy. The mean percentages of cancer cells expressing HLA-class I, MDR and AR among the 10 cancer samples were 41, 35 and 74%, respectively. In addition, double-staining of HLA and MDR revealed the four definite populations (HLA+/MDR+, HLA+/MDR-, HLA-/MDR+ and HLA-/MDR-) in cancer tissues from the majority of cancer patients tested, and the mean percentages of cells expressing these combinations were 13, 29, 22 and 38%, respectively. Similar results were obtained by double-staining of HLA and AR, except for 2 cases in which HLA-/AR+ cancer cells predominated. These results indicated that untreated prostate cancer cells acquired a wide range of genomic mutations, which may have been caused by internal host pressure to eliminate malignant cells, and would provide evidence of the robustness of untreated prostate cancer.

  1. CacyBP/SIP enhances multidrug resistance of pancreatic cancer cells by regulation of P-gp and Bcl-2.

    PubMed

    Chen, Xiong; Zheng, Peichan; Xue, Zengfu; Li, Jie; Wang, Wenwu; Chen, Xi; Xie, Fangwei; Yu, Zongyang; Ouyang, Xuenong

    2013-07-01

    Our former report indicates that calcyclin-binding protein or Siah-1-interacting protein (CacyBP/SIP) is over-expressed in the SGC7901/ADR cell line. However, the potential role of CacyBP/SIP in the development of multidrug resistance (MDR) of pancreatic cancer is still uncertain. In this paper, we investigated the role of CacyBP/SIP in MDR of pancreatic cancer cells and its possible underlying mechanisms, and found that CacyBP/SIP was over-expressed in the Gemcitabine induced MDR pancreatic cancer cell PC-3/Gem compared with its parental cell PC-3. Up-regulation of CacyBP/SIP expression could enhance resistance of chemotherapy drugs on PC-3 cells and inhibit Adriamycin-induced apoptosis accompanied by decreased accumulation of intracellular Adriamycin. Furthermore, CacyBP/SIP could significantly up-regulate the expression of P-gp, Bcl-2, and the transcription of the MDR1 gene. In addition, the decrease of CacyBP/SIP expression using RNA interference or P-gp inhibitor could partially reverse CacyBP/SIP-mediated MDR. In brief, our study demonstrated that CacyBP/SIP could enhance the MDR phenotype of pancreatic cancer cells by increasing the expression of P-gp and Bcl-2, thus inhibiting apoptosis of pancreatic cancer cell.

  2. 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

  3. Upregulating miR-146a by physcion reverses multidrug resistance in human chronic myelogenous leukemia K562/ADM cells

    PubMed Central

    Liu, Wenjun; He, Juan; Yang, Yiling; Guo, Qulian; Gao, Fei

    2016-01-01

    The aim of this study was to evaluate the role of miR-146a in the drug resistance of chronic myelogenous leukemia (CML) cells (K562/ADM) and to investigate the reversal effect of physcion, a natural compound, on the multidrug-resistance in CML. Our results showed that miR-146a was significantly downregulated in drug-resistant K562 cells and the overexpression of miR-146a in K562/ADM cells could restore the sensitivity to adriamycin (ADM). In addition, our results showed that the downregulation of miR-146a was associated with increase in CXCR4 expression, which was a direct target of miR-146a. Moreover, our findings also provided experimental evidence that physcion could enhance the anti-proliferative effect of ADM in K562/ADM cells by upregulating miR-146a. In conclusion, this present study showed that miR-146a conferred ADM resistance in CML cells and physcion could improve the sensitivity of K562/ADM cells by enhancing apoptosis via upregulating miR-146a. PMID:27904770

  4. Upregulating miR-146a by physcion reverses multidrug resistance in human chronic myelogenous leukemia K562/ADM cells.

    PubMed

    Liu, Wenjun; He, Juan; Yang, Yiling; Guo, Qulian; Gao, Fei

    2016-01-01

    The aim of this study was to evaluate the role of miR-146a in the drug resistance of chronic myelogenous leukemia (CML) cells (K562/ADM) and to investigate the reversal effect of physcion, a natural compound, on the multidrug-resistance in CML. Our results showed that miR-146a was significantly downregulated in drug-resistant K562 cells and the overexpression of miR-146a in K562/ADM cells could restore the sensitivity to adriamycin (ADM). In addition, our results showed that the downregulation of miR-146a was associated with increase in CXCR4 expression, which was a direct target of miR-146a. Moreover, our findings also provided experimental evidence that physcion could enhance the anti-proliferative effect of ADM in K562/ADM cells by upregulating miR-146a. In conclusion, this present study showed that miR-146a conferred ADM resistance in CML cells and physcion could improve the sensitivity of K562/ADM cells by enhancing apoptosis via upregulating miR-146a.

  5. Adding Vitamin E-TPGS to the Formulation of Genexol-PM: Specially Mixed Micelles Improve Drug-Loading Ability and Cytotoxicity against Multidrug-Resistant Tumors Significantly

    PubMed Central

    Fan, Zhuoyang; Chen, Cheng; Pang, Xiaoying; Yu, Zhou; Qi, Yang; Chen, Xinyi; Liang, Huihui; Fang, Xiaoling; Sha, Xianyi

    2015-01-01

    Genexol-PM, produced by Samyang Company (Korea) is an excellent preparation of paclitaxel (PTX) for clinical cancer treatment. However, it cannot resolve the issue of multidrug resistance (MDR)—a significant problem in the administration of PTX to cancer patients. To increase the efficacy of Genexol-PM against MDR tumors, a mixed micelle capable of serving as a vehicle for PTX was developed, and two substances were chosen as carrier materials: 1) Polyethylene glycol–polylactic acid (PEG-PLA), the original vehicle of Genexol-PM. 2) Vitamin E-TPGS, an inhibitor of P-glycoprotein (P-gp). P-gp has been proven to be the main cause of MDR. In vitro evaluation indicated that the mixed micelle was an ideal PTX delivery system for the treatment of MDR tumors; the mixed micelle also showed a significantly better drug-loading coefficient than Genexol-PM. PMID:25831130

  6. 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

  7. 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

  8. 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

  9. The uptake of hydroxypropyl methacrylamide based homo, random and block copolymers by human multi-drug resistant breast adenocarcinoma cells

    PubMed Central

    Barz, Matthias; Luxenhofer, Robert; Zentel, Rudolf; Kabanov, Alexander V.

    2011-01-01

    A series of well defined, fluorescently labelled homopolymers, random and block copolymers based on N-(2-hydroxypropyl)-methacrylamide was prepared by reversible addition-fragmentation chain transfer polymerization (RAFT-polymerization). The polydispersity indexes for all polymers were in the range of 1.2 to 1.3 and the number average of the molar mass (Mn) for each polymer was set to be in the range of 15 kDa to 30 kDa. The cellular uptake of these polymers was investigated in the human multi-drug resistant breast adenocarcinoma cell line MCF7/ADR. The uptake greatly depended on the polymer molecular mass and structure. Specifically, smaller polymers (approx. 15 kDa) were taken up by the cells at much lower concentrations than larger polymers (approx. 30 kDa). Furthermore, for polymers of the same molar mass, the random copolymers were more easily internalized in cells than block copolymers or homopolymers. This is attributed to the fact that random copolymers form micelle-like aggregates by intra- and interchain interactions, which are smaller and less stable than the block copolymer structures in which the hydrophobic domain is buried and thus prevented from unspecific interaction with the cell membrane. Our findings underline the need for highly defined polymeric carriers and excipients for future applications in the field of nanomedicine. PMID:19631373

  10. Reversal of multidrug resistance in human lung cancer cells by delivery of 3-octadecylcarbamoylacrylic acid–cisplatin-based liposomes

    PubMed Central

    Song, Juan; Ren, Weifang; Xu, Tingting; Zhang, Yi; Guo, Hongyu; Zhu, Shanshan; Yang, Li

    2017-01-01

    Liposome-based drug delivery system would be an innovative and promising candidate to circumvent multidrug resistance (MDR) of cisplatin (CDDP). However, the reversal efficacy of liposomal CDDP was severely impaired by weak cellular uptake and insufficient intracellular drug release. In this study, 3-octadecylcarbamoylacrylic acid–CDDP nanocomplex (OMI–CDDP–N)-based liposomes (OCP-L) with high cellular uptake and sufficient intracellular drug release were designed to circumvent MDR of lung cancer. OMI–CDDP–N was synthesized through a pH-sensitive monocarboxylato and an O→Pt coordinate bond, which is more efficient than CDDP. Also, OCP-L incorporated with OMI–CDDP–N could induce effective cellular uptake, enhanced nuclear distribution, and optimal cellular uptake kinetics. In particular, OCP-L presented superior effects on enhancing cell apoptosis and in vitro cytotoxicity in CDDP-resistant human lung cancer (A549/CDDP) cells. The mechanisms of MDR reversal in A549/CDDP cells by OCP-L could attribute to organic cation transporter 2 restoration, ATPase copper-transporting beta polypeptide suppression, hypoxia-inducible factor 1 α-subunit depletion, and phosphatidylinositol 3-kinase/Akt pathway inhibition. These results demonstrated that OCP-L may provide an effective delivery of CDDP to resistant cells to circumvent MDR and enhance the therapeutic index of the chemotherapy. PMID:28255230

  11. [Restorative effect of quercetin on subcellular distribution of daunorubicin in multidrug resistant leukemia cell lines K562/ADM and HL-60/ADM].

    PubMed

    Cai, Xun; Chen, Fang-Yuan; Han, Jie-Ying; Gu, Chun-Hong; Zhong, Hua; Ouyang, Ren-Rong

    2004-12-01

    Quercetin, a widely distributed natural flavonoid with a variety of biological functions, can reverse multidrug resistance (MDR) in leukemia according to recent researches. This study was to investigate the mechanism of quercetin restoring subcellular distribution of daunorubicin (DNR) in multidrug resistant leukemia cell lines, K562/ADM and HL-60/ADM, and reversing their MDR. MTT cell viability assay was used to verify the sensitization of DNR by quercetin in K562/ADM and HL-60/ADM cells,and determine the reverse concentration extent,confocal laser scanning microscope was used to observe the subcellular distribution of DNR in K562/ADM and HL-60/ADM cells,and relevant sensitive cell lines, K562/S and HL-60/S,before and after quercetin exposion. Compared with K562/S and HL-60/S cells,20-40 micromol/L of quercetin in vitro remarkably enhanced the sensitivity of K562/ADM and HL-60/ADM cells to DNR, restore the subcellular distribution of DNR, so as to reverse MDR. quercetin could be a candidate of effective multidrug resistance-reversing agent in leukemia chemotherapy.

  12. Euphorbiasteroid reverses P-glycoprotein-mediated multi-drug resistance in human sarcoma cell line MES-SA/Dx5.

    PubMed

    Choi, Jung Sook; Kang, Nam Sook; Min, Yong Ki; Kim, Seong Hwan

    2010-07-01

    In this study, we evaluated whether euphorbiasteroid isolated from Euphorbia lathyris has the potential to reverse P-glycoprotein (P-gp)-mediated multi-drug resistance (MDR) by using the drug-sensitive human sarcoma cell line MES-SA and its MDR counterpart MES-SA/Dx5. Interestingly, even at low concentrations of euphorbiasteroid (1-3 microM), it efficiently restored the toxicities of anticancer drugs including vinblastine, taxol and doxorubicin in MES-SA/Dx5 cells. Additionally, the computational Bayesian model for predicting potential P-gp substrates or inhibitors revealed that euphorbiasteroid showed 97% probability for substrate likeness having similar molecular features with 50 P-gp substrates. Consistent with this result, the substrate likeness of euphorbiasteroid was also experimentally confirmed by P-gp ATPase activity assay. In conclusion, our finding suggested that euphorbiasteroid could be a transport substrate for P-gp that can effectively inhibit P-gp-mediated drug transport and reverse resistance to anticancer drugs in MES-SA/Dx5 cells.

  13. 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.

  14. Jadomycins inhibit type II topoisomerases and promote DNA damage and apoptosis in multidrug resistant triple negative breast cancer cells.

    PubMed

    Hall, Steven R; Toulany, Jay; Bennett, Leah G; Martinez-Farina, Camilo F; Robertson, Andrew W; Jakeman, David L; Goralski, Kerry B

    2017-09-13

    Jadomycins are natural products that kill drug-sensitive and multidrug resistant (MDR) breast cancer cells. To date the cytotoxic activity of jadomycins has never been tested in MDR breast cancer cells that are also triple-negative. Additionally, there is only a rudimentary understanding of how jadomycins cause cancer cell death, which includes the induction of intracellular reactive oxygen species (ROS). We first created a paclitaxel-resistant, triple-negative breast cancer cell line (231-TXL) from drug-sensitive MDA-MB-231 cells (231-CON). Using MTT cell viability measuring assays, jadomycins B, S, and F were found to be equipotent in drug-sensitive 231-CON and MDR 231-TXL cells, and using ROS-detecting assays these jadomycins were determined to increase ROS activity in both cell lines by up to 7.3-fold. Jadomycins caused DNA double strand breaks in 231-CON and 231-TXL cells as measured by γH2AX western blotting. Co-incubation with the antioxidant N-acetyl cysteine (NAC) or pro-oxidant auranofin did not affect jadomycin-mediated DNA damage. Jadomycins induced apoptosis in 231-CON and 231-TXL cells as measured by annexin V affinity assays, a process which was retained when ROS were inhibited. This indicated that jadomycins are capable of inducing MDA-MB-231 apoptotic cell death independently of ROS activity. Using qPCR, western blotting, and direct topoisomerase inhibition assays, it was determined that jadomycins inhibit type II topoisomerases and that jadomycins B and F selectively poison topoisomerase IIβ. We therefore propose novel mechanisms through which jadomycins induce breast cancer cell death independently of ROS-activity, through inhibition or poisoning of type II topoisomerases, and induction of DNA damage and apoptosis. The American Society for Pharmacology and Experimental Therapeutics.

  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. In vitro antileukaemic activity of extracts from chokeberry (Aronia melanocarpa [Michx] Elliott) and mulberry (Morus alba L.) leaves against sensitive and multidrug resistant HL60 cells.

    PubMed

    Skupień, Katarzyna; Kostrzewa-Nowak, Dorota; Oszmiański, Jan; Tarasiuk, Jolanta

    2008-05-01

    The aim of the present study was to determine in vitro antileukaemic activities of extracts obtained from chokeberry (Aronia melanocarpa [Michx] Elliot) and mulberry (Morus alba L.) leaves against promyelocytic HL60 cell line and its multidrug resistant sublines exhibiting two different MDR phenotypes: HL60/VINC (overexpressing P-glycoprotein) and HL60/DOX (overexpressing MRP1 protein). It was found that the extracts from chokeberry and mulberry leaves were active against the sensitive leukaemic cell line HL60 and retained the in vitro activity against multidrug resistant sublines (HL60/VINC and HL60/DOX). The values of resistance factor (RF) found for these extracts were very low lying in the range 1.2-1.6.

  17. 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

  18. 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

  19. Acerinol, a cyclolanstane triterpenoid from Cimicifuga acerina, reverses ABCB1-mediated multidrug resistance in HepG2/ADM and MCF-7/ADR cells.

    PubMed

    Liu, Dao-Lu; Li, Ying-Jie; Yao, Nan; Xu, Jun; Chen, Zhe-Sheng; Yiu, Anita; Zhang, Cui-Xian; Ye, Wen-Cai; Zhang, Dong-Mei

    2014-06-15

    Persistent cancer chemotherapy can lead to multidrug resistance which is one of the most common reasons for failure of chemotherapy. The ABCB1 transporter is a member of the ATP-binding cassette superfamily and it is frequently over-expressed in multidrug resistant cancer cells. Active ingredients derived from traditional Chinese medicinal herbs have been reported to reverse multidrug resistance mediated by ATP-binding cassette transporters. In this study, acerinol, isolated from Cimicifuga acerina, was tested for its potential to modulate the ABCB1 transporter. Our results demonstrated that acerinol could increase the chemosensitivity of ABCB1-overexpressing HepG2/ADM and MCF-7/ADR cells to chemotherapeutic drugs, doxorubicin, vincristine and paclitaxel. Furthermore, it could also increase the retention of ABCB1 substrates doxorubicin and rhodamine 123 in HepG2/ADM and MCF-7/ADR cells. A mechanistic study showed that acerinol significantly stimulated the activity of ABCB1 ATPase without affecting the expression of ABCB1 on neither mRNA nor protein level. Acerinol was also found to reverse the resistance of MCF-7/ADR cells to vincristine, dependent partly on ABCB1. In addition, acerinol׳s action was reversible, suggesting that acerinol may act as a competitive inhibitor of ABCB1 by competing with other drug substrates like doxorubicin. Indeed, docking analysis indicated that acerinol would most likely bind to the sites on ABCB1 that partly overlapped with that of verapamil. In conclusion, the present study is the first to show that acerinol from C. acerina significantly enhances the cytotoxicity of chemotherapeutic drugs by modulating the function of ABCB1. It is hopeful to develop acerinol as a new multidrug resistance reversal agent. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Cytotoxic effect of the cyclosporin PSC 833 in multidrug-resistant leukaemia cells with increased expression of P-glycoprotein.

    PubMed Central

    Lehne, G.; Rugstad, H. E.

    1998-01-01

    Multidrug resistance (MDR) to anti-cancer agents is frequently associated with overexpression of the drug efflux transporter P-glycoprotein (Pgp) in cancer cells, ensuing drug expulsion and maintenance of tolerable intracellular levels of certain cytotoxic drugs. Pgp may also be present in normal tissue, providing protection against toxic substances, but the physiological role of Pgp is not fully understood. Recently, it was shown that Pgp also takes part in the transport of certain growth-regulating cytokines (Drach et al, 1996; Raghu et al, 1996). Therefore, we studied the effect of the highly potent Pgp inhibitor PSC 833 on proliferation of three pairs of MDR and parental human cell lines (HB8065 hepatoma cells, KG1a and K562 leukaemia cells). The MDR phenotypes were characterized by Pgp overexpression, which was demonstrated by flow cytometry using the anti-Pgp antibody MRK16. Electronic cell counting of 72-96 h cultures revealed a dose-dependent antiproliferative effect of PSC 833 in the resistant KG1a/200 and K562/150 cells. The half-maximal growth inhibitory concentrations (GI50) were 0.2 microM and 0.7 microM respectively. Exposure to PSC 833 induced cell death by apoptosis in both cell types, as revealed by flow cytometry and detection of 3'-hydroxy ends of DNA (the result of DNA fragmentation associated with apoptosis), by terminal transferase-mediated dUTP-biotin nick end-labelling (TUNEL). Similar effects were not found in the hepatoma cell lines or the parental leukaemia lines. These results demonstrated a discriminating cytotoxicity of PSC 833 in two human leukaemia MDR variants, representing a possible therapeutic indication which warrants consideration during the ongoing clinical evaluation of this drug. Images Figure 8 PMID:9744497

  1. Glutathione and multidrug resistance protein transporter mediate a self-propelled disposal of bismuth in human cells.

    PubMed

    Hong, Yifan; Lai, Yau-Tsz; Chan, Godfrey Chi-Fung; Sun, Hongzhe

    2015-03-17

    Glutathione and multidrug resistance protein (MRP) play an important role on the metabolism of a variety of drugs. Bismuth drugs have been used to treat gastrointestinal disorder and Helicobacter pylori infection for decades without exerting acute toxicity. They were found to interact with a wide variety of biomolecules, but the major metabolic pathway remains unknown. For the first time (to our knowledge), we systematically and quantitatively studied the metabolism of bismuth in human cells. Our data demonstrated that over 90% of bismuth was passively absorbed, conjugated to glutathione, and transported into vesicles by MRP transporter. Mathematical modeling of the system reveals an interesting phenomenon. Passively absorbed bismuth consumes intracellular glutathione, which therefore activates de novo biosynthesis of glutathione. Reciprocally, sequestration by glutathione facilitates the passive uptake of bismuth and thus completes a self-sustaining positive feedback circle. This mechanism robustly removes bismuth from both intra- and extracellular space, protecting critical systems of human body from acute toxicity. It elucidates the selectivity of bismuth drugs between human and pathogens that lack of glutathione, such as Helicobacter pylori, opening new horizons for further drug development.

  2. Glutathione and multidrug resistance protein transporter mediate a self-propelled disposal of bismuth in human cells

    PubMed Central

    Hong, Yifan; Lai, Yau-Tsz; Chan, Godfrey Chi-Fung; Sun, Hongzhe

    2015-01-01

    Glutathione and multidrug resistance protein (MRP) play an important role on the metabolism of a variety of drugs. Bismuth drugs have been used to treat gastrointestinal disorder and Helicobacter pylori infection for decades without exerting acute toxicity. They were found to interact with a wide variety of biomolecules, but the major metabolic pathway remains unknown. For the first time (to our knowledge), we systematically and quantitatively studied the metabolism of bismuth in human cells. Our data demonstrated that over 90% of bismuth was passively absorbed, conjugated to glutathione, and transported into vesicles by MRP transporter. Mathematical modeling of the system reveals an interesting phenomenon. Passively absorbed bismuth consumes intracellular glutathione, which therefore activates de novo biosynthesis of glutathione. Reciprocally, sequestration by glutathione facilitates the passive uptake of bismuth and thus completes a self-sustaining positive feedback circle. This mechanism robustly removes bismuth from both intra- and extracellular space, protecting critical systems of human body from acute toxicity. It elucidates the selectivity of bismuth drugs between human and pathogens that lack of glutathione, such as Helicobacter pylori, opening new horizons for further drug development. PMID:25737551

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

    PubMed

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

    2016-08-01

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

  4. 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

  5. Antiproliferative and proapoptotic effects of a pyrrole containing arylthioindole in human Jurkat leukemia cell line and multidrug-resistant Jurkat/A4 cells

    PubMed Central

    Philchenkov, Alex A; Zavelevich, Michael P; Tryndyak, Volodymyr P; Kuiava, Ludmila M; Blokhin, Dmitry Yu; Miura, Koh; Silvestri, Romano; Pogribny, Igor P

    2015-01-01

    Recently, a series of novel arylthioindole compounds, potent inhibitors of tubulin polymerization and cancer cell growth, were synthesized. In the present study the effects of 2-(1H-pyrrol-3-yl)-3-((3,4,5-trimethoxyphenyl)thio)-1H-indole (ATI5 compound) on cell proliferation, cell cycle progression, and induction of apoptosis in human T-cell acute leukemia Jurkat cells and their multidrug resistant Jurkat/A4 subline were investigated. Treatment of the Jurkat cells with the ATI5 compound for 48 hrs resulted in a strong G2/M cell cycle arrest and p53-independent apoptotic cell death accompanied by the induction of the active form of caspase-3 and poly(ADP-ribose) polymerase-1 (PARP-1) cleavage. ATI5 treatment also caused non-cell death related mitotic arrest in multidrug resistant Jurkat/A4 cells after 48 hrs of treatment suggesting promising opportunities for the further design of pyrrole-containing ATI compounds as anticancer agents. Cell death resistance of Jurkat/A4 cells to ATI5 compound was associated with alterations in the expression of pro-survival and anti-apoptotic protein-coding and microRNA genes. More importantly, findings showing that ATI5 treatment induced p53-independent apoptosis are of great importance from a therapeutic point of view since p53 mutations are common genetic alterations in human neoplasms. PMID:26785947

  6. 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.

  7. [Reversal effect and mechanism of lobeline on the multidrug-resistance of human breast cancer cells MCF-7/ADM].

    PubMed

    Chen, Jia; Shen, Liangfang; Zhou, Rongrong; Yao, Wei; Zhong, Meizuo; Zhu, Zhu Hong; Zeng, Shan

    2009-08-01

    To explore the reversal effect and mechanism of lobeline on the multidrug-resistance (MDR) of human breast cancer cells MCF-7/ADM. In human breast cancer cell line MCF-7/ADM, MTT assay was used to determine the cell growth inhibiting ratio of MCF-7/ADM by ADM and Fu. Fluorospectorphotometer was employed to investigate the intracellular concentration of rhodamine123 to reflect the effect of lobeline on the activity of MDR-related protein P-glycoprotein (P-gp). Taking untreated MCF-7/ADM cells as controls, flow cytometry was applied to detect the intracellular concentration of rhodamine123 in MCF-7/ADM cell intervened with lobeline of 20 micromol/L. The sensitivity of MCF-7/ADM to ADM and Fu was significantly increased by lobeline in a dose-dependent manner. The inhibitive concentration 50 (IC(50)) of ADM declined from (44.81+/-0.43) mg/L to (16.72+/-0.75) mg/L with a reversion index of 2.68. The IC(50) of Fu declined from (53.12+/-1.60) mg/L to (38.90+/-1.43) mg/L with a reversion index of 1.37. The fluorescence intensity of lobeline-treated cells was significantly higher than that of the controls, when the concentration of lobeline was more than 10 micromol/L. With fewer side effects, the reversal efficacy of 20 micromol/L lobeline was 71.6% of the classical MDR reversal agent of verapamil at the same concentration. Lobeline can reverse the MDR of MCF-7/ADM cells by inhibiting the activity of P-glycoprotein.

  8. Effects of Kampo medicines on MDR-1-mediated multidrug resistance in human hepatocellular carcinoma HuH-7/PTX cells.

    PubMed

    Hyuga, Sumiko; Shiraishi, Masumi; Hori, Atsushi; Hyuga, Masashi; Hanawa, Toshihiko

    2012-01-01

    Paclitaxel-resistant HuH-7 (HuH-7/PTX) cells were established by one-week exposure of HuH-7 cells to paclitaxel to analyze the effects of Kampo medicines on MDR-1-mediated multidrug resistance. HuH-7/PTX cells expressed high levels of MDR-1 and efficiently exported calcein-acetoxymethylester (calcein-AM), which is a substrate of MDR-1, suggesting that HuH-7/PTX cells resist paclitaxel by overexpressing MDR-1. We assessed the effects of 26 kinds of Kampo medicine on MDR-1 by calcein-AM efflux assay using HuH-7/PTX cells, and the results revealed that takushato and goreisan are potential inhibitors of drug efflux by MDR-1. Additionally, the sensitivity of HuH-7/PTX cells to paclitaxel was increased in combination with these Kampo medicines, indicating that takushato and goreisan overcame paclitaxel resistance in the cells by suppressing drug export by MDR-1. We further clarified that Alismatis Rhizoma contained in both takushato and goreisan reversed paclitaxel resistance by preventing drug efflux by MDR-1 without affecting the expression levels of MDR-1. Moreover, the principal components of Alismatis Rhizoma, Alisol A, Alisol B, and Alisol B acetate, were found to increase the sensitivity to paclitaxel in HuH-7/PTX by inhibiting drug export by MDR-1 without affecting the expression levels of MDR-1. These results suggested that the reversal effects of takushato and goreisan on paclitaxel resistance are derived from these principal components in Alismatis Rhizoma. Accordingly, Kampo medicines containing Alismatis Rhizoma such as takushato and goreisan may be useful as MDR-1 inhibitors.

  9. Honokiol synergizes chemotherapy drugs in multidrug resistant breast cancer cells via enhanced apoptosis and additional programmed necrotic death.

    PubMed

    Tian, Wei; Deng, Yongchuan; Li, Ling; He, Haifei; Sun, Jie; Xu, Dong

    2013-02-01

    Multidrug resistance (MDR) is a major challenge in cancer therapy. Apoptosis tolerance is one of the key mechanisms of MDR. Honokiol, a small-molecule pharmacologically active component, exhibits competent cytotoxicity in a variety of human cancer cells through apoptosis and other forms of programmed cell death (such as programmed necrosis). Although much work has been done on its antitumor effects, little attention has been paid on systemic evaluation of efficacy of honokiol combined with other chemotherapeutic agents, especially in drug‑resistant cell lines. Here, we systematically and quantitatively assess its combinational effect with different chemotherapeutic agents using the combination index (CI) equation. We found that honokiol synergized with chemotherapeutic agents both in sensitive and resistant, solid and non-solid (MCF-7, HL-60, MCF-7/ADR and HL-60/ADR) cell lines. Honokiol (40 µg/ml) induced necrotic cell death in MCF-7/ADR cells with characterized morphological and biochemical features. Co-incubation with honokiol and etoposide (VP-16) activated a complex death modality, which was composed of necrotic cell death and apoptosis. This dual-death pathway was shut down when pretreated with pan-caspase inhibitor (z-VAD-fmk) and cyclophilin D inhibitor (cyclosporin A). Western blot analysis results proved that honokiol also enhanced VP-16-induced apoptosis potentially via blocking nuclear factor‑κB (NF-κB) activation. Our data for the first time quantitatively demonstrate that honokiol synergizes frequently-used chemotherapeutic agents via enhanced apoptosis and additional programmed necrotic death. These findings indicate a promising way to circumvent MDR and apoptosis tolerance.

  10. Modulation of P-glycoprotein by Stemona alkaloids in human multidrug resistance leukemic cells and structural relationships.

    PubMed

    Umsumarng, Sonthaya; Pitchakarn, Pornsiri; Yodkeeree, Supachai; Punfa, Wanisa; Mapoung, Sariya; Ramli, Rosdayati Alino; Pyne, Stephen G; Limtrakul, Pornngarm

    2017-10-15

    Multidrug resistance (MDR) is a major reason for the failure of chemotherapy in the treatment of cancer patients. P-gp over-expression in MDR cancer cells is a multifactorial phenomenon with biochemical resistance mechanisms. Stemofoline (STF), isolated from Stemona bukillii, has been reported to be an MDR reversing compound. This study investigated whether other Stemona alkaloids that had been purified from Stemonaceae plants exerted MDR modulation activity. MTT assay was performed to determine the MDR reversing property of the alkaloids. Modulation of P-gp function by these compounds was investigated using cell cycle analysis and P-gp fluorescent substrate accumulation assays. P-gp expression was determined by Western blot analysis. We preliminarily examined the safety of these compounds in normal human fibroblasts and human peripheral blood mononuclear cells (PBMCs) using the MTT assay, and in red blood cells (human and rat) through in vitro hemolysis assays. Three of the eight alkaloids tested, isostemofoline (ISTF), 11Z -didehydrostemofoline (11Z-DSTF) and 11E-didehydrostemofoline (11E-DSTF), enhanced the chemotherapeutic sensitivity of MDR leukemic K562/Adr cells, which overexpressed P-gp. The P-gp functional studies showed that these three alkaloids increased the accumulation of P-gp substrates, calcein-AM (C-AM) and rhodamine123 (Rho 123) in K562/Adr cells, while this effect was not seen in drug sensitive parental K562 cells. Whereas, the alkaloids did not alter P-gp expression as was determined by Western blotting analysis. The alkaloids reversed MDR via the inhibition of P-gp function. For pharmaceutical safety testing, the alkaloids were found to be not toxic to normal human fibroblasts and PBMCs. Moreover, the effective compounds did not induce hemolysis in either human or rat erythrocytes. These compounds may be introduced as potential candidate molecules for treating cancers exhibiting P-gp-mediated MDR. Copyright © 2017 Elsevier GmbH. All rights

  11. Synergistic effect of hyperthermia and neferine on reverse multidrug resistance in adriamycin-resistant SGC7901/ADM gastric cancer cells.

    PubMed

    Huang, Chenghui; Li, Yaping; Cao, Peiguo; Xie, Zhaoxia; Qin, Zhiqiang

    2011-08-01

    Multidrug resistance (MDR) plays a major obstacle to successful gastric cancer chemotherapy. The purpose of this study was to investigate the MDR reversal effect and mechanisms of hyperthermia in combination with neferine (Nef) in adriamycin (ADM) resistant human SGC7901/ADM gastric cancer cells. The MDR cells were heated at 42°C and 45°C for 30 min alone or combined with 10 μg/mL Nef. The cytotoxic effect of ADM was evaluated by MTT assay. Cellular plasma membrane lipid fluidity was detected by fluorescence polarization technique. Intracellular accumulation of ADM was monitored with high performance liquid chromatography. Mdr-1 mRNA, P-glycoprotein (P-gp), γH2AX expression and γH2AX foci formation were determined by real-time PCR, Western blot and immunocytochemical staining respectively. It was found that different heating methods induced different cytotoxic effects. Water submerged hyperthermia had the strongest cytotoxicity of ADM and Nef combined with hyperthermia had a synergistic cytotoxicity of ADM in the MDR cells. The water submerged hyperthermia increased the cell membrane fluidity. Both water submerged hyperthermia and Nef increased the intracellular accumulation of ADM. The water submerged hyperthermia and Nef down-regulated the expression of mdr-1 mRNA and P-gp. The water submerged hyperthermia could damage DNA and increase the γH2AX expression of SGC7901/ADM cells. The higher temperature was, the worse effect was. Our results show that combined treatment of hyperthermia with Nef can synergistically reverse MDR in human SGC7901/ADM gastric cancer cells.

  12. 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.

  13. Selective Toxicity of NSC 73306 in MDR1-positive cells as a New Strategy to Circumvent Multidrug Resistance in Cancer

    PubMed Central

    Ludwig, Joseph A.; Martin, Scott E.; Chu, Benjamin F.; Cardarelli, Carol; Sauna, Zuben E.; Caplen, Natasha J.; Fales, Henry M.; Ambudkar, Suresh V.; Weinstein, John N.

    2006-01-01

    ATP-binding cassette (ABC) proteins include the best known mediators of resistance to anticancer drugs. In particular, ABCB1 (MDR1/P-gp) extrudes many types of drugs from cancer cells, thereby conferring resistance to those agents. Attempts to overcome P-gp-mediated drug resistance using specific inhibitors of P-gp has had limited success, and has faced many therapeutic challenges. As an alternative approach to using P-gp inhibitors, we characterize a thiosemicarbazone derivative (NSC73306) identified in a generic screen as a compound that exploits, rather than suppresses, P-gp function to induce cytotoxicity. Cytotoxic activity of NSC73306 was evaluated in vitro using human epidermoid, ovarian, and colon cancer cell lines expressing various levels of P-gp. Our findings suggest that cells become hypersensitive to NSC73306 in proportion to the increased P-gp function and multidrug resistance (MDR). Abrogation of both sensitivity to NSC73306 and resistance to P-gp substrate anticancer agents occurred with specific inhibition of P-gp function using either a P-gp inhibitor (PSC833, XR9576) or RNA interference (RNAi), suggesting that cytotoxicity was linked to MDR1 function, not to other, nonspecific factors arising during the generation of resistant or transfected cells. Molecular characterization of cells selected for resistance to NSC73306 revealed loss of P-gp expression and consequent loss of the MDR phenotype. Although hypersensitivity to NSC73306 required functional expression of P-gp, biochemical assays revealed no direct interaction between NSC73306 and P-gp. This work demonstrates that NSC73306 kills cells with intrinsic or acquired P-gp-induced MDR and indirectly acts to eliminate resistance to MDR1 substrates. PMID:16651436

  14. TPGS2k/PLGA nanoparticles for overcoming multidrug resistance by interfering mitochondria of human alveolar adenocarcinoma cells.

    PubMed

    Wang, Dong-Fang; Rong, Wen-Ting; Lu, Yu; Hou, Jie; Qi, Shan-Shan; Xiao, Qing; Zhang, Jue; You, Jin; Yu, Shu-Qin; Xu, Qian

    2015-02-25

    In this study, we successfully synthesized d-α-tocopheryl polyethylene glycol 2000 succinate (TPGS2k) and prepared TPGS2k-modified poly(lactic-co-glycolic acid) nanoparticles (TPGS2k/PLGA NPs) loaded with 7-ethyl-10-hydroxycamptothecin (SN-38), designated TPGS2k/PLGA/SN-38 NPs. Characterization measurements showed that TPGS2k/PLGA/SN-38 NPs displayed flat and spheroidal particles with diameters of 80-104 nm. SN-38 was encapsulated in TPGS2k emulsified PLGA NPs with the entrapment efficiency and loading rates of SN-38 83.6 and 7.85%, respectively. SN-38 could release constantly from TPGS2k/PLGA/SN-38 NPs in vitro. TPGS2k/PLGA/SN-38 NPs induced significantly higher cytotoxicity on A549 cells and the multidrug resistance (MDR) cell line (A549/DDP cells and A549/Taxol cells) compared with free SN-38. Further studies on the mechanism of the NPs in increasing the death of MDR cells showed that following the SN-38 releasing into cytoplasm the remaining TPGS2k/PLGA NPs could reverse the P-gp mediated MDR via interfering with the structure and function of mitochondria and rather than directly inhibiting the enzymatic activity of P-gp ATPase. Therefore, TPGS2k/PLGA NPs can reduce the generation of ATP and the release of energy for the requisite of P-gp efflux transporters. The results indicated that TPGS2k/PLGA NPs could become the nanopharmaceutical materials with the capability to reversal MDR and improve anticancer effects of some chemotherapy drugs as P-gp substrates.

  15. Targeting P-glycoprotein expression and cancer cell energy metabolism: combination of metformin and 2-deoxyglucose reverses the multidrug resistance of K562/Dox cells to doxorubicin.

    PubMed

    Xue, Chaojun; Wang, Changyuan; Liu, Qi; Meng, Qiang; Sun, Huijun; Huo, Xiaokui; Ma, Xiaodong; Liu, Zhihao; Ma, Xiaochi; Peng, Jinyong; Liu, Kexin

    2016-07-01

    P-glycoprotein (P-gp) is one of the major obstacles to efficiency of cancer chemotherapy. Here, we investigated whether combination of metformin and 2-deoxyglucose reverses the multidrug resistance (MDR) of K562/Dox cells and tried to elucidate the possible mechanisms. The combination of metformin and 2-deoxyglucose selectively enhanced the cytotoxicity of doxorubicin against K562/Dox cells. Metformin was not a substrate of P-gp but suppressed the elevated level of P-gp in K562/Dox cells. The downregulation of P-gp may be partly attributed to the inhibition of extracellular signal-regulated kinase pathway. The addition of 2-deoxyglucose to metformin initiated a strong metabolic stress in both K562 and K562/Dox cells. Combination of metformin and 2-deoxyglucose inhibited glucose uptake and lactate production in K562 and K562/Dox cells leading to a severe depletion in ATP and a enhanced autophagy. Above all, P-gp substrate selectively aggravated this ATP depletion effect and increased cell apoptosis in K562/Dox cells. In conclusion, metformin decreases P-gp expression in K562/Dox cells via blocking phosphorylation of extracellular signal-regulated kinase. P-gp substrate increases K562/Dox cell apoptosis via aggravating ATP depletion induced by combination of metformin and 2-deoxyglucose. Our observations highlight the importance of combination of metformin and 2-deoxyglucose in reversing multidrug resistance.

  16. A phenolic ester from Aglaia loheri leaves reveals cytotoxicity towards sensitive and multidrug-resistant cancer cells

    PubMed Central

    2013-01-01

    Background Bioactivity-guided fractionation of extracts of Aglaia loheri Blanco (Meliaceae) yielded a cytotoxic isolate, termed Maldi 531.2[M + H]+. This phenolic ester was further investigated for its in vitro cytotoxicity toward human CCRF-CEM leukemia cells and their multi-drug resistant (MDR) subline, CEM/ADR5000. The intrinsic mitochondrial membrane potential (ΔΨm) and induction of apoptosis by this isolate were evaluated. Methods Chromatography techniques, mass spectrometry and proton NMR were employed to isolate Maldi 531.2[M + H]+. XTT cell proliferation and viability assay was used for cytotoxic test, and JC-1[5’,5’,6,6’,-tetrachloro-1,1’,3,3’-tetraethylbenzimidazoyl carbocyanine iodide was used to assess ΔΨm and initiation of apoptosis; Annexin V/FITC-PI staining was employed to analyse apoptosis. Results Maldi 531.2[M + H]+ was cytotoxic towards both CCRF-CEM and CEM/ADR5000 cells with IC50 values of 0.02 and 0.03 μM, respectively. The mitochondrial membrane potential (ΔΨm) of MDR cells was significantly reduced in a dose-dependent manner leading to apoptosis as detected by flow cytometric Annexin V-FITC/ PI staining. Conclusion Maldi 531.2[M + H]+ may be a potential anti-cancer drug candidate whose mode of action include reduction of the mitochondrial membrane potential and induction of apoptosis. PMID:24160768

  17. 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

  18. 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

  19. 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

  20. Genomic and transcriptomic profiling of resistant CEM/ADR-5000 and sensitive CCRF-CEM leukaemia cells for unravelling the full complexity of multi-factorial multidrug resistance

    PubMed Central

    Kadioglu, Onat; Cao, Jingming; Kosyakova, Nadezda; Mrasek, Kristin; Liehr, Thomas; Efferth, Thomas

    2016-01-01

    We systematically characterised multifactorial multidrug resistance (MDR) in CEM/ADR5000 cells, a doxorubicin-resistant sub-line derived from drug-sensitive, parental CCRF-CEM cells developed in vitro. RNA sequencing and network analyses (Ingenuity Pathway Analysis) were performed. Chromosomal aberrations were identified by array-comparative genomic hybridisation (aCGH) and multicolour fluorescence in situ hybridisation (mFISH). Fifteen ATP-binding cassette transporters and numerous new genes were overexpressed in CEM/ADR5000 cells. The basic karyotype in CCRF-CEM cells consisted of 47, XX, der(5)t(5;14) (q35.33;q32.3), del(9) (p14.1), +20. CEM/ADR5000 cells acquired additional aberrations, including X-chromosome loss, 4q and 14q deletion, chromosome 7 inversion, balanced and unbalanced two and three way translocations: t(3;10), der(3)t(3;13), der(5)t(18;5;14), t(10;16), der(18)t(7;18), der(18)t(21;18;5), der(21;21;18;5) and der(22)t(9;22). CCRF-CEM consisted of two and CEM/ADR5000 of five major sub-clones, indicating genetic tumor heterogeneity. Loss of 3q27.1 in CEM/ADR5000 caused down-regulation of ABCC5 and ABCF3 expression, Xq28 loss down-regulated ABCD1 expression. ABCB1, the most well-known MDR gene, was 448-fold up-regulated due to 7q21.12 amplification. In addition to well-known drug resistance genes, numerous novel genes and genomic aberrations were identified. Transcriptomics and genetics in CEM/AD5000 cells unravelled a range of MDR mechanisms, which is much more complex than estimated thus far. This may have important implications for future treatment strategies. PMID:27824156

  1. Characterization of Siphoviridae phage Z and studying its efficacy against multidrug-resistant Klebsiella pneumoniae planktonic cells and biofilm.

    PubMed

    Jamal, Muhsin; Hussain, Tahir; Das, Chythanya Rajanna; Andleeb, Saadia

    2015-04-01

    Biofilm has many serious consequences for public health and is a major virulence factor contributing to the chronicity of infections. The aim of the current study was to isolate and characterize a bacteriophage that inhibits multidrug-resistant Klebsiella pneumonia (M) in planktonic form as well as biofilm. This phage, designated bacteriophage Z, was isolated from wastewater. Its adsorption rate to its host bacterium was significantly enhanced by MgCl2 and CaCl2. It has a wide range of pH and heat stability. From its one-step growth, latent time and burst size were determined to be 24 min and about 320 virions per cell, respectively. As analysed by transmission electron microscopy, phage Z had an icosahedral head of width 76±10 nm, length 92±14 nm and icosahedron side 38 nm, and a non-contractile tail 200±15 nm long and 14-29 nm wide. It belongs to the family Siphoviridae in the order Caudovirales. Six structural proteins ranging from 18 to 65 kDa in size were revealed by SDS-PAGE. The genome was found to comprise double-stranded DNA with an approximate size of 36 kb. Bacteria were grown in suspension and as biofilms to compare the susceptibility of both phenotypes to the phage lytic action. Phage Z was effective in reducing biofilm biomass after 24 and 48 h, showing more than twofold and threefold reduction, respectively. Biofilm cells and stationary-phase planktonic bacteria were killed at a lower rate than exponential-phase planktonic bacteria. © 2015 The Authors.

  2. Effect of glucose transport inhibitors on vincristine efflux in multidrug-resistant murine erythroleukaemia cells overexpressing the multidrug resistance-associated protein (MRP) and two glucose transport proteins, GLUT1 and GLUT3.

    PubMed Central

    Martell, R. L.; Slapak, C. A.; Levy, S. B.

    1997-01-01

    The relationship between mammalian facilitative glucose transport proteins (GLUT) and multidrug resistance was examined in two vincristine (VCR)-selected murine erythroleukaemia (MEL) PC4 cell lines. GLUT proteins, GLUT1 and GLUT3, were constitutively coexpressed in the parental cell line and also in the VCR-selected cell lines. Increased expression of the GLUT1 isoform was noted both in the PC-V40 (a non-P-glycoprotein, mrp-overexpressing subline) and in the more resistant PC-V160 (overexpressing mrp and mdr3) cell lines. Overexpression of GLUT3 was detected only in the PC-V160 subline. An increased rate of facilitative glucose transport (Vmax) and level of plasma membrane GLUT protein expression paralleled increased VCR resistance, active VCR efflux and decreased VCR steady-state accumulation in these cell lines. Glucose transport inhibitors (GTIs), cytochalasin B (CB) and phloretin blocked the active efflux and decreased steady-state accumulation of VCR in the PC-V40 subline. GTIs did not significantly affect VCR accumulation in the parental or PC-V160 cells. A comparison of protein sequences among GLUT1, GLUT3 and MRP revealed a putative cytochalasin B binding site in MRP, which displayed 44% sequence similarity/12% identity with that previously identified in GLUT1 and GLUT3; these regions also exhibited a similar hydropathy plot pattern. The findings suggested that CB bound to MRP and directly or indirectly lowered VCR efflux and/or CB bound to one or both GLUT proteins, which acted to lower the VCR efflux mediated by MRP. This is the first report of a non-neuronal murine cell line that expressed GLUT3. Images Figure 3 PMID:9010020

  3. Patients with Multidrug-Resistant Tuberculosis Display Impaired Th1 Responses and Enhanced Regulatory T-Cell Levels in Response to an Outbreak of Multidrug-Resistant Mycobacterium tuberculosis M and Ra Strains▿

    PubMed Central

    Geffner, Laura; Yokobori, Noemí; Basile, Juan; Schierloh, Pablo; Balboa, Luciana; Romero, María Mercedes; Ritacco, Viviana; Vescovo, Marisa; González Montaner, Pablo; Lopez, Beatriz; Barrera, Lucía; Alemán, Mercedes; Abatte, Eduardo; Sasiain, María C.; de la Barrera, Silvia

    2009-01-01

    In Argentina, multidrug-resistant tuberculosis (MDR-TB) outbreaks emerged among hospitalized patients with AIDS in the early 1990s and thereafter disseminated to the immunocompetent community. Epidemiological, bacteriological, and genotyping data allowed the identification of certain MDR Mycobacterium tuberculosis outbreak strains, such as the so-called strain M of the Haarlem lineage and strain Ra of the Latin America and Mediterranean lineage. In the current study, we evaluated the immune responses induced by strains M and Ra in peripheral blood mononuclear cells from patients with active MDR-TB or fully drug-susceptible tuberculosis (S-TB) and in purified protein derivative-positive healthy controls (group N). Our results demonstrated that strain M was a weaker gamma interferon (IFN-γ) inducer than H37Rv for group N. Strain M induced the highest interleukin-4 expression in CD4+ and CD8+ T cells from MDR- and S-TB patients, along with the lowest cytotoxic T-lymphocyte (CTL) activity in patients and controls. Hence, impairment of CTL activity is a hallmark of strain M and could be an evasion mechanism employed by this strain to avoid the killing of macrophages by M-specific CTL effectors. In addition, MDR-TB patients had an increased proportion of circulating regulatory T cells (Treg cells), and these cells were further expanded upon in vitro M. tuberculosis stimulation. Experimental Treg cell depletion increased IFN-γ expression and CTL activity in TB patients, with M- and Ra-induced CTL responses remaining low in MDR-TB patients. Altogether, these results suggest that immunity to MDR strains might depend upon a balance between the individual host response and the ability of different M. tuberculosis genotypes to drive Th1 or Th2 profiles. PMID:19720756

  4. Modulation of P-glycoprotein mediated drug accumulation in multidrug resistant CCRF VCR-1000 cells by chemosensitisers.

    PubMed

    Boer, R; Gekeler, V; Ulrich, W R; Zimmermann, P; Ise, W; Schödl, A; Haas, S

    1996-05-01

    P-glycoprotein (PGP) mediated transport of cytostatic drugs out of resistant cancer cells is a major cause of experimental and probably also of clinical multidrug resistance, which often leads to treatment failure during chemotherapy. The broad substrate specificity of PGP strongly restricts effective chemotherapy and diminishes the patients' prognosis. Inhibition of PGP's pumping function by chemosensitisers is one way to restore cellular responsiveness to otherwise ineffective cytostatics. Clinical trials with several chemosensitisers are under way. To date, it is not clear whether a certain chemosensitiser potentiates the action of different cytostatic drugs, transported by PGP equally well, or whether the chemosensitising potency is dependent on the cytostatic drugs used. Therefore, we compared the effects of five potent chemosensitisers on cellular accumulation using [3H]daunomycin, [3H]vincristine and rhodamine-123 as substrates for PGP. The acridonecarboxamide derivative GF 120918 was the most potent compound and a half-maximal effect was seen at concentrations ranging from 5 nM for rhodamine-123 accumulation to 14 and 19 nM for [3H]vincristine or [3H]daunomycin accumulation, respectively. The new chemosensitiser B9203-016 was slightly less effective than GF 120918 in all three test systems. Dexniguldipine was of intermediate potency with half-maximal effects at concentrations between 62 and 194 nM. The cyclic undecapeptide SDZ PSC 833 showed somewhat lower potency ranging from 151 to 331 nM. Cyclosporin A was less potent than SDZ PSC 833. Furthermore, enhancement of drug accumulation produced by each chemosensitiser was similar, regardless of which PGP substrate was measured, that is, the rank order of potency to increase accumulation was the same in each of the assays used. Our data point to similar, if not identical, mechanisms of drug transport by PGP and inhibition of drug transport by chemosensitisers at least for the substrates rhodamine-123

  5. Multidrug-resistant Enterobacteriaceae, Pseudomonas aeruginosa, and vancomycin-resistant enterococci: Three major threats to hematopoietic stem cell transplant recipients.

    PubMed

    Satlin, Michael J; Walsh, Thomas J

    2017-08-16

    Hematopoietic stem cell transplant (HSCT) recipients are uniquely threatened by the emergence of multidrug-resistant (MDR) bacteria because these patients rely on immediate active antimicrobial therapy to combat bacterial infections. This review describes the epidemiology and treatment considerations for three challenging MDR bacterial pathogens in HSCT recipients: MDR Enterobacteriaceae, including extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant Enterobacteriaceae (CRE), Pseudomonas aeruginosa, and vancomycin-resistant Enterococcus (VRE). These bacteria are common causes of infection in this population and bacteremias caused by these organisms are associated with high mortality rates. Carbapenems remain the treatments of choice for serious infections due to ESBL-producing Enterobacteriaceae in HSCT recipients. Administration of β-lactam agents as an extended infusion is associated with improved outcomes in patients with severe infections caused by P. aeruginosa. Older agents used for the treatment of CRE and MDR P. aeruginosa infections, such as polymyxins and aminoglycosides, have major limitations. Newer agents, such as ceftazidime-avibactam and ceftolozane-tazobactam have great potential for the treatment of Klebsiella pneumoniae carbapemenase-producing CRE and MDR P. aeruginosa, respectively, but more pre-clinical and clinical data are needed to better evaluate their efficacy. Daptomycin dosages ≥ 8 mg/kg/day are recommended to treat VRE infections in this population, particularly in the setting of increasing daptomycin resistance. Strategies to prevent these infections include strict adherence to recommended infection control practices and multidisciplinary antimicrobial stewardship. Lastly, gastrointestinal screening to guide empirical therapy and the use of polymerase chain reaction-based rapid diagnostics may decrease the time to administration of appropriate therapy for these infections, thereby leading to improved outcomes

  6. Lysosome-mediated Cell Death and Autophagy-Dependent Multidrug Resistance in Breast Cancer

    DTIC Science & Technology

    2008-10-01

    gene links mitochondria and cell death, the data suggests that Bcl2 may be involved in autophagic cell death and AD-MDR. GeneGo analysis also...parental MCF7 indicates that processes related to nucleotide metabolism, cell biogenesis , cell death, and intracellular organelles are among the most...Testis: Cellular and Molecular Characterization. Reproduction Nutrition and Development, 45: 210-211, 2005 8. Shah CA, Modi D, Sachdeva G, Gadkar

  7. Modulation of multidrug resistance P-glycoprotein activity by antiemetic compounds in human doxorubicin-resistant sarcoma cells (MES-SA/Dx-5): implications on cancer therapy.

    PubMed

    Angelini, A; Conti, P; Ciofani, G; Cuccurullo, F; Di Ilio, C

    2013-01-01

    Multidrug resistance (MDR) in cancer cells is often caused by the high expression of the plasma membrane drug transporter P-glycoprotein (Pgp) associated with an elevated intracellular glutathione (GSH) content in various human tumors. Several chemosensitizers reverse MDR but have significant toxicities. Antiemetic medications are often used for controlling chemotherapy-induced nausea and vomiting in cancer patient. In this in vitro study we investigated if the effects of two common antiemetic drugs such as dimenhydrinate (dime) and ondansentron (onda) and a natural compound (6)-gingerol (ginger), the active principle of ginger root, interfere on Pgp activity and intracellular GSH content in order to evaluate their potential use as chemosensitizing agents in anticancer chemotherapy. The human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx5) that overexpress Pgp, were treated with each antiemetic alone (1, 10 and 20 microM) or in combination with different doxo concentrations (2, 4, and 8 microM). We measured the intracellular accumulation and cytotoxicity of doxo (MTT assay), the cellular GSH content (GSH assay) and ROS production (DFC-DA assay), in comparison with verapamil (Ver), a specific inhibitor for Pgp, used as reference molecule. We found that exposure at 2, 4 and 8 microM doxo concentrations in the presence of dime, onda and ginger enhanced significantly doxo accumulation and cytotoxicity on resistant MES-SA/Dx5 cells when compared with doxo alone. Moreover, treatment with ginger (20 microM) increased cellular GSH content (greater than 10 percent) in resistant cells, while ROS production remained below the control values for all antiemetic compounds at all concentrations. These findings provide the rationale for innovative clinical trials of antiemetics or their derivatives as a new potential generation of chemosensitizers to improve effectiveness of the anticancer drugs in MDR human tumours.

  8. 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.

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

    PubMed

    Kuete, Victor; Voukeng, Igor K; Tsobou, Roger; Mbaveng, Armelle T; Wiench, Benjamin; Beng, Veronique P; Efferth, Thomas

    2013-10-02

    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. 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. 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. 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.

  10. Knockdown of nucleophosmin by RNA interference reverses multidrug resistance in resistant leukemic HL-60 cells.

    PubMed

    Lin, Minhui; Hu, Jianda; Liu, Tingbo; Li, Jing; Chen, Buyuan; Chen, Xinji

    2013-09-01

    Nucleophosmin, a multifunctional nucleolar phosphoprotein, is involved in many cellular activities. However, the role of NPM in drug-resistance of leukemia has not yet been explored. We designed and selected one shRNA targeting on NPM gene transduction into HL-60 and HL-60/ADR cell lines (an adriamycin resistant cell line) by lentivirus. Cell proliferation, apoptosis and differentiation were assessed. The expressions of the related genes and proteins were detected by real-time quantitative RT-PCR and Western blotting. The results showed obvious down-regulation of NPM mRNA and protein levels after NPM RNAi. NPM-targeted RNAi also resulted in many cellular changes, such as, suppressing cell proliferation and inducing cell differentiation. Down-regulation of NPM gene could arrest the cell cycle progression, an increase in the proportion of G0/G1 phase in knockdown groups. NPM gene silencing could also induce pro-apoptotic genes and proteins expression, and inhibit anti-apoptotic genes/proteins expression. Furthermore, IC50 of two chemotherapeutic agents (adriamycin and ADR; daunorubicin and DNR) to HL-60 and HL-60/ADR cells decreased, especially more remarkable on HL-60/ADR cells. IC50 of ADR on HL-60/ADR cells was reduced from 12.544 ± 0.851 μmol/L (before NPM RNAi) to 6.331 ± 0.522 μmol/L (after NPM RNAi), IC50 of DNR was reduced from 2.152 ± 0.143 μmol/L (before NPM RNAi) to 1.116 ± 0.093 μmol/L (after NPM RNAi). The relative reversal rate of HL-60/ADR cells on ADR was 50.2%, and on DNR was 48.9%. In conclusion, our results demonstrated that shRNA expression vectors could effectively reduce NPM expression and restore the drug sensitivity of resistant leukemic cells to conventional chemotherapeutic agents.

  11. The exposure of cancer cells to hyperthermia, iron oxide nanoparticles, and mitomycin C influences membrane multidrug resistance protein expression levels

    PubMed Central

    Franke, Karolin; Kettering, Melanie; Lange, Kathleen; Kaiser, Werner A; Hilger, Ingrid

    2013-01-01

    Purpose The presence of multidrug resistance-associated protein (MRP) in cancer cells is known to be responsible for many therapeutic failures in current oncological treatments. Here, we show that the combination of different effectors like hyperthermia, iron oxide nanoparticles, and chemotherapeutics influences expression of MRP 1 and 3 in an adenocarcinoma cell line. Methods BT-474 cells were treated with magnetic nanoparticles (MNP; 1.5 to 150 μg Fe/cm2) or mitomycin C (up to 1.5 μg/cm2, 24 hours) in the presence or absence of hyperthermia (43°C, 15 to 120 minutes). Moreover, cells were also sequentially exposed to these effectors (MNP, hyperthermia, and mitomycin C). After cell harvesting, mRNA was extracted and analyzed via reverse transcription polymerase chain reaction. Additionally, membrane protein was isolated and analyzed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Results When cells were exposed to the effectors alone or to combinations thereof, no effects on MRP 1 and 3 mRNA expression were observed. In contrast, membrane protein expression was influenced in a selective manner. The effects on MRP 3 expression were less pronounced compared with MRP 1. Treatment with mitomycin C decreased MRP expression at high concentrations and hyperthermia intensified these effects. In contrast, the presence of MNP only increased MRP 1 and 3 expression, and hyperthermia reversed these effects. When combining hyperthermia, magnetic nanoparticles, and mitomycin C, no further suppression of MRP expression was observed in comparison with the respective dual treatment modalities. Discussion The different MRP 1 and 3 expression levels are not associated with de novo mRNA expression, but rather with an altered translocation of MRP 1 and 3 to the cell membrane as a result of reactive oxygen species production, and with shifting of intracellular MRP storage pools, changes in membrane fluidity, etc, at the protein level. Our

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

    PubMed

    Lo, Yu-Li; Tu, Wei-Chen

    2015-12-05

    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

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

    2016-01-01

    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. 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. 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. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    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.

  15. 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

  16. The role of stereoselectivity of chemosensitizers in the reversal of multidrug resistance of mouse lymphoma cells.

    PubMed

    Szabó, D; Molnár, J

    1998-01-01

    The effect of three different stereoisomer pairs of CNS (central nervous system) active compounds was studied on the activity of human mdr1 p-glycoprotein. The methotrimeprazine, clopenthixol and butaclamol isomers had an antiproliferative effect (ID50) on the mdr1 expressing cells at 0.250 microgram/ml, while the parental cells were less sensitive having ID50 at 0.37-0.69 microgram/ml. Enantiomers of methotrimeprazine and clopenthixol had similar effectivity on the drug efflux of mdr cells. However, (-)butaclamol was found to inhibit mdr efflux-pump activity much more than the CNS active (+) isomer. Based on these results, tricyclic compounds does not seem to have stereoselectivity in methotrimeprazine and clopenthixol on the mdr reversal effect. In general, both active and inactive members of stereoisomers had a similar effect on the drug accumulation of the mdr cells. Therefore, hypothetically the CNS inactive member of stereoisomer pairs can be used as a resistance modifier without any risk in patients suffering from drug resistant cancer.

  17. R-Flurbiprofen Traps Prostaglandins within Cells by Inhibition of Multidrug Resistance-Associated Protein-4

    PubMed Central

    Wobst, Ivonne; Ebert, Lisa; Birod, Kerstin; Wegner, Marthe-Susanna; Hoffmann, Marika; Thomas, Dominique; Angioni, Carlo; Parnham, Michael J.; Steinhilber, Dieter; Tegeder, Irmgard; Geisslinger, Gerd; Grösch, Sabine

    2016-01-01

    R-flurbiprofen is the non-COX-inhibiting enantiomer of flurbiprofen and is not converted to S-flurbiprofen in human cells. Nevertheless, it reduces extracellular prostaglandin E2 (PGE2) in cancer or immune cell cultures and human extracellular fluid. Here, we show that R-flurbiprofen acts through a dual mechanism: (i) it inhibits the translocation of cPLA2α to the plasma membrane and thereby curtails the availability of arachidonic acid and (ii) R-flurbiprofen traps PGE2 inside of the cells by inhibiting multidrug resistance–associated protein 4 (MRP4, ABCC4), which acts as an outward transporter for prostaglandins. Consequently, the effects of R-flurbiprofen were mimicked by RNAi-mediated knockdown of MRP4. Our data show a novel mechanism by which R-flurbiprofen reduces extracellular PGs at physiological concentrations, particularly in cancers with high levels of MRP4, but the mechanism may also contribute to its anti-inflammatory and immune-modulating properties and suggests that it reduces PGs in a site- and context-dependent manner. PMID:28042832

  18. Effect of magnetic nanoparticles of Fe3O4 and wogonin on the reversal of multidrug resistance in K562/A02 cell line

    PubMed Central

    Cheng, Jian; Cheng, Lin; Chen, Baoan; Xia, Guohua; Gao, Chong; Song, Huihui; Bao, Wen; Guo, Qinglong; Zhang, Haiwei; Wang, Xuemei

    2012-01-01

    Background Multidrug resistance is the main obstacle to the efficiency of systemic chemotherapy against hematologic malignancy. This study investigated the reversible effect of the copolymer wogonin and daunorubicin coloaded into Fe3O4 magnetic nanoparticles, and the mechanism potentially involved. Methods The growth inhibition rate of K562/A02 cells was investigated by MTT assay, and apoptosis of cells and the intracellular daunorubicin concentration were detected by flow cytometry. Distribution of nanoparticles taken up by K562/A02 cells was observed under a transmission electron microscope and demonstrated by Prussian blue staining. The transcription level of MDR1 mRNA and expression of P-glycoprotein were determined by reverse transcriptase polymerase chain reaction and Western blotting assay, respectively. Results The reversible effect of daunorubicin-wogonin magnetic nanoparticles was 8.87-fold that of daunorubicin + wogonin and of daunorubicin magnetic nanoparticles. Transmission electron microscopy and Prussian blue staining revealed that the nanoparticles were located in the endosome vesicles of cytoplasm. Also, the apoptosis rate and accumulation of intracellular daunorubicin in the daunorubicin-wogonin magnetic nanoparticle group were significantly higher than that in the daunorubicin, daunorubicin + wogonin, and daunorubicin magnetic nanoparticle groups. Furthermore, transcription of MDR1 mRNA and expression of P-glycoprotein in K562/A02 cells were significantly downregulated in the daunorubicin-wogonin magnetic nanoparticle group compared with the other groups. Conclusion These findings suggest that the remarkable effects of the novel daunorubicin-wogonin magnetic nanoparticle formulation on multidrug resistant K562/A02 leukemia cells would be a promising strategy for overcoming multidrug resistance. PMID:22745547

  19. [Inhibitory effect of human mitochondria-targeted MPG recombinant on proliferation of human non-small cell lung cancer multidrug-resistant cell line A549/DDP].

    PubMed

    Yu, Shi-Cang; Qian, Gui-Sheng; Li, Yu-Ying; Lu, Wei-Zhong; Li, Jin; Huang, Gui-Jun

    2006-04-01

    Multidrug resistance is the key obstacle to the improvement of chemotherapy effect of lung cancer. This study was to construct eukaryotic expression vector of human mitochondria-targeted N-methylpurine DNA glycosylase (MPG), and explore its inhibitory effect on proliferation of human non-small cell lung cancer multidrug-resistant cell line A549/DDP. Manganese-superoxide dismutase mitochondria-targeted sequence-MPG fusion gene (mito-MPG) was constructed through splicing by overlap extension (SOE). Recombinant eukaryotic expression vector pCMV-Script/mito-MPG was constructed by molecule-cloning technique, and then transfected into A549/DDP cells. In the stably transfected cells which were screened out by G418, the expression of mito-MPG mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR); its expression in separated and purified mitochondria was detected by Western blot. The proliferation of A549/DDP cells was detected by trypan blue exclusion trial. Cell cycle distribution was analyzed by flow cytometry. The mito-MPG fusion gene was confirmed by DNA sequencing,the recombinant pCMV-Script/mito-MPG was confirmed by restrictive endonuclease digestion and DNA sequencing. mito-MPG mRNA and protein were detected in the cells transfected with pCMV-Script/mito-MPG (MPG group), but not in the cells transfected with pCMV-Script (P group) and untransfected cells (C group). The cell double time were 72.6 h in C group, 73.5 h in P group, and 98.9 h in MPG group. Cell cycle blockage and subdiploid peak were found in MPG group. The proliferation indexes were 51.3% in C group, 54.3% in P group, and 26.1% in MPG group. pCMV-Script/mito-MPG could be constructed and transfected into mitochondria of A549/DDP cells successfully, and inhibit proliferation and induce apoptosis of A549/DDP cells.

  20. Human sarcoma cell lines MES-SA and MES-SA/Dx5 as a model for multidrug resistance modulators screening.

    PubMed

    Wesolowska, Olga; Paprocka, Maria; Kozlak, Joanna; Motohashi, Noboru; Dus, Danuta; Michalak, Krystyna

    2005-01-01

    The choice of cell lines for multidrug resistance (MDR) modulators screening may affect the results obtained. Screening is most often performed in model systems which employ cell lines derived from haematological malignancies. Cell lines originating from solid tumours are far less popular. In the present work, we aimed to test the usefulness of the drug-sensitive human sarcoma cell line MES-SA, and its multidrug-resistant counterpart MES-SA/Dx5, as a model system for modulators' anti-MDR potency evaluation. Overexpression of P-glycoprotein in the resistant but not in the sensitive cell line was confirmed by flow cytometry and confocal microscopy. Flow cytometry demonstrated that verapamil and trifluoperazine reduced MDR in MES-SA/Dx5 cells as assessed by the rhodamine 123 accumulation test. Both modulators also restored in MES-SA/Dx5 cells the drug accumulation pattern typical for sensitive cells, as judged by confocal microscopy. We conclude that the MES-SA and MES-SA/Dx5 cell line pair constitute a good model for MDR modulators study.

  1. 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.

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

    PubMed Central

    Wang, Jun; Ma, Yan; Li, Wen-Xue; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-01-01

    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

  3. 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

  4. Quinoline derivative KB3-1 potentiates paclitaxel induced cytotoxicity and cycle arrest via multidrug resistance reversal in MES-SA/DX5 cancer cells.

    PubMed

    Koo, Jin-Suk; Choi, Won-Cheol; Rhee, Yun-Hee; Lee, Hyo-Jeong; Lee, Eun-Ok; Ahn, Kwang Seok; Bae, Hyun-Soo; Ahn, Kyoo-Seok; Kang, Jong-Min; Choi, Sang-Un; Kim, Myung Ok; Lu, Junxuan; Kim, Sung-Hoon

    2008-11-21

    The resistance to chemotherapeutic drugs is a major problem for successful cancer treatment. Multidrug resistance (MDR) phenotype is characterized by over-expression of P-glycoprotein (P-gp) on the cancer cell plasma membrane that extrudes drugs out of the cells. Therefore, novel MDR reversal agents are desirable for combination therapy to reduce MDR and enhance anti-tumor activity. Thus, the present study was aimed to evaluate the potent efficacy of novel quinoline derivative KB3-1 as a potent MDR-reversing agent for combined therapy with TAX. MDR reversing effect and TAX combined therapy were examined by Rhodamine accumulation and efflux assay and Confocal immunofluorescence microscopy, Western blotting, TUNEL assay, and cell cycle analysis. The discovery of quinoline-3-carboxylic acid [4-(2-[benzyl-3[-(3,4-dimethoxy-phenyl)-propionyl]-amino]-ethyl)-phenyl]-amide (KB3-1) as a novel MDR-reversal agent. KB3-1 significantly enhanced the accumulation and retention of a P-gp substrate, rhodamine-123 in the P-gp-expressing MES-SA/DX5 uterine sarcoma cells but not in the P-gp-negative MES-SA cells at non-toxic concentrations of 1 microM and 3 microM. Similarly, fluorescence microscopy observation revealed that KB3-1 reduced the effluxed rhodamine-123 expression on the membrane of MES-SA/DX5 cells. Consistent with decreased P-gp pumping activity, confocal microscopic observation revealed that KB3-1 effectively diminished the expression of P-gp in paclitaxel (TAX)-treated MES-SA/DX-5 cells. Furthermore, Western blotting confirmed that KB3-1 reduced P-gp expression and enhanced cytochrome C release and Bax expression in TAX treated MES-SA/DX-5 cells. In addition, KB3-1 enhanced TAX-induced apoptotic bodies in MES-SA/DX5 cells by TdT-mediated-dUTP nick-end labeling (TUNEL) staining assay aswell as potentiated TAX- induced cytotoxicity, G2/M phase arrest and sub-G1 apoptosis in MES-SA/DX5 cells but not in MES-SA cells. Interestingly, KB3-1 at 3 microM had comparable MDR

  5. Identification of two distinct intracellular sites that contribute to the modulation of multidrug resistance in P388/ADR cells expressing P-glycoprotein.

    PubMed

    Mayer, Lawrence D; Lim, Kye-Taek; Hartley, Daria

    2002-01-01

    Although the ability of chemosensitizers to modulate P-glycoprotein (PGP)-based multidrug resistance (MDR) has been extensively studied, relatively little is known about the cellular pharmacology of the PGP inhibitors themselves in MDR cells. The studies described here have correlated the in vitro accumulation and retention properties of verapamil (VRP) in murine P388 (sensitive) and P388/ADR (MDR) cells with doxorubicin (DOX) uptake and cytotoxicity modulation characteristics in order to better understand VRP-tumor cell interactions that give rise to MDR modulation. VRP is rapidly taken up by DOX-sensitive and -resistant P388 cells where greater than 50% maximal VRP uptake occurs within 10 min of initial exposure at 37 degrees C. Whereas chemosensitization and DOX uptake in P388/ADR cells increase with increasing VRP concentration until a plateau is achieved at approximately 5 microM VRP, cellular modulator levels increase proportionally with increasing VPR concentrations beyond 20 microM. Subsequent to removal of noncell-associated modulator, VRP levels in both sensitive and resistant cells rapidly fall below 10% of those obtained at uptake equilibrium. However, a residual amount of VRP remains associated with the cells for extended time periods after the cells are washed. Pulse exposures of P388/ADR cells to high concentrations of VRP (50-100 microM) are capable of providing extended cell-associated VRP levels comparable to those obtained with continuous exposure at biologically active VRP concentrations (1-3 microM) and this leads to chemosensitization. These results are consistent with the existence of high- and low-affinity intracellular VRP pools in P388 MDR cells, both of which can contribute to the reversal of drug resistance. It is suggested that these properties should be taken into consideration during the design and evaluation of preclinical in vivo MDR models where pulsed exposure to high concentrations of resistance modulators often occurs. Special

  6. Suppression of BCRP expression and restoration of sensitivity to chemotherapy in multidrug-resistant HCC cell line HEPG2/ADM by RNA interference.

    PubMed

    Li, Hongyang; Zhou, Shiji; Li, Tao; Liu, Zuojin; Wu, Jinfeng; Zeng, Guili; Liu, Changan; Gong, Jianping

    2012-10-01

    Breast cancer resistance protein (BCRP) is an ATP-binding cassette multidrug transporter that confers resistance to various anticancer drugs like Adriamycin. Overexpression of BCRP confers multidrug resistance (MDR) in hepatocellular carcinoma cells and is a frequent impediment to successful chemotherapy. We evaluated a new approach using RNA interference for the specific knockdown of BCRP in hepatocellular carcinoma cells. To overcome the BCRP-mediated atypical multidrug drug resistance, one small interfering RNA construct (RNAi) targeting one special region of BCRP gene were designed to inhibit the atypical MDR expression by transfecting them into HepG2/ADM cell lines. We found that the overexpression of BCRP gene was suppressed efficiently by the introduction of small interfering RNA, which caused sequence specific gene silence. The level of BCRP mRNA reduced to 22.55% after transfected by pSUPER-BCRPs compared with those of the controls. Similarly, the level of BCRP decreased too. Furthermore, the sensitivity to Adriamycin of pSUPER-BCRPs-treated HEPG2/ADM cells is increased 3.55-fold compared to their control (p<0.05). The relative reverse rate of HepG2/ADM cell to Adriamycin is 72.2%. These data indicated that pSUPER-BCRPs could modulate MDR and may present a new approach to overcome BCRP-mediated drug resistance in HEPG2/ADM cells. It may reverse multidrug resistance phenotype and therefore provide promising therapeutic modalities in the treatment of hepatocellular carcinoma.

  7. Reversal of doxorubicin, etoposide, vinblastine, and taxol resistance in multidrug resistant human sarcoma cells by a polymer of spermine.

    PubMed

    Gosland, M P; Gillespie, M N; Tsuboi, C P; Tofiq, S; Olson, J W; Crooks, P A; Aziz, S M

    1996-01-01

    We have previously described the synthesis of a cytotoxic polymeric conjugate of spermine (Poly-SPM) which is able to inhibit the transport of polyamines (spermine, spermidine, and putrescine) into normal and malignant cells. Recent studies examining the toxicity of Poly-SPM in parental and multidrug resistant (MDR) cancer cells have revealed a cross-resistance in the MDR variant Dx5 to the toxic effects of the conjugate in the MDR-positive cells. There were also differences in spermine and putrescine uptake rates between parental and MDR-positive with the MDR-positive cells having a lower Vmax and a higher Km. The ability of this Poly-SPM to reverse MDR was examined in MDR variants (Dx5 cells) of the human sarcoma cell line MES-SA. The cells express high levels of the mdr1 gene product, P-glycoprotein, and are 25-to 60-fold resistant to doxorubicin (DOX), etoposide (VP-16), vinblastine (VBL), and taxol (TAX). Cytotoxicity was measured by the MTT [3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Poly-SPM (50 microM) lowered the drug concentration IC50 values in the Dx5 cells by 37-fold with VBL, 42-fold with DOX, 29-fold with VP-16, and 25-fold with TAX when compared to the control IC50 values without Poly-SPM. This reversal of resistance was concentration dependent, decreasing 17-fold with DOX, 6.1-fold with VBL, 19-fold with VP-16, and 5-fold with TAX when 25 microM Poly-SPM was used. No modulation was observed in the parental cell line MES-SA, which does not express the mdr1 gene. Poly-SPM had no influence on the IC50 of non-MDR chemotherapeutic agents such as cisplatin. The modulation studies correlated with the ability of Poly-SPM to reverse the cellular accumulation defect of [3H]-VBL and [3H]-TAX in the Dx5 but not MES-SA cells. Pretreatment of the Dx5 cell with alpha-difluoromethylornithine (DFMO at 2 and 5 microM) for 24 h increased the function of the MDR transporter to further decrease the cellular accumulation of VBL and TAX when

  8. Nitric oxide storage and transport in cells are mediated by glutathione S-transferase P1-1 and multidrug resistance protein 1 via dinitrosyl iron complexes.

    PubMed

    Lok, Hiu Chuen; Suryo Rahmanto, Yohan; Hawkins, Clare L; Kalinowski, Danuta S; Morrow, Charles S; Townsend, Alan J; Ponka, Prem; Richardson, Des R

    2012-01-02

    Nitrogen monoxide (NO) plays a role in the cytotoxic mechanisms of activated macrophages against tumor cells by inducing iron release. We showed that NO-mediated iron efflux from cells required glutathione (GSH) (Watts, R. N., and Richardson, D. R. (2001) J. Biol. Chem. 276, 4724-4732) and that the GSH-conjugate transporter, multidrug resistance-associated protein 1 (MRP1), mediates this release potentially as a dinitrosyl-dithiol iron complex (DNIC; Watts, R. N., Hawkins, C., Ponka, P., and Richardson, D. R. (2006) Proc. Natl. Acad. Sci. U.S.A. 103, 7670-7675). Recently, glutathione S-transferase P1-1 (GST P1-1) was shown to bind DNICs as dinitrosyl-diglutathionyl iron complexes. Considering this and that GSTs and MRP1 form an integrated detoxification unit with chemotherapeutics, we assessed whether these proteins coordinately regulate storage and transport of DNICs as long lived NO intermediates. Cells transfected with GSTP1 (but not GSTA1 or GSTM1) significantly decreased NO-mediated 59Fe release from cells. This NO-mediated 59Fe efflux and the effect of GST P1-1 on preventing this were observed with NO-generating agents and also in cells transfected with inducible nitric oxide synthase. Notably, 59Fe accumulated in cells within GST P1-1-containing fractions, indicating an alteration in intracellular 59Fe distribution. Furthermore, electron paramagnetic resonance studies showed that MCF7-VP cells transfected with GSTP1 contain significantly greater levels of a unique DNIC signal. These investigations indicate that GST P1-1 acts to sequester NO as DNICs, reducing their transport out of the cell by MRP1. Cell proliferation studies demonstrated the importance of the combined effect of GST P1-1 and MRP1 in protecting cells from the cytotoxic effects of NO. Thus, the DNIC storage function of GST P1-1 and ability of MRP1 to efflux DNICs are vital in protection against NO cytotoxicity.

  9. [Perspectives of inhibition of multidrug resistance during cancer chemotherapy, in vitro and in vivo experiments].

    PubMed

    Engi, Helga

    2009-03-29

    The development of pharmacological agents able to counteract the mechanisms of multidrug resistance in oncology has remained a major goal for the past ten years. Our purpose was to find multidrug resistance reversal agents less toxic than verapamil among various synthetic compounds: cinnamylidene ketones; 1,4-dihydropyridines; phenothiazines; heat shock 90 inhibitor peptides; betti base derivative of tylosin and among some naturally occurring plant derived jatrophane and lathyrane-type diterpenes. The first part of this thesis presents the inhibition of multidrug resistance through inhibition of the P-glycoprotein efflux pump in various cell lines. In general, the newly identified multidrug resistance modifiers were able to enhance the antiproliferative activity of selected anticancer drugs in a synergistic or additive way in in vitro experiments. The in vitro activity of betti base derivative of tylosin was confirmed by further in vivo efficacy studies in DBA/2 mice. As an alternative way of antitumor effect, apoptosis inductions of resistance modifiers were studied. The substituted dihydropyridine 13 was the most promising apoptosis inducer on mouse lymphoma cells. Human cytomegalovirus was used in a modified in vitro model for characterizing lathyrane compounds with antipromotion effect on human lung cancer cells. All the six macrocyclic lathyrane-type diterpenoids reduced the promotion in vitro , except latilagascene D, decreased IE-antigen expression of cytomegalovirus to prevent progression of tumor malignancy.

  10. [The relationship between multi-drug resistance and proportion of leukemia stem cells and expression of drug transporters in drug-resistant leukemia K562/ADM cells].

    PubMed

    Yi, Juan; Chen, Jing; Sun, Jing; Wei, Hu-Lai

    2009-07-07

    To investigate the drug resistance, proportion of leukemia stem cells (LSC) and expression of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) in drug-sensitive and multidrug-resistant leukemia cell population. The multidrug-resistant leukemia K562/ADM cell and its parental K562 cell were used as the model cells. The drug sensitivity was tested with a MTT assay. Flow cytometry was employed to detect the immunophenotype of stem cells and the expression of P-gp and BCRP. The self-renewal and proliferating potential were examined with methylcellulose colony-forming unit assay. K562/ADM cells were highly resistant to adriamycin, daunorubicin and etoposide. The amount of CD34+, CD123+ and CD34+ CD38- cells in K562/ADM cells was much higher than that in K562 cells, and the proportion of CD34+ CD38- CD123+ cells (LSC) in K562/ADM cells was (5.23 +/- 0.21)% versus (1.27 + 0.17)% in K562 cells, which was 4.12-fold higher than that in K562 cells. Both P-gp and BCRP were overexpressed in K562/ADM cells relative to K562 cells, and the K562/ADM cells coexpressing P-gp and BCRP were 11.25-fold higher over K562 cells. The proportion of CD34+ CD38- CD123+ BCRP+ and CD34+ CD38- P-gp+ BCRP+ cells in K562/ADM cells were (4.13 +/- 0.40)% and (5.80 +/- 1.19)% respectively, which were 3.66- and 11.37-fold higher than the same cells in K562 cells [(1.13 +/- 0.15)% and (0.51 +/- 0.01)%]. Furthermore, drug-resistant K562/ADM cells displayed 4.17-time greater colony-forming ability over the parent K562 cells, corresponding to the proportion of LSCs in K562/ADM cells. The ABC transporters-overexpressing LSC population exists in drug-resistant leukemic K562/ADM cells relative to drug-sensitive K562 cells, and the drug-resistant LSCs may be the source of chemotherapeutic resistance of leukemia.

  11. 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

  12. Multidrug-Resistant TB

    PubMed Central

    Cox, Helen; Coomans, Fons

    2016-01-01

    Abstract The right to enjoy the benefits of scientific progress (REBSP) is a little-known but potentially valuable right that can contribute to rights-based approaches to addressing multidrug-resistant TB (MDR-TB). We argue that better understanding of the REBSP may help to advance legal and civil society action for health rights. While the REBSP does not provide an individual entitlement to have a new drug developed for MDR-TB, it sets up entitlements to expect a state to establish a legislative and policy framework aimed at developing scientific capacity to address the most important health issues and at disseminating the outcomes of scientific research. By making scientific findings available and accessible, people can be enabled to claim the use of science for social benefits. Inasmuch as the market fails to address neglected diseases such as MDR-TB, the REBSP provides a potential counterbalance to frame a positive obligation on states to both marshal their own resources and to coordinate the actions of multiple other actors towards this goal, including non-state actors. While the latter do not hold the same level of accountability as states, the REBSP can still enable the recognition of obligations at a level of “soft law” responsibilities. PMID:27780997

  13. S9788 modulation of P-glycoprotein- and Multidrug-related protein-mediated multidrug resistance by Servier 9788 in doxorubicin-resistant MCF7 cells.

    PubMed

    Bichat, F; Solis-Recendez, G; Poullain, M G; Poupon, M F; Khayat, D; Bastian, G

    1998-08-15

    Inherent or acquired resistance to multiple natural drugs, termed multidrug resistance (MDR), represents a major obstacle to chemotherapy. Expression of P-glycoprotein (P-gp) in MCF7mdr and MCF7R resistant cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. MCF7R, but not the MDR1 gene-transfected MCF7mdr cells, expressed multidrug-related protein (MRP) concomitantly. Efficacy of an MDR modulator, designated as Servier 9788 (S9788), was estimated by doxorubicin (Dox) sensitization, Dox incorporation, and functional rhodamine 123 assay on MCF7 cell lines. Results showed that S9788 modulates the P-gp-associated MDR of MCF7mdr cells as well as the Multidrug-related protein-associated MDR of MCF7R cells.

  14. Actin organization associated with the expression of multidrug resistant phenotype in osteosarcoma cells and the effect of actin depolymerization on drug resistance.

    PubMed

    Takeshita, H; Kusuzaki, K; Ashihara, T; Gebhardt, M C; Mankin, H J; Hirasawa, Y

    1998-04-10

    We have previously reported that P-glycoprotein (Pgp)-overexpressing multidrug resistant (MDR) osteosarcoma cells were functionally more differentiated than their parent cells. The present study showed that in the parent cells, the actin filaments were sparsely distributed or were diffusely spread throughout the cytoplasm, whereas the MDR osteosarcoma cells exhibited a remarkable increase in well-organized actin stress fibers. Furthermore, dihydrocytochalasin B, a specific inhibitor of actin polymerization, dramatically disrupted this network of stress fibers, increased the intracellular accumulation of doxorubicin (DOX) and modified the resistance against DOX. These results indicate that the organization of actin filaments associated with cellular differentiation may be involved in the expression of Pgp function in the MDR osteosarcoma cells.

  15. Identification of Important Compounds Isolated from Natural Sources that Have Activity Against Multidrug-resistant Cancer Cell Lines: Effects on Proliferation, Apoptotic Mechanism and the Efflux Pump Responsible for Multi-resistance Phenotype.

    PubMed

    Amaral, Leonard; Spengler, Gabriella; Molnar, Joseph

    2016-11-01

    The focus of this mini-review is to identify non-toxic compounds isolated from natural sources (plants) that exhibit specific activity against efflux pumps of specific multidrug-resistant (MDR) cancer cell lines, inhibit proliferation of the MDR cancer cell lines and inhibit the activity of overexpressed efflux pumps of the MDR cancer cell line.

  16. [Change of oxygen free radical in reversing multidrug-resistance of human leukemic cell line HL-60/ADM by cyclosporin A].

    PubMed

    Xu, Yu-Qiao; Hui, Yan-Ping; Ma, Shi-Rong; Wang, Ying-Mei

    2008-10-01

    This study was aimed to evaluate the reversed effects of cyclosporin A (CsA) on multidrug resistance (MDR) of human leukemic cell line HL-60/ADM, and to investigate the relationship of the oxygen free radical content between HL-60/ADM cells and the reversed HL-60/ADM cells (HL-60/ADM + CsA). The cytotoxicity and the reversed effects of CsA on multidrug resistance of human leukemic cell line HL-60/ADM were studied by MTT, flow cytometry (FCM) and immunohistochemical assay; the oxygen free radical for HL-60/ADM and HL-60/ADM + CsA cell lines were detected by colorimetric method. The results showed that the CsA less than 4 microg/ml had no significant cytotoxicity on HL-60/ADM, while the cytotoxicity was rised with CsA concentration increasing; And CsA (4 microg/ml) combined with ADM (1 microg/ml) could obviously restrain the growth of HL-60/ADM cells (p < 0.001). The P-gp expression of HL-60/ADM decreased obviously after exposure to CsA (4 microg/ml) for 72 hours, at the same cell conditions, MDA concentration of the reversed groups (HL-60/ADM + CsA cells) was higher than that of the control groups (HL-60/ADM cells) (p < 0.05), while the levels of SOD and GSH in the reversed groups were significantly lower than that in control groups (p < 0.001). It is concluded that MDR of HL-60/ADM can be reversed effectively by low dose of CsA, the level of oxygen free radical increases and the activity of antioxidants decreases in the reversed cells. Oxygen free radicals may be involved in this reverse process, which thereby lead to the cell death.

  17. 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

  18. The use of Tris-Lipidation to modify drug cytotoxicity in multidrug resistant cells expressing P-glycoprotein or MRP1

    PubMed Central

    Davey, Ross A; Davey, Mary W; Cullen, Karen V; Wells, Xanthe E; Francis, Craig L; Williams, Hua-Ming; Yang, Qi; Moghaddam, Minoo J; Widmer, Fred; Whittaker, Robert G

    2002-01-01

    Increasing the lipophilicity is a strategy often used to improve a compound's cellular uptake and retention but this may also convert it into a substrate for an ATP-dependent transporter such as P-glycoprotein or the multidrug resistance-associated protein (MRP1), which are involved in cellular efflux of drugs. Tris-Lipidation of compounds is a convenient way of modifying drug lipophilicity and generating an array of derivatives with diverse properties. To determine the effect of Tris-Lipidation on a drug's cytoxicity in multidrug resistant cells, various glycyl-Tris-mono- (GTP1), di- (GTP2) and tri-palmitate (GTP3) derivatives were prepared of the cancer chemotherapeutic drugs chlorambucil and methotrexate, and of the anti-HIV drug AZT. The cytotoxicity of these derivatives and their parent compounds was determined in the CEM/VLB100 cells with increased P-glycoprotein expression, the CEM/E1000 cells that overexpress MRP1 and the parent, drug-sensitive CCRF-CEM cells. Increasing the lipophilicity of AZT increased its cytotoxicity in the sensitive CCRF-CEM parental cell line while decreased cytotoxicity was observed for the methotrexate derivatives. For the chlorambucil derivatives, both increased (GTP1) and decreased (GTP2) cytotoxicity occurred in the CCRF-CEM cells. With the exception of AZT-GTP1, all GTP1 and GTP2 derivatives of chlorambucil, methotrexate and AZT had decreased cytotoxicity in the P-glycoprotein-expressing CEM/VLB100 cells while chlorambucil-GTP1, methotrexate-GTP2 and methotrexate-GTP3 were the only compounds with decreased cytotoxicity in the MRP1-overexpressing CEM/E1000 cells. The number of palmitate residues, the position of derivatisation and the type of linkage all may affect the P-glycoprotein and MRP1 substrate properties. Tris-Lipidation may therefore provide a useful way of manipulating the pharmacokinetic properties of drugs. PMID:12466237

  19. Explaining the high mutation rates of cancer cells to drug and multidrug resistance by chromosome reassortments that are catalyzed by aneuploidy.

    PubMed

    Duesberg, P; Stindl, R; Hehlmann, R

    2000-12-19

    The mutation rates of cancer cells to drug and multidrug resistance are paradoxically high, i.e., 10(-3) to 10(-6), compared with those altering phenotypes of recessive genes in normal diploid cells of about 10(-12). Here the hypothesis was investigated that these mutations are due to chromosome reassortments that are catalyzed by aneuploidy. Aneuploidy, an abnormal number of chromosomes, is the most common genetic abnormality of cancer cells and is known to change phenotypes (e.g., Down's syndrome). Moreover, we have shown recently that aneuploidy autocatalyzes reassortments of up to 2% per chromosome per mitosis because it unbalances spindle proteins, even centrosome numbers, via gene dosage. The hypothesis predicts that a selected phenotype is associated with multiple unselected ones, because chromosome reassortments unbalance simultaneously thousands of regulatory and structural genes. It also predicts variants of a selected phenotype based on variant reassortments. To test our hypothesis we have investigated in parallel the mutation rates of highly aneuploid and of normal diploid Chinese hamster cells to resistance against puromycin, cytosine arabinoside, colcemid, and methotrexate. The mutation rates of aneuploid cells ranged from 10(-4) to 10(-6), but no drug-resistant mutants were obtained from diploid cells in our conditions. Further selection increased drug resistance at similar mutation rates. Mutants selected from cloned cells for resistance against one drug displayed different unselected phenotypes, e.g., polygonal or fusiform cellular morphology, flat or three-dimensional colonies, and resistances against other unrelated drugs. Thus our hypothesis offers a unifying explanation for the high mutation rates of aneuploid cancer cells and for the association of selected with unselected phenotypes, e.g., multidrug resistance. It also predicts drug-specific chromosome combinations that could become a basis for selecting alternative chemotherapy against drug

  20. Cytotoxicity of Endoperoxides from the Caribbean Sponge Plakortis halichondrioides towards Sensitive and Multidrug-Resistant Leukemia Cells: Acids vs. Esters Activity Evaluation.

    PubMed

    Schirmeister, Tanja; Oli, Swarna; Wu, Hongmei; Della Sala, Gerardo; Costantino, Valeria; Seo, Ean-Jeong; Efferth, Thomas

    2017-03-03

    The 6-epimer of the plakortide H acid (1), along with the endoperoxides plakortide E (2), plakortin (3), and dihydroplakortin (4) have been isolated from a sample of the Caribbean sponge Plakortis halichondrioides. To perform a comparative study on the cytotoxicity towards the drug-sensitive leukemia CCRF-CEM cell line and its multi-drug resistant subline CEM/ADR5000, the acid of plakortin, namely plakortic acid (5), as well as the esters plakortide E methyl ester (6) and 6-epi-plakortide H (7) were synthesized by hydrolysis and Steglich esterification, respectively. The data obtained showed that the acids (1, 2, 5) exhibited potent cytotoxicity towards both cell lines, whereas the esters showed no activity (6, 7) or weaker activity (3, 4) compared to their corresponding acids. Plakortic acid (5) was the most promising derivative with half maximal inhibitory concentration (IC50) values of ca. 0.20 µM for both cell lines.

  1. Cytotoxicity of Endoperoxides from the Caribbean Sponge Plakortis halichondrioides towards Sensitive and Multidrug-Resistant Leukemia Cells: Acids vs. Esters Activity Evaluation

    PubMed Central

    Schirmeister, Tanja; Oli, Swarna; Wu, Hongmei; Della Sala, Gerardo; Costantino, Valeria; Seo, Ean-Jeong; Efferth, Thomas

    2017-01-01

    The 6-epimer of the plakortide H acid (1), along with the endoperoxides plakortide E (2), plakortin (3), and dihydroplakortin (4) have been isolated from a sample of the Caribbean sponge Plakortis halichondrioides. To perform a comparative study on the cytotoxicity towards the drug-sensitive leukemia CCRF-CEM cell line and its multi-drug resistant subline CEM/ADR5000, the acid of plakortin, namely plakortic acid (5), as well as the esters plakortide E methyl ester (6) and 6-epi-plakortide H (7) were synthesized by hydrolysis and Steglich esterification, respectively. The data obtained showed that the acids (1, 2, 5) exhibited potent cytotoxicity towards both cell lines, whereas the esters showed no activity (6, 7) or weaker activity (3, 4) compared to their corresponding acids. Plakortic acid (5) was the most promising derivative with half maximal inhibitory concentration (IC50) values of ca. 0.20 µM for both cell lines. PMID:28273803

  2. Cell-specific activity of cis-acting regulatory elements in the promoter of the mouse multidrug resistance gene mdr1.

    PubMed

    Raymond, M; Gros, P

    1990-11-01

    To define cis-acting elements implicated in transcriptional regulation of the mouse multidrug resistance gene mdr1, we have cloned and characterized the 5' end of the gene. Nucleotide sequence analysis identified TATA, GGGCGG, and CCAAT consensus sequence elements at positions -27, -47, and -83, respectively. The transcriptional activities of 5' deletion fragments from the promoter linked to a reporter gene were tested in mouse cell lines of different tissue origins shown to express different levels of endogenous mdr1 RNA. Sequences located between nucleotides -93 and +84 were able to confer basal promoter activity and cell specificity to the reporter gene. The addition to the basal promoter of sequences upstream of position -141 was found to up or down regulate the basal level of expression of the reporter gene in a cell-specific manner.

  3. Cryptotanshinone induces cell cycle arrest and apoptosis of multidrug resistant human chronic myeloid leukemia cells by inhibiting the activity of eukaryotic initiation factor 4E.

    PubMed

    Ge, Yuqing; Cheng, Rubin; Zhou, Yuhong; Shen, Jianping; Peng, Laijun; Xu, Xiaofeng; Dai, Qun; Liu, Pei; Wang, Haibing; Ma, Xiaoqiong; Jia, Jia; Chen, Zhe

    2012-09-01

    Cryptotanshinone (CPT), a diterpene quinone isolated from Salvia miltiorrhiza, is recently reported to have obvious anticancer activities against diverse cancer cells. However, the effect and regulatory mechanism of CPT remain unclear in human chronic myeloid leukemia (CML) cells. In this study, we investigated the antiproliferative activity of CPT on the multidrug resistant CML cells K562/ADM. Our results demonstrated that CPT decreased the cell viability of K562/ADM cells by inducing cell cycle arrest and apoptosis through suppressing the expression of cyclin D1 and Bcl-2. Further studies indicated that CPT mainly functions at post-transcriptional levels, suggesting the involvement of eukaryotic initiation factor 4E (eIF4E). CPT significantly reduced the expression and activity of eIF4E in K562/ADM cells. Overexpression of eIF4E obvious conferred resistance to the CPT antiproliferation and proapoptotic activity as well as the cyclin D1 and Bcl-2 expressions. Knockdown of eIF4E significantly reduced the inhibitory effect of CPT in K562/ADM, confirming the participation of eIF4E during CPT function process. More importantly, the relative inhibitory efficiency of CPT positively correlated with the reductions on eIF4E in primary CML specimens. These results demonstrated that CPT played antitumor roles in K562/ADM cells by inhibiting the eIF4E regulatory system. Our results provide a novel anticancer mechanism of CPT in human CML cells.

  4. 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

  5. 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.

  6. The short-time treatment with curcumin sufficiently decreases cell viability, induces apoptosis and copper enhances these effects in multidrug-resistant K562/A02 cells.

    PubMed

    Lu, Jin-Jian; Cai, Yu-Jun; Ding, Jian

    2012-01-01

    The anti-cancer activities of curcumin (CUR), a polyphenol derived from the plant Curcuma longa, has been extensively studied. In the present study, we found that CUR displayed anti-multidrug-resistant (MDR) activity in K562/A02 cells. A short-time treatment with CUR sufficiently and equally induced DNA damage, decreased cell viability, and triggered apoptosis in parent K562 and MDR K562/A02 cells. The short-time treatment with CUR also caused decrease of pro-caspase 3 in both cell lines and decrease of pro-caspase 9, increase of PARP cleavage and the ratio of Bax/Bcl-xL in MDR K562/A02 cells. Further experiment revealed that CUR was capable of down-regulating P-glycoprotein in MDR K562/A02 cells. Moreover, we observed that Cu(2+) enhanced CUR-mediated apoptosis which was blocked by antioxidants N-acetyl-cysteine and catalase. In summary, the short-time treatment with CUR sufficiently induced DNA damage, decreased cell viability and triggered apoptosis in MDR K562/A02 cells and Cu(2+) enhanced CUR-mediated apoptosis which due to reactive oxygen species generation.

  7. Purine analogs sensitize the multidrug resistant cell line (NCI-H460/R) to doxorubicin and stimulate the cell growth inhibitory effect of verapamil.

    PubMed

    Pesić, Milica; Podolski, Ana; Rakić, Ljubisa; Ruzdijić, Sabera

    2010-08-01

    The resistant cell line NCI-H460/R and its counterpart NCI-H460 were used to investigate the ability of purine analogs to overcome multidrug resistance (MDR) that seriously limit the efficacy of lung cancer regimens with chemotherapeutic agents. Two purine analogs, sulfinosine (SF) and 8-Cl-cAMP, exerted dose-dependent effects on cell growth in both parental and resistant cell lines. They significantly decreased mdr1 expression in NCI-H460/R cells. Low concentrations (1 microM) of SF and 8-Cl-cAMP in combination with doxorubicin (DOX) exerted synergistic growth inhibition in both cell lines. Pretreatment with SF and 8-Cl-cAMP improved the sensitivity to DOX more than verapamil (VER), the standard modulator of MDR. The increased accumulation of DOX observed after the treatment with SF and 8-Cl-cAMP was consistent with the results obtained with VER. VER stimulated the effect of 8-Cl-cAMP on DOX cytotoxicity and mdr1 expression. Combinations of either SF or 8-Cl-cAMP with VER at clinically acceptable concentrations exhibited synergistic effects on cell growth inhibition in the resistant cell line. SF and 8-Cl-cAMP modulated MDR in NCI-H460/R cells, especially when applied before DOX administration. This feature, together with their ability to reverse MDR, renders the purine analogs (in combination with VER) as potential candidates for improving the clinical activity of existing lung cancer therapeutics.

  8. The role of fnx1, a fission yeast multidrug resistance protein, in the transition of cells to a quiescent G0 state.

    PubMed

    Dimitrov, K; Sazer, S

    1998-09-01

    Most microorganisms live in conditions of nutrient limitation in their natural habitats. When exposed to these conditions they respond with physiological and morphological changes that enable them to survive. To obtain insights into the molecular mechanisms of this response a systematic genetic screen was performed to identify genes that when overexpressed can induce a starvation-like response in the yeast species Schizosaccharomyces pombe. One gene that meets these criteria, fnx1(+), induces, transcriptionally correlates with, and is required for the entry into the quiescent G0 state that is normally induced by nitrogen starvation. fnx1(+) encodes a protein with sequence similarity to the proton-driven plasma membrane transporters from the multidrug resistance group of the major facilitator superfamily of proteins. We propose that fnx1(+) plays a role in the entry into G0, possibly by facilitating the release of a signaling substance into the environment as a means of cell-to-cell communication.

  9. Multidrug Resistance: Physiological Principles and Nanomedical Solutions

    PubMed Central

    Storm, Gert; Kiessling, Fabian; Lammers, Twan

    2014-01-01

    Multidrug (MDR) resistance is a pathophysiological phenomenon employed by cancer cells which limits the prolonged and effective use of chemotherapeutic agents. MDR is primarily based on the over-expression of drug efflux pumps in the cellular membrane. Prominent examples of such efflux pumps, which belong to the ATP-binding cassette (ABC) superfamily of proteins, are Pgp (P-glycoprotein) and MRP (multidrug resistance-associated protein), nowadays officially known as ABCB1 and ABCC1. Over the years, several strategies have been evaluated to overcome MDR, based not only on the use of low-molecular-weight MDR modulators, but also on the implementation of 1-100(0) nm-sized drug delivery systems. In the present manuscript, after introducing the most important physiological principles of MDR, we summarize prototypic nanomedical strategies to overcome multidrug resistance, including the use of carrier materials with intrinsic anti-MDR properties, the use of nanomedicines to modify the mode of cellular uptake, and the co-formulation of chemotherapeutic drugs together with low- and high-molecular-weight MDR inhibitors within a single drug delivery system. While certain challenges still need to be overcome before such constructs and concepts can be widely applied in the clinic, the insights obtained and the progress made strongly suggest that nanomedicine formulations hold significant potential for improving the treatment of multidrug-resistant malignancies. PMID:24120954

  10. Targeting ETS1 with RNAi-based supramolecular nanoassemblies for multidrug-resistant breast cancer therapy.

    PubMed

    Wu, Min; Liu, Xingang; Jin, Weihong; Li, Yongbing; Li, Yang; Hu, Qinglian; Chu, Paul K; Tang, Guping; Ping, Yuan

    2017-05-10

    Overexpression of erythroblastosis virus E26 oncogene homolog 1 (ETS1) gene is correlated with both tumor progression and poor response to chemotherapy in cancer treatment, and the exploitation of RNA interference (RNAi) technology to downregulate ETS1 seems to be a promising approach to reverse multidrug-resistant cancer cells to chemotherapy. Hence, the RNAi-based nanomedicine which is able to simultaneously downregulate ETS1 expression and to deliver chemotherapeutic agents may improve multidrug-resistant cancer therapy synergistically. In this study, we developed a supramolecular nanoassembly that could deliver siRNA targeting ETS1 (siETS1) and doxorubicin (DOX) as an effective nanomedicine to achieve successful chemotherapy towards multidrug-resistant breast cancer. The nanotherapeutic system was prepared by loading adamantane-conjugated doxorubicin (AD) into polyethyleneimine-modified (2-hydroxypropyl)-γ-cyclodextrin (HP) through the supramolecular assembly to form AD-loaded HP (HPAD), followed by electrostatically-driven self-assembly between siETS1 and HPAD. When the HPAD/siETS1 nanoassemblies were delivered into drug-resistant MCF-7/ADR cells, the drug efflux was significantly reduced as a result of simultaneous silencing of ETS1 and MDR1 genes. Importantly, the HPAD/siETS1 nanoassembly could enhance drug residence time at tumor site, and effectively inhibit drug-resistant tumor growth due to the inhibition of angiogenesis and necrosis in tumor tissues. Western blot analysis indicated that the gene expression of both ETS1 and MDR1 in vivo was considerably downregulated after the drug-resistant tumor-bearing mouse was treated with HPAD/siETS1 nanoassemblies. This study offers a new therapeutic delivery strategy targeting ETS1 for the effective multidrug-resistant chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Modulation of P-glycoprotein activity by novel synthetic curcumin derivatives in sensitive and multidrug-resistant T-cell acute lymphoblastic leukemia cell lines.

    PubMed

    Ooko, Edna; Alsalim, Tahseen; Saeed, Bahjat; Saeed, Mohamed E M; Kadioglu, Onat; Abbo, Hanna S; Titinchi, Salam J J; Efferth, Thomas

    2016-08-15

    Multidrug resistance (MDR) and drug transporter P-glycoprotein (P-gp) represent major obstacles in cancer chemotherapy. We investigated 19 synthetic curcumin derivatives in drug-sensitive acute lymphoblastic CCRF-CEM leukemia cells and their multidrug-resistant P-gp-overexpressing subline, CEM/ADR5000. Cytotoxicity was tested by resazurin assays. Doxorubicin uptake was assessed by flow cytometry. Binding modes of compounds to P-gp were analyzed by molecular docking. Chemical features responsible for bioactivity were studied by quantitative structure activity relationship (QSAR) analyses. A 7-descriptor QSAR model was correlated with doxorubicin uptake values, IC50 values and binding energies. The compounds displayed IC50 values between 0.7±0.03 and 20.2±0.25μM. CEM/ADR5000 cells exhibited cross-resistance to 10 compounds, collateral sensitivity to three compounds and regular sensitivity to the remaining six curcumins. Molecular docking studies at the intra-channel transmembrane domain of human P-gp resulted in lowest binding energies ranging from -9.00±0.10 to -6.20±0.02kcal/mol and pKi values from 0.24±0.04 to 29.17±0.88μM. At the ATP-binding site of P-gp, lowest binding energies ranged from -9.78±0.17 to -6.79±0.01kcal/mol and pKi values from 0.07±0.02 to 0.03±0.03μM. CEM/ADR5000 cells accumulated approximately 4-fold less doxorubicin than CCRF-CEM cells. The control P-gp inhibitor, verapamil, partially increased doxorubicin uptake in CEM/ADR5000 cells. Six curcumins increased doxorubicin uptake in resistant cells or even exceeded uptake levels compared to sensitive one. QSAR yielded good activity prediction (R=0.797 and R=0.794 for training and test sets). Selected derivatives may serve to guide future design of novel P-gp inhibitors and collateral sensitive drugs to combat MDR. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. The synthetic ajoene analog SPA3015 induces apoptotic cell death through crosstalk between NF-κB and PPARγ in multidrug-resistant cancer cells.

    PubMed

    Hwang, Jee Won; Cho, Hyewon; Lee, Jae Yeon; Jeon, Youngsic; Kim, Su-Nam; Lee, Sang Jin; Bae, Gyu-Un; Yoon, Sungpil; Jeon, Raok; Kim, Yong Kee

    2016-10-01

    Multidrug resistance (MDR) caused by P-glycoprotein (P-gp) overexpression impedes successful cancer chemotherapy. In this study, we investigated the anticancer effects of SPA3015, a synthetic ajoene analog, in P-gp-overexpressing MDR cancer cells (KBV20C and MES-SA/DX5). Treatment with SPA3015 caused a dramatic decrease in the cell viabilities of both KBV20C and MES-SA/DX5 cells. This decrease was accompanied by apoptotic cell death without affecting the expression level or drug efflux function of P-gp. SPA3015 selectively suppressed NF-κB reporter gene activity, which led to decreased expression of NF-κB target genes such as CIAP1, CIAP2, XIAP, and Bcl-XL. Surprisingly, nuclear localization and DNA binding affinity of the p65 subunit were not affected by SPA3015, suggesting that SPA3015 inhibits the transcriptional activity of NF-κB at the nucleus. Indeed, SPA3015 treatment led to an increase in the physical interaction of p65 with PPARγ, which resulted in the inhibition of NF-κB activity. Our findings support the hypothesis that SPA3015 inhibits NF-κB transcriptional activity by facilitating the physical interaction of the p65 subunit and PPARγ, which leads to apoptotic cell death in MDR cancer cells.

  13. Multi-drug resistance mediated by P-glycoprotein overexpression is not correlated with ZAP-70/CD38 expression in B-cell chronic lymphocytic leukemia.

    PubMed

    Guillaume, Nicolas; Gouilleux-Gruart, Valérie; Claisse, Jean-François; Troussard, Xavier; Lepelley, Pascale; Damaj, Gandhi; Royer, Bruno; Garidi, Reda; Lefrere, Jean-Jacques

    2007-08-01

    ZAP-70 and CD38 expression can identify B-cell chronic lymphocytic leukemia with an inferior clinical outcome. Many groups have investigated the meaning of the expression of these two proteins and the correlation with the bad prognosis in B-CLL. But nobody has investigated the relation between the multidrug resistance mediated by Pgp overexpression (MDR1) and ZAP-70/CD38 coexpression. Forty-one untreated and stage A patients, either ZAP-70(+)CD38(+) or ZAP-70(-)CD38(-), were tested to determine the MDR1 status. MDR1 was observed in 41% of CLL ZAP-70(+)CD38(+) and in 37% of CLL ZAP-70(-)CD38(-). The difference was not significant (p = 0.745). Patients with ZAP-70 and CD38 positive CLL can not be candidates for MDR1 antagonists.

  14. Overexpression of the Gene Encoding the Multidrug Resistance-Associated Protein Results in Increased ATP-Dependent Glutathione S-Conjugate Transport

    NASA Astrophysics Data System (ADS)

    Muller, Michael; Meijer, Coby; Zaman, Guido J. R.; Borst, Piet; Scheper, Rik J.; Mulder, Nanno H.; de Vries, Elisabeth G. E.; Jansen, Peter L. M.

    1994-12-01

    The multidrug resistance-associated protein (MRP) is a 180- to 195-kDa glycoprotein associated with multidrug resistance of human tumor cells. MRP is mainly located in the plasma membrane and it confers resistance by exporting natural product drugs out of the cell. Here we demonstrate that overexpression of the MRP gene in human cancer cells increases the ATP-dependent glutathione S-conjugate carrier activity in plasma membrane vesicles isolated from these cells. The glutathione S-conjugate export carrier is known to mediate excretion of bivalent anionic conjugates from mammalian cells and is thought to play a role in the elimination of conjugated xenobiotics. Our results suggest that MRP can cause multidrug resistance by promoting the export of drug modification products from cells and they shed light on the reported link between drug resistance and cellular glutathione and glutathione S-transferase levels.

  15. Synergistic effects of the purine analog sulfinosine and curcumin on the multidrug resistant human non-small cell lung carcinoma cell line (NCI-H460/R).

    PubMed

    Andjelkovic, Tijana; Pesic, Milica; Bankovic, Jasna; Tanic, Nikola; Markovic, Ivanka D; Ruzdijic, Sabera

    2008-07-01

    Multidrug resistance (MDR) is the main obstacle to a successful chemotherapy of lung cancer. We tested the potential of sulfinosine and curcumin, alone and in combination, for modulating MDR in the human resistant, non-small cell lung carcinoma cell line (NCI-H460/R). First, we determined the mutational status of the p53 gene in NCI-H460/R cells by PCR-SSCP and DNA sequencing and identified mutations which could at least partially contribute to the development of the MDR phenotype. The effects of sulfinosine and curcumin were studied, both separately and in combination, at the level of cytotoxicity, cell cycle distribution and gene expression. Sulfinosine displayed dose-dependent growth inhibition in both resistant and control sensitive cell lines, whereas curcumin considerably inhibited their growth only at relatively high doses. When sulfinosine was combined with a low dose of curcumin the drugs exerted a synergistic cytotoxic effect in NCI-H460/R cells. The expression of MDR-related genes mdr1, gst-pi and topo IIalpha, was altered by sulfinosine and curcumin. The most pronounced effect was observed when the agents were applied together. Sulfinosine and curcumin caused perturbations in cell cycle distribution in the NCI-H460/R cell line. The combination of the two drugs induced a more pronounced cell cycle arrest in S and G(2)/M in NCI-H460/R cells. Our results show that sulfinosine and curcumin overcome MDR in non-small cell lung carcinoma cell line (NSCLC), especially in combination despite the presence of a mutated p53 gene.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Wnt5A regulates ABCB1 expression in multidrug-resistant cancer cells through activation of the non-canonical PKA/β-catenin pathway

    PubMed Central

    Hung, Tsai-Hsien; Hsu, Sheng-Chi; Cheng, Ching-Yi; Choo, Kong-Bung; Tseng, Ching-Ping; Chen, Tse-Ching; Lan, Ying-Wei; Huang, Tsung-Teng; Lai, Hsin-Chih; Chen, Chuan-Mu; Chong, Kowit-Yu

    2014-01-01

    Multidrug resistance in cancer cells arises from altered drug permeability of the cell. We previously reported activation of the Wnt pathway in ABCB1-overexpressed human uterus sarcoma drug-resistant MES-SA/Dx5 cells through active β-catenin and associated transactivation activities, and upregulation of Wnt-targeting genes. In this study, Wnt5A was found to be significantly upregulated in MES-SA/Dx5 and MCF7/ADR2 cells, suggesting an important role for the Wnt5A signaling pathway in cancer drug resistance. Higher cAMP response elements and Tcf/Lef transcription activities were shown in the drug-resistant cancer cells. However, expression of Wnt target genes and CRE activities was downregulated in Wnt5A shRNA stably-transfected MES-SA/Dx5 cells. Cell viability of the drug-resistant cancer cells was also reduced by doxorubicin treatment and Wnt5A shRNA transfection, or by Wnt5A depletion. The in vitro data were supported by immunohistochemical analysis of 24 paired breast cancer biopsies obtained pre- and post-chemotherapeutic treatment. Wnt5A, VEGF and/or ABCB1 were significantly overexpressed after treatment, consistent with clinical chemoresistance. Taken together, the Wnt5A signaling pathway was shown to contribute to regulating the drug-resistance protein ABCB1 and β-catenin-related genes in antagonizing the toxic effects of doxorubicin in the MDR cell lines and in clinical breast cancer samples. PMID:25401518

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

    SciTech Connect

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

    2016-08-05

    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. -- Highlights: •Adenovirus vector infection induced P-gp mRNA expression in three NSCLC cell lines. •Adenovirus vector infection enhanced P-gp-mediated doxorubicin efflux from the cells. •The increase of P-gp was not mediated by nuclear receptors (PXR, CAR) or COX-2.

  3. Reversion of multidrug resistance in the P-glycoprotein-positive human pancreatic cell line (EPP85-181RDB) by introduction of a hammerhead ribozyme.

    PubMed Central

    Holm, P. S.; Scanlon, K. J.; Dietel, M.

    1994-01-01

    A major problem in cytostatic treatment of many tumours is the development of multidrug resistance (MDR4). This is most often accompanied by the overexpression of a membrane transport protein, P-glycoprotein, and its encoding mRNA. In order to reverse the resistant phenotype in cell cultures, we constructed a specific hammerhead ribozyme possessing catalytic activity that cleaves the 3'-end of the GUC sequence in codon 880 of the mdr1 mRNA. We demonstrated that the constructed ribozyme is able to cleave a reduced substrate mdr1 mRNA at the GUC position under physiological conditions in a cell-free system. A DNA sequence encoding the ribozyme gene was then incorporated into a mammalian expression vector (pH beta APr-1 neo) and transfected into the human pancreatic carcinoma cell line EPP85-181RDB, which is resistant to daunorubicin and expresses the MDR phenotype. The expressed ribozyme decreased the level of mdr1 mRNA expression, inhibited the formation of P-glycoprotein and reduced the cell's resistance to daunorubicin dramatically; this means that the resistant cells were 1,600-fold more resistant than the parental cell line (EPP85-181P), whereas those cell clones that showed ribozyme expression were only 5.3-fold more resistant than the parental cell line. Images Figure 1 Figure 3 Figure 2 PMID:7914421

  4. Starvation, detoxification, and multidrug resistance in cancer therapy

    PubMed Central

    Lee, Changhan; Raffaghello, Lizzia; Longo, Valter D.

    2013-01-01

    The selection of chemotherapy drugs is based on the cytotoxicity to specific tumor cell types and the relatively low toxicity to normal cells and tissues. However, the toxicity to normal cells poses a major clinical challenge, particularly when malignant cells have acquired resistance to chemotherapy. This drug resistance of cancer cells results from multiple factors including individual variation, genetic heterogeneity within a tumor, and cellular evolution. Much progress in the understanding of tumor cell resistance has been made in the past 35 years, owing to milestone discoveries such as the identification and characterization of ABC transporters. Nonetheless, the complexity of the genetic and epigenetic rewiring of cancer cells makes drug resistance an equally complex phenomenon that is difficult to overcome. In this review, we discuss how the remarkable changes in the levels of glucose, IGF-I, IGFBP-1 and in other proteins caused by fasting have the potential to improve the efficacy of chemotherapy against tumors by protecting normal cells and tissues and possibly by diminishing multidrug resistance in malignant cells. PMID:22391012

  5. Inhibition of human 67-kDa laminin receptor sensitizes multidrug resistance colon cancer cell line SW480 for apoptosis induction.

    PubMed

    Lu, Chun-Lei; Xu, Jian; Yao, Hao-Jie; Luo, Kun-Lun; Li, Jie-Ming; Wu, Tao; Wu, Guo-Zhong

    2016-01-01

    The adhesion mediated drug resistance in cancer cells resulted from adhesion of the extracellular matrix is a major cause for multidrug resistance (MDR) and leads chemotherapeutic failure for colon cancer. In this study, we explored the role of 67-kDa laminin receptor (67LR) in chemotherapeutic drug resistance in colon cancer cells. SiRNA-mediated knockdown of 67LR decreased the cell adhesion when laminins were applied. Moreover, 67LR knockdown increased the expression of pro-apoptotic gene Bax but inhibited the expression of anti-apoptotic gene Bcl-2. Enhanced apoptosis was observed in 67LR siRNA-transfected SW480 cell when the cell was treated with doxorubicin for apoptosis induction. Furthermore, MTT assay revealed that the IC50 of chemotherapeutic toward SW480 cell adhesion to laminins was reduced after 67LR knockdown, indicating there was a significant increase of drug sensitivity in SW480 cell. In conclusion, our study demonstrated that 67LR plays a considerable role in the development of colon cancer MDR.

  6. Acquisition of multidrug resistance by L1210 leukemia cells decreases their tumorigenicity and enhances their susceptibility to the host immune response.

    PubMed

    Martín-Orozco, Elena; Ferragut, José Antonio; Garcia-Peñarrubia, Pilar; Ferrer-Montiel, Antonio

    2005-04-01

    The use of antineoplastic drugs for cancer treatment is frequently associated with the acquisition of a multidrug-resistant (MDR) phenotype that renders tumoural cells insensitive to antineoplastics. It remains elusive whether the acquisition of the MDR phenotype alters immunological parameters that could influence the cell sensitivity to an eventual host immune response. We report that immunisation of syngeneic mice with gamma-irradiated L1210S (parental line) and L1210R (MDR phenotype) cells results in a significant rejection of subsequently implanted L1210R-based tumours, but not of the L1210S ones. Notably, L1210R tumours display a twofold reduction in vivo proliferative capacity and are less aggressive in terms of mouse survival than their sensitive counterparts. Also, analysis of surface expression of molecules involved in antigen presentation and cytokine activity revealed a slight increase in IFN-gamma receptor expression, a decrease of Fas molecule, and a fourfold up-regulation of MHC class I molecules in L1210R cells. Nonetheless, both cell lines were able to induce a cytotoxic response in syngeneic mice and were equally susceptible to cytotoxicity by splenic cells. Together, these findings indicate that acquisition of drug resistance by L1210 cells is accompanied by pleiotropic changes that result in reduced tumour proliferative capacity and tumorigenicity in syngeneic mice. Hence, immunological studies of MDR tumours may assist in the design of specific therapeutic strategies that complement current chemotherapy treatments.

  7. Pien Tze Huang Overcomes Multidrug Resistance and Epithelial-Mesenchymal Transition in Human Colorectal Carcinoma Cells via Suppression of TGF-β Pathway

    PubMed Central

    Shen, Aling; Chen, Hongwei; Chen, Youqin; Lin, Wei; Liu, Liya; Sferra, Thomas J.; Peng, Jun

    2014-01-01

    The traditional Chinese medicine formula Pien Tze Huang (PZH) has long been used as a folk remedy for cancer. To elucidate the mode of action of PZH against cancer, in the present study we used a 5-FU resistant human colorectal carcinoma cell line (HCT-8/5-FU) to evaluate the effects of PZH on multidrug resistance (MDR) and epithelial-mesenchymal transition (EMT) as well as the activation of TGF-β pathway. We found that PZH dose-dependently inhibited the viability of HCT-8/5-FU cells which were insensitive to treatment of 5-FU and ADM, demonstrating the ability of PZH to overcome chemoresistance. Furthermore, PZH increased the intercellular accumulation of Rhodamine-123 and downregulated the expression of ABCG2 in HCT-8/5-FU cells. In addition, drug resistance induced the process of EMT in HCT-8 cells as evidenced by EMT-related morphological changes and alteration in the expression of EMT-regulatory factors, which however was neutralized by PZH treatment. Moreover, PZH inhibited MDR/EMT-enhanced migration and invasion capabilities of HCT-8 cells in a dose-dependent manner and suppressed MDR-induced activation of TGF-β signaling in HCT-8/5-FU cells. Taken together, our study suggests that PZH can effectively overcome MDR and inhibit EMT in human colorectal carcinoma cells via suppression of the TGF-β pathway. PMID:25505925

  8. Pien Tze Huang Overcomes Multidrug Resistance and Epithelial-Mesenchymal Transition in Human Colorectal Carcinoma Cells via Suppression of TGF-β Pathway.

    PubMed

    Shen, Aling; Chen, Hongwei; Chen, Youqin; Lin, Jiumao; Lin, Wei; Liu, Liya; Sferra, Thomas J; Peng, Jun

    2014-01-01

    The traditional Chinese medicine formula Pien Tze Huang (PZH) has long been used as a folk remedy for cancer. To elucidate the mode of action of PZH against cancer, in the present study we used a 5-FU resistant human colorectal carcinoma cell line (HCT-8/5-FU) to evaluate the effects of PZH on multidrug resistance (MDR) and epithelial-mesenchymal transition (EMT) as well as the activation of TGF-β pathway. We found that PZH dose-dependently inhibited the viability of HCT-8/5-FU cells which were insensitive to treatment of 5-FU and ADM, demonstrating the ability of PZH to overcome chemoresistance. Furthermore, PZH increased the intercellular accumulation of Rhodamine-123 and downregulated the expression of ABCG2 in HCT-8/5-FU cells. In addition, drug resistance induced the process of EMT in HCT-8 cells as evidenced by EMT-related morphological changes and alteration in the expression of EMT-regulatory factors, which however was neutralized by PZH treatment. Moreover, PZH inhibited MDR/EMT-enhanced migration and invasion capabilities of HCT-8 cells in a dose-dependent manner and suppressed MDR-induced activation of TGF-β signaling in HCT-8/5-FU cells. Taken together, our study suggests that PZH can effectively overcome MDR and inhibit EMT in human colorectal carcinoma cells via suppression of the TGF-β pathway.

  9. A combination of curcumin with either gramicidin or ouabain selectively kills cells that express the multidrug resistance-linked ABCG2 transporter.

    PubMed

    Rao, Divya K; Liu, Haiyan; Ambudkar, Suresh V; Mayer, Michael

    2014-11-07

    This paper introduces a strategy to kill selectively multidrug-resistant cells that express the ABCG2 transporter (also called breast cancer resistance protein, or BCRP). The approach is based on specific stimulation of ATP hydrolysis by ABCG2 transporters with subtoxic doses of curcumin combined with stimulation of ATP hydrolysis by Na(+),K(+)-ATPase with subtoxic doses of gramicidin A or ouabain. After 72 h of incubation with the drug combinations, the resulting overconsumption of ATP by both pathways inhibits the efflux activity of ABCG2 transporters, leads to depletion of intracellular ATP levels below the viability threshold, and kills resistant cells selectively over cells that lack ABCG2 transporters. This strategy, which was also tested on a clinically relevant human breast adenocarcinoma cell line (MCF-7/FLV1), exploits the overexpression of ABCG2 transporters and induces caspase-dependent apoptotic cell death selectively in resistant cells. This work thus introduces a novel strategy to exploit collateral sensitivity (CS) with a combination of two clinically used compounds that individually do not exert CS. Collectively, this work expands the current knowledge on ABCG2-mediated CS and provides a potential strategy for discovery of CS drugs against drug-resistant cancer cells. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. BZML, a novel colchicine binding site inhibitor, overcomes multidrug resistance in A549/Taxol cells by inhibiting P-gp function and inducing mitotic catastrophe.

    PubMed

    Bai, Zhaoshi; Gao, Meiqi; Zhang, Huijuan; Guan, Qi; Xu, Jingwen; Li, Yao; Qi, Huan; Li, Zhengqiang; Zuo, Daiying; Zhang, Weige; Wu, Yingliang

    2017-08-28

    Multidrug resistance (MDR) interferes with the efficiency of chemotherapy. Therefore, developing novel anti-cancer agents that can overcome MDR is necessary. Here, we screened a series of colchicine binding site inhibitors (CBSIs) and found that 5-(3, 4, 5-trimethoxybenzoyl)-4-methyl-2-(p-tolyl) imidazol (BZML) displayed potent cytotoxic activity against both A549 and A549/Taxol cells. We further explored the underlying mechanisms and found that BZML caused mitosis phase arrest by inhibiting tubulin polymerization in A549 and A549/Taxol cells. Importantly, BZML was a poor substrate for P-glycoprotein (P-gp) and inhibited P-gp function by decreasing P-gp expression at the protein and mRNA levels. Cell morphology changes and the expression of cycle- or apoptosis-related proteins indicated that BZML mainly drove A549/Taxol cells to die by mitotic catastrophe (MC), a p53-independent apoptotic-like cell death, whereas induced A549 cells to die by apoptosis. Taken together, our data suggest that BZML is a novel colchicine binding site inhibitor and overcomes MDR in A549/Taxol cells by inhibiting P-gp function and inducing MC. Our study also offers a new strategy to solve the problem of apoptosis-resistance. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Salinomycin enhances doxorubicin-induced cytotoxicity in multidrug resistant MCF-7/MDR human breast cancer cells via decreased efflux of doxorubicin.

    PubMed

    Kim, Kwang-Youn; Kim, Sang-Hun; Yu, Sun-Nyoung; Park, Suel-Ki; Choi, Hyeun-Deok; Yu, Hak-Sun; Ji, Jae-Hoon; Seo, Young-Kyo; Ahn, Soon-Cheol

    2015-08-01

    Salinomycin is a monocarboxylic polyether antibiotic, which is widely used as an anticoccidial agent. The anticancer property of salinomycin has been recognized and is based on its ability to induce apoptosis in human multidrug resistance (MDR). The present study investigated whether salinomycin reverses MDR towards chemotherapeutic agents in doxorubicin-resistant MCF-7/MDR human breast cancer cells. The results demonstrated that doxorubicin-mediated cytotoxicity was significantly enhanced by salinomycin in the MCF-7/MDR cells, and this occurred in a dose-dependent manner. This finding was consistent with subsequent observations made under a confocal microscope, in which the doxorubicin fluorescence signals of the salinomycin-treated cells were higher compared with the cells treated with doxorubicin alone. In addition, flow cytometric analysis revealed that salinomycin significantly increased the net cellular uptake and decreased the efflux of doxorubicin. The expression levels of MDR-1 and MRP-1 were not altered at either the mRNA or protein levels in the cells treated with salinomycin. These results indicated that salinomycin was mediated by its ability to increase the uptake and decrease the efflux of doxorubicin in MCF-7/MDR cells. Salinomycin reversed the resistance of doxorubicin, suggesting that chemotherapy in combination with salinomycin may benefit MDR cancer therapy.

  12. N,N-Dimethyl phytosphingosine sensitizes HL-60/MX2, a multidrug-resistant variant of HL-60 cells, to doxorubicin-induced cytotoxicity through ROS-mediated release of cytochrome c and AIF.

    PubMed

    Kim, Byeong Mo; Choi, Yun Jung; Lee, Yong Heon; Joe, Young Ae; Hong, Sung Hee

    2010-08-01

    Doxorubicin (Dox) is widely used to treat a variety of tumors. However, resistance to this drug is common, making successful treatment more difficult. Previously, we introduced a novel phytosphingosine derivative, N,N-dimethyl phytosphingosine (DMPS), as a potent anticancer therapeutic agent in human leukemia cells. This study was performed to investigate whether DMPS can sensitize HL-60/MX2, a multidrug-resistant variant of HL-60, to Dox-induced apoptosis. Low concentrations of DMPS sensitized HL-60/MX2 cells to Dox-induced apoptosis. Combined Dox + DMPS treatment-induced apoptosis was accompanied by the activation of caspase-8 and caspase-3 as well as PARP cleavage. Cytochrome c and AIF release were also observed in Dox + DMPS-treated HL60/MX2 cells. Pretreatment with z-VAD-fmk markedly prevented caspase-3 activation and moderately suppressed apoptosis, suggesting that Dox + DMPS-induced apoptosis is somewhat (not completely) dependent on caspase. Cytochrome c and AIF release were not affected by pretreatment with z-VAD-fmk. The ROS scavenger NAC efficiently suppressed not only ROS generation, but also caspase-3-mediated PARP cleavage, apoptosis, and release of cytochrome c and AIF, indicating a role of ROS in combined Dox + DMPS treatment-induced apoptotic death signaling. Taken together, these observations suggest that DMPS may be used as a therapeutic agent for overcoming drug-resistance in cancer cells by enhancing drug-induced apoptosis.

  13. Apoptotic effect of a novel kefir product, PFT, on multidrug-resistant myeloid leukemia cells via a hole-piercing mechanism

    PubMed Central

    GHONEUM, MAMDOOH; GIMZEWSKI, JAMES

    2014-01-01

    We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics. The aim of this study was to examine the apoptotic effect of PFT on human multidrug-resistant (MDR) myeloid leukemia (HL60/AR) cells in vitro and explore the mechanistic approach underlying its effect. HL60/AR cells were cultured with PFT (0.6–5.0 mg/ml) for 3 days. The apoptotic effect of PFT was assessed through examination of percent apoptosis, caspase 3 activation, Bcl-2 expression levels and changes in mitochondrial membrane potential (MMP). PFT induced apoptosis in HL60/AR cells in a dose-dependent manner which was maximal at 67.5% for 5 mg/ml. Induction of apoptosis was associated with activation of caspase 3, decreased expression of Bcl-2 and decreased polarization of MMP. In addition, PFT showed a unique characteristic of piercing holes in HL60/AR cells, as indicated by AFM studies. This hole induction may be responsible for the apoptotic effect on cancer cells. These results suggest that PFT may act as a potential therapy for the treatment of MDR leukemia. PMID:24430613

  14. Apoptotic effect of a novel kefir product, PFT, on multidrug-resistant myeloid leukemia cells via a hole-piercing mechanism.

    PubMed

    Ghoneum, Mamdooh; Gimzewski, James

    2014-03-01

    We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics. The aim of this study was to examine the apoptotic effect of PFT on human multidrug-resistant (MDR) myeloid leukemia (HL60/AR) cells in vitro and explore the mechanistic approach underlying its effect. HL60/AR cells were cultured with PFT (0.6-5.0 mg/ml) for 3 days. The apoptotic effect of PFT was assessed through examination of percent apoptosis, caspase 3 activation, Bcl-2 expression levels and changes in mitochondrial membrane potential (MMP). PFT induced apoptosis in HL60/AR cells in a dose-dependent manner which was maximal at 67.5% for 5 mg/ml. Induction of apoptosis was associated with activation of caspase 3, decreased expression of Bcl-2 and decreased polarization of MMP. In addition, PFT showed a unique characteristic of piercing holes in HL60/AR cells, as indicated by AFM studies. This hole induction may be responsible for the apoptotic effect on cancer cells. These results suggest that PFT may act as a potential therapy for the treatment of MDR leukemia.

  15. Regulation of Mucin 1 and multidrug resistance protein 1 by honokiol enhances the efficacy of doxorubicin-mediated growth suppression in mammary carcinoma cells.

    PubMed

    Thulasiraman, Padmamalini; Johnson, Andrea Butts

    2016-08-01

    Understanding the link between chemoresistance and cancer progression may identify future targeted therapy for breast cancer. One of the mechanisms by which chemoresistance is attained in cancer cells is mediated through the expression of multidrug resistance proteins (MRPs). Acquiring drug resistance has been correlated to the emergence of metastasis, accounting for the progression of the disease. One of the diagnostic markers of metastatic progression is the overexpression of a transmembrane protein called Mucin 1 (MUC1) which has been implicated in reduced survival rate. The objective of this study was to understand the relationship between MUC1 and MRP1 using natural phenolic compound isolated from Magnolia grandiflora, honokiol, in mammary carcinoma cells. We provide evidence that honokiol suppresses the expression level of MUC1 and MRP1 in mammary carcinoma cells. In a time-dependent manner, honokiol-mediated reduction of MUC1 is followed by a reduction of MRP1 expression in the breast cancer cells. Additionally, silencing MUC1 suppresses the expression level of MRP1 and enhances the efficacy of doxorubicin, an MRP1 substrate. Taken together, these findings suggest MUC1 regulates the expression of MRP1 and provides a direct link between cancer progression and chemoresistance in mammary carcinoma cells.

  16. Reversal of multidrug resistance by surfactants.

    PubMed Central

    Woodcock, D. M.; Linsenmeyer, M. E.; Chojnowski, G.; Kriegler, A. B.; Nink, V.; Webster, L. K.; Sawyer, W. H.

    1992-01-01

    Cremophor EL, a pharmacologically inactive solubilising agent, has been shown to reverse multidrug resistance (MDR). Using flow cytometric evaluation of equilibrium intracellular levels of daunorubicin (DNR), we found that eight other surface active agents will also reverse MDR. All the active detergents contain polyethoxylated moieties but have no similarities in their hydrophobic components. The properties of three polyethoxylated surfactants that showed the lowest toxicities, Cremophor, Tween 80 and Solutol HS15, were examined in more detail. The concentrations of Tween 80 and Solutol required to reverse DNR exclusion were 10-fold lower than for Cremophor. However while concentrations greater than or equal to 1:10(2) of the former two surfactants resulted in breakdown of cells, even 1:10 of Cremophor did not lyse cells. Studies of the effects of Cremophor on the uptake and efflux of DNR in normal and MDR cell types showed that Cremophor increases intracellular DNR primarily by locking the rapid efflux from the cells. This blockage of drug efflux may be mediated by a substantial alteration in the fluidity of cell membranes induced by Cremophor, as shown by decreased fluorescence anisotropy of a membrane probe. Consistent with these data, coinjection of adriamycin plus Cremophor into mice carrying a multidrug resistant P388 transplantable tumour significantly increased the survival time of the mice compared with adriamycin treatment alone. PMID:1637678

  17. Multidrug resistance P-glycoprotein dampens SR-BI cholesteryl ester uptake from high density lipoproteins in human leukemia cells

    PubMed Central

    Spolitu, Stefano; Uda, Sabrina; Deligia, Stefania; Frau, Alessandra; Collu, Maria; Angius, Fabrizio; Batetta, Barbara

    2016-01-01

    Tumor cells are characterised by a high content of cholesterol esters (CEs), while tumor-bearing patients show low levels of high-density lipoproteins (HDLs). The origin and significance of high CE levels in cancer cell biology has not been completely clarified. Recent evidence that lymphoblastic cells selectively acquire exogenous CE from HDL via the scavenger receptor SR-BI has drawn attention to the additional membrane proteins involved in this pathway. P-glycopotein-MDR1 (P-gp) is a product of the MDR1 gene and confers resistance to antitumor drugs. Its possible role in plasma membrane cholesterol trafficking and CE metabolism has been suggested. In the present study this aspect was investigated in a lymphoblastic cell line selected for MDR1 resistance. CEM were made resistant by stepwise exposure to low (LR) and high (HR) doses of vincristine (VCR). P-gp activity (3H-vinblastine), CE content, CE and triglycerides (TG) synthesis (14C-oleate), neutral lipids and Dil-HDL uptake (fluorescence), SR-BI, ABCA1 and P-gp protein expression (western blotting) were determined. To better evaluate the relationship between CE metabolism and P-gp activity, the ACAT inhibitor Sandoz-58035 and the P-gp inhibitors progesterone, cyclosporine and verapamil were used. CE content and synthesis were similar in the parental and resistant cells. However, in the latter population, SR-BI protein expression increased, whereas CE-HDL uptake decreased. These changes correlated with the degree of VCR-resistance. As well as reverting MDR1-resistance, the inhibitors of P-gp activity induced the CE-HDL/SR-BI pathway by reactivating membrane cholesterol trafficking. Indeed, CE-HDL uptake, SRBI expression and CE content increased, whereas there was a decrease in cholesterol esterification. These results demonstrated that P-gp overexpression impairs anticancer drug uptake as well as the SR-BI mediated selective CE-HDL uptake. This suggests that these membrane proteins act in an opposite manner on

  18. Cross-talk between EPAS-1/HIF-2α and PXR signaling pathway regulates multi-drug resistance of stomach cancer cell.

    PubMed

    Zhao, Jiuda; Bai, Zhenzhong; Feng, Fan; Song, Erlin; Du, Feng; Zhao, Junhui; Shen, Guoshuang; Ji, Faxiang; Li, Guoyuan; Ma, Xinfu; Hang, Xingyi; Xu, Binghe

    2016-03-01

    EPAS-1/HIF-2α (Endothelial PAS domain-containing protein 1/hypoxia-inducible transcription factors 2α) is a transcription factor expressed in a wide range of human cancers, including stomach cancer. Although EPAS-1 has been studied for years, its function in oncogenic transformation processes needs to be further investigated. In this study, we found that EPAS-1 would promote the growth of stomach cancer cell line BGC-823. Our results revealed that EPAS-1 interacts with Pregnane X Receptor (PXR), a nuclear receptor that regulates multiple genes' transcription involved in multi-drugs resistance (MDR) process. Protein-protein interaction between EPAS-1 and PXR was identified by co-immunoprecipitation and GST-pull down assays. By this interaction, EPAS-1 recruited PXR to its response elements in promoter/enhancer regions of CYP3A4, a PXR target gene. Over-expression of EPAS-1 increased the expression of PXR responsive genes, enhanced the proliferation of BGC-823 cells and boosted the resistance of BGC-823 cells against the cytotoxicity of chemotherapeutic drugs, e.g. Mitomycin C and Paclitaxel. Reduction of EPAS-1 level via its siRNA disrupted the proliferation, and enhanced the susceptibility of BGC-823 cells to those chemotherapeutic drugs. Our findings suggested that EPAS-1 and PXR may cooperatively participate in development and especially MDR process of stomach cancer. These findings may contribute to more effective targeted drugs discovery for the stomach cancer therapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Modulation of multidrug resistance p-glycoprotein activity by flavonoids and honokiol in human doxorubicin- resistant sarcoma cells (MES-SA/DX-5): implications for natural sedatives as chemosensitizing agents in cancer therapy.

    PubMed

    Angelini, Aantonio; Di Ilio, C; Castellani, M L; Conti, P; Cuccurullo, F

    2010-01-01

    Multidrug resistance (MDR) in cancer cells is often caused by the high expression of the plasma membrane drug transporter P-glycoprotein (Pgp) associated with an elevated intracellular glutathione (GSH) content in various human tumors. Several chemosensitizers reverse MDR but have significant toxicities. Sedatives are often used to control anxiety and depression in cancer patients. In this in vitro study we investigated the effects of three plant derived sedatives such as apigenin (Api), fisetin (Fis), flavonoids and honokiol (Hnk) on Pgp activity and cellular GSH content in order to evaluate their potential use as chemosensitizing agents in anticancer chemotherapy. Human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx5) that overexpress Pgp, were treated with each sedative alone (10 microM) or in combination with different doxo concentrations (2-8 microM). We measured the intracellular accumulation and cytotoxicity of doxo (MTT assay), the cellular GSH content (GSH assay) and ROS production (DFC-DA assay), in comparison with verapamil (Ver), a specific inhibitor for Pgp, used as reference molecule. We found that exposure at 2 and 8 microM doxo concentrations in the presence of Api, Fis and Hnk enhanced significantly doxo accumulation by 29+/-3.3, 20+/-4.8, 24+/-6.6 percent and 14+/-1.7, 8.3+/-4.2, 10.7+/-3.1 percent, respectively, when compared with doxo alone. These results were consistent with the increase of sensitivity towards doxo in MES-SA/Dx5, resulting in 1.7, 1.2, 1.4-fold and 1.2, 1.0 and 1.1-fold increases, respectively. Moreover, treatment with Api decreased markedly cellular GSH content (18 percent) and increased ROS production (greater than 20 percent) on MES-SA/Dx5 cells, while a significant reduction in ROS levels was observed in Hnk and Fis treated cells, when compared to untreated control. Our in vitro findings provide a rationale for innovative clinical trials to assess the use of natural sedatives or their derivatives as potential

  20. HOXB4 knockdown reverses multidrug resistance of human myelogenous leukemia K562/ADM cells by downregulating P-gp, MRP1 and BCRP expression via PI3K/Akt signaling pathway.

    PubMed

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

    2016-12-01

    Multidrug resistance (MDR) plays a pivotal role in human chronic myelogenous leukemia (CML) chemotherapy failure. MDR is mainly associated with the overexpression of drug efflux transporters of the ATP-binding cassette (ABC) proteins. Phosphoinositide 3-kinase (PI3K)/Akt signaling cascade is involved in the MDR phenotype and is correlated with multidrug resistance 1 (MDR1)/P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP) expression in many human malignancies. Homeobox (HOX) B4, a member of the HOX gene family, has been reported to be correlated with occurrence, development, poor prognosis and drug resistance of human leukemia. In the present study, HOXB4 expression was analyzed in K562 cell line and its MDR subline K562/ADM. Compared with K562 cells, drug-resistant K562/ADM cells demonstrated evidently higher HOXB4 expression. In addition, we firstly investigated the reversal effect of HOXB4 deletion on K562/ADM cells and the underlying mechanism. The Cell Counting kit-8 (CCK-8) and flow cytometry assays showed that knockdown of HOXB4 enhanced chemosensitivity and decreased drug efflux in K562/ADM cells. Moreover, HOXB4 knockout led to downregulation of P-gp, MRP1 and BCRP expression and PI3K/Akt signaling activity, suggesting that repression of HOXB4 might be a key point to reverse MDR of K562/ADM cells.

  1. Mycobacterium tuberculosis Multidrug-Resistant Strain M Induces Low IL-8 and Inhibits TNF-α Secretion by Bronchial Epithelial Cells Altering Neutrophil Effector Functions

    PubMed Central

    Kviatcovsky, Denise; Rivadeneyra, Leonardo; Yokobori, Noemí; López, Beatriz; Schattner, Mirta

    2017-01-01

    M strain, the most prevalent multidrug-resistant strain of Mycobacterium tuberculosis (Mtb) in Argentina, has mounted mechanisms to evade innate immune response. The role of human bronchial epithelium in Mtb infection remains unknown as well as its crosstalk with neutrophils (PMN). In this work, we evaluate whether M and H37Rv strains invade and replicate within bronchial epithelial cell line Calu-6 and how conditioned media (CM) derived from infected cells alter PMN responses. We demonstrated that M infects and survives within Calu-6 without promoting death. CM from M-infected Calu-6 (M-CM) did not attract PMN in correlation with its low IL-8 content compared to H37Rv-CM. Also, PMN activation and ROS production in response to irradiated H37Rv were impaired after treatment with M-CM due to the lack of TNF-α. Interestingly, M-CM increased H37Rv replication in PMN which would allow the spreading of mycobacteria upon PMN death and sustain IL-8 release. Thus, our results indicate that even at low invasion/replication rate within Calu-6, M induces the secretion of factors altering the crosstalk between these nonphagocytic cells and PMN, representing an evasion mechanism developed by M strain to persist in the host. These data provide new insights on the role of bronchial epithelium upon M infection. PMID:28852268

  2. Modulation of multidrug resistance gene expression in peripheral blood mononuclear cells of lung cancer patients and evaluation of their clinical significance.

    PubMed

    Melguizo, Consolación; Prados, Jose; Luque, Raquel; Ortiz, Raúl; Rama, Ana R; Caba, Octavio; Rodríguez-Serrano, Fernando; Álvarez, Pablo J; Aránega, Antonia

    2013-02-01

    Multidrug resistance is one of the major obstacles to the successful treatment of non-small cell lung cancer (NSCLC). An ability to identify molecular markers of drug resistance in peripheral blood cells in order to better target treatment would therefore be extremely useful in selecting therapy protocols for patients. The aim of the present study was to evaluate whether expression of resistance genes (MDR1, MRP3 and LRP) can predict clinical outcome in NSCLC patients treated with paclitaxel and carboplatin. Peripheral blood samples were obtained from lung cancer patients before and after chemotherapy and expression of the resistance gene in polymononuclear cells was detected by real-time reverse-transcription polymerase chain reaction. The results were correlated with treatment response and overall survival, which was calculated according to the Kaplan-Meier method. MDR1 expression levels in PMNs rose rapidly within 24 h post-administration of paclitaxel and carboplatin, whereas MRP and LRP expression levels remained unchanged. However, no significant correlation was observed between MDR1 expression and the patients' survival or treatment response. Modulation of MDR1 gene expression in PMNs after lung cancer treatment with paclitaxel and carboplatin cannot be used as a prognosis marker in these patients.

  3. Targeting Multidrug-resistant Staphylococci with an anti-rpoA Peptide Nucleic Acid Conjugated to the HIV-1 TAT Cell Penetrating Peptide

    PubMed Central

    Abushahba, Mostafa FN; Mohammad, Haroon; Seleem, Mohamed N

    2016-01-01

    Staphylococcus aureus infections present a serious challenge to healthcare practitioners due to the emergence of resistance to numerous conventional antibiotics. Due to their unique mode of action, peptide nucleic acids are novel alternatives to traditional antibiotics to tackle the issue of bacterial multidrug resistance. In this study, we designed a peptide nucleic acid covalently conjugated to the HIV-TAT cell penetrating peptide (GRKKKRRQRRRYK) in order to target the RNA polymerase α subunit gene (rpoA) required for bacterial genes transcription. We explored the antimicrobial activity of the anti-rpoA construct (peptide nucleic acid-TAT) against methicillin-resistant S. aureus, vancomycin-intermediate S. aureus, vancomycin-resistant S. aureus, linezolid-resistant S. aureus, and methicillin-resistant S. epidermidis in pure culture, infected mammalian cell culture, and in an in vivo Caenorhabditis elegans infection model. The anti-rpoA construct led to a concentration-dependent inhibition of bacterial growth (at micromolar concentrations) in vitro and in both infected cell culture and in vivo in C. elegans. Moreover, rpoA gene silencing resulted in suppression of its message as well as reduced expression of two important methicillin-resistant S. aureus USA300 toxins (α-hemolysin and Panton-Valentine leukocidin). This study confirms that rpoA gene is a potential target for development of novel antisense therapeutics to treat infections caused by methicillin-resistant S. aureus. PMID:27434684

  4. Control of P-glycoprotein activity by membrane cholesterol amounts and their relation to multidrug resistance in human CEM leukemia cells.

    PubMed

    Gayet, Landry; Dayan, Guila; Barakat, Stéphane; Labialle, Stéphane; Michaud, Mickaël; Cogne, Sylvain; Mazane, Abdellah; Coleman, Anthony W; Rigal, Dominique; Baggetto, Loris G

    2005-03-22

    P-glycoprotein (P-gp) is the most well-known ATP-binding cassette (ABC) transporter involved in unidirectional substrate translocation across the membrane lipid bilayer, thereby causing the typical multidrug resistance (MDR) phenotype expressed in many cancers. We observed that in human CEM acute lymphoblastic leukemia cells expressing various degrees of chemoresistance and where P-gp was the sole MDR-related ABC transporter detected, the amount of esterified cholesterol increased linearly with the level of resistance to vinblastine while the amounts of total and free cholesterol increased in a nonlinear way. Membrane cholesterol controlled the ATPase activity of P-gp in a linear manner, whereas the P-gp-induced daunomycin efflux decreased nonlinearly with the depletion of membrane cholesterol. All these elements suggest that cholesterol controls both the ATPase and the drug efflux activities of P-gp. In addition, in CEM cell lines that expressed increasing levels of elevated chemoresistance, the amount of P-gp increases to a plateau value of 40% of the total membrane proteins and remained unvaried while the amount of membrane cholesterol increased with the elevation of the MDR level, strongly suggesting that cholesterol may be directly involved in the typical MDR phenotype. Finally, we showed that the decreased daunomycin efflux by P-gp due to the partial depletion of membrane cholesterol was responsible for the efficient chemosensitization of resistant CEM cells, which could be totally reversed after cholesterol repletion.

  5. Discovery of 14-3-3 protein-protein interaction inhibitors that sensitize multidrug-resistant cancer cells to doxorubicin and the Akt inhibitor GSK690693.

    PubMed

    Mori, Mattia; Vignaroli, Giulia; Cau, Ylenia; Dinić, Jelena; Hill, Richard; Rossi, Matteo; Colecchia, David; Pešić, Milica; Link, Wolfgang; Chiariello, Mario; Ottmann, Christian; Botta, Maurizio

    2014-05-01

    14-3-3 is a family of highly conserved adapter proteins that is attracting much interest among medicinal chemists. Small-molecule inhibitors of 14-3-3 protein-protein interactions (PPIs) are in high demand, both as tools to increase our understanding of 14-3-3 actions in human diseases and as leads to develop innovative therapeutic agents. Herein we present the discovery of novel 14-3-3 PPI inhibitors through a multidisciplinary strategy combining molecular modeling, organic synthesis, image-based high-content analysis of reporter cells, and in vitro assays using cancer cells. Notably, the two most active compounds promoted the translocation of c-Abl and FOXO pro-apoptotic factors into the nucleus and sensitized multidrug-resistant cancer cells to apoptotic inducers such as doxorubicin and the pan-Akt inhibitor GSK690693, thus becoming valuable lead candidates for further optimization. Our results emphasize the possible role of 14-3-3 PPI inhibitors in anticancer combination therapies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Green Tea Catechin-Based Complex Micelles Combined with Doxorubicin to Overcome Cardiotoxicity and Multidrug Resistance

    PubMed Central

    Cheng, Tangjian; Liu, Jinjian; Ren, Jie; Huang, Fan; Ou, Hanlin; Ding, Yuxun; Zhang, Yumin; Ma, Rujiang; An, Yingli; Liu, Jianfeng; Shi, Linqi

    2016-01-01

    Chemotherapy for cancer treatment has been demonstrated to cause some side effects on healthy tissues and multidrug resistance of the tumor cells, which greatly limits therapeutic efficacy. To address these limitations and achieve better therapeutic efficacy, combination therapy based on nanoparticle platforms provides a promising approach through delivering different agents simultaneously to the same destination with synergistic effect. In this study, a novel green tea catechin-based polyion complex (PIC) micelle loaded with doxorubicin (DOX) and (-)-Epigallocatechin-3-O-gallate (EGCG) was constructed through electrostatic interaction and phenylboronic acid-catechol interaction between poly(ethylene glycol)-block-poly(lysine-co-lysine-phenylboronic acid) (PEG-PLys/PBA) and EGCG. DOX was co-loaded in the PIC micelles through π-π stacking interaction with EGCG. The phenylboronic acid-catechol interaction endowed the PIC micelles with high stability under physiological condition. Moreover, acid cleavability of phenylboronic acid-catechol interaction in the micelle core has significant benefits for delivering EGCG and DOX to same destination with synergistic effects. In addition, benefiting from the oxygen free radicals scavenging activity of EGCG, combination therapy with EGCG and DOX in the micelle core could protect the cardiomyocytes from DOX-mediated cardiotoxicity according to the histopathologic analysis of hearts. Attributed to modulation of EGCG on P-glycoprotein (P-gp) activity, this kind of PIC micelles could effectively reverse multidrug resistance of cancer cells. These results suggested that EGCG based PIC micelles could effectively overcome DOX induced cardiotoxicity and multidrug resistance. PMID:27375779

  7. Mitochondria of a human multidrug-resistant hepatocellular carcinoma cell line constitutively express inducible nitric oxide synthase in the inner membrane.

    PubMed

    Fantappiè, Ornella; Sassoli, Chiara; Tani, Alessia; Nosi, Daniele; Marchetti, Serena; Formigli, Lucia; Mazzanti, Roberto

    2015-06-01

    Mitochondria play a crucial role in pathways of stress conditions. They can be transported from one cell to another, bringing their features to the cell where they are transported. It has been shown in cancer cells overexpressing multidrug resistance (MDR) that mitochondria express proteins involved in drug resistance such as P-glycoprotein (P-gp), breast cancer resistant protein and multiple resistance protein-1. The MDR phenotype is associated with the constitutive expression of COX-2 and iNOS, whereas celecoxib, a specific inhibitor of COX-2 activity, reverses drug resistance of MDR cells by releasing cytochrome c from mitochondria. It is possible that COX-2 and iNOS are also expressed in mitochondria of cancer cells overexpressing the MDR phenotype. This study involved experiments using the human HCC PLC/PRF/5 cell line with and without MDR phenotype and melanoma A375 cells that do not express the MDR1 phenotype but they do iNOS. Western blot analysis, confocal immunofluorescence and immune electron microscopy showed that iNOS is localized in mitochondria of MDR1-positive cells, whereas COX-2 is not. Low and moderate concentrations of celecoxib modulate the expression of iNOS and P-gp in mitochondria of MDR cancer cells independently from inhibition of COX-2 activity. However, A375 cells that express iNOS also in mitochondria, were not MDR1 positive. In conclusion, iNOS can be localized in mitochondria of HCC cells overexpressing MDR1 phenotype, however this phenomenon appears independent from the MDR1 phenotype occurrence. The presence of iNOS in mitochondria of human HCC cells phenotype probably concurs to a more aggressive behaviour of cancer cells.

  8. Development of sulfasalazine resistance in human T cells induces expression of the multidrug resistance transporter ABCG2 (BCRP) and augmented production of TNFα

    PubMed Central

    van der Heijden, J; de Jong, M C; Dijkmans, B; Lems, W; Oerlemans, R; Kathmann, I; Schalkwijk, C; Scheffer, G; Scheper, R; Jansen, G

    2004-01-01

    Objective: To determine whether overexpression of cell membrane associated drug efflux pumps belonging to the family of ATP binding cassette (ABC) proteins contributes to a diminished efficacy of sulfasalazine (SSZ) after prolonged cellular exposure to this disease modifying antirheumatic drug (DMARD). Methods: A model system of human T cells (CEM) was used to expose cells in vitro to increasing concentrations of SSZ for a period of six months. Cells were then characterised for the expression of drug efflux pumps: P-glycoprotein (Pgp, ABCB1), multidrug resistance protein 1 (MRP1, ABCC1), and breast cancer resistance protein (BCRP, ABCG2). Results: Prolonged exposure of CEM cells to SSZ provoked resistance to SSZ as manifested by a 6.4-fold diminished antiproliferative effect of SSZ compared with parental CEM cells. CEM cells resistant to SSZ (CEM/SSZ) showed a marked induction of ABCG2/BCRP, Pgp expression was not detectable, while MRP1 expression was even down regulated. A functional role of ABCG2 in SSZ resistance was demonstrated by 60% reversal of SSZ resistance by the ABCG2 blocker Ko143. Release of the proinflammatory cytokine tumour necrosis factor α (TNFα) was threefold higher in CEM/SSZ cells than in CEM cells. Moreover, twofold higher concentrations of SSZ were required to inhibit TNFα release from CEM/SSZ cells compared with CEM cells. Conclusion: Collectively, ABCG2 induction, augmented TNFα release, and less efficient inhibition of TNFα production by SSZ may contribute to diminished efficacy after prolonged exposure to SSZ. These results warrant further clinical studies to verify whether drug efflux pumps, originally identified for their roles in cytostatic drug resistance, can also be induced by SSZ or other DMARDs. PMID:14722201

  9. Multidrug Resistant Protein-Three Gene Regulation by the Transcription Factor Nrf2 in Human Bronchial Epithelial and Non-Small Cell Lung Carcinoma

    PubMed Central

    Mahaffey, Christopher M.; Zhang, Hongqiao; Rinna, Alessandra; Holland, William; Mack, Philip C.; Forman, Henry Jay

    2009-01-01

    Multidrug Resistant Proteins (MRP) are members of the ATP-binding cassette superfamily that facilitate detoxification by transporting toxic compounds, including chemotherapeutic drugs, out of cells. Chemotherapy, radiation, and other xenobiotic stresses have been shown to increase levels of select MRPs, although, the underlying mechanism remains largely unknown. Additionally, MRP3 is suspected of playing a role in the drug resistance of non-small cell lung carcinoma (NSCLC). Analysis of the MRP3 promoter revealed the presence of multiple putative electrophile responsive elements (EpRE), sequences that suggested possible regulation of this gene by Nrf2, the key transcription factor that binds to EpRE. The goal of this investigation was to determine whether MRP3 induction was dependent upon the transcription factor Nrf2. Keap1, a key regulator of Nrf2, sequesters Nrf2 in the cytoplasm, preventing entry into the nucleus. The electrophilic lipid peroxidation product, 4-hydroxy-2-nonenal (HNE) has been shown to modify Keap1 allowing Nrf2 to enter the nucleus. We found that HNE up-regulated MRP3 mRNA and protein levels in cell lines with wild type Keap1 (human bronchial epithelial cell line HBE1 and the NSCLC cell line H358), but not in the Keap1 mutant NSCLC cell lines (A549 and H460). Cell lines with mutant Keap1 had constitutively higher MRP3 that was not increased by HNE treatment. In HBE1 cells, silencing of Nrf2 with siRNA inhibited induction of MRP3 and by HNE. Finally, we found that silencing Nrf2 also increased the toxicity of cisplatin in H358 cells. The combined results therefore support the hypothesis that MRP3 induction by HNE involves Nrf2 activation. PMID:19345732

  10. Risk Factors and Outcomes of Infections by Multidrug-Resistant Gram-Negative Bacteria in Patients Undergoing Hematopoietic Stem Cell Transplantation.

    PubMed

    Patriarca, Francesca; Cigana, Chiara; Massimo, Dozzo; Lazzarotto, Davide; Geromin, Antonella; Isola, Miriam; Battista, Marta Lisa; Medeot, Marta; Cerno, Michela; Sperotto, Alessandra; Candoni, Anna; Crapis, Massimo; Sartor, Assunta; Scarparo, Claudio; Bassetti, Matteo; Fanin, Renato

    2017-02-01

    The objective of this study was to determine risk factors and outcomes of infections by multidrug-resistant gram-negative (MDR GN) bacteria in 241 recipients of hematopoietic stem cell transplantation (HSCT). The cumulative incidence of infections was 10.5% (95% CI, 12.0% to 25.8%), with 57% of infections occurring during the period of severe neutropenia (neutrophil count < .1 × 10(6)/L). In multivariate analysis, allogeneic transplant and colonization with MDR GN bacteria at admission to the transplant unit were significantly associated with an increased risk of infection. Although we observed neither transplant-related mortality (TRM) nor deaths due to infections by MDR GN bacteria after autologous transplant, in the allogeneic setting a significant difference was reported in terms of overall survival (OS) and TRM between patients who developed infections and those who did not (1-year OS, 39% versus 68%; 1-year TRM, 42% versus 19%). In multivariate analysis, refractory disease and development of grades III to IV graft-versus-host disease (GVHD) were factors that affected both TRM and OS, whereas occurrence of infections by MDR GN pathogens significantly reduced OS. We conclude that eligibility to allogeneic HSCT in MDR GN bacteria carriers should be carefully evaluated together with all other factors that independently influence outcome (disease status, donor, and GVHD risk). Copyright © 2017. Published by Elsevier Inc.

  11. Epigallocatechin gallate sensitizes cisplatin-resistant oral cancer CAR cell apoptosis and autophagy through stimulating AKT/STAT3 pathway and suppressing multidrug resistance 1 signaling.

    PubMed

    Yuan, Chien-Han; Horng, Chi-Ting; Lee, Chiu-Fang; Chiang, Ni-Na; Tsai, Fuu-Jen; Lu, Chi-Cheng; Chiang, Jo-Hua; Hsu, Yuan-Man; Yang, Jai-Sing; Chen, Fu-An

    2017-03-01

    Epigallocatechin gallate (EGCG) is a green tea polyphenol that presents anticancer activities in multiple cancer cells, but no available report was addressed for the underling molecular mechanism of cytotoxic impacts on drug-resistant oral squamous cell carcinoma cells. In the present study, the inhibitory effects of EGCG were experienced on cisplatin-resistant oral cancer CAR cells. EGCG inhibited cell viability in a time- and concentration-dependent manner by a sulforhodamine B (SRB) assay. EGCG induced CAR cell apoptosis and autophagy by 4',6-diamidino-2-phenylindole (DAPI) dye, acridine orange (AO) staining and green fluorescent protein (GFP)-tagged LC3B assay, respectively. EGCG also significantly enhanced caspase-9 and caspase-3 activities by caspase activity assay. EGCG markedly increased the protein levels of Bax, cleaved caspase-9, cleaved caspase-3, Atg5, Atg7, Atg12, Beclin-1, and LC3B-II, as well as significantly decreased the expression of Bcl-2, phosphorylated AKT (Ser473) and phosphorylation of STAT3 on Tyr705 by western blotting in CAR cells. Importantly, the protein and gene expression of multidrug resistance 1 (MDR1) were dose-dependently inhibited by EGCG. Overall, downregulation of MDR1 levels and alterations of AKT/STAT3 signaling contributed to EGCG-induced apoptosis and autophagy in CAR cells. Based on these results, EGCG has the potential for therapeutic effect on oral cancer and may be useful for long-term oral cancer prevention in the future. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 845-855, 2017. © 2016 Wiley Periodicals, Inc.

  12. Multidrug Resistance-Associated Protein 2 Expression Is Upregulated by Adenosine 5’-Triphosphate in Colorectal Cancer Cells and Enhances Their Survival to Chemotherapeutic Drugs

    PubMed Central

    Vinette, Valérie; Placet, Morgane; Arguin, Guillaume; Gendron, Fernand-Pierre

    2015-01-01

    Extracellular adenosine 5’-triphosphate (ATP) is a signaling molecule that induces a plethora of effects ranging from the regulation of cell proliferation to modulation of cancerous cell behavior. In colorectal cancer, ATP was reported to stimulate epithelial cell proliferation and possibly promote resistance to anti-cancer treatments. However, the exact role of this danger-signaling molecule on cancerous intestinal epithelial cells (IECs) in response to chemotherapeutic agents remains unknown. To address how ATP may influence the response of cancerous IECs to chemotherapeutic agents, we used Caco-2 cells, which display enterocyte-like features, to determine the effect of ATP on the expression of multidrug resistance-associated protein 2 (MRP2). Gene and protein expression were determined by quantitative real-time PCR (qRT-PCR) and Western blotting. Resistance to etoposide, cisplatin and doxorubicin was determined by MTT assays in response to ATP stimulation of Caco-2 cells and in cells for which MRP2 expression was down-regulated by shRNA. ATP increased the expression of MRP2 at both the mRNA and protein levels. MRP2 expression involved an ATP-dependent stimulation of the MEK/ERK signaling pathway that was associated with an increase in relative resistance of Caco-2 cells to etoposide. Abolition of MRP2 expression using shRNA significantly reduced the protective effect of MRP2 toward etoposide as well as to cisplatin and doxorubicin. This study describes the mechanism by which ATP may contribute to the chemoresistance of cancerous IECs in colorectal cancer. Given the heterogeneity of colorectal adenocarcinoma responses to anti-cancer drugs, these findings call for further study to understand the role of P2 receptors in cancer drug therapy and to develop novel therapies aimed at regulating P2 receptor activity. PMID:26295158

  13. MicroRNA-93-5p increases multidrug resistance in human colorectal carcinoma cells by downregulating cyclin dependent kinase inhibitor 1A gene expression

    PubMed Central

    Wang, Shi-Jun; Cao, Yun-Fei; Yang, Zu-Qing; Jiang, Zhi-Yuan; Cai, Bin; Guo, Jiao; Zhang, Sen; Zhang, Xiao-Long; Gao, Feng

    2017-01-01

    Multidrug resistance (MDR) impedes successful chemotherapy in colorectal carcinoma (CRC) and emerging evidence suggests that microRNAs (miRs) are involved in the development of MDR. In the present study, the role of miR-93-5p in the modulation of drug resistance in CRC was investigated using HCT-8 and MDR HCT-8/vincristine (VCR) cell lines. The results demonstrated upregulated expression of miR-93-5p and MDR protein 1 (MDR1) in HCT-8/VCR cells, compared with the parental HCT-8 cells. Furthermore, cyclin-dependent kinase inhibitor 1A (CDKN1A) was identified as a potential target of miR-93-5p using miR target analysis tools, including PicTar, TargetScan and miRanda. In addition, inhibition of miR-93-5p expression in HCT-8/VCR cells markedly downregulated MDR1 gene expression, upregulated CDKN1A gene expression and induced cell cycle arrest in G1. Conversely, the overexpression of miR-93-5p in HCT-8/VCR cells upregulated MDR1 gene expression, downregulated CDKN1A gene expression and promoted G1/S transition. Furthermore, the in vitro drug sensitivity assay performed suggested that downregulation of miR-93-5p enhanced the sensitivity of HCT-8/VCR cells to VCR, while the upregulation of miR-93-5p decreased the sensitivity of HCT-8 cells to VCR. In conclusion, the results of the present study suggest that miR-93-5p serves a role in the development of MDR through downregulating CDKN1A gene expression in CRC.

  14. Persistent reversal of P-glycoprotein-mediated daunorubicin resistance by tetrandrine in multidrug-resistant human T lymphoblastoid leukemia MOLT-4 cells.

    PubMed

    Liu, Zhen-Li; Hirano, Toshihiko; Tanaka, Sachiko; Onda, Kenji; Oka, Kitaro

    2003-11-01

    Multidrug resistance (MDR) represents a major problem in cancer chemotherapy. P-glycoprotein (P-gp), the drug efflux pump that mediates this resistance, can be inhibited by compounds with a variety of pharmacological functions, thus circumventing the MDR phenotype. The present study was performed to evaluate a unique MDR-reversal feature of a bisbenzylisoquinoline alkaloid tetrandrine (TET) in a P-gp expressing MOLT-4 MDR line (MOLT-4/DNR) established in our laboratory. Cell viability was determined by an MTT assay. P-gp function was characterized by determining the Rh123 accumulation/efflux capacity. P-gp overexpression in resistant MOLT-4/DNR cells was confirmed by flow cytometry analysis after staining with phycoerythrin-conjugated anti-P-gp monoclonal antibody 17F9. Compared to ciclosporin A (CsA), TET exhibited stronger activity to reverse drug resistance to daunorubicin (DNR), vinblastine (VLB) and doxorubicin (DOX) in MOLT-4/DNR cells. TET showed no cytotoxic effects on parental MOLT-4 cells lacking P-gp expression or on the resistant MOLT-4/DNR cells. TET modulated DNR cytotoxicity even after it was washed with the medium for 24 h, while CsA almost completely lost its reversal capability 24 h after washing. TET and CsA similarly increased the accumulation of Rh123 in resistant MOLT-4/DNR cells. However, TET inhibited Rh123 efflux from resistant cells even after washing with the medium, while CsA rapidly lost its ability to inhibit Rh123 efflux after washing. The current study suggests that TET enhances the cytotoxicity of anticancer drugs in the P-gp expressing MDR cell line by modulating P-gp in a different manner to the well-known P-gp inhibitor CsA.

  15. P-glycoprotein attenuates DNA repair activity in multidrug-resistant cells by acting through the Cbp-Csk-Src cascade.

    PubMed

    Lin, Li-Fang; Wu, Ming-Hsi; Pidugu, Vijaya Kumar; Ho, I-Ching; Su, Tsann-Long; Lee, Te-Chang

    2017-02-03

    Recent studies have demonstrated that P-glycoprotein (P-gp) expression impairs DNA interstrand cross-linking agent-induced DNA repair efficiency in multidrug-resistant (MDR) cells. To date, the detailed molecular mechanisms underlying how P-gp interferes with Src activation and subsequent DNA repair activity remain unclear. In this study, we determined that the C-terminal Src kinase-binding protein (Cbp) signaling pathway involved in the negative control of Src activation is enhanced in MDR cells. We also demonstrated that cells that ectopically express P-gp exhibit reduced activation of DNA damage response regulators, such as ATM, Chk2, Braca1 and Nbs1 and hence attenuated DNA double-strand break repair capacity and become more susceptible than vector control cells to DNA interstrand cross-linking (ICL) agents. Moreover, we demonstrated that P-gp can not only interact with Cbp and Src but also enhance the formation of inhibitory C-terminal Src kinase (Csk)-Cbp complexes that reduce phosphorylation of the Src activation residue Y416 and increase phosphorylation of the Src negative regulatory residue Y527. Notably, suppression of Cbp expression in MDR cells restores cisplatin-induced Src activation, improves DNA repair capacity, and increases resistance to ICL agents. Ectopic expression of Cbp attenuates cisplatin-induced Src activation and increases the susceptibility of cells to ICL agents. Together, the current results indicate that P-gp inhibits DNA repair activity by modulating Src activation via Cbp-Csk-Src cascade. These results suggest that DNA ICL agents are likely to have therapeutic potential against MDR cells with P-gp-overexpression.

  16. 3D-QSAR AND CONTOUR MAP ANALYSIS OF TARIQUIDAR ANALOGUES AS MULTIDRUG RESISTANCE PROTEIN-1 (MRP1) INHIBITORS

    PubMed Central

    Kakarla, Prathusha; Inupakutika, Madhuri; Devireddy, Amith R.; Gunda, Shravan Kumar; Willmon, Thomas Mark; Ranjana, KC; Shrestha, Ugina; Ranaweera, Indrika; Hernandez, Alberto J.; Barr, Sharla; Varela, Manuel F.

    2016-01-01

    One of the major obstacles to the successful chemotherapy towards several cancers is multidrug resistance of human cancer cells to anti-cancer drugs. An important contributor to multidrug resistance is the human multidrug resistance protein-1 transporter (MRP1), which is an efflux pump of the ABC (ATP binding cassette) superfamily. Thus, highly efficacious, third generation MRP1 inhibitors, like tariquidar analogues, are promising inhibitors of multidrug resistance and are under clinical trials. To maximize the efficacy of MRP1 inhibitors and to reduce systemic toxicity, it is important to limit the exposure of MRP1 inhibitors and anticancer drugs to normal tissues and to increase their co-localization with tumor cells. Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) associated with 3D-Quantitiative structure-activity relationship (3D-QSAR) studies were performed on a series of tariquidar analogues, as selective MDR modulators. Best predictability was obtained with CoMFA model r2(non-cross-validated square of correlation coefficient) = 0.968, F value = 151.768 with five components, standard error of estimate = 0.107 while the CoMSIA yielded r2 = 0.982, F value = 60.628 with six components, and standard error of estimate = 0.154. These results indicate that steric, electrostatic, hydrophobic (lipophilic), and hydrogen bond donor substituents play significant roles in multidrug resistance modulation of tariquidar analogues upon MRP1. The tariquidar analogue and MRP1 binding and stability data generated from CoMFA and CoMSIA based 3D–contour maps may further aid in study and design of tariquidar analogues as novel, potent and selective MDR modulator drug candidates. PMID:26913287

  17. Drug Repurposing of the Anthelmintic Niclosamide to Treat Multidrug-Resistant Leukemia

    PubMed Central

    Hamdoun, Sami; Jung, Philipp; Efferth, Thomas

    2017-01-01

    Multidrug resistance, a major problem that leads to failure of anticancer chemotherapy, requires the development of new drugs. Repurposing of established drugs is a promising approach for overcoming this problem. An example of such drugs is niclosamide, a known anthelmintic that is now known to be cytotoxic and cytostatic against cancer cells. In this study, niclosamide showed varying activity against different cancer cell lines. It revealed better activity against hematological cancer cell lines CCRF-CEM, CEM/ADR5000, and RPMI-8226 compared to the solid tumor cell lines MDA-MB-231, A549, and HT-29. The multidrug resistant CEM/ADR5000 cells were similar sensitive as their sensitive counterpart CCRF-CEM (resistance ration: 1.24). Furthermore, niclosamide caused elevations in reactive oxygen species and glutathione (GSH) levels in leukemia cells. GSH synthetase (GS) was predicted as a target of niclosamide. Molecular docking showed that niclosamide probably binds to the ATP-binding site of GS with a binding energy of -9.40 kcal/mol. Using microscale thermophoresis, the binding affinity between niclosamide and recombinant human GS was measured (binding constant: 5.64 μM). COMPARE analyses of the NCI microarray database for 60 cell lines showed that several genes, including those involved in lipid metabolism, correlated with cellular responsiveness to niclosamide. Hierarchical cluster analysis showed five major branches with significant differences between sensitive and resistant cell lines (p = 8.66 × 105). Niclosamide significantly decreased nuclear factor of activated T-cells (NFAT) activity as predicted by promoter binding motif analysis. In conclusion, niclosamide was more active against hematological malignancies compared to solid tumors. The drug was particularly active against the multidrug-resistant CEM/ADR5000 leukemia cells. Inhibition of GSH synthesis and NFAT signaling were identified as relevant mechanisms for the anticancer activity of niclosamide

  18. Annosquacin B induces mitochondrial apoptosis in multidrug resistant human breast cancer cell line MCF-7/ADR through selectively modulating MAPKs pathways.

    PubMed

    Yuan, Fei; Bai, Ganggang; Miao, Yunjie; Chen, Yong; Li, Xiang; Chen, Jianwei

    2016-12-01

    Multidrug resistance (MDR) is a major obstacle to efficient therapy of cancers. It is a prime concern for researchers to find compounds with anti-proliferative activity on MDR cell lines. In recent years, annonaceous acetogenins (ACGs) were reported to have anti-proliferative activity. However, the underlying mechanisms are still unknown. This study determines the mechanisms of anti-proliferative activity induced by Annosquacin B (AB) against MCF-7/ADR cells. The cytotoxicity of AB at varying concentrations (0.64, 1.6, 4, 10, 25, 62.5, 156.25 μM) on MCF-7/ADR cells was assessed using the MTT assay. Annexin V-FITC/propidium iodide staining and Acrinidine orange and ethidium bromide (AO/EB) staining were employed to investigate whether AB (14, 7, 3.5 μM) could induce apoptosis in MCF-7/ADR cells. Levels of caspase-3 and caspase-9, Bax, Bcl-2 and MAPKs kinases were evaluated by western blot assay following treatment with various concentrations of AB (3.5, 7, 14 μM) at different time points (0, 0.5, 1, 2, 4, 8, 12 h). MTT assay showed that AB significantly decreased cell viability on MCF-7/ADR (IC50 of 14.69 μM). AB-induced apoptosis in MCF-7/ADR cells through mitochondrial apoptosis pathways. It induced typical apoptosis by morphologic changes; elevate levels of caspase-3, caspase-9 as well as the ratio of Bax/Bcl-2. In addition, AB increased the expression of p-p38 MAPK and decreased the expression of p-JNK, while whether ERK1/2 had an effect on the MCF-7/ADR apoptosis remains to be determined.

  19. Differential roles of ubiquitination in the degradation mechanism of cell surface-resident bile salt export pump and multidrug resistance-associated protein 2.

    PubMed

    Aida, Kensuke; Hayashi, Hisamitsu; Inamura, Kaori; Mizuno, Tadahaya; Sugiyama, Yuichi

    2014-03-01

    We previously showed that ubiquitination, a reversible post-translational modification, facilitates degradation of cell surface-resident bile salt export pump (BSEP) and multidrug resistance-associated protein 2 (MRP2), ABC transporters that are expressed at the canalicular membrane (CM) of hepatocytes. In the current study, its underlying mechanism was investigated by evaluating the role of ubiquitination in the processes of internalization and subsequent degradation of cell surface-resident BSEP and MRP2. Cell surface biotinylation analysis using Flp-In T-REx 293 cells showed that ectopic expression of Ub(Δ)(GG), which is ubiquitin (Ub) lacking the two C-terminal glycines essential for the Ub conjugation reaction, inhibited the internalization of 3× FLAG-BSEP, but not of MRP2, and the degradation of the internalized MRP2, but not of the internalized 3× FLAG-BSEP. Its inhibitory effect on BSEP internalization was also indicated by a time-lapse imaging analysis using the rat hepatoma cell line McA-RH7777 in which Ub(Δ)(GG) delayed the loss of fluorescence from photoactivated Dronpa-BSEP on the CM. The effect of Ub(Δ)(GG) on BSEP internalization in these experiments was abrogated by treatment with chlorpromazine, an inhibitor of clathrin-mediated endocytosis, and the introduction of a Y1311A mutation into BSEP. This mutation eliminates the ability of BSEP to interact with the AP2 adaptor complex, an adaptor protein required for cargo selection in clathrin-mediated endocytosis. In conclusion, our data suggest that ubiquitination facilitates clathrin-mediated endocytosis of BSEP and the degradation of internalized MRP2, leading to the degradation of the cell surface-resident form of both transporters.

  20. Reversing multidrug-resistant by RNA interference through silencing MDR1 gene in human hepatocellular carcinoma cells subline Bel-7402/ADM.

    PubMed

    Sheng, Long; Xiong, Maoming; Li, Cong; Meng, Xiangling

    2014-07-01

    Multidrug resistance (MDR) in hepatocellular carcinoma (HC) significantly impedes the effect of chemotherapy and is considered as a primary reason leading to its recurrences and metastasis. The aim of present study was to explore new molecular targets for the reversal of MDR in HC by screening the adriamycin (ADM)-induced, human MDR-resistant HC cell subline Bel-7402/ADM. Small interfering RNAs (siRNAs) of four (MDR1si326, MDR1si1513, MDR1si2631 and MDR1si3071) targeting MDR1 were designed and transfected into Bel-7402/ADM cell strains. The experiments involved the following: mRNA expression of MDR1 gene by RT-PCR, P-glycoprotein (P-gp) expression by Western blot, intracellular ADM accumulation flow cytometry, and IC50 of ADM by a cytotoxic MTT assay. Four siRNAs reversed MDR in HC mediated by MDR1 to varying degrees. The expression level of MDR1 mRNA in cells of MDR1si326 or MDR1si2631 group (0.190 ± 0.038 or 0.171 ± 0.011) was more decreased. The expression level of P-gp in cells of MDR1si326 group was the lowest. The accumulation of ADM in cells of MDR1si326 or MDR1si2631 group (77.0 ± 3.5 or 75.4 ± 2.9) was more increased. The IC50 of cells to ADM was lowest in MDR1si326 group (11.32 ± 0.69 mg/L). Compared with other three siRNAs, MDR1si326 performed the optimal reversal effect of drug resistance in human HC Bel-7402/ADM.

  1. Multi-drug Resistance Protein 4 (MRP4)-mediated Regulation of Fibroblast Cell Migration Reflects a Dichotomous Role of Intracellular Cyclic Nucleotides*

    PubMed Central

    Sinha, Chandrima; Ren, Aixia; Arora, Kavisha; Moon, Chang-Suk; Yarlagadda, Sunitha; Zhang, Weiqiang; Cheepala, Satish B.; Schuetz, John D.; Naren, Anjaparavanda P.

    2013-01-01

    It has long been known that cyclic nucleotides and cyclic nucleotide-dependent signaling molecules control cell migration. However, the concept that it is not just the absence or presence of cyclic nucleotides, but a highly coordinated balance between these molecules that regulates cell migration, is new and revolutionary. In this study, we used multidrug resistance protein 4 (MRP4)-expressing cell lines and MRP4 knock-out mice as model systems and wound healing assays as the experimental system to explore this unique and emerging concept. MRP4, a member of a large family of ATP binding cassette transporter proteins, localizes to the plasma membrane and functions as a nucleotide efflux transporter and thus plays a role in the regulation of intracellular cyclic nucleotide levels. Here, we demonstrate that mouse embryonic fibroblasts (MEFs) isolated from Mrp4−/− mice have higher intracellular cyclic nucleotide levels and migrate faster compared with MEFs from Mrp4+/+ mice. Using FRET-based cAMP and cGMP sensors, we show that inhibition of MRP4 with MK571 increases both cAMP and cGMP levels, which results in increased migration. In contrast to these moderate increases in cAMP and cGMP levels seen in the absence of MRP4, a robust increase in cAMP levels was observed following treatment with forskolin and isobutylmethylxanthine, which decreases fibroblast migration. In response to externally added cell-permeant cyclic nucleotides (cpt-cAMP and cpt-cGMP), MEF migration appears to be biphasic. Altogether, our studies provide the first experimental evidence supporting the novel concept that balance between cyclic nucleotides is critical for cell migration. PMID:23264633

  2. Multidrug resistance-associated protein 3 (Mrp3/Abcc3/Moat-D) is expressed in the SAE Squalus acanthias shark embryo-derived cell line.

    PubMed

    Kobayashi, Hiroshi; Parton, Angela; Czechanski, Anne; Durkin, Christopher; Kong, Chi-Chon; Barnes, David

    2007-01-01

    The multidrug resistance-associated protein 3 (MRP3/Mrp3) is a member of the ATP-binding cassette (ABC) protein family of membrane transporters and related proteins that act on a variety of xenobiotic and anionic molecules to transfer these substrates in an ATP-dependent manner. In recent years, useful comparative information regarding evolutionarily conserved structure and transport functions of these proteins has accrued through the use of primitive marine animals such as cartilaginous fish. Until recently, one missing tool in comparative studies with cartilaginous fish was cell culture. We have derived from the embryo of Squalus acanthias, the spiny dogfish shark, the S. acanthias embryo (SAE) mesenchymal stem cell line. This is the first continuously proliferating cell line from a cartilaginous fish. We identified expression of Mrp3 in this cell line, cloned the molecule, and examined molecular and cellular physiological aspects of the protein. Shark Mrp3 is characterized by three membrane-spanning domains and two nucleotide-binding domains. Multiple alignments with other species showed that the shark Mrp3 amino acid sequence was well conserved. The shark sequence was overall 64% identical to human MRP3, 72% identical to chicken Mrp3, and 71% identical to frog and stickleback Mrp3. Highest identity between shark and human amino acid sequence (82%) was seen in the carboxyl-terminal nucleotide-binding domain of the proteins. Cell culture experiments showed that mRNA for the protein was induced as much as 25-fold by peptide growth factors, fetal bovine serum, and lipid nutritional components, with the largest effect mediated by a combination of lipids including unsaturated and saturated fatty acids, cholesterol, and vitamin E.

  3. Hydrocinchonine, cinchonine, and quinidine potentiate paclitaxel-induced cytotoxicity and apoptosis via multidrug resistance reversal in MES-SA/DX5 uterine sarcoma cells.

    PubMed

    Lee, Sang-Yun; Rhee, Yun-Hee; Jeong, Soo-Jin; Lee, Hyo-Jeong; Lee, Hyo-Jung; Jung, Min-Hyung; Kim, Sun-Hyung; Lee, Eun-Ok; Ahn, Kwang Seok; Ahn, Kyoo Seok; Kim, Sung-Hoon

    2011-08-01

    Multidrug resistance (MDR) is one of important issues to cause the chemotherapy failure against cancers including gynecological malignancies. Despite some MDR reversal evidences of natural compounds including quinidine and cinchonine, there are no reports on MDR reversal activity of hydrocinchonine with its analogues quinidine and cinchonine especially in uterine sarcoma cells. Thus, in the current study, we comparatively investigated the potent efficacy of hydrocinchonine and its analogues quinidine and cinchonine as MDR-reversal agents for combined therapy with antitumor agent paclitaxel (TAX). Hydrocinchonine, cinchonine, and quinidine significantly increased the cytotoxicity of TAX in P-glycoprotein (gp)-positive MES-SA/DX5, but not in the P-gp-negative MES-SA cells at nontoxic concentrations by 3-(4,5-dimethylthiazol-2-yl)-2,5--diphenyltetrazolium bromide (MTT) assay. Rhodamine assay also revealed that hydrocinchonine, cinchonine, and quinidine effectively enhanced the accumulation of a P-gp substrate, rhodamine in TAX-treated MES-SA/DX5 cells compared with TAX-treated control. In addition, hydrocinchonine, cinchonine, and quinidine effectively cleaved poly (ADP-ribose) polymerase (PARP), activated caspase-3, and downregulated P-gp expression as well as increased sub-G1 apoptotic portion in TAX-treated MES-SA/DX5 cells. Taken together, hydrocinchonine exerted MDR reversal activity and synergistic apoptotic effect with TAX in MES-SA/DX5 cells almost comparable with quinidine and cinchonine as a potent MDR-reversal and combined therapy agent with TAX. Copyright © 2010 Wiley Periodicals, Inc.

  4. Transport of bile acids in multidrug-resistance-protein 3-overexpressing cells co-transfected with the ileal Na+-dependent bile-acid transporter.

    PubMed Central

    Zelcer, Noam; Saeki, Tohru; Bot, Ilse; Kuil, Annemieke; Borst, Piet

    2003-01-01

    Many of the transporters involved in the transport of bile acids in the enterohepatic circulation have been characterized. The basolateral bile-acid transporter of ileocytes and cholangiocytes remains an exception. It has been suggested that rat multidrug resistance protein 3 (Mrp3) fulfills this function. Here we analyse bile-salt transport by human MRP3. Membrane vesicles from insect ( Spodoptera frugiperda ) cells expressing MRP3 show time-dependent uptake of glycocholate and taurocholate. Furthermore, sulphated bile salts were high-affinity competitive inhibitors of etoposide glucuronide transport by MRP3 (IC50 approximately 10 microM). Taurochenodeoxycholate, taurocholate and glycocholate inhibited transport at higher concentrations (IC50 approximately 100, 250 and 500 microM respectively). We used mouse fibroblast-like cell lines derived from mice with disrupted Mdr1a, Mdr1b and Mrp1 genes to generate transfectants that express the murine apical Na+-dependent bile-salt transporter (Asbt) and MRP3. Uptake of glycocholate by these cells is Na+-dependent, with a K(m) and V(max) of 29+/-7 microM and 660 +/- 63 pmol/min per mg of protein respectively and is inhibited by several organic-aniontransport inhibitors. Expression of MRP3 in these cells limits the accumulation of glycocholate and increases the efflux from cells preloaded with taurocholate or glycocholate. In conclusion, we find that MRP3 transports both taurocholate and glycocholate, albeit with low affinity, in contrast with the high-affinity transport by rat Mrp3. Our results suggest that MRP3 is unlikely to be the principal basolateral bile-acid transporter of ileocytes and cholangiocytes, but that it may have a role in the removal of bile acids from the liver in cholestasis. PMID:12220224

  5. Multidrug-resistant phenotype in retinoblastoma correlates with P-glycoprotein expression.

    PubMed

    Chan, H S; Thorner, P S; Haddad, G; Gallie, B L

    1991-09-01

    Chemotherapy plays an important role in therapy for patients with extraocular and metastatic retinoblastoma. The authors used chemotherapy for management of selected patients with uncontrolled intraocular tumors or tumors larger and more posteriorly located than those conventionally treated with local cryotherapy or photocoagulation. Rapid regrowth of some tumors after an initial excellent chemotherapy response led us to investigate the hypothesis that failure of treatment is caused by P-glycoprotein-related multidrug resistance. By using a sensitive immunoperoxidase method, increased P-glycoprotein was detected in five multidrug-resistant and two selectively plant alkaloid-resistant retinoblastoma cell lines and in the intraocular and metastatic tumors from which they were derived. In four chemotherapy-treated cases, increased P-glycoprotein in the tumor samples correlated with clinically relevant drug resistance. None of the four chemosensitive tumor cell lines had increased P-glycoprotein expression. Continuous surveillance of P-glycoprotein levels in metastatic retinoblastoma may be a useful guide to drug therapy.

  6. Multidrug resistance protein (MRP) 4 attenuates benzo[a]pyrene-mediated DNA-adduct formation in human bronchoalveolar H358 cells.

    PubMed

    Gelhaus, Stacy L; Gilad, Oren; Hwang, Wei-Ting; Penning, Trevor M; Blair, Ian A

    2012-02-25

    Multi-drug resistance protein (MRP) 4, an ATP-binding cassette (ABC) transporter, has broad substrate specificity. It facilitates the transport of bile salt conjugates, conjugated steroids, nucleoside analogs, eicosanoids, and cardiovascular drugs. Recent studies in liver carcinoma cells and hepatocytes showed that MRP4 expression is regulated by the aryl hydrocarbon receptor (AhR) and nuclear factor E2-related factor 2 (Nrf2). The AhR has particular importance in the lung and is most commonly associated with the up-regulation of cytochrome P-450 (CYP)-mediated metabolism of benzo[a]pyrene (B[a]P) to reactive intermediates. Treatment of H358, human bronchoalveolar, cells with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or (-)-benzo[a]pyrene-7,8-dihydro-7,8-diol (B[a]P-7,8-dihydrodiol), the proximate carcinogen of B[a]P, revealed that MRP4 expression was increased compared to control. This suggested that MRP4 expression might contribute to the paradoxical decrease in (+)-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene-2'-deoxyguanosine ((+)-anti-trans-B[a]PDE-dGuo) DNA-adducts observed in TCDD-treated H358 cells. We have now found that decreased MRP4 expression induced by a short hairpin RNA (shRNA), or chemical inhibition with probenecid, increased (+)-anti-trans-B[a]PDE-dGuo formation in cells treated with (-)-B[a]P-7,8-dihydrodiol, but not the ultimate carcinogen (+)-anti-trans-B[a]PDE. Thus, up-regulation of MRP4 increased cellular efflux of (-)-B[a]P-7,8-dihydrodiol, which attenuated DNA-adduct formation. This is the first report identifying a specific MRP efflux transporter that decreases DNA damage arising from an environmental carcinogen. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Multidrug Resistance Protein (MRP) 4 Attenuates Benzo[a]Pyrene-Mediated DNA-adduct Formation in Human Bronchoalveolar H358 Cells

    PubMed Central

    Gelhaus, Stacy L.; Gilad, Oren; Hwang, Wei-Ting; Penning, Trevor M.; Blair, Ian A.

    2011-01-01

    Multi-drug resistance protein (MRP) 4, an ATP-binding cassette (ABC) transporter, has broad substrate specificity. It facilitates the transport of bile salt conjugates, conjugated steroids, nucleoside analogs, eicosanoids, and cardiovascular drugs. Recent studies in liver carcinoma cells and hepatocytes showed that MRP4 expression is regulated by the aryl hydrocarbon receptor (AhR) and nuclear factor E2-related factor 2 (Nrf2). The AhR has particular importance in the lung and is most commonly associated with the up-regulation of cytochrome P-450 (CYP)-mediated metabolism of benzo[a]pyrene (B[a]P) to reactive intermediates. Treatment of H358, human bronchoalveolar, cells with 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) or (−)-benzo[a]pyrene-7,8-dihydro-7,8-diol (B[a]P-7,8-dihydrodiol), the proximate carcinogen of B[a]P, revealed that MRP4 expression was increased compared to control. This suggested that MRP4 expression might contribute to the paradoxical decrease in (+)-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene-2′-deoxyguanosine ((+)-anti-trans-B[a]PDE-dGuo) DNA-adducts observed in TCDD-treated H358 cells. We have now found that decreased MRP4 expression induced by a short hairpin RNA (shRNA), or chemical inhibition with probenecid, increased (+)-anti-trans-B[a]PDE-dGuo formation in cells treated with (−)-B[a]P-7,8-dihydrodiol, but not the ultimate carcinogen (+)-anti-trans-B[a]PDE. Thus, up-regulation of MRP4 increased cellular efflux of (−)-B[a]P-7,8-dihydrodiol, which attenuated DNA-adduct formation. This is the first report identifying a specific MRP efflux transporter that decreases DNA damage arising from an environmental carcinogen. PMID:22155354

  8. Sensitization of multidrug resistant (MDR) cancer cells to vinblastine by novel acridones: correlation between anti-calmodulin activity and anti-MDR activity.

    PubMed

    Mayur, Y C; Padma, T; Parimala, B H; Chandramouli, K H; Jagadeesh, S; Gowda, N M Made; Thimmaiah, K N

    2006-01-01

    Multidrug resistance (MDR) of cancer cells remains to be an important cause of chemotherapy failure. Search for the new MDR reversal agents is still an unceasing challenge for the scientists. In an attempt to find clinically useful modulators of MDR, a series of 19 N(10)-substituted-2-bromoacridones has been synthesized. Parent compound 1, prepared by the Ullmann condensation of o-chlorobenzoic acid and p-bromoaniline, undergoes N-alkylation in the presence of a phase transfer catalyst. N-(omega-Chloroalkyl) analogues were subjected to iodide catalyzed nucleophilic substitution reaction with various secondary amines to get the products 3-10 and 12-19, which increased the uptake of vinblastine (VLB) in MDR KBCh(R)-8-5 cells to a greater extent (1.25 to 1.9-fold) than did a similar concentration of the standard modulator, verapamil (VRP). Results of the efflux experiment showed that each modulator significantly inhibited the efflux of VLB, suggesting that they may be competitors for P-gp. All the compounds effectively compete with [(3)H] azidopine for binding to P-gp, pointed out this transport membrane protein as their likely site of action. Compounds at IC(10) were evaluated for their efficacy to modulate the cytotoxicity of VLB in KBCh(R)-8-5 cells and found that the modulators enhanced the cytotoxicity of VLB by 3.8 to 34-fold. The study on the structure-activity relationship revealed that substitution of hydrogen atom at position C-2 in acridone nucleus by a bromine atom increased the cytotoxic and anti-MDR activities. The ability of acridones to inhibit calmodulin-dependent cyclic AMP phosphodiesterase has been determined and the results have shown a strong positive correlation between anti-calmodulin activity and cytotoxicity in KBCh(R)-8-5 cells or anti-MDR activity.

  9. Reversal of P-glycoprotein-mediated multidrug resistance in human sarcoma MES-SA/Dx-5 cells by nonsteroidal anti-inflammatory drugs.

    PubMed

    Angelini, Antonio; Iezzi, Manuela; Di Febbo, Concetta; Di Ilio, Carmine; Cuccurullo, Franco; Porreca, Ettore

    2008-10-01

    Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is one of the major reasons for the failure of cancer therapy. Several chemosensitizers are able to reverse in vitro MDR by inhibiting P-gp, although high toxicity limits their clinical application. In this study, we aimed to investigate the in vitro effectiveness of four common non-steroidal anti-inflammatory drugs (NSAIDs) such as Curcumin (Cur), Sulindac (Sul), Ibuprofen (Ibu) and NS-398 (NS) to inhibit P-gp activity at clinically achievable doses and to evaluate their potential use as sensitizers in anti-cancer chemotherapy. The human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx-5) expressing high levels of P-gp, were treated with different doxo concentrations in the presence or absence of NSAIDs. Cellular accumulation of doxo, cytotoxicity and apoptosis induction were measured in comparison with Verapamil, a specific P-gp inhibitor, used as a reference molecule. We found that Ibu, Cur and NS-398 enhanced significantly doxo retention, cytotoxicity and apoptosis on resistant MES-SA/Doxo-5 cells when compared with doxo alone. In contrast, no significant changes were found in resistant cells treated with Sul-doxo combinations. Our results demonstrate that Ibu, Cur and NS-398 below their therapeutic plasma concentrations were able to overcome P-gp-mediated MDR in MES-SA/Dx-5 cells. These findings provide the rationale for clinical studies of NSAIDs and/or derivatives as a new potential generation of chemosensitizers to improve effectiveness of the anti-cancer drugs in the treatment of human cancer.

  10. Nosocomial, Multidrug-Resistant Klebsiella pneumoniae Strains Isolated from Mexico City Produce Robust Biofilms on Abiotic Surfaces but Not on Human Lung Cells.

    PubMed

    Ostria-Hernandez, Martha Lorena; Juárez-de la Rosa, Karla Cecilia; Arzate-Barbosa, Patricia; Lara-Hernández, Antonino; Sakai, Fuminori; Ibarra, J Antonio; Castro-Escarpulli, Graciela; Vidal, Jorge E

    2017-09-15

    Klebsiella pneumoniae (Kpn) strains are a leading cause of hospital-acquired infections, including ventilator-associated pneumonia. Resistance to antibiotics, biofilm formation, and the production of certain fimbriae play an important role in the pathogenesis. We investigated the genetic relatedness, antibiotic resistance, virulence potential, and ability to form biofilms of Kpn strains isolated from hospital-acquired infections (n = 76). Strains were isolated at three major hospitals serving the largest metropolitan urban area in Mexico City, Mexico. Enterobacterial repetitive intergenic consensus (ERIC)-PCR demonstrated that clonal groups predominate in each hospital. Selected strains chosen from clonal groups (n = 47) were multidrug resistant (MDR, 83%), although the majority (∼70%) were susceptible to carbapenems. All strains produced robust biofilms on abiotic surfaces, and ∼90% harbored adhesin genes fimH, mrkA, and ecpA. The ultrastructure of biofilms was further studied by high-resolution confocal microscopy. The average height of Kpn biofilms on abiotic surfaces was ∼40 μm. We then assessed formation of biofilms on human lung cells, as a surrogate of lung infection. While Kpn strains formed robust biofilms on abiotic surfaces, studies on lung cells revealed attachment to human cells but scarce formation of biofilms. Gene expression studies revealed a differential temporal expression of an adhesin (ecpA) and a capsule (galF) gene when biofilms were formed on different substrates. Kpn strains isolated from nosocomial infections in Mexico City are MDR, although the majority are still susceptible to carbapenems and form more robust biofilms on polystyrene in comparison to those formed on human cells.

  11. Contribution of aquaporin 9 and multidrug resistance-associated protein 2 to differential sensitivity to arsenite between primary cultured chorion and amnion cells prepared from human fetal membranes

    SciTech Connect

    Yoshino, Yuta; Yuan, Bo; Kaise, Toshikazu; Takeichi, Makoto; Tanaka, Sachiko; Hirano, Toshihiko; Kroetz, Deanna L.; Toyoda, Hiroo

    2011-12-15

    Arsenic trioxide (arsenite, As{sup III}) has shown a remarkable clinical efficacy, whereas its side effects are still a serious concern. Therefore, it is critical to understand the effects of As{sup III} on human-derived normal cells for revealing the mechanisms underlying these side effects. We examined the effects of As{sup III} on primary cultured chorion (C) and amnion (A) cells prepared from human fetal membranes. A significant dose-dependent As{sup III}-mediated cytotoxicity was observed in the C-cells accompanied with an increase of lactate dehydrogenase (LDH) release. Higher concentrations of As{sup III} were required for the A-cells to show cytotoxicity and LDH release, suggesting that the C-cells were more sensitive to As{sup III} than the A-cells. The expression levels of aquaporin 9 (AQP9) were approximately 2 times higher in the C-cells than those in the A-cells. Both intracellular arsenic accumulation and its cytotoxicity in the C-cells were significantly abrogated by sorbitol, a competitive AQP9 inhibitor, in a dose-dependent manner. The protein expression levels of multidrug resistance-associated protein (MRP) 2 were downregulated by As{sup III} in the C-cells, but not in the A-cells. No significant differences in the expression levels of MRP1 were observed between C- and A-cells. The protein expression of P-glycoprotein (P-gp) was hardly detected in both cells, although a detectable amount of its mRNA was observed. Cyclosporine A, a broad-spectrum inhibitor for ABC transporters, and MK571, a MRP inhibitor, but not PGP-4008, a P-gp specific inhibitor, potently sensitized both cells to As{sup III}-mediated cytotoxicity. These results suggest that AQP9 and MRP2 are involved in controlling arsenic accumulation in these normal cells, which then contribute to differential sensitivity to As{sup III} cytotoxicity between these cells. -- Highlights: Black-Right-Pointing-Pointer Examination of effect of As{sup III} on primary cultured chorion (C) and amnion

  12. Intracellular pH and the Control of Multidrug Resistance

    NASA Astrophysics Data System (ADS)

    Simon, Sanford; Roy, Deborshi; Schindler, Melvin

    1994-02-01

    Many anticancer drugs are classified as either weak bases or molecules whose binding to cellular structures is pH dependent. Accumulation of these drugs within tumor cells should be affected by transmembrane pH gradients. Indeed, development of multidrug resistance (MDR) in tumor cells has been correlated with an alkaline shift of cytosolic pH. To examine the role of pH in drug partitioning, the distribution of two drugs, doxorubicin and daunomycin, was monitored in fibroblasts and myeloma cells. In both cell types the drugs rapidly accumulated within the cells. The highest concentrations were measured in the most acidic compartments-e.g., lysosomes. Modifying the cellular pH in drug-sensitive cells to mimic reported shifts in MDR caused an immediate change in the cellular drug concentration. Drug accumulation was enhanced by acidic shifts and reversed by alkaline shifts. All of these effects were rapid and reversible. These results demonstrate that the alkaline shift observed in MDR is sufficient to prevent the accumulation of chemotherapeutic drugs independent of active drug efflux.

  13. Intracellular pH and the control of multidrug resistance.

    PubMed Central

    Simon, S; Roy, D; Schindler, M

    1994-01-01

    Many anticancer drugs are classified as either weak bases or molecules whose binding to cellular structures is pH dependent. Accumulation of these drugs within tumor cells should be affected by transmembrane pH gradients. Indeed, development of multidrug resistance (MDR) in tumor cells has been correlated with an alkaline shift of cytosolic pH. To examine the role of pH in drug partitioning, the distribution of two drugs, doxorubicin and daunomycin, was monitored in fibroblasts and myeloma cells. In both cell types the drugs rapidly accumulated within the cells. The highest concentrations were measured in the most acidic compartments--e.g., lysosomes. Modifying the cellular pH in drug-sensitive cells to mimic reported shifts in MDR caused an immediate change in the cellular drug concentration. Drug accumulation was enhanced by acidic shifts and reversed by alkaline shifts. All of these effects were rapid and reversible. These results demonstrate that the alkaline shift observed in MDR is sufficient to prevent the accumulation of chemotherapeutic drugs independent of active drug efflux. Images PMID:8302842

  14. ABC transporters as multidrug resistance mechanisms and the development of chemosensitizers for their reversal

    PubMed Central

    Choi, Cheol-Hee

    2005-01-01

    One of the major problems related with anticancer chemotherapy is resistance against anticancer drugs. The ATP-binding cassette (ABC) transporters are a family of transporter proteins that are responsible for drug resistance and a low bioavailability of drugs by pumping a variety of drugs out cells at the expense of ATP hydrolysis. One strategy for reversal of the resistance of tumor cells expressing ABC transporters is combined use of anticancer drugs with chemosensitizers. In this review, the physiological functions and structures of ABC transporters, and the development of chemosensitizers are described focusing on well-known proteins including P-glycoprotein, multidrug resistance associated protein, and breast cancer resistance protein. PMID:16202168

  15. Oleanolic and maslinic acid sensitize soft tissue sarcoma cells to doxorubicin by inhibiting the multidrug resistance protein MRP-1, but not P-glycoprotein.

    PubMed

    Villar, Victor Hugo; Vögler, Oliver; Barceló, Francisca; Gómez-Florit, Manuel; Martínez-Serra, Jordi; Obrador-Hevia, Antònia; Martín-Broto, Javier; Ruiz-Gutiérrez, Valentina; Alemany, Regina

    2014-04-01

    The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds present in many plants and dietary products consumed in the Mediterranean diet (e.g., pomace and virgin olive oils). Several nutraceutical activities have been attributed to OLA and MLA, whose antitumoral effects have been extensively evaluated in human adenocarcinomas, but little is known regarding their effectiveness in soft tissue sarcomas (STS). We assessed efficacy and molecular mechanisms involved in the antiproliferative effects of OLA and MLA as single agents or in combination with doxorubicin (DXR) in human synovial sarcoma SW982 and leiomyosarcoma SK-UT-1 cells. As single compound, MLA (10-100 μM) was more potent than OLA, inhibiting the growth of SW982 and SK-UT-1 cells by 70.3 ± 1.11% and 68.8 ± 1.52% at 80 μM, respectively. Importantly, OLA (80 μM) or MLA (30 μM) enhanced the antitumoral effect of DXR (0.5-10 μM) by up to 2.3-fold. On the molecular level, efflux activity of the multidrug resistance protein MRP-1, but not of the P-glycoprotein, was inhibited. Most probably as a consequence, DXR accumulated in these cells. Kinetic studies showed that OLA behaved as a competitive inhibitor of substrate-mediated MRP-1 transport, whereas MLA acted as a non-competitive one. Moreover, none of both triterpenes induced a compensatory increase in MRP-1 expression. In summary, OLA or MLA sensitized cellular models of STS to DXR and selectively inhibited MRP-1 activity, but not its expression, leading to a higher antitumoral effect possibly relevant for clinical treatment.

  16. Factors influencing the transfection efficiency and cellular uptake mechanisms of Pluronic P123-modified polypropyleneimine/pDNA polyplexes in multidrug resistant breast cancer cells.

    PubMed

    Gu, Jijin; Hao, Junguo; Fang, Xiaoling; Sha, Xianyi

    2016-04-01

    Generally, the major obstacles for efficient gene delivery are cellular internalization and endosomal escape of nucleic acid such as plasmid DNA (pDNA) or small interfering RNA (siRNA). We previously developed Pluronic P123 modified polypropyleneimine (PPI)/pDNA (P123-PPI/pDNA) polyplexes as a gene delivery system. The results showed that P123-PPI/pDNA polyplexes revealed higher transfection efficiency than PPI/pDNA polyplexes in multidrug resistant breast cancer cells. As a continued effort, the present investigation on the factors influencing the transfection efficiency, cellular uptake mechanisms, and intracellular fate of P123-PPI/pDNA polyplexes is reported. The presence of P123 was the main factor influencing the transfection efficiency of P123-PPI/pDNA polyplexes in MCF-7/ADR cells, but other parameters, such as N/P ratio, FBS concentration, incubation time and temperature were important as well. The endocytic inhibitors against clathrin-mediated endocytosis (CME), caveolae-mediated endocytosis (CvME), and macropinocytosis were involved in the internalization to investigate their effects on the cellular uptake and transfection efficiency of P123-PPI/pDNA polyplexes in vitro. The data showed that the internalization of P123-PPI/pDNA polyplexes was obtained from both CME and CvME. Colocalization experiments with TRITC-transferrin (CME indicator), Alexa Fluor 555-CTB (CvME indicator), monoclonal anti-α-tubulin (microtubule indicator), and LysoTracker Green (Endosome/lysosome indicator) were carried out to confirm the internalization routes. The results showed that both CME and CvME played vital roles in the effective transfection of P123-PPI/pDNA polyplexes. Endosome/lysosome system and skeleton, including actin filament and microtubule, were necessary for the transportation after internalization.

  17. Dual drug-loaded biofunctionalized amphiphilic chitosan nanoparticles: Enhanced synergy between cisplatin and demethoxycurcumin against multidrug-resistant stem-like lung cancer cells.

    PubMed

    Huang, Wei-Ting; Larsson, Mikael; Lee, Yi-Chi; Liu, Dean-Mo; Chiou, Guang-Yuh

    2016-12-01

    Lung cancer kills more humans than any other cancer and multidrug resistance (MDR) in cancer stem-like cells (CSC) is emerging as a reason for failed treatments. One concept that addresses this root cause of treatment failure is the utilization of nanoparticles to simultaneously deliver dual drugs to cancer cells with synergistic performance, easy to envision - hard to achieve. (1) It is challenging to simultaneously load drugs of highly different physicochemical properties into one nanoparticle, (2) release kinetics may differ between drugs and (3) general requirements for biomedical nanoparticles apply. Here self-assembled nanoparticles of amphiphilic carboxymethyl-hexanoyl chitosan (CHC) were shown to present nano-microenvironments enabling simultaneous loading of hydrophilic and hydrophobic drugs. This was expanded into a dual-drug nano-delivery system to treat lung CSC. CHC nanoparticles were loaded/chemically modified with the anticancer drug cisplatin and the MDR-suppressing Chinese herbal extract demethoxycurcumin, followed by biofunctionalization with CD133 antibody for enhanced uptake by lung CSC, all in a feasible one-pot preparation. The nanoparticles were characterized with regard to chemistry, size, zeta potential and drug loading/release. Biofunctionalized and non-functionalized nanoparticles were investigated for uptake by lung CSC. Subsequently the cytotoxicity of single and dual drugs, free in solution or in nanoparticles, was evaluated against lung CSC at different doses. From the dose response at different concentrations the degree of synergy was determined through Chou-Talalay's Plot. The biofunctionalized nanoparticles promoted synergistic effects between the drugs and were highly effective against MDR lung CSC. The efficacy and feasible one-pot preparation suggests preclinical studies using relevant disease models to be justified.

  18. Deficient activation of CD95 (APO-1/ Fas)-mediated apoptosis: a potential factor of multidrug resistance in human renal cell carcinoma

    PubMed Central

    Ramp, U; Dejosez, M; Mahotka, C; Czarnotta, B; Kalinski, T; Wenzel, M; Lorenz, I; Müller, M; Krammer, P; Gabbert, H E; Gerharz, C D

    2000-01-01

    factor for the multidrug resistance phenotype of human RCCs. © 2000 Cancer Research Campaign PMID:10839301

  19. Reversing multidrug resistance in hepatocellular carcinoma cells by inhibiting extracellular signal-regulated kinase/mitogen-activated protein kinase signaling pathway activity

    PubMed Central

    CHEN, SIYUAN; WANG, YALI; RUAN, WENWEN; WANG, XIAOMIN; PAN, CHAO

    2014-01-01

    The aim of the present study was to evaluate whether downregulation of extracellular signal-regulated kinase 1/2 (ERK1/2) is involved in conventional reversal methods and whether the inhibitors of the ERK signaling pathway reverse multidrug resistance (MDR) in hepatocellular carcinoma (HCC) cells. The sensitivities of SMMC7721 and BEL7402, and the MDR SMMC7721/Adriamycin (ADM) and BEL7402/ADM HCC cell lines to ADM were evaluated by CellTiter-Glo® luminescent cell viability assay through calculating the half maximal inhibitory concentration (IC50) of ADM. In addition, the expression levels of ERK1/2 and phosphorylated (p)ERK1/2 were determined by western blot analysis subsequent to treatment of the cells with PD98059, an MEK inhibitor, or sorafenib, a multikinase inhibitor. The results revealed that the ADM IC50 for the SMMC7721/ADM cells was 16.44 times higher than that of the SMMC7721 cells (P<0.05), and the ADM IC50 for the BEL7402/ADM cells was 20.34 times higher than that of the BEL7402 cells (P<0.05). Following treatment with PD98059 or sorafenib, the expression levels of pERK1/2 in the MDR cells decreased in a dose-dependent manner. Subsequent to treatment with 5 μM PD98059, the ADM IC50 values for the SMMC7721/ADM and BEL7402/ADM cells were reduced to 0.8±0.056 and 1.583±0.284 μg/ml, respectively. Following treatment with 2.5 μM sorafenib, the ADM IC50 values for the SMMC7721/ADM and BEL7402/ADM cells were reduced to 0.264±0.049 and 1.099±0.135 μg/ml, respectively. Subsequent to incubation with 4 μg/ml cyclosporine A (CsA), a classic MDR reversal agent, the ADM IC50 values in the SMMC7721/ADM and BEL7402/ADM cells were reduced to 0.349±0.023 and 0.427±0.039 μg/ml, respectively. CsA treatment also increased the expression levels of pERK1/2 without affecting the total ERK1/2 levels. Therefore, the inhibition of ERK signaling pathway activity may be an important method to reverse the MDR of HCC cells, but is not unique. PMID:25295120

  20. Nonspecifically enhanced therapeutic effects of vincristine on multidrug-resistant cancers when coencapsulated with quinine in liposomes.

    PubMed

    Xu, Yuzhen; Qiu, Liyan

    2015-01-01

    The use of vincristine (VCR) to treat cancer has been limited by its dose-dependent toxicity and development of drug resistance after repeated administrations. In this study, we investigated the mechanism by which quinine hydrochloride (QN) acts as a sensitizer for VCR. Our experiments used three kinds of multidrug-resistant cancer cells and demonstrated that QN worked by inducing intracellular depletion of adenosine triphosphate, increasing adenosine triphosphatase activity, and decreasing P-glycoprotein expression. Based on these results, we designed and prepared a VCR and QN codelivery liposome (VQL) and investigated the effect of coencapsulated QN on the in vitro cytotoxicity of VCR in cells and three-dimensional multicellular tumor spheroids. The antitumor effects of the formulation were also evaluated in multidrug-resistant tumor-bearing mice. The results of this in vivo study indicated that VQL could reverse VCR resistance. In addition, it reduced tumor volume 5.4-fold when compared with other test groups. The data suggest that VQL could be a promising nanoscaled therapeutic agent to overcome multidrug resistance, and may have important clinical implications for the treatment of cancer.

  1. Sirolimus induces apoptosis and reverses multidrug resistance in human osteosarcoma cells in vitro via increasing microRNA-34b expression

    PubMed Central

    Zhou, Yan; Zhao, Rui-hua; Tseng, Kuo-Fu; Li, Kun-peng; Lu, Zhi-gang; Liu, Yuan; Han, Kun; Gan, Zhi-hua; Lin, Shu-chen; Hu, Hai-yan; Min, Da-liu

    2016-01-01

    Aim: Multi-drug resistance poses a critical bottleneck in chemotherapy. Given the up-regulation of mTOR pathway in many chemoresistant cancers, we examined whether sirolimus (rapamycin), a first generation mTOR inhibitor, might induce human osteosarcoma (OS) cell apoptosis and increase the sensitivity of OS cells to anticancer drugs in vitro. Methods: Human OS cell line MG63/ADM was treated with sirolimus alone or in combination with doxorubicin (ADM), gemcitabine (GEM) or methotrexate (MTX). Cell proliferation and apoptosis were detected using CCK-8 assay and flow cytometry, respectively. MiRNAs in the cells were analyzed with miRNA microarray. The targets of miR-34b were determined based on TargetScan analysis and luciferase reporter assays. The expression of relevant mRNA and proteins was measured using qRT-PCR and Western blotting. MiR-34, PAK1 and ABCB1 levels in 40 tissue samples of OS patients were analyzed using qRT-PCR and in situ hybridization assays. Results: Sirolimus (1–100 nmol/L) dose-dependently suppressed the cell proliferation (IC50=23.97 nmol/L) and induced apoptosis. Sirolimus (10 nmol/L) significantly sensitized the cells to anticancer drugs, leading to decreased IC50 values of ADM, GEM and MTX (from 25.48, 621.41 and 21.72 μmol/L to 4.93, 73.92 and 6.77 μmol/L, respectively). Treatment of with sirolimus increased miR-34b levels by a factor of 7.5 in the cells. Upregulation of miR-34b also induced apoptosis and increased the sensitivity of the cells to the anticancer drugs, whereas transfection with miR-34b-AMO, an inhibitor of miR-34b, reversed the anti-proliferation effect of sirolimus. Two key regulators of cell cycle, apoptosis and multiple drug resistance, PAK1 and ABCB1, were demonstrated to be the direct targets of miR-34b. In 40 tissue samples of OS patients, significantly higher miR-34 ISH score and lower PAK5 and ABCB1 scores were detected in the chemo-sensitive group. Conclusion: Sirolimus increases the sensitivity of human OS

  2. With no interaction, knockdown of Apollon and MDR1 reverse the multidrug resistance of human chronic myelogenous leukemia K562/ADM cells.

    PubMed

    Chen, Jie-Ru; Jia, Xiu-Hong; Wang, Hong; Yi, Ying-Jie; Li, You-Jie

    2017-05-01

    Chemotherapy is the main treatment method for patients with chronic myeloid leukemia (CML) and has achieved marked results. However, the acquisition of multidrug resistance (MDR) has seriously affected the quality of life and survival rate of patients. The overexpression of the inhibitors of apoptosis proteins (IAPs) and the adenosine triphosphate (ATP)-dependent binding cassette (ABC) transporters are the two main causes of MDR. Apollon and MDR1 are the most important and representative members, respectively, among the IAPs and ABC transporters. In the present study, we investigated the role of Apollon and MDR1 in chemotherapy resistance and their mechanism of interaction. We respectively knocked down the expression of Apollon and MDR1 using short hairpin RNA (shRNA) in adriamycin (ADM) resistant human CML K562 cells and examined the drug sensitivity, the consequences with regard to ADM accumulation and the alterations in the expression of Apollon and MDR1. The expression levels of Apollon and MDR1 mRNA were higher in the K562/ADM cells compared with the parental K562 cells as determined by reverse transcription‑polymerase chain reaction (RT-PCR). The plasmids of Apollon and MDR1 shRNA were respectively stably transfected into K562/ADM cells using Lipofectamine 2000. The transfection efficiency was detected by fluorescence microscopy. Cell Counting Kit-8 (CCK-8) assay revealed that Apollon or MDR1 knockdown significantly increased the chemosensitivity of the K562/ADM cells to ADM. Flow cytometric assay revealed that K562/ADM/shMDR1 cells exhibited a significantly increased intracellular accumulation of ADM, and that changes were not found in the K562/ADM/shApollon cells. Compared with the parental K562/ADM cells, a significantly decreased expression of Apollon mRNA and protein was determined in the K562/ADM/shApollon cells without affecting the expression of MDR1 as determined by RT-PCR and western blotting. Likewise, the expression levels of MDR1 m

  3. Control of Multidrug-Resistant Pseudomonas aeruginosa in Allogeneic Hematopoietic Stem Cell Transplant Recipients by a Novel Bundle Including Remodeling of Sanitary and Water Supply Systems.

    PubMed

    Kossow, Annelene; Kampmeier, Stefanie; Willems, Stefanie; Berdel, Wolfgang E; Groll, Andreas H; Burckhardt, Birgit; Claudia, Rossig; Groth, Christoph; Idelevich, Evgeny A; Kipp, Frank; Mellmann, Alexander; Stelljes, Matthias

    2017-09-15

    Infections by multidrug-resistant Pseudomonas aeruginosa (MDRPa) are an important cause of morbidity and mortality in patients after allogeneic hematopoietic stem cell transplantation (HSCT). Humid environments can serve as a reservoir and source of infection by this pathogen. To minimize the risk of infection from these reservoirs, we performed extensive remodeling of sanitation and water installations as the focus of our hygiene bundle. During the reconstruction of our transplantation unit (April 2011-April 2014) we implemented several technical modifications to reduce environmental contamination by and subsequent spreading of MDRPa, including a newly designed shower drain, disinfecting siphons underneath the sinks, and rimless toilets. During a 3-year study period (2012-2014), we tracked the number of patients affected by MDRPa (colonized and/or infected) and the outcome of infected patients, and monitored the environmental occurrence of this pathogen. We further performed whole-genome sequencing of nosocomial MDRPa strains to evaluate genotypic relationships between isolates. Whereas 31 (9.2%; 18 colonized, 13 infected) patients were affected in 2012 and 2013, the number decreased to 3 in 2014 (17%; 3 colonized, 0 infected). Lethality by MDRPa similarly decreased from 3.6% to 0%. Environmental detection of MDRPa decreased in toilets from 18.9% in 2012-2013 to 6.1% in the following year and from 8.1% to 3.0%, respectively, in shower outlets. Whole-genome sequencing showed close relationships between environmental and patient-derived isolates. Hospital construction measures aimed at controlling environmental contamination by and spread of MDRPa are effective at minimizing the risk of highly lethal MDRPa infections.

  4. Chlorhexidine bathing for the prevention of colonization and infection with multidrug-resistant microorganisms in a hematopoietic stem cell transplantation unit over a 9-year period

    PubMed Central

    Mendes, Elisa Teixeira; Ranzani, Otavio T.; Marchi, Ana Paula; da Silva, Mariama Tomaz; Filho, José Ulysses Amigo; Alves, Tânia; Guimarães, Thais; Levin, Anna S.; Costa, Silvia Figueiredo

    2016-01-01

    Abstract Health care associated infections (HAIs) are currently among the major challenges to the care of hematopoietic stem cell transplantation (HSCT) patients. The objective of the present study was to evaluate the impact of 2% chlorhexidine (CHG) bathing on the incidence of colonization and infection with vancomycin-resistant Enterococcus (VRE), multidrug-resistant (MDR) gram-negative pathogens, and to evaluate their CHG minimum inhibitory concentration (MIC) after the intervention. A quasi-experimental study with duration of 9 years was conducted. VRE colonization and infection, HAI rates, and MDR gram-negative infection were evaluated by interrupted time series analysis. The antibacterial susceptibility profile and mechanism of resistance to CHG were analyzed in both periods by the agar dilution method in the presence or absence of the efflux pump inhibitor carbonyl cyanide-m-chlorophenyl hydrazone (CCCP) and presence of efflux pumps (qacA/E, qacA, qacE, cepA, AdeA, AdeB, and AdeC) by polymerase chain reaction (PCR). The VRE colonization and infection rates were significantly reduced in the postintervention period (P = 0.001). However, gram-negative MDR rates in the unit increased in the last years of the study. The CHG MICs for VRE increased during the period of exposure to the antiseptic. A higher MIC at baseline period was observed in MDR gram-negative strains. The emergence of a monoclonal Pseudomonas aeruginosa clone was observed in the second period. Concluding, CHG bathing was efficient regarding VRE colonization and infection, whereas no similar results were found with MDR gram-negative bacteria. PMID:27861350

  5. Profiles of IFN-γ and its regulatory cytokines (IL-12, IL-18 and IL-10) in peripheral blood mononuclear cells from patients with multidrug-resistant tuberculosis

    PubMed Central

    LEE, J-S; SONG, C-H; KIM, C-H; KONG, S-J; SHON, M-H; KIM, H-J; PARK, J-K; PAIK, T-H; JO, E-K

    2002-01-01

    This study investigated the profiles of IFN-γ and its regulatory cytokines (IL-12, IL-18 and IL-10) in response to a purified protein derivative (PPD) antigen in peripheral blood mononuclear cells (PBMC) from 18 HIV-negative patients with multidrug-resistant tuberculosis (MDRTB), and compared them with those from 19 healthy tuberculin reactors (HTR). ELISA results showed that following stimulation with PPD, IFN-γ production was significantly reduced, whereas production of both IL-18 and IL-10 was significantly elevated in MDRTB patients compared with HTR. Three out of 18 patients with MDRTB of greater than 4 years duration showed significantly elevated IL-12 p70 production, induced by in vitro PPD stimulation of their PBMC, when compared with data from HTR. However, when taken as a group, MDRTB patients were similar to HTR in their IL-12 p70-producing capacity. IL-12 p70 protein paralleled IL-12 p40 protein expression. In addition, the production of IL-12 p40 was significantly correlated with IL-10 in all patients, but was not correlated with IFN-γ. Neutralization of IL-10 increased IL-12 p40 about twofold, but did not significantly alter IFN-γ induction in MDRTB. IFN-γ in MDRTB was highly correlated with lymphoproliferation and CD4 counts, but was not correlated with IL-12, IL-18 or IL-10 production. Our findings suggest that patients with MDRTB have dysregulated IL-12, IL-18 and IL-10 production during Mycobacterium tuberculosis infection, and the cytokine profiles are similar to those in patients with drug-sensitive advanced TB previously reported in the literature. In addition, IL-10 may not have a dominant role in defective IFN-γ production in patients with MDRTB. PMID:12067307

  6. Ethyl 2-amino-6-(3,5-dimethoxyphenyl)-4-(2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (CXL017) – a novel scaffold that re-sensitizes multidrug resistant leukemia cells to chemotherapy

    PubMed Central

    Das, Sonia G.; Hermanson, David L.; Bleeker, Nicholas; Lowman, Xazmin; Li, Yunfang; Kelekar, Ameeta; Xing, Chengguo

    2012-01-01

    Multidrug resistance (MDR) is a major hurdle in the treatment of cancer and there is a pressing need for new therapies. We have recently developed ethyl 2-amino-6-(3,5-dimethoxyphenyl)-4-(2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (CXL017), derived from a dual inhibitor of Bcl-2 and SERCA proteins – sHA 14-1, with selective cytotoxicity towards MDR cancer cell lines in vitro. In this study, we present new evidence for its therapeutic potential in treatment of MDR cancers and offer mechanistic insights towards its preferential targeting of drug resistant cancer. CXL017 selectively suppressed the growth of tumors derived from the MDR cancer cell line, HL60/MX2, in vivo. In addition, even after chronic exposure to CXL017, HL60/MX2 failed to develop stable resistance to CXL017, whereas it acquired > 2000-fold resistance to cytarabine (Ara-C) – the major first-line chemotherapy for the treatment of acute myeloid leukemia (AML). Remarkably, instead of acquiring further cross-resistance, HL60/MX2 cells exposed to CXL017 were re-sensitized to standard therapies (10 to 100-fold). Western blotting analyses revealed that CXL017 exposure significantly down-regulated Mcl-1 and Bax and up-regulated Noxa, Bim, Bcl-XL, SERCA2, and SERCA3 proteins, along with a reduction in endoplasmic reticulum (ER) calcium content. Given the well-established functions of Bcl-2 family proteins and ER calcium in drug resistance, our results suggest that the down-regulation of Mcl-1 and the up-regulation of Noxa and Bim along with the decrease in ER calcium content are likely responsible for CXL017 induced re-sensitization of MDR cancer cells. These data also demonstrate the unique potential of CXL017 to overcome MDR in cancer treatment. PMID:23102022

  7. Ethyl 2-amino-6-(3,5-dimethoxyphenyl)-4-(2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (CXL017): a novel scaffold that resensitizes multidrug resistant leukemia cells to chemotherapy.

    PubMed

    Das, Sonia G; Hermanson, David L; Bleeker, Nicholas; Lowman, Xazmin; Li, Yunfang; Kelekar, Ameeta; Xing, Chengguo

    2013-02-15

    Multidrug resistance (MDR) is a major hurdle in the treatment of cancer, and there is a pressing need for new therapies. We have recently developed ethyl 2-amino-6-(3,5-dimethoxyphenyl)-4-(2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (CXL017), derived from a dual inhibitor of Bcl-2 and SERCA proteins, sHA 14-1, with selective cytotoxicity toward MDR cancer cell lines in vitro. In this study, we present new evidence for its therapeutic potential in treatment of MDR cancers and offer mechanistic insights toward its preferential targeting of drug-resistant cancer. CXL017 selectively suppressed the growth of tumors derived from the MDR cancer cell line, HL60/MX2, in vivo. In addition, even after chronic exposure to CXL017, HL60/MX2 failed to develop stable resistance to CXL017, whereas it acquired >2000-fold resistance to cytarabine (Ara-C), the major first-line chemotherapy for the treatment of acute myeloid leukemia (AML). Remarkably, instead of acquiring further cross-resistance, HL60/MX2 cells exposed to CXL017 were resensitized to standard therapies (10- to 100-fold). Western blotting analyses revealed that CXL017 exposure significantly down-regulated Mcl-1 and Bax and up-regulated Noxa, Bim, Bcl-X(L), SERCA2, and SERCA3 proteins, along with a reduction in endoplasmic reticulum (ER) calcium content. Given the well-established functions of Bcl-2 family proteins and ER calcium in drug resistance, our results suggest that the down-regulation of Mcl-1 and the up-regulation of Noxa and Bim along with the decrease in ER calcium content are likely responsible for CXL017-induced resensitization of MDR cancer cells. These data also demonstrate the unique potential of CXL017 to overcome MDR in cancer treatment.

  8. Identification of the hepatic efflux transporters of organic anions using double-transfected Madin-Darby canine kidney II cells expressing human organic anion-transporting polypeptide 1B1 (OATP1B1)/multidrug resistance-associated protein 2, OATP1B1/multidrug resistance 1, and OATP1B1/breast cancer resistance protein.

    PubMed

    Matsushima, Soichiro; Maeda, Kazuya; Kondo, Chihiro; Hirano, Masaru; Sasaki, Makoto; Suzuki, Hiroshi; Sugiyama, Yuichi

    2005-09-01

    Until recently, it was generally believed that the transport of various organic anions across the bile canalicular membrane was mainly mediated by multidrug resistance-associated protein 2 (MRP2/ABCC2). However, a number of new reports have shown that some organic anions are also substrates of multidrug resistance 1 (MDR1/ABCB1) and/or breast cancer resistance protein (BCRP/ABCG2), implying MDR1 and BCRP could also be involved in the biliary excretion of organic anions in humans. In the present study, we constructed new double-transfected Madin-Darby canine kidney II (MDCKII) cells expressing organic anion-transporting polypeptide 1B1 (OATP1B1)/MDR1 and OATP1B1/BCRP, and we investigated the transcellular transport of four kinds of organic anions, estradiol-17beta-d-glucuronide (EG), estrone-3-sulfate (ES), pravastatin (PRA), and cerivastatin (CER), to identify which efflux transporters mediate the biliary excretion of compounds using double-transfected cells. We observed the vectorial transport of EG and ES in all the double transfectants. MRP2 showed the highest efflux clearance of EG among these efflux transporters, whereas BCRP-mediated clearance of ES was the highest in these double transfectants. In addition, two kinds of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, CER and PRA, were also substrates of all these efflux transporters. The rank order of the efflux clearance of PRA mediated by each transporter was the same as that of EG, whereas the contribution of MDR1 to the efflux of CER was relatively greater than for PRA. This experimental system is very useful for identifying which transporters are involved in the biliary excretion of organic anions that cannot easily penetrate the plasma membrane.

  9. Upregulation of the inwardly rectifying potassium channel Kir2.1 (KCNJ2) modulates multidrug resistance of small-cell lung cancer under the regulation of miR-7 and the Ras/MAPK pathway.

    PubMed

    Liu, Huanxin; Huang, Jie; Peng, Juan; Wu, Xiaoxia; Zhang, Yan; Zhu, Weiliang; Guo, Linlang

    2015-03-12

    KCNJ2/Kir2.1, a member of the classical inwardly rectifying potassium channel family, is commonly expressed in a wide range of tissues and cell types. Previous studies indicated that Kir2.1 may be associated with SCLC multidrug resistance (MDR). However, whether Kir2.1 can regulate MDR and its underlying mechanisms remain poorly understood in SCLC. KCNJ2/Kir2.1 expression was examined in tissues from fifty-two SCLC cases by immunohistochemistry. Overexpression or knockdown of KCNJ2/Kir21 was performed in multidrug-resistant SCLC cell lines (H69AR and H446AR) and their parental cell lines (H69 and H446) to assess its influence on cell growth, apoptosis, the cell cycle and chemoresistance. KCNJ2/Kir2.1 was expressed in 44.23% (23/52) of SCLC tissues. Overexpression of KCNJ2/Kir2.1 was correlated with the clinical stage and chemotherapy response in SCLC patients. Knockdown of KCNJ2/Kir2.1 expression using KCNJ2/Kir2.1 shRNA in H69AR and H446AR cells inhibited cell growth and sensitized the cancer cells to chemotherapeutic drugs by increasing cell apoptosis and cell cycle arrest. Forced KCNJ2/Kir2.1 expression in H69 and H446 cells promoted cell growth and enhanced multidrug resistance via reduced drug-induced apoptosis accompanied by cell cycle arrest. KCNJ2/Kir2.1 expression was also influenced by PKC and MEK inhibitors. In addition, multidrug resistance protein 1 (MRP1/ABCC1) was confirmed to interact with KCNJ2/Kir2.1 by Co-IP assays. KCNJ2/Kir2.1 modulates cell growth and drug resistance by regulating MRP1/ABCC1 expression and is simultaneously regulated by the Ras/MAPK pathway and miR-7. KCNJ2/Kir2.1 may be a prognostic predictor and a potentially novel target for interfering with chemoresistance in SCLC.

  10. Low dose of arsenic trioxide inhibits multidrug resistant-related P-glycoprotein expression in human neuroblastoma cell line.

    PubMed

    Liu, Ling; Li, Yang; Xiong, Xilin; Qi, Kai; Zhang, Chi; Fang, Jianpei; Guo, Haixia

    2016-12-01

    This study investigated arsenic trioxide (As2O3), cisplatin (DDP) and etoposide (Vp16) on the anticancer effects and P-glycoprotein (P-gp) expression in neuroblastoma (NB) SK-N-SH cells. The potential influence of As2O3, DDP and Vp16 currently included in NB routine treatment protocols on cytotoxicity in SK-N-SH cells was measured by flow cytometry and drug half-maximal inhibitory concentration (IC50) was established. Moreover, chemotherapeutic agent-mediated changes of cellular expression levels of resistant-related P-gp, was monitored using western blotting. The data showed that As2O3, DDP and Vp16 significantly inhibited the growth and survival of the SK-N-SH cells at different concentration. Notably, the levels of apoptosis were upregulated in SK-N-SH cells with an acceleration of the exposure time and the concentration of As2O3, DDP and Vp16. As2O3, DDP and Vp16 were observed with their IC50 values on SK-N-SH cells being 3 µM, 8 and 100 µg/ml, respectively. Flow cytometry analysis showed that As2O3 at low concentrations in SK-N-SH cells led to enhanced accumulation of cell populations in G2/M phase with increasing the exposure time, and increased levels of apoptosis. In contrast, we observed that SK-N-SH cell populations arrested in S phase by DDP and Vp16. In vitro examination revealed that following pretreatment of SK-N-SH cells with As2O3, the expression of P-gp was not increased. The expression of P-gp downregulation were noted following the group treated by As2O3 at 2 and 3 µM. Exposed to As2O3 at 3 µM for 72 h, SK-N-SH cells exhibited lower expression of P-gp than 2 µM As2O3 for 72 h. In contrast, the expression of P-gp was upregulated by DDP and VP16. In summary, SK-N-SH cells were responsive to chemotherapeutic agent-induced apoptosis in a dose-dependent and time-dependent manner. In particular, ours findings showed that low dose of As2O3 markedly reduced the P-gp expression and increased apoptotic cell death in human NB cell line.

  11. The enriched fraction of Elephantopus scaber Triggers apoptosis and inhibits multi-drug resistance transporters in human epithelial cancer cells

    PubMed Central

    Beeran, Asmy Appadath; Maliyakkal, Naseer; Rao, Chamallamudi Mallikarjuna; Udupa, Nayanabhirama

    2015-01-01

    Background: Medicinal plants have played an important role in the development of clinically useful anticancer agents. Elephantopus scaber (Asteraceae) (ES) is widely used in Indian traditional system of medicine for the treatment of various ailments including cancer. Objective: To investigate anticancer effects of ES in human epithelial cancer cells. Materials and Methods: Cytotoxicity of ethanolic extract of ES (ES-ET) and its fractions, such as ES Petroleum ether fraction (ES-PET), ES Dichloromethane fraction (ES DCM), n Butyl alcohol fraction (ES-BT), and ES-Rest (ES-R) were assessed in human epithelial cancer cell lines using sulforhodamine B (SRB) assay. Acridine orange/ethidium bromide assay and Hoechst 33342 assays were used to gauge induction of apoptosis. Cell cycle analysis and micronuclei assay were used to assess cell cycle specific pharmacological effects and drug induced genotoxicty. Further, the ability of ES to inhibit multi drug resistant (MDR) transporters (ABC-B1 and ABC-G2) was determined by Rhodamine (Rho) and Mitoxantrone (MXR) efflux assays. Results: The enriched fraction of ES (ES DCM) possessed dose-dependent potent cytotoxicity in human epithelial cancer cells. Further, treatment of cancer cells (HeLa, A549, MCF-7, and Caco-2) with ES DCM showed hall mark properties of apoptosis (membrane blebbing, nuclear condensation etc.). Similarly, ES DCM caused enhanced sub G0 content and micronuclei formation indicating the induction of apoptosis and drug induced genotoxicity in cancer cells, respectively. Interestingly, ES DCM inhibited MDR transporters (ABC B1 and ABC G2) in cancer cells. Conclusion: The enriched fraction of ES imparted cytotoxic effects, triggered apoptosis, induced genotoxicity, and inhibited MDR transporters in human epithelial cancer cells. Thus, ES appears to be potential anticancer agent. PMID:25829763

  12. [Effect of small interfering RNA targeting multidrug resistance-related protein and bcl-2 on drug resistance and apoptosis of K562 and K562/ADM cells].

    PubMed

    Song, Zhao-yang; Hu, Hai-yan; Deng, Lan; Wu, Bing-yi; Guo, Kun-yuan; Zhang, Mei-xia

    2008-07-01

    To observe the effect of small interfering RNA (siRNA) targeting multidrug resistance-related protein (MRP) and bcl-2 genes in modulating drug resistance and apoptosis of K562 and K562/ADM cells. Two siRNA constructs targeting respectively bcl-2 and MRP genes, were synthesized and transfected either alone or in combination into K562 and K562/ADM cells via lipofectamine2000. MTT assay was used to evaluate the viability of the transfected cells at 24, 48 and 72 h Post-fransfection, and RT-PCR was performed to determine the mRNA levels of bcl-2 and MRP. The effects of MRP siRNA and bcl2 siRNA on the apoptosis and the protein expression of Bcl-2 and MRP were evaluated with flow cytometry. In K562/ADM cells, the IC (50) decreased from 12.81 microg/ml (ADM group) to 3.74 microg/ml (ADM+MRP siRNA group), 6.82 microg/ml (ADM+bcl2 siRNA group) and 2.51 microg/ml (ADM+MRP siRNA+bcl2 siRNA). Similarly, in K562 cells, the IC50 decreased significantly from 6.75 microg/ml (ADM) to 3.22 microg/ml (ADM+MRP siRNA), 3.56 microg/ml (ADM+bcl2 siRNA) and 1.84 microg/ml (ADM+MRP siRNA+bcl2 siRNA) (P<0.05). Flow cytometry demonstrated significantly increased apoptosis of the cells following MRP siRNA and bcl2 siRNA transfection, which also resulted in significantly decreased expressions of MRP and bcl-2 proteins (P<0.05). Treatment with both MRP and bcl-2 siRNAs inhibits the target gene expression, and increases the drug sensitivity and apoptosis of K562 and K562/ADM cells.

  13. Cationic PEGylated liposomes incorporating an antimicrobial peptide tilapia hepcidin 2-3: an adjuvant of epirubicin to overcome multidrug resistance in cervical cancer cells.

    PubMed

    Juang, Vivian; Lee, Hsin-Pin; Lin, Anya Maan-Yuh; Lo, Yu-Li

    Antimicrobial peptides (AMPs) have been recently evaluated as a new generation of adjuvants in cancer chemotherapy. In this study, we designed PEGylated liposomes encapsulating epirubicin as an antineoplastic agent and tilapia hepcidin 2-3, an AMP, as a multidrug resistance (MDR) transporter suppressor and an apoptosis/autophagy modulator in human cervical cancer HeLa cells. Cotreatment of HeLa cells with PEGylated liposomal formulation of epirubicin and hepcidin 2-3 significantly increased the cytotoxicity of epirubicin. The liposomal formulations of epirubicin and/or hepcidin 2-3 were found to noticeably escalate the intracellular H2O2 and O2(-) levels of cancer cells. Furthermore, these treatments considerably reduced the mRNA expressions of MDR protein 1, MDR-associated protein (MRP) 1, and MRP2. The addition of hepcidin 2-3 in liposomes was shown to markedly enhance the intracellular epirubicin uptake and mainly localized into the nucleus. Moreover, this formulation was also found to trigger apoptosis and autophagy in HeLa cells, as validated by significant increases in the expressions of cleaved poly ADP ribose polymerase, caspase-3, caspase-9, and light chain 3 (LC3)-II, as well as a decrease in mitochondrial membrane potential. The apoptosis induction was also confirmed by the rise in sub-G1 phase of cell cycle assay and apoptosis percentage of annexin V/propidium iodide assay. We found that liposomal epirubicin and hepcidin 2-3 augmented the accumulation of GFP-LC3 puncta as amplified by chloroquine, implying the involvement of autophagy. Interestingly, the partial inhibition of necroptosis and the epithelial-mesenchymal transition by this combination was also verified. Altogether, our results provide evidence that coincubation with PEGylated liposomes of hepcidin 2-3 and epirubicin caused programmed cell death in cervical cancer cells through modulation of multiple signaling pathways, including MDR transporters, apoptosis, autophagy, and/or necroptosis

  14. Cationic PEGylated liposomes incorporating an antimicrobial peptide tilapia hepcidin 2–3: an adjuvant of epirubicin to overcome multidrug resistance in cervical cancer cells

    PubMed Central

    Juang, Vivian; Lee, Hsin-Pin; Lin, Anya Maan-Yuh; Lo, Yu-Li

    2016-01-01

    Antimicrobial peptides (AMPs) have been recently evaluated as a new generation of adjuvants in cancer chemotherapy. In this study, we designed PEGylated liposomes encapsulating epirubicin as an antineoplastic agent and tilapia hepcidin 2–3, an AMP, as a multidrug resistance (MDR) transporter suppressor and an apoptosis/autophagy modulator in human cervical cancer HeLa cells. Cotreatment of HeLa cells with PEGylated liposomal formulation of epirubicin and hepcidin 2–3 significantly increased the cytotoxicity of epirubicin. The liposomal formulations of epirubicin and/or hepcidin 2–3 were found to noticeably escalate the intracellular H2O2 and O2− levels of cancer cells. Furthermore, these treatments considerably reduced the mRNA expressions of MDR protein 1, MDR-associated protein (MRP) 1, and MRP2. The addition of hepcidin 2–3 in liposomes was shown to markedly enhance the intracellular epirubicin uptake and mainly localized into the nucleus. Moreover, this formulation was also found to trigger apoptosis and autophagy in HeLa cells, as validated by significant increases in the expressions of cleaved poly ADP ribose polymerase, caspase-3, caspase-9, and light chain 3 (LC3)-II, as well as a decrease in mitochondrial membrane potential. The apoptosis induction was also confirmed by the rise in sub-G1 phase of cell cycle assay and apoptosis percentage of annexin V/propidium iodide assay. We found that liposomal epirubicin and hepcidin 2–3 augmented the accumulation of GFP-LC3 puncta as amplified by chloroquine, implying the involvement of autophagy. Interestingly, the partial inhibition of necroptosis and the epithelial–mesenchymal transition by this combination was also verified. Altogether, our results provide evidence that coincubation with PEGylated liposomes of hepcidin 2–3 and epirubicin caused programmed cell death in cervical cancer cells through modulation of multiple signaling pathways, including MDR transporters, apoptosis, autophagy, and

  15. STROBE-compliant integrin through focal adhesion involve in cancer stem cell and multidrug resistance of ovarian cancer

    PubMed Central

    Wei, Luwei; Yin, Fuqiang; Zhang, Wei; Li, Li

    2017-01-01

    Abstract Cancer stem cells (CSCs) are considered to be the root of carcinoma relapse and drug resistance in ovarian cancer. Hunting for the potential CSC genes and explain their functions would be a feasible strategy to meet the challenge of the drug resistance in ovarian cancer. In this study, we performed bioinformatic approaches such as biochip data extraction and pathway enrichment analyses to elucidate the mechanism of the CSC genes in regulation of drug resistance. Potential key genes, integrins, were identified to be related to CSC in addition to their associations with drug resistance and prognosis in ovarian cancer. A total of 36 ovarian CSC genes involved in regulation of drug resistance were summarized, and potential drug resistance-related CSC genes were identified based on 3 independent microarrays retrieved from the Gene Expression Omnibus (GEO) Profiles. Pathway enrichment of CSC genes associated with drug resistance in ovarian cancer indicated that focal adhesion signaling might play important roles in CSC genes-mediated drug resistance. Integrins are members of the adhesion molecules family, and integrin subunit alpha 1, integrin subunit alpha 5, and integrin subunit alpha 6 (ITGA6) were identified as central CSC genes and their expression in side population cells, cisplatin-resistant SKOV3 (SKOV3/DDP2) cells, and cisplatin-resistant A2780 (A2780/DDP) cells were dysregulated as measured by real-time quantitative polymerase chain reaction. The high expression of ITGA6 in 287 ovarian cancer patients of TCGA cohort was significantly associated with poorer progression-free survival. This study provide the basis for further understanding of CSC genes in regulation of drug resistance in ovarian cancer, and integrins could be a potential biomarker for prognosis of ovarian cancer. PMID:28328815

  16. Multidrug Resistance-Associated Protein 4 (MRP4/ABCC4) Controls Efflux Transport of Hesperetin Sulfates in Sulfotransferase 1A3-Overexpressing Human Embryonic Kidney 293 Cells.

    PubMed

    Sun, Hua; Wang, Xiao; Zhou, Xiaotong; Lu, Danyi; Ma, Zhiguo; Wu, Baojian

    2015-10-01

    Sulfonation is an important metabolic pathway for hesperetin. However, the mechanisms for the cellular disposition of hesperetin and its sulfate metabolites are not fully established. In this study, disposition of hesperetin via the sulfonation pathway was investigated using human embryonic kidney (HEK) 293 cells overexpressing sulfotransferase 1A3. Two monosulfates, hesperetin-3'-O-sulfate (H-3'-S) and hesperetin-7-O-sulfate (H-7-S), were rapidly generated and excreted into the extracellular compartment upon incubation of the cells with hesperetin. Regiospecific sulfonation of hesperetin by the cell lysate followed the substrate inhibition kinetics (Vmax = 0.66 nmol/min per mg, Km = 12.9 μM, and Ksi= 58.1 μM for H-3'-S; Vmax = 0.29 nmol/min per mg, Km = 14.8 μM, and Ksi= 49.1 μM for H-7-S). The pan-multidrug resistance-associated protein (MRP) inhibitor MK-571 at 20 μM essentially abolished cellular excretion of both H-3'-S and H-7-S (the excretion activities were only 6% of the control), whereas the breast cancer resistance protein-selective inhibitor Ko143 had no effects on sulfate excretion. In addition, knockdown of MRP4 led to a substantial reduction (>47.1%; P < 0.01) in sulfate excretion. Further, H-3'-S and H-7-S were good substrates for transport by MRP4 according to the vesicular transport assay. Moreover, sulfonation of hesperetin and excretion of its metabolites were well characterized by a two-compartment pharmacokinetic model that integrated drug uptake and sulfonation with MRP4-mediated sulfate excretion. In conclusion, the exporter MRP4 controlled efflux transport of hesperetin sulfates in HEK293 cells. Due to significant expression in various organs/tissues (including the liver and kidney), MRP4 should be a determining factor for the elimination and body distribution of hesperetin sulfates. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  17. Multidrug resistance-associated protein (MRP1, 2, 4 and 5) expression in human corneal cell culture models and animal corneal tissue.

    PubMed

    Verstraelen, Jessica; Reichl, Stephan

    2014-07-07

    Preclinical studies addressing the transcorneal absorption of ophthalmic drugs are mainly performed using ex vivo animal corneas and in vitro corneal cell culture models, leaving open the question of transferability to humans in an in vivo situation. While passive drug absorption through corneal tissue is well understood, little is known about the expression of transporter proteins and active drug transport in human and animal corneas as well as corneal cell culture models. Therefore, the aim of this study was to conduct an expression analysis of four multidrug resistance-associated proteins (MRP1, 2, 4 and 5) in various in vitro and ex vivo corneal models, leading to a better understanding of the comparability of different corneal models regarding drug absorption and transferability to humans. Two well-established in vitro human corneal models, the HCE-T epithelial model and the more organotypic Hemicornea construct, both of which are based on the SV40 immortalized human corneal epithelial cell line HCE-T, were analyzed, as were excised rabbit and porcine cornea. Specimens of abraded epithelia from human donor corneas were also tested. MRP mRNA expression was determined via reverse transcriptase polymerase chain reaction. Protein expression was examined using Western blot experiments and immunohistochemistry. The functional activity of the MRP efflux transporter was detected in transport assays using specific marker and inhibitor substances. The functional expression of all of the tested MRP transporters was detected in the HCE-T epithelial model. Hemicornea constructs displayed a similar expression pattern for MRP1, 4 and 5, whereas no MRP2 protein expression or activity was detected. However, excised animal corneas exhibited different expression profiles. In porcine cornea, no functional expression of MRP1, 2, or 5 was observed, and we failed to detect MRP4 expression in rabbit cornea. The results suggest that MRP1, 2, 4, and 5 are expressed in the human corneal

  18. Cyclosporin A as a multidrug-resistant modulator in patients with renal cell carcinoma treated with teniposide.

    PubMed Central

    Toffoli, G.; Sorio, R.; Gigante, M.; Corona, G.; Galligioni, E.; Boiocchi, M.

    1997-01-01

    Patients with refractory metastatic renal cell carcinoma (RCC) were enrolled in a phase II study with teniposide (VM26) and cyclosporin A (CSA) to investigate (1) the effect of CSA on the response rate to VM26; and (2) the effect of CSA on the pharmacokinetics and pharmacodynamics of VM26. Sixteen patients initially received VM26 alone (200 mg m(-2) day(-1) i.v.). No objective responses were observed and all patients crossed over to receive at least an additional two courses (range 2-5) of VM26 plus CSA (5 mg kg(-1) 2h(-1) followed by 30 mg kg(-1) 48h(-1) i.v.). At the end of the 2-h loading dose of CSA, whole-blood CSA levels ranged from 2250 to 3830 ng ml(-1), whereas at the end of the 48-h CSA infusion, CSA ranged from 1830 to 4501 ng ml(-1). CSA significantly (P<0.01) increased the area under the curve (AUC) of VM26. The variation in the paired AUC of VM26 was 50%. Terminal half-life of VM26 was significantly (P<0.01) increased (1.72-fold) after CSA administration, whereas the systemic clearance of VM26 was decreased by 1.4-fold (P<0.01). The nadir neutrophil count after VM26 plus CSA (median 700 microl(-1), range <100 to 2860 microl(-1)) was lower than after VM26 alone (median 1900 microl(-1), range 200 to 6000 microl(-1)). Increased haematological toxicity after CSA could be explained by the increase in the VM26 AUC and by inhibition of P-glycoprotein (P-gp) activity in haematopoietic precursor cells. Bilirubin concentrations in the serum were increased after VM26 plus CSA compared with VM26 alone (P<0.01). Among the 15 patients evaluable for response, one had a minor response, eight had stable disease, and six had progressive disease. In conclusion, the dose of CSA we used achieved plasma concentrations within the effective range for P-gp inhibition. CSA affected both the pharmacokinetics and pharmacodynamics of VM26 in the patients, principally by increasing the plasma concentrations of the antineoplastic drug and VM26 haemopoietic toxicity. PMID:9043030

  19. Multidrug resistance: an emerging crisis.

    PubMed

    Tanwar, Jyoti; Das, Shrayanee; Fatima, Zeeshan; Hameed, Saif

    2014-01-01

    The resistance among various microbial species (infectious agents) to different antimicrobial drugs has emerged as a cause of public health threat all over the world at a terrifying rate. Due to the pacing advent of new resistance mechanisms and decrease in efficiency of treating common infectious diseases, it results in failure of microbial response to standard treatment, leading to prolonged illness, higher expenditures for health care, and an immense risk of death. Almost all the capable infecting agents (e.g., bacteria, fungi, virus, and parasite) have employed high levels of multidrug resistance (MDR) with enhanced morbidity and mortality; thus, they are referred to as "super bugs." Although the development of MDR is a natural phenomenon, the inappropriate use of antimicrobial drugs, inadequate sanitary conditions, inappropriate food-handling, and poor infection prevention and control practices contribute to emergence of and encourage the further spread of MDR. Considering the significance of MDR, this paper, emphasizes the problems associated with MDR and the need to understand its significance and mechanisms to combat microbial infections.

  20. Vitamin E Reverses Multidrug Resistance In Vitro and In Vivo

    PubMed Central

    Tang, Jingling; Fu, Qiang; Wang, Yongjun; Racette, Kelly; Wang, Dun; Liu, Feng

    2013-01-01

    Multidrug resistance (MDR) is a major obstacle to successful and effective chemotherapeutic treatments of cancers. This study explored the reversal effects of vitamin E on MDR tumor cells in vitro and in vivo, elucidating the potential mechanism of this reversal. VE at a concentration of 50 μM exhibited a significant reversal of the MDR effect (compared to only PTX in DMSO, p < 0.05) in two human MDR cell lines (H460/taxR and KB-8-5). The MDR cell xenograft model was established to investigate the effect of VE on reversing MDR in vivo. Mice intravenously injected with Taxol (10 mg/kg) with VE (500 mg/kg, IP) showed an ability to overcome the MDR. VE and its derivatives can significantly increase intracellular accumulation of rhodamine 123 and doxorubicin (P-gp substrate), but not alter the levels of P-gp expression. These treatments also did not decrease the levels of intracellular ATP, but were still able to inhibit the verapamil-induced ATPase activity of P-gp. The new application of VE as an MDR sensitizer will be attractive due to the safety of this treatment. PMID:23624302

  1. Overcoming cancer multidrug resistance by codelivery of doxorubicin and verapamil with hydrogel nanoparticles.

    PubMed

    Qin, Ming; Lee, Yong-Eun Koo; Ray, Aniruddha; Kopelman, Raoul

    2014-08-01

    The efficacy of chemotherapy is often inhibited by multidrug resistance (MDR). A highly engineerable hydrogel nanoparticle (NP) serves as a carrier for the optimal codelivery to tumor cells of the chemodrug, doxorubicin (Dox) and the chemosensitizer, verapamil (Vera), aiming at alleviating tumor MDR. The hydrogel NPs are prepared via the copolymerization of acrylamide and 2-carboxyethyl acrylate. Dox and Vera are post-loaded into the respective NPs, with drug loading around 7.7 wt% and 8.0 wt%, respectively. The codelivery of Dox-NPs and Vera-NPs increases the intracellular accumulation of Dox, and significantly enhances the cell killing ability of Dox with respect to NCI/ADR-RES cells in vitro. These findings suggest that such codelivery nanoplatforms provide a promising route for overcoming tumor MDR.

  2. Antitumor agents. 293. Nontoxic dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'-dicarboxylate (DDB) analogues chemosensitize multidrug-resistant cancer cells to clinical anticancer drugs.

    PubMed

    Hung, Hsin-Yi; Ohkoshi, Emika; Goto, Masuo; Bastow, Kenneth F; Nakagawa-Goto, Kyoko; Lee, Kuo-Hsiung

    2012-06-14

    Novel dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'-dicarboxylate (DDB) analogues were designed and synthesized to improve their chemosensitizing action on KBvin (vincristine-resistant nasopharyngeal carcinoma) cells, a multidrug resistant cell line overexpressing P-glycoprotein (P-gp). Structure-activity relationship analysis showed that aromatic and bulky aliphatic side chains at the 2,2'-positions effectively and significantly sensitized P-gp overexpressing multidrug resistant (MDR) cells to anticancer drugs, such as paclitaxel (TAX), vincristine (VCR), and doxorubicin (DOX). DDB derivatives 16 and 23 showed 5-10 times more effective reversal ability than verapamil (VRP) for TAX and VCR. Analogue 6 also exhibited five times greater chemosensitizing effect against DOX than VRP. Importantly, no cytotoxicity was observed by the active DDB analogues against both non-MDR and MDR cells, suggesting that DDB analogues serve as novel lead compounds for the development of chemosensitizers to overcome the MDR phenotype. The mechanism of action studies demonstrated that effective inhibition of P-glycoprotein by DDB analogues dramatically elevated the cellular concentration of anticancer drugs.

  3. Simulated microgravity reduces mRNA levels of multidrug resistance genes 4 and 5 in non-metastatic human melanoma cells

    NASA Astrophysics Data System (ADS)

    Eiermann, Peter; Tsiockas, Wasiliki; Hauslage, Jens; Hemmersbach, Ruth; Gerzer, Rupert; Ivanova, Krassimira

    Multidrug resistance proteins (MRP) are members of the ATP-binding cassette transporter superfamily that are able to export a large variety of substances into the extracellular space in-cluding nucleoside and nucleotide base analogs used in antiviral and anticancer therapy. MRP4 and 5 (MRP4/5) particularly transport cyclic nucleotides, e.g. guanosine 3',5'-cyclic monophos-phate (cGMP). The second messenger cGMP, which is synthesized by the catalytic activity of the guanylyl cyclase (GC), plays an import role in vasodilatation, smooth muscle relaxation, and nitric oxide (NO)-induced perturbation of melanocyte-extracellular matrix interactions. In previous studies we have reported that different GC isoforms are responsible for cGMP synthe-sis in melanocytic cells. Normal human melanocytes and non-metastatic melanoma cell lines predominantly express the NO-sensitive soluble GC isoform (sGC), a heterodimeric protein consisting of α and β subunits. Metastatic melanoma cells lack the expression of the β sub-unit and show up-regulated activities of the particulate isoforms. We have further found that long-term exposure to hypergravity (5 g for 24 h) induced an increased cGMP export in normal human melanocytes, and non-metastatic, but not in metastatic human melanoma cells as a re-sult of up-regulated MRP4/5 expression. The aim of the present study is to investigate whether simulated microgravity may also alter the expression of MRP4/5 in non-metastatic melanoma cells. Experiments were performed using a fast-rotating clinostat (60 rpm) with one rotation axis. The non-metastatic 1F6 melanoma cells were exposed to simulated microgravity (up to 1.21x10-2 g) for 24 h. The mRNA analyses were performed by a relative calibrator-normalized and efficiency corrected quantitative polymerase chain reaction (Light Cycler R , Roche). Our data show a reduced expression of approximately 35% for MRP4 and of 50% for MRP5 in simulated microgravity in comparison to 1 g controls. Also, the

  4. Induction of apoptosis and reversal of permeability glycoprotein-mediated multidrug resistance of MCF-7/ADM by ginsenoside Rh2

    PubMed Central

    Zhang, Hui; Gong, Jian; Zhang, Huilai; Kong, Di

    2015-01-01

    Multidrug resistance is a phenomenon that cancer cells develop a cross-resistant phenotype against several unrelated drugs, and permeability glycoprotein derived from the overexpression of multidrug resistance gene 1 has been taken as the most significant cause of multidrug resistance. In the present study, ginsenoside Rh2 was used to reverse permeability glycoprotein-mediated multidrug resistance of MCF-7/ADM cell line. Effects of ginsenoside Rh2 on the apoptotic process and caspase-3 activity of MCF-7 and MCF-7/ADM cell lines were determined using flow cytometry and microplate reader. Methyl thiazolyl tetrazolium test was conducted to assess the IC50 values of ginsenoside Rh2 and adriamycin on MCF-7 and MCF-7/ADM cultures; Rhodamin 123 assay was used to assess the retention of permeability glycoprotein after ginsenoside Rh2 treatment; flow cytometry and real time polymerase chain reaction were used to determine the expression levels of permeability glycoprotein and multidrug resistance gene 1 in drug-resistant cells and their parental cells after exposure to ginsenoside Rh2. The results showed that ginsenoside Rh2, except for inducing apoptosis, had the ability to reverse multidrug resistance in MCF-7/ADM cell line without changing the expression levels of permeability glycoprotein and multidrug resistance gene 1. Our findings provided some valuable information for the application of ginsenoside Rh2 in cancer therapy, especially for multidrug resistance reversal in clinic. PMID:26191135

  5. Induction of apoptosis and reversal of permeability glycoprotein-mediated multidrug resistance of MCF-7/ADM by ginsenoside Rh2.