scholarly journals Mitochondrial Breast Cancer Resistant Protein Sustains the Proliferation and Survival of Drug-Resistant Breast Cancer Cells by Regulating Intracellular Reactive Oxygen Species

2021 ◽  
Vol 9 ◽  
Author(s):  
He Zhang ◽  
Xingxing Han ◽  
Zhaosong Wang ◽  
Zhiyong Wang ◽  
Yanfen Cui ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Abc Transporters ◽  
Breast Cancer Cells ◽  
Intracellular Reactive Oxygen Species ◽  
Drug Resistant ◽  
Oxygen Species ◽  
Drug Pump ◽  
Resistant Cells

ATP-binding cassette (ABC) transporter family are major contributors to the drug resistance establishment of breast cancer cells. Breast cancer resistant protein (BCRP), one of the ABC transporters, has long been recognized as a pump that effluxes the therapeutic drugs against the concentration gradient. However, recent studies suggest that the biological function of BCRP is not limited in its drug pump activity. Herein, the role of BCRP in the proliferation and survival of drug-resistant breast cancer cells was investigated. We found that BCRP is not the major drug pump to efflux epirubicin in the resistant cells that express multiple ABC transporters. Silencing of BCRP significantly impairs cell proliferation and induces apoptosis of the resistant cells in vitro and in vivo. RNA-sequencing and high-throughput proteomics suggest that BCRP is an inhibitory factor of oxidative phosphorylation (OXPHOS). Further research suggests that BCRP is localized in the mitochondria of the resistant cells. Knockdown of BCRP elevated the intracellular reactive oxygen species level and eventually promotes the cell to undergo apoptosis. This study demonstrated that BCRP exerts important onco-promoting functions in the drug-resistant breast cancer cells independent of its well-recognized drug efflux activity, which shed new light on understanding the complex functional role of ABC transporters in drug-resistant cells.

scholarly journals Drug-resistant cancer cell-derived exosomal EphA2 promotes breast cancer metastasis via the EphA2-Ephrin A1 reverse signaling

2020 ◽  
Author(s):  
Zicong Gao ◽  
Xingxing Han ◽  
Yuying Zhu ◽  
He Zhang ◽  
Ran Tian ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Resistant Cell ◽  
Migration And Invasion ◽  
Drug Resistant ◽  
Resistant Cells

Abstract Background: The failure of chemotherapy is accompanied by the emergence of drug resistance and tumor relapse. Tumor metastasis induced by drug resistance is a major challenge in successful cancer treatment. Nevertheless, the mechanisms underlying the pro-invasive and metastatic ability of drug resistance remain elusive. Exosome-mediated intercellular communications between cancer cells and stromal cells in tumor microenvironment are required for cancer initiation and progression. Recent reports have shown that communications between cancer cells also promote tumor aggression. However, little attention has been regarded on this aspect. In this study, we aimed to investigate the mechanisms of exosomes derived from drug-resistant cells in regulating the invasion and metastasis of sensitive breast cancer cells.Methods: Exosomes isolated from drug-resistant breast cancer cells and their parental cells were used to treat breast cancer cells, and then the migration and invasion abilities were examined. The tandem mass tag (TMT)-based quantitative proteomic method was carried out to identify key molecules that regulate cancer aggressiveness. Lentivirus-mediated shRNAs, overexpression, point mutation, truncation mutation, Western blotting, tumor xenograft mice models, and in vivo breast cancer metastatic models were used to investigate the functional role of EphA2 on the invasion and metastatic potential of breast cancer cells.Results: We demonstrated that drug-resistant cell-derived exosomes promoted the migration and invasion of sensitive breast cancer cells. Quantitative proteomic analysis showed that EphA2 was rich in exosomes from drug-resistant cells. Exosomal EphA2 conferred the invasive/metastatic phenotype transfer from drug-resistant cells to sensitive cells. In addition, we provided considerable evidence that exosomal EphA2 activated ERK1/2 signaling through the ligand Ephrin A1-dependent reverse pathway rather than the forward pathway, thereby promoting breast cancer progression. Conclusions: Our findings indicate the key functional role of exosomal EphA2 in the transmission of aggressive phenotype between cancer cells that do not rely on direct cell–cell contact. Our study also suggests that the increase of EphA2 in drug-resistant cell-derived exosomes may be an important mechanism of chemotherapy/drug resistance-induced breast cancer progression.

Oestrogen treatment enhances the sensitivity of hormone-resistant breast cancer cells to doxorubicin

2010 ◽  
Vol 31 (2) ◽  
pp. 137-143 ◽  
Author(s):  
Alexander M. Scherbakov ◽  
Yulia S. Lobanova ◽  
Olga E. Andreeva ◽  
Valentina A. Shatskaya ◽  
Mikhail A. Krasil'nikov
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Nuclear Factor Κb ◽  
Apoptotic Response ◽  
Oestrogen Treatment ◽  
Interfering Rna ◽  
Mcf 7 ◽  
Resistant Cells

Recently, it was shown that the resistance of breast cancer cells to growth-stimulating oestrogen action may be accompanied with the paradoxical tumour sensitization to oestrogen apoptotic action. In the present paper, we studied the influence of oestrogens on the sensitivity of resistant breast tumours to cytostatic drugs, and to evaluate the role of NF-κB (nuclear factor κB) signalling in the regulation of the apoptotic response of the resistant cells. The experiments were carried out on the oestrogen-dependent MCF-7 breast cancer cells and resistant MCF-7/LS subline generated through long-term cultivation of the parental cells in the absence of oestrogen. The cell treatment with the combination of oestradiol and Dox (doxorubicin) was found to enhance the apoptotic action of Dox in MCF-7/LS cells but not in the parent cells. MCF-7/LS cells were characterized by the increased level of ROS (reactive oxygen species) and decreased NF-κB activity. Oestradiol in combination with Dox leads to significant NF-κB stimulation and its accumulation in the nucleus of MCF-7/LS cells. The knockdown of NF-κB with siRNA (small interfering RNA) increased the apoptotic response of the MCF-7/LS cells to both Dox and oestradiol demonstrating the important role of NF-κB in the protection of the MCF-7/LS cells against apoptosis. In general, the results obtained show that: (i) oestradiol enhances the apoptotic action of Dox in the resistant breast cancer cells; and (ii) suppression of NF-κB signalling amplifies the apoptotic response of the resistant cells to both oestrogen and Dox, demonstrating that NF-κB may serve as a potential target in the therapy of the resistant breast cancer.

scholarly journals Human drug efflux transporter ABCC5 confers acquired resistance to pemetrexed in breast cancer

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jihui Chen ◽  
Zhipeng Wang ◽  
Shouhong Gao ◽  
Kejin Wu ◽  
Fang Bai ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Line ◽  
Abc Transporters ◽  
Breast Cancer Cells ◽  
Breast Cancer Treatment ◽  
Control Group ◽  
Mcf 7

Abstract Aim Pemetrexed, a new generation antifolate drug, has been approved for the treatment of locally advanced or metastatic breast cancer. However, factors affecting its efficacy and resistance have not been fully elucidated yet. ATP-binding cassette (ABC) transporters are predictors of prognosis as well as of adverse effects of several xenobiotics. This study was designed to explore whether ABC transporters affect pemetrexed resistance and can contribute to the optimization of breast cancer treatment regimen. Methods First, we measured the expression levels of ABC transporter family members in cell lines. Subsequently, we assessed the potential role of ABC transporters in conferring resistance to pemetrexed in primary breast cancer cells isolated from 34 breast cancer patients and the role of ABCC5 in mediating pemetrexed transport and apoptotic pathways in MCF-7 cells. Finally, the influence of ABCC5 expression on the therapeutic effect of pemetrexed was evaluated in an in vivo xenograft mouse model of breast cancer. Results The expression levels of ABCC2, ABCC4, ABCC5, and ABCG2 significantly increased in the pan-resistant cell line, and the ABCC5 level in the MCF-7-ADR cell line was 5.21 times higher than that in the control group. ABCC5 expression was inversely correlated with pemetrexed sensitivity (IC50, r = 0.741; p < 0.001) in breast cancer cells derived from 34 patients. Furthermore, we found that the expression level of ABCC5 influenced the efflux and cytotoxicity of pemetrexed in MCF-7 cells, with IC50 values of 0.06 and 0.20 μg/mL in ABCC5 knockout and over-expression cells, respectively. In the in vivo study, we observed that ABCC5 affected the sensitivity of pemetrexed in breast tumor-bearing mice, and the tumor volume was much larger in the ABCC5-overexpressing group than in the control group when compared with their own initial volumes (2.7-fold vs. 1.3-fold). Conclusions Our results indicated that ABCC5 expression was associated with pemetrexed resistance in vitro and in vivo, and it may serve as a target or biomarker for the optimization of pemetrexed regimen in breast cancer treatment.

scholarly journals Proteomic Level Changes on Treatment in MCF-7/DDP Breast Cancer Drug- Resistant Cells

2020 ◽  
Vol 20 (6) ◽  
pp. 687-699 ◽  
Author(s):  
Gongshen Jin ◽  
Kangwei Wang ◽  
Yonghong Liu ◽  
Xianhu Liu ◽  
Xiaojing Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Culture ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Bioinformatics Analysis ◽  
Cancer Drug ◽  
Drug Resistant ◽  
Down Regulation ◽  
Cancer Pathways ◽  
Resistant Cells

Background: LCL161, a SMAC’S small molecule mimetic, can bind to a variety of IAPs and activate Caspases. We found that on its own, LCL161induces apoptosis of drug-resistant breast cancer cells by binding to a variety of IAPs and activating Caspases. However, when LCL161 is used in combination with Caspase Inhibitors (CI), its capacity to induce apoptosis of breast cancer cells is enhanced. Objective: To carry out proteomic and bioinformatics analysis of LCL161 in combination with CI. We aim to identify the key proteins and mechanisms of breast cancer drug-resistant apoptosis, thereby aiding in the breast cancer drug resistance treatment and identification of drug targeting markers. Methods: Cell culture experiments were carried out to explore the effect of LCL161 combined with CI on the proliferation of breast cancer drug-resistant cells. Proteomic analysis was carried out to determine the protein expression differences between breast cancer drug-resistant cells and LCL161 combined with CI treated cells. Bioinformatics analysis was carried out to determine its mechanism of action. Validation of proteomics results was done using Parallel Reaction Monitoring (PRM). Results: Cell culture experiments showed that LCL161 in combination with CI can significantly promote the apoptosis of breast cancer drug-resistant cells. Up-regulation of 92 proteins and down-regulation of 114 proteins protein were noted, of which 4 were selected for further validation. Conclusion: Our results show that LCL161 combined with CI can promote the apoptosis of drug-resistant breast cancer cells by down-regulation of RRM2, CDK4, and ITGB1 expression through Cancer pathways, p53 or PI3K-AKT signaling pathway. In addition, the expression of CDK4, RRM2, and CDC20 can be down-regulated by the nuclear receptor pathway to affect DNA transcription and replication, thereby promoting apoptosis of breast cancer drug-resistant cells.

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