Overexpression of ABCB4 contributes to acquired doxorubicin resistance in breast cancer cells in vitro
Overexpression of ABCB4 contributes to acquired doxorubicin resistance in breast cancer cells in vitro
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ABCB4的过度表达有助于体外乳腺癌细胞获得阿霉素耐药性
DOI：
10.1007/s00280-018-3603-y
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发表时间：
2018-08-01
影响因子：
3
通讯作者：
Zhou, Hong-Hao
中科院分区：
文献类型：
--
作者：
Huang, Jia-Feng;Wen, Chun-Jie;Zhou, Hong-Hao
目的阿霉素是转移性乳腺癌一线治疗中最有效的药物之一，但阿霉素耐药性的频繁出现在一定程度上限制了其应用。本研究旨在探讨三磷酸腺苷结合盒B亚家族成员4(ABCB4)在乳腺癌细胞获得性阿霉素耐药中的作用及其可能的机制。方法采用实时荧光定量聚合酶链式反应和Western印迹分析检测对阿霉素敏感和耐药的乳腺癌细胞株MCF-7和MDA-MB-231中ABCB4基因的表达水平，用亚硫酸氢盐测序聚合酶链式反应(BSP)和染色质免疫沉淀(ChIP)法检测ABCB4基因的DNA甲基化和组蛋白乙酰化状态，用细胞毒试验和流式细胞术观察ABCB4基因对阿霉素的敏感性和细胞内阿霉素蓄积情况。结果ABCB4在耐药乳腺癌细胞中的表达高于敏感细胞，这与ABCB4启动子上DNA甲基化减少和组蛋白乙酰化增加有关。ABCB4可以主动地将阿霉素泵出细胞外，并且ABCB4基因的敲除增加了阿霉素耐药乳腺癌细胞对阿霉素的敏感性和细胞内的聚集。结论ABCB4在获得性阿霉素耐药的乳腺癌细胞中高表达，这可能至少部分归因于ABCB4基因的表观遗传修饰。Abcb4介导阿霉素的外流转运，并参与乳腺癌细胞对阿霉素的获得性耐药。
PurposeDoxorubicin is one of the most active agents in the first-line therapy for metastatic breast cancer, but its utility is partially limited by the frequent emergence of doxorubicin resistance. In this study, we aimed to investigate the role of ATP-binding cassette sub-family B, member 4 (ABCB4) in acquired doxorubicin resistance in breast cancer cells, as well as its potential mechanism.MethodsIn doxorubicin-sensitive and -resistant breast cancer cell lines MCF-7 and MDA-MB-231, the expression levels of ABCB4 were detected using real-time quantitative PCR and Western blot analysis, the DNA methylation and histone acetylation status of ABCB4 gene were investigated by bisulfite-sequencing PCR (BSP) and chromatin immunoprecipitation (ChIP) assays, and the doxorubicin sensitivity and intracellular doxorubicin accumulation were observed using cell cytotoxicity assay and flow cytometry. In Madin–Darby Canine Kidney (MDCKII) cells, In vitro transport assay was used to assess the ABCB4-mediated transport of doxorubicin.ResultsABCB4 was overexpressed in doxorubicin-resistant breast cancer cells compared to their doxorubicin-sensitive counterparts, which was associated with reduced DNA methylation as well as increased histone acetylation at the ABCB4 promoter. ABCB4 could actively pump doxorubicin out of the cells, and knockdown of ABCB4 increased doxorubicin sensitivity and intracellular accumulation in doxorubicin-resistant breast cancer cells.ConclusionsOur results indicate that ABCB4 is overexpressed in breast cancer cells with acquired doxorubicin resistance, which could be attributed, at least partially, to the epigenetic modifications of ABCB4 gene. ABCB4 mediates the efflux transport of doxorubicin, and contributes to the acquired resistance of doxorubicin in breast cancer cells.