中文摘要：

目的探讨miR-487a调节米托蒽醌（MX）耐药的乳腺癌耐药细胞MCF-7/MX对MX敏感性的作用与机制。方法通过在乳腺癌耐药细胞MCF-7/MX中转染miR-487amimic构建miR-487a高表达乳腺癌耐药细胞模型,应用（qRT）-PCR、蛋白印迹法、流式等方法检测miR-487a通过靶向作用乳腺癌耐药蛋白BCRP增加乳腺癌细胞对MX的敏感性。结果在MCF-7/MX细胞中miR-487a高表达抑制BCRP的表达,增加MX的细胞内蓄积,提高该细胞对MX的敏感性。结论 miR-487a通过靶向作用BCRP,增加乳腺癌细胞对MX的敏感性。

英文摘要：

Objective To explore the mechanisms of miR-487 aregulating the sensitivity of breast cancer resistant cells MCF-7/MX to MX.Methods miR-487 amimic was transfected in breast cancer resistant cells MCF-7/MX to build cell models that overexpress miR-487 a.The expression of miR-487 aand breast cancer resistance protein（BCRP）mRNA was measured by qRT-PCR,and the protein expression and transport function of BCRP for MX after the transfection of miR-487 amimic in MCF-7/MX cells were examined by Western blotting and flow cytometry analysis.Results The overexpression of miR-487 ainhibited the mRNA and protein expression of BCRP in MCF-7/MX cells,increased the accumulation of MX,and improved the sensitivity of MCF-7/MX cells to MX.Conclusion miR-487 aincreased the sensitivity of breast cancer cells to MX by targeting BCRP.