MiR-302a/b/c/d cooperatively sensitizes breast cancer cells to adriamycin via suppressing P-glycoprotein(P-gp) by targeting MAP/ERK kinase kinase 1 (MEKK1).
MiR-302a/b/c/d cooperatively sensitizes breast cancer cells to adriamycin via suppressing P-glycoprotein(P-gp) by targeting MAP/ERK kinase kinase 1 (MEKK1).
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DOI：
10.1186/s13046-016-0300-8
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发表时间：
2016-02-03
期刊：
影响因子：
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通讯作者：
Wei M
中科院分区：
文献类型：
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作者：
Zhao L;Wang Y;Jiang L;He M;Bai X;Yu L;Wei M
个体microRNAs(MiRNAs)在肿瘤中的重要性已在不同的癌症中得到证实。然而，它们与肿瘤化疗耐药的关系还没有完全被了解。此前，我们发现了两个新的MDR相关microRNAs(MiRNAs)。在这篇报道中，我们研究了miRNA基因簇在乳腺癌化疗耐药中的联合作用。这项研究是在两种不同的乳腺癌细胞系(MCF-7和MCF-7/ADR)上进行的。用实时定量聚合酶链式反应检测miRNAs和mRNA的表达水平。Western blotting检测蛋白质分子水平。MTS法检测细胞存活率。生物信息学和荧光素酶报告实验检测miRNA与靶基因3‘-UTR区的结合。在P-糖蛋白(P-gp)高表达的MCF-7/ADR细胞中，miR-302S家族包括miR-302a、miR-302B、miR-302C和miR-302d显著下调。MiR-302的过表达增加了细胞内ADR的积聚，并使乳腺癌细胞对ADR增敏。最重要的是，miR-302产生的效果比单个成员单独产生的效果更强。四种miRNAs协同下调P-gp表达，调节药物敏感性。然而，我们的结果表明miR-302对P-gp表达的抑制不是通过典型的miRNA介导的mRNA降解而是在蛋白质和转录水平上的。进一步的研究证实MAP/ERK激酶1(MEKK1)是miR-302的直接和功能靶点。MIR-302对MKEE1的抑制和MEKK1介导的ERK通路具有联合作用。MEKK1过表达可逆转miR-302对P-gp的抑制作用。我们的结果表明miR-302通过靶向ERK通路的MEKK1抑制P-糖蛋白，协同增敏乳腺癌细胞对阿霉素的敏感性。MIR-302基因簇可能成为逆转P-gp介导的乳腺癌化疗耐药的潜在靶点。
The importance of individual microRNAs (miRNAs) in tumor has been established in different cancers. However, their association with tumor chemoresistance has not been fully understood. Previously, we found two novel MDR-associated microRNAs (miRNAs). In this report, we investigated the combined effects of miRNA gene cluster in chemoresistance of breast cancer. This study was performed in two different breast cancer cell lines (MCF-7 and MCF-7/ADR). The levels of miRNAs and mRNA expression were determined by using Quantitative Real-Time PCR. Western blotting was used to detect the levels of protein molecules. Cell viability was assessed by MTS assay. Bioinformatics and Luciferase reporter assay was performed to examine miRNA binding to the 3′-UTR of target genes. The miR-302S family including miR-302a, miR-302b, miR-302c, and miR-302d was significantly down-regulated in P-glycoprotein (P-gp)-overexpressing MCF-7/ADR cells. Overexpression of miR-302 increased intracellular accumulation of ADR and sensitized breast cancer cells to ADR. Most importantly, miR-302S produced stronger effects than each individual member alone. The four miRNAs cooperatively downregulate P-gp expression in regulating drug sensitivity. However, our results showed that the suppression of P-gp expression by miR-302 is not through typical miRNA-mediated mRNA degradation but at the level of protein and transcription. Further studies identified MAP/ERK kinase kinase 1 (MEKK1) as a direct and functional target of miR-302. miR-302 showed combinatorial effects on MKEE1 repression and MEKK1-mediated ERK pathway. The suppression of P-gp by miR-302 was reversed by MEKK1 overexpression. Our results indicate that miR-302 cooperatively sensitizes breast cancer cells to adriamycin via suppressing P-glycoprotein by targeting MEKK1 of ERK pathway. miR-302 gene cluster may be a potential target for reversing P-gp-mediated chemoresistance in breast cancer.