Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China.
Gene. 2013 Nov 15;531(1):8-14. doi: 10.1016/j.gene.2013.08.062. Epub 2013 Aug 29.
Adriamycin (Adr) and docetaxel (Doc) are two chemotherapeutic agents commonly used in the treatment of breast cancer. However, patients with breast cancer who are treated by the drugs often develop resistance to them and some other drugs. Recently studies have shown that microRNAs (miRNAs, miRs) play an important role in drug-resistance. In present study, miRNA expression profiles of MCF-7/S and its two resistant variant MCF-7/Adr and MCF-7/Doc cells were analyzed using microarray and the results were confirmed by real-time quantitative polymerase chain reaction. Here, 183 differentially expressed miRNAs were identified in the two resistant sublines compared to MCF-7/S. Then, five up-regulated miRNAs (miR-100, miR-29a, miR-196a, miR-222 and miR-30a) in both MCF-7/Adr and MCF-7/Doc were selected to explore their roles in acquisition of drug-resistance using transfection experiment. The results showed that miR-222 and miR-29a mimics and inhibitors had partially changed the drug-resistance of breast cancer cells, which was also confirmed by apoptosis assay. Western blot results suggested that miR-222 and -29a could regulate the expression of PTEN, maybe through which the two miRNAs conferred Adr and Doc resistance in MCF-7 cells. Finally, pathway mapping tools were employed to further analyze signaling pathways affected by the two miRNAs. In summary, this study demonstrates that altered miRNA expression pattern is involved in acquiring resistance to Adr and Doc in breast cancer MCF-7 cells, and that there are some miRNAs who displayed consistent up- or down-regulated expression changes in the two resistant sublines. The most importance is that we identify two miRNAs (miR-222 and miR-29a) involved in drug-resistance, at least in part via targeting PTEN.
阿霉素（阿霉素）和多西紫杉醇（多西他赛）是两种常用于乳腺癌治疗的化疗药物。然而，用这些药物治疗的乳腺癌患者往往对它们和其他一些药物产生耐药性。最近的研究表明，microRNAs（miRNAs，miRs）在耐药性中起重要作用。在本研究中，使用微阵列分析了 MCF-7/S 及其两种耐药变异体 MCF-7/Adr 和 MCF-7/Doc 细胞的 miRNA 表达谱，并通过实时定量聚合酶链反应进行了验证。在这里，与 MCF-7/S 相比，在这两个耐药亚系中鉴定出 183 个差异表达的 miRNA。然后，选择了五个上调的 miRNA（miR-100、miR-29a、miR-196a、miR-222 和 miR-30a）在 MCF-7/Adr 和 MCF-7/Doc 中用于探索它们在获得耐药性中的作用使用转染实验。结果表明，miR-222 和 miR-29a 模拟物和抑制剂部分改变了乳腺癌细胞的耐药性，这也通过凋亡测定得到了证实。Western blot 结果表明，miR-222 和 -29a 可以调节 PTEN 的表达，也许通过这种方式，这两个 miRNA 在 MCF-7 细胞中赋予了阿霉素和多西紫杉醇的耐药性。最后，使用通路映射工具进一步分析受这两个 miRNA 影响的信号通路。总之，这项研究表明，miRNA 表达模式的改变参与了乳腺癌 MCF-7 细胞对阿霉素和多西紫杉醇的耐药性获得，并且在这两个耐药亚系中存在一些 miRNA 显示出一致的上调或下调表达变化。最重要的是，我们鉴定出两个参与耐药性的 miRNA（miR-222 和 miR-29a），至少部分通过靶向 PTEN。
