MiR-222 promotes drug-resistance of breast cancer cells to adriamycin via modulation of PTEN/Akt/FOXO1 pathway
MiR-222 promotes drug-resistance of breast cancer cells to adriamycin via modulation of PTEN/Akt/FOXO1 pathway
复制标题
MiR-222通过调节PTEN/Akt/FOXO1通路促进乳腺癌细胞对阿霉素耐药
DOI：
10.1016/j.gene.2016.10.016
复制
发表时间：
2017-01-05
期刊：
影响因子：
3.5
通讯作者：
Tang, Jinhai
中科院分区：
文献类型：
--
作者：
Shen, Hongyu;Wang, Dandan;Tang, Jinhai
背景与目的：乳腺癌对阿霉素（ADR）的耐药是乳腺癌治疗中最重要的临床障碍之一，但其敏感性的分子机制仍不清楚。我们在前期的研究中，通过miRNA芯片和实验，强调了miR-222可以促进乳腺癌细胞的ADR耐药。方法：通过对miR-222的途径富集分析，发现PTEN/Akt/FOXO 1信号通路可能是miR-222影响ADR敏感性的重要途径。RT-qPCR分析和western blot分析证实了miR-222表达与靶基因之间的关系。免疫荧光进一步直观显示FOXO 1的位置。结果：RT-qPCR和Western blot结果显示，miR-222的表达与FOXO 1的表达呈负相关。此外，从免疫荧光观察到由于miR-222表达改变而导致的FOXO 1的亚细胞易位。此外，MCF-7/S细胞中miR-222表达的上调与PTEN表达水平降低和磷酸化Akt（p-Akt）表达增加相关。相反，在MCF-7/ADR细胞中，抑制miR-222导致PTEN表达增加和p-Akt表达减少。为了进一步验证，本研究的结果还表明，PTEN/Akt/FOXO 1信号通路负责乳腺癌细胞的ADR-抗性，因为LY 294002，Akt信号通路抑制剂，部分增加MCF-7/S细胞对ADR的敏感性。结论：miR-222可能通过调节PTEN/Akt/FOXO 1信号通路，抑制miR-222的表达，从而提高乳腺癌细胞的ADR耐药，改善乳腺癌患者的预后。(C)2016爱思唯尔B. V.保留所有权利。
Background and purpose: Acquisition of resistance to adriamycin (ADR) is one of the most important clinical obstacles in the treatment of breast cancer, but the molecular mechanisms underlying sensitivity to ADR remain elusive. In our previous study, through miRNA microarray and experiments, we have emphasized that miR-222 could promote the ADR-resistance in breast cancer cells. The aim of this study was to explore the possible mechanism by which miR-222 affects sensitivity to ADR.Methods: Through pathway enrichment analyses for miR-222, we found that PTEN/Akt/FOXO1 signaling pathway may be of importance. RT-qPCR analyses and western blot assays confirmed the relationship between miR-222 expression and target genes. Immunofluorescence further visually displayed the location of FOXO1. When blocking PTEN/Akt/FOXO1 signaling pathway, we demonstrated the effects of miR-222-mediated ADR resistance by MTT and apoptosis assays.Results: RT-qPCR and Western blot results showed that miR-222 expression was negatively correlated with FOXO1 expression. In addition, the subcellular translocation of FOXO1 due to the altered expression of miR-222 was observed from immunofluorescence. Moreover, upregulation of miR-222 expression in MCF-7/S cells is associated with decreased PTEN expression levels and increased phospho-Akt (p-Akt) expression. Conversely in MCF-7/ADR cells, inhibition of miR-222 resulted in increased PTEN expression and decreased p-Akt expression. For further validation, results of the present study also demonstrated that PTEN/Akt/FOXO1 signaling was responsible for the ADR-resistance of breast cancer cells since LY294002, an inhibitor of Akt signaling, partially increased the sensitivity of MCF-7/S cells to ADR. More importantly, we postulated that high expression of miR-222 is closely related to poor overall survival by TCGA database validation.Conclusions: Taken together, these data elucidated that miR-222 mediated ADR-resistance of breast cancer cells partly through regulation of PTEN/Akt/FOXO1 signaling pathway and inhibition of miR-222 may improve the prognosis of breast cancer patients. (C) 2016 Elsevier B.V. All rights reserved.