miR-200c通过激活Wnt/β-连环蛋白信号通路诱导膀胱癌细胞阿霉素耐药

目的:探讨miR-200c表达与膀胱癌细胞阿霉素（DOX）耐药的关系。方法:过表达或抑制miR-200c表达后，检测DOX对膀胱癌细胞（RT4、RT112、T24和TCCSUP）生长抑制作用的变化。Western blot检测miR-200c对Wnt/β-连环蛋白信号通路的影响，检测Wnt/β-连环蛋白信号激活剂Wnt3a干预对miR-200c诱导膀胱癌DOX耐药作用的影响。结果:抗miR-200c转染后，T24和RT4细胞DOX的耐药性显著下降。DOX干预后，与对照组细胞相比，抗miR-200c转染组膀胱癌细胞凋亡和S期积累明显增加。此外，抗miR-200c转染组膀胱癌细胞中Dkk1,Kremen2和sFRP2等Wnt/β-连环蛋白信号的负调控蛋白表达明显升高，Wnt/β-连环蛋白信号通路活性明显下降。Wnt3a干预能够拮抗抗miR-200c转染的膀胱癌细胞生长抑制作用。结论:miR-200c表达与膀胱癌细胞DOX耐药密切相关，且Wnt/β-连环蛋白信号通路激活介导了miR-200c诱导的膀胱癌细胞DOX耐药性。

miR-200c induces resistance to doxorubicin through the Wnt/beta-catenin signaling pathway in bladder cancer cells

AIM: To investigate the relationship between miR-200c expression and the response to DOX in bladder cancer cells. METHODS: Changes in the growth inhibitory effect of DOX on bladder cancer cells (RT4,RT112,T24 and TCCSUP) were examined after overexpression or suppression of miR-200c.The effect of miR-200c on the Wnt/beta-catenin signaling pathway were also examined to investigate whether the altered growth-inhibitory effect by miR-200c suppression was weakened after the addition of Wnt3a,a Wnt/beta-catenin signaling activator. RESULTS: RT4 and T24 cells transfected with anti-miR-200c showed significantly lower resistance to DOX. In the anti-miR-200c-transfected cells, DOX induced significantly larger numbers of apoptotic cells and S phase accumulation compared to control cells, demonstrated by Annexin V assay and flow cytometric analysis of the cell cycle, respectively. The transfected cells showed overexpression of putative target molecules including Dkk1, Kremen2 and sFRP2 and lower activation of the Wnt/beta-catenin signaling pathway.The addition of Wnt3a weakened the augmented growth-inhibitory effect of anti-miR-200c transfection. CONCLUSION: miR-200c expression correlates significantly with the growth-inhibitory effect of DOX and that activation of the Wnt/beta-catenin signaling pathway mediates the miR-200c-induced resistance to DOX in bladder cancer cell lines.