Effects of microRNA-200c on the proliferation and cell cycle of bladder cancer T24 cells

Objective To investigate the influence of microRNA (miRNA, miR)-200c on cell proliferation and cell cycle in bladder cancer T24 cells and the preliminary mechanism. Methods The expression of miR-200c in bladder cancer cell lines was detected using real-time quantitative polymerase chain reaction (Real-time PCR). T24 cells were transfected with miR-200c mimics (MU group) or nonsense control (NC group) individually to generate negative control group and over-expression group. Then cell proliferation was assessed using cell counting kit-8 (CCK-8) kits at 24, 48 and 72 h while cell cycle distribution was detected by flow cytometry. Finally, Western blotting was applied to detect the levels of cell cycle-related proteins. Results MiR-200c was up-regulated in bladder cancer cell lines EJ (13.204±0.946), T24 (18.259±0.776), 253J (8.333±0.543), 5637 (6.594±0.326), RT4 (11.348±0.513) as compared with normal urothelial cell line SV-Huc (1.053±0.078, P=0.000). MiR-200c mimics promoted cell proliferation at 48 and 72 h after transfection [(1.485±0.131 and 2.396±0.110) vs. (1.158±0.182 and 1.893±0.216), P=0.050, P=0.023] and induced G1/S checkpoint release (P=0.013). Meanwhile, the protein levels of cyclin-dependent kinase (CDK)2 (1.44±0.10 vs. 0.86±0.15, P=0.005), CDK4 (3.05±0.17 vs. 1.24±0.07, P=0.001), E2F3 (1.81±0.22 vs. 1.18±0.20, P=0.021) were upregulated after transfection. Conclusion MiR-200c promotes cell proliferation and induces G1/S transition in bladder cancer T24 cell lines via regulating cell cycle-related proteins. Key words: Bladder cancer; MicroRNA-200c; Cell cycle; Proliferation