Regulation of growth of human bladder cancer by miR-192.

The regulation of microRNA-192 (miR-192) is impaired in many cancers. Here, we investigated the role of miR-192 in the proliferation, cell cycle progression, and apoptosis of bladder cancer cells. Human bladder cancer cells were transfected with human miR-192 precursor or non-specific control miRNA. The effect of miR-192 on cell proliferation was assessed by a MTT assay. The effects of miR-192 on cell cycle regulation and apoptosis were evaluated by flow cytometry. Western blot was used to analyze the protein levels of cyclin D1, p21, p27, Bcl-2, Bax, and Mcl-1. We found that overexpression of miR-192 significantly decreased the proliferation of bladder cancer cells by 22 and 54 % at 48 and 72 h, respectively. MiR-192-overexpressing cells exhibited a significant increase in G0/G1 phase and a significant decrease in S phase compared to the control miRNA-transfected cells. Moreover, overexpression of miR-192 significantly induced apoptotic death in bladder cancer cells, increased the levels of p21, p27, and Bax, and decreased the levels of cyclin D1, Bcl-2, and Mcl-1. Taken together, these data suggest that miR-192 may be a suppressor for bladder cancer cells by cell cycle regulation.