Decreased expression of miR-430 promotes the development of bladder cancer via the upregulation of CXCR7

MicroRNAs (miRNAs) have been demonstrated to be involved in the development of numerous types of malignant tumor. However, the role of miRNA-430 (miR-430) in bladder cancer remains unclear. In the present study, we observed that the expression of miR-430 was significantly downregulated in bladder cancer. Furthermore, the overexpression of miR-430 in human bladder cancer 5637 cells significantly inhibited cell proliferation, migration and colony formation efficiency. These findings were contrary to those obtained following the overexpression of CXCR7, which was found to be a direct target of miR-430 in this study. Further analysis showed that cell proliferation- and migration-related genes, including ERK, matrix metalloproteinase-2 (MMP-2) and MMP-9, were significantly downregulated in miR-430 overexpressed 5637 cells, while they were markedly upregulated in CXCR7 overexpressed 5637 cells. In conclusion, our study reveals important roles of miR-430 and CXCR7 in bladder cancer, and suggests that the downregulation of miR-430 enhances the development of bladder cancer, partly via the upregulation of CXCR7.