The microRNA (miR)-200 family has been found to be involved in the process of mesenchymal-epithelial transition during renal development. Deregulation of miR-200c has been suggested to be involved in clear cell renal cell carcinoma (ccRCC). However, the precise role of miR-200c in the regulation of ccRCC metastasis has not been previously reported. In the present study, it was observed that miR-200c was frequently downregulated in ccRCC tissue compared with matched adjacent normal tissue. The expression of miR-200c was additionally reduced in ccRCC cell lines when compared with levels in normal renal cells. The DNA demethylation drug 5-Aza-2'-deoxycytidine (Aza) was used to treat several ccRCC cell lines, and it was observed that the expression of miR-200c was significantly increased following Aza treatment. Furthermore, treatment with Aza markedly inhibited ccRCC cell invasion and migration, while treatment with miR-200c inhibitor significantly enhanced invasion and migration of ccRCC cells. In addition, Aza treatment significantly promoted expression of E-cadherin and inhibited the expression of N-cadherin, while the inhibition of miR-200c downregulated E-cadherin and upregulated the expression of N-cadherin, suggesting that miR-200c has a suppressive role in epithelial-mesenchymal transition (EMT) of ccRCC cells. In conclusion, it was suggested that demethylation drug Aza-induced upregulation of miR-200c may inhibit migration, invasion and EMT in ccRCC cells.
Keywords: clear cell renal cell carcinoma; demethylation drug; epithelial-mesenchymal transition; invasion; microRNA-200c; migration.