MicroRNA-19a And MicroRNA-19b Promote The Malignancy Of Clear Cell Renal Cell Carcinoma Through Targeting The Tumor Suppressor RhoB

Clear cell renal cell carcinoma(ccRCC)is the most common subtype of renal cell carcinoma,which shows high aggressiveness and lacks biomarkers.RhoB is a member of the Rho family of small GTPases which exhibits potent tumor-suppressive role in several carcinomas.This study indicates that RhoB was significantly decreased in ccRCC specimens and cell lines compared to their matched normal kidney tissues and cell lines at both mRNA and protein level.Furthermore,the expression of RhoB showed a significant correlation with tumor size and tumor stage.Mechanism research showed both miR-19a and miR-19b,two oncogenic miRNAs,could directly target the 3'untranslated region(3'UTR)of RhoB,resulting in the reduced expression of RhoB.There is an inverse association between miR-19a/b and RhoB in specimens and cell lines.In addition the knockdown of RhoB or overexpression of miR-19a and miR-19b in ccRCC cells could promote cell proliferation,migration and invasion.These data demonstrate the direct roles of miR-19a and miR-19b on the repression of RhoB and its consequences on tumorigenesis,cancer cell proliferation and invasiveness.These results suggest the potential clinical impact of miR-19a and miR-19b as molecular targets for ccRCC.