MicroRNA-142-3p, a new regulator of RAC1, suppresses the migration and invasion of hepatocellular carcinoma cells.

RAC1 regulates a diverse array of cellular events including migration and invasion. MicroRNAs (miRNAs) have a key role in the regulation of gene expression. In this study, we demonstrated that microRNA-142-3p (miR-142-3p) acted as a negative regulator of human RAC1. Overexpression of miR-142-3p decreased RAC1 mRNA and protein levels. Moreover, the overexpression of miR-142-3p suppressed, while blocking of miR-142-3p increased colony formation, migration and invasion in hepatocellular carcinoma (HCC) cell lines (QGY-7703 and SMMC-7721). RAC1 overexpression without the 3'untranslated region abolished the effect of miR-142-3p in the QGY-7703 and SMMC-7721 cells. These results demonstrated that miR-142-3p directly and negatively regulates RAC1 in HCC cells, which highlights the importance of miRNAs in tumorigenesis.