MicroRNA-3194-3p inhibits metastasis and epithelial-mesenchymal transition of hepatocellular carcinoma by decreasing Wnt/β-catenin signaling through targeting BCL9

Local and systemic metastasis of hepatocellular carcinoma (HCC) causes the poor prognosis and increasing evidence confirms that aberrant miRNAs were involved in cancer progression. However, the expression and mechanisms of a specific miR-3194-3p in HCC remains unknown. In this research, we demonstrated that miR-3194-3p, significantly down-regulated in HCC tissues and cell lines, was associated with metastasis and recurrence of HCC. Notably, gain- and loss-of-function assays demonstrated that miR-3194-3p inhibited the migration, invasion and epithelial-mesenchymal transition (EMT) of HCC cells <i>in</i> <i>vitro</i> and <i>in</i> <i>vivo</i>. BCL9, up-regulated in HCC tissues, was a direct downstream target of miR-3194-3p and mediated the functional influence of miR-3194-3p. Most importantly, miR-3194-3p exerted its function by regulating β-catenin pathway. Moreover, miR-3194-3p and BCL9 expression were markedly correlated with adverse clinical features and poor prognosis of HCC patients. We showed that hypoxia was responsible for the down-expression of miR-3194-3p in HCC. Also, the promoting effects of hypoxia on metastasis and EMT of HCC cells were reversed by miR-3194-3p. Altogether, our study suggested that miR-3194-3p inhibits HCC EMT via decreasing Wnt/β-catenin signaling through targeting BCL9 and might be a therapeutic target for HCC.