Abstract: Objective To explore the expression of miR-188-3p in hepatocellular carcinoma (HCC ) and its molecular mechanism of inhibiting the invasion and migration of HCC cells. Methods The expression of miR-188-3p in human HCC tissues and cell lines was detected by RT-qPCR, and the clinical value of miR-188-3p expression in HCC was further analyzed. Western blotting was used to detect the effects of transfection of the miR-188-3p mimics and inhibitor on YAP1 protein in HCC cells. Transwell invasion and migration assay were used to measure the invasive and migratory abilities of cells in each group, respectively. Dual luciferase gene reporting assay was employed to identify the mechanism of miR-188-3p targeting YAP1. Finally, the recovery experiment was performed by co-transfection of miR-188-3p mimics and YAP1 overexpression plasmid in HCC cells. Results The expression level of miR-188-3p was significantly lower in HCC tissues than that in normal liver tissues, and its low expression was closely related to tumor size, tumor differentiation, and TNM stage ( P < 0. 05, respectively). Further survival analysis showed that low miR-188-3p expression level in HCC tissues suggested a poor prognosis (log-rankP = 0. 025). In vitro cell experiments showed that the overexpression of miR-188-3p significantly inhibited the invasion and migration of HCC cells, while inhibition of miR-188-3p expression showed an opposite effect. Dual luciferase reporter gene assay showed that miR-188-3p could inhibit the expression of YAP1 protein by binding to the 3′UTR of YAP1. The results of the recovery experiment confirmed that miR-188-3p inhibited the invasion and migration of HCC cells by inhibiting the expression of YAP1 protein. Conclusion The expression of miR-188-3p is down-regulated in HCC, and miR-188-3p inhibits the invasion and migration of HCC cells by targeting the expression of YAP1, thereby participating in the occurrence and progression of HCC.

Key words: hepatocellular carcinoma, miR-188-3p, YAP1, invasion, migration ,