MiR-486-5p Suppresses Proliferation and Migration of Hepatocellular Carcinoma Cells through Downregulation of the E3 Ubiquitin Ligase CBL

Abstract

MicroRNAs have been broadly implicated in cancer, but precise functions and mechanisms in carcinogenesis vary among cancer types and in many cases remain poorly understood. Hepatocellular carcinoma (HCC) is among the most frequent and lethal cancers. The aim of the present study was to investigate the role of miR-486-5p in HCC and identify its specific target. MiR-486-5p was significantly downregulated in HCC tissues and cell lines compared with noncancerous tissues and, respectively, although expression level was not correlated with the degree of infiltration or tumor stage. However, miR-486-5p overexpression in HCC cells inhibited proliferation and migration as evidenced by CCK-8 cell counting, wound healing, and transwell assays, indicating that miR-486-5p is an HCC suppressor. We employed four miRNA databases to predict the target genes of miR-486-5p and verified retrieved genes using qPCR and western blotting. The E3 ubiquitin ligase CBL was significantly downregulated by miR-486-5p overexpression in HCC cell lines at both mRNA and protein level, and overexpression of CBL counteracted the inhibitory effects of miR-486-5p on HCC cell proliferation and migration. Moreover, CBL expression was negatively correlated with miR-486-5p expression in HCC tissues. Collectively, our results suggest that miR-486-5p may act as a tumor suppressor gene in HCC by downregulating CBL expression.