Recent studies have shown that microRNA-34c-3p (miR-34c-3p) is down-regulated in various types of cancers and involved in tumor growth, invasion and metastasis. However, the roles of miR-34c-3p in hepatocellular carcinoma (HCC) are poorly understood. In this study, the expression profile of miR-34c-3pin HCC tissues and cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR). The correlations of miR-34c-3p expression and clinicopathological characteristics were analyzed. The biological role of MiR-34c-3pin cell proliferation, migration and invasion was examined. In addition, the targets of miR-34c-3p were identified. The results showed that miR-34c-3p expression was significantly down-regulated in HCC tissues and cell lines; low expression level of miR-34c-3p was correlated with vascular invasion and advanced TNM stage. In vitro functional assays showed that overexpression of miR-34c-3pin HepG2 and Huh7 cells significantly reduced cell proliferation, migration and invasion. Furthermore, target analysis and luciferase assay identified myristoylated alanine-rich protein kinase c substrate (MARCKS) as a specific target of miR-34c-3p. Knockdown of MARCKS in HepG2 cells reduced cell migration and invasion, but not cell proliferation. Taken together, our findings implicate the potential application of miR-34c-3p as a tumor suppressor in cancer therapy.
Keywords: MARCKS; MiR-34c-3p; hepatocellular carcinoma; tumor suppressor.