miR-34a regulates HDAC1 expression to affect the proliferation and apoptosis of hepatocellular carcinoma.

miR-34a is an important molecule that can inhibit the tumor growth. This study aimed to investigate the functional role of miR-34a in hepatocellular carcinoma (HCC) and explore the interaction between miR-34a and histone deacetylase 1 (HDAC1). RT-qPCR was employed to detect the mRNA expression of miR-34a and HDAC1 in 60 HCC tissues. Results showed miR-34a expression in HCC tissues was significantly lower than in normal tissues (P<0.05), but HDAC1 expression in HCC tissues was markedly higher than in normal tissues (P<0.05). In addition, miR-34a expression was negatively related to HDAC1 expression. miR-34a mimic was transfected into HCC cell lines (HepB3 and HepG2). CCK8 assay, colony formation assay and flow cytometry showed miR-34a over-expression could inhibit the proliferation of HCC cells and induce their apoptosis. Western blotting indicated miR-34a over-expression down-regulated the expression of Bcl-2, procaspase-3, procaspase-9 and c-Myc, but up-regulate p21 expression. Bioinformatics analysis indicated HDAC1 was a target gene of miR-34a. Dual Luciferase Reporter Gene Assay and retrieval assay showed miR-34a could act at the 3'UTR of HDAC1 gene to regulate its expression. Thus, miR-34a may inhibit the proliferation of HCC cells and induce their apoptosis via regulating HDAC1 expression. Our findings provide evidence for the diagnosis and therapeutic target of HCC.