Downregulation of microRNA-143 promotes cell proliferation by regulating PKCε in hepatocellular carcinoma cells.

The abnormal expression of microRNAs (miRNAs) has been reported in hepatocellular carcinoma (HCC), however, the functional role of miR‑143 in HCC remains to be fully elucidated. The present study aimed to investigate the effects of the downregulation of miR‑143 on HCC cell proliferation and apoptosis, and elucidated the underlying mechanism. Hepg2 and Hep3B human hepatoma cell lines cells were transfected with miR‑143 inhibitor. Following transfection, the cell viability and apoptosis were respectively determined using a 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2‑H‑tetrazolium bromide assay and flow cytometry, and the mRNA and protein levels of protein kinase Cε (PKCε) were examined. The expression levels of PKCε were downregulated by short hairpin (sh)RNA, and the effects of the downregulation of miR‑143 on HCC cell proliferation were measured. The results showed that the miR‑143 inhibitor significantly promoted cell proliferation and suppressed apoptosis in the Hepg2 and Hep3B cells. The miR‑143 inhibitor significantly increased the protein levels of PKCε in the Hepg2 and Hep3B cells; however, no significant differences were found in the mRNA levels of PKCε. In addition, the downregulation of PKCε markedly decreased the cell viability of the Hepg2 and Hep3B cells, and co‑transfection with the miR‑143 inhibitor and PKCε shRNA significantly alleviated the miR‑143 inhibitor‑induced high cell proliferation. Taken together, these results suggested that miR‑143 acts as a tumor suppressor gene in HCC. The downregulation of mi‑143 promoted cell proliferation by regulating PKCε in the HCC cells.