Effect of SMYD3 over-expression on miR-124 expression and proliferation ability in human intrahepatic cholangiocarcinoma cells

AIM：To explore the effect of SET and MYND domain-containing protein 3 (SMYD3) over-expression on miR-124 expression and proliferation ability of human intrahepatic cholangiocarcinoma cells. METHODS：Transient transfection of SMYD3 eukaryotic expression plasmid into human intrahepatic cholangiocarcinoma cell line HCCC-9810 were performed. The expression of SMYD3 at mRNA and protein levels was measured by qRT-PCR and Western blotting, respectively. The expression of miR-124 was detected by qRT-PCR, and the methylation status of miR-124 gene was determined by methylation-specific PCR. Cell proliferation was examined by CCK-8 assay and colony formation experiment. RESULTS：After transfected with SMYD3 eukaryotic expression plasmid, the over-expression of SMYD3 in HCCC-9810 cells was observed. Compared with the blank cells, the expression level of miR-124 was significantly decreased and miR-124 gene promoter methylation was significantly increased. In addition, SMYD3 over-expression significantly promoted the proliferation of HCCC-9810 cells. CONCLUSION：The transient transfection of SMYD3 plasmid increases the methylation of miR-124 gene promoter and induces under-expression of miR-124. Over-expression of SMYD3 promotes the proliferation of cholangiocarcinoma cells.