中文摘要：

目的：探讨肝内胆管癌细胞HCCC-9810中SET和MYND结构域含有蛋白3（SETandMYNDdo，main-containing protein3，SMYD3）过表达对miR-124表达及细胞增殖能力的影响。方法：瞬时转染SMYD3真核表达质粒后，Westernblotting检测细胞中SMYD3蛋白水平的变化；qRT-PCR检测细胞中SMYD3 mRNA和miR-124表达；甲基化特异性PCR检测m／R-124-I、miR-124-2和miR-124-3基因启动子甲基化水平；CCK-8和平板克隆形成实验检测细胞增殖能力。结果：以空白组为对照，肝内胆管癌细胞HCCC-9810在转染pEGFP-SMYD3质粒后，SMYD3蛋白及mRNA表达均显著上升（P〈0．05），miR-124-I、miR-124-2和miR-124-3基因启动子甲基化显著增加（P〈0．05），miR-124表达明显下降（P〈0．05），细胞增殖能力显著提高（P〈0．05）。结论：过表达SMYD3可引起miR-124基因启动子甲基化增加，导致胆管癌细胞中miR-124的表达下降，同时过表达SMYD3可增强细胞增殖能力。

英文摘要：

AIM ： To explore the effect of SET and MYND domain-containing protein 3 （SMYD3） over-expres- sion on miR-124 expression and proliferation ability of human intrahepatic cholangiocarcinoma cells. METHODS： Transi- ent 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 deter- mined by methylation-specific PCR. Cell proliferation was examined by CCK-8 assay and colony formation experiment. RE- SULTS： After transfected with SMYD3 eukaryotic expression plasmid, the over-expression of SMYD3 in HCCC-9810 cells was observed. Compared with the blank ceils, 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 pro- liferation 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.