Abstract: Objective To explore inhibitive effect of miR-214 on proliferation and cell cycle in hepatocellular carcinoma cells.Methods The expression of miR-214 in hepatocellular carcinoma cells of SMMC-7721,HepG2,SK-Hep-1,Huh 7,and Hep3B and normal liver cell L-02 was detected with realtime-PCR.Hepatocellular carcinoma cells were transfected with miR-214 NC and miR-214 mimics by liposome and the outcome of the transfection was determined with realtime-PCR.The cell viability,cell apoptosis and cell cycle was assessed with (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry,respectively.The expression of cyclin D1,cyclin-dependent protein kinases (CDK4),survivin,and proliferating cell nuclear antigen (PCNA) were detected with Western blot.Results The expression of miR-214 in the cells of SMMC-7721 (1.25±0.10),SK-Hep-1 (1.43±0.10),Huh 7 (0.95±0.09),Hep3B (0.98±0.0),and HepG2 (0.82±0.08) were all lower than that in L-02 cells (2.52±0.23) and the expression of miR-214 was the lowest in HepG2 cells.The expression of miR-214 in miR-214 mimics HepG2 cells (2.38±0.23) was higher than that in miR-214 NC HepG2 cells (0.83±0.08).The cell viability of miR-214 mimics HepG2 cells (0.37±0.03) was lower than that of miR-214 NC cells (0.78±0.07).Compared with those of the miR-214 NC HepG2 cells,the cell apoptotic rate was increased;cell cycle was arrested at G1;and expressions of cyclin D1,CDK4,survivin,and PCNA were down-regulated in miR-214 mimics HepG2 cells,with significant differences between the two groups (P<0.01 for all).Conclusion miR-214 mimics inhibits HepG2 cell proliferation;the mechanism of the inhibitive effect may be related to the expression of cell cycle regulation related protein.