Effect of Arsenic Trioxide on Apoptosis and Expression of Smac,Caspase-9,Caspase-3 in Human Hepatocellular Carcinoma SMMC-7721 Cells

Objective:To investigate the effect of As2O3on apoptosis and suppress the proliferation of the hepatocellular carcinoma cells and the effect on the expression of Smac,caspase-9,caspase-3 in hepatocellular carcinoma cells.Methods:SMMC-7721 cells were treated with As2O3,which were divided into four groups,including blank control group,low dose group,medium dose group and high dose group.Cell growth inhibitory rate was detected by MTT colorimetric assay every 24 hours.The nuclear morphology of apoptotic cells was observed by Hoechst 33258 staining,and the apoptotic effect of As2O3in cell nucleus in the way of fluorescence was obtained.Apoptosis rate was analyzed by Annexin V-FITC/PI fluorescence staining.The expression of Smac and caspase-9,caspase-3 was measured by Western blot.This expression value of apoptotic protein can illustrate the changes of the gene with the As2O3.Results:MTT tests suggested SMMC-7721 cells proliferation were inhibited by As2O3in time and dose-dependent in vitro.Compared with that in the blank control group,the rest of the three groups of cell survival rate decreased obviously,and difference have statistical significance(P0.05).N uclear morphology cha nges characterized by apoptotic cells were observed clearly by Hoechst 33258 staining in dose-dependent manner.Annexin V-FITC/PI showed that As2O3could induce SMMC-7721 cells apoptosis after 24 hours in dose-dependent manner.Compared with that in the blank control group(2.69±0.58),the rest of the three groups were statistically significant differences(4.01±0.58),(5.99±1.69),(9.26±2.34)(P0.05).Western blot indicated that the expression of Smac and caspase-9,caspase-3 increased in SMMC-7721 cells induced by As2O3after 24 hours.Compared with that in the blank control group,the rest of the three groups of protein expression quantity increased significantly,and difference have statistical significance(P0.05).Conclusions:The mechanistic study showed that As2O3acted through inhibit of SMMC-7721 cells proliferation and induce apoptosis in which Smac and caspase-9,caspase-3were activated.