Apoptosis and cell cycle-blockade of human hepatocarcinoma HepG_2 cells induced by arsenic trioxide

Objective To study on the inhibitory effect of arsenic trioxide(As2O3) on the growth of human hepatocarcinoma HepG2 cells,its inducing effect on the apoptosis of HepG2 cells,and its influence on cell cycle-blockade.Methods MTT,DNA laddering test and flow cytometry were used to detect the inhibitory effect of As2O3 on the growth of HepG2 cells,its inducing effect on the apoptosis of HepG2 cells,and its influence on cell cycle-blockade.Results In the treatment group MTT outcome showed that As2O3 inhibited significantly the growth of HepG2 cells with a time-dosage dependency.The result of DNA laddering test showed that typical apoptosis bands of DNA ladders were observed after 48 hours and 72 hours when 12 mol·L-1 As2O3 acting on HepG2 cells for 24,48 and 72 hours.The analysis result of flow cytometry showed that after the action of 12 mol·L-1 As2O3 for 24,48 or 72 hours the apoptosis rates were(9.74±1.22) %,(21.89±2.14) % or(42.72±0.83) % respectively,which were all higher than that of the control group(0.98±0.11) %(P0.01).At the same time As2O3 had significant blockade effects on the S and G2 phases of cell cycle.Conclusion As2O3 has the blockade effects on the S and G2 phases of cell cycle and can induce cell apoptosis,which may be one of its mechanisms of anti-tumor.