THE GROWTH INHIBITION AND THE APOPTOSIS OF HeLa CELLS INDUCED WITH TCS

Objective The purpose of the current study is to investigate the growth inhibition and the apoptosis of HeLa cells induced with TCS,and to explore the underlying molecular mechanism.Methods The antiproliferative effect of TCS on HeLa cells was measured with CCK-8.The FCM analysis was carried out to examine the effect of TCS on the cycle distribution of HeLa cells.Electron microscopy and FCM analysis were employed to observe the apoptosis of HeLa cells.The protein expression of caspase-3 was determined by Western blotting.The activity of caspase-3,8,9 was determined by a caspases colorimetric assay kit.Results 1.The proliferation of HeLa cells was significantly inhibited by TCS;2.TCS led a S-phase arrest in cell cycle;3.HeLa cell apoptosis was induced with TCS,which was characterized by chromatin condensation and apoptotic bodies.And the apoptotic rate of HeLa cells increased with time;4.The expression of caspase-3 protein was decreased significantly(P0.01) in a dose-and time-dependent manner and the activity of caspase-3 was increased with a time-dependent,which clearly indicated that caspase-3 was activated in the apoptosis of HeLa cells;5.The activity of caspase-8,9 also had a time-dependent increase in the experiment.In terms of temporal sequence of the caspase activation,caspase-8 was the first caspase triggered at 24h following 100mg/L TCS treatment,which was earlier than the activation of caspase-3.These results indicated that the activation of caspase-8 led to caspase-3 activated. Conclusion The results of our study showed that TCS inhibits the growth of HeLa cell through cell cycle arrestted in S phase and the apoptosis of HeLa cells,and the studies demonstrated also that the activation of caspase-3 is a pathway mediating the apoptosis of HeLa cells induced with TCS,in which caspase-8,9 are critically involved.