Abstract:

Objective  To study the effect of different concentrations of camptothecin(CPT) on the apoptosis of human cervical cancer cells (HeLa), and to explore the mechanism of apoptosis induced by CPT in HeLa cells. Methods  The cultured in vitro human cervical cancer cells (HeLa) were divided into the control group and CPT groups treated with various concentrations(100 nmol/L-10 μmol/L). The viability of HeLa cells were detected by methyl thiazolyl tetrazolium (MTT) assay. The morphology changes of HeLa cells were observed with an inverted microscope. The cells apoptosis was analyzed by 4’6-diamidino-2-phenylindole(DAPI) and flow cytometry (FCM). Western blotting was used to detect the expression of Bcl-2, Bax,Cleave-Caspase-3，Cyt-C and poly ADP-ribose polymerase(PARP). Results  Compared with the control group, the viability of HeLa cells decreased after treatment with different concentrations of CPT for 24 hours, and the cells morphology was changed in a dose-dependent manner. DAPI dying showed that there were apoptotic bodies FCM assay indicated that the early apoptosis ratios was increased after treatment with different concentrations of CPT for 24 hours. The cell apoptotic rate increased obviously in the CPT-treated groups than in the control group. The expression of Bcl-2 was decreased whereas the expressions of Bax,cleave-Caspase-3, Cyt-C into cell plasm and 89 kD phosphoribosyl pyrophosphate(PRPP) were increased when compared to that in the control group. Conclusion  CPT can induce HeLa cell apoptosis, and its mechanism may be to activate the mitochondrial dependent pathway, and further activate substrate PARP.

Key words: Camptothcin, Cell proliferation, HeLa cell, Western blotting, Human