Isoalantolactone induces apoptosis in human cervical cancer Hela cells through ROS generation and Mitochondrial dysfunction / 中国免疫学杂志

ABSTRACT

Objective:To investigate the induction of apoptosis by isoalantolactone in human cervical cancer Hela cells is mediated through ROS generation and Mitochondrial dysfunction. Methods: Cells were treated with isoalantolactone in a dose-dependent manner in the presence or absence of NAC for 24 h as the experimental group,and the normal cells were used as control group. Cell viabilities were determined by the MTT assay;the nuclear morphology of Hela cells were observed under fluorescence microscope using the Hoechst 33258 staining;apoptosiscell cycle and reactive oxygen species ( ROS ) and mitochondrial membrane potential(MMP) were measured by flow cytometry;the protein expression levels of cytochrome C,Bcl-2,Bax and Caspase-3 were detected by Western blot. Results:In the present study,we found that isoalantolactone inhibits growth in a dose-dependent manner in Hela cells. Further studies revealed that Hela cells were treated with 20 and 40 μmol/L isoalantolactone for 24 h,after which we could observe the fragmented nuclei and the increased apoptosis rate. And we also found that isoalantolactone arrested the cell cycle at S phase and increased generation of reactive oxygen species and dissipation of mitochondrial membrane potential (△ψm) in Hela cells. While pretreatment with NAC obviously blocked the apoptotic and inhibition effect of isoalantolactone indicating that induction of apoptosis is ROS-dependent,Western blot study showed that isoalantolactone increased the expression of Bax and cleaved Caspase-3 and decreased the expression of Bcl-2 with concomitant release of cytochrome C from mitochondria into cytosol. Conclusion: Isoalantolactone could inhibit the proliferation and induce the apoptosis of human cervical cancer Hela cells in vitro through mediating ROS generation and Mi-tochondrial dysfunction, the mechanism of which is also accompanied by up-regulation of Bax expression, down-regulation of Bcl-2 expression,activation of Caspase-3 and release of cytochrome C.