Methyl pyropheophorbide-a-mediated photodynamic therapy induces apoptosis in human ovarian cancer cells

Objective To investigate the mechanism by which methyl pyropheophorbide-a-mediated photodynamic therapy(Mppa-PDT)inhibit cell viability and induce apoptosis in human ovarian cancer cell line SKOV3.Methods Human ovarian cancer cells SKOV3 at the logarithmic growth phase were divided into Mppa-PDT treated group(both Mppa and PDT treated group)and control groups(the blank group,the only Mppa treated group and only PDT treated group).After Mppa-PDT treatment,the cell viability was examined with CCK-8assay;cell apoptosis was detected by flow cytometry with Annexin Ⅴ-FITC/PI;and nuclear morphological changes during cell apoptosis was detected by DAPI staning.Moreover,the celluar reactive oxygen species(ROS) were detected by DCFH-DA staining;DNA damage was observed by single cell gel electrophoresis;and the protein expression of p53,Caspase-3,Bax,and Bcl-2 were assessed by Western blotting analysis.Results(1)Mppa-PDT could greatly suppress the cell viability of human ovarian cancer cells SKOV3 in a dose-dependent manner.(2)The cell apoptosis rate of Mppa-PDT treated group was significanlty higher than those of three control groups(blank group,Mppagroup and PDT group)(P0.05),and there was no difference among the three control groups(P0.05).(3)After treating with Mppa-PDT,DAPI staining showed strongly stained nuclei of the apoptotic cells;DCFH-DA staining displayed higher level of ROS than those of the three control groups;single cell gel electrophoresis showed greater DNA damage than those of the three control groups;and Western blotting analysis showed that the expression of p53,Caspase-3and Bax protein was increased and Bcl-2protein was decreased(P0.05).Conclusion Mppa-PDT can significantly suppress cell viability and induce apoptosis in human ovarian cancer cell SKOV3,accompanied by DNA damage and the activation of mitochondrial apoptosis pathway.