RESUMO
Objective:To explore the effects of protoporphyrin Ⅸ (PpⅨ)-mediated photodynamic therapy (PDT) on induction of apoptosis and death in colon cancer cell and the underlying mechanisms.Methods:The cell killing effect of PDT on HCT116 cell was determined by cell counting kit (CCK).The cells were divided into a control group,a single light group,a single PpⅨ group,and a PDT group.Hoechst 33342 and flow cytometry was used to assess the cell apoptosis.Western blot was employed to analyze the expressions ofbd-2,bax,and caspase-3.Reactive oxygen species (ROS) was detected by flow cytometry.Results:The viability of HCT116 cell was decreased gradually with the increase of irradiation dose (P<0.05).Compared to the other 3 groups,ROS production,the number of apoptotic cells and the protein expressions ofbax and caspase-3 in PDT group increased,while bcl-2 expression was decreased (P<0.05).Conclusion:PpⅨ-mediated PDT can enhance the apoptosis in HCT116 cell,which may be related to mitochondrial apoptosis pathway.