Photodynamic inhibition of pyropheophorbide-a methyl ester in human nasopharyngeal carcinoma cells / 第三军医大学学报

ABSTRACT

Objective To explore photodynamic inhibition of pyropheophorbide-a methyl ester(MPPa) in nasopharyngeal carcinoma cells and the mechanism.Methods The poorly differentiated CNE2 cell line was chosen to investigate the photocytotoxic potency and efficacy of MPPa 24 h after PDT by MTT reduction assay.The apoptosis of CNE2 cells was analyzed 8 h after photosensitization of MPPa(2 ?mol/L) under red light irradiation at a light dose of 2 J/cm~(2) by flow cytometry with Annexin Ⅴ-FITC and PI staining and nuclear staining with Hoechst 33258,and the changes in mitochondrial membrane potential(△?m) were monitored by flow cytometry with Rhodamine123 staining. Results Drug-and light-dose response curves were observed,showing that MPPa mediates a dose-and light-dependent phototoxicity in the NPC/CNE2 cells.MPPa could significantly trigger the NPC/CNE2 cells into apoptosis and the collapse of △?m were observed in the NPC/CNE2 cells treated by PDT with MPPa.Conclusion MPPa can effectively photokill the NPC/CNE2 cells and induce apoptosis as a prominent mode of cell death probably through mitochondria-initiated apoptosis pathway.