title: Photodynamic therapy with pyropheophorbide-a methyl ester in human lung carcinoma cancer cell: efficacy, localization and apoptosis.
abstract: Pyropheophorbide-a methyl ester (MPPa) is a semisynthetic photosensitizer derived from chlorophyll a. The absorption peak of MPPa in organic solvent and in cells was at 667 and 674 nm, respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay showed that MPPa had no dark cytotoxicity. In vitro photodynamic activity was extensively evaluated using a human lung carcinoma cancer cell line (NCI-h446). MPPa exhibited no genotoxicity, as assayed by single-cell gel electrophoresis. Using confocal laser scanning microscopy and organelle-specific fluorescent probes, MPPa was found to localize in the intracellular membrane system, namely the endoplasmic reticulum, Golgi apparatus, lysosomes and mitochondria, in the NCI-h446 cells. Furthermore, nuclear staining and DNA gel electrophoresis revealed that DNA condensation and fragmentation occurred post-photodynamic therapy, indicating the cell death was in the apoptotic mode.
authors.affiliation: Department of Biology, Hong Kong Baptist University, Hong Kong, People's Republic of China.
authors.forename: X
authors.initials: X
authors.lastname: Sun
authors.forename: W N
authors.initials: WN
authors.lastname: Leung
mesh_terms: D017209:Apoptosis / Q000528:radiation effects*; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D018613:Microscopy, Confocal; D015394:Molecular Structure; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D011166:Porphyrins / Q000737:chemistry / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins; C452939:pyropheophorbide-a methylester