title: A hypothesis for the molecular mechanism of tumor killing by porphyrins and light.
abstract: Tumor cells have an absence or deficiency of mitochondrial superoxide dismutase. Superoxide is produced when hematoporphyrin derivative is exposed to visible light. A significant portion of the antitumor effect of porphyrin:light therapy is hypothesized to be mediated by superoxide.
mesh_terms: D006415:Hematoporphyrins / Q000528:radiation effects*; D006801:Humans; D008027:Light; D008954:Models, Biological; D009369:Neoplasms / Q000378:metabolism / Q000532:radiotherapy*; D009580:Nitroblue Tetrazolium; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*
chemical_list: D006415:Hematoporphyrins; D013481:Superoxides; D009580:Nitroblue Tetrazolium; D013482:Superoxide Dismutase; D010100:Oxygen