title: [Photocleavage of nucleic acids by photosensitizers--application to photodynamic cancer therapy].
abstract: Plasmid DNA has been efficiently photocleaved by sodium pheophorbides (Na-Phdes) a and b with visible light even in the absence of oxygen. Singlet oxygen production sensitized by Na-Phdes a and b has not been observed in the aqueous media. Electron transfer from DNA bases, guanine and adenine, to the porphyrin ring in the singlet excited state has been demonstrated. Fluorescence microscopic observation has shown a rapid incorporation of Na-Phde a into nuclei, mitochondria, and lysosome of human oral cells. In contrast, Na-Phde b has been incorporated only into the plasma membrane. Fluorescence intensity of Na-Phde a has rapidly decreased during microscopic observation, indicating that some photochemical reactions take place in the organelle. Fluorescein-attached oligonucleotide (11 mer) has bound covalently to a complementary strand DNA (28 mer) by visible light irradiation in aqueous media. This oligonucleotide with liposome treatment can be incorporated into nucleoli of cultured human keratinocytes, and its strong fluorescence has quickly decayed by irradiation. The first photohydrolysis has been achieved by several naphthol derivatives with visible light. Thus naphthol derivatives can be potent as the catalytic site of artificial photonuclease.
authors.affiliation: Department of Chemistry and Biotechnology, Faculty of Engineering, University of Tokyo.
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Komiyama
mesh_terms: D002735:Chlorophyllides / Q000627:therapeutic use; D004247:DNA; D006801:Humans; D006868:Hydrolysis; D009284:Naphthols / Q000627:therapeutic use; D009369:Neoplasms / Q000188:drug therapy*; D010778:Photochemotherapy; D010782:Photolysis; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D014966:Xanthenes / Q000627:therapeutic use
chemical_list: D002735:Chlorophyllides; D009284:Naphthols; D017319:Photosensitizing Agents; D014966:Xanthenes; D004247:DNA