The lengths of DNA fragments light-induced in the presence of a photosensitizer localized at the nuclear membrane of human cells.
DNA damage was apparently introduced selectively in the parts of DNA localized close to the nuclear membrane of human NHIK 3025 cells. This was obtained by illumination of the cells in the presence of a hydrophobic photosensitizer, Photofrin II, which was located in membrane structures but not in the nucleus. Photofrin II sensitizes DNA to light mainly via singlet oxygen, which diffuses about 0.1 microns in its intracellular lifetime. By measuring DNA unwinding in alkali after illumination or X-irradiation of cells, the distribution of the number of DNA bases between two adjacent, photodamaged DNA sites was estimated. The average length of these DNA fragments was found to be 155 kilobases (kb).
Kvam
E
E
Department of Biophysics, Institute for Cancer Research, Montebello, Oslo, Norway.
Stokke
T
T
Moan
J
J
D004247:DNA / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage; D017324:Hematoporphyrin Derivative; D006415:Hematoporphyrins / Q000494:pharmacology*; D006801:Humans; D008027:Light; D009685:Nuclear Envelope / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014965:X-Rays
D006415:Hematoporphyrins; D011838:Radiation-Sensitizing Agents; D017324:Hematoporphyrin Derivative; D004247:DNA