title: Photofrin II photosensitization is mutagenic at the tk locus in mouse L5178Y cells.
abstract: Photosensitization mediated by Photofrin II (PFII) was found to be mutagenic at the heterozygous thymidine kinase (tk) locus in mouse L5178Y lymphoma strains LY-S1 and LY-R16 but not in strain LY-R83 which is hemizygous at the tk locus. After treatments yielding 37% survival, the mutagenicity of photosensitization with PFII in strain LY-S1 was similar to that of other mutagenic agents including x-radiation, ethyl methanesulfonate, and photosensitization with chloroaluminum phthalocyanine (AlPcCl). Although both strain LY-S1 and strain LY-R16 were mutagenized by photosensitization with PFII, only strain LY-S1 was mutagenized by photosensitization with AlPcCl. The non-mutability of strain LY-R83 following photodynamic treatment with either sensitizer may be because of the poor recovery of mutants with intergenic mutations in this TK+/0 hemizygous strain, whereas the non-mutability of strain LY-R16 subjected to photodynamic treatment with AlPcCl may be because LY-R16 cells sustaining mutagenic damage do not survive for reasons other than the loss of an essential gene.
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, OH 44106.
authors.forename: R M
authors.initials: RM
authors.lastname: Rerko
authors.forename: M E
authors.initials: ME
authors.lastname: Clay
authors.forename: A R
authors.initials: AR
authors.lastname: Antunez
authors.forename: N L
authors.initials: NL
authors.lastname: Oleinick
authors.forename: H H
authors.initials: HH
authors.lastname: Evans
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D017323:Dihematoporphyrin Ether; D006415:Hematoporphyrins / Q000494:pharmacology*; D007940:Leukemia L5178 / Q000201:enzymology*; D008027:Light; D051379:Mice; D016296:Mutagenesis; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D013937:Thymidine Kinase / Q000235:genetics*; D014407:Tumor Cells, Cultured; D014965:X-Rays
chemical_list: D006415:Hematoporphyrins; D011838:Radiation-Sensitizing Agents; D017323:Dihematoporphyrin Ether; D013937:Thymidine Kinase