title: Identification of cellular defect in UVS1, a UV-sensitive Chinese hamster ovary mutant cell line.
abstract: UVS1 is an intermediately UV-sensitive Chinese hamster ovary mutant originally isolated by its hypersensitivity to an anticancer drug, 1-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-3-(2-chloroethyl)-3-nitrosour ea hydrochloride. By cell fusion analysis, UVS1 complemented the UV sensitivity of the mouse lymphoma cell line US31 from the eighth complementation group of UV-sensitive rodent cell lines. By enzyme-linked immunosorbent assay we found that within 3 h after UV irradiation both pyrimidine dimers and (6-4)photoproducts in UVS1 were not removed from chromosomal DNA in UVS1 at all. Twenty-four h after UV irradiation the removal rate of (6-4)photoproducts was intermediate between CHO9, the parental cell line, and 43-3B, a UV-hypersensitive Chinese hamster ovary mutant of the complementation group 1, whereas the pyrimidine dimers in UVS1 were removed less efficiently as 43-3B. Alkaline elution assay showed that the incising activity to damaged DNA after UV irradiation of UVS1 was as low as that of 43-3B. The number of 1-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-3-(2-chloroethyl)-3-nitrosour ea hydrochloride-induced DNA interstrand cross-links of UVS1 was almost equal to that of 43-3B and about 1.5 times more than that of CHO9, suggesting that the gene products defective in UVS1 and 43-3B are essential for the excision repair of DNA damages produced by 1-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-3-(2-chloroethyl)-3-nitrosour ea hydrochloride.
authors.affiliation: Research Institute for Tuberculosis and Cancer, Tohoku University, Sendai, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Numata
authors.forename: H
authors.initials: H
authors.lastname: Hata
authors.forename: T
authors.initials: T
authors.lastname: Shiomi
authors.forename: T
authors.initials: T
authors.lastname: Matsunaga
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.forename: O
authors.initials: O
authors.lastname: Nikaido
authors.forename: A
authors.initials: A
authors.lastname: Yasui
authors.forename: A
authors.initials: A
authors.lastname: Oikawa
mesh_terms: D000818:Animals; D016466:CHO Cells / Q000502:physiology / Q000528:radiation effects*; D002460:Cell Line; D006224:Cricetinae; D004247:DNA / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D004273:DNA, Neoplasm / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D016678:Genome; D007700:Kinetics; D008223:Lymphoma / Q000235:genetics / Q000503:physiopathology; D051379:Mice; D009154:Mutation; D015376:Nimustine / Q000494:pharmacology; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D004273:DNA, Neoplasm; D015376:Nimustine; D004247:DNA