title: Mitomycin C-induced postmitotic fibroblasts retain the capacity to repair pyrimidine photodimers formed after UV-irradiation.
abstract: The formation and excision of UV-C light-induced cyclobutane-type pyrimidine photodimers were determined in cultures of human skin fibroblasts at time zero and several weeks following treatment with mitomycin C (MMC). Characteristic morphological changes of the fibroblasts and specific shifts in the [35S]methionine polypeptide pattern of total cellular proteins support the notion that MMC accelerates the differentiation pathway from mitotic (MF) to post-mitotic fibroblasts (PMF). No discernible difference could be detected between the fluence-response curves of pyrimidine dimers for untreated and MMC-treated repair-deficient xeroderma pigmentosum cells of group A. Furthermore we investigated the removal of pyrimidine dimers in 3 normal human skin fibroblast strains frequently used in mutation, transformation and aging research. We were able to demonstrate that no significant difference exists in the rate and extent of the excision-repair response to thymine-containing pyrimidine dimers following UV-irradiation shortly after MMC treatment of fibroblasts and in the MMC-induced PMF stage of these cells.
authors.affiliation: Cosmital SA, Marly, Switzerland.
authors.forename: H J
authors.initials: HJ
authors.lastname: Niggli
authors.forename: K
authors.initials: K
authors.lastname: Bayreuther
authors.forename: H P
authors.initials: HP
authors.lastname: Rodemann
authors.forename: R
authors.initials: R
authors.lastname: Röthlisberger
authors.forename: P I
authors.initials: PI
authors.lastname: Francz
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology*; D008938:Mitosis; D011740:Pyrimidine Dimers / Q000378:metabolism*; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics
chemical_list: D008937:Mitomycins; D011740:Pyrimidine Dimers; D016685:Mitomycin; D004247:DNA