Excision repair in xeroderma pigmentosum group C cells is regulated differently in transformed cells and primary fibroblasts.
Excision repair in xeroderma pigmentosum group C cells occurs at about 20-30% of normal levels. In confluent fibroblasts a unique characteristic of this low repair is that it is clustered, representing very efficient repair in a small region of the genome. In SV40-transformed fibroblasts and Epstein-Barr virus-transformed lymphocytes of complementation group C, however, excision repair is randomly distributed. This may be a consequence of the high rate of proliferation of both of these cell types, because random repair is also observed in rapidly proliferating group C fibroblasts. The distribution of sites that can be mended in group C cells, therefore, varies according to the transformed and proliferative state of the cells, demonstrating that transformed cells do not always exhibit repair characteristics identical to those of primary fibroblasts.
Cleaver
J E
JE
Laboratory of Radiobiology and Environmental Health University of California, San Francisco 94143-0750.
D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D004260:DNA Repair; D004261:DNA Replication; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D012016:Reference Values; D013539:Simian virus 40 / Q000235:genetics; D013936:Thymidine / Q000378:metabolism; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics* / Q000473:pathology
D013936:Thymidine; D006918:Hydroxyurea