The cytotoxic and mutagenic effects of 5-bromodeoxyuridine-plus-black-light treatment in cultured mammalian cells.
The cytotoxic and mutagenic effects of the incorporation of 5-bromodeoxyuridine (BrdU) followed by exposure to black light were investigated with Chinese hamster ovary (CHO) cells in cell culture. Mutation induction at the hypoxanthine-guanine phosphoribosyl transferase (hgprt) locus was determined by selection for 6-thioguanine resistant (TGr) mutants (CHO/HGPRT system). BrdU alone has been shown to be mutagenic only at concentrations of 50 micro M or greater. This study was performed in an effort to determine whether BrdU is actually incorporated into the hgprt gene when lower, nonmutagenic concentrations are employed. Neither BrdU (1-20 micro M) nor exposure to black light alone was mutagenic, but the combined treatment did result in the induction of TGr mutants. The mutant frequency increased with increasing light exposure at constant BrdU and with increasing BrdU at constant light exposure. These results show that BrdU is incorporated into the hgprt gene, but that this does not result in mutation induction in the absence of light exposure. Such a BrdU-plus-light procedure might be applied to studies of DNA repair at this locus, since mutation induction requires both BrdU incorporation and subsequent exposure to black light.
D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002470:Cell Survival; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000528:radiation effects; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D009153:Mutagens / Q000494:pharmacology*; D010053:Ovary; D010777:Photochemistry; D014466:Ultraviolet Rays
D009153:Mutagens; D007041:Hypoxanthine Phosphoribosyltransferase; D001973:Bromodeoxyuridine