Polymerase chain reaction-based deletion analysis of spontaneous and arsenite-enhanced gpt mutants in CHO-AS52 cells.
In this study, we have examined the mutagenicity of sodium arsenite at the xanthine-guanine phosphoribosyltransferase locus (ypt) in a pSV2 gpt-transformed CHO cell line, AS52. Our results provide very weak evidence for arsenite as a gene mutagen because the chemical at high doses and at high cytotoxicity enhances barely a doubling of mutant frequency (MF) and a doubling of the gpt gene deletion frequency compared to controls. We suggest that the increase in MF in arsenite-treated cells results from arsenic, as comutagen, enhancing the induction effect of any unknown endogenous or exogenous factors on the spontaneous mutagenesis of AS52 cells. Nested PCR analysis mutants has a total deletion of the gpt gene. For the spontaneous, 50 microM arsenite- and 100 microM arsenite-enhanced spontaneous mutants in AS52 cells, the percentages of total deletion of the gpt gene are 36.00%, 54.72% and 66.67%, respectively. We suggest that a high proportion of the gene deletion in arsenite-enhanced mutants may be due to the high cytotoxicity of the chemical.
Meng
Z
Z
Division of Environmental Biological Toxicology, Shanxi University, Taiyuan, P.R. China.
Hsie
A W
AW
D000818:Animals; D018053:Arsenites / Q000633:toxicity*; D001426:Bacterial Proteins / Q000235:genetics*; D016466:CHO Cells; D002461:Cell Line, Transformed; D006224:Cricetinae; D029968:Escherichia coli Proteins; D014644:Genetic Variation; D009152:Mutagenicity Tests; D009153:Mutagens; D010430:Pentosyltransferases; D016133:Polymerase Chain Reaction; D011506:Proteins; D017384:Sequence Deletion; D017670:Sodium Compounds / Q000633:toxicity*
D018053:Arsenites; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D009153:Mutagens; D011506:Proteins; D017670:Sodium Compounds; C017947:sodium arsenite; D010430:Pentosyltransferases; C071962:Gpt protein, E coli