© 1994 Oxford University Press
research-article |
Modulation of urinary mutagenicity by genetically determined carcinogen metabolism in smokers
1Department of Industrial Hygiene and Toxicology, Institute of Occupational Health FIN-00250 Helsinki, Finland
2International Agency for Research on cancer F-69372 Lyon Cedex 08, France
We examined the genotypes of two polymorphic genes involved in the detoxification of several mutagenic and carcinogenic compounds in relation to tobacco smoking-associated urinary mutagenicity. The genes studied were the glutathione S-transferase-encoding GSTM1 gene and acetyltransferase-encoding NAT2 gene. Smokers with no GSTM1 gene (n = 7) had urine that was several times more mutagenic than that of smokers with the gene (n = 10). The mean level of urinary mutagenicity in presence of metabolic activation was 2527 ± 958 revertants/100 ml urine for GSTM1- smokers compared to 766 ± 560 revertants/100 ml for GSTM1+ smokers (P < 0.001) using the bacterial strain YG1024. The corresponding values using the TA98 strain were 336 ± 124 and 123 ± 75 (P < 0.001). In contrast, we failed to show any difference in the level of urinary mutagenicity between slow-acetylator and fast-acetylator NAT2 genotypes among smokers (n = 17) or non-smokers (n = 35). Our results offer one explanation for the recent findings that GSTM1 polymorphism is a risk modifier in smoking-related cancers, especially bladder cancer.