Chromosomal aberrations in workers exposed to low levels of benzene: association with genetic polymorphisms.
Benzene and its metabolites damage human lymphocytes, resulting in chromosomal aberrations and aneuploidy. Polymorphisms in the genes for benzene-metabolizing enzymes have been implicated in benzene-associated haematotoxicity. In this study, we examined the specificity of benzene-induced aneuploidy and the influence of genetic polymorphisms (GSTM1, GSTT1, GSTP1, NAT2, NQO1 and CYP2E1) on chromosomal aberrations. In total, 82 benzene-exposed workers from a coke oven plant and 76 matched controls were examined. The benzene concentration in the work-place air ranged from 0.014-0.743 p.p.m. (geometric mean 0.557 p.p.m.). Benzene exposure was associated with significant increases in both monosomy and trisomy of chromosomes 8 and 21. Translocations between chromosomes 8 and 21 [t(8:21)] were eight-fold more frequent in the high-level exposure group compared to the control group. Multiple regression analysis indicated that the frequencies of chromosome aberrations were significantly associated with benzene exposure and polymorphisms in the metabolic enzyme genes. A particular subset of genotypes, which included the GSTM1-null and GSTT1-null genotypes, the slow acetylator type of NAT2, a variant of the NQO1 genotype and the CYP2E1 DraI and RsaI genotypes, were either separately, or in combination, associated with increased frequencies of aneuploidy among the benzene-exposed individuals after adjustments for age, alcohol consumption and smoking. These results suggest that polymorphisms in the genes for benzene-metabolizing enzymes influence the susceptibility of individuals to chromosomal aberrations in relation to benzene exposure.
Kim
Su Young
SY
School of Public Health and Institute of Health and Environmental Sciences, Seoul National University, Seoul, Korea.
Choi
Jung Keun
JK
Cho
Yoon Hee
YH
Chung
Eun Jung
EJ
Paek
Domyung
D
Chung
Hai Won
HW
D000782:Aneuploidy; D002869:Chromosome Aberrations; D004798:Enzymes / Q000235:genetics; D006801:Humans; D016273:Occupational Exposure; D011110:Polymorphism, Genetic; D014314:Trisomy
D004798:Enzymes