NQO1, MPO, CYP2E1, GSTT1 and GSTM1 polymorphisms and biological effects of benzene exposure--a literature review.
BACKGROUND
Benzene is a ubiquitous toxic environmental pollutant. Biological effects have been detected as a result of low-level environmental exposures, suggesting that a large proportion of the population may potentially suffer ill health effects. Polymorphisms in genes involved in benzene metabolism are thought to influence individual susceptibility to various levels of benzene exposure.


METHODS
Medline literature database search for articles relating to benzene exposure and polymorphisms in genes known to be involved in benzene metabolism (NQO1, CYP2E1, GSTT1, GSTM1 and MPO). Twenty-two reports were included in this review.


RESULTS
A modest effect of the studied gene polymorphisms on the analyzed biomarkers was observed. GSTM1 and GSTT1 showed some consistent associations with both biomarkers of exposure and effect.


CONCLUSIONS
Genetic polymorphisms on the benzene metabolism pathway should be taken into account when studying the biological effects of benzene exposure. Unique combinations of genetic polymorphisms may increase susceptibility of individuals and/or population subgroups. However, gene-gene interactions, and the biological effects of long-term and low-level exposure to benzene are not yet analyzed with well-designed studies that incorporate multiple biological end-points and multiple genes.
Dougherty
Diana
D
Department of Epidemiology, University of Pittsburgh and University of Pittsburgh Cancer Institute, Pittsburgh, PA 15232, USA.
Garte
Seymour
S
Barchowsky
Aaron
A
Zmuda
Joe
J
Taioli
Emanuela
E
D000818:Animals; D001554:Benzene / Q000633:toxicity*; D015415:Biomarkers; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics / Q000378:metabolism*; D004781:Environmental Exposure / Q000009:adverse effects; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics / Q000378:metabolism*; D016273:Occupational Exposure / Q000009:adverse effects; D009195:Peroxidase / Q000235:genetics / Q000378:metabolism*; D011110:Polymorphism, Genetic / Q000235:genetics
D001554:Benzene; D015415:Biomarkers; D019392:Cytochrome P-450 CYP2E1; D005982:Glutathione Transferase; D016660:NAD(P)H Dehydrogenase (Quinone); D009195:Peroxidase; C447479:NQO1 protein, human; C413545:glutathione S-transferase T1