title: Influence of GSTM1 and GSTT1 genotypes and confounding factors on the frequency of sister chromatid exchange and micronucleus among road construction workers.
abstract: In the present study, we have investigated the influence of polymorphism of GSTM1 and GSTT1 genes and confounding factors such as age, sex, exposure duration and consumption habits on cytogenetic biomarkers. Frequency of sister chromatid exchanges (SCEs), high frequency cell (HFC) and cytokinesis blocked micronuclei (CBMN) were evaluated in peripheral blood lymphocytes of 115 occupationally exposed road construction workers and 105 unexposed individuals. The distribution of null and positive genotypes of glutathione-S transferase gene was evaluated by multiplex PCR among control and exposed subjects. An increased frequency of CBMN (7.03±2.08); SCE (6.95±1.76) and HFC (6.28±1.69) were found in exposed subjects when compared to referent (CBMN - 3.35±1.10; SCE - 4.13±1.30 and HFC - 3.98±1.56). These results were found statistically significant at p<0.05. When the effect of confounding factors on the frequency of studied biomarkers was evaluated, a strong positive interaction was found. The individuals having GSTM1 and GSTT1 null genotypes had higher frequency of CBMN, SCE and HFC. The association between GSTM1 and GSTT1 genotypes and studied biomarkers was found statistically significant at p<0.05. Our findings suggest that individuals having null type of GST are more susceptible to cytogenetic damage by occupational exposure regardless of confounding factors. There is a significant effect of polymorphism of these genes on cytogenetic biomarkers which are considered as early effects of genotoxic carcinogens.
authors.affiliation: Department of Biotechnology, Kurukshetra University, Kurukshetra, Haryana, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Kumar
authors.forename: Anita
authors.initials: A
authors.lastname: Yadav
authors.forename: Shiv Kumar
authors.initials: SK
authors.lastname: Giri
authors.forename: Kapil
authors.initials: K
authors.lastname: Dev
authors.forename: Sanjeev Kumar
authors.initials: SK
authors.lastname: Gautam
authors.forename: Ranjan
authors.initials: R
authors.lastname: Gupta
authors.forename: Neeraj
authors.initials: N
authors.lastname: Aggarwal
mesh_terms: D000328:Adult; D004785:Environmental Pollutants / Q000633:toxicity; D005260:Female; D005787:Gene Frequency; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D048629:Micronuclei, Chromosome-Defective; D008875:Middle Aged; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D012854:Sister Chromatid Exchange; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D005982:Glutathione Transferase; C413545:glutathione S-transferase T1