The association of three DNA repair genes polymorphisms on the frequency of chromosomal alterations detected by fluorescence in situ hybridization

Abstract

Purpose Gas station workers (GSWs) are exposed to carcinogenic agents. The aim was to study the association of high somatic chromosome alterations (CAs) rates in the blood of GSWs and the polymorphisms of three genes playing a role in DNA double-strand break repair. Methods This is a cross-sectional study with 114 GSWs and 115 age-matched controls. Cytogenetic analyses, blood exams, medical interviews and genotypes for RAD51/G135C (rs1801320), ATM/P1054R (rs1800057) and CHEK2/T470C (rs17879961) genes were performed. Results The CA rate in GSWs was 9.8 CAs/1000 metaphases, and 19.1% of the workers had > 10 CAs per 1000 metaphases (group two). GSWs had decreased levels of monocytes (P = 0.024) in their blood exams. The number of variant alleles of the RAD51/G135C polymorphism was higher in GSWs (P = 0.011) compared to the controls, and were associated with enhanced number of CAs per worker (P = 0.008). No allele variant was found for CHEK2/T470C in this study. Conclusion The RAD51/G135C polymorphism appears to be related to genome instability in gas station workers. Increasing the knowledge of DNA repair gene variations involved in maintaining genomic stability in GSWs may be crucial for future cancer prevention.

Tumors due to chronic exposure to benzene and biomarkers of exposure

“…A study conducted in the Czech Republic reinforced the association between increased levels of CAs and the incidence of cancer and mortality [37] . In BTEX-exposed workers, CAs in peripheral blood lymphocytes were already reported based on conventional/banding cytogenetics [22,38,39] or chromosome painting by fluorescence in situ hybridization (FISH) [40][41][42][43][44][45][46] . As for chromosome painting, whole chromosome probes are capable of labeling each pair of chromosomes with a different fluorescent color [47,48] .…”