The Effect of Glutathione S-transferase M1 Genotype on Benzo[α]pyrene-Induced Sister Chromatid Exchanges and Chromosomal Aberrations in Peripheral Blood Lymphocytes

Sister chromatid exchange (SCE) and chromosomal aberration (CA) in peripheral lymphocytes have been widely used inassessing exposure to mutagens and carcinogens. One of the extensively studied genotoxins is benzo[a]pyrene (BaP). The aim of thepresent study was to examine the ability of BaP to induce different individual cytogenetic response measured by SCE and CAfrequency. The possible influence of genetic polymorphism was also taken into account, by including donors representing positive ornull glutathione S-transferase M1 (GSTM1) genotypes. SCEs and CAs were analyzed from 72-h whole-blood lymphocyte cultures of16 GSTM1 positive and 15 GSTM1 null donors after treatment with 5 µM BaP, which do not decrease cell viability. We found noinfluence of the GSTM1 genotype on SCE or CA frequency. The rates of chromatid and chromosome-type gaps and breaks inducedin vitro by BaP were similar in all the groups. In the GSTM1 null genotype, however, chromatid-type breaks were seen morefrequently than chromosome-type breaks after a 48 h treatment with BaP. These findings suggest that SCEs and CAs induced invitro by BaP are not influenced by the genotype GSTM1.