mRNA expression levels among cell regulatory and DNA damage genes in benzene-exposed workers in China.

OBJECTIVE: We investigated how cells respond to the induction of DNA damage, focusing specifically on mRNA expression levels of cell regulatory and DNA repair genes under exposure to benzene. METHOD: The study sample was classified into three groups: direct exposure to benzene (A), indirect exposure to benzene (B), and non-exposed (C). Concentrations of benzene in the air of workplaces were monitored. Further blood biochemical parameters, cell cycle-regulated and DNA damage-related genes expression were analyzed. RESULTS: The mRNA expression levels of Apel, Rad51, Bcl-2, Bax, Xpa, and Xpc genes were significantly down-regulated in groups A and B, with a dramatic up-regulation of p21 gene in group A accompanied by significantly lower counts of white blood cells, hemoglobin, platelets and lymphocyte subsets of CD8+, CD4+, T and B cells. CONCLUSION: The results indicated that exposure to benzene had significantly altered mRNA expression of some critical cell regulatory and DNA repair genes.