CARCINOGENIC POTENTIAL OF BENZENE AND TOLUENE WHEN EVALUATED USING CYCLIN-DEPENDENT KINASE ACTIVATION AND P53-DNA BINDING

Benzene is carcinogenic, whereas toluene is thought to have little car cinogenic potential. Benzene and toluene were found to activate cyclin -dependent kinase 2 in rat liver epithelial (RLE) and HL60 cells. pRb1 05 was hyperphosphorylated in RLE cells treated with either solvent. K inase activation and subsequent hyperphosphorylation of pRb105 and p53 by benzene or toluene may be responsible for their growth promotional effects, but it does not account for increased potential of benzene t o induce cancer. Therefore, we examined the ability of these solvents to increase p53-DNA site-specific binding in RLE cells. Benzene increa sed p53-DNA site-specific DNA binding in RLE cells compared to control levels or the effects of toluene. Increased p53-DNA site-specific bin ding by benzene may be caused by damage to cellular DNA. If so, althou gh both solvents appear to have promotional activity, the increased po tential of benzene to damage DNA may be responsible to the difference in the ability of benzene to cause cancer.