Activation of polycyclic hydrocarbons in Reuber H4-II-E hepatoma cells. An in vitro system for the induction of SCEs.

Activation of polycyclic aromatic hydrocarbons (PAHs) was examined in the Reuber H4-II-E established cell line without the use of exogenous enzyme preparations. Metabolism of PAHs to genotoxic products was determined by the induction of sister-chromatid exchanges (SCEs). The induction of SCEs followed a dose-response pattern with plateaus at high doses of PAH. The effects of metabolic enzyme inducers (3-methylcholanthrene, phenobarbital, Aroclor 1254) and the epoxide hydrase inhibitor 1,1,1-trichloropropylene oxide were assessed as changes in SCE induction and enhanced production of water-soluble metabolites. Results indicate that Reuber H4-II-E cells can be employed in the testing of carcinogens activated by the P1-450 monooxygenase system and would be a useful in vitro system for the study of mechanisms of metabolic induction and their effect on genetic toxicity.