Differential sensitivity of human hepatoma cell line and primary rat hepatocyte culture to benzo(a)pyrene-induced unscheduled DNA synthesis and adduct formation.

We studied the genotoxic potential of a carcinogen in the human hepatoma cell line, HepG2, and in primary rat hepatocyte culture. HepG2 is a well differentiated human hepatoblastoma cell line with biotransforming capacity. Rat hepatocytes were obtained by the standard two-step in situ perfusion technique. Following benzo(a)pyrene treatment, both HepG2 and primary rat hepatocyte culture showed unscheduled DNA synthesis with different sensitivity. In 32P-postlabelling analysis, the chromatogram revealed quantitative and qualitative differences between HepG2 and primary rat hepatocyte cultures when treated with 10 microM benzo(a)pyrene for 18 hr. The results have demonstrated that the HepG2 cell line may be used in addition to primary rat hepatocytes in risk assessment for detection of environmental carcinogens.