Evidence for an epigenetic mode of action in organochlorine pesticide hepatocarcinogenicity: a lack of genotoxicity in rat, mouse, and hamster hepatocytes.

Genotoxicity was not elicited by any of a variety of organochlorine pesticides tested in the hepatocyte primary culture (HPC)/DNA repair assay utilizing hepatocytes from the rat, mouse, and hamster. DNA repair was observed in response to the positive control in all three systems. Thus the tumorigenicity of the organochlorine pesticides appears to reflect an epigenetic mechanism, probably involving a promotional effect resulting from a disruption in intercellular communication.