Xenobiotic Receptor-Mediated Carcinogenesis

A variety of xenobiotics classified as tumor promoters or non-genotoxic carcinogens result in tumors without directly damaging DNA. Instead, these compounds’ mode of action includes affecting cellular proliferation, apoptosis, or differentiation, resulting in initiated cells gaining a growth advantage over normal cells. The way many of these chemicals affect cellular fate is by altering gene expression initiated by interacting with soluble, intracellular receptors such as nuclear hormone receptors, the aryl hydrocarbon receptor, protein kinase C (PKC), and protein phosphatase 2A. In this article, the structure, function, and regulation of these proteins, as well as the downstream events that result from tumor promoters interacting with their cognate receptor, are described.