ABSTRACT
Dioxins and Dioxin-like compounds are among the most potent environmental pollutants, widespread in soil, water, food of animal origin by accumulating in fatty tissue thus leading to human exposure. Dioxins act as ligands for aryl hydrocarbon receptors (AHRs), leading to their activation, dimerization with aryl hydrocarbon nuclear translocators (ARNTs), and finally localizing in nucleus. Ligand activated AHR triggers several xenobiotic phase I and phase II metabolizing enzymes primarily cytochrome P4501A1. Toxic responses of dioxins are mediated by AHR includes dermal toxicity, reproductive and developmental toxicity, immunotoxicity, and carcinogenicity. Dioxins are considered to be non-mutagenic and non-genotoxic carcinogens altering the signaling pathways related to cell growth, differentiation, apoptosis, migration, and adhesion via AHR. In this chapter we summarize the role of dioxins as carcinogens with detailed insight into AHR-driven pathways and molecular mechanisms involved for tumorigenesis, more specifically in lung, breast, multiple myeloma, and hepato-pancreatic cancers.
