Carcinogenesis is a multistage process that consists of initiation, promotion, and progression stages. Chemicals or environmental factors may act at any of these stages to induce and/or enhance the carcinogenic process. Based on their mode-of-action, carcinogens can be classified as genotoxic or non-genotoxic. Genotoxic agent begins their action at the deoxyribonucleic acid (DNA) level, causing DNA damage through several mechanisms. Non-genotoxic carcinogens are chemicals that cause the development of tumors through multiple non-genotoxic events and epigenetic alterations without direct interaction with DNA. One non-genotoxic mechanism involves receptor activation. Biological mechanisms involving receptor activation fall into two broad categories: (i) those that involve cell surface receptors and some intracellular receptors that activate signal transduction pathways, resulting in biological responses, including gene transcription, and (ii) those that involve intracellular receptors that translocate into the nucleus and act as transcription factors regulating gene expression. Both classes of receptors can be involved in mechanisms of carcinogenesis.
Long-term nicotine exposure-induced chemoresistance is mediated by activation of Stat3 and downregulation of ERK1/2 via nAChR and beta-adrenoceptors in human bladder cancer cells.
Lee CH, Chang YC, Chen CS, Tu SH, Wang YJ, Chen LC, Chang YJ, Wei PL, Chang HW, Chang CH, Huang CS, Wu CH, Ho YS
Title
Crosstalk between nicotine and estrogen-induced estrogen receptor activation induces alpha9-nicotinic acetylcholine receptor expression in human breast cancer cells.
Sauer SJ, Tarpley M, Shah I, Save AV, Lyerly HK, Patierno SR, Williams KP, Devi GR
Title
Bisphenol A activates EGFR and ERK promoting proliferation, tumor spheroid formation and resistance to EGFR pathway inhibition in estrogen receptor-negative inflammatory breast cancer cells.
Yoo HS, Cichocki JA, Kim S, Venkatratnam A, Iwata Y, Kosyk O, Bodnar W, Sweet S, Knap A, Wade T, Campbell J, Clewell HJ, Melnyk SB, Chiu WA, Rusyn I
Title
The Contribution of Peroxisome Proliferator-Activated Receptor Alpha to the Relationship Between Toxicokinetics and Toxicodynamics of Trichloroethylene.
