Genotoxic and epigenetic chemical carcinogenesis: one process, different mechanisms.

Chemieals that induce cancer in an intact organism are called carcinogens. This term does not differentiale between their vaTiaus modes of action. In this reliiew, Wemer Lutz and Peter Maier make a mechanistic distinction between carcinogens that alter the genetic information and carcinogens that interfere with epigenetic processes. They considercardnogenesis tobe an ongoing, part1y unavoidable process which is based on a succession of mutations, most likely in stem cells, leading to autonomaus cellular growth regulation. Chemical carcinogens either induce such changes through mutations (genotoxic carcinogens) or they aceeierate the accumulation of critica1 spontaneaus mut11tions (epigenetic carcinogens). Ex11mples are given for both classes of carcinogens, and for the processes that act at genoto:tic/nuclear 11nd epigenetic/mitotic Ievels.