Mouse skin: a useful model system for studying the mechanism of chemical carcinogenesis.

Mouse skin has a long history as a useful model for the study of the mechanism of carcinogenesis (6). In particular, the availability of specific diterpene esters has made possible rapid progress in understanding the mechanism of tumor formation (4,6,8,19,36,41), although certain details may be unique to promotion by phorbol esters. Evidence is compatible with an essential role for elevated levels of polyamines in tumor promotion, but other components of phorbol ester action on mouse skin are also essential (27,40,54). These may include the production of dark cells (22), inhibition of maturation (2,19,41), and the elimination of metabolic cooperation (12,57). Factors modifying biochemical processes that are essential to tumor formation produce a parallel effect on tumor formation. Some of these inhibitors act synergistically to inhibit tumor formation (50,55), and knowledge of their action may lead to practical application for the prevention of human cancer.