Inhibition of skin carcinogenesis in vivo by caffeine and other agents.
The induction of skin cancer in mice of the Swiss (Carshalton) strain, by repeated irradiation with UV-light, was strikingly reduced by the local application of caffeine prior to each exposure. Theophylline displayed the same activity. These two substances have been selected as probable inhibitors of error-prone, postreplicative DNA repair. Conversely, reductone and chloroquine, which are considered as inhibitors of the error-free, prereplicative excision repair, did not modify the incidence of the tumors. Special emphasis has been given to the histologic behavior of radiolabeled caffeine in the normal and UV-irradiated epidermis of the mouse in vivo and to the ability of mouse epidermal cells in vitro to repair DNA after UV irradiation.
D000818:Animals; D002110:Caffeine / Q000378:metabolism / Q000494:pharmacology*; D002460:Cell Line; D002738:Chloroquine / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D004260:DNA Repair / Q000187:drug effects / Q000528:radiation effects; D005260:Female; D008315:Malondialdehyde / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D009374:Neoplasms, Experimental / Q000517:prevention & control; D009381:Neoplasms, Radiation-Induced / Q000517:prevention & control*; D012867:Skin / Q000378:metabolism; D012878:Skin Neoplasms / Q000209:etiology / Q000517:prevention & control*; D013806:Theophylline / Q000494:pharmacology; D014466:Ultraviolet Rays / Q000009:adverse effects*
D002110:Caffeine; D008315:Malondialdehyde; D002738:Chloroquine; D004247:DNA; D013806:Theophylline