Effects of dietary retinoic acid on skin papilloma and carcinoma formation in female SENCAR mice

Previously we have shown that dietary retinoids are essential for papilloma formation induced by either an initiation - promotion or a complete skin carcinogenesis protocol. The present study was conducted to further determine the effect of dietary retinoic acid (RA) on papilloma formation and the conversion of papillomas to carcinomas. Skin tumors were induced in 3 week old female SENCAR mice by an initiation - promotion protocol with one application of 20 μg of 7,12-dimethylbenz[a]anthracene (DMBA), followed by 20 weekly applications of 2 μg of 12-O-tetradecanoylphorbol-13-acetate (TPA)