Effects of dietary retinyl palmitate or 13-cis-retinoic acid on the promotion of tumors in mouse skin.
The present study was designed to determine the effects of dietary 13-cis-retinoic acid and retinyl palmitate on mouse skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA). Female CD-1 mice were initiated with 150 nmol of 7,12-dimethylbenz(a)anthracene and promoted twice weekly with 8 nmol of TPA. Diets supplemented with retinyl palmitate to yield 60,000 or 200,000 IU or 700,000 for 5 wk followed by 350,000 IU per kg of diet (700,000/350,000) fed to mice during tumor promotion resulted in 9%, 37%, and 65% inhibition of the papilloma yield, respectively, at 21 wk of promotion. Although topical applications of 13-cis-retinoic acid have been almost as effective as retinoic acid in preventing the appearance of mouse skin tumors, dietary 13-cis-retinoic acid at 200,000 or 700,000 IU per kg of diet resulted in no reduction in papilloma yield but did result in a dose-dependent decrease in the tumor burden (weight of tumors per mouse). Therefore, dietary retinyl palmitate yielded a dose-dependent inhibition of the number and weight of tumors promoted by TPA, whereas dietary 13-cis-retinoic acid resulted in a decrease in weight but not in number of tumors promoted by TPA.
Gensler
H L
HL
Watson
R R
RR
Moriguchi
S
S
Bowden
G T
GT
D000279:Administration, Cutaneous; D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D004032:Diet; D004224:Diterpenes; D004305:Dose-Response Relationship, Drug; D005260:Female; D015474:Isotretinoin; D051379:Mice; D010212:Papilloma / Q000139:chemically induced; D000084562:Retinyl Esters; D012867:Skin / Q000187:drug effects*; D012878:Skin Neoplasms / Q000139:chemically induced*; D013755:Tetradecanoylphorbol Acetate; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology*; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000494:pharmacology
D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; D014212:Tretinoin; D015474:Isotretinoin; D013755:Tetradecanoylphorbol Acetate