Dietary deficiency or enrichment of essential fatty acids modulates tumorigenesis in the whole body of cobalt-60-irradiated mice.
The effect of dietary polyunsaturated fatty acids (PUFAs) on whole body-induced tumorigenesis was assayed in mice fed on essential fatty acid sufficient (EFAS) or essential fatty acid deficient (EFAD) diets following cobalt-60 irradiation. Four groups of mice were maintained, one on a control stock diet and three on experimental diets: a) without added fat (fat free, FF); b) containing 5% olein (O), rich in n-9; and c) containing 5% corn oil, rich in n-6 EFA (CO). Only mice fed on FF or O diets showed clinical and biochemical signs of EFAD. Total incidence of tumors showed an increase in FF (P < 0.02) and O (P < 0.03) mice. Tumors developed mostly in the liver in each of the EFAD groups (P < 0.001). Slight promoting activity on lung tumorigenesis was recorded in the CO group when this parameter was compared in EFAD and EFA sufficient mice. It may be concluded that, when a tumor initiator injures the body as a whole, EFAD, achieved either through a fat-free or an oleic-supplemented diet, behaves as a general promoting condition for tumorigenesis. The borderline tumorigenic effect of n-6 corn oil on the lungs suggests that this effect, when present, is target specific.
Eynard
A R
AR
Instituto Biologia Celular (FCM-UNC), CONICET, Cordoba, Argentina.
Manzur
T
T
Moyano
A
A
Quiroga
P
P
Muñoz
S
S
Silva
S M
SM
D000818:Animals; D002273:Carcinogens / Q000008:administration & dosage; D003037:Cobalt Radioisotopes; D003043:Cocarcinogenesis; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005228:Fatty Acids, Essential / Q000008:administration & dosage* / Q000172:deficiency*; D005260:Female; D008114:Liver Neoplasms, Experimental / Q000209:etiology / Q000473:pathology; D008175:Lung Neoplasms / Q000209:etiology / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009381:Neoplasms, Radiation-Induced / Q000209:etiology* / Q000473:pathology; D014916:Whole-Body Irradiation
D002273:Carcinogens; D003037:Cobalt Radioisotopes; D004042:Dietary Fats, Unsaturated; D005228:Fatty Acids, Essential