Dietary Fatty Acid Quality Affects AR and PPARγ Levels and Prostate Growth

BACKGROUND. Fatty acids are among the most important nutritional factors associated with the ethiopathogenesis of prostate cancer, therefore the main objective of this work was to evaluate the effect of quality of fatty acid on the rat ventral prostate growth, tissue organization, and expression of androgen receptor (AR) and peroxisome proliferation activator receptor gamma (PPAR gamma). METHODS. Wistar rats were distributed into five groups, which were fed isocaloric normolipidic diets containing soybean oil (7% Control), linseed (7% or 3.5% linseed plus 3.5% soybean oil) and rendered pork fat (7% or 3.5% lard plus 3.5% soybean oil) for 10 weeks after weaning. RESULTS. At the end of treatment, the experiments demonstrated that lard and linseed oil caused opposite effects on prostatic growth. While the lard promoted an increase in prostatic weight associated to epithelial hyperplasia (confirmed by stereology); the linseed resulted in a significantly lighter organ. Immunohistochemistry and Western blotting demonstrated increased expression of AR and PPAR gamma in groups fed with lard diet, while linseed oil promoted a decrease. CONCLUSIONS. Prostatic growth is influenced by dietary fatty acids with concurrent variation in the expression of AR and PPAR gamma. PPAR gamma might represent the link between diet and prostate growth and AR expression and function. Since the levels of testosterone were altered it is also possible that prostatic changes are secondary to systemic effects of the diet. Prostate 69: 548-558,2009. (C) 2009 Wiley-Liss, Inc.