#B163 Lycopene and Vitamin E Interfere with Autocrine/Paracrine Loops in the Dunning Prostate Cancer Model. Ulrich Siler,1 Luca Barella,1 Volker Spitzer,1 Joerg Schnorr,2 Michael Lein,2 Regina Goralczyk,1 Karin Wertz.1 Roche Vitamins Ltd., Human Nutrition and Health, Carotenoid Group,1 Basel, Switzerland, Department of Urology, Charite University Hospital,2 Humbold University Berlin, Germany. Epidemiological studies have demonstrated that the intake of lycopene and the intake of vitamin E are associated with a reduced risk of prostate cancer. To gain insight into the in vivo action of lycopene and vitamin E, both compounds were tested in the MatLyLu Dunning prostate cancer model. Plasma and tumor tissue analyses showed that both compounds were taken up in plasma and accumulated in tumor tissue. Macroscopic evaluation of the tumors by magnetic resonance imaging showed a significant increase in necrotic area in the vitamin E and the lycopene treatment groups, as well as a considerable but non-significant increase by co-treatment. Microarray analysis of tumor tissues revealed that both compounds regulated local gene expression. Vitamin E reduced estrogen metabolism by downregulating aromatase. Furthermore, vitamin E reduced androgen signaling without affecting androgen metabolism. Lycopene interfered with the endocrine loop of local testosterone activation and signaling by downregulating 5-á -reductase and steroid target genes. Based on these findings, we suggest that lycopene and vitamin E contribute to the reduction of prostate cancer by interfering with internal autocrine or paracrine loops of sex steroid hormone activation and signaling in the prostate. Frontiers in Cancer Prevention Research, 2003 AACR Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.