Role of Testosterone, Estradiol, and Insulin in Diet- and Exercise-Induced Reductions in Serum-Stimulated Prostate Cancer Cell Growth In Vitro

• Published in: Nutrition and cancer 2002, Vol.42 (1), p.112-116
• Main Authors: Tymchuk, Christopher N, Barnard, R. James, Ngo, Tung H, Aronson, William J
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; cell culture; Cell Division - drug effects; cell growth; culture media; Diet; estradiol; Estradiol - pharmacology; Exercise; fetal bovine serum; Gynecology. Andrology. Obstetrics; high fat diet; Humans; insulin; Insulin - pharmacology; lifestyle; Male; Male genital diseases; Medical sciences; men; overweight; prostatic neoplasms; Prostatic Neoplasms - pathology; risk; testosterone; Testosterone - pharmacology; tissue culture; Tumor Cells, Cultured; Tumors
• ISSN: 0163-5581; 1532-7914
• DOI: 10.1207/S15327914NC421_15

Prostate cancer risk is associated with a high-fat diet and a sedentary lifestyle. Placing men on a low-fat diet-and-exercise intervention reduces serum hormones, including estradiol, insulin, and free testosterone, that may play a role in prostate cancer growth. Eight men participated in a low-fat diet-and-exercise program for a mean of 14.2 yr, and LNCaP cell growth in culture was measured in medium supplemented with 10% of each subject's serum as well as with testosterone, estradiol, and insulin added singly or in combination. These results were compared in the fetal bovine serum (FBS)-stimulated growth and cell growth in serum obtained from a control group of 14 overweight men. In separate tissue culture experiments, LNCaP and PC-3 cell growth was also measured in response to the addition of testosterone, estradiol, or insulin to steroid-stripped FBS. LNCaP cell growth in medium with subject serum was 40% less than in FBS-stimulated medium and 49% less than in medium with serum from control, overweight men. Addition of testosterone, estradiol, and insulin to serum from diet-and-exercise subjects significantly stimulated LNCaP cell growth in vitro but accounted for only about half of the difference between the control and diet-and-exercise subjects. Thus other serum changes must also account for the significant reduction in LNCaP cell growth observed using medium with serum from the diet-and-exercise subjects in the cell culture assay.