RESUMO
OBJECTIVES: To determine the effect of selenium supplementation on the human proteomic profile. DESIGN: Serum samples were collected in this pilot study from a randomized placebo controlled Phase 2 clinical trial (Watchful Waiting (WW)). SETTING: Subjects were followed every three months for up to five years at the University of Arizona Prostate Cancer Prevention Program. PARTICIPANTS: One hundred and forty men (age < 85 years) had biopsy-proven prostate cancer, a Gleason sum score less than eight, no metastatic cancer, and no prior treatment for prostate cancer. INTERVENTION: As part of the WW trial, men were randomized to placebo, selenium 200 µg/day or selenium 800 µg/day. For the purpose of the current study, 40 subjects enrolled in the WW study (20 from the placebo group and 20 from Se 800 µg/day group) were selected. MEASUREMENTS: Baseline serum samples were collected at each follow-up visit and stored at -80 degrees Celsius. A multiplexed proteomic panel investigated changes in 120 proteins markers simultaneously. RESULTS: Thirteen proteins (Apolipoprotein J, IL-10, IL-1 alpha, MMP-3, IL-12p70, IL-2 receptor alpha, cathepsin B, eotaxin, EGFR, FGF-basic, myeloperoxidase, RANTES, TGF-beta) were determined to be either statistically (p-value < 0.05) or marginally significantly (0.05 < p-value <0.1) changed in the selenium supplemented group as compared to placebo. CONCLUSION: Although independent validation of these results is needed, this study is the first of its kind to utilize high throughput fluorescence based protein multiplex panel in analyzing changes in the proteomic profile due to selenium supplementation. Results from this study provide insight into the ability of selenium to modulate numerous protein markers and thus impact various biological processes in humans.