BACKGROUND: Data from human epidemiological studies, cultured mammalian cells, 
and animal models have supported a potentially beneficial role of selenium (Se) 
in prostate cancer prevention. In addition, Se-containing proteins including 
members of the glutathione peroxidase (GPx) family and Selenium-Binding Protein 
1 (SBP1) have been linked to either cancer risk or development. For example, 
SBP1 levels are typically reduced in tumors compared to non-cancerous tissue, 
with the degree of reduction associated with increasingly poor clinical outcome.
METHODS: In order to investigate inter-relationships between blood and tissue Se 
levels and GPx activity, tissue SBP1 levels, and disease aggressiveness using 
the Gleason score, we measured levels of selenium and selected selenoproteins in 
fasting serum and histologically normal prostate tissues obtained from 24 men 
undergoing radical prostatectomy for the treatment of localized prostate cancer.
RESULTS: GPx enzyme activity was inversely correlated with SBP1 levels in 
prostate tissue as determined by densitometry of Western blots obtained using 
anti-SBP1 antibodies [partial Spearman's correlation coefficients and 
corresponding P-values overall and in African-Americans = -0.42 (0.08) and -0.53 
(0.10), respectively], which is consistent with previous observations in 
cultured cells and mice. Of particular interest was the positive correlation 
between tissue GPx activity and Gleason score, with this relationship achieving 
statistical significance among African-Americans (r = 0.67, P = 0.02).
CONCLUSION: These studies support the continued investigation of the role of Se 
and selenoproteins in prostate cancer prevention, development, and prognosis.