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Combination effects of dietary soy and methylselenocysteine in a mouse model of prostate cancer
Author(s) -
Christensen Merrill J.,
Quiner Trevor E.,
Nakken Heather L.,
Lephart Edwin D.,
Eggett Dennis L.,
Urie Paul M.
Publication year - 2013
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/pros.22646
Subject(s) - prostate cancer , medicine , prostate , soy protein , cancer , cancer research , pathology
BACKGROUND High dietary intake of soy or selenium (Se) is associated with decreased risk of prostate cancer. Soy constituents and various chemical forms of Se have each been shown to downregulate expression of the androgen receptor (AR) and AR‐regulated genes in the prostate. We hypothesized that downregulation of AR and AR‐regulated genes by the combination of these dietary components would inhibit tumorigenesis in the TRansgenic Adenocarcinoma of Mouse Prostate (TRAMP) mouse. METHODS Male mice were exposed from conception to stock diets high or low in soy, with or without a supplement of Se‐methylseleno‐ L ‐cysteine (MSC) in a 2 × 2 factorial design. Mice were sacrificed at 18 weeks. Prostate histopathology, urogenital tract (UGT) weight, hepatic activity of androgen‐metabolizing enzymes, and expression of AR, AR‐regulated, and AR‐associated FOX family genes, in the dorsolateral prostate were examined. RESULTS High soy intake decreased activity of hepatic aromatase and 5α‐reductase, expression of AR, AR‐regulated genes, FOXA1, UGT weight, and tumor progression, and upregulated protective FOXO3. Supplemental MSC upregulated AKR1C14, which reduces 5α‐dihydrotestosterone. CONCLUSIONS Soy is an effective pleiotropic dietary agent for prevention of prostate cancer. The finding of effects of soy on FOX family gene expression in animals is novel. Combination effects of supplemental MSC may depend upon the soy content of the basal diet to which it is added. Prostate 73: 986–995, 2013. © 2013 Wiley Periodicals, Inc.