Prostate Cancer Research Today is a free monthly online journal that collates and summarizes the latest research about Prostate Cancer, including details on symptoms, genetics, screening, treatment, information.

Selenomethionine induced transcriptional programs in human prostate cancer cells.

Zhao H, Brooks JD

Department of Urology, Stanford University School of Medicine, Stanford, California 94305-5118, USA.

PURPOSE: We determined the effects of selenomethionine, the major organic selenium containing compound found in the diet and the form of selenium being used in the Selenium and Vitamin E Cancer Prevention Trial, on prostate cancer cells. MATERIALS AND METHODS: We assessed global transcript profiles of selenomethionine treated LNCaP using cDNA microarrays and compared them to those of cells treated with methylselenic acid, a direct precursor of methylselenol, which is the active form of selenium in vivo. RESULTS: After treatment with selenomethionine 2,336 unique genes showed expression changes of at least 1.5-fold in at least 3 time points during 48 hours and 366 unique transcripts differed significantly between selenomethionine and methylselenic acid treated LNCaP. Approximately half of the 76 cell cycle regulated genes affected by selenomethionine were down-regulated and enriched for genes associated with the G2/M phase. Flow cytometry analysis showed that selenomethionine induced G2/M arrest in LNCaP at low concentrations. Selenomethionine also affected expression levels of 35 known androgen responsive genes and 18 of these transcripts showed changes that were the inverse of those seen after androgen stimulation. At high concentrations selenomethionine decreased prostate specific antigen promoter driven luciferase expression. CONCLUSIONS: Selenomethionine modulates transcript levels of genes involved in a number of biological processes, including cell cycle/apoptosis androgen signaling, signal transduction and transcriptional regulation. Although the pathways affected paralleled in many ways those that are modulated by methylselenic acid, distinct differences in transcript patterns and effects on cell cycle regulation suggest that different selenium compounds could exert unique effects in prostate cells.

Published 15 January 2007 in J Urol, 177(2): 743-50.
Full-text of this article is available online (may require subscription).

© 2004-2008 Prostate Cancer Research Today. All Rights Reserved.