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BMC Proceedings

Open Access

STEAP1 expression in prostate cancer and its regulation by androgens

  • Inês Gomes1,
  • Cecília RA Santos2,
  • Sílvia Socorro1,
  • Carlos Lopes2 and
  • Cláudio J Maia1Email author
BMC Proceedings20104(Suppl 2):P63

Published: 24 September 2010


Epithelial CellProstate CancerProtein ExpressionmRNA ExpressionClinical Significance

Six transmembrane epithelial antigen of the prostate 1 (STEAP1) was identified a gene overexpressed in human prostate cancer. It is localized in cell junctions of epithelial cells, and its structure with six transmembrane domains suggests that it may act as a membrane channel or transporter protein in tight junctions [1]. Although STEAP1 expression seems to be up-regulated in prostate cancer, the clinical significance of this finding remains to be clarified. Moreover, STEAP1 is more expressed in LNCaP than in PC3, suggesting that androgens may regulate its expression. Therefore, the goals of this experimental work were: i) to evaluate if STEAP1 expression correlates with clinical reports from patients; ii) to analyze if STEAP1 is regulated by 5α-dihydrotestosterone (DHT) in vitro and in vivo.

Immunohistochemical analysis shows that STEAP1 expression is mainly expressed in epithelial cells. Analysis of STEAP1 immunoreactivity in prostate cancer is underway. In vivo results demonstrated that castration increases STEAP1 protein expression when compared to intact rats, and treatment with DHT abrogates the effect of castration in STEAP1 expression, suggesting that STEAP1 protein is down-regulated by DHT. However, these results do not correlate with STEAP1 mRNA expression, suggesting that mechanisms at the translation level may be involved. In vitroresults demonstrated that both STEAP1 mRNA and protein expression are down-regulated by DHT after 24h of stimulation.

Authors’ Affiliations

CICS-Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
ICBAS- Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal


  1. Hubert RS, Vivanco I, Chen E, Rastegar S, Leong K, Mitchell SC, Madraswala R, Zhou Y, Kuo J, Raitano AB, Jakobovits A, Saffran DC, Afar DE: STEAP: a prostate-specific cell-surface antigen highly expressed in human prostate tumors. Proc Natl Acad Sci U S A. 1999, 96: 14523-14528. 10.1073/pnas.96.25.14523.PubMed CentralView ArticlePubMedGoogle Scholar


© Maia et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd.