91 ENDOGENOUSLY EXPRESSED SEX HORMONE-BINDING GLOBULIN (SHBG) MEDIATES THE STEROID RESPONSE OF PROSTATE CANCER CELLS

Abstract

Sex hormone binding globulin (SHBG), a protein that binds plasma androgens and estrogens, participates in the initial steps of a membrane based steroid signaling pathway in human prostate cells. We have recently shown that SHBG is locally expressed in prostate cells. Here, we used microarray analysis of human LNCaP prostate cancer cells that are engineered to inducibly overexpress SHBG to investigate whether locally expressed SHBG regulates the activation of membrane based androgen signaling through the SHBG receptor, RSHBG, and/or intracellular activation of the androgen receptor (AR). We hypothesize that alterations of endogenous SHBG expression in prostate cancer, such as those presumed to be accompanied by deletion of the linked p53/SHBG gene locus on chromosome 17p13.1, can affect androgen signaling through RSHBG and the AR, thus contributing to cancer progression.