Faculty Bibliography

Cofactors modulate nuclear receptor activity and impact human health and disease, yet surprisingly little is known about their transcriptional regulation. Androgen receptor trapped clone-27 (ART-27) is a cofactor that binds to androgen receptor (AR) amino terminus and modulates AR-dependent transcription. Interestingly, ART-27 displays both a cell type- and developmental stage-specific expression pattern. However, the cis-acting elements and trans-acting factors affecting ART-27 gene expression have not been elucidated. We found that ART-27 gene expression is repressed and its promoter is histone H3-K27 tri-methylated in human embryonic kidney cells, but not prostate cells, and the histone deacetylase inhibitor, trichostatin A, relieves this inhibition. The DNA response elements that control the induction of ART-27 gene expression were also characterized. The major cis-acting element corresponds to a consensus cAMP-responsive element (CRE) and binds the CRE-binding protein (CREB) as shown by EMSA and chromatin immunoprecipitation assays. Furthermore, ART-27 promoter activity is induced upon CREB overexpression. Epidermal growth factor, which activates CREB via phosphorylation, also induces ART-27 expression, whereas a reduction in CREB phosphorylation or expression blocks this induction in prostate cells. In human prostate development, both epithelial and stromal cells express CREB; however, active phosphorylated CREB is restricted to epithelial cells where ART-27 is expressed. Based on these findings, we propose a transcriptional regulatory circuit for the developmental expression of ART-27 that includes repression by chromatin modification through a trichostatin A-sensitive factor and activation upon growth factor stimulation via CREB

PURPOSE: Men with prostate cancer may live as long as men their age without prostate cancer. Those with low-risk disease may benefit from expectant management, which actively monitors disease progression. Dutasteride, a dual 5alpha-reductase inhibitor (5ARI), may delay prostate cancer progression or extend the time to initiation of more aggressive therapy. MATERIALS AND METHODS: The Reduction by Dutasteride of Clinical Progression Events in Expectant Management (REDEEM) trial will evaluate whether dutasteride decreases time to prostate cancer progression. Three hundred candidates for expectant management with biopsy-proven, low-risk, localized prostate cancer will receive dutasteride 0.5 mg/day or placebo for 3 years. Eligible men are between 50 and 80 years of age, have clinical stage T1c-T2a prostate cancer, a Gleason score of less than or equal to 6, and serum prostate-specific antigen (PSA) less than or equal to 10 ng/mL. Entry biopsy of at least 10 cores had to be performed within 6 months of screening and will be repeated at 1.5 and 3 years. Men will complete questionnaires to measure symptoms, quality of life (QOL), and anxiety. Because PSA is an important monitoring tool in expectant management that may impact patients' comfort levels, actual PSA values will be provided to physicians and subjects. Time-to-disease progression (primary therapy for prostate cancer or pathologic progression), positive cores, change in Gleason score, and QOL assessments will be compared between groups. RESULTS: The trial completed recruitment of 302 subjects in March 2007. The study will be completed in 2010. CONCLUSIONS: The REDEEM study will evaluate the potential for dutasteride to delay disease progression in men with low-risk, localized prostate cancer. This study will better define which patients with prostate cancer can be managed with less invasive and potentially less debilitating therapy