E-GEOD-4636 - Transcription profiling of human LNCaP cells treated with DHT, RTI-6413-018 or vehicle to identify useful Selective Androgen Receptor Modulators (SARMs)
Released on 19 December 2007, last updated on 12 October 2011
We have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful Selective Androgen Receptor Modulators (SARMs). As one of the approaches, we used a DNA microarray analysis to demonstrate that differently conformed receptors facilitate distinct patterns of gene expression in LNCaP cells. Interestingly, we observed a complete overlap in the identity of genes expressed following treatment with mechanistically distinct AR ligands. However, it was differences in the kinetics of gene regulation that distinguished these compounds. Follow-up studies, in cell-based assays of AR action, confirmed the importance of these alterations in gene expression. Together these studies demonstrate an important link between AR structure, gene expression and biological outcome. In this experiment LNCaP cells (400,000 per 75 cm2 flask) were first incubated in DMEM/8% charcoal-stripped serum to reduce the background hormone exposure, and then were treated with Vehicle (ethanol), DHT (10 nM) or RTI-6413-018 (100 nM). Treatment was done for 6 and 24 hrs. At the end of treatment, cells were collected by trypsization and immediately frozen in liquid nitrogen. Isolation of mRNA was performed using Qiagen Oligotex midi kit. cRNA synthesis, labeling and hybridization were performed by Expression Analysis Institute, Durham, NC. Samples were hybridized to Affymetrix HG.U133 A and B chips. Experiment was repeated three times.
transcription profiling by array, cell type comparison, co-expression, compound treatment, time series
Linking ligand-induced alterations in androgen receptor structure to differential gene expression: a first step in the rational design of selective androgen receptor modulators. Dmitri Kazmin,Tatiana Prytkova,C Edgar Cook,Russell Wolfinger,Tzu-Ming Chu,David Beratan,J D Norris,Ching-yi Chang,Donald P McDonnell.