The human prostate gland is an important target organ of androgenic
hormones. Testosterone and dihydrotestosterone interact with the
androgen receptor to regulate vital aspects of prostate growth
and function including cellular proliferation, differentiation,
apoptosis, metabolism, and secretory activity. Our objective in
this study was to characterize the temporal program of transcription
that reflects the cellular response to androgens and to identify
specific androgen-regulated genes (ARGs) or gene networks that
participate in these responses. We used cDNA microarrays representing
about 20,000 distinct human genes to profile androgen-responsive
transcripts in the LNCaP adenocarcinoma cell line and identified
146 genes with transcript alterations more than 3-fold. Of these,
103 encode proteins with described functional roles, and 43 represent
transcripts that have yet to be characterized. Temporal gene expression
profiles grouped the ARGs into four distinct cohorts. Five uncharacterized
ARGs demonstrated exclusive or high expression levels in the prostate
relative to other tissues studied. A search of available DNA sequence
upstream of 28 ARGs identified 25 with homology to the androgen
response-element consensus-binding motif. These results identify
previously uncharacterized and unsuspected genes whose expression
levels are directly or indirectly regulated by androgens; further,
they provide a comprehensive temporal view of the transcriptional
program of human androgen-responsive cells.