Androgen-regulated genes (ARGs) are essential for the development of the prostate. Ironically, ARGs are also responsible for the pathogenesis of
prostate cancer. We used
oligonucleotide array technology to study the expression profiles of ARGs in LNCaP
prostate cancer cells and identified 692
dihydrotestosterone-regulated genes. Representative clusters containing genes with similar expression patterns to
prostate-specific antigen and other known ARGs are discussed. Based on functional information, we categorized several candidate targets for
prostate cancer therapy and diagnosis. Although many of these candidate targets are known to play an important role in
cancer development, several are novel genes to the field of
prostate cancer. A cross-comparison study of our results with those that have been previously published from three other array experiments using a similar LNCaP model validated 13 of these candidate targets as
androgen-regulated. FKBP51 (
FK506-binding
immunophilin 51) was found in the same cluster as
prostate-specific antigen and its
protein expression was increased in LNCaP cells treated with either
dihydrotestosterone or
synthetic androgen R1881. Results from mining the Gene Logic BioExpress database showed that FKBP51 expression is significantly higher in the
prostate cancer group than in the normal and normal adjacent group. Additionally, the
androgen-independent prostate
tumor xenograft, CWR22R, had higher FKBP51
protein levels than that of the
androgen-dependent prostate
tumor xenograft, CWR22. A tissue microarray study further revealed that FKBP51
protein expression was higher in
prostate cancer specimens than in benign prostate
tumor samples. These results suggest the potential value of FKBP51 as a novel diagnostic marker or target for
prostate cancer therapy.