Second messenger up‐regulation of androgen receptor gene transcription is absent in androgen insensitive human prostatic carcinoma cell lines, PC‐3 and DU‐145

A theoretical pathway of transcriptional regulation of the androgen receptor (AR) gene is via a cAMP response element (CRE) present in its promoter region (−508 to −501). After 20 h of stimulation with 8-bromo-cAMP, AR mRNA was upregulated in LNCaP but not in either PC-3 or DU-145 cell lines. We have demonstrated that the level of CRE binding protein (CREB) was the same in all cell lines and that the putative AR-CRE forms specific and competable protein interactions with CREB. The ability to regulate AR gene transcription via the second messenger pathway is lost in the PC-3 and DU-145 cell lines. This may be an important primary mechanism of androgen insensitivity in prostate cancer.