Background The androgen receptor (AR) AR-V7 splice isoform is a constitutively active outlaw transcription factor. Transition of prostate cancer to the castration-resistant phenotype correlates with AR-V7 accumulation, suggesting that prostate cancer progression in patients refractory to conventional therapy is due to the activity of this AR isoform. The mechanism of AR-V7 constitutive activation is not known. Methods We analyzed potential signaling pathways associated with AR-V7 constitutive activation in PTEN (−) PC-3 and LNCaP cells. We used transient and stable transfection, reporter gene assay, RNAi technology together with a number of kinase inhibitors to determine if AR-V7 activation is linked to a kinase-dependent signaling pathway. Results In these cell lines, AR-V7 transcriptional activity was inhibited by LY294002, Wortmanin, and AKT inhibitor II. Analysis of the contributing mechanisms demonstrated the involvement of the Phosphatidylinositol 3-kinase (PI3K)-AKT-FOXO1 signaling pathway, and a significant reduction of AR-V7 constitutive activity under conditions of PTEN reactivation. Conclusions Our study identifies a pathway regulating AR-V7 constitutive activity and potential therapeutic targets for the treatment of castration resistant prostate cancer.

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This article contains a systematic review of the main developments that have occurred in the area of male hypogonadism between the publication of the Endocrine Society Guidelines of 2010 and 2018 and after 2018.