Advances in androgen receptor targeted therapy for prostate cancer.

Prostate cancer (PCa) is the second leading cause of cancer death in men. Current research findings suggest that the androgen receptor (AR) and its signaling pathway contribute significantly to the progression of metastatic PCa. The AR is a ligand activated transcription factor, where androgens such as testosterone (T) and dihydroxytestosterone (DHT) act as the activating ligands. However in many metastatic PCa, the AR functions promiscuously and is constitutively active through multiple mechanisms. Inhibition of enzymes that take part in androgen synthesis or synthesizing antiandrogens that can inhibit the AR are two popular methods of impeding the androgen receptor signaling axis; however, the inhibition of androgen-independent activated AR function has not yet been fully exploited. This article focuses on the development of emerging novel agents that act at different steps along the androgen-AR signaling pathway to help improve the poor prognosis of PCa patients.