Oxytocin In The Pathophysiology Of Prostate Cancer

Oxytocin (OT) is a nonapeptide with actions in both the female and male reproductive tracts. In males, local oxytocinergic systems are present in the testis, epididymis, vas deferens and prostate. It is known to have roles in spermiation, local smooth muscle contraction and steroidogenesis. In particular, OT regulates dihydrotestosterone (DHT) by modulating expression and activity of 5 alpha-reductase isoenzymes. Regulation of DHT in the prostate is of significant importance in this androgen dependent organ, and has been implicated in both benign prostatic hyperplasia and prostate cancer. Indeed, changes in both oxytocin expression (decreased) and its receptor (increased) are apparent during the progression of prostate cancer. Recent work has highlighted a direct role for oxytocin in regulating proliferation of prostate epithelium. Much debate exists as to whether oxytocin induces cell proliferation, is anti-proliferative or has no affect on cell proliferation.It is apparent that the various effects are dictated by the cell line that is studied. In turn the response of a cell to OT treatment is dependent on whether oxytocin receptors are located in caveolae, or dispersed throughout the cell membrane. Determining the mechanisms by which OT modulates the proliferation of prostate epithelial cells, and how these mechanisms and subsequent response to OT may differ between individual tumours is central to exploiting OT and pharmacological agonists/antagonists in the treatment of prostate cancer.