Permissive Role of Estrogens in Prostate Diseases

Estrogens are steroid hormones that act through their receptors (ER) α and β. They are involved mainly in female physiology but, in males, influence the homeostasis of some tissues like the prostate. In this organ, estrogens promote or limit cell proliferation depending on the activated receptor, with implications for the pathophysiology of benign prostatic hyperplasia (BPH) and prostate cancer (PCa). ERα promotes proliferation while ER β is a protective factor against proliferative diseases. However, in the advanced stages of PCa, ERβ has a permissive role in prostate cells, increasing patient mortality. These effects are mediated by activating androgen-independent signaling pathways that promote proliferation. Another essential aspect of ER actions is the regulation of its expression. Steroid hormones participate in this process, but some non-steroid factors, like environment and epigenetic marks, influence the prostate’s physiopathology. Knowledge of these and other aspects of estrogenic action in the prostate will contribute to developing strategies for treating and preventing BPH and PCa. For this reason, this chapter will review the main aspects of estrogens’ permissive role in prostate diseases.