Estrogen receptor-β:: Implications for the prostate gland

Estrogens can have profound effects on prostate growth and differentiation. These effects were thought to be mediated by the classical estrogen receptor; however, the discovery of a second estrogen receptor has redefined the estrogen signaling pathway and may have broad implications on estrogen-responsive tissues, including the prostate. The new estrogen receptor, named estrogen receptor-beta (ER beta), is preferentially expressed in the prostate and maintains some characteristics that are different from ER alpha. Establishing the distribution and function of ER beta in the various estrogen-responsive tissues is critical to defining its pharmacological and physiological impact. Differential expression of ER beta may facilitate development of tissue-specific estrogen agonists and antagonists, a goal in the treatment of diseases in estrogen-sensitive tissues such as breast cancer. This article reviews the current knowledge on ER beta and its potential impact on the prostate. Prostate 40:115-124, 1999. (C) 1999 Wiley-Liss, Inc.