Estrogen receptor-beta: 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 (ERbeta), is preferentially expressed in the prostate and maintains some characteristics that are different from ERalpha. Establishing the distribution and function of ERbeta in the various estrogen-responsive tissues is critical to defining its pharmacological and physiological impact. Differential expression of ERbeta 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 ERbeta and its potential impact on the prostate.