Evaluation of mRNA expression of estrogen receptor β and its isoforms in human normal and neoplastic endometrium

Abstract

Endometrial cancer is well known to be estrogen-dependent. Two estrogen receptor types, ERα and ERβ, are major mediators of a diversity of biologic functions of estrogen and play an important role in estrogen-dependent tissues and cancers. Cloning of ERβ was followed by the discovery of a variety of its isoforms. Using real-time RT-PCR, the relative expression levels of ERβ1, ERβ2 (ERβcx), ERβ3, ERβ4 and ERβ5 were studied. We observed coexpression of ERβ isoforms in the endometrium and upregulation of the ERβ5 transcript in malignant endometrium. We also observed downregulation of ERβ2Δ5 transcript in neoplastic endometrium, using a semiquantitative method. Our results suggest that analyzing the changes in ERβ and its isoforms may be important in the diagnosis, prognosis and treatment of endometrial cancer. © 2004 Wiley-Liss, Inc.