Characterization of estrogen receptors alpha and beta in uterine leiomyoma cells

Objective: Cellular and subcellular localization of estrogen receptor alpha (ER alpha) and estrogen receptor beta (ER beta) in uterine leiomyomas. Design: Retrospective study. Setting: University of La Laguna (ULL) and Canary University Hospital (HUC). Patient(s): Premenopausal and postmenopausal women with uterine leiomyomas. Intervention(s): Hysterectomy and myomectomy. Result(s): Estrogen receptor alpha was only present in smooth muscle cells with variation in the subcellular location in different leiomyomas. Estrogen receptor beta was widely distributed in smooth muscle, endothelial, and connective tissue cells with nuclear location in all cases studied; variations were only found in the muscle cells for this receptor. Conclusion(s): Estrogens operate in leiomyoma smooth muscle cells through different receptors, alpha and beta. However they only act through the ER beta in endothelial and connective cells.