Characteristics of expression of estrogen receptor-α and -β in uterine leiomyomas

Objective: To study the expression of estrogen receptor (ER)-α and -β messenger RNA(mRNA) in uterine leiomyomas. Methods: Samples of uterine leiomyomas and myometriums were obtained from the patients during surgery. Expression of ER-α and ER-β mRNA was detected with nonradioactive in situ hybridization (ISH) techniques. Results: ER-α and ER-β mRNA were mainly localized in uterine smooth muscle cells, but ER-α was significantly higher than ER-β. Expression of ER-α mRNA in leiomyomas was higher than that in myometrium. The expression of ER-β showed a decreasing trend in leiomyoma. Conclusion: The increase of ER_ α mRNA expression and decrease of ER_ β mRNA expression are related to the development of leiomyoma. The imbalance in expression of ER subtypes contributes to the pathogenesis of leiomyoma.