Characterization of messenger RNA expression of estrogen receptor-α and -β in patients with ovarian endometriosis

Abstract

Objective: To evaluate the expression of estrogen receptor (ER)-α and ER-β messenger RNA (mRNA) in ovarian endometriosis. Design: Prospective study. Setting: University hospital. Patient(s): Patients with endometriosis and patients with uterine leiomyoma or carcinoma in situ. Intervention(s): A sample of ovarian endometriotic cyst tissue was obtained from each of the 32 patients during laparoscopic cystectomy. Samples of ovarian tissue and endometrium were obtained from 15 patients during or just after surgery. Main Outcome Measure(s): Expression of mRNA for ER-α and ER-β with use of the reverse transcription-polymerase chain reaction (RT-PCR) and nonradioactive in situ hybridization (ISH) techniques. Result(s): Expression of mRNA for ER-α and ER-β was observed in all of the control tissues from the normal endometrium and normal ovaries in the RT-PCR and ISH analyses, although the distribution of positive signals changed in the ISH analysis during different phases of the menstrual cycle. Messenger RNA for ER-α was detected in all of the ovarian endometriotic cysts analyzed (19 of 19), but mRNA for the ER-β was limited (12 of 19) in the RT-PCR analysis. The ISH analysis confirmed the RT-PCR results and revealed that the two estrogen receptors were localized in both epithelial and stromal cells of endometriotic tissues. Conclusion(s): The results suggest that predominant expression of ER-α in both glandular epithelial and stromal cells may be essential to the development and growth of ovarian endometriosis.