Expression and regulation of estrogen-converting enzymes in ectopic human endometrial tissue

ObjectiveTo investigate the regulation of estrogen-converting enzymes in human ectopic endometrial tissue.DesignAnimal study.SettingAcademic medical center.Animal(s)Sixty female nude mice with implanted human endometrial tissue.Patient(s)Twenty-two premenopausal women undergoing endometrial biopsy or hysterectomy.Intervention(s)Human endometrial tissue was implanted into the peritoneal cavity of nude mice, and the effect of therapeutic drugs on transcription of steroid receptors and estrogen-converting enzymes was analyzed.Main Outcome Measure(s)Transcript levels of steroid hormone receptors, 17β-hydroxysteroid dehydrogenase type 1 and 2, aromatase, and steroid sulfatase as well as proliferation rate were analyzed in the human ectopic endometrial tissue.Result(s)Steroid receptors and estrogen-converting enzymes were expressed in the ectopic human endometrial fragments. Application of medroxyprogesterone acetate, dydrogesterone, danazol, and the aromatase inhibitor finrozole significantly inhibited aromatase transcription. In addition, danazol caused a significant decrease in transcription of steroid sulfatase, and finrozole, of 17β-hydroxysteroid dehydrogenase type 1 in parallel to a decrease in proliferation rate in the ectopic human endometrial tissue.Conclusion(s)Pharmacological regulation of transcription of estrogen-converting enzymes in human endometrium cultured in nude mice may help to develop new therapeutic concepts based on local regulation of estrogen metabolism in endometriosis.