Expression of Cathepsin B mRNA and Protein in Eutopic and Ectopic Endometrial Tissues of Patients with Endometriosis

Lee, Soo Jeong; Kim, Chung Hoon; Lee, Young Jin; Kim, Ji Sun; Koo, Yun Hee; Lee, Sa Ra; Kim, Sung Hoon; Chae, Hee Dong; Kang, Byung Moon

Abstract

OBJECTIVE
This study was performed to investigate the expression of cathepsin B mRNA and Protein in eutopic and ectopic endometrial tissues of patients with endometriosis and in normal endometrial tissues, to compare the expression respectively and to clarify the correlation between the cathepsin B expression and endometriosis.
METHODS
There were 34 women with endometriosis taken surgical treatment at Department of Obstetrics and Gynecology, Asan Medical Center, Seoul, Korea, from October 2004 to September 2005. All patients were pre-menopausal and not-pregnant, and had received neither hormones nor gonadotropin-releasing hormone agonist (GnRH-a) therapy for at least 6 months before surgical treatment. Control group consisted of 14 women who had undergone operative treatment for cervical intraepithelial neoplasia (CIN) or benign gynecologic conditions other than endometriosis during the same period at the same center. Eutopic endometrial tissues of both groups and ectopic endometrial tissue of study group were collected during the operations. We employed rea1 time quantitative reverse transcriptase-polymerase chain reaction (real time RT-PCR) to quantify cathepsin B mRNA of these tissues. And we performed western blot analysis to measure the quantity of cathepsin B protein. We compared the results using student's t-test and Mann-Whitney U-test.
RESULTS
The expressions of cathepsin B mRNA and protein were significantly higher in both eutopic and ectopic endometrial tissues of women with endometriosis than in control endometrial tissues. The expression of cathepsin B mRNA of mid-secretory phase was less than proliferative phase, but there was no statistical significance.
CONCLUSION
With marked expressions of cathepsin B in both eutopic and ectopic endometrial tissues of endometriosis, we might assume the association of cathepsin B with the development of endometriosis. In addition the eutopic endometrium in itself might play a role in the histogenesis of endometriosis.