Matrix Metalloproteinase-2, Membranous Type 1 Matrix Metalloproteinase, and Tissue Inhibitor of Metalloproteinase-2 Expression in Ectopic and Eutopic Endometrium

Objective: To investigate expression of matrix metalloproteinase-2 (MMP-2), membranous type 1 matrix metalloproteinase (MT1-MMP), and tissue inhibitor of metalloproteinase-2 (TIMP-2) in ectopic and eutopic endometrium from women with and without endometriosis throughout the menstrual cycle.

Design: Molecular studies in human tissue.

Setting: Reproductive immunology laboratory of a university medical center.

Patient(s): Fifty-three premenopausal woman (23 with endometriosis and 30 without endometriosis) undergoing laparoscopic surgery. Endometrium and ectopic endometriosis tissue were obtained at the time of surgery.

Main Outcome Measure(s): Messenger RNA and protein expression from eutopic and ectopic endometrium was analyzed by using quantitative competitive polymerase chain reaction, zymography, and Western blot assay.

Result(s): Uterine endometrium from women with endometriosis expressed higher levels of MMP-2 and MT1-MMP and lower levels of TIMP-2 than did endometrium from normal women.

Conclusion(s): Eutopic endometrium from patients with endometriosis may be more invasive and prone to peritoneal implantation because of greater expression of MMP-2 and MT1-MMP and lower expression of TIMP-2 messenger RNA, compared with endometrium from women without endometriosis. Thus, increased proteolytic activity may help to explain the invasive factors that result in endometriosis.