Increased invasion activity of endometrial stromal cells and elevated expression of matrix metalloproteinase messenger RNA in the uterine tissues of mice with experimentally induced adenomyosis

Objective: This study was undertaken to determine whether changes in stromal cell invasiveness and matrix metalloproteinase activity in mouse uterine tissues were involved in the development of adenomyosis that was induced by ectopic pituitary grafting. Study Design: The invasion activity of endometrial stromal cells into various kinds of extracellular matrix components was examined in experimentally induced adenomyotic and control uteri in vitro. The effect of an inhibitor of matrix metalloproteinase on the invasion activity was also examined. Differences between the expression of matrix metalloproteinases in adenomyotic and control uteri were examined with the use of degenerate primer-driven reverse transcription-polymerase chain reaction, dot-blot hybridization, and gelatin zymography. Results: Stromal cells that were obtained from adenomyotic uteri markedly invaded the reconstituted basement membrane matrix and gelatin, and the matrix metalloproteinase inhibitor suppressed the invasion. Expression of membrane-type matrix metalloproteinase –14 messenger RNA and gelatinase activity was elevated in accordance with the development of adenomyosis. Conclusion: An elevation of the invasion activity of stromal cells into the extracellular matrix is related to the development of adenomyosis; matrix metalloproteinase –14 may play an important role in the invasion of endometrial tissues into the myometrium. (Am J Obstet Gynecol 2001;185: 1374-80.)