NONMALIGNANT EPITHELIAL-CELLS, POTENTIALLY INVASIVE IN HUMAN ENDOMETRIOSIS, LACK THE TUMOR-SUPPRESSOR MOLECULE E-CADHERIN

Endometriosis is one of the most frequent diseases in gynecology, It i s a histologically defined nonmalignant disease in which endometrium-l ike tissue is found outside the uterus (for example, peritoneum, gut, or lung). The pathogenesis of endometriosis is unknown, but invasive m echanisms have been implicated in the development of the disease Indee d, primary cells from human endometriotic biopsies but not from human endometrial biopsies are invasive in an in vitro collagen invasion ass ay, In this study, these in vitro invasive endometriotic cells were fo und to be nonmalignant epithelial cells lacking E-cadherin, which acts as an invasion suppressor molecule in carcinomas. Immunocytochemistry showed that the E-cadherin-negative epithelial cell type was increase d in sections of endometriosis tissue as compared with sections of eut opic endometrium. On the basis of these data we propose that the E-cad herin-negative invasive endometriotic cells seen in vitro represent th e cell population that migrates to ectopic (extrauterine) locations an d thus causes endometriosis in viva Accordingly, the loss of E-cadheri n expression is postulated to constitute a crucial mechanism in the pa thogenesis of endometriosis.