A novel in vitro experimental model for ovarian endometriosis: the three-dimensional culture of human ovarian surface epithelial cells in collagen gels

Objective: To develop an in vitro experimental model of ovarian endometriosis using human cells and to investigate the pathogenesis of endometriosis. Design: Controlled in vitro coculture study. Setting: A department of obstetrics and gynecology at a university hospital. Patient(s): Ovaries and endometrium were obtained from patients who underwent a hysterectomy because of gynecologic disease. Intervention(s): Human ovarian surface epithelial (OSE) cells were cultured alone and OSE cells and endometrial stromal (ES) cells were cultured together in a three-dimensional collagen gel culture system with or without the addition of E-2. Main Outcome Measure(s): The aggregated collagen gels containing the cultured cells were examined morphologically. Result(s): The OSE cells in single culture with E-2 formed circular arrangements. These cells were immunohistochemically positive for cytokeratin but negative for epithelial membrane antigen. In the cocultures of OSE and ES cells with E-2, the OSE cells formed a lumen structure surrounded by ES cells. Immunoreactivity for cytokeratin and epithelial membrane antigen was detected in the glandular cells and cilia were identified on the cell surface by electron microscopy. Without the addition of E-2, no structures were detected. Conclusion(s): A new in vitro experimental model was established with the aid of human OSE cells. Endometriotic lesions can arise through a process of metaplasia from OSE cells in the presence of E-2 and ES cells. (C) 1998 by American Society for Reproductive Medicine.