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 E2.

MAIN OUTCOME MEASURE(S): The aggregated collagen gels containing the cultured cells were examined morphologically.

RESULT(S): The OSE cells in single culture with E2 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 E2, 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 E2, 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 E2 and ES cells.