Human endometriosis-derived permanent cell line (FbEM-1): establishment and characterization

A human epithelial-like cell line derived from peritoneal implants from a patient with gonadotrophin-releasing hormone (GnRH) agonist-resistant endometriosis graded as stage IVd according to the American Fertility Society classification was established in vitro. This cell line, designated FbEM-1, exhibited an epithelial-like morphology, grew in suspension and was immunoreactive for cytokeratins 8, 18, 19, vimentin and human leukocyte class I antigens. The cultured cells were negative for various haematopoietic cell markers, including the lymphoid cell antigens CD3, CD20 and CD45, von Willebrandt factor, carcinoembryonic antigen and the carcinoma antigen-125 (CA-125). In addition, the FbEM-1 cells were found to be moderately positive for periodic acid Schiff's (PAS) solution but were negative for alpha-naphthyl acetate esterase, peroxidase and chloroacetate esterase activities. Using specific antibodies against the progesterone, androgen and oestrogen receptors, approximately 40% and 5-10% of the cells immunostained for progesterone and androgen receptors respectively, while oestrogen receptors were not detected. On cytogenetic analysis using R-banding, these cells showed numerous chromosomal aberrations, including loss of one chromosome X, 4q+, 5q+, trisomy 7,8 and 10 and tetrasomy of chromosomes 17, 18, 19 and 20. These data show that the continuously growing FbEM-1 cell line established from endometriotic implants may be useful in achieving better understanding of the histogenesis of endometriosis.