Establishment of human endometriosis-derived immortalized eutopic endometrium stromal and epithelial cell lines

Endometriosis (EM) is commonly seen in women at reproductive age and can have a significant social and psychological impact. However, reliable, simple in vitro models of endometriosis are not common. To establish human EM-derived immortalized cell lines, we transfected cells from eutopic and ectopic endometria of endometriosis patients with the plasmid PCD2SV40T. The cells were then screened with G418, and monoclonal cells were isolated by the limited dilution method. Subclones were evaluated by karyotype analysis, immunocytochemistry, reverse transcription-polymerase chain reaction, cell doubling time, and nude mice implantation. The established immortalized eutopic stromal cell line was named hEM15A, and the ectopic epithelial cell line was named hEM5B2. hEM15A cells exhibited the characteristics of endometrium stromal cells, and no abnormalities in chromosome structure or number were observed. hEM5B2 cells exhibited the characteristics of epithelial cells, but had a polyploid karyotype. Both of these cell lines could be passaged continuously. No tumourigenicity was observed. hEM15A is the first immortalized EM-derived eutopic endometrium stromal cell line, and hEM5B2 is an immortalized ectopic endometrium epithelial cell line from Asian EM tissues. These cells could facilitate studies on the aetiology, molecular mechanisms, and therapeutic models of EM.