Development and Characterization of Spontaneously Immortalized Cell Lines Derived from Mouse Endometriotic Lesions

Abstract

Endometriosis affects approximately 1 in 10 women of reproductive age, where the tissue of the inner lining of the uterus, the endometrium, proliferates in and around the peritoneal cavity. Common symptoms of endometriosis include chronic pelvic pain, intense pain with menstruation, pain with urination and defecation, and infertility. Recently more attention is being brought to the links between endometriosis and other co‐morbidities such as heart disease, cancer, and autoimmune disorders. Other factors known to play a role in endometriosis are endocrine disrupting chemicals that are found in common household products that contain plasticizers. One of these environmental toxicants is a group of chemicals called phthalates. A challenge to the field of endometriosis is the availability of cell lines to study mechanism(s); therefore, we set forth to create cell lines from endometriosis lesions. In our model of endometriosis, uterine endometrial tissue expressing green fluorescent protein (GFP) is used to develop endometriosis lesions. From these lesions, multiple cell lines were generated, but for this study, the focus was on GFP positive (EmLe+) and GFP negative (EmLe‐) cell populations that emerged from the lesions. The EmLe+ line is phenotypically uterine derived exhibiting epithelial to mesenchymal transition (EMT) markers. The EmLe‐line phenotypically exhibits epithelial derived muscle markers. To characterize these lines and to determine their response to environmental toxicants, the cells were studied under normal conditions and exposure to a commonly found phthalate, bis (2‐ethylhexyl), also known as DEHP, to better understand the cellular properties in the development and progression of endometriosis. Cell proliferation, migration, and invasion assays were used to examine how endometrial cells cultured from a mouse model are able to proliferate, migrate, and invade under normal and DEHP exposure conditions. For the proliferation assay, each of the cell lines was plated at 5,000 cells per well in 24 well plates and counted each day under various conditions. To study cell migration and invasion, a 48‐well chemotaxis chamber was used with or without matrigel, respectively. From these studies, we find that the different cell types isolated from mouse endometriotic lesions differ in composition and behavior, and find that these cell lines may be a good model to study more in depth mechanisms of endometriosis development.Support or Funding InformationR00 ES021737P30 ES006096