PRODUCTION AND CHARACTERIZATION OF WEG-1, AN EPIDERMAL GROWTH-FACTOR TRANSFORMING GROWTH FACTOR-ALPHA-RESPONSIVE MOUSE UTERINE EPITHELIAL-CELL LINE

Uterine epithelial cells (UEC) isolated from 6-week-old CF-1 mice were immortalized using retroviral-mediated transfection of SV40 large T-a ntigen. One line, WEG-1, retained epithelial mol phology and reacted w ith antibodies to cytokeratins 18, 19, laminin, fibronectin, and beta- catenin. In addition, WEG-1 cells displayed strong nuclear immunoreact ivity to SV40 large T-antigen, confirming integration of the retroviru s vector and expression of this gene. WEG-1 cells were negative for no nepithelial markers such as desmin and factor 8. WEG-1 cells did not p roliferate in serum-free medium; however, addition of 0.5% FBS support ed proliferation to the same extent as 10% FBS. Addition of 50 ng/ml e pidermal growth factor to medium containing 0.5% charcoal-stripped FBS restored proliferation compara ble with 0.5% whole FBS. Epidermal gro wth factor or transforming growth factor-alpha (50 ng/ml), but not tra nsforming growth factor-beta, leukemia-inhibiting factor, or fibroblas t growth factor, induced the secretion of three proteins (M(r) similar or equal to 158K, 148K, and 36K). Comparison of protein secretions of WEG-1 cells and UEC showed shared as well as distinct bands. Like UEC , WEG-1 cells secreted PGF(2 alpha) and PGE(2) and expressed PG GH syn thase-2. Unlike UEC, WEG-1-cells showed no apical/basal preference for either uptake of methionine or secretion of proteins. The absence of immunoreactive E-cadherin or zona occludens-1 was consistent with the absence of cell polarity in WEG-1 cells. Primary UEC, which polarize i n vitro, do not support blastocyst attachment. WEG-1 cells, although n ot polarized in vitro, also exhibited delayed blastocyst attachment co mpared with nonuterine cell lines, suggesting that WEG-1 cells partial ly retained some aspects of UEC function relevant to embryo attachment . WEG-1 cells expressed messenger RNA for Muc-1, an UEC mucin suggeste d to have antiadhesive properties. Furthermore, WEG-1 cells did not di splay high affinity heparin binding sites, an activity associated with embryo attachment. WEG-1 cells may provide a model for studying vario us aspects of UEC function and murine embryo attachment.