Interaction between endometrium epithelial cells (SNG-M) and teratocarcinoma cells (HT-H) differentiated into trophoblast.

Many of the human teratocarcinoma cell lines resemble cells of preblastocyst to trophectoderm. The use of these cell lines is, however, limited since they differentiate poorly in vitro. HT-H cell line might be useful as it differentiates into syncytiotrophoblast. Because syncytiotrophoblast of the blastocyst are the cells which attach to the maternal endometrium epithelium during implantation, HT-H cells were examined for their adhesion to SNG-M cells, which feature exhibit cells of endometrium epithelium. Differentiated HT-H cells attached to SNG-M cells, and between these two cells desmosomes and adherent junctions were developed. Undifferentiated HT-H cells did not directly attach to SNG-M cells. Cell-to-cell adhesions are often mediated by the homophilic adhesion molecules present in both cells. As the first step in the investigation of adhesion between SNG-M and HT-H cells, we examined adhesion between SNG-M cells themselves. Calcium had no effect on aggregation of SNG-M cells, which may exclude the involvement of cadherin type molecule in this system. Development of monoclonal antibodies that bind to the cell surface and inhibit aggregation of SNG-M cells, and SNG-M to HT-H cells will allow us to identify the adhesion molecule(s) involved in ovum implantation in utero.