Tumor-host interactions regulate glucocorticoid-mediated epiglycanin expression in TA3Ha murine mammary carcinoma cells.

The mucin-type glycoprotein epiglycanin is highly expressed on the cell surface of TA3Ha mouse mammary carcinoma cells if the cells are maintained by serial intraperitoneal passage in mice. We found that upon transfer of the cells to growth in vitro in medium supplemented with fetal bovine serum, the expression level of epiglycanin slowly diminished to less than 15% of that in vivo. Repassage of the cells in vivo fully restored the expression of epiglycanin.