Cultured Ehrlich Ascites Tumor Cells Show Increased N-Linked α2,6-Sialytransferase Activity

Ehrlich ascites tumor cells (EAT cells) are routinely grown in the peritoneal cavity of mice. These cells, EAT-wt, grow in suspension and exhibit a high level of α-2,3-O-linked sialyltransferase activity with benzyl-T-antigen (Galβ1,3Ga1NAc-α-O-CH2C6H5) as acceptor. These cells also contain a very low level of α-2,6-O-linked and α-2,6-N-linked sialyltransferase activity. A variant of these cells, EAT-c, has been selected to grow in cell culture, attached to the surface of culture flasks. EAT-c cells exhibit a selective increase of two- to fivefold in the activity of α-2,6-N-linked sialyltransferase activity, using asialo-α1-acid glycoprotein as acceptor. Since a similar selective increase has been previously observed in metastatic human colorectal cancer tissues, the EAT-wt/EAT-c cell system may serve as a good experimental model for the investigation of sialyltransferases and their cell surface sialylated products in relation to cancer, metastasis, and cell-cell interaction.