The roles of terminal sugar residues of surface glycans in the metastatic potential of human hepatocarcinoma

Purpose: The roles of terminal sialyl and fucosyl residues in cell surface glycans in the metastatic potential of H7721 cells, a human hepatocarcinoma cell line, were studied. Methods: Neuraminidase and alpha-L-fucosidase were used to remove the sialyl and fucosyl residues, respectively. Cell adhesion to fibronectin (Fn), laminin (Ln), and human umbilical vein epithelial cell (HUVEC), as well as chemotactic cell migration and invasion, were selected as the parameters of metastatic potential ex vivo. Results: Sialyl residue is not essential for cell adhesion to Fn, but is important in cell adhesion to Ln and invasion, and is crucial in cell adhesion to HUVEC and migration. In contrast, fucosyl residue contributes more than sialyl residue to cell adhesion to Fn and Ln, but less to adhesion to HUVEC, and is not essential in chemotactic cell migration and invasion. Cell adhesion to HUVEC, migration, and invasion were inhibited by the monoclonal antibody of sialyl Lewis X, but not by the antibody of non-sialyl Lewis X. Conclusion: Terminal sialyl residues on cell surface glycans are more important than fucosyl residues in mediating cell adhesion to HUVEC and cell migration/invasion, but the reverse is true in cell adhesion to Fn and Ln.