?(1,3)Fucosyltransferase expression in E-selectin-mediated binding of gastrointestinal tumor cells

Abstract

E-selectin recognizes the oncofetal antigen sialyl-Lewis X, which is highly expressed in adenocarcinoma. Five alpha(1,3)fucosyltransferases (FT) have been cloned that confer cell-surface expression of sialyl-Lewis X on transfected cells. We show here that 12/18 gastrointestinal-tumor cell lines bind specifically to immobilized E-selectin and that in sialyl-Lewis-X-positive cells binding is inhibited with a monoclonal antibody against sialyl-Lewis X. Using RT-PCR, we determined the expression of the alpha(1,3)fucosyltransferases III, IV, V, VI and VII in gastrointestinal tumor cells. Transcripts of FT IV and FT VII are abundantly expressed in all tested cells. Therefore no single fucosyltransferase could be correlated with the expression of sialyl-Lewis X and the ability of the tumor cells to bind to E-selectin. The data suggest that in gastrointestinal-tumor cells sialyl-Lewis X is necessary but not sufficient for E-selectin binding.