α(1,2)-Fucosylation prevents sialyl Lewis x expression and E-selectin-mediated adhesion of fucosyltransferase VII-transfected cells

E-selectin is a cytokine-inducible, calcium-dependent endothelial cell adhesion molecule that plays a critical role in the leucocyte-endothelium interaction during inflammation and is thought to contribute to the metastatic dissemination of tumour cells. Like the other selectins, E-selectin binds to ligands carrying the tetrasaccharide sialyl-Lewis x (NeuAc alpha 2,3Gal beta 1,4[Fuc alpha 1,3]GlcNAc)(1) or its isomer sialyl-Lewis a (NeuAc alpha 2, 3Gal beta 1,3[Fuc alpha 1,4]GlcNAc). We examined the effect of expressing the H-type alpha(1,2)-fucosyltransferase or the alpha(2,6)-sialyltransferase on the synthesis of sialyl-Lewis x by alpha(1,3)fucosyltransferase. We found that H-type alpha(1,2)-fucosyltransferase but not alpha(2,6)-sialyltransferase, strongly inhibited sialyl-Lewis x expression and E-selectin adhesion. We assume that H-type alpha(1,2)-fucosyltransferase competes with the endogenous alpha(2,3)-sialyltransferase for the N-acetyllactosamine structures assigned to further serve as acceptors for alpha(1,3)fucosyltransferase.