Down-regulation of FUT3 and FUT5 by shRNA alters Lewis antigens expression and reduces the adhesion capacities of gastric cancer cells

Background: Lewis antigens are fucosylated glycoconjugates involved in the development of several pathologies. The adhesion of sialyl-Lewis antigens to E-selectin is a key step in the development of metastasis and the glycosidic component of CD44 plays a key role in the binding to hyaluronic acid, a component of the extracellular matrix associated to tumor development and invasion. Fucosyltransferases are enzymes that add fucose to precursor glycan structures: FUT3 and FUT5 catalyze the addition of fucose to the alpha 1-3,4 position and are detected in epithelial cells. In this study, we have analyzed the effects of silencing FUT3, FUT5 or FUT3/FUT5, in two gastric cancer cell lines, in the expression of Lewis antigens and in the adhesive and migratory capacities of the cells. Methods: FUT3, FUT5 and FUT3/FUT5 were down-regulated using lentiviral delivery of shRNAs in MKN45 and GP220 gastric cancer cells. Results: In the infected cells, decreased levels of FUT3 and FUT5 mRNA detected by quantitative RT-PCR; and lower levels of sialyl-Lewis antigens, evaluated by flow cytometry, were observed. The adhesion to endothelial cells trough the binding to E-selectin, and the binding to hyaluronic acid were reduced in the shFUT3, shFUT5 and shFUT3/FUT5, whereas the levels of CD44, analyzed by western blot did not change. General significance: The down-regulation of FUT3, FUT5 and FUT3/FUT5 reduces the expression of sialyl-Lewis antigens and the adhesion and binding capacities of gastric cancer cells; and allows to identify the specific alpha 1-3,4 fucosyltransferases implicated in the Lewis antigens synthesis in this cellular model. (C) 2011 Elsevier B.V. All rights reserved.