Cell surface sialic acid modulates extracellular matrix adhesion and migration in pancreatic adenocarcinoma cells

Tumor cells modulate their extracellular matrix (ECM) adhesion and migration to become more metastatic. Moreover, they show an increase in sialic acid, which could have an effect on their ECM adhesion and migration. This work describes the influence of pancreatic adenocarcinoma cell surface α2,3- and α2,6-sialic acid determinants on the aforementioned processes. We have characterized the cell surface α2,3- and α2,6-sialic acids, and sialyl-Lewis x levels and the integrin levels of 2 pancreatic adenocarcinoma cell lines, Capan-1 and MDAPanc-28, grown at different cell densities, and also of the ST3Gal III overexpressing Capan-1 cells, C31. We have measured their adhesion to several ECM proteins and their migration through collagen with and without blocking their sialic acid determinants. Adhesion to ECM proteins of Capan-1 and MDAPanc-28 grown at different cell densities, and of C31, depended on their cell surface sialic acid determinants repertoire, correlating the higher α2,6-sialic acid levels with their increased ECM adhesion. Cell migration also depended on their sialic acid determinants expression; and in this case, higher α2,3-sialic acid levels correlated with a more migratory phenotype. This study shows how the intrinsic heterogeneity of cell membrane sialylation regulates the adhesive and migratory potential of pancreatic adenocarcinoma cells.