Characterisation of α 3β 1 and α vβ 3 integrin N-oligosaccharides in metastatic melanoma WM9 and WM239 cell lines

Abstract

It is well documented that glycan synthesis is altered in some pathological processes, including cancer. The most frequently observed alterations during tumourigenesis are extensive expression of β1,6-branched complex type N-glycans, the presence of poly- N-acetyllactosamine structures, and high sialylation of cell surface glycoproteins. This study investigated two integrins, α 3β 1 and α vβ 3, whose expression is closely related to cancer progression. Their oligosaccharide structures in two metastatic melanoma cell lines (WM9, WM239) were analysed with the use of matrix-assisted laser desorption ionisation mass spectrometry. Both examined integrins possessed heavily sialylated and fucosylated glycans, with β1,6-branches and short polylactosamine chains. In WM9 cells, α 3β 1 integrin was more variously glycosylated than α vβ 3; in WM239 cells the situation was the reverse. Functional studies (wound healing and ELISA integrin binding assays) revealed that the N-oligosaccharide component of the tested integrins influenced melanoma cell migration on vitronectin and α 3β 1 integrin binding to laminin-5. Additionally, more variously glycosylated integrins exerted a stronger influence on these parameters. To the best of our knowledge, this is the first report concerning structural characterisation of α vβ 3 integrin glycans in melanoma or in any cancer cells.