title: Over-sulfated glycosaminoglycans are alternative selectin ligands: insights into molecular interactions and possible role in breast cancer metastasis.
abstract: Distant metastasis account for about 90 % of cancer associated deaths, and yet the oncology field is cruelly lacking tools to accurately predict and/or prevent metastasis. Distant metastasis occurs when circulating tumor cells interact with the endothelium of distant organs and extravasate from the blood vessel into the surrounding tissue. Selectins are a family of carbohydrate receptors well depicted for their role in tumor cells extravasation. They mediate primary interactions of cancer cells with endothelial cells, as well as secondary interactions with leucocytes and platelets, which are also promoting metastasis. The cancer associated carbohydrate antigen sialyl-Lewis x (sLe(x)) has been repeatedly shown to be involved, as selectin ligand, in these interactions. However, recent studies have highlighted that glycosaminoglycans (GAGs), another class of glycans, may also serve as ligands for selectins. We report herein that cancer-associated GAGs are differentially recognized by selectins according to their density of sulfation and the pH conditions of the binding. We also show that these parameters regulate platelets-cancer cells heterotypic aggregation, supporting the idea that GAGs may have pro-metastatic function. Combining our experimental results with in depth analyses of molecular dockings, we propose a model of GAG/selectin interactions robust enough to recapitulate the differential binding of selectins to GAGs, the competition between GAGs and sLe(x) for selectin binding and the effect of sub-physiological pH on GAGs affinities towards selectins. Altogether, our data suggest GAGs to be good ligands for selectins, potentially promoting distant metastasis in a complementary way to sLe(x).
authors.affiliation: Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche 8576 du Centre National de la Recherche Scientifique, Institut Fédératif de Recherche 147, Université Lille Nord de France-Université des Sciences et Technologies, Bat C9 Université Lille 1, 59655, Villeneuve d'Ascq, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Martinez
authors.forename: Gérard
authors.initials: G
authors.lastname: Vergoten
authors.forename: Florent
authors.initials: F
authors.lastname: Colomb
authors.forename: Marie
authors.initials: M
authors.lastname: Bobowski
authors.forename: Agata
authors.initials: A
authors.lastname: Steenackers
authors.forename: Mathieu
authors.initials: M
authors.lastname: Carpentier
authors.forename: Fabrice
authors.initials: F
authors.lastname: Allain
authors.forename: Philippe
authors.initials: P
authors.lastname: Delannoy
authors.forename: Sylvain
authors.initials: S
authors.lastname: Julien
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D009362:Neoplasm Metastasis; D019087:Selectins / Q000378:metabolism*
chemical_list: D006025:Glycosaminoglycans; D008024:Ligands; D019087:Selectins