Journal Article

Sialoglycoproteins and N-Glycans from Secreted Exosomes of Ovarian Carcinoma Cells

Costa, Júlia, Escrevente, Cristina, Zeiser, Johannes, Kandzia, Sebastian, Tranfield, Erin M., Grammel, Nicolas, Conradt, Harald S.

2013

Overview

Exosomes consist of vesicles that are secreted by several human cells, including tumor cells and neurons, and they are found in several biological fluids. Exosomes have characteristic protein and lipid composition, however, the results concerning glycoprotein composition and glycosylation are scarce. Here, protein glycosylation of exosomes from ovarian carcinoma SKOV3 cells has been studied by lectin blotting, NP-HPLC analysis of 2-aminobenzamide labeled glycans and mass spectrometry. An abundant sialoglycoprotein was found enriched in exosomes and it was identified by peptide mass fingerprinting and immunoblot as the galectin-3-binding protein (LGALS3BP). Exosomes were found to contain predominantly complex glycans of the di-, tri-, and tetraantennary type with or without proximal fucose and also high mannose glycans. Diantennary glycans containing bisecting N-acetylglucosamine were also detected. This work provides detailed information about glycoprotein and N-glycan composition of exosomes from ovarian cancer cells, furthermore it opens novel perspectives to further explore the functional role of glycans in the biology of exosomes.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Antigens, Neoplasm - metabolism / Biomarkers, Tumor - metabolism / Biomarkers, Tumor - secretion / Biosynthesis / Carbohydrate Conformation / Carbohydrate Sequence / Carrier Proteins - metabolism / Carrier Proteins - secretion / Cell Line, Tumor / Chromatography / Dendritic cells / Exosomes / Exosomes - metabolism / Exosomes - secretion / Female / Fingerprinting / Fucose / Galectin-3 / Glycan / Glycoprotein composition / Glycoproteins / Glycoproteins - metabolism / Glycoproteins - secretion / Glycosylation / High-performance liquid chromatography / Humans / Laboratories / Lectins / Lipid composition / Lipids / Liquid chromatography / Mannans - metabolism / Mannans - secretion / Mannose / Mass spectrometry / Mass spectroscopy / Microscopy / Molecular Sequence Data / N-Acetylglucosamine / N-glycans / Ovarian cancer / Ovarian carcinoma / Ovarian Neoplasms / Peptide mapping / Plasma / Polysaccharides / Polysaccharides - metabolism / Polysaccharides - secretion / Protein composition / Proteins / Proteomics / Sialoglycoproteins / Sialoglycoproteins - metabolism / Sialoglycoproteins - secretion / Streptococcus infections / Tumor cells / Urine