title: A recombinant fungal lectin for labeling truncated glycans on human cancer cells.
abstract: Cell surface glycoconjugates present alterations of their structures in chronic diseases and distinct oligosaccharide epitopes have been associated with cancer. Among them, truncated glycans present terminal non-reducing β-N-acetylglucosamine (GlcNAc) residues that are rare on healthy tissues. Lectins from unconventional sources such as fungi or algi provide novel markers that bind specifically to such epitopes, but their availability may be challenging. A GlcNAc-binding lectin from the fruiting body of the fungus Psathyrella velutina (PVL) has been produced in good yield in bacterial culture. A strong specificity for terminal GlcNAc residues was evidenced by glycan array. Affinity values obtained by microcalorimetry and surface plasmon resonance demonstrated a micromolar affinity for GlcNAcβ1-3Gal epitopes and for biantennary N-glycans with GlcNAcβ1-2Man capped branches. Crystal structure of PVL complexed with GlcNAcβ1-3Gal established the structural basis of the specificity. Labeling of several types of cancer cells and use of inhibitors of glycan metabolism indicated that rPVL binds to terminal GlcNAc but also to sialic acid (Neu5Ac). Analysis of glycosyltransferase expression confirmed the higher amount of GlcNAc present on cancer cells. rPVL binding is specific to cancer tissue and weak or no labeling is observed for healthy ones, except for stomach glands that present unique αGlcNAc-presenting mucins. In lung, breast and colon carcinomas, a clear delineation could be observed between cancer regions and surrounding healthy tissues. PVL is therefore a useful tool for labeling agalacto-glycans in cancer or other diseases.
authors.affiliation: CERMAV, UPR5301, CNRS, University Grenoble Alpes, 38041 Grenoble, France.
authors.forename: Aymeric
authors.initials: A
authors.lastname: Audfray
authors.affiliation: IAB, University Grenoble Alpes, F-38000 Grenoble, France; INSERM U823, IAB, F-38000 Grenoble, France; University El Hadj Lakhdar, 05000 Batna, Algeria.
authors.forename: Mona
authors.initials: M
authors.lastname: Beldjoudi
authors.affiliation: INSERM, UMR892, 44007 Nantes, France; CNRS, UMR6299, 44007 Nantes, France; IRS UN, University of Nantes, Nantes, France; Nantes University Hospital, 44000 Nantes, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Breiman
authors.affiliation: IAB, University Grenoble Alpes, F-38000 Grenoble, France; INSERM U823, IAB, F-38000 Grenoble, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Hurbin
authors.affiliation: Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Irene
authors.initials: I
authors.lastname: Boos
authors.affiliation: Bioorganische Chemie, Gebäude NW1, Universität Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Carlo
authors.initials: C
authors.lastname: Unverzagt
authors.affiliation: University El Hadj Lakhdar, 05000 Batna, Algeria.
authors.forename: Mourad
authors.initials: M
authors.lastname: Bouras
authors.affiliation: IAB, University Grenoble Alpes, F-38000 Grenoble, France; INSERM U823, IAB, F-38000 Grenoble, France; Grenoble University Hospital, F-38000 Grenoble, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lantuejoul
authors.affiliation: IAB, University Grenoble Alpes, F-38000 Grenoble, France; INSERM U823, IAB, F-38000 Grenoble, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Coll
authors.affiliation: CERMAV, UPR5301, CNRS, University Grenoble Alpes, 38041 Grenoble, France.
authors.forename: Annabelle
authors.initials: A
authors.lastname: Varrot
authors.affiliation: INSERM, UMR892, 44007 Nantes, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Le Pendu
authors.affiliation: IAB, University Grenoble Alpes, F-38000 Grenoble, France; INSERM U823, IAB, F-38000 Grenoble, France; Grenoble University Hospital, F-38000 Grenoble, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Busser
authors.affiliation: CERMAV, UPR5301, CNRS, University Grenoble Alpes, 38041 Grenoble, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Imberty
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D000363:Agaricales / Q000737:chemistry*; D002240:Carbohydrate Sequence; D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D000939:Epitopes / Q000378:metabolism; D006001:Glycoconjugates / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism*; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling; D013816:Thermodynamics; D015854:Up-Regulation
chemical_list: D000939:Epitopes; D006001:Glycoconjugates; D037102:Lectins; D009844:Oligosaccharides; D011134:Polysaccharides; D011994:Recombinant Proteins; D019158:N-Acetylneuraminic Acid; D000117:Acetylglucosamine