title: Seromic profiling of colorectal cancer patients with novel glycopeptide microarray.
abstract: Cancer-associated autoantibodies hold promise as sensitive biomarkers for early detection of cancer. Aberrant post-translational variants of proteins are likely to induce autoantibodies, and changes in O-linked glycosylation represent one of the most important cancer-associated post-translational modifications (PTMs). Short aberrant O-glycans on proteins may introduce novel glycopeptide epitopes that can elicit autoantibodies because of lack of tolerance. Technical barriers, however, have hampered detection of such glycopeptide-specific autoantibodies. Here, we have constructed an expanded glycopeptide array displaying a comprehensive library of glycopeptides and glycoproteins derived from a panel of human mucins (MUC1, MUC2, MUC4, MUC5AC, MUC6 and MUC7) known to have altered glycosylation and expression in cancer. Seromic profiling of patients with colorectal cancer identified cancer-associated autoantibodies to a set of aberrant glycopeptides derived from MUC1 and MUC4. The cumulative sensitivity of the array analysis was 79% with a specificity of 92%. The most prevalent of the identified autoantibody targets were validated as authentic cancer immunogens by showing expression of the epitopes in cancer using novel monoclonal antibodies. Our study provides evidence for the value of glycopeptides and other PTM-peptide arrays in diagnostic measures.
authors.affiliation: Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N, Denmark.
authors.forename: Johannes W
authors.initials: JW
authors.lastname: Pedersen
authors.forename: Ola
authors.initials: O
authors.lastname: Blixt
authors.forename: Eric P
authors.initials: EP
authors.lastname: Bennett
authors.forename: Mads A
authors.initials: MA
authors.lastname: Tarp
authors.forename: Imran
authors.initials: I
authors.lastname: Dar
authors.forename: Ulla
authors.initials: U
authors.lastname: Mandel
authors.forename: Steen S
authors.initials: SS
authors.lastname: Poulsen
authors.forename: Anders E
authors.initials: AE
authors.lastname: Pedersen
authors.forename: Susanne
authors.initials: S
authors.lastname: Rasmussen
authors.forename: Per
authors.initials: P
authors.lastname: Jess
authors.forename: Henrik
authors.initials: H
authors.lastname: Clausen
authors.forename: Hans H
authors.initials: HH
authors.lastname: Wandall
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000276:immunology; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis; D005260:Female; D006020:Glycopeptides / Q000097:blood* / Q000276:immunology; D006031:Glycosylation; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000097:blood* / Q000276:immunology; D011379:Prognosis; D040081:Protein Array Analysis; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D014408:Biomarkers, Tumor; D000939:Epitopes; D006020:Glycopeptides; D009077:Mucins; D011994:Recombinant Proteins