Cancer Biomarkers Defined by Autoantibody Signatures to Aberrant O-Glycopeptide Epitopes

Center for Glycomics, Departments of Cellular and Molecular Medicine and Oral Diagnostics, University of Copenhagen, Blegdamsvej 3, Copenhagen 2200 N, Denmark.
Cancer Research (Impact Factor: 9.33). 02/2010; 70(4):1306-13. DOI: 10.1158/0008-5472.CAN-09-2893
Source: PubMed


Autoantibodies to cancer antigens hold promise as biomarkers for early detection of cancer. Proteins that are aberrantly processed in cancer cells are likely to present autoantibody targets. The extracellular mucin MUC1 is overexpressed and aberrantly glycosylated in many cancers; thus, we evaluated whether autoantibodies generated to aberrant O-glycoforms of MUC1 might serve as sensitive diagnostic biomarkers for cancer. Using an antibody-based glycoprofiling ELISA assay, we documented that aberrant truncated glycoforms were not detected in sera of cancer patients. An O-glycopeptide microarray was developed that detected IgG antibodies to aberrant O-glycopeptide epitopes in patients vaccinated with a keyhole limpet hemocyanin-conjugated truncated MUC1 peptide. We detected cancer-associated IgG autoantibodies in sera from breast, ovarian, and prostate cancer patients against different aberrent O-glycopeptide epitopes derived from MUC1. These autoantibodies represent a previously unaddressed source of sensitive biomarkers for early detection of cancer. The methods we have developed for chemoenzymatic synthesis of O-glycopeptides on microarrays may allow for broader mining of the entire cancer O-glycopeptidome.

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Available from: Eric P Bennett, Jan 09, 2014
    • "Peptides were printed on Schott - Nexterion Slide H - MPX - 16 ( Schott AG ) ( Wandall et al . 2010 ; Chen et al . 2013 ) . Triplicates of all com - pounds were printed at 0 . 5 mg / mL in 150 mmol / L sodium phosphate ( pH 8 . 5 ) with 0 . 005% CHAPS . Slides were incubated with mAb 5E11 ( 1 µg / mL ) and then detected with Cy3 - conjugated goat anti - mouse IgG ( H+L ) ( The Jackson Laboratory ) diluted 1 : 5000 . Next , slides were"
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    ABSTRACT: The MUC16 mucin is overexpressed and aberrantly glycosylated in ovarian carcinomas. Immunodetection of circulating MUC16 is one of the most used cancer biomarker assays, but existing antibodies to MUC16 fail to distinguish normal and aberrant cancer glycoforms. Although all antibodies react with the tandem-repeat region, their epitopes appear to be conformational dependent and not definable by a short peptide. Aberrant glycoforms of MUC16 may constitute promising targets for diagnostic and immunotherapeutic intervention, and it is important to develop well-defined immunogens for induction of potent MUC16 immunity. Here, we developed a MUC16 vaccine based on a 1.7TR (264 aa) expressed in Escherichia coli and in vitro enzymatically glycosylated to generate the aberrant cancer-associated glycoform Tn. This vaccine elicited a potent serum IgG response in mice and we identified two major immunodominant linear peptide epitopes within the tandem repeat. We developed one monoclonal antibody, 5E11, reactive with a minimum epitope with the sequence FNTTER. This sequence contains potential N- and O-glycosylation sites and, interestingly, glycosylation blocked binding of 5E11. In immunochemistry of ovarian benign and cancer lesions, 5E11 showed similar reactivity as traditional MUC16 antibodies, suggesting that the epitope is not efficiently glycosylated. The study provides a vaccine design and immunodominant MUC16 TR epitopes.
    Glycobiology 07/2015; 25(11). DOI:10.1093/glycob/cwv056 · 3.15 Impact Factor
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    • "The altered glycosylation observed in cancer cells leads to the expression of modified tumorassociated glycans (TAG) such as Thomsen-Friedenreich antigen (Galí µí»½1-3GalNAcí µí»¼/í µí»½-O-Ser/Thr; TF, CD176) that may be autoimmunogenic and may be recognized by autoantibodies [1] [2] [3] [4] [5] [6]. TAG are considered as promising targets for cancer immunotherapy [6] [7] [8]. The TF glycotope overexpression observed in the majority of adenocarcinomas and the reduced level of anti-TF antibodies are associated with more aggressive tumors and the induction of invasion, cancer surveillance mechanisms, and patients survival rate [3, 7, 9– 13]. "
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    ABSTRACT: Aim: To study whether alterations in the sialylation of antibodies (Ab) specific to the Thomsen-Friedenreich (TF) glycotope have a diagnostic and prognostic potential in gastric cancer. Methods: Serum samples were taken from patients with gastric carcinoma (n = 142) and controls (n = 61). The level of TF-specific antibodies and their sialylation was detected using ELISA with synthetic TF-polyacrylamide conjugate as antigen and sialic acid-specific Sambucus nigra agglutinin (SNA). Results: The level of TF-specific IgM was significantly decreased in cancer compared with controls (P ≤ 0.001). Cancer patients showed a higher level of SNA binding to anti-TF IgM and IgA (P ≤ 0.001) irrespective of disease stage, tumor morphology, and gender. Changes in the SNA/Ab index demonstrated moderate sensitivity (66-71%) and specificity (60-73%) for stomach cancer. The best diagnostic accuracy (100%) was achieved in 29% patients with high SNA binding and low anti-TF IgM level. This subset of patients demonstrated the poorest survival. Conclusion: Our findings are the first evidence that the increased sialylation of TF-specific Abs combined with a low level of anti-TF IgM is strongly linked to gastric cancer and patients survival, which can be used as a novel biomarker for cancer detection and prognosis.
    BioMed Research International 09/2014; 2014:830847. DOI:10.1155/2014/830847 · 2.71 Impact Factor
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    • "Serum tumor-associated antigens (TAAs) have been extensively studied for early cancer detection because of the simplicity and reliability of the tests used for their determination, such as western blot and enzyme-linked immunosorbent assay (ELISA). Unfortunately, they are transiently secreted and rapidly eliminated from blood circulation [6, 7] and usually reach a detectable concentration only in advanced stage of the disease [8]. "
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    ABSTRACT: Purpose: Circulating autoantibodies have been extensively investigated as possible markers for early diagnosis of cancer. The present study was carried out to investigate whether anti-LGALS3BP IgG autoantibodies could be classified as a biomarker for malignant tumors. Methods: An in-house developed enzyme-linked immunosorbent assay was used to detect autoantibodies to LGALS3BP in sera from 71 patients with various types of cancers and 54 healthy subjects matched by age and gender. Results: Patients with cancer have significant higher circulating levels of anti-LGALS3BP antibodies as compared to control subjects (P < 0.001). The test has a sensitivity of 33% and a specificity of 98%. Conclusions: Anti-LGALS3BP IgG autoantibodies are a promising biomarker for malignant tumors and could play a role in the development of a multimarker assay for the early detection of cancer.
    Disease markers 11/2013; 35(6):747-752. DOI:10.1155/2013/214595 · 1.56 Impact Factor
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