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Updated: Apr 22, 2026
Isolation of Proximal Fluids to Investigate the Tumor Microenvironment of Pancreatic Adenocarcinoma
Published on: November 5, 2020
ABO blood group IgM isoagglutinins interact with tumor-associated O-glycan structures in pancreatic cancer
Bianca T Hofmann1, Anne Stehr2, Thorsten Dohrmann1
1Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Purpose:
The ABO gene locus is associated with the risk of developing pancreatic ductal adenocarcinoma (PDAC) resulting in an increased incidence in individuals with non-O blood groups. Up to 90% of PDAC specimens display alterations in mucin type O-GalNAc glycosylation. Because aberrant O-GalNAc glycans (Tn and T antigen) are structurally related to blood group A and B glycans, we investigated the role of IgM isoagglutinins in PDAC.
Experimental Design:
Binding studies of IgM isoagglutinins toward blood group A, B, Tn antigen, and T antigen glycoconjugates from patients with PDAC and healthy individuals were conducted. Isoagglutinin titers and total IgM were compared between patients with PDAC and control group. An anti-A antibody was used for immunoprecipitation of aberrant O-glycosylated tumor proteins and subsequent mass spectromic analysis.
Results:
We found that IgM isoagglutinins bind blood group antigens, Tn and T glycoconjugates as well as tumor-derived glycoproteins. Blood group A isoagglutinins exhibited a strong binding toward blood group B antigen and T antigen, whereas blood group B showed binding to blood group A antigen and Tn antigen. Furthermore, we confirmed a decreased frequency in individuals with blood group O and observed a significant decrease of IgM isoagglutinin titers in PDAC sera compared with control sera, whereas total IgM levels were unaltered. We identified new PDAC-derived O-GalNAc glycoproteins by mass spectrometry using a blood group A-specific antibody.
Conclusion:
Our data elucidated a novel interaction of blood group IgM isoagglutinins and PDAC O-GalNAc glycoproteins that may contribute to the pathogenesis and progression of pancreatic cancer.
