The high affinity selectin glycan ligand C2-O-sLex and mRNA transcripts of the core 2 beta-1,6-N-acetylglucosaminyltransferase (C2GnT1) gene are highly expressed in human colorectal adenocarcinomas

BMC Cancer. 2009 Mar 6;9:79. doi: 10.1186/1471-2407-9-79.

Abstract

Background: The metastasis of cancer cells and leukocyte extravasation into inflamed tissues share common features. Specialized carbohydrates modified with sialyl Lewis x (sLex) antigens on leukocyte membranes are ligands for selectin adhesion molecules on activated vascular endothelial cells at inflammatory sites. The activity of the enzyme core 2 beta1,6 N-acetylglucosaminyltransferase (C2GnT1) in leukocytes greatly increases their ability to bind to endothelial selectins. C2GnT1 is essential for the synthesis of core 2-branched O-linked carbohydrates terminated with sLex (C2-O-sLex). Our goal was to determine the expression profiles of C2-O-sLex in the malignant progression and metastasis of colorectal adenocarcinomas. The well characterized CHO-131 monoclonal antibody (mAb) specifically recognizes C2-O-sLex present in human leukocytes and carcinoma cells. Using CHO-131 mAb, we investigated whether C2-O-sLex was present in 113 human primary colorectal adenocarcinomas, 10 colorectal adenomas, 46 metastatic liver tumors, 28 normal colorectal tissues, and 5 normal liver tissues by immunohistochemistry. We also examined mRNA levels of the enzyme core 2 beta1,6-N-acetylglucosaminyltransferase (C2GnT1) in 20 well, 15 moderately, and 2 poorly differentiated colorectal adenocarcinomas, and in 5 normal colorectal tissues by using quantitative real-time polymerase chain reactions (RT-PCR).

Results: We observed high reactivity with CHO-131 mAb in approximately 70% of colorectal carcinomas and 87% of metastatic liver tumors but a lack of reactivity in colorectal adenomas and normal colonic and liver tissues. Positive reactivity with CHO-131 mAb was very prominent in neoplastic colorectal glands of well to moderately differentiated adenocarcinomas. The most intense staining with CHO-131 mAb was observed at the advancing edge of tumors with the deepest invasive components.Finally, we analyzed C2GnT1 mRNA levels in 37 colorectal adenocarcinomas and 5 normal colorectal tissues by RT-PCR. Significantly, we observed a greater than 15-fold increase in C2GnT1 mRNA levels in colorectal adenocarcinomas compared to normal colorectal tissues.

Conclusion: C2-O-sLex, detected by the CHO-131 mAb, is a tumor associated antigen whose expression is highly upregulated in colorectal adenocarcinomas and metastatic liver tumors compared to normal tissues. C2-O-sLex is a potentially useful early predictor of metastasis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenocarcinoma / diagnosis
  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / pathology
  • Antigens, Neoplasm / genetics
  • Antigens, Neoplasm / metabolism*
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Carbohydrate Metabolism
  • Colon / cytology
  • Colon / metabolism
  • Colorectal Neoplasms / diagnosis
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / pathology
  • E-Selectin / metabolism
  • Humans
  • Immunohistochemistry
  • Liver / cytology
  • Liver / metabolism
  • Liver Neoplasms / diagnosis
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / pathology
  • N-Acetylglucosaminyltransferases / genetics
  • N-Acetylglucosaminyltransferases / metabolism*
  • Neoplasm Metastasis
  • Neoplasm Staging
  • Polysaccharides / metabolism
  • Prognosis
  • Protein Binding
  • RNA, Messenger / analysis
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • E-Selectin
  • Polysaccharides
  • RNA, Messenger
  • N-Acetylglucosaminyltransferases
  • beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-acetylglucosaminyl transferase