Mucin 16 is a functional selectin ligand on pancreatic cancer cells

FASEB J. 2012 Mar;26(3):1349-59. doi: 10.1096/fj.11-195669. Epub 2011 Dec 9.

Abstract

Selectins promote metastasis by mediating specific interactions between selectin ligands on tumor cells and selectin-expressing host cells in the microvasculature. Using affinity chromatography in conjunction with tandem mass spectrometry and bioinformatics tools, we identified mucin 16 (MUC16) as a novel selectin ligand expressed by metastatic pancreatic cancer cells. While up-regulated in many pancreatic cancers, the biological function of sialofucosylated MUC16 has yet to be fully elucidated. To address this, we employed blot rolling and cell-free flow-based adhesion assays using MUC16 immunopurified from pancreatic cancer cells and found that it efficiently binds E- and L- but not P-selectin. The selectin-binding determinants are sialofucosylated structures displayed on O- and N-linked glycans. Silencing MUC16 expression by RNAi markedly reduces pancreatic cancer cell binding to E- and L-selectin under flow. These findings provide a novel integrated perspective on the enhanced metastatic potential associated with MUC16 overexpression and the role of selectins in metastasis.

Publication types

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

MeSH terms

  • Animals
  • Binding Sites
  • Blotting, Western
  • CA-125 Antigen / genetics
  • CA-125 Antigen / isolation & purification
  • CA-125 Antigen / metabolism*
  • CHO Cells
  • Cell Line
  • Cell Line, Tumor
  • Chromatography, Affinity
  • Cricetinae
  • Cricetulus
  • E-Selectin / genetics
  • E-Selectin / metabolism*
  • Flow Cytometry
  • Fucose / metabolism
  • Humans
  • Immunoprecipitation
  • L-Selectin / genetics
  • L-Selectin / metabolism*
  • Ligands
  • Membrane Proteins / genetics
  • Membrane Proteins / isolation & purification
  • Membrane Proteins / metabolism*
  • N-Acetylneuraminic Acid / metabolism
  • Neoplasm Metastasis
  • P-Selectin / genetics
  • P-Selectin / metabolism*
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Polysaccharides / metabolism
  • Protein Binding
  • RNA Interference
  • Tandem Mass Spectrometry

Substances

  • CA-125 Antigen
  • E-Selectin
  • Ligands
  • MUC16 protein, human
  • Membrane Proteins
  • P-Selectin
  • Polysaccharides
  • L-Selectin
  • Fucose
  • N-Acetylneuraminic Acid