title: Mucin 16 is a functional selectin ligand on pancreatic cancer cells.
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.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA.
authors.forename: Shih-Hsun
authors.initials: SH
authors.lastname: Chen
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Dallas
authors.forename: Eric M
authors.initials: EM
authors.lastname: Balzer
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Konstantopoulos
mesh_terms: D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D018394:CA-125 Antigen / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016466:CHO Cells; D002460:Cell Line; D045744:Cell Line, Tumor; D002846:Chromatography, Affinity; D006224:Cricetinae; D003412:Cricetulus; D019040:E-Selectin / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D005643:Fucose / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D019041:L-Selectin / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009362:Neoplasm Metastasis; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011134:Polysaccharides / Q000378:metabolism; D011485:Protein Binding; D034622:RNA Interference; D053719:Tandem Mass Spectrometry
chemical_list: D018394:CA-125 Antigen; D019040:E-Selectin; D008024:Ligands; C451759:MUC16 protein, human; D008565:Membrane Proteins; D019007:P-Selectin; D011134:Polysaccharides; D019041:L-Selectin; D005643:Fucose; D019158:N-Acetylneuraminic Acid