title: Loss of N-acetylgalactosaminyltransferase 3 in poorly differentiated pancreatic cancer: augmented aggressiveness and aberrant ErbB family glycosylation.
abstract: Aberrant glycosylation of several proteins underlie pancreatic ductal adenocarcinoma (PDAC) progression and metastasis. O-glycosylation is initiated by a family of enzymes known as polypeptide N-acetylgalactosaminyl transferases (GalNAc-Ts/GALNTs). In this study, we investigated the role of the O-glycosyltransferase GALNT3 in PDAC.
  
  
  
  Immunohistochemistry staining of GALNT3 was performed on normal, inflammatory and neoplastic pancreatic tissues. Several in vitro functional assays such as proliferation, colony formation, migration and tumour-endothelium adhesion assay were conducted in GALNT3 knockdown PDAC cells to investigate its role in disease aggressiveness. Expression of signalling molecules involved in growth and motility was evaluated using western blotting. Effect of GALNT3 knockdown on glycosylation was examined by lectin pull-down assay.
  
  
  
  N-acetylgalactosaminyl transferase 3 expression is significantly decreased in poorly differentiated PDAC cells and tissues as compared with well/moderately differentiated PDAC. Further, knockdown of GALNT3 resulted in increased expression of poorly differentiated PDAC markers, augmented growth, motility and tumour-endothelium adhesion. Pull-down assay revealed that O-glycans (Tn and T) on EGFR and Her2 were altered in PDAC cells, which was accompanied by their increased phosphorylation.
  
  
  
  Our study indicates that loss of GALNT3 occurs in poorly differentiated PDAC, which is associated with the increased aggressiveness and altered glycosylation of ErbB family proteins.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA.
authors.forename: Seema
authors.initials: S
authors.lastname: Chugh
authors.affiliation: Department of Biostatistics, UNMC College of Public Health, UNMC, Omaha, NE 68198-4375, USA.
authors.forename: Jane
authors.initials: J
authors.lastname: Meza
authors.affiliation: Department of Pathology and Microbiology, UNMC, Omaha, NE 68198-5900, USA.
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Sheinin
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA.|Fred and Pamela Buffett Cancer Center, UNMC, Omaha, NE 68198, USA.|Eppley Institute for Research in Cancer and Allied Diseases, UNMC, Omaha, NE 68198-5950, USA.
authors.forename: Moorthy P
authors.initials: MP
authors.lastname: Ponnusamy
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA.|Fred and Pamela Buffett Cancer Center, UNMC, Omaha, NE 68198, USA.|Eppley Institute for Research in Cancer and Allied Diseases, UNMC, Omaha, NE 68198-5950, USA.
authors.forename: Surinder K
authors.initials: SK
authors.lastname: Batra
mesh_terms: D021441:Carcinoma, Pancreatic Ductal / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D042783:Endothelial Cells / Q000473:pathology; D066246:ErbB Receptors / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006031:Glycosylation; D006801:Humans; D007150:Immunohistochemistry; D017350:N-Acetylgalactosaminyltransferases / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D000097763:Polypeptide N-acetylgalactosaminyltransferase
chemical_list: D066246:ErbB Receptors; D017350:N-Acetylgalactosaminyltransferases; D000097763:Polypeptide N-acetylgalactosaminyltransferase