title: Expression of the Novel Costimulatory Molecule B7-H5 in Pancreatic Cancer.
abstract: BACKGROUND
  This study investigated how the B7-H5 protein, a new member of the B7 family, is expressed in normal human pancreas tissues and examined its expression changes in pancreatic cancer.
  
  
  METHODS
  In this analysis, B7-H5 expression was examined by immunohistochemical staining of frozen specimens from patients undergoing pancreatic resection.
  
  
  RESULTS
  Membranous B7-H5 protein was expressed on normal ductal epithelium within the pancreas. Other cell types from the normal pancreas, such as acinar cells and islet cells, did not express B7-H5. In adenocarcinoma, B7-H5 staining was decreased or absent. Interestingly, B7-H5 expression in intraductal papillary mucinous neoplasms varied with grade. No B7-H5 expression was found with other cancer types such as neuroendocrine tumors, but normal ducts adjacent to tumors were highly positive.
  
  
  CONCLUSIONS
  The findings showed that B7-H5 expression was restricted to ductal cells in the normal pancreas and the expression was downregulated in pancreatic adenocarcinomas. In addition, the findings showed that B7-H5 expression changes within different stages of dysplasia. The study suggests that loss of the B7-H5 signal may contribute to immune evasion of pancreatic adenocarcinoma. However future studies are needed.
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Byers
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Paniccia
authors.affiliation: Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Kaplan
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Koenig
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Nate
authors.initials: N
authors.lastname: Kahn
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Lora
authors.initials: L
authors.lastname: Wilson
authors.affiliation: Department of Immunobiology, Yale University, New Haven, CT, USA.
authors.forename: Lieping
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Schulick
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Barish H
authors.initials: BH
authors.lastname: Edil
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO, USA. yuwen.zhu@ucdenver.edu.
authors.forename: Yuwen
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D007136:Immunoglobulins / Q000378:metabolism*; D009367:Neoplasm Staging; D010179:Pancreas / Q000378:metabolism* / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; C400341:HHLA2 protein, human; D007136:Immunoglobulins