title: RNA interference characterization of proteins discovered by proteomic analysis of pancreatic cancer reveals function in cell growth and survival.
abstract: OBJECTIVE
  There is a clear need for better therapeutics and diagnostics for pancreatic cancer. We aimed to discover plasma membrane-associated proteins overexpressed in pancreatic cancer using quantitative proteomics and apply RNA interference (RNAi) to uncover proteins associated with cancer cell survival.
  
  
  METHODS
  Cell surface glycoproteins from 5 pancreatic cancer cell lines were isolated, and differential analyses were performed using mass spectrometry and the "normoid" cell line Hs766T as the comparator. For validation, immunohistochemistry was performed on tissues from 10 independent patients and 2 normal donors. Correlation of protein and mRNA expression level was determined, and functional activity characterized using RNAi.
  
  
  RESULTS
  Integrin β6, CD46, tissue factor, and a novel protein, chromosome 14 open reading frame 1, were identified as overexpressed on pancreatic cancer cell lines. Immunohistochemistry demonstrated the 4 targets were overexpressed in 20% to 70% of primary pancreatic tumor specimens. Small interfering RNA knockdown resulted in a reduction of cellular proliferation by inhibiting DNA synthesis, blocking S-phase progression or induction of apoptosis.
  
  
  CONCLUSIONS
  By combining a mass spectrometry identification platform and an RNAi validation platform, we have identified a panel of cell surface glycoproteins that not only are overexpressed, but also play a functional role in pancreatic tumor cell survival.
authors.affiliation: Department of Protein Therapeutic, Celera, Rockville, MD 20850, USA. candynlee@gmail.com
authors.forename: Candy N
authors.initials: CN
authors.lastname: Lee
authors.forename: Jenny L
authors.initials: JL
authors.lastname: Heidbrink
authors.forename: Katherine
authors.initials: K
authors.lastname: McKinnon
authors.forename: Victoria
authors.initials: V
authors.lastname: Bushman
authors.forename: Henrik
authors.initials: H
authors.lastname: Olsen
authors.forename: William
authors.initials: W
authors.lastname: FitzHugh
authors.forename: Aiqun
authors.initials: A
authors.lastname: Li
authors.forename: Karen
authors.initials: K
authors.lastname: Van Orden
authors.forename: Tao
authors.initials: T
authors.lastname: He
authors.forename: Steven M
authors.initials: SM
authors.lastname: Ruben
authors.forename: Paul A
authors.initials: PA
authors.lastname: Moore
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D039641:Integrin beta Chains / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D051916:Membrane Cofactor Protein / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D040901:Proteomics / Q000379:methods*; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: C497857:CD46 protein, human; C121701:ERG28 protein, human; D039641:Integrin beta Chains; D051916:Membrane Cofactor Protein; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C072170:integrin beta6; D013925:Thromboplastin