title: Upregulation of Mrps18a in breast cancer identified by selecting phage antibody libraries on breast tissue sections.
abstract: One of the hallmarks of cancer is an altered energy metabolism, and here, mitochondria play a central role. Previous studies have indicated that some mitochondrial ribosomal proteins change their expression patterns upon transformation.
  
  
  
  In this study, we have used the selection of recombinant antibody libraries displayed on the surface of filamentous bacteriophage as a proteomics discovery tool for the identification of breast cancer biomarkers. A small subpopulation of breast cells expressing both cytokeratin 19 and cytokeratin 14 was targeted using a novel selection procedure.
  
  
  
  We identified the mitochondrial ribosomal protein s18a (Mrps18a) as a protein which is upregulated in breast cancer. However, Mrps18a was not homogeneously upregulated in all cancer cells, suggesting the existence of sub-populations within the tumor. The upregulation was not confined to cytokeratin 19 and cytokeratin 14 double positive cells.
  
  
  
  This study illustrates how phage display can be applied towards the discovery of proteins which exhibit changes in their expression patterns. We identified the mitochondrial protein Mrps18a as being upregulated in human breast cancer cells compared to normal breast cells.
authors.affiliation: Department of Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Aarhus, Denmark.
authors.forename: Karen Marie Juul
authors.initials: KM
authors.lastname: Sørensen
authors.affiliation: Department of Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Aarhus, Denmark.
authors.forename: Theresa
authors.initials: T
authors.lastname: Meldgaard
authors.affiliation: Department of Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Aarhus, Denmark.
authors.forename: Connie Jenning
authors.initials: CJ
authors.lastname: Melchjorsen
authors.affiliation: Department of Cellular and Molecular Medicine, Centre for Biological Disease Analysis and Danish Stem Cell Centre, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Agla J
authors.initials: AJ
authors.lastname: Fridriksdottir
authors.affiliation: Department of Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Aarhus, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Pedersen
authors.affiliation: Department of Cellular and Molecular Medicine, Centre for Biological Disease Analysis and Danish Stem Cell Centre, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Ole William
authors.initials: OW
authors.lastname: Petersen
authors.affiliation: Department of Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Aarhus, Denmark. pk@eng.au.dk.
authors.forename: Peter
authors.identifier: 0000-0001-7205-6853
authors.initials: P
authors.lastname: Kristensen
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D061505:Cell Surface Display Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D024101:Mitochondrial Proteins / Q000032:analysis / Q000096:biosynthesis*; D000069396:Mitochondrial Ribosomes / Q000378:metabolism; D040901:Proteomics; D012269:Ribosomal Proteins / Q000032:analysis / Q000096:biosynthesis*; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; D024101:Mitochondrial Proteins; D012269:Ribosomal Proteins
keywords: Breast cancer; Domain antibodies; Mitochondrial ribosomal protein s18a; Phage display; Shadow stick selection