title: ALCAM is a Novel Cytoplasmic Membrane Protein in TNF-α Stimulated Invasive Cholangiocarcinoma Cells.
abstract: BACKGROUND
  Cholangiocarcinoma (CCA), or bile duct cancer, is incurable with a high mortality rate due to a lack of effective early diagnosis and treatment. Identifying cytoplasmic membrane proteins of invasive CCA that facilitate cancer progression would contribute toward the development of novel tumor markers and effective chemotherapy.
  
  
  METHODS
  An invasive CCA cell line (KKU-100) was stimulated using TNF-α and then biotinylated and purified for mass spectrometry analysis. Novel proteins expressed were selected and their mRNAs expression levels were determined by real-time RT-PCR. In addition, the expression of ALCAM was selected for further observation by Western blot analysis, immunofluorescent imaging, and antibody neutralization assay.
  
  
  RESULTS
  After comparing the proteomics profile of TNF-α induced invasive with non-treated control cells, over-expression of seven novel proteins was observed in the cytoplasmic membrane of TNF-α stimulated CCA cells. Among these, ALCAM is a novel candidate which showed significant higher mRNA- and protein levels. Immunofluorescent assay also supported that ALCAM was expressed on the cell membrane of the cancer, with increasing intensity associated with TNF-α.
  
  
  CONCLUSIONS
  This study indicated that ALCAM may be a novel protein candidate expressed on cytoplasmic membranes of invasive CCA cells that could be used as a biomarker for development of diagnosis, prognosis, and drug or antibody-based targeted therapies in the future.
authors.affiliation: Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand E-mail : onrapak.rea@mahidol.ac.th.
authors.forename: Poom
authors.initials: P
authors.lastname: Adisakwattana
authors.forename: Nantana
authors.initials: N
authors.lastname: Suwandittakul
authors.forename: Songsak
authors.initials: S
authors.lastname: Petmitr
authors.forename: Sopit
authors.initials: S
authors.lastname: Wongkham
authors.forename: Polkit
authors.initials: P
authors.lastname: Sangvanich
authors.forename: Onrapak
authors.initials: O
authors.lastname: Reamtong
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D017209:Apoptosis; D001650:Bile Duct Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D015153:Blotting, Western; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D002465:Cell Movement; D049109:Cell Proliferation; D018281:Cholangiocarcinoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism*; D005326:Fetal Proteins / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D009361:Neoplasm Invasiveness; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D020410:Activated-Leukocyte Cell Adhesion Molecule
chemical_list: D015703:Antigens, CD; D015816:Cell Adhesion Molecules, Neuronal; D005326:Fetal Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C105613:ALCAM protein, human; D020410:Activated-Leukocyte Cell Adhesion Molecule; C439524:TNF protein, human