title: Serum levels of variants of transthyretin down-regulation in cholangiocarcinoma.
abstract: BACKGROUND
  Cholangiocarcinoma (CC) is devastating neoplasm and very few specific biomarkers could be used in clinical diagnosis. A study was taken to find novel serum biomarkers for CC.
  
  
  METHODS
  Surface enhanced laser desorption/ionization (SELDI) technology was used to analyze 427 serum samples including 56 CCs, 49 hepatobiliary diseases, 269 other cancer control, and 53 healthy individuals. The candidates were isolated and identified by SDS-PAGE, ESI/MS-MS, Western blot, and immunoprecipitation. Liver functions of CC patients were examined and enzyme-linked immunosorbent assay (ELISA) of transthyretin (TTR) and CA19-9 were further performed in some sets of serum samples.
  
  
  RESULTS
  13.76, 13.88, and 14.04 k m/z peaks in sera were significantly decreased in CC compared with the control groups (P < 0.001). Subsequently, these three peaks were identified as native TTR and its two variants. ELISA assay indicated that TTR levels were consistent with SELDI analysis in CC compared with healthy control and benign diseases of hepatobiliary (P < 0.001). Liver function test levels were obviously elevated for CC patients. TTR combining with CA19-9 to differentiate CC from benign hepatobiliary diseases showed sensitivity and specificity were 98.2% and 100%, respectively.
  
  
  CONCLUSIONS
  The levels of TTR were significantly down-regulated in sera of CC patients and may be complementary markers of CA19-9 in diagnosis for CC.
authors.affiliation: Key Laboratory for Cell Proliferation and Regulation Biology, Ministry of Education, Beijing Normal University, The People's Republic of China.
authors.forename: Liyun
authors.initials: L
authors.lastname: Liu
authors.forename: Jianing
authors.initials: J
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Songwei
authors.initials: S
authors.lastname: Dai
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Wang
authors.forename: Junzhou
authors.initials: J
authors.lastname: Chen
authors.forename: Lingyun
authors.initials: L
authors.lastname: Huang
authors.forename: Xueyuan
authors.initials: X
authors.lastname: Xiao
authors.forename: Dacheng
authors.initials: D
authors.lastname: He
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000097:blood* / Q000378:metabolism*; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism*; D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen / Q000096:biosynthesis; D016022:Case-Control Studies; D018281:Cholangiocarcinoma / Q000097:blood* / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D011228:Prealbumin / Q000096:biosynthesis*
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D011228:Prealbumin