title: Claudin-1 correlates with poor prognosis in lung adenocarcinoma.
abstract: BACKGROUND
  This study was conducted to investigate the clinical significance of claudin-1 (CLDN1) expression in patients with lung adenocarcinoma.
  
  
  METHODS
  We examined CLDN1 protein expression by immunohistochemistry in a tissue microarray from 258 patients with lung adenocarcinoma. We investigated messenger ribonucleic acid (mRNA) expression in H358 (formerly bronchioloalveolar carcinoma) and lung adenocarcinoma cell lines (A549) by real-time reverse transcriptase-polymerase chain reaction.
  
  
  RESULTS
  Multivariate analysis showed that prognostic factors for lung adenocarcinoma were histologic type, CLDN1, T stage and N stage. Patients with positive CLDN1 expression had a poorer prognosis than patients with negative CLDN1 expression. CLDN1 expression was correlated with Ras and epidermal growth factor receptor (EGFR) expression. Patients with positive expressions of both CLDN1 and Ras/EGFR had a poorer prognosis than patients with CLDN1 (+) Ras/EGFR(-) or CLDN1 (-) Ras/EGFR(+) and patients with negative expressions of both CLDN1 and Ras/EGFR. CLDN1 mRNA expression was lower in the H358 compared with the lung adenocarcinoma cell line (A549).
  
  
  CONCLUSIONS
  The combination of CLDN1 and Ras/EGFR is a valuable independent prognostic predictor for lung adenocarcinoma.
authors.affiliation: Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin Medical University, Tianjin, China.
authors.forename: Bing-Sheng
authors.initials: BS
authors.lastname: Sun
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Dalian Medical University, Dalian, China.
authors.forename: Yi-Qun
authors.initials: YQ
authors.lastname: Yao
authors.affiliation: Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin Medical University, Tianjin, China.
authors.forename: Bao-Xiang
authors.initials: BX
authors.lastname: Pei
authors.affiliation: Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin Medical University, Tianjin, China.
authors.forename: Zhen-Fa
authors.initials: ZF
authors.lastname: Zhang
authors.affiliation: Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin Medical University, Tianjin, China.
authors.forename: Chang-Li
authors.initials: CL
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D045744:Cell Line, Tumor; D062445:Claudin-1 / Q000235:genetics* / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D009367:Neoplasm Staging; D011379:Prognosis; D046888:Tissue Array Analysis / Q000379:methods*; D015854:Up-Regulation; D018631:ras Proteins / Q000235:genetics
chemical_list: C568108:CLDN1 protein, human; D062445:Claudin-1; C512478:EGFR protein, human; D066246:ErbB Receptors; D018631:ras Proteins
keywords: 
  CLDN1
  ; 
  EGFR
  ; Ras; lung adenocarcinoma