title: Clinical and experimental studies regarding the expression and diagnostic value of carcinoembryonic antigen-related cell adhesion molecule 1 in non-small-cell lung cancer.
abstract: BACKGROUND
  Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a multifunctional Ig-like cell adhesion molecule that has a wide range of biological functions. According to previous reports, serum CEACAM1 is dysregulated in different malignant tumours and associated with tumour progression. However, the serum CEACAM1 expression in non-small-cell lung carcinomas (NSCLC) is unclear. The different expression ratio of CEACAM1-S and CEACAM1-L isoform has seldom been investigated in NSCLC. This research is intended to study the serum CEACAM1 and the ratio of CEACAM1-S/L isoforms in NSCLC.
  
  
  METHODS
  The expression of the serum CEACAM1 was determined by enzyme-linked immunosorbent assay. The protein expression and the location of CEACAM1 in tumours were observed by immunohistochemical staining. The CEACAM1 mRNA levels in tumour and normal adjacent tissues were measured using quantitative real-time PCR, and the expression patterns and the rate of CEACAM1-S and CEACAM1-L were analysed by reverse transcription-PCR.
  
  
  RESULTS
  Serum CEACAM1 levels were significantly higher in NSCLC patients compared with that from normal healthy controls (P <0.0001). 17 patients (81%) among 21 showed high expression of CEACAM1 by immunohistochemical staining. Although no significant differences were found between tumour and normal tissues on mRNA expression levels of CEACAM1 (P >0.05), the CEACAM1-S and the CEACAM1-S/L (S: L) ratios were significantly higher in tumour than normal tissues (P <0.05).
  
  
  CONCLUSIONS
  Our data indicated that the serum levels of CEACAM1 could discriminate lung cancer patients from health donors and that CEACAM1 might be a useful marker in early diagnosis of NSCLC. Moreover, our results showed that the expression patterns of CEACAM1 isoforms could be changed during oncogenesis, even when total CEACAM1 in tumour tissues did not show significant changes. Our study suggested that the expression ratios of CEACAM1-S/CEACAM1-L might be a better diagnostic indicator in NSCLC than the quantitative changes of CEACAM1.
authors.affiliation: Department of Clinical Laboratory, the Sixth People's Hospital, Shanghai Jiao-tong University School of Medicine, 600 Yi-shan Road, Shanghai 200233, People's Republic of China.
authors.forename: Mu-qing
authors.initials: MQ
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Du
authors.forename: Yi-wen
authors.initials: YW
authors.lastname: Liu
authors.forename: Ying-zhi
authors.initials: YZ
authors.lastname: Wang
authors.forename: Yi-qing
authors.initials: YQ
authors.lastname: He
authors.forename: Cui-xia
authors.initials: CX
authors.lastname: Yang
authors.forename: Wen-juan
authors.initials: WJ
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000096:biosynthesis* / Q000097:blood; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000032:analysis / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis* / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms / Q000096:biosynthesis / Q000097:blood; D012372:ROC Curve; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; C069847:CD66 antigens; D015815:Cell Adhesion Molecules; D020033:Protein Isoforms