title: Identification of biomarkers to improve diagnostic sensitivity of sporadic colorectal cancer in patients with low preoperative serum carcinoembryonic antigen by clinical proteomic analysis.
abstract: BACKGROUND
  Colorectal cancer (CRC) is the third most common type of cancer worldwide. Carcinoembryonic antigen (CEA) assays usually give false negative results. To improve the diagnosis of primary sporadic CRC, there is an urgent need to identify new biomarkers.
  
  
  METHODS
  We used laser pressure catapulting and proteomics to analyze overexpressed cancer associated proteins from 48 sporadic CRC patients with low preoperative serum CEA (LPSC) (<5 ng/ml). Real-time Q-PCR was used to identify the target gene transcripts. Immunoblots were carried out to validate the biomarkers.
  
  
  RESULTS
  Alpha-enolase, HSP27 and macrophage migration inhibitory factor (MIF) were overexpressed in all tumor tissues from 48 LPSC CRC patients, as assessed by 2DE image analysis. The genes were also overexpressed at the transcript level in all tumor tissues from the same patients. In the immunoblot assay, only serum levels of Alpha-enolase and MIF were significantly overexpressed in the LPSC group compared to the mean levels in the control group. Combined with the determinations of preoperative CEA levels, screening for serum Alpha-enolase and MIF were shown to improve the diagnosis of primary CRC.
  
  
  CONCLUSIONS
  Serum Alpha-enolase and MIF may be potential biomarkers that can be used to improve clinical predication of primary CRC with LPSC.
authors.affiliation: Division of Colorectal Surgery, Department of Surgery, China Medical University Hospital, Taichung, Taiwan.
authors.forename: William Tzu-Liang
authors.initials: WT
authors.lastname: Chen
authors.forename: Sheng-Chi
authors.initials: SC
authors.lastname: Chang
authors.forename: Tao-Wei
authors.initials: TW
authors.lastname: Ke
authors.forename: Hua-Che
authors.initials: HC
authors.lastname: Chiang
authors.forename: Fuu-Jen
authors.initials: FJ
authors.lastname: Tsai
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Lo
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D015153:Blotting, Western; D002272:Carcinoembryonic Antigen / Q000097:blood*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D040901:Proteomics; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen