title: Discovery and verification of gelsolin as a potential biomarker of colorectal adenocarcinoma in the Chinese population: Examining differential protein expression using an iTRAQ labelling-based proteomics approach.
abstract: OBJECTIVE
  To identify and validate potential biomarkers of colorectal adenocarcinoma using a proteomic approach.
  
  
  METHODS
  Multidimensional liquid chromatography⁄mass spectrometry was used to analyze biological samples labelled with isobaric mass tags for relative and absolute quantitation to identify differentially expressed proteins in human colorectal adenocarcinoma and paired normal mucosa for the discovery of cancerous biomarkers. Cancerous and noncancerous samples were compared using online and offline separation. Protein identification was performed using mass spectrometry. The downregulation of gelsolin protein in colorectal adenocarcinoma samples was confirmed by Western blot analysis and validated using immunohistochemistry.
  
  
  RESULTS
  A total of 802 nonredundant proteins were identified in colorectal adenocarcinoma samples, 82 of which fell outside the expression range of 0.8 to 1.2, and were considered to be potential cancer-specific proteins. Immunohistochemistry revealed a complete absence of gelsolin expression in 86.89% of samples and a reduction of expression in 13.11% of samples, yielding a sensitivity of 86.89% and a specificity of 100% for distinguishing colorectal adenocarcinoma from normal tissue.
  
  
  CONCLUSIONS
  These findings suggest that decreased expression of gelsolin is a potential biomarker of colorectal adenocarcinoma.
authors.affiliation: Anal-Colorectal Surgery Institute, LuoYang, China.
authors.forename: Nai-Jun
authors.initials: NJ
authors.lastname: Fan
authors.forename: Chun-Fang
authors.initials: CF
authors.lastname: Gao
authors.forename: Chang-Song
authors.initials: CS
authors.lastname: Wang
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Lv
authors.forename: Guang
authors.initials: G
authors.lastname: Zhao
authors.forename: Xin-Hua
authors.initials: XH
authors.lastname: Sheng
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Li
authors.forename: Qing-Yin
authors.initials: QY
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Yin
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D044466:Asian People / Q000235:genetics; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D015153:Blotting, Western; D002681:China; D002853:Chromatography, Liquid / Q000379:methods*; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D018260:Gelsolin / Q000096:biosynthesis*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007202:Indicators and Reagents; D008297:Male; D008875:Middle Aged; D040901:Proteomics / Q000379:methods; D012004:Rectal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor; D018260:Gelsolin; D007202:Indicators and Reagents