title: Affinity peptide developed by phage display selection for targeting gastric cancer.
abstract: OBJECTIVE
  To develop an affinity peptide that binds to gastric cancer used for the detection of early gastric cancer.
  
  
  METHODS
  A peptide screen was performed by biopanning the PhD-12 phage display library, clearing non-specific binders against tumor-adjacent normal appearing gastric mucosa and obtaining selective binding against freshly harvested gastric cancer tissues. Tumor-targeted binding of selected peptides was confirmed by bound phage counts, enzyme-linked immunosorbent assay, competitive inhibition, fluorescence microscopy and semi-quantitative analysis on immunohistochemistry using different types of cancer tissues.
  
  
  RESULTS
  Approximately 92.8% of the non-specific phage clones were subtracted from the original phage library after two rounds of biopanning against normal- appearing gastric mucosa. After the third round of positive screening, the peptide sequence AADNAKTKSFPV (AAD) appeared in 25% (12/48) of the analyzed phages. For the control peptide, these values were 6.8 ± 2.3, 5.1 ± 1.7, 3.5 ± 2.1, 4.6 ± 1.9 and 1.1 ± 0.5, respectively. The values for AAD peptide were statistically significant (P < 0.01) for gastric cancer as compared with other histological classifications and control peptide.
  
  
  CONCLUSIONS
  A novel peptide is discovered to have a specific binding activity to gastric cancer, and can be used to distinguish neoplastic from normal gastric mucosa, demonstrating the potential for early cancer detection on endoscopy.
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Medical School, Xian Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Sui
authors.forename: Arun
authors.initials: A
authors.lastname: Budha
authors.forename: Jian-Bao
authors.initials: JB
authors.lastname: Zheng
authors.forename: Xue-Jun
authors.initials: XJ
authors.lastname: Sun
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Hou
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Wang
authors.forename: Shao-Ying
authors.initials: SY
authors.lastname: Lu
mesh_terms: D001667:Binding, Competitive; D001706:Biopsy; D045744:Cell Line, Tumor; D055088:Early Detection of Cancer; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D019151:Peptide Library; D010455:Peptides / Q000032:analysis*; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000175:diagnosis*
chemical_list: D019151:Peptide Library; D010455:Peptides