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AIM: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.Tumortargeted 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 signif icant(P < 0.01) for gastric cancer as compared with other histological classif ications and control peptide.CONCLUSION: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.
AIM: 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. Tumortargeted 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) 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. These values for AAD peptide were statistically significant (P <0.01) for gastric cancer as compared with other histological classifications and control peptides. CONCLUSION: 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.