MUC1/Y-Binding Peptides Generated by Biopanning a Phage Display Library

Objective: Using phage display randem peptide library to generate peptides as small molecular weight vec tors for tumor-targeting therapy. Methods: MUC1/Y extracellular domain was used as a target molecule to biopan Ph. D. 12 TM phage randem peptide library. Two protocols using affinity gel and cell culture plates respectively were carried out. Positive phage clones were identified by ELISA. ssDNA sequencing was done on 16 positive phage clones to get the amino acid sequences of MUC1/Y-binding peptides. Immunohistochemistry was done to show the capacity and specificity of positive phage clones to bind the tumor cell lines. Results: After 4 rounds biopanning, three MUC1/Y-binding peptides were generated including HHWHSRSQLSWF, HLKHUKNYLPPTP and GNWYRHPHYLQP. HXXHS may be the key motif for binding to MUCI/Y. The positive phage clones tested showed the ability to bind MCF, OVCA3 cell lines while no binding to normal peripheral blood lymphocytes( PBLs) was observed. Conclusion: The peptides generated by biopanning phage library showed some affinity and tumor-specificity and may be potential candidates as ligands for tumor-targeting therapy.