Recently, phage display has become widely used for many applications, including ligand generation for targeted imaging, drug delivery and therapy. In this work, we developed a panning procedure using a phage display peptide library to select a peptide that specifically binds to the VPAC1 receptor to develop a novel targeted probe for molecular imaging and therapy. Methods: CHO-K1 cells stably expressing VPAC1 receptors (CHO-K1/VPAC1 cells) were used to select a VPAC1-binding Ivacaftor in vivo peptide
from a 12-mer phage peptide library. DNA sequencing and homologous analysis of the randomly selected phage clones were performed. A cellular ELISA was used to determine the most selectively binding peptide for further investigation. Binding specificity to the VPAC1 receptor was analyzed by competitive inhibition ELISA and flow cytometry. Results: The binding ability of the selected peptide to CHO-K1/VPAC1 cells and colorectal cancer (CRC) cell lines was confirmed using fluorescence microscopy and flow cytometry. Results: A significant enrichment of phages that specifically bound to CHO-K1/VPAC1 cells was obtained after four rounds of panning.
Of the selected phage clones, 16 out of 60 shared the same peptide sequence, GFRFGALHEYNS, which we termed the VP2 peptide. VP2 and vasoactive intestinal peptide learn more (VIP) competitively bound to the VPAC1 receptor. selleck kinase inhibitor More importantly, we confirmed that VP2 specifically bound to CHO-K1/VPAC1 cells and several CRC cell lines. Conclusion: Our results demonstrate that the VP2 peptide could specifically bind to VPAC1 receptor and several CRC cell lines. And VP2 peptide may be a potential candidate to be developed as a useful diagnostic molecular imaging probe for early detection of CRC. Key Word(s): 1. VPAC1
receptor; 2. peptide; 3. targeted imaging; 4. tumor; Presenting Author: SEOK REYOL CHOI Additional Authors: JIN SEOK JANG Corresponding Author: SEOK REYOL CHOI Affiliations: DONG-A UNIVERSITY Objective: Apart from the diagnostic value of Positron Emission Tomography-Computed Tomography (PET-CT), the prognostic value of pretreatment PET-CT was not commonly evaluated in gastric cancer, so we investigated its preoperative prognostic value. Methods: Retrospectively we collected 107 cases of gastric cancer patients who had underwent surgical treatment after being observed FDG uptake by preoperative PET-CT at a Dong-A University Medical Center from April 2007 to December 2010.