title: Identification and in vitro characterization of phage-displayed VHHs targeting VEGF.
abstract: Vascular endothelial growth factor (VEGF) is a potential target for cancer treatment because of its role in angiogenesis and its overexpression in most human cancers. Currently, anti-VEGF antibodies have been shown to be promising tools for therapeutic applications. However, large size, poor tumor penetration, immunogenicity, and production in cost- and labor-intensive conditions are major drawbacks of such agents. The antigen-binding regions of camelid single-chain antibodies (VHHs), due to their unique biophysical characteristics, offer an alternative to conventional antibodies for tumor-targeting purposes. The present study was undertaken to generate and characterize anti-VEGF VHHs from an immune VHH library using phage display. Four rounds of panning were performed, and selected VHHs were characterized using various immunological techniques. Assessment of the antigenic profile of VHHs was done using competition enzyme-linked immunosorbent assay (ELISA). Selected VHHs reacted strongly to VEGF in indirect ELISA and cross-reactivity ELISA tests. The binding affinity of three VHHs, ZFR-1, ZFR-2, and ZFR-5, ranged from 2.5 to 80 nM, and among them, ZFR-5, which was selected for proliferation assay, significantly inhibited the endothelial cell growth in a dose-dependent manner. Taken together, our results indicate that ZFR-5 and other VHHs may be promising tools in cancer research and treatment.
authors.affiliation: 1Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Farajpour
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rahbarizadeh
authors.forename: Bahram
authors.initials: B
authors.lastname: Kazemi
authors.forename: Davoud
authors.initials: D
authors.lastname: Ahmadvand
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mohaghegh
mesh_terms: D000918:Antibody Specificity / Q000276:immunology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D061505:Cell Surface Display Techniques; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D004354:Drug Screening Assays, Antitumor; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology; D006801:Humans; D019151:Peptide Library; D011485:Protein Binding / Q000276:immunology; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*
chemical_list: D000939:Epitopes; D019151:Peptide Library; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; D042461:Vascular Endothelial Growth Factor A
keywords: VEGF; VHH; cancer; phage display