title: A nanobody directed to a functional epitope on VEGF, as a novel strategy for cancer treatment.
abstract: Compelling evidence suggests that vascular endothelial growth factor (VEGF), due to its essential role in angiogenesis, is a critical target for cancer treatment. Neutralizing monoclonal antibodies against VEGF are important class of drugs used in cancer therapy. However, the cost of production, large size, and immunogenicity are main drawbacks of conventional monoclonal therapy. Nanobodies are the smallest antigen-binding antibody fragments, which occur naturally in camelidae. Because of their remarkable features, we decided to use an immune library of nanobody to direct phage display to recognition of novel functional epitopes on VEGF. Four rounds of selection were performed and six phage-displayed nanobodies were obtained from an immune phage library. The most reactive clone in whole-cell ELISA experiments, was purified and assessed in proliferation inhibition assay. Purified ZFR-5 not only blocked interaction of VEGF with its receptor in cell ELISA experiments, but also was able to significantly inhibit proliferation response of human umbilical vein endothelial cells to VEGF in a dose-dependent manner. Taken together, our study demonstrates that by using whole-cell ELISA experiments, nanobodies against antigenic regions included in interaction of VEGF with its receptors can be directed. Because of unique and intrinsic properties of a nanobody and the ability of selected nanobody for blocking the epitope that is important for biological function of VEGF, it represents novel potential drug candidate.
authors.affiliation: Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Farajpour
authors.affiliation: Department of Medical Biotechnology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. Electronic address: rahbarif@modares.ac.ir.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rahbarizadeh
authors.affiliation: Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Bahram
authors.initials: B
authors.lastname: Kazemi
authors.affiliation: School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Davoud
authors.initials: D
authors.lastname: Ahmadvand
mesh_terms: D019138:Antibodies, Blocking / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use; D049109:Cell Proliferation; D061505:Cell Surface Display Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D009369:Neoplasms / Q000098:blood supply / Q000276:immunology / Q000628:therapy*; D009389:Neovascularization, Pathologic / Q000276:immunology; D019151:Peptide Library; D061905:Single-Domain Antibodies / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000276:immunology*
chemical_list: D019138:Antibodies, Blocking; D000939:Epitopes; D019151:Peptide Library; D061905:Single-Domain Antibodies; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A
keywords: Epitope; HUVEC; Nanobody; Phage display; VEGF