Abstract

EVALUATION OF THE BINDING AND ANTI-ANGIOGENIC CAPACITY OF ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR 2 NANOBODY (ANTI-VEGFR2 NANOBODY)

Desmond Omane Acheampong, Youfu Wang, Mingying Tang, Fang Liu, Juan Zhang* and Min Wang*

Abstract

The use of antibody in targeted therapy has become the credible option in the treatment of cancers due to its specificity and the fact that it is associated with relatively lower toxicity compared to the other treatment options like chemotherapy and radiotherapy. However, antibody targeting could be associated with certain functional limitations due to their large molecular sizes (150KD) and the presence of the Fc fragment. Generating antibody fragments of smaller molecular sizes devoid of Fc fragment may be the way forward in curbing these functional limitations. In this study, five nanobodies 4N, 5N, 32N, 71N and 91N targeting vascular endothelial growth factor receptor 2 (VEGFR2) were generated from camel. The nanobodies were then screened by ELISA, immunoblotting and surface plasmon resonance (SPR) to select the nanobodies with high binding affinities. The nanobodies 5N and 32N demonstrated the highest binding affinities and therefore were selected for further studies. This was further confirmed by flow cytometry assay. Additionally, the selected nanobodies 5N and 32N demonstrated significant anti-angiogenic and anti-neoplastic abilities by restraining the proliferation of VEGFR2 expressing human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. These nanobodies are therefore potential anti-angiogenic agents which could possibly be used in cancer therapy

Keywords: Nanobody, vascular endothial growth factor receptor 2, targeted therapy, antibody.