Development and Characterization of Monoclonal Antibody Specific to Oncogenic Variant AIMP2-DX2

Abstract

AIMP2-DX2 is known as an exon2-deleted splicing variant of AIMP2 (amonoacyl-tRNA synthetase-interacting multifunctional protein 2) showing high expression in lung cancer cells and patients tissues. AIMP2-DX2 inhibits a pro-apoptotic role of AIMP2, which is known as an tumor suppressor, through competing for the association with common binding partners such as p53, FBP (fuse-binding protein) and TRAF2 (TNF receptor-associated factor 2) under various stimuli and stresses. According to previous studies, the cells with higher level of AIMP2-DX2 tend to show increased resistance to cell death. Also, suppression of AIMP2-DX2 in xenograft mouse model significantly retarded tumor growth. Due to lack of monoclonal antibody specific to AIMP2-DX2, there has been a difficulty in developing diagnostic tools to classify patients with relatively higher level of AIMP2-DX2 for targeted cancer therapy. In this study, phage display technique was used to create monoclonal antibody that specifically binds to AIMP2-DX2. The newly generated monoclonal antibody was also validated and characterized by immunoblot, enzyme-linked immunosorbent assay, immunoprecipitation, surface plasmon resonance assay and immunofluorescence microscopy. The results showed that the selected monoclonal antibody clone, H5, could specifically recognize AIMP2-DX2 but not AIMP2 and it showed a prominent binding interaction with the epitope peptide as well as purified AIMP2-DX2 protein. Based on these evidences, I concluded that the newly generated monoclonal antibody hold a great potential in both research and clinical fields and it could be employed in cancer diagnosis at in various ways.