Atomic force microscopy study of the effect of HER 2 antibody on EGF mediated ErbB ligand–receptor interaction

• Published in: Nanomedicine 2013-07, Vol.9 (5), p.627-635
• Main Authors: Zhang, Xuejie, BS, Shi, Xiaoli, PhD, Xu, Li, PhD, Yuan, Jinghe, PhD, Fang, Xiaohong, PhD
• Format: Article
• Language: English
• Subjects: Antibodies, Monoclonal, Humanized - pharmacology; Atomic force microscopy (AFM); EGFR/HER2 heterodimerization; Epidermal Growth Factor - metabolism; ErbB Receptors - metabolism; Gene Expression Regulation, Neoplastic - drug effects; HEK293 Cells; Humans; Internal Medicine; Ligands; Microscopy, Atomic Force; Neoplasms - metabolism; Neoplasms - pathology; Pertuzumab; Protein Binding; Receptor, ErbB-2 - metabolism; Single-molecule force spectroscopy (SMFS); Trastuzumab
• ISSN: 1549-9634; 1549-9642
• DOI: 10.1016/j.nano.2012.11.005

Abstract HER2, a member of the epidermal growth factor receptor (ErbB) family, is over-expressed in many cancers. Trastuzumab and Pertuzumab are two monoclonal antibodies targeting different extracellular domains of HER2 for cancer therapy. As Pertuzumab binds to the dimerization arm of HER2, it can block HER2 heterodimerization and in turn ErbB signaling. Whether Trastuzumab has the same function is unclear. In this work, we have applied living-cell single-molecule force spectroscopy (SMFS) by Atomic Force Microscopy (AFM) to investigate the effect of Trastuzumab, as well as Pertuzumab, on HER2-modulated EGF–EGFR interaction. The results demonstrated that EGF bound to EGFR more stably in the cells co-expressing EGFR and HER2, and the binding enhancement in the presence of HER2 was inhibited by either Trastuzumab or Pertuzumab. Trastuzumab is expected to exert a similar inhibition effect on HER2/EGFR dimerization as Pertuzumab, although it does not bind directly to the dimerization arm of HER2. From the Clinical Editor Living-cell single-molecule force spectroscopy (SMFS) combined by Atomic Force Microscopy (AFM) was used by this team of scientists to investigate the effect of two monoclonal antibodies used in cancer therapy, Trastuzumab and Pertuzumab, on HER2-modulated EGF–EGFR interaction, demonstrating the utility of this technique in characterizing the effects of protein-based therapeutics on membrane receptors.