Bioactivity of Recombinant Humanized Monoclonal Antibody Against HER2 and Its Mechanism of Action on Ovarian Cancer
Abstract BACKGROUND: Human epidermal growth factor receptor 2 (HER2) protein is overexpressed on the surface of various epithelial ovarian cancer tissues, which mediates the proliferation, differentiation, metastasis and signal transduction of tumor cells and is a potential cancer therapeutic target.METHODS: In this paper, the recombinant anti-HER2 humanized IgG1 monoclonal antibody (rhHer2-mAb) was expressed in HEK293F cells by constructing mammalian cell expression vector and optimizing transfection conditions. The antibody was purified by rProtein A affinity chromatography, and its mediated antibody dependent cytotoxicity (ADCC) was identified by lactate dehydrogenase(LDH) lactate dehydrogenase release assay. The anti-tumor activity of rhHer2-mAb was evaluated in NOD/SCID mice. RESULTS: The expression of rhHer2-mAb in HEK293F cells was at the highest level (100.5 mg/L) when the ratios of DNA/PEI and light chain/heavy chain was 1:4 and 1:2, respectively. The IC50 on ADCC of antibodies against SK-OV-3, OVCAR-3 and A-2780 cells were 12.36, 5.43 and 102.90ng/ml, respectively. Animal experiments in mice showed that rhHer2-mAb could effectively inhibit the growth of SK-OV-3 tumor at the dose of 10 mg/kg.CONCLUSIONS: The recombinant monoclonal antibody was obtained by transient gene expression technology and its bioactivity was studied in vitro and in vivo , providing a novel insight for the development and production of future biotechnology-based drugs using transient gene expression technology of HEK293F.