Recombinant anti-HER2 humanized monoclonal antibody(Shenzhen Main Luck Pharmaceuticals, Inc.)

Human epidermal growth factor receptor 2 (HER2) protein is overexpressed on the surface of various epithelial ovarian cancer tissues, mediates the proliferation, differentiation, metastasis, and signal transduction of tumor cells, and thus is a potential cancer therapeutic target. However, its research in ovarian cancer is still limited, and how to quickly obtain a large number of antibodies remains a concern for researchers.

In this study, we expressed the recombinant anti-HER2 humanized monoclonal antibody (rhHER2-mAb) in human embryonic kidney 293 (HEK293) cells through transient gene expression (TGE) technology by constructing a mammalian cell expression vector. Firstly, the transfection conditions has been optimized, the ratio of light chain (LC) and heavy chain (HC) was optimized in the range of 4:1 to 1:2 and the ration DNA and polyethyleneimine was optimized in the range of 4:1 to 1:1. The antibody was purified by rProtein A affinity chromatography, and its mediated antibody-dependent cellular cytotoxicity (ADCC) was identified by lactate dehydrogenase release assays. The anti-tumor activity of rhHER2-mAb was evaluated in non-obese diabetic/severe combined immunodeficiency mice.

The expression of rhHER2-mAb in the HEK293F cells was at the highest level (100.5 mg/L) when the DNA/polyethyleneimine and light-chain/heavy-chain ratios were 1:4 and 1:2, respectively. The half-maximal inhibitory concentration of the ADCC of the antibodies against the SK-OV-3, OVCAR-3, and A-2780 cells were 12.36, 5.43, and 102.90 ng/mL, respectively. The animal experiments with the mice showed that rhHER2-mAb effectively inhibited the growth (P<0.01) of the SK-OV-3 tumors at a dose of 10 mg/kg.

TGE technology allows us to quickly obtain a large number of anti-HER2 antibodies compared to the traditional method of constructing stable cell lines, and its in vitro and in vivo studied shows that our anti-HER2 antibody have higher affinity and better biological activity bioactivity (P<0.01) compared to Herceptin. Our findings provide novel insights into the development and production of future biotechnology-based drugs using the TGE technology of HEK293F.

Pertuzumab is a recombinant anti-HER2 humanized monoclonal antibody widely used for the adjuvant treatment of HER2-positive breast cancer. Its safety is well established with the most common adverse effects being diarrhea and rash. To our knowledge, severe pertuzumab-induced ocular adverse events have never been reported. Herein, we describe several cases of pertuzumab/QL1209 (pertuzumab biosimilar)-induced blurred vision in healthy Chinese male subjects after a single injection of 420 mg pertuzumab/QL1209. Persistent optic nerve damage and vision loss occurred in the most severe case even after ophthalmic treatment. We conducted whole-exome sequencing (WES) of DNA samples from 5 cases and 13 controls to analyze the potential genetic factors and identified some associated variants (rs80303690 in RBM24, rs117375173 in CASR, rs1805097 in IRS2, and rs1227049 in CDH23). Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) terms gene enrichment analyses were carried out for differentially expressed genes clustered in the PI3K/AKT/mTOR and Ras/Raf/MAPK signaling pathways, which were exactly activated by HER2 phosphorylation. In summary, this is the first report describing the occurrence of ocular toxicity induced by pertuzumab in the Chinese population and exploring the possible genetic mechanisms. These findings could provide evidence for clinicians to raise concerns about the risk of ocular toxicity with the clinical use of pertuzumab.