title: Generation and characterization of a target-selectively activated antibody against epidermal growth factor receptor with enhanced anti-tumor potency.
abstract: Panitumumab, as a commercially available antibody, is an effective anticancer therapeutic against epidermal growth factor receptor (EGFR), although it exerts weak antibody-dependent cell-mediated cytotoxicity (ADCC) activity owing to its IgG2 nature. Here, we firstly engineered panitumumab by grafting its variable region into an IgG1 backbone. The engineered panitumumab (denoted as Pan) retained binding activity identical to the parental antibody while exhibiting stronger ADCC activity in vitro and more potent antitumor effect in vivo. To further enhance the target selectivity of Pan, we generated Pan-P by tethering an epitope-blocking peptide to Pan via a tumor-specific protease selective linker. Pan-P showed almost 40-fold weaker affinity compared with Pan, but functional activity was restored to a similar extent as Pan when Pan-P was selectively activated by urokinase-type plasminogen activator (uPA). More importantly, targeted localization of Pan-P was observed in tumor samples from colorectal cancer (CRC) patients and tumor-bearing nude mice, strongly indicating that specific activation also existed ex vivo and in vivo. Furthermore, Pan-P also exhibited effective in vivo antitumor potency similar to Pan. Taken together, our data evidence the enhanced antitumor potency and excellent target selectivity of Pan-P, suggesting its potential use for minimizing on-target toxicity in anti-EGFR therapy.
authors: a PLA General Hospital Cancer Center ; PLA School of Medicine ; Beijing , China.
authors: Yun
authors: Y
authors: Yang
authors: Qingcheng
authors: Q
authors: Guo
authors: Mao
authors: M
authors: Xia
authors: Yantao
authors: Y
authors: Li
authors: Xiaoyun
authors: X
authors: Peng
authors: Tao
authors: T
authors: Liu
authors: Xin
authors: X
authors: Tong
authors: Jin
authors: J
authors: Xu
authors: Huaizu
authors: H
authors: Guo
authors: Weizhu
authors: W
authors: Qian
authors: Sheng
authors: S
authors: Hou
authors: Jianxin
authors: J
authors: Dai
authors: Hao
authors: H
authors: Wang
authors: Rong
authors: R
authors: Liu
authors: Yajun
authors: Y
authors: Guo
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D000912:Antibodies, Neoplasm / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D016466:CHO Cells; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D006224:Cricetinae; D003412:Cricetulus; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology; D005260:Female; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D000077544:Panitumumab; D015202:Protein Engineering; D023041:Xenograft Model Antitumor Assays
chemical_list: D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D007135:Immunoglobulin Variable Region; D000077544:Panitumumab; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: ADCC; ADCC, antibody-dependent cell-mediated cytotoxicity; CCK-8, Cell Counting Kit 8Yun; CI, confidence interval; CRC, colorectal cancer; ECD, extracellular domain; EGFR; EGFR VIII, EGFR Type III Variant; EGFR, epidermal growth factor receptor; ELISA, enzyme-linked immunosorbent assay; HC, heavy chain; IgG, Immunoglobulin G; LC, light chain; Probody™; SEC, size exclusion chromatography; SPR, surface plasmon resonance; TKI, tyrosine kinase inhibitor; mAb, monoclonal antibody; monoclonal antibody; panitumumab; target-selective activation; uPA, urokinase-type plasminogen activator