Central Research Center, Green Cross Corp., Bojung-dong, Giheung-gu, Yongin City, Gyunggi-Do, Republic of Korea.
J Biotechnol. 2010 Jan 1;145(1):84-91. doi: 10.1016/j.jbiotec.2009.09.023.
The epidermal growth factor receptor (EGFR) overexpressed in many epithelial tumors is an attractive target for tumor therapy since numerous blocking agents of EGFR signaling have proven their anti-tumor activity. Here we report a novel monoclonal antibody (mAb), A13, which was generated from mice immunized with human cervical carcinoma A431 cells. In addition to binding to soluble EGFR with affinity of K(D) approximately 5.8nM, mAb A13 specifically bound to a variety of tumor cells and human placenta tissues expressing EGFR. A13 efficiently inhibited both EGF-dependant EGFR tyrosine phosphorylation in cervical and breast tumor cells and also in vitro colony formation of EGFR-overexpressing lung tumors. Competition and sandwich ELISAs, competitive surface plasmon resonance, and domain-level epitope mapping analyses demonstrated that mAb A13 competitively bound to the domain III (amino acids 302-503) of EGFR with EGF, but recognized distinct epitopes from those of cetuximab (Erbitux). Our results demonstrated that anti-EGFR mAb A13 interfered with EGFR proliferation signaling by blocking EGF binding to EGFR with different epitopes from those of cetuximab, suggesting that combination therapies of mAb A13 with cetuximab may prove beneficial for anti-tumor therapy.
表皮生长因子受体（EGFR）在许多上皮肿瘤中过度表达，是肿瘤治疗的一个有吸引力的靶点，因为许多 EGFR 信号通路的阻断剂已经证明了它们的抗肿瘤活性。在这里，我们报告了一种新型的单克隆抗体（mAb）A13，它是从小鼠免疫人宫颈癌 A431 细胞中产生的。除了与可溶性 EGFR 具有亲和力（K(D)约为 5.8nM）结合外，mAb A13 还特异性地与表达 EGFR 的多种肿瘤细胞和人胎盘组织结合。A13 能够有效地抑制依赖于 EGF 的宫颈和乳腺癌细胞中 EGFR 的酪氨酸磷酸化，以及 EGFR 过表达的肺肿瘤的体外集落形成。竞争和夹心 ELISA、竞争表面等离子体共振和域水平表位作图分析表明，mAb A13 与 EGFR 的 III 结构域（氨基酸 302-503）竞争性结合，与 EGF 竞争，但与 cetuximab（Erbitux）的表位不同。我们的研究结果表明，抗 EGFR mAb A13 通过阻断 EGF 与 EGFR 的结合，干扰 EGFR 增殖信号，与 cetuximab 的表位不同，这表明 mAb A13 与 cetuximab 的联合治疗可能对肿瘤治疗有益。
