Biological activity in vitro of anti-epidermal growth factor receptor monoclonal antibodies with different affinities
Biological activity in vitro of anti-epidermal growth factor receptor monoclonal antibodies with different affinities
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DOI：
10.1089/hyb.2007.0516
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发表时间：
2007-12-01
期刊：
影响因子：
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通讯作者：
Montero, Enrique
中科院分区：
文献类型：
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作者：
Miqueli, Arlhee Diaz;Blanco, Rances;Montero, Enrique
表皮生长因子受体（EGFR）在上皮性肿瘤中经常过度表达，并与不良预后相关。人们对开发抗 EGFR 疗法的兴趣日益浓厚，因此对能够与 EGFR 结合、抑制 EGFR 依赖性细胞转化的单克隆抗体进行了评估。不同的体内毒性和治疗效果与分子的亲和力和同种型有关。在本研究中，我们检查了三种单克隆抗体（MAb）-Ior egf/r3（小鼠 IgG2a，10(-9) M）、尼妥珠单抗（人源化 IgG1，10(-9) M）和西妥昔单抗（人/小鼠嵌合 IgG1，10(-9) M）的生物活性，考虑抑制鳞状细胞癌中的细胞增殖、凋亡和补体介导的细胞死亡A431 体外。通过流式细胞术、免疫细胞化学和蛋白质印迹测量，所有抗体均与这些细胞上的 EGFR 结合，抑制受体磷酸化。与对照相比，暴露于不同的抗体可抑制培养物中的细胞增殖，幅度为 50% 至 80%。此外，当肿瘤细胞暴露于抗体时，发现了类似的诱导补体介导的细胞毒性（范围在 70% 至 90% 之间）或凋亡细胞率增加两倍的能力。这些结果表明，特异性抗 EGFR 抗体与其受体之间的亲和力可能会影响但不能决定它们的生物活性，至少在那些对抑制 EGFR 表现出高敏感性的细胞系中。我们的研究结果还证实了之前的证据，即通过抗体阻断 A431 细胞中的 EGFR，通过促进细胞凋亡同时减少肿瘤细胞增殖，显着改变肿瘤细胞生物学。
Epidermal growth factor receptor (EGFR) is frequently overexpressed in epithelial tumors and is associated with a poor prognosis. An increasing interest in developing anti-EGFR therapies has resulted in the evaluation of monoclonal antibodies with the capacity to bind to the EGFR, inhibiting EGFR-dependent cellular transformation. A differential toxicity and therapeutic effect in vivo are associated with the affinity and isotype of the molecule. In this study, we examined the biological activities of three monoclonal antibodies (MAbs)-Ior egf/r3 (mouse IgG2a, 10(-9) M), Nimotuzumab (humanized IgG1, 10(-9) M), and Cetuximab (human/ mouse chimeric IgG1, 10(-9) M)-considering inhibition of cell proliferation, apoptosis, and complement-mediated cell death in squamous cell carcinoma A431 in vitro. All the antibodies bound to the EGFR on these cells, inhibiting the receptor phosphorylation, as measured by flow cytometry, inmunocytochemistry, and Western blot. Exposure to the different antibodies inhibited cell proliferation in culture in a range from 50 to 80% compared to controls. Furthermore, similar capabilities to induce either complement-mediated cytotoxicity (ranging between 70 and 90%) or a two-fold increase in the rate of apoptotic cells were found when tumor cells were exposed to the antibodies. These results suggest that the affinity between specific anti-EGFR antibodies and its receptor could affect, but not determine their biological activity at least in those cell lines that exhibit high sensitivity to withheld EGFR. Our findings also confirm previous evidences that blocking EGFR in A431 cells by means of antibodies significantly changes tumor cell biology by promoting apoptosis while decreasing tumor cell proliferation.