Engineered Antibody EGFR Antagonist Cancer Therapeutics

描述（由申请人提供）：在这个持续的生物工程研究合作项目中，我们寻求设计用于阻断癌症中表皮生长因子受体（EGFR）异常信号传导的改进抗体药物。一个在蛋白质工程（Wittrup，MIT）、结构生物学（Kuriyan，UC Berkeley）、细胞工程（Lauffenburger，MIT）、蛋白质组学（白色，MIT）和医学成像（Larson，MSKCC）方面具有专业知识的团队将进一步开发和表征在前一个项目期间分离的一组抗EGFR分子。我们的中心假设是结合EGFR结构域IV的抗体（抗IV）以配体非依赖性方式阻断信号传导，从而能够拮抗不被当前一代抗EGFR抗体拮抗的常见截短突变体（EGFRvIII）。抗IV抗体和基于荧光的生物物理技术将用于进一步研究对称配体结合的细胞外二聚化事件在细胞质中的不对称活性激酶二聚体的转导，最近表征为该项目的一部分。分子变构机制，导致激酶结构域激活配体结合后，将划定，以便更好地了解如何阻止这一进程。我们将应用质谱法同时定量EGFR下游信号传导途径中数百种特定酪氨酸的磷酸化动力学，特别是寻找抗IV抗体根除EGFRvIII作用的近端证据。将系统地研究和利用多价抗体增强受体下调以减少受体数量。将在自分泌细胞系中检查抗IV抗体对迁移和增殖的影响。将通过双光子显微镜研究抗体渗透到肿瘤球体中的动力学。在小鼠异种移植模型中，将通过PET研究这些抗体的药代动力学和药效学。该项目是一个由工程师，科学家和医生组成的团队的系统性努力，通过改善对癌细胞表面受体发出的常见一类不受控制的生长信号的机械理解和阻断来开发新一代抗癌药物。

DESCRIPTION (provided by applicant): In this continuing Bioengineering Research Partnership project, we seek to design improved antibody drugs for blocking aberrant signaling by epidermal growth factor receptor (EGFR) in cancer. A team with expertise in protein engineering (Wittrup, MIT), structural biology (Kuriyan, UC Berkeley), cell engineering (Lauffenburger, MIT), proteomics (White, MIT), and medical imaging (Larson, MSKCC) will further develop and characterize a panel of anti-EGFR molecules isolated in the previous project period. Our central hypothesis is that antibodies binding to domain IV of EGFR (anti-IV) block signaling in a ligand-independent manner, enabling antagonism of a common truncation mutant (EGFRvlll) that is not antagonized by the current generation of anti-EGFR antibodies. Anti-IV antibodies and fluorescence-based biophysical techniques will be used to further study the transduction of a symmetric ligand-bound extracellular dimerization event to an asymmetric active kinase dimer in the cytoplasm, recently characterized as part of this project. The molecular allosteric mechanisms that result in kinase domain activation upon ligand binding will be delineated so as to understand better how to block this process. We will apply mass spectrometry to simultaneously quantify the phosphorylation kinetics of hundreds of specific tyrosines in the signaling pathways downstream of EGFR, in particular looking for proximal evidence for eradication of EGFRvlll's effects by anti-IV antibodies. Enhanced receptor downregulation with multivalent antibodies will be systematically studied and exploited to reduce receptor number. Effects of anti-IV antibodies on migration and proliferation will be examined in autocrine cell lines. The kinetics of antibody penetration into tumor spheroids will be studied by 2-photon microscopy. In mouse xenograft models, the pharmacokinetics and pharmacodynamics of these antibodies will be studied by PET. This project is a systematic effort by a team of engineers, scientists, and physicians to develop a new generation of anticancer drugs through improved mechanistic understanding and blocking of a common class of uncontrolled growth signals sent by receptors on the surface of cancer cells.