The structural and functional basis of MET exon 14 activation and acquired drug resistance

项目总结/摘要 摘要：肺癌是最大的癌症杀手，但也是一种异质性疾病， 癌蛋白有助于基因亚型，其中一些携带特定的治疗。尽管有利 当治疗与驱动癌基因相匹配时，只有一小部分肺癌患者 以有针对性的方式治疗。我们的目标是优化大比例肺癌的靶向治疗 间充质上皮转化（MET）基因中携带激活突变的患者。 背景：MET突变是最近加入到可药物化的、反复突变的激酶列表中的， 非小细胞肺癌（NSCLC）。我们最近确定了NSCLC中MET畸变的频率， 并且鉴定MET的质膜结构域中的外显子14缺失为最常见的体细胞MET事件。 然而，其作用机制及其对现有靶向MET疗法的敏感性尚不明确， 阻止对这一庞大的NSCLC患者群体进行靶向治疗。 方法：我们将重点关注MET外显子14突变的信号传导和结构效应， 理解NSCLC中这种突变选择的潜在作用机制。我们将首先 用纯化的MET膜片段表征MET膜片段调节激酶的机制， 重组MET片段从其胞内结构域。接下来，我们将研究外显子14缺失如何影响 MET抑制剂的结合以及突变是否赋予对特定类别的激酶抑制剂的亲和力。最后， 我们将在体内模拟第一代（I型）MET抑制剂的耐药突变，并提出策略， 使用II型抑制剂和"脱MET"药物靶点的靶向方法克服它们。 影响：该项目的重点是肺癌中一种常见且未充分研究的突变，肺癌是最致命的癌症。 类型，到目前为止。每年有成千上万的美国人死于MET突变的肺癌，而且通常没有 正在考虑针对他们的肿瘤基因型进行靶向治疗。我们将阐明MET突变的作用 在肺癌中起作用，并将在结构上定义最常见的突变如何激活这种癌蛋白。 该项目将促进靶向MET外显子14突变的疗法的开发，并优化方法， 针对最常见的预期抵抗路线。

Project Summary/Abstract Summary: Lung cancer is the largest cancer killer but is also a heterogeneous disease in which different oncoproteins contribute to genetic subtypes, some of which carry specific treatments. Despite favorable outcomes when therapies are matched to driving oncogenes, only small fraction of lung cancer patients are treated in a targeted manner. Our goal is to optimize targeted therapy for the large proportion of lung cancer patients harboring activating mutations in the Mesenchymal Epithelial Transformation (MET) gene. Background: MET mutations are the most recent addition to the list of druggable, recurrently mutated kinases in nonsmall cell lung cancer (NSCLC). We have recently defined the frequency of MET aberrations in NSCLC, and identified exon 14 deletion in the juxtamembrane domain of MET as the most common somatic MET event. The mechanism for its action and its susceptibility to existing targeted MET therapies is however poorly defined, preventing targeted treatment of this large population of NSCLC patients. Methods: We will focus on the signaling and structural effects MET exon 14 mutations impart with the goal of understanding the mechanism of action underlying selection for this mutation in NSCLC. We will first characterize the mechanism by which the juxtamembrane segment of MET regulates the kinase, using purified recombinant MET fragments from its intracellular domain. Next, we will study how exon 14 deletions influence MET inhibitors' binding and whether mutation confers affinity for specific classes of kinase inhibitors. Finally, we will model resistance mutations to first generation (Type I) MET inhibitors in vivo, and suggest strategies to overcome them using targeted approaches with Type II inhibitors and “off-MET” drug targets. Impact: This project focuses on a common and understudied mutation in lung cancer, the most lethal cancer type, by far. Thousands of Americans die each year with MET-mutated lung cancer, and often do so without being considered for targeted therapy against their tumor's genotype. We will clarify the role MET mutation plays in lung cancer and will structurally define how the most common mutations activate this oncoprotein. This project will foster development of therapies targeting MET exon 14 mutations, and optimize approaches to targeting the most common anticipated routes of resistance.