A Genetically Defined System to Identify Factors Essential for KRas Oncogenesis

描述（由申请人提供）：KRAS突变是肿瘤学中的巨大问题，每年导致数十万人死于癌症。它在胰腺导管腺癌（PDA）中起着特别相关的作用，其中KRAS基因突变是绝大多数病例中的主要基因组事件。开发KRas药物的经典方法，通过在活性位点中胜过GTP，已经失败，可能是由于突变KRas对GTP的高亲和力与细胞中mM GTP浓度的组合。因此，需要新的想法，新的方法和从实验室到临床的协同合作，以想象我们治疗KRAS突变癌症的方法。该提案的目标是发现并最终利用KRAS突变癌细胞特有的遗传依赖性。这一目标建立在最近开发的遗传定义的PDA小鼠模型和源自它们的癌细胞系的基础上。我们的具体目标是利用战略性的耦合步骤，在基因工程小鼠的细胞系中整合小鼠shRNA文库的创新用途，然后在人类细胞系和小鼠模型中进行验证。值得注意的是，我们预计这些结果将为KRas加工和信号传导提供关键的机制见解，并提供突变KRas致癌程序所需的新靶分子。

DESCRIPTION (provided by applicant): KRAS mutation is enormous problem in oncology and results in hundreds of thousands of deaths from cancer each year. It plays a particularly relevant role in pancreatic ductal adenocarcinoma (PDA), where mutation of the KRAS gene is the cardinal genomic event in the vast majority of cases. The classical approach to developing a KRas drug, by outcompeting GTP in the active site, has failed, likely due to the high affinity of mutant KRas for GTP combined with mM GTP concentrations in the cell. Thus, new ideas, novel approaches and synergistic collaborations from lab bench to clinic are required to imagine the means by which we address KRAS mutant cancers therapeutically. The goal of this proposal is to discover, and eventually exploit genetic dependencies unique to KRAS mutant cancer cells. This goal builds on recently developed genetically defined mouse models of PDA, and cancer cell lines derived from them. Our specific aims utilize strategically coupled steps, integrating an innovative use of murine shRNA libraries in cell lines from genetically engineered mice followed by validation in both human cell lines and in mouse models. Significantly, we anticipate the results will provide key mechanistic insights into KRas processing and signaling, and provide new targets molecules that mutant KRas requires for its oncogenic program.