A scalable platform for target validation in GEMM models of gastrointestinal malignancies.

 描述(申请人提供)：胃肠道(GI)恶性肿瘤，如肝细胞癌、胆管细胞癌和结直肠癌，对大多数目前的治疗方法都是无效的，是西方世界最大的癌症杀手之一。虽然基因组技术已经对许多癌症特异性突变进行了分类，但定义那些推动疾病进展和代表潜在治疗靶点的变化仍然是一个重要的未得到满足的需求。基因工程小鼠模型(GEMM)提供了一个理想的环境来研究癌症发生和维持的遗传学和生物学，并作为强大的临床前模型来测试新的癌症治疗方法。然而，使用传统方法产生和分析新的GEMM的速度太慢，成本太高，即使是在体内评估中等数量的候选基因也是如此，因此，验证已建立的肿瘤治疗靶点的遗传策略仍然具有极大的挑战性。因此，GEMM模型在药物开发工作中一直没有得到充分利用。在这里，我们提出了一种概念上的新方法，能够在传统方法的一小部分时间内快速生产定制的、基因定义的动物。我们的建议是基于疾病特异性多等位基因胚胎干细胞(GEMM-ESCs)的派生和使用，这种干细胞可以定制为研究特定的、易患疾病的遗传背景中的任何基因，而不需要任何育种。每个模型都有一个归巢盒，允许快速靶向四环素反应短发夹RNA(ShRNAs)结构，从而能够生产出易患癌症的小鼠，在这种小鼠中，只需添加多西环素就可以在已建立的肿瘤和正常组织中抑制任何基因。这一新的建模范式建立在我们实验室先前创新的坚实基础上，这些创新导致了改进的RNAi和基因组编辑工具，并将能够快速评估与体内靶标抑制相关的潜在有效性和毒性。拟议工作的成功完成将极大地提高研究GI癌症的遗传关联和治疗靶点的速度和规模，并提供一个可能改变我们在肿瘤学研究中设计和使用老鼠的方式的范例。因此，我们相信我们的应用程序满足了FOA的所有三个主要目标，解决了确保鼠标模型有效翻译使用的一个或多个技术和实验参数，并解决了未满足的翻译要求。我们的新模型也将非常适合为肿瘤学模型论坛NCIP中心平台做出贡献并从中受益。

 DESCRIPTION (provided by applicant): Gastrointestinal (GI) malignancies such as hepatocellular carcinoma, cholangiocarcinoma, and colorectal carcinoma are refractory to most current therapies and are among the largest cancer killers in the western world. While genomic technologies have cataloged many cancer-specific mutations, defining those changes that drive disease progression and represent potential therapeutic targets remains a significant unmet need. Genetically engineered mouse models (GEMMs) offer an ideal setting to interrogate the genetics and biology of cancer initiation and maintenance, and serve as powerful preclinical models to test novel cancer therapies. Nevertheless, the generation and analysis of new GEMMs using conventional methods is simply too slow and costly to evaluate even moderate numbers of candidate genes in vivo, and thus, genetic strategies to validate therapeutic targets in established tumors remain exceedingly challenging. Consequently, GEMM models have been underutilized in drug development efforts. Here we propose a conceptually new approach that enables rapid production of tailored, genetically defined animals in a fraction of the time of conventional methods. Our proposal is based on the derivation and use of disease-specific, multi-allelic embryonic stem cells (GEMM- ESCs) that can be customized to investigate any gene in a defined, disease-prone genetic background, without any breeding. Each model harbors a homing cassette that allows rapid targeting of tetracycline responsive short hairpin RNAs (shRNAs) constructs, allowing the production of cancer prone mice in which any gene can be suppressed in established tumors and normal tissue simply by the addition of doxycycline. This new modeling paradigm is built on a solid foundation of previous innovation in our laboratory that has led to improved RNAi and genome editing tools and will enable rapid evaluation of the potential efficacies and toxicities associated with target inhibition in vivo. Successful completion of the proposed work will dramatically increase the speed and scale at which genetic-associations and therapeutic targets can be investigated GI cancers and provide a paradigm that may transform the way we design and use mice in oncology research. As such, we believe our application meets all three major goals of the FOA, addressing one or more of the technical and experimental parameters that ensure effective translational use of mouse models as well as addressing unmet translational requirements. Our new models also will be ideally suited to contribute to, and benefit from, the Oncology Models Forum NCIP Hub platform.