Systematic identification of oncogenic KRAS synthetic lethal interactions

 描述（由申请人提供）：KRAS的激活突变是人类癌症中发现的最常见突变之一，携带KRAS的癌症显然依赖于该癌基因的活性来维持肿瘤。然而，尽管付出了相当大的努力，但直接靶向KRAS或已知的KRAS效应子途径尚未导致对携带突变KRAS的癌症的有效治疗。一种直接靶向已知癌症等位基因的替代方法是利用合成致死性的遗传概念，其中基因产物被鉴定为，当被抑制或抑制时，仅在另一个等位基因存在时才导致细胞死亡。 非致命突变模式生物中的合成表型筛选提供了对广泛的生物过程的见解，并且在原则上;这种策略提供了一种靶向当前“不可用药”蛋白质的方法，同时降低了副作用的可能性。在过去的几年里，我们和其他人已经使用RNAi介导的基因表达抑制来鉴定依赖突变KRAS生存的细胞系中需要表达的基因。这些合成致命候选物中的一些的抑制剂现在是KRAS驱动的癌症的临床试验的主题。然而，这些早期研究使用不同的细胞和实验系统，并受到规模，技术问题或背景的限制。此外，Cas9-CRISPR等新基因操作技术的发现和开发，以及分离和繁殖人类肿瘤的方法，现在为全面鉴定KRAS依赖性癌症生存所需的新基因和途径提供了机会。在本申请中，我们建议使用新的基因组规模的基因操作技术，潜在的更相关的人类和小鼠实验模型和先进的分析方法，在一个综合的方法，系统地确定KRAS合成致死的关系，细胞，类器官和动物模型。具体来说，我们将执行 基因组规模CRISPR介导的功能丧失实验，以鉴定体外和体内模型系统中的KRAS共依赖性，并鉴定当被抑制时与已知的KRAS效应子途径协同作用以在KRAS驱动的癌症中诱导肿瘤消退的基因和途径。这些研究将使我们能够确定肿瘤维持和进展所必需的致癌KRAS干扰的信号网络。通过这些方法确定的靶点将形成转化研究的基础，以开发新的治疗方法。

 DESCRIPTION (provided by applicant): Activating mutations of KRAS are among the most common mutations found in human cancers, and cancers that harbor KRAS clearly depend on the activity of this oncogene for tumor maintenance. However, despite considerable effort, direct targeting of KRAS or known KRAS effector pathways has not yet led to effective therapies in cancers that harbor mutant KRAS. An alternative approach to direct targeting of known cancer alleles is to exploit the genetic concept of synthetic lethality, in which gene products are identified that, when suppressed or inhibited, result in cell death only in the presence of another non-lethal mutation. Synthetic phenotype screens in model organisms have provided insights into a broad spectrum of biological processes and in principle; this strategy provides a means to target currently "undruggable" proteins while simultaneously reducing the potential for side effects. Over the past several years, we and others have used RNAi-mediated suppression of gene expression to identify genes whose expression is required in cell lines that depend on mutant KRAS for survival. Inhibitors to some of these synthetic lethal candidates are now the subject of clinical trials in KRAS-driven cancers. However, these early studies used different cells and experimental systems and were limited by scale, technological issues or context. In addition, the discovery and development of new gene manipulation technologies such as Cas9-CRISPR, and methods to isolate and propagate human tumors now provide the opportunity to comprehensively identify novel genes and pathways that are required for the survival of KRAS-dependent cancers. In this application, we propose to use new genome scale gene manipulation technologies, potentially more relevant human and murine experimental models and advanced analytical approaches in an integrated approach to systematically identify KRAS synthetic lethal relationships in cell, organoid and animal models. Specifically, we will performed genome scale CRISPR mediated loss of function experiments to identify KRAS co-dependencies in both in vitro and in vivo model systems and identify genes and pathways that when inhibited synergize with known KRAS effector pathways to induce tumor regression in KRAS driven cancers. These studies will permit us to define the signaling network perturbed by oncogenic KRAS necessary for tumor maintenance and progression. Targets identified by these approaches will form the basis of translational studies to develop novel therapeutic approaches.