Identifying Metabolic Dependencies of Pancreatic Cancers

项目概要： 我的研究重点是胰腺导管腺癌（PDAC）的研究。这是一个 预计到 2020 年将成为美国第二大死亡原因。 通常在其病程晚期才被发现，不幸的是，已证明对大多数人来说治疗非常难治 治疗方法。在过去的十年中，我们的团队一直致力于了解 PDAC 如何 重新连接它们的新陈代谢，以支持营养贫乏、严峻的肿瘤中的高增殖率和细胞存活 微环境。我们使用新颖的小鼠模型来了解致癌性 Kras（其特征）是如何产生的 PDAC 的基因突变，协调这些肿瘤的代谢重编程，使其朝着更合成代谢的方向发展。 状态。事实上，该癌基因支持胰腺癌生长的关键方式之一是通过其作用 在肿瘤代谢中。通过对 PDAC 中碳源利用的进一步分析，我们发现了一种新的 通过 NADPH 的产生对 PDAC 氧化还原平衡至关重要的途径。该途径利用 谷氨酰胺碳和苹果酸-天冬氨酸穿梭的部分最终以苹果酸酶转化结束 苹果酸转化为NADPH和丙酮酸。该代谢途径任何节点的破坏都会导致氧化还原失衡 并减少增长。 我们工作中出现的主要主题之一是 PDAC 具有惊人的代谢可塑性。 这可能是在燃料来源和氧气匮乏的环境中蓬勃发展的重要适应。 限制和快速变化。了解这些适应对于目标代谢至关重要 治疗效果的脆弱性。事实上，我们已经证明这些肿瘤可以：1）快速重新编程 它们的代谢途径响应燃料来源的限制，2）利用溶酶体清除途径 提供必要的代谢中间体，3）通过新的代谢与基质细胞合作 互动。然而，这些代谢适应的整合以及这如何影响关键代谢 PDAC 在体内的依赖性尚不清楚，了解这一点对于开发有效的药物至关重要。 治疗方法。在这里，我们将采取全面的方法来回答这些关键问题。我们会 使用复杂的胰腺癌同基因模型来全面评估代谢依赖性 使用定制设计的小鼠 CRISPR 代谢文库与代谢示踪剂研究相结合。我们会 使用共培养系统来识别肿瘤细胞与多种其他细胞类型之间的代谢串扰 肿瘤微环境（免疫细胞、神经元、成纤维细胞群）。使用体内模型，我们将 剖析营养物清除途径并确定这些营养物的利用和潜在共享方式 细胞群之间。最后，我们将利用从这些研究中获得的知识来开发最 强大的代谢目标将使用遗传和药理学方法在体内进行测试。

Project Summary: The focus of my research has been on the study of pancreatic ductal adenocarcinoma (PDAC). This is a deadly tumor that is predicted by 2020 to be the second leading cause of death in the U.S. The disease is typically detected late in its course and unfortunately has proven to be highly treatment refractory to most therapeutic approaches. Over the past decade, our group has been focused on understanding how PDAC rewire their metabolism to support a high proliferative rate and cell survival in a nutrient poor, austere tumor microenvironment. We have used novel mouse models to understand how oncogenic Kras, the signature genetic mutation in PDAC, orchestrates metabolic reprogramming of these tumors towards a more anabolic state. In fact, one of the critical ways that this oncogene supports pancreatic cancer growth is through its role in tumor metabolism. Through further analysis of carbon source utilization in PDAC, we identified a novel pathway that is critical for PDAC redox balance through the production of NADPH. This pathway utilizes glutamine carbon and portions of the malate-aspartate shuttle ultimately ending with malic enzyme conversion of malate to NADPH and pyruvate. Disruption at any node of this metabolic pathway results in redox imbalance and decreased growth. One of the major themes that emerged from our work is that PDAC have an amazing metabolic plasticity. This is likely an important adaptation to flourish in an environment where fuel sources and oxygen are rate limiting and rapidly shifting. Understanding these adaptations will be essential in order to target metabolic vulnerabilities for therapeutic gain. Indeed, we have shown that that these tumors can: 1) rapidly reprogram their metabolic pathways in response to fuel source limitations, 2) use lysosomal scavenging pathways to provide necessary metabolic intermediates, and 3) cooperate with stromal cells through novel metabolic interactions. However, the integration of these metabolic adaptations and how this influences key metabolic dependencies of PDAC in vivo is not yet known and will be critical to understand in order to develop effective therapeutic approaches. Here, we will take a comprehensive approach to answer these key questions. We will use sophisticated syngeneic models of pancreatic cancer to comprehensively assess metabolic dependencies using a custom designed murine CRISPR metabolism library combined with metabolic tracer studies. We will use co-culture systems to identify metabolic cross-talk between tumor cells and the multiple other cell types in the tumor micro-environment (immunocytes, neurons, fibroblast populations). Using in vivo models, we will dissect nutrient scavenging pathways and identify how these nutrients are utilized and potentially shared between cell populations. Lastly, we will utilize the knowledge gained from these studies to develop the most robust metabolic targets which will be tested in vivo using genetic and pharmacologic approaches.