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 这种致命的肿瘤预计到2020年将成为美国第二大死亡原因。 通常在其病程晚期检测到，不幸的是，已被证明对大多数人来说是高度治疗难治性的。 治疗方法。在过去的十年里，我们的团队一直专注于了解PDAC如何 重组它们的代谢，以支持高增殖率和细胞在营养缺乏、严峻的肿瘤中存活 微环境我们已经使用了新的小鼠模型来了解致癌Kras是如何产生的， PDAC中的基因突变，协调这些肿瘤的代谢重编程， 状态事实上，这种癌基因支持胰腺癌生长的关键方式之一是通过它的作用， 在肿瘤代谢中。通过进一步分析PDAC的碳源利用，我们发现了一种新的 这是通过NADPH的生产PDAC氧化还原平衡的关键途径。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 转化为NADPH和丙酮酸。在这一代谢途径的任何节点中断导致氧化还原失衡 增长速度下降。 从我们的工作中出现的一个主要主题是PDAC具有惊人的代谢可塑性。 这可能是在燃料源和氧气充足的环境中蓬勃发展的重要适应 限制和快速变化。了解这些适应性将是至关重要的，以针对代谢 脆弱性来获得治疗效果事实上，我们已经证明，这些肿瘤可以：1）快速重编程 它们的代谢途径响应于燃料源限制，2）使用溶酶体清除途径， 提供必需的代谢中间体，和3）通过新的代谢途径与基质细胞合作， 交互.然而，这些代谢适应的整合以及这如何影响关键的代谢适应， PDAC在体内的依赖性尚不清楚，理解它对于开发有效的 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。我们将 使用复杂的胰腺癌同基因模型来全面评估代谢依赖性 使用定制设计的鼠CRISPR代谢文库结合代谢示踪剂研究。我们将 使用共培养系统来鉴定肿瘤细胞和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 剖析养分清除途径，并确定这些养分是如何被利用和潜在共享的 在细胞群体之间。最后，我们将利用从这些研究中获得的知识， 将使用遗传学和药理学方法在体内测试的稳健代谢靶点。

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.