Project 3: The AMPK Autophagy Pathway as a Metabolic Liability in Pancratic Ductal Adenocarcinoma

项目概要-项目3：自噬 胰腺导管腺癌（PDA）是最致命的癌症之一，几乎没有有效的治疗方法。 目前治疗效果不佳的部分原因是肿瘤和间质细胞的代谢适应性 细胞器可以通过增加自噬作用来回收蛋白质和细胞器。作为一个标志， PDA，自噬在限制性肿瘤微环境（TME）中提供了关键的营养来源。 越来越多的证据还表明，自噬程序是抵抗许多疾病的关键介质。 治疗剂，包括化疗、MEK抑制剂和免疫检查点抑制。基础研究 来自Shaw小组的研究人员解码了自噬启动的关键生化步骤，包括上游 AMPK的调节及其下游ULK 1和ULK 2的激活，这些激酶驱动自噬体 阵Shaw小组最近的工作也揭示了AMPK可以阻断 II类HDAC进入细胞核。尽管有这些进展，AMPK在自噬控制和 表观遗传调控从未在胰腺癌中进行过研究。此外，虽然自噬具有 作为胰腺癌的一个有吸引力的治疗靶点，将其转化为临床的努力已经取得了进展。 由于缺乏自噬特异性抑制剂，只有广泛的溶酶体药物如氯喹， 可供研究。为了解决这一差距，该实验室开发了新型的ULK 1和ULK 2的生物可利用抑制剂， 自噬途径特有的三种可药用酶中的两种。这些抑制剂提供了关键的工具 用它来剖析自噬对PDA生长的贡献，并为一种新的方法奠定基础， 克服这种致命疾病的治疗耐药性。在这里，目标1中提出的实验将定义何时 在疾病进展过程中，AMPK信号传导和自噬的不同方面被激活， PDA的本地小鼠KPC模型。与项目1合作，AMPK或其 下游靶点ULK 1/2和HDAC 3将用于评估它们对代谢适应的贡献 驱动肿瘤生长和介导肿瘤细胞功能的表观遗传变化。此外， AMPK通路组分支持PDA对化疗药物和靶向治疗的耐药性， 解剖。在目标2中，经典和非经典自噬在非细胞自主支持细胞凋亡中的作用被证实。 胰腺肿瘤生长将通过比较ULK 1/2和ATG 7的基质缺失来描绘。此外，本发明还提供了一种方法， 实验将剖析成纤维细胞和髓样细胞内自噬的细胞特异性要求 支持PDA治疗耐药性。在目标3中，将使用Shaw实验室的新型生物可利用ULK抑制剂 确定选择性抑制自噬如何通过重编程肿瘤影响PDA生长， 基质细胞功能ULK抑制剂在挽救自噬依赖性治疗耐药性中的潜力 将探索化学疗法、MEK抑制剂和免疫检查点抑制。

PROJECT SUMMARY – Project 3: Autophagy Pancreatic ductal adenocarcinoma (PDA) is one of the deadliest forms of cancer with few effective therapies. The poor performance of current treatments is partly due to metabolic adaptations in both the tumor and stromal compartments, such as the recycling of proteins and organelles through increased autophagy. As a hallmark of PDA, autophagy provides a key source of nutrients in the restrictive tumor microenvironment (TME). Accumulating evidence also implicates the autophagy program as a critical mediator of resistance to numerous therapeutics, including chemotherapy, MEK inhibitors, and immune checkpoint inhibition. Foundational research from the Shaw group decoded key biochemical steps involved in the initiation of autophagy, including upstream regulation of AMPK and its downstream activation of ULK1 and ULK2, the kinases that drive autophagosome formation. More recent work from the Shaw group has also revealed that AMPK can block the translocation of Class II HDACs to the nucleus. Despites these advances, the specific roles of AMPK in autophagy control and epigenetic regulation have never been investigated in pancreatic cancer. Moreover, while autophagy has emerged as an attractive therapeutic target in pancreatic cancer, efforts to translate this to the clinic have been hindered by a lack of autophagy-specific inhibitors, with only broad lysosomotropic agents like chloroquine available for study. To address this gap, the lab has developed novel, bioavailable inhibitors of ULK1 and ULK2, two of only three druggable enzymes specific to the autophagy pathway. These inhibitors provide critical tools with which to dissect the contributions of autophagy to PDA growth and form the basis for a new approach for overcoming therapeutic resistance in this deadly disease. Here, experiments proposed in Aim 1 will define when and where different facets of AMPK signaling and autophagy are activated during disease progression in the autochthonous mouse KPC model of PDA. In collaboration with Project 1, conditional deletions of AMPK or its downstream targets ULK1/2 and HDAC3 will be used to evaluate their contribution to metabolic adaptations driving tumor growth and epigenetic changes mediating tumor cellular functions. In addition, the contribution of AMPK pathway components in supporting PDA resistance to chemotherapeutics and targeted therapies will be dissected. In Aim 2, the roles of canonical and noncanonical autophagy in non-cell autonomous support of pancreatic tumor growth will be delineated by comparing stromal deletion of ULK1/2 and ATG7. In addition, experiments will dissect cell-specific requirements for autophagy within the fibroblast and myeloid compartments in supporting PDA therapeutic resistance. In Aim 3, the Shaw lab’s novel, bioavailable ULK inhibitor will be used to determine how selective inhibition of autophagy impacts PDA growth through reprogrammed tumor and stromal cell function. The potential of ULK inhibitors in rescuing autophagy-dependent therapeutic resistance to chemotherapies, MEK inhibitors, and immune checkpoint inhibition will be explored.