Metabolic interactions in the pancreatic tumor microenvironment

项目总结 胰腺导管腺癌(Pda)是一种致命的癌症，治疗方案很少。 病人。化疗和免疫治疗的现代进展尚未提供有效的治疗方法。 虽然Kras的致癌基因突变在PDA中几乎是普遍的，但到目前为止，Kras仍然无法用药治疗。显然， 需要新的战略来制定更有效的战略来改善PDA的结果。 PDA细胞利用的代谢途径为治疗提供了有吸引力的靶点。中的单元格 胰腺肿瘤缺乏营养，在低氧环境中持续存在。高肿瘤内压 由癌症相关成纤维细胞(CAF)细胞外基质过度沉积所致 适当的血管形成、营养输送和废物清除。可以预见，PDA细胞劫持了正常的新陈代谢 满足生存和繁殖所需的生物合成和能量需求的途径。此外, 癌细胞也利用非细胞自主途径来满足新陈代谢需求。因此，战略目标确定 肿瘤新陈代谢还必须考虑不同类型的细胞在肿瘤中的作用 微环境。 我实验室以前的工作表明，PDA细胞利用谷氨酸草酰乙酸酯转氨酶2(GOT2)来 抵御压力，支持核扩散。尽管在体外有这种深刻的生长抑制作用，但我发现 GOT2基因敲除(KD)PDA肿瘤能够在体内生长。我的初步数据显示，培养 在肿瘤相关成纤维细胞(CAF)条件下培养的PDA GOT2KD细胞，这种细胞非常普遍 在体内胰腺肿瘤中，在体外恢复增殖。然后我确定丙酮酸是 在GOT2基因敲除后恢复生长的CAF培养液，并保护PDA细胞免受线粒体抑制剂的影响。 这一建议的工作假设是，CAF在氧化还原动态平衡和 线粒体的呼吸被打乱。这一假设将在两个目标上得到检验。在目标1中，我将寻求 了解CAF是如何产生和释放丙酮酸的。目标2将阐明 丙酮酸在线粒体抑制期间支持PDA的生长。此外，我将测试这条途径在 用临床前小鼠胰腺癌模型判断PDA肿瘤生长的治疗作用 靶向PDA中的线粒体代谢和丙酮酸释放的CAF。

PROJECT SUMMARY Pancreatic ductal adenocarcinoma (PDA) is a deadly form of cancer with few treatment options available to patients. Modern advances in chemotherapy and immunotherapy have yet to provide effective treatments. While oncogenic mutations in Kras are nearly universal in PDA, to date Kras remains undruggable. Clearly, new strategies are needed to develop more effective strategies to improve outcomes in PDA. The metabolic pathways utilized by PDA cells present attractive targets to exploit therapeutically. The cells in a pancreatic tumor are nutrient-deprived and persist in a hypoxic environment. High intratumoral pressure caused by excessive extracellular matrix deposition from the cancer-associated fibroblasts (CAFs) prevents proper vascularization, nutrient delivery, and waste removal. Predictably, PDA cells hijack normal metabolic pathways to meet the biosynthetic and energetic demands required to survive and proliferate. In addition, cancer cells also utilize non-cell autonomous pathways to meet metabolic demands. Thus, strategies targeting tumor metabolism must also take into consideration the role of the diverse cell types in the tumor microenvironment. Previous work in my lab revealed that PDA cells utilize glutamate oxaloacetate transaminase 2 (GOT2) to protect against stress and support proliferation. Despite this profound growth inhibitory effect in vitro, I found that GOT2 knockdown (KD) PDA tumors were able to grow in vivo. My preliminary data indicate that culturing PDA GOT2KD cells in media conditioned by cancer-associated fibroblasts (CAFs), which are highly prevalent in an in vivo pancreatic tumor, restores proliferation in vitro. I then identified pyruvate as the single factor in CAF media that restored growth upon GOT2 knockdown and protected PDA cells from mitochondrial inhibitors. The working hypothesis of this proposal is that CAFs support PDA metabolism when redox homeostasis and mitochondrial respiration are disrupted. This hypothesis will be tested in two aims. In Aim 1, I will seek to discover how CAFs are producing and releasing pyruvate. Aim 2 will elucidate the mechanism by which pyruvate supports PDA growth during mitochondrial inhibition. Further, I will test the role of this pathway in PDA tumor growth using preclinical mouse models of pancreatic cancer to determine the therapeutic utility of targeting mitochondrial metabolism and pyruvate-releasing CAFs in PDA.