Defining metabolic adaptations within the PDAC "arid" tumor microenvironment

定义 PDAC“干旱”肿瘤微环境中的代谢适应

• 批准号: 10728412
• 负责人: CHI V. DANG
• 金额: $ 46.22万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10728412
• 关键词: Defining; metabolic; adaptations; within; PDAC

PROJECT SUMMARY The goal of our proposal is to identify therapeutic vulnerabilities associated with nutrient-poor conditions in tumors. Pancreatic ductal adenocarcinoma (PDAC) remains a major clinical challenge and is characterized by a dense stroma and paucity of blood vessels. The resulting hypoxia and scarcity of nutrients forces cancer cells to seek alternative sources of nutrients for growth. Paradoxically, cells residing in these nutrient- deprived microenvironments are among the most resistant to therapy as a result of poor drug diffusion and reduced cell proliferation (rendering DNA-damaging agents less effective). To target these cells, therefore, a better understanding of the adaptive mechanisms by which they cope with nutrient deprivation is urgently needed. In preliminary studies, we developed a culture protocol – limiting for oxygen, glucose, amino acids, and serum – to model the “arid conditions” of pancreatic tumors. Under such conditions, tumor cells slow down proliferation and metabolic activity. Using this system, we performed a whole genome CRISPR screen to identify genes required under arid conditions but dispensable under nutrient-replete (“fertile”) conditions. This revealed a strong dependency on the TCA cycle and oxidative phosphorylation for survival, but also suggested that genes involved in many biosynthetic activities (e.g. translation and cell division) are detrimental under arid conditions. Based on these results, we hypothesize that cells survive severe nutrient and oxygen deprivation by maximizing energy generation from limited fuel supplies while minimizing the use of such resources for macromolecule production. We further hypothesize that nutrient and oxygen deprivation alters the dynamic crosstalk between cancer cells and other cells comprising the tumor microenvironment (TME). Importantly, individual tumors may respond to these metabolic changes in different ways, contributing to inter-tumoral heterogeneity. Our proposal will explore these ideas to develop strategies that target therapy-resistant cancer cells residing in these nutrient-deprived niches. Aim 1. Characterize the heterogeneity in metabolic adaptations to arid conditions. Aim 2. Determine how arid conditions influence cellular crosstalk in the TME. Aim 3. Test the activity of metabolic inhibitors against cells in arid conditions in vitro and in vivo.

项目总结 我们建议的目标是确定与营养不良条件相关的治疗脆弱性 肿瘤。胰腺导管腺癌(PDAC)仍然是一个主要的临床挑战，其特点是 间质致密，血管稀少。由此导致的缺氧和营养的匮乏迫使癌症 细胞为生长寻找替代的营养来源。矛盾的是，这些营养物质中的细胞- 由于药物扩散不良，被剥夺的微环境是对治疗最具抵抗力的人群之一 并减少细胞增殖(使DNA损伤剂的效果降低)。因此，为了针对这些细胞， 迫切需要更好地了解它们应对营养匮乏的适应机制。 需要的。 在初步研究中，我们制定了限制氧气、葡萄糖、氨基酸和血清的培养方案。 --模拟胰腺肿瘤的“干旱状况”。在这种情况下，肿瘤细胞会减慢速度 增殖和代谢活动。利用这个系统，我们进行了全基因组CRISPR筛查 确定干旱条件下所需的基因，但在营养充足(“肥沃”)条件下却是可有可无的。这 揭示了对TCA循环和氧化磷酸化生存的强烈依赖，但也表明 参与许多生物合成活动(例如，翻译和细胞分裂)的基因在干旱条件下是有害的 条件。根据这些结果，我们假设细胞在严重的营养和缺氧条件下存活下来。 通过最大限度地利用有限的燃料供应产生能源，同时将此类资源的使用降至最低 大分子生产。我们进一步假设，营养和缺氧的缺乏改变了动态 癌细胞与构成肿瘤微环境(TME)的其他细胞之间的串扰。重要的是 不同的肿瘤可能以不同的方式对这些代谢变化作出反应，从而导致肿瘤间的相互作用。 异质性。我们的提案将探索这些想法，以开发针对抗药性治疗的策略 癌细胞居住在这些营养匮乏的壁龛里。 目的1.研究干旱条件下代谢适应的异质性。 目的2.确定干旱条件如何影响TME中的蜂窝串扰。 目的3.测定代谢抑制剂在干旱条件下的体外和体内抗细胞活性。