Investigating the roles of extracellular cGAMP and harnessing it for cancer treatment

研究细胞外 cGAMP 的作用并将其用于癌症治疗

• 批准号: 10596514
• 负责人: Aaron F Straight
• 金额: $ 49.06万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10596514
• 关键词: ATP Hydrolysis; Ablation; Address; Advanced Malignant Neoplasm; Atlas of Cancer Mortality in the United States; Binding; Biochemical; Biology; Breast Cancer Model; Cancer Model; Cells; Chemicals; Chromosomal Instability; Cyclic GMP; DNA Binding; DNA Damage; Dendritic Cells; Detection; Development; Enzymes; Exhibits; Functional disorder; Genetic; Goals; Hydrolase; Hydrolysis; Immune; Immune response; Immunologics; Immunotherapeutic agent; In Vitro; Infiltration; Innate Immune System; Interferon Type I; Ionizing radiation; Kinetics; Knock-out; Lead; Malignant Neoplasms; Membrane; Modeling; Molecular; Mouse Strains; Mus; Mutation; Natural Immunity; Pathway interactions; Patients; Physiological; Physiology; Play; Point Mutation; Production; Role; Second Messenger Systems; Signal Pathway; Signal Transduction; Site; Structure-Activity Relationship; Substrate Specificity; Testing; Tissues; Tumor Immunity; Tumor Promotion; analog; anti-cancer; anti-tumor immune response; antitumor effect; cancer cell; cancer immunotherapy; cancer therapy; cancer type; drug development; ds-DNA; extracellular; fighting; immune activation; immune checkpoint blockers; improved; in vivo; inhibitor; innate immune checkpoint; mouse genetics; mouse model; mutant; nucleoside triphosphate; overexpression; pancreatic cancer model; paracrine; pharmacologic; prevent; receptor; response; side effect; small molecule; standard of care; synergism; tool; tumor; tumor growth; tumor microenvironment

PROJECT SUMMARY The goal of cancer immunotherapy is to awaken the body’s anti-tumoral immune response to fight against all cancers in all patients. Our lab recently identified a key mechanism by which cancer cells are detected by our innate immune system. We now know that cancer cells, with intrinsic chromosomal instability, constantly secret the soluble small molecule 2’3’-cyclic-GMP-AMP (cGAMP). Acting as an immunotransmitter, extracellular cGAMP is taken up by surrounding tissues and immune cells to activate its receptor STING in a paracrine fashion, resulting in downstream anti-cancer immune responses. The importance of extracellular cGAMP is demonstrated by our finding that it is required for the curative effect of ionizing radiation in a murine model of breast cancer. Furthermore, we identified the extracellular enzyme ENPP1 as the only detectable hydrolase of extracellular cGAMP that blocks its signaling pathway. Therefore, we hypothesize that ENPP1 is an innate immune checkpoint that could be targeted to expand the reach of cancer immunotherapy. Although ENPP1 is cGAMP’s only hydrolase, it hydrolyzes extracellular ATP at comparable potency. Therefore, genetic and pharmacological tools that are based on complete ablation of ENPP1 activity cannot be used to distinguish the physiological role between extracellular cGAMP and ATP. Here, we propose selective genetic and chemical biology approaches: we will characterize genetic tools that selectively abolish ENPP1’s hydrolase activity toward extracellular cGAMP but not ATP (dENPP1cGAMP); in parallel we will develop substrate- specific ENPP1 inhibitors as tool compounds and potential immunotherapeutics. In Aim 1, we will fully characterize the kinetics, selectivity, and mechanisms of action of mutant dENPP1cGAMP, as well as the pathophysiology of dEnpp1cGAMP mice. In Aim 2, we will evaluate multiple tumor models in the dEnpp1cGAMP mouse strain to determine the physiological roles of extracellular cGAMP in controlling tumor growth and synergism with checkpoint blockers. In Aim 3, we will first characterize mechanism of substrate selectivity of our lead cGAMP-selective ENPP1 inhibitor and then use this inhibitor to harness the anti-tumoral effects of extracellular cGAMP. This proposal combines careful biochemical analyses with mouse genetics and tool compound development to address the role of extracellular cGAMP in cancer, with the goal of improving cancer immunotherapy.

项目摘要 癌症免疫疗法的目的是唤醒人体的抗肿瘤免疫响应以与 所有患者中的所有癌症。我们的实验室最近确定了一种关键机制，我们的 先天免疫系统。我们现在知道，具有内在染色体不稳定性的癌细胞不断秘密 可溶性小分子2'3'-cycle-gmp-amp（CGAMP）。充当免疫递质，细胞外 CGAMP被周围的组织和免疫细胞占用，以旁分泌方式激活其接收器刺激器， 导致下游抗癌免疫反应。表现出细胞外CGAMP的重要性 通过发现，在乳腺癌的鼠模型中，离子化辐射的治愈作用是必需的。 此外，我们确定细胞外酶ENPP1是唯一可检测的细胞外水解酶 CGAMP阻止其信号通路。因此，我们假设ENPP1是先天免疫 可以针对扩展癌症免疫疗法的检查点。 尽管ENPP1是CGAMP唯一的水解酶，但它以可比的效力水解细胞外ATP。 因此，基于ENPP1活动完全消融的遗传和药物工具不能是 用于区分细胞外CGAMP和ATP之间的身体作用。在这里，我们提出选择性 遗传和化学生物学方法：我们将表征有选择地废除ENPP1的遗传工具 水解酶对细胞外CGAMP的活性，而不是ATP（DENPP1CGAMP）；同时，我们将开发底物 - 特定的ENPP1抑制剂作为工具化合物和潜在的免疫疗法。 在AIM 1中，我们将充分表征突变体作用的动力学，选择性和机制 DENPPP1CGAMP以及DENPPP1CGAMP小鼠的病理生理学。在AIM 2中，我们将评估多个肿瘤 DENPP1CGAMP小鼠应变中的模型，以确定细胞外CGAMP的物理作用 控制肿瘤的生长和与检查点阻滞剂的协同作用。在AIM 3中，我们将首先描述机制 我们的铅CGAMP选择性ENPP1抑制剂的底物选择性，然后使用此抑制剂来利用 细胞外CGAMP的抗肿瘤作用。该建议将仔细的生化分析与小鼠结合在一起 遗传学和工具复合开发以解决细胞外CGAMP在癌症中的作用，目的是 改善癌症免疫疗法。