Regulation of Angpt1 and DIPG blood-brain barrier integrity by H3K27M mutations

H3K27M 突变对 Angpt1 和 DIPG 血脑屏障完整性的调节

• 批准号: 10364327
• 负责人: Timothy N Phoenix
• 金额: $ 41.63万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-15 至 2026-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10364327
• 关键词: Adult; Affinity; Agonist; Astrocytes; Blood; Blood - brain barrier anatomy; Blood Vessels; Brain; Brain Neoplasms; CRISPR/Cas technology; Cell Lineage; Cells; Childhood; Childhood Brain Neoplasm; Clinical; Data; Development; Diffuse intrinsic pontine glioma; Disease; Electroporation; Endothelium; Functional disorder; Future; Gene Expression Profile; Genetic Transcription; Genome; Genomics; Glioma; H3 K27M mutation; Histologic; Human; Knock-out; Link; Location; Maintenance; Malignant Glioma; Malignant neoplasm of brain; Methods; Modeling; Molecular; Mus; Mutation; Oligodendroglia; Pathogenesis; Pathway interactions; Patient-Focused Outcomes; Patients; Pattern; Pharmaceutical Preparations; Phenotype; Play; Recurrence; Regulation; Reporter; Role; Signal Pathway; Signal Transduction; TIE-2 Receptor; Techniques; Testing; Therapeutic; Treatment outcome; Tumor Subtype; Work; angiogenesis; antagonist; base; blood-brain barrier function; blood-brain barrier penetration; cell type; differential expression; efficacious treatment; experimental study; glioma cell line; high throughput screening; improved; in utero; in vivo; in vivo evaluation; inhibitor; insight; loss of function; molecular subtypes; mouse model; neoplastic cell; nervous system disorder; oligodendrocyte progenitor; overexpression; patient stratification; pre-clinical; predicting response; progenitor; programs; response; response to injury; small molecule; stem cells; therapy resistant; tool; transgene expression; treatment strategy; tumor; whole genome

Malignant gliomas encompass a diverse set of diseases, including pediatric and adult high-grade gliomas. Recent genomic profiling techniques have advanced our understanding of these tumors by identifying molecular subtypes and recurrent mutations, yet treatment options remain limited. The blood-brain barrier (BBB) is commonly cited as a major factor in treatment resistance since the majority of drugs and small molecules display limited BBB penetration. Advancing our understanding of the cellular and molecular mechanisms that regulate brain tumor BBB function will be crucial to improve treatment strategies and outcomes for patients. Our recent work demonstrated that BBB integrity can be dictated by brain tumor subtype specific mutations. In preliminary studies using diffuse intrinsic pontine glioma (DIPG) and cortical high-grade glioma (HGG) mouse models we have created by in utero electroporation (IUE), we identified differences in Angiopoietin1 (Angpt1) expression, a high affinity agonist of the endothelial Tie2 receptor. The Angpt1-Tie2 signaling axis plays a key role in vascular response to injury, but its endogenous expression and function in brain tumors not been thoroughly evaluated. Preliminary data in human tumors and mouse models reveal Angpt1 expression is elevated in glial brain tumors, and displays differences within glioma subtypes. These differences mirror Angpt1 expression patterns we have found in normal brain development, suggesting expression in gliomas may be linked in part to cell state programs or upstream signaling pathways that promote particular cell states. Initial experiments in IUE DIPG mouse models have shown that overexpression of the Tie2 antagonist Angpt2, or knockout of Angpt1, result in vascular alterations. These findings form the basis of our hypothesis that Angpt1 is differentially expressed in gliomas, and that its endogenous expression participates in regulating high-grade glioma blood-brain barrier integrity. To test our hypothesis, we propose the following aims: (1) Define the expression and function of Angpt1 in high- grade glioma blood-brain barrier integrity. In this aim we will (1A) determine the cellular expression pattern of Angpt1 within gliomas, (1B,C) perform a detailed analysis of BBB, vascular phenotype and transcriptional signatures to determine the role of endogenous Angpt1 in glioma BBB integrity, and (1D) assess how differences in endogenous Angpt1 expression between glioma subtypes impacts current therapeutic strategies that target this signaling axis. Aim 2 will determine the mechanisms that regulate Angpt1 expression. We will examine the influence of cell lineage states and upstream signaling determinants, along with applying unbiased genome level screens to define regulators of Angpt1. The proposed set of experiments will significantly improve our understanding of how brain tumors regulate BBB integrity, and the dynamic interactions that occur between brain tumor cells and their microenvironment. Taken together, the results and tools generated will yield new insights into the expression and function of Angpt1, with broader implications relevant to other brain cancers and neurological disorders that involve vascular alterations and BBB dysfunction.

恶性胶质瘤包括一系列不同的疾病，包括儿童和成人高级别胶质瘤。 最近的基因组图谱技术通过识别分子，促进了我们对这些肿瘤的理解 亚型和反复发生的突变，然而治疗选择仍然有限。血脑屏障(BBB)是 通常被认为是治疗耐药性的一个主要因素，因为大多数药物和小分子表现出 血脑屏障渗透率有限。促进我们对调节细胞和分子机制的理解 脑肿瘤的血脑屏障功能将是改善治疗策略和患者预后的关键。我们最近 研究表明，脑肿瘤亚型特异性突变可以决定血脑屏障的完整性。在预赛中 弥漫性桥脑胶质瘤(DIPG)和皮质高级别胶质瘤(HGG)小鼠模型的研究 通过宫内电穿孔(IUE)，我们确定了血管生成素1(Angpt1)表达的差异，a 内皮细胞Tie2受体的高亲和力激动剂。Angpt1-Tie2信号轴在血管生成中起关键作用 但其在脑肿瘤中的内源性表达和功能尚未得到彻底的评价。 在人类肿瘤和小鼠模型中的初步数据显示，Angpt1在胶质脑瘤中的表达升高， 并显示了胶质瘤亚型之间的差异。这些差异反映了我们拥有的Angpt1表达模式 在正常脑发育中发现，这表明胶质瘤中的表达可能部分与细胞状态程序有关 或促进特定细胞状态的上游信号通路。IUE DIPG小鼠的初步实验 模型表明，Tie2拮抗剂Angpt2的过度表达或Angpt1的敲除会导致血管 改装。这些发现构成了我们假设Angpt1在胶质瘤中差异表达的基础， 其内源性表达参与调节高级别脑胶质瘤血脑屏障的完整性。至 为了验证我们的假设，我们提出了以下目标：(1)明确Angpt1在HIGH中的表达和功能。 分级脑胶质瘤血脑屏障完整。在这个目标中，我们将(1A)确定 在胶质瘤中，(1B，C)对血脑屏障、血管表型和转录进行了详细的分析 确定内源性Angpt1在胶质瘤血脑屏障完整性中的作用的签名，以及(1D)评估差异 在不同胶质瘤亚型之间内源性Angpt1的表达影响目前针对 这个信号轴。目标2将确定调节Angpt1表达的机制。我们将研究 细胞谱系状态和上游信号决定因素的影响，以及应用无偏见的基因组水平 筛选以定义Angpt1的调节因子。拟议的一系列实验将显著改善我们的 了解脑瘤如何调节血脑屏障的完整性，以及脑与脑之间发生的动态相互作用 肿瘤细胞及其微环境。综上所述，生成的结果和工具将产生新的见解 Angpt1的表达和功能，与其他脑癌和 涉及血管改变和血脑屏障功能障碍的神经系统疾病。