Evaluating ADGRB3 as a tumor suppressor epigenetically silenced in WNT medulloblastoma

评估 ADGRB3 作为 WNT 髓母细胞瘤中表观遗传沉默的肿瘤抑制因子

• 批准号: 10583473
• 负责人: ERWIN G VAN MEIR
• 金额: $ 41.66万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10583473
• 关键词: Adhesions; Attenuated; Behavior; Binding; Binding Proteins; Brain; Brain Stem; CRISPR/Cas technology; CTNNB1 gene; Cell Proliferation; Cells; Central Nervous System; Central Nervous System Neoplasms; Cerebellar Neoplasms; Cerebellum; Child; Childhood Brain Neoplasm; Chromatin; Clinical; Clinical Trials; Cognitive; Combination Drug Therapy; CpG Islands; DNA Methylation; DNA-Binding Proteins; Data; Data Set; Development; Dorsal; EZH2 gene; Epigenetic Process; G-Protein-Coupled Receptors; Gene Activation; Gene Expression; Gene Expression Profile; Gene Silencing; Genes; Growth; Hippocampus; Human; In Vitro; Intellectual functioning disability; Knockout Mice; Knowledge; Lip structure; MBD2 protein; Malignant neoplasm of brain; Malignant neoplasm of central nervous system; Mediating; Methylation; Molecular Profiling; Monitor; Morbidity - disease rate; Morphogenesis; Mus; Neurologic; Neurons; Neurosecretory Systems; Nude Mice; Oncogenic; Operative Surgical Procedures; Orphan; Outcome Study; PTEN gene; Pathway interactions; Patients; Pediatric Neoplasm; Phosphorylation; Physiological; Predisposition; Property; Protein Methyltransferases; Protein Microchips; Radiation; Radiation therapy; Regulation; Repression; Reverse Transcriptase Polymerase Chain Reaction; Role; SHH gene; Scaffolding Protein; Secondary to; Serine; Signal Pathway; Signal Transduction; Subgroup; Survival Rate; Survivors; Synaptic plasticity; System; Testing; Therapeutic; Therapeutic Effect; Therapeutic Intervention; Tissues; Transgenic Mice; Translations; Treatment Side Effects; Tumor Suppressor Proteins; Tumorigenicity; WNT Signaling Pathway; Xenograft procedure; antagonist; beta catenin; bisulfite sequencing; blood-brain barrier permeabilization; cell growth; cell transformation; chemotherapy; design; developmental neurobiology; epigenetic regulation; epigenetic therapy; experimental study; histone methyltransferase; histone modification; in vivo; inhibitor; insight; mRNA Expression; medulloblastoma; medulloblastoma cell line; member; molecular subtypes; mutant; myogenesis; nerve stem cell; neurosurgery; novel; novel therapeutic intervention; novel therapeutics; pharmacologic; physically handicapped; promoter; receptor; restoration; seven-transmembrane G-protein-coupled receptor; side effect; small molecule; synaptogenesis; therapeutically effective; transcriptome sequencing; tumor; tumor growth; tumorigenic; young adult

Project Summary/Abstract There is an urgent need to develop novel therapies for patients with medulloblastoma (MB), the most common malignant central nervous system (CNS) tumor in children. Current treatments include surgery, radiotherapy, and chemotherapy and result in 5-year survival rates of 40-90% depending on subtype. However, children suffer important morbidity secondary to treatment, including neurological, intellectual and physical disabilities. The overall purpose of the present project is to investigate the role of the ADGRB3 receptor in susceptibility of cerebellar transformation, and explore new therapies for MB based on the related mechanisms. ADGRB3 is an orphan seven transmembrane G protein-coupled receptor (GPCR) specifically expressed in the brain, and belonging to the adhesion-type sub-family. Our new preliminary data show that ADGRB3 expression is significantly reduced in patients with MBs of the WNT group, and the promoter is epigenetically silenced, suggesting that ADGRB3 loss may facilitate WNT-MB formation. We present evidence for the involvement of methylated CpG binding protein MBD2 and histone methyltransferase EZH2 in switch to a silent chromatin. Moreover, we show that reactivation of ADGRB3 can reduce cell proliferation and tumor growth, supporting a tumor suppressive role. To test this in the physiological setting, we generated ADGRB3 knockout (KO) mice, which we plan to cross with mice expressing mutant b-catenin in neural progenitors of the rhombic lip and dorsal brainstem, which are the cells of origin of WNT-MB. Based on these results, we hypothesize that ADGRB3 is a tumor suppressor in the cerebellum and that restoration of its expression with epigenetic therapy may represent a novel therapeutic intervention for children with WNT-MB. To test our hypothesis, we propose the following aims: (i) identify and target the epigenetic mechanism(s) underlying ADGRB3 gene silencing in WNT-MB, (ii) determine whether and how restoration of ADGRB3 expression can inhibit MB cell growth, oncogenic signaling and tumorigenic properties, and (iii) determine whether loss of ADGRB3 gene expression in the background of oncogenic Ctnnb1 activation predisposes mice to cerebellar transformation and MB tumor development. These studies are important as they increase our knowledge about developmental neurobiology in the CNS, and may lead to the development of novel therapeutic approaches for patients with medulloblastoma.

项目总结/摘要 目前迫切需要为髓母细胞瘤（MB）患者开发新的治疗方法， 儿童中枢神经系统恶性肿瘤目前的治疗方法包括手术、放疗、 和化疗，根据亚型，5年生存率为40-90%。但儿童 因治疗而导致严重的疾病，包括神经、智力和身体残疾。 本项目的总体目的是研究ADGRB 3受体在糖尿病易感性中的作用。 小脑转化，并根据相关机制探索MB的新疗法。ADGRB 3是一种 孤儿七跨膜G蛋白偶联受体（GPCR），在脑中特异性表达，和 属于粘附型亚家族。我们的新的初步数据表明，ADGRB 3表达是 在WNT组的MB患者中显著降低，并且启动子在表观遗传学上沉默， 这表明ADGRB 3损失可能促进WNT-MB形成。我们提供的证据表明 甲基化的CpG结合蛋白MBD 2和组蛋白甲基转移酶EZH 2转变为沉默的染色质。 此外，我们发现ADGRB 3的重新激活可以减少细胞增殖和肿瘤生长，支持了对肿瘤的治疗。 肿瘤抑制作用。为了在生理环境中测试这一点，我们产生了ADGRB 3敲除（KO）小鼠， 我们计划将其与在菱形唇的神经祖细胞中表达突变的b-连环蛋白的小鼠杂交， 背侧脑干，其是WNT-MB的起源细胞。基于这些结果，我们假设， ADGRB 3是小脑中的肿瘤抑制因子，通过表观遗传疗法恢复其表达 可能代表WNT-MB儿童的一种新的治疗干预。为了验证我们的假设，我们建议 （i）鉴定和靶向ADGRB 3基因沉默背后的表观遗传机制， WNT-MB，（ii）确定ADGRB 3表达的恢复是否以及如何抑制MB细胞生长， 致癌信号传导和致瘤特性，和（iii）确定ADGRB 3基因表达的丧失是否 在致癌Ctnnb 1激活的背景下，小鼠易发生小脑转化和MB肿瘤 发展这些研究很重要，因为它们增加了我们对发育神经生物学的了解 在中枢神经系统，并可能导致新的治疗方法的发展， 髓母细胞瘤