权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Project 3: A New Therapeutic Target for TERT Promoter Mutant Glioma

项目3：TERT启动子突变胶质瘤的新治疗靶点

基本信息

批准号：
10472562
负责人：
Joseph F Costello
金额：
$ 35.11万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-09-20 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10472562
关键词：
Affect Apoptosis Binding Proteins Biological Assay Biotechnology Brain Neoplasms CRISPR/Cas technology Cancer Patient Cell Aging Cell Death Cell Survival Cell division Cells Central Nervous System Neoplasms Cessation of life Clonality DNA Damage DNA-Binding Proteins Data Dependence Diagnosis Evolution Exons Failure Functional disorder GA-binding protein transcription factor Genes Genetic Genetic Transcription Geography Glioblastoma Glioma Goals Grant Growth Human In Vitro Length Longevity Malignant Neoplasms Maps Mitotic Molecular Mutation Normal Cell Nucleotides Pathway interactions Patients Phenotype Positioning Attribute Proliferating Protein Isoforms Protein Subunits Proteins Publishing RNA-Directed DNA Polymerase Recurrence Research Sampling Somatic Cell System Telomerase Telomere Shortening Testing Therapeutic Tumor Cell Line base cancer cell cell immortalization deep sequencing drug development drug discovery in vivo industry partner insight mutant neoplastic cell new therapeutic target novel therapeutics oligodendroglioma programs promoter recruit response senescence single-cell RNA sequencing small molecule inhibitor telomere therapeutic target transcription factor transcriptome tumor tumor heterogeneity

项目摘要

PROJECT SUMMARY/ABSTRACT The goal of this project is to develop GABP as a therapeutic target to reverse immortality of tumors harboring a mutant telomerase reverse transcriptase (TERT) promoter. TERT promoter mutation is the third most common mutation in human cancer, affecting over 80% of GBM and oligodengroglioma (OD). Due to a lack of TERT transcription in somatic cells, telomeres shorten with each successive cell division until they reach a critical level that triggers senescence and limits cell lifespan. Reactivation of TERT expression overcomes these barriers, enabling tumor cells to proliferate indefinitely. Although proteins controlling mutant TERT promoter reactivation and tumor cell immortalization may be ideal therapeutic targets, the exact identity of these molecules remained unknown. We discovered that a single ubiquitously expressed transcription factor, GABP, uniquely bound to the mutant TERT promoter and drove TERT reactivation in TERT-promoter-mutant glioma and other cancers. GABP binds DNA as a heterodimer or a heterotetramer which regulate functionally distinct transcriptional programs. In our preliminary data, we identify a specific heterotetramer forming GABPβ1 isoform (GABPβ1L) that is dispensable in normal cells but may be critical for mutant TERT promoter activation and tumor cell immortalization. If the mutant TERT promoter is uniformly present throughout each tumor, and if GABPβ1L modulation leads to tumor cell death while sparing normal cells, the GABP pathway may represent a new therapeutic option for mutant TERT promoter-driven malignancies. We will test this hypothesis with three specific aims: In Aim 1, we will determine the extent to which the TERT promoter mutation is clonal at diagnosis and recurrence. We devised a robust system to collect and analyze clonality in 10 spatially mapped samples from each GBM and OD, representing maximal tumor geography. In Aim 2, we will determine if the GABP heterotetramer is required to maintain cellular immortality in TERT promoter mutant CNS tumors. We will use CRISPR-Cas9 genetic targeting of the GABPB1L isoform to determine the consequences on TERT expression, telomere length, cell viability and tumor formation. The transcriptome effects and death mechanism of GABPβ1L deficient tumor cells will be determined to identify vulnerabilities to exploit with existing therapies. In Aim 3, we will identify therapies that will increase cell death in TERT promoter mutant tumors deficient in GABPβ1L. In our preliminary data, failure of GBM cells to fully activate TERT expression by a GABP heterotetramer culminates in telomere dysfunction and DNA damage. We will perform a focused, exploratory screen of DNA damaging and DNA damage response-inhibiting agents on GABPβ1L deficient cells to identify therapies that will increase cell death and decrease tumor formation. These studies could establish the GABPβ1L isoform as a valuable therapeutic target specifically for TERT promoter mutant CNS tumors, and potentially many others. In parallel, we will advance drug discovery and development efforts towards small molecule inhibitors of different GABP subunits with industry partners Telo Therapeutics and GlaxoSmithKline.

项目概要/摘要该项目的目标是开发 GABP 作为治疗靶点，以逆转携带 GABP 的肿瘤的永生性。突变端粒酶逆转录酶（TERT）启动子。 TERT 启动子突变是第三常见的人类癌症中的突变，影响超过 80% 的 GBM 和少突神经胶质瘤 (OD)。由于缺乏TERT 体细胞中的转录，端粒随着每次连续的细胞分裂而缩短，直到达到临界点触发衰老并限制细胞寿命的水平。 TERT 表达的重新激活克服了这些问题障碍，使肿瘤细胞无限增殖。虽然控制突变TERT启动子的蛋白质再激活和肿瘤细胞永生化可能是理想的治疗靶点，这些的确切身份分子仍然未知。我们发现一个普遍表达的转录因子 GABP 独特地与突变的 TERT 启动子结合，并在 TERT 启动子突变的神经胶质瘤中驱动 TERT 重新激活和其他癌症。 GABP 以异二聚体或异四聚体的形式结合 DNA，调节不同的功能转录程序。在我们的初步数据中，我们确定了形成 GABPβ1 的特定异四聚体同种型 (GABPβ1L) 在正常细胞中是可有可无的，但对于突变 TERT 启动子激活可能至关重要和肿瘤细胞永生化。如果突变的 TERT 启动子均匀存在于每个肿瘤中，并且如果 GABPβ1L 调节导致肿瘤细胞死亡，同时保留正常细胞，GABP 途径可能代表突变 TERT 启动子驱动的恶性肿瘤的新治疗选择。我们将用三个测试来检验这个假设具体目标：在目标 1 中，我们将确定 TERT 启动子突变克隆的程度诊断和复发。我们设计了一个强大的系统来收集和分析 10 个空间映射的克隆性来自每个 GBM 和 OD 的样本，代表最大的肿瘤地理。在目标 2 中，我们将确定是否在 TERT 启动子突变的 CNS 肿瘤中，需要 GABP 异四聚体来维持细胞永生。我们将使用 CRISPR-Cas9 基因靶向 GABPB1L 亚型来确定对 TERT 的影响表达、端粒长度、细胞活力和肿瘤形成。转录组效应和死亡机制将确定 GABPβ1L 缺陷肿瘤细胞的数量，以确定现有疗法可利用的漏洞。在目标 3 中，我们将确定能够增加 TERT 启动子突变肿瘤细胞死亡的疗法，这些肿瘤缺乏 TERT 启动子突变肿瘤。 GABPβ1L。在我们的初步数据中，GBM 细胞未能通过 GABP 完全激活 TERT 表达异四聚体最终导致端粒功能障碍和 DNA 损伤。我们将进行一次重点突出、探索性的在 GABPβ1L 缺陷细胞上筛选 DNA 损伤剂和 DNA 损伤反应抑制剂以鉴定增加细胞死亡并减少肿瘤形成的疗法。这些研究可以确定 GABPβ1L亚型作为一种有价值的治疗靶点，专门用于TERT启动子突变的中枢神经系统肿瘤，以及可能还有很多其他的。与此同时，我们将推动药物发现和开发工作向小型化方向发展。与行业合作伙伴 Telo Therapeutics 和 GlaxoSmithKline 合作开发不同 GABP 亚基的分子抑制剂。