Defining PRC1.1 as a gatekeeper of lineage plasticity and response to anti-GD2 therapy

将 PRC1.1 定义为谱系可塑性和抗 GD2 治疗反应的看门人

• 批准号: 10644278
• 负责人: Nathaniel Mabe
• 金额: $ 14.72万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-09 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10644278
• 关键词: Adoption; Adrenergic Agents; Advisory Committees; Antigens; CRISPR screen; Cell Line; Cell Maintenance; Cell surface; Cells; Cephalic; Chemistry; Chemoresistance; Chromatin; Committee Members; Complex; Credentialing; Dependence; Development; Disease; Down-Regulation; EZH2 gene; Enhancers; Enzymes; Epigenetic Process; Gangliosides; Gatekeeping; Gene Expression; Genes; Genetic; Genetic Transcription; Glycolipids; Goals; Heterogeneity; Immunooncology; Immunotherapy; In Vitro; Individual; Intervention; Knock-out; Knowledge; Link; Malignant Childhood Neoplasm; Malignant Neoplasms; Maps; Mediating; Mesenchymal; Mining; Modeling; Neural Crest; Neuroblastoma; Neuronal Differentiation; PRC1 Protein; Pathology; Pathway interactions; Patients; Pharmacology; Polycomb; Postdoctoral Fellow; Protein Subunits; Proteins; Refractory; Regulation; Repression; Resistance; Role; Solid Neoplasm; Testing; Therapeutic; Therapeutic Intervention; Tissues; Training; Tretinoin; Variant; Work; combinatorial; design; early childhood; high risk; in vivo; inhibitor; loss of function; member; nerve stem cell; neuroblastoma cell; novel strategies; pediatric patients; pharmacologic; prevent; programs; resistance mechanism; response; single cell sequencing; single-cell RNA sequencing; small molecule inhibitor; targeted treatment; therapeutic target; therapy resistant; transcription factor; tumor

Project Summary Epigenetic dysregulation is frequently observed in pediatric cancers, including neuroblastoma (NB), the most common extracranial solid tumor in pediatric patients. In my postdoctoral work, I identified that a cell state transition from an adrenergic to a mesenchymal epigenetic state is associated with the loss of GD2 expression and resistance to anti-GD2 therapy. Given the important role of anti-GD2 therapy in treating high-risk neuroblastoma patients, I designed a CRISPR-Cas9 screening platform to study epigenetic regulators of GD2 expression. I identified that individual knockout of several members of the PRC1.1/BCOR complex increases GD2 expression in GD2-low cell lines. AIM 1 will establish the relationship between the PRC1.1/BCOR complex and GD2 regulation by rigorously testing the necessity of the PRC1.1 complex to maintain low ST8SIA1 expression in mesenchymal cell lines. Mining genetic dependencies across 25 tumor lineages, I identified that the PRC1.1 complex is an enriched dependency in neuroblastoma independently of its ability to regulate GD2 expression. AIM 2 will validate that the gene PCGF1, the top enriched PRC1.1 subunit dependency in neuroblastoma, is a genetic dependency in multiple models of neuroblastoma. I will intersect chromatin and single-cell RNA-sequencing studies to determine the consequences of PCGF1 knockout on chromatin regulation and differentiation/cell state trajectories. No known small molecule inhibitors of PRC1.1 currently exist. The correlation of USP7 genetic dependency in the Dependency Map portal against all other gene dependencies revealed a strong correlation with PCGF1 dependency, suggesting a tractable pharmacologic approach to inhibiting PRC1.1. AIM 3 will establish USP7 inhibition as a mechanism to modulate PRC1.1 activity. These specific aims will test the capacity of highly potent and selective USP7 inhibitor to selectively upregulate GD2 expression and reduce neuroblastoma viability in vitro and in vivo. I anticipate that these findings will directly link PRC1.1 to epigenetic state and differentiation in neuroblastoma. Moreover, it will credential USP7 inhibition as a combinatorial therapy to restore the response to anti-GD2 therapy and directly target neuroblastoma cells. To complete the studies in this proposal, I will apply my strong expertise in epigenetics and pharmacology. To fill in critical gaps in knowledge and expand my scientific training, I’ve assembled a training plan that includes advisory committee members that are experts in immuno-oncology, single-cell sequencing, and USP7 chemistry. This proposal lays a strong framework for my long-term goal of establishing a lab that focuses on targeting epigenetic plasticity/heterogeneity as an intervention to overcome therapeutic resistance.

项目摘要 表观遗传失调经常在儿科癌症中观察到，包括神经母细胞瘤（NB）， 最常见的儿童颅外实体瘤。在我的博士后工作中，我发现一个细胞状态 从肾上腺素能到间充质表观遗传状态的转变与GD 2表达的丧失有关 和抗GD 2治疗的抗性。鉴于抗GD 2治疗在治疗高风险 在神经母细胞瘤患者中，我设计了一个CRISPR-Cas9筛选平台来研究GD 2的表观遗传调节因子 表情我发现PRC1.1/BCOR复合物的几个成员的单独敲除增加了 GD 2-低细胞系中的GD 2表达。AIM 1将建立PRC1.1/BCOR复合物之间的关系 通过严格测试PRC1.1复合物维持低ST 8 SIA 1的必要性， 在间充质细胞系中表达。 通过挖掘25种肿瘤谱系的遗传依赖性，我发现PRC1.1复合体是一种 在神经母细胞瘤中的依赖性增强，与其调节GD 2表达的能力无关。AIM 2将 验证基因PCGF 1，在神经母细胞瘤中最高富集的PRC1.1亚基依赖性，是一个遗传性的， 神经母细胞瘤的多种模型中的依赖性。我会将染色质和单细胞RNA测序 确定PCGF 1敲除对染色质调节和分化/细胞状态的影响的研究 轨迹 目前不存在已知的PRC1.1小分子抑制剂。USP 7基因的相关性 Dependency Map门户网站中的依赖性与所有其他基因依赖性显示出很强的相关性 与PCGF 1依赖性，这表明了一个易于处理的药理学方法来抑制PRC1.1。AIM 3将 建立USP 7抑制作为调节PRC1.1活性机制。这些具体目标将考验 高效和选择性的USP 7抑制剂选择性上调GD 2表达， 体外和体内的神经母细胞瘤活力。 我预计这些发现将直接将PRC1.1与表观遗传状态和分化联系起来， 神经母细胞瘤此外，它将证明USP 7抑制作为恢复应答的组合疗法。 抗GD 2治疗并直接靶向神经母细胞瘤细胞。为了完成本计划书中的学习，我将申请 我在表观遗传学和药理学方面的专业知识为了填补知识的关键空白，并扩大我的 科学培训，我已经制定了一个培训计划，其中包括咨询委员会成员，他们是专家， 免疫肿瘤学、单细胞测序和USP 7化学。这一建议为我的工作提供了一个强有力的框架。 长期目标是建立一个实验室，专注于靶向表观遗传可塑性/异质性， 采取干预措施克服治疗阻力。