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 表观遗传失调常见于儿童癌症，包括神经母细胞瘤(NB)、 儿童最常见的颅外实体瘤。在我的博士后研究中，我发现一种细胞状态 从肾上腺素能到间充质表观遗传状态的转变与GD2表达的丧失有关 对抗GD2治疗耐药。鉴于抗GD2治疗在治疗高危人群中的重要作用 神经母细胞瘤患者，我设计了CRISPR-Cas9筛查平台来研究GD2的表观遗传调控 表情。我发现PRC1.1/BCOR复合体中几个成员的单个敲除增加 GD2-Low细胞系中GD2的表达。目标1将建立PRC1.1/BCOR复合体之间的关系 通过严格测试PRC1.1复合体维持低ST8SIA1的必要性来调节GD2 在间充质细胞系中的表达。 通过挖掘25个肿瘤谱系的遗传相关性，我发现PRC1.1复合体是一种 神经母细胞瘤中丰富的依赖性独立于其调节GD2表达的能力。目标2将 证实PCGF1基因是神经母细胞瘤中最高富含的PRC1.1亚单位依赖基因 多种神经母细胞瘤模型的依赖性。我将交叉染色质和单细胞RNA测序 确定PCGF1基因敲除对染色质调节和分化/细胞状态影响的研究 轨迹。 目前还没有已知的PRC1.1小分子抑制剂存在。USP7基因的相关性研究 依赖图门户中的依赖关系与所有其他基因依赖关系显示出很强的相关性 PCGF1依赖，提示了一种抑制PRC1.1的易处理的药理学方法。目标3将 建立USP7抑制作为调节PRC1.1活性的机制。这些具体目标将考验这一能力 高效、选择性的USP7抑制剂选择性上调GD2表达并降低 神经母细胞瘤在体外和体内的活性。 我预计这些发现将直接将PRC1.1与表观遗传状态和 神经母细胞瘤。此外，它还将证明抑制USP7是恢复反应的联合疗法 抗GD2治疗和直接靶向神经母细胞瘤细胞。为了完成这份提案中的研究，我将申请 我在表观遗传学和药理学方面的专业知识。填补知识的关键空白，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 免疫肿瘤学、单细胞测序和USP7化学。这项建议为我的 建立以表观遗传可塑性/异质性为目标的实验室的长期目标 克服治疗抵抗的干预措施。