Characterizing and Targeting the Epigenetic Mechanisms Maintaining Neuroblastoma Tumor Initiating Cells

表征和靶向维持神经母细胞瘤肿瘤起始细胞的表观遗传机制

• 批准号: 10579019
• 负责人: Saurabh Agarwal
• 金额: $ 49.2万
• 依托单位: ST. JOHN'S UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10579019
• 关键词: Biopsy Specimen; Cancer Etiology; Cancer Relapse; Cell Line; Cells; Cessation of life; Characteristics; Chemoresistance; Childhood; Clinical; Clinical Protocols; Code; Colony-Stimulating Factor Receptors; Complex; Data; Development; Diagnosis; Disease; Drug resistance; Epigenetic Process; Exhibits; Future; Future Generations; Gene Expression; Genes; Goals; Granulocyte Colony-Stimulating Factor; Granulocyte Colony-Stimulating Factor Receptors; Growth; Heterogeneity; High-Risk Cancer; Histones; Human; In Vitro; MLL gene; Maintenance; Malignant Childhood Neoplasm; Malignant Neoplasms; Mediating; Menin; Methodology; Methyltransferase; Mixed-Lineage Leukemia; Modeling; Molecular; Molecular Biology; Natural regeneration; Neoplasm Metastasis; Neuroblastoma; Neutropenia; Pathogenesis; Patients; Pharmaceutical Preparations; Phenotype; Preclinical Testing; Proliferating; Proteins; Publishing; Recurrent disease; Refractory; Refractory Disease; Relapse; Research; Research Project Grants; Resistance; Role; Scientist; Site; Solid Neoplasm; Surface; Testing; Therapeutic; Tissue-Specific Gene Expression; Training; Transgenic Mice; Treatment Failure; Treatment Protocols; Tumor Biology; Tumorigenicity; Work; Xenograft procedure; cancer cell; cancer stem cell; cancer therapy; chemotherapy; cytokine; epigenetic regulation; genotoxicity; graduate student; high risk; histone methyltransferase; improved; in vivo; inhibitor; innovation; insight; leukemia; mouse model; neoplastic cell; neuroblastoma cell; novel; novel therapeutic intervention; overexpression; preclinical trial; promoter; protein complex; relapse prevention; self renewing cell; self-renewal; small molecule inhibitor; stem cell biology; targeted treatment; therapeutically effective; translational applications; treatment strategy; tumor; tumor growth; tumor initiation; tumorigenesis; tumorigenic; undergraduate student

Abstract: Cancer cell heterogeneity and the existence of phenotypically distinct subpopulations of cells with enhanced tumor-initiating and drug-resistant capacities is a major challenge in cancer treatment. These drug-resistant cells are known to drive cancer relapse, which is a major cause of therapy failure and deaths from high-risk cancers, such as pediatric neuroblastoma (NB). Deregulated differential expression of genes due to epigenetic machinery malfunction is the primary cause of cancer cell heterogeneity. Determining the role of specific epigenetic modifiers in maintaining tumor-initiating cancer stem cell sub-populations and developing targeted therapies to block these modifiers is mandatory for effectively battling cancer and its relapse. Recently, we discovered a drug-resistant, highly tumorigenic, metastatic, and self-renewing cell sub-population with features of tumor-initiating cells (TICs) in neuroblastoma. This sub-population, characterized by surface expression of the G-CSF receptor (CD114), can escape initial therapy and cause refractory and aggressively invasive relapsed disease. These TICs can differentiate to bulk tumor cells (CD114-) and produce complex neuroblastoma tumors with as few as 10 cells in vivo. Our recent preliminary data show that the CSF3R gene that codes for CD114 is expressed specifically in CD114+ NB TICs but not in CD114- bulk tumor cells. We hypothesize that this differential gene expression is epigenetically regulated and supports the maintenance of heterogeneous NB TICs. We also found that the epigenetic regulator mixed-lineage leukemia-1 (MLL1; an H3K4me3 methyltransferase) is overexpressed in CD114+ cells and regulates the expression of the TIC specific genes including CSF3R. MLL1 forms a protein complex with WDR5, and Menin to act as an active histone methyltransferase epigenetic regulator. Our preliminary data show that targeting MLL1-WDR5 and MLL1-Menin interactions using specific small molecule inhibitors inhibit NB TICs and in vivo NB growth and metastasis. These data support our hypothesis that epigenetic regulators maintain NB TICs and point towards a novel therapeutic strategy of blocking MLL1 activation to inhibit NB TIC-mediated tumorigenicity, metastasis, and disease relapse. In the proposed research, we will determine: a) the role of MLL1 in maintaining NB TIC subpopulation, b) the effects of blocking epigenetic regulators via specific small molecule inhibitors on NB tumorigenesis and metastasis in vivo, c) the effects of concomitantly targeting both NB TICs and bulk tumor cells by combining epigenetic inhibitors with standard chemotherapy drugs, and d) further developing novel epigenetic inhibitors to target MLL1 epigenetic functions. As specific small molecule inhibitors of MLL1, WDR5, and Menin are currently under extensive pre-clinical trials for solid tumors and leukemias, our findings will provide insights into NB tumor biology and a new epigenetic based therapeutic approach for high-risk NB.

抽象的： 癌细胞异质性和表型不同的细胞亚群的存在 肿瘤起始能力和耐药能力是癌症治疗的主要挑战。这些耐药细胞 已知会导致癌症复发，这是治疗失败和高风险癌症死亡的主要原因， 例如小儿神经母细胞瘤（NB）。表观遗传机制导致基因差异表达失调 功能障碍是癌细胞异质性的主要原因。确定特定表观遗传的作用 维持肿瘤起始癌症干细胞亚群和开发靶向治疗的修饰剂 为了有效对抗癌症及其复发，必须阻止这些修饰剂。 最近，我们发现了一种耐药性、高致瘤性、转移性和自我更新的细胞亚群 具有神经母细胞瘤中肿瘤起始细胞（TIC）的特征。该亚群的特征是表面 G-CSF 受体 (CD114) 的表达，可以逃避初始治疗并导致难治性和侵袭性 侵袭性复发性疾病。这些 TIC 可以分化为大量肿瘤细胞 (CD114-) 并产生复杂的 神经母细胞瘤体内只有 10 个细胞。我们最近的初步数据表明，CSF3R 基因 编码 CD114 的蛋白在 CD114+ NB TIC 中特异性表达，但在 CD114- 肿瘤细胞中不表达。我们 假设这种差异基因表达受到表观遗传调节并支持维持 异质 NB TIC。我们还发现表观遗传调节因子混合谱系白血病-1（MLL1；一种 H3K4me3 甲基转移酶）在 CD114+ 细胞中过表达，并调节 TIC 特异性的表达 基因包括CSF3R。 MLL1 与 WDR5 和 Menin 形成蛋白质复合物，充当活性组蛋白 甲基转移酶表观遗传调节剂。我们的初步数据显示，针对 MLL1-WDR5 和 MLL1-Menin 使用特定小分子抑制剂的相互作用抑制 NB TIC 和体内 NB 生长和转移。这些 数据支持我们的假设，即表观遗传调节因子维持 NB TIC 并指向一种新的治疗方法 阻断 MLL1 激活以抑制 NB TIC 介导的致瘤性、转移和疾病复发的策略。 在拟议的研究中，我们将确定：a) MLL1 在维持 NB TIC 亚群中的作用，b) 通过特定小分子抑制剂阻断表观遗传调节因子对 NB 肿瘤发生的影响 体内转移，c) 通过结合同时靶向 NB TIC 和大量肿瘤细胞的效果 表观遗传抑制剂与标准化疗药物的结合，以及 d) 进一步开发新型表观遗传抑制剂 靶向 MLL1 表观遗传功能。作为 MLL1、WDR5 和 Menin 的特异性小分子抑制剂，目前 根据针对实体瘤和白血病的广泛临床前试验，我们的研究结果将为 NB 肿瘤提供见解 生物学和一种新的基于表观遗传学的高危 NB 治疗方法。