Targeting the p62 signalosome in leukemia.

靶向白血病中的 p62 信号体。

• 批准号: 10221634
• 负责人: Jing Fang
• 金额: $ 33.51万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10221634
• 关键词: Adaptor Signaling Protein; Binding; Cell Proliferation; Cell Survival; Cell physiology; Chronic; Clinical; Dependence; Development; Disease model; Follow-Up Studies; Goals; Hematologic Neoplasms; Hematopoietic stem cells; Human; In Vitro; Knock-in Mouse; Leukemic Cell; MLL-AF9; MLL-rearranged leukemia; Maintenance; Malignant - descriptor; Malignant neoplasm of lung; Malignant neoplasm of prostate; Mediating; Mixed-Lineage Leukemia; Molecular; Multiple Myeloma; Mus; Normal Cell; Outcome; Pathway interactions; Patients; Phenotype; Preleukemia; RIPK1 gene; RNA Interference; Refractory; Resistance; Role; Signal Pathway; Solid Neoplasm; Specificity; TNF gene; Testing; Therapeutic; base; cell growth; chromosome 5q loss; conventional therapy; design; improved; in vivo; knock-down; leukemia; leukemic stem cell; leukemogenesis; loss of function; mutant; new therapeutic target; novel therapeutic intervention; overexpression; preservation; recruit; response; side effect; small molecule; stem cell function; stem cell population; targeted treatment; therapy resistant

Project Summary/Abstract Patients with certain subtypes of leukemia are associated with dismal outcomes due to resistance to current treatment options, particularly for those with MLL rearrangements. Chronic NF-κB activity is observed in leukemia cells, especially within the leukemia stem cell (LSC) population, and is implicated as a requirement for leukemogenesis, including the MLL-driven leukemia. Given the pleotropic function of NF-κB, targeting the leukemia-specific function of NF-κB is urgently needed. However, the molecular mechanism of the leukemia- specific function of NF-κB is unclear. Previous studies implicate the adaptor protein Sequestosome 1 (also known as p62) as dispensable for normal hematopoietic stem and progenitor cell (HSPC) function. Intriguingly we find that p62 is overexpressed in leukemia cells, and associated with increased TNFα in leukemia patients. p62 was shown to form a signalosome with RIPK1 (p62/RIPK1) via its ZZ domain in response to TNFα, leading to NF-κB activation. Our functional study reveals that p62 is required for leukemia cell function through activating NF-κB, indicating HSPC acquire a dependency on p62 function during transformation and p62-mediated signaling pathway represents a leukemia-specific mechanism that activates NF-κB. My long-term goal is to improve the targeted therapy by identifying leukemia-specific signaling pathways and testing novel therapeutic approaches. The objectives of this proposal are to: (1) determine the contribution of p62 to promoting leukemia; (2) elucidate the molecular mechanism of p62 in activating NF-κB in leukemia; and (3) test targeting the leukemia-specific p62 signalosome with a small molecule compound as a means to inactive NF-κB and inhibit leukemia cell and LSC while preserving normal HSPC. We hypothesize that p62 promotes leukemia by forming a leukemia- specific p62/RIPK1 signalosome that activates NF-κB. In particular, given that p62 supports MLL leukemia cell growth and NF-κB mediates MLL-driven leukemogenesis, we will determine the contribution of p62 in promoting MLL leukemia by examining preleukemia and leukemia phenotype in Mll-AF9 knockin mice followed by p62 deletion (Mll-AF9+/-;p62?/?mice). We will determine whether p62 promotes leukemia through activating NF-κB. In addition, we will determine whether p62 binds RIPK1 in leukemia cells, and whether the p62/RIPK1 signalosome is essential for NF-κB activation and leukemogenesis. Moreover, we will examine whether the ZZ domain on p62 is required for forming the p62/RIP signalosome, activating NF-κB and promoting leukemia. Finally, we will test a small molecule compound that specifically targets the p62 ZZ domain in disrupting the p62/RIPK1 signalosome, inactivating NF-κB and inhibiting leukemia cells and LSC while preserving normal HSPC. We anticipate that targeting the leukemia-specific p62 signalosome exerts antileukemia effect without damaging normal cells. The proposed study will impact on our understanding on leukemia-specific signaling pathways. The findings from this study will help us design novel therapeutic strategies that improve the specificity of targeted therapy for aggressive subtypes of leukemia.

项目总结/摘要 某些亚型的白血病患者由于对电流的抵抗而与令人沮丧的结果相关。 治疗选择，特别是对于那些与MLL重排。慢性NF-κB活性在 白血病细胞，特别是白血病干细胞（LSC）群体中的白血病细胞，并涉及作为一种需要， 白血病发生，包括MLL驱动的白血病。考虑到NF-κB的多效性功能，靶向NF-κB的表达可能是一个潜在的靶点。 因此，研究NF-κB B在白血病中的特异性功能是迫切需要的。但是白血病的分子机制 NF-κB具体功能尚不清楚。先前的研究表明衔接蛋白Sequestosome 1（也称为 作为p62）作为正常造血干细胞和祖细胞（HSPC）功能的抑制剂。有趣的是我们发现 p62在白血病细胞中过表达，并与白血病患者TNFα升高相关。p62是 显示通过其ZZ结构域与RIPK 1（p62/RIPK 1）形成信号体以响应TNFα，导致NF-κB activation.我们的功能研究表明，p62通过激活NF-κB， 表明HSPC在转化和p62介导的信号转导过程中获得对p62功能的依赖性 NF-κ B通路代表了激活NF-κB的白血病特异性机制。我的长期目标是改善 通过识别白血病特异性信号通路和测试新的治疗方法来进行靶向治疗。 本提案的目标是：（1）确定p62对促进白血病的贡献;（2）阐明 p62在白血病中激活NF-κB的分子机制;（3）靶向白血病特异性 p62信号体与小分子化合物作为使NF-κB失活并抑制白血病细胞的手段， LSC，同时保持正常HSPC。我们假设p62通过形成白血病- 激活NF-κB的特异性p62/RIPK 1信号体。特别是，考虑到p62支持MLL白血病细胞， 生长和NF-κB介导MLL驱动的白血病发生，我们将确定p62在促进白血病发生中的作用。 MLL白血病，通过检查MII-AF 9敲入小鼠中的白血病前和白血病表型，随后用p62 缺失（M11-AF 9 +/-;p62？/？小鼠）。我们将确定p62是否通过激活NF-κB促进白血病。 此外，我们将确定p62是否在白血病细胞中结合RIPK 1，以及p62/RIPK 1是否在白血病细胞中结合。 信号体在NF-κB活化和白血病发生中起重要作用。此外，我们将研究ZZ是否 p62上的结构域是形成p62/RIP信号体、激活NF-κB和促进白血病所必需的。 最后，我们将测试一种特异性靶向p62 ZZ结构域的小分子化合物， p62/RIPK 1信号体，失活NF-κB并抑制白血病细胞和LSC，同时保持正常 HSPC。我们预期靶向白血病特异性p62信号体发挥抗白血病作用， 破坏正常细胞。这项研究将影响我们对白血病特异性信号的理解 途径。这项研究的发现将帮助我们设计新的治疗策略，提高特异性， 针对白血病侵袭性亚型的靶向治疗。

项目成果

Cyclosporine Broadens the Therapeutic Potential of Lenalidomide in Myeloid Malignancies.

• DOI: 10.33696/immunology.2.049
• 发表时间: 2020
• 期刊: Journal of cellular immunology
• 作者: Dou A;Fang J
• 通讯作者: Fang J

G protein-coupled receptor 68 increases the number of B lymphocytes.

G 蛋白偶联受体 68 增加 B 淋巴细胞的数量。

• 发表时间: 2020
• 期刊: American journal of blood research
• 作者: He,Xiaofei;Feng,Saran;Hawkins,Caleb;Lawley,Lauren;Fan,Wenxin;Xu,Yan;Zha,Xiang-Ming;Fang,Jing
• 通讯作者: Fang,Jing