Sensitizing Leukemia Stem Cells to NF-kB Inhibition by Blocking TNF Signaling

通过阻断 TNF 信号传导使白血病干细胞对 NF-kB 抑制敏感

• 批准号: 8641557
• 负责人: Andrew Volk
• 金额: $ 2.55万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-08 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8641557
• 关键词: Acute Myelocytic Leukemia; Adverse effects; American; Apoptosis; Biological Assay; Blood Cells; Bone Marrow; Cell Death; Cell Proliferation; Cell Survival; Cell physiology; Cells; Cessation of life; Clinic; Clinical; Data; Development; Disease; Dose; Elements; Equilibrium; Future; Genes; Genetic; Goals; Hematopoietic; Hematopoietic stem cells; Homeostasis; Human; Immune system; In Vitro; Inflammation; Inflammatory; Integumentary System Part; Knock-out; Leukemic Cell; Liver; MAP3K7 gene; MAPK14 gene; MAPK8 gene; MLL-AF9; Measures; Mediating; Modeling; Monoclonal Antibodies; Mus; NF-kappa B; Nervous system structure; Newly Diagnosed; Pancytopenia; Pathogenesis; Pathway interactions; Patients; Phosphotransferases; Proto-Oncogene Proteins c-akt; Receptor Activation; Receptor Signaling; Relapse; Role; Sampling; Signal Pathway; Signal Transduction; Skin; Staining method; Stains; Stem cells; Testing; Therapeutic; Tissues; Toxic effect; Transplantation; Tumor Necrosis Factor Receptor; Tumor Necrosis Factor-alpha; annexin A5; caspase-8; cell growth; cytokine; enhancing factor; fusion gene; hematopoietic tissue; human TNFRSF1A protein; in vivo; inhibitor/antagonist; killings; leukemia; leukemic stem cell; novel; novel strategies; novel therapeutics; prevent; progenitor; public health relevance; receptor; research study; small molecule; treatment effect; tumor necrosis factor alpha receptor

DESCRIPTION (provided by applicant): Leukemia stem cells (LSCs) are the key subset of leukemic cells (LCs) required for leukemia initiation, progression and relapse. Complete elimination of LSCs is currently the ultimate goal of leukemia therapy. In 2001, it was found that using an inhibitor against NF-?B (a transcriptional regulator of many survival genes) resulted in significant death of LSCs in human acute myeloid leukemia samples while preserving healthy hematopoietic stem cells /progenitors (HSC/Ps).1 Unfortunately, the clinical use of NF-?B inhibitors at therapeutic levels is limited by the development of severe inflammation-related side-effects in the skin, the liver, and elements of the nervous, and immune systems. These side effects were uncovered during testing in mice.2-4. Therefore, we need new therapies that reduce side-effects either by using a better NF-?B inhibitor at a lower dose or by developing novel therapies which prevent the inflammation caused by NF-?B inhibitor. Tumor Necrosis Factor alpha (TNF) is a major inflammatory signal released by hematopoietic cells and is implicated in NF-?B modulation therapies.5, 6 While TNF's inflammatory signals causes cell death and growth arrest in normal HSC/Ps, its role in leukemia development is not yet clear.7, 8 What is clear is that managing inflammation is critical for the successful treatment of leukemia.9, 10 Our preliminary studies show that LCs utilize TNF-mediated inflammation as both a survival and proliferation signal by activating a signaling network that depends in part on NF-?B. By knocking out both receptors of TNF (Tnfr1a-/-1b-/-), we can sensitize LCs 100-fold to NF-?B inhibitor treatment when compared to normal HSC/Ps. Therefore, we hypothesize that inhibiting both TNF receptor signaling and NF-?B would provide a double benefit: clinicians could use NF-?B inhibitors at a lower dose while simultaneously blocking TNF-dependent inflammation. Our broad goal in this study is to identify novel leukemia-specific therapeutic strategies that can augment NF-?B inhibition. Our immediate goal is to determine whether blocking TNF signaling augments NF- ?B inhibition in eliminating both leukemic cells and leukemic stem cells. In our study, we will compare treatments in LCs and bone marrow (BM) HSC/Ps, and will take advantage of the murine genetic leukemia models we have generated. We will utilize pharmacological approaches to alter the activity of signaling pathways in order to maximally kill LCs while preserving normal HSC/Ps. We will measure global effects on cell death by Annexin V/PI staining, colonigenic capacity of progenitor cells by CFU assay, and hematopoietic reconstitutive capacity of normal HSC/Ps and leukemogenic capacity of LSCs by in vivo transplantation. The first aim of our study explores the effects of blocking TNF in conjunction with NF-?B inhibitor treatment. Our second aim explores small molecule inhibition of TNF receptor downstream targets in combination with NF-?B inhibitor treatment. The expected results of this study will significantly contribute to furthering the understanding of leukemia, an may also point the way toward novel strategies for future therapies.

描述（由申请人提供）：白血病干细胞（LSC）是白血病发生、进展和复发所需的白血病细胞（LC）的关键亚群。完全消除LSC是目前白血病治疗的最终目标。在2001年，人们发现，使用抑制剂对NF-？B（许多存活基因的转录调节因子）导致人类急性髓性白血病样本中LSC的显著死亡，同时保留健康的造血干细胞/祖细胞（HSC/Ps）。治疗水平的B抑制剂受到皮肤、肝脏、神经和免疫系统元件中严重炎症相关副作用的发展的限制。这些副作用在小鼠试验期间未被发现。2 -4.因此，我们需要新的治疗方法，减少副作用，通过使用更好的NF-？B抑制剂在一个较低的剂量或通过开发新的疗法，防止炎症引起的NF-？B抑制剂。 肿瘤坏死因子α（TNF）是造血细胞释放的主要炎症信号，与NF-？B调节疗法。5，6虽然TNF的炎症信号导致正常HSC/Ps中的细胞死亡和生长停滞，但其在白血病发展中的作用尚不清楚。7，8清楚的是，控制炎症对于成功治疗白血病至关重要。9， 我们的初步研究表明，LC利用TNF介导的炎症作为生存和增殖信号，通过激活部分依赖于NF-？B。通过敲除两种TNF受体（Tnfr 1a-/-1b-/-），我们可以使LC对NF-？与正常HSC/Ps相比，B抑制剂治疗。因此，我们假设，抑制TNF受体信号和NF-？B将提供双重好处：临床医生可以使用NF-？B抑制剂在较低剂量，同时阻断TNF依赖性炎症。 我们在这项研究中的广泛目标是确定新的白血病特异性治疗策略， 增加NF-？B抑制。我们的直接目标是确定是否阻断TNF信号增强NF-？B抑制在消除白血病细胞和白血病干细胞中的作用。在我们的研究中，我们将比较LC和骨髓（BM）HSC/Ps中的治疗，并将利用我们产生的小鼠遗传性白血病模型。我们将利用药理学方法来改变信号通路的活性，以最大限度地杀死LC，同时保留正常的HSC/Ps。我们将通过膜联蛋白V/PI染色来测量对细胞死亡的整体影响，通过CFU测定来测量祖细胞的集落形成能力，以及通过体内移植来测量正常HSC/Ps的造血重建能力和LSC的致白血病能力。我们研究的第一个目的是探讨阻断TNF与NF-？B抑制剂治疗。我们的第二个目标是探讨小分子抑制TNF受体下游的目标结合NF-？B抑制剂治疗。这项研究的预期结果将大大有助于进一步了解白血病，也可能为未来治疗的新策略指明方向。