Novel Targeted Therapy for AML

AML 的新型靶向治疗

• 批准号: 8655146
• 负责人: KAPIL BHALLA
• 金额: $ 31.7万
• 依托单位: METHODIST HOSPITAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-22 至 2015-03-17
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8655146
• 关键词: Acute Myelocytic Leukemia; Apoptosis; Attenuated; Biogenesis; Cell Proliferation; Cells; Centrosome; Clinical; Clinical Data; Combined Modality Therapy; DNA Repair; Development; Diagnosis; Disease remission; Dislocations; FLT3 gene; Genes; Growth; Histone Deacetylase Inhibitor; Histones; Human; In Vitro; Knowledge; Molecular Chaperones; Mutation; Myeloproliferative disease; N-terminal; NPM1 gene; Nucleic Acids; Patients; Phenotype; Phosphoproteins; Protein Tyrosine Kinase; Proteins; Refractory; Relapse; Reporting; Ribosomes; Role; Testing; Toxic effect; Transcriptional Regulation; Tretinoin; Tumor Suppressor Proteins; Tyrosine Kinase Inhibitor; base; cell growth; chemotherapy; founder mutation; gain of function; high throughput screening; in vivo; mouse model; mutant; novel; nucleophosmin; outcome forecast; pre-clinical; public health relevance

DESCRIPTION (provided by applicant): There is a clear unmet need to develop novel, targeted and safer therapies for acute myeloid leukemia (AML). Approximately 30% of AML carry a heterozygous mutation in the nucleophosmin 1 (NPM1), which results in the cytoplasmic dislocation of the mutant NPM1 (mtNPM1). Wild-type NPM1 (wtNPM1) is a nucleolar phosphoprotein, which functions as a molecular chaperone for proteins and nucleic acids (4). The N-terminal conserved oligomerization domain of NPM1 is critical for its multiple functions. In AML, presence of the cytoplasmic, dislocated mtNPM1 attenuates the levels of the nucleolar wtNPM1. As a founder mutation in AML, mtNPM1 is a haploinsufficient tumor suppressor of myeloid malignancies and appears to also confer a gain of function for the AML phenotype. Although its presence is associated with a relatively better prognosis in AML, mtNPM1 is often co-expressed with mutant FLT-3-ITD (internal tandem duplication), which represents an aggressive and relatively treatment-refractory sub-type of AML. Recently, we reported that knockdown of the levels and/or function of NPM1 induces growth arrest, differentiation and apoptosis of AML cells with mtNPM1, as well as sensitizes the AML cells to differentiation induced by all-trans retinoic acid (ATRA). Therefore, there is a strong rationale and need for fully evaluating the anti-AML efficacy and its mechanism following the targeted knockdown of the level and/or function of NPM1 along with a differentiation inducing agent or a FLT3-TKI. Based on this, the objectives of this proposal are to fill the gap in our knowledge about the mechanism by which knockdown of NPM1 induces differentiation and apoptosis and increases sensitivity of AML cells with mtNPM1 to differentiation-inducing therapy and FLT3-TKI. Proposed in vitro and in vivo studies in mouse models will create the supportive pre-clinical data for further clinical development of the novel combinations of NPM1 antagonist-based therapy of AML. These studies will test the unifying hypothesis that knockdown of NPM1 levels/function overcomes differentiation arrest and sensitizes AML cells that express mtNPM1 to differentiation-inducing agents, as well as sensitizes AML cells that co-express FLT3-ITD and mtNPM1 to FLT3-TKI. The specific aims of the proposal are: AIM 1: To determine the in vitro and in vivo effects of the knockdown of NPM1 (mtNPM1 versus wtNPM1 plus mtNPM1) levels or function on cell growth, differentiation and survival of cultured and patient-derived primary AML cells expressing mtNPM1. AIM 2: To determine the sensitizing effect of knockdown of NPM1 levels or function on the in vitro and in vivo activity of differentiation- inducing agents, e.g., all-trans retinoic acid (ATRA) or a histone deacetylase (HDAC) inhibitor, against cultured and primary AML cells. AIM 3: To determine the in vitro and in vivo anti-AML activity of combined targeting of NPM1 and FLT3-ITD in cultured and primary AML cells that co-express mtNPM1 and FLT3-ITD. Overall, these aims will establish NPM1 as a 'druggable' target and pave the way for performing high throughput screening and development of novel compounds that target NPM1 for the therapy of AML expressing mtNPM1.

描述（由申请人提供）：对于开发针对急性髓系白血病（AML）的新颖、有针对性且更安全的疗法，显然存在未满足的需求。大约 30% 的 AML 携带核磷蛋白 1 (NPM1) 杂合突变，导致突变 NPM1 (mtNPM1) 的细胞质错位。野生型 NPM1 (wtNPM1) 是一种核仁磷蛋白，充当蛋白质和核酸的分子伴侣 (4)。 NPM1 的 N 端保守寡聚结构域对其多种功能至关重要。在 AML 中，细胞质中脱位的 mtNPM1 的存在会减弱核仁 wtNPM1 的水平。作为 AML 的始祖突变，mtNPM1 是骨髓恶性肿瘤的单倍体不足的肿瘤抑制因子，似乎也赋予 AML 表型功能增益。尽管 mtNPM1 的存在与 AML 相对较好的预后相关，但 mtNPM1 通常与突变体 FLT-3-ITD（内部串联重复）共表达，后者代表了一种侵袭性且相对难治性的 AML 亚型。最近，我们报道，NPM1 水平和/或功能的敲低可诱导 mtNPM1 AML 细胞的生长停滞、分化和凋亡，并使 AML 细胞对全反式视黄酸 (ATRA) 诱导的分化敏感。因此，有充分的理由和需要全面评估靶向敲除 NPM1 的水平和/或功能以及分化诱导剂或 FLT3-TKI 后的抗 AML 功效及其机制。基于此，本提案的目的是填补我们对 NPM1 敲低诱导分化和凋亡机制的认识空白，并增加 mtNPM1 AML 细胞对分化诱导治疗和 FLT3-TKI 的敏感性。拟议的小鼠模型体外和体内研究将为基于 NPM1 拮抗剂的 AML 治疗新组合的进一步临床开发提供支持性临床前数据。这些研究将检验统一的假设，即敲低 NPM1 水平/功能可以克服分化停滞，并使表达 mtNPM1 的 AML 细胞对分化诱导剂敏感，并使共表达 FLT3-ITD 和 mtNPM1 的 AML 细胞对 FLT3-TKI 敏感。该提案的具体目标是： 目标 1：确定 NPM1（mtNPM1 与 wtNPM1 加 mtNPM1）水平敲低或功能对表达 mtNPM1 的培养的和源自患者的原代 AML 细胞的细胞生长、分化和存活的体外和体内影响。目标 2：确定敲低 NPM1 水平或功能对分化诱导剂（例如全反式视黄酸 (ATRA) 或组蛋白脱乙酰酶 (HDAC) 抑制剂）针对培养和原代 AML 细胞的体外和体内活性的敏化作用。目标 3：确定在共表达 mtNPM1 和 FLT3-ITD 的培养和原代 AML 细胞中联合靶向 NPM1 和 FLT3-ITD 的体外和体内抗 AML 活性。总体而言，这些目标将把 NPM1 确立为“可成药”靶点，并为进行高通量筛选和开发靶向 NPM1 的新型化合物铺平道路，以治疗表达 mtNPM1 的 AML。