Novel Targeted Therapy for AML

AML 的新型靶向治疗

• 批准号: 9247879
• 负责人: KAPIL BHALLA
• 金额: $ 33.2万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-15 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9247879
• 关键词: Acute Myelocytic Leukemia; Apoptosis; Attenuated; Biogenesis; Cell Proliferation; Cells; Centrosome; Clinical Data; Combined Modality Therapy; DNA Repair; Development; Diagnosis; Disease remission; Dislocations; FLT3 gene; Genes; Growth; HDAC4 gene; Histone Deacetylase Inhibitor; Histones; Human; In Vitro; Knowledge; Molecular Chaperones; Mutation; Myeloproliferative disease; N-terminal; NPM1 gene; Nucleic Acids; Pathogenicity; Patients; Phenotype; Phosphoproteins; Protein Tyrosine Kinase; Proteins; Refractory; Relapse; Reporting; Ribosomes; Role; Testing; Transcriptional Regulation; Treatment-related toxicity; Tretinoin; Tumor Suppressor Proteins; Tyrosine Kinase Inhibitor; base; cell growth; chemotherapy; clinical development; founder mutation; gain of function; high throughput screening; in vivo; knock-down; mouse model; mutant; new therapeutic target; novel; nucleophosmin; outcome forecast; pre-clinical; public health relevance; targeted treatment

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）：开发新型、靶向和更安全的急性髓性白血病（AML）治疗方法的需求明显未被满足。大约30%的AML携带核磷蛋白1 （NPM1）的杂合突变，导致突变的NPM1 （mtNPM1）的细胞质错位。野生型NPM1 （wtNPM1）是一种核仁磷酸化蛋白，其功能是蛋白质和核酸的分子伴侣(4)。NPM1的n端保守寡聚化结构域对其多种功能至关重要。在AML中，细胞质中脱位的mtNPM1的存在降低了核仁wtNPM1的水平。作为AML的创始突变，mtNPM1是髓系恶性肿瘤的单倍不足肿瘤抑制因子，并且似乎也赋予AML表型的功能增益。尽管mtNPM1的存在与AML相对较好的预后相关，但mtNPM1经常与突变型FLT-3-ITD（内部串联重复）共表达，后者代表了一种侵袭性和相对治疗难治的AML亚型。最近，我们报道了NPM1水平和/或功能的下调可诱导含有mtNPM1的AML细胞生长停滞、分化和凋亡，并使AML细胞对全反式维甲酸（ATRA）诱导的分化敏感。因此，有充分的理由和需要在靶向敲除NPM1的水平和/或功能以及分化诱导剂或FLT3-TKI后，全面评估抗aml的功效及其机制。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的机制的空白，并增加带有mtNPM1的AML细胞对诱导分化治疗和FLT3-TKI的敏感性。拟在小鼠模型中进行的体外和体内研究将为进一步临床开发基于NPM1拮抗剂的新型AML治疗组合提供支持性的临床前数据。这些研究将验证一个统一的假设，即NPM1水平/功能的下调克服了分化阻滞，并使表达mtNPM1的AML细胞对分化诱导剂敏感，以及使共同表达FLT3-ITD和mtNPM1的AML细胞对FLT3-TKI敏感。该提案的具体目的是：目的1：确定NPM1 （mtNPM1与wtNPM1 + mtNPM1）水平或功能的敲低对表达mtNPM1的培养和患者源性原发性AML细胞的细胞生长、分化和存活的体外和体内影响。目的2：确定NPM1水平或功能下调对诱导分化剂（如全反式维甲酸（ATRA）或组蛋白去乙酰化酶（HDAC）抑制剂）对培养和原代AML细胞的体外和体内活性的增敏作用。目的3：在共表达mtNPM1和FLT3-ITD的培养细胞和原代AML细胞中，检测联合靶向NPM1和FLT3-ITD的体外和体内抗AML活性。总的来说，这些目标将确立NPM1作为一个“可药物”靶点，并为高通量筛选和开发靶向NPM1治疗表达mtNPM1的AML的新化合物铺平道路。