Aberrant activation of HGF/MET signaling as a therapeutic target in AML

HGF/MET 信号传导异常激活作为 AML 的治疗靶点

• 批准号: 8165860
• 负责人: Alex Kentsis
• 金额: $ 15.63万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8165860
• 关键词: Accounting; Acute Myelocytic Leukemia; Acute Promyelocytic Leukemia; Adult; Advisory Committees; Alternative Therapies; Antibodies; Award; Biochemistry; Biological; Biological Assay; Biophysics; Bone marrow biopsy; Candidate Disease Gene; Cell Line; Cell Survival; Cells; Cellular biology; Cessation of life; Chemicals; Child; Chromosome abnormality; Clinical; Clinical Trials; Combination Drug Therapy; Complex; Critiques; Dana-Farber Cancer Institute; Dasatinib; Dependence; Development; Diagnosis; Diagnostic; Disease; Elements; Engineering; Environment; FLT3 gene; Foundations; Future; Gene Expression; Gene Expression Profiling; Genetic; Genomic Instability; Genomics; Growth; Hematologic Neoplasms; Hematology; Hepatocyte Growth Factor; Immunohistochemistry; In Vitro; Individual; Investigation; Karyotype; Lead; Libraries; Ligands; Lymphoma; MET Oncogene; Mediating; Mentors; Mentorship; Methods; Modeling; Molecular; Multiple Myeloma; Mus; Mutate; Mutation; Oncogenes; Oncogenic; Pathway interactions; Patients; Pediatric Hematology/Oncology; Pediatric Oncology; Phosphotransferases; Physicians; Play; Protein Tyrosine Kinase; Proteomics; RNA Interference; Receptor Protein-Tyrosine Kinases; Refractory; Relapse; Research Proposals; Resistance; Resistance development; Risk; Role; Scientist; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Specimen; Surveys; System; Testing; Therapeutic; Therapeutic Intervention; Training; Transduction Gene; Treatment Efficacy; Tyrosine Kinase Inhibitor; Writing; addiction; autocrine; cancer cell; carcinogenesis; career; cell growth; clinically relevant; combinatorial; functional genomics; genome-wide; high risk; improved; in vivo; in vivo Model; inhibitor/antagonist; innovation; insight; kinase inhibitor; leukemia; meetings; mouse model; new therapeutic target; oncology; preclinical study; receptor; small hairpin RNA; therapeutic target; therapy resistant; tool

DESCRIPTION (provided by applicant): Despite improvement in treatment of acute myeloid leukemia (AML), high-risk disease such as complex karyotype AML remains largely refractory to current therapy, and is mostly fatal. Identification of effective therapeutic targets by using candidate gene approaches has been limited by the number and variety of genetic defects associated with AML. To identify new therapeutic targets, I carried out a genome-wide functional screen by using a retroviral library of short hairpin RNAs (shRNAs) in complex karyotype AML cells. I discovered that shRNA mediated depletion of hepatocyte growth factor (HGF), ligand of the receptor tyrosine kinase MET, specifically inhibits growth of AML but not other hematologic cancer cells. MET is a potent oncogene, whose aberrant activation is widely implicated in carcinogenesis, causing enhanced growth, survival, and genomic instability of cancer cells. However, mechanisms of carcinogenic MET signaling are currently not well understood, and HGF/MET signaling is not thought to play a role in AML. To validate this observation in patient specimens, I carried out immunohistochemistry of diagnostic bone marrow biopsies. I observed that HGF is aberrantly expressed and associated with activation of MET in about 15% of patients with AML, including most patients with complex karyotype disease. Analysis of cell lines derived from such patients showed that HGF expression was associated with autocrine activation of its receptor MET. Depletion of HGF or MET using shRNA or inhibition of MET using tyrosine kinase inhibitors and neutralizing anti-HGF antibody profoundly reduced proliferation and induced death of AML cells lines that express HGF but not those that lack HGF expression. This indicates the functional dependence or "oncogene addiction" to this pathway, and suggests that therapeutic inhibition of HGF/MET signaling may be used to improve the treatment of AML. However, detailed understanding of the molecular mechanisms by which this pathway promotes AML cell growth and survival is currently lacking. By genetically engineering AML cell lines to deplete and express specific signaling molecules, and isolating cell lines that are resistant to HGF/MET inhibition, I will identify signaling components that mediate HGF/MET "oncogene addiction," and strategies to overcome resistance to therapeutic inhibition of HGF/MET signaling. These studies will be combined with the investigation of antileukemic efficacy of HGF/MET inhibition in murine models of AML in vivo using functional nanoimmunoassay, phosphoproteomic and genomic methods to identify not only the optimal strategy to target this pathway clinically, but also how to optimally integrate it with other targeted inhibitors of AML signaling. These technical advances will circumvent limitations associated with empiric discovery of novel therapeutic targets in AML, and will identify the principal signaling pathways required for AML cell growth and survival. The cell line systems and mouse models will also allow for detailed analysis of gene expression and proteomic changes that accompany signaling by receptor tyrosine kinases, thus providing key mechanistic insights that will be important to a wide variety of biological and disease phenomena. Results of the in vitro and in vivo studies will be further investigated using primary patient specimens, and will lay the foundation for future preclinical studies and clinical trials of targeted therapies of AML. The specific aims are: Specific Aim 1: Dissect the molecular signaling pathways responsible for the HGF/MET dependence of AML cell growth and survival, and identify mechanisms that account for resistance to HGF/MET inhibition (years 1-3). Specific Aim 2: Assess the antileukemic efficacy of HGF/MET inhibition in murine AML models in vivo, both by itself and in concert with the inhibition of other leukemogenic tyrosine kinases, including FLT3 and KIT (years 3-5). The applicant, Dr. Alex Kentsis, a pediatric hematology/oncology fellow at the Dana-Farber Cancer Institute (DFCI) has outlined a 5-year career plan that will build upon his background in biophysics and clinical hematology/oncology. Under the mentorship of Dr. Thomas Look, a recognized leader in cancer cell biology and translational investigations of leukemia, Dr. Kentsis seeks to utilize powerful functional genomic and proteomic approaches using a combination of in vitro systems and murine models in vivo to study the role of aberrant HGF/MET signaling in AML. Dr. Kentsis will be mentored by an Advisory Committee of internationally recognized experts in the field. Finally, the plan is ideally carried out in the Department of Pediatric Oncology at DFCI, given its distinguished record for training physician-scientists in a rich and collaborative environment. With the support provided by the K08 award, Dr. Kentsis' project will lead to the development of clinically effective HGF/MET targeted therapy for AML. PUBLIC HEALTH RELEVANCE: Despite improvement in treatment of acute myeloid leukemia (AML), high-risk disease such as complex karyotype AML remains largely refractory to current therapy, and is mostly fatal. To identify new therapeutic targets, I carried out a genome-wide functional screen, and discovered that hepatocyte growth factor (HGF) and its receptor tyrosine kinase MET are aberrantly activated in AML cells, particularly among patients with the highest-risk disease. This research proposal will investigate the molecular mechanisms responsible for HGF/MET-dependent AML cell growth and survival, means for its therapeutic targeting in patients, and optimal strategies to overcome potential resistance to therapy, leading to the development of improved, rationally combined targeted therapy for the treatment of AML. The written critiques and criteria scores of individual reviewers are provided in essentially unedited form in the "Critique" section below. Please note that these critiques and criteria scores were prepared prior to the meeting and may not have been revised subsequent to any discussions at the review meeting. The "Resume and Summary of Discussion" section above summarizes the final opinions of the committee.

描述（由申请人提供）：尽管急性髓系白血病（AML）的治疗有所改善，但诸如复杂核型 AML 之类的高风险疾病在目前的治疗中仍然难以治愈，并且大多是致命的。使用候选基因方法鉴定有效的治疗靶点受到与 AML 相关的遗传缺陷的数量和种类的限制。为了确定新的治疗靶点，我使用复杂核型 AML 细胞中的短发夹 RNA (shRNA) 逆转录病毒文库进行了全基因组功能筛选。我发现 shRNA 介导的肝细胞生长因子 (HGF)（受体酪氨酸激酶 MET 的配体）的消耗可以特异性抑制 AML 的生长，但不能抑制其他血液癌细胞的生长。 MET 是一种强效致癌基因，其异常激活广泛参与致癌作用，导致癌细胞生长、存活和基因组不稳定。然而，致癌 MET 信号传导的机制目前尚不清楚，并且 HGF/MET 信号传导不被认为在 AML 中发挥作用。为了在患者标本中验证这一观察结果，我对诊断性骨髓活检进行了免疫组织化学分析。我观察到大约 15% 的 AML 患者（包括大多数患有复杂核型疾病的患者）中 HGF 异常表达并与 MET 激活相关。对来自此类患者的细胞系的分析表明，HGF 表达与其受体 MET 的自分泌激活相关。使用shRNA消耗HGF或MET或使用酪氨酸激酶抑制剂和中和性抗HGF抗体抑制MET显着减少表达HGF的AML细胞系的增殖并诱导死亡，但不影响那些缺乏HGF表达的AML细胞系。这表明该途径的功能依赖性或“癌基因成瘾”，并表明 HGF/MET 信号传导的治疗性抑制可用于改善 AML 的治疗。然而，目前尚缺乏对该途径促进 AML 细胞生长和存活的分子机制的详细了解。通过对 AML 细胞系进行基因改造以消耗和表达特定信号分子，并分离对 HGF/MET 抑制具有抗性的细胞系，我将确定介导 HGF/MET“癌基因成瘾”的信号成分，以及克服对 HGF/MET 信号传导治疗抑制的抗性的策略。这些研究将与使用功能性纳米免疫测定、磷酸蛋白质组学和基因组方法对 AML 小鼠模型中 HGF/MET 抑制的抗白血病功效的研究相结合，不仅确定临床上针对该通路的最佳策略，而且还确定如何将其与 AML 信号传导的其他靶向抑制剂进行最佳整合。这些技术进步将规避与 AML 新治疗靶点的经验发现相关的局限性，并将确定 AML 细胞生长和存活所需的主要信号传导途径。细胞系系统和小鼠模型还将允许详细分析伴随受体酪氨酸激酶信号传导的基因表达和蛋白质组变化，从而提供对多种生物和疾病现象非常重要的关键机制见解。体外和体内研究结果将利用原发患者标本进行进一步研究，为未来AML靶向治疗的临床前研究和临床试验奠定基础。具体目标是： 具体目标 1：剖析负责 AML 细胞生长和存活的 HGF/MET 依赖性的分子信号传导途径，并确定抵抗 HGF/MET 抑制的机制（1-3 年）。具体目标 2：评估 HGF/MET 抑制在小鼠 AML 模型中的体内抗白血病功效，无论是其本身还是与其他致白血病酪氨酸激酶（包括 FLT3 和 KIT）的抑制相结合（3-5 年）。申请人 Alex Kentsis 博士是达纳法伯癌症研究所 (DFCI) 的儿科血液学/肿瘤学研究员，他概述了一个基于其生物物理学和临床血液学/肿瘤学背景的 5 年职业计划。在癌细胞生物学和白血病转化研究领域公认的领导者 Thomas Look 博士的指导下，Kentsis 博士寻求利用强大的功能基因组和蛋白质组学方法，结合体外系统和体内小鼠模型来研究异常 HGF/MET 信号传导在 AML 中的作用。肯特西斯博士将接受由该领域国际知名专家组成的咨询委员会的指导。最后，鉴于 DFCI 儿科肿瘤科在丰富的协作环境中培训医师科学家的杰出记录，该计划非常适合在 DFCI 儿科肿瘤科实施。在 K08 奖的支持下，Kentsis 博士的项目将致力于开发临床有效的 AML 的 HGF/MET 靶向疗法。 公共卫生相关性：尽管急性髓性白血病 (AML) 的治疗有所改善，但复杂核型 AML 等高风险疾病在目前的治疗中仍然难以治愈，并且大多是致命的。为了确定新的治疗靶点，我进行了全基因组功能筛选，发现肝细胞生长因子 (HGF) 及其受体酪氨酸激酶 MET 在 AML 细胞中异常激活，特别是在患有最高风险疾病的患者中。该研究计划将研究 HGF/MET 依赖性 AML 细胞生长和存活的分子机制、其在患者中的治疗靶向手段以及克服潜在治疗耐药性的最佳策略，从而开发出改进的、合理组合的 AML 靶向治疗。 下面的“评论”部分以基本上未经编辑的形式提供了个人评论者的书面评论和标准分数。请注意，这些批评和标准分数是在会议之前准备的，在审查会议上进行任何讨论后可能不会进行修改。上面的“讨论简历和摘要”部分总结了委员会的最终意见。