Elucidating the molecular mechanism of Daple- FLT3 and Daple-PDGFRB gene fusion in blood cancers

阐明Daple-FLT3和Daple-PDGFRB基因融合在血癌中的分子机制

• 批准号: 10666603
• 负责人: Jason Ear
• 金额: $ 18.38万
• 依托单位: CALIFORNIA STATE POLY U POMONA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10666603
• 关键词: Address; Affect; Award; BAY 54-9085; Biochemical; Biological Assay; Blood Vessels; Cell Count; Cell Line; Cells; Centrosome; Chromosomal Rearrangement; Chromosomes; Coiled-Coil Domain; Combined Modality Therapy; Cultured Cells; Dimerization; Disease model; Dominant-Negative Mutation; Drug resistance; Embryo; Embryonic Development; Exposure to; FLT3 gene; Fluorescence Resonance Energy Transfer; GTP-Binding Proteins; Gene Activation; Gene Fusion; Genes; Health; Hematopoietic; Hematopoietic Neoplasms; Heterotrimeric GTP-Binding Proteins; Homeostasis; Human; Imatinib; In Vitro; Lead; Leukemic Cell; Life; Ligand Binding Domain; Liquid substance; Lymphocyte; Lymphoma cell; MAPK3 gene; MEKs; Malignant Neoplasms; Messenger RNA; Microscopy; Modality; Modeling; Molecular; Monitor; Mus; Mutation; Myeloproliferative disease; Nature; Oncogenic; Organism; PDGFRB gene; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Phosphotransferases; Play; Population; Proteins; Proto-Oncogene Proteins c-akt; Ras/Raf; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Regulation; Resistance; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Signaling Protein; Solid Neoplasm; Students; Testing; Therapeutic; Therapeutic Intervention; Time; Training; Tyrosine Kinase Domain; Tyrosine Kinase Inhibitor; Up-Regulation; WNT Signaling Pathway; Western Blotting; Work; Zebrafish; biological research; cancer cell; cancer therapy; career; cell growth; dosage; embryo tissue; fluorescence imaging; gene product; in vivo Model; inhibitor therapy; insight; leukemia; mutant; new therapeutic target; novel; novel therapeutics; overexpression; patient response; patient subsets; protein oligomer; protein protein interaction; receptor; response; side effect; therapeutic evaluation; therapeutic protein; tool; transcriptomics; tumor; tumor progression

PROJECT SUMMARY/ABSTRACT: Receptor tyrosine kinases (RTKs) are a major class of cell signaling receptors and they play major roles in cancer progression. In leukemia, and many cancers, aberrant activation of the RAS-RAF-MEK-ERK signal transduction pathway is often observed. Various RTK mutations, such as those found on PDGFRB and FLT3, are found in leukemia patients and often lead to hyperactivation of the kinase domain. This activation causes the subsequent increase in the RAS-RAF-MEK-ERK signaling pathway. Because the cancer is driven by kinase domain activation, many patients are responsive to tyrosine kinase inhibitor (TKI) treatment such as imatinib and sorafenib. However, in a subset of patients, they become unresponsive to TKIs over time due to a resistance in the cancer cells. One mechanism by which cancer cells can acquire resistance is through gaining a secondary mutation in the kinase domain that makes the kinase insensitive to the TKI. In response, patients are often given higher drug dosage or an approach to target multiple pathways simultaneously using combination therapy is taken. These approaches are often impractical due to cumulative side effects that may be life-threatening. Thus, further insights into the inner workings of cancer cells and mutations that lead to aggressive cancer phenotypes are essential to identifying new therapeutic targets, especially, those on which multiple cancer-fueling signaling pathways may converge. Daple/CCDC88C is scaffold protein that serves as a convergence point for three major signaling pathways in a cell: Wnts, G-proteins, and RTKs. Because protein scaffolds can serve as central hubs integrating cellular signaling, this raises the possibility of exploiting these proteins for therapeutic intervention. Several gene fusion between Daple and PDGFRB or FLT3 have been found in cases of myeloproliferative disorders and leukemias. The exact mechanism by which these gene fusions lead to constitutive activation of the kinase domain remains to be tested and whether regions on Daple that is involved in the gene fusion can be leveraged for therapy remains a mystery. Finally, because these mutations are rare, generating an in vivo model for therapeutic testing in mice is often seen as unpractical. This proposal seeks to address these questions and problems. Specifically, it seeks to understand how the Daple gene fusion affects hematopoietic cell expansion using cell-based models and zebrafish. Also planned in this proposal is to expose how the coiled-coil domain of the Daple-PDGFRB or Daple-FLT3 gene fusion affects protein subcellular localization and to determine if it is responsible for the dimerization and activation of the kinase domain in cells. The strategy that will be employed to target the dimerization point may also serve as a therapeutic strategy. Overall, these studies will give novel insights into how Daple associated mutations affect leukemia cell signaling and growth and it will also establish whether targeting this protein scaffold can be leveraged for cancer therapy.

项目总结/摘要： 受体酪氨酸激酶（receptor tyrosine kinases，RTKs）是一类重要的细胞信号受体，在肿瘤的发生发展中起重要作用 进展在白血病和许多癌症中，RAS-RAF-MEK-ERK信号转导的异常激活 经常观察到的路径。各种RTK突变，如在PDGFRB和FLT 3上发现的那些，在 白血病患者，并经常导致激酶结构域的过度活化。这种激活导致随后的 RAS-RAF-MEK-ERK信号通路增加。因为癌症是由激酶结构域驱动的 激活，许多患者对酪氨酸激酶抑制剂（TKI）治疗如伊马替尼和 索拉非尼。然而，在一部分患者中，随着时间的推移，他们对TKI无反应，这是由于TKI中的耐药性。 癌细胞癌细胞获得耐药性的一种机制是通过获得第二个 激酶结构域中的突变使得激酶对TKI不敏感。作为回应，患者经常被给予 更高的药物剂量或使用组合疗法同时靶向多个途径的方法， 满员你这些方法通常是不切实际的，因为累积的副作用可能危及生命。因此，在本发明中， 进一步深入了解癌细胞的内部运作和导致侵袭性癌症表型的突变 对于确定新的治疗靶点至关重要，特别是那些在其上存在多种癌症助长信号的靶点， 路径可以收敛。Daple/CCDC 88 C是支架蛋白，其充当三种主要的蛋白质的会聚点。 细胞中的信号通路：Wnt、G蛋白和RTK。因为蛋白质支架可以作为中心枢纽 通过整合细胞信号，这提高了利用这些蛋白质进行治疗干预的可能性。 Daple与PDGFRB或FLT 3之间的几种基因融合已在骨髓增生性疾病中发现。 疾病和白血病。这些基因融合导致组成性激活的确切机制是： 激酶结构域仍有待测试，Daple上参与基因融合的区域是否可以被 用于治疗仍然是个谜最后，由于这些突变是罕见的， 在小鼠中进行治疗试验通常被认为是不切实际的。本提案旨在解决这些问题， 问题具体来说，它旨在了解Daple基因融合如何影响造血细胞扩增 使用细胞模型和斑马鱼。本提案中还计划揭示螺旋结构域的 Daple-PDGFRB或Daple-FLT 3基因融合体影响蛋白质亚细胞定位， 负责细胞中激酶结构域的二聚化和活化。将采用的策略是 靶向二聚化点也可以用作治疗策略。总的来说，这些研究将提供新的 深入了解Daple相关突变如何影响白血病细胞信号传导和生长， 靶向这种蛋白质支架是否可以用于癌症治疗。