Study of Anti-Survival signals in NF1

NF1抗生存信号的研究

• 批准号: 8701248
• 负责人: CHANGYAN CHEN
• 金额: $ 8.75万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8701248
• 关键词: Affect; Anaphase; Apoptosis; Apoptotic; Applications Grants; Benign; Binding; Biological; Cell Cycle Checkpoint; Cell Death; Cell division; Cells; Complex; Cyclins; Cytokinesis; Data; Defect; Development; Disease; Disease Outcome; Ensure; Event; GTP Binding; GTPase-Activating Proteins; Genetic; Genetic Techniques; Goals; Hereditary Malignant Neoplasm; Human; Individual; Induction of Apoptosis; Knowledge; Link; Longevity; MAP Kinase Gene; Malignant Peripheral Nerve Sheath Tumor; Mammalian Cell; Mediating; Mission; Mitosis; Mitotic; Mitotic Checkpoint; Molecular; Mus; Mutate; Mutation; NF1 gene; NF1 tumor suppressor; Nervous system structure; Neurofibromatoses; Neurofibromatosis 1; Neurofibromatosis Type 1 Protein; Oncogenic; Pathway interactions; Patients; Phosphoric Monoester Hydrolases; Population; Process; Protein Kinase; Protein Kinase C; Protein Kinase C Inhibitor; Proteins; Regulation; Research; Research Project Grants; Role; Schwann Cells; Series; Signal Pathway; Signal Transduction; Sister Chromatid; Syndrome; Testing; Therapeutic; Therapeutic Intervention; Tumor Suppressor Genes; United States National Institutes of Health; Yeasts; base; cancer type; chemical genetics; cyclin B1; design; in vivo; inhibitor/antagonist; loss of function mutation; mouse model; neoplastic cell; novel; novel therapeutic intervention; novel therapeutics; outcome forecast; research study; treatment strategy; ubiquitin-protein ligase

DESCRIPTION (provided by applicant: Type 1 neurofibromatosis (NF1) is a prevalent familial cancer syndrome affecting certain numbers of human beings. The abnormal genetic locus in neurofibromatosis is Nf1, a tumor suppressor gene. The protein product of Nf1 (neurofibromin) is a GTPase-activating protein (GAP) that negatively regulates Ras signaling and expresses in a high level in Schwann cells that are the cell origin of NF1 disease. Loss-of- function mutations or deletion of Nf1 are responsible for hyper-activation of Ras pathway in NF1 patients. Our preliminary data demonstrated that mutated Nf1, together with the suppression of protein kinase C (PKC), is synthetically lethal, via the activation of the mitotic exit checkpoint. In this process, Plk1 was activated in a Chk1-dependent fashion. Through binding to cdc14B, Plk1 blocked its functions and further silenced Cdh1 activity, resulting in the increase of cyclin B1 stability and accumulation of Nf1 deficient neurofibromatosis cells in the M phase of the cell cycle. Importantly, the activation of this mitotic exit checkpoint coincided with the induction of apoptosis. In yeast and mammalian cells, mitotic exit involves an intricately ordered series of events, leading from the splitting of sister chromatids at anaphase onset to the completion of cell division by cytokinesis. If insults target late stages of mitosis, mitotic exit checkpoint would be activated and subsequently induce mitotic catastrophe to eliminate unwanted cells or terminates mitosis. Based on our preliminary data and our knowledge of the mitotic exit checkpoint, we hypothesize that Nf1 mutation, together with loss of PKC, is synthetically lethal, which is through the activation of the mitotic exit checkpoint. Identification of critical molecular events in this mitotic crisis will allow efficient therapeutic interventions of neurofibromatosis 1. To test this hypothesis, we will: 1) investigate the mechanism by which Plk1/cdc14B axis regulates the activation of this mitotic exit checkpoint in HMG- treated Nf1 deficient neurofibromatosis 1 cells; 2) investigate the role of Cdh1 in the mitotic exit checkpoint induced by PKC suppression in the Nf1 deficient cells; and 3) determine how Ras-mediated pathways trigger the mitotic exit checkpoint in HMG-treated Nf1 deficient cells and further induce apoptosis in vivo. Since Nf1 defect affects a large of human population and the poor prognosis for patients with advanced malignant peripheral nerve sheath tumor (MPNST) emphasize the urgent need for new chemotherapeutic approaches to treat this disease, the outcomes of this proposed study will have translational importance in the design of new therapeutic strategies to manipulate intracellular signaling and specifically re-direct the Nf1 deficient cells to undergo apoptosis, which is fully in accord with the central mission of NIH.

描述(申请人提供：1型神经纤维瘤病(NF1)是一种流行的家族性癌症综合征，影响一定数量的人类。神经纤维瘤病的异常遗传位点是肿瘤抑制基因Nf1。神经纤维蛋白1(NF1)的蛋白产物是一种GTP酶激活蛋白(GAP)，它负向调节RAS信号，并在NF1病的细胞起源的雪旺细胞中高水平表达。NF1功能缺失突变或缺失是NF1患者RAS通路过度激活的原因。我们的初步数据表明，突变的NF1与蛋白激酶C(PKC)的抑制一起，通过激活有丝分裂出口检查点，是合成致命的。在这个过程中，Plk1以依赖Chk1的方式被激活。Plk1通过与cdc14B结合，阻断其功能，进一步抑制CDH1的活性，导致细胞周期蛋白B1的稳定性增加，并使NF1缺陷型神经纤维瘤细胞在细胞周期的M期积累。重要的是，这个有丝分裂出口检查点的激活与细胞凋亡的诱导是一致的。在酵母和哺乳动物细胞中，有丝分裂退出涉及一系列复杂有序的事件，从姐妹染色单体在后期开始分裂到通过胞质分裂完成细胞分裂。如果INSET针对有丝分裂的晚期，有丝分裂出口检查点将被激活，随后引发有丝分裂灾难，以消除不需要的细胞或终止有丝分裂。根据我们的初步数据和我们对有丝分裂出口检查点的了解，我们假设Nf1突变和PKC的丢失是综合致命的，这是通过激活有丝分裂出口检查点来实现的。为了验证这一假说，我们将：1)研究Plk1/cdc14B轴调节HMG处理的NF1缺陷神经纤维瘤病1细胞中这个有丝分裂退出检查点的激活的机制；2)研究CDH1在由PKC抑制在NF1缺陷细胞中诱导的有丝分裂退出检查点中的作用；以及3)确定RAS介导的通路如何在HMG处理的NF1缺陷细胞中触发有丝分裂退出检查点并进一步诱导体内的细胞凋亡。由于NF1缺陷影响了大量人群和晚期恶性周围神经鞘瘤(MPNST)患者的不良预后，强调了迫切需要新的化疗方法来治疗这种疾病，本研究的结果将对设计新的治疗策略来操纵细胞内信号转导和特异性地重定向NF1缺陷细胞进行凋亡具有翻译意义，这完全符合NIH的中心使命。