Identification of Novel Drug Targets For Use in Preventing Deafness Caused by NF2

鉴定用于预防 NF2 引起的耳聋的新药物靶点

基本信息

批准号：
7878605
负责人：
CRISTINA Maria FERNANDEZ-VALLE
金额：
$ 29.66万
依托单位：
UNIVERSITY OF CENTRAL FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-01 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7878605
关键词：
Acoustic Nerve Acoustic Neuroma Actins Adult Apoptosis Auditory Brain Stem Implants Autocrine Communication Axon Basal lamina Binding Brain Stem Cancer Biology Cell Death Cell Shape Cell membrane Cell physiology Cell-Cell Adhesion Cells Cellular Morphology Complete Hearing Loss Complex Cues Cyclic AMP-Dependent Protein Kinases Cytokinesis Cytoskeleton Defect Development Disease Drug Delivery Systems Effectiveness Equilibrium Excision Facial paralysis Genes Goals Growth Hearing Human In Vitro Individual Integrins Investigation LIM Domain Kinase 1 Laminin Life Ligands Link Malignant Neoplasms Measures Membrane Membrane Proteins Mitotic spindle Molecular Monitor Morphology Mus Mutate Mutation Nerve Neuregulins Neurilemmoma Neurofibromatoses Neurofibromatosis 2 Neurofibromin 2 Neurons Operative Surgical Procedures Orphan Outcome Pathogenesis Pathway interactions Patients Peptides Pharmaceutical Preparations Pharmacological Treatment Phenotype Phosphorylation Plasmids Play Positioning Attribute Process Proteins Rattus Reagent Regulation Reporting Research Personnel Risk Role Schwann Cells Serine Shapes Signal Pathway Signal Transduction Signaling Protein Site Spinal Ganglia Stream Subfamily lentivirinae Symptoms Teenagers Testing Therapeutic Tumor Suppressor Proteins Virus Work bilateral acoustic schwannoma bilateral vestibular Schwannoma cell motility cofilin cofilin 2 deafness density effective therapy experience extracellular genetic regulatory protein hearing impairment in vitro Model irradiation novel novel therapeutics p21 activated kinase paxillin polymerization prevent receptor repaired response success tumor tumor growth

项目摘要

DESCRIPTION (provided by applicant): Neurofibromatosis type 2 (NF2) is a tumor disorder characterized by development of bilateral vestibular schwannomas also called acoustic neuromas. 98% of all NF2 patients experience partial to complete loss of hearing. Treatment for NF2 is balanced between monitoring tumor growth and the slow but progressive loss of hearing with surgical removal of larger tumors impinging on brainstem function and complete and permanent deafness. Cochlear and auditory brainstem implants have been used to partially restore hearing in a subset of patients with varying success. Therapeutics that slow or reverse tumor growth whilst maintaining hearing are currently lacking. This proposal tests the hypothesis that correcting the cytoskeletal defects in supernumerary schwannoma cells lacking function of the nf2 gene product, schwannomin/merlin, will allow these cells to interact with axons and receive cues promoting their differentiation and/or apoptosis. Identifying proteins that directly bind actin and regulate Schwann cell morphology is of the utmost importance. These proteins can serve as targets for drugs that will repair actin dynamics in schwannoma cells and restore axonal contact. Alternatively, drugs that modify actin regulatory proteins could promote cell death as a result of failed cytokinesis and mitotic spindle organization. One function of schwanomin/merlin is to inhibit Cdc42/Rac activation of p21 activated kinase (PAK). We will investigate LIM kinase (LIMK) and cofilin, terminal targets in a PAK signaling pathway. LIMK is a substrate for PAK, thus its activity is predicted to be high in schwannomas. Cofilin is a ubiquitously expressed actin-binding factor that depolymerizes f-actin and creates nucleation sites for new actin polymerization. Cofilin's function is inhibited by phosphorylation on serine-3 by LIMK. Our preliminary studies demonstrate that LIMK and cofilin modulate actin dynamics and function in Schwann cells. Moreover, our results suggest that LIMK and cofilin act down-stream of Schwannomin/merlin. We propose studies to: 1) identify the role of these proteins in controlling actin polymerization and cellular function in normal rat Schwann cells, 2) establish an in vitro model for NF2 using nf2ex2deleted mouse SCs to determine if inactivation of schwannomin/merlin leads to de-regulation of LIMK and cofilin activity and loss of SC function, and 3) determine if modulators of LIMK and cofilin restore the morphology and function of nf2ex2deleted SCs. These studies are initial steps in validating LIMK and/or cofilin as drug targets for development of an effective treatment for NF2 aimed at preserving hearing. The work in this proposal is relevant to the loss of hearing caused by Neurofibromatosis type 2. This disorder is characterized by development of bilateral acoustic schwannomas and loss of hearing in 98% of patients. As an outcome of this proposal, we hope to create a well characterized in vitro model for NF2 and advance a novel therapeutic direction, the actin modifying proteins LIMK and cofilin.

描述（由申请人提供）：2型神经纤维瘤病（NF2）是一种肿瘤疾病，其特征是发育于双侧前庭schwannomas，也称为声学神经瘤。在所有NF2患者中，有98％的患者经历了完全丧失听力的部分。 NF2的治疗在监测肿瘤的生长与缓慢但逐渐逐渐丧失的听力丧失之间是平衡的，手术清除较大的肿瘤会影响脑干功能以及完全和永久的耳聋。耳蜗和听觉脑干植入物已被用于部分恢复成功的患者的一部分。目前缺乏在保持听力的同时缓慢或反向肿瘤生长缓慢或反向肿瘤的治疗方法。该提案检验了以下假设：纠正NF2基因产物缺乏功能Schwannomin/Merlin功能的上努力型造型瘤细胞中的细胞骨架缺陷，将允许这些细胞与轴突相互作用并获得促进其分化和/或凋亡的提示。鉴定直接结合肌动蛋白并调节schwann细胞形态的蛋白质至关重要。这些蛋白质可以用作可以修复Schwannoma细胞中肌动蛋白动力学并恢复轴突接触的药物的靶标。或者，通过细胞因子和有丝分裂纺锤体组织失败，修饰肌动蛋白调节蛋白的药物可以促进细胞死亡。 Schwanomin/Merlin的一个功能是抑制p21活化激酶（PAK）的Cdc42/RAC激活。我们将研究PAK信号通路中的LIM激酶（Limk）和Cofilin，末端靶标。 Limk是PAK的底物，因此其活性预计在schwannomas中会很高。 Cofilin是一种普遍表达的肌动蛋白结合因子，可解聚，将F-肌动蛋白解散并为新的肌动蛋白聚合创建成核位点。 Cofilin的功能通过limk对丝氨酸3的磷酸化抑制。我们的初步研究表明，schwann细胞中的limk和cofilin调节肌动蛋白动力学和功能。此外，我们的结果表明，Schwannomin/Merlin的Limk和Cofilin Act Act Down-Stream。我们提出研究以：1）确定这些蛋白质在正常大鼠schwann细胞中控制肌动蛋白聚合和细胞功能中的作用，2）使用NF2EX2删除小鼠SC为NF2建立一个体外模型，以确定Schwannomin/Merlin是否会导致limk和cofilin Action of Scofin Activin和3）的作用，并确定scofilin Action和3）是否会降低。 NF2EX2DEATED SC的形态和功能。这些研究是验证肢体和/或cofilin作为开发旨在保存听力的有效治疗方法的药物靶标的初步步骤。该提案中的工作与2型神经纤维瘤病引起的听力丧失有关。该疾病的特征是发育于双侧声学schwannomas和98％的患者的听力丧失。作为该提案的结果，我们希望为NF2创建一个良好的体外模型，并促进新颖的治疗方向，肌动蛋白修饰蛋白质limk和cofilin。