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：
8278031
负责人：
CRISTINA Maria FERNANDEZ-VALLE
金额：
$ 28.81万
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/8278031
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 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

PROJECT SUMMARY 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.

项目摘要神经纤维瘤病2型（NF2）是一种肿瘤疾病，其特征是双侧前庭的发展 Schwannomas也称为声学神经瘤。在所有NF2患者中，有98％的患者遭受了部分损失听力。 NF2的治疗在监测肿瘤生长和缓慢但进行性丧失之间是平衡的通过手术去除较大肿瘤的聆听，这些肿瘤会影响脑干功能并完整而永久耳聋。人工耳蜗和听觉脑干植入物已用于在一部分中部分恢复听力成功的患者。在保持听力时缓慢或反向肿瘤生长缓慢或反向肿瘤的治疗剂是目前缺乏。该提案检验了以下假设：纠正超级骨骼的细胞骨架缺陷 Schwannoma细胞缺乏NF2基因产物Schwannomin/Merlin的功能，这些细胞将使这些细胞得以实现与轴突相互作用，并获得提示其分化和/或凋亡的提示。识别蛋白质直接结合肌动蛋白并调节schwann细胞形态至关重要。这些蛋白质可以充当将修复造型蛋白细胞中肌动蛋白动力学并恢复轴突接触的药物的靶标。另外，修饰肌动蛋白调节蛋白的药物可能会因失败而促进细胞死亡细胞因子和有丝分裂主轴组织。 Schwanomin/Merlin的功能是抑制CDC42/RAC P21激活激酶（PAK）的激活。我们将研究LIM激酶（Limk）和Cofilin，A PAK信号通路。 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，可解聚于F-肌动蛋白并创建成核位点用于新的肌动蛋白聚合。 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。我们建议研究至：1）确定这些蛋白质在控制肌动蛋白聚合和细胞功能中的作用大鼠Schwann细胞，2）使用NF2EX2DEMETED小鼠SC建立NF2的体外模型，以确定是否是否雪旺霉素/梅林的失活导致肢体和cofilin活性以及SC功能的丧失， 3）确定Limk和Cofilin的调节剂是否恢复了NF2EX2DEATED SC的形态和功能。这些研究是验证肢体和/或Cofilin作为开发有效的药物靶标的初步步骤 NF2的治疗旨在保存听力。