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

• 批准号: 8495967
• 负责人: CRISTINA Maria FERNANDEZ-VALLE
• 金额: $ 27.37万
• 依托单位: UNIVERSITY OF CENTRAL FLORIDA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8495967
• 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 Targeting; 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

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.

项目总结 神经纤维瘤病2型(NF2)是一种以双侧前庭发育为特征的肿瘤疾病。 神经鞘瘤也称为听神经瘤。98%的NF2患者经历部分或完全丧失 听证。NF2的治疗是在监测肿瘤生长和缓慢但渐进性的丧失之间取得平衡。 影响脑干功能的较大肿瘤的手术切除和完全永久性听力 耳聋。人工耳蜗和听性脑干植入物已被用于部分恢复听力 患者的治疗效果各不相同。在保持听力的同时减缓或逆转肿瘤生长的治疗方法是 目前还不够。这一建议检验了这样一种假设，即纠正编外患者的细胞骨架缺陷 神经鞘瘤细胞缺乏NF2基因产物Schwannomin/Merlin的功能，将允许这些细胞 与轴突相互作用，并接收促进其分化和/或凋亡的信号。识别那些能够 直接结合肌动蛋白，调节雪旺细胞的形态是至关重要的。这些蛋白质可以 作为药物的靶点，修复神经鞘瘤细胞中的肌动蛋白动力学，恢复轴突接触。 或者，改变肌动蛋白调节蛋白的药物可以促进细胞死亡，因为失败的结果是 胞质分裂和有丝分裂的纺锤体组织。Schwanomin/Merlin的一个功能是抑制CDc42/Rac 激活p21激活的蛋白激酶(PAK)。我们将研究LIM激酶(LIMK)和Cofilin，这两个末端靶标在 PAK信号通路。LIMK是PAK的底物，因此其活性被预测在神经鞘瘤中很高。 Cofilin是一种普遍表达的肌动蛋白结合因子，它能解聚f-肌动蛋白并创建成核位点。 用于新的肌动蛋白聚合。LIMK对丝氨酸-3的磷酸化抑制了Cofilin的功能。我们的 初步研究表明，LIMK和Cofilin调节雪旺细胞中肌动蛋白的动力学和功能。 此外，我们的结果表明LIMK和Cofilin在Schwannomin/Merlin的下游起作用。我们建议 研究目的：1)确定这些蛋白在控制肌动蛋白聚合和正常细胞功能中的作用 2)利用nf2ex2缺失的小鼠干细胞建立NF2的体外模型，以确定 Schwannomin/Merlin的失活导致LIMK和Cofilin活性的去调节和SC功能的丧失， 3)确定LIMK和Cofilin的调节剂是否能恢复nf2ex2缺失的SCs的形态和功能。 这些研究是验证LIMK和/或Cofilin作为开发有效药物靶点的初步步骤 NF2的治疗旨在保护听力。

项目成果

LIM domain kinases as potential therapeutic targets for neurofibromatosis type 2.

LIM 结构域激酶作为 2 型神经纤维瘤病的潜在治疗靶点。

• DOI: 10.1038/onc.2013.320
• 发表时间: 2014-07-03
• 期刊: Oncogene
• 影响因子: 8

The actin-severing protein cofilin is downstream of neuregulin signaling and is essential for Schwann cell myelination.

• DOI: 10.1523/jneurosci.6207-11.2012
• 发表时间: 2012-04-11
• 期刊: The Journal of neuroscience : the official journal of the Society for Neuroscience
• 作者: Sparrow N;Manetti ME;Bott M;Fabianac T;Petrilli A;Bates ML;Bunge MB;Lambert S;Fernandez-Valle C
• 通讯作者: Fernandez-Valle C

Inhibition of SIRT2 in merlin/NF2-mutant Schwann cells triggers necrosis.

• DOI: 10.18632/oncotarget.1422
• 发表时间: 2013-12
• 期刊: Oncotarget
• 作者: Petrilli A;Bott M;Fernández-Valle C
• 通讯作者: Fernández-Valle C

Role of Merlin/NF2 inactivation in tumor biology.

• DOI: 10.1038/onc.2015.125
• 发表时间: 2016-02-04
• 期刊: Oncogene
• 影响因子: 8
• 作者: Petrilli AM;Fernández-Valle C
• 通讯作者: Fernández-Valle C

Schwannomin/merlin promotes Schwann cell elongation and influences myelin segment length.

• DOI: 10.1016/j.mcn.2010.12.006
• 发表时间: 2011-05
• 期刊: MOLECULAR AND CELLULAR NEUROSCIENCE
• 影响因子: 3.5
• 作者: Thaxton, Courtney;Bott, Marga;Walker, Barbara;Sparrow, Nicklaus A.;Lambert, Stephen;Fernandez-Valle, Cristina
• 通讯作者: Fernandez-Valle, Cristina