Identify OTX2-interacting proteins repressing differentiation in medulloblastoma

鉴定抑制髓母细胞瘤分化的 OTX2 相互作用蛋白

• 批准号: 8883429
• 负责人: Renyuan Bai
• 金额: $ 8.1万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8883429
• 关键词: Address; Adverse effects; Affinity; Amino Acids; Apoptosis; Binding; Binding Proteins; Biological Assay; Brain; Cancer Etiology; Cell Cycle Arrest; Cell Nucleus; Cells; Cerebellum; Cessation of life; Chemicals; Child; Child Development; Childhood; Co-Immunoprecipitations; Complex; DNA Binding; DNA Methyltransferase Inhibitor; DNA Modification Methylases; DNA Sequence; Development; Enhancers; Enzymes; Epigenetic Process; Exhibits; Gatekeeping; Genes; Genetic Transcription; Goals; Health; Histologic; Histone Deacetylase; Histones; Homeobox; In Vitro; Knowledge; Late Effects; Lead; Libraries; Link; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Medullomyoblastoma; Membrane; Methods; Molecular; Morbidity - disease rate; Muscle; Muscle Cells; Nature; Neurocognitive; Neuronal Differentiation; Neurons; Oncogenic; Patients; Population; Primitive Neuroectodermal Tumor; Procedures; Protein Binding; Proteins; Reporter; Reporter Genes; Reporting; Repression; Series; Small Interfering RNA; System; Testing; Therapeutic; Transcription Coactivator; Transcription Repressor/Corepressor; Transcriptional Regulation; Ubiquitin; Undifferentiated; Validation; Xenograft Model; Yeasts; base; cDNA Library; chemoradiation; crosslink; gene repression; high risk; histone methylation; histone methyltransferase; immunoaffinity chromatography; in vivo; inhibitor/antagonist; medulloblastoma; neoplastic cell; neurodevelopment; novel; overexpression; prevent; protein crosslink; screening; small hairpin RNA; tandem mass spectrometry; targeted treatment; therapeutic development; transcription factor; tumor; yeast two hybrid system

DESCRIPTION (provided by applicant): Medulloblastoma, the most common type of pediatric brain malignancy, is an aggressive primitive neuroectodermal tumor arising from the cerebellum. It presents a significant cause of cancer-related death in children and current treatment of radio-chemotherapy impairs children's development and causes long-term adverse effects. Therefore, targeted therapies based on the molecular features of medulloblastoma are needed to minimize the treatment-related side effects in children. The transcription factor OTX2 is overexpressed and/or genomically amplified in most medulloblastomas. It is overexpressed in over 60% of medulloblastoma. Our previous study has identified OTX2 as a transcriptional repressor and a gatekeeper of myogenic and neuronal differentiation in medulloblastoma cells. The strong repressor activity exhibited by its homeobox domain (HD) renders OTX2 transcriptionally repressive. In medullomyoblastoma, a subtype of medulloblastoma with differentiated myogenic cells mixed with tumor cells, we have linked the loss of expression of OTX2 to the myogenic differentiation in tumor cell populations. Inducible knockdown of OTX2 by shRNA led to significant extension of survival in an orthotopic medulloblastoma xenograft model. Owing to the remarkable repressor activity displayed by the 60 amino acid OTX2-HD and its lack of functional motif related to transcriptional regulators, we hypothesize that this transcriptional repression is the result of interactions with epigenetic regulators. We therefore propose to test inhibitors of potential epigenetic regulators to characterize the nature of OTX2-HD mediated repression. We propose to perform in vivo crosslinking/immuno-purification/tandem mass spectrometry to identify binding partners of OTX2-HD. As a complementary strategy, we suggest additionally to use split-ubiquitin yeast two-hybrid system to identify novel interacting partners of OTX2-HD in a D425 medulloblastoma cDNA library. Subsequently, we will analyze and validate the interacting proteins in vitro and in vivo in medulloblastoma cells, and study the functionality of those binding proteins. In summary, understanding the molecular mechanism of OTX2 will advance our knowledge to develop targeted therapies that initiate the differentiation suppressed by OTX2 in medulloblastoma. This goal can be achieved by identifying the inhibitors of epigenetic regulators associated with OTX2- HD and by manipulating the potential interacting partners relevant in OTX2-mediated suppression of differentiation, which is the long term purpose of the study.

描述（由申请人提供）：髓母细胞瘤是最常见的小儿脑恶性肿瘤类型，是由小脑产生的侵略性原始神经皮质肿瘤。它提出了儿童与癌症相关的死亡的重要原因，当前对无线电化学疗法的治疗损害了儿童的发育并引起长期不良反应。因此，需要基于髓母细胞瘤的分子特征的靶向疗法来最大程度地减少儿童治疗相关的副作用。在大多数髓母细胞瘤中，转录因子OTX2过表达和/或基因组扩增。它在超过60％的髓母细胞瘤中过表达。我们先前的研究已将OTX2鉴定为髓母细胞瘤细胞中肌原性和神经元分化的转录阻遏物和看门人。其同源蛋白域（HD）表现出的强烈阻遏活性使OTX2转录抑制作用。在髓质细胞瘤中，髓质细胞瘤的亚型具有分化的肌原性细胞与肿瘤细胞混合的，我们已经将OTX2的表达丧失与肿瘤细胞群体中的肌源分化相关联。 shRNA对OTX2的诱导敲低导致在原位髓母细胞瘤异种移植模型中生存的显着扩展。由于60个氨基酸OTX2-HD表现出的显着阻遏活性及其与转录调节剂相关的功能基序，我们假设这种转录抑制是与表观遗传调节剂相互作用的结果。因此，我们建议测试潜在表观遗传调节剂的抑制剂，以表征OTX2-HD介导的抑制的性质。我们建议执行体内交联/免疫纯化/串联质谱法，以识别OTX2-HD的结合伙伴。作为一种补充策略，我们建议使用分裂泛素酵母两杂交系统来识别D425髓母细胞瘤cDNA库中OTX2-HD的新型相互作用伴侣。随后，我们将在髓母细胞瘤细胞中分析和验证体外和体内相互作用的蛋白质，并研究这些结合蛋白的功能。总而言之，了解OTX2的分子机制将提高我们的知识，以开发靶向疗法，从而启动髓母细胞瘤中OTX2抑制的分化。可以通过确定与OTX2-HD相关的表观遗传调节剂的抑制剂以及操纵与OTX2介导的分化抑制相关的潜在相互作用伙伴的抑制剂，这是研究的长期目的。

项目成果

Investigational new drugs for brain cancer.

• DOI: 10.1080/13543784.2016.1182497
• 发表时间: 2016-08
• 期刊: Expert opinion on investigational drugs
• 影响因子: 6.1
• 作者: Staedtke V;Bai RY;Laterra J
• 通讯作者: Laterra J

Cancer of the Peripheral Nerve in Neurofibromatosis Type 1.

1 型神经纤维瘤病中的周围神经癌。

• DOI: 10.1007/s13311-017-0518-y
• 发表时间: 2017
• 期刊: Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics
• 作者: Staedtke,Verena;Bai,Ren-Yuan;Blakeley,JaishriO'Neill
• 通讯作者: Blakeley,JaishriO'Neill