Elucidating the epigenetic landscape of neurofibromatosis and development of therapeutic targets

项目摘要 神经纤维瘤病2型(NF2)是一种遗传性疾病，由NF2肿瘤的胚系突变引起。 抑制基因，其特征是发生在第七脑神经的神经鞘瘤。梅林， NF2基因产物在散发性神经鞘瘤、脑膜瘤、 室管膜瘤和间皮瘤。尽管过去对这种疾病的理解取得了进展 几年来，这还没有转化为治疗方法。因此，有一种迫切和未得到满足的需要需要发展。 NF2患者的治疗选择。在分子水平上，Merlin已被证明是一个关键的调节器 包括由小G蛋白和河马/YAP调控的多种信号转导途径 路径。 为了确定NF2缺陷肿瘤的治疗脆弱性，我们评估了BET的活性 (溴结构域和末端外结构域)蛋白抑制物抑制NF2缺失的雪旺细胞。BET蛋白是 其特征是存在两个串联的溴结构域和一个额外的末端结构域。溴域 可以特异性地结合组蛋白上的乙酰化赖氨酸残基，作为表观遗传阅读器，破译 组蛋白乙酰化密码。我们的初步数据表明，BET抑制可抑制NF2- Null Schwann和Schwannoma细胞的培养和体内肿瘤的生长，这是通过 抑制溴域蛋白4(BRD4)。初步数据表明，BRD4的影响被中介到 这在很大程度上是通过监管YAP来实现的。重要的是，我们最近演示了YAP是 促进NF2缺陷雪旺细胞的增殖和肿瘤的发生。这项提议的目标是 确定雪旺细胞中BET蛋白的基本功能，并确定BET抑制是否是一种 治疗方法应进一步发展为NF2的治疗方式。

Project Summary Neurofibromatosis type 2 (NF2) is an inherited disorder caused by germ line mutations of the NF2 tumor suppressor gene and is characterized by development of schwannomas of the VIIIth cranial nerve. Merlin, the product of the NF2 gene, is also inactivated to a significant extent in sporadic schwannomas, meningioma, ependymoma and mesothelioma. In spite of progress made in the understanding of the disease over the past several years, this has not yet translated into therapies. Thus, there is an urgent and unmet need to develop therapeutic options for NF2 patients. At a molecular level, Merlin has been shown to function as a key regulator of multiple signal transduction pathways including those regulated by small G-proteins and the Hippo/YAP pathway. In an effort to identify therapeutic vulnerabilities in NF2-deficient tumors, we assessed the activity of the BET (Bromodomain and Extra-Terminal domain) protein inhibitors NF2-null Schwann cells. The BET proteins are characterized by the presence of two tandem bromodomains and an extra-terminal domain. The bromodomains can specifically bind acetylated lysine residues on histones, serving as epigenetic readers that decipher the histone acetylation code. Our preliminary data indicate that BET inhibition suppresses the proliferation of NF2- null Schwann and schwannoma cells in culture and tumor growth in vivo, and that this is mediated through inhibition of bromodomain protein 4 (BRD4). Preliminary data indicates that the effects of BRD4 are mediated to a significant extent via regulation of YAP. Importantly, we recently demonstrated that YAP is required for the accelerated proliferation of NF2-deficient Schwann cells and tumorigenesis. The goals of this proposal are to identify the essential functions of BET proteins in Schwann cells and determine whether BET inhibition is a therapeutic approach that should be further developed as a treatment modality for NF2.