Traditional and systems biology based drug discovery for the rare tumor syndrome neurofibromatosis type 2

Neurofibromatosis 2 (NF2) is a rare tumor suppressor syndrome that manifests with multiple schwannomas and meningiomas. There are no effective drug therapies for these benign tumors and conventional therapies have limited efficacy. Various model systems have been created and several drug targets have been implicated in NF2-driven tumorigenesis based on known effects of the absence of merlin, the product of the NF2 gene. We tested priority compounds based on known biology with traditional dose-concentration studies in meningioma and schwann cell systems. Concurrently, we studied functional kinome and gene expression in these cells pre- and post-treatment to determine merlin deficient molecular phenotypes. Cell viability results showed that three agents (GSK2126458, Panobinostat, CUDC-907) had the greatest activity across schwannoma and meningioma cell systems, but merlin status did not significantly influence response. In vivo, drug effect was tumor specific with meningioma, but not schwannoma, showing response to GSK2126458 and Panobinostat. In culture, changes in both the transcriptome and kinome in response to treatment clustered predominantly based on tumor type. However, there were differences in both gene expression and functional kinome at baseline between meningioma and schwannoma cell systems that may form the basis for future selective therapies. This work has created an openly accessible resource (www.synapse.org/SynodosNF2) of fully characterized isogenic schwannoma and meningioma cell systems as well as a rich data source of kinome and transcriptome data from these assay systems before and after treatment that enables single and combination drug discovery based on molecular phenotype.

神经纤维瘤病2型（Neurofibromatosis 2, NF2）是一种罕见的肿瘤抑制综合征，以多发施万细胞瘤和脑膜瘤为主要临床表现。针对这类良性肿瘤，目前尚无有效药物治疗手段，常规疗法的疗效亦较为有限。基于NF2基因编码产物默林蛋白（merlin）缺失的已知生物学效应，学界已构建多种模型系统，并确定了数个参与NF2驱动肿瘤发生的药物靶点。我们基于已明确的生物学机制，在脑膜瘤与施万细胞模型系统中采用传统剂量-浓度实验方案，对优先级化合物开展了活性筛选与验证。与此同时，我们对处理前后的细胞开展功能激酶组（functional kinome）分析与基因表达检测，以阐明merlin缺陷相关的分子表型。细胞活力实验结果显示，GSK2126458、帕比司他（Panobinostat）、CUDC-907这三种药物在施万细胞瘤与脑膜瘤细胞系统中活性最强，但merlin的表达状态并未对药物响应产生显著影响。体内实验中，GSK2126458与帕比司他仅对脑膜瘤表现出肿瘤特异性疗效，施万细胞瘤则未出现药物响应。体外培养实验中，经药物处理后的转录组与激酶组变化主要按照肿瘤类型进行聚类。不过，脑膜瘤与施万细胞瘤细胞系统在基线状态下的基因表达与功能激酶组均存在差异，这可为未来开发选择性治疗策略提供重要理论基础。本研究构建了经过全面表征的同基因施万细胞瘤与脑膜瘤细胞系统的公开可访问资源库（www.synapse.org/SynodosNF2），同时提供了这些检测系统在处理前后的激酶组与转录组数据集，可用于基于分子表型开展单药与联合药物的研发工作。