NF2-associated meningiomas: From omics discovery to targeted therapy

神经纤维瘤病2(NF2)以前庭神经鞘瘤和脑膜瘤为特征，表现为 NF2肿瘤抑制基因。脑膜瘤起源于脑膜上皮蛛网膜帽细胞，是最常见的 成人常见的原发颅内肿瘤。NF2失活经常与零星的 脑膜瘤，特别是在原发非典型(WHO II级)肿瘤中。脑膜瘤尽管有进展，但 外科手术和放射治疗是导致严重发病率和死亡率的原因。因此，有效的系统性 治疗是非常需要的。对于脑膜瘤建模和临床前药物筛选，我们使用了人类 手术切除肿瘤来源的原发脑膜瘤(MN)细胞系和CRISPR-Cas9基因组编辑 表达或不表达NF2的同基因人类蛛网膜瘤细胞系(ACS)。利用这些模型，我们 证实NF2缺陷脑膜瘤表现出mTORC1/mTORC2信号的异常激活，这 导致了NF2和脑膜瘤的临床试验。最近，我们进行了大规模的基因组、转录组和 在我们的AC和MN细胞模型中进行药物筛选研究，以确定其他潜在的靶点。Kinome和 转录组数据显示几个EPH受体家族酪氨酸的激活和表达增加 激酶(EPH-RTK)、Src家族成员(SFK)和c-kit，这些都是达沙替尼的靶点，而达沙替尼是 最近出版的。我们的组学方法还发现了其他有趣的候选分子，包括配体NRG1， HBEGF和apelin，以及AMPK相关的激酶，特别是NUAK2，在 NF2缺失的AC/MN细胞的激动组和转录组。我们最近的研究结果表明，NRG1的表达和 ErbB3信号受mTORC1信号调节。我们计划研究NRG1本身或这些因素 在NF2缺失的MN细胞中，HBEGF和APLN也受mTOR调控或在下游信号转导中发挥作用。 我们建议理解上调表达和激活的机制和生物学意义。 脑膜瘤中的NUAK2。此外，我们的大规模药物筛选工作，与NIH-NCATS合作， 揭示了一系列与蛋白酶体途径相关的药物在NF2缺失细胞中表现出的细胞毒作用。在这里我们 建议研究三种不同的针对蛋白酶体的药物(千禧武田公司提供 药物)，单独和与TAK-228(mTOR抑制剂)联合治疗5例I级、5例II级和5例III级 具有NF2损耗的MN线。更重要的是，我们建议与阵列CGH一起进行单细胞RNAseq 在NF2缺陷的脑膜瘤及其相应的原代细胞系中定义肿瘤的异质性和 与药物反应有关。蛋白酶体药物的抗肿瘤效果也将在原位NF2- 良恶性脑膜瘤模型存在缺陷。我们的总体方法是：(I)利用“组学和药物” 筛选结果，(Ii)肿瘤异质性的特征和与药物反应的相关性，以及(Iii)测试 原位NF2缺乏体内模型的潜在药物是及时的、新颖的，并将提供一个框架 在NF2和脑膜瘤研究中寻求临床护理的新途径。

Neurofibromatosis 2 (NF2) is characterized by vestibular schwannomas, and meningiomas that show loss of the NF2 tumor suppressor gene. Meningiomas arise from meningothelial arachnoid cap cells and are the most common primary intracranial tumors in adults. NF2 inactivation is frequently associated with sporadic meningiomas, particularly in primary atypical (WHO grade II) tumors. Meningiomas that progress despite surgery and radiation are responsible for significant morbidity and mortality. Therefore, effective systemic therapies are greatly needed. For meningioma modeling and preclinical drug screening, we employ human primary meningioma (MN) cell lines derived from surgically resected tumors and CRISPR-Cas9 genome-edited isogenic, human arachnoidal cell lines (ACs) that either express or lack NF2. Employing these models, we established that NF2-deficient meningiomas reveal aberrant activation of mTORC1/mTORC2 signaling, which led to clinical trials for NF2 and meningiomas. Recently, we undertook large-scale kinome, transcriptome and drug screening studies in our AC and MN cell models to identify other potential targets. Kinome and transcriptome data revealed increased activation and expression of several EPH receptor family tyrosine kinases (EPH-RTKs), Src family kinase members (SFKs) and c-KIT, which are all targets of dasatinib, which is recently published. Our ‘omics approach also identified other interesting candidates, including ligands NRG1, HBEGF and apelin, and AMPK-related kinases, particularly NUAK2, to be consistently upregulated in the kinome and transcriptome of NF2-null AC/MN cells. Our recent results suggest that NRG1 expression and ERBB3 signaling is regulated by mTORC1 signaling. We plan to examine whether NRG1 alone or factors such as HBEGF and APLN are also regulated by mTOR or play a role in downstream signaling in NF2-null MN cells. We propose to understand the mechanism and biological significance of elevated expression and activation of NUAK2 in meningioma. Further, our large-scale drug screening efforts, in collaboration with NIH-NCATS, revealed a set of proteasome pathway related drugs exhibiting cytotoxic effects in NF2-null cells. Here we propose to examine three different drugs targeting the proteasome (provided by Millennium-Takeda Pharmaceuticals), alone and combined with TAK-228 (mTOR inhibitor) in 5 grade I, 5 grade II and 5 grade III MN lines with NF2 loss. More importantly, we propose to undertake single cell RNAseq along with array CGH in NF2-deficient meningiomas and their corresponding primary cell lines to define tumor heterogeneity and correlate with drug response. Anti-tumor efficacy of proteasome drugs will also be evaluated in orthotopic NF2- deficient benign and malignant meningioma models. Our overall approach of (i) leveraging the ‘omics and drug screening results, (ii) characterizing tumor heterogeneity and correlating with drug response, and (iii) testing potential drugs in orthotopic NF2-deficient in vivo models is timely, novel and will provide a framework to pursue new avenues in NF2 and meningioma research for clinical care.