神经纤维瘤病2型(NF2)是一种遗传性疾病，由NF2抑癌基因双等位基因失活引起。NF2相关肿瘤包括神经鞘瘤和脑膜瘤，对化疗有抵抗力，手术和/或放疗后通常会复发，并且一般对信号转导通路抑制剂呈现细胞静止反应，突出了改进细胞毒性治疗的必要性。利用我们以前在NF2临床前模型中进行的高通量药物筛选的数据，我们首先确定了一类靶向泛素蛋白酶体途径(UPP)的化合物，并使用候选UPP抑制剂ixazomib/MLN9708，pevonedistat/MLN4924和TAK-243/MLN7243进行研究。我们使用人类原代和永生化的脑膜瘤(MN)细胞系、CRISPR修饰的Schwann细胞(SCs)和小鼠Nf2-/-SCs进行剂量反应测试、基于流式细胞术的Annexin V和细胞周期分析、RNA测序以确定可能的凋亡机制的潜在基础。在原位NF2缺失的脑膜瘤和神经鞘瘤肿瘤模型中也进行了体内疗效评估。三种UPP抑制剂的测试表明，ixazomib或TAK-243能强烈降低细胞存活率并诱导凋亡，而pevonedistat则不能。体外分析揭示，ixazomib或TAK-243降低了c-KIT和PDGFRα的表达，以及E3泛素连接酶SKP2的表达，同时上调与内质网应激介导的展开蛋白反应(UPR)激活相关的基因。小鼠模型的体内治疗显示延迟肿瘤生长，提示具有治疗潜力。本研究证明蛋白酶体途径抑制剂在脑膜瘤和神经鞘瘤临床前模型中的有效性，并为使用这些药物作为NF2患者的有前途的新治疗策略奠定了基础。©作者2023年。由牛津大学出版社代表神经肿瘤学会出版。保留所有权利。有关权限，请发送电子邮件至：journals.permissions@oup.com。

Neurofibromatosis 2 (NF2) is an inherited disorder caused by bi-allelic inactivation of the NF2 tumor suppressor gene. NF2-associated tumors, including schwannoma and meningioma, are resistant to chemotherapy, often recurring despite surgery and/or radiation, and have generally shown cytostatic response to signal transduction pathway inhibitors, highlighting the need for improved cytotoxic therapies.Leveraging data from our previous high-throughput drug screening in NF2 preclinical models, we identified a class of compounds targeting the ubiquitin-proteasome pathway (UPP), and undertook studies using candidate UPP inhibitors, ixazomib/MLN9708, pevonedistat/MLN4924, and TAK-243/MLN7243. Employing human primary and immortalized meningioma (MN) cell lines, CRISPR-modified Schwann cells (SCs), and mouse Nf2 -/- SCs, we performed dose response testing, flow cytometry-based Annexin V and cell cycle analyses, and RNA-sequencing to identify potential underlying mechanism of apoptosis. In vivo efficacy was also assessed in orthotopic NF2-deficient meningioma and schwannoma tumor models.Testing of three UPP inhibitors demonstrated potent reduction in cell viability and induction of apoptosis for ixazomib or TAK-243, but not pevonedistat. In vitro analyses revealed that ixazomib or TAK-243 downregulates expression of c-KIT and PDGFRα, as well as the E3 ubiquitin ligase SKP2 while upregulating genes associated with endoplasmic reticulum stress-mediated activation of the unfolded protein response (UPR). In vivo treatment of mouse models revealed delayed tumor growth, suggesting a therapeutic potential.This study demonstrates the efficacy of proteasomal pathway inhibitors in meningioma and schwannoma preclinical models and lays the groundwork for use of these drugs as a promising novel treatment strategy for NF2 patients.© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.