Functional genomics of Non-NF2 meningioma development and progression [RNA-seq]. Functional genomics of Non-NF2 meningioma development and progression [RNA-seq]

Meningiomas are the most common primary brain tumors, where complete surgical resection is often challenging giving rise to recurrence. Mutations of the E3 ubiquitin ligase TRAF7 are found in one-fourth of meningioma patients and typically co-occur with mutations in either KLF4, AKT1, or PI3KCA. By creating an in vitro meningioma model derived from primary meningeal cells, we elucidated the cooperative interactions that conspire meningioma development. A multi-omics framework on meningeal cells revealed TRAF7-mediated rewiring of the proteome with the majority of protein expression being post‐transcriptionally‐regulated. Integrating TRAF7-driven ubiquitinome and proteome alterations and TRAF7 interactome highlight the role of TRAF7 in posttranslational regulation of the cytoskeleton organization. TRAF7 controls actin dynamics by acting as a proteostatic regulator of the RAS-related small GTPases. TRAF7 loss-of-function diminishes ubiquitination of RAS and CDC42, leading to the activation of the PAK and MAPK signaling pathways. Up-regulation of CDC42 signaling promotes anchorage-independent growth of meningeal cells. On the other hand, the RAS/MAPK pathway triggers the tumor suppressive activity of KLF4 that inhibits meningeal cell growth due to the activation of the Semaphorin pathway. Simultaneous loss of KLF4 and TRAF7 function enhances tumorigenic transformation of meningeal cells, functionally confirming their roles in meningioma development. Overall design: RNA sequencing was performed to identify differentially regulated genes upon expression of different constructs in normal human meningeal cells (HMCs) and mengioma HBL-52 cells Cells were infected with viral vectors expressing genes of interest and kept in culture

脑膜瘤（Meningiomas）是最常见的原发性脑肿瘤，完整手术切除往往颇具挑战，易引发肿瘤复发。约四分之一的脑膜瘤患者可检出E3泛素连接酶（E3 ubiquitin ligase）TRAF7突变，该突变通常与KLF4、AKT1或PI3KCA突变共现。本研究通过构建源自原发性脑膜细胞的体外脑膜瘤模型，阐明了协同推动脑膜瘤发生发展的相互作用机制。针对脑膜细胞的多组学分析框架揭示，TRAF7介导的蛋白质组（proteome）重编程过程中，绝大多数蛋白的表达均受转录后调控。整合TRAF7驱动的泛素组（ubiquitinome）与蛋白质组变化，以及TRAF7相互作用组数据，突显了TRAF7在细胞骨架组织的翻译后调控中的关键作用。TRAF7可作为RAS相关小GTP酶的蛋白稳态调节因子，调控肌动蛋白动力学。TRAF7功能缺失会减弱RAS与CDC42的泛素化水平，进而激活PAK与MAPK信号通路。CDC42信号通路的上调可促进脑膜细胞的非锚定依赖性生长。另一方面，RAS/MAPK通路可触发KLF4的肿瘤抑制活性，而KLF4可通过激活Semaphorin通路抑制脑膜细胞增殖。同时敲除KLF4与TRAF7的功能会增强脑膜细胞的致瘤转化能力，从功能层面证实了二者在脑膜瘤发生发展中的作用。总体实验设计：对正常人类脑膜细胞（HMCs）及脑膜瘤HBL-52细胞转染不同表达载体后，开展RNA测序（RNA sequencing）以鉴定差异表达基因。细胞经携带目标基因的病毒载体感染后，置于体外培养体系中维持培养。