EGFR signaling network adaptations to overcome RAS-induced membrane stress in glioblastoma

摘要 胶质母细胞瘤(GBM)最常见的基因改变是受体酪氨酸激酶的扩增 EGFR。在GBM中，一些扩增的EGFR进一步突变，产生外显子缺失的EGFRvIII，这是结构性的 活性和内吞作用受损，从而向有利于生存而不是增殖的效应器通路发出信号。它 目前尚不清楚为什么EGFRvIII被特意用于这种疾病，但GBM细胞对无节制的耐受性很差 来自EGFR效应器RAS的信号。慢性RAS信号对原癌基因诱导的细胞应激 引起过度微胞吞噬和空泡化的膜，以替代方案结束 一种称为甲硫磷的细胞死亡形式。这项工作的目标是协调EGFR扩增和 EGFR/RAS通过EGFRvIII及其共同的信号中间产物诱导膜应激。 初步证据表明，EGFRvIII可能通过重新连接来实现缓解压力的信号适应 基底膜细胞内不同亚细胞位置的蛋白质-蛋白质相互作用网络。我们的假设是 EGFRvIII是一种GBM特异性的适应机制，用于克服甲硫磷中毒。我们将构建一个计算性的 通过解释蛋白质网络来验证这一假说的EGFR/EGFRvIII信号模型 与甲硫磷表型相关的相互作用和信号传递。具体目标是：1)定义关键 EGFR信号网络中的分子间相互作用和机制预测 网络对EGFRvIII表达的适应；2)MAP差异EGFR信令网络激活 通过混合机制和数据驱动计算对胶质母细胞瘤细胞甲基化表型的影响 模型；以及3)使用新工具进行体外和体内甲硫磷信号控制的测试模型预测 同时无创监测RAS-ERK和AKT活性。这个项目汇集了一支 在受体的机制和数据驱动的计算模型方面具有互补专业知识的研究人员- 介导信号、蛋白质-蛋白质相互作用、GBM体内移植和GBM的治疗 使用调查方法的患者。通过定量检验关于EGFRvIII的假设作为关键 胶质母细胞瘤中癌基因诱导的质膜应激的调节，我们的合作项目成立 承诺从概念上确定新的方法，以驱动高度 化疗耐药癌症，迫切需要持久的治疗方法。

SUMMARY The most common genetic alteration in glioblastoma (GBM) is amplification of the receptor tyrosine kinase EGFR. In GBM, some amplified EGFR further mutates to yield exon-deleted EGFRvIII, which is constitutively active and endocytosis impaired, thereby signaling to effector pathways that favor survival over proliferation. It is not clear why EGFRvIII is specifically selected for in this disease, but GBM cells poorly tolerate unbridled signaling from the EGFR effector RAS. Chronic RAS signaling places an oncogene-induced stress on cell membranes that gives rise to excessive micropinocytosis and vacuolization, concluding with an alternative form of cell death called methuosis. The objective of this work is to reconcile EGFR amplification and EGFR/RAS-induced membrane stress through EGFRvIII and the signaling intermediates they share. Preliminary evidence suggests that EGFRvIII may achieve stress-relieving signaling adaptations by rewiring the network of protein-protein interactions at different subcellular locations within GBM cells. Our hypothesis is that EGFRvIII is a GBM-specific adaptive mechanism for overcoming methuosis. We will build a computational model of EGFR/EGFRvIII signaling that tests this hypothesis by accounting for the network of protein interactions and signaling relevant for the methuosis phenotype. The specific aims are to 1) define the key intermolecular interactions in the EGFR signaling network and mechanistically predict the consequences of network adaptations to EGFRvIII expression; 2) map differential EGFR signaling network activation among glioblastoma cells to the methuosis phenotype through a hybrid mechanistic and data-driven computational model; and 3) test model predictions about signaling control of methuosis in vitro and in vivo using new tools to monitor RAS-ERK and AKT activities concurrently and noninvasively. This project brings together a team of investigators with complementary expertise in mechanistic and data-driven computational models of receptor- mediated signaling, protein-protein interactions, in vivo transplantations of GBM, and treatment of GBM patients using investigational approaches. By quantitatively testing the hypothesis about EGFRvIII as a key regulator of oncogene-induced plasma membrane stress in glioblastoma, our collaborative project holds promise for identifying conceptually new approaches for driving alternative cell-death phenotypes in a highly chemotherapy-resistant cancer for which durable therapies are desperately needed.