Biophysical Interrogation of Signals that Drive GBM Invasion

多形性胶质母细胞瘤（GBM）的成功治疗的一个主要问题是高度恶性肿瘤的存在。 侵入性细胞扩散到脑实质中。这些细胞逃避手术切除， 在脑实质的远端。在单个GBM内存在多个和空间上不同的异型群体， 引起疾病的遗传异质性，并导致复杂的细胞内在和外在 入侵机制。表皮生长因子受体（EGFR）扩增，标志性突变 存在于60%的病例中，最常以异质性方式发生，并且经常与 缺失外显子2-7，产生组成型活性突变体EGFRvIII。虽然重要的重点是 关于EGFRvIII的激酶活性，相对而言，关于EGFRvIII通过以下途径增强迁移的能力知之甚少： 与粘附受体的相互作用。我们的初步数据支持EGFRvIII的双重作用， 与内在的粘附受体，也通过外在信号招募非转化的对应物， 减少混合种群的粘附。根据我们的发现，我们假设这种粘合剂的差异 活性是由于与EGFRvIII相关的差异信号传导，并且该受体传递这种表型 转化为非转化的对应物（Inda，Genes & Dev，2010; Zanca，Genes & Dev， 2017）合作侵入薄壁组织。在此假设下，我们将使用粘附测量 技术来剖析细胞内在的EGFR介导的侵袭机制;考虑到细胞内的异质性， 肿瘤，我们还将联合收割机结合新开发的粘附分选技术与高通量测序 技术，以确定细胞外在机制和后续干预的目标。以下行 实验将进行：1）生物物理测定和信号通路分析的实施 探讨EGFRvIII的细胞内在活性如何导致不稳定的粘附和侵袭性表型; 2） EGFRvIII细胞外源性分泌组介导的wtEGFR教育的生物化学和功能分析 细胞粘附表型; 3）将使用粘附分选群体的表达和表观遗传分析 定义迁移组特征，暴露于EGFRvIII分泌组后其在wtEGFR细胞中的稳定性，以及 “受教育”wtEGFR将表观遗传标记传播到幼稚wtEGFR细胞的能力。

One major issue confounding successful treatment of glioblastoma multiforme (GBM) is the presence of highly invasive cells disseminating into the brain parenchyma. These cells evade surgical resection and often spread distally in brain parenchyma. Multiple and spatially distinct heterotypic populations exist within a single GBM, giving rise to the disease’s genetic heterogeneity and leading to complex cell intrinsic and extrinsic mechanisms of invasion. Amplification of the epidermal growth factor receptor (EGFR), a hallmark mutation present in 60% of cases, most often occurs in a heterogeneous manner and is frequently associated with deletion of exons 2-7, creating a constitutively active mutant, EGFRvIII. While significant focus has been placed on its kinase activity, comparatively little is known about EGFRvIII’s ability to enhance migration via interaction with adhesion receptors. Our preliminary data supports a dual role for EGFRvIII where it interferes with intrinsic adhesion receptors and also recruits non-transformed counterparts via extrinsic signaling to reduce adhesion of a mixed population. Based on our findings, we hypothesize that this difference in adhesive activity is due to differential signaling associated with EGFRvIII, and that this receptor conveys this phenotype to non-transformed counterparts through cytokine production (Inda, Genes & Dev, 2010; Zanca, Genes & Dev, 2017) to cooperatively invade parenchyma. With this hypothesis, we will use adhesion measurement technologies to dissect cell intrinsic EGFR-mediated invasion mechanisms; given the heterogeneity within tumors, we will also combine newly developed adhesion sorting technologies with high throughput sequencing technologies to identify cell extrinsic mechanisms and targets for subsequent intervention. The following lines of experimentation will be carried out: 1) implementation of biophysical assays and signaling pathway analyses to interrogate how cell intrinsic activity of EGFRvIII leads to labile adhesion and an invasive phenotype; 2) biochemical and functional analysis of the EGFRvIII cell extrinsic, secretome-mediated education of wtEGFR cell adhesive phenotype; 3) expression and epigenetic analyses on adhesion-sorted populations will be used to define a migratome signature, its stability in wtEGFR cells after exposure to the EGFRvIII secretome, and the ability of “educated” wtEGFR to propagate that epigenetic signature to naïve wtEGFR cells.