Enhancing Treatment Response by Leveraging STAT5-OLIG2 signaling in GBM

利用 GBM 中的 STAT5-OLIG2 信号传导增强治疗反应

• 批准号: 10263545
• 负责人: SHWETAL MEHTA
• 金额: $ 58.02万
• 依托单位: MAYO CLINIC ARIZONA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-30 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10263545
• 关键词: Affect; Animals; Brain; Cell Line; Cells; Clinical; Complex; Epidermal Growth Factor Receptor; Genetic; Genetic Transcription; Glioblastoma; Glioma; Goals; Heterogeneity; Human; Immunocompetent; In Vitro; Invaded; JAK1 gene; Malignant Neoplasms; Mediating; Modeling; Molecular; Mutation; Oncogenic; Pathway interactions; Patients; Pharmacology; Phosphorylation; Pimozide; Population; Proteins; Receptor Protein-Tyrosine Kinases; Recurrence; Regimen; Regulation; Reporting; Residual state; Resistance; Resistance profile; Role; Signal Pathway; Signal Transduction; Stat5 protein; Testing; Therapeutic Agents; Treatment Efficacy; Tumor Cell Invasion; Tumor Necrosis Factor Receptor; Up-Regulation; Variant; Xenograft Model; Xenograft procedure; brain tissue; cancer cell; cell motility; combinatorial; constitutive active receptor; epidermal growth factor receptor VIII; genetic resistance; improved; inhibitor/antagonist; member; mouse model; mutant; self-renewal; stem cells; success; targeted treatment; temozolomide; therapeutic target; therapy development; therapy resistant; treatment response; tumor; tumor growth; tumorigenic

Project Summary Glioblastoma (GBM) is among the most treatment resistant and lethal of all human cancers. Effective GBM treatment is hindered by aggressive tumor cell invasion into surrounding healthy brain tissue that invariably leads to tumor recurrence. Therefore, the development of therapies that target the infiltrative, residual cells are greatly needed in order to improve the survival of GBM patients. We previously reported that the expression of the TNF receptor superfamily member Fn14 is high in infiltrating glioma cells. Increased Fn14 signaling promotes GBM cell migration/invasion and chemoresistance in vitro while Fn14 depletion increases sensitivity to temozolomide (TMZ) and survival in an intracranial xenograft model. Fn14 is an inducible protein that can be activated by constitutively active receptor tyrosine kinases such as amplified EGFR and its active mutant EGFRvIII. EGFRvIII-induced Fn14 upregulation is mainly driven by STAT5 activity to promote glioma invasion and therapeutic resistance. Notably, both Fn14 expression and STAT5 activation are elevated in GBM patient-derived xenograft (PDX) lines selected for temozolomide (TMZ) resistance. Inhibition of JAK1/2 expression/activity in EGFRvIII expressing GBM cells did not affect the phosphorylation of STAT5 (pSTAT5), which is essential for its activation, or Fn14 expression suggesting that STAT5 activation is independent of JAK1/2. Intriguingly, we find that expression of OLIG2, a key cell fate factor important for the tumorigenic potential of glioma stem cells (GSCs), affects STAT5 activation and Fn14 expression. In GSCs, STAT5 interacts with OLIG2 and treatment with the STAT5 inhibitor, pimozide results in decreased Fn14 expression and invasion of GSCs. The upstream molecular mechanisms involved in JAK-independent activation of STAT5 and downstream signaling pathway(s) regulated by OLIG2-STAT5 complex must be identified to ultimately target invasive GSCs. We hypothesize that the STAT5/OLIG2/Fn14 signaling pathway is a node of vulnerability in the invasive, residual GBM cells and targeting this pathway will decrease therapeutic resistance and increase survival in PDX models. In Aim 1, we will determine the mechanism(s) by which STAT5 signaling induces Fn14 expression downstream of EGFRvIII to enhance GBM cell invasion and therapeutic resistance. Aim 2 will identify the molecular mechanism(s) involved in OLIG2-mediated regulation of STAT5-Fn14 expression in GSCs. In Aim 3 we will determine the impact of STAT5 inhibition in combination with TMZ and IR on GBM tumor growth and therapeutic resistance in intracranial xenografts and syngeneic immunocompetent mouse models of GBM. Success of the proposal will identify, validate, and place into a clinically meaningful context the STAT5/OLIG2/Fn14 signaling pathway as a therapeutic target for infiltrating cells that commonly underlie GBM fatality.

项目摘要 胶质母细胞瘤（GBM）是所有人类癌症中最具治疗方法和致命性的之一。有效的GBM 侵略性肿瘤细胞侵入周围健康的脑组织会阻碍治疗 导致肿瘤复发。因此，靶向浸润性残留细胞的疗法的发展 为了提高GBM患者的存活，非常需要。我们以前报道了 TNF受体超家族成员FN14的表达在浸润性神经胶质瘤细胞中很高。增加 FN14信号传导在体外促进GBM细胞迁移/侵袭和化学抗性，而FN14耗竭 在颅内异种移植模型中增加对替莫唑胺（TMZ）和存活的敏感性。 FN14是一个 可诱导蛋白可以通过组成性活性受体酪氨酸激酶（例如扩增）激活的诱导蛋白 EGFR及其主动突变体EGFRVIII。 EGFRVII诱导的FN14上调主要由STAT5驱动 促进神经胶质瘤侵袭和治疗性抗性的活性。值得注意的是，FN14表达和STAT5既 选择用于替莫唑胺（TMZ）的GBM患者衍生异种移植（PDX）线中的激活升高 反抗。 EGFRVIII表达GBM细胞中JAK1/2表达/活性的抑制不会影响 STAT5（PSTAT5）的磷酸化，这对于其激活至关重要，或FN14表达表明 该STAT5激活与JAK1/2无关。有趣的是，我们发现Olig2的表达是一个钥匙单元 命运因素对神经胶质瘤干细胞（GSC）的致瘤潜力很重要，会影响STAT5激活 和FN14表达。在GSC中，STAT5与Olig2相互作用并与STAT5抑制剂治疗， Pimozide导致FN14表达和GSC的侵袭降低。上游分子 STAT5和下游信号通路涉及的机制与JAK无关激活 必须确定受Olig2-STAT5复合物调控，以最终靶向侵入性GSC。我们 假设STAT5/OLIG2/FN14信号通路是侵入性脆弱性的节点 残留的GBM细胞和靶向该途径将降低治疗性抗性并增加存活率 在PDX模型中。在AIM 1中，我们将确定STAT5信号诱导FN14的机制 EGFRVIII下游的表达以增强GBM细胞侵袭和治疗性抗性。 AIM 2意志 确定参与Olig2介导的STAT5-FN14表达调节的分子机制 GSC。在AIM 3中，我们将确定STAT5抑制与TMZ和IR对GBM的影响 颅内异种移植物和合成性免疫能力的肿瘤生长和治疗性 GBM的鼠标模型。该提案的成功将识别，验证并置于临床上有意义的 上下文STAT5/OLIG2/FN14信号通路是浸润细胞的治疗靶标的 GBM死亡的基础。