Chemosensitization of Glioblastoma by Propentofylline

摘要 胶质母细胞瘤(GBM)是中枢神经系统最常见的原发肿瘤，治疗方法有限，预后差。 临床预后。标准护理治疗，包括手术切除、放射治疗和同时进行 替莫唑胺(TMZ)治疗后辅助剂TMZ在新诊断的GBM中产生中位生存期 约15个月。肿瘤复发是由于耐药的肿瘤细胞所致；因此，治疗策略 提高肿瘤细胞对化疗的敏感性是改善患者预后所必需的。 TROY(TNFRSF19)是肿瘤坏死因子受体超家族的成员之一，最近被发现影响基底膜 进步。简而言之，Troy的表达随着胶质瘤分级的增加而增加，并且与 病人存活率。Troy的高表达促进GBM细胞在体内外的迁移/侵袭 在体外增加对TMZ或辐射的抵抗力，而下调Troy表达则抑制细胞侵袭， 在小鼠患者来源的异种移植(PDX)模型中，增加对TMZ的敏感性，并延长存活时间。这些 更多的研究表明，Troy代表了一种潜在的治疗GBM的新靶点。 丙戊茶碱(PPF)，一种已经在多个非GBM的临床试验中进行研究的药物 适应症，下调Troy，抑制GBM侵袭，增加体内外对TMZ的敏感性 和放射治疗。PPF表现出良好的药理学特征，包括良好的大脑分布 和有利的安全指标。重新调整PPF的用途可能会更快地进入临床试验，比 新化学实体的传统药物开发途径。 这项提议的主要目标是测试PPF使GBM对TMZ敏感的能力。次要目标 包括评估：特洛伊对PPF活动的必要性，PPF诱导特洛伊的作用机制 下调，以及PPF治疗和Troy表达对促肿瘤小胶质细胞的影响。 以下目标旨在回答这些问题。具体目标1：测试PPF的能力 TMZ耐药的GBM肿瘤对颅内PDX模型的治疗敏感性 同基因模式。PPF使GBM细胞对TMZ增敏的能力将在5个耐TMZ的PDX中进行评估 小鼠模型和一种具有免疫功能的同基因模型。IVIS-监测肿瘤生长、持续时间 将对肿瘤和肿瘤微环境的生存以及组织病理学和分子分析 已评估。特定目标2：确定PPF的细胞和分子靶点以预测临床 响应性。活细胞自动成像和分子技术将被用来帮助定义细胞 和PPF的分子靶点。我们将测试PPF对20个人GBM PDX的不同小组的敏化能力 代表不同分子和预后亚型的菌株体外治疗TMZ并评估其效果 PPF在体外对小胶质细胞的作用。

SUMMARY Glioblastoma (GBM) is the most common primary tumor of the CNS with limited treatment options and a poor clinical prognosis. Standard of care treatment, including surgical resection, radiation therapy and concurrent temozolomide (TMZ) treatment followed by adjuvant TMZ, produces a median survival in newly diagnosed GBM of ~15 months. Tumor recurrence happens due to therapy resistant tumor cells; therefore, therapeutic strategies that improve tumor cell sensitivity to chemotherapy are needed to improve patient outcomes. TROY (TNFRSF19), a member of the TNF receptor superfamily, has recently been discovered to impact GBM progression. Briefly, TROY expression increases with increasing glial tumor grade and inversely correlates with patient survival. Increased expression of TROY stimulates GBM cell migration/invasion in vitro and in vivo and increases resistance to TMZ or radiation in vitro, while knockdown of TROY expression inhibits cell invasion, increases sensitivity to TMZ, and prolongs survival in a murine patient-derived xenograft (PDX) model. These and additional studies indicate that TROY represents a potential novel therapeutic target for GBM. Propentofylline (PPF), a drug that has been studied in numerous clinical trials for several non-GBM indications, downregulates TROY, inhibits GBM invasion and increases sensitivity in vitro and in vivo to TMZ and radiotherapy. PPF exhibits a well-characterized pharmacological profile, including good brain distribution and favorable safety metrics. Repurposing PPF could be faster to clinical trials, less risky and less costly than the traditional drug development pathway for new chemical entities. The primary goal of this proposal is to test the ability of PPF to sensitize GBM to TMZ. Secondary goals include assessing: the necessity of TROY for PPF activity, the mechanisms of action for PPF-induced TROY downregulation, and the impact of PPF treatment and TROY expression on tumor-promoting microglia. The following aims have been designed to answer these questions. Specific Aim 1: Test the ability of PPF to sensitize TMZ resistant GBM tumors to therapeutic treatment in intracranial PDX models and a syngeneic model. The ability of PPF to sensitize GBM cells to TMZ will be evaluated in five TMZ resistant PDX mouse models and one immunocompetent syngeneic model. IVIS-monitoring of tumor growth, duration of survival as well as histopathological and molecular analysis of tumor and tumor microenvironment will be evaluated. Specific Aim 2: Characterize the cellular and molecular targets of PPF to predict clinical responsiveness. Live-cell automated imaging and molecular techniques will be used to help define the cellular and molecular targets of PPF. We will test the ability of PPF to sensitize a diverse panel of 20 human GBM PDX lines, representing varied molecular and prognostic subtypes, to TMZ treatment ex vivo and assess the effects of PPF on microglia in vitro.