Stem cell mediated targeting of tumor cells and associated vasculature in gliomas

描述(由申请人提供)：一些先前的临床前研究表明，抗血管生成药物创建了“正常化窗口”，在此期间，同时使用的细胞毒药的输送和疗效都得到了提高。然而，最近的研究表明，血管正常化导致血脑屏障的恢复，从而导致低效率的血管依赖性细胞毒药物输送到脑肿瘤。这些结果提出了关于给药方式和抗血管生成药物和细胞毒药物组合类型的基本问题，这些药物组合用于1)使肿瘤血管正常化；2)在脑瘤正常化后增强细胞毒治疗的结果？这促使了新疗法的设计，这些疗法允许使用1)针对原发肿瘤和脑内次级微侵袭沉积的替代给药模式；2)专门针对肿瘤细胞和相关血管的工程治疗蛋白；以及3)允许跟踪药物输送载体、治疗蛋白和肿瘤体内命运的诊断蛋白。在这项建议中，我们将利用分泌型抗血管生成(AA)、凝血酶敏感蛋白(TSP)-1和促凋亡分泌型肿瘤坏死因子凋亡诱导配体(S-TRAIL)来工程人神经干细胞(NSC)，并初步比较NSC-aaTSP-1在已建立的恶性和原发侵袭性脑肿瘤(胶质瘤)中的“正常化”潜力。根据我们的合作者Lawler博士最近的研究，TSP-1使血管系统正常化，并诱导肿瘤相关内皮细胞(EC)上死亡受体(DR)4/5的表达，从而启动TRAIL诱导的杀伤，S-TRAIL血管后归一化和aATSP-1启动EC的治疗效果将在恶性和侵袭性胶质瘤模型中进行测试。我们推测aaTSP-1可能通过调节血管生成和上调内皮细胞中DR4/5的表达来增强S-TRAIL对肿瘤细胞的杀伤作用。这将最终导致肿瘤细胞的增强根除，并在原发肿瘤块和逃脱原发肿瘤块的微侵袭肿瘤细胞中杀死EC。将荧光和生物发光成像标记物紧密整合到胶质瘤细胞、EC和NSC中，将使我们能够及早和快速评估治疗效果，从而调整和微调拟议的治疗方法。为了模拟临床场景，治疗性神经干细胞将被封装到生物相容的合成细胞外基质(SECMs)中，并在我们最近开发的胶质瘤切除模型中进行测试。一旦得到验证，我们设想了一种治疗模式，在脑肿瘤手术时，主要肿瘤肿块将被移除，基因工程治疗细胞将被引入sECM，并允许靶向剩余的肿瘤细胞和大脑中的微侵袭肿瘤沉积。这将对挽救许多脑癌患者的生命产生重大影响。

DESCRIPTION (provided by applicant): A number of previous pre-clinical studies suggest that anti-angiogenic agents create "normalization window" during which delivery and efficacy of concurrently administered cytotoxic agents is enhanced. However, recent studies have shown that vessel normalization results in the restoration of blood brain barrier and consequential inefficient vessel dependent delivery of cytotoxic drugs to brain tumors. These results have raised fundamental questions about modes of delivery and the types of anti-angiogenic and cytotoxic drug combinations used to 1) normalize tumor vasculature; and 2) enhance the outcome of cytotoxic therapy post-normalization for brain tumors? This has prompted the design of novel therapies that allow use of 1) alternative modes of drug delivery that targets both the primary tumors and secondary micro-invasive deposits in the brain; 2) engineered therapeutic proteins that specifically target both tumor cells and associated vasculature; and 3) diagnostic proteins that allow tracking of drug delivery vehicles, therapeutic proteins and fate of tumors in vivo. In this proposal, we will engineer human neural stem cells (NSC) with secretable antiangiogenic (aa), thrombospondin (TSP)-1 and pro-apoptotic secretable tumor necrosis factor apoptosis inducing ligand (S-TRAIL) which is known to induce apoptosis via death receptor (DR)4/5 and initially compare the "normalization" potential of NSC-aaTSP-1 with systemic delivery of known anti-angiogenic agents in established malignant and primary invasive brain tumors (gliomas). Based on the recent studies by our Co-Investigator, Dr. Lawler, that TSP-1 normalizes vasculature and also induces death receptor (DR)4/5 expression on tumor associated endothelial cells (EC) priming them to TRAIL-induced killing, the therapeutic effect of S-TRAIL post vessel normalization and EC priming by aaTSP-1 will be tested in both malignant and invasive glioma models. We hypothesize that aaTSP-1 will enhance the cytotoxic effects of S-TRAIL on tumor cells by normalizing the vasculature and also upregulation of DR4/5 expression in EC. This will ultimately lead to enhanced eradication of tumor cells and also killing of EC in both the primary tumor mass and the micro-invasive tumor cells escaping the primary tumor mass. A close integration of fluorescent and bioluminescent imaging markers into glioma cells, EC and NSC will allow us to assess therapeutic efficacy early and quickly and thus to adjust and fine-tune the proposed therapeutic approaches. In an effort to simulate a clinical scenario, the therapeutic NSC will be encapsulated into biocompatible synthetic extracellular matrix (sECMs) and tested in our recently developed resection model of glioma. Once validated, we envision a therapeutic modality in which at the time of brain tumor surgery, the main tumor mass will be removed and genetically engineered therapeutic cells will be introduced in sECMs and allowed to target the remaining tumor cells and micro-invasive tumor deposits in the brain. This will have a major impact in saving the lives of many brain cancer patients.