Systemic gene therapy for glioblastoma

 描述：多形性胶质母细胞瘤（GBM）是最常见的原发性脑恶性肿瘤，预后很差。目前，对这种疾病没有有效的治疗方法。基因治疗一直被认为是治疗该病的一种有前途的方法，然而，在过去的几十年里，基因治疗并没有取得多大进展。这可能归因于两个主要因素，包括：1）缺乏同时克服血脑屏障（BBB）和细胞屏障的方法，血脑屏障用于药物递送至脑，细胞屏障用于以足够的效率将遗传物质诱导至细胞;和2）缺乏也可被有效操纵以消除GBM肿瘤细胞的分子靶标，包括大量细胞群中的干细胞样细胞。在这里，我们提出测试一种新的策略，旨在充分克服这些障碍：自催化递送载有Cas9/sgRNA的脑肿瘤靶向纳米颗粒，这些纳米颗粒旨在消除调节大量细胞群体以及GBM内干细胞样细胞群体存活的基因。在初步工作中，我们提出并测试了一种用于全身药物递送到大脑的创新机制，称为自催化脑肿瘤靶向（ABTT）递送，基于此，我们使用新型固体聚合物合成了ABTT纳米颗粒（NP）。我们证明ABTT纳米颗粒有效地克服血脑屏障和细胞屏障，并能够介导有效的基因治疗脑肿瘤的治疗。沿着这一进展，我们通过全基因组RNAi筛选鉴定了一组基因作为GBM基因治疗的新候选基因。此外，我们证明了Cas9/sgRNA介导的基因敲除允许产生比传统RNAi方法更持久的抑制作用。基于这一进展，我们提出通过在目标1中优化和表征用于将Cas9/sgRNA全身递送至GBM的ABTT NP，在目标2中表征和选择在抑制GBM中具有优异生物活性的基因，以及在目标3中确定全身基因疗法的治疗益处来测试我们的策略。成功完成拟议的研究将建立一个新的方案，有效治疗GBM患者。

 DESCRIPTION: Glioblastoma multiforme (GBM), the most common primary brain malignancy, carries a grim prognosis. Currently, there are no effective treatments for this disease. Gene therapy has been long time considered as a promising approach for this disease, which, however, has not seen much progress over the past many decades. This can be potentially attributed to two major factors, including: 1) the lack of approaches for simultaneously overcoming the blood-brain barrier (BBB) for drug delivery to the brain and the cellular barriers for induction of genetic materials to cells with adequate efficiency; and 2) the lack of molecular targets that can also be effectively manipulated for elimination of GBM tumor cells, including the stem-like cells within the bulk cell population. Here, we propose testing a new strategy that is designed for adequately overcoming these hurdles: autocatalytic delivery of brain tumor-targeted nanoparticles loaded with Cas9/sgRNAs designed for elimination of genes that regulate the survival of bulk cell population as well as the stem-like cell population within GBM. In preliminary work, we proposed and tested an innovative mechanism for systemic drug delivery to the brain, called autocatalytic brain tumor-targeted (ABTT) delivery, based on which we synthesized ABTT nanoparticles (NPs) using a novel solid polymer. We demonstrated that ABTT NPs efficiently overcome the BBB and the cellular barrier and were capable of mediating effective gene therapy for treatment of brain tumors. Along this progress, we identified a group of genes through a genome wide RNAi screening as novel candidates for GBM gene therapy. In addition, we demonstrated that Cas9/sgRNA-mediated genetic knockout allowed producing more persistent inhibitory effects than the traditional RNAi approach. Based on this progress, we propose to test our strategy by optimizing and characterizing ABTT NPs for systemic delivery of Cas9/sgRNAs to GBM in Aim 1, characterizing and selecting genes with excellent biological activity in inhibition of GBM in Aim 2, and determining the therapeutic benefit of systemic gene therapy in Aim 3. Successful completion of the proposed study will establish a novel regimen for effective treatment of patients with GBM.