Project 3: Using RNAi-based Spherical Nucleic Acid (SNA) Nanoconjugates Targeting Bcl2L12 to Promote Therapy-Induced Apoptosis in Glioblastoma

项目3：概要 胶质母细胞瘤（GBM）是恶性胶质瘤中最具侵袭性和最普遍的表现，其特征在于： 对现有治疗方式的抵抗，并表现出最终导致死亡的神经衰弱过程， 通常在确诊后14个月内。在改善治疗结果的关键挑战中， GBM患者正在识别和表征新的药物靶点，以克服臭名昭著的治疗方法 GBM的耐药性，以及靶向不可治疗的遗传病变的药物递送平台的开发。 p53活性的恢复代表了用于治疗GBM的有吸引力的治疗策略，因为约65%的GBM患者的p53活性的恢复代表了用于治疗GBM的有吸引力的治疗策略。 原发性GBM患者表达野生型但功能抑制的p53。扩增和过度表达 非典型Bcl 2家族蛋白Bcl 2L 12（Bcl 2-Like-12）通过阻断p53的功能而损害p53的功能。 p53的转录活性。为了抑制Bcl 2L 12功能，我们建议使用新的基于RNAi的 纳米缀合物，称为球形核酸（SNA），以中和建立的GBM中的Bcl 2L 12表达。 我们已经发现Bcl 2L 12靶向SNA（siBcl 2L 12-SNA）能够穿过细胞膜 包括血脑屏障我们确定siBcl 2L 12-SNA不需要使用毒性助剂 试剂，并在GBM肿瘤细胞中在穿过血脑/血肿瘤屏障时有效地积累。 在全身施用SNA后，在脑内GBM异种移植物中观察到的细胞毒性。SNA表现出稳定性， 生理环境，引起强烈的肿瘤内Bcl 2L 12 mRNA和蛋白质敲低， p53再活化，并减缓GBM患者来源的异种移植物（PDX）模型中的肿瘤生长。在这里，我们将进一步 研究通过SNA治疗的Bcl 2L 12消融增加p53肿瘤抑制，减缓 GBM进展，并且可以与常规遗传毒性治疗以及靶向治疗相结合。 用于改善对肿瘤生长的抑制以及可能用于引起肿瘤消退的治疗剂。在目标1中， 我们将在体外测定siBcl 2L 12在患者源性神经胶质瘤起始细胞（GIC）中的治疗效果，并在PDX中测定siBcl 2L 12在PDX中的治疗效果。 体内模型，作为单一疗法和与放射疗法（RT）组合。在目标2中，使用PDX 新诊断和复发肿瘤的模型，以及同基因的免疫活性小鼠模型， 我们将联合收割机siBc 1 2L 12与细胞毒性和p53激活化疗药物，即，DNA烷化剂 替莫唑胺和MDM 2抑制剂RG 7388。目标3提出了一项0期临床试验， siBcl 2L 12-SNA，以确定SNA药代动力学、生物分布和下调GBM-的能力 相关的Bcl 2L 12 mRNA和蛋白。这项建议的结果将提供一个深入的特点， Bcl 2L 12癌蛋白作为一种可操作的GBM癌蛋白，并将为成功实施 SNA介导的多模式p53再激活作为临床实践中的治疗方法。

PROJECT 3: SUMMARY Glioblastoma (GBM), the most aggressive and prevalent manifestation of malignant glioma, is characterized by resistance to extant therapeutic modalities, and exhibit a neurologically debilitating course culminating in death, often within 14 months after diagnosis. Among the critical challenges for improving treatment outcomes for GBM patients are the identification and characterization of new drug targets to overcome the notorious therapy resistance of GBM, and the development of drug delivery platforms to target undruggable genetic lesions. Restoration of p53 activity represents an attractive therapeutic strategy for the treatment of GBM, as ~65% of primary GBM patients express wildtype but functionally suppressed p53. Amplification and overexpression of the atypical Bcl2 family protein Bcl2L12 (Bcl2-Like-12) compromises p53 function by blocking the transcriptional activity of p53. To inhibit Bcl2L12 function, we propose to use novel RNAi-based nanoconjugates, termed Spherical Nucleic Acids (SNAs) to neutralize Bcl2L12 expression in established GBM. We have found that Bcl2L12-targeting SNAs (siBcl2L12-SNAs) are able to traverse cellular membranes including the blood-brain-barrier. We established that siBcl2L12-SNAs do not require the use of toxic auxiliary reagents and accumulate effectively in GBM tumor cells upon crossing the blood-brain/blood-tumor barrier in intracerebral GBM xenografts following systemic administration of the SNAs. SNAs exhibit stability in physiological environments, provoke robust intratumoral Bcl2L12 mRNA and protein knockdown resulting in p53 reactivation, and slow tumor growth in GBM patient derived xenograft (PDX) models. Here, we will further investigate the hypothesis that Bcl2L12 ablation by SNA treatment increases p53 tumor suppression, slows GBM progression, and can be combined with conventional genotoxic therapies as well as with targeted therapeutics for improved suppression of tumor growth, and possibly for causing tumor regression. In Aim 1, we will determine siBcl2L12 treatment effect in patient-derived glioma-initiating cells (GICs) in vitro, and in PDX models in vivo, as monotherapy and in combination with radiation therapy (RT). In Aim 2, using both PDX models for newly diagnosed and recurrent tumor, together with syngeneic, immunocompetent mouse models, we will combine siBcl2L12 with cytotoxic and p53-activating chemotherapeutic drugs, i.e., the DNA alkylator temozolomide and the MDM2 inhibitor RG7388, respectively. Aim 3 proposes a phase 0 clinical trial of siBcl2L12-SNAs, to determine SNA pharmacokinetics, biodistribution, and ability to downregulate GBM- associated Bcl2L12 mRNA and protein. The results of this proposal will provide an in-depth characterization of the Bcl2L12 oncoprotein as an actionable GBM oncoprotein, and will pave the way to successfully implement SNA-mediated, multi-modal p53 reactivation as a therapeutic approach to incorporate in clinical practice.