Identifying vulnerabilities and therapeutic targets in Glioma Stem Cells

 描述（由申请人提供）：本申请的目的是发展Christian Badr博士的职业生涯，以促进向稳定的独立阶段过渡，并实现他成为独立科学家的最终目标，并建立自己的研究计划。候选人制定的职业发展计划将大大有助于他的科学发展，并进一步促进他在蛋白质组学，RNAi和癌症干细胞生物学方面的培训。在K22的建议机会将提供PI保护的时间，同时开始他的独立教师的位置，并引导他走向一个成功的职业生涯在开发治疗脑肿瘤。拟议的研究还将作为R 01提案的基础，该提案将在该奖项的第二年结束前提交。神经胶质瘤干细胞（GSC）代表恶性神经胶质瘤中的亚群，并且具有高度致瘤性，对当前疗法具有内在抗性，并且能够自我更新和分化成成熟神经胶质瘤细胞（GC）。GSC有两种主要亚型：前神经（PN）和间充质（MES），后者更具侵袭性，对常规治疗更具抵抗力。我们已经确定了一个亚群的GSCs，称为浮动细胞（FC），可以从体外培养的胶质瘤细胞分离。这些细胞具有干细胞样特征，具有突出的间充质特征。与其亲本GSC系相比，它们在植入裸鼠脑中时往往更具攻击性，并且对放射和治疗具有上级抗性。由于这些特性，FC代表了鉴定和测试新GBM疗法的理想模型。在本提案的目标1中，我们将使用定量质谱法对PN和MES GSC（包括FC群体）的不同模型进行蛋白质组学分析。这项工作将提供FC的更深入的表征，并确定PN和MES GSC中差异表达的蛋白质/途径，这可以用于开发新的治疗方法。在目标2中，我们将使用基于成像的报告基因并进行RNAi筛选，以鉴定GSC调节剂，这些调节剂要么将GSC推向更分化的状态，使其对常规治疗敏感，要么简单地杀死这些细胞。最后，我们将测试一种新的基因递送方法，该方法基于包装在腺相关病毒载体（vAAV）中的细胞外囊泡，以将我们的治疗性RNAi递送到小鼠脑肿瘤中。这项工作可以为理解这种难以捉摸的肿瘤群体的生物学和GSC亚型之间的可塑性增加有价值的信息。它也有可能确定PN和MES胶质瘤的新的脆弱性和治疗途径。

 DESCRIPTION (provided by applicant): The objective of this application is to develop the career of Dr. Christian Badr to facilitate the transition to a stable independent phase and attain his ultimate goal to become an independent scientist and establish his own research program. The career development plan created by the candidate will contribute substantially to his scientific development and further his training in proteomics, RNAi and cancer stem cells biology. The proposed opportunity in the K22 will provide the PI protected time while starting his independent Faculty position and direct him towards a successful career in developing therapeutics for brain tumors. The proposed research will also serve as the foundation for an R01 proposal prior to the end of the second year of this award. Glioma stem cells (GSC) represent a subset population within malignant gliomas, and are highly tumorigenic, intrinsically resistant to current therapies, and capable of self-renewal and differentiation into mature glioma cells (GCs). There are two major subtypes of GSCs: Proneural (PN) and Mesenchymal (MES), the latter being more aggressive and more resistant to conventional treatment. We have identified a subpopulation of GSCs, termed floating cells (FC) that could be isolated from in vitro-cultured glioma cells. These cells possess a stem-like signature with prominent mesenchymal features. They tend to be more aggressive when implanted into the brain of nude mice as compared to their parental GSCs line and have a superior resistance to radiation and therapy. Due to such properties, FC represents an ideal model to identify and test new GBM therapeutics. In Aim 1 of this proposal we will use quantitative mass spectrometry to perform a proteomic analysis on different models of PN and MES GSCs including the FC population. This work will provide a deeper characterization of the FCs and identify differentially expressed proteins/pathways in PN and MES GSCs, which could be exploited to develop new therapeutics. In Aim 2, we will use imaging-based reporters and perform an RNAi screen to identify GSCs modulators which either push GSCs to a more differentiated state, making them susceptible to conventional therapy, or simply kill these cells. Finally we will test a novel gene delivery approach based on extracellular vesicles packaged in adeno-associated virus vectors (vAAV) to deliver our therapeutic RNAi to brain tumors in mice. This work can add valuable information for understanding the biology of this elusive tumor population and plasticity between GSCs subtypes. It also has the potential to identify new vulnerabilities and therapeutic avenues for PN and MES gliomas.