Improving CDK 4/6 inhibition in the treatment of medulloblastoma

建议书摘要 这项提议将开发CDK4/6抑制剂治疗髓母细胞瘤，使用一种新的纳米颗粒 帕波西利的处方，在转基因髓母细胞瘤易感小鼠体内研究，并与 OLIG2抑制剂CT-179。髓母细胞瘤是儿童最常见的恶性脑肿瘤。新的 髓母细胞瘤需要治疗，因为目前的手术、放疗和化疗都失败了。 20%的患者，并使幸存者面临神经认知损伤、生长缺陷和心理社会的风险 减损。虽然髓母细胞瘤是一种异质性疾病，有四个亚型，但所有亚型都有完整的 Rb和需要CDK4/6活性。因此，细胞周期蛋白D1/CDK4/6/视网膜母细胞瘤通路是一个可用药的靶点 在髓母细胞瘤亚组之间共享。我发现FDA的一种纳米制剂- 与母药相比，批准的CDK4/6抑制剂Palbociclib的全身毒性降低，并且可以 延长内源性SHH驱动的髓母细胞瘤转基因小鼠的存活时间。在这里，我展示了 Palbociclib既产生了减少Rb磷酸化的预期效果，也产生了意想不到的效果， 包括持久延长S期和增加表达OLIG2的干细胞。 我现在建议在SA1中定义S相变的机制，并识别敏感和抗性 髓母细胞瘤细胞群体，用单细胞转录分析(scRNA-seq)，蛋白质印迹和 免疫组织化学。这些研究将展示规范和非规范的作用机制，以及 确定未来研究中可以针对的抗性机制。在SA2中，我建议测试治疗方法 帕波西利联合OLIG2抑制剂CT-179的疗效。临床实践表明，没有。 作为单一药物使用的药物对髓母细胞瘤是治愈的，目前所有的治疗方法都依赖于联合治疗。 特工的身份。根据我的初步数据，合理地选择了帕博西利和CT-179的组合。 完成我的研究计划和培训计划将为我提供指导性和体验式学习 机会多种多样，从小鼠遗传学到多维细胞分析， 涉及scRNA-seq数据的计算分析。这次培训将使我能够发展基本的和翻译的能力 研究技能，并为作为一名创新、独立的研究科学家的职业生涯奠定基础。

PROPOSAL ABSTRACT This proposal will develop CDK4/6 inhibitor therapy for medulloblastoma, using a novel, nanoparticle formulation of palbociclib, studied in vivo in transgenic medulloblastoma-prone mice and combining with the OLIG2 inhibitor CT-179. Medulloblastoma is the most common malignant pediatric brain tumor. New medulloblastoma treatments are needed because current therapy with surgery radiation and chemotherapy fails 20% of patients and leaves survivors at risk for neurocognitive injury, growth defects, and psychosocial impairment. While medulloblastoma is a heterogenous disease with four subgroups, all subgroups have intact RB and require CDK4/6 activity. The CyclinD1/CDK4/6/Retinoblastoma pathway is therefore a druggable target shared amongst the medulloblastoma subgroups. I have found that a nanoparticle formulation of the FDA- approved CDK 4/6 inhibitor palbociclib shows reduced systemic toxicity compared to the parent drug and can extend the survival of transgenic mice with endogenous, SHH-driven medulloblastoma. Here, I show that palbociclib produces both the expected effect of reduced RB phosphorylation and also unexpected effects, including a durable prolongation of S phase and an increase in OLIG2-expressing stem cells. I now propose in SA1 to define the mechanism of S phase alterations and identify sensitive and resistant populations of medulloblastoma cells, using single-cell transcriptomic analysis (scRNA-seq), western blot and immunohistochemistry. These studies will demonstrate canonical and non-canonical mechanisms of action, and identify mechanisms of resistance that can be targeted in future studies. In SA2, I propose to test the therapeutic efficacy of combining palbociclib therapy with the OLIG2 inhibitor CT-179. Clinical practice has shown that no drug used as a single agent is curative for medulloblastoma, and all current treatments depend on combinations of agents. The combination of palbociclib and CT-179 is rationally chosen based on my preliminary data. Completing my Research Proposal and Training Plan will provide me with didactic and experiential learning opportunities in a diverse range are approaches, from mouse genetics, to multi-dimensional cytometric assays, to computational analysis of scRNA-seq data. This training will allow me to develop basic and translational research skills and build a foundation for a career as an innovative, independent research scientist.