Functional Genomic Dissection of Refractory Anemia

摘要 来那度胺是一种高效治疗骨髓增生异常综合征（MDS）患者的药物， 染色体5 q（del（5 q）），约50%的患者达到完全细胞遗传学缓解。在 在前一个资助期，我们确定了来那度胺治疗有效性的机制基础， del（5 q）MDS，产生了第一个对来那度胺有反应的鼠模型，并开发了定量质量 使用基于光谱的方法来评估来那度胺和相关分子的活性。我们现建议 研究来那度胺不完全应答和获得性耐药的分子基础， 开发一种绕过耐药性的新治疗方法。首先，我们的目标是确定 以前没有研究过的敏感性和耐药性：来那度胺对干细胞的影响， 骨髓微环境和免疫系统。这些实验由CRBNI 391 V 在先前资助期间开发的对来那度胺敏感的鼠模型。接下来我们就 检查CSNK 1A 1和GSPT 1与新型沙利度胺衍生物CC-885的组合靶向作用， 在del（5 q）MDS模型中研究GSPT 1介导的细胞毒性的机制。最后，我们将调查 CRL 4CRBN E3泛素连接酶对癌蛋白的来那度胺依赖性降解的生物化学， 验证通过全基因组CRISPR筛选鉴定的基因。这些研究将告知生物学 沙利度胺衍生物一般，提供了全面的描述和机制的理解， 沙利度胺衍生物对免疫系统稳态的影响，并有助于开发新的 用于del（5 q）MDS的治疗剂。

ABSTRACT Lenalidomide is a highly effective treatment for patients with myelodysplastic syndrome (MDS) with deletion of Chromosome 5q (del(5q)), with approximately 50% of patients achieving a complete cytogenetic response. In the previous funding period, we determined the mechanistic basis for the therapeutic efficacy of lenalidomide in del(5q) MDS, generated the first murine model that responds to lenalidomide, and developed a quantitative mass spectrometry-based approach to evaluate the activity of lenalidomide and related molecules. We now propose to investigate the molecular basis for incomplete responses to lenalidomide and acquired resistance, and to develop a novel therapeutic approach that bypasses resistance. First, we aim to determine mechanisms of sensitivity and resistance that have not been previously investigated: the impact of lenalidomide on stem cells, the bone marrow microenvironment, and the immune system. These experiments are enabled by the CRBNI391V murine model, developed during the previous funding period, that is sensitive to lenalidomide. Next, we will examine combinatorial targeting of CSNK1A1 and GSPT1 with a new thalidomide derivative, CC-885, and investigate the mechanism of GSPT1-mediated cytotoxicity in models of del(5q) MDS. Finally, we will investigate the biochemistry of lenalidomide-dependent degradation of oncoproteins by the CRL4CRBN E3 ubiquitin ligase, validating genes identified through genome-wide CRISPR screens. These studies will inform the biology of thalidomide derivatives in general, provide a comprehensive description and mechanistic understanding of thalidomide derivative effects on immune system homeostasis, and contribute to the development of novel therapeutics for del(5q) MDS.