U2AF1 mutations in myelodysplastic syndromes: from mechanism to therapy

描述（由申请人提供）：骨髓增生异常综合征（MDS）是一组异质性血液疾病，其特征是无效和发育不良的造血功能。MDS的有效治疗方法很少，部分原因是我们对这种疾病的分子基础了解不完全。最近发现的影响MDS中RNA剪接机制的高频突变为我们进一步了解MDS生物学并为新疗法的开发提供了重要机会。然而，剪接体突变的分子后果尚不清楚，这阻碍了了解这些突变如何导致造血发育异常并带来新的治疗机会的努力。为了解决这一知识空白，我们建议确定影响剪接体基因U2AF1的突变的机制，功能和治疗后果，U2AF1是MDS中最常见的突变基因之一。我们已经建立了一个具有RNA剪接机制和剪接治疗经验的团队（Bradley），以及MDS生物学和患者护理（Ramakrishnan, Shimamura）。在Aim 1中，我们将确定mds相关突变如何改变U2AF1在3'剪接位点识别中的正常作用，包括在U2AF1:RNA相互作用中引起序列特异性改变。在Aim 2中，我们将鉴定在U2AF1突变的细胞中错误剪接并随后翻译成蛋白质的mrna，并验证U2AF1突变引起MDS细胞分子特征的假设。在Aim 3中，我们将验证化学抑制剪接位点识别将选择性杀死U2AF1突变细胞的假设。在本研究的结论中，我们将确定U2AF1突变对剪接过程的机制后果，展示这些突变如何促进MDS细胞的分子病理特征，并测试靶向RNA剪接过程本身作为MDS新治疗途径的潜力。最终，我们期望所提出的工作能够加快开发治疗MDS的新疗法的步伐。

DESCRIPTION (provided by applicant): Myelodysplastic syndromes (MDS) are a heterogeneous group of blood disorders characterized by ineffective and dysplastic hematopoiesis. There are few effective treatments for MDS, due in part to our incomplete understanding of the molecular basis of this disease. The recent discovery of high-frequency mutations affecting the RNA splicing machinery in MDS presents a significant opportunity to further our knowledge of MDS biology and inform the development of new therapeutics. However, the molecular consequences of spliceosomal mutations ARE unknown, hindering efforts to understand how these mutations contribute to dysplastic hematopoiesis and lead to new therapeutic opportunities. To address this gap in knowledge, we propose to determine the mechanistic, functional, and therapeutic consequences of mutations affecting the spliceosomal gene U2AF1, one of the most commonly mutated genes in MDS. We have built a team with experience in RNA splicing mechanisms and splicing-based therapeutics (Bradley), as well as MDS biology and patient care (Ramakrishnan, Shimamura). In Aim 1, we will determine how MDS-associated mutations alter U2AF1's normal role in 3' splice site recognition, including causing sequence-specific alterations in U2AF1:RNA interactions. In Aim 2, we will identify mRNAs that are mis-spliced in cells with U2AF1 mutations and subsequently translated into protein, and test the hypothesis that U2AF1 mutations give rise to molecular hallmarks of MDS cells. In Aim 3, we will test the hypothesis that chemical inhibition of splice site recognition wil selectively kill cells with U2AF1 mutations. At the conclusion of this study, we will have determined the mechanistic consequences of U2AF1 mutations for the splicing process, shown how these mutations contribute to molecular pathologies characteristic of MDS cells, and tested the potential of targeting the RNA splicing process itself as a new therapeutic avenue for MDS. Ultimately, we expect the proposed work to accelerate the pace at which new therapeutics may be developed to treat MDS.