Examining role of splicing factor mutations in myelodysplastic syndrome (PQ11)

检查剪接因子突变在骨髓增生异常综合征 (PQ11) 中的作用

• 批准号: 8384741
• 负责人: Shalini Sharma
• 金额: $ 20.1万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8384741
• 关键词: Affect; Apoptosis; Biochemical; Blast Cell; Blood Cells; Bone Marrow; CD34 gene; Cell Cycle Progression; Cell Cycle Regulation; Cells; Chromosome abnormality; Chronic Lymphocytic Leukemia; Chronic Myelomonocytic Leukemia; Colorectal Cancer; Complex; Core Protein; Defect; Development; Diagnosis; Differentiation and Growth; Disease; Disease Outcome; Disease Progression; Dysmyelopoietic Syndromes; Dysplasia; Event; Excision; Exons; Frequencies; Gene Expression Profile; Gene Mutation; Generations; Goals; Growth; Growth and Development function; Hematopoiesis; Hematopoietic; Human; Induced Mutation; Introns; Knowledge; Lead; Link; Malignant Neoplasms; Malignant neoplasm of pancreas; Mediating; Messenger RNA; Mitosis; Molecular; Mutation; Myeloproliferative disease; Pathogenesis; Patients; Pattern; Point Mutation; Prognostic Marker; Property; Protein Splicing; Proteins; RNA; RNA Interference; RNA Sequences; RNA Splicing; Recurrence; Refractory; Refractory Anemia with Excess Blasts in Transformation; Refractory Anemia with Ringed Sideroblasts; Refractory anaemia with excess blasts; Refractory anemias; Ribonucleoproteins; Ringed Sideroblast; Role; Site; Small Nuclear Ribonucleoproteins; Somatic Mutation; Spliceosomes; Stem cells; Techniques; Testing; Transcript; U2 Small Nuclear Ribonucleoprotein; Umbilical Cord Blood; United States; base; cytopenia; density; disease phenotype; exome; genome-wide; insight; mRNA Precursor; malignant breast neoplasm; melanoma; mutant; new therapeutic target; protein function; stem

DESCRIPTION (provided by applicant): Regulated splicing of the cellular transcriptome is essential for normal growth and development. Aberrant expression of splicing patterns is linked to cancers and many other diseases. These abnormal splicing patterns may arise from mutations in pre-mRNA splice sites or in the protein components of the splicing machinery. Recent exome analysis of myelodysplastic syndrome (MDS) patients indicates a link between point mutations in core proteins of the splicing machinery and disease pathogenesis. Somatic mutations in eight splicing proteins were found to be recurrent in MDS cases. This association makes it essential to understand the mechanisms by which these spliceosomal proteins mutations lead to a disease phenotype. We hypothesize that the pathogenic effects of MDS mutations in splicing factors are mediated through changes in their splicing functions. The MDS mutations affect the normal functions of these proteins, resulting in generation of abnormal splicing patterns of transcripts that are important in hematopoiesis. This causes aberrant growth control in HSPCs. The goal of this project is to determine the molecular effects of MDS mutations on splicing factor function and to identify genome-wide splicing aberrations they induce during hematopoiesis that contribute to MDS pathogenesis. We will focus on mutations in SF3B1 and U2AF35 proteins. Distribution of mutations in these two proteins differs amongst the MDS types. SF3B1 mutations are frequent in MDS types that are characterized by ringed sideroblasts (RS), whereas U2AF35 mutations occur in forms of MDS without RS. This mutually exclusive occurrence and their very specific disease outcomes indicate differences in their pathogenic effect and likely distinct mechanisms of disease progression. We will use advanced high density RNA sequencing techniques to identify the MDS mutation induced aberrations in splicing profile of hematopoietic stem/progenitor cells. Effect of these mutations on normal proliferation and differentiation of HSPCs will be determined. Mechanisms underlying aberrant splicing will be determined by defining the MDS mutation- induced changes in U2AF35 and SF3B1 splicing functions using biochemical techniques. Using this approach we expect to define specific splicing events controlled by U2AF35 and SF3B1 during normal hematopoiesis and then elucidates how their mutation contributes to MDS pathogenesis. PUBLIC HEALTH RELEVANCE: Myelodysplastic syndromes (MDS) are a phenotypically diverse group of blood cell cancers that arise from abnormal growth and differentiation of HSPCs. In United States, about 12,000 MDS cases are diagnosed every year. To develop better prognostic markers, and to identify new druggable targets, it is essential to understand the mechanisms that lead to transformation of normal hematopoietic cells to MDS.

描述（由申请人提供）：细胞转录组的调节剪接对正常生长和发育至关重要。剪接模式的异常表达与癌症和许多其他疾病有关。这些异常剪接模式可能是由前mRNA剪接位点或剪接机制的蛋白质组分中的突变引起的。最近对骨髓增生异常综合征（MDS）患者的外显子组分析表明剪接机制核心蛋白的点突变与疾病发病机制之间存在联系。在MDS病例中发现8个剪接蛋白的体细胞突变是复发性的。这种关联使得了解这些剪接体蛋白突变导致疾病表型的机制至关重要。我们假设MDS剪接因子突变的致病作用是通过剪接功能的改变介导的。MDS突变影响这些蛋白质的正常功能，导致在造血中重要的转录物的异常剪接模式的产生。这导致HSPC中的异常生长控制。本项目的目标是确定MDS突变对剪接因子功能的分子效应，并确定它们在造血过程中诱导的有助于MDS发病机制的全基因组剪接畸变。我们将重点关注SF 3B 1和U2 AF 35蛋白的突变。这两种蛋白质的突变分布在MDS类型中不同。SF 3B 1突变常见于以环形铁粒幼细胞（RS）为特征的MDS类型，而U2 AF 35突变则以不含RS的MDS形式发生。这种相互排斥的发生及其非常特定的疾病结局表明其致病作用的差异和疾病进展的可能不同机制。我们将使用先进的高密度RNA测序技术来鉴定MDS突变诱导的造血干/祖细胞剪接谱畸变。将确定这些突变对HSPC的正常增殖和分化的影响。异常剪接的潜在机制将通过使用生物化学技术定义MDS突变诱导的U2 AF 35和SF 3B 1剪接功能的变化来确定。使用这种方法，我们希望定义特定的剪接事件控制的U2 AF 35和SF 3B 1在正常的造血，然后阐明他们的突变如何有助于MDS的发病机制。 公共卫生相关性：骨髓增生异常综合征（MDS）是由HSPC的异常生长和分化引起的一组表型多样的血细胞癌症。在美国，每年约有12，000例MDS病例被诊断出来。为了开发更好的预后标志物，并确定新的药物靶点，必须了解导致正常造血细胞转化为MDS的机制。