Hematopoietic consequences of gain-of-function SAMD9 and SAMD9L mutations

功能获得性 SAMD9 和 SAMD9L 突变的造血后果

• 批准号: 10549853
• 负责人: Jason Ross Schwartz
• 金额: $ 14.87万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-11-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10549853
• 关键词: ANXA5 gene; Addison' s disease; Advisory Committees; Alleles; Apoptosis; Architecture; Ataxia; Autophagocytosis; Award; Biological Models; Bone Marrow Diseases; CD34 gene; CRISPR/Cas technology; Caspase; Cell Count; Cell Cycle Arrest; Cell Line; Cell Separation; Cells; Cellular Assay; Childhood; Chromosome 7; Chromosome Deletion; Chromosomes; Clinical; Clonal Evolution; Data; Development; Development Plans; Diagnosis; Disease; Dysmyelopoietic Syndromes; Educational workshop; Ensure; Evolution; Faculty; Flow Cytometry; Genes; Genetic; Genital; Genitalia; Genome engineering; Genomics; Germ-Line Mutation; Goals; Growth; Hematologic Neoplasms; Hematopoietic; Hematopoietic stem cells; Heterozygote; Hypocellular Bone Marrow; In Vitro; Infection; Inhibition of Cell Proliferation; Institution; Interferon alpha; Interferons; K-Series Research Career Programs; Lead; Lesion; Location; Malignant Neoplasms; Maps; Mentors; Modeling; Molecular; Monosomy 7; Mutate; Mutation; Myelogenous; Myeloid Cells; Myelopoiesis; Myeloproliferative disease; Neoplasms; Nucleotides; Outcome; Output; Pancytopenia; Pathogenesis; Pathologic; Pathway interactions; Patients; Pediatric Hematology; Phenotype; Physicians; Prognosis; Proteins; Publishing; Recovery; Reporting; Research; Research Support; Resolution; Resource Sharing; Saint Jude Children' s Research Hospital; Sampling; Scientist; Series; Somatic Mutation; Stains; Syndrome; Time; Uniparental Disomy; alanine aminopeptidase; career; career development; chromosome 7 loss; clinical phenotype; cohort; cytotoxic; differential expression; experience; gain of function; gain of function mutation; genome sequencing; hematopoietic cell transplantation; improved; in vivo; induced pluripotent stem cell; insight; lectures; mutant; pediatric myelodysplastic syndrome; pressure; repaired; senescence; skills; stem; stem cell model; stem cells; success; tool; transcriptome sequencing

PROJECT SUMMARY Heterozygous germline mutations in SAMD9 and SAMD9L have recently been described as a new class of MDS predisposing lesions and are present in approximately 10-20% of pediatric MDS cases. We and others have shown in published reports that MDS-associated germline mutations in SAMD9/9L increase the antiproliferative activity of the encoded protein and lead to hypocellular bone marrow with decreased myeloid cell numbers. In addition, we have shown that the development of a myeloid disease is associated with partial or full loss of chromosome 7 that results from the non-random loss of the pathologic mutation. Interestingly, somatic revertant mutations including in cis single nucleotide changes and conversion of the mutant allele to the wild-type through uniparental disomy occur in some cases which leads to hematopoietic recovery. Remarkably, some patients with monosomy 7, leading to a presumptive diagnosis of MDS, also achieve hematopoietic recovery through spontaneous disappearance of the monosomy 7 clone. These data lead to the hypothesis that gain-of- function (GoF) SAMD9/9L proteins are cytotoxic and cause strong selective pressure for cells lacking the mutant allele. The molecular mechanisms through which SAMD9/9L GoF mutations inhibit myelopoiesis, and the spectrum of secondary mutations leading to either MDS, MDS/AML (e.g. SETBP1), or spontaneous recovery is unknown. The proposed studies will investigate these questions through two specific aims: 1.) to determine the molecular and functional impact of mutant SAMD9 and SAMD9L expression during myeloid differentiation using and iPSC model system of pediatric MDS, and 2.) to determine the clonal architecture of cells expressing mutant SAMD9 and SAMD9L using serial patient samples and single cell genomics. A Mentored Clinical Scientist Research Career Development Award (K08) will provide the candidate with the amount of protected time needed to achieve his career goal of independence as a physician scientist and focus on improving the clinical outcomes of pediatric MDS patients through understanding the mechanisms of their disease pathogenesis. A strong career development plan including an experienced and successful faculty advisory committee, clear plans for progress assessments, and attendance at numerous courses, lectures, and workshops to increase proficiency in technical and management skills will accompany these research goals to ensure success as an independent physician scientist. This award will be completed at St. Jude Children’s Research Hospital (St. Jude), one of the world’s leading academic institutions focused on the research and treatment of pediatric catastrophic diseases, making it an exemplary location for an early career physician scientist to develop his career. In addition to the strong institutional support, St. Jude offers unmatched research support with facilities including the Genome Sequencing Facility at the Hartwell Center, a Flow Cytometry and Cell Sorting Shared Resource, and the Center for Advanced Genome Engineering (CAGE).

项目摘要 SAMD 9和SAMD 9 L中的杂合生殖系突变最近被描述为一类新的MDS 易发性病变，存在于约10-20%的儿童MDS病例中。我们和其他人已经 在已发表的报告中显示，SAMD 9/9 L中MDS相关的生殖系突变增加了抗增殖活性， 这导致编码蛋白质的活性降低，并导致骨髓细胞减少，骨髓细胞数量减少。在 此外，我们已经表明，骨髓疾病的发展与部分或全部丧失有关。 7号染色体，由病理性突变的非随机丢失引起。有趣的是，体细胞回复突变体 突变，包括顺式单核苷酸变化和突变等位基因通过 在某些情况下发生单亲二体性，这导致造血恢复。值得注意的是，有些病人 与单体7，导致MDS的推定诊断，也实现造血恢复，通过 单体7克隆的自发消失。这些数据导致的假设，增益- SAMD 9/9 L蛋白是细胞毒性的，并对缺乏功能（GoF）的细胞造成强烈的选择压力。 突变等位基因SAMD 9/9 L GoF突变抑制骨髓生成的分子机制， 以及导致MDS、MDS/AML（例如SETBP 1）或自发性AML的继发性突变谱 恢复情况尚不清楚。拟议的研究将通过两个具体目标调查这些问题：1。到 确定突变型SAMD 9和SAMD 9 L表达在髓系分化过程中的分子和功能影响。 使用儿科MDS的分化和iPSC模型系统，和2.）来确定 使用连续患者样品和单细胞基因组学，在表达突变体SAMD 9和SAMD 9 L的细胞中进行。 指导临床科学家研究职业发展奖（K 08）将为候选人提供 作为一名医生科学家和专注于实现他的独立职业目标所需的受保护时间 通过了解儿童MDS患者的机制， 发病机理一个强大的职业发展计划，包括经验丰富和成功的教师 咨询委员会，明确的进度评估计划，并参加了许多课程，讲座， 在实现这些研究目标的同时，还将举办提高技术和管理技能熟练程度的研讨会， 确保作为一名独立的医生科学家取得成功。该奖项将在圣裘德儿童医院完成 研究医院（圣裘德），世界领先的学术机构之一，专注于研究和 治疗儿科灾难性疾病，使其成为早期职业医生的典范 科学家发展自己的事业。除了强大的机构支持，圣裘德提供无与伦比的研究 支持设施包括基因组测序设施在哈特韦尔中心，流式细胞仪和 细胞分选共享资源，和先进基因组工程中心（CAGE）。