Pax5:Hematopoietic Transcription Factor Involved in ALL

Pax5：参与 ALL 的造血转录因子

• 批准号: 8256532
• 负责人: Harold Phillip Koeffler
• 金额: $ 36.53万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-05 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8256532
• 关键词: Acute; Acute Lymphocytic Leukemia; Acute leukemia; Adult; Affect; B cell differentiation; B-Lymphocytes; Biology; Cell Differentiation process; Cells; ChIP-seq; Characteristics; Childhood; Chimeric Proteins; Clinical; Development; ETV6 gene; Event; Fostering; Frequencies; Gel; Gene Targeting; Genes; Genetic; Genomics; Goals; Grant; Hematopoiesis; Hematopoietic; Human; Lead; Lymphocyte; Lymphoid; Lymphopoiesis; Mediating; Microarray Analysis; Mutation; Myeloid Cells; PAX5 gene; Pathogenesis; Pathologic; Patients; Proteins; Relapse; Reporter Genes; Sampling; T-Lymphocyte; Techniques; Testing; Time; Validation; Xenograft procedure; cDNA Arrays; clinically significant; disease classification; genome wide association study; in vivo Model; insight; leukemia; mutant; new therapeutic target; prevent; public health relevance; transcription factor

DESCRIPTION (provided by applicant): PAX5 is one of the key transcription factors mediating differentiation of B-lymphocytes. It transcriptionally activates and represses a very large number of genes that permits the development of B-lymphocytes and prevents differentiation to T-lymphocytes or myeloid cells. We examined by SNP chip 633 acute lymphocytic leukemia (ALL) samples for PAX5 alterations (469 pediatric cases, 70 pediatric relapse cases, 74 adult cases and 50 ALL samples growing as xenografts). PAX5 genomic abnormalities occurred in H 27% of the samples including 26 PAX5 fusions to one of 5 other genes. Overall goal of the grant is to understand the clinical and pathologic significance of PAX5 alterations in ALL. Specific Aim 1 will determine frequency of genomic abnormalities of PAX5 in ALL and determine their clinical impact. Specific Aim 2 will define and understand the aberrant functions of PAX5 fusion and mutant proteins in ALL (Ex Vivo Studies). Studies will include gel retardation and reporter gene analysis as well as testing the ability of these proteins transcriptionally to activate selected target genes. Detailed studies will be done using two of the PAX5 fusions [PAX5-ETV6; PAX5- C20orf112 (C20)] including genome-wide identification of target genes of PAX5 fusion proteins in ALL using cDNA microarray analysis and high through-put ChIP sequencing studies. Comprehensive validation of the results will use a variety of techniques. Also, effect of PAX5 fusion proteins on hematopoietic cell differentiation will be determined. Specific Aim 3 will use in vivo models to examine the aberrant function of PAX5 fusions and deletions. First, we will determine if expression of PAX5 fusion proteins disrupts normal steady-state lymphopoiesis or hematopoiesis by impairing differentiation, promoting survival and/or proliferation of specific compartments? Second, we will identify secondary events that synergize with PAX5 fusion proteins to induce ALL. Third, we will determine if PAX5 deletions affect the course of human Ph1+ ALL xenografts. In summary, we will for the first time, correlate PAX5 alterations with clinical and pathological characteristics of the patients and define fully the functional significance of these alterations. These studies will have importance for classification of the disease, offer new therapeutic targets and foster our understanding of the pathogenesis of ALL. PUBLIC HEALTH RELEVANCE: PAX5 lymphoid transcription factor is structurally abnormal in approximately 27% of 634 ALL samples. Our studies will for the first time provide insights into the clinical significance of PAX5 alterations in acute lymphocyte leukemia (ALL), as well as provide an understanding of the functional ramifications of PAX5 alterations in ALL. Our studies should lead to new therapeutic targets for acute leukemias, as well as provide a greater understanding of the biology of ALL.

描述(申请人提供)：Pax5是介导B淋巴细胞分化的关键转录因子之一。它在转录上激活和抑制大量的基因，这些基因允许B淋巴细胞的发育，并阻止分化为T淋巴细胞或髓系细胞。我们用SNP芯片检测了633例急性淋巴细胞白血病(ALL)标本中PAX5的改变(469例儿童、70例儿童复发、74例成人和50例异种移植的ALL)。Pax5基因异常出现在27%的样本中，包括26个PAX5与其他5个基因之一的融合。赠款的总体目标是全面了解PAX5基因改变的临床和病理意义。具体目标1将确定所有患者中PAX5基因异常的频率，并确定它们的临床影响。特定目标2将定义和理解ALL中PAX5融合蛋白和突变蛋白的异常功能(Ex Vivo研究)。研究将包括凝胶延迟和报告基因分析，以及测试这些蛋白质转录激活选定目标基因的能力。将使用其中两个PAX5融合[PAX5-ETV6；PAX5-C20orf112(C20)]进行详细研究，包括使用cDNA微阵列分析和高通量芯片测序研究在全基因组范围内鉴定PAX5融合蛋白的目标基因。对结果的全面验证将使用各种技术。此外，还将确定PAX5融合蛋白对造血细胞分化的影响。特殊目的3将使用活体模型来检查PAX5融合和缺失的异常功能。首先，我们将确定PAX5融合蛋白的表达是否通过损害分化、促进特定隔室的存活和/或增殖来破坏正常的稳态淋巴系或造血系？其次，我们将确定与PAX5融合蛋白协同作用的次要事件，以诱导ALL。第三，我们将确定PAX5缺失是否会影响人PH1+ALL异种移植的进程。综上所述，我们将首次将PAX5的改变与患者的临床和病理特征联系起来，并充分定义这些改变的功能意义。这些研究将对ALL的疾病分类、提供新的治疗靶点和促进我们对ALL发病机制的理解具有重要意义。公共卫生相关性：在634个ALL样本中，大约27%的Pax5淋巴转录因子结构异常。我们的研究将首次为PAX5改变在急性淋巴细胞白血病(ALL)中的临床意义提供见解，并提供对PAX5改变在ALL中的功能分支的理解。我们的研究应该会为急性白血病带来新的治疗目标，并提供对ALL生物学的更多了解。