Role of hsnf5/BAF47 Loss in Human Cancer Development

hsnf5/BAF47 缺失在人类癌症发展中的作用

• 批准号: 8322896
• 负责人: Bernard E. Weissman
• 金额: $ 3.76万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8322896
• 关键词: Affect; Apoptosis; Appearance; Binding; Biochemical; Bioinformatics; Biological; Biological Assay; Birth; CDKN1A gene; Candidate Disease Gene; Cell Culture Techniques; Cell Cycle Regulation; Cell physiology; Child; Chromatin Remodeling Factor; Chromatin Structure; Complex; DNA; DNA Repair; DNA Sequence; Data; Development; Disease; Dissection; Family member; Funding; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetically Engineered Mouse; Genomic Instability; Genomics; Germ-Line Mutation; Grant; Health; Human; Human Development; Kidney; Lead; Malignant - descriptor; Malignant Childhood Neoplasm; Malignant Neoplasms; Mating Types; Modeling; Molecular; Mus; Mutation; Neoplastic Cell Transformation; Nerve Tissue; Neuraxis; Neurons; Nucleosomes; Pattern; Play; Positioning Attribute; Promoter Regions; Proteins; Research; Rhabdoid Tumor; Role; SMARCB1 gene; Sampling; Signal Pathway; Signaling Pathway Gene; Spinal Cord; Spinal Cord Neoplasms; Sucrose; Technology; Testing; Transcription Coactivator; Tumor Cell Line; Tumor Suppressor Genes; Tumor Suppressor Proteins; Western Blotting; base; brain tissue; cell growth; chromatin modification; gene function; genetically modified cells; insight; integrase interactor 1; man; member; mouse model; neoplastic cell; nervous system development; neurodevelopment; novel; promoter; relating to nervous system; soft tissue; transcription factor; tumor; tumorigenesis

DESCRIPTION (provided by applicant): The identification of tumor suppressor genes has led to new insights into the mechanisms of human cancer development. The normal functions of these genes often lie in the control of gene expression, especially in the realm of cell cycle control and cellular differentiation. Several recent studies have implicated aberrant activity of chromatin remodeling complexes in the development of human cancer. Mutations in the INI1/SNF5/BAF47 gene, a component of the SWI/SNF chromatin remodeling complex, occur in virtually all malignant rhabdoid tumors (MRTs). The SWI/SNF complex acts as a global transcriptional activator that alters nucleosome positioning on DNA via an energy-dependent mechanism. During the previous funding period, we have determined that loss of SNF5 expression affects cell cycle regulation in all MRT cell lines. We also developed 2 genetically engineered mouse (GEM) models for MRT development where loss of expression of the pRb family members or decreased expression of p53 accelerates the appearance of spinal cord MRTs. Importantly, our preliminary studies have now put forward 4 candidate genes suspected of supporting SNF5 tumor suppressor action. Based on these results, we hypothesize that loss of SNF5 expression can lead to MRT development through disruption of neural differentiation. To test this hypothesis, we propose 3 specific aims. In the first specific aim, we will characterize novel targets of SNF5 in human MRT cell lines using Taq-Man(R) assays, Western blotting and ChIPs, determine their role in MRT oncogenesis using cell culture models and assess the effects of SNF5 loss on chromatin structure and modifications in their promoter regions. The second specific aim will identify downstream targets of SNF5 associated with MRT development using a combination of high-throughput DNA sequencing approach (ChIP-seq) and gene expression array analyses. In the third specific aim, we will determine the role of Snf5 inactivation in neural cell development and malignant rhabdoid tumorigenesis using novel genetically engineered mouse models, neurosphere cultures and a comparison of mouse spinal cord MRTs with human MRTs of the central nervous system. The dissection of the role SNF5 plays in MRT development will broaden our understanding of its normal biological and biochemical activities, provide new insights into the function of the SWI/SNF complex in cell cycle regulation and normal development and identify new avenues of treatment for this highly aggressive tumor. PUBLIC HEALTH RELEVANCE: Tumor suppressor genes are turned off in many human cancers and are often responsible for the familial forms of this disease. We are studying one of these genes called INI1/SNF5/BAF47 that plays an important role in the development of an aggressive childhood cancer of the kidney, brain and soft tissues called malignant rhabdoid tumor (MRT). Our previous studies have suggested that the loss of this gene before or early after birth may interfere with normal nervous system development leading to the appearance of MRT in children. This current grant will carry out further studies to test this hypothesis using MRT cells grown in culture, DNA and protein from these cells and genetically-modified mice that will lose INI1/SNF5/BAF47 expression in nervous tissues. By doing these studies, we will broaden our understanding of its normal biological and biochemical activities and identify new avenues of treatment for this highly aggressive tumor.

描述（由申请人提供）：鉴定肿瘤抑制基因已导致对人类癌症发育机制的新见解。这些基因的正常功能通常在于基因表达的控制，尤其是在细胞周期控制和细胞分化领域。最近的一些研究表明，染色质重塑复合物在人类癌症的发展中的异常活性。 INI1/SNF5/BAF47基因的突变是SWI/SNF染色质重塑络合物的一个组成部分，实际上是在所有恶性横纹肌肿瘤（MRTS）中发生的。 SWI/SNF复合物充当一种全局转录激活剂，通过能量依赖性机制来改变在DNA上的核小体定位。在上一个资金期间，我们确定SNF5表达的丧失会影响所有MRT细胞系中的细胞周期调节。我们还开发了2种基因工程小鼠（GEM）模型，用于MRT发育，其中PRB家族成员的表达丧失或p53表达降低可加速脊髓MRT的外观。重要的是，我们的初步研究已经提出了4个涉嫌支持SNF5肿瘤抑制作用作用的候选基因。基于这些结果，我们假设SNF5表达的丧失会通过破坏神经分化而导致MRT发展。为了检验这一假设，我们提出了3个具体目标。在第一个特定目标中，我们将使用TAQ-MAN（R）测定，Western印迹和芯片来表征人类MRT细胞系中SNF5的新靶标，确定其使用细胞培养模型在MRT癌症发生中的作用，并评估SNF5损失对启动子区域中染色质结构和修饰的影响。第二个特定目标将使用高通量DNA测序方法（CHIP-SEQ）和基因表达阵列分析的组合来识别与MRT发育相关的SNF5的下游靶标。在第三个特定目的中，我们将使用新型的基因工程小鼠模型，神经圈培养物以及将小鼠脊髓MRT与中枢神经系统的人类MRT进行比较，确定SNF5失活在神经细胞发育和恶性胸腺肿瘤中的作用。 SNF5在MRT发育中的作用的解剖将扩大我们对其正常生物学和生化活性的理解，为SWI/SNF复合物在细胞周期调节和正常发育中的功能提供新的见解，并确定对这种高度侵略性肿瘤的新治疗途径。公共卫生相关性：许多人类癌症中关闭肿瘤抑制基因，通常是该疾病家族形式的原因。我们正在研究这些称为INI1/SNF5/BAF47的基因之一，该基因在肾脏，大脑和软组织的侵略性儿童癌中起着重要作用，称为恶性胸腺瘤（MRT）。我们以前的研究表明，出生前或早期的丧失可能会干扰正常的神经系统发育，从而导致儿童出现MRT。目前的赠款将进行进一步的研究，以使用这些细胞中培养，DNA和蛋白质中生长的MRT细胞以及遗传改性的小鼠在神经组织中失去INI1/SNF5/BAF47表达。通过进行这些研究，我们将扩大对其正常生物学和生化活性的理解，并确定这种高度侵略性肿瘤的新治疗途径。