Cancer-Specific Targeting and Function of Mammalian SWI/SNF (BAF) Chromatin Remodeling Complexes

哺乳动物 SWI/SNF (BAF) 染色质重塑复合物的癌症特异性靶向和功能

• 批准号: 10112848
• 负责人: Cigall Kadoch
• 金额: $ 43.62万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-21 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10112848
• 关键词: Acetylation; Affect; Affinity; Alleles; Amino Acids; Binding; Binding Proteins; Biological; Biological Assay; Biology; Biophysics; Cell Line; Cell Proliferation; Cells; ChIP-seq; Chromatin; Chromatin Remodeling Factor; Chromosomal translocation; Combinatorics; Complex; Coupled; DNA; Development; Disease; Ectopic Expression; Enhancers; Fibroblasts; Foundations; Fusion Oncogene Proteins; Gene Expression; Gene Expression Profile; Genes; Genomics; Goals; Histones; Human; In Vitro; Knowledge; Length; Maintenance; Malignant Neoplasms; Maps; Mass Spectrum Analysis; Mediating; Mesenchymal Stem Cells; Molecular; Mutate; Mutation; Nucleosomes; Oncogenic; Pattern; Peptides; Polycomb; Positioning Attribute; Primary Neoplasm; Property; Proteins; Proteomics; Reader; Recombinants; Recruitment Activity; Regulation; Role; SMARCB1 gene; Site; Sodium Chloride; Surface; System; Tail; Therapeutic Intervention; Time; Variant; design; exome sequencing; experimental study; gain of function; genetic regulatory protein; genome-wide; interfacial; mutant; novel therapeutic intervention; overexpression; promoter; sarcoma; soft tissue; synovial sarcoma; targeted treatment; transcription factor; transcriptome

PROJECT SUMMARY/ABSTRACT Recent whole-exome sequencing studies in human cancer have unmasked frequent mutations in genes encoding chromatin regulatory proteins. Specifically, genes encoding subunits of the mammalian SWI/SNF ATP- dependent chromatin remodeling complexes (also called mSWI/SNF or BAF complexes) are perturbed in over 20% of human malignancy, underscoring their critical roles in the maintenance of timely and appropriate gene expression. A major question lies in the mechanisms by which mSWI/SNF complexes are targeted on chromatin. Indeed, studies by our group and others seek to systematically evaluate the role for each of the 29 subunits pieced together combinatorically in to 12-15 subunit entities, as well as the interfacial surfaces and domains that contribute specific binding interactions on chromatin, either by direct engagement with the histone landscape or via tethering to transcription factors. Human synovial sarcoma (SS) is uniformly driven by the t(X;18) chromosomal translocation, which results in the fusion of 78 amino acids of SSX to the C-terminus of the BAF complex subunit, SS18. The SS18-SSX fusion oncoprotein dominantly integrates in to BAF complexes, displacing the product of the remaining wild-type allele. This results in altered genome-wide distribution of BAF complexes on chromatin, suggesting that SS18-SSX actively recruits BAF complexes to specific features on the chromatin landscape. The mechanism underpinning this highly cancer-specific targeting of BAF complexes in synovial sarcoma remains unknown and represents a major barrier to progress in the field. Indeed, understanding the molecular basis for SSX-driven targeting of BAF complexes may facilitate the identification of new strategies for therapeutic intervention. As such, the goals of this proposal are to: (1) define the genomic targets of SS18-SSX-containing BAF complexes and the impact of this cancer-specific targeting on chromatin accessibility and gene expression in SS cell lines and primary tumors; (2) Identify SS18-SSX binding partners and histone landscape targets on mammalian nucleosomes that engage the 78aa SSX tail; (3) determine the features of the SSX 78aa tail required for SS-specific targeting on chromatin, gene expression, and maintenance of SS cell proliferation. Taken together, successful completion of these aims will provide a major and highly needed advance at the intersection of the chromatin regulation and sarcoma biology fields, and contribute important knowledge regarding the mechanism of targeting of BAF complexes across a range of both normal and oncogenic states. A major impediment to the development of on-target inhibitory agents of SS18-SSX function lie in the lack of biological understanding of SS18-SSX-mediated targeting. The results of this proposal are likely to provide the foundation for a new set of approaches toward targeted disruption of the interaction between SS18-SSX-containing BAF complexes and chromatin.

项目摘要/摘要 人类癌症的最新全外观测序研究在基因中具有透明的频繁突变 编码染色质调节蛋白。具体而言，编码哺乳动物SWI/SNF ATP-亚基的基因 依赖性的染色质重塑络合物（也称为MSWI/SNF或BAF复合物）被扰动 人类恶性肿瘤的20％，强调其在维持及时和适当基因中的关键作用 表达。一个主要问题在于MSWI/SNF复合物靶向染色质的机制。 实际上，我们小组和其他人的研究试图系统地评估29个亚基的每个角色 将组合组合到12-15个亚基实体，以及界面表面和域 通过直接与组蛋白景观互动或 通过束缚转录因子。人类滑膜肉瘤（SS）由T（x; 18）统一驱动 染色体易位，导致SSX的78个氨基酸融合到BAF的C端 复杂亚基SS18。 SS18-SSX融合癌蛋白主要整合到BAF复合物中， 取代其余野生型等位基因的产物。这导致BAF的全基因组分布改变 染色质上的复合物，表明SS18-SSX主动将BAF复合物招募到特定特征 染色质景观。 BAF复合物中这种高度癌症特异性靶向的机制 滑膜肉瘤仍然未知，代表了该领域进步的主要障碍。的确， 了解BAF复合物的SSX驱动靶向的分子基础可能有助于鉴定 治疗干预的新策略。因此，该提案的目标是：（1）定义基因组 含SS18-SSX的BAF复合物的靶标以及该癌症特异性靶向对染色质的影响 SS细胞系和原发性肿瘤中的可及性和基因表达； （2）识别SS18-SSX绑定伙伴 和组蛋白景观靶标在接合78AA SSX尾巴的哺乳动物核小体上； （3）确定 SSX 78AA尾巴的特异性靶向染色质，基因表达和维护所需的特征 SS细胞增殖。综上所述，这些目标的成功完成将提供主要且高度的 在染色质调节和肉瘤生物学领域的交集中需要进步，并有助于 关于靶向BAF复合物在两种正常范围的靶向机制的重要知识 和致癌状态。 SS18-SSX的靶向抑制剂的发展的主要障碍 功能在于缺乏对SS18-SSX介导的靶向的生物学理解。该提议的结果 很可能为针对互动的针对性破坏的新方法提供基础 在含Ss18-SSX的BAF复合物和染色质之间。