ATP-Dependent Chromatin Remodeling in Human Malignancy

摘要 最近的外显子组测序研究发现，超过20%的人类癌症在外显子组中具有有害突变。 编码mSWI/SNF（BAF）复合物亚基的基因。更多的肿瘤 这些基因的扩增或缺失。这些复合物是由15个亚基组成的多态性组装体 由28个基因编码，产生显著的组合特异性。这种生物特异性反映在 特定癌症中特定亚单位的致癌突变的高度选择性模式。癌症突变 通常具有肿瘤抑制因子的特征，并且通常是杂合的，这意味着它们 在抑制肿瘤形成中起遗传主导作用。我们实验室和其他人的工作导致了 结论这些复合物的能力，以反对polycomb介导的镇压有助于他们 在发育和肿瘤发生中的作用。因此，我们将把工作重点放在 BAF和polycomb之间的对立及其治疗后果。首先，我们将使用一个新的， 设计了体内染色质重塑试验，以充分表征分钟的对立性质， 分钟的基础上。其次，我们将定义BAF-polycomb反对派的能量要求， ATP在调节BAF结合和释放PRC 1中的重要作用。第三，我们将全面描述 BAF和多梳阻遏复合物1（PRC 1）在亚基和结构域方面的直接相互作用 对这种互动至关重要。第四，我们将探讨BAF-polycomb中断的后果 修复、重组和转录的对立。最后，我们将定义治疗 这是我们在早期筛选中发现的一组小分子BAF抑制剂的潜力。结束时 这些研究，我们应该有一个机械的理解BAF polycomb反对，并探讨了在 至少有两条潜在的生产癌症特异性药物的途径。

ABSTRACT Recent exome sequencing studies have found that over 20% of human cancers have deleterious mutations in the genes encoding the subunits of mSWI/SNF (BAF) complexes. A much larger number of tumors have amplifications or deletions of these genes. These complexes are polymorphic assemblies of 15 subunits encoded by 28 genes giving rise to remarkable combinatorial specificity. This biologic specificity is reflected in the highly selective pattern of oncogenic mutations in specific subunits in specific cancers. Cancer mutations generally have the characteristics of tumor suppressors and are generally heterozygous, implying that they play a genetically dominant role in suppressing tumor formation. Work in our lab and others has led to the conclusion that the ability of these complexes to oppose polycomb-mediated repression contributes to their roles in both development and oncogenesis. Hence, we will focus our work on the mechanisms underlying the opposition between BAF and polycomb and its therapeutic consequences. First we will use a novel, newly designed in vivo chromatin remodeling assay to fully characterize the nature of the opposition on a minute-by- minute basis. Secondly, we will define the energetic requirements for BAF-polycomb opposition and the essential role of ATP in regulating binding and release of PRC1 from BAF. Third, we will fully characterize the direct interaction between BAF and polycomb repressive complex 1 (PRC1) in terms of subunits and domains that are essential for this interaction. Fourth, we will explore the consequences of disruption of BAF-polycomb opposition for repair, recombination and transcription over the genome. Finally, we will define the therapeutic potential of a group of small molecule BAF inhibitors that we identified in earlier screens. At the conclusion of these studies we should have a mechanistic understanding of BAF-polycomb opposition and have explored at least two potential paths for the production of cancer-specific drugs.