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%的人类癌症具有有害的基因突变 编码mSWI/SNF(BAF)复合体亚单位的基因。数量多得多的肿瘤 这些基因的扩增或缺失。这些复合体是由15个亚基组成的多态组合 由28个基因编码，具有显著的组合特异性。这种生物学上的特殊性反映在 特定癌症中特定亚基中致癌基因突变的高度选择性模式。癌症突变 通常具有肿瘤抑制基因的特征，并且通常是杂合子，这意味着它们 在抑制肿瘤形成方面发挥基因主导作用。我们实验室和其他实验室的工作已经导致了 结论：这些复合体对抗多梳介导的抑制的能力有助于它们的 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与Polycomb的对立及其治疗后果。首先，我们将使用一本小说，新的 设计了体内染色质重塑实验，以充分表征反对的性质上的一分钟一分钟- 以分钟为基准。其次，我们将明确BAF-Polycomb对抗的能量要求和 ATP在调节BAF结合和释放PRC1中的重要作用。第三，我们将充分描述 BAF与多梳抑制物1的亚基和结构域的直接相互作用 对于这种互动来说是必不可少的。第四，我们将探讨BAF-Polycomb中断的后果 反对基因组的修复、重组和转录。最后，我们将定义治疗性 我们在早期筛选中发现的一组小分子BAF抑制剂的潜力。在……结束时 这些研究我们应该对BAF-Polycomb对立有一个机械性的理解，并在 至少有两条生产抗癌药物的潜在途径。

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.