Usp16-Mediated Histone H2A Deubiquitination Regulates Breast Cancer Cell Invasion

项目摘要/摘要 许多重要的细胞事件是由拮抗机制调节的，并理解因子是如何 参与肿瘤发生的调控，发挥其拮抗作用尤为重要。组蛋白 多梳抑制复合体1(Prc1)介导的K119位H_2A的单泛素化是一种重要的 表观遗传标志与早期上皮-间充质转化和细胞侵袭的关系 转移。然而，对组蛋白H_2A去泛素化在这些过程中的作用知之甚少。 我们的长期研究目标是阐明组蛋白H2A调控的分子机制 泛素化和去泛素化，并确定这种组蛋白修饰在细胞调节中的作用 周期与肿瘤发生。为此，拟议研究的目标是研究组蛋白H2A的功能 泛素特异肽酶16(Usp16)介导的去泛素化在EMT和侵袭力调节中的作用 乳腺癌细胞。我们的初步数据显示，PRC1的成员BMI1促进EMT和 乳腺癌细胞的侵袭。由于Usp16在K119位特别去泛素化H_2A，中心假说 这一应用的目的是Usp16拮抗BMI1的功能，抑制EMT和侵袭 乳腺癌细胞。此外，我们先前已经确定Usp16是一种新的Polo样激酶底物。 1(PLK1)。因此，PLK1在Usp16介导的EMT和细胞侵袭调节中的作用也将是 下定决心。这一假说的基本原理如下：一旦Usp16介导的过氧化氢酶的作用 一种新的肿瘤发生机制--去泛素化在EMT和癌细胞侵袭中的调节作用 可以定义同时涉及H2A泛素化和去泛素化的调控机制。这个 中心假说将通过以下活动进行检验：(1)确定Usp16是否介导 组蛋白H_2A去泛素化抑制乳腺癌细胞的EMT和侵袭。紧跟在过度表达和 Usp16基因敲除、EMT标志物表达变化与乳腺癌细胞侵袭力的关系 将会被分析。(2)确定PLK1在Usp16介导的EMT调控和乳腺侵袭中的作用 癌细胞。由于已经确定了Usp16上的磷酸化位点，我们将利用非 可磷酸化和磷酸化的Usp16构建，以仔细评估Usp16的功能 PLK1的磷酸化在调节EMT和细胞侵袭中的作用这项研究的预期结果包括 组蛋白H_2A泛素化和去泛素化是组蛋白失活的重要机制 乳腺癌转移的调控以及细胞周期调控非依赖性功能的揭示 PLK1在肿瘤发生中的作用对这些机制的了解可能有助于小说的发展 转移性乳腺癌的防治方法。 好了！

PROJECT SUMMARY/ABSTRACT Many important cellular events are regulated by antagonistic mechanisms, and understanding how factors involved in the regulation of tumorigenesis execute their antagonistic functions is particularly important. Histone H2A mono-ubiquitination at K119 mediated by polycomb repressive complex 1 (PRC1) is an important epigenetic mark associated with epithelial-mesenchymal transition (EMT) and cell invasion during early metastasis. However, less is known about the function of histone H2A deubiquitination during these processes. Our long-term research goal is to elucidate the molecular mechanism underlying the regulation of histone H2A ubiquitination and deubiquitination, and determine the role of this histone modification in the regulation of cell cycle and tumorigenesis. To this end, the goal of the proposed research is to study the function of histone H2A deubiquitination mediated by ubiquitin specific peptidase 16 (USP16) in the regulation of EMT and invasion of breast cancer cells. Our preliminary data has shown that BMI1, a member of PRC1, promotes EMT and invasion of breast cancer cells. Since USP16 specifically deubiquitinates H2A at K119, the central hypothesis of this application is that the USP16 antagonizes the function of BMI1 and inhibits the EMT and invasion of breast cancer cells. Furthermore, we have previously identified USP16 as a novel substrate of polo-like kinase 1 (PLK1). Therefore, the role of PLK1 in USP16-mediated regulation of EMT and cell invasion will also be determined. The rationale for this hypothesis rests on the following: once the role of USP16-mediated H2A deubiquitination in the regulation of EMT and invasion of cancer cells is established, a novel tumorigenesis regulatory mechanism that involves both the ubiquitination and deubiquitination of H2A can be defined. The central hypothesis will be tested through the activities including: (1) Determine whether USP16-mediated deubiquitination of histone H2A inhibits EMT and invasion of breast cancer cells. Following overexpression and knockdown of USP16, the changes in the expression of EMT markers and invasiveness of breast cancer cells will be analyzed. (2) Determine the role of PLK1 in USP16-mediated regulation of EMT and invasion of breast cancer cells. As the phosphorylation sites on USP16 have been identified, we will utilize both non- phosphorylatable and phosphomimic USP16 constructs to carefully evaluate the function of USP16 phosphorylation by PLK1 in regulating EMT and cell invasion. The expected outcomes of this study include the identification of ubiquitination and deubiquitination of histone H2A as an important mechanism for the regulation of metastasis in breast cancer, and the revealing of a cell cycle regulation-independent function of PLK1 in tumorigenesis. Knowledge of these mechanisms may contribute to the development of novel approaches in the prevention and treatment of metastatic breast cancer. !