Project 1: Chromosome Inheritance

项目摘要--项目1 癌细胞表现出不受控制的染色体遗传，包括DNA复制和有丝分裂错误。 这些错误导致并传播了进一步加剧癌症的突变和染色体异常。 项目1在研究人类基因组遗传的机制和控制方面一直处于领先地位 已经确定了许多关键蛋白质，这些蛋白质参与了复制分叉和其他 参与启动DNA复制的蛋白质。在拟议的研究中，项目1将继续 重点阐述了DNA复制启动的机制和调控。项目1发现 某些起始蛋白参与细胞分裂周期的许多方面，包括中心体。 复制、着丝粒功能和胞质分裂。最近的研究结果还表明，一些启动蛋白是 密切参与新生细胞是否会致力于新一轮细胞的基本决定 分裂或进入静止期。拟议的研究将分为三个领域。具体目标1 将重点介绍起源识别复合体(ORC)亚单位ORC1及其相关蛋白CDC6在 此外，通过控制E2F1调节基因的表达来调节细胞分裂的承诺 与肿瘤抑制蛋白Rb和组蛋白协同作用的编码Cyclin E的基因 甲基转移酶SUV39H1。AIM 1还将重点介绍CDC6如何与ORC、RB、SUV39H1和 促进DNA复制启动的细胞周期蛋白依赖性蛋白激酶。《特定目标2》将继续研究该角色 ORC亚单位ORC2和ORC3在着丝粒。ORC2与主轴组件检查点交互 只有在有丝分裂过程中被磷酸化的BUBR1蛋白和BUBR1结合域中的缺陷才是蛋白质 ORC2导致不能在中期平板对齐的染色体的持久性。目标2将决定 ORC2如何与BUBR1绑定并控制BUBR1的访问。如何招募ORC2和ORC3来 着丝粒，以及ORC3与染色体上HP1异染色质蛋白的相互作用 还将研究种族隔离问题。项目3还将在一个子集中研究E2F1对细胞增殖的调控 乳腺癌和结肠上皮癌中有一种死盒RNA解旋酶DDX5的获得性依赖。 急性髓系白血病(AML)的进展也需要DDX5。这一目标将调查DDX5如何 在一些成人癌症和AML中是必不可少的，而在正常上皮和正常的情况下则是必不可少的 造血细胞。将确定RNA和蛋白质结合伙伴，比较依赖于DDX5的 (DDX5-D)和不依赖于DDX5(DDX5-I)的乳腺癌细胞。利用差值依赖关系 将开发DDX5反义寡核苷酸(ASO)来研究DDX5在小鼠模型中的作用 治疗乳腺癌和急性髓细胞白血病。

PROJECT SUMMARY- PROJECT 1 Cancer cells display uncontrolled inheritance of chromosomes, including errors in DNA replication and mitosis. These errors cause and propagate mutations and chromosomal abnormalities that further enhance cancer. Project 1 has been a leader in studying the mechanisms and control of inheritance of the human genome and has identified many of the key proteins that are involved in DNA synthesis at the replication fork and other proteins that are involved in the initiation of DNA replication. In the proposed studies, Project 1 will continue focusing on the mechanism and regulation of the initiation of DNA replication. Project 1 has discovered that certain initiation proteins are involved in many aspects of the cell division cycle, including centrosome duplication, centromere function and cytokinesis. Recent results also show that some initiation proteins are intimately involved in the fundamental decision of whether newly born cells will commit to a new round of cell division or enter into a period of quiescence. The proposed research will fall into three areas. Specific Aim 1 will focus on the role of the Origin Recognition Complex (ORC) subunit ORC1 and its related protein CDC6 in regulation of the commitment to cell division by controlling the expression of E2F1-regulated genes, in addition to the gene encoding Cyclin E, in cooperation with the tumor suppressor protein RB and the histone methyltransferase SUV39H1. Aim 1 will also focus on how CDC6 cooperates with ORC, RB, SUV39H1 and Cyclin dependent kinases to promote initiation of DNA replication. Specific Aim 2 will continue to study the role of the ORC subunits ORC2 and ORC3 at centromeres. ORC2 interacts with the Spindle Assembly Checkpoint protein BUBR1 only when it is phosphorylated during mitosis and defects in the BUBR1 binding domain of ORC2 cause the persistence of chromosomes that fail to align at the metaphase plate. Aim 2 will determine how ORC2 binds to BUBR1 and controls access of BUBR1. How ORC2 and ORC3 are recruited to centromeres, and the role of ORC3 interaction with the HP1 heterochromatin protein in chromosome segregation will also be studied. Project 3 will also study E2f1-regulated control of cell proliferation in a subset of breast and colon epithelial cancers have an acquired dependence of the DEAD-box RNA helicase DDX5. DDX5 is also required for progression of Acute Myeloid Leukemia (AML). This Aim will investigate how DDX5 becomes essential in some adult cancers and AML, while dispensable in normal epithelial and normal hematopoietic cells. Both RNA and protein binding partners will be identified, comparing both DDX5-dependent (DDX5-D) and DDX5-independent (DDX5-I) breast cancer cells. Exploiting the differential dependence on DDX5, Anti-Sense Oligonucleotides (ASO) will be developed for studying the role of DDX5 in mouse models for breast cancer and AML.