Role of EVI1 Modifications in Cell Transformation

产品说明：肿瘤转化是一个多步骤的过程，需要解除控制祖细胞扩增和分化的关键细胞通路的调控。EVI1癌基因在许多组织中被不适当地激活，导致侵袭性实体癌和造血系统癌。EVI1在不同组织学的组织转化中起作用的机制尚不清楚。 该提案的总体目标是确定EVI1如何赋予细胞逃避包括分化和增殖在内的几种细胞途径控制的能力，以及它如何有助于细胞转化。这些研究表明，EVI1与主调节蛋白相互作用，破坏细胞周期，细胞增殖和正常分化。 在之前的资助周期中，我们还确定了EVI1与几种转录辅助调节因子和蛋白质修饰剂相互作用，这些转录辅助调节因子和蛋白质修饰剂通过可逆的乙酰化或sumoylation对EVI1进行后修饰。更重要的是，通过使用点突变，我们已经建立了与这些修饰剂的特异性相互作用是改变原代正常细胞的增殖和分化所需的EVI1，并诱导永生化或转化。因此，我们认为EVI1破坏多个通路的能力是EVI1阳性癌症非常具有侵袭性表型特征的基础。我们还提出，EVI1必须进行后修饰，以与关键的细胞调节因子相互作用，诱导细胞转化。我们确定，EVI1修改所需的离散核斑点EVI1的组装，我们建议，这些斑点是EVI1活动的中心。因此，很可能破坏EVI1修饰将损害EVI1改变这些途径中至少一种的能力，导致肿瘤转化减弱或延迟。 这种竞争性更新有两个总体目标：鉴定和分析EVI1参与的多蛋白复合物，并确定改变增殖和分化所需的蛋白质修饰。该提案的具体目标是： 1.研究EVI1类小泛素化和乙酰化在转录调控中的作用。 2.鉴定核EVI1多蛋白复合物的组成和功能。 3.研究EVI1在体内的SUMO化和乙酰化，并确定其在EVI1诱导转化中的作用。

DESCRIPTION: Neoplastic transformation is a multistep process that requires the deregulation of key cellular pathways that control the expansion and the differentiation of progenitor cells. The EVI1 oncogene is inappropriately activated in many tissues resulting in aggressive solid and hematopoietic cancers. The mechanism by which EVI1 operates in the transformation of tissues of different histology is not clear. The overall goal of the proposal that was funded 3 years ago was to determine how EVI1 confers to the cell the ability to escape the control of several cellular pathways including differentiation and proliferation and how it contributes to cell transformation. These studies have shown that EVI1 interacts with master regulatory proteins to disrupt cell cycling, cell proliferation, and normal differentiation. During the prior funding cycle, we have also determined that EVI1 interacts with several transcription coregulators and protein modifiers, which post-translationally modify EVI1 by reversible acetylation or sumoylation. More importantly, by using point mutations we have established that specific interactions with these modifiers are required to alter proliferation and differentiation of primary normal cells by EVI1 and to induce immortalization or transformation. Therefore, we propose that the ability of EVI1 to disrupt multiple pathways is the basis of the very aggressive phenotype characteristic of EVI1-positive cancers. We also propose that EVI1 must be post-translationally modified in order to interact with key cell regulators and induce cell transformation. We determined that EVI1 modifications are required for the assembly of EVI1 in discrete nuclear speckles and we propose that these speckles are centers of EVI1 activity. Therefore, it is likely that disruption of EVI1 modification will impair the ability of EVI1 to alter at least one of these pathways, leading to attenuated or delayed neoplastic transformation. This competing renewal has two overall goals: to identify and analyze multi-protein complexes in which EVI1 participates and to determine which protein-modifications are required to alter proliferation and differentiation. The specific aims of the proposal are: 1. To characterize EVI1 sumoylation and acetylation and to define their role in transcription regulation. 2. To identify the components and the functions of the nuclear EVI1 multiprotein complexes. 3. To characterize the sumoylation and acetylation of EVI1 in vivo and to define their role in EVI1- induced transformation.