Telomere dysfunction, p53 and tumorigenesis

端粒功能障碍、p53 和肿瘤发生

基本信息

批准号：
7932617
负责人：
YIBIN DENG
金额：
$ 9.21万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-30 至 2011-09-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7932617
关键词：
A Mouse Address Apoptosis Apoptotic Ataxia-Telangiectasia-Mutated protein kinase Binding Biological Process Cell Aging Cell Cycle Arrest Cells Characteristics Chromosomal Stability Chromosome abnormality Chromosomes Complex Cytogenetic Analysis DNA DNA Damage DNA damage checkpoint Data Development Dicentric chromosome Embryo Ensure Fibroblasts Functional disorder Galactosidase Generations Genome Stability Genomic Instability Genotype Goals Hand Heterochromatin Human In Vitro Incidence Invaded Knockout Mice Length Maintenance Malignant - descriptor Malignant Neoplasms Mammals Mediating Molecular Molecular Conformation Molecular Target Monitor Mus Nucleoproteins Oncogenes Pathway interactions Play Process Protein Array Reciprocal Translocation Regulation Repetitive Sequence Research Project Grants Risk Role Sampling Signal Transduction Single-Stranded Telomere-Binding Proteins Small Interfering RNA Spectral Karyotyping Structure Subfamily lentivirinae System TP53 gene Telomere-Binding Proteins Testing Tissues Tumor Suppressor Proteins base cancer cell cancer initiation cohort comparative genomic hybridization human CCR6 protein in vivo mouse model p53 Signaling Pathway prevent research study response senescence sensor telomere tumor tumor initiation tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Telomeres, the nucleoprotein structures that cap the ends of eukaryotic chromosomes, are composed of TTAGGG repetitive sequences that terminate in a 3' single-stranded G-rich overhang. Telomeres are bound by a complex array of proteins that help stabilize its formation and serve essential roles in preventing DNA damage checkpoint activation. Recent evidence suggests that telomere dysfunction is associated with increased human cancer incidence. Telomere dysfunction leads to the generation of dicentric chromosomes that initiate the breakage-fusion-bridge (BFB) cycle to elicit a cancer promoting genotype. We observed that conditional deletion of Pot1 (protection of telomere), a critical telomere binding protein, in mouse embryo fibroblasts (MEFs) resulted in telomere dysfunction, activation of DNA damage response (DDR), and p53-dependent replicative senescence in vitro. In addition, loss of Pot1 cooperated with p53 deficiency to initiate tumorigenesis in vivo. The objective of this research project is to generate a conditional Pot1 knockout mouse model to: 1) characterize the molecular determinants of Pot1-induced p53-dependent replicative senescence; 2) to determine the biological function of p53 in loss of Pot1 initiated tumorigenesis in vivo; and 3) to cytogenetically characterize chromosomal aberrations in tumor samples, and investigate the function of these aberrations in human tumor initiation and progression. To achieve the objectives, Pot1-deficient mice will be crossed with mice bearing loss of cellular senescence (p21 knockout mouse) or apoptosis components (p53R172P knockin mice) to compare the latency of tumor development and tumor spectrum in mouse cohorts with dysfunctional telomeres. Finally, molecular cytogenetic techniques such as spectral karyotyping (SKY), array-comparative genomic hybridization (aCGH) and lentivirus-based siRNA will be used to identify chromosomal aberrations and validate potential molecular targets involved in tumorigenesis in conditionally deleted Pot1 mouse cohorts. The long-term goal of this study is to identify molecular targets involved in human cancer initiation or/and progression in the setting of telomere dysfunction.

描述（由申请人提供）：端粒是覆盖真核染色体末端的核蛋白结构，由终止于 3' 单链富含 G 突出端的 TTAGGG 重复序列组成。端粒由一系列复杂的蛋白质结合，有助于稳定其形成，并在防止 DNA 损伤检查点激活中发挥重要作用。最近的证据表明端粒功能障碍与人类癌症发病率增加有关。端粒功能障碍导致双着丝粒染色体的产生，启动断裂-融合-桥（BFB）循环，从而引发癌症促进基因型。我们观察到，在小鼠胚胎成纤维细胞 (MEF) 中条件性删除 Pot1（端粒保护）（一种关键的端粒结合蛋白）会导致端粒功能障碍、DNA 损伤反应 (DDR) 激活和体外 p53 依赖性复制衰老。此外，Pot1 的缺失与 p53 的缺陷共同启动体内肿瘤的发生。本研究项目的目的是建立条件性 Pot1 敲除小鼠模型，以：1）表征 Pot1 诱导的 p53 依赖性复制衰老的分子决定因素； 2) 确定p53在Pot1缺失启动体内肿瘤发生中的生物学功能； 3）从细胞遗传学角度表征肿瘤样本中的染色体畸变，并研究这些畸变在人类肿瘤发生和进展中的作用。为了实现这些目标，Pot1缺陷小鼠将与细胞衰老丧失（p21敲除小鼠）或细胞凋亡成分（p53R172P敲除小鼠）的小鼠杂交，以比较端粒功能失调的小鼠群体中肿瘤发展的潜伏期和肿瘤谱。最后，分子细胞遗传学技术，如光谱核型分析 (SKY)、阵列比较基因组杂交 (aCGH) 和基于慢病毒的 siRNA，将用于鉴定染色体畸变并验证条件删除 Pot1 小鼠群体中参与肿瘤发生的潜在分子靶点。这项研究的长期目标是确定在端粒功能障碍的情况下参与人类癌症发生或/和进展的分子靶点。