Role of the DNA Damage Response in Prostate Cancer Initiation

DNA 损伤反应在前列腺癌发生中的作用

• 批准号: 8555289
• 负责人: Edward P Gelmann
• 金额: $ 25.04万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-16 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8555289
• 关键词: 8p21; Abate; Affect; Androgen Receptor; Androgens; Binding; Cancer Family; Cell Aging; Cell Culture Techniques; Cell Survival; Cells; Cellular Stress; Cessation of life; Characteristics; Chromosomal Loss; Chromosomal Rearrangement; Collaborations; Complex; DNA; DNA Damage; DNA Sequence Rearrangement; Data; Development; Diagnosis; Down-Regulation; ERG gene; Environmental Exposure; Epigenetic Process; Epithelial; Epithelial Cells; Epithelium; Event; Frequencies; Gene Dosage; Gene Fusion; Gene Rearrangement; Genetic; Genome; Goals; Homeobox Genes; Human; Hyperplasia; In Vitro; Inflammatory; Inherited; Intraepithelial Neoplasia; Investigation; LNCaP; Laboratories; Lead; Link; Malignant neoplasm of prostate; Mediating; Molecular; Mus; Mutant Strains Mice; Mutation; NKX3-1 gene; Pathway interactions; Phenotype; Phosphorylation; Phosphotransferases; Play; Post-Translational Protein Processing; Predisposition; Prostate; Prostatic Neoplasms; Proteins; Publishing; Relative (related person); Role; Services; Signal Transduction; Staging; Stem cells; Stimulus; TMPRSS2 gene; Time; Tissues; Tumor Suppression; Tumor Suppressor Proteins; Tyrosine Phosphorylation; Up-Regulation; Work; base; cancer cell; cancer initiation; cancer therapy; carcinogenesis; cell growth; cytokine; early onset; high risk; homeodomain; in vivo; insight; kindred; knock-down; men; molecular pathology; mouse model; programs; prostate cancer prevention; prostate carcinogenesis; protein expression; research study; response; tumor initiation; tumor progression

This project investigates the role of NKX3.1 in protection against DNA damage in the prostate epithelium, which may provide a key mechanism for its function in tumor suppression, NKX3.I is a prostate specific homeobox gene located on 8p21, the target for the most frequent chromosomal loss in human prostate cancer. NKX3.I is also a tumor suppressor for which reduced protein expression is sufficient to deregulate prostate epithelial cell growth and cause Intraepithelial neoplasia; moreover, Nkx3.1 haploinsufficiency results in prostate epithelial dysplasia in mice. Consistent with its role as a tumor suppressor in human prostate cancer, we have shown that an Inactivating mutation In the NKX3.I homeodomain cosegregates with early onset prostate cancer in a prostate cancer family. In recent studies, we have shown that NKX3.1 enhances cell survival after DNA damage and affects the earliest events in recognition of DNA breaks, including formation of YH2AX foci and phosphorylation of ATM. Based on our hypothesis that a key mechanism by which NKX3.1 loss contributes to tumor initiation is through its impact on the DNA damage response, our studies will define the mechanistic role of NKX3.I in the DNA damage response in vitro, as well as its impact on DNA damage in vivo. We also will determine whether NKX3.I mediates the susceptibility of prostate cells to formation of the characteristic TMPRSS2- ERG chromosomal rearrangement that occurs in approximately 50% of prostate cancers. Taken together, our three aims will delineate the role of NKXS.I in the DNA damage response in distinct contexts, thereby providing a comprehensive investigation of this key mechanism of tumor suppression. In Aim 1, our experiments will define the dynamics of the functional interaction between NKX3.1 and ATM, which occurs within minutes of DNA damage. In Aim 2, we will determine whether Nkx3.I gene copy number affects the DNA damage response in vivo in the prostate epithelium, and particularly in prostate epithelial stem cells. Finally, in Aim 3, using unique lines of LNCaP cells that we have derived, we will determine whether NKX3.1 affects the frequency of TMPRSS2-ERG gene rearrangements. These proposed studies will be highly integrated with the overall program project. Notably, the experiments in Aim 2 include quantitative immunostaining analyses in collaboration with Core A, the work in Aim 2 on the prostate stem cells will be performed in collaboration with Michael Shen (Project 1), and the entirety of this project is linked to the molecular analyses of Nkx3.1 in cellular senescence by Cory Abate-Shen (Project 2).

本项目研究了NKX3.1在保护前列腺上皮细胞免受DNA损伤中的作用，这可能是其抑制肿瘤功能的关键机制。NKX3.1是位于8p21的前列腺特异性同源异位盒基因，8p21是人类前列腺癌中最常见的染色体丢失的靶点。NKX3.I也是一种肿瘤抑制基因，其蛋白表达的降低足以解除对前列腺上皮细胞生长的调控，导致上皮内肿瘤；此外，NKX3.1单倍体不足会导致小鼠前列腺上皮细胞异型增生。与其在人类前列腺癌中作为肿瘤抑制因子的作用一致，我们已经证明了NKX3.I同源结构域的失活突变与前列腺癌家族中的早发性前列腺癌相关。在最近的研究中，我们发现NKX3.1增强了DNA损伤后细胞的存活，并影响了识别DNA断裂的最早事件，包括YH2 AX焦点的形成和ATM的磷酸化。 基于我们的假设，即NKX3.1缺失对DNA损伤反应的影响是导致肿瘤发生的一个关键机制，我们的研究将确定NKX3.I在体外DNA损伤反应中的机制作用，以及它对体内DNA损伤的影响。我们还将确定NKX3.I是否介导了前列腺细胞对形成特有的TMPRSS2-ERG染色体重排的敏感性，这种重排发生在大约50%的前列腺癌中。综上所述，我们的三个目标将描述NKXS.I在不同背景下的DNA损伤反应中的作用，从而提供对这一关键的肿瘤抑制机制的全面研究。在目标1中，我们的实验将定义NKX3.1和ATM之间的功能相互作用的动力学，这种相互作用发生在DNA损伤的几分钟内。在目标2中，我们将确定Nkx3.I基因拷贝数是否影响体内前列腺上皮，特别是前列腺上皮干细胞的DNA损伤反应。最后，在目标3中，使用我们获得的独特的LNCaP细胞系，我们将确定NKX3.1是否影响TMPRSS2-ERG基因重排的频率。这些拟议的研究将与整个方案项目高度整合。值得注意的是，目标2中的实验包括与Core A合作进行的定量免疫染色分析，目标2中关于前列腺干细胞的工作将与Michael Shenin合作进行(项目1)，整个项目与Cory Abate-shen的Nkx3.1在细胞衰老中的分子分析(项目2)相联系。