Regulation of p53 by BRCA1 in Breast Cancer

BRCA1 在乳腺癌中对 p53 的调节

基本信息

批准号：
8535539
负责人：
Joy Chieh-Yu Lin
金额：
$ 5.77万
依托单位：
UNIVERSITY OF CALIFORNIA RIVERSIDE
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-01 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8535539
关键词：
Abnormal Cell Acetylation Affect Apoptosis BRCA1 gene Biological Assay Biological Process Breast Breast Cancer Cell CREB-binding protein Cancer-Predisposing Gene Cell Aging Cell Cycle Checkpoint Cells Cellular Stress DNA Binding DNA Damage DNA Repair Data Defect EP300 gene Embryo Event Fibroblasts Frequencies Gene Targeting Genes Genetic Transcription Genome Stability Germ-Line Mutation Growth In Vitro Individual Lead Link Lysine Maintenance Malignant Neoplasms Mammary Tumorigenesis Mediating Molecular Mus Mutation Pathogenesis Pathway interactions Phosphorylation Play Post-Translational Protein Processing Process Proteins RNA Interference Recruitment Activity Regulation Research Design Role Specificity Staining method Stains Stress Testing Transcriptional Activation Transcriptional Regulation Tumor Suppressor Genes Tumor Suppressor Proteins beta-Galactosidase cancer risk carcinogenesis chromatin remodeling cofactor design effective therapy high risk human CREBBP protein improved in vivo insight interest malignant breast neoplasm new therapeutic target novel overexpression promoter public health relevance research study response senescence

项目摘要

DESCRIPTION (provided by applicant): The overall frequency of p53 mutation in breast cancer is much lower compared to other cancers despite a high risk of breast cancer associated with p53 germ-line mutations. This implicates the importance of the inactivation of wild type p53 regulation in breast cancer and mechanisms other than mutation that inactivate p53 need to be characterized. Recently, it was found that BRCA1 is required for maintenance of high p53 acetylation in response to DNA damage in breast cancer cells (preliminary data). As p53 acetylation has been linked to cell senescence, the proposed study is intended to test the role of BRCA1 in p5S-mediated cell senescence in breast cancer. Hypothesis: BRCA1 may induce cell senescence through modulation of p3OO-dependent p53 acetylation in breast cancer cells. This study will examine whether BRCA1-mediated p53 activation is perturbed through disruption of p53 acetylation. Mounting data support a role for p53 in mammary tumorigenesis but the role of p53 in BRCA1-mediated carcinogenesis is still unclear. The long-term objectives are to identify novel relationships between p53 and BRCA1 in breast cancer which will improve our understanding of the pathogenesis of breast cancer, potentially revealing new therapeutic targets to design more specific and effective therapy. Specific Aims: (1) Determine the effect of BRCA1 on p53-p300 interaction and on p53 acetylation. (2) Define the role of the modulation of p53 acetylation by BRCA1 in p53-dependent transcription. (3) Determine the function of the modulation of p53 acetylation by BRCA1 in cell senescence. Study design: RNAi and overexpression studies will be used to characterize how BRCA1 affect p5S-p300 interaction and p53 acetylation in breast cancer cells. ChIP assays and transcriptional activation assays on p21/bax promoter in the presence/absence of p53, p3OO or BRCA1 will be used to dissect the functional connections between those proteins and to determine the sequence of events leading to p53-mediated transcriptional activation. Lastly, RNAi and overexpression approaches will be used to characterize p53-mediated cell senescence induced by BRCA1 using beta- galactosidase staining which is a marker of senescence. PUBLIC HEALTH RELEVANCE: This study is directly relevant to cancer as both p53 and BRCA1 are important tumor suppressors. This study is unique because most studies focus on mutations in tumor suppressor genes while it points out the importance of wild-type p53 regulation in breast cancer and define a novel pathway other than mutations that lead to p53 inactivation. These novel links between BRCA1 and p53 will help identify those individuals at increased breast cancer risk and to devise more specific therapies.

描述（由申请人提供）：尽管与 p53 种系突变相关的乳腺癌风险很高，但与其他癌症相比，乳腺癌中 p53 突变的总体频率要低得多。这暗示了野生型 p53 调节失活在乳腺癌中的重要性，以及需要表征除突变之外的 p53 失活机制。最近发现，BRCA1 是维持高 p53 乙酰化以应对乳腺癌细胞 DNA 损伤所必需的（初步数据）。由于 p53 乙酰化与细胞衰老有关，因此拟议的研究旨在测试 BRCA1 在 p5S 介导的乳腺癌细胞衰老中的作用。假设：BRCA1 可能通过调节乳腺癌细胞中 p3OO 依赖性 p53 乙酰化来诱导细胞衰老。这项研究将检查 BRCA1 介导的 p53 激活是否因 p53 乙酰化的破坏而受到干扰。越来越多的数据支持 p53 在乳腺肿瘤发生中的作用，但 p53 在 BRCA1 介导的癌发生中的作用仍不清楚。长期目标是确定 p53 和 BRCA1 在乳腺癌中的新关系，这将提高我们对乳腺癌发病机制的理解，有可能揭示新的治疗靶点，从而设计出更特异和有效的治疗方法。具体目标： (1) 确定 BRCA1 对 p53-p300 相互作用和 p53 乙酰化的影响。 (2) 定义 BRCA1 对 p53 乙酰化的调节在 p53 依赖性转录中的作用。 (3)确定BRCA1调节p53乙酰化在细胞衰老中的作用。研究设计：RNAi 和过度表达研究将用于表征 BRCA1 如何影响乳腺癌细胞中的 p5S-p300 相互作用和 p53 乙酰化。在存在/不存在 p53、p300 或 BRCA1 的情况下，对 p21/bax 启动子进行 ChIP 测定和转录激活测定将用于剖析这些蛋白质之间的功能连接，并确定导致 p53 介导的转录激活的事件序列。最后，RNAi 和过表达方法将用于使用 β-半乳糖苷酶染色（衰老标记）来表征 BRCA1 诱导的 p53 介导的细胞衰老。公共健康相关性：这项研究与癌症直接相关，因为 p53 和 BRCA1 都是重要的肿瘤抑制因子。这项研究的独特之处在于，大多数研究都集中在肿瘤抑制基因的突变上，而它指出了野生型 p53 调控在乳腺癌中的重要性，并定义了除导致 p53 失活的突变之外的新途径。 BRCA1 和 p53 之间的这些新联系将有助于识别那些乳腺癌风险增加的个体，并设计出更具体的治疗方法。