Functional genomics approach to evaluate mechanisms of mutant p53 gain-of-function phenotypes

评估突变 p53 功能获得表型机制的功能基因组学方法

• 批准号: 9908583
• 负责人: Lindsay Redman
• 金额: $ 2.97万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-09 至 2022-07-08
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9908583
• 关键词: Affect; African American; Amino Acids; Aneuploidy; Apoptosis; Binding; Biochemical; Breast Cancer cell line; Cell Cycle; Cell Cycle Arrest; Cell Cycle Regulation; Cell Fractionation; Cell Line; Cells; Cessation of life; Chromosomal Instability; Chromosome abnormality; Clinical; Clinical Data; Clone Cells; Clustered Regularly Interspaced Short Palindromic Repeats; Co-Immunoprecipitations; Complex; Cytotoxic Chemotherapy; Development; Disease; Dissection; Epithelial; Evaluation; Event; Evolution; Family member; Frequencies; Future; Gene Expression; Genes; Genome; Genomic Instability; Genomic approach; Genomics; Goals; Heat-Shock Proteins 90; Heterogeneity; Human; Immunofluorescence Immunologic; Maintenance; Malignant Neoplasms; Mammary gland; Mass Spectrum Analysis; Mediating; Metabolic; Metabolism; Missense Mutation; Modeling; Molecular; Mutation; Neoplasm Metastasis; Oncogenic; Outcome; Phenotype; Prevention strategy; Property; Protein Analysis; Protein p53; Proteins; Relapse; Reporting; Reproducibility; Research; Research Proposals; Role; TP53 gene; Techniques; Testing; Therapeutic; Time; Tumor Suppressor Genes; Tumor Suppressor Proteins; Tumor-Derived; Woman; base; clinical translation; experimental study; functional genomics; functional loss; gain of function; genome editing; genomic data; improved; inhibitor/antagonist; loss of function; malignant breast neoplasm; metabolomics; mutant; neoplastic cell; new therapeutic target; novel; overexpression; pre-clinical; promoter; protein expression; protein protein interaction; senescence; standard of care; stem; survival outcome; targeted treatment; therapeutic development; therapeutic target; transcription factor; triple-negative invasive breast carcinoma; tumorigenesis; validation studies

Project Summary/Abstract Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks traditional clinical targets; as a result, cytotoxic chemotherapy is the current standard of care. Development of targeted therapies for TNBC is challenging due to molecular heterogeneity and a lack of therapeutically targetable, high-frequency “driver” alterations. The most unifying feature across TNBC cases is that ~80% harbor a mutation in the tumor suppressor gene TP53. Mutations in p53 are commonly missense and have been proposed to result in gain-of- function (GOF) activity leading to novel oncogenic phenotypes. Although the mechanistic underpinnings of this GOF activity are not understood, alterations in TP53 are highly correlated with increased chromosomal instability (CIN) and the development of aneuploidy, and have been associated with dysregulated metabolism. To study p53 GOF mutant proteins, our lab developed two isogenic cell line models (non-transformed mammary epithelial and TNBC cell lines) using CRISPR/Cas-mediated genome editing. The models include clonal cell lines expressing two common “hotspot mutant” p53 proteins (R175H and R273H), wild-type (WT) protein, or no p53 protein (Null). This panel of cell lines allows for the study of various forms of p53, all expressed and regulated by the endogenous gene promoter and without the confounding effects caused by ectopic and unregulated overexpression. Additionally, these models afford a unique opportunity to both dissect novel and evaluate proposed GOF mechanisms and phenotypes that stem from loss of functional (LOF) p53 and/or concomitant gain of mutant p53 protein expression. We have shown that our isogenic cell lines with mutant p53 have higher levels of CIN, development of aneuploidy and dysregulated metabolism. Additionally, we have found that stabilization of mutant protein significantly correlates with the development of aneuploidy. In Aim 1 I will deploy biochemical techniques and analysis of an array of genomics data sets generated from our cell line models to evaluate the relationship between mutant p53 and p73 interactions and CIN. In Aim 2 I will use biochemical techniques and targeted metabolomics to study how development of aneuploidy underlies the GOF phenotypes of mutant p53 stabilization and altered metabolism. Through these aims I will test the hypothesis that discovery and dissection of mutant p53 LOF and/or GOF mechanisms, which generate cellular states associated with aneuploidy in tumor cells, will lead to the identification of novel pre- clinical targets for TNBC. I anticipate that the dissection of novel mechanisms as well as the evaluation of the reproducibility of proposed mechanisms for mutant p53 GOF phenotypes will improve the current understanding of the role mutant p53 in tumorigenesis. The results generated from our studies have the potential for clinical translation, not only in TNBC (for which the need for a targeted therapy is critical), but also in other types of human cancer that have high-frequency p53 mutation.

项目摘要/摘要 三阴性乳腺癌（TNBC）是缺乏传统临床的乳腺癌的侵略性亚型 目标；结果，细胞毒性化疗是当前的护理标准。靶向疗法的发展 因为TNBC由于分子异质性和缺乏治疗性，高频而具有挑战性 “驱动程序”更改。 TNBC案例中最统一的特征是约80％的肿瘤中有突变 抑制基因TP53。 p53中的突变通常是错义的，已提议导致 - 功能（GOF）活性导致新型致癌表型。虽然机械基础 GOF活性尚不清楚，TP53的改变与染色体的增加相关 不稳定性（CIN）和非整倍性的发展，并与代谢失调有关。 为了研究p53 GOF突变蛋白，我们的实验室开发了两个同基因细胞系模型（未转换） 使用CRISPR/CAS介导的基因组编辑的乳腺上皮和TNBC细胞系）。模型包括 表达两个常见“热点突变体” p53蛋白（R175H和R273H）的克隆细胞系，野生型（WT） 蛋白质，或无p53蛋白（NULL）。该细胞系允许研究各种形式的p53 由内源基因启动子表达和调节，没有由 生态和不受监管的过表达。此外，这些模型提供了一个独特的机会来剖析 新颖和评估了源于功能丧失（LOF）p53的GOF机制和表型 和/或突变体p53蛋白表达的增益。我们已经证明了我们的同基因细胞系 突变p53具有较高的CIN，非整倍性的发展和代谢失调。此外， 我们发现，突变蛋白的稳定与非整倍性的发展显着相关。 在AIM 1中，我将部署生化技术和分析从 我们的细胞系模型评估突变体p53和p73相互作用与CIN之间的关系。在目标2我 将使用生化技术和靶向代谢组学来研究非整倍性基础的发展 突变体p53稳定和代谢改变的GOF表型。通过这些目标，我将测试 假设突变体p53 LOF和/或GOF机制的假设，这会产生 肿瘤细胞中与非整倍性相关的细胞态将导致新的鉴定 TNBC的临床目标。我预计新机制的解剖以及对 突变体p53 GOF表型的提议机制的可重复性将改善电流 了解突变体p53在肿瘤发生中的理解。我们研究产生的结果具有 临床翻译的潜力不仅在TNBC中（对目标治疗的需求至关重要），而且还 在其他具有高频p53突变的人类癌症中。