Targeting Gain-of-Function p53 Missense Mutants

靶向功能获得性 p53 错义突变体

• 批准号: 8649726
• 负责人: Timothy MacKenzie Shaver
• 金额: $ 2.73万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8649726
• 关键词: Age; Alleles; Amino Acid Substitution; Amino Acids; Apoptosis; Automobile Driving; Breast Cancer Cell; Cancer Patient; Cancer cell line; Cell Aging; Cell Cycle Arrest; Cell Line; Cell Proliferation; Cells; Cellular Stress; Clinical; Clonality; Collection; Data; Data Set; Diagnosis; Disease; Dominant-Negative Mutation; Drug resistance; Engineering; Epidermal Growth Factor; Estrogen Receptors; Event; Exhibits; Frequencies; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Gene Targeting; Genes; Genetic Screening; Genome; Genomics; Goals; Growth; Health; Hormones; Human; Laboratories; Left; Malignant Neoplasms; Malignant neoplasm of ovary; Mediating; Missense Mutation; Modeling; Molecular; Molecular Profiling; Molecular Target; Mutate; Mutation; Neoplasm Metastasis; Oncogenic; Outcome; Ovarian Serous Adenocarcinoma; Pathway interactions; Patients; Pharmacologic Substance; Phenotype; Process; Production; Progesterone Receptors; Property; Protein Binding; Protein p53; Proteins; Publishing; RNA; RNA Sequence Analysis; Relapse; Research; Resistance; Resources; Sampling; Signal Pathway; Small Interfering RNA; Squamous Cell Lung Carcinoma; Stimulus; TP53 gene; Tamoxifen; Techniques; Testing; The Cancer Genome Atlas; Tissue-Specific Gene Expression; Tissues; Toxic effect; Transcriptional Regulation; Translations; Trastuzumab; Tumor Suppressor Proteins; Work; base; cancer cell; cancer type; cell motility; chemotherapeutic agent; chemotherapy; disorder subtype; fight against; gain of function; improved; inhibitor/antagonist; insight; malignant breast neoplasm; migration; mouse model; mutant; overexpression; public health relevance; receptor; receptor expression; repository; screening; small hairpin RNA; standard of care; therapeutic development; therapeutic target; therapy development; triple-negative invasive breast carcinoma; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): Triple-negative breast cancer (TNBC) is a serious health concern. Representing 10-20% of all breast cancers, TNBC is more aggressive than other forms of the disease, with a younger average age of diagnosis, increased rate of relapse, and decreased survival. One of the greatest challenges presented by TNBC is the lack of common oncogenic 'drivers' associated with the disease, thus limiting strategies for targeted therapeutics. Currently, there are no effective targeted therapies available to treat the disease, unlike other forms of breast cancer driven by estrogen receptor and HER2 in which treatment with tamoxifen and trastuzumab has made a substantial impact on survival. Profiling of a large number of TNBC tumors has identified a wide variety of low- frequency mutations, and our laboratory recently published a study showing that there are at least six distinct molecular subtypes of the disease. The long-term goals of our research are to identify pathways that can be therapeutically targeted in TNBC. One feature shared by a majority of TNBC cases is missense mutations in the gene encoding the p53 tumor suppressor (TP53), which result in the production of a non-functional version of the protein with a single amino acid difference. Recent studies have identified special "gain of function" properties conferred by some of these mutant proteins that enhance cell proliferation, migration and resistance to chemotherapeutic agents. Further, our laboratory has preliminary data showing growth inhibition of certain mutant-p53 cells after shRNA expression that decreases the levels of p53 RNA and protein, confirming previously published data. Based on these collective data, we hypothesize that tumors with p53 missense mutations exist in a mutant p53-adpated state, and determining the molecular underpinnings of this state will provide insight into targets for therapeutic development. In order to test this hypothesis, we propose three aims: 1) to determine mechanisms contributing to the mutant p53-adapted state, 2) to identify genes whose knockdown specifically inhibits p53-mutant TNBC cells, and 3) to develop missense mutant- specific molecular signatures through differential gene expression analysis of clinical tumor samples. We will leverage modern techniques including transcriptional analysis and whole-genome genetic screening across a wide array of cell lines and distinct p53 missense mutants. In addition, we will incorporate an ever-growing body of transcriptional and genomic datasets from publically available resources such as The Cancer Genome Atlas in order to identify molecular features associated with specific p53 missense mutants in the context of patient tumor samples. In the process, we will increase our understanding of how tumors adapt to mutant p53 and test our hypothesis that targeting this adapted state is a way to specifically inhibit cancer cells. The results generated from our studies will have potential translation to nearly every form of human cancer, and could help in the fight against TNBC as well as other diseases with high-frequency p53 mutation, such as ovarian cancer and lung squamous cell carcinoma, for which no effective targeted therapy has yet been found.

描述（由申请人提供）：三阴性乳腺癌（TNBC）是一个严重的健康问题。TNBC占所有乳腺癌的10-20%，比其他形式的疾病更具侵袭性，平均诊断年龄更小，复发率增加，生存率降低。由TNBC提出的最大挑战之一是缺乏与疾病相关的常见致癌“驱动因素”，从而限制了靶向治疗的策略。目前，没有有效的靶向治疗可用于治疗该疾病，不像其他形式的乳腺癌由雌激素受体和HER 2驱动，其中他莫昔芬和曲妥珠单抗治疗对生存产生了重大影响。对大量TNBC肿瘤的分析已经确定了各种各样的低频突变，我们的实验室最近发表了一项研究，显示该疾病至少有六种不同的分子亚型。我们研究的长期目标是确定可以在TNBC中治疗靶向的途径。大多数TNBC病例共有的一个特征是编码p53肿瘤抑制因子（TP 53）的基因中的错义突变，这导致产生具有单一氨基酸差异的非功能性蛋白质。最近的研究已经确定了这些突变蛋白中的一些所赋予的特殊的“功能获得”特性，其增强细胞增殖、迁移和对化疗剂的抗性。此外，我们的实验室有初步数据显示，在shRNA表达后，某些muploma-p53细胞的生长抑制降低了p53 RNA和蛋白质的水平，证实了先前发表的数据。基于这些收集的数据，我们假设p53错义突变的肿瘤存在于突变的p53 adpated状态，确定这种状态的分子基础将提供深入了解治疗发展的目标。为了 为了验证这一假设，我们提出了三个目标：1）确定导致突变型p53适应状态的机制，2）鉴定敲低特异性抑制p53突变型TNBC细胞的基因，3）通过临床肿瘤样品的差异基因表达分析开发错义突变型特异性分子标记。我们将利用现代技术，包括转录分析和全基因组遗传筛选广泛的细胞系和不同的p53错义突变体。此外，我们还将整合不断增长的转录和基因组数据集，这些数据集来自医学上可用的资源，如癌症基因组图谱，以便在患者肿瘤样本的背景下识别与特定p53错义突变体相关的分子特征。在这个过程中，我们将增加我们对肿瘤如何适应突变型p53的理解，并测试我们的假设，即靶向这种适应状态是一种特异性抑制癌细胞的方法。从我们的研究中产生的结果将有可能转化为几乎所有形式的人类癌症，并可能有助于对抗TNBC以及其他具有高频p53突变的疾病，如卵巢癌和肺鳞状细胞癌，尚未发现有效的靶向治疗。