Role of p53 Missense Mutations on Tumorigenesis in Vivo

p53 错义突变在体内肿瘤发生中的作用

• 批准号: 9883907
• 负责人: GUILLERMINA LOZANO
• 金额: $ 38.48万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-04 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9883907
• 关键词: Alleles; Apoptosis; BRCA1 gene; Biology; Breast; CRISPR/Cas technology; Cancer cell line; Cell Culture Techniques; Cell Cycle Arrest; Cell Line; Cells; Cessation of life; Collection; Complex; DNA Binding; Defect; Development; Disease; Exhibits; Frequencies; GATA3 gene; Gene Expression; Genes; Genetic Transcription; Genetically Engineered Mouse; Growth; Histology; Hot Spot; Human; Human Genetics; Immune; Immune response; Immune system; Immunotherapy; Incidence; Infiltration; Inherited; Knock-in Mouse; Lead; Maintenance; Malignant Neoplasms; Mammary Neoplasms; Metabolism; Missense Mutation; Modeling; Molecular; Mus; Mutant Strains Mice; Mutation; PIK3CA gene; PTEN gene; Pathway interactions; Pharmaceutical Preparations; Phenotype; Positioning Attribute; Preclinical Testing; Proteins; Recurrence; Role; Sequence Analysis; T-Lymphocyte; TP53 gene; Testing; Therapeutic; Transcriptional Activation Domain; Tumor Suppressor Genes; Tumor Suppressor Proteins; Woman; Work; addiction; cancer care; driver mutation; exome; experimental study; functional genomics; gain of function; genomic profiles; in vivo; malignant breast neoplasm; mammary epithelium; molecular pathology; mouse model; mutant; neoplastic cell; novel; pre-clinical; programs; response; senescence; tool; transcription factor; transcriptome sequencing; triple-negative invasive breast carcinoma; tumor; tumor microenvironment; tumor-immune system interactions; tumorigenesis

Project Summary Cancer is a collection of complex, heterogeneous, and devastating diseases; however, one common theme is recurrent and high-frequency mutations in the TP53 tumor suppressor gene. In contrast to other tumor suppressors, most TP53 alterations are missense mutations and these exhibit gain-of-function phenotypes that are dependent of transcriptional rewiring. This proposal is focused on the role of p53 missense mutations in triple negative breast cancer (TNBC). Breast cancers are widespread malignancies representing 15% of all cancer deaths in women worldwide. 80-88% of basal-like breast cancers, the majority of which are TNBC, have mutations in the TP53 tumor suppressor. We have recently developed the first genetically engineered mouse model of somatic breast cancer driven by p53 missense mutations. This conditional model represents a major advance as it expresses mutant p53 from the endogenous locus and maintains wild-type p53 in the stroma and immune system. Moreover, our model faithfully mimics the histology of human TNBC, and develops TNBC with a one year latency. Moreover, in these mice, deletion of mutant p53 with CRISPR-Cas9 results in tumor regression and increased survival, indicating that the breast tumors are addicted to mutant p53. In addition, we see increased infiltration of T lymphocytes upon tumor regression. In this study, we propose to understand the biology of TNBC initiated by a somatic p53 driver mutation and determine why these tumors are addicted to mutant p53. This work combines our elegant and disease relevant mouse models of TNBC with state-of-the- art genomic profiling to comprehensively understand the mechanisms underlying mutant p53 driven breast cancer. Moreover, we will use cell lines recently derived from our model that are also addicted to mutant p53 as a platform to undertake a functional genomics screen to identify novel vulnerabilities in these cancers. Immune based therapies have revolutionized cancer care. Therefore to effectively advance mutant p53 directed therapies, a comprehensive understanding of the immune landscape and response is needed. Since our somatic breast model uniquely retains a WT p53 microenvironment and immune compartment, we are in an ideal position to examine the immune response to mutant p53 directed therapies. Our specific aims are: Aim 1. To understand the underlying biology that drives breast cancer development in p53-null versus mutant mice, we will perform whole exome sequence analyses. To identify the molecular pathways that lead to addiction of mutant p53 breast cancers, we will perform RNA-seq analyses of somatic p53R172H breast tumors with and without deletion of mutant p53. Aim 2. To determine the molecular pathways downstream of mutant p53 that are essential for tumor maintenance using CRISPR/Cas9 functional screens. Aim 3. To understand and exploit the immune response to therapeutic inhibition of mutant p53 in breast cancer. Because our conditional mouse model shares the underlying molecular pathology with human sporadic tumors, it will be more predictive of human responses to drugs, and thus a valuable tool in preclinical testing.

项目摘要 癌症是复杂，异质和破坏性疾病的集合。但是，一个常见的主题是 TP53肿瘤抑制基因中的复发和高频突变。与其他肿瘤相反 抑制器，大多数TP53改变是错义突变，这些表现出功能奖励表型 取决于转录重新布线。该提议的重点是p53错义突变在 三重阴性乳腺癌（TNBC）。乳腺癌是普遍的恶性肿瘤，占所有癌症的15％ 全世界女性的癌症死亡。 80-88％的基底乳腺癌（大多数是TNBC）具有 TP53肿瘤抑制器中的突变。我们最近开发了第一个基因工程的鼠标 由p53错义突变驱动的体乳腺癌模型。该条件模型代表一个主要的 前进是从内源基因座表达突变p53，并在基质中保持野生型p53 免疫系统。此外，我们的模型忠实地模仿了人类TNBC的组织学，并与 一年的潜伏期。此外，在这些小鼠中，具有CRISPR-CAS9的突变体p53的缺失导致肿瘤 回归和生存增加，表明乳腺肿瘤沉迷于突变体p53。另外，我们 请参阅肿瘤消退后T淋巴细胞浸润的增加。在这项研究中，我们建议了解 由体p53驱动器突变引发的TNBC的生物学，并确定为什么这些肿瘤会上瘾 突变p53。这项工作结合了我们优雅和疾病相关的TNBC小鼠模型和最先进的 艺术基因组分析以全面了解突变体p53驱动乳房的机制 癌症。此外，我们将使用最近从模型中得出的细胞系，这些细胞系也沉迷于突变体p53 作为进行功能基因组学筛查以识别这些癌症中新型漏洞的平台。 基于免疫的疗法已彻底改变了癌症护理。因此有效地推进了突变体p53 疗法，需要对免疫景观和反应的全面理解。自从我们 躯体乳房模型独特地保留了WT p53微环境和免疫室，我们在 检查对突变体p53定向疗法的免疫反应的理想位置。我们的具体目标是：目标 1。了解驱动p53-null与突变小鼠乳腺癌发展的潜在生物学， 我们将执行整个外显子组序列分析。确定导致成瘾的分子途径 突变的p53乳腺癌，我们将对带有和 没有删除突变体p53。目标2。确定突变体p53下游的分子途径 对于使用CRISPR/CAS9功能屏幕维护至关重要。目标3。了解和利用 对乳腺癌中突变体p53治疗抑制的免疫反应。因为我们的有条件鼠标 模型与人类零星肿瘤共享潜在的分子病理学，它将更加预测 人类对药物的反应，因此是临床前测试中的有价值工具。