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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要癌症是复杂、异质且具有破坏性的疾病的集合。然而，一个共同的主题是 TP53抑癌基因的反复出现和高频突变。与其他肿瘤相比抑制子，大多数 TP53 改变是错义突变，并且这些突变表现出功能获得表型依赖于转录重连。该提案的重点是 p53 错义突变在三阴性乳腺癌（TNBC）。乳腺癌是一种广泛存在的恶性肿瘤，占所有恶性肿瘤的 15% 全球女性癌症死亡人数。 80-88% 的基底样乳腺癌（其中大多数为 TNBC）具有 TP53肿瘤抑制基因突变。我们最近开发出了第一只基因工程小鼠 p53错义突变驱动的体细胞乳腺癌模型。这个条件模型代表了一个主要的进步，因为它从内源基因座表达突变型p53并在基质中维持野生型p53，并且免疫系统。此外，我们的模型忠实地模仿了人类 TNBC 的组织学，并开发了 TNBC 一年的延迟。此外，在这些小鼠中，用 CRISPR-Cas9 删除突变体 p53 会导致肿瘤消退和存活率增加，表明乳腺肿瘤对突变型 p53 上瘾。此外，我们观察肿瘤消退后 T 淋巴细胞浸润增加。在这项研究中，我们建议了解由体细胞 p53 驱动突变引发的 TNBC 生物学，并确定这些肿瘤为何成瘾突变型p53。这项工作将我们优雅且与疾病相关的 TNBC 小鼠模型与最先进的艺术基因组分析全面了解突变 p53 驱动乳腺的机制癌症。此外，我们将使用最近从我们的模型衍生的细胞系，这些细胞系也对突变 p53 上瘾作为进行功能基因组学筛选的平台，以识别这些癌症的新漏洞。基于免疫的疗法彻底改变了癌症治疗。因此，有效推进突变p53定向治疗时，需要对免疫状况和反应有全面的了解。自从我们的体细胞乳腺模型独特地保留了 WT p53 微环境和免疫区室，我们处于检查对突变 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. 为了了解 p53 缺失小鼠与突变小鼠乳腺癌发展的基础生物学，我们将进行全外显子组序列分析。确定导致成瘾的分子途径突变 p53 乳腺癌，我们将对体细胞 p53R172H 乳腺癌进行 RNA-seq 分析，没有删除突变体p53。目标 2. 确定突变 p53 下游的分子途径对于使用 CRISPR/Cas9 功能筛选维持肿瘤至关重要。目标 3. 理解和利用乳腺癌中突变 p53 治疗抑制的免疫反应。因为我们的条件鼠标模型与人类散发性肿瘤共享潜在的分子病理学，它将更能预测人类对药物的反应，因此是临床前测试的宝贵工具。