Mechanism of RAD51C fork protection and environmental carcinogenesis

RAD51C叉保护与环境致癌机制

基本信息

批准号：
10406253
负责人：
Katharina Schlacher
金额：
$ 36万
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：
2018
资助国家：
美国
起止时间：
2018-09-15 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10406253
关键词：
ATPase Domain Alleles Aromatic Polycyclic Hydrocarbons Automobile Driving BRCA3 gene Benign Biochemical Breast Cancer Risk Factor CRISPR/Cas technology Carcinogen exposure Carcinogens Cell physiology Cellular Assay DNA DNA Binding DNA Damage DNA Repair DNA Replication Damage DNA biosynthesis DNA replication fork Data Defect Development Disease Double Strand Break Repair Environmental Carcinogens Environmental Exposure Environmental Impact Event Exposure to Family Gene Family Gene Mutation Genes Genetic Genetically Engineered Mouse Genome Stability Genomic Instability Guidelines Human Cell Line In Vitro Individual Knock-in Knowledge Link Longevity Loss of Heterozygosity Malignant Neoplasms Mammary Tumorigenesis Mediating Molecular Mus Mutation National Institute of Environmental Health Sciences Outcome Pathway interactions Patients Penetrance Persons Phenotype Point Mutation Population Population Study Predisposition Prevention Prevention strategy Process Proteins RAD51C gene Recording of previous events Reporting Research Risk Assessment Sequence Homology Susceptibility Gene Testing Toxic effect Tumor Suppression Tumorigenicity Woman base brca gene cancer risk disorder risk environmental agent environmental carcinogenesis environmental stressor gene function genome integrity homologous recombination in vivo malignant breast neoplasm mammary member mouse model mutant nuclease p53-binding protein 1 prevent prognostic repair function repaired response success tumor tumorigenesis virtual

项目摘要

SUMMARY Environmental carcinogens generate DNA damage that stalls DNA replication. This jeopardizes genomic integrity critical to diverse disease-suppression. Accumulating reports show that individuals with mutations in breast cancer predisposition genes (BRCA) (found in more than 1 in 150 people) have increased cancer rates upon exposure to environmental carcinogens. The underlying cause for this has recently come under debate. In this application, we will determine the molecular mechanism of DNA replication fork protection (FP) mediated by BRCA3/RAD51C and how RAD51C and FP suppress carcinogen-induced tumorigenesis. RAD51C is the newest and perhaps least understood member of the BRCA disease suppressor family. Because of sequence homology to RAD51, which is regulated by BRCA1/2 during homology-directed double- strand (DSB) break repair, RAD51C studies have focused on its repair function. However, patient data suggests an additional tumor suppression function; 8 out of 10 disease-linked RAD51C patient mutations initially identified, do not cause DSB-repair deficiencies and based on this were designated unclassified. Yet, multiple subsequent independent breast cancer population studies identified the same alleles, suggesting significance for disease penetrance. BRCA genes have cellular functions besides DNA repair. Importantly, this includes the protection of stalled DNA replication forks from degradation by MRE11 nuclease, a new functional pathway that we have recently defined. Excitingly, our preliminary data shows many of the unclassified cancer- associated RAD51C mutations compromise FP, irrespective of DSB-repair. FP prevents genome instability ubiquitously at stalled DNA replication forks as induced by virtually all environmental carcinogens. We thus hypothesize that BRCA3/RAD51C safeguards against environmental carcinogens through protection of stalled DNA replication forks. In Aim 1) we will define the mechanism of RAD51C mediated fork stability, enabled by our discovery and understanding of new BRCA gene functions in FP, by our development of a single-cell assay for protein-DNA replication fork interactions (SIRF), by our structural understanding of the RAD51C DNA binding and ATPase domains and by having established CRISPR/CAS9 knock-in mutant RAD51C human cell lines. In Aim 2) we will determine if FP defects promote environmental carcinogen-induced mammary tumorigenesis in vivo, enabled by our having established a viable mutant RAD51C mouse model with FP defects, but no apparent DSB-repair defects, and by our understanding of genetic control of FP and DSBs by PTIP and 53BP1, that allows us to genetically test and distinguish FP from DSB repair contributions to carcinogen-induced mammary carcinogenesis. Collectively the proposed research will provide fundamental knowledge of how RAD51C-mediated FP suppresses environmentally induced genome instability and tumors. As many genes besides BRCA genes are now known to control FP, the outcome of our studies can have important broad implications for accurate and efficient disease-risk assessment for a large group of people.

概括环境致癌物会产生DNA损伤，使DNA复制失速。这危害基因组对多样化疾病抑制至关重要的完整性。累积报告表明，有突变的人乳腺癌易感基因（BRCA）（在150人中有1人中发现）癌症率提高暴露于环境致癌物后。最近的根本原因最近受到了辩论。在此应用中，我们将确定DNA复制叉保护（FP）的分子机制由BRCA3/RAD51C介导，以及RAD51C和FP如何抑制致癌物诱导的肿瘤发生。 RAD51C是BRCA疾病抑制剂家族中最新，也许最少的成员。由于与rad51的序列同源性，该序列在同源指导的双 - 链（DSB）断裂修复，RAD51C研究集中在其修复功能上。但是，患者数据提出额外的肿瘤抑制功能；在10个疾病连接的RAD51C患者突变中，有8个最初被确定的，不会引起DSB修复缺陷，并基于此被指定为未分类。然而，随后的多个独立乳腺癌人群研究确定了相同的等位基因，表明疾病外渗的重要性。 BRCA基因除了DNA修复以外还具有细胞功能。重要的是，这个包括保护失速的DNA复制叉免受MRE11核酸酶降解的保护，这是一种新功能我们最近定义的途径。令人兴奋的是，我们的初步数据显示了许多未分类的癌症 - 相关的RAD51C突变会损害FP，而与DSB修复无关。 FP防止基因组不稳定性几乎所有环境致癌物诱导的停滞的DNA复制叉处无处不在。我们这样假设BRCA3/RAD51C通过保护因停滞而抵抗环境致癌物的保障措施 DNA复制叉。在AIM 1）我们将定义RAD51C介导的叉稳定性的机制，启用通过我们对FP中新的BRCA基因功能的发现和理解，通过我们开发单细胞通过我们对RAD51C DNA的结构理解，蛋白-DNA复制叉相互作用（SIRF）的测定结合和ATPase域，并通过建立CRISPR/CAS9敲入突变体Rad51C人类细胞线。在目标2）我们将确定FP缺陷是否促进了环境致癌物诱导的乳腺在体内的肿瘤发生，我们已经建立了具有FP的活体突变体RAD51C小鼠模型。缺陷，但没有明显的DSB修复缺陷，并且通过我们对FP和DSB的遗传控制的理解 PTIP和53BP1，这使我们能够基因测试和区分DSB维修贡献致癌诱导的乳腺癌发生。拟议的研究集体将提供基本了解RAD51C介导的FP如何抑制环境引起的基因组不稳定性和肿瘤。由于现在已经知道除BRCA基因以外的许多基因控制FP，因此我们的研究结果可以对大量人的准确有效疾病风险评估的重要广泛含义。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Sense and sensibility: ATM oxygen stress signaling manages brain cell energetics.

理智与情感：ATM 氧应激信号控制脑细胞能量。

DOI：
10.1083/jcb.201901050
发表时间：
2019
期刊：
The Journal of cell biology
影响因子：
0
作者：
Schlacher,Katharina
通讯作者：
Schlacher,Katharina

MRE11-dependent instability in mitochondrial DNA fork protection activates a cGAS immune signaling pathway.

DOI：
10.1126/sciadv.abf9441
发表时间：
2021-12-17
期刊：
Science advances
影响因子：
13.6
作者：
Luzwick JW;Dombi E;Boisvert RA;Roy S;Park S;Kunnimalaiyaan S;Goffart S;Schindler D;Schlacher K
通讯作者：
Schlacher K

Hypomorphic Brca2 and Rad51c double mutant mice display Fanconi anemia, cancer and polygenic replication stress.

DOI：
10.1038/s41467-023-36933-y
发表时间：
2023-03-11
期刊：
NATURE COMMUNICATIONS
影响因子：
16.6
作者：
Tomaszowski, Karl-Heinz;Roy, Sunetra;Guerrero, Carolina;Shukla, Poojan;Keshvani, Caezaan;Chen, Yue;Ott, Martina;Wu, Xiaogang;Zhang, Jianhua;DiNardo, Courtney D.;Schindler, Detlev;Schlacher, Katharina
通讯作者：
Schlacher, Katharina