Understanding the role of TP53 mutation in genetic susceptibility to ovarian cancer

了解 TP53 突变在卵巢癌遗传易感性中的作用

• 批准号: 10608934
• 负责人: Rosa Ana Risques
• 金额: $ 51.25万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10608934
• 关键词: Age; Aging; Autopsy; BRCA1 gene; Biological; Biopsy; Blood; Cells; Centenarian; Clonal Evolution; Clonal Expansion; Clonality; Clustered Regularly Interspaced Short Palindromic Repeats; Collecting Tube; Constitution; Constitutional; Coupled; DNA; Data; Detection; Disease; Distal; Early Diagnosis; Environmental Risk Factor; Evaluation; Excision; Frequencies; Gene Order; General Population; Genetic Predisposition to Disease; Genetic Risk; Germ-Line Mutation; Goals; Grant; Gynecologic; High Risk Woman; Histologic; Human; Incidence; Incidental Findings; Knowledge; Lesion; Life; Location; Longevity; Malignant Neoplasms; Malignant neoplasm of ovary; Mammalian Oviducts; Methods; Mutation; Natural History; Nature; Newborn Infant; Normal tissue morphology; Operative Surgical Procedures; Organ; Ovarian; Ovary; Pap smear; Pathogenesis; Pathogenicity; Pathologic; Peritoneal Fluid; Peritoneum; Population Process; Positioning Attribute; Predisposition; Process; Proteins; Recommendation; Reporting; Research; Resolution; Risk; Risk Reduction; Role; Salpingo-Oophorectomy; Sampling; Serous; Site; TP53 gene; Testing; Tissues; Woman; cancer genetics; carcinogenesis; driver mutation; early screening; high risk; improved; lifetime risk; mutant; mutation carrier; neoplastic; normal aging; novel; ovarian cancer prevention; overexpression; prevent; prophylactic; repository; risk variant; trait; tumorigenesis

Project Summary Understanding the role of TP53 mutation in genetic susceptibility to ovarian cancer Women with germline mutations in BRCA1 and BRCA2 (BRCA carriers) are at high risk of developing high-grade serous ovarian cancer (OC) but little is known about the biological mechanisms that underlie this susceptibility. BRCA-associated OC is believed to originate from TP53 mutant cells in the fallopian tube, where precursor lesions synchronous to OC and carrying the same TP53-driver mutation have been identified. However, early precursor lesions overexpressing TP53 but histologically normal (called p53 foci) have been reported in women without OC, questioning their significance to carcinogenesis. The goal of this grant is to elucidate the role of TP53 clonal expansions in BRCA-associated carcinogenesis by using ultra-sensitive sequencing to detect TP53 mutations at a resolution never possible before. Using ultra-sensitive TP53 sequencing, we discovered that most women, with and without OC, carry TP53 mutations in peritoneal fluid and Pap test DNA, but these mutations are more abundant in women with OC and in BRCA carriers. We also obtained pilot data that indicates that TP53 mutations are frequent in the fallopian tubes of women without cancer, increasing in abundance and pathogenicity with age. These results are consistent with recent findings of cancer driver mutations in normal tissues and the notion of cancer as an evolutionary process that takes place through life. Based on these findings, we hypothesize that TP53 clonal evolution takes place in the fallopian tubes of women in the general population but this process is enhanced in women with genetic susceptibility to ovarian cancer. As a result, women at high risk of OC will carry more pathogenic TP53 mutant clones, which we can detect with unprecedented sensitivity (>4,000 depth) using CRISPR-DS, a novel ultra-sensitive sequencing method developed by our group. In Aim 1, we will sequence TP53 in fallopian tubes collected at autopsy from 82 women at all decades of life from newborn to centenarian, pioneering the discovery of the natural history of TP53 mutations in this organ and providing a baseline control for Aim 2. In Aim 2, we will sequence TP53 in fallopian tubes of 235 women that underwent prophylactic removal of fallopian tubes and ovaries due to susceptibility to OC, including BRCA carriers and women with mutations in other OC risk genes or without identified germline mutations. We will perform a comprehensive characterization of mutation traits (type, location, functional impact, pathogenicity) and we will compare TP53 mutation frequency and traits with those of women in Aim 1, across groups in Aim 2 and with standard pathological findings of p53 foci. For the same women, in Aim 3, we will sequence peritoneal fluid, Pap test, and blood DNA collected at surgery to compare TP53 mutations in those samples with those identified in fallopian tube. These studies will provide a high-resolution picture of the landscape of TP53 mutation in the fallopian tube during normal aging and in women with OC susceptibility, improving our understanding of the pathogenesis of OC and opening new venues for OC prevention and early detection.

项目摘要 TP 53突变在卵巢癌遗传易感性中的作用 BRCA 1和BRCA 2生殖系突变的女性（BRCA携带者）发生高级别乳腺癌的风险很高。 浆液性卵巢癌（OC），但很少有人知道这种易感性的生物学机制。 BRCA相关的OC被认为起源于输卵管中的TP 53突变细胞，其中前体 已经鉴定出与OC同步并携带相同TP 53驱动突变的病变。然而，早 在女性中曾报道过过度表达TP 53但组织学正常的前驱病变（称为p53灶 没有OC，质疑它们对致癌作用的重要性。这项资助的目的是阐明 用超灵敏测序法检测TP 53在BRCA相关致癌过程中的克隆性扩增 以前所未有的分辨率进行突变。使用超灵敏的TP 53测序，我们发现大多数 有和没有OC的妇女，在腹膜液和巴氏试验DNA中携带TP 53突变，但这些突变 在OC和BRCA携带者中更常见。我们还获得了试验数据，表明TP 53 在没有癌症的女性输卵管中，突变频繁，数量增加， 随着年龄的增长致病性。这些结果与最近在正常人中发现的癌症驱动突变一致。 组织和癌症作为一个进化过程的概念，发生在整个生命。根据这些发现， 我们假设TP 53克隆进化发生在一般人群中女性的输卵管中， 但这一过程在具有卵巢癌遗传易感性的女性中得到加强。因此，妇女在高 OC的风险将携带更多的致病性TP 53突变克隆，我们可以检测到前所未有的灵敏度 （> 4，000深度）使用CRISPR-DS，这是我们小组开发的一种新型超灵敏测序方法。在Aim中 1，我们将对82名妇女在所有几十年的生活中尸检时收集的输卵管中的TP 53进行测序， 从新生儿到百岁老人，率先发现了这个器官中TP 53突变的自然史， 为目标2提供基线控制。在目标2中，我们将对235名女性的输卵管中的TP 53进行测序， 由于对OC（包括BRCA）易感，接受了输卵管和卵巢预防性切除术 携带者和其他OC风险基因突变或未确定生殖系突变的女性。我们将 对突变性状（类型、位置、功能影响、致病性）进行全面表征， 我们将比较TP 53突变频率和特征与目标1中的女性，目标2中的各组， 具有p53病灶的标准病理学发现。对于相同的女性，在目标3中，我们将对腹膜液进行测序， 巴氏试验和手术时收集的血液DNA，以比较这些样本中的TP 53突变与鉴定的TP 53突变。 在输卵管里这些研究将提供一个高分辨率的图片的景观TP 53突变在 输卵管在正常老化和妇女与OC易感性，提高我们的理解， 发病机制和开辟新的OC预防和早期发现的场所。