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

项目摘要 了解TP53突变在卵巢癌遗传易感性中的作用 BRCA1和BRCA2胚系突变的女性(BRCA携带者)患上高级别乳腺癌的风险很高 浆液性卵巢癌(OC)，但对这种易感性的生物学机制知之甚少。 BRCA相关的OC被认为起源于输卵管中的TP53突变细胞，在那里前体 与OC同步并携带相同的TP53驱动程序突变的病变已被鉴定。然而，早些时候 已有女性报告过高表达TP53但组织学正常的前驱病变(称为P53灶)。 没有OC，质疑它们对癌症发生的意义。这笔赠款的目的是为了阐明 超敏测序检测BRCA相关癌变过程中TP53的克隆性扩增 一种以前不可能实现的分辨率突变。使用超灵敏的TP53测序，我们发现大多数 患有和不患有OC的女性在腹腔液和巴氏试验DNA中携带TP53突变，但这些突变 在OC女性和BRCA携带者中更为丰富。我们还获得了飞行员数据，表明TP53 突变在未患癌症的女性输卵管中频繁出现，数量增加， 致病性随年龄增长。这些结果与最近发现的正常人群癌症驱动基因突变是一致的。 组织和癌症的概念是一个发生在生命中的进化过程。基于这些发现， 我们假设TP53的克隆进化发生在普通人群中的女性输卵管中。 但这一过程在卵巢癌遗传易感性女性中得到了加强。因此，女性处于高位 OC的风险将携带更多致病的TP53突变克隆，我们可以前所未有的灵敏度检测到这些克隆 (&gt；4,000深度)，使用我们团队开发的一种新的超灵敏测序方法CRISPR-DS。在AIM 1，我们将对尸检收集的82名女性的输卵管中的TP53进行测序，这些女性来自 新生儿到百岁老人，率先发现了这个器官中TP53突变的自然历史和 为目标2提供基线对照。在目标2中，我们将对235名女性输卵管中的TP53进行测序 由于对OC的易感性，包括BRCA，接受了预防性的输卵管和卵巢切除 携带者和女性，有其他OC风险基因突变或没有已识别的种系突变。我们会 对突变特征(类型、位置、功能影响、致病性)和 我们将比较TP53突变频率和特征与目标1中女性的突变频率和特征，以及目标2和 有标准的P53癌灶病理表现。对于同样的女性，在目标3中，我们将对腹腔液进行排序， PAP试验和在手术中收集的血液DNA以比较这些样本中的TP53突变与已鉴定的样本 在输卵管中。这些研究将提供TP53突变的高分辨率图像。 在正常年龄和OC易感性女性中，输卵管，提高了我们对 OC的发病机制，为OC的预防和早期发现开辟了新的场所。

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.