Colibactin-Producing Escherichia coli as an Environmental Stimulus Shaping Pre-Cancer Progression

产生大肠杆菌素的大肠杆菌作为塑造癌症前期进展的环境刺激物

基本信息

批准号：
10518848
负责人：
Martha J. Shrubsole
金额：
$ 40.42万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-15 至 2027-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10518848
关键词：
Address Adoption Adverse event Affect Anesthesia procedures Automobile Driving Bacteroides fragilis Biological Markers Biological Specimen Banks Biology Cancer Etiology Cells Cessation of life Characteristics Collaborations Colon Colonic Neoplasms Colonoscopy Colorectal Colorectal Cancer DNA DNA Sequence Alteration Data Data Set Detection Developed Countries Development Diet Disease Ecosystem Epidemiology Epithelial Epithelial Cells Escherichia coli Fostering Gene Mutation Genes Genomics Hand Hemorrhage Human Immunofluorescence Immunologic Individual Indolent Induced Mutation Intercept Investigation Lead Lesion Malignant - descriptor Malignant Neoplasms Modeling Molecular Mucous Membrane Mutagens Mutate Mutation Neoplasms Obesity Pathogenesis Pathway interactions Perforation Persons Polypectomy Polyps Prevention Prevention strategy Public Health Publishing Reporting Risk Risk Factors Science Seminal Shapes Smoking Stimulus Testing Time United States Virulence Woman adenoma base burden of illness carcinogenesis clinical predictors cohort colon carcinogenesis colon microbiota colorectal cancer risk colorectal cancer screening cost effective design early onset exome sequencing human data improved improved outcome lifetime risk longitudinal design men microbial microbiome microbiota molecular marker polyketide synthase risk stratification screening single-cell RNA sequencing uptake

项目摘要

Sporadic colorectal cancer (CRC) is a public health problem, affecting over a million people each year globally and, in the United States, consistently ranks in the top 2-3 causes of cancer-related death in men and women despite the wide adoption of colonoscopy. Metachronous pre-cancers are also high following polypectomy. However, only a small percent of colon pre-cancers (conventional adenomas or sessile serrated lesions) progress to CRC, and we lack both molecular markers to identify these individuals and an understanding of the mechanisms fostering pre-cancer. The large disease burden of CRC, co-localized with the densely populated colon microbiota, and the recognition that many CRC risk factors (e.g., smoking, obesity, carnivorous diet) modify the colon microbiota has spurred investigations into ‘if and how’ the microbiota contributes to CRC pathogenesis. Accrued data now strongly support the hypothesis that the microbiota is a key environmental contributor to colon carcinogenesis. Nonetheless, little is yet known about ‘if and how’ the microbiota contributes to colon pre- cancers. Our preliminary data identify Escherichia coli that release the non-ribosomal, metabolite genotoxin, colibactin, known as pks+ E. coli (Ecpks), as strongly associated with detection of colon pre-cancers. Further, colibactin is reported to induce specific mutational signatures in colon epithelial cell DNA, in particular, mutations in APC, a CRC driver gene particularly important in adenoma development. Notably, these Ecpks mutations have been associated with CRC. In our COLON MAP study, we have also identified that sessile serrated lesions which account for a large proportion of interval CRC, are likely a result of microbial insult. However, it remains unknown whether Ecpks contributes to SSL development and progression. The few previous human studies, including our preliminary studies, are based on a cross-sectional design. Thus, to address this gap and understand the temporal sequence, we will also include a longitudinal design and human colonoids models to test our core hypothesis that a subset of Ecpks associate with and contribute to driving human pre-cancer progression. We will use a wide array of iterative approaches and conceptual and experimental integration of this project with Projects 1 and 3 and the cores of this U54. Our specific aims in this translational project are: 1) To evaluate the association of Ecpks colonization with human colorectal pre-cancers with greater progressive vs. lower (“indolent”) potential using in-hand human cohorts, clinical predictors, and longitudinal data; 2) To examine mechanisms associated with pre-cancer colon lesions stratified by disease state (indolent or progressive) and Ecpks status using whole exome sequencing, single cell RNAseq and multiplex immunofluorescence (MxIF) approaches; and 3) To identify Ecpks virulence determinants associated with progressive (vs indolent) colon pre-cancer and disease mechanisms using human colonoid models. Together, our studies have the potential to accelerate noninvasive, cost-effective CRC screening and surveillance for a critical subset of individuals at increased risk for sporadic CRC.

散发性结直肠癌 (CRC) 是一个公共卫生问题，每年影响全球超过一百万人在美国，它一直位居男性和女性癌症相关死亡原因的前 2-3 位尽管结肠镜检查被广泛采用，但息肉切除术后异时性癌前病变的发生率也很高。然而，只有一小部分结肠癌前病变（传统腺瘤或无蒂锯齿状病变） CRC 的进展，我们缺乏识别这些个体的分子标记以及对 CRC 的巨大疾病负担与人口稠密地区共同存在。结肠微生物群，以及认识到许多 CRC 危险因素（例如吸烟、肥胖、肉食饮食）会改变结肠微生物群引发了人们对微生物群“是否以及如何”影响结直肠癌发病机制的研究。现在积累的数据强烈支持这样的假设：微生物群是结肠的关键环境贡献者然而，我们对微生物群“是否以及如何”促进结肠癌的发生知之甚少。我们的初步数据确定了释放非核糖体代谢基因毒素的大肠杆菌，大肠杆菌素，称为 pks+ 大肠杆菌 (Ecpks)，与结肠癌前病变的检测密切相关。据报道，大肠杆菌素可诱导结肠上皮细胞 DNA 中的特定突变特征，特别是突变在 APC 中，CRC 驱动基因在腺瘤发展中特别重要，值得注意的是，这些 Ecpks 突变。在我们的结肠图研究中，我们还发现了无蒂锯齿状病变。在间期结直肠癌中占很大一部分，很可能是微生物损伤的结果，但这种情况仍然存在。尚不清楚 Ecpks 是否有助于 SSL 的发展和进展。包括我们的初步研究，都是基于横截面设计，因此，为了解决这一差距并为了理解时间序列，我们还将包括纵向设计和人类结肠模型检验我们的核心假设，即 Ecpks 的一个子集与人类癌前病变相关并有助于其发生我们将使用一系列广泛的迭代方法以及概念和实验整合这个项目以及项目 1 和 3 以及这个 U54 的核心目标是：1) 评估 Ecpks 定植与进展性更大的人类结直肠癌前期的关联与使用现有人类队列、临床预测因子和纵向数据的较低（“惰性”）潜力相比；检查与按疾病状态（惰性或惰性）分层的癌前结肠病变相关的机制使用全外显子组测序、单细胞 RNAseq 和多重分析进行渐进式）和 Ecpks 状态免疫荧光 (MxIF) 方法；以及 3) 鉴定与 Ecpks 相关的毒力决定因素使用人类结肠模型研究进展性（与惰性）结肠癌前病变和疾病机制。我们的研究有可能加速非侵入性、具有成本效益的 CRC 筛查和监测散发性结直肠癌风险增加的关键人群。