A Major Nutritional Effect on Intestinal Stem Cells and Tumors

营养对肠道干细胞和肿瘤的主要影响

基本信息

批准号：
9926086
负责人：
LEONARD H AUGENLICHT
金额：
$ 46.15万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
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：
2018-07-17 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9926086
关键词：
Address Affect Alleles Automobile Driving Cell Compartmentation Cell physiology Cells Cellular biology Cholecalciferol Colon Carcinoma Colonic Neoplasms Complement DNA Repair Data Developed Countries Development Diet Dietary Intervention Down-Regulation Epidemiology Epigenetic Process Epithelial Cells Gene Expression Profile Genes Genetic Genetic Models Genetic Predisposition to Disease Genetic Transcription Genome High-Risk Cancer Histologic Histopathology Homeostasis Human Image In Situ Individual Intake Intervention Intestinal Cancer Intestinal Neoplasms Intestines Intuition LGR5 gene Link LoxP-flanked allele Methods Molecular Molecular Biology Monitor Mucous Membrane Mus Mutation Nature Nutrient Nutritional Pathway interactions Phenotype Population Prevention Probability Publications Publishing RNA Regulation Relative Risks Reporting Risk Risk Factors Risk Marker Sentinel Serum Signal Transduction Testing Time Tissues Vitamin D Wild Type Mouse base biomarker identification cell type clinically relevant colorectal cancer risk crypt cell early detection biomarkers exome sequencing experimental study feeding genetic analysis high risk imaging modality in vivo intestinal homeostasis mouse genetics neoplastic cell novel recruit repaired response self-renewal stem cells transcriptome sequencing tumor tumorigenesis

项目摘要

We have dissected impact of a western style purified diet (NWD1) on intestinal and colonic tumorigenesis. NWD1 recapitulates mouse intake of key nutrients each at their levels epidemiologically linked to higher risk for intestinal cancer in western developed countries. We established that NWD1 amplifies and accelerates intestinal tumors in many mouse genetic models, regardless of genetic etiology and aggressiveness driven by single or multiple genetic drivers. Moreover, when fed to wild-type mice long-term, we and others established that NWD1 causes sporadic intestinal and colon tumors. At least 1 year before these sporadic tumors develop, there is altered maturation of epithelial cells and underlying molecular pathways in the histopathologically normal mucosa. This led to investigating how the cell and molecular biology of intestinal stem cells are altered by the NWD1, We reported the surprising discovery that NWD1 compromises stem cell functions of Lgr5hi cells in intestinal homeostasis and tumorigenesis, but that this is compensated for by mobilization of Bmi1+ cells as stem cells for these functions. Moreover, genetic and dietary experiments identify decreased vitamin D exposure and Vdr signaling as important in these effects, consistent with Clevers' reported stem cell expression signature strongly implicating Vdr signaling in Lgr5hi stem cell functions. Further, we noted that mouse experiments on intestinal stem cells have used diets establishing vitamin D levels well above the range of that for the US population. This raises significant questions regarding which and how stem cells function in homeostasis and tumorigenesis. Extensive new data since the prior review (submitted for publication) establish profound effects of dietary exposures: i) on programming of Lgr5hi and Bmi1+ cells (RNAseq); ii) on capacity for DNA repair in these cells; iii) on subsequent extent, spectrum and signature of mutations that accumulate in cells of these crypt compartments (sequencing of FACS isolated single cells). Aim 1 addresses the hypothesis that dietary induced changes in Lgr5hi stem cell programming, function, and epigenetic alterations can be exceptionally long lived, and therefore that stem cells can be used as “sentinel cells” to monitor the ability of dietary intervention to modulate these alterations as potential markers of risk and targets for intervention. This will provide fundamental data regarding coordination of genes and pathways in regulation of stem cell function, identification of markers of relative risk, and how intervention strategies can be optimized. Aim2 of the initial submission has been largely accomplished, and Aim 2 is revised to investigate the hypothesis that altered DNA repair is important in differential dietary effects on tumorigenesis from the Lgr5+ and Bmi1+ populations when conditional Apc mutations are targeted specifically to each of these cell populations. Aim2 also determines the impact of diet on the nature of mutations in Apc and throughout the genome in the tumors that arise. Aim 3 determines impact of diet on tumor histopathology and programming of tumor epithelial cells when tumors are initiated from either the Lgr5+ or Bmi1+ stem cell compartments. RNAscope and a novel method of transcriptional imaging then determine relative contribution of Lgr5+ and Bmi1+ stem cells to intestinal homeostasis and tumorigenesis under different dietary conditions.

我们剖析了西式纯化饮食（NWD1）对肠道和结肠肿瘤发生的影响。 NWD1 概括了小鼠对关键营养素的摄入量，每种营养素的摄入量在流行病学上都与较高的风险相关我们确定NWD1在西方发达国家会放大和加速肠道癌的发生。许多小鼠遗传模型中都存在肿瘤，无论遗传病因和单一或单一驱动的侵袭性如何此外，当长期喂养野生型小鼠时，我们和其他人确定了 NWD1 导致散发性肠道和结肠肿瘤至少在这些散发性肿瘤发生前 1 年，就会出现散发性肿瘤。改变上皮细胞的成熟和组织病理学正常粘膜中的潜在分子途径。这导致研究 NWD1 如何改变肠道干细胞的细胞和分子生物学，我们报告了一个令人惊讶的发现，即 NWD1 损害肠道中 Lgr5hi 细胞的干细胞功能体内平衡和肿瘤发生，但这可以通过动员 Bmi1+ 细胞作为干细胞来补偿此外，遗传和饮食实验发现维生素 D 暴露和 Vdr 减少。信号传导在这些效应中很重要，与 Clevers 报告的干细胞表达特征强烈一致此外，我们注意到小鼠肠道实验表明 Vdr 信号传导与 Lgr5hi 干细胞功能有关。干细胞使用的饮食建立的维生素 D 水平远高于美国人口的水平。提出了关于哪些干细胞以及如何在稳态和肿瘤发生中发挥作用的重要问题。自上次审查（提交发表）以来的大量新数据证实了饮食的深远影响暴露：i) Lgr5hi 和 Bmi1+ 细胞的编程 (RNAseq)；ii) 这些细胞的 DNA 修复能力； iii) 这些隐窝细胞中积累的突变的后续范围、谱和特征隔室（FACS 分离的单细胞测序）目标 1 提出了饮食诱导的假设。 Lgr5hi 干细胞编程、功能和表观遗传改变的变化可以非常长久，并且因此，干细胞可以作为“前哨细胞”来监测饮食干预的调节能力这些变化作为潜在的风险标记和干预目标，这将为干预提供基础数据。关于干细胞功能调节中基因和途径的协调、干细胞标记物的鉴定相对风险，以及如何优化初始提交的 Aim2 策略。目标 2 已完成，并进行了修订，以研究改变 DNA 修复在条件 Apc 时饮食对 Lgr5+ 和 Bmi1+ 人群肿瘤发生的不同影响 Aim2 突变专门针对这些细胞群，也决定了饮食对这些细胞群的影响。 Apc 和整个基因组中突变的性质决定了 Aim 3 所产生的影响。饮食对肿瘤组织病理学和肿瘤上皮细胞编程的影响 Lgr5+ 或 Bmi1+ 干细胞区室和转录成像的新方法。确定 Lgr5+ 和 Bmi1+ 干细胞对肠道稳态和肿瘤发生的相对贡献不同的饮食条件。