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

• 批准号: 10404987
• 负责人: LEONARD H AUGENLICHT
• 金额: $ 28.81万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-17 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10404987
• 关键词: APC mutation; Address; Affect; Alleles; Automobile Driving; Cell Compartmentation; 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; colon tumorigenesis; colorectal cancer risk; crypt cell; dietary; dietary control; early detection biomarkers; exome sequencing; experimental study; feeding; genetic analysis; high risk; imaging modality; in vivo; intestinal homeostasis; intestinal tumorigenesis; mouse genetics; neoplastic cell; novel; recruit; repaired; response; self-renewal; stem cell function; stem cells; transcriptome sequencing; tumor; tumorigenesis

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.

我们已经解剖了西方风格纯化饮食（NWD1）对肠道和结肠肿瘤发生的影响。 NWD1在流行病学上概括了小鼠的关键营养素的摄入量，与更高的风险有关 西方发达国家的肠癌。我们确定NWD1放大器并加速肠道 许多小鼠遗传模型中的肿瘤，无论遗传病因学和侵略性如何 多个遗传驱动因素。此外，当长期喂入野生型小鼠时，我们和其他人确定NWD1 引起零星的肠道和结肠肿瘤。至少在这些零星肿瘤出现之前的1年 在组织病理正常粘膜中上皮细胞和潜在的分子途径的成熟改变。 这导致研究了肠道干细胞的细胞和分子生物学如何通过NWD1的改变， 我们报道了一个令人惊讶的发现，即NWD1损害了肠道中LGR5HI细胞的干细胞功能 稳态和肿瘤发生，但这是通过动员BMI1+细胞作为干细胞的动员来补偿的 这些功能。此外，遗传和饮食实验鉴定了改善的维生素D暴露和VDR 信号在这些效果中同样重要，与CLEVERS报道的干细胞表达签名一致 LGR5HI干细胞功能中的隐式VDR信号传导。此外，我们注意到鼠标在肠道上实验 干细胞已经使用了建立维生素D水平远高于美国人群的饮食。这 关于干细胞在稳态和肿瘤发生中的作用以及如何发挥作用，提出了重大问题。 自从先前的审查（提交出版）以来，广泛的新数据建立了饮食的深刻影响 暴露：i）关于LGR5HI和BMI1+细胞的编程（RNASEQ）； ii）这些细胞中DNA修复的能力； iii）在随后的范围内，突变的频谱和特征在这些加密细胞中积累 隔室（FACS的测序分离的单细胞）。 AIM 1解决了饮食诱发的假设 LGR5HI干细胞编程，功能和表观遗传学改变的变化可能非常长，并且 因此，该干细胞可以用作“前哨细胞”来监测饮食干预调节的能力 这些改变是风险和干预目标的潜在标志。这将提供基本数据 相关基因和途径在调节干细胞功能时的协调，鉴定的标记 相对风险以及如何优化干预策略。最初提交的AIM2主要是 已完成和AIM 2进行了修订，以研究改变DNA修复在 有条件的APC时，饮食对LGR5+和BMI1+种群的肿瘤发生的影响差异 突变专门针对这些细胞群体。 AIM2还决定了饮食对 APC中突变的性质以及整个肿瘤中的整个基因组。 AIM 3决定了 从肿瘤组织病理学和肿瘤上皮细胞编程的饮食饮食中 LGR5+或BMI1+干细胞室。然后，rnascope和一种新颖的转录成像方法 确定LGR5+和BMI1+干细胞对肠内稳态和肿瘤发生的相对贡献 不同的饮食条件。