Microbiome-triggered reprogramming and mutation of colon epithelial cells leading to tumor stem-like cells

微生物触发结肠上皮细胞重编程和突变，形成肿瘤干样细胞

• 批准号: 10368086
• 负责人: MARK M HUYCKE
• 金额: $ 45.8万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10368086
• 关键词: 4 hydroxynonenal; Allografting; Attenuated; Automobile Driving; Bacteria; Bifidobacterium; Bystander Effect; Cancer Etiology; Cells; Chromosomal Instability; Chromosomes; Colon; Colonic Adenoma; Colorectal Cancer; Data; Development; Diffuse; Down-Regulation; Encapsulated; Enterococcus faecalis; Environment; Epigenetic Process; Epithelial Cells; Etiology; Event; Gene Expression; Genes; Health Promotion; Human; Human Microbiome; Immune; Immune response; Immunodeficient Mouse; In Vitro; Inflammation; Intestines; Laboratories; Lactobacillus; Malignant - descriptor; Malignant Neoplasms; Mediator of activation protein; Methylation; Modeling; Molecular; Morphogenesis; Mutagenesis; Mutate; Mutation; Oncogenes; Organoids; Outcome; Phosphotransferases; Play; Prevention; Prevention strategy; Preventive; Primary Neoplasm; Probiotics; Process; Research; Role; Scheme; Scientist; Signal Transduction; Small Interfering RNA; Structure; TNF gene; TNFRSF1A gene; Time; Tissues; Tumor Stem Cells; Tumor-Suppressor Gene Inactivation; Work; advanced disease; base; beta catenin; cancer cell; cancer stem cell; carcinogenesis; cell transformation; colon carcinogenesis; colon microbiome; colorectal cancer prevention; cost; cyclooxygenase 2; experimental study; genome-wide; gut microbiome; in vivo Model; intestinal epithelium; macrophage; member; microbiome; mouse model; nanoparticle; pluripotency; prevent; progenitor; screening; stem cells; stem-like cell; stemness; transcription factor; tumor

Colorectal cancer is the third leading cause of cancer with more than half of cases occurring in advanced stages that are difficult to cure. New prevention strategies are needed. The colonic microbiome plays an important role in the etiology of colorectal cancer (CRC). Our laboratory has studied Enterococcus faecalis in models of inflammation-associated CRC. This human commensal can polarize (or activate) macrophages to reprogram and transform epithelial cells into cancer cells. This process is referred to as the “microbiome-induced bystander effect.” In CRC, tumor stem-like cells are believed to originate from stem cells at the base of crypts. However, newer data supports fully differentiated epithelial cells at the top of crypts as cells of origin for CRC. This fits with a “top-down” model of morphogenesis for human colon adenomas in which transformed stem-like cells expand downward to replace normal crypt structures. In this project, we hypothesize that microbiome-polarized colon macrophages cause mutagenesis and reprogramming of differentiated epithelial cells in the upper portion of crypts toward pluripotency and stemness, thereby driving malignant transformation. Using established in vitro and in vivo models for microbiome-triggered and macrophage-induced malignant transformation, we will assess differentiated colon epithelial cells for reprogramming and mutation during transfor- mation into tumor stem-like cells. Mutations in key driver genes along with genome-wide changes in chromosomes, gene expression, and methylation will be assessed to establish the sequence of events during reprogramming and transformation. Finally, transformed malignant clones will be enriched by organoid culture and allografts characterized in immunodeficient mice. The preventive effect of probiotics (Lactobacillus and Bifidobacterium) on a microbiome- induced bystander effect will also be assessed. Using these same in vitro and in vivo models, the role of signaling by tumor necrosis factor alpha as a key mediator for the microbiome- induced bystander effect will be assessed. We hypothesize that blocking a receptor for tumor necrosis factor alpha will lead to downregulation of a functional tumor stem-like cell marker, doublecortin-like kinase 1, and thereby prevent microbiome-driven colon carcinogenesis. These experiments will help determine how intestinal commensals polarize innate immune cells to produce bystander effects and thereby induce mutagenesis, reprogramming and transformation of colon epithelial cells. Finally, we will investigate whether probiotics can inhibit microbiome- driven carcinogenesis and thereby bolster this as an approach to CRC prevention.

结直肠癌是第三大癌症原因，超过一半的病例发生在 晚期，难以治愈。需要新的预防策略。结肠 微生物组在结直肠癌（CRC）的病因学中发挥着重要作用。我们的实验室 研究了炎症相关结直肠癌模型中的粪肠球菌。这个人类 共生体可以极化（或激活）巨噬细胞以重新编程和转化上皮细胞 进入癌细胞。这个过程被称为“微生物引起的旁观者效应”。在 CRC，肿瘤干样细胞被认为起源于隐窝底部的干细胞。 然而，较新的数据支持隐窝顶部完全分化的上皮细胞为 CRC 的起源。这符合人类结肠腺瘤形态发生的“自上而下”模型 其中转化的干细胞样细胞向下扩展以取代正常的隐窝结构。在这个 项目中，我们假设微生物组极化的结肠巨噬细胞会引起突变并 隐窝上部分化的上皮细胞重编程为多能性 和干性，从而驱动恶性转化。使用已建立的体外和体内 微生物组触发和巨噬细胞诱导的恶性转化模型，我们将 评估分化的结肠上皮细胞在转化过程中的重编程和突变 分化为肿瘤干细胞样细胞。关键驱动基因以及全基因组突变 将评估染色体、基因表达和甲基化的变化，以确定 重编程和转化过程中的事件顺序。最后转化为恶性 克隆将通过类器官培养和具有免疫缺陷特征的同种异体移植物来富集 老鼠。益生菌（乳酸菌和双歧杆菌）对微生物组的预防作用 还将评估引起的旁观者效应。使用这些相同的体外和体内模型， 肿瘤坏死因子α作为微生物组关键介质的信号传导作用 将评估引起的旁观者效应。我们假设阻断肿瘤受体 坏死因子α会导致功能性肿瘤干细胞样细胞标记物的下调， 双皮质素样激酶 1，从而预防微生物组驱动的结肠癌发生。这些 实验将有助于确定肠道共生体如何极化先天免疫细胞 产生旁观者效应，从而诱导诱变、重编程和转化 结肠上皮细胞。最后，我们将研究益生菌是否可以抑制微生物组- 驱动致癌，从而支持将其作为预防结直肠癌的一种方法。