CMA: Cancer Stem Cells in the Pathogenesis and Treatment of Colorectal Cancer

摘要 这项提案是作为来自全国退伍军人管理局的一组相关功绩审查申请的一部分提交的 结直肠癌(CRC)专家组成了结直肠癌细胞基因组学联盟(VA4C) 在参加了2017年5月在芝加哥成功举行的实地会议之后(由退伍军人事务部资助)。 具体地说，这项建议将是一系列优点审查项目的一部分，这些项目旨在推动我们的 了解结直肠癌的发病机制和治疗反应，重点是微生物组和 结直肠癌干细胞。肠道微生物群对结直肠癌的发展和进展的重要性是 由一系列证据支持，包括饮食和结直肠癌风险之间的流行病学联系，可重现 梭杆菌等特定微生物与人类结直肠癌的相关性，小鼠模型表明 微生物区系促进结直肠癌的形成和转移，小鼠模型显示 微生物组调节化疗反应。我们假设：1)肠道微生物群，通过 肿瘤组织的直接侵袭和生物活性微生物产物的释放与特异性结直肠癌相关 由转录图谱定义的临床/组织表型和分子亚类。2)肠道 微生物群通过调节抗肿瘤作用影响手术和化疗后复发风险 免疫和化疗药物的代谢。3)局部晚期结直肠癌的外科治疗 切除和化疗改变了肠道微生物群，这可能会影响未来的可能性 反复发作。为了研究这些假设，在目标1中，我们将利用该中心的多中心临床基础设施 CMA将收集400名患有I-III期结直肠癌的男女退伍军人的粪便和肿瘤样本进行分析 微生物组、代谢组和转录组。肠道微生物和代谢物将被鉴定为 与肿瘤表型和分子特征有关，如基因转录本所定义的，功能 途径和非编码RNA。在目标2中，我们将对200名处于第二阶段的退伍军人进行纵向随访- III结直肠癌以阐明预测随后复发风险的基线微生物和代谢物。 此外，我们将在手术前、手术中和手术后采集粪便样本，然后进行化疗，并每年 此后，确定治疗过程中的微生物转移及其与未来复发的关系。在目标3中，我们 将使用C57BL/6 ApcMin将肠道微生物组的组成和功能变化与结直肠癌联系起来 对自发性肠腺瘤形成高度敏感的小鼠品系。我们将研究 高、低免疫浸润型和低免疫型患者体内人微生物区系定植的影响 免疫转录状态，以评估腺瘤/结直肠癌的形成和瘤内免疫反应。我们会 同时研究移植结直肠癌细胞的小鼠对化疗的反应。 复发或持续缓解的患者，以评估微生物组介导的差异 治疗反应。

ABSTRACT This proposal is being submitted as part of a group of linked merit review applications from nationwide VA experts in colorectal cancer (CRC) who have formed a colorectal cancer cell-genomics consortium (VA4C) after participating in a successful field-based meeting in Chicago in May 2017 (funded by VA ORD). Specifically, this proposal will be part of a cluster of merit review projects that are aimed at advancing our understanding of CRC pathogenesis and treatment response with a focus on the roles of the microbiome and CRC stem cells. The importance of the intestinal microbiome to the development and progression of CRC is supported by a range of evidence including epidemiological links between diet and CRC risk, reproducible associations of specific microbes such as Fusobacterium with human CRC, mouse models indicating augmentation of CRC formation and metastasis by microbiota, and mouse models showing that the microbiome modulates chemotherapy response. We hypothesize that: 1) The intestinal microbiome, through direct invasion of tumor tissue and release of bioactive microbial products, is associated with specific CRC clinical/histologic phenotypes and molecular subclasses defined by transcriptional profiles. 2) The intestinal microbiome influences the risk of recurrence after surgery and chemotherapy by modulating anti-tumor immunity and the metabolism of chemotherapeutics. 3) The treatment of locally advanced CRC with surgical resection and chemotherapy alters the intestinal microbiome, which may influence the likelihood of future recurrences. To study these hypotheses, in Aim 1 we will utilize the multi-center clinical infrastructure of this CMA to collect fecal and tumor samples from 400 male and female Veterans with stage I-III CRC for analysis of the microbiome, metabolome, and transcriptome. Intestinal microbes and metabolites will be identified that are associated with tumor phenotype and molecular signature, as defined by gene transcripts, functional pathways and non-coding RNAs. In Aim 2, we will perform longitudinal follow-up of 200 Veterans with stage II- III colorectal cancer to elucidate baseline microbes and metabolites that predict subsequent risk for recurrence. In addition, we will obtain fecal samples before, during and after surgery then chemotherapy, and annually thereafter to identify microbial shifts with treatment and their association with future recurrence. In Aim 3, we will link compositional and functional shifts in the intestinal microbiome to CRC by using the C57BL/6 ApcMin strain of mice that is highly susceptible to spontaneous intestinal adenoma formation. We will examine the effect of colonization with human microbiota obtained from patients with high or low immune infiltration and immune transcriptional state, to assess adenoma/CRC formation and the intratumor immune response. We will also study the response to chemotherapy in mice engrafted with CRC cells and colonized with the stool of patients that had a recurrence, or a sustained remission, to evaluate microbiome-mediated differences in therapeutic response.