Folic Acid Supplementation and Colitis-associated Colon Carcinogenesis

叶酸补充剂和结肠炎相关的结肠癌发生

基本信息

批准号：
10446361
负责人：
MARGIE L. CLAPPER
金额：
$ 42.39万
依托单位：
RESEARCH INST OF FOX CHASE CAN CTR
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：
2022-05-11 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10446361
关键词：
16S ribosomal RNA sequencing Acids Address Adult Age Apoptosis Architecture Area Attention Bacteria Biological Markers CRISPR/Cas technology Cell Cycle Progression Cell Line Cells Chronic Clinical Clustered Regularly Interspaced Short Palindromic Repeats Colectomy Colitis Colitis associated colorectal cancer Colon Colon Carcinoma Colonic Neoplasms Colonic inflammation Colorectal Cancer Colorectal Neoplasms DNA biosynthesis Data Development Diagnosis Diet Dietary Administration Dietary intake Disease Management Dose Dysplasia Engineering Ensure Epithelial Cells Event Exposure to Face Flare Folic Acid Folic Acid Deficiency Gatekeeping Gene Expression Genetic Transcription Goals Guidelines Human In Vitro Incidence Inflammation Inflammatory Inflammatory Bowel Diseases Intake Interleukin-6 Intestines Lead Maintenance Therapy Malabsorption Syndromes Malignant Epithelial Cell Malignant Neoplasms Measures Mediating Mesalamine Molecular Mucous Membrane Mus Mutation Nuclear Oncogenic PTGS2 gene Pathway interactions Patients Pharmaceutical Preparations Population Prevention strategy Preventive Property Ribosomal RNA Risk Safety Serum Folate Level Severity of illness Signal Transduction Standardization Suggestion Surface TP53 gene Testing Therapeutic Time Tumor Burden Ulcerative Colitis Vitamin B Complex Western Blotting base clinically relevant colitis associated cancer colon cancer risk colon carcinogenesis colorectal cancer risk cyclooxygenase 2 cytokine dextran sulfate sodium induced colitis experimental study folic acid supplementation gut inflammation gut microbiota high risk population illness length in vivo insight metagenomic sequencing metaplastic cell transformation microbiome mutant neoplastic cell p65 prevent primary endpoint response transcriptome sequencing tumor tumorigenesis

项目摘要

Project Summary/Abstract Patients with ulcerative colitis, a form of inflammatory bowel disease, face an increased risk of developing colorectal cancer. Although advances have been made in the therapeutic management of this disease, much less attention has been given to the development of cancer preventive strategies for this high-risk population. Ulcerative colitis patients often develop folate deficiencies that require supplementation with folic acid (FA), a synthetic form of folate. The effect of FA on risk for colorectal cancer remains unclear and the recent suggestion that FA supplements may be useful in preventing colitis-associated colorectal cancer is of great concern. Preliminary studies from this group provide the first evidence that FA supplementation (8 mg/kg diet) causes a dose-dependent increase in the formation of colorectal tumors in mice with AOM/DSS-induced colitis. Results from associated RNASeq and in vitro analyses suggest that FA promotes tumorigenesis by activating ERK and inducing NF-κB signaling in colonic epithelial cells with dysfunctional p53, the gatekeeping event in the development of colitis-associated cancers. The hypothesis of the proposed studies is that FA supplementation promotes UC-associated cancer in cells with dysfunctional/mutant p53, but not in cells with wild type p53, via an inflammatory pathway mediated by ERK and NF-κB. The mechanism by which FA induces tumor formation will be investigated in Aim 1 using CRISPR engineered isogenic human RKO colon carcinoma cells with varying p53 status (p53+/+, p53-/- and p53+/Mut). The impact of FA and dysfunctional p53 on activation of ERK, NF-κB signaling, as well as cell cycle progression will be evaluated. In vitro findings will be validated in Aim 2, where complimentary in vivo analyses will examine the combined effect of FA and mutant p53 on DSS-induced colitis-associated tumorigenesis and associated biomarkers in p53+/+ and p53+/515A (mutant) mice. In addition, the impact of high dose FA given prior to the induction of colitis will be examined. Tumor incidence and multiplicity, as well as degree of intestinal inflammation, will serve as primary endpoints of these studies. Based on the important contribution of intestinal microbiota to colitis and their ability to synthesize folate de novo, the impact of FA administration on the diversity and relative abundance of fecal and adherent bacteria within the intestine of p53+/515A mice with DSS-induced colitis will be examined in Aim 3. Mice will be treated with 5-aminosalicylic acid (5-ASA), a common maintenance therapy for ulcerative colitis, for the duration of FA exposure to recapitulate the clinical therapy of a patient following a diagnosis of colitis. The composition of the fecal and colon-adherent microbiomes, determined from 16S rRNA and metagenomic sequencing data, will be correlated with colonic inflammation, barrier function and tumor incidence/multiplicity. The results are expected to provide significant insight into the impact of FA supplementation on colitis-associated tumorigenesis and inform the first guidelines for the use of FA supplements by patients with ulcerative colitis.

项目概要/摘要患有溃疡性结肠炎（一种炎症性肠病）的患者面临着更高的罹患溃疡性结肠炎的风险尽管结直肠癌的治疗已取得进展，但仍有很多进展。针对这一高危人群制定癌症预防策略的关注较少。溃疡性结肠炎患者经常出现叶酸缺乏，需要补充叶酸（FA），叶酸是一种叶酸的合成形式对结直肠癌风险的影响尚不清楚，最近的建议也是如此。 FA 补充剂可能有助于预防结肠炎相关的结直肠癌，这一点引起了人们的极大关注。该小组的初步研究提供了第一个证据，表明补充 FA（8 毫克/公斤饮食）会导致 AOM/DSS 诱导的结肠炎小鼠结直肠肿瘤形成呈剂量依赖性增加。相关 RNASeq 和体外分析表明 FA 通过激活 ERK 和诱导具有功能障碍的 p53 的结肠上皮细胞中 NF-κB 信号传导，p53 是结肠中的看门事件所提出的研究的假设是补充 FA。通过一种机制，在 p53 功能失调/突变的细胞中促进 UC 相关癌症，但在野生型 p53 的细胞中则不会 ERK 和 NF-κB 介导的炎症通路 FA 诱导肿瘤形成的机制在目标 1 中使用 CRISPR 工程改造的具有不同 p53 的同基因人 RKO 结肠癌细胞进行研究状态（p53+/+、p53-/- 和 p53+/Mut） FA 和功能失调的 p53 对 ERK、NF-κB 信号传导的影响。以及细胞周期进程将在目标 2 中得到验证。互补的组合体内分析将检查 FA 和突变体 p53 对 DSS 诱导的影响 p53+/+ 和 p53+/515A（突变）小鼠中结肠炎相关的肿瘤发生和相关生物标志物。将检查诱导结肠炎之前给予高剂量 FA 的影响和肿瘤发生率。多样性以及肠道炎症程度将作为这些研究的主要终点。关于肠道微生物群对结肠炎的重要贡献及其从头合成叶酸的能力， FA 施用对粪便和粘附细菌多样性和相对丰度的影响将在目标 3 中检查患有 DSS 诱导结肠炎的 p53+/515A 小鼠的肠道。将用 5-氨基水杨酸 (5-ASA)，溃疡性结肠炎的常见维持疗法，用于 FA 期间回顾结肠炎诊断后患者的临床治疗。根据 16S rRNA 和宏基因组测序数据确定的粪便和结肠粘附微生物组将被与结肠炎症、屏障功能和肿瘤发生率/多样性相关。结果是预期的。深入了解 FA 补充剂对结肠炎相关肿瘤发生的影响，以及为溃疡性结肠炎患者使用 FA 补充剂提供首个指南。