METHYLATION BIOMARKER DEVELOPMENT FOR NONINVASIVE DETECTION OF COLORECTAL CANCER

项目简介：结直肠癌(CRC)是美国第三大常见癌症， 据估计，每年有15万新病例发生。早期发现临床相关的结直肠癌 肿瘤(CRN)，即结直肠癌和晚期结直肠腺瘤(A-CRA)是提高生存率的最好方法。 然而，由于侵袭性和成本(即结肠镜检查)或 诊断准确性不足(即基于粪便的血液测试)。一种更好的筛查和监测方法 将是非常可取的。DNA甲基化异常是一种重要的表观遗传学机制 与大肠肿瘤的发生发展密切相关。异常的DNA甲基化是 可在血清中检测，使其成为非侵入性筛查的理想候选生物标志物物种。上一首 在为结直肠癌开发确定的甲基化生物标记物方面，研究取得的成功有限 筛选不全面的方法，以及未能将所有CRN作为有意义的目标纳入 临床发现。此外，在基于血清的研究中使用的队列也缺乏足够的动力和力量 独立验证集。在这项提案中，将应用创新的策略来实现基因组规模 CRN患者组织和血清的甲基化图谱及其与CRN患者组织和血清的比较 没有CRN的个体。一种新颖而强大的新方法正在被提出，以识别新的生物标记物和 甲基化靶标具有最高的敏感度和特异度，并将使用大型、良好的 通过以下具体目标确定了样本集的特征。 目的1：使用下一代亚硫酸氢盐测序将发现候选DNA甲基化生物标记物 来自CRN患者和正常结肠的匹配组织和血清。 目的2：候选血清甲基化生物标志物将被发现用于区分CRN患者和那些 不含CRN，并使用定量PCR分析验证生物标记物。 目标3：目标2b中确定的优先血清甲基化生物标志物的临床验证将在#年进行 无症状的平均风险个体。 该项目的创新是基于首次使用新的、基于下一代测序的 使用连锁甲基化位点的基因组规模分析来识别基于甲基化的生物标志物的方法 到结直肠肿瘤，并用一个大的、特征良好的 CRN患者和对照组的队列。这个项目的长期目标和潜在影响是开发一个 灵敏、特异、无创、廉价的早期大肠肿瘤诊断试验。

PROJECT SUMMARY: Colorectal carcinoma (CRC) is the third most common cancer in the United States, with an estimated 150,000 new cases occurring annually. Early detection of clinically relevant colorectal neoplasia (CRN), i.e., CRC and advanced colorectal adenomas (A-CRA), is the best way to improve survival. However, available screening modalities are impractical due to invasiveness and cost (i.e., colonoscopy) or insufficient diagnostic accuracy (i.e., fecal-based blood tests). A better approach to screening and surveillance would be highly desirable. Abnormal DNA methylation is an important epigenetic mechanism that has been strongly implicated in the pathogenesis and progression of colorectal neoplasia. Aberrant DNA methylation is detectable in serum making it an ideal candidate biomarker species for non-invasive screening. Previous studies have achieved limited success in developing definitive sets of methylation biomarkers for CRC screening due non-comprehensive approaches, and a failure to include all CRNs as meaningful targets for clinical discovery. Also, cohorts used in serum-based studies have been insufficiently powered and lacked independent validation sets. In this proposal, innovative strategies will be applied to permit genome-scale methylation mapping using tissues and sera from patients with CRN, and compared with tissues and sera from individuals without CRN. A novel and powerful new approach is being proposed to identify new biomarkers and methylation targets with the highest sensitivity and specificity, and will be validated using large, well- characterized sample sets through the following Specific Aims. Aim 1: Candidate DNA methylation biomarkers will be discovered using next generation bisulfite sequencing in matched tissue and serum from patients with CRN and individuals with a normal colon. Aim 2: Candidate serum methylation biomarkers will be discovered that distinguish patients with CRN vs those without CRN, and validated biomarkers using quantitative PCR assays. Aim 3: Clinical validation of prioritized serum methylation biomarkers identified in Aim 2b will be performed in asymptomatic average risk individuals. The innovation of this project is based upon the first use of a novel, next generation sequencing-based approach for identifying methylation-based biomarkers using a genome-scale assay for methylation sites linked to colorectal neoplasia, and validating these newly discovered biomarkers using a large, well-characterized cohort of patients with CRN and controls. The long-term goal and potential impact of this project is to develop a sensitive, specific, non-invasive and inexpensive diagnostic test for early colorectal neoplasia.