Development of microRNA Biomarkers For Noninvasive Detection of Colorectal Cancer

描述(申请人提供)：结直肠癌(CRC)是一种潜在的可预防的疾病；然而，它仍然是美国第三大常见癌症和第二大癌症相关死亡原因，估计每年有50,000人死亡。早期发现临床相关的大肠肿瘤(CRN)，即CRC和晚期CRA(A-CRA)是提高生存率的最好方法。然而，由于侵袭性和成本(如结肠镜检查)或诊断准确性(如粪便血液检测)不足，现有的筛查方法诊断这些病变是不切实际的。一种更好的筛查和监测方法将是非常可取的，最好是通过有助于早期诊断的非侵入性生物标志物。MicroRNAs(MiRNAs)是一种参与基因调控和癌症发展的非编码小RNA，比较大的RNA更强大和稳定，对组织、血液、粪便和其他体液中的降解具有抵抗力。以前的研究由于不全面的方法，在开发用于CRC筛查的确定的miRNA生物标志物方面取得了有限的成功，并且未能将所有CRN作为临床发现的有意义的靶点。此外，在基于血清的研究中使用的队列一直没有足够的动力，并且缺乏独立的验证集。在这项提案中，包括基于下一代测序(NGS)的miRNA-Seq在内的创新策略将被应用，以允许使用CRN患者的组织和匹配血清进行全基因组miRNA图谱绘制，并与来自非CRN患者的组织和血清进行比较。一种新颖而强大的新方法正在被提出，以识别具有最高灵敏度和特异度的新的miRNA生物标记物，该方法将通过以下特定目标使用大的、特征良好的样本集进行验证。目的1：利用全基因组NGS方法在CRN患者和正常结肠患者的匹配组织和血清样本中发现候选miRNA生物标记物。目的：候选的非侵入性miRNA生物标记物将被开发来区分CRN患者和非CRN患者，并用定量PCR方法进行验证。目的3：目标2b中确定的优先非侵入性miRNA生物标记物的临床验证将在无症状的平均风险个体中进行。该项目的创新基于首次使用基于NGS的新型miRNA-Seq平台，用于发现与大肠肿瘤相关的所有miRNAs和iso-miRNAs的全基因组图谱的生物标记物，并使用大量具有良好特征的CRN患者和对照患者队列进行验证。该项目的长期目标和潜在影响是开发一种敏感、特异、非侵入性和廉价的早期结直肠肿瘤诊断试验。

DESCRIPTION (provided by applicant): Colorectal cancer (CRC) is a potentially preventable disease; however, it still ranks as the third most common cancer and second leading cause of cancer-related deaths in the U.S., with an estimated 50,000 deaths annually. Early detection of clinically relevant colorectal neoplasia (CRN), i.e. CRC and advanced CRAs (A-CRA), is the best way to improve survival. However, available screening modalities to diagnose these lesions 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, preferably through noninvasive biomarkers that can facilitate earlier diagnosis of CRC would be highly desirable. MicroRNAs (miRNAs), small non-coding RNAs involved in gene regulation and cancer development, are more robust and stable than larger RNAs, being resistant to degradation in tissues, blood, stool, and other body fluids. Previous studies have achieved limited success in developing definitive sets of miRNA 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 that include Next Generation Sequencing (NGS)-based miRNA-Seq will be applied to permit genome-wide miRNA mapping using tissues and matching 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 novel miRNA biomarkers with the highest sensitivity and specificity, which will be validated using large, well-characterized sample sets through the following Specific Aims. Aim 1: Candidate miRNA biomarkers will be discovered using genome-wide NGS approaches in matched tissue and serum specimens from patients with CRN and individuals with a normal colon. Aim 2: Candidate non-invasive miRNA biomarkers will be developed that distinguish patients with CRN vs. those without CRN, and validated using quantitative PCR assays. Aim 3: Clinical validation of prioritized non-invasive miRNA 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, NGS-based miRNA-Seq platform for the biomarker discovery of genome-wide profiling of all miRNAs and iso-miRNAs that are linked to colorectal neoplasia, and validating these 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.