Mitochondrial biomarkers for early detection of cancer in ulcerative colitis

描述（由申请人提供）：结肠直肠癌是溃疡性结肠炎（UC）最可怕的并发症之一，溃疡性结肠炎是一种炎症性肠病，在美国影响超过50万人。为了降低癌症发病率和死亡率，患者 UC患者每1-2年进行一次结肠镜检查，以监测癌前发育不良。UC中的肿瘤发生是一个多步骤过程，涉及通过低度异型增生（LGD）、高度异型增生（HGD）和癌症进展。由于UC的异型增生通常是平坦的，难以检测，因此在结肠镜检查时从每10 cm结肠取4象限活检以进行组织学评估。患有HGD或癌症的患者接受结肠切除术。LGD患者接受结肠切除术，如果是多灶性，或每3-6个月重复结肠镜检查，如果是单灶性。这种密集的监测方案是耗时的，昂贵的，并有限的敏感性，以发现发育不良。该系统的局限性由于UC的患病率正在增加而加剧，但UC中癌症进展的风险正在降低。因此，比以往任何时候都更重要的是找到生物标志物来检测谁是癌症高风险患者，以便临床资源可以针对他们，同时减少大多数患者的焦虑和结肠镜检查，而不会增加癌症风险。我们以前已经证明，可以通过分析分子改变来识别有癌症风险的患者，这些分子改变存在于发育异常病灶周围的大的非发育异常区域中，并且通常扩展到涉及整个结肠。然而，以前的生物标志物未能进入临床，因为它们是基于依赖于冷冻活检的技术，而冷冻活检无法大量用于进行必要的验证研究。在这个提议中，我们提出了强有力的初步数据，表明线粒体改变发生在大的，非发育异常领域，发育异常之前，可以检测到福尔马林固定，石蜡包埋（FFPE）活检免疫组化和Nanostring，一种新的技术，允许数字计数的mRNA表达。我们的目标是根据生物标志物开发的EDRN阶段，基于这两种技术开发线粒体生物标志物。第I阶段包括生物标志物的训练，将在Aim 1中通过免疫组织化学对线粒体蛋白进行训练，并在Aim 2中通过Nanostring对线粒体基因表达进行训练。生物标志物将被设计为通过仅分析来自患有HGD或癌症（进展者）的UC患者和无异型增生（非进展者）的UC患者的3-6个随机结肠活检来检测结肠中其他部位HGD或癌症的存在。在目标3中，我们将在一组独立的患者中验证生物标志物。在目标4中，我们将测试生物标志物预测非异型增生或LGD活检患者进展为BGR的能力。这些研究可能会产生一个有用的和急需的UC癌症风险的生物标志物，它可以由其他小组使用档案FFPE材料复制，以完成其验证和快速翻译到临床。

DESCRIPTION (provided by applicant): Colorectal cancer is one of the most feared complications of ulcerative colitis (UC), an inflammatory bowel disease that affects more than half a million individuals in the United States. To reduce cancer morbidity and mortality, patients with UC undergo colonoscopies every 1-2 years to monitor precancerous dysplasia. Tumorigenesis in UC is a multistep process that involves progression through low-grade dysplasia (LGD), high-grade dysplasia (HGD), and cancer. Because dysplasia in UC is often flat and difficult to detect, 4-quadrant biopsies from every 10cm of colon are taken at colonoscopy to be histologically evaluated. Patients with HGD or cancer undergo colectomy. Patients with LGD undergo colectomy, if multifocal, or repeated colonoscopies every 3-6 months, if unifocal. This intensive surveillance protocol is time-consuming, expensive, and of limited sensitivity to find dysplasia. The limitations of this system are aggravated by the fact that the prevalence of UC is increasing, but the risk of cancer progression in UC is decreasing. Thus, it is more crucial than ever to find biomarkers to detect who are the patients at high risk of cancer, so that clinical resources can be directed to them, while reducing anxiety and colonoscopies for the majority of patients without increased cancer risk. We have previously demonstrated that the patients at risk of cancer can be identified by analyzing molecular alterations that are present in large, non-dysplastic fields that surround dysplastic foci and often expand to involve the whole colon. Previous biomarkers, however, failed to reach the clinic because they were based on techniques that rely on frozen biopsies, which are not available in large numbers to perform the necessary validations studies. In this proposal, we present strong preliminary data that demonstrates that mitochondrial alterations occur in large, non-dysplastic fields that precede dysplasia, and can be detected in formalin-fixed, paraffin-embedded (FFPE) biopsies by immunohistochemistry and Nanostring, a novel technology that allows digital counting of mRNA expression. Our goal is to develop mitochondrial biomarkers based on these two techniques according to the EDRN phases for biomarker development. Phase I consists on the training of the biomarker and it will be performed for mitochondrial proteins by immunohistochemistry in Aim 1 and for mitochondrial gene expression by Nanostring in Aim 2. The biomarkers will be designed to detect the presence of HGD or cancer elsewhere in the colon by analyzing only 3-6 random colon biopsies from UC patients with HGD or cancer (Progressors) and UC patients dysplasia-free (Non Progressors). In Aim 3, we will validate the biomarkers in an independent set of patients. In Aim 4 we will test the ability of the biomarkers to predict progression to cancr in patients with non-dysplastic or LGD biopsies. These studies are likely to produce a useful and much needed biomarker of cancer risk in UC, which could be replicated by other groups using archival FFPE material in order to complete its validation and quick translation to the clinic.