Clonal Reconstruction and Targeting of the Correa Sequence

项目摘要/摘要 现在公认的是，上皮癌是由癌前病变经过几十年的过程而产生的。 食管腺癌是一种癌症，其发病率自1950年以来增加了5倍，开始于癌前病变。 被称为“Barrett‘s食道”，进展到不典型增生，最终出现恶性食管腺癌 沿着一条与胃腺癌的科雷亚序列平行的路径。作为患者的平均预期寿命 诊断为食管腺癌大约需要一年时间，目前正在做出相当大的努力来确定其 科雷亚序列，特别是其癌前阶段，作为发病前阻断的潜在目标 恶性疾病。为此，我们应用了最初在我们的 实验室用正常人胃肠道干细胞重建早期胃肠道疾病患者的Correa序列 食管腺癌。值得注意的是，这些与患者匹配的Barrett‘s、异型增生和 食管腺癌产生离散的干细胞群体，分别产生肠化生， 不典型增生(但不是肿瘤)，以及移植到免疫缺陷小鼠后的侵袭性腺癌。从一个 近100个独立克隆的详细分子遗传学分析，这些克隆来自Barrett‘s、异型增生和 一位患者的腺癌病变，我们已经能够以前所未有的分辨率重建两种直接的 导致这种肿瘤的系统发育序列，以及在Barrett‘s和异型增生阶段的“死胡同”， 对最终的肿瘤没有贡献。此外，Barrett‘s、异型增生和腺癌的每一个克隆干细胞 病变代表着永久的线，使强大的药物发现方法得以实现，最终导致了线索 选择性地靶向整个Correa序列，同时保留正常的食道干细胞。在三个具体目标中，我们 威尔1.)(1)克隆重建10例早期食管腺癌患者的COREA序列；建立 高通量筛选，包括正常食道和Correa序列干细胞的共培养，以发现铅； 和3.)建立患者相合的正常食道和Correa序列干细胞体内异种移植模型 验证针对这些损伤的铅组合。基于广泛的初步研究，我们预计将分析 这些进行性病变的患者配对干细胞将为食道的演变提供基本的见解 腺癌以及一般的上皮性癌。从填补病人护理方面的重要空白的角度来看， 这些皮损干细胞的药物发现为预防发病提供了有希望的新干预措施 食管腺癌以及那些已经根深蒂固的疾病的治疗。

PROJECT SUMMARY/ABSTRACT It is now well established that epithelial cancers arise in a multi-decade process from precancerous lesions. Esophageal adenocarcinoma, a cancer whose incidence has risen 5-fold since 1950, initiates with precancerous lesions known as “Barrett's esophagus”, progresses to dysplasia, and finally emerges as malignant esophageal adenocarcinoma along a path that parallels the Correa Sequence for gastric adenocarcinoma. As the average life expectancy of patients diagnosed with esophageal adenocarcinoma is approximately one-year, considerable efforts are underway to define its Correa sequence, and especially its pre-malignant stages, as potential targets for interdiction ahead of the onset of malignant disease. Toward this end, we have applied novel stem cell cloning technologies originally developed in our laboratories for normal human gastrointestinal tract stem cells to reconstructing the Correa sequence in patients with early esophageal adenocarcinoma. Significantly, each of these patient-matched endoscopic biopsies of Barrett's, dysplasia, and esophageal adenocarcinoma yields discrete populations of stem cells that respectively yield intestinal metaplasia, dysplasia (but not tumors), and aggressive adenocarcinoma following transplantation to immunodeficient mice. From a detailed molecular genetics analysis of nearly 100 independent clones from across the Barrett's, dysplasia, and adenocarcinoma lesions of one patient, we have been able to reconstruct, at unprecedented resolution, both the direct phylogenetic sequence that led to this tumor as well as identify “dead-ends” at both the Barrett's and dysplasia stages that did not contribute to the final tumor. Moreover, each of the cloned stem cells of Barrett's, dysplasia, and adenocarcinoma lesions represent permanent lines that have enabled powerful approaches to drug discovery that has culminated in leads that selectively target the entire Correa sequence while sparing normal esophageal stem cells. In three specific aims, we will 1.) clonally reconstruct the Correa sequence from 10 patients with early esophageal adenocarcinoma; 2.) establish high-throughput screens involving co-cultures of normal esophageal and Correa sequence stem cells for lead discovery; and 3.) develop in vivo xenograft models of patient-matched normal esophageal and Correa sequence stem cells for validating lead combinations targeting these lesions. Based on extensive preliminary studies, we anticipate the analysis of patient-matched stem cells of these progressive lesions will provide fundamental insights into the evolution of esophageal adenocarcinoma and as well as epithelial cancers in general. From the standpoint of filling important gaps in patient care, the drug discovery enabled by these sets of lesional stem cells offers promising and novel interventions to prevent to onset of esophageal adenocarcinoma as well as ones to address disease that has already taken hold.