Early TP53 Mutations and Genomic Doubling as a Novel Path for Barrett's Esophagus Progression

 描述(申请人提供)：食管肠化，称为巴雷特食道(BE)，被认为是对慢性酸和胆汁反流的反应，具有重要的临床意义，因为它是食管腺癌(EAC)的先兆。BE的发病率相当高，估计至少在1：100人中发现。虽然进展到癌症的人相对较少，但能够发现那些有进展风险的人是非常重要的。到目前为止，在BE患者中筛查高危疾病的努力还没有 非常成功。因此，有必要明确BE进展为EAC的过程，开发生物标志物来诊断BE组织的早期进展并评估进展风险。这项有指导的研究生涯发展建议的目的是调查Barrett食道进展的分子基础，长期目标是开发更好的筛查策略和生物标记物，以在早期可治愈阶段识别进展风险的人。为了确定BE进展中的关键改变发生的时间和地点，将进行激光捕获显微解剖和组织学定义的BE、异型增生和EAC区域的测序。然后将在体外和体内环境中对这些变化进行建模，以确定它们的功能意义。酸和胆汁暴露对疾病进展的作用以及这些暴露如何与基因改变相互作用将使用相同的模型系统进行研究。这些研究涵盖广泛的学科，包括胃肠病理学、Barrett‘s生物学、大规模平行测序/遗传学以及体外和体内(小鼠)模型开发，这些研究将有助于定义BE的进展过程，并通过以下特定目标提供全面的职业发展途径，以成为一名独立的研究人员：目标1：确定与异型增生和其他基因组变化的开始相关的Barrett食道进展中TP53突变和基因组加倍的时间。目的：在体外和体内Barrett‘s食道模型中验证TP53突变促进基因组倍增、非整倍体和癌基因扩增导致肿瘤转化的假说。目的：探讨酸性pH和胆盐暴露对Barrett‘s上皮病变的影响。这位职业发展奖候选人是医学博士/博士，拥有解剖学和分子遗传学方面的董事会认证。这项拨款申请中提出的研究将在达纳-法伯癌症研究所和波士顿布里格姆妇女医院的Massimo Loda博士和Adam Bass博士的共同指导下进行。这位候选人致力于内科科学家的职业生涯，并寻求进一步的培训，以促进他过渡到NIH资助的胃肠道疾病领域的独立研究员。

 DESCRIPTION (provided by applicant): Intestinalization of the esophagus, termed Barrett's esophagus (BE), is thought to develop in response to chronic acid and bile reflux and carries great clinical significance because it is the precursor to esophageal adenocarcinoma (EAC). The incidence of BE is quite high, estimated to be found in at least 1:100 people. While relatively few with BE progress to cancer there is great importance to being able to detect those at risk of progression. Efforts to screen for high risk disease in those with BE have, to date, not been very successful. Therefore, there is profound need to define the process by which BE progresses into EAC, to develop biomarkers to diagnose early progression and assess progression risk in BE tissues. The objective of this mentored research career development proposal is to investigate the molecular underpinnings of Barrett's esophagus progression with the long term goal to develop better screening strategies and biomarkers to identify those at risk of progression at an early curable stage. To determine when and where key alterations in BE progression occur, laser capture microdissection and sequencing of histologically defined areas of BE, dysplasia, and EAC will be performed. These alterations will then be modeled in both an in vitro and in vivo setting to determine their functional significance. The role of acid and bile exposure to BE progression and how these exposures interact with genetic alterations will be investigated using the same model systems. These research studies encompass a wide array of disciplines including gastrointestinal pathology, Barrett's biology, massively parallel sequencing/genetics, and in vitro and in vivo (mouse) model development, which together will help define the process of BE progression as well as provide a well-rounded career development pathway to becoming an independent investigator through the following specific aims: Aim 1: To define the timing of TP53 mutations and genomic doubling in Barrett's esophagus progression relative to onset of dysplasia and acquisition of other genomic alterations. Aim 2: To test the hypothesis in in vitro and in vivo models of Barrett's esophagus that TP53 mutations facilitate acquisition of genomic doubling, aneuploidy, and oncogene amplification leading to neoplastic transformation. Aim 3: To determine the effect of acidic pH and bile salt exposure on Barrett's epithelial progression. This career development award candidate is a M.D./Ph.D. with board certification in anatomic and molecular genetic pathology. The research proposed in this grant application will be conducted under the co- mentorship of Drs. Massimo Loda and Adam Bass at Dana-Farber Cancer Institute and Brigham and Women's Hospital in Boston. The candidate is committed to a career as a physician scientist and seeks further training to facilitate his transition to become a NIH-funded independent investigator in the field of gastrointestinal disease.