SOX4-Mediated Transcription Program in Esophageal Adenocarcinoma

摘要/总结 食管腺癌（EAC）的发病率在过去的三十年中增加了600%。治疗 然而，选择是有限的，特别是对于晚期诊断的EAC。因此，确定新的 治疗目标是必要的，以改善总体令人沮丧的5年生存率不到15%。这 该提案是P01计划的一个组成部分，该计划的重点是识别机械脆弱性，同时提供 EAC治疗的潜在疗法。该申请将直接解决新的分子机制， 控制从干细胞到腺癌起始细胞的转变，并且其抑制具有潜在的 阻止EAC的发展。长期反流，其中酸性胆汁盐异常反流到下 食管与Barrett食管（BE，也称为肠源性食管）的发病率密切相关。 化生），一种被认为是EAC前体的实体。我们实验室和其他机构的研究表明， 干/祖细胞的恶性转化是食管癌发生的关键机制， 入会仪式在EAC的情况下，我们已经确定了新的过渡性基底细胞（TBCs）位于 食管-胃交界处（EGJ）能够在Cdx 2过表达时产生Barrett食管。我们 初步数据显示，在延长Cdx 2过表达和胆汁酸刺激后， 倒流然而，驱动干细胞转化和癌症维持的基因调控程序， 仍然难以捉摸我们发现SOX 4转录因子在小鼠EAC模型中高度表达， 人类EAC活检。SOX 4蛋白水平的降低与癌症生长的减少有关。使用 结合RNA-Seq、ChIP-Seq和靶向RNAi筛选，我们鉴定了EGFR和ELF 3作为潜在的 在肿瘤发展中介导SOX 4功能的下游靶点。因此，我们假设SOX 4是 这对于EAC的启动和维持至关重要，抑制以SOX 4为中心的信号传导可能是 用于EAC治疗中的治疗增益。我们的研究与本P01中的其他项目结合良好 我们将测试APE 1氧化还原功能和isolevuglandin蛋白加合物在调节SOX 4中的作用。我们 我们设计了三个目标来验证这一假设：（1）确定SOX 4在EAC发育中的作用;（2） 以检验SOX 4在EAC中转录调节EGFR和ELF 3的假设;以及（3）确定 在EAC治疗中S 0X 4抑制的治疗作用。我们将使用多种小鼠模型（例如，SOX 4增益- 和功能丧失）与类器官和患者来源的异种移植模型组合以解决这些目标， 测试通过无偏筛选确定的两种候选药物。我们的研究将提供新的见解， EAC启动和进展的细胞和分子机制，促进 致命EAC的新疗法的发展。

ABSTRACT/SUMMARY The incidence of esophageal adenocarcinoma (EAC) has increased 600% in the last three decades. Treatment options, however, are limited, especially for EACs diagnosed at the late stages. Thus, identifying new therapeutic targets is necessary to improve the overall dismal 5-year survival rate of less than 15%. This proposal is an integral part of a P01 Program focused on identifying mechanistic vulnerability while providing potential therapy for EAC treatment. This application will directly address novel molecular mechanisms that control the transition from stem cells to adenocarcinoma-initiating cells and whose inhibition has the potential to block EAC development. Prolonged reflux where acidic bile salts abnormally refluxate into the lower esophagus is closely associated with the incidence of Barrett’s esophagus (BE, also known as intestinal metaplasia), an entity considered as the precursor to EAC. Studies from our lab and others have shown that malignant transformation of stem/progenitor cells is a critical mechanism that occurs during esophageal cancer initiation. In the case of EAC, we have identified that the novel transitional basal cells (TBCs) located at the esophageal-gastric junction (EGJ) are able to generate Barrett’s esophagus upon Cdx2 overexpression. Our preliminary data show that EAC develops at the EGJ following prolonged Cdx2 overexpression and bile acid reflux. The genetic regulatory program that drives stem cell transformation and cancer maintenance, however, remains elusive. We found that SOX4 transcription factor is highly expressed in mouse EAC models and human EAC biopsies. Decreased levels of SOX4 protein are associated with reduced cancer growth. Using a combination of RNA-Seq, ChIP-Seq, and targeted RNAi screening, we identified EGFR and ELF3 as potential downstream targets mediating SOX4 function in tumor development. Therefore, we hypothesize that SOX4 is critical for EAC initiation and maintenance and that suppressing SOX4-centered signaling can be utilized for therapeutic gains in EAC treatment. Our studies integrate well with other projects in this P01 and we will test the roles of APE1 redox function and isolevuglandin protein adducts in regulating SOX4. We have designed three aims to test this hypothesis: (1) To determine the role of SOX4 in EAC development; (2) to test the hypothesis that SOX4 transcriptionally regulates EGFR and ELF3 in EAC; and (3) to determine the therapeutic role of SOX4 inhibition in EAC treatment. We will use multiple mouse models (e.g., SOX4 gain- and loss-of-function) combined with organoid and patient-derived xenograft models to address these aims and test two candidate drugs identified through an unbiased screen. Our studies will provide novel insights into the cellular and molecular mechanisms underlying the EAC’s initiation and progression, facilitating the development of novel treatments of deadly EAC.