Inhibition of Reflux-Induced Esophageal Adenocarcinoma by Proanthocyanidins

描述（由申请方提供）：在过去三十年中，食管腺癌（EAC）的发病率增加了500%，导致EAC被确定为美国所有癌症类型中增长最快的癌症。食管癌是一种极其致命的恶性肿瘤，5年生存率始终低于20%。EAC发生率增加的确切原因是一个活跃的研究领域。胃和十二指肠内容物的持续性、症状性、反流，称为胃食管疾病（GERD），与EAC的发展密切相关，并且它是唯一已知的通过刺激细胞增殖和凋亡抵抗的前体病变巴雷特食管（BE）。其他EAC风险因素包括肥胖，动物性饮食以及较小程度的烟草和酒精使用。植物性饮食通常与EAC风险降低有关。因此，本研究项目的长期目标是开发使用标准化富含原花青素的蔓越莓提取物（C-PAC）预防食管腺癌的有效策略。这项临床前研究提案源于我们已发表和初步未发表的结果，这些结果表明，当凋亡和自噬机制有缺陷时，C-PAC通过诱导细胞死亡，经由凋亡、自噬和坏死来降低EAC细胞活力。C-PAC处理还诱导S期延迟，导致G2-M细胞周期停滞，并显著抑制裸鼠中OE 19 EAC异种移植物的生长。尽管有希望的结果支持C-PAC的化学预防性应用，但关于C-PAC诱导细胞死亡的机制仍存在大量知识空白。本申请中提出的研究将告知C-PAC细胞死亡诱导能力中涉及的信号传导机制，利用临床相关的EAC反流诱导啮齿动物模型确定C-PAC预防食管腺癌的体内疗效，并测试新型成像方式。目标1将利用一组经鉴定的食管细胞系，这些细胞系基于病理学、肿瘤抑制基因状态和酸敏感性而不同，以剖析与C-PAC癌症抑制潜力相关的信号通路;正常食管细胞系（HET 1A）、Barrett癌前细胞系将使用C-PAC细胞系（CP-A、CP-B、CP-C、CP-D）和食管腺癌细胞系（FLO-1、JHEso-AD 1、OE 19、OE 33）来评估与C-PAC治疗相关的癌症抑制机制。目的2将着重于评估C-PAC对EAC的化学预防潜力在大鼠食管胃十二指肠吻合术（EGDA）模型，并提高我们对C-PAC在体内潜力的机制的理解。目的3将评估使用一种新的成像技术，并行频域光学相干断层扫描（FDOCT），以检测与癌前病变，生物标志物调制的发展相关的核形态或亚细胞结构的早期变化，并可能检测早期化学预防疗效。拟议研究的积极结果将为将这些临床前发现快速转化为EAC风险增加的队列（包括BE患者或食管发育不良患者）的临床干预奠定基础。

DESCRIPTION (provided by applicant): Esophageal adenocarcinoma (EAC) rates have increased 500% over the last three decades resulting in EAC being identified as the fastest increasing of all cancer types in the US. Esophageal cancer is an extremely deadly malignancy with 5-year survival rates consistently under 20%. The precise reasons for increasing rates of EAC are an active area of investigation. Persistent, symptomatic, reflux of gastric and duodenal contents, known as gastroesophageal disease (GERD), strongly correlate with EAC development and it's only known precursor lesion Barrett's esophagus (BE) via stimulation of cellular proliferation and apoptosis resistance. Other EAC risk factors include obesity, animal-based diets and to a lesser extent tobacco and alcohol use. Plant-based diets have generally been associated with a reduction of risk for EAC. Thus, the long-term goal of this research project is to develop efficacious strategies for the prevention of esophageal adenocarcinoma using a standardized proanthocyanidin rich cranberry extract (C-PAC). This preclinical research proposal stems from our published and preliminary unpublished results demonstrating that C-PAC decreases EAC cell viability by inducing cell death via apoptosis, autophagy and necrosis when apoptotic and autophagy machinery is defective. C-PAC treatment also induces an S-phase delay, causes G2-M cell cycle arrest, and significantly inhibits the growth of OE19 EAC xenografts in nude mice. Despite promising results supporting the chemopreventive application of C-PAC, substantial knowledge gaps remain with regard to the mechanisms of C-PAC-induced cell death. Studies proposed in this application will inform the signaling mechanisms involved in C-PACs cell death-inducing capacity, determine the in vivo efficacy of C-PAC for the prevention of esophageal adenocarcinoma utilizing a clinically relevant reflux-induced rodent model of EAC and test a novel imaging modality. Aim 1 will utilize a panel of authenticated esophageal cell lines that differ based on pathology, tumor suppressor gene status and acid sensitivity to dissect signaling pathways associated with C- PACs cancer inhibitory potential; the normal esophageal cell line (HET1A), Barrett's premalignant lines (CP- A,CP-B,CP-C,CP-D) and esophageal adenocarcinoma lines (FLO-1,JHEso-AD1,OE19,OE33) will be used to access cancer inhibitory mechanisms associated with C-PAC treatment. Aim 2 will focus on assessing the chemopreventive potential of C-PAC against EAC in the rat esophagogastroduodenal anastomosis (EGDA) model and improve our mechanistic understanding of C-PACs in vivo potential. Aim 3 will evaluate the use of a novel imaging technology, parallel frequency-domain optical coherence tomography (FDOCT), to detect early changes in nuclear morphology or sub-cellular structures linked with the development of preneoplasia, biomarker modulation and potentially to detect early chemopreventive efficacy. Positive outcomes of the proposed research will lay the foundation to rapidly translate these preclinical findings to clinical interventions in cohorts at increased risk for EAC, including BE patients or patients with esophageal dysplasia.