Role of IL-6/STAT3 Signaling in the Neoplastic Progression of Barrett's Esophagus

IL-6/STAT3 信号转导在 Barrett 食管肿瘤进展中的作用

• 批准号: 8445155
• 负责人: RHONDA F SOUZA
• 金额: --
• 依托单位: VA NORTH TEXAS HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8445155
• 关键词: Address; Adenocarcinoma; Animal Model; Apoptosis; Attention; Automobile Driving; Barrett Esophagus; Barrett' s Adenocarcinoma; Benign; Biological Models; Biopsy Specimen; Blood Vessels; Cancerous; Carcinogenesis Mechanism; Cell Cycle; Cell Line; Cell Proliferation; Cell Survival; Cells; Chronic; Clinical; Colon; Colorectal Cancer; Contact Inhibition; Cytokine Inducible SH2-Containing Protein; Data; Development; Diagnosis; Disease; Epithelial; Epithelial Cells; Esophageal; Esophageal Adenocarcinoma; Esophageal Diseases; Event; Exhibits; Frequencies; Funding; Gastroesophageal reflux disease; Genetic; Growth; Healthcare; Human; Incidence; Inflammation; Inflammatory; Injury; Interleukin-6; Invaded; Longevity; Longitudinal Studies; MAPK3 gene; Malignant - descriptor; Malignant Neoplasms; Messenger RNA; Metaplasia; Metaplastic Cell; Molecular; Molecular Abnormality; Mutation; Neoplasm Metastasis; Neoplasms; Neoplastic Cell Transformation; Non-Malignant; Normal Cell; Oncogenic; Organ; PIAS3 Gene; PTPN11 gene; Pathway interactions; Patients; Peptic Esophagitis; Phenotype; Physiological; Physiology; Play; Population; Premalignant Cell; Prevention; Prevention strategy; Process; Protein Secretion; Protein Tyrosine Phosphatase; Proteins; Regulatory Pathway; Research; Risk Factors; Role; STAT3 gene; Series; Signal Pathway; Signal Transduction; Staging; Structure; T-Lymphocyte; Telomerase; Time; Tissues; Transformed Cell Line; Tumorigenicity; Veterans; abstracting; angiogenesis; base; cancer cell; carcinogenesis; cell growth; cell transformation; colon carcinogenesis; cytokine; in vitro Model; in vivo; migration; mutant; neoplastic; neoplastic cell; prevent; promoter; protein inhibitors of activated STAT; public health relevance; species difference; therapy development; transcription factor; treatment strategy; tumor; tumor microenvironment; tumor progression

DESCRIPTION (provided by applicant): Project Summary/Abstract Gastroesophageal reflux disease and Barrett's esophagus, common disorders in Veteran patients, are the major risk factors for esophageal adenocarcinoma, a lethal tumor whose frequency has increased more than six-fold in the past few decades. The development of therapies to prevent or cure this lethal tumor has been hampered by limited understanding of the molecular events underlying the neoplastic progression of Barrett's metaplasia. During carcinogenesis in Barrett's esophagus, genetic alterations accumulate that enable the cells to provide their own growth signals, avoid growth inhibitory signals, resist apoptosis, replicate without limit, synthesize new blood vessels, invade adjacent organs and metastasize. These physiologic "hallmarks" of cancer, which were described by Hanahan and Weinberg in 2000, can be acquired by normal cells through disruptions in surprisingly few key growth regulatory pathways. Recently, cancer-related inflammation has been proposed as another physiologic hallmark of cancer that can be established through two pathways: 1) an extrinsic pathway in which disorders such as reflux esophagitis cause tissue inflammation that contributes to carcinogenesis, and 2) an intrinsic pathway in which the precancerous cells acquire genetic abnormalities that produce an inflammatory tumor microenvironment. Both pathways can converge on certain key downstream targets such as IL-6, a potent inflammatory cytokine that is known to promote cellular growth, and STAT3, a transcription factor that has a key role in IL-6 signal transduction. Chronic esophageal inflammation due to reflux esophagitis is widely regarded as the extrinsic pathway for promoting carcinogenesis in Barrett's esophagus, but little attention has been directed at the intrinsic inflammatory pathway and the role of IL-6/STAT3 signaling in the malignant progression of Barrett's metaplasia. Studies on the early molecular events that transform Barrett's metaplasia into adenocarcinoma have been hampered by the lack of appropriate model systems. During our last cycle of Merit Review funding, we addressed this deficiency by establishing cultures of non- neoplastic Barrett's epithelial (BAR-T) cells that we immortalized through the forced expression of telomerase. Using a combination of p53 knockdown and forced expression of oncogenic H- RasG12V, we have induced the malignant transformation of those BAR-T cells and, in the process, established a series of Barrett's epithelial cell lines with well defined genetic alterations representing various stages in the transition from benign Barrett's metaplasia to cancer. Our preliminary data demonstrate that the transformed Barrett's cells express IL-6 mRNA and exhibit a significant increase in IL-6 protein secretion. Moreover, we have found that IL-6 signaling causes an increase in phospho-STAT3 levels in the transformed cells, and that activation of the IL-6/STAT3 pathway endows the cells with the ability to resist apoptosis and to secrete angiogenesis-promoting factors. We propose to use our unique series of Barrett's epithelial cell lines to explore the role of the IL-6/STAT3 pathway in driving the malignant transformation of Barrett's esophagus. We hypothesize that activation of the IL-6/STAT3 signaling pathway plays a key role in driving the neoplastic transformation of Barrett's metaplasia. Based on our preliminary data, the objectives of our study are to delineate the mechanism(s) whereby p53 inactivation and Ras activation result in activation of the IL-6/STAT3 signaling pathway in Barrett's epithelial cells, to determine the effects of activation and inactivation of the IL-6/STAT3 pathway on the level of neoplastic transformation in Barrett's cell lines, and to correlate p53 inactivation and Ras pathway activation with the activation of the IL-6/STAT3 pathway during the neoplastic progression of Barrett's esophagus in vivo using biopsy specimens from patients with non- dysplastic Barrett's esophagus, dysplastic Barrett's esophagus (low-grade and high-grade), and Barrett's adenocarcinoma.

描述（由申请人提供）： 项目摘要/摘要胃食管反流病和巴雷特食管是退伍军人患者的常见疾病，是食管腺癌的主要危险因素，食管腺癌是一种致命的肿瘤，其发病率在过去几十年中增加了六倍多。由于对巴雷特化生肿瘤进展的分子事件了解有限，预防或治愈这种致命肿瘤的疗法的开发受到阻碍。 在巴雷特食管癌变过程中，基因改变不断积累，使细胞能够提供自己的生长信号，避免生长抑制信号，抵抗细胞凋亡，无限制复制，合成新血管，侵入邻近器官并转移。 Hanahan 和 Weinberg 在 2000 年描述了癌症的这些生理“标志”，正常细胞可以通过破坏极少的关键生长调节途径来获得这些标志。最近，癌症相关炎症被认为是癌症的另一个生理标志，可以通过两种途径建立：1）外在途径，其中反流性食管炎等疾病引起组织炎症，从而促进癌变；2）内在途径，癌前细胞获得遗传异常，产生炎症性肿瘤微环境。这两种途径都可以汇聚到某些关键下游靶标，例如 IL-6（一种已知可促进细胞生长的强效炎症细胞因子）和 STAT3（一种在 IL-6 信号转导中起关键作用的转录因子）。反流性食管炎引起的慢性食管炎症被广泛认为是促进Barrett食管癌变的外在途径，但很少有人关注内在炎症途径以及IL-6/STAT3信号在Barrett化生恶性进展中的作用。 由于缺乏适当的模型系统，对巴雷特化生转变为腺癌的早期分子事件的研究受到了阻碍。在我们最后一轮的优秀评审资助期间，我们通过建立非肿瘤性巴雷特上皮（BAR-T）细胞培养物来解决这一缺陷，并通过端粒酶的强制表达使这些细胞永生化。通过结合 p53 敲低和致癌 H-RasG12V 的强制表达，我们诱导了这些 BAR-T 细胞的恶性转化，并在此过程中建立了一系列具有明确遗传改变的 Barrett 上皮细胞系，代表了从良性 Barrett 化生到癌症转变的各个阶段。我们的初步数据表明，转化的 Barrett 细胞表达 IL-6 mRNA，并表现出 IL-6 蛋白分泌显着增加。此外，我们发现IL-6信号传导导致转化细胞中磷酸STAT3水平增加，并且IL-6/STAT3途径的激活赋予细胞抵抗凋亡和分泌血管生成促进因子的能力。我们建议使用我们独特的 Barrett 上皮细胞系系列来探索 IL-6/STAT3 通路在驱动 Barrett 食管恶性转化中的作用。 我们假设 IL-6/STAT3 信号通路的激活在驱动 Barrett 化生的肿瘤转化中发挥关键作用。基于我们的初步数据，我们研究的目的是阐明p53失活和Ras激活导致Barrett上皮细胞中IL-6/STAT3信号通路激活的机制，确定IL-6/STAT3通路激活和失活对Barrett细胞系肿瘤转化水平的影响，并将p53与p53相关联。 使用来自非发育不良巴雷特食管、发育不良巴雷特食管（低级别和高级别）和巴雷特腺癌患者的活检标本，研究在体内巴雷特食管肿瘤进展过程中IL-6/STAT3途径的失活和Ras途径激活以及IL-6/STAT3途径的激活。