The Role of t-Darpp in Esophageal Adenocarcinoma

t-Darpp 在食管腺癌中的作用

• 批准号: 7737986
• 负责人: WAEL EL-RIFAI
• 金额: $ 23.25万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-13 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7737986
• 关键词: Adenocarcinoma; Adopted; Apoptosis; Apoptotic; Arts; Automobile Driving; Biological; Biological Process; Butyrates; Camptothecin; Cancer Etiology; Cancer cell line; Cell Death; Cell Survival; Cells; Ceramides; Cessation of life; Classification; Cloning; Complex; DARPP; Data; Diagnostic; Dopamine- and cAMP-regulated neuronal phosphoprotein; Doxycycline; Drug resistance; Esophageal; Esophageal Adenocarcinoma; Foundations; Gene Combinations; Gene Targeting; Gleevec; In Vitro; Incidence; Malignant Neoplasms; Malignant neoplasm of gastrointestinal tract; Mediating; Mitochondria; Molecular; Names; Normal tissue morphology; Oncogenes; PIK3CG gene; PTEN gene; Pathway interactions; Pharmaceutical Preparations; Phosphorylation; Phosphorylation Site; Population; Preventive; Protein Isoforms; Proteins; Proteomics; Proto-Oncogene Proteins c-akt; Relative (related person); Reporting; Roche brand of trastuzumab; Role; Signal Pathway; Signal Transduction; Stomach; Survival Rate; Testing; Therapeutic; Tumor Suppressor Genes; Tumor Suppressor Proteins; United States; Up-Regulation; Western World; addiction; base; cancer cell; carcinogenesis; functional outcomes; gastroesophageal junction adenocarcinoma; gastrointestinal; improved; in vivo; innovation; insight; mutant; new therapeutic target; novel; overexpression; public health relevance; research study; response; tumor; tumor growth

DESCRIPTION (provided by applicant): The incidence of upper gastrointestinal adenocarcinomas (UGCs; adenocarcinomas of the esophagus and stomach) has been rising steadily. Moreover, a sharp increase in the incidence of lower esophageal and gastroesophageal junction adenocarcinomas has been observed over the past three decades bearing the distinction of the fastest rising incidence of all cancers in the Western world. Overall relative 5-year survival rates are currently less than 20%. Improvement in our presently limited diagnostic, preventive, and therapeutic approach to UGCs is currently a pressing issue. This proposal is based on our original findings through the use of multiple molecular analyses in UGCs that led to the cloning and identification of t-DARPP as a novel cancer gene. We found over-expression of t-DARPP in approximately two-thirds of UGCs and analysis of its biological functions indicated that t-DARPP is a potent pro-survival protein. Using several drugs (camptothecin, butyrates, ceramides) we found that t-DARPP protects cancer cells against drug-induced cell death by a mechanism that includes activation of AKT survival pathway and up-regulation of BCL-2. We hypothesize that t-DARPP provides critical potent pro-survival and anti-apoptotic advantages to cancer cells leading to resistance to drug- induced cell death. We plan to investigate the molecular and biological roles of t-DARPP and determine the potential therapeutic value of its knockdown in UGCs. In Aim 1 of this proposal, we will investigate the molecular mechanism(s) by which t-DARPP phosphorylation sites regulate the AKT survival pathway. Based on our preliminary data, we will investigate the mechanisms by which t-DARPP regulates the PTEN tumor suppressor activity, localization, and stability in cancer cells. In Aim 2, we plan to investigate the effect of t- DARPP on drug resistance by testing its ability to abrogate drug-induced cell death. We will examine the role of t-DARPP in regulating the complex intrinsic apoptosis. Several recent reports suggest the oncogene addiction concept in cancer cells, where cancer cell survival becomes dependent on the expression of a critical survival protein. We will test the therapeutic potential of t-DARPP knockdown in vivo and whether its knockdown alone or in combination with the existing chemotherapeutics can boost the therapeutic response. In Aim 3, we will adopt powerful proteomic approaches for a systematic characterization of proteins that interact with t-DARPP and those that are downstream effectors in order to identify novel signaling pathways and biological functions that t-DARPP could mediate in cancer cells that remain unknown. In all our experiments, we will test its phosphorylation mutants in order to characterize the molecular and functional role(s) of each of these phosphorylation sites in cancer cells. We anticipate that completion of the suggested experiments will provide a significant insight into the role of t-DARPP, as a novel protein, in upper gastrointestinal adenocarcinomas. PUBLIC HEALTH RELEVANCE: This proposal connects in vitro and in vivo experiments in order to characterize the role(s) of t-DARPP in upper gastrointestinal carcinogenesis. We plan to investigate the role of t-DARPP in regulating the intrinsic apoptosis and evaluate its potential as a novel therapeutic target. State-of-the-art proteomic approaches will be employed to identify t-DARPP interacting proteins as well as its molecular signaling targets.

描述（由申请人提供）：上消化道腺癌（UGC；食管和胃腺癌）的发病率一直在稳步上升。此外，在过去三十年中，食管下段和胃食管交界处腺癌的发病率急剧增加，成为西方世界所有癌症中发病率上升最快的。目前总体相对 5 年生存率低于 20%。改进目前有限的 UGC 诊断、预防和治疗方法是目前的一个紧迫问题。该提议基于我们通过在 UGC 中使用多种分子分析的原始发现，从而克隆并鉴定了 t-DARPP 作为一种新型癌症基因。我们发现 t-DARPP 在大约三分之二的 UGC 中过度表达，对其生物学功能的分析表明 t-DARPP 是一种有效的促生存蛋白。使用多种药物（喜树碱、丁酸盐、神经酰胺），我们发现 t-DARPP 通过激活 AKT 存活途径和上调 BCL-2 等机制，保护癌细胞免受药物诱导的细胞死亡。我们假设 t-DARPP 为癌细胞提供了关键的有效的促生存和抗凋亡优势，从而导致对药物诱导的细胞死亡的抵抗。我们计划研究 t-DARPP 的分子和生物学作用，并确定其敲低在 UGC 中的潜在治疗价值。在本提案的目标 1 中，我们将研究 t-DARPP 磷酸化位点调节 AKT 存活途径的分子机制。根据我们的初步数据，我们将研究 t-DARPP 调节癌细胞中 PTEN 肿瘤抑制活性、定位和稳定性的机制。在目标 2 中，我们计划通过测试 t-DARPP 消除药物诱导的细胞死亡的能力来研究 t-DARPP 对耐药性的影响。我们将研究 t-DARPP 在调节复杂的内在细胞凋亡中的作用。最近的几份报告提出了癌细胞中的癌基因成瘾概念，其中癌细胞的存活变得依赖于关键存活蛋白的表达。我们将在体内测试 t-DARPP 敲低的治疗潜力，以及单独敲低它或与现有化疗药物组合是否可以增强治疗反应。在目标 3 中，我们将采用强大的蛋白质组学方法对与 t-DARPP 相互作用的蛋白质以及下游效应蛋白进行系统表征，以确定 t-DARPP 可能在未知的癌细胞中介导的新信号传导途径和生物功能。在我们所有的实验中，我们将测试其磷酸化突变体，以表征癌细胞中每个磷酸化位点的分子和功能作用。我们预计，完成所建议的实验将为 t-DARPP 作为一种新型蛋白质在上消化道腺癌中的作用提供重要的见解。公共健康相关性：该提案将体外和体内实验联系起来，以表征 t-DARPP 在上消化道癌发生中的作用。我们计划研究 t-DARPP 在调节内在细胞凋亡中的作用，并评估其作为新型治疗靶点的潜力。最先进的蛋白质组学方法将用于鉴定 t-DARPP 相互作用蛋白及其分子信号传导靶标。