Develop and Characterize a Novel Animal Model of Pancreatic Cancer

开发并表征新型胰腺癌动物模型

• 批准号: 8333345
• 负责人: Baoan Ji
• 金额: $ 20.75万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8333345
• 关键词: Acinar Cell; Adult; Animal Model; Automobile Driving; Biology; Breeding; Cell Line; Cells; Child; Development; Disease; Duct (organ) structure; Early Diagnosis; Elderly; Embryo; Embryonic Development; Engineering; Gene Expression; Genes; Genetic; Genetic Models; Human; Human Development; Investigation; K-ras Gene; Malignant neoplasm of pancreas; Modeling; Molecular; Mus; Mutation; Oncogenes; Other Genetics; Pancreas; Pancreatic Ductal Adenocarcinoma; Pancreatic duct; Pancreatic enzyme; Pharmaceutical Preparations; Physiological; Prevention; Regulation; Reporter; Research Personnel; Sampling; Site; Specificity; Specimen; System; TP53 gene; Tamoxifen; Testing; Time; Tissues; Transgenic Mice; Translational Research; Tumor Suppressor Proteins; base; blastomere structure; cancer cell; cancer diagnosis; cell type; clinically relevant; design; human disease; improved; in vitro testing; mouse model; mutant; novel; novel strategies; precursor cell; promoter; success; treatment strategy

DESCRIPTION (provided by applicant): Animal models of pancreatic ductal adenocarcinoma (PDAC) that faithfully mimic the human disease are necessary to allow researchers to develop effective early diagnosis, prevention, and treatment strategies. In recent years, several genetic mouse models of PDAC have been developed and have greatly improved our understanding of its biology. The genetic models in widespread usage today were developed by genetically altering either the embryonic pancreas or the adult cells that produce digestive enzymes, pancreatic acinar cells. That these models faithfully mimic the development of human PDAC is controversial because it is generally felt that in humans this disease develops within a different cell type, duct cells. Furthermore, PDAC is a disease of the elderly and is not found in children. Clearly, a genetic model based on genetical changes in adult pancreatic duct cells would provide an important model for investigation of this disease. Previous attempts to develop pancreatic duct-specific models relying on gene promoters that were duct specific but not pancreas specific (e.g. CK19) have failed because broad expression of oncogenes in all CK19-positive cells is embryonically lethal. In the proposed project, we will develop a mouse model in which gene expression is controlled specifically in adult pancreatic duct cells rather than any other cells. In order to do so, we have developed a novel strategy that uses a combination of two gene promoters that must be activated in tandem. For duct cell specificity, we will use the well-characterized CK19 promoter, which is active in duct cells throughout the body. For pancreatic specificity, we will use the PDX1 promoter, which is expressed in pancreatic precursor cells during embryonic development. We will assemble these promoters in a construct such that the duct cell- specific promoter CK19 is under the control of the pancreas-specific promoter PDX1. To control gene expression temporally, we will utilize our system to express a molecule that can be activated by a drug, tamoxifen. Once induced, this molecular is capable of activating or deleting genes in mice engineered specifically for this purpose, many of which are already available. This model will allow for the first time the specific regulation of pancreatic duct cell gene expression, which is useful for many physiological and pathological studies. Once the pancreatic duct-specific expression system is established, we will use it to activate an oncogene and inhibit a tumor suppressor to mimic the situation commonly found in humans to generate PDAC. Specimens of the PDAC that develops in this model will be compared with those from other genetic mouse models and with the human disease. We expect that this animal model of pancreatic cancer will be more clinically relevant and appropriate for translational research.

描述（由申请人提供）：胰腺导管腺癌（PDAC）的动物模型，即忠实地模仿人类疾病对于允许研究人员发展有效的早期诊断，预防和治疗策略是必要的。近年来，已经开发了几种PDAC的遗传小鼠模型，并大大提高了我们对其生物学的理解。当今广泛使用中的遗传模型是通过基因改变胚胎胰腺或产生消化酶，胰腺腺泡细胞的成年细胞而开发的。这些模型忠实地模仿了人类PDAC的发展是有争议的，因为通常认为在人类中，这种疾病在不同的细胞类型的导管细胞内发展。此外，PDAC是老年人的一种疾病，在儿童中找不到。显然，基于成年胰管细胞基因变化的遗传模型将为研究该疾病提供重要模型。以前的尝试开发胰管特异性模型的尝试依赖于特异性导管但不是胰腺特异性的基因启动子（例如CK19）的尝试失败了，因为在所有CK19阳性细胞中癌基因的广泛表达都是胚胎致死的。在拟议的项目中，我们将开发一个小鼠模型，其中基因表达在成年胰管细胞而不是任何其他细胞中都专门控制。为此，我们制定了一种新颖的策略，该策略使用了必须串联激活的两个基因启动子的组合。对于管道细胞的特异性，我们将使用特征良好的CK19启动子，该启动子在整个体内的管道细胞中都活跃。对于胰腺特异性，我们将使用PDX1启动子，该启动子在胚胎发育过程中在胰腺前体细胞中表达。我们将在构造中组装这些启动子，以使导管细胞特异性启动子CK19受胰腺特异性启动子PDX1的控制。为了在时间上控制基因表达，我们将利用我们的系统表达可以通过他的他莫昔芬激活的分子。诱导后，该分子能够在专门为此目的设计的小鼠中激活或删除基因，其中许多已经可用。该模型将首次允许胰管细胞基因表达的特定调节，这对于许多生理和病理研究很有用。一旦建立了胰管特异性表达系统，我们将使用它来激活癌基因并抑制肿瘤抑制剂，以模仿人类在人类中产生PDAC的情况。在该模型中开发的PDAC的标本将与其他遗传小鼠模型和人类疾病的标本进行比较。我们预计，这种胰腺癌动物模型将在临床上更相关，适合转化研究。