Inducible colon-specific transgenic mouse for cancer research

用于癌症研究的诱导性结肠特异性转基因小鼠

• 批准号: 8246227
• 负责人: James C. Fleet
• 金额: $ 16.27万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-16 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8246227
• 关键词: APC gene; Aberrant crypt foci; Address; Adult; Affect; Affinity; Alleles; Animal Model; Automobile Driving; Biology; Birth; Cancer Etiology; Cancer Model; Carcinogenesis Mechanism; Cecum; Colon; Colon Carcinoma; Core Facility; Crohn' s disease; Development; Diagnosis; Dietary Factors; Disease; Distal; Drug or chemical Tissue Distribution; Embryo; Environmental Risk Factor; Epithelial Cells; Epithelium; Estrogen Analogues; Estrogen Receptors; Etiology; Gene Mutation; Genes; Goals; Health; Hereditary Malignant Neoplasm; Human; Hyperplasia; Incidence; Induced Mutation; Inflammation; Inflammatory; Intestines; Knockout Mice; Knowledge; Large Intestine; Learning; Life; Ligand Binding Domain; Location; Malignant Neoplasms; Modeling; Modification; Molecular; Molecular Profiling; Mus; Mutation; Normal tissue morphology; Nuclear; Prevention; Prevention strategy; Research; Research Personnel; Rodent Model; Scientist; Sodium Dextran Sulfate; Staging; Surface; Syndrome; Tamoxifen; Testing; Therapeutic Agents; Time; Tissues; Transgenes; Transgenic Animals; Transgenic Mice; Transgenic Model; Work; animal model development; anticancer research; base; cancer prevention; cancer therapy; carbonate dehydratase; disorder risk; effective therapy; flexibility; fusion gene; improved; interest; mouse genome; mouse model; programs; promoter; recombinase; transgene expression; treatment strategy; tumor; vector

DESCRIPTION (provided by applicant): Over the past 20 years our understanding of the molecular etiology of colon cancer has expanded dramatically. Despite this, colon cancer remains a significant health problem in the US. One of the barriers to progress in the field is the lack of well-characterized animal models that recapitulate the etiology of human colon cancer. While we have learned a great deal from cancers resulting from various chemically induced- or genetically programmed-rodent models, the cancer that develops in these models is often significantly different from human colon cancer in terms of latency, intestinal location, or molecular signature. Mechanistic and prevention focused colon cancer research requires the development of animal models that permit precisely timed, colon-specific modification of intestinal biology. Our goal for the proposed research is to use the promoter that drives large intestine-specific expression of the carbonic anhydrase 1 (CA1) gene to create a transgenic mouse with colon-epithelial cell-specific expression of Cre recombinase (Cre)-fused to a modified estrogen receptor (ER) ligand binding domain with high affinity only for the estrogen analog tamoxifen (CAC- ERT2). The ERT2 portion of the fusion gene confers taxomifen-inducibility to the transgene and permits temporally controlled deletion of floxed alleles in the mouse genome. A transgene vector has been produced and it will be used to produce mice at the Purdue Transgenic Mouse Core Facility. Transgene expression level and tissue distribution will be assessed by PCR. Inducibility of transgene function by tamoxifen will be assessed after crossing the CAC-ERT2 mouse to the ROSA26R indicator mouse. The ability of tamoxifen to induce tumor formation will be assessed in CAC-ERT2 mice crossed to mice with one or two floxed APC alleles. Additional studies will be done in the presence of colonic inflammation induced by dextran sulfate sodium (DSS). Upon completion of the project, the CAC-ERT2 mouse will be the only transgenic model that both limits Cre expression to the epithelial cells of the large intestine and permits control over when Cre functions to delete floxed alleles. This will permit colon cancer researchers to easily combine genetic mutations (i.e. with multiple floxed alleles relevant to colon cancer etiology) and initiate colon cancer at any stage of life. This will permit more careful assessment of mechanisms of carcinogenesis and improved testing of chemopreventative or therapeutic agents in adult mice. While our interests are in using this model for colon cancer, this model will also be useful for researchers interested in inflammatory conditions of the lower bowel (i.e. IBD, Crohn's disease). 1 PUBLIC HEALTH RELEVANCE: Colon cancer is a common form of cancer in the US and scientists. Research to develop effective treatment and prevention strategies is hampered by the lack of animal models that reproduce the features of human sporadic colon cancer. Our proposed research will create a new genetically modified mouse model that overcomes the limitations of existing animal models for colon cancer research.

描述（由申请人提供）：在过去的20年中，我们对结肠癌分子病因的理解已大大扩展。尽管如此，在美国，结肠癌仍然是一个重大的健康问题。该领域进步的障碍之一是缺乏特征良好的动物模型，这些模型概括了人类结肠癌的病因。尽管我们从各种化学引起的或遗传编程的循环模型中从癌症那里学到了很多东西，但在这些模型中发展的癌症通常与人类结肠癌在潜伏期，肠道位置或分子签名方面显着不同。以机械性和预防为重点的结肠癌研究需要开发动物模型，这些模型允许精确定时，结肠特定的肠生物学修饰。我们提出的研究的目标是使用启动子，该启动子驱动碳酸酐酶1（CA1）基因的大肠特异性表达，以创建具有CRE重新组合酶（CRE）的结肠上皮细胞特异性表达的转基因小鼠，用于依靠雌激素受体（ER）coardifitor（ER）coardiftif domain（ER）coardiftif the Expogengen（ER）coptif to andif the Extrif the Expogentif（ER）的coctif（ER）。 ERT2）。融合基因的ERT2部分赋予了对转基因的分类素诱导性，并允许在小鼠基因组中暂时控制的floxed等位基因的缺失。已经产生了转基因载体，它将用于在普渡（Purdue）的转基因小鼠核心设施上产生小鼠。转基因表达水平和组织分布将通过PCR评估。将他莫昔芬转基因功能的诱导性将在将CAC-ERT2小鼠与ROSA26R小鼠携带后评估。他莫昔芬诱导肿瘤形成的能力将在与一个或两只Floxed APC等位基因的小鼠交叉的CAC-ERT2小鼠中进行评估。在存在硫酸葡萄糖钠（DSS）诱导的结肠炎症的情况下，将进行其他研究。项目完成后，CAC-ERT2小鼠将是唯一将CRE表达限制为大肠上皮细胞的唯一转基因模型，并允许CRE何时删除Flox的等位基因。这将使结肠癌研究人员可以轻松地结合遗传突变（即与与结肠癌病因相关的多个Floxed等位基因），并在生命的任何阶段启动结肠癌。这将允许对成年小鼠的癌变机制以及改进化学预防剂或治疗剂的测试进行更仔细的评估。尽管我们对使用该模型进行结肠癌的兴趣，但该模型也将对对肠道炎症状况感兴趣的研究人员（即IBD，克罗恩病）有用。 1 公共卫生相关性：结肠癌是美国和科学家的一种常见癌症形式。缺乏重现人类零星结肠癌特征的动物模型，阻碍了制定有效治疗和预防策略的研究。我们提出的研究将创建一种新的转基因小鼠模型，以克服现有动物模型对结肠癌研究的局限性。