A Mouse Model for Dietary Effects on Epigenetic Silencing

饮食对表观遗传沉默影响的小鼠模型

• 批准号: 7738680
• 负责人: MITCHELL S TURKER
• 金额: $ 16.94万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7738680
• 关键词: A Mouse; Affect; Animal Model; Binding; Biological Assay; Broccoli - dietary; Canned Foods; Cell Culture Techniques; Cell Fraction; Cells; Code; Diet; Doxycycline; Epigenetic Process; Food; Frequencies; Gene Expression; Gene Silencing; Gene Targeting; Genetic Transcription; Goals; Histone Deacetylase; Histone Deacetylase Inhibitor; Histone Deacetylation; Histone deacetylase inhibition; Incidence; Lead; Link; Malignant Neoplasms; Mediating; Messenger RNA; Modeling; Mouse Strains; Mus; Outcome; Pathway interactions; Play; Prevention; Prevention strategy; Proteins; Repression; Role; Somatic Cell; Sulforaphane; Testing; Tetracyclines; Time; Tissues; Transgenic Mice; Tumor Suppressor Genes; Tumor-Suppressor Gene Inactivation; Work; cancer prevention; design; dietary supplements; drinking water; feeding; gene repression; in vivo; inhibitor/antagonist; mouse model; prevent; promoter; public health relevance; research study; tool

DESCRIPTION (provided by applicant): Epigenetic silencing plays a major role in cancer formation because it leads to aberrant inactivation of tumor suppressor genes. Therefore, a fundamental goal for cancer prevention is to inhibit aberrant silencing in somatic cells. Diet provides a potential tool to help reduce cancer incidence because some food components affect epigenetic processes. However, whether diet can prevent aberrant silencing is not known, in part because animal models to study silencing are not available. Thus, approaches to determine if specific foods, or mixtures of foods, can prevent aberrant silencing in vivo are not possible at this time. The goal of this R21 application is to create a mouse model of inducible silencing and then use the model to demonstrate dietary inhibition of silencing. Two specific aims are proposed. The first is to create a transgenic mouse strain in which silencing of a target gene promoter is induced when transcription is repressed to low levels. This mouse model will contain a doxycycline (Dox) repressible promoter linked to the selectable mouse Aprt coding region. Promoter repression will be achieved by placing Dox in the mouse drinking water, which will lead to gene silencing in cells in a variety of mouse tissues. Silencing will be detected with an assay that identifies cells that are Aprt deficient and correlated with promoter repression. Prevention of histone deacetylation at the target promoter inhibits the Dox-mediated reduction in mRNA levels and resultant silencing. Therefore, the second aim will demonstrate that a mouse diet containing broccoli sprouts, which are enriched for a histone deacetylase inhibitor, will prevent both the reduction of mRNA levels and the induction of silencing in mouse tissues. Successful completion of these aims will establish that diet can prevent epigenetic silencing in vivo and provide an animal model to explore this relationship in a variety of experimental contexts. PUBLIC HEALTH RELEVANCE: Diet can play a major role in increasing or decreasing cancer incidence, but the mechanisms by which it does so remain to be determined. One pathway for cancer formation is epigenetic silencing of tumor suppressor genes. The goal of this application is to create a mouse model for inducible gene silencing and then demonstrate that a diet enriched with a compound that can inhibit an epigenetic process can also inhibit epigenetic silencing.

描述（由申请人提供）：表观遗传沉默在癌症形成中起主要作用，因为它导致肿瘤抑制基因的异常失活。因此，预防癌症的基本目标是抑制体细胞中异常的沉默。饮食提供了一种潜在的工具来帮助减少癌症发病率，因为某些食物成分会影响表观遗传过程。但是，尚不清楚饮食是否可以防止异常的沉默，部分原因是要研究沉默的动物模型不可用。因此，目前无法确定特定食物或食物混合物是否可以防止异常沉默的方法。该R21应用的目的是创建一个可诱导沉默的小鼠模型，然后使用该模型来证明对沉默的饮食抑制。提出了两个具体目标。首先是创建一个转基因小鼠菌株，在该菌株中，当转录被抑制至低水平时，诱导靶基因启动子的沉默。该鼠标模型将包含链接到可选鼠标APRT编码区域的强力霉素（DOX）抑制启动子。通过将DOX放置在小鼠饮用水中，可以实现启动子的抑制，这将导致各种小鼠组织中的细胞中的基因沉默。将通过一种测定法检测到沉默，该测定法可以识别出APRT缺乏且与启动子抑制相关的细胞。预防目标启动子上的组蛋白脱乙酰化抑制了DOX介导的mRNA水平的降低和导致的沉默。因此，第二个目的将表明，富含组蛋白脱乙酰基酶抑制剂的西兰花芽的小鼠饮食将防止mRNA水平的降低和小鼠组织中的沉默诱导。这些目标的成功完成将确定饮食可以防止体内表观遗传沉默，并提供动物模型，以在各种实验环境中探索这种关系。公共卫生相关性：饮食可以在增加或降低癌症发病率方面发挥重要作用，但是这样做的机制仍有待确定。癌症形成的一种途径是对肿瘤抑制基因的表观遗传沉默。该应用的目的是创建用于诱导基因沉默的小鼠模型，然后证明富含化合物的饮食可以抑制表观遗传过程，也可以抑制表观遗传沉默。