Exploring arsenic and its metabolites in a transgenic model

在转基因模型中探索砷及其代谢物

基本信息

批准号：
7842476
负责人：
IAIN L CARTWRIGHT
金额：
$ 22.11万
依托单位：
UNIVERSITY OF CINCINNATI
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-01 至 2012-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7842476
关键词：
Accounting Acute Address Affect Ally Anabolism Animal Model Appearance Area Arsenic Arsenicals Arsenites Bangladesh Biological Biological Assay Cancer Etiology Carbon Carcinogens Cell Cycle Cells Chromosome abnormality Chronic Communities Complex Cultured Cells DNA Development Disasters Disease model Dissection Drosophila genus Drug Metabolic Detoxication Environmental Health Enzymes Evaluation Excretory function Exposure to Force of Gravity Future Genes Genetic Genetic Models Genetic Polymorphism Genetic Recombination Genetic Variation Health Homologous Gene Human Human Pathology Individual Ingestion Intake Investigation Lead Learning Light Long-Term Effects Malignant Neoplasms Mass Spectrum Analysis Mediating Metabolic Metabolism Methionine Methylation Methyltransferase Modeling Molecular Monitor Nature Organ Organism Outcome Oxidation-Reduction Oxidative Phosphorylation Pathology Pathway interactions Pattern Poison Population Predisposition Process Production Public Health Relative (related person)Resources Role Screening procedure Severities Signaling Pathway Gene Skin System Techniques Testing Time Tissues Toxic effect Toxicogenetics Transgenes Transgenic Animals Transgenic Model Transgenic Organisms Transplantation Urine Variant Water Pollution Water Supply drinking water fly genetic resource global environment in vivo in vivo Model insight interest mutant overexpression oxidative damage public health relevance research study response toxic metal tumor tumorigenesis tumorigenic uptake

项目摘要

DESCRIPTION (provided by applicant): Among the most serious issues confronting the global public health community is the long term consequence of arsenic ingestion in drinking water, a situation that has affected an estimated 100 million people worldwide, albeit disproportionately so in Bangladesh and West Bengal owing to the widespread provision of wells drawing arsenic-laced groundwater. Though arsenic is a well-known acute poison of oxidative phosphorylation when ingested in large quantities, chronic, low-level exposure leads to a variety of pathologies, among which are numerous forms of cancer. Mechanistically it has proven difficult to assign the specific cause of arsenic-induced cancer, though DNA and/or chromosomal aberrations typically accompany its appearance, and there has been much debate regarding whether or not arsenic can act as a complete carcinogen. Moreover, progress in these areas has been hampered by a relative lack of suitable animal models. Recently, the realization that metabolic methylation of arsenic may actually lead to a more potent carcinogen rather than to its presumed detoxification has prompted interest in the mechanism of methylation, the species formed, and the possibility that polymorphisms in the gene(s) involved in uptake, metabolism and excretion of arsenic may have profound effects on susceptibility of exposed individuals. To address some of these issues with a well-defined, genetically amenable, in vivo system we propose to create a Drosophila transgenic model, in which control, and precise analysis, of arsenic methylation (catalyzed by human gene variants that occur naturally in the population) can be married with a variety of in vivo assays investigating specific features of DNA metabolism (oxidative damage, strand breakage, recombination), cellular response (chromosomal aberrations, cell cycle aberrations), and carcinogenic potential via tumor formation in a transplantation assay. With the enormous versatility available in the Drosophila system, allowing controllable over- and underexpression of virtually any endogenous gene to be easily achieved, it is anticipated that critical molecular pathways intersected by arsenic and its methylated metabolites can be identified as a result of phenotypic variation occurring in one or more of the above assays when tested in such altered genetic backgrounds. Thus, we propose that a model higher eukaryotic organism, one that has consistently proved to be an unparalleled resource in uncovering critical molecular features of numerous human pathological conditions, can be harnessed to shed light on a vitally important toxicogenetic problem. PUBLIC HEALTH RELEVANCE: The long-term ingestion of arsenic via drinking water by human populations in many parts of the world has proven to be one of the largest global public health disasters of modern times owing to the variety of detrimental health consequences that ensue, including numerous forms of organ cancer. Though much of interest has been learned from studies in cultured cells, investigation of the mechanisms by which this toxic metal affects biological pathways (particularly in its ability to cause cancer) has been hampered by a relative lack of good animal models that duplicate the human pathologies. We aim to develop a model for arsenic cellular toxicity and tumorigenesis by introducing critical human genes involved in arsenic metabolism into the fruit fly, Drosophila, where a combination of assays, allied to the unparalleled genetic manipulability of this organism, are anticipated to shed new light on questions related to how arsenic induces cancer and why individuals show widely variable susceptibility to its effects.

描述（由申请人提供）：全球公共卫生界面临的最严重问题之一是饮用水中砷摄入的长期后果，这种情况已影响到全世界约 1 亿人，但孟加拉国和西孟加拉邦的影响尤为严重由于广泛使用抽取含砷地下水的井。尽管砷是一种众所周知的氧化磷酸化急性毒物，但大量摄入时，慢性、低水平的暴露会导致多种病理，其中包括多种癌症。尽管DNA和/或染色体畸变通常伴随着砷的出现，但从机制上来说，很难确定砷诱发癌症的具体原因，并且关于砷是否可以作为一种完全致癌物存在很多争论。此外，由于相对缺乏合适的动物模型，这些领域的进展受到阻碍。最近，认识到砷的代谢甲基化实际上可能会导致更强的致癌物，而不是其假定的解毒作用，这引起了人们对甲基化机制、形成的物种以及参与吸收的基因多态性的可能性的兴趣。，砷的代谢和排泄可能对暴露个体的易感性产生深远的影响。为了通过一个明确定义的、遗传上可接受的体内系统解决其中一些问题，我们建议创建一个果蝇转基因模型，在该模型中控制和精确分析砷甲基化（由群体中自然发生的人类基因变异催化））可以与各种体内测定结合，研究 DNA 代谢（氧化损伤、链断裂、重组）、细胞反应（染色体畸变、细胞周期畸变）的特定特征，以及移植试验中肿瘤形成的潜在致癌性。果蝇系统具有巨大的多功能性，可以轻松实现几乎任何内源基因的可控过度和不足表达，预计砷及其甲基化代谢物交叉的关键分子途径可以通过发生表型变异来识别当在这种改变的遗传背景中进行测试时，在上述一项或多项测定中。因此，我们提出，一种高等真核生物模型，一直被证明是揭示许多人类病理状况的关键分子特征方面无与伦比的资源，可以用来阐明至关重要的毒理学问题。公共卫生相关性：世界许多地区的人们通过饮用水长期摄入砷已被证明是现代最大的全球公共卫生灾难之一，因为随之而来的是各种有害的健康后果，包括多种形式的器官癌。尽管人们从培养细胞的研究中获得了很多兴趣，但由于相对缺乏复制人类病理的良好动物模型，对这种有毒金属影响生物途径（特别是其致癌能力）的机制的研究受到了阻碍。。我们的目标是通过将参与砷代谢的关键人类基因引入果蝇（果蝇）来开发砷细胞毒性和肿瘤发生的模型，其中结合该生物体无与伦比的遗传可操作性的分析组合预计将揭示新的线索关于砷如何诱发癌症以及为什么个体对其影响表现出广泛不同的易感性的问题。