De novo CNV formation in vivo with sickle cell anemia therapy

镰状细胞性贫血治疗体内从头形成 CNV

基本信息

批准号：
8219623
负责人：
THOMAS W GLOVER
金额：
$ 37.6万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-01-30 至 2016-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8219623
关键词：
Adult Affect American Animal Model Animal Testing Animals Autistic Disorder Biological Models Cell Culture Techniques Cell Therapy Cells Child Clinical Treatment Clinical Trials Country Data Disease Environmental Risk Factor Female Fetal Development Fetal Hemoglobin Fetus Frequencies Future Generations Generations Genes Genetic Genetic Polymorphism Genetic Risk Genetic Variation Genomics Germ-Line Mutation Goals Health Hereditary Disease Human Inbred Strain Incidence Individual Infant Inherited Location Mammals Mental Retardation Methods Mitotic Modeling Molecular Genetics Monitor Mosaicism Multiple Anatomic Sites Mus Mutagens Mutation Oogenesis Oogonia Parents Partner in relationship Patients Phenotype Pregnancy Production Replication Error Resolution Risk Risk Factors Schizophrenia Serum Severities Sickle Cell Sickle Cell Anemia Somatic Cell Somatic Mutation Spermatogenesis Staging Stress Structure Testing Time Tissue Sample Tissues Variant Weaning clastogen clinically significant genetic evolution grandchild high risk hydroxyurea improved in vivo inhibitor/antagonist male mouse model offspring oxygen transport pregnant public health relevance

项目摘要

DESCRIPTION (provided by applicant): Sickle cell disease (SCD) is the first molecular genetic disorder identified in humans, affecting over 50,000 Americans and millions of people worldwide. Hydroxyurea (HU) is currently the only approved disease- modifying therapy for adult SCD and is in late-stage clinical trials for treatment of affected infants and children. HU stimulates fetal hemoglobin production and is therefore effective in improving oxygen transport while reducing the incidence and severity of vaso-occlusive crises. However, HU is also a known replication inhibitor, mutagen and clastogen, yet the genetic effects of HU in the offspring and grandchildren of treated subjects have not been studied, particularly at the genomic level for effects of replication stress such as copy number variant (CNV) mutations. CNVs are a key factor in normal genetic variation and evolution and are a common and important class of mutation in genetic disorders, including mental retardation, autism, schizophrenia and many others. We have developed a human cell culture model system to investigate the genetic and environmental risk factors for CNV mutations. We have found that HU, at concentrations identical to serum concentrations in treated patients, significantly induces CNVs in normal human cells. These findings have important and direct genetic implications for deleterious, de novo CNV risk in the children and grandchildren of patients treated with HU for SCD and other disorders. We propose to extend these findings to direct studies in animal models in vivo. We will evaluate the genetic effects of HU on CNV induction in both the male and female germlines by examining F1 and F2 generations of treated mice using high-resolution genomic microarrays. We will determine parental origins of de novo CNVs, examine their genomic structures to infer cellular and mechanistic origins and compare findings with those from phenotyping of study group animals. In addition, we will assess somatic mosaicism for CNVs in cells and tissues of mice treated prenatally with HU and controls. These studies will provide the first in vivo test in mammals of the somatic mutation/replication stress hypothesis for CNVs using a model inhibitor of replication. The results obtained will have important implications for defining genetic and environmental risk factors for both germline and somatic deleterious CNVs in humans. Moreover they will have important and immediate clinical significance to a large number of individuals with SCD and the future generations of HU-treated patients. PUBLIC HEALTH RELEVANCE: Public Health Relevance: CNVs are a major factor in genetic variation and are a common and important class of mutation in genetic disorders, yet there is limited understanding of how CNVs arise and risk factors involved. Using a cell culture model system, our data shows that hydroxyurea (HU) at concentrations used in sickle cell therapy induces de novo CNVs. This finding has important genetic implications for de novo deleterious CNV risk in offspring and grandchildren of patients treated with HU for sickle cell disease. To determine the extent of this risk, we will extend our findings directly to animal studies. In doing so, we will for the first time test the somatic cell/replication stress origin hypothesis for a large class of CNVs directly in vivo. Our studies will have important implications for defining risk factors for deleterious CNVs in all humans. Moreover they will be important in determining if HU treatment is a risk factor for deleterious CNVs in future generations of thousands of individuals treated with HU in this country and potentially millions worldwide.

描述（由申请人提供）：镰状细胞病 (SCD) 是人类中发现的第一种分子遗传性疾病，影响着超过 50,000 名美国人和全世界数百万人。羟基脲 (HU) 是目前唯一获批治疗成人 SCD 的疾病缓解疗法，目前正处于治疗受影响婴儿和儿童的后期临床试验中。 HU 刺激胎儿血红蛋白的产生，因此可有效改善氧气输送，同时降低血管闭塞危机的发生率和严重程度。然而，HU也是一种已知的复制抑制剂、诱变剂和断裂剂，但尚未研究HU对治疗受试者的后代和孙辈的遗传影响，特别是在基因组水平上复制应激的影响，例如拷贝数变异（CNV））突变。 CNV是正常遗传变异和进化的关键因素，也是遗传性疾病（包括智力低下、自闭症、精神分裂症等）中常见且重要的一类突变。我们开发了人类细胞培养模型系统来研究 CNV 突变的遗传和环境风险因素。我们发现，HU 在与治疗患者的血清浓度相同的浓度下，可显着诱导正常人类细胞中的 CNV。这些发现对于因 SCD 和其他疾病接受 HU 治疗的患者的子代和孙代的有害的新发 CNV 风险具有重要和直接的遗传意义。我们建议将这些发现扩展到直接动物模型体内研究。我们将通过使用高分辨率基因组微阵列检查治疗小鼠的 F1 和 F2 代，评估 HU 对雄性和雌性种系中 CNV 诱导的遗传影响。我们将确定 de novo CNV 的亲本起源，检查其基因组结构以推断细胞和机械起源，并将结果与研究组动物的表型分析结果进行比较。此外，我们将评估产前接受 HU 治疗的小鼠和对照组小鼠细胞和组织中 CNV 的体细胞嵌合现象。这些研究将首次使用复制抑制剂模型在哺乳动物体内测试 CNV 的体细胞突变/复制应激假说。获得的结果对于确定人类种系和体细胞有害 CNV 的遗传和环境风险因素具有重要意义。此外，它们对于大量 SCD 患者和未来接受 HU 治疗的患者具有重要且直接的临床意义。公共卫生相关性：公共健康相关性：CNV 是遗传变异的主要因素，也是遗传性疾病中常见且重要的一类突变，但对 CNV 的产生方式及其涉及的风险因素的了解有限。使用细胞培养模型系统，我们的数据表明，镰状细胞疗法中使用的羟基脲 (HU) 浓度可诱导新生 CNV。这一发现对于接受 HU 治疗的镰状细胞病患者的后代和孙辈的新发有害 CNV 风险具有重要的遗传意义。为了确定这种风险的程度，我们将把我们的发现直接扩展到动物研究中。在此过程中，我们将首次直接在体内测试一大类 CNV 的体细胞/复制应激起源假说。我们的研究对于确定全人类有害 CNV 的危险因素具有重要意义。此外，它们对于确定 HU 治疗是否是该国数千名接受 HU 治疗的人以及全球数百万人的后代中产生有害 CNV 的危险因素非常重要。