DNA SEQUENCE DIVERSITY IN THE HUMAN PREGNANE X RECEPTOR

人类妊娠 X 受体 DNA 序列多样性

基本信息

批准号：
6520127
负责人：
ERIN G SCHUETZ
金额：
$ 23.71万
依托单位：
ST. JUDE CHILDREN'S RESEARCH HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-03-01 至 2004-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6520127
关键词：
clinical research cytochrome P450 gene mutation genetic polymorphism genotype human tissue laboratory rabbit liver cells molecular cloning nucleic acid sequence pharmacogenetics pharmacokinetics phenotype polymerase chain reaction pregnane compound receptor expression single nucleotide polymorphism steroid hormone receptor

项目摘要

The discovery of the Pregnane X receptor (PXR) has led to a greater understanding of the fundamental mechanisms underlying upregulation of cytochrome P4503A and potentially other drug detoxification enzymes. We hypothesize that sequence variations (including single nucleotide polymorphisms, SNPs) in PXR or its cognate binding element (PXRE) in the CYP3A4 gene are central to human variation in both basal and inducible CYP3A expression. To critically study the importance of PXR SNPs to regulation of CYP3A a safe, reliable, and convenient assay will be needed to determine an individual s PXR genotype. Towards this goal we have cloned, mapped and are sequencing PXR. Our overall objectives are: (1) to identify sequence variations in PXR (or in the CYP3A4 PXRE) and determine their functional importance; (2) to correlate PXR SNPs to phenotypic variations in CYP3A; (3) to determine the overall frequency and pattern of sequence variations in PXR; and (4) to determine the functional importance of PXR SNPs and the molecular mechanisms leading to non- functional PXR in cellular and biochemical assays. Our pharmacogenomic approach takes advantage of our unique resources - genomic DNAs from CYP3A phenotyped human tissues and human study populations from numerous clinical trials with CYP3A substrates and inducers. Additionally, using cultures of human hepatocytes phenotyped for CYP3A induction we will prospectively identify the outliers in inductive drug response. The goal of our study is to use these defined patient populations simultaneously as a source of genotype-phenotype relationships and as a SNP discovery resource. Our hypothesis driven approach will immediately elucidate the functional consequences of PXR or PXRE SNPs to not only PXR function but CYP3A drug response as well and will serve as an important gentotype-phenotype/SNP pharmacogenomics model and provide further insights into mechanisms responsible for the highly variable pharmacokinetics of CYP3A metabolized drugs.

妊娠X受体（PXR）的发现使对细胞色素P4503A上调的基本机制有了更多的了解，并可能是其他药物排毒酶。我们假设PXR中的序列变化（包括单核苷酸多态性，SNP）或其CYP3A4基因中的同源结合元件（PXRE）在基础和诱导的CYP3A表达中都是人类变异的核心。为了批判性地研究PXR SNP对CYP3A调节的重要性，需要进行安全，可靠和方便的测定，以确定单个S PXR基因型。为了实现这一目标，我们已经克隆，映射并正在测序PXR。我们的总体目标是：（1）确定PXR（或CYP3A4 PXRE）中的序列变化并确定其功能重要性；（2）将PXR SNP与CYP3A中的表型变化相关联；（3）确定PXR中序列变化的总频率和模式；（4）确定PXR SNP的功能重要性以及导致细胞和生化测定中非功能性PXR的分子机制。我们的药物基因组方法利用了我们独特的资源 - 来自CYP3A表型人体组织的基因组DNA和来自CYP3A底物和诱导剂的众多临床试验的人类研究人群。此外，使用用于CYP3A诱导的人类肝细胞的培养物，我们将前瞻性地识别诱导药物反应中的异常值。我们研究的目的是同时使用这些定义的患者人群作为基因型 - 表型关系的来源和SNP发现资源。我们的假设驱动方法将立即阐明PXR或PXRE SNP的功能后果，不仅对PXR功能，还可以阐明CYP3A药物反应，并将作为重要的Gentotype-Phenotype/SNP药物基因组学模型，并提供进一步的洞察力，并提供了对高度可变的CYP3A药物代理药物的机制。