Genetic Polymorphism in Prostate Cancer

前列腺癌的基因多态性

• 批准号: 6796723
• 负责人: Edward P Gelmann
• 金额: $ 22.12万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6796723
• 关键词: affinity chromatography; binding sites; cancer risk; gene expression; genetic polymorphism; genetic regulation; genetic transcription; homeobox genes; human tissue; immunocytochemistry; immunoprecipitation; microarray technology; neoplasm /cancer genetics; polymerase chain reaction; prostate neoplasms; protein binding; protein protein interaction; protein structure function; site directed mutagenesis; transcription factor; western blottings

DESCRIPTION (provided by applicant): NKX3.1 is a prostate-specific homeobox gene that maps to a region of chromosome 8p21 that is lost in up to 85% of prostate cancer cases. Although NKX3.1 does not undergo somatic mutations in prostate cancer, expression of the protein is lost with tumor progression, suggesting a role for NKX3.1 in prostate cancer pathogenesis. In Nkx3.1 mice haploinsufficiency is dominant, resulting in prostatic epithelial hyperplasia and dysplasia that worsens with age. Moreover, Nkx3.1 haploinsufficiency cooperates with loss of other suppressor genes such as Pten to enhance prostate carcinogenesis. These data suggest that loss of NKX3.1 expression may be important in pathogenesis of a large fraction of human prostate cancers and that NKX3.1 is a candidate gatekeeper gene. We described an NKX3.1 polymorphism, C154T, that resulted in an arginine to cysteine alteration of codon 52 (NKX3.1 R52C). In the initial grant period we showed that a single NKX3.1 C154T allele, present in 11% of the population, conferred an increased risk for aggressive prostate cancer. We also showed that the R52C variant altered phosphorylation at the adjacent serine 48 (S48) and that S48 phosphorylation regulated DNA binding in vitro. But NKX3.1 influences gene expression not only by DNA binding, but also by complexing with transcription factors and regulating their activity as a coactivator. Preliminary data shows that the region of amino acids 44-64 is critical for autoregulation of NKX3.1 coactivation activity, presumably by mediating binding to the C-terminus. We now will determine biochemical properties of NKX3.1 critical for its action. In Aim 1 we will perform genetic analysis of NKX3.1 to identify critical elements that regulate protein activity. In Aim 2 we will perform affinity chromatography with NKX3.1 to isolate and identify proteins that bind to NKX3.1. In Aim 3 we will identify and characterize genes whose expression is regulated by NKX3.1. In Aim 4, we will analyze tumor specimens from patients with high-grade prostate cancer to determine whether in those with the C154T polymorphic allele it is preferentially retained after loss of chromosome 8p heterozygosity.

描述（由申请人提供）：NKX3.1是一种前列腺特异性同源基因，它映射到8p21染色体的区域，该区域在多达85％的前列腺癌病例中丢失。尽管NKX3.1在前列腺癌中不接受体细胞突变，但蛋白质的表达随肿瘤进展而丧失，这表明NKX3.1在前列腺癌发病机理中的作用。在NKX3.1中，小鼠单倍体不足是主导的，导致前列腺上皮增生和发育不良随着年龄的增长而恶化。此外，NKX3.1单倍弥弥漫与其他抑制基因（如PTEN）的丧失，以增强前列腺癌发生。这些数据表明，NKX3.1表达的丧失在大量人类前列腺癌的发病机理中可能很重要，而NKX3.1是候选守门员基因。我们描述了NKX3.1多态性C154T，导致精氨酸对密码子52（NKX3.1 R52C）的半胱氨酸改变。在最初的赠款期间，我们表明，有11％的人口中的单个NKX3.1 C154T等位基因赋予了侵略性前列腺癌的风险增加。我们还表明，R52C变体在相邻的丝氨酸48（S48）上改变了磷酸化，并且S48磷酸化调节了体外的DNA结合。但是NKX3.1不仅​​会影响基因表达，不仅通过DNA结合，而且会与转录因子复合并调节其作为共激活因子的活性。初步数据表明，氨基酸44-64的区域对于NKX3.1的自动调节至关重要，这可能是通过介导与C末端的结合而进行的。现在，我们将确定NKX3.1对其作用至关重要的生化特性。在AIM 1中，我们将对NKX3.1进行遗传分析，以确定调节蛋白质活性的关键元素。在AIM 2中，我们将与NKX3.1进行亲和色谱法分离并鉴定与NKX3.1结合的蛋白质。在AIM 3中，我们将识别并表征其表达受NKX3.1调节的基因。在AIM 4中，我们将分析来自高级前列腺癌患者的肿瘤标本，以确定在患有C154T多态性等位基因的患者中是否在8p杂合性染色体丧失后优先保留。