DNA methylation in the development of pediatric leukemias

DNA甲基化在儿童白血病发展中的作用

• 批准号: 7738454
• 负责人: Sheng Zhong
• 金额: $ 7.73万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-07 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7738454
• 关键词: Archives; Biological Assay; Biological Markers; Birth; Blood; Bone Marrow; CD34 gene; Candidate Disease Gene; Carcinogens; Cell Line; Child; Childhood; Childhood Leukemia; Chromosomal translocation; Clinical; Complement; Coupled; Coupling; CpG Islands; Cytogenetics; DNA; DNA Methylation; Data; Development; Diagnostic; Diet; Disease; Early Diagnosis; Early treatment; Epigenetic Process; Etiology; Event; Exons; Gene Expression; Gene Silencing; Gene Targeting; Genes; Genetic; Genomics; Germ Cells; Goals; Hematopoietic; Histone Deacetylation; Hypermethylation; Knowledge; Malignant Neoplasms; Methods; Methylation; Modification; Mutation; Neonatal; Normal Cell; Pathogenesis; Patients; Play; Predictive Value; Predisposition; Procedures; Prophylactic treatment; Protocols documentation; Public Health; Research; Retrospective Studies; Role; Sampling; Screening procedure; Spottings; Staging; TEL-AML1 Oncogene; Techniques; Testing; Time; Validation; Virus Diseases; abstracting; base; bisulfite; gene function; genome-wide; imprint; leukemia; novel; population based; prenatal; promoter; public health relevance; research study; response

DESCRIPTION (provided by applicant): PROJECT SUMMARY / ABSTRACT: It is well recognized that genetic aberrations, such as chromosomal translocations, are complemented by secondary aberrations (possible epigenetic) that give rise to leukemic clones. However, complementary epigenetic event(s) and their roles in development of common subtypes of childhood leukemias are not well characterized. Our goals are to understand the scope of genome-wide epigenetic alterations in childhood leukemia, and then develop epigenetic screening markers to test archived neonatal blood spots (Guthrie cards) for early detection of leukemia. We have successfully performed preliminary experiments using GoldenGate Methylation Cancer Panel I microarrays (Illumina, Inc), using leukemic bone marrows, and corresponding archived Guthrie cards of childhood leukemias patients, to test the contribution of a large panel of cancer- related genes in the development of leukemia. We have also performed experiments with leukemia cell lines to test the gene expression response to a demethylating agent. This technique involved pharmacologic inhibition of epigenetic modifications, coupled with gene expression microarrays (Affymetrix Exon 1.0), and has yielded a number of candidate genes for which gene promoter methylation may play a functional role in leukemia. Our current focus is to focus on a panel of preliminary candidate genes using validation assays in primary leukemia samples, and then focusing further in Guthrie cards for our chosen targets. In the current application we will use methylation-specific PCR and bisulfite sequencing to reduce the size, and to focus our current large panel of 90 gene targets. We will choose the 30 which are methylated in the highest fraction of TEL-AML1 leukemia and which are not methylated in normal CD34 cells and normal Guthrie card DNA. We will then test this panel of epigenetic markers in Guthrie cards from children who grew up to get TEL-AML1 leuekmia and compare to a group of 500 children who did not, to assess predictive value. We focus exclusively on the most common cytogenetic subltype, those with TEL-AML1 translocations who are 22% of all ALL. This research aims ultimately at the characterization of early epigenetic mutations and imprinting abnormalities in the development of leukemia, and the use these markers for the early detection of pediatric leukemia. PUBLIC HEALTH RELEVANCE: PROJECT NARRATIVE: With this project we are exploring the existence of early markers of leukemia at birth. This will impact public health by increasing our knowledge in the mechanisms of the etiology of childhood leukemia and providing markers for the early detection of, or predisposition to, leukemia at birth.

项目概述/摘要：众所周知，遗传畸变，如染色体易位，是由继发性畸变（可能是表观遗传）补充的，从而导致白血病克隆。然而，互补的表观遗传事件及其在儿童白血病常见亚型发展中的作用尚未得到很好的表征。我们的目标是了解儿童白血病全基因组表观遗传改变的范围，然后开发表观遗传筛查标记来检测存档的新生儿血斑（Guthrie卡），以便早期发现白血病。我们已经成功地使用GoldenGate Methylation Cancer Panel I微阵列（Illumina, Inc）进行了初步实验，使用白血病骨髓和相应存档的儿童白血病患者的Guthrie卡片，测试了大量癌症相关基因在白血病发展中的作用。我们还对白血病细胞系进行了实验，以测试基因表达对去甲基化剂的反应。该技术涉及表观遗传修饰的药理学抑制，结合基因表达微阵列（Affymetrix外显子1.0），并产生了许多候选基因，其中基因启动子甲基化可能在白血病中发挥功能作用。我们目前的重点是在原发性白血病样本中使用验证分析来关注一组初步候选基因，然后进一步关注我们选择的目标的Guthrie卡片。在目前的应用中，我们将使用甲基化特异性PCR和亚硫酸盐测序来减小尺寸，并集中我们目前的90个基因靶点的大型面板。我们将选择在最高比例的TEL-AML1白血病中甲基化的30个，以及在正常CD34细胞和正常Guthrie卡DNA中未甲基化的30个。然后，我们将在患有TEL-AML1白血病的儿童的Guthrie卡片中测试这组表观遗传标记，并与500名未患白血病的儿童进行比较，以评估预测价值。我们专注于最常见的细胞遗传学亚型，即TEL-AML1易位占所有all的22%。本研究的最终目的是表征白血病发展过程中的早期表观遗传突变和印迹异常，并利用这些标记物早期检测儿童白血病。