DNA Methylation in Non-Hodgkin's Lymphomas

非霍奇金淋巴瘤中的 DNA 甲基化

• 批准号: 6736333
• 负责人: CHARLES W CALDWELL
• 金额: $ 25.81万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-16 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6736333
• 关键词: B lymphocyte; CpG islands; DNA methylation; cell differentiation; cell transformation; clinical research; data management; gene expression; gene induction /repression; genetic promoter element; genetic transcription; human tissue; imaging /visualization /scanning; immunomagnetic separation; microarray technology; neoplasm /cancer genetics; nonHodgkin' s lymphoma; nucleic acid sequence; oligonucleotides; polymerase chain reaction; technology /technique development

The major activity in our laboratory is studies of DNA methylation in tumorigenesis, a process commonly observed in GC-rich sequences called CpG islands in many types of human cancers and is often associated with transcriptional silencing. Using non-Hodgkin's lymphoma (NHL) as a model system, our discovery-driven preliminary studies demonstrate that DNA hypermethylation is not a random event; many CpG island loci are susceptible to methylation alteration. As a result of this epigenetic mutation, the expression of genes that govern key functions of the cell may become silent, leading to clonal proliferation of tumor cells. Differential susceptibility of critical CpG island loci to DNA hypermethylation may therefore influence the development of different NHL subtypes and may help explain differences in tumor growth and treatment outcomes. We have identified several loci that are differentially methylated and may be involved in lymphomagenesis. Our Central Hypothesis: B-cell differentiation is affected by methylation of CpG islands and this frequently leads to silencing of gene transcription. We further hypothesize that 1) Histological classes of NHL actually contain more than one clinical disease; 2) Hypermethylation of CpG island loci in NHL cells can generate unique molecular signatures that are associated with clinical subtypes and; 3) Dissecting these complex epigenetic profiles requires an understanding of gene methylation in normal, as well as neoplastic, B-cell differentiation. This application will expand a current version of our Methylation-Specific Oligonucleotide (MSO) microarray, an invention that combines the power of the bisulfite treatment protocol with the versatility of oligonucleotide microarrays, and apply this innovative technique to study DNA methylation in cases of B-cell NHL and normal B-cells at similar stages of differentiation, and relate these changes to gene silencing and classification. We plan to test our hypotheses by pursuing 4 specific aims; 1. Generate an MSO microarray for analysis of promoter hypermethylation at about 4,000 loci in 80 genes; 2. Determine patterns of CpG island methylation that characterize subsets of NHL classes and their putative normal stage of B-cell differentiation; 3. Correlate the status of promoter hypermethylation defined by MSO with gene expression; 4. Develop and apply data management, analysis and visualization tools to decipher methylation profiles of NHL classes. The proposed studies are expected to yield important insights into potential mechanisms of DNA methylation-driven gene silencing related to B-cell differentiation and development of clinical subtypes of NHL.

我们实验室的主要活性是肿瘤发生中DNA甲基化的研究，这是在许多类型的人类癌症中称为CpG岛的富含GC序列中通常观察到的过程，并且通常与转录沉默有关。使用非霍奇金淋巴瘤（NHL）作为模型系统，我们的发现驱动的初步研究表明，DNA高甲基化不是随机的事件。许多CpG岛基因座易受甲基化改变。由于这种表观遗传突变，控制细胞关键功能的基因的表达可能 保持沉默，导致肿瘤细胞的克隆增殖。因此，关键CpG岛基因座对DNA高甲基化的差异敏感性可能会影响不同的NHL亚型的发展，并可能有助于解释肿瘤生长和治疗结果的差异。我们已经确定了几个基因座，这些基因座差异化，可能参与淋巴作用。我们的中心假设：B细胞分化受CpG岛的甲基化影响，这通常会导致基因转录的沉默。我们进一步假设 1）NHL的组织学类别实际上含有多种临床疾病； 2）NHL细胞中CpG岛基因座的高甲基化可以产生与临床亚型相关的独特分子特征。 3）解剖这些复杂的表观遗传谱需要了解正常和肿瘤中的基因甲基化 分化。该应用将扩大我们甲基化特异性寡核苷酸（MSO）微阵列的当前版本，该发明结合了Bisulfite治疗方案的力量与寡核苷酸微阵列的多功能性，并将这种创新的技术应用于B-Cell NHL和正常的NHL和正常情况下的DNA甲基化的多功能性，并在B-cell NHL和正常情况下进行了不同，并将其固定在这些不同的情况下，并在其他情况下进行了不同的变化。 分类。我们计划通过追求4个具体目标来检验我们的假设； 1。产生一个MSO微阵列，用于分析80个基因中约4,000个基因座的启动子高甲基化； 2。确定CpG岛甲基化的模式，该模式表征了NHL类的亚集及其假定的B细胞分化的正常阶段； 3。将MSO定义的启动子高甲基化的状态与基因表达相关。 4。开发和应用数据管理，分析和可视化工具来解密NHL类的甲基化概况。拟议的研究有望产生对与B细胞相关的DNA甲基化驱动基因沉默的潜在机制的重要见解 NHL临床亚型的分化和发展。