DNA global hypomethylation in squamous cell head and neck cancer associated with smoking, alcohol consumption and stage
DNA global hypomethylation in squamous cell head and neck cancer associated with smoking, alcohol consumption and stage
复制标题
DOI：
10.1002/ijc.22889
复制
发表时间：
2007-10-15
影响因子：
6.4
通讯作者：
Califano, Joseph A.
中科院分区：
文献类型：
--
作者：
Smith, Ian M.;Mydlarz, Wojciech K.;Califano, Joseph A.
表观遗传学变化与实体瘤（包括头颈部鳞状细胞癌（HNSCC））的发病机制有关。先前的工作主要是研究区域启动子超甲基化作为肿瘤抑制基因表达的沉默子。为了分析HNSCC基因组中甲基化的整体状态，我们利用重复元件的焦磷酸测序（LINEs）来比较HNSCC与正常呼吸消化道粘膜中的整体甲基化状态。消化137个样品（119个HNSCC肿瘤和18个正常粘膜组织）以提取DNA并进行亚硫酸氢盐处理。使用重复LINEs序列的PCR引物扩增处理的DNA，并从许多基因组基因座产生产物的异质样品。对这些产物进行焦磷酸测序以定量评估其整体基因组甲基化状态。HNSCC标本显示整体低甲基化，平均基因组甲基化水平为46.8%，标准差为9.0。相反，正常上呼吸道粘膜的总体甲基化水平为54.0，标准差为4.6（Mann-Whitney p值<0.001）。肿瘤标本还显示与晚期肿瘤阶段相关的低甲基化程度增加（ANOVA p值为0.003）。当相对于正常粘膜标本中的最低甲基化水平进行评价时，约67%的HNSCC是整体低甲基化的。在单变量分析中，总体低甲基化程度与吸烟史、饮酒和分期相关（p值0.02），然而，在多变量分析中，只有HNSCC诊断仍具有显著性。尽管存在区域性启动子高甲基化，HNSCC表现出全局基因组低甲基化。阶段，饮酒和吸烟对全球低甲基化的影响没有独立的显着性。(C)2007 Wiley-Liss，Inc.
Epigenetic changes have been implicated in the pathogenesis of solid tumors, including head and neck squamous cell carcinoma (HNSCC). Prior efforts have primarily examined regional promoter hypermethylation as a silencer of tumor suppressor gene expression. To analyze the global state of methylation in the HNSCC genome, we utilize pyrosequencing of repetitive elements (LINEs) to compare the state of global methylation in HNSCC to normal aerodigestive mucosa. 137 samples (119 HNSCC tumors and 18 normal mucosal tissues) were digested to extract DNA and subjected to bisulfite treatment. Treated DNA was amplified using PCR primers for the repetitive LINEs sequence and produced a heterogeneous sample of products, from many genomic loci. These products were pyrosequenced to quantitatively evaluate their global genomic methylation status. HNSCC specimens showed global hypomethylation, with a mean level of genomic methylation of 46.8% methylated with a standard deviation of 9.0. Conversely, the normal upper airway mucosa had a global methylation level of 54.0 and a standard deviation of 4.6 (Mann-Whitney p value < 0.001). The tumor specimens also showed an increasing degree of hypomethylation associated with advanced tumor stage (ANOVA p-value of 0.003). About 67% of HNSCC's are globally hypomethylated when evaluated against the minimum level of methylation in the normal mucosal specimens. Degree of global hypomethylation was associated with smoking history, alcohol use and stage in univariate analysis (p-value 0.02), however, only HNSCC diagnosis remained significant on multivariate analysis. Despite the presence of regional promoter hypermethylation, HNSCC demonstrates global genomic hypomethylation. The effects of stage, alcohol use and smoking on global hypomethylation were not independently significant. (C) 2007 Wiley-Liss, Inc.