IRX1在胰腺癌中的表达及其启动子区甲基化状态  

Expression and methylation of Iroquois homeobox protein 1 in pancreatic cancer

作　　者：卫巍[1] 徐凌[1] 王锋[1] 何珊珊[1] 杨丽娟[1] 郭传勇[1] 王兴鹏[1] 

机构地区：[1]同济大学附属第十人民医院肝胆胰内科,上海200072

出　　处：《中华胰腺病杂志》2011年第5期309-311,共3页Chinese Journal of Pancreatology

基　　金：国家自然基金（81072065）;上海市科委基金（08411963000,09410705400）

摘　　要：目的检测胰腺癌的易洛魁族同源盒基因（IRX1）的表达及其启动子区的甲基化状态，探讨两者间的相关性。方法采用实时PCR法检测12例胰腺癌组织及6株胰腺癌细胞株的IRX1mRNA表达。基因序列分析1RX1基因启动子区结构。应用甲基化抑制剂5-氮杂-2’-脱氧胞苷（5-Aza—dC）处理胰腺癌细胞，采用甲基化特异性PCR（MSP）、非甲基化特异性PCR（USP）及实时PCR检测处理前后IRX1启动子甲基化状态和IRX1mRNA表达。结果胰腺癌组织IRX1mRNA的表达量为0．31±0．11，显著低于癌旁正常胰腺组织的1．05±0．32（P〈0．01）。胰腺癌细胞AsPCI、BxPC3、Capan-2、PANCl、PaTu8988和SW1990的IRX1mRNA表达量分别为0．36±0．08、0．34±0．16、0．37±0．11、0．25±0．06、0．31±0．04、0．36±0．02，均显著低于人肾上皮293细胞的1．03±0．28（P〈0．05或〈0．01）。IRX1基因启动子区富含CpG岛。各胰腺癌细胞株IRX1基因启动子CpG岛对应位点均有甲基化，经5-Aza-dC处理后甲基化状态得以逆转，IRXmRNA的表达也得以恢复。结论胰腺癌的IRX1mRNA表达下降，与其IRX1基因启动子区CpG岛高甲基化状态相关。Objective To investigate the expression of Iroquois homeobox protein 1 （IRX1） gene and the hypermethylation status of its promoter in pancreatic cancer, and their relationship. Methods Real-time PCR was used to quantitatively detect IRX1 gene expression level of 12 sets of resected pancreatic cancer tissue and 6 sets of pancreatic cancer cell lines; gene sequences analysis was used to detect the structure of IRX1 promoter; DNA methylation inhibitor 5-Aza-2＇-deoxycytidine （5-Aza-dC） was tlsed in pancreatic cancer cell lines, and then the methylation of IRX 1 was measured by methylation-specific PCR （MSP） and unmethylation sequence-PCR （USP） methods. Results Expression of IRXI mRNA in pancreatic cancer tissue was 0.31 ± 0.11, which were significantly lower than that in normal pancreatic tissue （ 1.05 ± 0.32, P 〈 0.01 ）. IRX1 mRNA expression of AsPC1, BxPC3, Capan 2, PANC1, PaTu8988 and SW1990 were 0.36 ± 0.08, 0.34 ± 0.16, 0.37 ± 0.11,0.25 ± 0.06, 0.31 ± 0.04, 0.36 ± 0.02, which were significantly lower than that in human kidney epithelial 293 cells （ 1.03 ± 0.28, P 〈 0.05 or 〈 0.01 ）. Analysis of IRX1 gene sequence showed abundant CpG islands in promoter. Hypermethylation of IRX1 promoter site was found in all pancreatic cancer cell lines. However, its methylation status could be reversed by 5-Aza-dC, and the IRX1 expression was also restored. Conclusions IRX1 mRNA expression is down-regulated in pancreatic cancer, and it is related with promoter CpG islands hypermethylation.

关 键 词：胰腺肿瘤 启动子 甲基化 IRX1 

分 类 号：R735.9[医药卫生—肿瘤]