Early growth response gene-1 plays a pivotal role in down-regulation of a cohort of genes in uterine leiomyoma
Early growth response gene-1 plays a pivotal role in down-regulation of a cohort of genes in uterine leiomyoma
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DOI：
10.1677/jme-06-0069
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发表时间：
2007-11-01
影响因子：
3.5
通讯作者：
Inoue, Masaki
中科院分区：
文献类型：
--
作者：
Ishikawa, Hiroshi;Shozu, Makio;Inoue, Masaki
微阵列研究已经确定了许多基因在子宫平滑肌瘤中的表达与肌层相比下调，包括早期生长反应基因1（EGR 1）。然而，该基因组协调下调的潜在机制仍然未知。为了阐明EGR 1在平滑肌瘤中的转录作用，通过染色质免疫沉淀（ChIP）试验在平滑肌瘤组织和子宫肌层衍生的KW细胞中评估EGR 1与靶基因启动子序列的结合。计算机分析表明，在阵列报告中列出的135个下调基因中，有50个在1 kb启动子序列内具有潜在的EGFR 1结合位点。随机选择13个具有EGFR 1潜在结合位点的基因（A组）、3个在其他组织中被称为EGFR 1靶标的基因（B组）和4个对照基因进行ChIP测定。与子宫肌层相比，子宫肌瘤组织中16个基因中有11个（A +B组）的EGFR 1结合率显著降低，组织样本中11个基因中有7个的mRNA水平实际上降低。对KW细胞进行的ChIP分析显示，除了一个A+B组基因外，所有基因的启动子区均诱导EGR 1结合，但对照基因均未结合。这些结果表明，EGR 1是一个关键的球员在协调下调基因在平滑肌瘤。应用ChIP-定量PCR分析与计算机辅助分析的基因组数据库的援助出现阵列数据的全面解释是有用的。
Microarray studies have identified many genes that are down-regulated in uterine leiomyoma compared with myometrium, including early growth response gene-1 (EGR1). However, the mechanisms underlying coordinated down-regulation of this gene cohort remain unknown. To address the transcriptional role of EGR1 in leiomyoma, EGR1 binding to promoter sequences on target genes was assessed by chromatin immunoprecipitation (ChIP) assay in leiomyoma tissues and myometrium-derived KW cells. Computer analysis demonstrated that 50 out of 135 genes listed as down-regulated in array reports possessed potential binding sites for EGR1 within 1 kb promoter sequence. ChIP assay was performed for a random selection of 13 genes possessing potential binding sites for EGR1 (GroupA), 3 genes known as EGR1 targets in other tissues (Group B), and 4 control genes. Decreased EGR1 bindings were significant for 11 out of 16 genes (GroupA+B) in leiomyoma tissues compared with myometrium, and mRNA levels in tissue samples were actually decreased for 7 out of the 11 genes. ChIP analyses performed on KW cells showed induction of EGR1 binding to the promoter region of all genes except one Group A+B gene, but for none of the control genes. These results indicate that EGR1 is a key player in coordinated downregulation of genes in leiomyoma. Application of ChIP-quantitative PCR assay with the aid of computer-assisted analysis of genome databases appears useful for the comprehensive interpretation of array data.