过表达E2F6基因抑制BRD7基因启动子活性

Overexpression of E2F6 Gene Inhibits Promoter Activity of BRD7 Gene

BRD7基因是采用cDNA代表性差异分析法克隆的一个新bromodomain基因(GenBank登录号AF152604).它在鼻咽癌细胞和组织中表达明显下调,过表达BRD7基因可抑制鼻咽癌细胞的生长和细胞周期的进程.前期工作已克隆了BRD7基因启动子区,并将其启动子定位于450bp(-404～+46bp)的区域.为了进一步揭示BRD7基因在鼻咽癌细胞和组织中表达下调的分子机制,生物信息学分析表明,BRD7基因启动子-229至-243bp为一个E2F6转录因子结合位点共有序列,电泳迁移率实验结果表明转录因子E2F6特异性地结合于BRD7启动子区.荧光素酶检测和绿色荧光蛋白表达检测都证实,过表达E2F6基因能抑制BRD7基因启动子活性.

BRD7 is a novel bromodomain gene isolated by cDNA representational difference analysis （GenBank accession number： AF152604）. It is obviously down-regulated in nasopharyngeal carcinoma （NPC） cells and tissues. Over expression of BRD7 in NPC cells can inhibit cell proliferation and cell cycle progression. Previous studies determined the promoter region of BRD7 gene, and located this region in 450 bp （ -404～ ＋ 46 bp）. In order to further explore the molecular mechanisms involved in the down-expression of BRD7 gene in NPC cells, we adopted bioinformatic approaches and found a consensus E2F6 binding site （ -229～ -243 bp） in the promoter region of BRD7 gene. Results from EMSA indicated that transcription factor E2F6 could bind to BRD7 promoter. Over-expression of BRD7 gene inhibited BRD7 promoter activity detected by either luciferase assay or the expression of green fluorescent protein.