ETS-2转录因子与启动子的+1^+40区结合是肝癌相关基因HCCS1的转录所必需  

ETS-2 binding to the +1-+40 region of the promoter and transcription regulation of HCCS1 gene

作　　者：王鹏[1] 毛大芩[1] 蓝斐[1] 朱景德[2] 

机构地区：[1]复旦大学上海医学院,上海200032 [2]上海交通大学肿瘤研究所癌基因与相关基因国家重点实验室

出　　处：《肿瘤》2006年第5期407-413,共7页Tumor

基　　金：国家自然科学基金资助项目(编号:30450001);国家973计划项目(编号:2004CB518804);国家863计划项目(编号:2002AA2Z3352);上海市科学技术委员会基金(编号:04DZ14006)

摘　　要：目的:阐明HCCS1基因启动子的转录调控机制。方法:引物延伸法确定HCCS1基因的转录起始点,通过限制性内切酶酶切介导对HCCS1基因全长启动子做进行性的5'缺失,用瞬时转染/双荧光素酶报告系统确定最小启动子,连接体扫描突变分析来确定启动子功能的关键顺式序列区,电泳迁移率实验并附以抗体介导超迁移实验来确定关键的反式因子。结果:HCCS1基因的转录起始点被定位于-177/-178处的C残基(ATG为+1)。最小启动子位于-60^+148区(转录起始点为+1)之中。在关键的调控区(+1^+40)所含的已知顺式序列中有2个ETS转录因子识别序列,而不是p53或NF-κB,识别序列与其相应的转录因子(ETS-2)的结合有着重要的功能内涵。结论:ETS-2转录因子与启动子的+1^+40区中相应的顺式序列结合,在肝癌相关基因HCCS1的转录活性中起着关键作用。Objective：To unveil the molecular details of the mechanisms underlying the transcriptional regulation of human hepatocellular carcinoma suppressor 1 （HCCS1） gene. Methods： A primer extension assay was used to determine the transcriptional start of the HCCS1 gene. Restriction endonuclease digestion was used to obtain the 5＇ serially deleted constructs of HCCS1 gene whole length promoter. A transient transfection/double luciferase reporter assay was carried out to measure the minimal promoter activities of a set of the mutants. Linker-scanning mutational analysis in the -60-＋ 14 region of the HCCS1 gene was used to identify the crucial cis-elements within the promoter region. Finally, a mobility shift assay in conjunction with the antibody mediated super-shift analysis was executed to identify the crucial transcription factor. Results： The major start of transcription was mapped at the C residue, -177/-178 upstream of the ATG codon （A： ＋ 1）. The minimal promoter was mapped in the -60-＋148 region （the mapped start of transcription was referred as ＋1）. The sequence of the ＋1-＋40 segment contains the crucial cis-elements, which was preferentially bound by epithelium specific Ets-2 （ETS-2）, but not ETS-1 ,p53, p50 and p65 subunits of the NF-κB transcription factors. Conclusion： A sequence-specific binding of the ETS-2 transcription factor to its cognate cis-elements in the ＋ 1-＋40 region of the promoter is essential to the transcription activity of the HCCS1 gene in cell.

关 键 词：肝肿瘤 癌 肝细胞 基因表达调控 基因 肿瘤抑制 基因 HCCS1 SMMC-7721细胞 

分 类 号：R735.7[医药卫生—肿瘤] R730.231[医药卫生—临床医学]