ASPP2基因启动子区DNA甲基化及转录因子DNA结合位点的干湿研究

Dry and Wet Studies on the DNA Methylation and Transcription Factor Binding Sites of the Promotor Region of ASPP2 Gene

对p53凋亡刺激蛋白2(ASPP2)基因启动子区进行了甲基化及转录因子结合位点(TFBS)的生物信息学分析及实验研究。结果表明,在该基因近端启动子区存在一个长1391bp的CpG岛,且此区域中包含19个转录因子的37个结合位点,其中有13个转录因子的结合位点含有CpG;甲基化预测发现在含CpG的23个TFBS中有18个位点的CpG易发生甲基化。由此推断ASPP2是典型的多因子调控的CpG岛基因,CpG岛的异常甲基化将影响转录因子结合,导致ASPP2基因表达下调。通过对人肝癌细胞株HepG和人成纤维细胞HFL-1的ASPP2基因启动子CpG岛中含4个E2F结合位点区域的甲基化实验检测,证明这种推断是正确的。这一研究说明,对重要基因启动子区DNA甲基化及TFBS的生物信息学研究可为相关的实验研究提供指南,对促进基因表达的表观遗传调控研究具有重要意义。

This paper performed the bioinformatic and experimental studies on the methylation and transcription factor(TF) binding sites(TFBS) of the promoter region of ASPP2 gene.The results revealed that there was a 1391-bp CpG island in this region,which containsed 37 TFBSs of 19 TFs.Morover,23 binding sites of 13 TFs contained CpG dinucleotide and 78% of them(18 sites) were predicted methylated.Therefore,ASPP2 was deduced as a typical CpG-island gene regulated by multiple TFs and the abnormal methylation in this CpG island could interfere the binding of TFs and down regulate the expression of ASPP2.The experimental detection of the methylation of a DNA fragment containing 4 E2F-binding sites in this CpG island of human hepatocarcinoma cell HepG2 and human fibroblast cell HFL-1 verified this bioinformatic prediction.This study demonstrate that the bioinformatic prediction of DNA methylation and TFBS in the promoter region of important genes can provide directions for the related wet experimental studies.