Transcription Factor Sp1 Role In The Regulation Of Expression In Hepatoma Cells Nrage

Hepatocellular carcinoma (HCC) represents the third most frequent oncological cause of death in the world,and the second in China. It is a kind of malignant tumor with high fatality rate.The genesis of HCC is a complicated multifactorial process. Once the HCC generated, it grows rapidly because of the high cell division and reproductive activity and the plentiful blood supply in liver.NRAGE mediates various cellular functions such as regulation of apoptosis, transcription, cell cycle, cell adhesion and metastasis of turner. Therefore, it is reduced in many tumor tissues. But our research shows that NRAGE is over expressed in hepatoma carcinoma cell in contrast to normal liver cell.To study the reasons of NRAGE high expression in Hepatocellular carcinoma, the promoter of NRAGE was analysed by software. We found that NRAGE promoter contains three Sp1 binding sites. Spl is believed to play an important role in the transcription of many genes involved in cancer that have an abundance of GC boxes in their promoter region. Numerous studies have documented that Spl expression level was elevated in various human cancers and involved in the regulation of cell proliferation, invasion, angiogenesis and other biological functions. Studies has also shown that Spl is high expression in HCC. So we hypothesized that Spl can regulate the transcription of NRAGE and lead NRAGE increased in liver cancer.Here we studied the role of transcription factor spl in transcriptional regulation of NRAGE By building NRAGE promoter deletion mutant reporter gene.We cloned the promoter region of NRAGE, and detected-300 to-1OObp and lbp to 60bp of NRAGE promoter play an important role in NRAGE transcription.Then we established that the Sp1 transcription factor regulates NRAGE expression by Spl RNA interference and point mutation of Spl binding site.Finally, Using the ChIP assay,we tested that the Sp1 transcription factor binds to the NRAGE promoter region and regulate its transcription.These results show that the high expression of NRAGE in hepatoma carcinoma cell is caused by the expression of Sp1. Sp1 transcription factor binds to the NRAGE promoter region and regulate its transcription.