AEG1 induces COX-2 expression via activation of NF-κB and AP-1 in hepatoma HepG2 cells

Objective： The aim of this study was to investigate whether astrecyte elevated gene 1 （AEG1） regulates COX-2 expression in human hepatoma HepG2 cells and related pathways involved in this process. Methods： Human hepatoma HepG2 cells were transfected with pcDNA3.1（-）-AEG1 plasmid or psilencer2.0-AEGl-shRNA1 plasmid to up/down-regulate AEG1 expression, pcDNA3.1（-） and psilencer 2.0 empty vector plasmids were transfected respectively as control. Real-time RT-PCR was carried out to measure the expression levels of AEG1 and COX-2 mRNA. The expression levels of AEG1 and COX-2 protein were detected by Western blot. NF-KB signaling was blocked by PDTC, and AP-1 signaling was blocked by curcumin. Results： AEG1 mRNA and protein levels were increased after pcDNA3.1（-）-AEG1 transfection, and decreased after psilencer2.0-AEGl-shRNAs transfection. COX-2 mRNA and protein levels were increased in AEGl-overexpressing cells and decreased in AEGl-knockdown cells. Phosphorylations of p65 and c-jun were up-regulated in AEGl-overexpressing cells. Both PDTC and curoumin reduced COX-2 expression in HepG2 cells with AEG1 overexpression. Conclusion： AEG1- overexpressing and -knockdown HepG2 cells are established successfully. AEG1 could induce COX-2 expression though activating NF-KB and AP-1 in human hepatoma HepG2 cells.