Abstract: AIM: To study the effects of selective COX-2 inhibitor NS-398 on apoptosis of HepG₂ cell line and to evaluate the modulation activity of Bcl-2 on the procession of HepG₂ cell apoptosis.METHODS: HepG₂ cells were cultured in RPMI1640 media and treated by NS-398 for 24, 48 and 72 hours.The apoptosis of HepG₂ cells was observed by fluorescent microscopy, transmission electronmicroscopy and flow cytometric analysis.The expression of Bcl-2 in HepG₂ cells during the apoptosis was measured by immunocellularchemical staining.RESULTS: NS-398 obviously induced some morphologic features of HepG₂ cell apoptosis such as cellular nucleus shrinking, nucleus fragments, luniform chromatin agglutinating and chromatin fragmentation.Compared with the control group, the NS-398 group significantly decreased the expression of Bcl-2.CONCLUSION: COX-2 selective inhibitor NS-398 can significantly induce the apoptosis of hepG₂ cells, and Bcl-2 may play an important role in modulating apoptosis induced by NS-398.

Key words: hepatic carcinoma, cyclooxygenase-2 inhibitor, NS-398, apoptosis, Bcl-2