[Mechanism and effect of selective cyclooxygenase-2 inhibitor NS-398 on human cervical carcinoma cells].

OBJECTIVE: To investigate the effect and mechanism of the selective COX-2 inhibitor NS-398 and carboplatin on the human cervical carcinoma cell line Hela. METHODS: The effect of NS-398, carboplatin, and both on the proliferation of Hela cells was assessed by methyl-thiazolyl tetrazolium (MTT) method, and the apoptosis assay and cell cycle distribution were analyzed by flow cytometry. RESULTS: NS-398, and carboplatin inhibited the growth of Hela cells in a dose and time-dependent manner. When combining carboplatin with NS-398, the combined inhibition rate was increased, which nearly equaled the inhibition rate of the double concentrations of carboplatin. Flow cytometry demonstrated that the cell cycle was redistributed: the G(1)-phase cell fraction was increased while the S-phase cell fraction was significantly decreased after the cells were treated with NS-398 (P<0.05), However,the result was just the opposite after being treated with carboplatin. The apoptotic rate was 1.48%+/-0.03% and 3.43%+/-0.02% for pre-treatment and post-treatment with NS-398 respectively (P>0.05) while the apoptotic rate was 9.32%+/-0.02% after the treatment with carboplatin (P<0.05). CONCLUSION: NS-398 can inhibit the growth of Hela cells. The effect of NS-398 on Hela cells may not be related to the apoptosis. NS-398 and carboplatin can bring about synergistic effect in chemotherapy on Hela cells.