Effects Of Nimesulide Combined With Platinum Chemotherapy Drugs On The Proliferation And Apoptosis Of Human Liver Cancer Cells

Objective: To investigate the mechanism of cycloxygenase-2 (COX-2) selective inhibitor Nimesulide's cytostatic effects on cell proliferation and apoptosis of human liver cancer cell line SMMC-7721, and the effects of its combined with Cisplatin (DDP) or Oxaliplatin (L-OHP).Methods:1 The human hepatocellular carcinoma SMMC-7721 cell lines were cultured 24,48,72 hours with Nimesulide at various concentrations (0,25,50,100,200,400μmol/ L) of the medium.Cell morphology changes was detected using inverted microscopy;cell proliferation changes was determined using MTT; cell apoptosis was determined using flow cytometry. The expression of Bcl-2, Bax and Cox-2 in SMMC-7721 cells was detected with Power visionTM immunohisto-chemical(ICC)method. PGE2 was examined in the supernatant fluid using ELISA.Nimesulide concentration of the combination screened from this experiment.2 The human hepatocellular carcinoma SMMC-7721 cell lines were cultured 48 hours with DDP or L-OHP at various concentrations (0.5,1.0,2.0,4.0mg/ L) and combined with Nimesulide of the medium.Cell morphology changes was detected using inverted microscopy;cell proliferation changes was determined using MTT; cell apoptosis was determined using flow cytometry.Results:1 Nimesulide on the human hepatoma cell line SMMC-7721 has growth inhibition,and the inhibitive effect was dose-dependent and time-dependent. Flow cytometry analysis showed that Nimesulide to be effective induced SMMC-7721 cell apoptosis. The expressions of COX-2 and Bcl-2 were downregulated,there were many eumorphism in cells in control group,however the expression of bax was upregulated significantly as the density of Nimesulide increased.many eumorphism could be in cell membrane and emdochylema rather than control group. PGE2 was measured by ELISA,the results revealed that the level of PGE2 significantly decreased in contrast to the control group with the increasing of concentration of Nimesulide (P<0.05).This indicated the activity of COX-2 was inhibited. Nimesulide concentration of 50μmol/L significantly inhibited SMMC-7721 cell proliferation, so chosen that as the concentration of joint experiments.2 DDP or L-OHP on the human hepatoma cell line SMMC-7721 has growth inhibition,and the inhibitive effect was dose-dependent,and L-OHP strong inhibition than DDP. The inhibitory effect of 50μmol/L Nimesulide combined with DDP or L-OHP was a joint synergy (q> 1.15). Flow cytometry analysis showed that the two platinum-based drugs can be effectively induced SMMC-7721 cells apoptosis, and when combined with the induction of Nimesulide enhanced effect.Conclusion: It suggests that nimesulide has the capabilities of inhibiting proliferation and inducing apoptpsis in SMMC-7721 cells,the effects is in a dose and time dependt-manner,its cytostatic mechanism may be associated with reducing the expression of COX-2 and bcl-2,dwonregulating the expression of bax.DDP, L-OHP on the human hepatoma cell line SMMC-7721 inhibited both proliferation and promote apoptosis, and Nimesulide in combination with the latter two have a synergistic effect.