AIM:To compare the effect of nimesulide or/and 5-fluorouracil (5-FU) on tumor growth inhibition and apoptosisin mice with the implanted hepatoma and to observe theirpossible interactions.METHODS:The inhibitory effects on tumor growth wasevaluated by inhibition rate.Apoptosis was assessed by theultrastructural,flow cytometry features and the DNA ladderdemonstrated by agarose gel electrophoresis.PGE_2 levelwas determined by radioimmunoassay.Expression levels ofc-jun,c-fos and p53 were evaluated by western blotting.RESULTS:Nimesulide or 5-FU alone inhibited the growthof hepatoma,while a synergistic effect was observed for acombined use of both.More pronounced morphologicchanges for tumor cell apoptosis and the DNA ladder werefound for the latter treatment.Expression levels of c-junand p53 were found to be elevated for the tumors frommice treated with nimesulide and 5-FU comparing to thosewith either of them,but a reduced PGE_2 level was observedonly for the treatment with nimesulide.No change wasdetected on c-fos expression.CONCLUSION:Nimesulide and 5-FU appear to havesynergistic effects for the growth inhibition and apoptosisinduction.Both were found to be overexpressed in p53 andc-jun proteins,rather than that of c-fos,associations withthe resulted apoptosis. AIM: To compare the effect of nimesulide or / and 5-fluorouracil (5-FU) on tumor growth inhibition and apoptosisin mice with the implanted hepatoma and to observe theirpossible interactions.METHODS: The inhibitory effects on tumor growth wasevaluated by inhibition rate. Apoptosis was assessed by theultrastructural, flow cytometry features and the DNA ladderdemonstrated by agarose gel electrophoresis. PGE_2 levelwas determined by radioimmunoassay. Expression levels ofc-jun, c-fos and p53 were evaluated by western blotting.RESULTS: Nimesulide or 5-FU alone inhibited the growth of hepatoma, while a synergistic effect was observed for acombined use of both. Momen pronounced morphologic changes for tumor cell apoptosis and the DNA ladder were found for the latter treatment. Expression levels of c-jun and p53 were found to be elevated for the tumors from mouse treated with nimesulide and 5-FU comparing to those with either of them, but a reduced PGE_2 level was observed simply for the treatment with nimesulide. No ch ange wasdetected on c-fos expression. CONCLUSION: Nimesulide and 5-FU appear to havesynergistic effects for the growth inhibition and apoptosisinduction. Both were found to be overexpressed in p53 andc-jun proteins, rather than that of c-fos, associations with the resulting apoptosis.