[Effects of paclitaxel and 5-fluorouracil on growth inhibition and apoptosis of hepatoma cells: a comparative study].

OBJECTIVE: To investigate the effect of paclitaxel and 5-flurouracil (5-Fu) on growth inhibition and apoptosis of human hepatoma BEL-7402 cells. METHODS: Growth inhibition of BEL-7402 cells treated with paclitaxel and 5-Fu, respectively, was measured by ATP-tumor chemosensitivity assay (ATP-TCA), and the cell cycle kinetics and apoptosis were analyzed by flow cytometry and microscopic examination. RESULTS: BEL-7402 cells were highly sensitive to paclitaxel with growth inhibition observed in both dose- and time-dependent manners (IC(50)=5.58 x 10(-7) mol/L). Paclitaxel induced significantly higher rate of cell apoptosis than the control group (P<0.05) but significantly lower rate than that induced by 5-Fu (P<0.01). Necrosis was observed predominantly in paclitaxel-treated cells whereas 5-Fu caused mainly cell apoptosis (P<0.05). Levels of apoptosis increased in proportion to the decrement of paclitaxel concentration but directly proportional to increment of 5-Fu concentration. CONCLUSIONS: Paclitaxel and 5-Fu are effective in inducing growth inhibition and apoptosis of BEL-7402 cells. While 5-Fu causes mainly apoptosis in hepatoma cells, the anticancer mechanism of paclitaxel is predominantly through induction of necrosis.