ABSTRACT
OBJECTIVE： To investigate the inhibitory effect and potential mechanism of Brucein D （BD） combined with Taxol on the proliferation of human pancreatic cancer Capan-2 cells. METHODS： Using Capan-2 cells as object， the proliferations after treated with BD （5， 10， 15， 20 μmol/L）， Taxol （10， 20， 30， 40 nmol/L） and BD+Taxol （5 μmol/L+10 nmol/L， 10 μmol/L+20 nmol/L， 15 μmol/L+30 nmol/L， 20 μmol/L+40 nmol/L） for 48 h were determined by sulfonyl rhodamine B method. Survival rate of cells and combination index （CI） were calculated. The clone formation assay was performed to detect the formation of clonal colonies after treated with BD （20 μmol/L，hereinafter）， Taxol （40 nmol/L，hereinafter）、BD+Taxol （20 μmol/L+40 nmol/L，hereinafter） for 24 h. The rate of clone formation was calculated. DAPI method was used to observe the apoptosis of cells after treated with BD， Taxol and BD+Taxol for 24 h. Western blotting was used to detect the expression of apoptosis-related protein （Bcl-2， PARP， Caspase-3， Cleaved-caspase-3） after treated by BD， Taxol， BD+Taxol for 48 h and the expression of JNK and p-JNK after treated by BD， Taxol， BD+Taxol for 4， 6， 12 h. RESULTS： After treated with 10， 15 and 20 μmol/L BD， 20， 30 and 40 nmol/L Taxol or two-drug combination for 48 h， survival rates of cells were decreased significantly； the survival rate of drug combination group was significantly lower than the same dose of BD group and Taxol group （P＜0.05）. CI values of drug combination groups （BD 5 μmol/L+Taxol 10 nmol/L， BD 10 μmol/L+Taxol 20 nmol/L， BD 15 μmol/L+Taxol 30 nmol/L， BD 20 μmol/L+Taxol 40 nmol/L） were 0.63±0.04， 0.68±0.08， 0.89±0.12 and 0.84±0.05. After treated with 20 μmol/L BD， 40 nmol/L Taxol and two-drug combination， the formation of clonal colonies was decreased with different degrees of chromatin concentration and nuclear shrinkage； the rate of clone formation （24 h）， the expression of Bcl-2 （48 h）， PARP （48 h）， Caspase-3 （48 h） and JNK （4， 6 h， except for Taxol group） were decreased significantly， while the relative expression of Cleaved-caspase-3 （48 h） and p-JNK （4， 6， 12 h） were increased significantly. Those of BD+Taxol group were significantly better than those of BD group and Taxol group [except for JNK （4， 6， 12 h）， p-JNK （4 h）] （P＜0.05 or P＜0.01）. CONCLUSIONS： Both BD and Taxol can inhibit the proliferation and promote apoptosis of human pancreatic cancer Capan-2 cells， and the combination have a certain synergistic effect， which is better than any single drug. It may be associated with activating Caspase pathway and JNK phosphorylation.