Extrinsic folate preconditioning interferes inhibitory effects of pemetrexed on adenocarcinoma A549 cell line in vitro

Objective To investigate the influence of extrinsic folate on the pemetrexed-induced growth inhibition and apoptosis of A549 cell line in vitro.Methods The proliferation capacity of A549 cell line was studied by MTT method after the cells were treated by different concentrations(0.0001,0.001,0.01,0.1,1,10,100,1000 μg/ml) of pemetrexed for 24 h in vitro.The effects of extrinsic folate preconditioning in different concentrations(0,3,9,27,81 nmol/L) on the pemetrexed-induced growth inhibition and apoptosis of A549 cell were investigated.Results After A549 cell was cultured with pemetrexed for 24 h,OD value was found to be decreased correspondingly in A549 cell group as the concentration of pemetrexed increased from 0.0001 μg/ml to 0.1 μg/ml.The IC50 of A549 cell treated by pemetrexed was gradually increased and apoptotic rate of A549 cell was decreased as the concentration of extrinsic folate increased(P0.05).Conclusion Pemetrexed markedly inhibits the growth of A549 cell line in a concentration-dependent manner,which can be attenuated by extrinsic folate pre-treating.