study of paclitaxel on growth-inhibiting effects for human lung adenocarcinoma A549 cells

Objective: To assess the growth-inhibiting effects of paclitaxel on human lung adenocarcinoma A549 cell line in vitro.Methods: A549 cells were exposed to paclitaxel at different concentration or different treating time,then the growth inhibiting effects of the cell line were detected with MTT assay,and the change of the cell cycle and apoptosis were analyzed with flow cytometry.Results: The growth inhibition effect of paclitaxel on A549 cells was time dependent（P＜0.05）.The inhibition effects caused by paclitaxel from 10 nmol/L to 1 000 nmol/L had no significant difference（P＞0.05）.At the concentration-dependent experiment,the proportion of apoptosis was highest at 10 nmol/L paclitaxel,while the percentage of G₂-M phase increased in accordance with raise of the paclitaxel concentration,when paclitaxel concentration changed from 0.1 nmol/L to（100 nmol/L）（P＜0.05）.At the time-dependent experiment,the inducement of apoptosis was time dependent（P＜0.05） and the percentage of G₂-M phase was highest at 12 h when paclitaxel was 10 nmol/L.At 1 000 nmol/L paclitaxel,G₂-M arrest was time dependent（P＜0.05）,but its function to apoptosis was later than 10 nmol/L’s.Apoptosis had no relationship with G₂-M arrest（（P＞0.05））.Conclusion: Paclitaxel inhibits the growth of A549 cells in vitro in time-dependent manner.It can induce apoptosis and G₂-M arrest but the late two have no relationship between each other.Low concentration paclitaxel can also inhibit effectively the growth of A549 cells by prolonging treatment.