Effects About Metformin On Human Lung Adenocarcinoma A549 Cell Proliferation And The Expression Of COX-2 And VEGF

Objective:The inhibition of human lung adenocarcinoma cell line A549 by metformin was studied and the expression of cyclooxygenase-2(COX-2)and vascular endothelial growth factor(VEGF) was detected to discuss the inhibitory effect and its mechanism of metformin on human lung adenocarcinoma cell line A549. Methods:(1)The human lung adenocarcinoma A549 cells were cultured in vitro on the condition of 5%CO2,37℃,using logarithmic growth phase cell in the experiment. According to the experimental design, logarithmic growth phase cells were divided into 6 groups, including experimental and control groups. The experimental groups include metformin(concentrations of 2.5mmol/L,5.0mmol/L,10mmol/L,20 mmol /L,40mmol/L), the control groups without drugs.Each group was detected the absorbance values(OD)by MTT method at 24 h, 48 h or 72 h, and then we contrasted the differences of proliferation inhibition rate in each group.(2)The expression of COX-2 and VEGF in the supernatant was detected the by enzyme-linked immunosorbent assay(ELISA) at 72 h which is best inhibition time of metformin on human lung adenocarcinoma A549 cells. At last the concentrations of COX-2 and VEGF in each group were compared. Results:(1)Metformin intervention 24 h OD value was 0.717±0.143 in control group. Experimental group OD values were 0.684±0.048, 0.645±0.073, 0.613±0.037, 0.593±0.058, 0.573±0.045;cell inhibition rates were 4.60%, 10.04%, 14.50%, 17.29%, 20.08%. There was no statistical meaning with the difference between the control groups and the experimental groups(P>0.05).(2)The OD value was 0.857±0.035 after 48 hours metformin intervention in control group.Experimental groups OD values were 0.681±0.057, 0.613±0.032, 0.557±0.065, 0.506±0.063, 0.453±0.034; cell inhibition rates were 20.05%, 28.47%, 35.00%, 40.95%, 47.14%.There was statistical meaning with the difference between the control group and the experimental groups and the experimental groups between(P>0.05).(3)The OD value was 1.074±0.143 after 72 hours metformin intervention in control group.Experimental groups OD values were 0.728±0.047,0.635±0.083, 0.575±0.059,0.519±0.053,0.451±0.039; cell inhibition rates were 32.21%,40.87%,46.46%,51.67%,58.00%.There was statistical meaning with the difference between the control group and the experimental groups and the experimental groups between(P>0.05).(4)ELISA to detect 72 h groups adenocarcinoma A549 cell supernatant on the content of COX-2 and VEGF, the results show that the experimental groups compared with control group there was a decrease in the expression of VEGF and COX-2,and the difference is statistically significant(P<0.05).Calculation of COX-2 and VEGF correlation coefficient is 0.947, which is significant positive correlation(P<0.01).Conclusion:(1)Metformin can inhibit human lung adenocarcinoma A549 cell proliferation, and the inhibition rate increased with time and concentration extention.(2)Metformin can inhibit human lung adenocarcinoma A549 cell COX-2 and the expression of VEGF, which might be one of the mechanism that metformin inhibits human lung adenocarcinoma A549 cell proliferation.(3)COX-2 and VEGF may play synergetic action in lung cancer development.