The Effect Of Juglone On Proliferation And Drug Resitance Of Human Lung Cancer Cells In Vitro

Objective：To explore the effect and mechanism of PIN1inhibitor Juglone onproliferation and drug resistance of human lung cancer cells in vitro.Theresearch will improve the experiment basis of Juglone as a molecularinhibitors for targeted therapy on lung cancer and drug resistance.Methods：A549cells were treated by different concentrations of Juglone. Cellproliferation was measured by MTT assay respectively. The correlation ofdoses and inhibition ratio was analyzed statistically. A549/DDP cells weretreated by different concentrations of Juglone and cisplatin alone ortogether. Growth inhibition rate and drug resistance reversal index ofA549/DDP cells were measured by MTT assay respectively. Real-timePCR was carried to detect the mRNA expression of PIN1and AKT in A549cells. Western blot were used to observe the protein expression of PIN1,AKT and AKT-pS473in A549cells. The immunocytochemical method andwestern blot were used to observe the protein expression of PIN1andAKT-pS473in A549/DDP cells. Results：1.With the increasing of Juglone’s concentration, the inhibition effecton proliferation of A549enhanced (24h6.34%,21.24%,45.40%,56.14%.48h8.09%,27.14%,55.9%,63.67%）,and there was obvious linearcorrelation between Juglone concentrations and growth inhibition rate.2.Real-time PCR result showed the mRNA level of PIN1（0.807±0.005,0.708±0.067,0.521±0.040,0.282±0.020）in A549cellsdecreased（P＜0.05) and the mRNA level of AKT didn’t have significantdifference when treated by Juglone Similarly（P＞0.05). Western blotshowed the protein expression of PIN1(1.032±0.056,0.892±0.024,0.596±0.023,0.396±0.021) and AKT-pS473(0.554±0.023,0.464±0.018,0.362±0.015,0.228±0.020) in A549cells reduced（P＜0.05). Meanwhile,the expression of AKT protein had no significant difference in Juglonegroups（P＞0.05).3. The growth inhibition rate of Juglone (3.125μM,6.25μM)combined with cisplatin group significantly increased, and the maximumgrowth inhibition rate was81.05%±0.58%. Juglone (3.125μM,6.25μM)reduced IC50value of cisplatin from68.553μM to43.077μM (RI=1.591)and22.607μM (RI=3.032) respectively.4. Compared with normal control group and cisplatin alone group, theimmunocytochemical method and western blot showed the proteinexpression of PIN1and AKT-pS473reduced in A549/DDP cells treated by Juglone（P＜0.05).Conclusion：1. Inhibiting the expression of PIN1with Juglone can significantlydepress the proliferation activity of A549cells through decreasing theexpression of AKT-pS473.2. PIN1inhibitor Juglone can reverse the drug resistance of A549/DDP cells to cisplatin. Juglone can improve the sensitivity of A549/DDPcells to cisplatin to some extent by reducing AKT activity.