Study On Proliferation,Apoptosis And Drug Resistance Of NSCLC Cells Induced By PRDX5-Nrf2 Under Oxidative Stress

Lung cancer is a very common malignancy.Its mortality ranks first in the global malignancy[1],while non-small cell lung cancer(NSCLC)accounts for 80%of all lung cancer cases.It has the characteristics of short survival,high recurrence rate and widespread drug resistance.The research on the pathogenesis,development and prognosis of non-small cell lung cancer has become a hot spot.Reactive oxidative species(ROS)is important for tumor cell proliferation,apoptosis,migration and drug resistance which has become a hot research field.In recent years,there are reports in the literature that Nrf2 and PRDX5 belong to the same antioxidant protein and have a certain regulatory effect on the proliferation,apoptosis,and resistance of tumor cells.At the same time,previous studies in the research group have demonstrated that Nrf2 and PRDX5 have a synergistic effect.Based on the facts,we further explored the effect of PRDX5-Nrf2 interaction on proliferation,apoptosis and drug resistance of NSCLC under oxidative stress conditions.Methods:Overpressing or interfering the expression of PRDX5 in non-small cell lung cancer cells and stimulated with 100?M H2O2 for 0 min,10 min,30 min,1 h,3 h,and 6 h.Protein and RNA were collected and detected the changes in the expression of PCNA,NQO1,KI67,and Cleaved Caspase3 by Western blot and RT-QPCR respectively.Afterwards,the cells interfered by siRNA PRDX5 were stimulated with(0,25,50,100,200?M H2O2 for 24 hours,then collected the protein,and detected the expression of PARP,NQO1,and Cleaved Caspase3 by Western Blot.The results showed that ROS can promote the synthesis of intracellular PRDX5,and it can activate the expression of NQO1,which an antioxidant target gene downstream of Nrf2,under oxidative stress conditions,with time or concentration of H2O2 growed.It also can promote the synthesis of proliferative-related molecules PCNA and KI67,thereby inhibit the expression of Cleaved Caspase3,the cell apoptosis-related gene.PARP showed the trend of first upward and then downward.After overexpression of PRDX5,the expression of NQO1,PCNA,and KI67 increased more markedly compared with the control group,while Cleaved Caspase3 did not change significantly.In addition,after PRDX5 expression was disturbed,NQO1,PCNA and KI67 were decreased while the expression of Cleaved Caspase3 increased,but as the time or concentration of H2O2-affected cells growed,the expression levels of NQO1 and PARP were up-regulated,PCNA and KI67 were down-regulated,and Cleaved Caspase3 was down-regulated overall.According to the changes of MRP1 in over-expressing PRDX5 group under oxidative stress,the expression of multidrug resistance protein 1(MRP1)in cells was enhanced with the improvement of oxidative stress intensity.We can see that the ability to resistance the cisplatin drugs idecreased when the Nrf2 was interfered even improved the expression of PRDX5,because of the synergistic effect of PRDX5 and Nrf2 was reduced,which lead to the expression level of MRP 1 was significantly reduced.From this we can conclude that the interaction between PRDX5 and Nrf2 can improve the proliferation activity and the drug resistance of non-small cell lung cancer cells,as well as inhibit the apoptotic behavior under oxidative stress conditions.