The Mechanism Of Curcumin Inducing Apoptosis Of Human Lung Adenocarcinoma Cell

In this study,we explore the effect of curcumin on human lung adenocarcinoma cells and found the inhibitory effect of curcumin on lung adenocarcinoma cells,which laid a foundation for subsequent clinical application.Lung cancer is currently one of the major diseases that seriously endanger human health and life.In China,the rate of lung cancer incidence is increased rapidly and ranked first in the total number of lung cancer patients in the world.The treatment effect of lung cancer in the past decade did not significantly improve,80%of lung cancer patients is already advanced when they are diagnosized.In recent years,the drug development and treatment programs have made great progress,but lung cancer patients 5-year survival rate was only 13%[1,2],the average survival time is only 6 months.So it is became a hot spot in cancer research to find new and effective chemotherapy drugs and reverse the drug-resistant drug.Lung cancer is generally divided into two types,non-small cell lung cancer and small cell lung cancer.Of which,non-small cell lung cancer accounts for about 80%of lung cancer[3,4],it is necessary to to study the treatment of lung cancer using non-small cell lung cancer cell.Curcumin,a chemical composition extracted from curcuma,turmeric,Curcuma and calamus and other traditional Chinese medicine rhizomes,is very rare in the plant industry with diketone pigment,diketone compounds,are natural phenolic anti-oxidants[5,6].Medical research shows that curcumin has hypolipidemic,anti-tumor effects[7].Curcumin has been reported in the lung adenocarcinoma cell proliferation inhibition,induced apoptosis[7,8],but the mechanism of induction of lung cancer cell apoptosis has not yet fully elucidated.The aim of this study was to investigate the mechanism of curcumin-induced apoptosis of human lung adenocarcinoma cells and to provide experimental evidence for the clinical application of curcumin in lung adenocarcinoma.The inhibition of curcumin on human lung adenocarcinoma A549 and SPC-A-1 cells was tested by MTS.The cytotoxicity of curcumin on A549 and SPC-A-1 cells was dose-and time-dependent.To determine whether curcumin could induce apoptosis of human lung adenocarcinoma cells,A549 and SPC-A-1 cells were detected by flow cytometry with Annexin V-FITC and 7-AAD dye double staining.A549 and SPC-A-1 cells treated by curcumin(0,5,10μmol/L)for 48h,and the apoptosis of A549 and SPC-A-1 cells was induced by curcumin in a certain range.The apoptosis rate also increased.In order to study the molecular mechanism of curcumin-induced apoptosis of lung adenocarcinoma cells,we focused on the downstream molecular changes of PI3K/Akt signaling pathway.We detected the expression of key protein in the mitochondrial apoptosis signal pathway.CYP1A2,Caspase-9,Caspase-3,and PARP proteins were decreased in A549 and SPC-A-1 cells after treating by curcumin 48 h.While the cleaved-Caspase-9,cleaved-Caspase-3,cleaved-PARP and Cytochrome C protein were increased.These results suggested that curcumin-induced apoptosis of A549 and SPC-A-1 cells is mediated by mitochondrial apoptotic signaling pathway.Taken together,we found that curcumin could inhibit the proliferation and induced apoptosis of lung adenocarcinoma cells at the cellular level and make it play a role in the activation of downstream mitochondrial apoptotic signaling proteins by inhibiting Akt phosphorylation.This study demonstrated the role of curcumin in lung adenocarcinoma cells and plays an important role in PI3K-AKT signaling pathways,providing new strategies for gene targeted therapy of lung adenocarcinoma.