Reversal Effect And Its Mechanism Of Orlistat On Cisplatin Resistance In Lung Adenocarcinoma Cell Lines A549/DDP

ObjectiveTo explore the reversal effect of orlistat on the lung cancer cisplatin-resistant cell lines A549/DDP and to explore its possible molecular mechanisms.Methods1.The effects of different concentrations of DDP（Cisplatin,DDP）on the growth of A549 cells and A549/DDP cells were detected by CCK-8method,and the corresponding IC₅₀0 and resistance index were calculated.CCK-8 method was used to screen the best experimental concentration of orlistat and to observe the effect of reversing resistance to A549/DDP cells.2.The morphological changes of cells in each experimental group and morphological changes of apoptosis after Hoechst33258 staining were observed under a microscope.The effects of different drug on cell apoptosis rate were detected by flow cytometry.3.The expression of P-gp,FASN,PI3K,Akt,p-Akt,NF-κB,Bcl-2 and cleved-caspase-3 in each experimental group were detected by Western blot.Results1.Orlistat inhibits the proliferation of A549/DDP drug-resistant cell lines with concentration dependence.The combination of orlistat with DDP increased the sensitivity of A549/DDP resistant cell lines to DDP,and the reversal folds was 5.02.2.Inverted fluorescence microscope showed that the combination group of cells showed obvious apoptosis morphological changes.Flow cytometry showed that compared with the control group and the single-drug group,the apoptosis rate of the combination group increased significantly（P<0.05）.3.Western blot showed that compared with the other three groups,the expression of P-gp was down-regulated P<0.01)and the expression of PI3K,p-Akt and NF-κB in combination group were significantly decreased（p<0.01）.The expression of Bcl-2 was decreased（p<0.01）and the expression of cleved-caspase-3 was up-regulated（p<0.01）in combination group.Although the expression of FASN was decreased in orlistat group and combination group,there was no significant difference in FASN expression between the two groups.ConclusionOrlistat increases the sensitivity of A549/DDP drug-resistant cell lines to chemotherapeutic drug DDP and reverses drug resistance of lung adenocarcinoma.The mechanism related to down-regulation of P-gp expression,inhibition of PI3K/Akt/NF-κB signaling pathway and regulation of apoptosis-related proteins.