The Role And Molecular Mechanism Of Reelin In The Metastasis And Cisplatin Resistance Of Lung Adenocarcinoma

Objective Lung cancer is one of the most common causes of cancer-related deaths worldwide.At present,drug treatment is the main treatment for lung cancer.However,the resistance of lung cancer to chemotherapy drugs has always been a problem that plagues its treatment.Therefore,a better understanding of the underlying mechanisms that produce chemoresistance is of great clinical significance for the successful treatment of lung cancer.Reelin is a large secreted extracellular glycoprotein involved in the regulation of neuronal migration,adhesion,and positioning.Recent studies have shown that Reelin is expressed in tumors and promotes its chemoresistance.However,the correlation of reelin expression with the cisplatin sensitivity of lung cancer cells remains unclear and requires further elucidation.Methods:(1)CCK-8 assay was used to examine cell viability.Cells were treated with increasing concentrations of DDP for 48 h,and the cell viability was assessed by CCK-8 assay,then calculate resistance index(RI).(2)Western Blot and q RT-PCR were used to detect the protein and m RNA expression of Reelin in A549 cells and A549/DDP cells.(3)CCK-8 and Annexin V/PI staining flow cytometry were used to detect changes in cisplatin resistance after A549 up-regulated Reelin expression and A549/DDP silencing Reelin expression,respectively.(4)Western blot was used to detect the expression changes of E-cadherin,Ncadhernin,and EMT-related transcription factor proteins after A549 and A549/DDP overexpression and silence Reelin.(5)Transwell was used to detect the invasion and metastasis ability of A549 and A549/DDP,and the invasion and metastasis ability after silence or overexpression of Reelin.(6)Western blot was used to detect the effects of Reelin on PIK/AKT and MAPK signal pathways.Results(1)Compared with A549 cells,A549 / DDP cells acquired the EMT phenotype,and the expression of Reelin at m RNA and protein levels was significantly increased.(2)Knockdown of Reelin expression in A549 / DDP cells can inhibit its cisplatin resistance,and overexpression of Reelin expression in A549 cells can promote its cisplatin resistance.(3)Reelin knockdown in A549 / DDP cells can reverse its EMT phenotype and reduce the ability to invade and metastasize.Overexpression of Reelin in A549 cells can promote its EMT transformation and enhance its ability to invade and metastasize.(4)Reelin promotes EMT-related transcription factor snail expression,promotes EMT transformation and cisplatin resistance.(5)Reelin promotes lung cancer cell invasion and metastasis and cisplatin resistance through the P38 / GSK-3? / snail pathway.This phenomenon can be partially reversed with p38 specific inhibitor SB230580.Conclusion The expression of Reelin was significantly upregulated in cisplatinresistant NSCLC cells.Reelin promoted cisplatin resistance in NSCLC cells through activation of the p38/GSK3?/Snail/EMT signaling pathway.