NHE1 Regulates Invasion And Metastasis Of Human Lung Cancer A549 Cells Through P38MAPK Signaling Pathway

BackgroundWith the acceleration of industrialization,the increase of environmental pollution,the aging of the population,and the unhealthy lifestyle,the morbidity and mortality of lung cancer has increased year by year.It has become the leading cause of malignancy in China,seriously threatens people's health.Although the clinical diagnosis and treatment of lung cancer have improved in recent decades,but the effect is poor,and morbidity and mortality continue to increase.Studies have shown that the invasion and metastasis of lung cancer are the main factors that affect the treatment effect and cause death of patients.Therefore,it is an important issue to explore the mechanism of lung cancer invasion and metastasis,and to find effective ways to prevent,diagnose and treat lung cancer.Sodium hydrogen exchanger one is a protein widely expressed in mammalian cell membranes,which stimulates cell growth,regulates cell function,maintains cytoskeletal integrity,and regulates cell motility under physiological conditions.But in tumor cells,sodium hydrogen exchanger one shows an overexpressed state,which not only reverses the internal and external pH of tumor cells,prevents the acidosis of tumor cells,but also promotes the degradation of extracellular matrix,changes the invasive structure of tumor cells,and changes the signaling pathway,in order to promote tumor invasion and metastasis.Matrix metalloproteinases are a group of proteolytic enzymes containing zinc ions and calcium ions that can promote tumor motion by degrading the extracellular matrix.Membrane type matrix metalloproteinases are a subfamily of MMPs,of which membrane-type metalloproteinase-one is the first identified membrane-type matrix,regulating cell growth,migration,invasion,apoptosis and gene expression,affect tumor cell invasion and metastasis,and plays an important role in the occurrence and development of tumors.Membrane matrix metalloproteinase one overexpression has been observed in lung cancer and is closely related to its invasion and metastasis.Mitogen-activated protein kinase can regulate and control many physiological and pathological activities,and can be activated by many extracellular stimulating signals,and then regulate signal transduction from the cell membrane to the nucleus.p38 MAPK is one of the subclasses of MAPKs and is a stress-activated protein kinases,involved in a variety of intracellular message delivery processes,also affect tumor invasion and metastasis.Previous studies have shown that sodium hydrogen exchanger one regulates the p38 MAPK signaling pathway and participates in sodium hydrogen exchanger one-mediated invasion and metastasis.However,in lung adenocarcinoma cell line A549,whether sodium hydrogen exchanger one regulates the p38 MAPK signaling pathway and whether its invasion and metastasis mechanism is related to membrane-type metalloproteinase-one is not yet clear.Therefore,the purpose of this study was to investigate whether sodium hydrogen exchanger one regulates the invasion and metastasis of human lung cancer A549 cells through the p38 MAPK signaling pathway and the effect on the expression of membrane matrix metalloproteinase one,in order to provide new ideas for the treatment of lung cancer.ObjectiveTo investigate whether NHE1 can mediate p38 MAPK signaling pathway to regulate the invasion and metastasis of human lung cancer A549 cells and its effect on the expression of MT1-MMP.Methods1.Cell immunofluorescence technique was used to detect the expression of NHE1 and MT1-MMP in human lung cancer A549 cells.2.A549 cells were treated with different concentrations of NHE1 specific inhibitor Cariporide.Then MTT assay was used to detect the toxic effects of drugs on the cells,and a appropriate drug concentration was selected for further experiments.3.Western blotting was used to detect the expression of NHE1,MT1-MMP protein and phosphorylation of p38 MAPK in A549 cells.4.Cell migration assay,transwell migration and transwell invasion assay were used to observe the effects of A549 cell migration and invasion ability.5.Gelatin zymography was used to determine the activity of MT1-MMP in the supernatant of the cells.Result1.Cellular immunofluorescence results suggest that human lung cancer A549 cells express NHE1,MT1-MMP;2.The results of MTT indicated that Caripoide had toxic effects on A549 cells.When the concentration of Cariporide was 20 uM,the cell viability was not affected.3.Western blotting showed that the expression of NHE1,MT1-MMP protein decreased and the phosphorylation of p38 MAPK decreased after Cariporide and SB203580 were used.4.Cell migration assay,transwell migration,and transwell invasion assays indicated that after Cariporide,SB203580 were used,the migration and invasion ability of A549 cells were significantly decreased.5.Gelatin zymography suggested that the amount of pro-MMP2 activation to MMP-2 was significantly decreased after Cariporide were used in A549 cells,which indicated that the activity of MT1-MMP was decreased.ConclusionNHE1 can regulate the invasion and metastasis of human lung cancer A549 cells through the p38 MAPK signaling pathway,and its mechanism is related to the expression of MT1-MMP.