The Mechanism Of MicroRNA-188-5p Targeting LAPTM4B To Regulate MTOR And Suppressing The Proliferation And Invasion Of Gastric Cancer Cells

ObjectiveThis study analyzed the correlation between the expressions of miR-188-5p and LAPTM4B by detecting the expressions of miR-188-5p and LAPTM4B in gastric cancer tissues and para-carcinoma tissues.And then we explored whether LAPTM4B is the target gene of miR-188-5p and analyzed the mechanism of miR-188-5p targeting LAPTM4B to regulate the mTOR pathway and its role in the proliferation apoptosis,migration,invasion cycle and other biological processes of gastric cancer cells.MethodsA total of 12 patients tissues with gastric cancer by surgery were collected from the pathology department of the affiliated hospital of Binzhou Medical University.All patients received no treatment before surgical treatment,and all patients were followed up through the return visit center and telephone.The most easily transfected cells were selected when the dual-luciferase reported gene.SGC7901 cell line was selected as the research object to explore the mechanism of miR-188-5p on LAPTM4B gene.1.The expression of miR-188-5p and LAPTM4B mRNA were determined by RT-qPCR2.The expression of LAPTM4B and mTOR pathways related proteins were determined by IHC and western blot3.Whether miR-188-5p directly targeted LAPTM4B gene was determined by the dual-luciferase reporter assay.4.The biology behavior of cell,such as,proliferation,migration,invasion apoptosis and cycle were determined by MTT,clone formation transwell,flow cytometry,respectively.Results1.The expression of miR-188-5p in gastric cancer tissues was significantly lower than that in para-carcinoma tissues by RT-qPCR.2.The expression of LAPTM4B and LAPTM4B mRNA in gastric cancer has been significantly increased compared with para-carcinoma tissue by RT-qPCR,immunohistochemical staining and western blot,respectively.3.MiR-188-5p was negatively correlated with the expression of LAPTM4B.4.The dul-luciferase reporter gene results showed that LAPTM4B was the target gene of miR-188-5p,which confirmed that miR-188-5p played a targeted inhibitory effect on LAPTM4B gene by binding to 3'-UTR of LAPTM4B.5.After transfection of mimic-miR-188-5p into SGC7901 cells,LAPTM4B-35 protein and the expression of mTOR pathway related protein was reduced.And the results of transfecting inhibitor-miR-188-5p were contrary to the results of transfected mimic-miR-188-5p.6.The capacity of proliferation,migration,invasion,cycle of G1 phase transforming into S phase were weakened and apoptosis was enhanced after transfected mimic-miR-188-5p into SGC7901 cells.The results of transfecting inhibitor-miR-188-5p were contrary to the results of transfected mimic-miR-188-5p.ConclusionMiR-188-5p inhibits mTOR pathway activation by targeting LAPTM4B and inhibits gastric cancer cell proliferation,migration,invasion,cell cycle G1 phase to S phase transformation,and promotes apoptosis of gastric cancer cells...