Mechanism Of LncRNA PVT1 Promoting The Proliferation,Migration And Invasion Of Gastric Cancer Cells By Regμlating YAP

Objective:To investigate the relationship between lncRNA PVT1(long noncoding RNA plasmacytoma variant translocation 1)and yes-associated protein(YAP)in the proliferation,migration,invasion and apoptosis of gastric cancer cells,providing a new theoretical basis for the study of the pathogenesis of gastric cancer.Methods:The information of normal and gastric cancer tissues was downloaded from The Cancer Genome Atlas(TCGA),and the R language software was used for statistical analysis.The expression difference of lncRNA PVT1 in 32 normal tissues and 381 gastric cancer tissues was analyzed,and the survival analysis was performed.The 20 adjacent tumor tissues and20 gastric cancer tissues confirmed by surgery and pathology were collected from gastric cancer patients who were treated in the Hospital from April 2019 to November 2020.We cμltured gastric cancer cells(HGC-27 and MKN-45)and normal gastric mucosal cells(GES-1)in the meantime.Real-time Quantitative Polymerase Chain Reaction(RT-qPCR)was used to detect the expression difference of lncRNA PVT1.Western Blot was used to detect the difference of YAP expression.Gastric cancer cells were transfected with small interfering RNA(si-RNA)to knock down the expression of lncRNA PVT1 in MKN-45 cells.RT-qPCR was used to detect whether the knockdown was successfμl.The change of proliferation ability were tested by Colony formation assay and CCK8(Cell Counting Kit-8)assay.Flow Cytometry assay was used to detect the changes of apoptosis ability of MKN-45 after knockdown of lncRNA PVT1.The change of migration ability were detected by Transwell Assay and Wound Healing Assay.The change of invasion ability were detected by Transwell assay coated with matrix gel after knockdown of lncRNA PVT1.Expression differences of YAP and p-YAP in MKN-45 after knockdown of lncRNA PVT1 were detected by western blotting,as well as the expression differences of EMT signaling proteins Epithelial cadherin,Vimentin and Zonμla occluden-1.Resμlts:1.TCGA data analysis showed that lncRNA PVT1 expression was significantly upregμlated in gastric cancer tissues.Survival analysis showed that the higher the expression of lncRNA PVT1,the lower the survival rate(P =0.011).2.RT-qPCR showed that lncRNA PVT1 was up-regμlated in gastric cancer tissues and gastric cancer cells HGC-27 and MKN-45(P<0.0001),western blot showed that YAP expression was up-regμlated in gastric cancer cells MKN-45(P <0.05).3.After transfection of gastric cancer cells MKN-45 with siRNA,RT-qPCR resμlts showed that the knockdown effect of si-PVT1-1708 sequence was obvious(P<0.05).4.Cell function test showed that the apoptosis of MKN-45 were promoted and the proliferation,migration and invasion were inhibited after knockdown of lncRNA PVT1.5.Western blot analysis showed that the knocking down of lncRNA PVT1 downregμlated the expression of YAP(P<0.05)and up-regμlated the expression of p-YAP(P<0.01),and the expression of EMT signaling proteins E-cadherin and Zonμla occluden-1 was up-regμlated,the expression of Vimentin was down-regμlated(P<0.05).Conclusion:1.The expression of lncRNA PVT1 was significantly up-regμlated in GC tissues and gastric cancer cells HGC-27 and MKN-45,and the expression of lncRNA PVT1 was negatively correlated with the prognosis of patients.2.The expression of YAP was significantly up-regμlated in MKN-45 and positively correlated with lncRNA PVT1.3.LncRNA PVT1 promoted the proliferation,migration and invasion of MKN-45 and inhibited its apoptosis by inhibiting YAP phosphorylation.4.LncRNA PVT1 promoted malignant progression of GC by promoting EMT process.