| Background and ObjectiveGastric cancer is the most common gastrointestinal cancer in the world.The regulation of gastrointestinal hormones in vivo plays a key role in the occurrence and development of gastric cancer.among the numerous related factors,somatostatin(somatostatin,SST)has received widespread attention.Somatostatin is a regulatory peptide which plays an important role in exocrine,endocrine,paracrine and autocrine.Most studies have shown that SST and somatostatin analogues(SSTA)inhibit the proliferation of many tumor cells,but some scholars have pointed out that different concentrations of SSTA(1 ? g/L-200 ?g/L)can stimulate the growth of gastric cancer cells,which suggests that the role of SST in different tumor behaviors is different and its mechanism is unclear.In this study,lentiviral overexpression of SST was used to observe the ultrastructural changes of gastric cancer cells,the effects of SST on the proliferation,migration and invasion of gastric cancer cells,to detect whether gastric cancer cells have epithelial mesenchymal transition(EMT),and to explore the mechanism of Wnt/?-catenin signaling pathway and its relationship with EMT.It may provide new therapeutic targets for gastric cancer.Methods1.pCMV-dR8.2dvpr,pCMV-VSV-G and pHBLV-SST plasmids were cotransfected into HEK293T cells by using the second generation lentivirus overexpression vector system,and the virus particles were obtained by collecting the supernatant of cells.The replication defective lentivirus vector particles were directly used to infect gastric cancer cells BGC823,SGC7901 and MGC803.2.Real-time fluorescence quantitative PCR and Western blotting were used to verify the changes of expression of SST gastric cancer cell lines at mRNA and protein levels.3.The changes of organelles of gastric cancer cells BGC823,SGC7901 and MGC803 were detected by overexpressing SST gene.The changes of mitochondria,endoplasmic reticulum and Golgi apparatus in organelles of gastric cancer were observed by transmission electron microscope.4.The effects of overexpressed SST gene on the proliferation,migration and invasion of gastric cancer cells BGC823,SGC7901 and MGC803 were detected.MTT test was used to detect cell proliferation,scratch test to detect cell migration and Transwell test to detect cell invasion.5.The effect of overexpressed SST gene on Epithelial mesenchymal transition of gastric cancer cells BGC823,SGC7901 and MGC803 was detected.The protein expression changes of E-cadherin,N-cadherin,Vimentin and ?-catenin were detected by western blot technique.6.To investigate whether the effect of SST genes on epithelial mesenchymal transformation is mediated by Wnt/?-catenin signaling pathway by adding Licl reagent to activate Wnt/?-catenin signaling pathway.The protein expression changes of ?-catenin,E-cadherin,N-cadherin,Vimentin were detected by western blot technique.Results1.The gastric cancer cell strain BGC823,SGC7901 and MGC803 with SST overexpression were successfully established.2.SST of overexpression affected the organelle morphology of gastric cancer cells BGC823,SGC7901,MGC803.3.SST of overexpression inhibited the proliferation,migration and invasion of gastric cancer cells BGC823,SGC7901 and MGC803 to some extent.4.SST of overexpression reverses epithelial interstitial transformation to some extent.5.SST may affect epithelial mesenchymal transition through Wnt/?-catenin signaling pathway.ConclusionsSST inhibits proliferation,migration and invasion of gastric cancer cell BGC823?SGC7901?MGC803 by regulating epithelial interstitial transformation through Wnt/?-catenin signaling pathways. |
PDF Full Text Request