The Role And Mechanism Of FXYD5 And MMP2 In Gastric Cancer Metastasis

Objective: Based on the previous study about xenograft model of gastric cancer established by our research group,we screened FXYD5 and MMP2 genes from metastasis model.In this study we expect to explore the role and mechanism of FXYD5 and MMP2 in gastric cancer metastasis,in order to provide new markers and prognostic indicators for gastric cancer metastasis.Methods: The expression of FXYD5 and MMP2 in normal gastric epithelial cells and five gastric cancer cell lines were detected by RT-PCR and Western Blot.Two cell lines with high expression of FXYD5 or MMP2 were selected for small interfering RNA transfection,and the expression of FXYD5 or MMP2 was detected after transfection.The best silencing effect of small interfering RNA base sequence for FXYD5 or MMP2 were synthesized and screened.We further constructed the gastric cancer cell lines with FXYD5 and MMP2 low expression by transfection of lentiviruses.The expressions of FXYD5 or MMP2 were detected by RT-PCR and Western Blot,respectively,to confirm the successful construction of corresponding stable cell lines with low expression.Transwell assay was performed on two low expression cell lines and also we detect the changes of invasion ability of gastric cancer cells after low expression of FXYD5 and MMP2.The effect of low expression of FXYD5 and MMP2 on the migration of gastric cancer cells was detected by cell scratch assay.CCK8 assay was used to detect the effects of FXYD5 and MMP2 on gastric cancer cell proliferation.Those two low expression cell lines(FXYD5 and MMP2)and corresponding control cells were injected subcutaneously into nude mice respectively to observe tumor growth.Those cell lines were further injected into nude mice through tail vein to observe tumor metastasis in vivo.Further,we detected the effects of reducing MMP2 expression on EMT and apoptosis,and to explore the specific mechanism of MMP2 affecting tumor metastasis.Results: The stable transfection cell strains with low expression of FXYD5 or MMP2 were successfully established including MKN-1 sh-FXYD5,BGC-823 sh-FXYD5,MKN-1 sh-MMP2 and C61262 sh-MMP2.Cell scratch test showed that low expression of FXYD5 or MMP2 reduced the invasion ability of tumor cells.Cell scratch test displayed that low expression of FXYD5 and MMP2 weaken the migration ability of tumor cells.CCK8 assay demonstrated that low expression of FXYD5 and MMP2 decreased the proliferation ability of tumor cells.In vivo experiments revealed that low expression of FXYD5 and MMP2 reduced tumor growth and metastasis.Decreasing MMP2 expression also influence FXYD5 expression.Low expression of MMP2 can inhibit the development of gastric cancer by inhibiting EMT process and increasing apoptosis.Conclusion: Low expression of FXYD5 or MMP2 genes can weaken the invasion,migration and proliferation of gastric tumor cells,and slow down the growth of tumor cells in vivo,and reduce the metastasis of tumor cells in vivo.In addition,MMP2 expression was decreased after FXYD5 gene expression was inhibited,which can slow down the EMT process and increase cell apoptosis,thus inhibiting the development of gastric cancer.