Effect Of New Mutant SMAD4 Y353C On Migration And Invasion Of Pancreatic Cancer Cells

Research purpose Pancreatic cancer is one of the common malignant tumors,due to the incidence of pancreatic cancer is increasing year by year and lack of effective treatment,more effective treatment methods and therapeutic drugs are essential for improving the prognosis of this disease.More and more evidences show that mutations or deletions of SMAD4 gene are closely related to the development of pancreatic cancer.A new mutation site,SMAD4 Y353 C,was found in pathological section of pancreatic cancer,which is closely related to the diameter of pancreatic cancer and lymph node metastasis,but the mechanism of this mutation site in the development of pancreatic cancer is still unclear,so we believe this mutation may affect the expression of SMAD4 and lead to the occurrence of pancreatic cancer.The purpose of this study was to investigate the biological effects and potential mechanisms of the new mutant SMAD4 Y353 C on the development of pancreatic cancer cell line PANC-1.Research methods The constructed plasmids were divided into negative control(NC),wild type(SMAD4 wt)and mutant type(SMAD4 Y353C)and transfected into pancreatic cancer cell PANC-1 respectively.Firstly,the effects of three groups of plasmids on SMAD4 mRNA and protein in PANC-1 cells were analyzed by real-time quantitative PCR(qRT-PCR)and Western blot,the effects of three sets of plasmids on the migration and invasion of PANC-1 cells were examined by wound healing experiments and Transwell experiments.Finally,the expression levels of E-cadherin and Vimentin mRNA and protein in PANC-1 cells were detected by qRT-PCR and Western blot after transfected three sets of plasmids.Data were statistically analyzed using SPSS 23.0 software.Results The expression of SMAD4 mRNA and protein in PANC-1 cells transfected with SMAD4 Y353 C was lower than that of cells transfected with SMAD4 wt(P<0.05),the migration and invasion ability of PANC-1 cells transfected with SMAD4 Y353 C was significantly stronger than that of transfected SMAD4 wt(P < 0.05),Moreover,compared with transfected SMAD4 wt,SMAD4 Y353 C inhibited the expression of E-cadherin mRNA and protein in PANC-1 cells,but promoted the expression of Vimentin mRNA and protein,the difference was statistically significant(P<0.05).Moreover,compared with transfected SMAD4 wt,SMAD4 Y353 C inhibited the expression of E-cadherin mRNA and protein in PANC-1cells,but promoted the expression of Vimentin mRNA and protein(P<0.05).Conclusion Our results indicated that SMAD4 Y353 C can inhibit the expressionof SMAD4 mRNA and protein,promote the migration and invasion in pancreatic cancer cell line PANC-1,morever it also inhibit the expression of E-cadherin and promote the expression of Vimentin.