The Role Of MSI2 In Epithelial Mesenchymal Transformation In Pancreatic Cancer

Objective: To investigate the role of Musashi2(MSI2)in epithelial mesenchymal transition(EMT)of pancreatic cancer and its related molecular mechanisms.Methods: Forty-three pancreatic cancer specimens with complete clinicopathological and postoperative follow-up data was collected in current study.,27 cases of men and women in 16 cases,age 29?80(median 58),postoperative pathology were confirmed as pancreatic ductal adenocarcinoma.Immunohistochemistry was used to detect the correlation and clinical significance of MSI2,ZEB1 and ZO-1 in pancreatic cancer tissues,and the relationship among the expression levels of the three at the pancreatic cancer tissues and the clinicopathological parameters was statistically analyzed.Statistical analysis of the correlation between MSI2,ZEB1 and ZO-1 at the tissue level of pancreatic cancer.MSI2 silencing stable pancreatic cancer cell lines were constructed by CRISPR-Cas9,which was investigated the effect of cell biology and molecular mechanism of MSI2.Western blot and immunoprecipitation were used to investigate the correlation between the expression of MSI2 and EMT-related proteins in pancreatic cancer cells.Chi-square test,Wilcoxon Rank test,Pearson correlation coefficient method,Kaplan-Meier single factor analysis,Log-rank test and other statistical methods were used for statistical analysis.Results: Immunohistochemical results showed that MSI2 and ZEB1 were mainly expressed in cytoplasm and nucleus,while ZO-1 was mainly expressed in cell membrane.The high expression rates of MSI2,ZEB1 and ZO-1 in pancreatic cancer tissues were 65.1%(28/43),62.7%(27/43)and 39.5%(17/43),respectively.High MSI2 expression was positively correlated with pancreatic cancer tissue size(r=0.306,p=0.045),but not with age,gender,tumor site,differentiation,lymph node metastasis,etc.Single factor analysis showed that high MSI2 expression is low pearson with poor prognosis(x2=7.750,p=0.005),lower expression ZO-1 had a poor survival prognosis(x2=9.520,p=0.002).Moreever,combination of high MSI2 and ZEB1 expression contributed to the worse prognosis(x2=7.212,p=0.007),high MSI2 expression and ZO-1 lower expression contributed to the worse prognosis(x2=10.610,p=0.001).Correlation analysis showed that MSI2 was positively correlated with ZEB1 expression in pancreatic cancer tissues(r=0.547,p=0.000)and negatively correlated with ZO-1(r=-0.506,p=0.001).In Capan-2 and SW1990 pancreatic cancer cells,Western Blot showed decreased ZEB1 expression and increased ZO-1 expression in MSI2 silenced cells.Co-Immunoprecipitation suggesting that MSI2 and ZEB1 proteins could have protein-associated binding in pancreatic cancer cells.Conclusion: In the tissue and cell level of pancreatic cancer,MSI2 is positively correlated with ZEB1 expression and negatively correlated with ZO-1 expression,suggesting that MSI2 promote the EMT process of pancreatic cancer by regulating ZEB1 and ZO-1.