MiR-711 Regulate The Epithelial Mesenchymal Transition Of Gastric Cancer Cells Through CD44

Objective: On the basis of our previous studies,we further study the regulation of mi R-711 to CD44 and the correlation with the occurrence of epithelial mesenchymal transition(EMT) of human gastric carcinoma cell lines MGC-803 and SGC-7901,initially reveal the regulatory mechanisms of mi R-711 on the invasion and metastasis of gastric cancer.Methods: 1) Use the target gene prediction database Target Scan to retrieve the binding site between mi R-711 and CD44 3'UTR. Mi R-711 mimics and CD443'UTR plasmids were transfected into 293 T cell together. Luciferase reporter assay was used to measure the luciferase activity and validate the targeting regulation of mi R-711 to CD44.2) Mi R-711 mimics,mi R-711 inhibitors and mi R-711 empty plasmids were transfected into the human gastric carcinoma cell lines MGC-803 and SGC-7901 by the method of liposomes transient transfection. Take the group of mi R-711 empty plasmids transfection as negative control and the group of blank transfection as blank control. The transfection effectiveness was observed under the fluorescence microscope after 48 hours. Western blot technology was employed to detect the expression of CD44 protein.3) CD44 interference plasmids(silent group) and CD44 empty plasmids were transfected into the human gastric carcinoma cell lines MGC-803 and SGC-7901 by the method of liposomes transient transfection. Take the group of CD44 empty plasmids transfection as negative control and the group of blank transfection as blank control. The transfection effectiveness was observed under the fluorescence microscope after 48 hours. Western blot technology was employed to detect the expression of CD44 protein and the expression of EMT related proteins like vimentin and E-cadherin protein.Results:1)Bioinformatics analysis showed that there are binding site between mi R-711 and CD44 3'UTR. Luciferase reporter assay showed that after transfecting mi R-711 mimics and CD44 3'UTR plasmids into 293 T cell together, the relative luciferase activity was lesser than the control groups(p<0.05).2) After transfecting the mi R-711 mimics, mi R-711 inhibitors and mi R-711 empty plasmids into the human gastric carcinoma cell lines MGC-803 and SGC-7901,both the Western blot technology revealed that :the expression of CD44 protein of the mi R-711 mimics group were lower than the mi R-711 inhibitors group, negative control group and blank control group(p<0.05) and the mi R-711 inhibitors group were higher than the negative control group and blank control group(p<0.05),while it had no statistically significant between the negative control group and blank control group(p>0.05).3) After transfecting the CD44 interference plasmids and CD44 empty plasmids into the human gastric carcinoma cell lines MGC-803 and SGC-7901,both the Western blot technology revealed that :the CD44 protein and vimentin protein were lower expression and the E-cadherin protein were higher expression in the silent group than the negative control group and blank control group(both p<0.05),while it had no statistically significant between the negative control group and blank control group(p>0.05).Conclusion: 1. CD44 is one of the target genes of mi R-711.2. mi R-711 can inhibit the occurrence of epithelial mesenchymal transition(EMT) in human gastric carcinoma cell lines MGC-803 and SGC-7901 through down-regulation the expression of CD44.