Fig. 5

CircDLG1 functions as a sponge for miR-141-3p to regulate CXCL12 expression. a The results of RNA immunoprecipitation for AGO2 in SGC7901 cells stably expressing Flag-AGO2 and Flag-GFP. **P < 0.01, Student’s t-test; the experiment was repeated three times. b The luciferase activity of the circDLG1 reporter after transfection of circDLG1 shRNA in SGC7901 cells. *P < 0.05, Student’s t-test; the experiment was repeated three times. c A luciferase screen with a miRNA mimic library was constructed in SGC7901 cells. d The luciferase activity of the circDLG1 reporter after transfection with four miRNAs (miR-141-3p, miR-138-5p, miR-651-3p, and miR-155-3p) in SGC7901 cells. *P < 0.05, one-way ANOVA test for the comparison of all groups, followed by Student’s t-test for the comparison of miR-138-5p, miR-141-3p, miR-651-3p, and miR-155-3p with the control group. Multigroup comparisons were adjusted using the Bonferroni method. The experiment was repeated three times. e RIP analysis with a biotin-labeled circDLG1 probe in SGC7901 cells. *P < 0.05, Student’s t-test; the experiment was repeated three times. f RIP analysis with a biotin-labeled circDLG1 probe in SGC7901 cells treated with sh-circDLG1. *P < 0.05, Student’s t-test; the experiment was repeated three times. g The association between the expression of circDLG1 and miR-141-3p in gastric cancer tissues. n = 82, P < 0.001, Pearson correlation analysis. h RNA FISH assay of circDLG1 and miR-141-3p in gastric cancer cells. Scale bar, 50 μm. i The mRNA level of CXCL12 in gastric cancer cells after the expression of miR-141-3p. *P < 0.05, Student’s t-test; the experiment was repeated three times. j SGC7901 cells and SGC7901 cells with circDLG1 knockdown (SGC7901-sh-circDLG1#1/SGC7901-sh-NC) were treated with miR-NC, miR-141-3p, or miR-141-3p inhibitor, the protein was extracted, and western blot analysis of CXCL12 protein levels was performed. k SGC7901 cells and SGC7901 cells with circDLG1 knockdown (SGC7901-sh-circDLG1#1/SGC7901-sh-NC) were cotransfected with miR-NC, miR-141-3p, or miR-141-3p inhibitor and pGL-luc-CXCL12 3′-UTR (wild-type) or pGL-luc-CXCL12 3′-UTR (mutant-type). Luciferase activity was detected using the dual-luciferase reporter assay system (Promega, USA) according to the manufacturer’s instructions. *P < 0.05, one-way ANOVA test for the comparison of all groups, followed by Student’s t-test for the comparison of the other groups with the sh-NC + miR-NC group. Multigroup comparisons were adjusted using the Bonferroni method. The experiment was repeated three times. l The association between miR-141-3p expression and CXCL12 expression in gastric cancer tissues. n = 82, P < 0.001, Pearson correlation analysis