Fig. 4

USF2 was confirmed to be a direct target of miR-875-5p. A The luciferase reporter assays were performed to confirm that miR-875-5p directly bound to the 3′-UTR of USF2. Putative miR-875-5p binding site in the human USF2 3′-UTR and luciferase constructs with the wild-type and mutant miR-875-5p target sequences. The red colours indicate the wild sequences of the USF2 3′-UTR. The green colours indicate the mutant sequences of the USF2 3′-UTR. The luciferase activity results were analysed in cells treated with miR-875-5p mimics or negative control and miR-875-5p inhibitor or negative control. B The expression level of USF2 mRNA was detected by qRT–PCR in AGS and MKN-45 cells after transfection. C The expression level of USF2 protein was detected by western blot in AGS and MKN-45 cells after transfection. D Expression of USF2 mRNA in GC tissues and matched normal gastric tissues. E USF2 showed a negative correlation with miR-875-5p in 30 GC tissue samples detected by qRT–PCR. All experiments were repeated three times. *P < 0.05; Data expressed as the mean ± SD