Figure 4

miR-24 targeted the 3′UTR of RegIV gene and immunostaining of RegIV in gastric tissues. (A) Schematic graph of the putative binding sites of miR-24 in the RegIV 3′UTR. RegIV-mut indicates the RegIV-3′UTR with mutation in miR-24-binding sites. (B) miR-24 mimics downregulated activity of a luciferase reporter containing wild-type RegIV 3′UTR (*P < 0.05), but not the reporter with mutant RegIV 3′UTR. (C) Anti-miR-24 increased the luciferase activity of wild-type Luc-RegIV (*P < 0.05), but had no effect on the mutant. (D) Forty-eight hours after miR-24 mimic and control transfection of SGC-7901 cells, the protein level of RegIV was significantly decreased compared with the miR-control as determined by ELISA. Anti-miR-24 increased the expression of RegIV compared with the anti-miR-control (*P < 0.05, **P < 0.01). (E) Twenty-four hours after miR-24 mimic or inhibitor and the respective control transfection in SGC-7901 cells, there was no difference in the mRNA level of RegIV compared with the miR-control as determined by qRT-PCR (P > 0.05). Data are shown as mean ± S.D. of three independent experiments. (F) No expression of RegIV was detected in normal gastric mucosa. (G) RegIV was expressed in intestinal metaplasia of stomach. (H) Strong expression of RegIV was observed in gastric signet-ring cell carcinoma.