Fig. 3

DKK1 was a direct target of miR-613. RASFs were transfected with miR-613 mimic or miR-NC for 48 h. (a) Relative miR-613 level in RA tissues and their corresponding adjacent normal tissues. (b) Relative miR-613 level analyzed by RT-PCR in RASFs and their corresponding adjacent normal SFs were normalized with U6 snRNA. (c) Pearson’s correlation analysis of relative expression levels of miR-613 and relative DKK1 mRNA levels in RA tissues. (d) Schematic representation of DKK1 3′UTRs showing putative miRNA target site. (e) Analysis of relative luciferase activities of DKK1-WT and DKK1-MUT. (f) Protein and mRNA expression of DKK1 was determined by Western blot and qRT-PCR, respectively. All data are presented as mean ± SEM, n = 6. **P < 0.01, ***P < 0.001 vs. normal tissues or SFs; ^##P < 0.01 vs. miR-NC