Fig. 3. MiR-297 directly targets the 3'-UTR of STAT3 mRNA. (A) Expression of STAT3 in HEK-293T cells co-transfected with miR-297 mimics or miR-NC, and STAT3 vector containing the Wt or Mut 3'-UTR was assessed by Western blot. (B) Band intensities were measured by densitometry. Variations in protein levels were expressed as fold change compared with control after normalization to GAPDH. (C,D) The wild and mutant types of 3′-UTR of STAT3 mRNA were constructed in the reporter vector, then co-transfected with miR-297 mimics into HEK-293T cells, and finally tested by a double luciferase reporter gene system. Each experiment was performed in triplicate independently. Asterisks indicated statistically significant differences. Data was represented as means ± SD. * P < 0.001, v.s. control.