Figure 4: MiR-449a suppresses c-Myc expression by targeting the 3′-UTR of c-Myc mRNA.

(a) Comparison of human miR-449a and miR-34a, b and c sequences. Seed sequences are shown in bold. (b) Putative miR-449a binding site within the human c-Myc 3′-UTR is shown at the top. The sequences of mature miR-449a aligned to the target site and the 3′-UTR mutated in the miR-449a seed-pairing sequence was shown below. (c) Luciferase reporter assay was performed 48 h after co-transfection in LNCaP cells with Wt c-Myc or Mut c-Myc vectors together with miR-449a or negative control. (d) qRT-PCR analysis of miR-449a expression at the indicated time points after transfection with miR-449a into LNCaP cells. (e) c-Myc expression is repressed by miR-449a at the mRNA level. qRT-PCR was conducted to quantify c-Myc expression at the indicated time point after transfection with miR-449a into LNCaP cells. (f) c-Myc expression is repressed by miR-449a at the protein level. Western blotting was performed at the indicated time points after transfection with miR-449a into LNCaP cells. Data are representative of at least three independent experiments. *p < 0.05 and **p < 0.01 versus the control group.