Figure 4. Programmed cell death 4 (PDCD4), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) mRNA expressions after transfection (MOCK: blank control group; NC: negative control group; miR-21: microRNA-21). In the PDCD4 siRNA and miR-21 mimics groups, the expression of PDCD4 mRNA was lower compared with MMP-2 and MMP-9 mRNA (P<0.05). After miR-21 was inhibited, the expression of PDCD4 mRNA was significantly increased, but MMP-2 and MMP-9 mRNA were decreased. *P<0.05, compared with MOCK and NC groups; ^#P<0.05 compared with miR-21 inhibitor group (Student t-test).