Figure 5.

NQO1 siRNA decreased MMP/TIMP ratios. NQO1-knockdown cells using siRNA were subjected to RT-qPCR analysis. The mRNA levels of MMP2, MMP3, MMP9, TIMP1 and TIMP2 were normalized using β-actin mRNA as an internal control of each gene expression. The (A) MMP/TIMP1 and (B) MMP/TIMP2 mRNA ratios were determined in order to evaluate the relative inhibition of the MMP activity. Data are presented as the mean ± standard error of the mean from three independent experiments. *P<0.05 vs. control. RT-qPCR, reverse transcription-quantitative polymerase chain reaction; NQO1, NAD(P)H:quinone oxidoreductase 1; siRNA, small interfering RNA; MMP, matrix metalloproteinase; TIMP, tissue inhibitor of metalloproteinases; NT, non-targeting siRNA.