Fig. 3. Pra-B inhibits TPA-induced MMP-2/-9 expression in HeLa cells. (A) The cells were pretreated with TPA (50 ng/ml) for 2 h and then incubated with Pra-B (10 and 20 μM) for 24 h. Cell lysates were analyzed through Western blotting with anti-MMP-2/-9 antibody and β-actin as a loading control. (B) Total RNA was collected, MMP-2/-9 mRNA levels were analyzed through RT-PCR, and GAPDH was used as an internal control. (C) MMP-2/-9 promoter activity levels were measured using the luciferase assay. The values shown are the mean ± SE. **P<0.01 compared with untreated cells. #P<0.01 compared with TPA alone.