Figure 4

Effects of STE on mRNA level and MMP-9 promoter activity. (A) HONE-1 cells were treated with TPA (50 ng/mL) for 1, 3, 6, and 24 h and then subjected to RT-PCR to analyze the mRNA levels of MMP-9. (B-C) HONE-1 cells were treated with STE (0, 25, 50, 75, and 100 μg/mL) in the presence or absence of TPA (50 ng/mL) for 6 h and then subjected to (B) RT-PCR and (C) TaqMan quantitative real-time PCR to analyze the mRNA levels of MMP-9. (D) HONE-1 cells were treated with STE (0, 25, 50, 75, and 100 μg/mL) in the presence or absence of TPA (50 ng/mL) for 6 h and then subjected to promoter-driven luciferase assays to analyze the promoter activity of MMP-9. The values represented the means±SD of at least three independent experiments. #p< 0.05 compared to the vehicle group; *p< 0.05 compared to the TPA treatment group.