The role of AP-1 on MMP-9 expression and chrysin-inhibited MMP-9 expression by interfering with transcription factor AP-1 in AGS cells.

The AP-1 decoy oligonucleotide was co-transfected with a pGL4-MMP-9 promoter into AGS cells. After incubation with 100 nM PMA for 4 h, MMP-9 promoter luciferase activity was examined using a luminometer (A), and MMP-9 mRNA was examined by RT-PCR (B). # P<0.05 versus control; * P<0.05 versus only PMA. C-Jun and c-Fos siRNA transfected AGS cells were incubated with 100 nM PMA for 4h, and after cell harvest MMP-9 mRNA was examined by RT-PCR. # P<0.05 versus control; * P<0.05 versus only PMA (C). AGS cells pretreated with the indicated concentration of curcumin for 1 h were incubated with 100 nM PMA for 4 h. After incubation, MMP-9 mRNA in the cell lysates was determined by RT-PCR. # P<0.05 versus control; * P<0.05 versus only PMA (D). The pGL3-AP-1 transfected cells were pretreated with the indicated concentrations of chrysin for 1 h, and then were incubated with 100 nM PMA for 4 h, and AP-1 luciferase activity was determined using a luminometer. # P<0.05 versus control; * P<0.05 versus only PMA (E). AGS cells pretreated with the indicated concentrations of chrysin for 1 h were incubated with 100 nM PMA for 4 h. After incubation, c-Jun and c-Fos mRNA in the cell lysates was determined by RT-PCR (F). Cells pretreated with the indicated concentrations of chrysin were incubated with 100 nM PMA, and cell lysates were analyzed for the phosphorylated c-Jun (G), phosphorylated c-Fos (H), total c-Jun and total c-Fos by western blot analysis. # P<0.05 versus control; * P<0.05 versus only PMA. The above data represents the mean ± SD from triplicate measurements.