Silencing MMP-9 in CD9-HT1080 cells is sufficient to suppress the invasive phenotype.

<p>CD9-HT1080 cells were transiently transfected with short-interfering RNA directed to MMP-9 (CD9+ MMP-9 siRNA). Likewise, Mock- and CD9- HT1080 cells were transfected with a scrambled siRNA as a negative control (Mock+Ctr siRNA or CD9+ Ctr siRNA). (<b>A</b>) qRT-PCR analysis was used to measure changes in MMP-9 mRNA levels among Ctr and MMP-9 siRNA transfected cells. (<b>B</b>) Changes in release of MMP-9 (ng/ml) in to the cleared culture supernatant were examined using a MMP-9 specific ELISA kit. (<b>C</b>) Pro-MMP-9 levels in the supernatants of transiently transfected cells was measured using gelatin zymography and (<b>D</b>) quantified by densitometry. (<b>E</b>) A representative image of cells invading though matrigel after transfection with siRNA. (<b>F</b>) Percent cell invasion through matrigel-coated inserts after 20 hours was quantified and the results were normalized to Mock+Ctr siRNA treated cells *, p<0.05; **, p<0.001.