ANT2 shRNA down-regulates MMP2 and MMP9 expression and activity in SK-BR3 cells. (A) Cells were transfected with scramble shRNA or ANT2 shRNA and cultured for 24 hours. Total RNA was extracted from respective cell lines and subjected to RT-PCR using specific primers for human MMP2, MMP9, or GAPDH (internal control). (B) Cells were transfected with scramble shRNA or ANT2 shRNA and cultured in conditioned medium for 24 hours. Conditioned medium and cell lysates were electrophoresed in a polyacrylamide gel containing 1 mg/ml of gelatin. Proteolysis was detected as a white zone in a dark blue field. Band at 92 kDa indicates the active MMP9, 72 kDa the inactive MMP2, and 62 kDa active MMP2.