Figure 6.

HEY1-regulated osteosarcoma invasion is mediated by MMP9. (A) ELISA assay was performed to examine the expression of MMP9 following control siRNA or HEY1 siRNA transfection. (B) Control siRNA/143B or HEY1 siRNA/143B transfected cells were examined by using the invasion assay. The number of invasive cells was decreased in HEY1 shRNA-expressing cells. To determine if a decrease of invasion due to HEY1 knockdown could be reversed by the addition of active MMP9 protein or not, the invasion assay was performed with and without active MMP9. The experiment was performed in triplicate with similar results. *P<0.05, **P<0.01, Student's t-test.