Figure 3

PinX1 inhibits migration and invasion of breast cancer cells by suppressing MMP-9 expression and activity. (A) Western blot analysis of the relative protein levels of PinX1, MMP-2, MMP-9, TIMP-1 and TIMP-2 in PinX1 siRNA and control siRNA group for both MDAMB-231 and BT-549 cell lines. (B) Western blot analysis of the relative protein levels of PinX1, MMP-2, MMP-9, TIMP-1 and TIMP-2 in PinX1^OE and Vector groups for both MDA-MB-231 and BT-549 cell lines. (C) Top panel, gelatin zymography analysis of the relative enzyme activities of MMP-9 in PinX1 knockdown and control siRNA group for both MDA-MB-231 and BT-549 cell lines. Bottom panel, gelatin zymography analysis of the relative enzyme activities of MMP-9 in PinX1^OE and Vector groups for both MDA-MB-231 and BT-549 cell lines. (D) Western blotting of PinX1 and MMP-9 in there groups of control siRNA, PinX1 siRNA, and PinX1 siRNA co-treated with MMP-9 inhibitor I for both MDA-MB-231 and BT-549 cell lines. (E) Gelatin zymography analysis of MMP-9 in there groups of control siRNA, PinX1 siRNA, and PinX1 siRNA co-treated with MMP-9 inhibitor I for both MDA-MB-231 and BT-549 cell lines. (F) and (G) The increased abilities of migration and invasion regulated by PinX1 knockdown in breast cancer cells was blocked by MMP-9 inhibitor I. All experiments were carried out in triplicate. Histograms represent means ± SD. ***, P < 0.001.