ROS-NFκΒ mediates TGF-β1-induced expression of urokinase-type plasminogen activator, matrix metalloproteinase-9 and cell invasion

TGF-β1 has been postulated as a pro-oncogenic factor in the late step of the tumoral progression. In transformed cells, TGF-β1 enhances the capacity to degrade the extracellular matrix, cell invasiveness and epithelial-mesenchymal transition, which are crucial steps for metastasis. Urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-9 (MMP-9) are critical components in cell migration and invasion induced by TGF-β1, however, the exact mechanism by which TGF-β1 regulates uPA and MMP-9 is not well elucidated so far. In the present study, we analyzed the role of ROS-NFκΒ, signal as mediator in the cell malignity enhancement by TGF-β1. We found that TGF-β1 activates NFκΒ, through Rac1-NOXs-ROS-dependent mechanism. Our results shows that TGF-β1 stimulation of uPA and MMP-9 expression involve NOXs-dependent ROS and NFκΒ, activation, demonstrated by using DPI, NOXs inhibitor, ROS scavenger N-acetylcysteine and SN50, an NFkb inhibitor. Furthermore, we found that the inhibition of ROS and NFκΒ, abrogates TGF-β1 stimulation of EMT, cell motility and invasion. Thus, ROS-NFκΒ acts as the crucial signal in TGF-β1-induced uPA and MMP-9 expression thereby mediating the enhancement of cellular malignity by TGF-β1.