TGF-β1 increases invasiveness of SW1990 cells through Rac1/ROS/NF-κB/IL-6/MMP-2

Human pancreatic cancer invasion and metastasis have been found to correlate with increased levels of active matrix metalloproteinase 2 (MMP-2). The multifunctional cytokine transforming growth factor beta 1 (TGF-β1) has been shown to increase both secretion of MMP-2 and invasion by several pancreatic cancer cell types. In the present study, we investigated the signaling pathway involved in TGF-β1-promoted MMP-2 secretion and invasion by human pancreatic cancer cells SW1990. Using specific inhibitors, we found that stimulation of these tumor cells with TGF-β1 induced secretion and activation of the collagenase MMP-2, which was required for TGF-β1-stimulated invasion. Our results also indicate that signaling events involved in TGF-β1-enhanced SW1990 invasiveness comprehend activation of Rac1 followed by generation of reactive oxygen species through nicotinamide adenine dinucleotide phosphate-oxidase, activation of nuclear factor-kappa beta, release of interleukin-6, and secretion and activation of MMP-2.

Research highlights
► Rac1 mediates TGF-β1-induced SW1990 invasion through MMP-2 secretion and activation.
► NADPH-generated ROS act downstream of Rac1 in TGF-β1-challenged SW1990 cells.
► TGF-β1-stimulated ROS activate NF-κB in SW1990 cells.
► NFκB-induced IL-6 release is required for secretion and activation of MMP-2 in SW1990 cells.