Thioredoxin stimulates MMP-9 expression, de-regulates the MMP-9/TIMP-1 equilibrium and promotes MMP-9 dependent invasion in human MDA-MB-231 breast cancer cells

► We model the effect of Trx-1 on MMP-9 expression and involvement in breast cancer. ► Trx-1 stimulates MMP-9 expression by increasing NF-κB mediated transcription. ► Trx-1 de-regulates the MMP-9/TIMP-1 equilibrium and promotes MMP-9-dependent invasion. ► Trx-1 effects on MMP-9 are reversed by dominant negative Trx-1 and NF-κB inhibitors. ► Trx-1 and NF-κB are targets for reducing MMP-9 involvement in breast cancer.