Modulation of markers associated with aggressive phenotype in MDA-MB-231 breast carcinoma cells by sulforaphane

Metastasis as a complex process involves loss of adhesion, migration, invasion and proliferation of cancer cells. Sulforaphane (SFN) is one of naturally occurring cancer chemopreventive isothiocyanates found in cruciferous vegetables, consumption of which has been associated with reduced risk of cancer. In this study, we describe effect of SFN on various aspects determining invasive behavior of MDA-MB-231 human breast carcinoma cells. We studied modulation of molecules associated with epithelial to mesenchymal transition (EMT), hypoxic marker CA IX and mitochondrially located peripheral benzodiazepine receptor (PBR) using flow cytometry, gene expression of matrix metalloproteinases MMP1, 3, 7, 9, 14, transcription factors POU5F1 and Twist1 mRNA by RT PCR, and cytokine production by multiplex bead assay. SFN downregulated PBR and vimentin expression in a dose dependent manner, but significantly affected neither HIF-1alpha, nor CA IX protein expression, nor VEGF and GLUT1 mRNA levels. Among studied MMPs, MMP7 and MMP14 mRNA were downregulated while no apparent effect on MMP1, MMP3 and MMP9 was observed. Further, we found significant down regulation of Twist1 and POU5F1, transcription factors that mediate EMT and the self-renewal of undifferentiated embryonic stem cells. SFN reduced also the production of pro-inflammatory cytokines IL-1beta, IL-6, TNF-alpha, IFN-gamma, immunomodulating cytokine IL-4 and growth factors involved in angiogenesis PDGF and VEGF. Our study shows that SFN efficacy is associated with the reversal of several biological characteristics connected with EMT or implicated in the matrix degradation and extracellular proteolysis, as well as with reduced production of pro-inflammatory cytokines and pro-angiogenic growth factors in MDA-MB-231 cells.