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Sulforaphane [1-isothiocyanato-4-(methylsulfinyl)-butane] is an isothiocyanate found in some cruciferous vegetables, especially broccoli. Sulforaphane has been shown to display anti-cancer properties against various cancer cell lines. Matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix (ECM), plays an important role in cancer cell invasion. In this study, we investigated the effect of sulforaphane on 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced MMP-9 expression and cell invasion in MCF-7 cells. TPA-induced MMP-9 expression and cell invasion were decreased by sulforaphane treatment. TPA substantially increased NF-κB and AP-1 DNA binding activity. Pre-treatment with sulforaphane inhibited TPA-stimulated NF-κB binding activity, but not AP-1 binding activity. In addition, we found that sulforaphane suppressed NF-κB activation, by inhibiting phosphorylation of IκB in TPA-treated MCF-7 cells. In this study, we demonstrated that the inhibition of TPA-induced MMP-9 expression and cell invasion by sulforaphane was mediated by the suppression of the NF-κB pathway in MCF-7 cells.
Effects of protein concentration and detergent on endotoxin reduction by ultrafiltration Chromatography;Detergent;Endotoxin;Lipopolysaccharide (LPS);Ultrafiltration; Lipopolysaccharide (LPS), found in the outer membrane of Gram negative bacteria, only exerts its toxic effects when in free form. LPS has three major parts, lipid A, the toxic component, along with a core polysaccharide and O-specific polysaccharide. LPS monomers are known to have molecular masses between 10 to 30 kDa. Under physiological conditions, LPS exists in equilibrium between monomer and vesicle forms. LPS removal by 100 kDa ultrafiltration was more efficient (99.6% of LPS removed) with a low concentration of protein (2.0 mg/ml) compared to a high concentration (20.1 mg/ml). In the presence of different detergents (0.5% Tween 20, 1.0% taurodeoxycholate and 1.0% Triton X-100), LPS removal was more efficient at low protein concentrations (2.0 mg/ml) compared to high protein concentrations (20.1 mg/ml).
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is considered to have applications in cancer prevention and treatment. The beneficial effects of DHA against cancer metastasis are well established; however, the mechanisms underlying these effects in breast cancer are not clear. Cell invasion is critical for neoplastic metastasis, and involves the degradation of the extracellular matrix by matrix metalloproteinase (MMP)-9. The present study investigated the inhibitory effect of DHA on MMP-9 expression and cell invasion induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in the MCF-7 breast cancer cell line. DHA inhibited the TPA‑induced activation of mitogen‑activated protein kinase (MAPK) and the transcription of nuclear factor (NF)‑κB, but did not inhibit the transcription of activator protein‑1. DHA increased the activity of peroxisome proliferator‑activated receptor (PPAR)‑γ, an effect that was reversed by the application of the PPAR‑γ antagonist GW9662. In addition, combined treatment with GW9662 and DHA increased NF‑κB‑related protein expression. These results indicate that DHA regulates MMP‑9 expression and cell invasion via modulation of the MAPK signaling pathway and PPAR‑γ/NF‑κB activity. This suggests that DHA could be a potential therapeutic agent for the prevention of breast cancer metastasis.
1 December 2008 in Biochemical and Biophysical Research Communications