The Effect Of Curcumin On MMP-9and Invasion Ability Via Inhibiting TGF-β/Smad, TGF-β/ERK Signaling In Human Breast Cancer MDA-MB-231Cells

Objective: To evaluate the effect of Curcumin on the expression ofMMP-9and invasion ability induced by TGF-β1. And to furtherinvestigate the possible mechanism of Curcumin on the prevention ofTGF-β1-regulated invasion and migration through TGF-β/Smad and/orTGF-β/MAPKs signaling in human breast cancer MDA-MB-231cells.Method：1. The cell toxicity of curcumin on MDA-MB-231cellswas measured with CCK-8assay.2. Transwell chamber checked invasion of MDA-MB-231cells w-hich treated with10ng/ml TGF-β1and/or Curcumin(≤10μM).3.The role of Curcumin on TGF-β1-stimulated protein expression ofMMP-9and Smad2, ERK1/2, p38phosphorylation were examined bywestern blot.4.The conditioned media were collected to analyze the activity ofMMP-9via zymography assay.5. Effects of Cur, PD98059(a special inhibitor of ERK), SB203580(aspecial inhibitor of p38)on TGF-β1-stimulated protein expression and activity of MMP-9were examined by western blot and zymography assay.Results：1.After treated with Curcumin, low concentrations (≤10μM)didn’t significantly affect the growth of MDA-MB-231cells during48hours(P＞0.05)，but Concentrations greater than10μM can inhibit it indose and time dependent fashion(P＜0.05).2. The invasion assay demonstrated a Cur concentration-dependent re-duction in invasion ability of the cells which were induced by TGF-β1.3. Western analysis showed that Curcumin(≤10μM) markedly inhibit–ed TGF-β1-regulated MMP-9expression and phosphorlation (activation)of Smad2, ERK1/2and p38in a dose-and time-dependent manner(P＜0.05).4. Zymography also showed TGF-β1-stimulated activity of MMP-9was blocked by Curcumin in a dose-dependent fashion(P＜0.05).5. The inhibitory effect of PD98059(30μM) on the expression andactivity of MMP-9was similar to Curcumin(P＜0.05), but SB20358(20μM)had no evident function on MMP-9（P＞0.05）.Conclusion：Curcumin reduced TGF-β1-stimulated expression andactivity of MMP-9through TGF-β/Smad and TGF-β/ERK signaling,andthen inhibiting the invasion ability of MDA-MB-231cells.