Repressions of MMP-9 expression and NF-κB localization are involved in inhibition of lung carcinoma 95-D cell invasion by (–)-epigallocatechin-3-gallate

Epigallocatechin-3-gallate (EGCG) repressed the invasion of lung carcinoma 95-D cells in invasion assay. RT-PCR analysis illuminated that 40 μM EGCG down-regulated the expression of MMP-9 by 45.7% and the result of Western blot analysis provided further evidence. NF-κB localized in the nucleus of the 95-D cells was diminished in a dose-dependent manner in EGCG-treated cells as shown by Western blot. Intracellular oxidants were more abundant in invasive cells than in invasion-suppressed cells fed with EGCG for 18 h. Thus, the inhibition of tumor invasion by EGCG was shown to be attributed to decreases of the expression of MMP-9 and NF-κB, which may result from decrease of intracellular oxidants.