Epigallocatechin-3-gallate (EGCG) downregulates gelatinase-B (MMP-9) by involvement of FAK/ERK/NFκB and AP-1 in the human breast cancer cell line MDA-MB-231

Abstract

Epigallocatechin-3-gallate (EGCG) is effective against the initiation, progression, and invasion of carcinogenesis.Matrix-metalloproteinases (MMPs) are a family of endopeptidases that hydrolyze the majority of extracellular proteins. MMP-9 is one of the most important members of the family and we observed the effect of EGCG on MMP-9 in the human breast cancer cell line, MDA-MB-231.The effect of EGCG on MMP-9 was studied by gelatin zymography, western blot, quantitative and semiquantitative real-time RT-PCR, immunoflourescence, cell adhesion assay, enzyme-linked immunosorbent assay,and electrophoretic mobility shift assay. EGCG treatment reduced the activity, protein, and mRNA expression ofMMP-9 and enhanced the expression of the tissue inhibitor of MMP 1 (TIMP-1). EGCG downregulated the activation of focal adhesion kinase (FAK) and extracellular regulated kinase (ERK), reduced the adhesion of MDA-MB-231 cells to fibronectin and vitronectin, and reduced the mRNA expression of the integrin receptors alpha5beta1 and alphavbeta3. The expression of the nuclear factor kappa B (NFjB), and the DNA binding activity of NFjB and activator protein 1 (AP1)to MMP-9 promoter were noticeably reduced on EGCG treatment. Upregulation of TIMP-1 and disruption of the functional status of integrin receptors may indicate decreased MMP-9 activation; inhibition of FAK andERK activation might indicate disruption in the FAK/ERK-induced MMP-9 secretion and induction. Decreased DNA binding activity of NFjB and AP1 to MMP-9 promoter might indicate transcriptional deregulation of MMP-9 gene on EGCG treatment. We propose EGCG as a potential inhibitor of the expression and activity of MMP-9 by a process involving FAK/ERK and transcription factorsin MDA-MB-231.

Silibinin inhibits TPA-induced cell migration and MMP-9 expression in thyroid and breast cancer cells

“…The DNA binding activity of a variety of transcription factors such as NF-kB and AP-1 is regulated by ERK activity (26)(27)(28). Recently, we reported that TPA-induced transcriptional activity of AP-1 is mediated through the Raf/MEK/ERK-dependent pathway (3).…”

“…The region of the MMP-9 promoter contains cis-acting regulatory elements for transcription factors, including two AP-1 sites and an NF-κB site (26,27). The DNA binding activity of a variety of transcription factors such as NF-kB and AP-1 is regulated by ERK activity (26)(27)(28).…”

The Beneficial Effects of Nutritional Compounds on Breast Cancer Metastasis

“…E-cadherin is an example of a prometastatic protein that is activated by MMP-3 and MMP9. Expression of the MMPs is driven in part by signaling through the NFκB and AP-1 pathways (Sato & Seiki, 1993;Sen et al, 2010). Therefore, nutritional compounds that have bioactive components that inhibit NFκB may down-regulate expression of the key MMPs for metastasis.…”

“…Nuclear factor kappa B (NFκB) is a transcription factor that is the end result of a large number of signaling cascades including those responsible for pro-metastatic protein expression (Helbig et al, 2003;Sato & Seiki, 1993;Sen et al, 2010). Under normal circumstances, NFκB is kept inactive by the inhibitors of κB (IκB) (Perkins, 2007).…”

Studies on Focal Adhesion Kinase in human breast cancer cell MDA-MB-231

“…MDA-MB-231 cells (300,000 cells/ml) were treated with 20 µM of ATRA, Curcumin and EGCG separately for 24 hr [29][30][31]. Control cells were treated with equal concentration of DMSO.…”