Comparative effects of selected plant polyphenols, gallic acid and epigallocatechin gallate, on matrix metalloproteinases activity in multidrug resistant MCF7/DOX breast cancer cells

Abstract

The aim of the study was to investigate the effect of selected polyphenols: gallic acid (GA) and epigallocatechin gallate (EGCG) on matrix metalloproteinase (MMP-2 and MMP-9) activity in multidrug resistant (MDR) human breast adenocarcinoma cells: MCF7/DOX cells and obtained recently in our laboratory MCF7/DOX₅₀₀ cells by the permanent selection of MCF7/DOX cells with 500 nM doxorubicin (DOX). The activity of MMP-2 and MMP-9 and the effect of studied polyphenols on these matrix proteases were examined by gelatin zymography assays. We have found that the activity of MMP-2 and MMP-9 significantly increased in resistant MCF7/DOX and MCF7/DOX₅₀₀ cells whereas they were not detected in sensitive MCF7 cells. It was also observed that GA (30, 60, 100 and 120 µM) and EGCG (5, 10 and 20 µM) caused a comparable concentration-dependent inhibition of MMP-2 and MMP-9 activity in MCF7/DOX and MCF7/DOX₅₀₀ cells. Control experiments confirmed that examined compounds in these ranges of concentration did not affect the cell growth of MCF7/DOX and MCF7/DOX₅₀₀ sublines (80-100% of control cell growth was observed in the presence of studied polyphenols).