Epidermal Growth Factor Receptor Regulates Matrix Metalloproteinase-2 Activity in MDA-MB-231 Human Breast Cancer Cells

Abstract

Aims and Study Design: Overexpression of epidermal growth factor receptor (EGFR) and its phosphorylated form (p-EGFR) in breast carcinomas has been associated with an increase in invasive potential and decreased survival. EGFR mediated signal transduction has been reported to be involved in regulation of matrix metalloproteinases (MMPs). Elevated MMP-2 expression and activity shows significant correlation with increased invasive potential in breast cancer. As MMP-2 plays a crucial role in tumour invasion, the role of EGFR in regulation of MMP-2 expression and activity in breast cancer was studied using the human breast adenocarcinoma cell line MDA-MB-231 as a model. Methodology: MDA-MB-231 cells were cultured on 1 µg/ml epidermal growth factor (EGF) coated culture dishes for 24 hours. Control cells were cultured without EGF. MMP-2 activity was assayed by gelatin zymography. Expression of EGFR, MMP-2, focal adhesion kinase (FAK) and mitogen activated protein kinase (p38MAPK) and phosphorylation of EGFR were assayed by Western blot. Results: When MDA-MB- 231 cells were cultured on EGF, increased activation of MMP-2 and an overall increase in MMP-2 expression and activity was observed. The observed upregulation of MMP-2 was appreciably inhibited if cells were pre-treated with anti-EGFR antibody, thus blocking EGFR. Phosphorylation of EGFR and expression of p38MAPK and FAK were appreciably increased upon culture of cells on EGF. Conclusion: In MDA-MB-231 breast cancer cells, EGFR-EGF interactions promote activation of MMP-2 and an increase in MMP-2 expression and activity via EGFR mediated signal transduction cascades involving FAK and p38MAPK. As elevated MMP-2 expression and activity correlate with tumour aggressiveness, tumour cell EGF interaction via EGFR might increase the invasive potential of breast cancer cells.