Metformin suppresses the proliferation and invasion through NF-kB and MMPs in MCF-7 cell line

Abstract

Objective: MCF-7 cells, a breast cancer cell line, are used for experiments of estrogen receptor (ER)-positive breast cancer and many sub-clones representing different classes of ER-positive tumors. We aimed to determine the efficacy of metformin, a potential anti-cancer agent, on the cell proliferation, and the expressions of NF-kB (p65), MMP-2 and MMP-9 in MCF-7 cell line. Materials and methods: MCF-7 cells (human breast adenocarcinoma) were treated with elevating doses of metformin (0-50 mM) for 24 h. The anti-proliferative effect of metformin was studied by BrdU proliferation assay, and the expression levels of NF-kB (p65), MMP-2 and MMP-9 were analyzed by immunocytochemical staining. Results: The percentage of cell proliferation was reduced significantly by 10 and 50 mM doses of metformin (p < 0.001). The expression levels of nuclear NF-kB (p65), MMP-9 and MMP-2 were considerably reduced in 50 mM metformin treated cells while the expression of cytoplasmic NF-kB (p65) elevated compared to control group (p < 0.05). Ten millimolar metformin also reduced expression of MMP-9 significantly (p < 0.05). Conclusion: Metformin may act on the proliferation, and the processes of invasion and metastasis of MCF-7 cells through blocking NF-kB, which is intensely expressed in breast cancer cells, and through diminishing the expression of MMP-2 and MMP-9 significantly.