Abstract
Calcium channel upregulation has been implicated in cancer cell proliferation and progression including in breast cancer. Fortunately, the function of calcium channels can be manipulated pharmacologically using calcium channel blockers (CCBs). Amlodipine, a dihydropyridine CCB, has been demonstrated to exert cytotoxic effects in several types of cancers. The present study evaluated the effects of amlodipine on proliferation, caspase activation, colony formation, and invasion of human breast cancer cells. Cell viability was assessed using a colorimetric MTT assay. An Apo-ONE® caspase-3/7 assay was used to measure caspase-3/7 levels. Cell invasion was evaluated using Matrigel invasion chambers. The expression of phospho-(p-)ERK1/2, Bcl-2, and integrin β1 proteins were analyzed using western blotting. A one-way ANOVA with a post-hoc Tukey's multiple comparison tests was used for statistical analysis. Amlodipine significantly inhibited the growth of both MDA-MB-231 and MCF-7 human breast cancer cells in a dose-dependent manner and inhibited colony formation of MCF-7 cells, and this was accompanied by the downregulation of p-ERK1/2 in MDA-MB-231 cells. In addition, treatment with amlodipine resulted in increased caspase-3/7 levels in MDA-MB-231 cells, which was accompanied by the downregulation of the anti-apoptotic protein, Bcl-2. Moreover, amlodipine impaired the invasive abilities of MDA-MB-231 cells, and integrin β1 expression was concurrently downregulated. The present study illustrates the anticancer effects of amlodipine on breast cancer proliferation, colony formation, and invasion in vitro and highlights the potential value of amlodipine as an anticancer agent.