Amlodipine Inhibits Cell Proliferation and Induces Cell Cycle Arrest in Colorectal Cancer Cells

Abstract

Amlodipine, a dihydropyridine Ca2+ channel blocker, was previously shown to exhibit antitumor effects on different human cancer cells both in vitro and in vivo through the inhibition of Ca2+ cell entry. However, according to our current knowledge, amlodipine antitumor effect has not been previously examined on colorectal cancer cells (CRC). In this study, the effects of amlodipine on CRC cell proliferation, cell cycle and apoptosis were examined. In two different cell lines, treatment of CRC cells with 50 μM of amlodipine resulted in a significant reduction in cell viability compared to cells treated with dimethyl sulfoxide (DMSO) (with IC50 values of 27.17 μM for HCT116 cells and 37.69 μM for SW480 cells). Flow cytometric analysis using propidium iodide revealed that treatment with amlodipine (50 μM for 48 hours) induced G1 phase cell accumulation in both cell lines compared to DMSO-treated cells. However, treatment with amlodipine (50 μM for 48 hours) did not induce cellular apoptosis in CRC cells. Our findings showed that amlodipine has significant antiproliferative effect on CRC cells, where G1 cell cycle arrest is partially responsible for this growth inhibitory action.