Verapamil enhances the antiproliferative effect of chemotherapeutic reagents and inhibits tumor growth of chemoresistant side population in pancreatic cancer

Introduction: Verapamil is an L-type calcium channel blocker and has been used in the treatment of hypertension, angina pectoris, cardiac arrhythmia, and most recently, cluster headaches. Increasing evidence shows that Verapamil is able to enhance the cytotoxic effect of certain chemotherapies and reverse multidrug resistance by competitively inhibiting drug transport through P-glycoprotein. The side population (SP) is a small subtype of tumor cells with stem-like properties which could substantially be blocked by verapamil. In this study, we focus on the therapeutic potential of verapamil on stem-like SP cells…