Chloroquine and Valproic Acid Combined Treatment in Vitro has Enhanced Cytotoxicity in an Osteosarcoma Cell Line

Choroquine (CQ) and valproic acid (VPA) have been extensively studied for biological effects. Here, wefocused on efficacy of combined CQ and VPA on osteosarcoma cell lines. Viability of osteosarcoma cell lines (U20Sand HOS) was analyzed by MTT assay. Apoptotic assays and colony formation assays were also applied. ROSgeneration and Western Blotting were performed to determine the mechanism of CQ and VPA combination inthe process of apoptosis. The viability of different osteosarcoma cell lines significantly decreased after CQ andVPA combination treatment compared with either drug used alone, and apoptosis was increased significantly.ROS generation was triggered leading to expression of apoptosis related genes being increased and of antiapoptoticrelated genes being decreased. From our data shown here, CQ and VPA combination treatment invitro enhanced cytotoxicy to osteosarcoma cells.