Resistance of tumor cells to many chemotherapeutic agents is a major obstacle in the treatment of several types of human cancer. To explore the reversal effects of verapamil on drug-resistance of hepatic cancer cells, verapamil was used as the reversal reagent for drug-resistance in hepatic cancer cells. The cytotoxicity of ADM and other anticancer drugs to SMMC-7721/ ADM was measured by MTT assay. It shows that the reversal effect was increased with the concentration of VPL (VPL 2. 5ug/ ml, SMMC-7721/ADM c...