Figure 2. Knockdown of amphiregulin expression suppresses cisplatin resistance in human chondrosarcoma cells. (A) Intracellular AR levels in whole cell lysates were analyzed by Western blot and qPCR assays. (B) Chondrosarcoma cells were treated with different concentrations of cisplatin for 24 h and cell viability was analyzed using the MTT assay. (C) Cell proliferation rates were determined by the MTT assay. (D–F) Chondrosarcoma cells were treated with cisplatin (10 μM) for 24 h and cell apoptosis was examined by caspase-3 activity (D), PI staining (E), and Annexin V-FITC binding. (F) The results were obtained from 3 independent experiments and are expressed as the mean ± SEM. * p < 0.05; ** p < 0.01; *** p < 0.001 compared with controls.