Figure 1. Amphiregulin is involved in cisplatin resistance in human chondrosarcoma cells. (A) SW (SW1353) and cis-SW (cisplatin-resistant) cells were treated with different concentrations of cisplatin for 24 h and cell viability was analyzed using the MTT assay. (B) Intracellular AR levels in whole cell lysates were analyzed by Western blot and qPCR assays. (C) Chondrosarcoma cells were incubated with various concentrations of AR for 24 h. Cell viability was examined by MTT assay. (D) Chondrosarcoma cells were treated with cisplatin (1 μM) for 24 h and cell apoptosis was studied according to levels of caspase-3 activity. 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; #p < 0.05; ##p < 0.01; ###p < 0.001 compared with cisplatin-treated controls.