FIGURE 2.

Cryptotanshinone sensitizes TRAIL-induced apoptosis in A375 melanoma cells. A, cell viability was assessed by the MTT assay. *, p < 0.05 versus control, CT, and TRAIL. B, crystal violet staining of A375 cells treated with CT and TRAIL as described under “Experimental Procedures.” C, Western blotting of lysates from A375 cells that had been pretreated with CT for 12 h followed by treatment with TRAIL for 3 h using the indicated antibodies. D, caspase activities in A375 cells that had been treated with 20 μm CT for 12 h and then TRAIL for 8 h. *, p < 0.05 versus control, CT, and TRAIL. E, cells were treated as described above and stained with PI/annexin V and then analyzed by FACS. At least two independent experiments revealed largely comparable results. F, DAPI staining. Cells were treated as described above nuclei with apoptotic morphological change (arrow) were visualized using fluorescence microscopy (original magnification, ×400). G, cells were treated as described above. Cell death was determined by the live/dead cell viability assay.