Figure 1. Activation of Fas/Fas-L pathway in melanoma cells. DM6 or A2058 melanoma cells were cultured in absence or presence of agonistic anti-Fas antibody, CH-11, at a concentration of 1 µg/mL for 72 h. (A) western blot and bar graphs of procaspase-8 expression after CH-11 treatment. Bars represent mean ± SEM expressed as percentage of change from three separate experiments, (*p < 0.05) decrease in the level of expression. (B) MTT assay was used to determine cell survival. Treatment of A2058 cells with CH-11 induced significant cytotoxicity compared with non-treated cells. Each bar represents the mean ± SD of three independent experiments (*p < 0.05). (C) Annexin V staining was used to determine the percentage of apoptosis. Cells were stained with annexin V-PE and 7-AAD 72 h after treatment. Cells positive for annexin V-PE and 7-AAD staining were analyzed by FACScan flow cytometer with FlowJo software. One representative experiment is shown from three performed.