Figure 3. Identification of novel ceramide analogs that sensitize human colon carcinoma cells to FasL-induced apoptosis.

(A) Human colon carcinoma SW480, RKO and HCT116 cells were cultured in the presence of the indicated ceramide analogs (10 μM), with or without MegaFasL (SW480 = 25 ng/ml, RKO = 50 ng/ml, and HCT116 = 10 ng/ml) for approximately 24 h. Both floating and adherent cells were harvested, stained with Annexin V and PI, and analyzed by flow cytometry. Shown are representative plots of apoptotic cell death. (B) Quantification of apoptotic cell death. % apoptotic cell death was calculated as % Annexin V⁺PI⁺ cells in the presence of ceramide analogs plus MegaFasL - % Annexin V⁺PI⁺ cells in the control group. Column: mean; Bar: SD.