Treatment with C
-ceramide induced different apoptotic profiles in lung cancer H1299 cells. Cells were treated with 0, 10, 20, and 50 μM C2-ceramide for 24 h. (a) Representative apoptotic profiles obtained by Annexin V/PI double staining in C2-ceramide-treated H1299 cells. (b) Quantification analysis results for late apoptosis population (%). Only annexin V (+)/PI (+) regions were analyzed. Data, mean ± SD (n = 3). Asterisks indicate statistically significant differences compared to control (P < 0.001).