New ceramide analogs 315 and 403 induce significant PEL apoptosis and cell-cycle arrest. (A-C) BCBL-1 (A-B) and BCP-1 (C) cells were treated with the indicated concentrations of analog 315, 403, or vehicle for 24 hours. Cell viability and apoptosis were then measured by Annexin V-PI staining and flow cytometry analysis. (D-E) Protein expression was detected using immunoblots, and β-actin was used as a loading control. (F-H) BCBL-1 and BCP-1 cells were treated with 10 µM of analog 315, 403, or vehicle for 24 hours and then stained by PI and analyzed by flow cytometry. Representative results from one of 3 independent experiments are shown. Protein expression was detected as above. Error bars represent SD for 3 independent experiments. *P < .05; **P < .01.