Perifosine induces SAPK/JNK-dependent MM cell apoptosis. (A) MM.1S and BCWM.1 cells were cultured with perifosine (5-50 μM) for 48 hours. Then the percentage of cells undergoing apoptosis was studied using Apo2.7 staining and flow cytometry. (B) BCWM.1 cells were cultured with perifosine (10 μM) for the indicated periods. Whole cell lysates were subjected to Western blotting using anti-caspase 9, -caspase 8, -PARP, and α-tubulin antibodies. Horizontal lines have been inserted to indicate a repositioned gel lane. (C) BCWM.1 cells were cultured with perifosine (2-20 μM) for 6 hours. Whole cell lysates were subjected to Western blotting using anti–p-SAPK/JNK and α-tubulin antibodies. (D) BCWM.1 was cultured with control media, perifosine (10 μM), SP600125 (5-20 μM), or perifosine (10 μM) plus SP600125 (10 μM and 20 μM) for 10 hours. Whole cell lysates were subjected to Western blotting using anti–p-SAPK/JNK, -caspase 9, -caspase 8, -PARP, and α-tubulin antibodies. Horizontal lines have been inserted to indicate a repositioned gel lane. (E) BCWM.1 cells were cultured for 48 hours with media and with perifosine (5-20 μM) in the absence or presence of 5 to 20 μM of JNK inhibitor SP600125. Cytotoxicity was assessed by the MTT assay. All data represent mean (± SD) of triplicate experiment (A,E).