Journal: PLoS ONE

Article Title: β-Elemene Piperazine Derivatives Induce Apoptosis in Human Leukemia Cells through Downregulation of c-FLIP and Generation of ROS

doi: 10.1371/journal.pone.0015843

Figure Lengend Snippet: ( A ) Apoptotic cells. HL-60, HP100-1, NB4 and K562 cells were treated with 10 µM DX1 for 9 h. The percentage of apoptotic cells was determined by morphological observation after AO/EB staining as described in . ( B ) The protein levels and cleavage of PARP, caspase-8 and c-FLIP. NB4, HP100-1 and K562 cells were treated with or without 10 µM DX1 for 10 h. The levels of each protein were detected using specific antibodies as described in . ( C ) MG-132 enhancement of DX1-induced apoptosis. Cells were treated with DMSO (control), MG-132 0.5 µM, DX1 8 µM or MG132 plus DX1 for 10 h (NB4 and HP100-1 cells) or for 36 h (K562 cells). The percentage of apoptotic cells was determined morphologically after AO/EB staining as described in . * P <0.05 compared to cells treated with DX1 alone. ( D ) MG-132 enhancement of DX1-induced cleavage of PARP and caspase-8 in K562 cells. K562 cells were treated with DMSO (control), MG-132 0.5 µM, DX1 8 µM or MG-132 plus DX1 for 36 h. The levels of each protein were detected using specific antibodies as described in . ( E ) The influence of c-FLIP siRNA on DX1-induced cleavage of PARP and caspase-8 in K562 cells. K562 cells were incubated with control siRNA or c-FLIP siRNA for 15 h and then treated with or without 10 µM DX1 for 24 h. The levels of each protein were deteced using specific antibodies as described in .

Article Snippet: FLIP S/L siRNA (sc-35388) and a negative control siRNA (sc-37007) were purchased from Santa Cruz Biotechnology, Inc. siRNA was transfected into the K562 cells by electroporation (Amaxa, Gaithersburg, MD) following the manufacturer's instructions.

Techniques: Staining, Control, Incubation