AICAR induces apoptosis through the mitochondrial pathway in CLL cells. (A) Cells were preincubated without (−) or with 50μM IETD.fmk or 200μM Z-VAD.fmk for 30 minutes, and 0.5mM AICAR (+) was added for 24 hours. Viability was measured by flow cytometry, and it is expressed as the percentage of the viability. The top line represents the 75% quartile, and the bottom line represents the 25% quartile, with the middle line showing the median. The ends of the whiskers represent the minimum and maximum of all the data (n = 6). ***P < .005, AICAR-treated versus untreated or versus Z-VAD.fmk + AICAR, or IETD + AICAR versus IETD-treated cells. (B) Cells were preincubated without (CT) or with 200μM Z-VAD.fmk for 30 minutes, and 0.5mM AICAR was added for 6 and 12 hours. Control extracts were obtained at 12 hours. Cytochrome c and BID were analyzed in cytosolic extracts by Western blot, and viability was measured by flow cytometry. ERK was used as a control of protein loading. A representative sample is shown (n = 2).