Figure 8. Effects of VPA or SAHA on apoptosis in AML cells not expressing AML1/ETO. THP-1 (A) or NB4 (B) cells were incubated or not (time 0) in the presence of 2 mM VPA or 1 μM SAHA for the indicated times (hours). Cells were then lysed and Western Blotting performed with the indicated antibodies. Results are from one typical experiment out of two. THP-1 (C) or NB4 (D) cells were incubated in the presence or the absence (NT) of 2 mM VPA or 1 μM SAHA for the indicated times (days). Apoptosis was then measured by the Annexin V test and flow cytometry. Values are means ± SEM of the percentages of apoptotic cells obtained from three independent experiments. The statistical significance of differences was determined by the Student’s t-test for paired samples (*p < 0.05). (E) Cells were incubated in the presence or the absence (NT) of 2 mM VPA or 1 μM SAHA for 3 d. Cytospin preparations were stained with May–Grünwald/Giemsa and the percentages of blasts (gray) or differentiated (white) cells determined as described in Materials and Methods. Differences, as determined by the Student’s t-test for paired samples, were not significant. (F) Cells were incubated or not (NT) in the presence of 2 mM VPA or 1 μM SAHA for 24 h and lysed. Western Blotting was then performed with the indicated antibodies. Results are from one typical experiment out of two.