American Society of Hematology

Figure 1.

$Figure 1. Generation of apoptosis by antitumor drugs and PI3K/Akt inhibitors in human myeloid leukemia cell lines. (A) Frequency of apoptotic cells, as determined by chromatin fragmentation, in untreated U-937 cell cultures (Cont); in cultures treated for 24 hours with LY294002 (LY), wortmannin (Wt), or Akti5 alone; and in cultures treated for 24 hours with the indicated concentrations of As2O3, either alone (As) or in combination with LY294002 (LY/As), wortmannin (Wt/As), or Akti5 (Akti5/As). The inset represents the relative level of total and phosphorylated Akt (t-Akt and p-Akt, respectively) in total cellular extracts obtained from untreated cells (Cont) and cells treated for 24 hours with LY294002 and wortmannin, as determined by immunoblot. (B) Frequency of apoptosis in U-937 cell cultures treated for the indicated time periods with 4 μMAs2O3, alone or in combination with LY294002. (C) Cell distribution according to their DNA content in untreated U-937 cell cultures (Cont) and in cultures treated for 24 hours with 4 μM As2O3 and LY294002, alone and in combination. The fraction of cells with sub-g1 DNA content (Ap) is considered as apoptotic. (D) Frequency of apoptosis in U-937 cell cultures treated for 24 hours with 4 μMAs2O3, alone or with LY294002, either in the absence (-) or the presence (+)of 50 μM Z-VAD-FMK (Z-VAD). (E) Frequency of apoptosis in human NB4 and HL-60 cell cultures, treated for 24 hours with LY294002 and the indicated concentrations of As2O3, alone or in combination. (F) Frequency of apoptosis in U-937 cell cultures treated for 24 hours with the indicated concentrations of lonidamine (Lon), 20 nM camptothecin (Cpt), and 4 μM cisplatin (CDDP), alone (-) and in combination with LY294002 or wortmannin. The asterisks indicate significant differences (*P < .02, **P < .0005, Student t test), in relation to cells treated with the correspondent antitumor drug alone. LY294002, wortmannin, and Akti5 were used at 30, 0.5, and 30 μM, respectively. All agents (antitumor drugs, kinase inhibitors, and Z-VAD-FMK) were applied simultaneously. The data in panels A-B and D-F represent the mean ± SD of at least 3 determinations. The data in panel C and the inset in panel A are representative of 2 determinations with similar results.$

Generation of apoptosis by antitumor drugs and PI3K/Akt inhibitors in human myeloid leukemia cell lines. (A) Frequency of apoptotic cells, as determined by chromatin fragmentation, in untreated U-937 cell cultures (Cont); in cultures treated for 24 hours with LY294002 (LY), wortmannin (Wt), or Akt_i5 alone; and in cultures treated for 24 hours with the indicated concentrations of As₂O₃, either alone (As) or in combination with LY294002 (LY/As), wortmannin (Wt/As), or Akt_i5 (Akt_i5/As). The inset represents the relative level of total and phosphorylated Akt (t-Akt and p-Akt, respectively) in total cellular extracts obtained from untreated cells (Cont) and cells treated for 24 hours with LY294002 and wortmannin, as determined by immunoblot. (B) Frequency of apoptosis in U-937 cell cultures treated for the indicated time periods with 4 μMAs₂O₃, alone or in combination with LY294002. (C) Cell distribution according to their DNA content in untreated U-937 cell cultures (Cont) and in cultures treated for 24 hours with 4 μM As₂O₃ and LY294002, alone and in combination. The fraction of cells with sub-g₁ DNA content (Ap) is considered as apoptotic. (D) Frequency of apoptosis in U-937 cell cultures treated for 24 hours with 4 μMAs₂O₃, alone or with LY294002, either in the absence (-) or the presence (+)of 50 μM Z-VAD-FMK (Z-VAD). (E) Frequency of apoptosis in human NB4 and HL-60 cell cultures, treated for 24 hours with LY294002 and the indicated concentrations of As₂O₃, alone or in combination. (F) Frequency of apoptosis in U-937 cell cultures treated for 24 hours with the indicated concentrations of lonidamine (Lon), 20 nM camptothecin (Cpt), and 4 μM cisplatin (CDDP), alone (-) and in combination with LY294002 or wortmannin. The asterisks indicate significant differences (^*P < .02, ^**P < .0005, Student t test), in relation to cells treated with the correspondent antitumor drug alone. LY294002, wortmannin, and Akt_i5 were used at 30, 0.5, and 30 μM, respectively. All agents (antitumor drugs, kinase inhibitors, and Z-VAD-FMK) were applied simultaneously. The data in panels A-B and D-F represent the mean ± SD of at least 3 determinations. The data in panel C and the inset in panel A are representative of 2 determinations with similar results.

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