Table 2.

HL-60 AR Cells Are Resistant to a Wide Variety of Drugs

Cell TreatmentPercentage of Apoptotic Cells
HL-60 PT (6 h)HL-60 AR (6 h)HL-60 AR (24 h)
None (control)4.6 ± 1.41.5 ± 1.12.1 ± 1.4
Campthotecin (0.1 μg/ml)64.5 ± 6.23.6 ± 1.24.5 ± 1.7
Camptothecin (4.0 μg/ml)89.1 ± 7.03.4 ± 2.05.4 ± 2.3
Etoposide (5.0 μg/ml)48.7 ± 5.13.5 ± 0.94.2 ± 2.1
Etoposide (20 μg/ml)72.7 ± 5.52.4 ± 1.33.3 ± 2.6
Cytarabine (40 μg/ml)42.5 ± 5.42.6 ± 1.44.9 ± 3.0
Doxorubicin (100 μg/ml)26.4 ± 2.93.1 ± 1.65.1 ± 1.8
Mitoxantrone (40 μg/ml)28.9 ± 3.12.8 ± 1.64.4 ± 2.3
Vincristine (4 μg/ml)34.4 ± 3.82.9 ± 1.94.7 ± 2.9
  • Note: Cells were exposed for either 6 or 24 h to the drugs. Quantitative analysis of apoptosis was then carried out by flow cytometry. Data are the means ± SD of three separate experiments and show the percentage of apoptotic cells.