Nucleoside cytotoxicity on B-CLL cells.

(A) B-CLL cells were treated with 2CdA (▪), CaFdA (■), F-Ara-A (●), and dAdo (○) at 10 μmol/L for the indicated time points. Viability was assessed by counting the cells after staining with erythrosin B and is represented as percentage of the control. (B) The same cells were tested for mitochondria membrane potential by flow cytometry analysis of incorporation of DiOC₆. (C) Cells were lysed in caspase buffer and incubated with 100 μmol/L of fluorometric substrate, and caspase-9 activity was measured by fluorometric analysis. (D) Caspase-3 enzymatic activity. These data (± SD) were obtained from a single patient studied in duplicate and are representative of 6 different patients.