Table 4

Insensitivity of ara-CTP metabolism to bryostatin 1 and safingol

Treatmentara-CTP formation
pmol/1.5 × 107 cells
Vehicle251  ± 38
Bryostatin247  ± 14
Safingol218  ± 43

HL-60 cells were treated with ara-C (10 μm) for 6 hr in conjunction with either 24-hr pretreatment with bryostatin 1 (10 nm) or 6-hr cotreatment with safingol (1 μm). Intracellular levels of ara-CTP were then determined by high pressure liquid chromatography as described in Experimental Procedures. Values reflect mean ± standard error of triplicate determinations.