Effect of protein synthesis inhibitors on ceramide metabolism in HL-60/VCR cells.

Cells (500 000/well) were seeded in 6-well plates in complete medium containing 1.0 μCi [³H]palmitic acid, and incubated for 6 hours with the agents indicated: emetine (0.5 μg/mL); hygromycin B (80 μg/mL); GM-CSF (1.0 nM); DT₃₈₈–GM-CSF (1.0 nM), or combinations. Total cellular lipids were extracted, and [³H]ceramide was quantitated. The concentrations of emetine and hygromycin B are those that promote a 50% suppression of protein synthesis in HL-60/VCR cells at approximately 6 hours. Each experimental group represents the average of 3 cultures with variation less than 10%.