Cytokinetics of a human neuroblastoma cell line following treatment with dianhydrogalactitol

Studies were carried out on the effect of dianhydrogalactitol on a human neuroblastoma cell line in culture. The drug was cytotoxic at concentrations of 5 micrograms/ml and 10 micrograms/ml for 1 hour, but not at 1 microgram/ml. Flow cytometry of DNA showed that cell kill was preceded by a transient accumulation of cells in early S at 10 hours, and in late S at 36 hours. Smaller increases in the percent of cells in S phase were seen after treatment with 1 microgram/ml, without cell kill. It may be concluded that dianhydrogalactitol causes an S-phase block, followed by death of cells in late S at concentrations above 5 micrograms/ml.