The effect of cyclopentenyl cytosine on human sk-n-be (2)-C neuroblastoma cells

Human neuroblastoma SK-N-BE(2)-C cell-line cells were cultured in the presence of various concentrations of cyclopentenyl cytosine (CPEC). In the absence of cytidine, the IC 50 value of CPEC for SK-N-BE(2)-C cells was 100 nM after 72 hr drug exposure. The IC 20 value was 1μM after 24 hr of exposure to CPEC in the presence of 10 μM cytidine, whereas in the absence of cytidine, CPEC at 1 μM resulted in an IC 40 value after 24 hr. Therefore, cytidine partially prevented the cytostatic effect of CPEC. Cells cultured with 1 μM CPEC for 72 hr were enriched by approximately 410% with monoand oligonucleosomes in comparison with cells cultured without CPEC. This enrichment was partially prevented with 10 μM deoxycytidine and completely prevented with 10μM cytidine.