Etoposide induces programmed death in neurons cultured from the fetal rat central nervous system.

The effects of etoposide on the death of neurons cultured from the central nervous system (CNS) of fetal rats were examined. The cultured neurons died in the presence of 1-40 micrograms/ml of etoposide, which is known to induce programmed death in some kinds of cells, and this cytotoxic effect was prevented by inhibition of protein synthesis and/or RNA synthesis. Furthermore, DNA degradation, including a ladder-like pattern, became evident in these neurons 3 h after incubation with etoposide (10 micrograms/ml), whereas cell death commenced after about 6 h. These results indicate that etoposide-treated CNS neurons require new protein and RNA synthesis to undergo an active death programme, and that internucleosomal fragmentation of DNA mediates the etoposide-induced programmed cell death. This culture system of etoposide-treated CNS neurons is thought to be a useful model for the study of programmed neuronal cell death.