Cytotoxicity of ether phospholipid BM 41.440 on neuroblastoma cells

The thioether lysophospholipid BM 41.440 proved to be toxic against cells of two neuroblastoma cell lines in a dose- and time-dependent manner. The ID50 estimated in three different in vitro test systems declined from about 10 micrograms/ml after 24 h to 1 microgram/ml after a 1-week treatment of the neuroblastoma cells. These values are comparable to the ID50 found for neoplastic cells derived from other tissues. In comparison, hematopoietic progenitor cells (granulocyte/monocyte-colony-forming units) proved to be less sensitive to short-term treatment with BM 41.440. After long exposure to this drug the selectivity towards neuroblastoma cells decreased. This observation makes it unlikely that BM 41.440 can be used for treatment of neoplasia such as neuroblastoma, because only short-term treatment is acceptable considering the high bone marrow toxicity.