Enhancement of in vitro activity against neuroblastoma by doxorubicin and deferoxamine.

A colorimetric assay was used to compare the in vitro effects on neuroblastoma cell viability of 3.75-60 microM deferoxamine or 0.125-2 microM doxorubicin alone with those of the two drugs in combination. For each of two human neuroblastoma cell lines (CHP 100 and CHP 126), exposure to each drug individually produced dose-related cytotoxic effects within 3 days. When these cells were simultaneously exposed to both drugs, even at concentrations achievable in vivo, cell death was greater than what could be accounted for by either drug alone. Cytotoxicity was further potentiated to a variable extent when the cells were sequentially exposed to deferoxamine and doxorubicin at 24-hour intervals. Thus, this combination of drugs warrants further study.