Deferoxamine and human neuroblastoma and primitive neuroectodermal tumor cell lines.

Deferoxamine at concentrations of 3.28 microM to 32.8 microM for five days causes in vitro growth inhibitory and cytolytic activities in human neuroblastoma and neuroectodermal cell lines. These effects are most likely due to intracellular iron depletion and vary with each cell line tested. A 3.28 microM threshold for cytolytic effects was observed in the most sensitive cell lines SK-N-DZ and SK-PN-LI, while proportionate responses ranging from lysis to relative growth inhibition was observed in the more refractory VA-N-BR, SK-N-LO and SK-N-AS cell lines. Cytolytic effects may represent an artifact of the in vitro setting where maximum exposure of cells to the drug can be achieved. Different sensitivities to deferoxamine in controlled in vitro conditions suggest variable anti-tumor effects can be expected in the clinical setting. Deferoxamine in patients may require a maximum tolerated dosage as a constant infusion for greater than 72 hours.