EFFECT OF DIFFERENT EXPOSURES TO DESFERRIOXAMINE ON NEUROBLASTOMA CELL-LINES

Desferrioxamine (DFO) has shown anti-proliferative and cytotoxic effec ts on, several tumor cells. DFO is used at present in. the treatment o f neuroblastoma in combination with chemotherapy (D-CECaT regimen: cyc lophosphamide, etoposide, carboplatin, and thiotepa). We compared the effect of continuous or intermittent exposures to DFO on H-3-thymidine uptake, viability, and cell cycle of human neuroblastoma (NB) cell li nes. Our results show that continuous exposures to DFO cause dose- and time-dependent cytotoxicity of NB cells, while intermittent exposures result in. significant NE cell toxicity only when using high DFO conc entrations. By 3H-thymidine uptake, a significant inhibition of prolif eration was observed only in continuous exposures. In addition, a cons istent arrest in G(1) phase was detected only in cultures treated cont inuously with high DFO concentrations. Our data indicate that H-3-thym idine uptake, viability, and cell cycle changes are proportional to th e extent of exposure and concentration of DFO, suggesting that in vivo DFO continuous infusion may improve anti-neuroblastoma activity.