Background: 6-Hydroxydopamine (6-OHDA) was used for ex vivo purging of bone marrow from neuroblastoma cells before autologous transplantation. However, this concept failed because of the rapid autoxidation of 6-OHDA, which leads to the generation of cytotoxic reactive oxygen species (ROS), mainly in the incubation medium before 6-OHDA can be incorporated by neuroblastoma cells.
Procedure: We based our experiments on the theory that, in contrast, 6-fluorodopamine (6-FDA), which is slowly converted to 6-OHDA at neutral pH, is able to enter neuroblastoma cells via the noradrenaline transporter (NA-T). Therefore, most ROS are generated inside the target cells.
Results: Small amounts of ascorbate prevent the extracellular conversion of 6-FDA to 6-OHDA without affecting its cytotoxicity, leading to an even more selective effect of 6-FDA.
Conclusions: We conclude that 6-FDA is a promising substance for selective destruction of NA-T-positive neuroblastoma cells.
Copyright 2000 Wiley-Liss, Inc.