Neuroblastoma Cells Expressing the Noradrenaline Transporter Are Destroyed More Selectively by 6‐Fluorodopamine than by 6‐Hydroxydopamine
6‐Hydroxydopamine (6‐OHDA) has been used for lesioning catecholaminergic neurons and attempted purging of neuroblastoma cells from hematopoietic stem cells in autologous bone marrow transplantation (ABMT). Neurotoxicity is mediated primarily by reactive oxygen species. In ABMT, 6‐OHDA, as a purging...
Saved in:
Published in | Journal of neurochemistry Vol. 75; no. 2; pp. 511 - 520 |
---|---|
Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford UK
Blackwell Science Ltd
01.08.2000
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | 6‐Hydroxydopamine (6‐OHDA) has been used for lesioning catecholaminergic neurons and attempted purging of neuroblastoma cells from hematopoietic stem cells in autologous bone marrow transplantation (ABMT). Neurotoxicity is mediated primarily by reactive oxygen species. In ABMT, 6‐OHDA, as a purging agent, has been unsuccessful. At physiological pH it autooxidizes before targeted uptake, resulting in nonspecific cytotoxicity of nontarget cells. A catecholamine analogue, similar to 6‐OHDA but with a lower rate of autooxidation enabling uptake by target cells, is thus required. Electron paramagnetic resonance spectra in this study show that 6‐fluorodopamine (6‐FDA) hydrolyzes slowly to 6‐OHDA at physiological pH. Oxygen consumption, H2O2, and quinone production are found to be
intermediate between those of 6‐OHDA and dopamine (DA). Relative neurotoxicity
of these compounds was assessed by cell viability and DNA damage in the human
neuroblastoma lines SH‐SY5Y and SK‐N‐LO, which express and lack the
noradrenaline transporter, respectively. Specific uptake of DA and 6‐FDA by
SH‐SY5Y cells was demonstrated by competitive
m‐[131I]iodobenzylguanidine uptake inhibition. The competition by 6‐OHDA was low owing to rapid autooxidation during incubation with equal toxicity toward both cell types. 6‐FDA toxicity was preferential for SH‐SY5Y cells and reduced in the presence of desipramine, a catecholamine uptake inhibitor. We demonstrate that 6‐FDA cytotoxicity is more specific for cells expressing catecholamine reuptake systems than is 6‐OHDA cytotoxicity. |
---|---|
Bibliography: | iodobenzylguanidine ; MTT, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide ; NA‐T, noradrenaline transporter ; 6‐OHDA, 6‐hydroxydopamine ; PBS, phosphate‐buffered saline ; TH, tyrosine hydroxylase. ABMT, autologous bone marrow transplantation ; DA, dopamine ; DBH, dopamine‐β‐hydroxylase ; DMSO, dimethyl sulfoxide ; EPR, electron paramagnetic resonance ; 6‐FDA, 6‐fluorodopamine ; GAP‐DH, glyceraldehyde‐3‐phosphate dehydrogenase ; mIBG m Abbreviations used ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0022-3042 1471-4159 |
DOI: | 10.1046/j.1471-4159.2000.0750511.x |