Abstract
The metal chelator Triapine®, 3-aminopyridine-2-carboxaldehyde thiosemicarbazone, is a potent inhibitor of ribonucleotide reductase. EPR spectra consistent with signals from Fe-transferrin, heme, and low-spin iron or cupric ion were observed in peripheral blood mononuclear cells (PBMCs) obtained from patients treated with Triapine®. One signal that is unequivocally identified is the signal for Fe-transferrin. It is hypothesized that Fe uptake is blocked by reactive oxygen species generated by FeT2 or CuT that damage transferrin or transferrin receptor. A potential source for the increase in the heme signal is cytochrome c released from the mitochondria. These results provide valuable insight into the in vivo mechanism of action of Triapine®.
Original language | English |
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Pages (from-to) | 693-698 |
Number of pages | 6 |
Journal | Journal of Inorganic Biochemistry |
Volume | 102 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2008 |
Bibliographical note
Funding Information:The EPR facilities of the Department of Biophysics at the Medical College of Wisconsin are supported by Grant EB001980 (National Biomedical EPR Center) from the National Institutes of Health.
Funding
The EPR facilities of the Department of Biophysics at the Medical College of Wisconsin are supported by Grant EB001980 (National Biomedical EPR Center) from the National Institutes of Health.
Funders | Funder number |
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National Institutes of Health (NIH) | |
National Institute of Biomedical Imaging and Bioengineering | P41EB001980 |
Keywords
- 3-aminopyridine-2-carboxaldehyde thiosemicarbazone
- Electron paramagnetic resonance (EPR)
- Iron
- Patients with solid tumors
- Peripheral blood mononuclear cells (PBMCs)
- Reactive oxygen species (ROS)
- Ribonucleotide reductase
- Transferrin
- Transferrin receptor
- Triapine
ASJC Scopus subject areas
- Biochemistry
- Inorganic Chemistry