Iodoazomycin riboside (1-(5'-iodo-5'-deoxyribofuranosyl)-2-nitroimidazole), a hypoxic cell marker. I. Synthesis and in vitro characterization
Misonidazole (MISO), a selective radiosensitizer of hypoxic cells, forms adducts with cellular biomolecules with rates which are 30-50 X higher under hypoxic as compared to aerobic conditions of incubation. This technique of sensitizer adduct formation was proposed as a possible means of measuring the hypoxic fraction of solid tumors by noninvasive procedures. Iodoazomycin riboside (5'-IAZR) and 5'-(125I)AZR were synthesized and chemically characterized. Measurements of in vitro cytotoxicity and radiosensitizing ability with EMT-6 tumor cells in vitro indicated that 5'-IAZR is approximately 3 X more toxic and effective than is azomycin riboside (AZR) and approximately 10 X more toxic and effective than is MISO. 5'-(125I)AZR was shown to selectively bind to hypoxic EMT-6 cells at rates which were 2.5-3 X faster than those of MISO. The absolute rates of binding of 5'-IAZR to hypoxic cells at concentrations of 10-100 microM are the highest observed in this laboratory for any hypoxic cell radiosensitizer tested to date. These data suggest that 5'-IAZR, when labeled with an appropriate radioisotope (e.g., 131I), might be a useful marker for hypoxic cells in solid tumors amenable to noninvasive detection. Additional studies with animal tumor models appear to be warranted.
- Research Organization:
- Univ. of Alberta, Edmonton
- OSTI ID:
- 5617059
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 2; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
ANOXIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
DRUGS
ELEMENTS
IN VITRO
INTERMEDIATE MASS NUCLEI
IODINE 131
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LABELLING
MAMMALS
MICE
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
OXYGEN
RADIOISOTOPES
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
RODENTS
SYNTHESIS
TESTING
TRACER TECHNIQUES
TUMOR CELLS
VERTEBRATES