Biomaterial Database

Radiosensitization of hypoxic tumor cells in vitro by nitric oxide. 1996

R J Griffin, and C M Makepeace, and W J Hur, and C W Song

University of Minnesota Medical School, Department of Therapeutic Radiology-Radiation Oncology, Minneapolis, MN 55455, USA.

OBJECTIVE The effects of nitric oxide (NO) on the radiosensitivity of SCK tumor cells in oxic and hypoxic environments in vitro were studied. METHODS NO was delivered to cell suspensions using the NO donors 2,2-diethyl-1-nitroso-oxyhydrazine sodium salt (DEA/NO), and a spermine/nitric oxide complex (SPER/NO), which release NO at half-lives of 2.1 min and 39 min at pH 7.4, respectively. The cells were suspended in media containing DEA/NO or SPER/NO for varying lengths of time under oxic or hypoxic conditions, irradiated, and the clonogenicity determined. RESULTS Both compounds markedly radiosensitized the hypoxic cells. The drug enhancement ratios (DER) for 0.1, 1.0, and 2.0 mM DEA/NO were 2.0, 2.3 and 3.0, respectively, and those for 0.1, 1.0, and 2.0 mM SPER/NO were 1.6, 2.3, and 2.8, respectively. Aerobic cells were not radiosensitized by DEA/NO or SPER/NO. When DEA/ NO and SPER/NO were incubated in solution overnight to allow release of NO, they were found to have no radiosensitizing effect under hypoxic or oxic conditions indicating the sensitization by the NO donors was due to the NO molecule released from these drugs. At the higher concentrations, SPER/NO was found to be cytotoxic in aerobic conditions but not in hypoxic conditions. DEA/NO was only slightly toxic to the cells in both aerobic and hypoxic conditions. CONCLUSIONS NO released from NO donors DEA/NO and SPER/NO is as effective as oxygen to radiosensitize hypoxic cells in vitro. Its application to the radiosensitization of hypoxic cells in solid tumors remains to be investigated.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009569	Nitric Oxide	A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.	Endogenous Nitrate Vasodilator,Mononitrogen Monoxide,Nitric Oxide, Endothelium-Derived,Nitrogen Monoxide,Endothelium-Derived Nitric Oxide,Monoxide, Mononitrogen,Monoxide, Nitrogen,Nitrate Vasodilator, Endogenous,Nitric Oxide, Endothelium Derived,Oxide, Nitric,Vasodilator, Endogenous Nitrate
D011838	Radiation-Sensitizing Agents	Drugs used to potentiate the effectiveness of radiation therapy in destroying unwanted cells.	Radiation Sensitizer,Radiosensitizing Agent,Radiosensitizing Agents,Agents, Radiation-Sensitizing,Radiation Sensitizers,Radiation Sensitizing Agents,Radiation-Sensitizing Drugs,Radiation-Sensitizing Effect,Radiation-Sensitizing Effects,Radiosensitizing Drugs,Radiosensitizing Effect,Radiosensitizing Effects,Agent, Radiosensitizing,Agents, Radiation Sensitizing,Agents, Radiosensitizing,Drugs, Radiation-Sensitizing,Drugs, Radiosensitizing,Effect, Radiation-Sensitizing,Effect, Radiosensitizing,Effects, Radiation-Sensitizing,Effects, Radiosensitizing,Radiation Sensitizing Drugs,Radiation Sensitizing Effect,Radiation Sensitizing Effects,Sensitizer, Radiation,Sensitizers, Radiation,Sensitizing Agents, Radiation
D000332	Aerobiosis	Life or metabolic reactions occurring in an environment containing oxygen.	Aerobioses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D015674	Mammary Neoplasms, Animal	Tumors or cancer of the MAMMARY GLAND in animals (MAMMARY GLANDS, ANIMAL).	Animal Mammary Carcinoma,Mammary Carcinoma, Animal,Mammary Neoplasms,Neoplasms, Mammary,Animal Mammary Carcinomas,Animal Mammary Neoplasm,Animal Mammary Neoplasms,Carcinoma, Animal Mammary,Carcinomas, Animal Mammary,Mammary Carcinomas, Animal,Mammary Neoplasm,Mammary Neoplasm, Animal,Neoplasm, Animal Mammary,Neoplasm, Mammary,Neoplasms, Animal Mammary
D015687	Cell Hypoxia	A condition of decreased oxygen content at the cellular level.	Anoxia, Cellular,Cell Anoxia,Hypoxia, Cellular,Anoxia, Cell,Anoxias, Cell,Anoxias, Cellular,Cell Anoxias,Cell Hypoxias,Cellular Anoxia,Cellular Anoxias,Cellular Hypoxia,Cellular Hypoxias,Hypoxia, Cell,Hypoxias, Cell,Hypoxias, Cellular
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus