Effects of hyperthermia on repair of radiation-induced DNA strand breaks. [X-ray]

Journal Article · Sat Aug 01 04:00:00 EDT 1981 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575586· OSTI ID:6060901

Mills, M D; Meyn, R E

Previous reports have suggested a relationship between the heat-induced changes in nucleoprotein and the hyperthermic enhancement of radiation sensitivity. In an effort to further understand these relationships, we measured the level of initial DNA strand break damage and the DNA strand break rejoining kinetics in Chinese hamster ovary cells following combined hyperthermia and ionizing radiation treatments. The amount of protein associated with DNA measured as the ratio of (/sup 3/H)leucine to (/sup 14/C)thymidine was also compared in chromatin isolated from both heated and unheated cells. The results of these experiments show that the initial level of radiation-induced DNA strand breaks is significantly enhanced by a prior hyperthermia treatment of 43/sup 0/C for 30 min. Treatments at higher temperatures and longer treatments at the same temperature magnified this effect. Hyperthermia was also shown to cause a substantial inhibition of the DNA strand break rejoining after irradiation. Both the initial level of DNA damage and the rejoining kinetics recovered to normal levels with incubation at 37/sup 0/C between the hyperthermia and radiation treatments. Recovery of these parameters coincided with the return of the amount of protein associated with DNA to normal values, further suggesting a relationship between the changes in nucleoprotein and the hyperthermic enhancement of radiation sensivivity.

• Research Organization: Univ. of Texas System Cancer Center, Houston
• OSTI ID: 6060901
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 87:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
560201 -- Thermal Effects-- Cells-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BODY TEMPERATURE
CARBON 14 COMPOUNDS
CHROMATIN
CONNECTIVE TISSUE CELLS
DNA
ELECTROMAGNETIC RADIATION
FIBROBLASTS
HAMSTERS
HYPERTHERMIA
IONIZING RADIATIONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RECOVERY
REPAIR
RODENTS
SOMATIC CELLS
STRAND BREAKS
SURVIVAL CURVES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES
X RADIATION