Covalent DNA-protein crosslinking occurs after hyperthermia and radiation
Covalent DNA-protein crosslinks occur in exponentially growing mouse leukemia cells (L1210) after exposure to ionizing radiation. The amount of DNA-protein crosslinks as measured by a filter binding assay is dose dependent upon x irradiation. Although hyperthermia and radiation in combination are synergistic with respect to cell lethality, the combination does not result in an increase of DNA-protein crosslinks when assayed immediately following treatments. Hyperthermia (43/sup 0/C/15 min) given prior to radiation dose not alter the radiation dose dependency of the amount of initial crosslinking. In addition, the amount of DNA-protein crosslinking produced by heat plus radiation is independent of the length of heating the cells at 43/sup 0/C. The DNA-protein crosslinks produced y 50-Gy x ray alone are removed after 2 hr at 37/sup 0/C. However, if hyperthermia (43/sup 0/C/15 min) is given prior to 100-Gy x ray, the removal of DNA-protein crosslinks is delayed until 4.0 hr after radiation. Phospho-serine and phospho-threonine bonds are not produced with either radiation or the combination of hyperthermia plus radiation as judged by the resistance of the bonds to guanidine hydrochloride. However, hyperthermia plus radiation causes an increase in phosphate to nitrogen type bonding. These results show that radiation alone causes covalent DNA-protein crosslinks. Hyperthermia in combination with radiation does not increase the total amount of the crosslinks but delays the removal of the crosslinks and alters the distribution of the types of chemical bonding.
- Research Organization:
- Univ. of Arizona, Tucson
- OSTI ID:
- 5653417
- Journal Information:
- Radiat. Res.; (United States), Vol. 95:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CROSS-LINKING
RADIOINDUCTION
DNA
BIOLOGICAL RADIATION EFFECTS
TEMPERATURE EFFECTS
PROTEINS
CHEMICAL BONDS
HYPERTHERMIA
MICE
SYNERGISM
TUMOR CELLS
X RADIATION
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BODY TEMPERATURE
CHEMICAL REACTIONS
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
POLYMERIZATION
RADIATION EFFECTS
RADIATIONS
RODENTS
VERTEBRATES
560111* - Radiation Effects on Biochemicals- In Vitro- (-1987)
560121 - Radiation Effects on Cells- External Source- (-1987)
560201 - Thermal Effects- Cells- (-1987)