Covalent DNA-protein crosslinking occurs after hyperthermia and radiation

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576104· OSTI ID:5515021

Cress, A E; Bowden, G T

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 degrees C/15 min) given prior to radiation does 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 degrees C. The DNA-protein crosslinks produced by 50-Gy X ray alone are removed after 2 hr at 37 degrees C. However, if hyperthermia (43 degrees 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. These data suggest that the synergistic action on hyperthermia with radiation is more related to the rate of removal and the type of chemical bonding involved in the covalent DNA-protein crosslinks rather than the amount of DNA-protein crosslinks.

• Research Organization: Department of Radiology/Division of Radiation Oncology, University of Arizona Health Sciences Center, Tucson
• OSTI ID: 5515021
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 95:3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560114* -- Radiation Effects on Biochemicals-- In Animals-- (-1987)
560121 -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BODY TEMPERATURE
CELL CULTURES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CROSS-LINKING
DISEASES
DNA
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
HEMIC DISEASES
HYPERTHERMIA
IONIZING RADIATIONS
LEUKEMIA
MAMMALS
MICE
NEOPLASMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
POLYMERIZATION
PROTEINS
QUANTITATIVE CHEMICAL ANALYSIS
RADIATIONS
RADIOSENSITIVITY EFFECTS
RODENTS
SYNERGISM
TEMPERATURE EFFECTS
VERTEBRATES
X RADIATION