Combined electron radiation and hyperthermia. Repair of DNA strand breaks in NHIK 3025 cells irradiated and incubated at 37, 42. 5, or 45/sup 0/C

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

DOI:https://doi.org/10.2307/3576161· OSTI ID:5653377

McGhie, J B; Wold, E; Pettersen, E O; Moan, J

Induction of DNA strand breaks by a short electron pulse (18.5 Gy) and the subsequent strand-break rejoining were investigated at hyperthermia (42.5 and 45/sup 0/C) and at 37/sup 0/C during irradiation and repair. The cells were irradiated immediately aftr 2.5 min equilibration (i.e., from 37 to 42.5 or 45/sup 0/C) to investigate the effect of short-duration hyperthermia on radiation damage and subsequent repair. Due to a high radiation dose rate and a rapid lysis technique, the cells could be kept at the actual temperature during irradiation and repair, and the strand-break frequency could be measured only seconds after irradiation. At all temperatures, a constant or possible increase in the initial number of breaks was observed during the first 7 sec after the electron pulse. At 37/sup 0/C, strand-break rejoining was nearly complete within 1 hr. Hyperthermia at 42.5/sup 0/C had only minor influence on the net rate of strand-break rejoining. At 45/sup 0/C, 50% of the breaks remained after 1 hr. Subsequent incubation for 23 hr at 37/sup 0/C reduced by half the number of breaks remaining at 1 hr in irradiated samples. Unirradiated samples exposed to the same heat treatment showed a significant increase in the number of DNA strand breaks. Thus, heat treatment at 45/sup 0/C may lead to a combined effect of reduced rejoining capacity and formation of breaks after the electron pulse which in turn may be responsible for increased cell death when both modalities are employed.

• Research Organization: Inst. for Cancer Research, Olso, Norway
• OSTI ID: 5653377
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 96:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

550300 -- Cytology
560121* -- Radiation Effects on Cells-- External Source-- (-1987)
560201 -- Thermal Effects-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
BEAMS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BODY TEMPERATURE
DNA
ELECTRON BEAMS
HYPERTHERMIA
LEPTON BEAMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PARTICLE BEAMS
RADIATION EFFECTS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RECOVERY
REPAIR
STRAND BREAKS
TEMPERATURE EFFECTS