Repair of double-strand DNA breaks correlates with radiosensitivity of L5178Y-S and L5178Y-R cells
To better understand the basis for the difference in radiosensitivity between the variant murine leukemic lymphoblast cell lines L5178Y-R (resistant) and L5178Y-S (sensitive), the production and repair of DNA damage after X irradiation were measured by the DNA alkaline and neutral elution techniques. The initial yield of single-strand DNA breaks and the rates of their repair were found to be the same in both cell lines by the DNA alkaline elution technique. Using the technique of neutral DNA elution, L5178Y-S cells exhibited slightly increased double-strand breakage immediately after irradiation, most significantly at lower doses (i.e., less than 10 Gy). Nevertheless, even at doses that yielded equal initial double-strand breakage of both cell lines, the survival of L5178Y-S cells was significantly less than that of L5178Y-R cells. When the technique of neutral DNA elution was employed to measure the kinetics of DNA double-strand break repair, both cell lines exhibited biphasic fast and slow components of repair. However, the double-strand repair rate was much lower in the radiosensitive L5178Y-S cells than in the L5178Y-R cells (T1/2 of 60 vs 16 min). This difference was more pronounced in the fast-repair component. These results suggest that the repair of double-strand DNA breaks is an important factor determining the radiosensitivity of L5178Y cells.
- Research Organization:
- Univ. of Texas M. D. Anderson Hospital and Tumor Institute, Houston
- OSTI ID:
- 5849002
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 112:1; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BIOLOGICAL VARIABILITY
DISEASES
DNA
DNA REPAIR
ELECTROMAGNETIC RADIATION
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
GENETIC VARIABILITY
HEMIC DISEASES
IONIZING RADIATIONS
LEUKEMIA
MAMMALS
MICE
NEOPLASMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RADIOSENSITIVITY
RECOVERY
REPAIR
RODENTS
STRAND BREAKS
SURVIVAL TIME
TUMOR CELLS
VERTEBRATES
X RADIATION