Deficiency in DNA repair in mouse lymphoma strain L5178Y-S

Journal Article · Sun Nov 01 04:00:00 EST 1987 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.84.21.7562· OSTI ID:7071861

Evans, H H; Ricanati, M; Horng, M F

The production and repair of radiation-induced DNA damage were measured by filter elution in strains of mouse lymphoma L5178Y cells differing in their sensitivity to ionizing radiation. The induction of radiation-induced damage, as measured by filter elution at pH 12.1, 9.6, and 7.2, was similar in the resistant strain LY-R and the sensitive strain LY-S. The repair of single-strand breaks and alkali-labile sites, as measured by filter elution at pH 12.1 at various times after irradiation, was somewhat slower in strain LY-S than in strain LR-R. However, when filter elution was performed at either pH 9.6 or pH 7.2, the repair of x-radiation-induced damage was much less extensive in strain LY-S than in strain LY-R. The authors have assumed that the extent of filter elution at pH 9.6 is a measure of the occurrence of frank double-strand breaks as well as closely opposing single-strand breaks and pH 9.6-labile sites (and combinations thereof), and that the extent of elution at pH 7.2 is a measure of the occurrence of frank double-strand breaks alone. If these assumptions are correct, the results suggest that the sensitivity of strain LY-S to the cytotoxic effects of ionizing radiation is caused by a deficiency in the ability of this strain to repair frank double-strand breaks and pH 9.6-labile lesions. The results suggest that there is a difference in the nature of DNA damage measured by filter elution at pH 9.6 vs. pH 7.2 and that a deficiency in the repair of pH 9.6-labile lesions does not contribute to cell lethality in the case of the radiation-resistant variants. The radiation resistance of these variants in comparison to strain LY-S may be due at least in part to recovery of the ability to rejoin frank DNA double-strand breaks.

• Research Organization: Case Western Reserve Univ., Cleveland, OH (USA)
• OSTI ID: 7071861
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 84:21; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
AZINES
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CARBON 14 COMPOUNDS
DISEASES
DNA
DNA REPAIR
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
IMMUNE SYSTEM DISEASES
IONIZING RADIATIONS
LABELLED COMPOUNDS
LYMPHOMAS
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MICE
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NEOPLASMS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY
RECOVERY
REPAIR
RIBOSIDES
RODENTS
STRAND BREAKS
SURVIVAL CURVES
THYMIDINE
TRITIUM COMPOUNDS
TUMOR CELLS
VERTEBRATES
X RADIATION