Radiosensitivity in ataxia-telangiectasia: a new explanation

Journal Article · Mon Dec 01 04:00:00 EST 1980 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.77.12.7315· OSTI ID:6621540

Painter, R B; Young, B R

The cause of increased radiosensitivity in ataxia-telangiectasis (AT) cells may be a defect in their ability to respond to DNA damage rather than a defect in their ability to repair it. Doses of x-radiation that markedly inhibited the rate of DNA synthesis in normal human cells caused almost no inhibition in AT cells and thus less delay during which x-ray damage could be repaired. The radioresistance of DNA synthesis in AT cells was primarily due to a much smaller inhibition of replicon initiation than in normal cells; the AT cells were also more resistant to damage that inhibited chain elongation. AT cells have been reported to undergo less radiation-induced mitotic delay than normal cells, which may cause them to move from G/sub 2/ phase into mitosis before repair is complete and may result in the increased incidence of chromatid aberrations observed by others. Therefore, AT cells fail to go through those delays that allow normal cells to repair DNA damage before it can be expressed.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 6621540
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 77:12; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
AZINES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CARBON 14 COMPOUNDS
CELL CYCLE
CHROMOSOMAL ABERRATIONS
DISEASES
DNA
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
IONIZING RADIATIONS
LABELLED COMPOUNDS
MITOTIC DELAY
MUTATIONS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY
RECOVERY
REPAIR
RIBOSIDES
SKIN DISEASES
TELANGIECTASIS
THYMIDINE
TRITIUM COMPOUNDS
VASCULAR DISEASES
X RADIATION