Repair of chromosome damage induced by X-irradiation during G/sub 2/ phase in a line of normal human fibroblasts and its malignant derivative

Journal Article · Sun Aug 01 04:00:00 EDT 1982 · JNCI, J. Natl. Cancer Inst.; (United States)

OSTI ID:6515249

Parshad, R ^[1]; Gantt, R; Sanford, K K; Jones, G M; Tarone, R E

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1. Howard Univ. College of Medicine, Washington, DC

A line of normal human skin fibroblasts (KD) differed from its malignant derivative (HUT-14) in the extent of cytogenetic damage induced by X-irradiation during G/sub 2/ phase. Malignant cells had significantly more chromatid breaks and gaps after exposure to 25, 50, or 100 rad. Results from alkaline elution of cellular DNA immediately after irradiation showed that the normal and malignant cells in asynchronous population were equally sensitive to DNA single-strand breakage by X-irradiation. Caffeine or ..beta..-cytosine arabinoside (ara-C), inhibitors of DNA repair, when added directly following G/sub 2/ phase exposure, significantly increased the incidence of radiation-induced chromatid damage in the normal cells. In contrast, similar treatment of the malignant cells had little influence. Ara-C differed from caffeine in its effects; whereas both agents increased the frequency of chromatid breaks and gaps, only ara-C increased the frequency of gaps to the level observed in the irradiated malignant cells. Addition of catalase, which destroys H/sub 2/O/sub 2/, or mannitol, a scavenger of the derivative free hydroxyl radical (.OH), to the cultures of malignant cells before, during, and following irradiation significantly reduced the chromatid damage; and catalase prevented formation of chromatid gaps. The DNA damage induced by X-ray during G/sub 2/ phase in the normal KD cells was apparently repaired by a caffeine- and ara-C-sensitive mechanism(s) that was deficient or absent in their malignant derivatives.

• OSTI ID: 6515249
• Journal Information: JNCI, J. Natl. Cancer Inst.; (United States), Journal Name: JNCI, J. Natl. Cancer Inst.; (United States) Vol. 69:2; ISSN JJIND
• 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.
AMINES
ANALEPTICS
ANIMAL CELLS
ANIMALS
AZINES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CAFFEINE
CARBOXYLIC ACIDS
CATALASE
CELL KILLING
CENTRAL NERVOUS SYSTEM AGENTS
CONNECTIVE TISSUE CELLS
CYTOSINE
DNA
DRUGS
ELECTROMAGNETIC RADIATION
ENZYMES
EXTERNAL IRRADIATION
FIBROBLASTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
IN VITRO
IONIZING RADIATIONS
IRRADIATION
MAMMALS
MAN
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXIDOREDUCTASES
PEROXIDASES
PORPHYRINS
PRIMATES
PURINES
PYRIMIDINES
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOINDUCTION
RECOVERY
REPAIR
SOMATIC CELLS
STRAND BREAKS
TUMOR CELLS
VERTEBRATES
X RADIATION
XANTHINES