Effect of confluent holding on potentially lethal damage repair, cell cycle progression, and chromosomal aberrations in human normal and ataxia-telangiectasia fibroblasts

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576305· OSTI ID:5930523

Little, J B; Nagasawa, H

The effects of confluent holding recovery on survival, chromosomal aberrations, and progression through the life cycle after subculture of human diploid fibroblasts X-irradiated during density inhibition of growth have been examined. The responses of three normal strains were determined and compared with those of four ataxia-telangiectasia (AT), an AT heterozgote, and two hereditary retinoblastoma strains. The capacity for potentially lethal damage repair (PLDR) was slightly reduced in retinoblastoma cells and almost absent in AT cells, but normal in an AT heterozygote. The decline in chromosomal aberrations seen in normal cells during confluent holding was absent in AT cells, consistent with the lack of PLDR. Following subculture, all irradiated AT fibroblasts progressed through the cell cycle to the first mitosis with no delay. AT heterozygotic and retinoblastoma cells showed both an enhanced delay in the initiation of DNA synthesis and a large fraction of cells irreversibly blocked in G/sub 1/ as compared with normal cells. Both the delayed entry into S and G/sub 1/ block were reduced by confluent holding. These results indicate that AT homozygotic and heterozygotic cells respond quite differently to X irradiation.

• Research Organization: Harvard Univ. School of Public Health, Boston, MA
• OSTI ID: 5930523
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 101:1; ISSN RAREA
• 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
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CYCLE
CELL KILLING
CHROMOSOMAL ABERRATIONS
CONNECTIVE TISSUE CELLS
DATA
DISEASES
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
FIBROBLASTS
INFORMATION
IONIZING RADIATIONS
LABELLED COMPOUNDS
MITOTIC DELAY
MUTATIONS
NUMERICAL DATA
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RECOVERY
REPAIR
SKIN DISEASES
SOMATIC CELLS
SURVIVAL CURVES
TELANGIECTASIS
TRITIUM COMPOUNDS
TUMOR CELLS
VASCULAR DISEASES
X RADIATION