Radiation lethality and the cellular genome

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5808109

Yasui, L S

Synchronized suspension cultures of Chinese hamster ovary (CHO) cells were labeled with /sup 125/I-iododeoxyuridine (/sup 125/IUdR) in the presence and absence of drugs to permit the selective incorporation of /sup 125/IUdR into different subfractions of DNA. To evaluate the possibility that damage to mitochondrial DNA might contribute to the lethal effects of radiation, the /sup 125/I response was examined for cells labeled in the presence of berenil, a drug which selectivity inhibits mitochondrial DNA replication. Inhibition of /sup 125/I incorporation into mitochondrial DNA did not change the overall radiation response of CHO cells. To test the hypothesis that the nuclear genome represents a homogenous target for radiation damage, the /sup 125/I response of randomly labeled cells was compared to that of cells where only a minute subfraction of the nuclear DNA was labeled. /sup 125/I decays in this subfraction of DNA proved to be considerably more toxic to CHO cells then randomly distributed /sup 125/I decays. These findings suggest that the cellular genome is not a uniform target for radiation damage. The presence or absence of mitochondrial DNA damage does not influence the extent of radiation-induced cell death. Even within the nuclear genome, /sup 125/I decays in different subfractions of DNA result in radically different biological effects. It must be concluded, therefore, that the cellular genome is subdivided into target loci which are inhomogenous with respect to radiation sensitivity.

• Research Organization: Florida State Univ., Tallahassee (USA)
• OSTI ID: 5808109
• Country of Publication: United States
• Language: English

Related Subjects

560111 -- Radiation Effects on Biochemicals-- In Vitro-- (-1987)
560122* -- Radiation Effects on Cells-- Internal Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
ANTIMETABOLITES
AZINES
BETA DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CELL CONSTITUENTS
CELL KILLING
CHO CELLS
DAYS LIVING RADIOISOTOPES
DNA
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HAMSTERS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
IODODEOXYURIDINE
IODOURACILS
ISOTOPES
MAMMALS
MITOCHONDRIA
NUCLEI
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
PYRIMIDINES
RADIATION EFFECTS
RADIOINDUCTION
RADIOISOTOPES
RIBOSIDES
RODENTS
SURVIVAL CURVES
URACILS
VERTEBRATES