Ionizing radiation-induced mutation of human cells with different DNA repair capacities
We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that TK6 has a reduced capacity for recombination compared with WTK1, and therefore, these results indicate that recombinational repair may contribute to both cell survival and mutation-induction following exposure to ionizing radiation. Such a mechanism may aid cell survival, but could also result in increased deleterious effects such as the unmasking of recessive mutations in cancer suppresser genes.
- Research Organization:
- Los Alamos National Lab., NM (United States)
- Sponsoring Organization:
- National Insts. of Health, Bethesda, MD (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 10114536
- Report Number(s):
- LA-UR--94-4389; CONF-9407154--2; ON: DE95005237
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
560120
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALPHA PARTICLES
ANIMAL CELLS
BIOLOGICAL RADIATION EFFECTS
DNA REPAIR
GENE RECOMBINATION PROTEINS
GENETICS
IONIZING RADIATIONS
MUTATIONS
RADIATION EFFECTS ON BIOCHEMICALS, CELLS, AND TISSUE CULTURE