Normal inhibition of DNA synthesis following gamma-irradiation of radiosensitive cell lines from patients with Down's syndrome and Alzheimer's disease.
Inhibition of DNA synthesis was studied in gamma-irradiated lymphoblastoid cells from patients with Alzheimer's disease and Down's syndrome. A normal biphasic pattern of inhibition was observed over a dose range of 0-4 krad of gamma-rays in all of the cell lines. 3 out of 4 Down's and all the Alzheimer's cell lines were shown to be hypersensitive to ionizing radiation based on induced chromosomal aberrations. Increased G2 phase delay, comparable to that occurring in ataxia-telangiectasia cells, was observed for some of the cell lines, after exposure to gamma-rays. Contrary to other data in the literature these results demonstrate that radioresistant DNA synthesis is not an intrinsic feature of all disorders characterized by radiosensitivity.
Lavin
M F
MF
Joint Oncology Program, Queensland Institute of Medical Research, Herston, Australia.
Bates
P
P
Le Poidevin
P
P
Chen
P C
PC
D000544:Alzheimer Disease / Q000235:genetics* / Q000378:metabolism; D002461:Cell Line, Transformed; D002869:Chromosome Aberrations; D004247:DNA / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000528:radiation effects; D004314:Down Syndrome / Q000235:genetics* / Q000378:metabolism; D005347:Fibroblasts / Q000528:radiation effects; D005434:Flow Cytometry; D006801:Humans; D011836:Radiation Tolerance
D004247:DNA