Reduced DNA repair in progeria cells and effects of gamma-ray irradiation on UV-induced unscheduled DNA synthesis in normal and progeria cells.
A reduction in the amount of UV-induced unscheduled DNA synthesis (UDS), and reduced cell survival and host-cell reactivation against UV exposure in Hutchinson-Gilford progeria syndrome cell strains were shown. UV-induced UDS in 4 progeria cell strains was 33-50% of the normal level. A similar reduction in the UV-induced UDS in normal cells was caused by gamma-ray irradiation to the cells before UV irradiation. The dose of gamma-rays required to cause a reduction in UDS of normal cells to the level of progeria cells was 40 Gy and the reduction was reversible after 2 days. In progeria cells, gamma-ray irradiation further reduced UDS with a lower gamma-ray dose required than in normal cells, and the reduction was also reversible but with less relative recovery than in normal cells. The presence of a 'built-in' defect in progeria cells responsible for the reduced DNA-repair capacity was suggested, and such defect may share a common mechanism with the reduction of UV-induced UDS in normal cells caused by gamma-ray irradiation.
Wang
S M
SM
Department of Experimental Radiology, Faculty of Medicine, Kyoto University, Japan.
Nishigori
C
C
Yagi
T
T
Takebe
H
H
D000293:Adolescent; D000328:Adult; D000375:Aging; D002470:Cell Survival / Q000235:genetics / Q000528:radiation effects*; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000096:biosynthesis*; D004260:DNA Repair / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D011371:Progeria / Q000235:genetics*; D014466:Ultraviolet Rays
D004247:DNA