Identification of 4 ataxia telangiectasia cell lines hypersensitive to gamma-irradiation but not to hydrogen peroxide.
The effect of hydrogen peroxide on the rate of semi-conservative DNA synthesis in ataxia telangiectasia (AT) and normal human lymphoblastoid cells was investigated. The rate of DNA synthesis in AT cells was not depressed to a lesser extent than in normal cells, as might have been expected since H2O2 is a radiomimetic agent. On the contrary, 4 AT cell lines displayed a higher sensitivity to the inhibitory effect of H2O2 on DNA synthesis than 2 normal cell lines. Comparable levels of cytotoxicity were detected in cell viability studies. Furthermore, neither the level of DNA breakage produced by H2O2, nor the rate of repair of these lesions was significantly different in normal and AT cells. Together, these results indicate that the AT cell lines utilized in this study are not hypersensitive to the oxidant. It is suggested that H2O2 may not induce lethality via the direct action of the hydroxyl radical (OH.).
Cantoni
O
O
Istituto di Farmacologia e Farmacognosia, Università degli Studi di Urbino, Italy.
Sestili
P
P
Fiorilli
M
M
Santoro
M P
MP
Tannoia
M C
MC
Novelli
G
G
Cattabeni
F
F
Dallapiccola
B
B
D001260:Ataxia Telangiectasia; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage; D004261:DNA Replication / Q000187:drug effects / Q000528:radiation effects*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007700:Kinetics
D004247:DNA; D006861:Hydrogen Peroxide