Adenine-induced arrest of mammalian cells in early S-phase is related to the prevention of DNA synthesis inhibition caused by gamma-irradiation.
Adenine prevents the down-regulation of DNA synthesis in gamma-irradiated EAT and HL60 cells. This protective effect is related to the initiation of DNA replication. The effectiveness of this protection increases with the concentration of adenine in both cell lines. The maximum protective effect of adenine induced in EAT cells occurs at about 10 times lower concentration as compared with HL60 cells; however, the level of this effect is almost the same in both cell lines. The results indicate that the prevention of the down-regulation of DNA synthesis in gamma-irradiated EAT and HL60 cells is conditioned mainly by the arrest of the cells in the early S-phase. It is evident that DNA synthesis in cells beyond G1/S boundary is insensitive to gamma-radiation.
Mlejnek
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P
Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
Kozubek
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S
D000225:Adenine / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis / Q000528:radiation effects*; D004261:DNA Replication / Q000528:radiation effects*; D005720:Gamma Rays; D006801:Humans; D016196:S Phase / Q000528:radiation effects*
D004247:DNA; D000225:Adenine