RESUMO
Objective To investigate the change of ATM phosphorylation in HepG2 cells following a condnuous low dose-rate irradiation.Methods Cells were pemistendy exposed to low dose-rate(8.28 cGy/h) irradiation.Indirect immunofluorescence and Western blot were used to detect the expression of ATM phosphorylated proteins.Colony forming assay Was used to observe the effect of a low dose-rate irradiation on HepG2 cell survival.Results After 30 min of low dose-rate irradiation.the phosphorylation of ATM occurred.After 6 h persistent irradiation,the expression of ATM phosphorylated protein reached the peak value,then gradually decreased.After ATM phosphorylation was inhibited with Wortmannin,the surviving fraction of HepG2 cells was lower than that of the irradiation alone group at each time point(P<0.05).Conclusions Continuous low dose-rate irradiation attenuated ATM phosphorylation.suggesting that continuous low dose-rate irradiation has a potential effect for increasing the radiosensitivity of HepG2 cells.