@article{oai:nagasaki-u.repo.nii.ac.jp:00019029,
 author = {Hirao, Tomohito and Urata, Yoshishige and Kageyama, Kan and Ikezaki, Midori and Kawakatsu, Miho and Matsuse, Michiko and Matsuo, Takayuki and Akishita, Masahiro and Nagata, Izumi and Kondo, Takahito},
 issue = {11-12},
 journal = {Free radical research},
 month = {Nov},
 note = {Dehydroepiandrosterone (DHEA) modulates sensitivity to radiation-induced injury in human neuroglioma cells (H4) through effects on Akt signalling by glutathione (GSH)-dependent redox regulation. Previous treatment of H4 cells with DHEA for 18 h reduced the gamma-ray-induced phosphorylation of Akt, activated p21(waf1) synthesis and up-regulated phosphorylation of Rb independent of p53. These reactions were followed by a decrease in cell number and an increase in apoptosis and G(2)/M checkpoint arrest. The suppression of phosphorylation of Akt by DHEA was due to regulation of the dephosphorylation by protein phosphatase 2A (PP2A). DHEA up-regulated the expression of gamma-glutamylcysteine synthetase, a rate-limiting enzyme of glutathione (GSH) synthesis, and the levels of GSH to maintain PP2A activity. The results suggested that DHEA increases the sensitivity of cells to gamma-ray irradiation by inducing apoptosis and cell cycle arrest through GSH-dependent regulation of the reduced form of PP2A to down-regulate the Akt signalling pathway., Free Radical Research, 42(11-12), pp.957-965; 2008},
 pages = {957--965},
 title = {Dehydroepiandrosterone augments sensitivity to gamma-ray irradiation in human H4 neuroglioma cells through down-regulation of Akt signaling.},
 volume = {42},
 year = {2008}
}