title: Hypergravity modifies the signal transduction of ionizing radiation through p53.
abstract: To determine the possible effect of hypergravity to modify the signal transduction of ionizing radiation, we analyzed the accumulation of p53 and the expression of p53-dependent genes, Waf-1 and Bax, using the western blot analysis. Hypergravity (20 x g) induced the accumulation of p53 in the human glioblastoma cell line A172 after 3 h of incubation. Low-dose (0.5 Gy) irradiation to the cells accumulated p53 1.5 h after irradiation, and induced Waf-1 and Bax. Under the condition of hypergravity (20 x g), the peak of p53 accumulation was shifted from 1.5 h to 3 h after irradiation, and the inductions of Waf-1 and Bax were suppressed entirely. These results indicate that hypergravity modifies the signal transduction of ionizing radiation through p53 in the cells.
authors.affiliation: Department of Radiation Biophysics, Radiation Effect Research Unit, Atomic Bomb Disease Institute, Nagasaki University School of Medicine, Nagasaki 852-8523, Japan. okaichi@net.nagasaki-u.ac.jp
authors.forename: Kumio
authors.initials: K
authors.lastname: Okaichi
authors.forename: Aya
authors.initials: A
authors.lastname: Usui
authors.forename: Takeo
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Okumura
mesh_terms: D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D006801:Humans; D018471:Hypergravity; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D015398:Signal Transduction / Q000502:physiology* / Q000528:radiation effects*; D013997:Time Factors; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D051028:bcl-2-Associated X Protein
chemical_list: C494826:BAX protein, human; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein