Abstract
It is well established that high dose exposure will result in severe lesions on cellular structure and physiological function, late carcinogenesis and even lethality, while low dose exposure might lead to adaptive response, bystander effect and hyper-radiosensitivity. In order to explore the molecular bases of these diversity effects induced by ionizing radiation, we have investigated the global changes of transcriptional profiles induced by different doses of gamma-rays. AHH-1 human lymphoblastoid cells were irradiated with 0, 0.05Gy, 0.2Gy 0.5Gy, 2Gy, 10Gy of gamma-ray respectively. After 4h of post-irradiation culture, the samples were subjected to microarray assay as compared with the sample from un-irradiated control cells. Our results demonstrate the following scenarios of genes expression alterations: 1) Dose specific, i.e. some genes’ expression change only occurred under a certain dose irradiation 2) Dose-dependent effect manner, the extent of down- or up-regulation in some genes increased along with the augment of doses, e.g. Connexin 43, IER5, XPC, tumor protein p53 inducible protein 3 gene, EI24, etc; 3) There were about 250 genes with expression changes in 10Gy irradiated cells, the largest amount among all the investigated doses, and most of these changed genes (95%) were depressed. Next is 0.5Gy irradiation with about 200 genes with changed expression (nearly half and half for the up- and down-regulation) and then 2Gy; 4) a few genes were found up-regulated by 0.05 Gy, e.g. GPR124, NOL6, LYK5, MAPK8IP2, ANXA13, connexin 43, GRIA3. These observations provide the further information for elucidating the molecular mechanisms of the diverse biological effects of ionizing radiation.
* This work was supported by grants of Chinese National High Technology "863" Programs #2004AA221160 and Chinese National Natural Science Foundation #30270423.
