Radiation-Induced Changes in Gene Expression Involve Recruitment of Existing Messenger RNAs to and from Polysomes
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ABSTRACT: Although ionizing radiation has been shown to influence gene transcription, little is known about the effects of radiation on gene translational efficiency. To obtain a genome-wide perspective of the effects of radiation on gene translation, microarray analysis was done on polysome-bound RNA isolated from irradiated human brain tumor cells; to allow for a comparison with the effects of radiation on transcription, microarray analysis was also done using total RNA. The number of genes whose translational activity was modified by radiation was f10-fold greater than those whose transcription was affected. The radiation-induced change in a gene’s translational activity was shown to involve the recruitment of existing mRNAs to and away from polysomes. Moreover, the change in a gene’s translational activity after irradiation correlated with changes in the level of its corresponding protein. These data suggest that radiation modifies gene expression primarily at the level of translation. In contrast to transcriptional changes, there was considerable overlap in the genes affected at the translational level among brain tumor cell lines and normal astrocytes. Thus, the radiation-induced translational control of a subset of mRNAs seems to be a fundamental component of cellular radioresponse. (Cancer Res 2006; 66(2): 1052-61) There are 32 samples in total in this study. Each sample has a technical duplicate (16samples x2). Comparison of radiation-induced gene expression profiles generated from microarray analysis of total and polysome-bound RNA isolated from three brain tumor cell lines U87, SF126, SF539 and normal astrocytes. Cells were irradiated at the dose of 7gy and collected 6 hours later for isolation of total cellar RNA or polysome-bound RNA. Gene expression was directly compared between irradiated and unirradiated control cells for total and polysome RNA. The array labeling is two-dye method. Labeling two dye samples are labeled using CY3 dye. All the human reference RNA from Stratagene are labeled using CY5 dye.
ORGANISM(S): Homo sapiens
SUBMITTER: Lü X
PROVIDER: S-ECPF-GEOD-11517 | biostudies-other | 2006 Jan
REPOSITORIES: biostudies-other
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