Abstract
Transcriptome analysis permits to explore the field of low doses of radiation and potentially it can provide a global view of radiation responsive pathways. We have exposed a human lymphoblastoid cell line to either 0.02 or 2 Gy of ionizing radiation that yielded relatively little or faint cytotoxicity and little or no apoptotic DNA fragmentation. We used cDNA microarrays to examine the modulation of gene expression at various time points within 72 hours following gamma radiation exposure. We observed that 1) a lower number of genes are deregulated after 0.02 compared to 2 Gy, 2) some genes are specifically deregulated according to the dose while others are similarly deregulated whatever the dose, 3) all responsive genes after both doses and those specifically deregulated after 2 Gy are mainly involved in signal transduction, cytoskeleton, protein metabolism and catabolism, intracellular trafficking and transcription factors whereas genes specifically deregulated after 0.02 Gy are mainly related to signal transduction, cytoskeleton, stress response, ionic transport and channel 4) after both doses, responsive genes related to cell survival and death are in good agreement with data obtained on cell survival and death and 5) overall results support the hypothesis that low doses of ionizing radiation lead to a typical stress-induced translation inhibition and RNA processing alteration. This work underlines the need of further efforts to explore the effects of low doses of radiation.
