For around ten years, microarrays have been suggested for the diagnosis of ionizing radiation exposure. We assessed for the first time the relevance of gene expression profiling in a real accidental case. This study was performed on peripheral blood mononuclear cells of 41 potential victims. The different strategies of analysis highlighted a huge effect of the blood sample handling on the gene expression profiles. This effect was so high that it could mask specific modulations as a potential effect of ionizing radiation exposure. Thus, we assessed a new way of blood sampling adapted to gene expression analysis: PAXgene. With this method, more than 70% of the modulations of gene expression induced 3 hours after an ex vivo exposure to 0.5 Gy were preserved even in a 24-hour delayed analysis (as for transportation of blood sample from the accident location to the laboratory). We validated a new methodology in order to propose a new strategy of blood sampling and handling for gene profiling. This system could be used in case of accidental overexposure to study whether gene expression is a relevant biomarker of ionizing radiation exposure.
Overall design
Radiation induced gene expression in human blood was measured at 3 hours after exposure to doses of 0 and 0.5 grays. Following the incubation of 3 hours at 37°C, the RNA extractions were performed either immediately or 24h later (as for transportation of blood sample at room temperature). Two different blood preservation methods were compared: classical anticoagulant and PAXgene Blood RNA System. Venous blood samples of 6 donors were used (3 for anticoagulant study, 3 for Paxgene study). Each sample was hybridized twice.
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