GENE EXPRESSION PROFILING TO MONITOR IONIZING RADIATION EXPOSURE

The estimation of exposure risk to ionizing radiation in the environment is a public health challenge. The use of radioactive materials in medicine, power generation and industry raises questions concerning also the effects due to low doses of ionizing radiation. As complex molecular mechanisms at the cellular level, in response to environmental stresses, are evoked, the application of high-throughput screening, like the microarray technology, may provide a more detailed analysis of a potential damage. In this study we focused on workers exposed to low-LET ionizing radiations and we compared the expression profile of their peripheral blood lymphocytes (PBMC) with a reference sample of non-exposed people, working at the same hospital. According to our technology, the experimental design that better fitted our objective was the balanced block consisting in the equal distribution of cyanine 5 and cyanine 3 labels within the two classes of exposed and control samples. The purpose was to combine the oligo microarray technology with informatics in order to develop a specific stress gene profile to be used as a molecular signature of the radiation exposure. Our study aims at providing further insight into the harmful effects of low-dose radiation exposure in humans in order to increase the bulk of information on the radiation-inducible genes that have been identified so far, and whose modulation was mainly described as the result of an immediate-early response in ex-vivo irradiated PBMC. The identification of such a gene set in human peripheral blood lymphocytes would improve the classical methods to estimate ionizing radiation exposure, enabling a rapid and non-invasive monitoring for any populations at risk.