Habibeh Vosoughi - Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Hosein Azimian - Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Sara Khademi - Department of Radiology Technology, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
Abdul-Rahim Rezaei - Immunology Research Center, Inflammation and Inflammatory Diseases Division, Mashhad University of Medical Sciences, Mashhad, Iran

Objective(s): Nowadays, ionizing radiation (IR) has a significant contribution to the diagnostic and therapeutic medicine, and following that, health risks to individuals through unexpected exposure is greatly increased. Therefore, biological and molecular technology for estimation of dose (biodosimetry) is taken into consideration. In biodosimetry methods stimulation of cells to proliferation is routine to achieve more sensitivity of techniques. However, this concept has recently been challenged by new molecular methods such as gene expression analysis. This study aims to investigate the stimulation effects on gene expression biodosimetry.Materials and Methods: The blood samples were taken from15 patients who were irradiated by TC-99 MIBI, before radiopharmaceutical injection and 24 hr after injection. Lymphocytes were extracted immediately and activated by (phytohemagglutinin) PHA for 24 hr and XPA and FDXR expression levels were investigated by employing relative quantitative Real-Time PCR.Results: The results of this study show a significant increase in the FDXR expression level and a significant decrease in the XPA after stimulation of irradiated lymphocytes. Interestingly, a significant increasing trend in the FDXR expression level (at 0.05 significance level) following cell stimulation to the division was observed.Conclusion: Our results suggest that the PHA activation role in gene expression-based biodosimetry is strongly depended on the target genes and the relevant protein pathways. Finally, cell stimulation looks to be useful for some specific genes, such as FDXR, due to the increasing trend in expression and improvement of sensitivity of gene expression-based biodosimetry method.

Gene expression, Ionizing radiation, Low dose, Phytohemagglutinin, Radiation Dose