Quantification of damage due to low-dose radiation exposure in XXXX : construction and application of a biodosimetric model using mRNA indicators in circulating white blood cells.

@entity1 @entity35186 @entity1380 @entity18122 @entity19 @entity5207
UNASSIGNED: Biodosimetry, the measurement of radiation damage in a biologic sample, is a reliable tool for increasing the accuracy of dose estimation. Although established chromosome analyses are suitable for estimating the absorbed dose after high-dose irradiation, biodosimetric methodology to measure damage following low-dose exposure is underdeveloped. RNA analysis of circulating blood containing radiation-sensitive cells is a candidate biodosimetry method. Here we quantified RNA from a small amount of blood isolated from @entity19 following low-dose body irradiation (<0.5 Gy) aimed at developing biodosimetric tools for situations that are difficult to study in @entity1 . By focusing on radiation-sensitive undifferentiated cells in the blood based on @entity18122 RNA expression, we quantified the relative levels of RNA for DNA damage-induced (DDI) genes, such as @entity1380 , @entity35186 and @entity5207 . The RNA ratios of DDI genes/ @entity18122 in the blood increased in a dose-dependent manner 4 h after whole-body irradiation at doses ranging from 0.1 to 0.5 Gy (air-kerma) of X-rays, regardless of whether the @entity19 were in an active or resting state. The RNA ratios were significantly increased after 0.014 Gy (air-kerma) of single X-ray irradiation. The RNA ratios were directly proportional to the absorbed doses in water ranging from 0.1 to 0.5 Gy, based on gamma-irradiation from (137)Cs. Four hours after continuous irradiation with gamma-rays or by internal contamination with a beta-emitter, the increased RNA ratios resembled those following single irradiation. These findings indicate that the RNA status can be utilized as a biodosimetric tool to estimate low-dose radiation when focusing on undifferentiated cells in blood.
