Radiation Effects Department, Cancer Mechanisms and Biomarkers Group, Centre for Radiation, Chemical & Environmental Hazards, Public Health England, Chilton, Oxfordshire, United Kingdom.
Int J Radiat Biol. 2021;97(5):675-686. doi: 10.1080/09553002.2021.1906464. Epub 2021 Apr 7.
For triage purposes following a nuclear accident or a terrorist event, gene expression biomarkers in blood have been demonstrated to be good bioindicators of ionizing radiation (IR) exposure and can be used to assess the dose received by exposed individuals. Many IR-sensitive genes are regulated by the DNA damage response pathway, and modulators of this pathway could potentially affect their expression level and therefore alter accurate dose estimations. In the present study, we addressed the potential influence of temperature, sample transport conditions and the blood cell fraction analyzed on the transcriptional response of the following radiation-responsive genes: FDXR, CCNG1, MDM2, PHPT1, APOBEC3H, DDB2, SESN1, P21, PUMA, and GADD45.
Whole blood from healthy donors was exposed to a 2 Gy X-ray dose with a dose rate of 0.5 Gy/min (output 13 mA, 250 kV peak, 0.2 mA) and incubated for 24 h at either 37, 22, or 4 °C. For mimicking the effect of transport conditions at different temperatures, samples incubated at 37 °C for 24 h were kept at 37, 22 or 4 °C for another 24 h. Comparisons of biomarker responses to IR between white blood cells (WBCs), peripheral blood mononuclear cells (PBMCs) and whole blood were carried out after a 2 Gy X-ray exposure and incubation at 37 °C for 24 hours.
Hypothermic conditions (22 or 4 °C) following irradiation drastically inhibited transcriptional responses to IR exposure. However, sample shipment at different temperatures did not affect gene expression level except for SESN1. The transcriptional response to IR of specific genes depended on the cell fraction used, apart from FDXR, CCNG1, and SESN1.
In conclusion, temperature during the incubation period and cell fraction but not the storing conditions during transport can influence the transcriptional response of specific genes. However, FDXR and CCNG1 showed a consistent response under all the different conditions tested demonstrating their reliability as individual biological dosimetry biomarkers.
在核事故或恐怖事件发生后进行分诊时，血液中的基因表达生物标志物已被证明是电离辐射（IR）暴露的良好生物标志物，可用于评估暴露个体所接受的剂量。许多 IR 敏感基因受 DNA 损伤反应途径调控，该途径的调节剂可能会影响其表达水平，从而改变准确的剂量估计。在本研究中，我们研究了温度、样品运输条件和分析的血细胞分数对以下辐射反应基因的转录反应的潜在影响：FDXR、CCNG1、MDM2、PHPT1、APOBEC3H、DDB2、SESN1、P21、PUMA 和 GADD45。
将来自健康供体的全血暴露于 2Gy X 射线剂量下，剂量率为 0.5Gy/min（输出 13mA、250kV 峰值、0.2mA），并在 37、22 或 4°C 下孵育 24 小时。为了模拟不同温度下运输条件的影响，将在 37°C 孵育 24 小时的样品在 37、22 或 4°C 下再孵育 24 小时。在 37°C 下进行 2Gy X 射线照射和孵育 24 小时后，比较白细胞（WBC）、外周血单核细胞（PBMC）和全血中生物标志物对 IR 的反应。
照射后低温条件（22 或 4°C）强烈抑制了对 IR 暴露的转录反应。然而，除了 SESN1 之外，样品运输温度对基因表达水平没有影响。除了 FDXR、CCNG1 和 SESN1 之外，IR 对特定基因的转录反应取决于所用的细胞分数。
总之，孵育期间的温度以及细胞分数，而不是运输过程中的储存条件，可能会影响特定基因的转录反应。然而，FDXR 和 CCNG1 在所有测试的不同条件下表现出一致的反应，证明了它们作为个体生物剂量测定生物标志物的可靠性。
