Unverricht-Yeboah Marcus, Giesen Ulrich, Kriehuber Ralf
Radiation Biology Unit, Department of Safety and Radiation Protection, Forschungszentrum Jülich, Jülich, Germany.
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, Braunschweig, Germany.
J Radiat Res. 2018 Jul 1;59(4):411-429. doi: 10.1093/jrr/rry038.
Gene expression analysis was carried out in Jurkat cells in order to identify candidate genes showing significant gene expression alterations allowing robust discrimination of the Auger emitter 123I, incorporated into the DNA as 123I-iododeoxyuridine (123IUdR), from α- and γ-radiation. The γ-H2AX foci assay was used to determine equi-effect doses or activity, and gene expression analysis was carried out at similar levels of foci induction. Comparative gene expression analysis was performed employing whole human genome DNA microarrays. Candidate genes had to show significant expression changes and no altered gene regulation or opposite regulation after exposure to the radiation quality to be compared. The gene expression of all candidate genes was validated by quantitative real-time PCR. The functional categorization of significantly deregulated genes revealed that chromatin organization and apoptosis were generally affected. After exposure to 123IUdR, α-particles and γ-rays, at equi-effect doses/activity, 155, 316 and 982 genes were exclusively regulated, respectively. Applying the stringent requirements for candidate genes, four (PPP1R14C, TNFAIP8L1, DNAJC1 and PRTFDC1), one (KLF10) and one (TNFAIP8L1) gene(s) were identified, respectively allowing reliable discrimination between γ- and 123IUdR exposure, γ- and α-radiation, and α- and 123IUdR exposure, respectively. The Auger emitter 123I induced specific gene expression patterns in Jurkat cells when compared with γ- and α-irradiation, suggesting a unique cellular response after 123IUdR exposure. Gene expression analysis might be an effective tool for identifying biomarkers for discriminating different radiation qualities and, furthermore, might help to explain the varying biological effectiveness at the mechanistic level.
为了鉴定出在基因表达上有显著改变的候选基因，从而能够可靠地区分作为123I - 碘脱氧尿苷（123IUdR）掺入DNA中的俄歇电子发射体123I与α射线和γ射线，我们在Jurkat细胞中进行了基因表达分析。使用γ-H2AX焦点试验来确定等效剂量或活度，并在相似的焦点诱导水平上进行基因表达分析。采用全人类基因组DNA微阵列进行比较基因表达分析。候选基因在暴露于待比较的辐射质量后，必须表现出显著的表达变化，且基因调控无改变或无相反调控。所有候选基因的基因表达通过定量实时PCR进行验证。对显著失调基因的功能分类显示，染色质组织和细胞凋亡通常受到影响。在等效剂量/活度下暴露于123IUdR、α粒子和γ射线后，分别有155、316和982个基因受到特异性调控。应用对候选基因的严格要求，分别鉴定出四个基因（PPP1R14C、TNFAIP8L1、DNAJC1和PRTFDC1）、一个基因（KLF10）和一个基因（TNFAIP8L1），分别能够可靠地区分γ射线与123IUdR暴露、γ射线与α射线辐射以及α射线与123IUdR暴露。与γ射线和α射线照射相比，俄歇电子发射体123I在Jurkat细胞中诱导了特定的基因表达模式，表明123IUdR暴露后有独特的细胞反应。基因表达分析可能是一种有效的工具，用于识别区分不同辐射质量的生物标志物，此外，还可能有助于在机制层面解释不同的生物学效应。
