Comparable dose estimates of blinded whole blood samples are obtained independently of culture conditions and analytical approaches. Second RENEB gene expression study

Abstract

Purpose: This collaboration of five established European gene expression labs investigated the potential impact of culture conditions on the transcriptional response of peripheral blood to radiation exposure. Materials and methods: Blood from one healthy donor was exposed ex vivo to a Cobalt 60 source to produce a calibration curve in addition to four unknown doses. After exposure, the blood samples were either diluted with RPMI medium or left untouched. After 24-h incubation at 37 C the diluted blood samples were lysed, while the undiluted samples were mixed with the preservative RNALater and all samples were shipped frozen to the participating labs. Samples were processed by each lab using microarray (one lab) and QRT-PCR (four labs). Results: We show that although culture conditions affect the total amount of RNA recovered (p < .0001) and its integrity (p < .0001), it does not significantly affect dose estimates (except for the true dose at 1.1 Gy). Most importantly, the different analysis approaches provide comparable mean absolute difference of estimated doses relative to the true doses (p ¼ .9) and number of out of range (>0.5 Gy) measurements (p ¼ .6). Conclusion: This study confirms the robustness of gene expression as a method for biological dosimetry. ARTICLE HISTORY

Radiotherapy-Associated Long-term Modification of Expression of the Inflammatory Biomarker Genes ARG1, BCL2L1, and MYC

“…Many investigations on global gene expression profiling of IR-exposed whole blood samples have identified genes associated with the DNA-damage response. Among others, we found many genes activated by the transcription factor p53 (encoded by the gene TP53) via the nuclear ataxia-telangiectasia mutated gene, the sensor of double-strand breaks (5–7), and some are promising biomarkers of radiation exposure for biological dosimetry purposes, e.g., PCNA, DDB2, FDXR, CCNG1 , and MDM2 (8–10). …”

Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans – joint RENEB and EURADOS inter-laboratory comparisons

“…The organisation of the inter-comparison and the materials, methods and results for the DCA and RS assays are here presented in detail; the results of the GE and TL assays are given only in brief with the detailed materials, methods and results presented in two additional papers (GE: Manning et al 2016;TL: Woda et al in preparation).…”

“…Additional data and fully detailed results for the GE assay will appear in Manning et al (2016) and for the TL assay will appear in Woda et al (in preparation). In brief, the GE results are given in Table 3, which is reproduced from Manning et al (2016).…”

Generation of a Transcriptional Radiation Exposure Signature in Human Blood Using Long-Read Nanopore Sequencing

“…APOBEC3H transcriptional response to radiation in ex vivo irradiated blood followed a sublinear dose-response relationship similar to FDXR. Dose estimates provided with FDXR have proven to be very accurate at low and high doses (14) and have been used successfully in exercises on blind samples (16,18,19). The similar dose-response curve observed for APOBEC3H suggests that this gene could become a useful, possibly standalone biomarker of radiation exposure for dose estimations in humans.…”

“…Although many studies have used microarrays (5,6), qPCR analyses have proven to provide accurate dose estimates by focusing on specific radiationresponsive genes (7)(8)(9)(10)(11)(12)(13)(14)(15) in only 7 h (16) and now in only 4 h (17). This methodology has been validated through several NATO and RENEB exercises (16,18,19). A single gene expression analysis [e.g., ferredoxin reductase, (FDXR), also reported to be a protein biomarker of radiation exposure, (20)] can offer accurate information on dose received in vivo in humans across a large range of doses from CT scan to total-body exposure (14).…”