Raavi Venkateswarlu, Surendran J, Karthik K, Paul Solomon F D, Thayalan K, Arunakaran J, Venkatachalam Perumal
Department of Human Genetics, Sri Ramachandra Medical College and Research Institute (Deemed to be University), Porur, Chennai, 600 116, India.
Department of Radiation Oncology, Kamakshi Memorial Hospital, Pallikaranai, Chennai, 600 100, India.
Radiat Environ Biophys. 2019 Mar;58(1):69-80. doi: 10.1007/s00411-018-0767-0. Epub 2018 Nov 22.
Radiological accidents and nuclear terrorism pose an increased threat to members of the public who, following such an event, would need to be assessed for medical care by fast triage. Assay methods such as chromosome aberrations (CA), cytokinesis-block micronucleus (CBMN) and fluorescence in situ hybridization (FISH) techniques have been well established for dose estimation and their potential for handling more samples has also been proved with automation. However, culturing of lymphocytes is an inevitable step, which limits the potential of these markers for triage. In vitro analysis of gamma-H2AX (γ-H2AX), gene and microRNA (miRNA) markers do not require culturing of lymphocytes, and as such have been suggested as attractive tools for triage. Despite studies reporting in vitro dose-response curves, limited evidence is available evaluating the suitability of these assays in real situations. In this study, we have measured the absorbed dose using γ-H2AX, gene (GADD45A, FDXR, and CDKN1A) and miRNA-101 expression in blood samples of cancer patients (n = 20) who had undergone partial-body radiotherapy and compared with the derived equivalent whole-body doses (EWBD). The obtained results from all patients showed a significant (p < 0.05) increase of γ-H2AX foci in post-irradiated as compared to pre-irradiated samples. Moreover, estimated doses using γ-H2AX foci showed a correlation with the derived EWBD (r = 0.60, p = 0.0003) and was also shown to be dependent on the irradiated body volume. Consistent with γ-H2AX foci frequency, an increase in fold change expression of genes and miRNA-101 was observed. However, the estimated dose significantly varied among the subjects and showed poor correlation (r = 0.09, 0.04, 0.01 and 0.03 for GADD45A, FDXR, CDKN1A and miRNA-101, respectively) with EWBD. The overall results suggest that the established in vitro γ-H2AX assay is suitable for the detection of radiation exposure and can also provide an estimate of the dose in in vivo irradiated samples. The genes and miRNA-101 markers showed increased expression; nevertheless, there is a need for further improvements to measure doses accurately using these markers.
放射事故和核恐怖主义对公众构成了越来越大的威胁，在发生此类事件后，需要通过快速分诊对公众进行医疗评估。诸如染色体畸变（CA）、胞质分裂阻滞微核（CBMN）和荧光原位杂交（FISH）技术等检测方法已被广泛用于剂量估算，并且其处理更多样本的潜力也已通过自动化得到证明。然而，淋巴细胞培养是一个不可避免的步骤，这限制了这些标志物在分诊中的应用潜力。γ-H2AX、基因和微小RNA（miRNA）标志物的体外分析不需要淋巴细胞培养，因此被认为是有吸引力的分诊工具。尽管有研究报道了体外剂量反应曲线，但评估这些检测方法在实际情况中的适用性的证据有限。在本研究中，我们测量了接受局部身体放疗的癌症患者（n = 20）血液样本中γ-H2AX、基因（GADD45A、FDXR和CDKN1A）和miRNA-101的表达，并将其与导出的全身等效剂量（EWBD）进行比较。所有患者的结果显示，与照射前样本相比，照射后γ-H2AX焦点显著增加（p < 0.05）。此外，使用γ-H2AX焦点估计的剂量与导出的EWBD相关（r = 0.60，p = 0.0003），并且还显示取决于照射的身体体积。与γ-H2AX焦点频率一致，观察到基因和miRNA-101的表达倍数变化增加。然而，估计剂量在受试者之间存在显著差异，并且与EWBD的相关性较差（GADD45A、FDXR、CDKN1A和miRNA-101分别为r = 0.09、0.04、0.01和0.03）。总体结果表明，已建立的体外γ-H2AX检测方法适用于检测辐射暴露，并且还可以提供体内照射样本的剂量估计。基因和miRNA-101标志物显示表达增加；然而，需要进一步改进以使用这些标志物准确测量剂量。
