Suitability of the &amp;#947;-H2AX Assay for Human Radiation Biodosimetry

Roch-Lefèvre, Sandrine; Valente, Marco; Voisin, Philippe; Barquinero, Joan Francesc

doi:10.5772/36561

Cited by 3 publications

(3 citation statements)

References 26 publications

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“…The number of publications highlighting the possibilities and limitations of surrogate end points based on DNA damage repair as predictors of NTT far exceeds the limits of this review. Nevertheless, γ-H2AX foci is claimed as a useful tool in triage biodosimetry and recommended for inclusion into the toolbox of radiation cytogenetic laboratories [ 112 , 113 , 114 , 115 , 116 ], thus it is appropriate to present a brief analysis of the predictive value of this particular end-point.…”

Section: Review Of Existing Studiesmentioning

confidence: 99%

Prediction of the Acute or Late Radiation Toxicity Effects in Radiotherapy Patients Using Ex Vivo Induced Biodosimetric Markers: A Review

Vinnikov

Hande

Wilkins

et al. 2020

JPM

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A search for effective methods for the assessment of patients’ individual response to radiation is one of the important tasks of clinical radiobiology. This review summarizes available data on the use of ex vivo cytogenetic markers, typically used for biodosimetry, for the prediction of individual clinical radiosensitivity (normal tissue toxicity, NTT) in cells of cancer patients undergoing therapeutic irradiation. In approximately 50% of the relevant reports, selected for the analysis in peer-reviewed international journals, the average ex vivo induced yield of these biodosimetric markers was higher in patients with severe reactions than in patients with a lower grade of NTT. Also, a significant correlation was sometimes found between the biodosimetric marker yield and the severity of acute or late NTT reactions at an individual level, but this observation was not unequivocally proven. A similar controversy of published results was found regarding the attempts to apply G2- and γH2AX foci assays for NTT prediction. A correlation between ex vivo cytogenetic biomarker yields and NTT occurred most frequently when chromosome aberrations (not micronuclei) were measured in lymphocytes (not fibroblasts) irradiated to relatively high doses (4–6 Gy, not 2 Gy) in patients with various grades of late (not early) radiotherapy (RT) morbidity. The limitations of existing approaches are discussed, and recommendations on the improvement of the ex vivo cytogenetic testing for NTT prediction are provided. However, the efficiency of these methods still needs to be validated in properly organized clinical trials involving large and verified patient cohorts.

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Section: Review Of Existing Studiesmentioning

confidence: 99%

Prediction of the Acute or Late Radiation Toxicity Effects in Radiotherapy Patients Using Ex Vivo Induced Biodosimetric Markers: A Review

Vinnikov

Hande

Wilkins

et al. 2020

JPM

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“…However, visual scoring of γH2AX foci in individual cell nuclei is extremely time consuming and subjective . Thus, different technical approaches for automated foci quantification have recently been developed to establish fast and standardized γH2AX analysis .…”

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confidence: 99%

“…In fact, the majority of currently available applications are based on pure image analysis of previously acquired microscopic images. Depending on the program, the measurement can either be executed in a semi‐automatic way, where a user has to investigate the images one by one, or automatically, where a set of images is loaded into the software which further classifies nuclei and foci . An intriguing development is the RABiT workstation, a fully automated system, which includes every step from cell isolation to γH2AX analysis .…”

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confidence: 99%

Fully automated analysis of chemically induced γH2AX foci in human peripheral blood mononuclear cells by indirect immunofluorescence

et al. 2013

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Analysis of phosphorylated histone protein H2AX (cH2AX) foci is currently the most sensitive method to detect DNA double-strand breaks (DSB). This protein modification has the potential to become an individual biomarker of cellular stress, especially in the diagnosis and monitoring of neoplastic diseases. To make cH2AX foci analysis available as a routine screening method, different software approaches for automated immunofluorescence pattern evaluation have recently been developed. In this study, we used novel pattern recognition algorithms on the AKLIDES V R platform to automatically analyze immunofluorescence images of cH2AX foci and compared the results with visual assessments. Dose-and time-dependent cH2AX foci formation was investigated in human peripheral blood mononuclear cells (PBMCs) treated with the chemotherapeutic drug etoposide (ETP). Moreover, the AKLIDES system was used to analyze the impact of different immunomodulatory reagents on cH2AX foci formation in PBMCs. Apart from cH2AX foci counting the use of novel pattern recognition algorithms allowed the measurement of their fluorescence intensity and size, as well as the analysis of overlapping cH2AX foci. The comparison of automated and manual foci quantification showed overall a good correlation. After ETP exposure, a clear dose-dependent increase of cH2AX foci formation was evident using the AKLIDES as well as Western blot analysis. Kinetic experiments on PBMCs incubated with 5 lM ETP demonstrated a peak in cH2AX foci formation after 4 to 8 h, while a removal of ETP resulted in a strong reduction of cH2AX foci after 1 to 4 h. In summary, this study demonstrated that the AKLIDES system can be used as an efficient automatic screening tool for cH2AX foci analysis by providing new evaluation features and facilitating the identification of drugs which induce or modulate DNA damage. V C 2013 International Society for Advancement of CytometryKey terms cH2AX foci; automated microscopy; image analysis; DNA double-strand breaks; etoposide; human PBMCs THE damage of DNA is a critical event able to affect cellular functions and development. Thus, it is essential for cells to maintain DNA integrity and repair such lesions effectively. Among different kinds of DNA lesion, double strand breaks (DSB) are considered to be the most critical type of DNA damage and misrepair can lead to tumorgenesis or cell death (1,2). To ensure detection and repair of DNA damage sites a variety of proteins are involved in different DNA damage response (DDR) pathways (3). After induction of DSB, the histone protein H2AX is rapidly phosphorylated at serine 139, termed cH2AX. Large amounts of cH2AX molecules form a focus in the

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A deep learning model (FociRad) for automated detection of γ-H2AX foci and radiation dose estimation

Wanotayan

Chousangsuntorn

Petisiwaveth

et al. 2022

Sci Rep

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DNA double-strand breaks (DSBs) are the most lethal form of damage to cells from irradiation. γ-H2AX (phosphorylated form of H2AX histone variant) has become one of the most reliable and sensitive biomarkers of DNA DSBs. However, the γ-H2AX foci assay still has limitations in the time consumed for manual scoring and possible variability between scorers. This study proposed a novel automated foci scoring method using a deep convolutional neural network based on a You-Only-Look-Once (YOLO) algorithm to quantify γ-H2AX foci in peripheral blood samples. FociRad, a two-stage deep learning approach, consisted of mononuclear cell (MNC) and γ-H2AX foci detections. Whole blood samples were irradiated with X-rays from a 6 MV linear accelerator at 1, 2, 4 or 6 Gy. Images were captured using confocal microscopy. Then, dose–response calibration curves were established and implemented with unseen dataset. The results of the FociRad model were comparable with manual scoring. MNC detection yielded 96.6% accuracy, 96.7% sensitivity and 96.5% specificity. γ-H2AX foci detection showed very good F1 scores (> 0.9). Implementation of calibration curve in the range of 0–4 Gy gave mean absolute difference of estimated doses less than 1 Gy compared to actual doses. In addition, the evaluation times of FociRad were very short (< 0.5 min per 100 images), while the time for manual scoring increased with the number of foci. In conclusion, FociRad was the first automated foci scoring method to use a YOLO algorithm with high detection performance and fast evaluation time, which opens the door for large-scale applications in radiation triage.

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Suitability of the γ-H2AX Assay for Human Radiation Biodosimetry

Cited by 3 publications

References 26 publications

Prediction of the Acute or Late Radiation Toxicity Effects in Radiotherapy Patients Using Ex Vivo Induced Biodosimetric Markers: A Review

Prediction of the Acute or Late Radiation Toxicity Effects in Radiotherapy Patients Using Ex Vivo Induced Biodosimetric Markers: A Review

Fully automated analysis of chemically induced γH2AX foci in human peripheral blood mononuclear cells by indirect immunofluorescence

A deep learning model (FociRad) for automated detection of γ-H2AX foci and radiation dose estimation

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