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. 2009 Jun;171(6):771-5.
doi: 10.1667/RR1560.1.

Expression of activated checkpoint kinase 2 and histone 2AX in exfoliative oral cells after exposure to ionizing radiation

Angela J Yoon  1 , Jing Shen, Hui-Chen Wu, Christos Angelopoulos, Steven R Singer, Rongzhen Chen, Regina M Santella
Affiliations

Expression of activated checkpoint kinase 2 and histone 2AX in exfoliative oral cells after exposure to ionizing radiation

Angela J Yoon et al. Radiat Res. 2009 Jun.

Abstract

Gamma-H2AX (activated histone 2AX) and pChk2 (activated checkpoint kinase 2), which are DNA damage response molecules, are produced in irradiated cells and may be signature molecules of radiation exposure. We investigated their use as potential biomarkers to identify individuals exposed to ionizing radiation. We collected exfoliated oral epithelial cell samples from 100 healthy individuals undergoing routine dental radiographic examination (2.34 cGy) both before and after the radiograph using a non-invasive technique. The expression levels of pChk2 and gamma-H2AX in oral cells were assessed by immunohistochemical assay. Both biomarkers showed statistically significant increases in levels of expression after the radiation exposure (P < 0.001). This suggests that pChk2 and gamma-H2AX may serve as sensitive indicators of low-dose radiation exposure.

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Figures

FIG. 1
FIG. 1
Photomicrograph of immunohistochemical staining of exfoliative oral cells. Panel A: pChk2; panel B: γ-H2AX.
FIG. 2
FIG. 2
Box plot of biomarker expression levels before and after radiation exposures. Before and after indicate the status of radiation exposure. Staining intensity indicates the biomarker expression level. Boxes are the interquartile ranges of the distribution (25th–75th percentile); horizontal lines within the boxes are medians, horizontal lines outside the boxes are the 5th and 9th percentiles, and black dots are outliers.
FIG. 3
FIG. 3
Comparison of pChk2 and γ-H2AX expression levels in each participant before and after the exposure to ionizing radiation.
See this image and copyright information in PMC

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