title: Expression of activated checkpoint kinase 2 and histone 2AX in exfoliative oral cells after exposure to ionizing radiation.
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.
authors: Columbia University College of Dental Medicine, Columbia University Medical Center, 630 West 168th Street, PH15W-1562, New York, NY 10032, USA. ajk55@columbia.edu
authors: Angela J
authors: AJ
authors: Yoon
authors: Jing
authors: J
authors: Shen
authors: Hui-Chen
authors: HC
authors: Wu
authors: Christos
authors: C
authors: Angelopoulos
authors: Steven R
authors: SR
authors: Singer
authors: Rongzhen
authors: R
authors: Chen
authors: Regina M
authors: RM
authors: Santella
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D064447:Checkpoint Kinase 2; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism / Q000528:radiation effects*; D005260:Female; D015870:Gene Expression / Q000528:radiation effects*; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects; D010784:Photomicrography; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D011839:Radiation, Ionizing; D011861:Radiography, Dental; D055815:Young Adult
chemical_list: D015415:Biomarkers; C468783:H2AX protein, human; D006657:Histones; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases