Early gene expression in human lymphocytes after gamma-irradiation-a genetic pattern with potential for biodosimetry.
OBJECTIVE
Identification of early radiation response genes (ERG) in human lymphocytes after gamma-irradiation by using the whole-human-genome DNA-microarrays and the evaluation of their possible role in rapid radiation biodosimetry by applying real-time quantitative polymerase chain reaction (RT-qPCR) methodology for validation in a small group of human individuals.


METHODS
Whole blood from a healthy human donor was exposed at 37 degrees C to 137Cs gamma-radiations (absorbed dose: 1-4 Gy). Fifteen minutes following irradiation the lymphocytes were isolated from the blood (for 2 h at 20 degrees C) and their gene expression was investigated using the DNA-microarrays. Subsequently, 14 genes were selected and validated using the TaqMan probes based upon the RT-qPCR assay within a group of 6 human donors.


RESULTS
A dose-related relative change in quantitative gene expression using the DNA-microarray assay was demonstrated in 24 of 102 genes. Up-regulation of expression was observed in 15 genes: CD69 (CD69 molecule), CDKN1A (cyclin-dependent kinase inhibitor 1A), EGR1 (early growth response 1), EGR4 (early growth response 4), FLJ35725 (chromosome 4 ORF 23), hCG2041177 (hCG - human Celera Genome), hCG1643466.2, IFN-gamma (interferon-gamma), ISG20L (interferon stimulated exonuclease gene 20 kDa - like 1), c-JUN (jun oncogene), MDM2 (mouse double minute 2), MUC5B (mucine), PLK2 (polo-like kinase 2), RND1 (rho-family GTPase 1) and TNFSF9 (tumour necrosis factor superfamily member 9). Down-regulation of expression was found in the remaining nine genes: GRIK3 (glutamate receptor ionotropic kainate 3), hCG1985174, hCG1998530, hCG2038519, OCLN (occludin), RPL10A (ribosomal protein L10a), SERHL2 (serine hydrolase-like 2), SGK3 (serum/glucocorticoid regulated kinase 3) and STARD13 (START domain containing 13).


CONCLUSIONS
A significant correlation between absorbed radiation dose and change in relative gene expression was particularly evident for EGR1, EGR4, IFN-gamma, c-JUN and TNFSF9 (p < or = 0.05). Results warrant the further investigation of these ERG as potential biodosimetric markers.
Turtoi
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A
Research Centre Jülich, Department of Safety and Radiation Protection, Laboratory of Radiation Biology, Germany. turtoia@hotmail.com
Brown
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I
Oskamp
D
D
Schneeweiss
F H A
FH
D049109:Cell Proliferation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000528:radiation effects*; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism* / Q000528:radiation effects; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000378:metabolism; D011839:Radiation, Ionizing; D011874:Radiometry / Q000379:methods*; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
D012333:RNA, Messenger; D014157:Transcription Factors