Microarray analysis of radiation response genes in primary human fibroblasts.
OBJECTIVE
To identify radiation-induced early transcriptional responses in primary human fibroblasts and understand cellular pathways leading to damage correction.


METHODS
Primary human fibroblast cell lines were irradiated with 2 Gy gamma-radiation and RNA isolated 2 h later. Radiation-induced transcriptional alterations were investigated with microarrays covering the entire human genome. Time- and dose dependent radiation responses were studied by quantitative real-time polymerase chain reaction (RT-PCR).


RESULTS
About 200 genes responded to ionizing radiation on the transcriptional level in primary human fibroblasts. The expression profile depended on individual genetic backgrounds. Thirty genes (28 up- and 2 down-regulated) responded to radiation in identical manner in all investigated cells. Twenty of these consensus radiation response genes were functionally categorized: most of them belong to the DNA damage response (GADD45A, BTG2, PCNA, IER5), regulation of cell cycle and cell proliferation (CDKN1A, PPM1D, SERTAD1, PLK2, PLK3, CYR61), programmed cell death (BBC3, TP53INP1) and signaling (SH2D2A, SLIC1, GDF15, THSD1) pathways. Four genes (SEL10, FDXR, CYP26B1, OR11A1) were annotated to other functional groups. Many of the consensus radiation response genes are regulated by, or regulate p53. Time- and dose-dependent expression profiles of selected consensus genes (CDKN1A, GADD45A, IER5, PLK3, CYR61) were investigated by quantitative RT-PCR. Transcriptional alterations depended on the applied dose, and on the time after irradiation.


CONCLUSIONS
The data presented here could help in the better understanding of early radiation responses and the development of biomarkers to identify radiation susceptible individuals.
Kis
Enikö
E
Department of Molecular and Tumor Radiobiology, NCPH-Frederic Joliot-Curie National Research Institute for Radiobiology and Radiohygiene, Budapest, Hungary.
Szatmári
Tünde
T
Keszei
Márton
M
Farkas
Róbert
R
Esik
Olga
O
Lumniczky
Katalin
K
Falus
András
A
Sáfrány
Géza
G
D000368:Aged; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D002460:Cell Line; D002648:Child; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005347:Fibroblasts / Q000528:radiation effects*; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors; D014158:Transcription, Genetic
D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins