Comparison of the abundance of 10 radiation-induced proteins with their differential gene expression in L929 cells.
OBJECTIVE
To determine whether radiation-induced changes in protein abundance can be correlated with their differential gene expression in a murine fibroblast L929 cell line.


METHODS
L929 cells were irradiated with 6 Gy. Cell lysates were collected at different points in time (20 min, 12, 24, 36, 48 and 72 h). The extracted proteins were separated by two-dimensional gel electrophoresis and quantified using computerized image analysis. Proteins exhibiting a differential expression equal to or more than twofold were identified by mass spectrometry following trypsin digestion. From these, 10 proteins characterized by large changes of radiation-induced abundance were selected in order to measure their corresponding gene expression using RTQ-PCR (real-time quantitative polymerase chain reaction).


RESULTS
Up to 15-fold changes in the abundance of these 10 proteins were associated with no detectable changes more than twofold on the gene expression level. However, one gene (VEGF-D) showed a significant (p=0.005) up-regulation (1.8-fold).


CONCLUSIONS
Deducing protein abundance from mRNA expression levels and vice versa appears to be of limited use. Furthermore, examination of transcriptional and translational changes provides different but complementary information.
Szkanderová
S
S
Institute of Radiobiology and Immunology, Purkyne Military Medical Academy, Hradec Králové, Czech Republic.
Port
M
M
Stulík
J
J
Hernychová
L
L
Kasalová
I
I
Van Beuningen
D
D
Abend
M
M
D000818:Animals; D002460:Cell Line; D005786:Gene Expression Regulation / Q000528:radiation effects; D006019:Glycolysis / Q000528:radiation effects; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D014176:Protein Biosynthesis / Q000528:radiation effects*; D017510:Protein Folding; D011506:Proteins / Q000235:genetics; D016601:RNA-Binding Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000528:radiation effects; D014158:Transcription, Genetic / Q000528:radiation effects*
D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D016601:RNA-Binding Proteins; C072621:Psmd7 protein, mouse