Biomedical Engineering Reference
In-Depth Information
Table 21.2
Gene ontology analysis using eGOn
Gene Ontology categories
0.1 Gy
Up
Down
0.5 Gy
Up
Down
Response to DNA damage
8
8
-
5
5
-
Programmed cell death
13
13
-
17
16
1
Regulation of cell cycle
6
5
1
17
12
5
Regulation of cell proliferation and growth
3
3
-
6
5
1
Regulation of cell differentiation
2
2
-
7
6
1
Intracellular signaling cascade
28
26
2
38
34
4
Cell surface receptor linked signal transduction
12
11
1
28
25
3
Protein metabolism
16
15
1
24
24
-
Nucleotide, nucleic acid metabolism
1
1
-
5
4
1
Cell-cell adhesion
10
9
1
21
20
1
Others
102
96
6
88
78
10
Not-annotated
165
158
7
246
221
25
Sum
366
347
19
502
450
52
%
94.81
5.4
89.64
10.36
Fig. 21.1
Stylized Venn
diagram depicting the
changes in gene expression
levels induced by 0.1 Gy or
0.5 Gy gamma-radiations
500mGy
100mGy
376
126
240
processes were the protein kinase cascade and apoptosis (Table
21.2
). Of the 366
differentially expressed genes following 0.1 Gy irradiation, 13 genes had known
roles in apoptosis, and all of them were induced. These included three members
of the tumor necrosis factor (TNF)-receptor superfamily (TNFRSF16,) and other
genes generally considered to be pro-apoptotic (BNIP2, BCLAF1) [
1
]. On the
other hand, several anti-apoptotic genes were also up-regulated (GAS2L3 and
CCAR1). Among repressed genes there were some known signal transduction
targets (CNP and NBL1). Out of 502 differentially expressed genes after 0.5 Gy,
17 genes were involved in cell death/apoptosis, and 16 of them were induced.
Four members of the tumor necrosis factor (TNF)-receptor superfamily (TNFRSF4,
TNFRSF10C, TNFRSF11B and FAS) were induced following 0.5 Gy gamma-
irradiation in comparison to 0.1 Gy exposures. The other difference regarding
apoptosis-related gene expression changes following 0.1 and 0.5 Gy radiation was
that few known genes involved in apoptotic mitochondrial pathway (BBC3) were
differentially expressed in the latter case. In addition, cell cycle regulation, DNA
damage response and intracellular signaling cascade related genes significantly
dominated radiation responses. Eight DNA damage response/DNA repair genes
