Radiation-response in primary fibroblasts of long-term survivors of childhood cancer with and without second primary neoplasms: the KiKme study
Background The etiology and most risk factors for a sporadic first primary neoplasm in childhood or subsequent second primary neoplasms are still unknown. One established causal factor for therapy-associated second primary neoplasms is the exposure to ionizing radiation during radiation therapy as a...
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Published in | Molecular medicine (Cambridge, Mass.) Vol. 28; no. 1; pp. 1 - 19 |
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Main Authors | , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
London
BioMed Central
06.09.2022
BMC |
Subjects | |
Online Access | Get full text |
ISSN | 1076-1551 1528-3658 1528-3658 |
DOI | 10.1186/s10020-022-00520-6 |
Cover
Summary: | Background
The etiology and most risk factors for a sporadic first primary neoplasm in childhood or subsequent second primary neoplasms are still unknown. One established causal factor for therapy-associated second primary neoplasms is the exposure to ionizing radiation during radiation therapy as a mainstay of cancer treatment. Second primary neoplasms occur in 8% of all cancer survivors within 30 years after the first diagnosis in Germany, but the underlying factors for intrinsic susceptibilities have not yet been clarified. Thus, the purpose of this nested case–control study was the investigation and comparison of gene expression and affected pathways in primary fibroblasts of childhood cancer survivors with a first primary neoplasm only or with at least one subsequent second primary neoplasm, and controls without neoplasms after exposure to a low and a high dose of ionizing radiation.
Methods
Primary fibroblasts were obtained from skin biopsies from 52 adult donors with a first primary neoplasm in childhood (N1), 52 with at least one additional primary neoplasm (N2+), as well as 52 without cancer (N0) from the KiKme study. Cultured fibroblasts were exposed to a high [2 Gray (Gy)] and a low dose (0.05 Gy) of X-rays. Messenger ribonucleic acid was extracted 4 h after exposure and Illumina-sequenced. Differentially expressed genes (DEGs) were computed using
limma
for R, selected at a false discovery rate level of 0.05, and further analyzed for pathway enrichment (right-tailed Fisher’s Exact Test) and (in-) activation (z ≥|2|) using
Ingenuity Pathway Analysis
.
Results
After 0.05 Gy, least DEGs were found in N0 (n = 236), compared to N1 (n = 653) and N2+ (n = 694). The top DEGs with regard to the adjusted
p
-value were upregulated in fibroblasts across all donor groups (
SESN1
,
MDM2
,
CDKN1A
,
TIGAR
,
BTG2
,
BLOC1S2
,
PPM1D
,
PHLDB3
,
FBXO22
,
AEN
,
TRIAP1
, and
POLH)
. Here, we observed activation of
p53 Signaling
in N0 and to a lesser extent in N1, but not in N2+. Only in N0, DNA (excision-) repair (involved genes:
CDKN1A
,
PPM1D
, and
DDB2
) was predicted to be a downstream function, while molecular networks in N2+ were associated with cancer, as well as injury and abnormalities (among others, downregulation of
MSH6
,
CCNE2
, and
CHUK
). After 2 Gy, the number of DEGs was similar in fibroblasts of all donor groups and genes with the highest absolute log
2
fold-change were upregulated throughout (
CDKN1A, TIGAR, HSPA4L
,
MDM2
,
BLOC1SD2
,
PPM1D
,
SESN1
,
BTG2
,
FBXO22
,
PCNA
, and
TRIAP1
). Here, the
p53 Signaling
-
Pathway was activated in fibroblasts of all donor groups. The
Mitotic Roles of Polo Like Kinase
-
Pathway was inactivated in N1 and N2+.
Molecular Mechanisms of Cancer
were affected in fibroblasts of all donor groups.
P53
was predicted to be an upstream regulator in fibroblasts of all donor groups and
E2F1
in N1 and N2+. Results of the downstream analysis were
senescence
in N0 and N2+,
transformation of cells
in N0, and no significant effects in N1. Seven genes were differentially expressed in reaction to 2 Gy dependent on the donor group (
LINC00601
,
COBLL1
,
SESN2
,
BIN3
,
TNFRSF10A
,
EEF1AKNMT
, and
BTG2
).
Conclusion
Our results show dose-dependent differences in the radiation response between N1/N2+ and N0. While mechanisms against genotoxic stress were activated to the same extent after a high dose in all groups, the radiation response was impaired after a low dose in N1/N2+, suggesting an increased risk for adverse effects including carcinogenesis, particularly in N2+. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 |
ISSN: | 1076-1551 1528-3658 1528-3658 |
DOI: | 10.1186/s10020-022-00520-6 |