scholarly journals Observation of Unique Circulating miRNA Signatures in Non-Human Primates Exposed to Total-Body vs. Whole Thorax Lung Irradiation

2021 ◽  
Author(s):  
Claude J. Rogers ◽  
Espoir M. Kyubwa ◽  
Agnes I. Lukaszewicz ◽  
Mark A. Starbird ◽  
Michelle Nguyen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dna Damage ◽  
Growth Factor ◽  
Signaling Pathways ◽  
Dna Damage Repair ◽  
Damage Repair ◽  
Radiation Induced ◽  
Partial Body ◽  
Lung Irradiation ◽  
Total Body

A radiological/nuclear (RAD-NUC) incident, especially in an urban setting, results in diverse radiation-induced injuries due to heterogeneities in dose, the extent of partial-body shielding, human biodiversity and pre-existing health conditions. For example, acute radiation syndrome (ARS) can result in death within days to weeks of exposure to 0.7–10 Gy doses and is associated with destruction of the bone marrow, known as hematopoietic ARS (H-ARS). However, partial-body shielding that spares a portion of the bone marrow from exposure can significantly reduce the occurrence of H-ARS, but delayed effects of acute radiation exposure (DEARE) can still occur within months or years after exposure depending on the individual. In a mass casualty event, ideal triage must be able to pre-symptomatically identify individuals likely to develop radiation-induced injuries and provide an appropriate treatment plan. Today, while there are FDA approved treatments for hematopoietic ARS, there are no approved diagnosis for radiation injury and no approved treatments for the broad spectra of injuries associated with radiation. This has resulted in a major capability gap in the nations preparedness to a potentially catastrophic RAD-NUC event. Circulating microRNA (miRNA) are a promising class of biomarkers for this application because the molecules are accessible via a routine blood draw and are excreted by various tissues throughout the body. To test if miRNA can be used to predict distinct tissue-specific radiation-induced injuries, we compared the changes to the circulating miRNA profiles after total-body irradiation (TBI) and whole thorax lung irradiation (WTLI) in non-human primates at doses designed to induce ARS (day 2 postirradiation; 2–6.5 Gy) and DEARE (day 15 postirradiation; 9.8 or 10.7 Gy), respectively. In both models, miRNA sequences were identified that correlated with the onset of severe neutropenia (counts <500 μL–1; TBI) or survival (WTLI). This method identified panels of eleven miRNA for both model and assigned functional roles for the panel members using gene ontology enrichment analysis. A common signature of radiation-induced injury was observed in both models: apoptosis, DNA damage repair, p53 signaling, pro-inflammatory response, and growth factor/cytokine signaling pathways were predicted to be disrupted. In addition, injury-specific pathways were identified. In TBI, pathways associated with ubiquitination, specifically of histone H2A, were enriched, suggesting more impact to DNA damage repair mechanisms and apoptosis. In WTLI, pro-fibrotic pathways including transforming growth factor (TGF-β) and bone morphogenetic protein (BMP) signaling pathways were enriched, consistent with the onset of late lung injury. These results suggest that miRNA may indeed be able to predict the onset of distinct types of radiation-induced injuries.

Radiation Induced DNA-Damage/Repair and Associated Signaling Pathways

2008 ◽  
pp. 249-266 ◽  
Author(s):  
Bo Stenerlöw ◽  
Lina Ekerljung ◽  
Jörgen Carlsson ◽  
Johan Lennartsson
Keyword(s):  
Dna Damage ◽  
Signaling Pathways ◽  
Dna Damage Repair ◽  
Damage Repair ◽  
Radiation Induced

The Bone Marrow Environment Promotes Resistance to Mitoxantrone and Etoposide By Distinct Mechanisms in Pediatric AML

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3943-3943
Author(s):  
Xin Long ◽  
Michele S. Redell
Keyword(s):  
Bone Marrow ◽  
Dna Damage ◽  
Signaling Pathways ◽  
Stromal Cells ◽  
Dna Damage Repair ◽  
Dna Damage Signaling ◽  
Damage Repair ◽  
Etoposide Treatment ◽  
Pediatric Aml ◽  
Cells Cultured

Abstract Despite aggressive treatments, death from chemoresistant disease still occurs for almost half of children with AML. One possible mechanism of chemoresistance is enhanced DNA damage repair. Mitoxantrone and etoposide are standard chemotherapy for AML, both leading to DNA damage by inhibition of topoisomerase II. Homologous recombination (HR) and non-homologous end joining (NHEJ) are the two main processes for DNA damage repair, with ataxia-telangiectaxia mutated (ATM) kinase and DNA-dependent protein kinase (DNA-PK) as key components, respectively. Both kinases phosphorylate histone H2AX (gH2AX), which facilitates DNA damage repair. Additionally, the bone marrow stromal environment protects a subset of cells from chemotherapy, but the mechanisms of resistance remain unknown. To study leukemia-stroma interactions, we used HS5 and HS27A human bone marrow stromal cells. In co-culture studies, we found that stroma-mediated resistance to mitoxantrone was mediated by both stromal soluble factors and cell-cell contact, whereas resistance to etoposide mainly by physical contact with stroma. Further, we recently reported that stromal CYR61 promotes resistance to mitoxantrone, but not etoposide (Long, et al, 2015, Br J Haematol, 170:704). To further study the mechanism underlying stroma-induced chemotherapy resistance, 44 diagnostic AML patient samples from the Children's Oncology Group were co-cultured on stromal cells, or cultured alone. The samples were treated with 100 nM mitoxantrone (n=27) or 10 µM etoposide (n=32) for 24h. Fifteen samples had sufficient cells for both chemotherapy treatments. Cells were analyzed by FACS, and stromal cells, which express mOrange, and lymphocytes (CD45high, SSClow) were excluded. We measured intracellular levels of cleaved PARP (cPARP) as an apoptosis marker, and gH2AX as a DNA damage signaling marker. As expected, AML cell viability (%cPARP-) after etoposide treatment was significantly higher in the stromal co-cultures (61.2 ±3.3% for AML cells cultured alone, v. 83.2 ±1.8% in HS5 co-cultures, p<0.0001). Results were similar for mitoxantrone treatment. We also found increased DNA damage signaling (%cPARP-/gH2AX+) after mitoxantrone treatment for AML cells in stromal co-culture (34.5 ±3.0% in cells cultured alone, v. 58.6 ±3.1% in HS5 co-cultures, p<0.0001). However, DNA damage signaling was not significantly increased after etoposide treatment. For 5 samples treated with both chemotherapy agents, we also measured pDNA-PKcs and pATM by FACS. Treatment with mitoxantrone, but not etoposide, induced more pDNA-PKcs (MFI, 25.7 ±4.2 untreated, v. 61.7 ±5.1 mitoxantrone, p<0.001, v. 31.5 ±4.8 etoposide) in AML cells cultured alone. However, stroma did not further increase pDNA-PKcs. These results suggest that the NHEJ pathway is important for the repair of DNA damage caused by mitoxantrone, and that stromal cells increase DNA damage signaling by a mechanism not involving increased pDNA-PKcs. To better understand etoposide resistance, 29 of the 44 primary AML samples were cultured on stroma overnight, and activation of intracellular signaling pathways, including pY-STAT3, pY-STAT5, and pERK1/2, was measured by FACS. Responses were heterogeneous overall, but we found several patterns of stroma-induced signaling. For example, a sample that strongly activated a given pathway when co-cultured with HS5 also responded strongly to HS27A cells, and this was particularly true for pY-STAT3 (R=0.71, p<0.0001) and pY-STAT5 (R=0.76, p<0.0001). We also found a correlation between pY-STAT3 and pY-STAT5, such that samples that showed a strong activation of STAT3 with stromal co-culture had a similar activation of STAT5 (R=0.94, p<0.0001, on HS27A). As for signaling pathways in relationship to apoptosis, higher levels of pERK1/2 were associated with lower levels of apoptosis (R=-0.5182, p<0.01, on HS27A), suggesting that ERK1/2 activation may promote resistance to etoposide. In summary, we found that DNA damage signaling is induced in AML cells by mitoxantrone, and it is augmented in cells co-cultured with stroma, likely contributing to mitoxantrone resistance. This mechanism does not occur with etoposide. Instead, we found that stromal environment-induced ERK1/2 signaling may enhance etoposide resistance in pediatric AML patient samples. Further studies to confirm the role of pERK1/2 in stroma-induced etoposide resistance are underway. Disclosures No relevant conflicts of interest to declare.

scholarly journals PDTB-10. INHIBITION OF RADIATION-INDUCED DNA DAMAGE REPAIR MEDIATED CHROMATIN MODIFICATION BY HISTONE H3 DEMETHYLASE INHIBITOR IN PEDIATRIC BRAINSTEM GLIOMA

2016 ◽  
Vol 18 (suppl_6) ◽  
pp. vi151-vi152
Author(s):  
Quanhong Ma ◽  
Andrea Plunti ◽  
Amanda Saratsis ◽  
Rishi Lulla ◽  
Jason R Fangusaro ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Repair ◽  
Chromatin Modification ◽  
Histone H3 ◽  
Brainstem Glioma ◽  
Damage Repair ◽  
Radiation Induced

Analysis of ionizing radiation-induced foci of DNA damage repair proteins

2005 ◽  
Vol 574 (1-2) ◽  
pp. 22-33 ◽  
Author(s):  
Lieneke R. van Veelen ◽  
Tiziana Cervelli ◽  
Mandy W.M.M. van de Rakt ◽  
Arjan F. Theil ◽  
Jeroen Essers ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ionizing Radiation ◽  
Dna Damage Repair ◽  
Damage Repair ◽  
Radiation Induced

scholarly journals Tumor Cell–Accelerated Senescence Is Associated With DNA-PKcs Status and Telomere Dysfunction Induced by Radiation

Dose-Response ◽  
2018 ◽  
Vol 16 (2) ◽  
pp. 155932581877152 ◽  
Author(s):  
Miaomiao Zhang ◽  
Xiaopeng Guo ◽  
Yue Gao ◽  
Dong Lu ◽  
Wenjian Li
Keyword(s):  
Dna Damage ◽  
Real Time ◽  
Genome Instability ◽  
Dna Damage Repair ◽  
Cancer Cell Line ◽  
Histochemical Staining ◽  
Damage Repair ◽  
Radiation Induced ◽  
Accelerated Senescence ◽  
Mcf 7

Whether telomere structure integrity is related to radiosensitivity is not well investigated thus far. In this study, we investigated the relation between telomere instability and radiation-induced accelerated senescence. Partial knockdown of DNA-dependent catalytic subunit of protein kinase (DNA-PKcs) in human breast cancer cell line MCF-7 was established by small interfering RNA. Radiosensitivity of control and DNA-PKcs knockdown MCF-7 cells was analyzed by clonogenetic assay. Cell growth was measured by real-time cell electronic sensing. Senescence and apoptosis were evaluated by β-galactosidase histochemical staining and fluorescence-activated cell sorting, respectively. DNA damage was determined by long polymerase chain reaction (PCR). Telomere length and integrity were analyzed by real-time PCR and cytogenetic assay, respectively. DNA-PKcs knockdown MCF-7 cells were more sensitive to X-irradiation than control cells. Further investigation revealed that accelerated senescence is more pronounced than apoptosis in cells after radiation, particularly in DNA-PKcs knockdown cells. The cytogenetic assay and kinetics of DNA damage repair revealed that the role of telomere end-capping in DNA-PKcs, rather than DNA damage repair, was more relevant to radiosensitivity. To our knowledge, this is the first study to show that DNA-PKcs plays an important role in radiation-induced accelerated senescence via maintenance of telomere integrity in MCF-7 cells. These results could be useful for future understanding of the radiation-induced genome instability and its consequences.

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