scholarly journals Autophagy confers DNA damage repair pathways to protect the hematopoietic system from nuclear radiation injury

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Weiwei Lin ◽  
Na Yuan ◽  
Zhen Wang ◽  
Yan Cao ◽  
Yixuan Fang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dna Damage ◽  
Radiation Exposure ◽  
Radiation Injury ◽  
Dna Damage Repair ◽  
Nuclear Radiation ◽  
Hematopoietic System ◽  
Damage Repair ◽  
Repair Pathways

Abstract Autophagy is essentially a metabolic process, but its in vivo role in nuclear radioprotection remains unexplored. We observed that ex vivo autophagy activation reversed the proliferation inhibition, apoptosis and DNA damage in irradiated hematopoietic cells. In vivo autophagy activation improved bone marrow cellularity following nuclear radiation exposure. In contrast, defective autophagy in the hematopoietic conditional mouse model worsened the hematopoietic injury, reactive oxygen species (ROS) accumulation and DNA damage caused by nuclear radiation exposure. Strikingly, in vivo defective autophagy caused an absence or reduction in regulatory proteins critical to both homologous recombination (HR) and non-homologous end joining (NHEJ) DNA damage repair pathways, as well as a failure to induce these proteins in response to nuclear radiation. In contrast, in vivo autophagy activation increased most of these proteins in hematopoietic cells. DNA damage assays confirmed the role of in vivo autophagy in the resolution of double-stranded DNA breaks in total bone marrow cells as well as bone marrow stem and progenitor cells upon whole body irradiation. Hence, autophagy protects the hematopoietic system against nuclear radiation injury by conferring and intensifying the HR and NHEJ DNA damage repair pathways and by removing ROS and inhibiting apoptosis.

366-OR: TCF19 Promotes Functional Beta-Cell Mass and Proliferative Capacity by Regulating DNA Damage Repair Pathways

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 366-OR
Author(s):  
GRACE H. YANG ◽  
JEE YOUNG HAN ◽  
SUKANYA LODH ◽  
JOSEPH T. BLUMER ◽  
DANIELLE FONTAINE ◽  
...  
Keyword(s):  
Dna Damage ◽  
Beta Cell ◽  
Dna Damage Repair ◽  
Cell Mass ◽  
Beta Cell Mass ◽  
Proliferative Capacity ◽  
Damage Repair ◽  
Repair Pathways

scholarly journals Targeting DNA Replication Stress and DNA Double-Strand Break Repair for Optimizing SCLC Treatment

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1289 ◽  
Author(s):  
Xing Bian ◽  
Wenchu Lin
Keyword(s):  
Lung Cancer ◽  
Dna Damage ◽  
Dna Replication ◽  
Dna Damage Repair ◽  
Predictive Biomarkers ◽  
Replication Stress ◽  
Genotoxic Stress ◽  
Repair System ◽  
Damage Repair ◽  
Repair Pathways

Small cell lung cancer (SCLC), accounting for about 15% of all cases of lung cancer worldwide, is the most lethal form of lung cancer. Despite an initially high response rate of SCLC to standard treatment, almost all patients are invariably relapsed within one year. Effective therapeutic strategies are urgently needed to improve clinical outcomes. Replication stress is a hallmark of SCLC due to several intrinsic factors. As a consequence, constitutive activation of the replication stress response (RSR) pathway and DNA damage repair system is involved in counteracting this genotoxic stress. Therefore, therapeutic targeting of such RSR and DNA damage repair pathways will be likely to kill SCLC cells preferentially and may be exploited in improving chemotherapeutic efficiency through interfering with DNA replication to exert their functions. Here, we summarize potentially valuable targets involved in the RSR and DNA damage repair pathways, rationales for targeting them in SCLC treatment and ongoing clinical trials, as well as possible predictive biomarkers for patient selection in the management of SCLC.

scholarly journals PAICS contributes to gastric carcinogenesis and participates in DNA damage response by interacting with histone deacetylase 1/2

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Nan Huang ◽  
Chang Xu ◽  
Liang Deng ◽  
Xue Li ◽  
Zhixuan Bian ◽  
...  
Keyword(s):  
Dna Damage ◽  
Histone Deacetylase ◽  
Dna Damage Response ◽  
De Novo ◽  
Dna Damage Repair ◽  
Histone Deacetylase 1 ◽  
Damage Repair ◽  
Damage Response

AbstractPhosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), an essential enzyme involved in de novo purine biosynthesis, is connected with formation of various tumors. However, the specific biological roles and related mechanisms of PAICS in gastric cancer (GC) remain unclear. In the present study, we identified for the first time that PAICS was significantly upregulated in GC and high expression of PAICS was correlated with poor prognosis of patients with GC. In addition, knockdown of PAICS significantly induced cell apoptosis, and inhibited GC cell growth both in vitro and in vivo. Mechanistic studies first found that PAICS was engaged in DNA damage response, and knockdown of PAICS in GC cell lines induced DNA damage and impaired DNA damage repair efficiency. Further explorations revealed that PAICS interacted with histone deacetylase HDAC1 and HDAC2, and PAICS deficiency decreased the expression of DAD51 and inhibited its recruitment to DNA damage sites by impairing HDAC1/2 deacetylase activity, eventually preventing DNA damage repair. Consistently, PAICS deficiency enhanced the sensitivity of GC cells to DNA damage agent, cisplatin (CDDP), both in vitro and in vivo. Altogether, our findings demonstrate that PAICS plays an oncogenic role in GC, which act as a novel diagnosis and prognostic biomarker for patients with GC.

scholarly journals Imaging DNA Damage Repair In Vivo After 177Lu-DOTATATE Therapy

2019 ◽  
Vol 61 (5) ◽  
pp. 743-750 ◽  
Author(s):  
Edward O’Neill ◽  
Veerle Kersemans ◽  
P. Danny Allen ◽  
Samantha Y.A. Terry ◽  
Julia Baguña Torres ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Repair ◽  
Damage Repair

scholarly journals SIRT7-mediated ATM deacetylation is essential for its deactivation and DNA damage repair

2019 ◽  
Vol 5 (3) ◽  
pp. eaav1118 ◽  
Author(s):  
Ming Tang ◽  
Zhiming Li ◽  
Chaohua Zhang ◽  
Xiaopeng Lu ◽  
Bo Tu ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Repair ◽  
Class Iii ◽  
Ataxia Telangiectasia Mutated ◽  
Damage Repair ◽  
Damage Response ◽  
Late Stages

The activation of ataxia-telangiectasia mutated (ATM) upon DNA damage involves a cascade of reactions, including acetylation by TIP60 and autophosphorylation. However, how ATM is progressively deactivated after completing DNA damage repair remains obscure. Here, we report that sirtuin 7 (SIRT7)–mediated deacetylation is essential for dephosphorylation and deactivation of ATM. We show that SIRT7, a class III histone deacetylase, interacts with and deacetylates ATM in vitro and in vivo. In response to DNA damage, SIRT7 is mobilized onto chromatin and deacetylates ATM during the late stages of DNA damage response, when ATM is being gradually deactivated. Deacetylation of ATM by SIRT7 is prerequisite for its dephosphorylation by its phosphatase WIP1. Consequently, depletion of SIRT7 or acetylation-mimic mutation of ATM induces persistent ATM phosphorylation and activation, thus leading to impaired DNA damage repair. Together, our findings reveal a previously unidentified role of SIRT7 in regulating ATM activity and DNA damage repair.

scholarly journals A Novel Role for Cathepsin S as a Potential Biomarker in Triple Negative Breast Cancer

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Richard D. A. Wilkinson ◽  
Roberta E. Burden ◽  
Sara H. McDowell ◽  
Darragh G. McArt ◽  
Stephen McQuaid ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Dna Damage ◽  
Adjuvant Therapy ◽  
Dna Damage Repair ◽  
Cathepsin S ◽  
Damage Repair ◽  
Potential Biomarker ◽  
Repair Pathways ◽  
Improved Outcome

Cathepsin S (CTSS) has previously been implicated in a number of cancer types, where it is associated with poor clinical features and outcome. To date, patient outcome in breast cancer has not been examined with respect to this protease. Here, we carried out immunohistochemical (IHC) staining of CTSS using a breast cancer tissue microarray in patients who received adjuvant therapy. We scored CTSS expression in the epithelial and stromal compartments and evaluated the association of CTSS expression with matched clinical outcome data. We observed differences in outcome based on CTSS expression, with stromal-derived CTSS expression correlating with a poor outcome and epithelial CTSS expression associated with an improved outcome. Further subtype characterisation revealed high epithelial CTSS expression in TNBC patients with improved outcome, which remained consistent across two independent TMA cohorts. Furtherin silicogene expression analysis, using both in-house and publicly available datasets, confirmed these observations and suggested high CTSS expression may also be beneficial to outcome in ER-/HER2+ cancer. Furthermore, high CTSS expression was associated with the BL1 Lehmann subgroup, which is characterised by defects in DNA damage repair pathways and correlates with improved outcome. Finally, analysis of matching IHC analysis reveals an increased M1 (tumour destructive) polarisation in macrophage in patients exhibiting high epithelial CTSS expression. In conclusion, our observations suggest epithelial CTSS expression may be prognostic of improved outcome in TNBC. Improved outcome observed with HER2+ at the gene expression level furthermore suggests CTSS may be prognostic of improved outcome in ER- cancers as a whole. Lastly, from the context of these patients receiving adjuvant therapy and as a result of its association with BL1 subgroup CTSS may be elevated in patients with defects in DNA damage repair pathways, indicating it may be predictive of tumour sensitivity to DNA damaging agents.

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