SARS–CoV–2 Spike Impairs DNA Damage Repair and Inhibits V(D)J Recombination In Vitro

Severe acute respiratory syndrome coronavirus 2 (SARS–CoV–2) has led to the coronavirus disease 2019 (COVID–19) pandemic, severely affecting public health and the global economy. Adaptive immunity plays a crucial role in fighting against SARS–CoV–2 infection and directly influences the clinical outcomes of patients. Clinical studies have indicated that patients with severe COVID–19 exhibit delayed and weak adaptive immune responses; however, the mechanism by which SARS–CoV–2 impedes adaptive immunity remains unclear. Here, by using an in vitro cell line, we report that the SARS–CoV–2 spike protein significantly inhibits DNA damage repair, which is required for effective V(D)J recombination in adaptive immunity. Mechanistically, we found that the spike protein localizes in the nucleus and inhibits DNA damage repair by impeding key DNA repair protein BRCA1 and 53BP1 recruitment to the damage site. Our findings reveal a potential molecular mechanism by which the spike protein might impede adaptive immunity and underscore the potential side effects of full-length spike-based vaccines.

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

Cell Death and Disease ◽

10.1038/s41419-020-2708-5 ◽

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.

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

Science Advances ◽

10.1126/sciadv.aav1118 ◽

2019 ◽

Vol 5 (3) ◽

pp. eaav1118 ◽

Cited By ~ 19

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.

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Antitumor Activity of a Novel Tyrosine Kinase Inhibitor AIU2001 Due to Abrogation of the DNA Damage Repair in Non-Small Cell Lung Cancer Cells

International Journal of Molecular Sciences ◽

10.3390/ijms20194728 ◽

2019 ◽

Vol 20 (19) ◽

pp. 4728 ◽

Cited By ~ 2

Author(s):

Hwani Ryu ◽

Hyun-Kyung Choi ◽

Hyo Jeong Kim ◽

Ah-Young Kim ◽

Jie-Young Song ◽

...

Keyword(s):

Lung Cancer ◽

Dna Damage ◽

Tyrosine Kinase ◽

Small Molecule ◽

Parp Inhibitor ◽

Dna Damage Repair ◽

Class Iii ◽

Damage Repair ◽

Repair Genes

Class III receptor tyrosine kinase (RTK) inhibitors targeting mainly FLT3 or c-KIT have not been well studied in lung cancer. To identify a small molecule potentially targeting class III RTK, we synthesized novel small molecule compounds and identified 5-(4-bromophenyl)-N-(naphthalen-1-yl) oxazol-2-amine (AIU2001) as a novel class III RKT inhibitor. In an in vitro kinase profiling assay, AIU2001 inhibited the activities of FLT3, mutated FLT3, FLT4, and c-KIT of class III RTK, and the proliferation of NSCLC cells in vitro and in vivo. AIU2001 induced DNA damage, reactive oxygen species (ROS) generation, and cell cycle arrest in the G2/M phase. Furthermore, AIU2001 suppressed the DNA damage repair genes, resulting in the ‘BRCAness’/‘DNA-PKness’ phenotype. The mRNA expression level of STAT5 was downregulated by AIU2001 treatment and knockdown of STAT5 inhibited the DNA repair genes. Our results show that compared to either drug alone, the combination of AIU2001 with a poly (ADP-ribose) polymerase (PARP) inhibitor olaparib or irradiation showed synergistic efficacy in H1299 and A549 cells. Hence, our findings demonstrate that AIU2001 is a candidate therapeutic agent for NSCLC and combination therapies with AIU2001 and a PARP inhibitor or radiotherapy may be used to increase the therapeutic efficacy of AIU2001 due to inhibition of DNA damage repair.

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Antiparallel Coiled-Coil Interactions Mediate the Homodimerization of the DNA Damage-Repair Protein PALB2

Biochemistry ◽

10.1021/acs.biochem.8b00789 ◽

2018 ◽

Vol 57 (47) ◽

pp. 6581-6591 ◽

Cited By ~ 6

Author(s):

Fei Song ◽

Minxing Li ◽

Gaohua Liu ◽

G.V.T. Swapna ◽

Nourhan S. Daigham ◽

...

Keyword(s):

Dna Damage ◽

Dna Damage Repair ◽

Coiled Coil ◽

Damage Repair ◽

Repair Protein ◽

Antiparallel Coiled Coil

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Altered expression of DNA damage repair genes in the brain tissue of mice conceived by in vitro fertilization

MHR Basic science of reproductive medicine ◽

10.1093/molehr/gaaa010 ◽

2020 ◽

Vol 26 (3) ◽

pp. 141-153

Author(s):

Minhao Hu ◽

Yiyun Lou ◽

Shuyuan Liu ◽

Yuchan Mao ◽

Fang Le ◽

...

Keyword(s):

Dna Methylation ◽

Dna Damage ◽

Brain Tissue ◽

Dna Damage Repair ◽

Damage Repair ◽

Gene And Protein Expression ◽

The Brain ◽

Repair Genes

Abstract Our previous study revealed a higher incidence of gene dynamic mutation in newborns conceived by IVF, highlighting that IVF may be disruptive to the DNA stability of IVF offspring. However, the underlying mechanisms remain unclear. The DNA damage repair system plays an essential role in gene dynamic mutation and neurodegenerative disease. To evaluate the long-term impact of IVF on DNA damage repair genes, we established an IVF mouse model and analyzed gene and protein expression levels of MSH2, MSH3, MSH6, MLH1, PMS2, OGG1, APEX1, XPA and RPA1 and also the amount of H2AX phosphorylation of serine 139 which is highly suggestive of DNA double-strand break (γH2AX expression level) in the brain tissue of IVF conceived mice and their DNA methylation status using quantitative real-time PCR, western blotting and pyrosequencing. Furthermore, we assessed the capacity of two specific non-physiological factors in IVF procedures during preimplantation development. The results demonstrated that the expression and methylation levels of some DNA damage repair genes in the brain tissue of IVF mice were significantly changed at 3 weeks, 10 weeks and 1.5 years of age, when compared with the in vivo control group. In support of mouse model findings, oxygen concentration of in vitro culture environment was shown to have the capacity to modulate gene expression and DNA methylation levels of some DNA damage repair genes. In summary, our study indicated that IVF could bring about long-term alterations of gene and protein expression and DNA methylation levels of some DNA damage repair genes in the brain tissue and these alterations might be resulted from the different oxygen concentration of culture environment, providing valuable perspectives to improve the safety and efficiency of IVF at early embryonic stage and also throughout different life stages.

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Molecular landscape of gastric cancer (GC) harboring mutations of histone methyltransferases.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.4_suppl.418 ◽

2020 ◽

Vol 38 (4_suppl) ◽

pp. 418-418

Author(s):

Jingyuan Wang ◽

Joanne Xiu ◽

Yasmine Baca ◽

Richard M. Goldberg ◽

Philip Agop Philip ◽

...

Keyword(s):

Dna Damage ◽

Cancer Progression ◽

Dna Damage Repair ◽

Treatment Strategies ◽

Gene Mutations ◽

Mutation Rates ◽

Aberrant Expression ◽

Damage Repair

418 Background: Alteration of histone modifications participating in transcription and genomic instability, has been recognized as an important role in tumorigenesis. Aberrant expression of histone-lysine N-methyltransferase 2 ( KMT2) family, which methylate histone H3 on lysine 4, is significantly correlated with poor survival in GC. Understanding how gene mutations of KMT2 family interact to affect cancer progression could lead to new treatment strategies. Methods: A total of 1,245 GC were analyzed using next-generation sequencing (NGS) and immunohistochemistry (IHC; Caris Life Sciences, Phoenix, AZ). Tumor mutational burden (TMB) was calculated based on somatic nonsynonymous mutations, and MSI status was evaluated by a combination of IHC, fragment analysis and NGS. PD-L1 status was analyzed by IHC (SP142). Gene fusions were detected by Archer (N = 59) or whole-transcriptome sequencing (N = 129). Results: The overall mutation rate of genes in KMT2 family was 10.6% ( KMT2A: 1.7 %, KMT2C: 4.7%, KMT2D: 7.1%). Overall, the mutation rates were significantly higher in KMT2-mutated (MT) GC than KMT2-wild type (WT) GC, except for TP53 (43% vs 63%, p < .0001). Interestingly, among the genes with significant higher mutation rates in KMT2-MT GC, 28% (21/76) of them were related to DNA damage repair (including BRCA1/ 2, RAD50) and 33% (25/76) of them were related to chromatin remodeling (including ARID1A/ 2, SMARCA4). Overexpression of HER2, amplifications of KRAS, CDK6 and HER2 were significant lower, while PCM1 and BCL3 amplifications were significant higher in KMT2-MT, compared to KMT2-WT GC ( p < .05). Significantly higher prevalence of TMB-high ( > 17mut/MB) (49% vs 3%), MSI-H (53% vs 2%), and PD-L1 overexpression (20% vs 7%) were present in KMT2-MT GC, compared to KMT2-WT GC ( p < .001). The rates of fusions involving ARHGAP26 (19% vs 3%, p < .01)and RELA (29% vs 0%, p < .0001) were significantly higher in KMT2-MT than those in KMT2-WT GC. Conclusions: This is the largest study to investigate the distinct genomic landscape between KMT2-MT and WT GC. Our data indicates that KMT2-MT GC patients could potentially benefit from agents targeting DNA damage repair and immunotherapy, which warrants further in-vitro and in-vivo investigation.

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The DNA damage repair protein Ku70 regulates tumor cell and hepatic carcinogenesis by interacting with FOXO4

Pathology - Research and Practice ◽

10.1016/j.prp.2015.12.012 ◽

2016 ◽

Vol 212 (3) ◽

pp. 153-161 ◽

Cited By ~ 7

Author(s):

Tingting Zhang ◽

Xiubing Zhang ◽

Weidong Shi ◽

Jian Xu ◽

Hui Fan ◽

...

Keyword(s):

Dna Damage ◽

Tumor Cell ◽

Dna Damage Repair ◽

Damage Repair ◽

Repair Protein ◽

Hepatic Carcinogenesis

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The extracellular role of DNA damage repair protein APE1 in regulation of IL-6 expression

Cellular Signalling ◽

10.1016/j.cellsig.2017.07.019 ◽

2017 ◽

Vol 39 ◽

pp. 18-31 ◽

Cited By ~ 10

Author(s):

Somsubhra Nath ◽

Shrabasti Roychoudhury ◽

Matthew J. Kling ◽

Heyu Song ◽

Pranjal Biswas ◽

...

Keyword(s):

Dna Damage ◽

Dna Damage Repair ◽

Damage Repair ◽

Repair Protein

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NUSAP1 Enhances Drug Resistance By Binding to RAD51 through DNA Damage Repair Pathway in Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood-2020-141815 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 13-14

Author(s):

Yang Han ◽

Ya Zhang ◽

Xinting Hu ◽

Xiang Sun ◽

Xin Wang

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Dna Damage ◽

Drug Resistance ◽

Dna Damage Repair ◽

Repair Process ◽

Lymphocytic Leukemia ◽

Repair Pathway ◽

Damage Repair

Introduction: Enhanced DNA damage repair effect is an important mechanism for drug-resistance in chronic lymphocytic leukemia (CLL). Moreover, the ability of cancer cells to repair under radiation or chemotherapy drug induced DNA damage also serves as one of the mechanisms for therapy resistance. It is reported that nucleolar and spindle associated protein 1 (NUSAP1), a microtubule binding protein, has been involved in DNA damage repair process and plays important roles in the development, progression, and metastasis in several types of cancer. However, its role and mechanism in the development of CLL are still unclear. Methods: Expression levels of NUSAP1 mRNA and protein in CLL cell lines and patient specimens were detected by qRT-PCR and Western blot, and Kaplan-Meier survival curve and overall survival were analyzed by log-rank test. Peripheral blood samples from de novo CLL patients and healthy volunteers were collected with informed consents at the Department of Hematology in Shandong Provincial Hospital Affiliated to Shandong University (SPHASU). Microarray datasets GSE22762 were obtained from Gene Expression Omnibus. With altering NUSAP1 expression by lentivirus-transfected cells in vitro, the effects of NUSAP1 on cell proliferation, apoptosis and cycle were detected by CCK8, Annexin V-PE /7AAD staining and PI/RNase staining respectively. Bioinformatics analysis, luciferase reporter analysis, immunoprecipitation and were applied to discern and examine the relationship between NUSAP1 and its potential targets. Results: According to clinical specimens and bioinformatics analysis, the expression level of NUSAP1 gene in samples of CLL patients was significantly increased than that of healthy donors (P<0.05) (Figure A). Besides, the results indicated that the OS of patients with highly expressed NUSAP1 was significantly worse than in patients with low expression with the statistical analysis database GSE22762. mRNA and protein expression levels of NUSAP1 were significantly higher in CLL cell lines than in PBMCs from healthy donors (Figure C). Our findings indicated that NUSAP1 knockdown notably inhibited cell proliferation when compared with the Scramble group (Figure D). Moreover, the amounts of DNA fragmentation of the apoptotic cells were remarkably increased by NUSAP1 shRNA in MEC-1 and EHEB cells when compared with the Scramble group (Figure E). In addition, after knocking down NUSAP1, MEC-1 and EHEB cells were blocked in G0/G1 phase (Figure F). Moreover, addition to fludarabine or ibrutinib with shNUSAP1 group showed enhanced cytotoxicity in CLL cells (Figure G). The differential genes were analyzed via RNA-seq between Scramble and ShNUSAP1 group. Intriguingly, annotations of gene ontology (GO) analysis indicated that NUSAP1 was closely related to biological processes including cell cycle and response to drug. Kyoto encyclopedia of genes and genomes (KEGG) analysis showed that NUSAP1 were enriched in pathways in cancer, DNA replication and cell cycle. Gene set enrichment analysis (GSEA) implicated that NUSAP1 was functionally enriched in DNA replication, cell cycle and proteasome (Figure H). Immunofluorescence showed that NUSAP1 was mainly distributed in the cell nucleus, and the expression level of RAD51 was positively correlated with the change of NUSAP1 expression (Figure I). Surppression of NUSAP1 inhibited the action of proteins in DNA damage repair pathway (Figure J). Through COIP, NUSAP1 was identified to bind with RAD51 and play an important role in DNA damage repair pathway (Figure K). Hence, NUSAP1 participates in the DNA damage repair process and enhances the drug resistance in CLL. Conclusions: This study first demonstrated that the high expression of NUSAP1 in CLL patients is associated with poor prognosis through database analysis and experiments in vitro. Interference of NUSAP1 expression led to a slower CLL cell proliferation and a higher apoptosis rate, meanwhile induced the G1 phase arrest. Collectively, our findings demonstrated that NUSAP1 contributes to DNA damage repairing by binding to RAD51 and enhances drug resistance in CLL. Therefore, NUSAP1 is expected to be a potential target for the treatment of CLL with drug-resistance. Figure 1 Disclosures No relevant conflicts of interest to declare.

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PARP inhibition in Ewing sarcoma: impact of germline DNA damage repair defects and activation of immunoregulatory pathways

10.1101/2020.09.18.304238 ◽

2020 ◽

Author(s):

Lisa M. Maurer ◽

Rosemarie E. Venier ◽

Elina Mukherjee ◽

Claire M. Julian ◽

Jessica D. Daley ◽

...

Keyword(s):

Dna Damage ◽

Ewing Sarcoma ◽

Immune Checkpoint ◽

Dna Damage Repair ◽

Germline Mutations ◽

Parp Inhibition ◽

Damage Repair ◽

The Impact ◽

Ewing Tumor

ABSTRACTEwing sarcoma, an oncofusion-driven primary bone tumor, can occur in the setting of various germline mutations in DNA damage repair pathway genes. We recently reported our discovery of a germline mutation in the DNA damage repair protein BARD1 (BRCA1-associated RING domain-1) in a patient with Ewing sarcoma. BARD1 is recruited to the site of DNA double stranded breaks via the poly(ADP-ribose) polymerase (PARP) protein and plays a critical role in DNA damage response pathways including homologous recombination. PARP inhibitors (PARPi) are effective against Ewing sarcoma cells in vitro, though have demonstrated limited success in clinical trials to date. In order to assess the impact of BARD1 loss on Ewing sarcoma sensitivity to PARP inhibitor therapy, we generated the novel PSaRC318 patient-derived Ewing tumor cell from our patient with a germline BARD1 mutation and then analyzed the response of these cells to PARPi. We demonstrate that PSaRC318 cells are sensitive to PARP inhibition and by testing the effect of BARD1 depletion in additional Ewing sarcoma cell lines, we confirm that loss of BARD1 enhances PARPi sensitivity. In certain malignancies, DNA damage can activate the IRF1 (interferon response factor 1) immunoregulatory pathway, and the activation of this pathway can drive immunosuppression through upregulation of the immune checkpoint protein PD-L1. In order to determine the ability of PARPi to alter Ewing tumor immunoregulation, we evaluated whether PARPi results in upregulation of the IRF1-PDL1 pathway. Indeed, we now demonstrate that PARPi leads to increased PD-L1 expression in Ewing sarcoma. Together, these data thus far suggest that while Ewing tumors harboring germline mutations in DNA damage repair proteins may in respond to PARPi in vitro, in vivo benefit of PARPi may only be demonstrated when counteracting the immunosuppressive effects of DNA damage by concurrently targeting immune checkpoint proteins.

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