Objective:RECQL4(a member of the RECQ helicase family)upregulation has been reported to be associated with tumor progression in several malignancies.However,whether RECQL4 sustains esophageal squamous cell carcinoma(E...Objective:RECQL4(a member of the RECQ helicase family)upregulation has been reported to be associated with tumor progression in several malignancies.However,whether RECQL4 sustains esophageal squamous cell carcinoma(ESCC)has not been elucidated.In this study,we determined the functional role for RECQL4 in ESCC progression.Methods:RECQL4 expression in clinical samples of ESCC was examined by immunohistochemistry.Cell proliferation,cellular senescence,the epithelial-mesenchymal transition(EMT),DNA damage,and reactive oxygen species in ESCC cell lines with RECQL4 depletion or overexpression were analyzed.The levels of proteins involved in the DNA damage response(DDR),cell cycle progression,survival,and the EMT were determined by Western blot analyses.Results:RECQL4 was highly expressed in tumor tissues when compared to adjacent non-tumor tissues in ESCC(P<0.001)and positively correlated with poor differentiation(P=0.011),enhanced invasion(P=0.033),and metastasis(P=0.048).RECQL4 was positively associated with proliferation and migration in ESCC cells.Depletion of RECQL4 also inhibited growth of tumor xenografts in vivo.RECQL4 depletion induced G0/G1 phase arrest and cellular senescence.Importantly,the levels of DNA damage and reactive oxygen species were increased when RECQL4 was depleted.DDR,as measured by the activation of ATM,ATR,CHK1,and CHK2,was impaired.RECQL4 was also shown to promote the activation of AKT,ERK,and NF-k B in ESCC cells.Conclusions:The results indicated that RECQL4 was highly expressed in ESCC and played critical roles in the regulation of DDR,redox homeostasis,and cell survival.展开更多
Objective:DNA damage response(DDR)genes have low mutation rates,which may restrict their clinical applications in predicting the outcomes of immune checkpoint inhibitor(ICI)treatment.Thus,a systemic analysis of multip...Objective:DNA damage response(DDR)genes have low mutation rates,which may restrict their clinical applications in predicting the outcomes of immune checkpoint inhibitor(ICI)treatment.Thus,a systemic analysis of multiple DDR genes is needed to identify potential biomarkers of ICI efficacy.Methods:A total of 39,631 patients with mutation data were selected from the cBioPortal database.A total of 155 patients with mutation data were obtained from the Fudan University Shanghai Cancer Center(FUSCC).A total of 1,660 patients from the MSK-IMPACT cohort who underwent ICI treatment were selected for survival analysis.A total of 249 patients who underwent ICI treatment from the Dana-Farber Cancer Institute(DFCI)cohort were obtained from a published dataset.The Cancer Genome Atlas(TCGA)level 3 RNA-Seq version 2 RSEM data for gastric cancer were downloaded from cBioPortal.Results:Six MMR and 30 DDR genes were included in this study.Six MMR and 20 DDR gene mutations were found to predict the therapeutic efficacy of ICI,and most of them predicted the therapeutic efficacy of ICI,in a manner dependent on TMB,except for 4 combined DDR gene mutations,which were associated with the therapeutic efficacy of ICI independently of the TMB.Single MMR/DDR genes showed low mutation rates;however,the mutation rate of all the MMR/DDR genes associated with the therapeutic efficacy of ICI was relatively high,reaching 10%–30%in several cancer types.Conclusions:Coanalysis of multiple MMR/DDR mutations aids in selecting patients who are potential candidates for immunotherapy.展开更多
Objective:Mitotic arrest-deficient protein 1(MAD1)is a kinetochore protein essential for the mitotic spindle checkpoint.Proteomic studies have indicated that MAD1 is a component of the DNA damage response(DDR)pathway....Objective:Mitotic arrest-deficient protein 1(MAD1)is a kinetochore protein essential for the mitotic spindle checkpoint.Proteomic studies have indicated that MAD1 is a component of the DNA damage response(DDR)pathway.However,whether and how MAD1 might be directly involved in the DDR is largely unknown.Methods:We ectopically expressed the wild type,or a phosphorylation-site--mutated form of MAD1 in MAD1 knockdown cells to look for complementation effects.We used the comet assay,colony formation assay,immunofluorescence staining,and flow cytometry to assess the DDR,radiosensitivity,and the G2/M checkpoint.We employed co-immunoprecipitation followed by mass spectrometry to identify MAD1 interacting proteins.Data were analyzed using the unpaired Student'st-test.Results:We showed that MAD1 was required for an optimal DDR,as knocking down MAD1 resulted in impaired DNA repair and hypersensitivity to ionizing radiation(IR).We found that IR-induced serine 214 phosphorylation was ataxia-telangiectasia mutated(ATM)kinase-dependent.Mutation of serine 214 to alanine failed to rescue the phenotypes of MAD1 knockdown cells in response to IR.Using mass spectrometry,we identified a protein complex mediated by MAD1 serine 214 phosphorylation in response to IR.Among them,we showed that KU80 was a key protein that displayed enhanced interaction with MAD1 after DNA damage.Finally,we showed that MAD1 interaction with KU80 required serine 214 phosphorylation,and it was essential for activation of DNA protein kinases catalytic subunit(DNA-PKcs).Conclusions:MAD1 serine 214 phosphorylation mediated by ATM kinase in response to IR was required for the interaction with KU80 and activation of DNA-PKCs.展开更多
The activation of some oncogenes promote cancer cell proliferation and growth,facilitate cancer progression and metastasis by induce DNA replication stress,even genome instability.Activation of the cyclic GMP-AMP synt...The activation of some oncogenes promote cancer cell proliferation and growth,facilitate cancer progression and metastasis by induce DNA replication stress,even genome instability.Activation of the cyclic GMP-AMP synthase(cGAS)mediates classical DNA sensing,is involved in genome instability,and is linked to various tumor development or therapy.However,the function of cGAS in gastric cancer remains elusive.In this study,the TCGA database and retrospective immunohistochemical analyses revealed substantially high cGAS expression in gastric cancer tissues and cell lines.By employing cGAS high-expression gastric cancer cell lines,including AGS and MKN45,ectopic silencing of cGAS caused a significant reduction in the proliferation of the cells,tumor growth,and mass in xenograft mice.Mechanistically,database analysis predicted a possible involvement of cGAS in the DNA damage response(DDR),further data through cells revealed protein interactions of the cGAS and MRE11-RAD50-NBN(MRN)complex,which activated cell cycle checkpoints,even increased genome instability in gastric cancer cells,thereby contributing to gastric cancer progression and sensitivity to treatment with DNA damaging agents.Furthermore,the upregulation of cGAS significantly exacerbated the prognosis of gastric cancer patients while improving radiotherapeutic outcomes.Therefore,we concluded that cGAS is involved in gastric cancer progression by fueling genome instability,implying that intervening in the cGAS pathway could be a practicable therapeutic approach for gastric cancer.展开更多
DNA is highly vulnerable to spontaneous and environmental timely damage in living cells.DNA damage may cause genetic instability and increase cancer risk if the damages are not repaired timely and efficiently.Human ce...DNA is highly vulnerable to spontaneous and environmental timely damage in living cells.DNA damage may cause genetic instability and increase cancer risk if the damages are not repaired timely and efficiently.Human cells possess several DNA damage response(DDR)mechanisms to protect the integrity of their genome.Clarification of the mechanisms under-lying the DNA damage response following lethal damage will facilitate the identification of therapeutic targets for cancers.Histone post-translational modifications(PTMs)have been indicated to play different roles in the repair of DNA damage.In this context,histone PTMs regulate recruitment of downstream effectors,and facilitate appropriate repair response.This review outlines the current understanding of different histone PTMs in response to DNA dam-age repair,besides,enumerates the role of new type PTMs such as histone succinylation and crotonylation in regulating DNA damage repair processes.展开更多
Genomic instability remains an enabling feature of cancer and promotes malignant transformation.Alterations of DNA damage response(DDR)pathways allow genomic instability,generate neoantigens,upregulate the expression ...Genomic instability remains an enabling feature of cancer and promotes malignant transformation.Alterations of DNA damage response(DDR)pathways allow genomic instability,generate neoantigens,upregulate the expression of programmed death ligand 1(PD-L1)and interact with signaling such as cyclic GMPe AMP synthase-stimulator of interferon genes(cGASe STING)signaling.Here,we review the basic knowledge of DDR pathways,mechanisms of genomic instability induced by DDR alterations,impacts of DDR alterations on immune system,and the potential applications of DDR alterations as biomarkers and therapeutic targets in cancer immunotherapy.展开更多
BRCA1 is a well-established tumor suppressor gene,which is frequently mutated in familial breast and ovarian cancers.The gene product of BRCA1 functions in a number of cellular pathways that maintain genomic stability...BRCA1 is a well-established tumor suppressor gene,which is frequently mutated in familial breast and ovarian cancers.The gene product of BRCA1 functions in a number of cellular pathways that maintain genomic stability,including DNA damage-induced cell cycle checkpoint activation,DNA damage repair,protein ubiquitination,chromatin remodeling,as well as transcriptional regulation and apoptosis.In this review,we discuss recent advances regarding our understanding of the role of BRCA1 in tumor suppression and DNA damage response,including DNA damage-induced cell cycle checkpoint activation and DNA damage repair.展开更多
Gastric cancer remains one of the leading causes of cancer-related death worldwide,and most of the cases are associated with Helicobacter pylori infection.This bacterium promotes the production of reactive oxygen spec...Gastric cancer remains one of the leading causes of cancer-related death worldwide,and most of the cases are associated with Helicobacter pylori infection.This bacterium promotes the production of reactive oxygen species(ROS),which cause DNA damage in gastric epithelial cells.In this study,we evaluated the expression of important genes involved in the recognition of DNA damage(ATM,ATR,and H2AX)and ROS-induced damage repair(APE1)and the expression of some miRNAs(miR-15a,miR-21,miR-24,miR-421 and miR-605)that target genes involved in the DNA damage response(DDR)in 31 fresh tissues of gastric cancer.Cytoscape v3.1.1 was used to construct the postulated miRNA:mRNA interaction network.Analysis performed by real-time quantitative PCR exhibited significantly increased levels of the APE1(RQ=2.55,p<0.0001)and H2AX(RQ=2.88,p=0.0002)genes beyond the miR-421 and miR-605 in the gastric cancer samples.In addition,significantly elevated levels of miR-21,miR-24 and miR-421 were observed in diffuse-type gastric cancer.Correlation analysis reinforced some of the gene:gene(ATM/ATR/H2AX)and miRNA:mRNA relationships obtained also with the interaction network.Thus,our findings show that tumor cells from gastric cancer presents deregulation of genes and miRNAs that participate in the recognition and repair of DNA damage,which could confer an advantage to cell survival and proliferation in the tumor microenvironment.展开更多
The DNA damage response(DDR)is a signal transduction pathway that decides the cell’s fate either to repair DNA damage or to undergo apoptosis if there is too much damage.Post-translational modifications modulate the ...The DNA damage response(DDR)is a signal transduction pathway that decides the cell’s fate either to repair DNA damage or to undergo apoptosis if there is too much damage.Post-translational modifications modulate the assembly and activity of protein complexes during the DDR pathways.MicroRNAs(miRNAs)are emerging as a class of endogenous gene modulators that control protein levels,thereby adding a new layer of regulation to the DDR.In this review,we describe a new role for miRNAs in regulating the cellular response to DNA damage with a focus on DNA double-strand break damage.We also discuss the implications of miRNA’s role in the DDR to stem cells,including embryonic stem cells and cancer stem cells,stressing the potential applications for miRNAs to be used as sensitizers for cancer radiotherapy and chemotherapy.展开更多
Background:Desmoplastic small round cell tumor(DSRCT)is a rare,aggressive,and poorly investigated simple sarcoma with a low frequency of genetic deregulation other than an Ewing sarcoma RNA binding protein 1(EWSR1)-W...Background:Desmoplastic small round cell tumor(DSRCT)is a rare,aggressive,and poorly investigated simple sarcoma with a low frequency of genetic deregulation other than an Ewing sarcoma RNA binding protein 1(EWSR1)-Wilm’s tumor suppressor(WT1)translocation.We used whole-exome sequencing to interrogate six consecutive pretreated DSRCTs whose gene expression was previously investigated.Methods:DNA libraries were prepared from formalin-fixed,paraffin-embedded archival tissue specimens following the Agilent SureSelectXT2 target enrichment protocol and sequenced on Illumina NextSeq 500.Raw sequence data were aligned to the reference genome with Burrows-Wheeler Aligner algorithm.Somatic mutations and copy number alterations(CNAs)were identified using MuTect2 and EXCAVATOR2,respectively.Biological functions associated with altered genes were investigated through Ingenuity Pathway Analysis(IPA)software.Results:A total of 137 unique somatic mutations were identified:133 mutated genes were case-specific,and 2 were mutated in two cases but in different positions.Among the 135 mutated genes,27%were related to two biological categories:DNA damage-response(DDR)network that was also identified through IPA and mesenchymal-epithelial reverse transition(MErT)/epithelial-mesenchymal transition(EMT)already demonstrated to be relevant in DSRCT.The mutated genes in the DDR network were involved in various steps of transcription and particularly affected pre-mRNA.Half of these genes encoded RNA-binding proteins or DNA/RNA-binding proteins,which were recently rec-ognized as a new class of DDR players.CNAs in genes/gene families,involved in MErT/EMT and DDR,were recurrent across patients and mostly segregated in the MErT/EMT category.In addition,recurrent gains of regions in chromosome 1 involving many MErT/EMT gene families and loss of one arm or the entire chromosome 6 affecting relevant immune-regulatory genes were recorded.Conclusions:The emerging picture is an extreme inter-tumor heterogeneity,characterized by the concurrent deregulation of the DDR and MErT/EMT dynamic and plastic programs that could favour genomic instability and explain the refractory DSRCT profile.展开更多
Resistance of cancer patients to DNA damaging radiation therapy and chemotherapy remains a major problem in the clinic.The current review discusses the molecular mechanisms of therapy resistance in acute myeloid leuke...Resistance of cancer patients to DNA damaging radiation therapy and chemotherapy remains a major problem in the clinic.The current review discusses the molecular mechanisms of therapy resistance in acute myeloid leukemia(AML)conferred by cooperative chemotherapy-induced DNA damage response(DDR)and mutational activation of PI3K/AKT signaling.In addition,strategies to overcome resistance are discussed,with particular focus on studies underpinning the vast potential of therapies combining standard chemotherapy AML regimens with small molecule inhibitors targeting key regulatory hubs at the interface of DDR and oncogenic signaling pathways.展开更多
DNA damage response(DDR)is a highly conserved genome surveillance mechanism that preserves cell viability in the presence of chemotherapeutic drugs.Hence,small molecules that inhibit DDR are expected to enhance the an...DNA damage response(DDR)is a highly conserved genome surveillance mechanism that preserves cell viability in the presence of chemotherapeutic drugs.Hence,small molecules that inhibit DDR are expected to enhance the anti-cancer effect of chemotherapy.Through a recent chemical library screen,we identified shikonin as an inhibitor that strongly suppressed DDR activated by various chemotherapeutic drugs in cancer cell lines derived from different origins.Mechanistically,shikonin inhibited the activation of ataxia telangiectasia mutated(ATM),and to a lesser degree ATM and RAD3-related(ATR),two master upstream regulators of the DDR signal,through inducing degradation of ATM and ATR-interacting protein(ATRIP),an obligate associating protein of ATR,respectively.As a result of DDR inhibition,shikonin enhanced the anti-cancer effect of chemotherapeutic drugs in both cell cultures and in mouse models.While degradation of ATRIP is proteasome dependent,that of ATM depends on caspase-and lysosome-,but not proteasome.Overexpression of ATM significantly mitigated DDR inhibition and cell death induced by shikonin and chemotherapeutic drugs.These novel findings reveal shikonin as a pan DDR inhibitor and identify ATM as a primary factor in determining the chemo sensitizing effect of shikonin.Our data may facilitate the development of shikonin and its derivatives as potential chemotherapy sensitizers through inducing ATM degradation.展开更多
Decabrominated diphenyl ether(BDE-209)is generally utilized in multiple polymer materials as common brominated flame retardant.BDE-209 has been listed as persistent organic pollutants(POPs),which was considered to be ...Decabrominated diphenyl ether(BDE-209)is generally utilized in multiple polymer materials as common brominated flame retardant.BDE-209 has been listed as persistent organic pollutants(POPs),which was considered to be reproductive toxin in the environment.But it still remains unclear about the effects of BDE-209 on DNA methylation and the inducedmale reproductive toxicity.Due to the extensive epigenetic regulation in germ line development,we hypothesize that BDE-209 exposure impacts the statue of DNA methylation in spermatocytes in vitro.Therefore,the mouse GC-2spd(GC-2)cells were used for the genome wide DNA methylation analysis after treated with 32μg/mL BDE-209 for 24 hr.The results showed that BDE-209 caused genomic methylation changes with 32,083 differentially methylated CpGs in GC-2 cells,including 16,164(50.38%)hypermethylated and 15,919(49.62%)hypomethylated sites.With integrated analysis ofDNAmethylation data and functional enrichment,we found that BDE-209 might affect the functional transcription in cell growth and sperm development by differential gene methylation.qRT-PCR validation demonstrated the involvement of p53-dependent DNA damage response in the GC-2 cells after BDE-209 exposure.In general,our findings indicated that BDE-209-induced genome wide methylation changes could be interrelated with reproductive dysfunction.This study might provide new insights into the mechanisms of male reproductive toxicity under the environmental exposure to BDE-209.展开更多
Accumulating evidence indicates that ataxia-telangiectasia mutated kinase is critical for maintaining cellular homeostasis and that it has both nuclear and cytoplasmic functions.However,the functions of ataxia-telangi...Accumulating evidence indicates that ataxia-telangiectasia mutated kinase is critical for maintaining cellular homeostasis and that it has both nuclear and cytoplasmic functions.However,the functions of ataxia-telangiectasia mutated that when lost lead to cerebellar degeneration are still unknown.In this review,we first describe the role of ataxia-telangiectasia mutated in cerebellar pathology.In addition to its canonical nuclear functions in DNA damage response circuits,ataxia-telangiectasia mutated functions in various cytoplasmic and mitochondrial processes that are critically important for cellular homeostasis.We discuss these functions with a focus on the role of ataxia-telangiectasia mutated in maintaining the homeostatic redox state.Finally,we describe the unique functions of ataxia-telangiectasia mutated in various types of neuronal and glial cells including cerebellar granule neurons,astrocytes,and microglial cells.展开更多
Clinical application of doxorubicin(DOX)is heavily hindered by DOX cardiotoxicity.Several theories were postulated for DOX cardiotoxicity including DNA damage and DNA damage response(DDR),although the mechanism(s)invo...Clinical application of doxorubicin(DOX)is heavily hindered by DOX cardiotoxicity.Several theories were postulated for DOX cardiotoxicity including DNA damage and DNA damage response(DDR),although the mechanism(s)involved remains to be elucidated.This study evaluated the potential role of TBC domain family member 15(TBC1D15)in DOX cardiotoxicity.Tamoxifen-induced cardiac-specific Tbcldi5 knockout(Tbcldi5^(CKO))or Tbcldi5 knockin(Tbcldi5^(CKI))male mice were challenged with a single dose of DOx prior to cardiac assessment 1 week or 4 weeks following DOX challenge.Adenoviruses encoding TBC1D15 or containing shRNA targeting Tbcld15 were used for Tbcld15 overexpression or knockdown in isolated primary mouse cardiomyocytes.Our results re-vealed that DOX evoked upregulation of TBC1D15 with compromised myocardial function and overt mortality,the effects of which were ameliorated and accentuated by Tbcldi5 deletion and Tbcld15 overexpression,respectively.DOX overtly evoked apoptotic cell death,the effect of which was alleviated and exacerbated by Tbcld15 knockout and overexpression,respectively.Meanwhile,DOX provoked mitochondrial membrane potential collapse,oxidative stress and DNA damage,the effects of which were mitigated and exacerbated by Tbcld15 knockdown and overexpression,respectively.Further scrutiny revealed that TBC1D15 fostered cytosolic accumulation of the cardinal DDR element DNA-dependent protein kinase catalytic subunit(DNA-PKcs).Liquid chromatography-tandem mass spectrometry and coimmunoprecipitation denoted an interaction between TBCID15 and DNA-PKcs at the segment 594-624 of TBC1D15.Moreover,overexpression of TBC1D15 mutant(A594-624,deletion of segment 594-624)failed to elicit accentuation of DOX-induced cytosolic retention of DNA-PKcs,DNA damage and cardiomyocyte apoptosis by TBC1D15 wild type.However,Tbcld15 deletion ameliorated DOXinduced cardiomyocyte contractile anomalies,apoptosis,mitochondrial anomalies,DNA damage and cytosolic DNA-PKcs accumulation,which were canceled off by DNA-PKcs inhibition or ATM activation.Taken together,our findings denoted a pivotal role for TBCID15 in DOX-induced DNA damage,mitochondrial injury,and apoptosis possibly through binding with DNA-PKcs and thus gate-keeping its cytosolic retention,a route to accentuation of cardiac contractile dysfunction in DOX-induced cardiotoxicity.展开更多
Objective To investigate the function of primary cilia in regulating the cellular response to temozolomide(TMZ)and ionizing radiation(IR)in glioblastoma(GBM).Methods GBM cells were treated with TMZ or X-ray/carbon ion...Objective To investigate the function of primary cilia in regulating the cellular response to temozolomide(TMZ)and ionizing radiation(IR)in glioblastoma(GBM).Methods GBM cells were treated with TMZ or X-ray/carbon ion.The primary cilia were examined by immunostaining with Arl13 b andγ-tubulin,and the cellular resistance ability was measured by cell viability assay or survival fraction assay.Combining with cilia ablation by IFT88 depletion or chloral hydrate and induction by lithium chloride,the autophagy was measured by acridine orange staining assay.The DNA damage repair ability was estimated by the kinetic curve ofγH2 AX foci,and the DNAdependent protein kinase(DNA-PK)activation was detected by immunostaining assay.Results Primary cilia were frequently preserved in GBM,and the induction of ciliogenesis decreased cell proliferation.TMZ and IR promoted ciliogenesis in dose-and time-dependent manners,and the suppression of ciliogenesis significantly enhanced the cellular sensitivity to TMZ and IR.The inhibition of ciliogenesis elevated the lethal effects of TMZ and IR via the impairment of autophagy and DNA damage repair.The interference of ciliogenesis reduced DNA-PK activation,and the knockdown of DNA-PK led to cilium formation and elongation.Conclusion Primary cilia play a vital role in regulating the cellular sensitivity to TMZ and IR in GBM cells through mediating autophagy and DNA damage repair.展开更多
Proteins are major functional units that are tightly connected to form complex and dynamic networks.These networks enable cells and organisms to operate properly and respond efficiently to environmental cues.Over the ...Proteins are major functional units that are tightly connected to form complex and dynamic networks.These networks enable cells and organisms to operate properly and respond efficiently to environmental cues.Over the past decades,many biochemical methods have been developed to search for protein-binding partners in order to understand how protein networks are constructed and connected.At the same time,rapid development in proteomics and mass spectrometry(MS)techniques makes it possible to identify interacting proteins and build comprehensive protein-protein interaction networks.The resulting interactomes and networks have proven informative in the investigation of biological functions,such as in the field of DNA damage repair.In recent years,a number of proteins involved in DNA damage response and DNA repair pathways have been uncovered with MS-based protein-protein interaction studies.As the technologies for enriching associated proteins and MS become more sophisticated,the studies of protein-protein interactions are entering a new era.In this review,we summarize the strategies and recent developments for exploring protein-protein interaction.In addition,we discuss the application of these tools in the investigation of protein-protein interaction networks involved in DNA damage response and DNA repair.展开更多
Biological reactions require self-assembly of factors in the complex cellular milieu.Recent evidence indicates that intrinsically disordered,low-complexity sequence domains(LCDs)found in regulatory factors mediate div...Biological reactions require self-assembly of factors in the complex cellular milieu.Recent evidence indicates that intrinsically disordered,low-complexity sequence domains(LCDs)found in regulatory factors mediate diverse cellular processes from gene expression to DNA repair to signal transduction,by enriching specific biomolecules in membraneless compartments or hubs that may undergo liquidliquid phase separation(LLPS).In this review,we discuss how embryonic stem cells take advantage of LCD-driven interactions to promote cell-specific transcription,DNA damage response,and DNA repair.We propose that LCDmediated interactions play key roles in stem cell maintenance and safeguarding genome integrity.展开更多
DNA replication is a highly regulated process involving a number of licensing and replication factors that function in a carefully orchestrated manner to faithfully replicate DNA during every cell cycle.Loss of proper...DNA replication is a highly regulated process involving a number of licensing and replication factors that function in a carefully orchestrated manner to faithfully replicate DNA during every cell cycle.Loss of proper licensing control leads to deregulated DNA replication including DNA re-replication,which can cause genome instability and tumorigenesis.Eukaryotic organisms have established several conserved mechanisms to prevent DNA re-replication and to counteract its potentially harmful effects.These mechanisms include tightly controlled regulation of licensing factors and activation of cell cycle and DNA damage checkpoints.Deregulated licensing control and its associated compromised checkpoints have both been observed in tumor cells,indicating that proper functioning of these pathways is essential for maintaining genome stability.In this review,we discuss the regulatory mechanisms of licensing control,the deleterious consequences when both licensing and checkpoints are compromised,and present possible mechanisms to prevent re-replication in order to maintain genome stability.展开更多
Upper tract urothelial carcinoma(UTUC)is rare but can occur sporadically outside the context of Lynch syndrome.In these cases,knowing whether non-mismatch repair(MMR),DNA damage response and repair(DDR),and cell cycle...Upper tract urothelial carcinoma(UTUC)is rare but can occur sporadically outside the context of Lynch syndrome.In these cases,knowing whether non-mismatch repair(MMR),DNA damage response and repair(DDR),and cell cycle gene alterationsmay predict responses to chemotherapy orimmunotherapy and survival is of clinical importance.This study examined the germline and somatic mutational landscape of two UTUC patients with differential responses to programmed death 1(PD-1)/PD-ligand 1(PD-L1)immune checkpoint inhibitors and queried three independent UTUC cohort studies for co-occurrence of key cell cycle and DDR genes,as well as for their associations with overall survival(OS).TP53 and RB1 emerged as potential determinants of shorter OS in UTUC cohort patients,regardless of concurrent DDR alterations,and if prospectively assessed in larger studies they might also explain resistance to PD-1/PD-L1 blockade despite PD-L1 expression.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.81572785,31771260,and 81201750)a Ministry of Science and Technology(Grant No.2011CB966200)+2 种基金the Excellent Young and Mid-Career Scientist Award of Shandong Province(Grant No.BS2013YY023)the Key Research Project of Shandong Province(Grant No.2016GSF201072)the Project of State Key Laboratory of Radiation Medicine and Protection,Soochow University(Grant No.GZN1201804)。
文摘Objective:RECQL4(a member of the RECQ helicase family)upregulation has been reported to be associated with tumor progression in several malignancies.However,whether RECQL4 sustains esophageal squamous cell carcinoma(ESCC)has not been elucidated.In this study,we determined the functional role for RECQL4 in ESCC progression.Methods:RECQL4 expression in clinical samples of ESCC was examined by immunohistochemistry.Cell proliferation,cellular senescence,the epithelial-mesenchymal transition(EMT),DNA damage,and reactive oxygen species in ESCC cell lines with RECQL4 depletion or overexpression were analyzed.The levels of proteins involved in the DNA damage response(DDR),cell cycle progression,survival,and the EMT were determined by Western blot analyses.Results:RECQL4 was highly expressed in tumor tissues when compared to adjacent non-tumor tissues in ESCC(P<0.001)and positively correlated with poor differentiation(P=0.011),enhanced invasion(P=0.033),and metastasis(P=0.048).RECQL4 was positively associated with proliferation and migration in ESCC cells.Depletion of RECQL4 also inhibited growth of tumor xenografts in vivo.RECQL4 depletion induced G0/G1 phase arrest and cellular senescence.Importantly,the levels of DNA damage and reactive oxygen species were increased when RECQL4 was depleted.DDR,as measured by the activation of ATM,ATR,CHK1,and CHK2,was impaired.RECQL4 was also shown to promote the activation of AKT,ERK,and NF-k B in ESCC cells.Conclusions:The results indicated that RECQL4 was highly expressed in ESCC and played critical roles in the regulation of DDR,redox homeostasis,and cell survival.
基金This work was supported by the National Key R&D Program of China(Grant No.2018YFC1313300)the National Natural Science Foundation of China(Grant No.81572331).
文摘Objective:DNA damage response(DDR)genes have low mutation rates,which may restrict their clinical applications in predicting the outcomes of immune checkpoint inhibitor(ICI)treatment.Thus,a systemic analysis of multiple DDR genes is needed to identify potential biomarkers of ICI efficacy.Methods:A total of 39,631 patients with mutation data were selected from the cBioPortal database.A total of 155 patients with mutation data were obtained from the Fudan University Shanghai Cancer Center(FUSCC).A total of 1,660 patients from the MSK-IMPACT cohort who underwent ICI treatment were selected for survival analysis.A total of 249 patients who underwent ICI treatment from the Dana-Farber Cancer Institute(DFCI)cohort were obtained from a published dataset.The Cancer Genome Atlas(TCGA)level 3 RNA-Seq version 2 RSEM data for gastric cancer were downloaded from cBioPortal.Results:Six MMR and 30 DDR genes were included in this study.Six MMR and 20 DDR gene mutations were found to predict the therapeutic efficacy of ICI,and most of them predicted the therapeutic efficacy of ICI,in a manner dependent on TMB,except for 4 combined DDR gene mutations,which were associated with the therapeutic efficacy of ICI independently of the TMB.Single MMR/DDR genes showed low mutation rates;however,the mutation rate of all the MMR/DDR genes associated with the therapeutic efficacy of ICI was relatively high,reaching 10%–30%in several cancer types.Conclusions:Coanalysis of multiple MMR/DDR mutations aids in selecting patients who are potential candidates for immunotherapy.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.81672743 and 81974464)Beijing Tianjin Hebei Basic Research Cooperation Project(Grant No.19JCZDJC64500(Z))+4 种基金Shenzhen Basic Research Project(Grant No.JCYJ20160331114230843)Tianjin Municipal Health Commission(Grant Nos.2015KR11 and 2013KG134)Tianjin Municipal Science and Technology Bureau(Grant No.18JCYBJC27800)US NIH grant RO 1 CAI33093,the Alabama Innovation Fund of the United Statesthe Tianjin Medical University Cancer Institute and Hospital Innovation Fund(Grant No.1803)。
文摘Objective:Mitotic arrest-deficient protein 1(MAD1)is a kinetochore protein essential for the mitotic spindle checkpoint.Proteomic studies have indicated that MAD1 is a component of the DNA damage response(DDR)pathway.However,whether and how MAD1 might be directly involved in the DDR is largely unknown.Methods:We ectopically expressed the wild type,or a phosphorylation-site--mutated form of MAD1 in MAD1 knockdown cells to look for complementation effects.We used the comet assay,colony formation assay,immunofluorescence staining,and flow cytometry to assess the DDR,radiosensitivity,and the G2/M checkpoint.We employed co-immunoprecipitation followed by mass spectrometry to identify MAD1 interacting proteins.Data were analyzed using the unpaired Student'st-test.Results:We showed that MAD1 was required for an optimal DDR,as knocking down MAD1 resulted in impaired DNA repair and hypersensitivity to ionizing radiation(IR).We found that IR-induced serine 214 phosphorylation was ataxia-telangiectasia mutated(ATM)kinase-dependent.Mutation of serine 214 to alanine failed to rescue the phenotypes of MAD1 knockdown cells in response to IR.Using mass spectrometry,we identified a protein complex mediated by MAD1 serine 214 phosphorylation in response to IR.Among them,we showed that KU80 was a key protein that displayed enhanced interaction with MAD1 after DNA damage.Finally,we showed that MAD1 interaction with KU80 required serine 214 phosphorylation,and it was essential for activation of DNA protein kinases catalytic subunit(DNA-PKcs).Conclusions:MAD1 serine 214 phosphorylation mediated by ATM kinase in response to IR was required for the interaction with KU80 and activation of DNA-PKCs.
基金supported by Zhengzhou Major Collaborative Innovation Project(No.18XTZX12003)Key Projects of Discipline Construction in Zhengzhou University(No.XKZDJC202001)+2 种基金National Key Research and Development Program in China(No.2020YFC2006100)Excellent Foreign Scientist Studio of Henan Province in China(No.GZS2018001)Medical Service Capacity Improvement Project of Henan Province in China(Grant No.Yu Wei Medicine[2017]No.66).
文摘The activation of some oncogenes promote cancer cell proliferation and growth,facilitate cancer progression and metastasis by induce DNA replication stress,even genome instability.Activation of the cyclic GMP-AMP synthase(cGAS)mediates classical DNA sensing,is involved in genome instability,and is linked to various tumor development or therapy.However,the function of cGAS in gastric cancer remains elusive.In this study,the TCGA database and retrospective immunohistochemical analyses revealed substantially high cGAS expression in gastric cancer tissues and cell lines.By employing cGAS high-expression gastric cancer cell lines,including AGS and MKN45,ectopic silencing of cGAS caused a significant reduction in the proliferation of the cells,tumor growth,and mass in xenograft mice.Mechanistically,database analysis predicted a possible involvement of cGAS in the DNA damage response(DDR),further data through cells revealed protein interactions of the cGAS and MRE11-RAD50-NBN(MRN)complex,which activated cell cycle checkpoints,even increased genome instability in gastric cancer cells,thereby contributing to gastric cancer progression and sensitivity to treatment with DNA damaging agents.Furthermore,the upregulation of cGAS significantly exacerbated the prognosis of gastric cancer patients while improving radiotherapeutic outcomes.Therefore,we concluded that cGAS is involved in gastric cancer progression by fueling genome instability,implying that intervening in the cGAS pathway could be a practicable therapeutic approach for gastric cancer.
基金supported by National Natural Science Foundation of China(No.82071695,82060535)Natural Science Foundation of Gansu Province,China(No.21JR7RA450)。
文摘DNA is highly vulnerable to spontaneous and environmental timely damage in living cells.DNA damage may cause genetic instability and increase cancer risk if the damages are not repaired timely and efficiently.Human cells possess several DNA damage response(DDR)mechanisms to protect the integrity of their genome.Clarification of the mechanisms under-lying the DNA damage response following lethal damage will facilitate the identification of therapeutic targets for cancers.Histone post-translational modifications(PTMs)have been indicated to play different roles in the repair of DNA damage.In this context,histone PTMs regulate recruitment of downstream effectors,and facilitate appropriate repair response.This review outlines the current understanding of different histone PTMs in response to DNA dam-age repair,besides,enumerates the role of new type PTMs such as histone succinylation and crotonylation in regulating DNA damage repair processes.
基金supported in part by a grant from National Natural Science Foundation of China(81802255)Shanghai Pujiang Program(17PJD036,China)+6 种基金a grant from Shanghai Municipal Commission of Health and Family Planning Program(20174Y0131,China)National Key Research&Development Project(2016YFC0902300,China)major disease clinical skills enhancement program of three year action plan for promoting clinical skills and clinical innovation in municipal hospitalsShanghai Shen Kang Hospital Development Center Clinical Research Plan of SHDC(16CR1001A,China)“Dream Tutor”Outstanding Young Talents Program(fkyq1901,China)key disciplines of Shanghai Pulmonary Hospital(2017ZZ02012,China)grant of Shanghai Science and Technology Commission(16JC1405900,China)。
文摘Genomic instability remains an enabling feature of cancer and promotes malignant transformation.Alterations of DNA damage response(DDR)pathways allow genomic instability,generate neoantigens,upregulate the expression of programmed death ligand 1(PD-L1)and interact with signaling such as cyclic GMPe AMP synthase-stimulator of interferon genes(cGASe STING)signaling.Here,we review the basic knowledge of DDR pathways,mechanisms of genomic instability induced by DDR alterations,impacts of DDR alterations on immune system,and the potential applications of DDR alterations as biomarkers and therapeutic targets in cancer immunotherapy.
基金This work was supported in part by grants from the National Institutes of Health(CA132755 to XY)the Developmental fund from the University of Michigan Cancer Center.
文摘BRCA1 is a well-established tumor suppressor gene,which is frequently mutated in familial breast and ovarian cancers.The gene product of BRCA1 functions in a number of cellular pathways that maintain genomic stability,including DNA damage-induced cell cycle checkpoint activation,DNA damage repair,protein ubiquitination,chromatin remodeling,as well as transcriptional regulation and apoptosis.In this review,we discuss recent advances regarding our understanding of the role of BRCA1 in tumor suppression and DNA damage response,including DNA damage-induced cell cycle checkpoint activation and DNA damage repair.
基金financed by Sāo Paulo Research Foundation(FAPESP,grant number 2015/21464-0)Coordination for the Improvement of Higher Education Personnel(CAPES,grant number 1460154)the National Council for Scientific and Technological Development(CNPq,grant number 310120/2015-2).
文摘Gastric cancer remains one of the leading causes of cancer-related death worldwide,and most of the cases are associated with Helicobacter pylori infection.This bacterium promotes the production of reactive oxygen species(ROS),which cause DNA damage in gastric epithelial cells.In this study,we evaluated the expression of important genes involved in the recognition of DNA damage(ATM,ATR,and H2AX)and ROS-induced damage repair(APE1)and the expression of some miRNAs(miR-15a,miR-21,miR-24,miR-421 and miR-605)that target genes involved in the DNA damage response(DDR)in 31 fresh tissues of gastric cancer.Cytoscape v3.1.1 was used to construct the postulated miRNA:mRNA interaction network.Analysis performed by real-time quantitative PCR exhibited significantly increased levels of the APE1(RQ=2.55,p<0.0001)and H2AX(RQ=2.88,p=0.0002)genes beyond the miR-421 and miR-605 in the gastric cancer samples.In addition,significantly elevated levels of miR-21,miR-24 and miR-421 were observed in diffuse-type gastric cancer.Correlation analysis reinforced some of the gene:gene(ATM/ATR/H2AX)and miRNA:mRNA relationships obtained also with the interaction network.Thus,our findings show that tumor cells from gastric cancer presents deregulation of genes and miRNAs that participate in the recognition and repair of DNA damage,which could confer an advantage to cell survival and proliferation in the tumor microenvironment.
基金supported by NIH U19AI067769-9001 pilot research grant (H.H.)California Breast Cancer Research Program 16IB-0016 (H.H.)+1 种基金NIH RO1NS052528 (R.A.G.)the Ataxia-Telangiectasia Medical Research Foundation (Los Angeles,CA, (R.A.G.)).
文摘The DNA damage response(DDR)is a signal transduction pathway that decides the cell’s fate either to repair DNA damage or to undergo apoptosis if there is too much damage.Post-translational modifications modulate the assembly and activity of protein complexes during the DDR pathways.MicroRNAs(miRNAs)are emerging as a class of endogenous gene modulators that control protein levels,thereby adding a new layer of regulation to the DDR.In this review,we describe a new role for miRNAs in regulating the cellular response to DNA damage with a focus on DNA double-strand break damage.We also discuss the implications of miRNA’s role in the DDR to stem cells,including embryonic stem cells and cancer stem cells,stressing the potential applications for miRNAs to be used as sensitizers for cancer radiotherapy and chemotherapy.
基金supported by Associazione Italiana Ricerca Cancro(IG201314102 to Silvana Pilotti).
文摘Background:Desmoplastic small round cell tumor(DSRCT)is a rare,aggressive,and poorly investigated simple sarcoma with a low frequency of genetic deregulation other than an Ewing sarcoma RNA binding protein 1(EWSR1)-Wilm’s tumor suppressor(WT1)translocation.We used whole-exome sequencing to interrogate six consecutive pretreated DSRCTs whose gene expression was previously investigated.Methods:DNA libraries were prepared from formalin-fixed,paraffin-embedded archival tissue specimens following the Agilent SureSelectXT2 target enrichment protocol and sequenced on Illumina NextSeq 500.Raw sequence data were aligned to the reference genome with Burrows-Wheeler Aligner algorithm.Somatic mutations and copy number alterations(CNAs)were identified using MuTect2 and EXCAVATOR2,respectively.Biological functions associated with altered genes were investigated through Ingenuity Pathway Analysis(IPA)software.Results:A total of 137 unique somatic mutations were identified:133 mutated genes were case-specific,and 2 were mutated in two cases but in different positions.Among the 135 mutated genes,27%were related to two biological categories:DNA damage-response(DDR)network that was also identified through IPA and mesenchymal-epithelial reverse transition(MErT)/epithelial-mesenchymal transition(EMT)already demonstrated to be relevant in DSRCT.The mutated genes in the DDR network were involved in various steps of transcription and particularly affected pre-mRNA.Half of these genes encoded RNA-binding proteins or DNA/RNA-binding proteins,which were recently rec-ognized as a new class of DDR players.CNAs in genes/gene families,involved in MErT/EMT and DDR,were recurrent across patients and mostly segregated in the MErT/EMT category.In addition,recurrent gains of regions in chromosome 1 involving many MErT/EMT gene families and loss of one arm or the entire chromosome 6 affecting relevant immune-regulatory genes were recorded.Conclusions:The emerging picture is an extreme inter-tumor heterogeneity,characterized by the concurrent deregulation of the DDR and MErT/EMT dynamic and plastic programs that could favour genomic instability and explain the refractory DSRCT profile.
基金This work was supported by a grant from the Danish Cancer Society to ME(R167-A10932-17-S2)Theilgaard-Mönch K is supported by a clinical research fellowship and a center grant from the Novo Nordisk Foundation(grant no.100191,Novo Nordisk Foundation Center for Stem Cell Biology,DanStem+5 种基金grant no.NNF17CC0027852,KTM)by grants from the Danish Council for Strategic Research(grant no.133100153)the Danish Cancer Society(grant no.R72-A4572-13-S2,KTM)Børnecancerfonden(2016-0255)Læge Sofus Carl Emil Friis og Hustru Olga Doris Friis Foundation(Theilgaard-Mönch K)Tømrermester Jørgen Holm og Hustru Elisa,Brødrene Hartmans Fond,F.Hansen’s Mindelegat(Theilgaard-Mönch K).
文摘Resistance of cancer patients to DNA damaging radiation therapy and chemotherapy remains a major problem in the clinic.The current review discusses the molecular mechanisms of therapy resistance in acute myeloid leukemia(AML)conferred by cooperative chemotherapy-induced DNA damage response(DDR)and mutational activation of PI3K/AKT signaling.In addition,strategies to overcome resistance are discussed,with particular focus on studies underpinning the vast potential of therapies combining standard chemotherapy AML regimens with small molecule inhibitors targeting key regulatory hubs at the interface of DDR and oncogenic signaling pathways.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2021A1515011244,China)to Jinshan Tangthe National 111 Project of China(No.B13038,China)to Xinsheng Yao。
文摘DNA damage response(DDR)is a highly conserved genome surveillance mechanism that preserves cell viability in the presence of chemotherapeutic drugs.Hence,small molecules that inhibit DDR are expected to enhance the anti-cancer effect of chemotherapy.Through a recent chemical library screen,we identified shikonin as an inhibitor that strongly suppressed DDR activated by various chemotherapeutic drugs in cancer cell lines derived from different origins.Mechanistically,shikonin inhibited the activation of ataxia telangiectasia mutated(ATM),and to a lesser degree ATM and RAD3-related(ATR),two master upstream regulators of the DDR signal,through inducing degradation of ATM and ATR-interacting protein(ATRIP),an obligate associating protein of ATR,respectively.As a result of DDR inhibition,shikonin enhanced the anti-cancer effect of chemotherapeutic drugs in both cell cultures and in mouse models.While degradation of ATRIP is proteasome dependent,that of ATM depends on caspase-and lysosome-,but not proteasome.Overexpression of ATM significantly mitigated DDR inhibition and cell death induced by shikonin and chemotherapeutic drugs.These novel findings reveal shikonin as a pan DDR inhibitor and identify ATM as a primary factor in determining the chemo sensitizing effect of shikonin.Our data may facilitate the development of shikonin and its derivatives as potential chemotherapy sensitizers through inducing ATM degradation.
基金supported by the National Natural Science Foundation of China(Nos.31770441,31971415).
文摘Decabrominated diphenyl ether(BDE-209)is generally utilized in multiple polymer materials as common brominated flame retardant.BDE-209 has been listed as persistent organic pollutants(POPs),which was considered to be reproductive toxin in the environment.But it still remains unclear about the effects of BDE-209 on DNA methylation and the inducedmale reproductive toxicity.Due to the extensive epigenetic regulation in germ line development,we hypothesize that BDE-209 exposure impacts the statue of DNA methylation in spermatocytes in vitro.Therefore,the mouse GC-2spd(GC-2)cells were used for the genome wide DNA methylation analysis after treated with 32μg/mL BDE-209 for 24 hr.The results showed that BDE-209 caused genomic methylation changes with 32,083 differentially methylated CpGs in GC-2 cells,including 16,164(50.38%)hypermethylated and 15,919(49.62%)hypomethylated sites.With integrated analysis ofDNAmethylation data and functional enrichment,we found that BDE-209 might affect the functional transcription in cell growth and sperm development by differential gene methylation.qRT-PCR validation demonstrated the involvement of p53-dependent DNA damage response in the GC-2 cells after BDE-209 exposure.In general,our findings indicated that BDE-209-induced genome wide methylation changes could be interrelated with reproductive dysfunction.This study might provide new insights into the mechanisms of male reproductive toxicity under the environmental exposure to BDE-209.
文摘Accumulating evidence indicates that ataxia-telangiectasia mutated kinase is critical for maintaining cellular homeostasis and that it has both nuclear and cytoplasmic functions.However,the functions of ataxia-telangiectasia mutated that when lost lead to cerebellar degeneration are still unknown.In this review,we first describe the role of ataxia-telangiectasia mutated in cerebellar pathology.In addition to its canonical nuclear functions in DNA damage response circuits,ataxia-telangiectasia mutated functions in various cytoplasmic and mitochondrial processes that are critically important for cellular homeostasis.We discuss these functions with a focus on the role of ataxia-telangiectasia mutated in maintaining the homeostatic redox state.Finally,we describe the unique functions of ataxia-telangiectasia mutated in various types of neuronal and glial cells including cerebellar granule neurons,astrocytes,and microglial cells.
基金supported by the National Science Foundation of China(82130011,81770261,91749128,and 81900233)the Fundamental Research Funds for the Central Universities(2042022kf1125,China)the Outstanding Young and Middleaged Talents Training Program of Zhongnan Hospital of Wuhan University(ZNYQ2022002,China).
文摘Clinical application of doxorubicin(DOX)is heavily hindered by DOX cardiotoxicity.Several theories were postulated for DOX cardiotoxicity including DNA damage and DNA damage response(DDR),although the mechanism(s)involved remains to be elucidated.This study evaluated the potential role of TBC domain family member 15(TBC1D15)in DOX cardiotoxicity.Tamoxifen-induced cardiac-specific Tbcldi5 knockout(Tbcldi5^(CKO))or Tbcldi5 knockin(Tbcldi5^(CKI))male mice were challenged with a single dose of DOx prior to cardiac assessment 1 week or 4 weeks following DOX challenge.Adenoviruses encoding TBC1D15 or containing shRNA targeting Tbcld15 were used for Tbcld15 overexpression or knockdown in isolated primary mouse cardiomyocytes.Our results re-vealed that DOX evoked upregulation of TBC1D15 with compromised myocardial function and overt mortality,the effects of which were ameliorated and accentuated by Tbcldi5 deletion and Tbcld15 overexpression,respectively.DOX overtly evoked apoptotic cell death,the effect of which was alleviated and exacerbated by Tbcld15 knockout and overexpression,respectively.Meanwhile,DOX provoked mitochondrial membrane potential collapse,oxidative stress and DNA damage,the effects of which were mitigated and exacerbated by Tbcld15 knockdown and overexpression,respectively.Further scrutiny revealed that TBC1D15 fostered cytosolic accumulation of the cardinal DDR element DNA-dependent protein kinase catalytic subunit(DNA-PKcs).Liquid chromatography-tandem mass spectrometry and coimmunoprecipitation denoted an interaction between TBCID15 and DNA-PKcs at the segment 594-624 of TBC1D15.Moreover,overexpression of TBC1D15 mutant(A594-624,deletion of segment 594-624)failed to elicit accentuation of DOX-induced cytosolic retention of DNA-PKcs,DNA damage and cardiomyocyte apoptosis by TBC1D15 wild type.However,Tbcld15 deletion ameliorated DOXinduced cardiomyocyte contractile anomalies,apoptosis,mitochondrial anomalies,DNA damage and cytosolic DNA-PKcs accumulation,which were canceled off by DNA-PKcs inhibition or ATM activation.Taken together,our findings denoted a pivotal role for TBCID15 in DOX-induced DNA damage,mitochondrial injury,and apoptosis possibly through binding with DNA-PKcs and thus gate-keeping its cytosolic retention,a route to accentuation of cardiac contractile dysfunction in DOX-induced cardiotoxicity.
基金supported by the National Natural Sciences Foundation of China[31870851 and 31471953]the Nonprofit Central Research Institute Fund of Chinese Academy of Medical Sciences[2019PT320005]+1 种基金the Science and Technology Research Project of Gansu Province[145RTSA012 and 20JR5RA555]the Youth Innovation Promotion Association CAS[2021415]
文摘Objective To investigate the function of primary cilia in regulating the cellular response to temozolomide(TMZ)and ionizing radiation(IR)in glioblastoma(GBM).Methods GBM cells were treated with TMZ or X-ray/carbon ion.The primary cilia were examined by immunostaining with Arl13 b andγ-tubulin,and the cellular resistance ability was measured by cell viability assay or survival fraction assay.Combining with cilia ablation by IFT88 depletion or chloral hydrate and induction by lithium chloride,the autophagy was measured by acridine orange staining assay.The DNA damage repair ability was estimated by the kinetic curve ofγH2 AX foci,and the DNAdependent protein kinase(DNA-PK)activation was detected by immunostaining assay.Results Primary cilia were frequently preserved in GBM,and the induction of ciliogenesis decreased cell proliferation.TMZ and IR promoted ciliogenesis in dose-and time-dependent manners,and the suppression of ciliogenesis significantly enhanced the cellular sensitivity to TMZ and IR.The inhibition of ciliogenesis elevated the lethal effects of TMZ and IR via the impairment of autophagy and DNA damage repair.The interference of ciliogenesis reduced DNA-PK activation,and the knockdown of DNA-PK led to cilium formation and elongation.Conclusion Primary cilia play a vital role in regulating the cellular sensitivity to TMZ and IR in GBM cells through mediating autophagy and DNA damage repair.
基金support from the Pamela and Wayne Garrison Distinguished Chair in Cancer Research,the Cancer Prevention&Research Institute of Texas(Nos.RP160667 and RP180813)the National Institutes of Health(NIH)(Nos.CA210929,CA216911,and CA216437)。
文摘Proteins are major functional units that are tightly connected to form complex and dynamic networks.These networks enable cells and organisms to operate properly and respond efficiently to environmental cues.Over the past decades,many biochemical methods have been developed to search for protein-binding partners in order to understand how protein networks are constructed and connected.At the same time,rapid development in proteomics and mass spectrometry(MS)techniques makes it possible to identify interacting proteins and build comprehensive protein-protein interaction networks.The resulting interactomes and networks have proven informative in the investigation of biological functions,such as in the field of DNA damage repair.In recent years,a number of proteins involved in DNA damage response and DNA repair pathways have been uncovered with MS-based protein-protein interaction studies.As the technologies for enriching associated proteins and MS become more sophisticated,the studies of protein-protein interactions are entering a new era.In this review,we summarize the strategies and recent developments for exploring protein-protein interaction.In addition,we discuss the application of these tools in the investigation of protein-protein interaction networks involved in DNA damage response and DNA repair.
基金Supported by National Institute of Health,No.R01HL125527.
文摘Biological reactions require self-assembly of factors in the complex cellular milieu.Recent evidence indicates that intrinsically disordered,low-complexity sequence domains(LCDs)found in regulatory factors mediate diverse cellular processes from gene expression to DNA repair to signal transduction,by enriching specific biomolecules in membraneless compartments or hubs that may undergo liquidliquid phase separation(LLPS).In this review,we discuss how embryonic stem cells take advantage of LCD-driven interactions to promote cell-specific transcription,DNA damage response,and DNA repair.We propose that LCDmediated interactions play key roles in stem cell maintenance and safeguarding genome integrity.
基金supported by the NIH R01 Grant CA102361 and NIH R01 Grant GM080677 to X.W.,and the NIH Training Grant DK007022-30 to L.T.
文摘DNA replication is a highly regulated process involving a number of licensing and replication factors that function in a carefully orchestrated manner to faithfully replicate DNA during every cell cycle.Loss of proper licensing control leads to deregulated DNA replication including DNA re-replication,which can cause genome instability and tumorigenesis.Eukaryotic organisms have established several conserved mechanisms to prevent DNA re-replication and to counteract its potentially harmful effects.These mechanisms include tightly controlled regulation of licensing factors and activation of cell cycle and DNA damage checkpoints.Deregulated licensing control and its associated compromised checkpoints have both been observed in tumor cells,indicating that proper functioning of these pathways is essential for maintaining genome stability.In this review,we discuss the regulatory mechanisms of licensing control,the deleterious consequences when both licensing and checkpoints are compromised,and present possible mechanisms to prevent re-replication in order to maintain genome stability.
文摘Upper tract urothelial carcinoma(UTUC)is rare but can occur sporadically outside the context of Lynch syndrome.In these cases,knowing whether non-mismatch repair(MMR),DNA damage response and repair(DDR),and cell cycle gene alterationsmay predict responses to chemotherapy orimmunotherapy and survival is of clinical importance.This study examined the germline and somatic mutational landscape of two UTUC patients with differential responses to programmed death 1(PD-1)/PD-ligand 1(PD-L1)immune checkpoint inhibitors and queried three independent UTUC cohort studies for co-occurrence of key cell cycle and DDR genes,as well as for their associations with overall survival(OS).TP53 and RB1 emerged as potential determinants of shorter OS in UTUC cohort patients,regardless of concurrent DDR alterations,and if prospectively assessed in larger studies they might also explain resistance to PD-1/PD-L1 blockade despite PD-L1 expression.
