The DNA damage repair complex MoMMS21-MoSMC5 is required for infection-related development and pathogenicity of Magnaporthe oryzae

The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic fungi,particularly in the highly destructive rice blast fungus Magnaporthe oryzae,remains unknown.In this study,we functionally characterized the homologues of this complex,MoMMS21 and MoSMC5,in M.oryzae.We first demonstrated the importance of DNA damage repair in M.oryzae by showing that the DNA damage inducer phleomycin inhibited vegetative growth,infection-related development and pathogenicity in this fungus.Additionally,we discovered that MoMMS21 and MoSMC5 interacted in the nuclei,suggesting that they also function as a complex in M.oryzae.Gene deletion experiments revealed that both MoMMS21 and MoSMC5 are required for infection-related development and pathogenicity in M.oryzae,while only MoMMS21 deletion affected growth and sensitivity to phleomycin,indicating its specific involvement in DNA damage repair.Overall,our results provide insights into the roles of MoMMS21 and MoSMC5 in M.oryzae,highlighting their functions beyond DNA damage repair.

LncRNA HOTAIR promotes DNA damage repair and radioresistance by targeting ATR in colorectal cancer

Long non-coding RNAs(lncRNAs)have been implicated in cancer progression and drug resistance development.Moreover,there is evidence that lncRNA HOX transcript antisense intergenic RNA(HOTAIR)is involved in colorectal cancer(CRC)progression.The present study aimed to examine the functional role of lncRNA HOTAIR in conferring radiotherapy resistance in CRC cells,as well as the underlying mechanism.The relative expression levels of HOTAIR were examined in 70 pairs of CRC tumor and para-cancerous tissues,as well as in radiosensitive and radioresistant samples.The correlations between HOTAIR expression levels and clinical features of patients with CRC were assessed using the Chi-square test.Functional assays such as cell proliferation,colony formation and apoptosis assays were conducted to determine the radiosensitivity in CRC cells with HOTAIR silencing after treatment with different doses of radiation.RNA pull-down assay andfluorescence in situ hybridization(FISH)were used to determine the interaction between HOTAIR and DNA damage response mediator ataxia-telangiectasia mutated-and Rad3-related(ATR).HOTAIR was significantly upregulated in CRC tumor tissues,especially in radioresistant tumor samples.The elevated expression of HOTAIR was correlated with more advanced histological grades,distance metastasis and the poor prognosis in patients with CRC.Silencing HOTAIR suppressed the proliferation and promoted apoptosis and radiosensitivity in CRC cells.HOTAIR knockdown also inhibited the tumorigenesis of CRC cells and enhanced the sensitivity to radiotherapy in a mouse xenograft model.Moreover,the data showed that HOTAIR could interact with ATR to regulate the DNA damage repair signaling pathway.Silencing HOTAIR impaired the ATR-ATR interacting protein(ATRIP)complex and signaling in cell cycle progression.Collectively,the present results indicate that lncRNA HOTAIR facilitates the DNA damage response pathway and promotes radioresistance in CRC cells by targeting ATR.

Development of a prognostic signature for esophageal cancer based on a novel 7-DNA damage repair genes signature

Esophageal cancer(EC)was an aggressive malignant neoplasm characterized by high morbidity and poor prognosis.Identifying the changes in DNA damage repair genes helps to better understand the mechanisms of carcinoma progression.In this study,by comparing EC samples and normal samples,we found a total of 132 DDR expression with a significant difference.Moreover,we revealed higher expression of POLN,PALB2,ATM,PER1,TOP3B and lower expression of HMGB1,UBE2B were correlated to longer OS in EC.In addition,a prognostic risk score based on 7 DDR gene expression(POLN,HMGB1,TOP3B,PER1,UBE2B,ATM,PALB2)was constructed for the prognosis of EC.Meanwhile,EC cancer samples were divided into 3 subtypes based on 132 DDR genes expressions.Clinical profile analysis showed cluster C1 and C2 showed a similar frequency of T2,which was remarked higher than that in cluster 3.Moreover,we found the immune cell inflation levels were significantly changed in different subtypes of EC.The infiltration levels of T cell CD8+,B cell and NK cells were greatly higher in cluster 2 than that in cluster 1 and cluster 3.The results showed T cell CD4+infiltration levels were dramatically higher in cluster 1 than that in cluster 2 and cluster 3.Finally,we perform bioinformatics analysis of DEGs among 3 subtypes of EC and found DDR genes may be related to multiple signaling,such as Base excision repair,Cell cycle,Hedgehog signaling pathway,and Glycolysis/Gluconeogenesis.These results showed DDR genes may serve as new target for the prognosis of EC and prediction of the potential response of immune therapy in EC.

Platinum-based chemotherapy for metastatic insulinoma harboring germline mutation in DNA damage repair pathway:a case report

Malignant insulinomas are rare neuroendocrine tumors that require management for both symptomatic control and tumor reduction.It is clinically challenging to optimize treatment strategies for refractory malignant insulinoma.We report a case of metastatic grade 3 insulinoma presented with recurrent hypoglycemia in a 23-year-old female with RAD51D p.Q192 germline mutation.During the disease course of 5 years,the tumor has continuously progressed despite locoregional therapy and multiple lines of systemic treatment.However,oxaliplatin-based chemotherapy achieved a partial response,which was maintained for 2 years.The hypoglycemic symptoms were controlled after the treatment response and did not recur.The platinum-based regimen could be a feasible therapeutic strategy for malignant insulinoma.The relationship between germline mutation in the DNA damage repair pathway and treatment response to platinum-based regimens in neuroendocrine tumors warrants further investigation.

Effects of SWI/SNF complex on DNA damage repair in heterochromatin of embryonic fibroblast cells

Objective:To investigate the impact of SWI/SNF complex on heterochromatin DNA damage repair after exposure to X-ray irradiation,in order to explore the underlying mechanism.Methods:NIH3T3 and MRC5 cells were treated with 50 nmol/L siRNA targeting SWI/SNF complex subunits(BRM,ARID1A,BRG1 and SNF5),and YAP/TAZ.At 24 h after transfection,the cells were irradiated with 0.5 and 1 Gy of X-rays.At 20,60 and 240 min post-irradiation,γH2AX assay was performed to evaluate the radiation response in total or heterochromatin.Comet assay was used to determine the role of YAP/TAZ in DNA damage when the cells were irradiated with 4 Gy of X-rays.NIH3T3 were treated with 50 nmol/L siRNA targeting BRM/BRG1 and YAP/TAZ to determine their relationship on heterochromatin DNA damage repair.Results:In NIH3T3,SWI/SNF complex subunits(BRM,ARID1A and BRG1)knock-down increasedγH2AX in total and heterochromatin at 1 Gy 60 min post-irradiation(P<0.05),while SNF5 knock-down decreased heterochromatinγH2AX at 1 Gy 20 min post-irradiation(P<0.05).In MRC5,BRM and BRG1 knock-down increasedγH2AX in total and heterochromatin at 1 Gy 60 min post-irradiation(P<0.05).Inconsistently,ARID1A knockdown did not affect it,and SNF5 knock-down increased heterochromatinγH2AX at 1 Gy 60 min post-irradiation(P<0.05).Moreover,YAP/TAZ knock-down decreased heterochromatinγH2AX in NIH3T3 and MRC5(P<0.05).Meanwhile,YAP/TAZ knock-down decreased Tail Moment in comet assay at 4 Gy 60 min post-irradiation(P<0.05).BRM/BRG1 combining with YAP/TAZ knock-down significantly decreased heterochromatinγH2AX compared with single BRM/BRG1 knock-down at 0.5 Gy 60 min post-irradiation(P<0.05).Conclusions:The SWI/SNF complex subunits exhibited varying effects on DNA damage repair.BRM/BRG1 knockdown promotedγH2AX accumulation in heterochromatin through YAP/TAZ.This study provides a novel direction for DNA damage repair and sheds light on the role of SWI/SNF complex in response to DNA damage repair in heterochromatin.

MRN complex is an essential effector of DNA damage repair

Genome stability can be threatened by both endogenous and exogenous agents.Organisms have evolved numerous mechanisms to repair DNA damage,including homologous recombination(HR)and non-homologous end joining(NHEJ).Among the factors associated with DNA repair,the MRE11-RAD50-NBS1(MRN)complex(MRE11-RAD50-XRS2 in Saccharomyces cerevisiae)plays important roles not only in DNA damage recognition and signaling but also in subsequent HR or NHEJ repair.Upon detecting DNA damage,the MRN complex activates signaling molecules,such as the protein kinase ataxia-telangiectasia mutated(ATM),to trigger a broad DNA damage response,including cell cycle arrest.The nuclease activity of the MRN complex is responsible for DNA end resection,which guides DNA repair to HR in the presence of sister chromatids.The MRN complex is also involved in NHEJ,and has a species-specific role in hairpin repair.This review focuses on the structure of the MRN complex and its function in DNA damage repair.

Protective role of electrophile-reactive glutathione for DNA damage repair inhibitory effect of dibromoacetonitrile

Dibromoacetonitrile(DBAN) is a disinfection byproduct(DBP) and linked with cancer in rodents, but the mechanism of its carcinogenicity has not been fully elucidated. We recently reported that DBAN induced inhibition of nucleotide excision repair(NER). In this study, we investigated if glutathione(GSH) is involved in the DBAN-induced inhibition of NER. Human keratinocytes Ha Ca T were pretreated with L-buthionine-(S,R)-sulfoximine(BSO) to deplete intracellular GSH. BSO treatment markedly potentiated the DBAN-induced NER inhibition as well as intracellular oxidation. The recruitment of NER proteins(transcription factor IIH, and xeroderma pigmentosum complementation group G) to DNA damage sites was inhibited by DBAN, which was further exacerbated by BSO treatment. Our results suggest that intracellular GSH protects cells from DBAN-induced genotoxicity including inhibition of DNA damage repair.

ADP-ribosylhydrolases:from DNA damage repair to COVID-19

Adenosine diphosphate(ADP)-ribosylation is a unique post-translational modification that regulates many biological processes,such as DNA damage repair.During DNA repair,ADP-ribosylation needs to be reversed by ADP-ribosylhydrolases.A group of ADP-ribosylhydrolases have a catalytic domain,namely the macrodomain,which is conserved in evolution from prokaryotes to humans.Not all macrodomains remove ADP-ribosylation.One set of macrodomains loses enzymatic activity and only binds to ADP-ribose(ADPR).Here,we summarize the biological functions of these macrodomains in DNA damage repair and compare the structure of enzymatically active and inactive macrodomains.Moreover,small molecular inhibitors have been developed that target macrodomains to suppress DNA damage repair and tumor growth.Macrodomain proteins are also expressed in pathogens,such as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).However,these domains may not be directly involved in DNA damage repair in the hosts or pathogens.Instead,they play key roles in pathogen replication.Thus,by targeting macrodomains it may be possible to treat pathogen-induced diseases,such as coronavirus disease 2019(COVID-19).

Dynamic Changes in DNA Damage and Repair Biomarkers with Employment Length among Nickel Smelting Workers

Our study explored the dynamic changes in andthe relationship between the DNA damage marker8-hydroxy-2＇-deoxyguanosine （8-OHdG） and theDNA repair marker 8-hydroxyguanine DNAglycosidase 1 （hOGG1） according to the length ofoccupational employment in nickel smeltingworkers. One hundred forty nickel-exposedsmelting workers and 140 age-matched unexposedoffice workers were selected from the Jinchangcohort. The 8-OHdG levels in smelting workers wassignificantly higher than in office workers （Z=-8.688,P〈0.05） and the 8-OHdG levels among nickelsmelting workers in the 10-14 y employment lengthcategory was significantly higher than among allpeers. The hOGG1 levels among smelting workerswere significantly lower than those of non-exposedworkers （Z=-8.948, P〈0.05）. There were significantdifferences between employment length andhOGG1 levels, with subjects employed in nickelsmelting for 10-14 y showing the highest levels ofhOGG1. Correlation analysis showed positivecorrelations between 8-OHdG and hOGG1 levels（r=0.413; P〈0.01）. DNA damage was increased withemployment length among nickel smelting workersand was related to the inhibition of hOGG1 repaircapacity.

DNA plasticity and damage in amyotrophic lateral sclerosis

The pathophysiology of amyotrophic lateral sclerosis （ALS） is particularly challenging due to the heteroge- neity of its clinical presentation and the diversity of cellular, molecular and genetic peculiarities involved. Molecular insights unveiled several novel genetic factors to be inherent in both familial and sporadic dis- ease entities, whose characterizations in terms of phenotype prediction, pathophysiological impact and putative prognostic value are a topic of current researches. However, apart from genetically well-defined high-confidence and other susceptibility loci, the role of DNA damage and repair strategies of the genome as a whole, either elicited as a direct consequence of the underlying genetic mutation or seen as an autono- mous parameter, in the initiation and progression of ALS, and the different cues involved in either process are still incompletely understood. This mini review summarizes current knowledge on DNA alterations and counteracting DNA repair strategies in ALS pathology and discusses the putative role of unconventional DNA entities including transposable elements and extrachromosomal circular DNA in the disease process. Focus is set on SODl-related pathophysiology, with extension to FUS, TDP-43 and C90RF72 mutations. Advancing our knowledge in the field will contribute to an improved understanding of this relentless dis- ease, for which therapeutic options others than symptomatic approaches are almost unavailable.

The DNA damage and regulatory strategy in hematopoietic stem cells after irradiation exposure:Progress and challenges

The hematopoietic system is susceptible to ionizing radiation(IR),which can cause acute hematopoietic failure or long-term myelosuppression.As the most primitive cells of the hematopoietic hierarchy,hematopoietic stem cells(HSCs)maintain lifelong hematopoietic homeostasis and promote hematopoietic regeneration during stress.Numerous studies have shown that nuclear and mitochondrial genomes are the main targets of radiation injury in HSCs.More importantly,the damage of DNA may trigger a series of biological responses that largely determine HSC fate following IR exposure.Although some essential pathways and factors involved in DNA injury and damage in HSCs have been revealed,a comprehensive understanding of the biological effects of radiation on HSCs still needs to be improved.This review focuses on recent insights into the molecular mechanisms underlying DNA damage and repair in HSCs after IR.Then summarize corresponding regulatory measures,which may provide a reference for further research in this field.

Proteomic Alterations in Human Dermal Fibroblasts under Photo-Induced Pollution Caused by Excessive Solar Irradiations such as Infra-Red, Blue Light, UVA and UVB

Background: The skin serves as the first line of defense for the human body. Direct sunlight contains damaging radiations that can speed up the ageing process of the skin, resulting in wrinkles, leathery skin, dark patches, and solar elastosis. Objectives: To evaluate the effect of multiple solar irradiation related factors at the protein level in human dermal fibroblast (HDF). The overall effect of individual solar irradiations such as Infrared A (IRA), blue light (BL), UVA, and UVB on HDF cells and the extent of molecular level aberrations to be assessed and compared against each. Methods: Label-free quantitative proteomics (MS/MS) approach has been adopted in this study to observe the protein level changes induced in the HDF cells through various exposures of full light sources. Following that, downstream insilico analysis has been carried out. Results: In this study, it is demonstrated all the four different solar irradiations significantly contribute to the molecular degeneration of skin cells through various mechanisms. This study confirms that BL down-regulates DNA repair proteins and the skin cells-HDF stimulate the histone proteins as a response mechanism to maintain the chromosomal integrity. Conclusions: The proteomics experiment carried out in the current study intends to support the future sun care products based on full light protection technology that can be custom designed to provide complete protection from the solar radiation. Similar technology could enhance the further investigations for deeper understanding of induction, mode of action, and prevention of skin damage from extensive solar irradiation.

Targeting androgen receptor-independent pathways in therapy-resistant prostate cancer

Since androgen receptor(AR)signaling is critically required for the development of prostate cancer(PCa),targeting AR axis has been the standard treatment of choice for advanced and metastatic PCa.Unfortunately,although the tumor initially responds to the therapy,treatment resistance eventually develops and the disease will progress.It is therefore imperative to identify the mechanisms of therapeutic resistance and novel molecular targets that are independent of AR signaling.Recent advances in pathology,molecular biology,genetics and genomics research have revealed novel AR-independent pathways that contribute to PCa carcinogenesis and progression.They include neuroendocrine differentiation,cell metabolism,DNA damage repair pathways and immune-mediated mechanisms.The development of novel agents targeting the non-AR mechanisms holds great promise to treat PCa that does not respond to AR-targeted therapies.

The mutation landscape of multiple cancer predisposition genes in Chinese familial/hereditary breast cancer families

Objective:Approximately 5%–10%of breast cancer(BC)patients display familial traits that are genetically inherited among the members of a family.The purpose of this study was to profile the germline mutations in 43 genes with different penetration rates and their correlations with phenotypic traits in Chinese familial BC families.Methods:Ion Torrent S5™-based next generation sequencing was conducted on 116 subjects from 27 Chinese familial BC families.Results:Eighty-one germline mutations in 27 BC predisposition genes were identified in 82.8%(96/116)of the cases.Among these,80.8%of the mutated genes were related to DNA damage repair.Fourteen possible disease-causing variants were identified in 13 of 27 BC families.Only 25.9%(7/27)of the BC families exhibited hereditary deficiency in BRCA1/2 genes,while 22.2%of the BC families exhibited defects in non-BRCA genes.In all,41.7%(40/96)of the mutation carriers had BRCA mutations,88.5%(85/96)had non-BRCA mutations,and 30.2%(29/96)had both BRCA and non-BRCA mutations.The BC patients with BRCA mutations had a higher risk of axillary lymph node metastases than those without mutations(P<0.05).However,the BC patients with non-BRCA mutations frequently had a higher occurrence of benign breast diseases than those without mutations(P<0.05).Conclusions:In addition to BRCA1/2,genetic variants in non-BRCA DNA repair genes might play significant roles in the development of familial/hereditary BC.Therefore,profiling of multiple BC predisposition genes should be more valuable for screening potential pathogenic germline mutations in Chinese familial/hereditary BC.

Profiling of the assembly of RecA nucleofilaments implies a potential target for environmental factors to disturb DNA repair

Double-strand breaks(DSBs),one class of the most harmful DNA damage forms that bring elevated health risks,need to be repaired timely and effectively.However,an increasing number of environmental pollutants have been identified to impair DSB repair from various mechanisms.Our previous work indicated that the formation of unsaturated Rec A nucleofilaments plays an essential role in homology recombination(HR) pathway which can accurately repair DSBs.In this study,by developing a benzonase cutting protection assay and combining it with traditional electrophoretic mobility shift assay(EMSA) analysis,we further investigated the assembly patterns of four Rec A mutants that display differential DSB repair ability and ATPase activity.We observed that the mutants(G204S and S69G) possessing both ATP hydrolysis and DSB repair activities form unsaturated nucleofilaments similar to that formed by the wild type Rec A,whereas the other two ATP hydrolysis-deficient mutants(K72R and E96D) that fail to mediate HR form more compacted nucleofilaments in the presence of ATP.These results establish a coupling of ATPase activity and effective DSB repair ability via the assembly status of Rec A nucleofilaments.This linkage provides a potential target for environmental factors to disturb the essential HR pathway for DSB repair by suppressing the ATPase activity and altering the assembly pattern of nucleofilaments.

The interplay of cell cycle and DNA repair gene alterations in upper tract urothelial carcinoma:predictive and prognostic implications

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.

Modulation of the DNA repair system and ATR-p53 mediated apoptosis is relevant for tributyltin-induced genotoxic effects in human hepatoma G2 cells

The toxic effects of tributyltin（TBT） have been extensively documented in several types of cells, but the molecular mechanisms related to the genotoxic effects of TBT have still not been fully elucidated. Our study showed that exposure of human hepatoma G2 cells to 1–4 μmol/L TBT for 3 hr caused severe DNA damage in a concentration-dependent manner. Moreover, the expression levels of key DNA damage sensor genes such as the replication factor C, proliferating cell nuclear antigen and poly（ADP-ribose）polymerase-1 were inhabited in a concentration-dependent manner. We further demonstrated that TBT induced cell apoptosis via the p53-mediated pathway, which was most likely activated by the ataxia telangiectasia mutated and rad-3 related（ATR）protein kinase. The results also showed that cytochrome c, caspase-3, caspase-8,caspase-9, and the B-cell lymphoma 2 were involved in this process. Taken together, we demonstrated for the first time that the inhibition of the DNA repair system might be more responsible for TBT-induced genotoxic effects in cells. Then the generated DNA damage induced by TBT initiated ATR-p53-mediated apoptosis.

Human umbilical cord mesenchymal stem cells attenuate diabetic nephropathy through the IGF1R-CHK2-p53 signalling axis in male rats with type 2 diabetes mellitus

diabetes mellitus(DM)is a disease syndrome characterized by chronic hyperglycaemia.A long-term high-glucose environment leads to reactive oxygen species(ROS)production and nuclear DNA damage.human umbilical cord mesenchymal stem cell(HUcMSC)infusion induces significant antidiabetic effects in type 2 diabetes mellitus(T2DM)rats.Insulin-like growth factor 1(IGF1)receptor(IGF1R)is important in promoting glucose metabolism in diabetes;however,the mechanism by which HUcMSC can treat diabetes through IGF1R and DNA damage repair remains unclear.In this study,a DM rat model was induced with high-fat diet feeding and streptozotocin(STZ)administration and rats were infused four times with HUcMSC.Blood glucose,interleukin-6(IL-6),IL-10,glomerular basement membrane,and renal function were examined.Proteins that interacted with IGF1R were determined through coimmunoprecipitation assays.The expression of IGF1R,phosphorylated checkpoint kinase 2(p-CHK2),and phosphorylated protein 53(p-p53)was examined using immunohistochemistry(IHC)and western blot analysis.Enzyme-linked immunosorbent assay(ELISA)was used to determine the serum levels of 8-hydroxydeoxyguanosine(8-OHdG).Flow cytometry experiments were used to detect the surface markers of HUcMSC.The identification of the morphology and phenotype of HUcMSC was performed by way of oil red“O”staining and Alizarin red staining.DM rats exhibited abnormal blood glucose and IL-6/10 levels and renal function changes in the glomerular basement membrane,increased the expression of IGF1 and IGF1R.IGF1R interacted with CHK2,and the expression of p-CHK2 was significantly decreased in IGF1R-knockdown cells.When cisplatin was used to induce DNA damage,the expression of p-CHK2 was higher than that in the IGF1R-knockdown group without cisplatin treatment.HUcMSC infusion ameliorated abnormalities and preserved kidney structure and function in DM rats.The expression of IGF1,IGF1R,p-CHK2,and p-p53,and the level of 8-OHdG in the DM group increased significantly compared with those in the control group,and decreased after HUcMSC treatment.Our results suggested that IGF1R could interact with CHK2 and mediate DNA damage.HUcMSC infusion protected against kidney injury in DM rats.The underlying mechanisms may include HUcMSC-mediated enhancement of diabetes treatment via the IGF1R-CHK2-p53 signalling pathway.

Effects of the PARP inhibitor Niraparib on the radiosensitivity of human lung and cervical cancer cells

ObjectiveTo investigate the effect of Niraparib,a clinically approved PARP inhibitor on the radiosensitivity of human lung and cervical cancer cells,and preliminarily explore the underlying mechanism.MethodsThe human lung cancer cell line A549 and human cervical cancer cell line Siha were both treated with Niraparib for 1h,or X-ray irradiation with 4y,or Niraparib for 1h combined with X-ray irradiation with 4Gy.The effect was examined via measurements of cell proliferation by the cell counting kit-8 assay,and cell viability was detected by clone formation assays.Cell apoptosis and cell cycle distribution were investigated by flow cytometry.ResultsIn human lung and cervical cancer cell lines,Niraparib combined with radiation therapy significantly inhibited cell proliferation.The proportion of apoptotic cells in cell lines treated with Niraparib plus radiation(the combination group)was significantly higher compared with control,radiation,and Niraparib groups(P<0.05).Additionally,the proportion of A549 cells in the G_(2)/M phase was significantly increased in the combination group compared with the radiation group(P<0.05).ConclusionPARP inhibitor Niraparib increases the radiosensitivity of tumorcells,promotes their apoptosis,and induces cell cycle redistribution.The possible mechanism is associated with the inhibition of radiation-induced DNA damage repair.

Current understanding of adenoid cystic carcinoma in the gene expression and targeted therapy

Adenoid Cystic Carcinoma(ACC)has been considered as a"quiet"tumor.It is typically malignancy arising from exocrine glands with poor long-term prognosis due to high rate of recurrence and distant metastasis.It is characterized by perineural infiltration,distant metastasis,and positive incision edge.Surgery is the first line treatment for ACC,followed by cytotoxic chemotherapy and/or radiotherapy as adjuvant treatments to avoid recurrence.But recurrence or metastasis still occurs in more than 50%ACC.Recurrent and/or metastasis(R/M)ACC is usually incurable,and no systemic agent has been found effective.With the widespread use of whole exome sequencing(WES)and whole genome sequencing(WGS),its internal oncogenic mechanism is gradually revealed,which involving molecular mutations such as the MYB family gene translocation,Notch signal pathway,DNA damage repair(DDR)pathway and epigenetic molecular mutations.The review helps us to understand the linkage among the pathways and targeted genes in diagnosis and related treatment of ACC till now.