BACKGROUND Radiotherapy is widely employed in colorectal cancer(CRC)treatment,but the occurrence of radioresistance severely limits the clinical benefit to patients and significantly contributes to treatment failure a...BACKGROUND Radiotherapy is widely employed in colorectal cancer(CRC)treatment,but the occurrence of radioresistance severely limits the clinical benefit to patients and significantly contributes to treatment failure and recurrent metastasis.AIM To explore the role and underlying mechanism of the lncRNA FTX in radiotherapy resistance in CRC.METHODS LncRNA FTX expression in colorectal parent cells(HT29 and HCT116)and radioresistant cells(HT29R and HCT116R)was determined by real-time quantitative PCR,and the viability of HT29R-shFTX and HCT116R-shFTX cells under ionizing radiation was evaluated using the cell counting kit-8 assay and colony formation experiment.The levels of glutathione and reactive oxygen species in cells after irradiation were determined,and the association between ferroptosis and lncRNA FTX expression in cancer cells was tested.A dual-luciferase assay was used to validate gene interactions.A xenotransplantation mouse model was established to explore the effects of FTX on the CRC tumor radiosensitivity in vivo.RESULTS FTX was upregulated in radioresistant CRC cells,and FTX knockdown inhibited cell survival and increased cell ferroptotic death in response to ionizing radiation.Moreover,lncRNA FTX restricted the SLC7A11 expression by sponging with miR-625-5p,and inhibition of the lncRNA FTX or SLC7A11 significantly increased cellular oxidant levels and DNA damage to ionizing radiation in cancer cells.However,SLC7A11 overexpression reversed the effects of decreased FTX levels on ferroptosis and high oxidation levels in cancer cells exposed to ionizing radiation.CONCLUSION Inhibition of the lncRNA FTX/miR-625-5p/SLC7A11 axis can induce ferroptosis and disturb intracellular redox balance,further sensitizing CRC cells to ionizing radiation,suggesting its potential as a therapeutic target for improving CRC response to radiation therapy.展开更多
Objectives:Fractionated radiotherapy represents a standardized and widely adopted treatment modality for cancermanagement,with approximately 40% of non-small cell lung cancer(NSCLC)patients receiving it.However,repeat...Objectives:Fractionated radiotherapy represents a standardized and widely adopted treatment modality for cancermanagement,with approximately 40% of non-small cell lung cancer(NSCLC)patients receiving it.However,repeated irradiationmay induce radioresistance in cancer cells,reducing treatment effectiveness and raising recurrence risk.The long noncoding RNA CRYBG3(lncRNA CRYBG3),which is upregulated in lung cancer cells after Xray irradiation,contributes to the radioresistance of NSCLC cells by promoting wild-type p53 protein degradation.This study aims to elucidate the mechanism of fractionated irradiation-induced radioresistance,in which lncRNA CRYBG3 regulates radiation-induced mitochondrial damage and reactive oxygen species(ROS)generation through the p53 downstream signaling pathway.Methods:To investigate the critical roles of lncRNA CRYBG3 in mediating radioresistance induced by fractionated irradiation in NSCLC,we established radioresistant NSCLC cells by irradiating the A549 and H460 cell lines with 60 Gy of X-rays in 12 fractions,and named the radioresistant cells A549R and H460R,respectively.Lentiviral vectors were used to deliver short hairpin RNA(shRNA)into cells to knock down lncRNA CRYBG3,thereby investigating its contribution to adaptive radioresistance in A549R and H460R cells.All cells were irradiated with 4 Gy of X-rays,and subsequent analyses were conducted to evaluate mitochondrial damage,ROS generation,apoptosis,and the expression of oxidative stress-related proteins.Results:Increased expression levels of lncRNA CRYBG3 were positively associated with the acquisition of radioresistance in NSCLC cells.Additionally,suppressing lncRNA CRYBG3 increased mitochondrial damage and promoted radiation-induced apoptosis in radioresistant NSCLC cells.Mechanistically,the downregulation of lncRNA CRYBG3 led to increased p53 levels,resulting in decreased expression of heat shock factor 1(HSF1)and tumor necrosis factor receptor-associated protein 1(TRAP1),as well as enhanced radiation-induced mitochondrial oxidative damage and apoptosis.Conclusion:The results indicate that lncRNA CRYBG3 plays a regulatory role in adaptive radioresistance in NSCLC cells through the p53/HSF1/TRAP1 axis.Therefore,targeting lncRNA CRYBG3 could potentially improve the efficacy of fractionated radiotherapy in NSCLC.展开更多
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 c...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.展开更多
BACKGROUND Gliomas pose a significant challenge to effective treatment despite advancements in chemotherapy and radiotherapy.Glioma stem cells(GSCs),a subset within tumors,contribute to resistance,tumor heterogeneity,...BACKGROUND Gliomas pose a significant challenge to effective treatment despite advancements in chemotherapy and radiotherapy.Glioma stem cells(GSCs),a subset within tumors,contribute to resistance,tumor heterogeneity,and plasticity.Recent studies reveal GSCs’role in therapeutic resistance,driven by DNA repair mechanisms and dynamic transitions between cellular states.Resistance mechanisms can involve different cellular pathways,most of which have been recently reported in the literature.Despite progress,targeted therapeutic approaches lack consensus due to GSCs’high plasticity.AIM To analyze targeted therapies against GSC-mediated resistance to radio-and chemotherapy in gliomas,focusing on underlying mechanisms.METHODS A systematic search was conducted across major medical databases(PubMed,Embase,and Cochrane Library)up to September 30,2023.The search strategy utilized relevant Medical Subject Heading terms and keywords related to including“glioma stem cells”,“radiotherapy”,“chemotherapy”,“resistance”,and“targeted therapies”.Studies included in this review were publications focusing on targeted therapies against the molecular mechanism of GSC-mediated re-sistance to radiotherapy resistance(RTR).RESULTS In a comprehensive review of 66 studies on stem cell therapies for SCI,452 papers were initially identified,with 203 chosen for full-text analysis.Among them,201 were deemed eligible after excluding 168 for various reasons.The temporal breakdown of studies illustrates this trend:2005-2010(33.3%),2011-2015(36.4%),and 2016-2022(30.3%).Key GSC models,particularly U87(33.3%),U251(15.2%),and T98G(15.2%),emerge as significant in research,reflecting their representativeness of glioma characteristics.Pathway analysis indicates a focus on phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin(mTOR)(27.3%)and Notch(12.1%)pathways,suggesting their crucial roles in resistance development.Targeted molecules with mTOR(18.2%),CHK1/2(15.2%),and ATP binding cassette G2(12.1%)as frequent targets underscore their importance in overcoming GSC-mediated resistance.Various therapeutic agents,notably RNA inhibitor/short hairpin RNA(27.3%),inhibitors(e.g.,LY294002,NVP-BEZ235)(24.2%),and monoclonal antibodies(e.g.,cetuximab)(9.1%),demonstrate versatility in targeted therapies.among 20 studies(60.6%),the most common effect on the chemotherapy resistance response is a reduction in temozolomide resistance(51.5%),followed by reductions in carmustine resistance(9.1%)and doxorubicin resistance(3.0%),while resistance to RTR is reduced in 42.4%of studies.CONCLUSION GSCs play a complex role in mediating radioresistance and chemoresistance,emphasizing the necessity for precision therapies that consider the heterogeneity within the GSC population and the dynamic tumor microenvironment to enhance outcomes for glioblastoma patients.展开更多
Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncol- ogy. The hypoxia-inducible factor （HIF）-lα plays a crucial role in radiosensitivity, but the detailed mechanisms remain...Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncol- ogy. The hypoxia-inducible factor （HIF）-lα plays a crucial role in radiosensitivity, but the detailed mechanisms remain elusive. A relationship has been suggested to exist between hypoxia and autophagy recently. In the current study, we studied the effect of hypoxia-induced autophagy on radioresistance in lung cancer cell lines. A549 and H1299 cells were cultured under normoxia or hypoxia, followed by ir- radiation at dosage ranging from 0 to 8 Gy. Clonogenic assay was performed to calculate surviving frac- tion. EGFP-LC3 plasmid was stably transfected into cells to monitor autopbagic processes. Western blotting was used to evaluate the protein expression levels of HIF-lα, c-Jun, phosphorylated c-Jun, Be- clin 1, LC3 and p62. The mRNA levels of Beclin 1 were detected by qRT-PCR. We found that under hypoxia, both A549 and H1299 cells were radio-resistant compared with normoxia. Hypoxia-induced elevated HIF-1α protein expression preferentially triggered autophagy, accompanied by LC3 induction, EGFP-LC3 puncta and p62 degradation. In the meantime, HIF-1α increased downstream c-Jun phos- phorylation, which in turn upregulated Beclin 1 mRNA and protein expression. The upregulation of Be- clin 1 expression, instead of HIF-1α, could be blocked by SP600125 （a specific inhibitor of c-Jun NH2- terminal kinase）, followed by suppression of autophagy. Under hypoxia, combined treatment of irradia- tion and chloroquine （a potent autophagy inhibitor） significantly decreased the survival potential of lung cancer cells in vitro and in vivo. In conclusion, hypoxia-induced autophagy through evaluating Beclinl expression may be considered as a target to reverse the radioresistance in cancer cells.展开更多
AIM:To investigate the association between nuclearβ-catenin overexpression in rectal adenocarcinoma and radioresistance.METHODS:A retrospective analysis was conducted.The analysis involved 136 patients with locally a...AIM:To investigate the association between nuclearβ-catenin overexpression in rectal adenocarcinoma and radioresistance.METHODS:A retrospective analysis was conducted.The analysis involved 136 patients with locally advanced rectal adenocarcinoma who underwent shortcourse preoperative radiotherapy and radical resection.The expression ofβ-catenin in both pretreatment biopsy specimens and resected primary tumor tissues was examined by immunohistochemistry.The correlation ofβ-catenin expression with radioresistance was evaluated using the tumor regression grading(TRG)system.The relationship betweenβ-catenin expression and clinicopathological characteristics was also analyzed.Univariate and logistic multivariate regression analyses were adopted to determine the independent factors of radioresistance.RESULTS:Nuclearβ-catenin overexpression was more evident in radioresistant rectal adenocarcinoma than in radiosensitive rectal adenocarcinoma(57.6%vs 16.7%,P<0.001).Nuclearβ-catenin was overexpressed in favor of poor TRG(≤2),whereas membraneβ-catenin was expressed in favor of good TRG(≥3).Nuclearβ-catenin expression in tumor cell differentiation(P=0.018),lymph node metastasis(P=0.022),and TRG(P<0.001)showed significant differences.Univariate analyses demonstrated that radioresistance is associated with nuclearβ-catenin overexpression(P<0.001).In addition,logistic multivariate regression analysis indicated that only three factors,namely,tumor size(P<0.001),tumor cell differentiation(P<0.001),and nuclearβ-catenin overexpression(P<0.001),are associated with radioresistance.By using radioresistance as a prediction target,nuclearβ-catenin-based prediction alone achieved 83%accuracy,65%sensitivity,and88%specificity.CONCLUSION:Nuclearβ-catenin overexpression may be a valuable candidate to predict the response of rectal adenocarcinoma to preoperative radiotherapy.展开更多
Hepatocellular carcinoma(HCC), one of the most common cancers in the world, is characterized by poor prognosis and recurrence after resection. Its prevalence is highest in developing countries, particularly where ther...Hepatocellular carcinoma(HCC), one of the most common cancers in the world, is characterized by poor prognosis and recurrence after resection. Its prevalence is highest in developing countries, particularly where there is high incidence of hepatitis B virus infection. Several curative treatments are available for early stage HCC; however, these options are not available for advanced disease. New techniques allowing the specific delivery of high-dose radiotherapy enable their use in the treatment of HCC, which has been avoided in the past due to low hepatic tolerance for radiation. This presents a new challenge—the development of resistance to radiotherapy and subsequent disease recurrence. Recently, the mechanisms controlling radioresistance have begun to be elucidated. Understanding the molecular basis of radioresistance is key to developing new strategies with better treatment response and increased patient survival.展开更多
We present evidence here that abundantly expressed b-catenin-triggered NF-kB-dependent upregulation of inducible nitric oxide synthase(iNOS) found in hepatoma Mahlavu cells (RT-resistant variant designated as RR-Mal),...We present evidence here that abundantly expressed b-catenin-triggered NF-kB-dependent upregulation of inducible nitric oxide synthase(iNOS) found in hepatoma Mahlavu cells (RT-resistant variant designated as RR-Mal), but not in Hep 3B cells (RT-sensitive variant designated as RS-3B) is a key element contribrting to the radioresisitance through the activation of two prominent radioprotective pathways. First, high iNOS expression found in RR-Mal, but not in RS-3B cells was found to perturb calcium homeostasis that triggered ER stress response leading to the overproduction of ER chaperone GRP-78 via robust generation of cleaved ATF-6a (50 kDa) subunits and their nuclear translocation. Meanwhile, both abundantly expressed NF-κB and COX-2 found in RR-Mal cells could also provoke an increased production of PGE2 resulting in robust production of Bcl-2. Interestingly, when RR-Mal cells were treated with PDTC (a NF-κB inhibitor) or celecoxib (a COX-2 inhibitor), a concentration-dependent downregulation of Bcl-2 could be demonstrated implying that Bcl-2 overexpression was indeed mediated through NF-κB/Cox-2/PGE2 pathway. Importantly, we also unveiled that siRNA-mediated silencing of survivin in RR-Mal cells could result in a concomitant downregulation of GRP-78 due to a severe inhibition of ATF-6a (50 kDa) expression. Taken together, our data demonstrate that constitutively overexpressed b-catenin/NF-κB/iNOS and NF-κB/COX-2/PGE2 pathways that overproducing GRP-78, survivin and Bcl-2 expressions are responsible for radioresistance acquisition in RR-Mal cells. Thus, both pathways could be served as potential targets for overcoming radioresistance.展开更多
Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer, which is the leading cause of death in lung cancer patient. Routine treatment of NSCLC cannot effectively change the survival rate of patients, one i...Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer, which is the leading cause of death in lung cancer patient. Routine treatment of NSCLC cannot effectively change the survival rate of patients, one important reason is the increased radioresistance of tumor cells after conventional radiotherapy.展开更多
The molecular mechanisms of radioresistance of manganese ssuperoxide dismutase (MnSOD) was investigated in thisstudy. We assayed cell necrocis and apoptosis induced by ionizing radiation. Furthermore, the possible rol...The molecular mechanisms of radioresistance of manganese ssuperoxide dismutase (MnSOD) was investigated in thisstudy. We assayed cell necrocis and apoptosis induced by ionizing radiation. Furthermore, the possible roles of oncogenes bc1-2and p53 mRNA expression in MnSOD gene-transfected cells were for investigated. me results showed that 10 Gy X-ray could induce the expression of bc1-2 mRNA and suppress p53 mRNA expression in sense MnSOD transfected cells, whereas Bc1-2 mRNAexpression did not change and p53 mRNA expression increased in antisense MnSOD transfected cells. It is suggested that Bc1-2 isrequired for the radioresistance of MnSOD and the status of p53 play a role in radiation-induced cell death.展开更多
Radiotherapy(RT)resistance in head and neck squamous cell carcinoma(HNSCC)significantly hampers local control and patient prognosis.This study investigated the efficacy and molecular mechanisms of high-energy X-ray-ba...Radiotherapy(RT)resistance in head and neck squamous cell carcinoma(HNSCC)significantly hampers local control and patient prognosis.This study investigated the efficacy and molecular mechanisms of high-energy X-ray-based ultra-high dose rate radiotherapy(UHDR-RT)in overcoming RT resistance.The established RT-resistant HNSCC cell lines and animal models were subjected to UHDR-RT or conventional RT(Conv-RT)via a high-power rhodotron accelerator.Cellular assays assessed the malignant phenotype,viability,and degree of DNA damage,whereas in vivo evaluations focused on tumor proliferation and the tumor immune microenvironment(TiME).Transcriptome sequencing and Olink proteomics were employed to explore the underlying mechanisms involved.In vitro experiments indicated that UHDR-RT suppressed radioresistant cell proliferation and invasion,while promoting apoptosis and exacerbating DNA damage.In contrast,its efficacy in radiosensitive cells was comparable to that of Conv-RT.In vivo studies using patient-derived xenograft nude mice models demonstrated that UHDR-RT only partially reversed RT resistance.Transcriptomic and proteomic analyses of C57BL/6J mice models revealed the predominant role of TiME modulating in reversing radioresistance.Immunofluorescence and flow cytometry confirmed increased CD8^(+)T cells and an increased M1/M2 macrophage ratio post-UHDR-RT.Mechanistically,UHDR-RT activated CD8^(+)T cells,which stimulated M1 macrophages through paracrine IFN-y signaling,thereby enhancing TiME activation.Furthermore,the activated M1 macrophages secreted CXCL9,which in turn reactivated CD8^(+)T cells,forming a feedforward loop that amplifed TiME activation.This study elucidates the dual role of UHDR-RT in directly inducing DNA damage and modulating the TiME,highlighting its potential in treating radioresistant HNSCC.展开更多
Chemo-/radioresistance of malignant tumors hampers cancer control and increases patient mortality.Efficient repair of damaged DNA is critical for the maintenance of genomic integrity and fidelity of genetic informatio...Chemo-/radioresistance of malignant tumors hampers cancer control and increases patient mortality.Efficient repair of damaged DNA is critical for the maintenance of genomic integrity and fidelity of genetic information.In reverse,increased DNA repair capability in cancer cells contributes to chemo-/radioresistance of malignant tumors.DNA double-strand break(DSB)is the most serious DNA damage and is also the principal molecular basis of radiotherapy.Upon DNA damage,the Ku80 is recruited and forms a critical DNA-PK complex at the DSB sites with Ku70 and the catalytic subunit(DNA-PKcs)to initiate DNA repair.How DNA-PK is assembled and activated is not fully understood.Based on the identification of radiation-reduced Ku80 K568 crotonylation through quantitative global lysine crotonylome analysis,we reveal that Ku80 K568 is crotonylated by p300-CBP-associated factor(PCAF).Upon DNA damage,the K568cr is decrotonylated by HDAC8(Histone deacetylase 8).Decrotonylation of K568cr empties this site for the subsequent SUMOylation of Ku80 by CBX4.The conversion of Ku80 from K568 crotonylation to SUMOylation facilitates the assembly of DNA-PK complex and autophosphorylation of DNA-PKcs S2056,consequently activating the DSB repair.Moreover,mutation disrupting the post-translational modification(PTM)of Ku80 K568 site sensitizes cancer cells to radiotherapy in tumorbearing nude mice models.This study elucidates the conversion model between two different forms of PTMs in the regulation of DNA-PK complex assembly and DSB repair,highlighting this model’s potential in controlling chemo-/radioresistance of malignant tumors,as well as expands the atlas of therapeutic targets.展开更多
Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous subpopulations.Here,we showed that MZ B cells can be divid...Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous subpopulations.Here,we showed that MZ B cells can be divided into two distinct subpopulations according to their CD80 expression levels.CD80^(high)MZ B cells exhibited greater Ab-producing,proliferative,and IL-10-secreting capacities than did CD80^(low)MZ B cells.Notably,CD80^(high)MZ B cells survived 2-Gy whole-body irradiation,whereas CD80^(low)MZ B cells were depleted by irradiation and then repleted with one month after irradiation.Depletion of CD80^(low)MZ B cells led to accelerated development of type II collagen(CII)-induced arthritis upon immunization with bovine CII.CD80^(high)MZ B cells exhibited higher expression of genes involved in proliferation,plasma cell differentiation,and the antioxidant response.CD80^(high)MZ B cells expressed more autoreactive B cell receptors(BCRs)that recognized double-stranded DNA or CII,expressed more immunoglobulin heavy chain sequences with shorter complementarity-determining region 3 sequences,and included more clonotypes with no N-nucleotides or with B-1a BCR sequences than CD80^(low)MZ B cells.Adoptive transfer experiments showed that CD21^(+)CD23^(+)transitional 2 MZ precursors preferentially generated CD80^(low)MZ B cells and that a proportion of CD80^(low)MZ B cells were converted into CD80^(high)MZ B cells;in contrast,CD80^(high)MZ B cells stably remained CD80^(high)MZ B cells.In summary,MZ B cells can be divided into two subpopulations according to their CD80 expression levels,Ab-producing capacity,radioresistance,and autoreactivity,and these findings may suggest a hierarchical composition of MZ B cells with differential stability and BCR specificity.展开更多
Objective:To investigate the potential role of the regulator of G protein signaling 20(RGS20)in radioresistance of non-small cell lung cancer(NSCLC).Methods:A total of 35 lung adenocarcinoma(LUAD)patients from The Can...Objective:To investigate the potential role of the regulator of G protein signaling 20(RGS20)in radioresistance of non-small cell lung cancer(NSCLC).Methods:A total of 35 lung adenocarcinoma(LUAD)patients from The Cancer Genome Atlas(TCGA),who un-derwent radiotherapy,were enrolled and divided into radiosensitive(n=16)and radioresistant(n=19)groups based on clinical prognosis.The expression and prognosis of RGS20 were analyzed by Gene Expression Profiling Interactive Analysis(GEPIA)database.A radioresistant cell line(A549R)was constructed by irradiating A549 cells with 6 Gy X-rays for 10 fractions.Cell survival was measured by colony formation assay.The regulatory effect of RGS20 on pyroptosis were verified by LDH release and Western blot assay,and the underlying mech-anism was investigated by transfecting RGS20 siRNA and applying a GSDMD inhibitor.Results:A total of 2,181 differentially expressed genes(DEGs)were identified by analyzing the data of radio-sensitive and radioresistant individuals from the TCGA-LUAD dataset.These DEGs were enriched in G alpha(z)signalling events analyzed by Reactome database.RGS20 exhibited significant upregulation among the DEGs,and its higher expression predicted poor prognosis in LUAD patients.In vitro,the expression of RGS20 protein was increased by irradiation in A549 cells,whereas it remained at much high levels in A549R cells regardless of irradiation.After irradiation,the expressions of pyroptosis-related proteins were significantly increased in A549 cells(P<0.05),with no significant changes were observed in A549R cells.Treatment with LDC7559 significantly reduced LDH release(P<0.01)and improved the survival rate of irradiated A549 cells(P<0.01).Furthermore,knockdown of RGS20 gene in A549R cells significantly increased LDH release(P<0.001)and enhanced radiosensitivity(P<0.01),while LDC7559 administration reversed LDH release(P<0.01)and radiation-induced cell death increased by siRGS20(P<0.05).Meantime,the increased expression level of GSDMD-NT was observed in A549 and A549R cells transfected with siRGS20(P<0.05).Conclusion:RGS20 contributes to the radioresistance of NSCLC cells,which might be a potential target for NSCLC radiotherapy.展开更多
Radioresistance reduces the antitumor efficiency of radiotherapy and further restricts its clinical application,which is mainly caused by the aggravation of immunosuppressive tumor microenvironment(ITM).Especially tum...Radioresistance reduces the antitumor efficiency of radiotherapy and further restricts its clinical application,which is mainly caused by the aggravation of immunosuppressive tumor microenvironment(ITM).Especially tumor-associated macrophages(TAMs)usually display the tumor-promoting M2 phenotype during high-dose fractional radiotherapy mediating radiotherapy resistance.Herein,the toll like receptor agonist TLR7/8a was conjugated with radiosensitive peptide hydrogel(Smac-TLR7/8 hydrogel)to regulate TAMs repolarization from M2 type into M1 type,thus modulating the ITM and overcoming the radioresistance.The Smac-TLR7/8 hydrogel was fabricated through self-assembly with nanofibrous morphology,porous structure and excellent biocompatibility.Uponγ-ray radiation,Smac-TLR7/8 hydrogel effectively polarized the macrophages into M1 type.Notably,combined with radiotherapy,TAMs repolarization regulated by Smac-TLR7/8 hydrogel could increase tumor necrosis factor secretion,activate antitumor immune response and effectively inhibit tumor growth.Moreover,TAMs repolarization rebuilt the ITM and elicited the immunogenic phenotypes in solid tumors,thus enhanced the PD1-blockade efficacy through increasing tumor infiltrating lymphocytes(TILs)and decreasing Treg cells in two different immune activity tumor mice models.Overall,this study substantiated that recruiting and repolarization of TAMs were critical in eliciting antitumor immune response and overcoming radioresistance,thus improving the efficacy of radiotherapy and immunotherapy.展开更多
The conclusion based on transmission electron microscopy, "the tightly packed ring-like nucleoid of the Deinococcus radiodurans R1 is a key to radioresistance", has instigated lots of debates. In this study,...The conclusion based on transmission electron microscopy, "the tightly packed ring-like nucleoid of the Deinococcus radiodurans R1 is a key to radioresistance", has instigated lots of debates. In this study, according to the previous research of PprI’s crucial role in radioresistance of D. radiodurans, we have attempted to examine and compare the nucleoid morphology differences among wild-type D. ra-diodurans R1 strain, pprI function-deficient mutant (YR1), and pprI function-complementary strains (YR1001, YR1002, and YR1004) before and after exposure to ionizing irradiation. Fluorescence mi-croscopy images indicate: (1) the majority of nucleoid structures in radioresistant strain R1 cells ex-hibit the tightly packed ring-like morphology, while the pprI function-deficient mutant YR1 cells carrying predominate ring-like structure represent high sensitivity to irradiation; (2) as an extreme radioresistant strain similar to wild-type R1, pprI completely function-complementary strain YR1001 almost displays the loose and irregular nucleoid morphologies. On the other hand, another radioresistant pprI partly function-complementary strain YR1002’s nucleiods exhibit about 60% ring-like structure; (3) a PprI C-terminal deletion strain YR1004 consisting of approximately 60% of ring-like nucleoid is very sensi-tive to radiation. Therefore, our present experiments do not support the conclusion that the ring-like nucleoid of D. radiodurans does play a key role in radioresistance.展开更多
Hypoxia is a big roadblock for cancer radiotherapy,in which the hypoxia-inducible factor(HIF-1)creates a microenvironment and cancer cells’intrinsic signaling networks conferring radioresistance to cancers.HIF-1 is a...Hypoxia is a big roadblock for cancer radiotherapy,in which the hypoxia-inducible factor(HIF-1)creates a microenvironment and cancer cells’intrinsic signaling networks conferring radioresistance to cancers.HIF-1 is a heterodimeric transcription factor HIF-1α/HIF-1β,that regulates the transcription of a broad range of downstream genes possessing an E-box-like hypoxia response element(HRE).The expression of HIF-1αis oxygensensitive while HIF-1βis constitutively expressed.In addition to hypoxia,ionizing radiation can also induce the expression of HIF-1α.The HIF-1 modulates a set of signaling pathways to cause profound effects on the response of cancer to radiotherapy,including radiation-induced DNA damage response(DDR),vasculogenesis and glucose metabolism reprograming,epithelial mesenchymal transition(EMT),etc.In this review,our aim is to summarize the current knowledge about the role and the related signal pathways of HIF-1 in association with the resistance of cancers to radiotherapy.Targeting HIF-1 and its signal pathways is a promising strategy for sensitization of cancers to radiotherapy.展开更多
Radiotherapy induces DNA damage,resulting in cell cycle arrest and activation of cell-intrinsic death pathways.However,the radioresistance of some tumour entities such as malignant melanoma limits its clinical applica...Radiotherapy induces DNA damage,resulting in cell cycle arrest and activation of cell-intrinsic death pathways.However,the radioresistance of some tumour entities such as malignant melanoma limits its clinical application.The innate immune sensing receptor retinoic acid-inducible gene I(RIG-I)is ubiquitously expressed and upon activation triggers an immunogenic form of cell death in a variety of tumour cell types including melanoma.To date,the potential of RIG-I ligands to overcome radioresistance of tumour cells has not been investigated.Here,we demonstrate that RIG-I activation enhanced the extent and immunogenicity of irradiation-induced tumour cell death in human and murine melanoma cells in vitro and improved survival in the murine B16 melanoma model in vivo.Transcriptome analysis pointed to a central role for p53,which was confirmed using p53^(-/-)B16 cells.In vivo,the additional effect of RIG-I in combination with irradiation on tumour growth was absent in mice carrying p53^(-/-)B16 tumours,while the antitumoural response to RIG-I stimulation alone was maintained.Our results identify p53 as a pivotal checkpoint that is triggered by RIG-I resulting in enhanced irradiation-induced tumour cell death.Thus,the combined administration of RIG-I ligands and radiotherapy is a promising approach to treating radioresistant tumours with a functional p53 pathway,such as melanoma.展开更多
Lesions on the DNA template can impact transcription via distinct regulatory pathways.Ionizing radiation(IR)as the mainstay modality for many malignancies elicits most of the cytotoxicity by inducing a variety of DNA ...Lesions on the DNA template can impact transcription via distinct regulatory pathways.Ionizing radiation(IR)as the mainstay modality for many malignancies elicits most of the cytotoxicity by inducing a variety of DNA damages in the genome.How the IR treatment alters the transcription cycle and whether it contributes to the development of radioresistance remain poorly understood.Here,we report an increase in the paused RNA polymerase II(RNAPII),as indicated by the phosphorylation at serine 5 residue of its C-terminal domain,in recurrent nasopharyngeal carcinoma(NPC)patient samples after IR treatment and cultured NPC cells developing IR resistance.Reducing the pool of paused RNAPII by either inhibiting TFIIH-associated CDK7 or stimulating the positive transcription elongation factor b,a CDK9-CycT1 heterodimer,attenuates IR resistance of NPC cells.Interestingly,the poly(ADP-ribosyl)ation of CycT1,which disrupts its phase separation,is elevated in the IR-resistant cells.Mutation of the major poly(ADP-ribosyl)ation sites of CycT1 decreases RNAPII pausing and restores IR sensitivity.Genome-wide chromatin immunoprecipitation followed by sequencing analyses reveal that several genes involved in radiation response and cell cycle control are subject to the regulation imposed by the paused RNAPII.Particularly,we identify the NIMA-related kinase NEK7 under such regulation as a new radioresistancefactor,whose downregulation results in the increased chromosome instability,enabling the development of IR resistance.Overall,our results highlight a novel link between the alteration in the transcription cycle and the acquisition of IR resistance,opening up new opportunities to increase the efficacy of radiotherapy and thwart radioresistance in NpC.展开更多
Objective:Hepatitis B X-interacting protein(HBXIP)plays an important role in breast tumorigenesis,tumor growth and metastasis,but its functional contribution in radioresistance remains poorly understood.As radiotherap...Objective:Hepatitis B X-interacting protein(HBXIP)plays an important role in breast tumorigenesis,tumor growth and metastasis,but its functional contribution in radioresistance remains poorly understood.As radiotherapy served as an essential adjuvant treatment,uncovering the role of HBXIP as well as its downstream molecular XIAP in radioresistance could benefit for the development of individual therapy strategy.Methods:Immunohistochemistry of 42 breast cancer tissue samples and Western blot analysis of proteins from MCF-7 and MDA-MB-231 cells exposed to fractioned doses(γ-rays)were used to identify the expression of HBXIP/XIAP in breast cancer.To verify the radioresistance effects and potential mechanism,the cells were treated with designed pCMV and siRNA of targeting genes,and then measured with MTT assay,clonogenic survival assay and flow cytometry.Furthermore,a subcutaneous xenotransplanted tumor model of breast cancer was established in nude mice to validate the radioresistization effect of HBXIP in vivo.Results:HBXIP and XIAP expression levels in breast cancer tissues were positively correlated with chemoradiotherapy resistance of breast cancer.Overexpression of HBXIP could desensitize MCF-7 and MDA-MB-231 cells to irradiation by inhibiting radiation-induced cell apoptosis,and knockdown of HBXIP in these cells had the converse response.Moreover,up-regulation of HBXIP resulted in the increase of XIAP and NF-κB levels in vitro and in vivo,while down-regulation of HBXIP led to the opposite effects.In addition,inhibition of XIAP and NF-κB abrogated the HBXIP overexpression induced radioresistization and increased cell apoptosis(25.8%augment for siRNA XIAP and 28.1%for NF-κB in MDA-MB-231 cells;25.4%augment for siRNA XIAP and 27.2%for NF–κB in MCF-7 cells).Conclusions:HBXIP enhances radioresistance of human breast cancer cells via upregulating XIAP,and targeting the HBXIP–NF–κB-XIAP pathway may be a potentially effective strategy to enhance the efficacy of radiotherapy for human breast cancer.展开更多
基金Supported by the National Natural Science Foundation of China,No.81960506Science and Technology Fund Project of Guizhou Provincial Health Commission,No.gzwkj2022-299Key Projects of Zunyi Science and Technology Fund,No.zunshikeheHZzi(2023)24 and No.zunshikeheHZzi(2024)9.
文摘BACKGROUND Radiotherapy is widely employed in colorectal cancer(CRC)treatment,but the occurrence of radioresistance severely limits the clinical benefit to patients and significantly contributes to treatment failure and recurrent metastasis.AIM To explore the role and underlying mechanism of the lncRNA FTX in radiotherapy resistance in CRC.METHODS LncRNA FTX expression in colorectal parent cells(HT29 and HCT116)and radioresistant cells(HT29R and HCT116R)was determined by real-time quantitative PCR,and the viability of HT29R-shFTX and HCT116R-shFTX cells under ionizing radiation was evaluated using the cell counting kit-8 assay and colony formation experiment.The levels of glutathione and reactive oxygen species in cells after irradiation were determined,and the association between ferroptosis and lncRNA FTX expression in cancer cells was tested.A dual-luciferase assay was used to validate gene interactions.A xenotransplantation mouse model was established to explore the effects of FTX on the CRC tumor radiosensitivity in vivo.RESULTS FTX was upregulated in radioresistant CRC cells,and FTX knockdown inhibited cell survival and increased cell ferroptotic death in response to ionizing radiation.Moreover,lncRNA FTX restricted the SLC7A11 expression by sponging with miR-625-5p,and inhibition of the lncRNA FTX or SLC7A11 significantly increased cellular oxidant levels and DNA damage to ionizing radiation in cancer cells.However,SLC7A11 overexpression reversed the effects of decreased FTX levels on ferroptosis and high oxidation levels in cancer cells exposed to ionizing radiation.CONCLUSION Inhibition of the lncRNA FTX/miR-625-5p/SLC7A11 axis can induce ferroptosis and disturb intracellular redox balance,further sensitizing CRC cells to ionizing radiation,suggesting its potential as a therapeutic target for improving CRC response to radiation therapy.
基金supported by the National Natural Science Foundation of China(No.12205215)Suzhou Fundamental Research Project(No.SJC2023001)+2 种基金Basic Research Program of Nantong Science and Technology Bureau(No.JC12022103)College Student Innovation Training Program Project of Soochow University(No.202410285101Z)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Objectives:Fractionated radiotherapy represents a standardized and widely adopted treatment modality for cancermanagement,with approximately 40% of non-small cell lung cancer(NSCLC)patients receiving it.However,repeated irradiationmay induce radioresistance in cancer cells,reducing treatment effectiveness and raising recurrence risk.The long noncoding RNA CRYBG3(lncRNA CRYBG3),which is upregulated in lung cancer cells after Xray irradiation,contributes to the radioresistance of NSCLC cells by promoting wild-type p53 protein degradation.This study aims to elucidate the mechanism of fractionated irradiation-induced radioresistance,in which lncRNA CRYBG3 regulates radiation-induced mitochondrial damage and reactive oxygen species(ROS)generation through the p53 downstream signaling pathway.Methods:To investigate the critical roles of lncRNA CRYBG3 in mediating radioresistance induced by fractionated irradiation in NSCLC,we established radioresistant NSCLC cells by irradiating the A549 and H460 cell lines with 60 Gy of X-rays in 12 fractions,and named the radioresistant cells A549R and H460R,respectively.Lentiviral vectors were used to deliver short hairpin RNA(shRNA)into cells to knock down lncRNA CRYBG3,thereby investigating its contribution to adaptive radioresistance in A549R and H460R cells.All cells were irradiated with 4 Gy of X-rays,and subsequent analyses were conducted to evaluate mitochondrial damage,ROS generation,apoptosis,and the expression of oxidative stress-related proteins.Results:Increased expression levels of lncRNA CRYBG3 were positively associated with the acquisition of radioresistance in NSCLC cells.Additionally,suppressing lncRNA CRYBG3 increased mitochondrial damage and promoted radiation-induced apoptosis in radioresistant NSCLC cells.Mechanistically,the downregulation of lncRNA CRYBG3 led to increased p53 levels,resulting in decreased expression of heat shock factor 1(HSF1)and tumor necrosis factor receptor-associated protein 1(TRAP1),as well as enhanced radiation-induced mitochondrial oxidative damage and apoptosis.Conclusion:The results indicate that lncRNA CRYBG3 plays a regulatory role in adaptive radioresistance in NSCLC cells through the p53/HSF1/TRAP1 axis.Therefore,targeting lncRNA CRYBG3 could potentially improve the efficacy of fractionated radiotherapy in NSCLC.
基金This study was supported by the Inner Mongolia Science and Technology Department Science and Technology Research Project(No.2021GG0270)National Natural Science Foundation of China(81860534)+5 种基金Natural Science Foundation of Inner Mongolia(2021MS08152)Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT22004)Scientific and Technological Innovative Research Team for Inner Mongolia Medical University of Transformation Application of Organoid in Medical and Industrial Interdiscipline(YKD2022TD002)Major Project of Inner Mongolia Medical University(YKD2022 ZD002)Radiobiology System and Team Construction of Radiotherapy for Inner Mongolia Medical University(YKD2022XK014)Key Laboratoy of Radiation Physics and Biology of Inner Mongolia Medical University(PIKY2023030).
文摘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.
文摘BACKGROUND Gliomas pose a significant challenge to effective treatment despite advancements in chemotherapy and radiotherapy.Glioma stem cells(GSCs),a subset within tumors,contribute to resistance,tumor heterogeneity,and plasticity.Recent studies reveal GSCs’role in therapeutic resistance,driven by DNA repair mechanisms and dynamic transitions between cellular states.Resistance mechanisms can involve different cellular pathways,most of which have been recently reported in the literature.Despite progress,targeted therapeutic approaches lack consensus due to GSCs’high plasticity.AIM To analyze targeted therapies against GSC-mediated resistance to radio-and chemotherapy in gliomas,focusing on underlying mechanisms.METHODS A systematic search was conducted across major medical databases(PubMed,Embase,and Cochrane Library)up to September 30,2023.The search strategy utilized relevant Medical Subject Heading terms and keywords related to including“glioma stem cells”,“radiotherapy”,“chemotherapy”,“resistance”,and“targeted therapies”.Studies included in this review were publications focusing on targeted therapies against the molecular mechanism of GSC-mediated re-sistance to radiotherapy resistance(RTR).RESULTS In a comprehensive review of 66 studies on stem cell therapies for SCI,452 papers were initially identified,with 203 chosen for full-text analysis.Among them,201 were deemed eligible after excluding 168 for various reasons.The temporal breakdown of studies illustrates this trend:2005-2010(33.3%),2011-2015(36.4%),and 2016-2022(30.3%).Key GSC models,particularly U87(33.3%),U251(15.2%),and T98G(15.2%),emerge as significant in research,reflecting their representativeness of glioma characteristics.Pathway analysis indicates a focus on phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin(mTOR)(27.3%)and Notch(12.1%)pathways,suggesting their crucial roles in resistance development.Targeted molecules with mTOR(18.2%),CHK1/2(15.2%),and ATP binding cassette G2(12.1%)as frequent targets underscore their importance in overcoming GSC-mediated resistance.Various therapeutic agents,notably RNA inhibitor/short hairpin RNA(27.3%),inhibitors(e.g.,LY294002,NVP-BEZ235)(24.2%),and monoclonal antibodies(e.g.,cetuximab)(9.1%),demonstrate versatility in targeted therapies.among 20 studies(60.6%),the most common effect on the chemotherapy resistance response is a reduction in temozolomide resistance(51.5%),followed by reductions in carmustine resistance(9.1%)and doxorubicin resistance(3.0%),while resistance to RTR is reduced in 42.4%of studies.CONCLUSION GSCs play a complex role in mediating radioresistance and chemoresistance,emphasizing the necessity for precision therapies that consider the heterogeneity within the GSC population and the dynamic tumor microenvironment to enhance outcomes for glioblastoma patients.
基金supported by the National Natural Science Foundation of China(No.81201779)
文摘Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncol- ogy. The hypoxia-inducible factor （HIF）-lα plays a crucial role in radiosensitivity, but the detailed mechanisms remain elusive. A relationship has been suggested to exist between hypoxia and autophagy recently. In the current study, we studied the effect of hypoxia-induced autophagy on radioresistance in lung cancer cell lines. A549 and H1299 cells were cultured under normoxia or hypoxia, followed by ir- radiation at dosage ranging from 0 to 8 Gy. Clonogenic assay was performed to calculate surviving frac- tion. EGFP-LC3 plasmid was stably transfected into cells to monitor autopbagic processes. Western blotting was used to evaluate the protein expression levels of HIF-lα, c-Jun, phosphorylated c-Jun, Be- clin 1, LC3 and p62. The mRNA levels of Beclin 1 were detected by qRT-PCR. We found that under hypoxia, both A549 and H1299 cells were radio-resistant compared with normoxia. Hypoxia-induced elevated HIF-1α protein expression preferentially triggered autophagy, accompanied by LC3 induction, EGFP-LC3 puncta and p62 degradation. In the meantime, HIF-1α increased downstream c-Jun phos- phorylation, which in turn upregulated Beclin 1 mRNA and protein expression. The upregulation of Be- clin 1 expression, instead of HIF-1α, could be blocked by SP600125 （a specific inhibitor of c-Jun NH2- terminal kinase）, followed by suppression of autophagy. Under hypoxia, combined treatment of irradia- tion and chloroquine （a potent autophagy inhibitor） significantly decreased the survival potential of lung cancer cells in vitro and in vivo. In conclusion, hypoxia-induced autophagy through evaluating Beclinl expression may be considered as a target to reverse the radioresistance in cancer cells.
基金Supported by Natural Science Foundation of Shandong Province,China,No.ZR2012HQ032China Postdoctoral Science Foundation funded project,No.2013M531614
文摘AIM:To investigate the association between nuclearβ-catenin overexpression in rectal adenocarcinoma and radioresistance.METHODS:A retrospective analysis was conducted.The analysis involved 136 patients with locally advanced rectal adenocarcinoma who underwent shortcourse preoperative radiotherapy and radical resection.The expression ofβ-catenin in both pretreatment biopsy specimens and resected primary tumor tissues was examined by immunohistochemistry.The correlation ofβ-catenin expression with radioresistance was evaluated using the tumor regression grading(TRG)system.The relationship betweenβ-catenin expression and clinicopathological characteristics was also analyzed.Univariate and logistic multivariate regression analyses were adopted to determine the independent factors of radioresistance.RESULTS:Nuclearβ-catenin overexpression was more evident in radioresistant rectal adenocarcinoma than in radiosensitive rectal adenocarcinoma(57.6%vs 16.7%,P<0.001).Nuclearβ-catenin was overexpressed in favor of poor TRG(≤2),whereas membraneβ-catenin was expressed in favor of good TRG(≥3).Nuclearβ-catenin expression in tumor cell differentiation(P=0.018),lymph node metastasis(P=0.022),and TRG(P<0.001)showed significant differences.Univariate analyses demonstrated that radioresistance is associated with nuclearβ-catenin overexpression(P<0.001).In addition,logistic multivariate regression analysis indicated that only three factors,namely,tumor size(P<0.001),tumor cell differentiation(P<0.001),and nuclearβ-catenin overexpression(P<0.001),are associated with radioresistance.By using radioresistance as a prediction target,nuclearβ-catenin-based prediction alone achieved 83%accuracy,65%sensitivity,and88%specificity.CONCLUSION:Nuclearβ-catenin overexpression may be a valuable candidate to predict the response of rectal adenocarcinoma to preoperative radiotherapy.
文摘Hepatocellular carcinoma(HCC), one of the most common cancers in the world, is characterized by poor prognosis and recurrence after resection. Its prevalence is highest in developing countries, particularly where there is high incidence of hepatitis B virus infection. Several curative treatments are available for early stage HCC; however, these options are not available for advanced disease. New techniques allowing the specific delivery of high-dose radiotherapy enable their use in the treatment of HCC, which has been avoided in the past due to low hepatic tolerance for radiation. This presents a new challenge—the development of resistance to radiotherapy and subsequent disease recurrence. Recently, the mechanisms controlling radioresistance have begun to be elucidated. Understanding the molecular basis of radioresistance is key to developing new strategies with better treatment response and increased patient survival.
文摘We present evidence here that abundantly expressed b-catenin-triggered NF-kB-dependent upregulation of inducible nitric oxide synthase(iNOS) found in hepatoma Mahlavu cells (RT-resistant variant designated as RR-Mal), but not in Hep 3B cells (RT-sensitive variant designated as RS-3B) is a key element contribrting to the radioresisitance through the activation of two prominent radioprotective pathways. First, high iNOS expression found in RR-Mal, but not in RS-3B cells was found to perturb calcium homeostasis that triggered ER stress response leading to the overproduction of ER chaperone GRP-78 via robust generation of cleaved ATF-6a (50 kDa) subunits and their nuclear translocation. Meanwhile, both abundantly expressed NF-κB and COX-2 found in RR-Mal cells could also provoke an increased production of PGE2 resulting in robust production of Bcl-2. Interestingly, when RR-Mal cells were treated with PDTC (a NF-κB inhibitor) or celecoxib (a COX-2 inhibitor), a concentration-dependent downregulation of Bcl-2 could be demonstrated implying that Bcl-2 overexpression was indeed mediated through NF-κB/Cox-2/PGE2 pathway. Importantly, we also unveiled that siRNA-mediated silencing of survivin in RR-Mal cells could result in a concomitant downregulation of GRP-78 due to a severe inhibition of ATF-6a (50 kDa) expression. Taken together, our data demonstrate that constitutively overexpressed b-catenin/NF-κB/iNOS and NF-κB/COX-2/PGE2 pathways that overproducing GRP-78, survivin and Bcl-2 expressions are responsible for radioresistance acquisition in RR-Mal cells. Thus, both pathways could be served as potential targets for overcoming radioresistance.
基金Key Program of National Natural Science Foundation of China(U1432248)
文摘Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer, which is the leading cause of death in lung cancer patient. Routine treatment of NSCLC cannot effectively change the survival rate of patients, one important reason is the increased radioresistance of tumor cells after conventional radiotherapy.
文摘The molecular mechanisms of radioresistance of manganese ssuperoxide dismutase (MnSOD) was investigated in thisstudy. We assayed cell necrocis and apoptosis induced by ionizing radiation. Furthermore, the possible roles of oncogenes bc1-2and p53 mRNA expression in MnSOD gene-transfected cells were for investigated. me results showed that 10 Gy X-ray could induce the expression of bc1-2 mRNA and suppress p53 mRNA expression in sense MnSOD transfected cells, whereas Bc1-2 mRNAexpression did not change and p53 mRNA expression increased in antisense MnSOD transfected cells. It is suggested that Bc1-2 isrequired for the radioresistance of MnSOD and the status of p53 play a role in radiation-induced cell death.
基金supported by Postdoctoral Fellowship Program of CPSF(GZC20231809)Sichuan Science and Technology Program(24NSFSC2900)+6 种基金National Natural Sciences Foundation of China(82473434)Sichuan Provincial Science and Technology Department Key Research and Development Program(2022YFSY0012)Sichuan Science and Technology Program(2024YFHZ0041,2024ZYD0054)Science and Technology Project of Sichuan Provincial Health Commission(Clinical Research Special Project JH2023082)International Science and Technology Cooperation Program of Chengdu Science and Technology Bureau(2024-YF06-00011-HZ and 2022-GH03-00004-HZ)1.3.5 project for disciplines of excellence from West China Hospital of Sichuan University(ZYYC23006)Clinical Research Incubation Project of West China Hospital(23HXFH001).
文摘Radiotherapy(RT)resistance in head and neck squamous cell carcinoma(HNSCC)significantly hampers local control and patient prognosis.This study investigated the efficacy and molecular mechanisms of high-energy X-ray-based ultra-high dose rate radiotherapy(UHDR-RT)in overcoming RT resistance.The established RT-resistant HNSCC cell lines and animal models were subjected to UHDR-RT or conventional RT(Conv-RT)via a high-power rhodotron accelerator.Cellular assays assessed the malignant phenotype,viability,and degree of DNA damage,whereas in vivo evaluations focused on tumor proliferation and the tumor immune microenvironment(TiME).Transcriptome sequencing and Olink proteomics were employed to explore the underlying mechanisms involved.In vitro experiments indicated that UHDR-RT suppressed radioresistant cell proliferation and invasion,while promoting apoptosis and exacerbating DNA damage.In contrast,its efficacy in radiosensitive cells was comparable to that of Conv-RT.In vivo studies using patient-derived xenograft nude mice models demonstrated that UHDR-RT only partially reversed RT resistance.Transcriptomic and proteomic analyses of C57BL/6J mice models revealed the predominant role of TiME modulating in reversing radioresistance.Immunofluorescence and flow cytometry confirmed increased CD8^(+)T cells and an increased M1/M2 macrophage ratio post-UHDR-RT.Mechanistically,UHDR-RT activated CD8^(+)T cells,which stimulated M1 macrophages through paracrine IFN-y signaling,thereby enhancing TiME activation.Furthermore,the activated M1 macrophages secreted CXCL9,which in turn reactivated CD8^(+)T cells,forming a feedforward loop that amplifed TiME activation.This study elucidates the dual role of UHDR-RT in directly inducing DNA damage and modulating the TiME,highlighting its potential in treating radioresistant HNSCC.
基金supported by the National Natural Science Foundation of China(No.82230108,32171238,82173466,and 82273581).
文摘Chemo-/radioresistance of malignant tumors hampers cancer control and increases patient mortality.Efficient repair of damaged DNA is critical for the maintenance of genomic integrity and fidelity of genetic information.In reverse,increased DNA repair capability in cancer cells contributes to chemo-/radioresistance of malignant tumors.DNA double-strand break(DSB)is the most serious DNA damage and is also the principal molecular basis of radiotherapy.Upon DNA damage,the Ku80 is recruited and forms a critical DNA-PK complex at the DSB sites with Ku70 and the catalytic subunit(DNA-PKcs)to initiate DNA repair.How DNA-PK is assembled and activated is not fully understood.Based on the identification of radiation-reduced Ku80 K568 crotonylation through quantitative global lysine crotonylome analysis,we reveal that Ku80 K568 is crotonylated by p300-CBP-associated factor(PCAF).Upon DNA damage,the K568cr is decrotonylated by HDAC8(Histone deacetylase 8).Decrotonylation of K568cr empties this site for the subsequent SUMOylation of Ku80 by CBX4.The conversion of Ku80 from K568 crotonylation to SUMOylation facilitates the assembly of DNA-PK complex and autophosphorylation of DNA-PKcs S2056,consequently activating the DSB repair.Moreover,mutation disrupting the post-translational modification(PTM)of Ku80 K568 site sensitizes cancer cells to radiotherapy in tumorbearing nude mice models.This study elucidates the conversion model between two different forms of PTMs in the regulation of DNA-PK complex assembly and DSB repair,highlighting this model’s potential in controlling chemo-/radioresistance of malignant tumors,as well as expands the atlas of therapeutic targets.
基金supported by National Research Foundation of Korea grant funded by the Korea government(MSIT)(2023R1A2C2004510)Korea Basic Science Institute(National Research Facilities and Equipment Center)grant(2020R1A6C101A191)of the Ministry of Education(Korea)the BK21 FOUR Program(Graduate School Innovation)of Sungkyunkwan University.
文摘Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous subpopulations.Here,we showed that MZ B cells can be divided into two distinct subpopulations according to their CD80 expression levels.CD80^(high)MZ B cells exhibited greater Ab-producing,proliferative,and IL-10-secreting capacities than did CD80^(low)MZ B cells.Notably,CD80^(high)MZ B cells survived 2-Gy whole-body irradiation,whereas CD80^(low)MZ B cells were depleted by irradiation and then repleted with one month after irradiation.Depletion of CD80^(low)MZ B cells led to accelerated development of type II collagen(CII)-induced arthritis upon immunization with bovine CII.CD80^(high)MZ B cells exhibited higher expression of genes involved in proliferation,plasma cell differentiation,and the antioxidant response.CD80^(high)MZ B cells expressed more autoreactive B cell receptors(BCRs)that recognized double-stranded DNA or CII,expressed more immunoglobulin heavy chain sequences with shorter complementarity-determining region 3 sequences,and included more clonotypes with no N-nucleotides or with B-1a BCR sequences than CD80^(low)MZ B cells.Adoptive transfer experiments showed that CD21^(+)CD23^(+)transitional 2 MZ precursors preferentially generated CD80^(low)MZ B cells and that a proportion of CD80^(low)MZ B cells were converted into CD80^(high)MZ B cells;in contrast,CD80^(high)MZ B cells stably remained CD80^(high)MZ B cells.In summary,MZ B cells can be divided into two subpopulations according to their CD80 expression levels,Ab-producing capacity,radioresistance,and autoreactivity,and these findings may suggest a hierarchical composition of MZ B cells with differential stability and BCR specificity.
基金funded by the National Natural Science Foundation of China(No.12235004,12175044,32171235,12375338).
文摘Objective:To investigate the potential role of the regulator of G protein signaling 20(RGS20)in radioresistance of non-small cell lung cancer(NSCLC).Methods:A total of 35 lung adenocarcinoma(LUAD)patients from The Cancer Genome Atlas(TCGA),who un-derwent radiotherapy,were enrolled and divided into radiosensitive(n=16)and radioresistant(n=19)groups based on clinical prognosis.The expression and prognosis of RGS20 were analyzed by Gene Expression Profiling Interactive Analysis(GEPIA)database.A radioresistant cell line(A549R)was constructed by irradiating A549 cells with 6 Gy X-rays for 10 fractions.Cell survival was measured by colony formation assay.The regulatory effect of RGS20 on pyroptosis were verified by LDH release and Western blot assay,and the underlying mech-anism was investigated by transfecting RGS20 siRNA and applying a GSDMD inhibitor.Results:A total of 2,181 differentially expressed genes(DEGs)were identified by analyzing the data of radio-sensitive and radioresistant individuals from the TCGA-LUAD dataset.These DEGs were enriched in G alpha(z)signalling events analyzed by Reactome database.RGS20 exhibited significant upregulation among the DEGs,and its higher expression predicted poor prognosis in LUAD patients.In vitro,the expression of RGS20 protein was increased by irradiation in A549 cells,whereas it remained at much high levels in A549R cells regardless of irradiation.After irradiation,the expressions of pyroptosis-related proteins were significantly increased in A549 cells(P<0.05),with no significant changes were observed in A549R cells.Treatment with LDC7559 significantly reduced LDH release(P<0.01)and improved the survival rate of irradiated A549 cells(P<0.01).Furthermore,knockdown of RGS20 gene in A549R cells significantly increased LDH release(P<0.001)and enhanced radiosensitivity(P<0.01),while LDC7559 administration reversed LDH release(P<0.01)and radiation-induced cell death increased by siRGS20(P<0.05).Meantime,the increased expression level of GSDMD-NT was observed in A549 and A549R cells transfected with siRGS20(P<0.05).Conclusion:RGS20 contributes to the radioresistance of NSCLC cells,which might be a potential target for NSCLC radiotherapy.
基金supported by the National Natural Science Foundation of China(No.81971731,82001963,82172082)PUMC Youth Fund and the Fundamental Research Funds for the Central Universities(No.3332020058)+1 种基金the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2018PT35031)the Natural Science Fund for Distinguished Young Scholars of Tianjin(18JCJQJC47300)and the CAMS Innovation Fund for Medical Sciences(2021-I2M042).
文摘Radioresistance reduces the antitumor efficiency of radiotherapy and further restricts its clinical application,which is mainly caused by the aggravation of immunosuppressive tumor microenvironment(ITM).Especially tumor-associated macrophages(TAMs)usually display the tumor-promoting M2 phenotype during high-dose fractional radiotherapy mediating radiotherapy resistance.Herein,the toll like receptor agonist TLR7/8a was conjugated with radiosensitive peptide hydrogel(Smac-TLR7/8 hydrogel)to regulate TAMs repolarization from M2 type into M1 type,thus modulating the ITM and overcoming the radioresistance.The Smac-TLR7/8 hydrogel was fabricated through self-assembly with nanofibrous morphology,porous structure and excellent biocompatibility.Uponγ-ray radiation,Smac-TLR7/8 hydrogel effectively polarized the macrophages into M1 type.Notably,combined with radiotherapy,TAMs repolarization regulated by Smac-TLR7/8 hydrogel could increase tumor necrosis factor secretion,activate antitumor immune response and effectively inhibit tumor growth.Moreover,TAMs repolarization rebuilt the ITM and elicited the immunogenic phenotypes in solid tumors,thus enhanced the PD1-blockade efficacy through increasing tumor infiltrating lymphocytes(TILs)and decreasing Treg cells in two different immune activity tumor mice models.Overall,this study substantiated that recruiting and repolarization of TAMs were critical in eliciting antitumor immune response and overcoming radioresistance,thus improving the efficacy of radiotherapy and immunotherapy.
基金Supported by the National Basic Research Program of China (Grant No. 2004CB19604)the National Natural Science Foundation of China (Grant No. 30330020)the National Science fund for Distinguished Young Scholars (Grant No. 30425038)
文摘The conclusion based on transmission electron microscopy, "the tightly packed ring-like nucleoid of the Deinococcus radiodurans R1 is a key to radioresistance", has instigated lots of debates. In this study, according to the previous research of PprI’s crucial role in radioresistance of D. radiodurans, we have attempted to examine and compare the nucleoid morphology differences among wild-type D. ra-diodurans R1 strain, pprI function-deficient mutant (YR1), and pprI function-complementary strains (YR1001, YR1002, and YR1004) before and after exposure to ionizing irradiation. Fluorescence mi-croscopy images indicate: (1) the majority of nucleoid structures in radioresistant strain R1 cells ex-hibit the tightly packed ring-like morphology, while the pprI function-deficient mutant YR1 cells carrying predominate ring-like structure represent high sensitivity to irradiation; (2) as an extreme radioresistant strain similar to wild-type R1, pprI completely function-complementary strain YR1001 almost displays the loose and irregular nucleoid morphologies. On the other hand, another radioresistant pprI partly function-complementary strain YR1002’s nucleiods exhibit about 60% ring-like structure; (3) a PprI C-terminal deletion strain YR1004 consisting of approximately 60% of ring-like nucleoid is very sensi-tive to radiation. Therefore, our present experiments do not support the conclusion that the ring-like nucleoid of D. radiodurans does play a key role in radioresistance.
基金This study is supported by grants from the National Natural Science Foundation of China(Grant No.31530085,31870847,U1803124).
文摘Hypoxia is a big roadblock for cancer radiotherapy,in which the hypoxia-inducible factor(HIF-1)creates a microenvironment and cancer cells’intrinsic signaling networks conferring radioresistance to cancers.HIF-1 is a heterodimeric transcription factor HIF-1α/HIF-1β,that regulates the transcription of a broad range of downstream genes possessing an E-box-like hypoxia response element(HRE).The expression of HIF-1αis oxygensensitive while HIF-1βis constitutively expressed.In addition to hypoxia,ionizing radiation can also induce the expression of HIF-1α.The HIF-1 modulates a set of signaling pathways to cause profound effects on the response of cancer to radiotherapy,including radiation-induced DNA damage response(DDR),vasculogenesis and glucose metabolism reprograming,epithelial mesenchymal transition(EMT),etc.In this review,our aim is to summarize the current knowledge about the role and the related signal pathways of HIF-1 in association with the resistance of cancers to radiotherapy.Targeting HIF-1 and its signal pathways is a promising strategy for sensitization of cancers to radiotherapy.
基金funded by Deutsche Forschungsgemeinschaft(DFG,GermanResearch Foundation)under Germany's Excellence Strategy EXC2151390873048 of which E.B.,G.H.,and M.S.are memberssupported by other grants of DFG,including Project-ID 369799452 TRR237 to E.B.,G.H.,and M.S.,Project-ID 397484323 TRR259 to G.H.,GRK 2168 to E.B.and M.S.,and DFG SCHL1930/1-2+1 种基金funded by the Deutsche Krebshilfe through a Mildred Scheel Nachwuchszentrum(70113307)the recipient of a PhD scholarship from Bayer Pharma AG(40860128).
文摘Radiotherapy induces DNA damage,resulting in cell cycle arrest and activation of cell-intrinsic death pathways.However,the radioresistance of some tumour entities such as malignant melanoma limits its clinical application.The innate immune sensing receptor retinoic acid-inducible gene I(RIG-I)is ubiquitously expressed and upon activation triggers an immunogenic form of cell death in a variety of tumour cell types including melanoma.To date,the potential of RIG-I ligands to overcome radioresistance of tumour cells has not been investigated.Here,we demonstrate that RIG-I activation enhanced the extent and immunogenicity of irradiation-induced tumour cell death in human and murine melanoma cells in vitro and improved survival in the murine B16 melanoma model in vivo.Transcriptome analysis pointed to a central role for p53,which was confirmed using p53^(-/-)B16 cells.In vivo,the additional effect of RIG-I in combination with irradiation on tumour growth was absent in mice carrying p53^(-/-)B16 tumours,while the antitumoural response to RIG-I stimulation alone was maintained.Our results identify p53 as a pivotal checkpoint that is triggered by RIG-I resulting in enhanced irradiation-induced tumour cell death.Thus,the combined administration of RIG-I ligands and radiotherapy is a promising approach to treating radioresistant tumours with a functional p53 pathway,such as melanoma.
基金This project has been supported by grants from the National Natural ScienceFoundation of China(32170821 and 92153301 to K.Y.and 32101034 to F.C.)the Ministry of Science and Technologyyof the People's Republic of China(2021YFC2701202)+2 种基金Department of Science&Technology of Hunan Province(2021J10054 and 2019SK1012 to K.Y.,2021J41049 to C.Y.,and the Innovative Team Program 2019RS1010)Central South University(the Innovationdriven Team Project 2020CX016)K.Y.is supported by the National Thousand Talents Program for Young Outstanding Scientists.
文摘Lesions on the DNA template can impact transcription via distinct regulatory pathways.Ionizing radiation(IR)as the mainstay modality for many malignancies elicits most of the cytotoxicity by inducing a variety of DNA damages in the genome.How the IR treatment alters the transcription cycle and whether it contributes to the development of radioresistance remain poorly understood.Here,we report an increase in the paused RNA polymerase II(RNAPII),as indicated by the phosphorylation at serine 5 residue of its C-terminal domain,in recurrent nasopharyngeal carcinoma(NPC)patient samples after IR treatment and cultured NPC cells developing IR resistance.Reducing the pool of paused RNAPII by either inhibiting TFIIH-associated CDK7 or stimulating the positive transcription elongation factor b,a CDK9-CycT1 heterodimer,attenuates IR resistance of NPC cells.Interestingly,the poly(ADP-ribosyl)ation of CycT1,which disrupts its phase separation,is elevated in the IR-resistant cells.Mutation of the major poly(ADP-ribosyl)ation sites of CycT1 decreases RNAPII pausing and restores IR sensitivity.Genome-wide chromatin immunoprecipitation followed by sequencing analyses reveal that several genes involved in radiation response and cell cycle control are subject to the regulation imposed by the paused RNAPII.Particularly,we identify the NIMA-related kinase NEK7 under such regulation as a new radioresistancefactor,whose downregulation results in the increased chromosome instability,enabling the development of IR resistance.Overall,our results highlight a novel link between the alteration in the transcription cycle and the acquisition of IR resistance,opening up new opportunities to increase the efficacy of radiotherapy and thwart radioresistance in NpC.
基金This study was supported by the grants from the National Natural Science Foundation of China (No.31770910 and No.81730086).
文摘Objective:Hepatitis B X-interacting protein(HBXIP)plays an important role in breast tumorigenesis,tumor growth and metastasis,but its functional contribution in radioresistance remains poorly understood.As radiotherapy served as an essential adjuvant treatment,uncovering the role of HBXIP as well as its downstream molecular XIAP in radioresistance could benefit for the development of individual therapy strategy.Methods:Immunohistochemistry of 42 breast cancer tissue samples and Western blot analysis of proteins from MCF-7 and MDA-MB-231 cells exposed to fractioned doses(γ-rays)were used to identify the expression of HBXIP/XIAP in breast cancer.To verify the radioresistance effects and potential mechanism,the cells were treated with designed pCMV and siRNA of targeting genes,and then measured with MTT assay,clonogenic survival assay and flow cytometry.Furthermore,a subcutaneous xenotransplanted tumor model of breast cancer was established in nude mice to validate the radioresistization effect of HBXIP in vivo.Results:HBXIP and XIAP expression levels in breast cancer tissues were positively correlated with chemoradiotherapy resistance of breast cancer.Overexpression of HBXIP could desensitize MCF-7 and MDA-MB-231 cells to irradiation by inhibiting radiation-induced cell apoptosis,and knockdown of HBXIP in these cells had the converse response.Moreover,up-regulation of HBXIP resulted in the increase of XIAP and NF-κB levels in vitro and in vivo,while down-regulation of HBXIP led to the opposite effects.In addition,inhibition of XIAP and NF-κB abrogated the HBXIP overexpression induced radioresistization and increased cell apoptosis(25.8%augment for siRNA XIAP and 28.1%for NF-κB in MDA-MB-231 cells;25.4%augment for siRNA XIAP and 27.2%for NF–κB in MCF-7 cells).Conclusions:HBXIP enhances radioresistance of human breast cancer cells via upregulating XIAP,and targeting the HBXIP–NF–κB-XIAP pathway may be a potentially effective strategy to enhance the efficacy of radiotherapy for human breast cancer.
