Quercetin Alleviates Lipopolysaccharide-Induced Cardiac Inflammation via Inhibiting Autophagy and Programmed Cell Death

Objective The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide(LPS)induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos(n=120)were allocated untreated control,phosphate buffer solution(PBS)vehicle,PBS with ethanol vehicle,LPS(500 ng/egg),LPS with quercetin treatment(10,20,or 40 nmol/egg,respectively),Quercetin groups(10,20,or 40 nmol/egg).Fifteenday-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity.At embryonic day 19,the hearts of the embryos were collected for histopathological examination,RNA extraction,real-time polymerase chain reaction,immunohistochemical investigations,and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction.The LPS-induced higher mRNA expressions of inflammation-related factors(TLR4,TNFα,MYD88,NF-κB1,IFNγ,IL-1β,IL-8,IL-6,IL-10,p38,MMP3,and MMP9)were blocked by quercetin with three dosages.Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of TLR4,IFNγ,MMP3,and MMP9 when compared with the LPS group.Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1,and significantly decreased protein expression of claudin 1 when compared with the LPS group.Quercetin significantly downregulated autophagyrelated gene expressions(PPARα,SGLT1,APOA4,AMPKα1,AMPKα2,ATG5,ATG7,Beclin-1,and LC3B)and programmed cell death(Fas,Bcl-2,CASP1,CASP12,CASP3,and RIPK1)after LPS induction.Quercetin significantly decreased immunopositivity to APOA4,AMPKα2,and LC3-II/LC3-I in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of AMPKα1,LC3-I,and LC3-II.Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy,programmed cell death,and myocardiocytes permeability.

Efficacy and predictive factors of transarterial chemoembolization combined with lenvatinib plus programmed cell death protein-1 inhibition for unresectable hepatocellular carcinoma

BACKGROUND The efficacy and safety of transarterial chemoembolization(TACE)combined with lenvatinib plus programmed cell death protein-1(PD-1)for unresectable hepato-cellular carcinoma(HCC)have rarely been evaluated and it is unknown which factors are related to efficacy.AIM To evaluate the efficacy and independent predictive factors of TACE combined with lenvatinib plus PD-1 inhibitors for unresectable HCC.METHODS This study retrospectively enrolled patients with unresectable HCC who received TACE/lenvatinib/PD-1 treatment between March 2019 and April 2022.Overall survival(OS)and progression-free survival(PFS)were determined.The objective response rate(ORR)and disease control rate(DCR)were evaluated in accordance with the modified Response Evaluation Criteria in Solid Tumors.Additionally,the prognostic factors affecting the clinical outcome were assessed.RESULTS One hundred and two patients were enrolled with a median follow-up duration of 12.63 months.The median OS was 26.43 months(95%CI:17.00-35.87),and the median PFS was 10.07 months(95%CI:8.50-11.65).The ORR and DCR were 61.76%and 81.37%,respectively.The patients with Barcelona Clinic Liver Cancer Classification(BCLC)B stage,early neutrophil-to-lymphocyte ratio(NLR)response(decrease),or early alpha-fetoprotein(AFP)response(decrease>20%)had superior OS and PFS than their counterparts.CONCLUSION This study showed that TACE/lenvatinib/PD-1 treatment was well tolerated with encouraging efficacy in patients with unresectable HCC.The patients with BCLC B-stage disease with early NLR response(decrease)and early AFP response(decrease>20%)may achieve better clinical outcomes with this triple therapy.

Effectiveness and tolerability of programmed cell death protein-1 inhibitor+chemotherapy compared to chemotherapy for upper gastrointestinal tract cancers

BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,it is unclear whether this combination is superior to chemotherapy alone.AIM To assess the comparative effectiveness and tolerability of combining PD-1 inhibitors with chemotherapy vs chemotherapy alone in patients with advanced gastric cancer,gastroesophageal junction(GEJ)cancer,or oesophageal carcinoma.METHODS We searched the PubMed and Embase databases for studies that compared the efficacy and tolerance of PD-1 inhibitors in combination with chemotherapy vs chemotherapy alone in patients with advanced oesophageal or gastric cancer.We employed either random or fixed models to analyze the outcomes of each clinical trial,en-compassing data on overall survival(OS),progression-free survival(PFS),objective response rate,and adverse events(AEs).RESULTS Nine phase 3 clinical trials(7016 advanced oesophageal and gastric cancer patients)met the inclusion criteria.Our meta-analysis demonstrated that the pooled PD-1 inhibitor+chemotherapy group had a significantly longer OS than the chemotherapy-alone group[hazard ratio(HR)=0.76,95%confidence interval(CI):0.71-0.81];the pooled PFS result was consistent with that of OS(HR=0.67,95%CI:0.61-0.74).The count of patients achieving an objective response in the PD-1 inhibitor+chemotherapy group surpassed that of the chemotherapy-alone group[odds ratio(OR)=1.86,95%CI:1.59-2.18].AE incidence was also higher in the combination-therapy group than in the chemotherapy-alone group,regardless of whether≥grade 3 only(OR=1.30,95%CI:1.07-1.57)or all AE grades(OR=1.88,95%CI:1.39-2.54)were examined.We performed a subgroup analysis based on the programmed death-ligand 1(PD-L1)combined positive score(CPS)and noted extended OS and PFS durations within the CPS≥1,CPS≥5,and CPS≥10 subgroups of the PD-1 inhibitor+chemotherapy group.CONCLUSION In contrast to chemotherapy alone,the combination of PD-1 inhibitor and chemotherapy appears to present a more favorable option for initial or subsequent treatment in patients with gastric cancer,GEJ tumor,or oesophageal cancer.This holds true particularly for individuals with PD-L1 CPS scores of≥5 and≥10.

Elucidating the molecular basis of ATP-induced cell death in breast cancer: Construction of a robust prognostic model

BACKGROUND Breast cancer is a multifaceted and formidable disease with profound public health implications.Cell demise mechanisms play a pivotal role in breast cancer pathogenesis,with ATP-triggered cell death attracting mounting interest for its unique specificity and potential therapeutic pertinence.AIM To investigate the impact of ATP-induced cell death(AICD)on breast cancer,enhancing our understanding of its mechanism.METHODS The foundational genes orchestrating AICD mechanisms were extracted from the literature,underpinning the establishment of a prognostic model.Simultaneously,a microRNA(miRNA)prognostic model was constructed that mirrored the gene-based prognostic model.Distinctions between high-and low-risk cohorts within mRNA and miRNA characteristic models were scrutinized,with the aim of delineating common influence mechanisms,substantiated through enrichment analysis and immune infiltration assessment.RESULTS The mRNA prognostic model in this study encompassed four specific mRNAs:P2X purinoceptor 4,pannexin 1,caspase 7,and cyclin 2.The miRNA prognostic model integrated four pivotal miRNAs:hsa-miR-615-3p,hsa-miR-519b-3p,hsa-miR-342-3p,and hsa-miR-324-3p.B cells,CD4+T cells,CD8+T cells,endothelial cells,and macrophages exhibited inverse correlations with risk scores across all breast cancer subtypes.Furthermore,Kyoto Encyclopedia of Genes and Genomes analysis revealed that genes differentially expressed in response to mRNA risk scores significantly enriched 25 signaling pathways,while miRNA risk scores significantly enriched 29 signaling pathways,with 16 pathways being jointly enriched.CONCLUSION Of paramount significance,distinct mRNA and miRNA signature models were devised tailored to AICD,both potentially autonomous prognostic factors.This study's elucidation of the molecular underpinnings of AICD in breast cancer enhances the arsenal of potential therapeutic tools,offering an unparalleled window for innovative interventions.Essentially,this paper reveals the hitherto enigmatic link between AICD and breast cancer,potentially leading to revolutionary progress in personalized oncology.

Genetic polymorphisms in genes regulating cell death and prognosis of patients with rectal cancer receiving postoperative chemoradiotherapy

Objective:The identification of biomarkers for predicting chemoradiotherapy efficacy is essential to optimize personalized treatment.This study determined the effects of genetic variations in genes involved in apoptosis,pyroptosis,and ferroptosis on the prognosis of patients with locally advanced rectal cancer receiving postoperative chemoradiotherapy(CRT).Methods:The Sequenom MassARRAY was used to detect 217 genetic variations in 40 genes from 300 patients with rectal cancer who received postoperative CRT.The associations between genetic variations and overall survival(OS)were evaluated using hazard ratios(HRs)and 95%confidence intervals(CIs)computed using a Cox proportional regression model.Functional experiments were performed to determine the functions of the arachidonate 5-lipoxygenase(ALOX5)gene and the ALOX5 rs702365 variant.Results:We detected 16 genetic polymorphisms in CASP3,CASP7,TRAILR2,GSDME,CASP4,HO-1,ALOX5,GPX4,and NRF2 that were significantly associated with OS in the additive model(P<0.05).There was a substantial cumulative effect of three genetic polymorphisms(CASP4 rs571407,ALOX5 rs2242332,and HO-1 rs17883419)on OS.Genetic variations in the CASP4 and ALOX5 gene haplotypes were associated with a higher OS.We demonstrated,for the first time,that rs702365[G]>[C]represses ALOX5 transcription and corollary experiments suggested that ALOX5 may promote colon cancer cell growth by mediating an inflammatory response.Conclusions:Polymorphisms in genes regulating cell death may play essential roles in the prognosis of patients with rectal cancer who are treated with postoperative CRT and may serve as potential genetic biomarkers for individualized treatment.

Suberoylanilide hydroxamic acid upregulates reticulophagy receptor expression and promotes cell death in hepatocellular carcinoma cells

BACKGROUND Hepatocellular carcinoma(HCC)is a common clinical condition with a poor prognosis and few effective treatment options.Potent anticancer agents for treating HCC must be identified.Epigenetics plays an essential role in HCC tumorigenesis.Suberoylanilide hydroxamic acid(SAHA),the most common histone deacetylase inhibitor agent,triggers many forms of cell death in HCC.However,the underlying mechanism of action remains unclear.Family with sequence similarity 134 member B(FAM134B)-induced reticulophagy,a selective autophagic pathway,participates in the decision of cell fate and exhibits anticancer activity.This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death.AIM To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death.METHODS The viability,apoptosis,cell cycle,migration,and invasion of SAHA-treated Huh7 and MHCC97L cells were measured.Proteins related to the reticulophagy pathway,mitochondria-endoplasmic reticulum(ER)contact sites,intrinsic mitochondrial apoptosis,and histone acetylation were quantified using western blotting.ER and lysosome colocalization,and mitochondrial Ca^(2+)levels were characterized via confocal microscopy.The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization.Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region.RESULTS After SAHA treatment,the proliferation of Huh7 and MHCC97L cells was significantly inhibited,and the migration and invasion abilities were greatly blocked in vitro.This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner.Following treatment with SAHA,ER-phagy was activated,thereby triggering autophagy-mediated cell death of HCC cells in vitro.Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B promoter region.Further,SAHA disturbed the Ca^(2+)homeostasis and upregulated the level of autocrine motility factor receptor and proteins related to mitochondria-endoplasmic reticulum contact sites in HCC cells.Additionally,SAHA decreased the mitochondrial membrane potential levels,thereby accelerating the activation of the reticulophagy-mediated mitochondrial apoptosis pathway and promoting HCC cell death in vitro.CONCLUSION SAHA stimulates FAM134B-mediated ER-phagy to synergistically enhance the mitochondrial apoptotic pathway,thereby enhancing HCC cell death.

Immunogenic cell death-related long noncoding RNA influences immunotherapy against lung adenocarcinoma

Lung adenocarcinoma(LUAD)is the leading cause of cancer-related deaths,accounting for over a million deaths worldwide annually.Immunogenic cell death(ICD)elicits an adaptive immune response.However,the role of ICD-related long noncoding RNAs(lncRNAs)in LUAD is unknown.In this study,we investigated the characteristics of the tumor microenvironment in LUAD,the prognostic significance of ICD-related lncRNAs,and the half-maximal inhibitory concentration(IC50)of possible chemotherapeutic drugs.We sorted prognostic lncRNAs using univariate Cox regression and constructed a risk signature based on them.We then confirmed the model’s accuracy and generated a nomogram.Additionally,we performed immune microenvironment analysis,somatic mutation calculation,Tumor Immune Dysfunction and Exclusion(TIDE)analysis,and anticancer pharmaceutical IC50 prediction.Least absolute shrinkage and selection operator Cox regression identified 27 prognostic lncRNAs related to ICD,and a unique risk signature using 10 ICD-related lncRNAs was constructed.The risk score was confirmed to be a reliable predictor of survival,with the highest c-index score.The signature had a remarkable predictive performance with clinical applicability and could accurately predict the overall survival in LUAD.Furthermore,the lncRNA signature was closely associated with immunocyte invasion.We also analyzed the correlation between the risk score,tumor-infiltrating immune cells,and prognosis and identified high immune and ESTIMATE scores in low-risk patients.Moreover,we observed elevated checkpoint gene expression and low TIDE scores in high-risk patients,indicating a good immunotherapy response.Finally,high-risk patients were shown to be susceptible to anticancer medications.Therefore,our unique risk signature comprising 10 ICD-related lncRNAs was demonstrated to indicate the characteristics of the tumor-immune microenvironment in LUAD,predict patients’overall survival,and guide individualized treatment.

An Immunogenic Cell Death-Related Classification Predicts Prognosis and Response to Immunotherapy in Glioblastoma

To investigate the immunogenic Cell Death gene’s potential mechanism and prognostic value in glioblastoma. Information on GBM samples from The Cancer Genome Atlas database was downloaded, ICD genes were obtained, genotyping, integrated bioinformatics to verify the prognostic value of genotyping, and finally, prognostic model construction. Two subtypes associated with the ICD gene were obtained by consensus clustering, and the high ICD subtype (risk) group was associated with poor prognosis, high mutations in the PTEN gene, high stromal score, and high immune score. We also constructed a new classification system for GBM based on ICD characteristics. This study is the first to use immunogenic cell death genes for genotyping and successfully build a prognostic model.

Adenosine triphosphate induced cell death: Mechanisms and implications in cancer biology and therapy

Adenosine triphosphate(ATP)induced cell death(AICD)is a critical cellular process that has garnered substantial scientific interest for its profound relevance to cancer biology and to therapeutic interventions.This comprehensive review unveils the intricate web of AICD mechanisms and their intricate connections with cancer biology.This review offers a comprehensive framework for comprehending the multifaceted role of AICD in the context of cancer.This is achieved by elucidating the dynamic interplay between systemic and cellular ATP homeostasis,deciphering the intricate mechanisms governing AICD,elucidating its intricate involvement in cancer signaling pathways,and scrutinizing validated key genes.Moreover,the exploration of AICD as a potential avenue for cancer treatment underscores its essential role in shaping the future landscape of cancer therapeutics.

Role of selenium in cell death

Selenium is an essential nutrient closely related to redox homeostasis in the body.A redox imbalance will adversely affect the microenvironment inside and outside the cell,leading to cell death.Various types of cell death have been discovered in recent years,but the role(s)of selenium and the associated mechanism(s)of action require further elaboration.We review the roles and mechanisms of action of selenium in cell necrosis,apoptosis,ferroptosis,autophagy,and pyroptosis.Under normal conditions,selenium inhibits cell necrosis,apoptosis,ferroptosis,autophagy,and pyroptosis by downregulating the nuclear factorκB pathway,upregulating antiapoptotic proteins,decreasing oxidative stress,increasing antioxidant enzyme activity,enhancing the mTOR pathway,and downregulating the NLRP3/caspase-1 pathway,thereby helping to maintain the normal physiological functions of cells.On the other hand,selenium deficiency leads to activation of the PI3K/AKT and Notch/Hes1 pathways,causing a significant increase in the level of oxidative stress in the organism,resulting in cell necrosis,apoptosis,and pyroptosis.In the case of malignancy,the in vivo metabolite of inorganic selenium,hydrogen selenide,plays an antitumor role by inducing apoptosis and ferroptosis in tumor cells because of its high redox activity.In conclusion,an adequate level of selenium in the body is essential for maintaining normal cellular physiological functions and reducing fibrotic alterations.Furthermore,the in vivo metabolites of inorganic selenium may have some clinical value in antitumor therapy.

Recent advances in plant immunity with cell death:A review

Cell death is an important physiological phenomenon in life.It can be programmed or unprogrammed.Unprogrammed cell death is usually induced by abiotic or biotic stress.Recent studies have shown that many proteins regulate both cell death and immunity in plants.Here,we provide a review on the advances in plant immunity with cell death,especially the molecular regulation and underlying mechanisms of those proteins involved in both cell death and plant immunity.In addition,we discuss potential approaches toward improving plant immunity without compromising plant growth.

Research progress regarding programmed cell death 1/programmed cell death ligand 1 inhibitors combined with targeted therapy for treating hepatocellular carcinoma

In recent years,a number of targeted therapeutic agents have achieved success in phase III trials in patients with advanced hepatocellular carcinoma(HCC),including sorafenib,lenvatinib,and regorafenib.Immunotherapy is considered to be an effective treatment for advanced HCC.Immune checkpoint inhibitors targeting programmed cell death 1(PD-1)/programmed cell death ligand 1(PDL1)are important antitumor immunotherapy agents that represent breakthroughs in the treatment of advanced HCC.However,treating advanced HCC is still a great challenge,and the need for new treatments remains urgent.This review briefly summarizes the research progress in the use of PD-1/PD-L1 inhibitors combined with targeted therapy for treating HCC.

Crosstalk of liver immune cells and cell death mechanisms in different murine models of liver injury and its clinical relevance

BACKGROUND： Liver inflammation or hepatitis is a result of pluripotent interactions of cell death molecules, cytokines, chemokines and the resident immune cells collectively called as microenvironment. The interplay of these inflammatory mediators and switching of immune responses during hepatotoxic, viral, drug-induced and immune cell-mediated hepatitis decide the fate of liver pathology. The present review aimed to describe the mechanisms of liver injury, its relevance to human liver pathology and insights for the future therapeutic interventions.DATA SOURCES： The data of mouse hepatic models and rele- vant human liver diseases presented in this review are system- atically collected from PubMed, ScienceDirect and the Web of Science databases published in English. RESULTS： The hepatotoxic liver injury in mice induced by the metabolites of CC14, acetaminophen or alcohol represent ne- crotic cell death with activation of cytochrome pathway, for- mation of reactive oxygen species （ROS） and mitochondrial damage. The Fas or TNF-a induced apoptotic liver injury was dependent on activation of caspases, release of cytochrome c and apoptosome formation. The ConA-hepatitis demonstrat- ed the involvement of TRAIL-dependent necrotic/necroptotic cell death with activation of RIPK1/3. The a-GalCer-induced liver injury was mediated by TNF-a. The LPS-induced hepatitis involved TNF-a, Fas/FasL, and perforin/granzyme cell death pathways. The MHV3 or Poly（I：C） induced liver injury was mediated by natural killer cells and TNF-a signaling. The necrotic ischemia-reperfusion liver injury was mediated by hypoxia, ROS, and pro-inflammatory cytokines; however, necroptotic cell death was found in partial hepatectomy. The crucial role of immune ceils and cell death mediators in viral hepatitis （HBV, HCV）, drug-induced liver injury, non-alcohol- ic fatty liver disease and alcoholic liver disease in human were discussed. CONCLUSIONS： The mouse animal models of hepatitis provide a parallel approach for the study of human liver pathology. Blocking or stimulating the pathways associated with liver cell death could unveil the novel therapeutic strategies in the management of liver diseases.

Programmed cell death, antioxidant response and oxidative stress in wheat f lag leaves induced by chemical hybridization agent SQ-1

Male sterility induced by a chemical hybridization agent （CHA） is an important tool for utilizing crop heterosis. Leaves, especially the flag leaves, as CHA initial recipients play a decisive role in inducing male sterility. To investigate effects of different treatment times of CHA-SQ-1 used, morphological, biochemical and physiological responses of wheat flag leaves were detected in thistudy. CHA induced programmed cell death （PCD） as shown in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling （TUNEL） and DNA laddering analysis. In the early phase, CHA-SQ-1 trig- gered organelle changes arid PCD in wheat leaves accompanied by excess production of reactive oxygen species （O2- and H202） and down-regulation of the activities of superoxide dismutase （SOD）, catalase （CAT） and guaiacol peroxidase （POD）. Meanwhile, leaf cell DNAs showed ladder-like patterns on agarose gel, indicating that CHA-SQ-1 led to the activation of the responsible endonuclease. The oxidative stress assays showed that lipid peroxidation was strongly activated and photosynthesis was obviously inhibited in SQ-l-induced leaves. However, CHA contents in wheat leaves gradually reduced along with the time CHA-SQ-1 applied. Young flags returned to an oxidative/antioxidative balance and ultimately developed into mature green leaves. These results provide explanation of the relations between PCD and anther abortion and practical application of CHA for hybrid breeding.

Discovery of a small molecule targeting ULK1-modulated cell death of triple negative breast cancer in vitro and in vivo

OBJECTIVE To discover a small molecule targeting ULK1-modulated cell death of triple negative breast cancer and exploreits potential mechanisms.METHODS ULK1 expression was analyzed by The Cancer Genome Atlas(TCGA)analysis and tissue microarray(TMA)analysis.ULK1agonist was designed by using in silico screening,as well as modified by chemical synthesis and screened by kinase and anti-proliferative activities.The amino acid residues that key to the activation site of LYN-1604 were determined by site-directed mutagenesis,as well as in vitro kinase assay and ADP-Glo kinase assay.The mechanisms of LYN-1604 induced cell death were investigated by fluorescence microscope,western blotting,flow cytometry analysis,immunocytochemistry,as well as si RNA and GFP-m RFP-LC3 plasmid transfections.Potential ULK1 interactors were discovered by performing comparative microarray analysis and the therapeutic effect of LYN-1604 was assessed by xenograft breast cancer mouse model.RESULTS We found that ULK1 was remarkably downregulated in breast cancer tissue samples,especial y in triple negative breast cancer(TNBC).32 candidate smal molecules were synthesized,and we discovered a small molecule named LYN-1604 as the best candidate ULK1agonist.Additionally,we identified that three amino acid residues(LYS50,LEU53 and TYR89)were key to the activation site of LYN-1604 and ULK1.Subsequently,we demonstrated that LYN-1604 could induce autophagy-associated cell death via ULK complex(ULK1-m ATG13-FIP200-ATG101)in MDA-MB-231 cells.We also found that LYN-1604 induced cell death involved in ATF3,RAD21 and caspase 3,accompanied with autophagy and apoptosis.Moreover,we demonstrated that LYN-1604 had a good therapeutic potential on TNBC by targeting ULK1-modulated cell death in vivo.CONCLUSION We discovered a small molecule(LYN-1604)has therapeutic potential by targeting ULK1-modulated cell death associated with autophagy and apoptosis of TNBC in vitro and in vivo,which could be utilized as a new anti-TNBC drug candidate.

The clinical association of programmed cell death protein 4(PDCD4) with solid tumors and its prognostic significance:a meta-analysis

Background: Programmed cell death protein 4(PDCD4) is a novel tumor suppressor protein involved in pro?grammed cell death. Its association with cancer progression has been observed in multiple tumor models, but evidence supporting its association with solid tumors in humans remains controversial. This study aimed to determine the clinical signiicance and prognostic value of PDCD4 in solid tumors.Methods: A systematic literature review was performed to retrieve publications with available clinical informa?tion and survival data. The eligibility of the selected articles was based on the criteria of the Dutch Cochrane Centre proposed by the Meta?analysis Of Observational Studies in Epidemiology group. Pooled odds ratios(ORs), hazard ratios(HRs), and 95% conidence intervals(CIs) for survival analysis were calculated. Publication bias was examined by Begg's and Egger's tests.Results: Clinical data of 2227 cancer patients with solid tumors from 23 studies were evaluated. PDCD4 expression was signiicantly associated with the diferentiation status of head and neck cancer(OR 4.25, 95% CI 1.87–9.66) and digestive system cancer(OR 2.87, 95% CI 1.84–4.48). Down?regulation of PDCD4 was signiicantly associated with short overall survival of patients with head and neck(HR: 3.44, 95% CI 2.38–4.98), breast(HR: 1.86, 95% CI 1.36–2.54), digestive system(HR: 2.12, 95% CI 1.75–2.56), and urinary system cancers(HR: 3.16, 95% CI 1.06–9.41).Conclusions: The current evidence suggests that PDCD4 down?regulation is involved in the progression of several types of solid tumor and is a potential marker for solid tumor prognoses. Its clinical usefulness should be conirmed by large?scale prospective studies.

Autophagy prevents autophagic cell death in Tetrahymena in response to oxidative stress

Autophagy is a major cellular pathway used to degrade long-lived proteins or organelles that may be damaged due to increased reactive oxygen species（ROS） generated by cellular stress. Autophagy typically enhances cell survival, but it may also act to promote cell death under certain conditions. The mechanism underlying this paradox, however, remains unclear. We showed that Tetrahymena cells exerted increased membranebound vacuoles characteristic of autophagy followed by autophagic cell death（referred to as cell death with autophagy） after exposure to hydrogen peroxide. Inhibition of autophagy by chloroquine or 3-methyladenine significantly augmented autophagic cell death induced by hydrogen peroxide. Blockage of the mitochondrial electron transport chain or starvation triggered activation of autophagy followed by cell death by inducing the production of ROS due to the loss of mitochondrial membrane potential. This indicated a regulatory role of mitochondrial ROS in programming autophagy and autophagic cell death in Tetrahymena. Importantly, suppression of autophagy enhanced autophagic cell death in Tetrahymena in response to elevated ROS production from starvation, and this was reversed by antioxidants. Therefore, our results suggest that autophagy was activated upon oxidative stress to prevent the initiation of autophagic cell death in Tetrahymena until the accumulation of ROS passed the point of no return, leading to delayed cell death in Tetrahymena.

Comparison of labeling methods and time course of traumatic brain injury-induced cell death in mice

BACKGROUND：Various molecular mechanisms of cell death following traumatic brain injury have been previously described.However,the time course of cell death remains unclear.TUNEL and Fluoro-Jade B labeling have been widely used to label apoptotic cells and neuronal degeneration.Propidium iodide （PI） functions as a biomarker of cell death in vivo.OBJECTIVE：To explore the role of PI labeling compared to TUNEL and Fluoro-Jade B staining for detecting neural cell death,and to observe time course of traumatic brain injury-induced cell death in mice.DESIGN,TIME AND SETTING：A randomized,controlled,animal experiment was performed at the Laboratory of Aging and Nervous Diseases,Soochow University from September 2007 to December 2008.MATERIALS：PI （B1221） was purchased from Sigma,USA.TUNEL kit was purchased from Roche Molecular Biochemicals,USA.Fluoro-Jade B was purchased from Chemicon,USA.METHODS：A total of 70 healthy,male,Kunming mice were randomly assigned to sham-surgery （n = 5） and model （n = 65） groups.Traumatic brain injury was established using the controlled cortical impact method.PI was intraperitoneally injected at 1 hour prior to animal sacrifice.MAIN OUTCOME MEASURES：TUNEL,Fluoro-Jade B,and Pl-positive cells were quantified using a double-labeling method to determine the time course of traumatic brain injury-induced cell death.RESULTS：PI labeled cells in an earlier phase of cell death than TUNEL and Fluoro-Jade B labeling.Pl-positive cells were observed immediately following injury,and the numbers rapidly increased in injured brain areas at 1 hour,peaked at 24-48 hours,and subsequently decreased at 3-21 days post-injury.TUNEL-labeled cells were significantly increased at 12 hours,while Fluoro-Jade B-labeled cells were increased at 6 hours after injury,with cells still visible at 6-48 hours post-injury.Moreover,a greater number of Pl-positive cells were observed compared to TUNEL- and Fluoro-Jade B-labeled cells.CONCLUSION：PI labeling is more sensitive and reliable than TUNEL and Fluoro-Jade B staining for detecting cell death following traumatic brain injury.Moreover,PI labeling can function as a reliable marker to estimate the entire time course of cell death.

Function of flavonoids on different types of programmed cell death and its mechanism:a review

Cell death in the living system plays a vital role in maintaining the homeostasis and balancing the cell count in the body.Programmed cell death(PCD)is a crucial component of several development and defense mechanisms.PCD is also important in terms of aging which avoids the accumulation of cellular damage by maintaining cell division.Depending on the execution of cell death and its role in destruction,PCD is categorized into several subtypes.The major different forms of PCD in animals are apoptosis,autophagy and necrosis,which can be distinct in morphological terms.More intense investigations of cell death have given close insight showing other important types of cellular destruction and their pivotal roles in treating disease conditions like cancer.Flavonoids have been acquired a great interest for disease therapies and chemoprevention through activation of several PCD mechanisms.The significant potential of natural flavonoids in the induction of distinct signaling cascades is being a massive approach for targeting uncontrolled cell growth.For these reasons,understanding PCD mechanisms is a promising approach for the interventions in treating cancer.Thus,it is intriguing that understanding the different forms of PCD mechanism induced by flavonoids with more accurate descriptions on the biochemical and cellular processes are gaining more significance in cancer research.Here,we provide a brief overview on the different types of PCD and aim to discuss the functional role of flavonoids in promoting different types of cell death as well as an extensive brief review on their mechanism of action has been highlighted.

Discovery of a small-molecule bromodomain-containing protein 4 inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer

OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mechanisms.METHODS BRD4 interactors were analyzed by PPI network prediction and The Cancer Genome Atlas(TCGA)analysis.The interaction between BRD4 and AMPK was confirmed by co-immunoprecipitation assay.Novel BRD4 inhibitors were designed and synthesized based upon pharmacophore analysis of BRD4(1),then screened by antiproliferative activity and Alpha Screen of BRD4(1).The selectivity of the best candidate compound 8f was validated by co-crystallization,FRET assay and co-immuno precipitation assay.The mechanisms of 8f were investigated by fluorescence microscopy,electron microscopy,Western blotting,immunocytochemistry,si RNA and GFP-m RFP-LC3 plasmid transfections,as well as immunohistochemistry and immunofluorescence.Potential mechanisms were discovered by i TRAQ-based proteomics analysis and the therapeutic effect of 8f was assessed by xenograft breast cancer mouse and zebrafish models.RESULTS We identified that BRD4 interacted with AMPK,which was remarkably downregulated in breast cancer.We next designed and synthesized 49 candidate compounds,and eventually discovered a selective small-molecule inhibitor of BRD4(8f).Subsequently,8f was discovered to induce autophagyassociated cell death(ACD)by BRD4-AMPK interaction,and thus activating AMPK-m TOR-ULK1-modulated autophagic pathway in breast cancer cells.Interestingly,the i TRAQ-based proteomics analyses revealed that 8f induced ACD pathways,involved in HMGB1,VDAC1/2 and e EF2.Moreover,8f displayed a therapeutic potential on both xenograft breast cancer mouse and zebrafish models.CONCLUSION We discovered a novel small-molecule inhibitor of BRD4 that induces BRD4-AMPK-modulated ACD in breast cancer,which may provide a candidate drug for future cancer therapy.