Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Gastric cancer is one of the most common malignant tumors in the digestive system, characterized by high incidence and mortality rates. In recent years, with the rapid develop-ment of molecular immunology, the application of immune checkpoint inhibitors (ICIs) in neoadju-vant therapy has significantly improved pathological response rates and survival outcomes for patients with resectable locally advanced gastric cancer. The authors systematically review current research progress on combination strategies involving immune checkpoint inhibitors in neoadjuvant therapy for locally advanced gastric cancer, aiming to provide an evidence for optimizing individua-lized therapeutic regimens.

Objective:To investigate the differences in clinical outcomes of septic children with varying serum zinc levels,and to analyze the relationship between reduced serum zinc levels and organ dysfunction as well as 28-day mortality in septic children.Methods:This study conducted a retrospective analysis of clinical data from pediatric patients diagnosed with sepsis or septic shock in the Department of critical care medicine of the children's Hospital of Soochow University between January 2017 and December 2022.Clinical characteristics,organ dysfunction,and prognosis were compared between two groups:children with low serum zinc levels and those with normal zinc levels.Results:The serum zinc level of septic children within 24 hours of admission was 9.60(5.52,13.80)μmol/L,with 50.54%(94/186)of the children exhibiting low serum zinc levels(<10.07 μmol/L).Compared to the normal serum zinc group,the low serum zinc group had a significantly lower Pediatric Critical Illness Score(PCIS)[(78.71±9.35)vs.(85.12±8.51),P=0.005]and higher 28-day mortality(46.80%vs.14.13%,P<0.001).The low serum zinc group also had a higher proportion of invasive mechanical ventilation(64.89%vs.47.82%,P=0.019),renal replacement therapy(15.59%vs.3.26%,P=0.003),and use of vasoactive drugs(56.38%vs.30.43%,P<0.001).The rate of underlying conditions in the low serum zinc group was significantly higher than that in the normal serum zinc group(57.44%vs.36.95%,P=0.005).Additionally,the low serum zinc group had a higher incidence of disseminated intravascular coagulation(DIC),respiratory failure,acute kidney injury,shock,and multiple organ dysfunction syndrome(MODS)compared to the normal serum zinc group(P<0.05).Serum zinc levels had predictive value for 28-day mortality in septic children(AUC=0.813;95%CI:0.725～0.902;P<0.001).A serum zinc level of less than 6.950 μmol/L predicted the death of septic children with a sensitivity of 0.618 and a specificity of 0.902.Conclusion:Sepsis in children is commonly associated with low serum zinc levels,especially in those with underlying conditions such as hematologic and oncologic disorders.Sepsis patients hypozincemia with a higher incidence of DIC,respiratory failure,acute kidney injury,shock,and MODS.A serum zinc level below 6.95 μmol/L serves as a significant predictor of 28-day mortality in children with severe sepsis.

Objective To explore the effect of PSMA gene on the biological behavior of prostate cancer cells and its molecular mechanism.Methods The expression of PSMA in prostate cancer and its relationship with prognosis were analyzed based on the GEPIA database.The mRNA and protein expression levels of PSMA in normal prostate epithelial cell RWPE-2 and prostate cancer cells DU145 and PC-3 were detected by RT-qPCR and Western blot,respectively.DU145 cells were used to construct knockdown cell lines,which were transfected with PSMA lentiviral knockdown plasmid and its negative control,serving as the sh PSMA group and the sh NC group,respectively;PC-3 cells were used to construct overexpression cell lines,which were transfected with PSMA lentiviral overexpression plasmid and its negative control,serving as the OE PSMA group and the OE NC group.CCK-8 assay and clone formation assay were used to detect the cell proliferation ability,wound healing assay and Transwell assay were used to detect the cell migration and invasion abilities,flow cytometry was used to detect the cell apoptosis,and Western blot was used to detect the expression of PI3K,Akt,BAX and Bcl-2 proteins.Prostate cancer cells of DU145 cell line were inoculated into the left armpit of BALB/c nude mice to form tumors,the tumor size was observed,and the tumor weight was measured;HE staining was used to evaluate the degree of damage;and the expression of PSMA was detected by immunohistochemistry.Results GEPIA database analysis showed that PSMA gene was highly expressed in prostate cancer and was related to the prognosis of prostate cancer.The results of RT-qPCR and Western blot showed that the mRNA and protein expression levels of PSMA in PC-3 and DU145 cells were higher than those in RWPE-2 cell(P<0.01).Compared with the sh NC group,the sh PSMA group showed decreased cell proliferation,migration and invasion abilities(P<0.05),and increased cell apoptosis rate(P<0.05).Compared with the OE NC group,the OE PSMA group demonstrated increased cell proliferation,migration and invasion abilities(P<0.05),and decreased apoptosis rate(P<0.05).Compared with the sh NC group,the protein expression of PI3K,Akt and Bcl-2 in the sh PSMA group decreased(P<0.05),and the protein expression of BAX increased(P<0.05).Compared with the OE NC group,the protein expression of PI3K,Akt and Bcl-2 in the OE PSMA group increased(P<0.05),and the protein expression of BAX decreased(P<0.05).Results of subcutaneous transplantation of prostate cancer in nude mice showed that the tumor weight of nude mice decreased(P<0.05),tumor cells exhibited irregular shapes,nuclei were deeply stained,and PSMA expression was weakly positive,after knocking down the PSMA.Conclusion PSMA gene may participate in regulating the proliferation,invasion,migration,and apoptosis of prostate cancer cells through the PI3K/Akt signaling pathway.

Objective:To investigate the efficacy and safety of sintilimab combined with the SOX regimen for adjuvant treatment of stage Ⅲgastric cancer after D2 radical resection and to provide a reference for individualized clinical treatment.Methods:The clinical data of 245 pa-tients with stage III gastric cancer who underwent D2 radical resection at the 940th Hospital of the Joint Support Force of the People's Liber-ation Army from June 2019 to May 2022 were retrospectively analyzed.The 180 patients who received only the SOX regimen were desig-nated the control group,and the 65 patients who received sintilimab combined with the SOX regimen were designated the experimental group.The 3-year disease-free survival(DFS)rate,overall survival(OS)rate,and adverse reactions among the two groups and different sub-groups(HER-2 positive,dMMR,CPS≥5)were compared.Results:The 3-year DFS(81.5%vs.59.4%)and OS(84.6%vs.70.6%)rates in the experimental group were significantly higher than those in the control group(both P<0.05).Group analysis showed that in patients with CPS≥5,the 3-year DFS(91.5%vs.67.0%)and OS(95.7%vs.71.6%)rates within the experimental group were significantly better than those in the control group(both P<0.05).Intra-group analysis within the experimental group showed that the 3-year DFS rate(91.5%vs.55.6%)and OS rate(95.7%vs.55.6%)of patients with CPS≥5 were significantly better than those of patients with CPS<5(both P<0.05).The overall and grade≥3 incidences of liver and kidney function damage,thyroid dysfunction,colitis,pneumonia,and rash in the experimental group were higher than those in the control group(all P<0.05),while the differences in other adverse reactions,including leukopenia were not statistic-ally significant(all P>0.05).Conclusions:Sintilimab combined with the SOX regimen can significantly improve 3-year DFS and OS rates in pa-tients with stage Ⅲ gastric cancer after surgery,especially in the CPS≥5 subgroup,with significant benefits and controllable safety.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.

Objective To investigate the changing antibiotic resistance profiles of E.coli isolated from patients in the 52 hospitals participating in the CHINET program from 2015 to 2021.Methods Antimicrobial susceptibility was tested for clinical isolates of E.coli according to the unified protocol of CHINET program.WHONET 5.6 and SPSS 20.0 software were used for data analysis.Results Atotal of 289 760 nonduplicate clinical strains ofE.coli were isolated from 2015 to 2021,mainly from urine samples(44.7±3.2)％.The proportion of E.coli strains isolated from urine samples was higher in females than in males(59.0％vs 29.5％).The proportion of E.coli strains isolated from respiratory tract and cerebrospinal fluid samples was significantly higher in children than in adults(16.7％vs 7.8％,0.8％vs 0.1％,both P＜0.05).The isolates from internal medicine department accounted for the largest proportion(28.9±2.8)％with an increasing trend over years.Overall,the prevalence of ESBLs-producing E.coli and carbapenem resistant E.coli(CREco)was 55.9％and 1.8％,respectively during the 7-year period.The prevalence of ESBLs-producing E.coli was the highest in tertiary hospitals each year from 2015 to 2021 compared to secondary hospitals.The prevalence of CREco was higher in children's hospitals compared to secondary and tertiary hospitals each year from 2015 to 2021.The prevalence of ESBLs-producing E.coli in tertiary hospitals and children's hospitals and the prevalence of CREco in children's hospitals showed a decreasing trend over the 7-year period.The prevalence of CREco in secondary and tertiary hospitals increased slowly.Antibiotic resistance rates changed slowly from 2015 to 2021.Carbapenem drugs(imipenem,meropenem)were the most active drugs amongβ-lactams against E.coli(resistance rate≤2.1％).The resistance rates of E.coli to β-lactam/β-lactam inhibitor combinations(piperacillin-tazobactam,cefoperazone-sulbactam),aminoglycosides(amikacin),nitrofurantoin and fosfomycin(for urinary isolates only)were all less than 10％.The resistance rate of E.coli strains to antibiotics varied with the level of hospitals and the departments where the strains were isolated,especially for cefazolin and ciprofloxacin,to which the resistance rate of E.coli strains from children in non-ICU departments was significantly lower than that of the strains isolated from other departments(P＜0.05).The E.coli isolates from ICU showed higher resistance rate to most antimicrobial agents tested(excluding tigecycline)than the strains isolated from other departments.The E.coli strains isolated from tertiary hospitals showed higher resistance rates to the antimicrobial agents tested(excluding tigecycline,polymyxin B,cefepime and carbapenems)than the strains from secondary hospitals and children's hospitals.Conclusions E.coli is an important pathogen causing clinical infection.More than half of the clinical isolates produced ESBL.The prevalence of CREco is increasing in secondary and tertiary hospitals over the 7-year period even though the overall prevalence is still low.This is an issue of concern.

Objective To describe the clinical features of patients with primary sclerosing cholangitis(PSC)in China based on a nationwide multicenter patient cohort,and to investigate the risk factors for prognosis.Methods A retrospective cohort study was conducted among the patients with a confirmed diagnosis of PSC based on the electronic medical record system of seven grade A tertiary hospitals across the country,and related data were extracted.The Mann-Whitney U test was used for comparison of continuous data between groups,and the chi-square test was used for comparison of categorical data between groups.The Kaplan-Meier method was used to estimate liver transplant-free survival,and the log-rank test was used for comparison of survival rate between PSC patients with different features.The Cox regression model was used to identify independent risk factors for the prognosis of PSC patients and the interactions between key factors.Results A total of 107 patients were enrolled,among whom 55.6%(55/99)had large-duct PSC and 29.0%(31/107)had comorbidity with inflammatory bowel disease(IBD).The positivity rate of anti-neutrophil cytoplasmic antibody(ANCA)was 32.9%(24/73),and 50.0%(40/80)of the patients had an increase in IgG/IgM.The median symptom-to-diagnosis interval was 1 year(<1-4.0),and 38.3%(41/107)of the patients had progressed to decompensated cirrhosis at the time of diagnosis.The median liver transplant-free survival time was 114 months(95%confidence interval[CI]:62-166),with a 5-year survival rate of 65.7%.The multivariate analysis showed that an increase in total bile acid(TBA)(hazard ratio[HR]=1.006,95%CI:1.002-1.010,P=0.001)and a prolonged symptom-to-diagnosis interval(HR=1.252,95%CI:1.059-1.480,P=0.009)were independent risk factors for prognosis.The interaction analysis showed that compared with the female patients with TBA<50 μmol/L,both male and female patients with TBA≥50 μmol/L had a significant increase in the risk of liver transplantation or death(male:HR=16.563,95%CI:2.103-130.449,P<0.001;female:HR=17.009,95%CI:2.113-136.934,P<0.001),and compared with the patients with an age of<45 years and a TBA level of<50 μmol/L,the patients with an age of≥45 years and a TBA level of≥50 μmol/L had a significant increase in the risk of liver transplantation or death(HR=10.729,95%CI:1.325-86.859,P=0.026).Compared with the female patients with an symptom-to-diagnosis interval of≤2 years,the male patients with a symptom-to-diagnosis interval of>2 years had an increased risk of liver transplantation or death(HR=4.825,95%CI:1.725-13.644,P=0.003),and compared with the patients with an age of<45 years and a symptom-to-diagnosis interval of≤2 years,the patients with an age of<45 years and a symptom-to-diagnosis interval of>2 years had an increased risk of liver transplantation or death(HR=4.983,95%CI:1.366-18.173,P=0.015).Conclusion Compared with the reports from Western countries,large-duct PSC is also the main type of PSC in China,but with a relatively low proportion,and there is also a relatively low proportion of patients with IBD or positive ANCA.An increase in TBA and a prolonged symptom-to-diagnosis interval are independent risk factors for prognosis,with significant interactions with age and sex.This suggests that early screening and intervention should be enhanced to improve prognosis.