Tumor drug resistance is an important problem in the failure of chemotherapy and targeted drug therapy, which is a complex process involving chromatin remodeling. SWI/SNF is one of the most studied ATP-dependent chromatin remodeling complexes in tumorigenesis, which plays an important role in the coordination of chromatin structural stability, gene expression, and post-translation modification. However, its mechanism in tumor drug resistance has not been systematically combed. SWI/SNF can be divided into 3 types according to its subunit composition: BAF, PBAF, and ncBAF. These 3 subtypes all contain two mutually exclusive ATPase catalytic subunits (SMARCA2 or SMARCA4), core subunits (SMARCC1 and SMARCD1), and regulatory subunits (ARID1A, PBRM1, and ACTB, etc.), which can control gene expression by regulating chromatin structure. The change of SWI/SNF complex subunits is one of the important factors of tumor drug resistance and progress. SMARCA4 and ARID1A are the most widely studied subunits in tumor drug resistance. Low expression of SMARCA4 can lead to the deletion of the transcription inhibitor of the BCL2L1 gene in mantle cell lymphoma, which will result in transcription up-regulation and significant resistance to the combination therapy of ibrutinib and venetoclax. Low expression of SMARCA4 and high expression of SMARCA2 can activate the FGFR1-pERK1/2 signaling pathway in ovarian high-grade serous carcinoma cells, which induces the overexpression of anti-apoptosis gene BCL2 and results in carboplatin resistance. SMARCA4 deletion can up-regulate epithelial-mesenchymal transition (EMT) by activating YAP1 gene expression in triple-negative breast cancer. It can also reduce the expression of Ca²⁺ channel IP3R3 in ovarian and lung cancer, resulting in the transfer of Ca²⁺ needed to induce apoptosis from endoplasmic reticulum to mitochondria damage. Thus, these two tumors are resistant to cisplatin. It has been found that verteporfin can overcome the drug resistance induced by SMARCA4 deletion. However, this inhibitor has not been applied in clinical practice. Therefore, it is a promising research direction to develop SWI/SNF ATPase targeted drugs with high oral bioavailability to treat patients with tumor resistance induced by low expression or deletion of SMARCA4. ARID1A deletion can activate the expression of ANXA1 protein in HER2+ breast cancer cells or down-regulate the expression of progesterone receptor B protein in endometrial cancer cells. The drug resistance of these two tumor cells to trastuzumab or progesterone is induced by activating AKT pathway. ARID1A deletion in ovarian cancer can increase the expression of MRP2 protein and make it resistant to carboplatin and paclitaxel. ARID1A deletion also can up-regulate the phosphorylation levels of EGFR, ErbB2, and RAF1 oncogene proteins.The ErbB and VEGF pathway are activated and EMT is increased. As a result, lung adenocarcinoma is resistant to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Although great progress has been made in the research on the mechanism of SWI/SNF complex inducing tumor drug resistance, most of the research is still at the protein level. It is necessary to comprehensively and deeply explore the detailed mechanism of drug resistance from gene, transcription, protein, and metabolite levels by using multi-omics techniques, which can provide sufficient theoretical basis for the diagnosis and treatment of poor tumor prognosis caused by mutation or abnormal expression of SWI/SNF subunits in clinical practice.

ObjectiveTo explore the regulatory effects and mechanisms of Astragali Radix polysaccharide （APS） on inhibitor of differentiation1 （ID1） and protein kinase B （Akt） in gastric cancer. MethodsImmunohistochemical staining was used to detect the expression of ID1 and Akt in 61 gastric cancer tissue samples and 20 adjacent normal gastric tissue samples. Immunofluorescence was used to detect the localization of ID1 and Akt. The effects of APS at the concentrations of 0.625， 1.25， 2.5， 5， 10， 20 mg·L^-1 on the proliferation of gastric cancer MGC-803 cells were examined by the cell counting kit-8（CCK-8） method and the colony formation assay. The target information of APS was retrieved from the Traditional Chinese Medicine Systems Pharmacology and Analysis Platform and Swiss Target Prediction. Keywords such as gastric cancer， gastric tumor， and stomach cancer were searched against GeneCards， UniProt， DisGeNET， and Online Mendelian Inheritance in Man （OMIM） for the screening of gastric cancer-related targets. The online tool jvenn was used to create the Venn diagram to identify the common targets， and STRING and Cytoscape were used to construct the protein-protein interaction network. Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analyses were conducted via R 4.2.2 to predict the potential roles of APS in the development of gastric cancer. The cell scratch assay was employed to assess the effect of APS on the migration of MGC-803 cells. The protein and mRNA levels of ID1 and Akt in the cells treated with APS were determined by Western blot and Real-time PCR， respectively. ResultsCompared with the adjacent normal gastric tissue， the gastric adenocarcinoma tissue showed increased positive expression of ID1 （χ² =81.00， P<0.01）. Immunofluorescence detection showed that ID1 and Akt were mainly located in the cytoplasm of gastric adenocarcinoma cells. Bioinformatics analysis identified 14 common genes shared between APS and gastric cancer. The average degree of protein-protein interaction network nodes was 14.29. GO and KEGG pathway enrichment results showed that ID1 and Akt were significantly enriched in the Rap1 and phosphatidylinositol-3-kinase （PI3K） /Akt signaling pathways. Cell experiments demonstrated that 5-fluorouracil （0.1 mg·L^-1） and APS （10， 20 mg·L^-1） groups showed decreased cell proliferation， migration， and colony formation. Compared with the control group， 10， 20 mg·L^-1 APS inhibited the proliferation of MGC-803 cells （P<0.01）， with 10 mg·L^-1 APS demonstrating stronger inhibitory effect. In addition， APS at 10， 20 mg·L^-1 inhibited the migration （P<0.01） and colony formation （P<0.05， P<0.01） of MGC-803 cells. Compared with the control group， APS at 10， 20 mg·L^-1 down-regulated the protein levels of ID1 （P<0.01） and Akt （P<0.05） and the mRNA levels of ID1 （P<0.05， P<0.01） and Akt （P<0.05， P<0.01） in MGC-803 cells. ConclusionID1 and Akt are highly expressed in the gastric adenocarcinoma tissue， which may be related to the development of gastric cancer. APS can down-regulate the protein and mRNA levels of ID1 and Akt to exert anti-tumor effects， which is expected to provide new therapeutic targets for gastric cancer treatment.

Objective:To investigate the effects of multidisciplinary small-class teaching on expertise and skill acquisition and learning experience in standardized residency training in general surgery.Methods:Sixty residents of grade 2021 rotating in general surgery from January to August 2023 were divided into multidisciplinary teaching group ( n=30) and traditional teaching group ( n=30, to receive tradition one-on-one teaching). All the residents underwent a theoretical examination and Mini-Clinical Evaluation Exercise (Mini-CEX) skill assessment before admission, and the scores were compared between the two groups. At the end of training, the two groups were compared in terms of theoretical and Mini-CEX skill assessment scores and the degree of satisfaction with teaching. Statistical analysis was conducted using SPSS 26.0. Results:There were no significant differences in the theoretical assessment and Mini-CEX skill assessment scores before admission between the two groups ( P>0.05). At the end of training, the multidisciplinary teaching group had a significantly higher theoretical examination score [(88.15±3.45) vs. (72.25±4.36), P<0.05] and a significantly higher Mini-CEX score [(86.35±2.24) vs. (76.28±3.92), P<0.05] compared with the traditional teaching group. According to the survey, the residents in the multidisciplinary teaching group were more satisfied with teaching and more likely to recognize the teaching effects. Conclusions:Multidisciplinary small-class teaching can help improve the quality of standardized general surgery residency training on gastrointestinal tumor treatment, which is a highly accepted and effective attempt at standardized residency training.

Aim To explore whether platelet-derived growth factor C(PDGFC)derived from cancer-associat-ed fibroblasts(CAFs)can promote resistance of breast cancer cells to doxorubicin(DOX)and the underlying mechanisms.Methods CAFs and normal fibroblasts(NFs)were extracted from freshly resected breast cancer tissue and adjacent normal breast tissue respec-tively.Conditioned medium(CM)from CAFs and NFs was collected and co-cultured with breast cancer cells.Cell proliferation and toxicity were assessed using a Cell Counting Kit-8(CCK-8).The expression of PDG-FC in CAFs,NFs and corresponding CM was detected by Western blot and ELISA respectively.The influence of CAFs-CM on intracellular doxorubicin content in breast cancer cells was observed by fluorescence mi-croscopy.The impact of CAFs-CM on apoptosis-related proteins BAX and BCL2 was predicted and valifated u-sing the Starbase database and Western blot.The changes in ROS levels,mitochondrial membrane po-tential,and mitochondrial membrane proteins TOM20 and COX Ⅳ in breast cancer cells were measured using DCFH-DA fluorescence staining,JC-1 assay,and Western blot.Results CAFs-CM decreased the intra-cellular doxorubicin content and inhibited the sensitivi-ty of breast cancer cells to doxorubicin.Additionally,the expression of apoptosis protein BAX decreased while the anti-apoptotic protein BCL2 increased in breast cancer cells cultured with CAFs-CM.Further-more,CAFs-CM led to decreased ROS levels and in-creased mitochondrial membrane potential in breast cancer cells accompanied with elevated expression of mitochondrial membrane proteins TOM20 and COX Ⅳ.Further study found that PDGEF was highly expressed in CAFs and CAFs-CM,recombinant human PDGFC produced resistance of breast cancer cells to DOX simi-lar to CAFs-CM,and the specific inhibitors of PDGFRα significantly inhibited CAFs-CM.Further mechanistic studies revealed that PDGFC in CAFs-CM induced chemoresistance by activating PI3K-mTOR signaling pathway.Conclusion PDGFC secreted by CAFs promotes doxorubicin resistance in breast cancer cells through PI3K-mTOR signaling pathway,which provides a new perspective for the development of anti-cancer drugs targeting CAFs.

Aim To observe the behavioral effects of exogenous allopregnanolone(ALLO)and its inhibitor finasteride on the receptive period(R)and non-recep-tive period(NR)of PMDD liver-qi inversion model rats and the expression of GABAARα4,GABAARδ mR-NA and protein effects to explore its pathogenesis.Methods The PMDD liver-qi reverse syndrome rat model was prepared.The rats were divided into the normal group R and NR(control-R,control-NR),model group R and NR(Model-R,Model-NR),nor-mal group R+ALLO and NR+ALLO(Control+A-R,Control+A-NR),and model group R+ALLO and NR+ALLO(Model+A-R,Model+A-NR),model group R+finasteride and NR+finasteride(Model+F-R,Model+F-NR).The elevated cross labyrinth ex-periment and social interaction experiment were used to detect the behaviors of rats;fluorescence quantitative PCR and immunofluorescence were used to detect the expression of GABAARα4 and 8 mRNA and protein in rat amygdala and hippocampus.Results In the be-havioral evaluation,in the NR period,in the elevated cross maze test and in the social interaction test,the rats in the model group had anxiety behavior and de-creased social communication ability(P＜0.05),while the rats in the Model+A group could effectively relieve anxiety symptoms and improve their social com-munication ability(P＜0.05),and the rats in the Model+F group had increased anxiety behavior and social disorder(P＜0.05).In fluorescence quantita-tive PCR and immunofluorescence experiments,the ex-pression of GABAARα4 subunit in the model group was up-regulated in the hippocampus(P＜0.01),and the expression of δ subunit was down-regulated(P＜0.01);the expression of GABAARα4 subunit in the a-mygdala and hippocampus of the Model+A group de-creased(P＜0.01),and the expression of δ subunit increased in the hippocampus(P＜0.01).Conclu-sions The abnormal expression of GABAARα4 and 8 subunits mediated by ALLO improves the anxiety symptoms and social interaction ability of PMDD,which is the pathogenesis of PMDD liver-qi reverse syndrome,and provides basis and support for subse-quent exploration of the pathogenesis of PMDD liver-qi reverse syndrome.

Aim To construct CX3CR1GFP transgenic mice based on the Cre/Loxp system,and to analyze the expression efficiency of CX3CR1GFP.Methods Targeted vectors were designed using restriction enzyme-based cloning technology to create a linearized targeted vector for transfecting embryonic stem cells(ES).The ES cells with a deletion of the neomycin resistance gene(neo)were then cloned into blastocysts to generate chimeric CX3CR1+/GFPmice.These mice were subsequently bred with wild-type mice(WT),and repeated backcrossing was performed to obtain CX3CR1GFP/GFP mice.DNA and mRNA from WT and CX3CR1GFP mice were extracted and genotyped using agarose gel electrophoresis.The expression level of CX3CR1 in various tis-sues of the mice was detected by RT-qPCR.Western blot analy-sis was used to analyze the expression of GFP protein in periph-eral blood mononuclear cells(PBMC)and various tissues.The labeling efficiency of immune cells in bone marrow was detected by flow cytometry.The expression of GFP in different mouse tis-sues was observed by immunofluorescence.Results The results of agarose gel electrophoresis showed that the transgenic mouse genotype was CX3CR1GFP/GFP homozygote.RT-qPCR and West-ern blot showed that EGFP were targeted to replace CX3CR1 gene,so CX3CR1 expression was very low in CX3CR1GFP mice,while GFP expression was significantly upregulated.Flow cytom-etry and immunofluorescence showed that GFP effectively marked CX3CR1GFP mice,expressed in various tissues and cells with different expression levels.Conclusion This study con-structs and identifies the CX3CR1GFP genetic reporter mice,and GFP is stably expressed in mice,which provides a foundation for further research into the potential mechanisms of CX3CR1 in im-mune regulation.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.