Objective To map the genome-wide distribution profile of histone H3K27me3 modification in diffuse gastric cancer tissues,identify target genes regulated by H3K27me3,and primarily explore the potential mechanism of its modification reprogramming in the occurrence and development of the tumor.Methods Normal gastric mucosal tissues and diffuse gastric cancer tissues were harvested from the patients who underwent examinations or treatments in the departments of gastroenterology and gastrointestinal surgery of our medical center between 2021 and 2023.There were 14 patients in the normal group(6 males and 8 females,average age of 46 years)and 14 patients in the gastric cancer group(8 males and 6 females,average age of 63 years).Cleavage under target and tagmentation(CUT&Tag)technology was employed to capture genomic regions modified by H3K27me3,and analyze the reprogramming characteristics of these modifications.RNA sequencing data,data from high-throughput chromosome conformation capture(Hi-C)technology,and publicly available single-cell data were integrated to investigate the target genes regulated by the reprogramming of H3K27me3 modifications in diffuse gastric cancer cells.Results The quality of the CUT&Tag and RNA sequencing data met the standards required for subsequent analysis.Histone H3K27me3 modifications in normal gastric mucosa and diffuse gastric cancer tissues were primarily distributed in distal intergenic regions and intronic regions.In gastric cancer tissues,compared to normal tissues,there was significant reprogramming of H3K27me3 modifications,characterized by a marked reduction in overall H3K27me3 signal intensity.The loss of 2 912 H3K27me3 signal peaks might lead to the up-regulation of 822 tumor-associated genes.Among them,56 genes displayed the most significant up-regulation(fold change in signal intensity≥2,P<0.05),with notable enrichment in the mammalian target of rapamycin complex 1(mTORC1)signaling pathway.Specifically,the methionine transporter SLC7A5 and the cystine transporter SLC7A11 were found to have the highest expression levels in gastric cancer tissues.Single-cell data revealed that the abnormal overexpression of SLC7A11 in diffuse gastric cancer was primarily observed in tumor epithelial cells.Further validation using public data and immunohistochemical experiments confirmed the elevated expression of SLC7A11 in diffuse gastric cancer,which is associated with poor prognosis in gastric cancer patients.Conclusion The reprogramming of histone H3K27me3 modification is an important epigenetic characteristic in diffuse gastric cancer.Loss of H3K27me3 signal peaks may up-regulate the expression of SLC7A11 in diffuse gastric cancer cells,and thereby promote tumor progression.

Objective To draw the genome-wide distribution and remodeling characteristics of H3K27me3 silencers in signet-ring cell carcinoma of the stomach(SRCC)through epigenetic sequencing technology,and to investigate their roles in transcriptional regulation in order to elucidate the regulatory mechanism of SRCC malignant progression.Methods The study was conducted on 35 gastric samples obtained by gastroendoscopic biopsy(15 normal and 20 SRCC tissues)from Department of Gastroenterology of Army Medical Center of PLA between January 2021 and December 2023.Multi-omics analyses,including assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq),cleavage under targets and tagmentation(CUT&Tag)and transcriptome sequencing(RNA-seq),were performed to identify chromatin accessibility,H3K27me3 silencer regions,and transcriptional changes,with aid of Illumina NovaSeq 6000.H3K27me3 related differentially expressed genes(|Log2FC|>1,FDR<0.05)were screened using DESeq2.Gene Ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis were employed to analyze the enrichment function,and Homer was employed to identify transcription factor motifs.A regulatory network was constructed using Cytoscape,and then validated using immunohistochemistry to explore its regulatory mechanism.Results H3K27me3 silencers were primarily located in distal intergenic regions(37.06%)in SRCC.Compared with the normal tissues,SRCC showed a significant reduction in H3K27me3 silencer signals(95%CI:1.34～2.30,P=0.007)with 6 257 lost sites(FDR<0.01).Integrating CUT&Tag and RNA-seq revealed 380 up-regulated immune-related genes,particularly in T cell receptor signaling(OR=4.2,95%CI:2.8～6.3,P=0.002).Immunohistochemistry confirmed elevated expression of transcription factor EHF(P<0.05).Conclusion There is the remodeling of H3K27me3 silencers in SRCC,and EHF may potentially play a crucial role in the SRCC malignant progression.

ObjectiveTo investigate the effect and mechanism of Polygonatum neutral polysaccharides from sibiricum （PSP-NP） on colon injury in mice with chronic obstructive pulmonary disease （COPD）. MethodsMale C57BL/6J mice were randomly divided into a control group， a COPD model group， and a PSP-NP group. The COPD model was established using smoke exposure combined with intranasal LPS administration. The PSP-NP group was simultaneously treated daily with 200 mg/kg of PSP-NP via intragastric gavage， while the other groups received an equal volume of saline. HE staining was used to observe the pathological changes in the colon. ELISA was employed to detect the levels of LPS in serum and the expressions of ZO-1， Occludin， IL-6， and TNF-α in colon tissue. UPLC-MS was used to detect the types and contents of bile acids in colonic content， and to screen for differential bile acids. Differential microbial flora were identified using 16S rRNA gene sequencing， and correlation analysis was conducted with differential bile acids. PSP-NP was combined with the differential bile acids cholic acid （CA）， and deoxycholic acid （DCA） in vitro to analyze the binding capacity of PSP-NP for CA and DCA. PSP-NP was applied to NCM460 normal colonic epithelial cells cultured in CA and DCA. Cell migration ability was assessed using the scratch assay， and the mRNA expression levels of inflammatory cytokines TNF-α， IL-6， and NF-κB were measured by RT-qPCR. ResultsPSP-NP effectively improved colonic damage in COPD model mice， enhanced mechanical barrier function， alleviated inflammatory response， and regulated abnormal changes in colonic flora and bile acid metabolism. Correlation analysis further revealed that PSP-NP regulated colonic bile acid metabolism and reduced the redundancy of secondary bile acids by increasing the relative abundance of Bacteroidota， Verrucomicrobiota， Bacteroides， and Akkermansia， while decreasing the relative abundance of Lactobacillus and Bifidobacterium. Notably， in vitro binding assays demonstrated that PSP-NP bound to differential bile acids DCA and CA， with the strongest binding capacity for DCA at 58.2%. In cellular functional studies， DCA inhibited the migration ability of colonic epithelial cells NCM460 and significantly increased the relative mRNA expression levels of inflammatory factors TNF-α， IL-6， and NF-κB. Importantly， co-treatment with PSP-NP significantly ameliorated the impact of DCA on NCM460 cells. ConclusionsPSP-NP may significantly improve colonic damage in COPD model mice. The mechanism may involve the regulation of colonic bile acid metabolism and bile acid profiles through both microbial modulation and direct binding， thereby reducing the damage caused by secondary bile acids such as DCA to colonic epithelial cells.

Objective To investigate the effect of the mediator of DNA damage check point protein 1(MDC1)on proliferation,migration,invasion,cell cycle and cell apoptosis in cholangiocarcinoma(CCA)and the potential molecular mechanism.Methods The small interfering RNA(siRNA)specifically targeting MDC1 was used to transiently knock down MDC1.Recombined plasmid containing MDC1 was transiently transfected into RBE and Huh28 cells for over-expression of MDC1.Real time quantitative PCR(qPCR)and Western blotting were adopted to verify the effectiveness of MDC1 knockdown or overexpression.The proliferation of CCA cells was measured via CCK-8 and cell colony formation assays.Transwell and Invasion assays were used to detect cell migration and invasion while flow cytometry assays were employed to detect cell cycle and apoptosis.Gene set enrichment analysis(GSEA)was conducted to investigate the pathways which were significantly associated with MDC1,and the expression of p53 downstream protein was verified by Western blotting assay.Co-immunoprecipitation(Co-IP)assays were used to verify the interactions between MDC1 and p53.Flow cytometry and Western blotting assays were performed to find out whether MDC1 promoted cell cycle and cell apoptosis through p53 pathway.Based on The Cancer Genome Altas(TCGA)database,the difference in MDC1 expression levels between CCA and normal tissues was analyzed,and the correlations between the MDC1 expression levels and the clinical prognosis of CCA patients were investigated.Results Knockdown of MDC1 in RBE and Huh28 cells significantly inhibited cells proliferation,migration and invasion,significantly decreased the proportion of cells in S phase,and significantly increased the proportion of cells in G0/G1 phase and apoptosis rate while overexpression of MDC1 could significantly promote cell proliferation,migration and invasion,significantly increase the proportion of cells in S phase,and significantly decrease the proportion of cells in G0/G1 phase and apoptosis rate.It was found that MDC1 interacted with p53 in RBE and Huh28 cells,and MDC1 significantly down-regulated the expressions of p53,p-p53(Ser-15),BAX,PUMA and p21,but significantly up-regulated the expression of Bcl-2,which in turn promoted the tumorigenesis of CCA.MDC1 was up-regulated in CCA tissues compared to the normal tissues,and the high expressions of MDC1 were significantly associated with poor clinical outcomes of CCA patients.Conclusion MDC1 promotes the development of CCA by suppressing the p53 pathway,and MDC1 may be a candidate marker for the poor prognosis in CCA.

In order to investigate the effects of porin genes ompW,ompS and ompD on the biological properties and virulence of Salmonella typhimurium,the corresponding mutant strains were con-structed using the λ Red homologous recombination system,and the growth curves,motility,bio-chemical properties,in vitro genetic stability,biofilm-forming ability,drug resistance,and lethal dose at half capacity(LD50)between the standard strain and each mutant strain were detected by comparative assays for Salmonella typhimurium.The results showed that,compared with the standard strain,the ompD and ompW mutation had less effect on the growth rate and motility of the bacteria,while the ompS mutation significantly reduced the growth rate and motility;none of the three genetic mutation affected the biochemical characteristics of Salmonella typhimurium,nor the genetic stability,but affected its susceptibility to a variety of commonly used antibiotics to varying degrees and caused a highly significant decrease(P＜0.01)in the ability to form a biofilm,and the results showed that the three mutant strains had a significant reduction in the ability to form a biofilm.The result of LD50 virulence assay showed that all three genetic mutation led to a decrease in the virulence of Salmonella typhimurium,among which the ompS mutant strain showed the most obvious decrease in virulence,LD50 was 25 times that of the standard strain.In conclusion,mutations of the pore protein ompW,ompS,and ompD genes can affect some biological properties of Salmonella typhimurium.The results of this study laid an experimental foundation for further research on the biological functions of the pore protein ompW,ompS and ompD genes and Salmonella pathogenicity.

Objective To establish and evaluate a gas chromatography-tandem mass spectrometry(GC-MS/MS)method for the detection of six common drugs(methamphetamine,meperidine,caffeine,codeine,cocaine and ketamine)in blood,and to improve the determination basis of results.Methods The above six drugs were added into the blank blood,and GC-MS/MS was used for detection after ether extraction.The collection,quantification and confirmation were carried out under the mode of multi-reaction monitoring(MRM).The qualitative results of the above six drugs were evaluated based on the maximum allowable deviation of the retention time and relative ion abundance ratio in the qualitative results of GC-MS/MS.Results There was a good linear relationship between the six common drugs,among which ketamine and caffeine had the lowest detection limit(0.01 μg/mL),methamphetamine had the highest detection limit(0.5 μg/mL).The retention time(RT)and relative retention time(RRT)of the target substance were stable under the six supplemental levels,and the absolute deviation(ΔRTabsolute)of RT was within±0.025 min.The absolute deviation of RRT(ΔRRTabsolute)was within±0.004.The relative ion abundance ratio absolute deviation(ΔIabsolute)is±20%,and the relative ion abundance ratio relative deviation(ΔIrelative)is±50%.Conclusion This study clarified the reference range for qualitative determination of six common drugs in blood matrix detected by GC-MS/MS,and effectively supplemented the qualitative determination indicators of existing instrumental analysis methods.

OBJECTIVE To investigate the regulatory effects of couplet medicinals of Atractylodes macrocephala-Aucklandia lappa on gut microbiota and short-chain fatty acids （SCFAs） in the diarrhea-type irritable bowel syndrome （IBS-D） rats with spleen deficiency. METHODS The IBS-D rat model with spleen deficiency was induced by intragastric administration of Senna alexandrina combined with restraint stimulation. The model rats were divided into model group， positive control group （pinaverium bromide 1.5 mg/kg）， A. macrocephala-A. lappa low-dose， medium-dose and high-dose groups （0.7， 1.4， 2.8 g/kg）， with 6 rats in each group. Another 6 healthy rats were taken as the blank control group. The blank control group and the model group were given normal saline intragastrically， and other groups were given relevant drug liquid intragastrically， once a day， for consecutive 14 days. The general characteristics of rats and fecal water content were observed， and intestinal sensitivity [evaluating by abdominal wall withdrawal reflex （AWR） threshold] and the intestinal propulsion rate were determined. The serum levels of 5- hydroxytryptamine（5-HT）and SP were detected， and the pathological changes of colon tissue were observed； the protein expressions of 5-HT-3 receptor（5-HT3R）， 5-HT4R and 5-HT transporter（SERT） in colon tissue of rats were detected. 16S rRNA sequencing was performed for the feces of rats in blank control group， model group and A. macrocephala-A. lappa high-dose group； the contents of acetic acid， propionic acid and butyric acid in the feces of the rats were determined. RESULTS Compared with the model group， the body weight after 7 and 14 days of medication， fecal water content， AWR threshold， and the protein expressions of 5-HT4R and SERT in colon tissue were increased significantly in the A. macrocephala-A. lappa medium-dose and high-dose groups （P＜0.05 or P＜0.01）； serum contents of 5-HT and SP， intestinal propulsion rate （except for A. macrocephala-A. lappa medium-dose group）， the protein expression of 5-HT3R in colon tissue were decreased significantly （P＜0.01）； diarrhea relief， mental state recovery， and partially recovery of the structure of colon tissue were all found； moreover， the diversity and species number of gut microbiota were reduced in A. macrocephala-A. lappa high-dose group and the content of butyric acid in fecal samples was significantly reduced （P＜0.05）. CONCLUSIONS The compatibility of A. macrocephala and A. lappa can improve intestinal motility and sensitivity of IBS-D model rats with spleen deficiency， and alleviate diarrhea. This may be related to improving changes in intestinal microbiota structure， reducing 5-HT expression and butyric acid content， and increasing 5-HT4R and SERT expression.

【Objective】 To investigate the effectiveness of current indicators in initial screening and retest before donation and access the optimal testing strategies. 【Methods】 Data of initial screening (rate method for ALT, colloidal gold method for HBsAg) and retest (rate method for ALT, ELISA for HBsAg) of 18 510 platelet donors in our center from January 2019 to December 2021 were collected, and the results were retrospectively analyzed and compared in terms of different years and number of donations. 【Results】 From 2019 to 2021, data of initial screening and retest of platelet donors were as follows: 1) the deferral rate of ALT and HBsAg was 12.98% (2 403/18 510) vs 0.26%(40/15 412); 2) the deferral rate of ALT was 13.19% (712/5 398) vs 0.20%(9/4 410)in 2019, 13.33% (873/6 549) vs 0.06%(3/5 387)in 2020 and 11.05% (725/6 563) vs 0.07%(4/5 615)in 2021; for initial screening, significant difference was noticed in ALT reactivity in 2021 as in comparison to other two years(P<0.05); 3) the reactive rate of HBsAg was 0.43% (23/5 398) vs 0.18%(8/4 410)in 2019, 0.66% (43/6 549) vs 0.20%(11/5 387)in 2020 and 0.41% (27/6 563) vs 0.09%(5/5, 615) in 2021. For initial screening, HBsAg deferral in 2021 was significantly different from 2019, while similar with 2020. 4) Among ALT deferral samples in the retest, 68.75% (11/16) were ALT≥45 U/L. Among HBsAg reactive samples, 91.67% (22/24) were reactive by single reagent. 【Conclusion】 Setting the threshold value of ALT for platelet donors in initial screening as less than 45 U/L can effectively reduce the reactive rate in the retest. HBsAg screening only for first-time platelet donors can reduce the detection cost. Adding pre-donation detection indicators according to local prevalence of transfusion transmitted diseases is conductive to reduce the discarding rate of platelets.

Uncommon epidermal growth factor receptor (EGFR) mutations account for 10%-20% of all EGFR mutations in non-small-cell lung cancer (NSCLC). The uncommon EGFR-mutated NSCLC is associated with poor clinical outcomes and generally achieved unsatisfactory effects to the current therapies using standard EGFR-tyrosine kinase inhibitors (TKIs), including afatinib and osimertinib. Therefore, it is necessary to develop more novel EGFR-TKIs to treat uncommon EGFR-mutated NSCLC. Aumolertinib is a third-generation EGFR-TKI approved in China for treating advanced NSCLC with common EGFR mutations. However, it remains unclear whether aumolertinib is effective in uncommon EGFR-mutated NSCLC. In this work, the in vitro anticancer activity of aumolertinib was investigated in engineered Ba/F3 cells and patient-derived cells bearing diverse uncommon EGFR mutations. Aumolertinib was shown to be more potent in inhibiting the viability of various uncommon EGFR-mutated cell lines than those with wild-type EGFR. And in vivo, aumolertinib could also significantly inhibit tumor growth in two mouse allograft models (V769-D770insASV and L861Q mutations) and a patient-derived xenografts model (H773-V774insNPH mutation). Importantly, aumolertinib exerts responses against tumors in advanced NSCLC patients with uncommon EGFR mutations. These results suggest that aumolertinib has the potential as a promising therapeutic candidate for the treatment of uncommon EGFR-mutated NSCLC.

Objective: To investigate the role of long non-coding RNA double homeobox A pseudogene 9 (DUXAP9) in head and neck squamous cell carcinoma (HNSCC) and to evaluate the expression level, molecular function and mechanism of DUXAP9 in HNSCC cells. Methods: Differential expression of lncRNAs between normal and tumor tissues in HNSCC tissues were screened using lncRNA microarray, the expression level of DUXAP9 in HNSCC tissues and its relationship with prognosis were analyzed in the TCGA database. The expression levels of DUXAP9 in HNSCC tissues and cell lines were detected using qRT-PCR. The function in HNSCC cells after DUXAP9 silencing was evaluated using the CCK-8 assay, wound healing assay, Transwell migration assay and subcutaneous xenograft assay in nude mice. Changes in the transcription and translation of epithelial-mesenchymal transition (EMT)-related proteins in head and neck squamous cell carcinoma cells after DUXAP9 silencing were detected using qRT-PCR and Western blot. Results: lncRNA microarray results showed that, compared to adjacent normal tissues, DUXAP9 was abnormally upregulated in HNSCC tissues. Analysis from TCGA database showed that, compared to HNSCC patients with low DUXAP9 expression, HNSCC patients with high DUXAP9 expression had poorer survival. The relative expression of DUXAP9 in HNSCC tissues and 4 HNSCC cell lines increased compared to paired adjacent normal tissues as detected using qRT-PCR. Silencing DUXAP9 significantly inhibited the proliferation, migration and expression of EMT-related genes in HNSCC cells. The silencing of DUXAP9 significantly inhibited subcutaneous tumorigenesis of the HNSCC cell line CAL27 in nude mice. Conclusion Silencing DUXAP9 significantly inhibited the proliferation of HNSCC cells and subcutaneous xenografts in nude mice. DUXAP9 may mediate the migration of head and neck squamous cell carcinoma cells via the EMT pathway.