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Angiogenesis significantly correlates with tumor microenvironment remodeling and immunotherapy response. Our study aimed to construct a prognostic angiogenesis-related model for gastric cancer. Using public database, a angiogenetic related five-gene (FGF1, GRB14, PAK3, PDGFRA, and PRKD1) model was identified. The top 25 % of patients were defined as high-risk, and the remaining as low-risk. The area under the curve for 1-, 3-, and 5-year overall survival (OS) were 0.646, 0.711, and 0.793, respectively. Survival analysis showed a better 10-year OS in low-risk patients in the construction (HR = 0.57, p = 0.002) and validation cohorts. GO and GSEA revealed that DEGs were enriched in extracellular matrix receptor interactions, dendritic cell antigen processing/presentation regulation, and angiogenesis pathways. CIBERSORT analysis revealed abundant naïve B cells, resting mast cells, resting CD4 + memory T cells, M2 macrophages, and monocytes in high-risk subgroups. The TIMER database showed strong positive correlations between PAK3, FGF1, PRKD1, and PDGFRA expression levels and the infiltration of CD4 + T cells and macrophages. The IOBR analysis revealed an immunosuppressive environment in the high-risk subgroup. Low-risk patients show a higher response rate to anti-PD1 treatment. TMA showed that FGF1 overexpression was associated with poor prognosis and CD4 + T cells and macrophage infiltration. In vivo study based on the 615 mice indicated that inhibiting FGF1 function could suppress tumor growth and enhance anti-PD1 therapeutic efficacy. In summary, we established a five-angiogenesis-related gene model to predict survival outcomes and immunotherapy responses in patients with gastric cancer and identified FGF1 as a prognostic gene and potential target for improving immune treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Objectives: Cluster of Differentiation 73 (CD73) is expressed on immune cells and plays a significant role in tumor inhibition by suppressing antitumor immunity. The objectives of this study were to explore the expression and functional mechanisms of CD73 on B cells in patients with gastric cancer (GC)., Methods: The prognostic significance of CD19 + CD73 + B cells was evaluated in 390 GC patients through dual immunohistochemistry staining. Flow cytometry was employed to analyze the phenotype of the CD19 subpopulation using fresh tumor and non-tumor tissue samples from 8 GC patients. A bioinformatics analysis of CD19 + CD73 + B cells was also performed within the scRNA-seq cohort, and the CD19 + B cell subtype was assessed using multiple immunofluorescence staining., Results: The infiltration of CD19 + CD73 + B cells was observed to be elevated in gastric cancer (GC) tissue compared to normal tissues. A strong correlation was observed between high CD19 + CD73 + B cell infiltration, poor overall survival, and diminished responsiveness to neoadjuvant immunotherapy in GC. These cells emerged as a novel subset of regulatory B cells (Bregs) linked to adenosine metabolism and the exhaustion of CD8 + T cells. The CD19 + CD73 + B cells also correlated with the production of immunosuppressive cytokines IL-10 and TGFB1. Further analysis indicated an association between CD19 + CD73 + B cells and advanced-stage GC., Conclusions: The presence of CD19 + CD73 + B cells in GC may serve as a prognostic indicator for clinical outcomes and a predictive marker for poor responsiveness to neoadjuvant immunotherapy. The correlation between the presence of CD19 + CD73 + B cells and CD8 + T cell exhaustion, along with immunosuppression, highlights the tumor-promoting function of these cells., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: HER2(+) gastric cancer (GC) can benefit from trastuzumab. However, the impact of additional trastuzumab in preoperative treatment on immune cells remains largely unknown., Methods: In cohort I, immune cells were detected by immunohistochemistry in 1321 patients. Then 88 HER2(+) patients received preoperative therapy were collected as cohort II. Immune cell profiles and changes were analyzed in paired pre- and post-operative specimens using multiple immunohistochemistry staining., Results: In the treatment-naive GC patients (n = 1002), CD3+ and CD8+ T cell infiltration was significantly lower in the HER2(+) GC patients together with higher FoxP3+ T cells compared with HER2(-). However, FoxP3+ T and CD20+ B cell infiltration was significantly higher in HER2(+) GC after neoadjuvant chemotherapy (n = 319). The trastuzumab-exposed group had higher CD8+ T and lower FoxP3+ T cell infiltration and CD8+ T cell was even more significant in responders. Additionally, tertiary lymphoid structure (TLS) density increased in invasion margin of residual tumors. Patients with lower TLS in the tumor core or lower FoxP3+ T cells had better overall survival in the trastuzumab-exposed group., Conclusion: Addition of trastuzumab modulates the immune microenvironment, suggesting the potential mechanism of the favorable outcome of anti-HER2 therapy and providing a theoretical rationale for the combinational immunotherapy in resectable HER2(+) GC patients., (© 2024. The Author(s).)

Metabolic changes are key drivers of tumor progression. Understanding how metabolic reprogramming promotes tumor development and identifying key metabolic activities are essential for improving tumor diagnosis and treatment. Among the numerous transporters in the body, solute carriers (SLCs) are particularly significant, often overexpressed in cancer cells to meet the tumor's demand for nutrients and energy. While the role of SLCs in nutrient absorption within the gastrointestinal tract is well-established, their specific role in gastric cancer (GC) remains unclear. Recently, Xiaodi Zhao's team investigated the critical role of taurine and its transporter, SLC6A6, in anti-tumor immunity and clinical outcomes. Notably, this research marks the first instance of taurine exhibiting a dual role. It promotes tumor growth in immunodeficient mice while inhibiting it in immunocompetent mice. The study found that taurine exerts its anti-cancer effects by modulating CD8 + T cells rather than directly inhibiting tumor cells, revealing the SP1-SLC6A6 axis as a key mechanism behind chemotherapy-induced immune evasion. Our work further explored the potential, advantages, and challenges of using taurine and SLC6A6 as biomarkers and therapeutic targets in gastric cancer. We aim to underscore their importance in both basic research and clinical applications, providing valuable insights and guidance for future investigations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: This study aimed to reveal the effect of TP53 status on clinical outcomes and underlying mechanism in gastric cancer (GC) patients., Methods: TP53 status was divided into three groups according to genome sequencing, namely clonal mutations with LOH (C-LOH), clonal diploid or subclonal mutations (CD-SC), and wild type (WT). The p53 protein activity was divided into over-expression (OE), Null and WT according to immunohistochemical staining. Four cohorts, including the TCGA, SMC, ZSHS and FUSCC cohort, were analyzed for association between TP53 mutation status and clinical outcomes and the underlying mechanism., Results: In TCGA cohort, TP53 CD-SC were associated with superior overall survival compared to TP53 C-LOH cases. GC patients could benefit from ACT only in TP53 CD-SC/ p53 OE and TP53/ p53 WT subgroups, and TP53 C-LOH subgroup demonstrated the worst response to pembrolizumab among three subgroups. Genomic and immunophenotypic deconvolution revealed that TP53 C-LOH, CD-SC and WT differed for genomic and immune-related features., Conclusions: TP53 C-LOH GCs with genomic instability and immune evasion phenotype have poor clinical outcomes in patients treated with ACT or immunotherapy., (© 2024. The Author(s).)

Background: Tumor-associated macrophages (TAMs) have been demonstrated to be associated with tumor progression. However, the different subpopulations of TAMs and their roles in gastric cancer (GC) remain poorly understood. This study aims to assess the effects of Spi-1 proto-oncogene (SPI1) + CD68 + TAMs in GC., Methods: The distribution of SPI1 + CD68 + TAMs in GC tissue was estimated by immunohistochemistry, immunofluorescence, and flow cytometry. Single-cell transcriptome analysis and multiplex fluorescence immunohistochemistry were applied to explore the role of SPI1 + CD68 + TAMs in an immune contexture. SPI1 overexpression or knockdown cells were constructed to evaluate its role in macrophage polarization and angiogenesis in vitro and in vivo. Chromatin immunoprecipitation was used to verify the mechanism of SPI1 transcriptional function. The effect of combined antiangiogenic and immunotherapy was further validated using mouse peritoneal metastasis models., Results: Single-cell transcriptome analysis and immunohistochemistry demonstrated that SPI1 was expressed in macrophages, with a higher enrichment in metastatic lesions than in primary tumors. Higher SPI1 + CD68 + TAMs infiltration was associated with poor overall survival. Mechanically, SPI1 promoted the M2-type macrophage polarization. SPI1 could bind to the promoter of vascular endothelial growth factor A and facilitate angiogenesis. Moreover, the level of SPI1 + CD68 + TAMs infiltration was closely related to the efficacy of immunotherapy, especially when combined with antiangiogenic therapy., Conclusions: The present study showed that SPI1 + CD68 + TAMs are a promising biomarker for predicting prognosis, antiangiogenic drug sensitivity, and combination target of immunotherapy in patients with GC., Competing Interests: Competing interests: No, there are no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

This study reviews the contrasting finding regarding the impact of Helicobacter pylori infection on the efficacy of immunotherapy in gastric cancer (GC). While a large retrospective study reported a positive association between H. pylori infection and progression-free survival (PFS)/overall survival (OS) in patients with GC undergoing PD-1/PD-L1 therapy, previous studies had given rise to a contrary outcome. Potential explanations of the inconsistency include the divergent immune responses induced by different H. pylori status (current infection, postinfection and negative status) directly, as well as the indirect influence of gut microbiota alterations. Tumor molecular subtypes, particularly Epstein-Barr virus (EBV) infection status, may also play a role in the discrepancy by altering the profile of immune infiltration. However, data on EBV status are absent in studies showing H. pylori infection as an unfavorable factor for GC immunotherapy. Moreover, a combined positive score (CPS) <1 might exert a positive influence, as more patients with CPS<1 enrolled in the study reported a positive association between H. pylori infection and immunotherapy. The review highlights the need for further research to clarify the complex interplay between H. pylori infection, immune response, and immunotherapy efficacy in GC, aiming to develop more targeted and personalized treatment strategies., Competing Interests: Competing interests: No, there are no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Gastric cancer (GC) is a leading malignant disease in numerous countries, including Taiwan with limited therapeutic options. Animal viruses including oncolytic avian reovirus (ARV) have the possibility to avoid pre-existing immunity in humans, while being safe and immunostimulatory. Here, we provide a novel insight into oncolytic ARV and UV-ARV-sensitized patient's peripheral blood mononuclear cells (P-PBMCs) and tumor infiltrating lymphocytes (TILs) killing primary GC (PGC) cells through the surface TLR3 and TRAIL/DR4/DR5 immunogenic apoptosis pathway., Methods: We conducted a comprehensive study to reveal whether ARV- or UV-inactivated ARV (UV-ARV)-modulated P-PBMCs or TILs killing ARV- and UV-ARV-sensitized AGS cells and PGC cells derived from clinical patients and to investigate the regulation of surface TLR3 receptor and upstream signaling pathways. Apoptosis analysis by flow cytometry and Western blot, suppression of signal pathway by specific inhibitors, in situ proximity ligation assay (PLA), time-resolved flurometry and lactate dehydrogenase (LDH) cytotoxicity assays, and an in vitro co-culture model were established to study the interplay between ARV- and UV-ARV-sensitized P-PBMCs and TILs to kill PGC cells and their upstream pathways., Results: Our results reveal that increased levels of DR4 and DR5 were observed in ARV and UV-ARV sensitized PGC cells through the TLR3/p38/p53 signaling pathway. Importantly, we found that the σC protein of ARV or UV-ARV interacted with surface TLR3 of CD8 + TILs, thereby triggering the TLR3/NF-κB/IFN-γ/TRAIL signaling pathway which induces immunogenic apoptosis of PGC cells. This study sheds further light on the molecular basis behind ARV oncolysis and facilitates the ARV or UV-ARV as a cancer therapeutic., Conclusions: The study provides novel insights into ARV- or UV-ARV-sensitized P-PBMCs and CD8 + TILs to kill PGC cells through the immunogenic apoptosis pathway. We conclude that P-PBMCs can easily be obtained from GC patients and provide a rich source as TILs to kill PGC cells., (© 2024. The Author(s).)

Gastric adenocarcinoma (STAD) is characterized by high heterogeneity and aggressiveness, leading to poor prognostic outcomes worldwide. This study explored the prognostic significance of lactylation-related gene sets and mitochondrial functions in STAD by integrating large-scale genomic datasets, including TCGA and several GEO datasets. We utilized Spatial transcriptomics and single-cell RNA sequencing to delineate the tumor microenvironment and assess the heterogeneity of cellular responses within the tumor. Additionally, the study identified distinct molecular subtypes within STAD that correspond with unique survival outcomes and immune profiles, enhancing the molecular classification beyond current paradigms. Prognostic models incorporating these molecular markers demonstrated superior predictive capabilities over existing models across multiple validation datasets. Furthermore, our analysis of immune landscapes revealed that variations in lactylation could influence immune cell infiltration and responsiveness, pointing towards novel avenues for tailored immunotherapy approaches. These comprehensive insights provide a foundation for targeted therapeutic strategies and underscore the potential of metabolic and immune modulation in improving STAD treatment outcomes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yin, Xing, Yi, Zhou, Chen, Jiang, Ma and Xia.)

(1) Introduction: Toll-like receptors (TLRs) are key in immune response by recognizing pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). In gastric cancer (GC), TLR2, TLR3, TLR4, and TLR9 are crucial for modulating immune response and tumor progression. (2) Objective: This study aimed to assess the percentage of dendritic cells and monocytes expressing TLR2, TLR3, TLR4, and TLR9, along with the concentration of their soluble forms in the serum of GC patients compared to healthy volunteers. Factors such as disease stage, tumor type, age, and gender were also analyzed. (3) Materials and Methods: Blood samples from newly diagnosed GC patients and healthy controls were immunophenotyped using flow cytometry to assess TLR expression on dendritic cell subpopulations and monocytes. Serum-soluble TLRs were measured by ELISA. Statistical analysis considered clinical variables such as tumor type, stage, age, and gender. (4) Results: TLR expression was significantly higher in GC patients, except for TLR3 on classical monocytes. Soluble forms of all TLRs were elevated in GC patients, with significant differences based on disease stage but not tumor type, except for serum TLR2, TLR4, and TLR9. (5) Conclusions: Elevated TLR expression and soluble TLR levels in GC patients suggest a role in tumor pathogenesis and progression, offering potential biomarkers and therapeutic targets.

Background: Gastric cancer is caused by different exogenous risk factors. Polymerase beta (POLB) is critical to repair oxidative and alkylating-induced DNA damage in genome maintenance. It is unknown whether overexpression of POLB genes in GC modulates tumor immunogenicity and plays a role in its prognostic value., Methods: RNA-Seq of GC data retrieved from TCGA and GEO database and patient survival were compared using Kaplan-Meier statistical test. The TIMER algorithm was used to calculate the abundance of tumor-infiltrating immune cells. Furthermore, ROC analysis was applied to evaluate the prognostic value of POLB overexpression., Results: Our data analysis of TCGA and GEO gastric cancer genomics datasets reveals that POLB overexpression is significantly associated with intestinal subtypes of stomach cancer. In addition, POLB overexpression is associated with low expression of innate immune signaling genes. In contrast, POLB-overexpressed tumor harbors high mutation frequency and MSI score. Furthermore, POLB-overexpressed tumor with high immune score exhibits a better prognosis. Interestingly, our ROC analysis results suggested that POLB overexpression has a potential for prognostic markers for stomach cancer., Conclusions: Our analysis suggests that aberrant POLB overexpression in stomach cancer impacts the diverse aspects of tumor immune microenvironment. In addition, POLB might be a potential prognosis marker and/or an attractive target for immune-based therapy in GC. However, our observation still requires further experimental-based scientific validation studies., (© 2024. The Author(s).)

Background: The high prevalence and detrimental effects on patient outcomes make gastric cancer (GC) a significant health issue that persists internationally. Existing treatment modalities exhibit limited efficacy, prompting the exploration of immune checkpoint inhibitors as a novel therapeutic approach. However, resistance to immunotherapy poses a significant challenge in GC management, necessitating a profound grasp of the intrinsic molecular pathways., Methods: This study focuses on investigating the immunosuppressive mechanisms of quiescent cancer cells (QCCs) in GC, particularly their resistance to T-cell-mediated immune responses. Utilizing mouse models, gene editing techniques, and transcriptome sequencing, we aim to elucidate the interactions between QCCs, immune cells, and key regulatory factors like HIF1A. Functional enrichment analysis will further underscore the role of glycolysis-related genes in mediating immunosuppression by QCCs., Results: The cancer cells that survived GC treated with T-cell therapy lost their proliferative ability. QCCs, as the main resistance force to immunotherapy, exhibit stronger resistance to CD8 + T-cell attack and possess higher cancer-initiating potential. Single-cell sequencing analysis revealed that the microenvironment in the QCCs region harbors more M2-type tumor-associated macrophages and fewer T cells. This microenvironment in the QCCs region leads to the downregulation of T-cell immune activation and alters macrophage metabolic function. Transcriptome sequencing of QCCs identified upregulated genes related to chemo-resistance, hypoxia, and glycolysis. In vitro cell experiments illustrated that HIF1A promotes the transcription of glycolysis-related genes, and silencing HIF1A in QCCs enhances T-cell proliferation and activation in co-culture systems, induces apoptosis in QCCs, and increases QCCs' sensitivity to immune checkpoint inhibitors. In vivo, animal experiments showed that silencing HIF1A in QCCs can inhibit GC growth and metastasis., Conclusion: Unraveling the molecular mechanisms by which QCCs resist T-cell-mediated immune responses through immunosuppression holds promising implications for refining treatment strategies and enhancing patient outcomes in GC. By delineating these intricate interactions, this study contributes crucial insights into precision medicine and improved therapeutic outcomes in GC management., (© 2024. The Author(s).)

Stomach adenocarcinoma (STAD) is a prevalent malignancy that is highly aggressive and heterogeneous. Intratumor heterogeneity (ITH) showed strong link to tumor progression and metastasis. High ITH may promote tumor evolution. An ITH-related signature (IRS) was created using as integrative technique including 10 machine learning methods based on TCGA, GSE15459, GSE26253, GSE62254 and GSE84437 datasets. The relevance of IRS in predicting the advantages of immunotherapy was assessed using a number of prediction scores and three immunotherapy datasets (GSE78220, IMvigor210 and GSE91061). Vitro experiments were performed to verify the biological functions of AKR1B1. The RSF + Enet (alpha = 0.1) projected model was proposed as the ideal IRS because it had the highest average C-index. The IRS demonstrated a strong performance in serving as an independent risk factor for the clinical outcome of STAD patients. It performed exceptionally well in predicting the overall survival rate of STAD patients, as seen by the TCGA cohort's AUC of 1-, 3-, and 5-year ROC curves, which were 0.689, 0.683, and 0.669, respectively. A low IRS score demonstrated a superior response to immunotherapy, as seen by a lower TIDE score, lower immune escape score, greater TMB score, higher PD1&CTLA4 immunophenoscore, higher response rate, and improved prognosis. Common chemotherapeutic and targeted treatment regimens had lower IC50 values in the group with higher IRS scores. Vitro experiment showed that AKR1B1 was upregulated in STAD and knockdown of AKR1B1 obviously suppressed tumor cell proliferation and migration. The present investigation produced the best IRS for STAD, which may be applied to prognostication, risk stratification, and therapy planning for STAD patients., (© 2024. The Author(s).)

The Human Leukocyte Antigen (HLA) system contains a set of genes involved at many levels in the innate and adaptive immune response. Among the non-classical HLA class I genes, HLA-G stands out for the numerous studies about its pivotal role in regulating/modulating immune responses. Also, its involvement in extravillous cytotrophoblast function, viral infections, autoimmunity, and cancer has been extensively documented. The present study explores for the first time the relationship between natural alleles of HLA-G, rather than STSs, SNPs, or partial gene polymorphisms, and the development of gastric adenocarcinoma, by analyzing the genetic profile of a cohort of 40 Spanish patients with this type of tumor using DNA extracted from paired biopsies of tumoral and adjacent non-tumoral gastric tissue. Our results reveal a significant statistical relationship between the presence of the HLA-G*01:01:01 allele and the development of gastric cancer, while other common alleles such as -G*01:04 or -G*01:05N did not demonstrate a significant correlation. Studying the involvement of HLA genes in the development of many diseases is relevant to understanding their pathophysiology. However, the absence of specific mechanisms underlying these associations suggests that investigating complete HLA natural alleles' extended haplotypes or complotypes may offer a more precise and valuable approach to elucidating the association of HLA with the pathogenesis of disease.

Gastric cancer (GC) is one of the most challenging malignant tumors worldwide, primarily because of its high incidence and mortality rates. Prolyl 4-hydroxylase subunit alpha 3 (P4HA3) has been established as a pivotal factor for facilitating cell proliferation, invasion, and metastasis across multiple human tumors. Nevertheless, the precise role of P4HA3in GC has not been fully elucidated. In this study, we used data from The Cancer Genome Atlas (TCGA) to examine the role of P4HA3 as a potential biomarker for predicting immunotherapy response in patients with GC. Our comprehensive analysis of data from the TCGA, TIMER, and other databases revealed a significant association between elevated P4HA3 expression in GC and adverse prognostic outcomes. Furthermore, we confirmed that P4HA3 expression was strongly correlated with immune infiltrating cells, immune infiltration markers, the tumor mutational burden (TMB), microsatellite instability (MSI), the immune score, the stromal score, and immune checkpoints, thus highlighting P4HA3 as a crucial and dependable therapeutic target within the context of immune-based antitumor strategies. Our findings suggest that P4HA3 may function as an immune-related biomarker in the pathogenesis and treatment of GC, indicating that P4HA3 is a promising prognostic and therapeutic target for this malignancy., (© 2024. The Author(s).)

Objective To investigate the impact of dipeptidyl peptidase 3 (DPP3) on the immune escape of gastric cancer cells by regulating the expression of major histocompatibility complex class I chain-related gene B (MICB). Methods Knocking down DPP3 in MKN-45 human gastric cancer cells and overexpressing DPP3 in MGC-803 human gastric cancer cells, observing changes in cell proliferation, migration ability, and responses to natural killer (NK) cell cytotoxicity; using whole-transcriptome sequencing to identify the MICB gene, and knocking down MICB in DPP3-overexpressing cells to verify changes in cellular behavior. In C57 mice, the in vivo tumorigenic ability of DPP3-knockout cells and the infiltration of CD56 + cells in tissues were examined. Results Knocking out DPP3 promoted the proliferation and migration of gastric cancer cells, reduced MICB expression, and made the cells less sensitive to NK cell cytotoxicity; the tumorigenic ability in mice increased and CD56 + cells tissue infiltration decreased by DPP3 knocking out in the gastric cancer cells, but DPP3 overexpression showed the opposite results. Knocking down MICB could reverse the phenotypic changes induced by high DPP3 expression. Conclusion DPP3 inhibits the immune escape of gastric cancer cells by downregulating MICB expression.

Objective: To explore the effects of Weitiao No. 3 (3, WD-3) on anti-programmed cell death protein-1 (PD-1) immunotherapy in gastric cancer (GC)., Methods: The intestinal microbiota was analyzed by 16S rDNA sequencing of fecal samples from three groups: healthy people (Health), GC patients (GC), and WD-3-treated GC patients (WD-3). Next, we established an orthotopic model of GC mice, which were treated with anti-PD-1, WD-3, or an inoculation of intestinal bacteria. Immune markers CD3, CD4, CD8, and forkhead box protein P3 (FOXP3), and the cell proliferation marker Ki67, were evaluated by immunohistochemistry. Cell apoptosis in GC tumors was assessed by terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling staining. Enzyme-linked immunosorbent assays (ELISAs) were performed to analyze the serum levels of the following cytokines in GC mice: tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-6, IL-10, interferon (IFN)-γ, and transforming growth factor (TGF)-β., Results: Sequencing data showed that there were significant differences in the composition of the gut microbial community among the three human groups. The gut bacteria in the three groups mainly comprised the phyla Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. At the genus level, the relative abundances of Bifidobacterium and Coprococcus showed significant decreases in the GC group, and an obvious increase in the WD-3 group, compared with the Health group. Interestingly, the relative abundance of Saccharopolyspora was only detected in the WD-3 group. The results of in vivo experiments in GC mice showed that WD-3 or anti-PD-1 treatment increased the levels of CD3+, CD4+, and CD8+ T cells, but decreased the levels of FOXP3+ regulatory T cells. Furthermore, WD-3 or PD-1 antibody treatment inhibited proliferation and promoted apoptosis of GC tumor cells. ELISA analysis showed that WD-3 or PD-1 antibody treatment facilitated TNF-α, IL-2, and IFN-γ expression, while suppressing IL-6, IL-10, and TGF-β expression. Combination therapy with WD-3 and anti-PD-1 intensified all of these effects., Conclusion: WD-3 enhanced the immunotherapeutic efficacy of anti-PD-1 by modulating the intestinal microbiota in an orthotopic model of GC mice.

Introduction: Gastric adenocarcinoma (GAC) remains a prevalent cancer worldwide and its incidence is increasing in South America. The heterogenous nature of GAC makes advances in management challenging., Areas Covered: Despite challenges, recent therapeutic targets are individualizing treatment. For localized disease with microsatellite-instability-high/deficient mismatch repair, immunotherapy is now an adopted practice. In the advanced unresectable setting, those harboring human epidermal growth factor receptor-2 (HER2) expression continue to be a separate entity., Expert Opinion: Future targets are developing. Among these include claudin 18.2 (CLDN18.2), fibroblast growth factor receptor 2b (FGFR2b), and trophoblast cell surface antigen-2 (TROP-2). FDA approval of zolbetuximab's, an anti-CLDN 18.2 monoclonal antibody, is expected soon. Additionally, bemarituzumab, ananti-FGFR2b monoclonal antibody, has shown improvements in combination with chemotherapy in those with HER2 negative GAC with FGFR2 overexpression. This combination is now being investigated in a phase 3 trial. Lastly, TROP-2 has emerged as an exciting solid tumor target and study is expected in GAC. All three of these therapeutic targets have seen an abundance of drug development in recent years, and we anticipate newer targeted agents driving therapeutic decisions in GAC in the coming years.

The success of immunotherapy for cancer treatment is limited by the presence of an immunosuppressive tumor microenvironment (TME); Therefore, identifying novel targets to that can reverse this immunosuppressive TME and enhance immunotherapy efficacy is essential. In this study, enrichment analysis based on publicly available single-cell and bulk RNA sequencing data from gastric cancer patients are conducted, and found that tumor-intrinsic interferon (IFN) plays a central role in TME regulation. The results shows that KDM3A over-expression suppresses the tumor-intrinsic IFN response and inhibits KDM3A, either genomically or pharmacologically, which effectively promotes IFN responses by activating endogenous retroviruses (ERVs). KDM3A ablation reconfigures the dsRNA-MAVS-IFN axis by modulating H3K4me2, enhancing the infiltration and function of CD8 T cells, and simultaneously reducing the presence of regulatory T cells, resulting in a reshaped TME in vivo. In addition, combining anti-PD1 therapy with KDM3A inhibition effectively inhibited tumor growth. In conclusions, this study highlights KDM3A as a potential target for TME remodeling and the enhancement of antitumor immunity in gastric cancer through the regulation of the ERV-MAVS-IFN axis., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Local immunotherapy represents a promising solution for preventing tumor recurrence and metastasis post tumor surgical resection by eliminating residue tumor cells as well as eliciting tumor-specific immune responses. Minimally invasive surgery has become a mainstream surgical method worldwide due to its advantages of aesthetics and rapid postoperative recovery. Unfortunately, the currently reported local immunotherapy strategies are mostly designed to be used after open laparotomy, which go against the current surgical philosophy of minimally invasive therapy and is not suitable for clinical translation. Aiming at this problem, a minimally invasive injectable gel (MIGel) is herein reported loaded with immunotherapeutic agents for gastric and liver cancer postoperative treatment. The MIGel is formed by crosslinking between oxidized dextran (ODEX) and 4-arm polyethylene glycol hydroxylamine (4-arm PEG-ONH 2 ) through oxime bonds, which can be injected through a clinic-used minimally invasive drainage tube and adhered tightly to the tissue. The loaded oxaliplatin (OxP) and resiquimod (R848) can be released constantly over two weeks and resulted in over 75% cure rate in orthotopic mouse gastric and liver cancer model. Collectively, a concept of minimally invasive local immunotherapy is proposed and MIGel is designed for local intraperitoneal cancer immunotherapy through minimally invasive surgery, with good clinical translation potential., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Purpose: It is highly important to be able to predict the therapeutic efficacy of chemotherapy on patients with unresectable advanced or recurrent gastric cancer (GC). The Gustave Roussy Immune Score (GRIm-s) is a predictor of therapeutic sensitivity to chemotherapy and immune checkpoint inhibitors (ICIs) in other cancers. The present study aimed to analyze the association of the GRIm-s with the therapeutic sensitivity of first-line chemotherapy in GC patients., Methods: We included 156 patients receiving primary chemotherapy treatment for unresectable or advanced recurrent GC between January 2012 and December 2021 at our institution. We evaluated the correlation between the GRIm-s and therapeutic sensitivities to chemotherapy. The GRIm-s was assessed before the start of first-line chemotherapy., Results: Among the 156 patients, 138 (88.5%) and 18 (11.5%) were classified in the low- and high-risk groups, respectively. The GRIm-s high-risk group was significantly older (p = 0.013), had more advanced unresectable cancer (p = 0.0098), and was significantly less likely to progress to second-line chemotherapy (p = 0.014). The overall survival rate (OS) (p = 0.039) and the progression free survival rate (PFS) (p = 0.017) were significantly worse in the GRIm-s high-risk group. The high GRIm-s was an independent prognostic factor for poor survival in multivariate analysis (p = 0.0094)., Conclusions: Focusing on the GRIm-s before first-line chemotherapy initiation for unresectable advanced or postoperative recurrent GC was useful in predicting the therapeutic resistance to chemotherapy, transition to second-line chemotherapy, and poor prognosis., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Gastric cancer (GC) is a prevalent malignant tumor of the gastrointestinal (GI) system. However, the lack of reliable biomarkers has made its diagnosis, prognosis, and treatment challenging. Immunogenic cell death (ICD) is a type of programmed cell death that is strongly related to the immune system. However, its function in GC requires further investigation., Method: We used multi-omics and multi-angle approaches to comprehensively explore the prognostic features of ICD in patients with stomach adenocarcinoma (STAD). At the single-cell level, we screened genes associated with ICD at the transcriptome level, selected prognostic genes related to ICD using weighted gene co-expression network analysis (WGCNA) and machine learning, and constructed a prognostic model. In addition, we constructed nomograms that incorporated pertinent clinical features and provided effective tools for prognostic prediction in clinical settings. We also investigated the sensitivity of the risk subgroups to both immunotherapy and drugs. Finally, in addition to quantitative real-time polymerase chain reaction, immunofluorescence was used to validate the expression of ICD-linked genes., Results: Based on single-cell and transcriptome WGCNA analyses, we identified 34 ICD-related genes, of which 11 were related to prognosis. We established a prognostic model using the least absolute shrinkage and selection operator (LASSO) algorithm and identified dissimilarities in overall survival (OS) and progression-free survival (PFS) in risk subgroups. The nomograms associated with the ICD-related signature (ICDRS) demonstrated a good predictive value for clinical applications. Moreover, we detected changes in the tumor microenvironment (TME), including biological functions, mutation landscapes, and immune cell infiltration, between the high- and low-risk groups., Conclusion: We constructed an ICD-related prognostic model that incorporated features related to cell death. This model can serve as a useful tool for predicting the prognosis of GC, targeted prevention, and personalized medicine., (© 2024 Wiley Periodicals LLC.)

Purpose: Gastric cancer exhibits molecular heterogeneity, with the microsatellite instability-high (MSI-H) subtype drawing attention for its distinct features. Despite a higher survival rate, MSI-H gastric cancer lack significant benefits from conventional chemotherapy. The immune checkpoint inhibitors, presents a potential avenue, but a deeper understanding of the tumor immune microenvironment of MSI-H gastric cancer is essential., Materials and Methods: We explored the molecular characteristics of CD8+ T-cell subtypes in three MSI-H and three microsatellite stable (MSS) gastric cancer samples using single-cell RNA sequencing and spatial transcriptome analysis., Results: In MSI-H gastric cancer, significantly higher proportions of effector memory T cell (Tem), exhausted T cell (Tex), proliferative exhausted T cell (pTex), and proliferative T cell were observed, while MSS gastric cancer exhibited significantly higher proportions of mucosal-associated invariant T cell and natural killer T cell. In MSI-H gastric cancer, Tex and pTex exhibited a significant upregulation of the exhaustion marker LAG3, as well as elevated expression of effector function markers such as IFNG, GZMB, GZMH, and GZMK, compared to those in MSS gastric cancer. The interferon γ (IFN-γ) signaling pathway of Tex and pTex was retained compared to those of MSS gastric cancer. The spatial transcriptome analysis demonstrates the IFN-γ signaling pathway between neighboring Tex and malignant cell, showcasing a significantly elevated interaction in MSI-H gastric cancer., Conclusion: Our study reveals novel finding indicating that IFN-γ signaling pathway is retained in Tex and pTex of MSI-H gastric cancer, offering a comprehensive perspective for future investigations into immunotherapy for gastric cancer.

Background: CD8+ T lymphocyte infiltration is closely associated with the prognosis and immunotherapy response of gastric cancer (GC). For now, the examination of CD8 infiltration levels relies on endoscopic biopsy, which is invasive and unsuitable for longitude assessment during anti-tumor therapy., Purpose: This work aims to develop and validate a noninvasive workflow based on contrast-enhanced CT (CECT) images to evaluate the CD8+ T-cell infiltration profiles of GC., Methods: GC patients were retrospectively and consecutively enrolled and randomly assigned to the training (validation) or test cohort at a 7:3 ratio. All patients were binary classified into the CD8-high (infiltrated proportion ≥ 20%) or CD8-low group (infiltrated proportion < 20%) group. A total of 1170 radiomics features were extracted from each presurgical CECT series. After feature selection, fifteen radiomics features were transmitted to three independent machine-learning models for the computation of predictive radiological scores. Multilayer perceptron (MLP) was applied to merge the radiological scores with clinical factors. The predictive efficacy of the radiological scores and of the combined model was evaluated by receiver operating characteristic curve, calibration curve, and decision curve analysis in both the training and test cohorts., Results: A total of 210 patients were enrolled in this study (mean age: 63.22 ± 8.74 years, 151 men), and were randomly assigned to the training set (n = 147) or the test set (n = 63). The merged radiological score was correlated with CD8 infiltration in both the training (p = 1.8e-10) and test cohorts (p = 0.00026). The combined model integrating the radiological scores and clinical features achieved an area under the curve (AUC) value of 0.916 (95% CI: 0.872-0.960) in the training set and 0.844 (95% CI: 0.742-0.946) in the test set for classifying CD8-high GCs. The model was well-calibrated and exhibited net benefit over "treat-all" and"treat-none" strategies in decision curve analysis., Conclusions: Artificial intelligent systems combining radiological features and clinical factors could accurately predict CD8 infiltration levels of GC, which may benefit personalized treatment of GC in the context of immunotherapy., (© 2024 The Author(s). Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.)

N 6 -methyladenosine (m 6 A) functions as an important regulator in various human cancers, including gastric cancer. The immunotherapy targeting PD-1/PD-L1 has brought hope for advanced gastric cancer therapeutic. Here, present research aims to investigate the roles of m 6 A reader IGF2BP1 on gastric cancer tumor development and immune escape. Results indicated that IGF2BP1 up-regulated in the gastric cancer tissue and correlated with poor prognosis of gastric cancer patients. IGF2BP1 overexpression augmented the proliferation of co-cultured gastric cancer cells, and mitigated the CD8+ T cells mediated anti-tumor response, including IFN-γ secretion, surface PD-L1 level, and cytotoxicity of CD8+ T cells. Meanwhile, IGF2BP1 silencing exerted the opposite effects. In silico analysis revealed that there was a remarkable m 6 A modified site on PD-L1 mRNA. Moreover, the IGF2BP1 overexpression enhanced the stability of PD-L1 mRNA, thereby deteriorating the immune escape of gastric cancer cells. Collectively, these results describe a novel regulatory mechanism of IGF2BP1 by regulating PD-L1 through m 6 A epigenetic modification, which might provide insights for gastric cancer immunotherapies., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Gastric adenocarcinoma (STAD) is the most prevalent malignancy of the human digestive system and the fourth leading cause of cancer-related death. Calcium pools, especially Ca2+ entry (SOCE) for storage operations, play a crucial role in maintaining intracellular and extracellular calcium balance, influencing cell activity, and facilitating tumor progression. Nevertheless, the prognostic and immunological value of SOCE in STAD has not been systematically studied. The objective of this study was to develop a risk model for SOCE signature and to explore its correlation with clinical characteristics, prognosis, tumor microenvironment (TME), as well as response to immunotherapy, chemotherapy, and targeted drugs. We used the TCGA, GEO (GSE84437 and GSE159929), cBioPortal and TIMER databases to acquire mRNA expression data for STAD, along with patient clinical indicators, single-cell sequencing data, genomic variation information, and correlations of immune cell infiltration. An analysis of SOCE genes based on tumor vs. normal tissue comparisons, pan-cancer dimension, single-cell sequencing, DNA mutation, and copy number variation revealed that SOCE genes significantly impact the survival of STAD patients and are differentially involved in the immune response. SOCE co-expressed genes were identified by Pearson analysis, and subsequently protein-protein interaction (PPI) and gene function enrichment analysis indicated that coexpressed genes were associated with multicellular pathways. Based on TCGA and GSE84437 datasets, a multifactor Cox proportional hazard regression analysis was conducted to identify SOCE co-expressed genes associated with overall survival in STAD patients. Several mRNA prognostic genes, including PTPRJ, GPR146, LTBP3, FBLN1, EFEMP2, ADAMTS7 and LBH, were identified, which could be used as effective prognostic predictors for STAD patients. In both training and test datasets, receiver operating characteristic (ROC) curves were utilized to evaluate and illustrate the predictive capability of this characteristic in forecasting overall survival of STAD patients. The qPCR and human protein atlas (HPA) were employed to assess mRNA expression and protein levels. Furthermore, the ESTIMATE, TIMER, CIBERSORT, QUANTISEQ, MCPCOUNTER, xCell and EPIC algorithms were utilized to perform immune score and analyze immune cell infiltration. It effectively revealed the difference in prognosis and immune cell infiltration in TME between high-risk and low-risk groups based on the risk signature associated with SOCE. Notably, significant differences in tumor immune dysfunction and rejection (TIDE) scores between the two groups, suggesting that patients in the low-risk group may exhibit a more favorable response to ICIS treatment. The GDSC database and R packages for predictive analysis were utilized to analyze responses to chemotherapy and targeted drugs in high-risk and low-risk groups. In summary, the 7-gene signature associated with SOCE serves as a significant biomarker for evaluating the TME and predicting the prognosis of STAD patients. In addition, it may provide valuable insights for developing effective immunotherapy and chemotherapy regiments for patients with STAD., (© 2024. The Author(s).)

LSD1 (histone lysine-specific demethylase 1) has been gradually disclosed to act as an immunomodulator to enhance antitumor immune response. Despite the identification of numerous potent LSD1 inhibitors, there remains a lack of LSD1 inhibitors approved for marketing. Novel LSD1 inhibitors with different mechanisms are therefore needed. Herein, we reported a series of novel quinazoline-based LSD1 inhibitors. Among them, compound Z-1 exhibited the best LSD1 inhibitory activity (IC 50 = 0.108 μM). Z-1 also acted as a selective and cellular active as an LSD1 inhibitor. Furthermore, Z-1 promoted response of gastric cancer cells to T-cell killing effect by decreasing PD-L1 expression and further attenuated the PD-1/PD-L1 interaction. In vivo, Z-1 exhibited significant suppression effect on the growth of gastric cancer cells without obvious toxicity. Therefore, Z-1 represents a potential novel immunomodulator that targets LSD1, providing a lead compound with new function mechanism for gastric cancer treatment.

Background: Opioid anesthesia can modulate the impaired immune response and opioid-sparing anesthesia may preserve immune functions. This study was performed to assess the effects of opioid-free anesthesia (OFA) and opioid-based anesthesia (OA) on perioperative macrophages differentiation, cytokine changes, and perioperative complications in locally advanced GC (LAGC) patients., Methods: We used quality of recovery-15 (QoR-15) questionnaire scores and visual analog scale (VAS) scores to compare postoperative quality of recovery and pain level. In addition, the adverse reactions of patients in the two groups were compared. The perioperative serum level of inflammatory cytokines and the ratio of macrophage subtypes were detected., Results: The OFA group had significantly longer extubation time and PACU stay, whereas the OA group had significantly higher rate of hypotension, higher doses of norepinephrine, higher PONV and dizziness rate, and delayed flatus passage time. The QoR-15 score on postoperative 24 h was significantly higher in OFA group than in OA group. At the end of or after the surgery, the OFA group had higher levels of interleukin (IL)-12, IL-1β, tumor necrosis factor (TNF)-α, CD68+CD163- macrophage rate, but lower levels of IL-10, transforming growth factor (TGF)-β, and CD68+CD163+ macrophage rate, indicating OFA attenuated perioperative immunosuppression by diminishing M2 and promoting M1 macrophage polarization. And the reversal tendency is more obvious in LAGC patients with neoadjuvant PD-1 inhibitor., Conclusions: The OFA may attenuate perioperative immunosuppression by diminishing M2 and promoting M1 macrophage polarization in LAGC patients with neoadjuvant PD-1 inhibitor., Clinical Trial Registration: http://gcpgl.sysucc.org.cn, identifier 2022-FXY-001., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Liu, Ou, Xue, Yang, Ye, Wang and Xie.)

Tumor microenvironment (TME) immune cells and gastric mucosal microbiome constitute two vital elements of tumor tissue. Increasing evidence has elucidated their clinicopathological significance in predicting outcomes and therapeutic efficacy. However, comprehensive characterization of immune cell-associated microbiome signatures in the TME is still in the early stages of development. Here, we characterized the gastric mucosa microbiome and its associations with immune-activated related transcripts (IATs) in 170 GC tumor tissues and matched non-tumor tissues using 16s rRNA gene sequencing and quantitative reverse transcription-PCR. Microbial diversity and richness were significantly higher in GC tumor tissues than in non-tumor tissues. Differences in microbial composition between the groups were evident, with Firmicutes, Proteobacteria, Bacteroidota, Campilobacterota, Actinobacteria, Fusobacteriota, Verrucomicrobiota, Acidobacteriota, and Cyanobacteria being the dominant phyla in the gastric mucosal microbiota. Microbial interaction network analysis revealed distinctive centralities of oral bacteria (such as Fusobacterium, Porphyromonas, Prevotella , etc.) in both tumor and normal mucosae networks, suggesting their significant influence on GC microbial ecology. Furthermore, we analyzed the expression of IATs (CXCL9, CXCL10, GZMA, GZMB, PRF1, CD8A, IFNG, TBX2, and TNF) and characterized IAT-relevant gastric microbiome signatures in GC patients. Our results showed that the expression of CXCL9, CXCL10, GZMA, GZMB, PRF1 and IFNG was significantly higher in tumor tissues than in adjacent normal tissues in GC patients. Notably, high expression of IATs in tumor tissues was associated with improved survival in GC patients and could serve as a powerful predictor for disease-free survival. Additionally, analysis of IAT levels and mucosal microbiota diversity revealed a correlation between higher IAT expression and increased microbiota richness and evenness in the IATs high group, suggesting potential interactions between mucosal microbiota and tumor immunopathology. Spearman correlation analysis showed positive associations between IAT expression and specific mucosal bacterial species. Notably, Akkermansia muciniphila demonstrated potential involvement in modulating GZMB expression in the GC mucosal microenvironment. These findings underscore the importance of mucosal microbiota alterations in GC and suggest potential therapeutic targets focusing on modulating the tumor microbiota for improved clinical outcomes. The detailed characterization of these elements has profound implications for both treatment and survival prediction in GC. We observed that microbial diversity and richness were significantly higher in GC tumor tissues compared to non-tumor tissues. These differences highlight the unique microbial landscape of GC tumors and suggest that the microbiome could influence tumor development and progression. Importantly, our study demonstrated that high expression levels of IATs in GC tumor tissues were associated with improved patient survival. This suggests that IATs not only reflect immune activation but also serve as valuable biomarkers for predicting disease-free survival. The potential of IATs as predictive markers underscores their utility in guiding therapeutic strategies and personalizing treatment approaches. Moreover, the correlation between higher IAT expression and increased microbiota richness and evenness suggests that a diverse and balanced microbiome may enhance immune responses and contribute to better clinical outcomes. These findings highlight the critical need to consider mucosal microbiota alterations in GC management. Targeting the tumor microbiota could emerge as a promising therapeutic strategy, potentially leading to more effective treatments and improved patient outcomes. Understanding and modulating the microbiome's role in GC opens new avenues for innovative therapeutic interventions and personalized medicine., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Qian, Hui, Peng, Sun and Zhang.)

Gastric cancer (GC) is a prevalent malignancy with high mortality rates. Immunogenic cell death (ICD) is a unique form of programmed cell death that is closely linked to antitumor immunity and plays a critical role in modulating the tumor microenvironment (TME). Nevertheless, elucidating the precise effect of ICD on GC remains a challenging endeavour. ICD-related genes were identified in single-cell sequencing datasets and bulk transcriptome sequencing datasets via the AddModuleScore function, weighted gene co-expression network (WGCNA), and differential expression analysis. A robust signature associated with ICD was constructed using a machine learning computational framework incorporating 101 algorithms. Furthermore, multiomics analysis, including single-cell sequencing analysis, bulk transcriptomic analysis, and proteomics analysis, was conducted to verify the correlation of these hub genes with the immune microenvironment features of GC and with GC invasion and metastasis. We screened 59 genes associated with ICD and developed a robust ICD-related gene signature (ICDRS) via a machine learning computational framework that integrates 101 different algorithms. Furthermore, we identified five key hub genes (SMAP2, TNFAIP8, LBH, TXNIP, and PIK3IP1) from the ICDRS. Through single-cell analysis of GC tumor s, we confirmed the strong correlations of the hub genes with immune microenvironment features. Among these five genes, LBH exhibited the most significant associations with a poor prognosis and with the invasion and metastasis of GC. Finally, our findings were validated through immunohistochemical staining of a large clinical sample set, and the results further supported that LBH promotes GC cell invasion by activating the epithelial-mesenchymal transition (EMT) pathway., (© 2024. The Author(s).)

Background: While small extracellular vesicles (sEVs)-derived circular RNAs (circRNAs) have been emerged as significant players in cancer, the function and underlying mechanism of sEVs-derived circRNAs in anti-cancer immunity remain unclear., Methods: Gastric cancer (GC)-derived circRNAs were identified using RNA-seq data from GEO datasets and quantitative reverse transcription polymerase chain reaction (qRT-PCR), RNA immunoprecipitation, dual-luciferase assay, and bioinformatics analysis were performed to investigate the regulatory axis. Transwell assay, wound healing assay, cell counting kit-8 (CCK-8) assay, and xenograft models were used to evaluate its role in GC progression in vivo and in vitro. The delivery of specific circRNAs into sEVs were verified through electron microscopy, nanoparticle tracking analysis (NTA) and fuorescence in situ hybridization (FISH). Flow cytometric analysis and immunohistochemical staining were conducted to find out how specific circRNAs mediated CD8 +  T cell exhaustion and resistant to anti-programmed cell death 1 (PD-1) therapy., Results: We identified that circ&#95;0001947, packaged by GC-derived sEVs, was obviously elevated in GC and was associated with poor clinical outcome. High circ0001947 level augmented the proliferation, migration, and invasion of GC cells. Mechanistically, circ0001947 sponged miR-661 and miR-671-5p to promote the expression of CD39, which further facilitated CD8 +  T cell exhaustion and immune resistance. Conversely, blocking circ&#95;0001947 attenuated CD8 +  T cell exhaustion and increased the response to anti-PD-1 therapy., Conclusions: Our study manifested the therapeutic potential of targeting sEVs-transmitted circ&#95;0001947 to prohibit CD8 +  T cell exhaustion and immune resistance in GC., (© 2024. The Author(s).)

Purpose: A multicenter, randomized, open-label, phase II study (HERIZON; NCT02795988) was conducted to evaluate the clinical and immunologic efficacy of HER-Vaxx (IMU-131), a B-cell, peptide-based vaccine targeting HER2 overexpressed in 6% to 30% of gastroesophageal adenocarcinomas (GEA)., Patients and Methods: Patients (n = 36) with GEA were treated with standard-of-care chemotherapy (n = 17) or HER-Vaxx plus chemotherapy (n = 19), using the recommended phase 2 dose for the vaccine. Overall survival (OS; primary endpoint), safety, progression-free survival (PFS), clinical response (secondary endpoints), and vaccine-induced HER2-specific antibody levels in serum and correlation with tumor response rates (exploratory endpoints) were investigated., Results: A 40% OS benefit [HR, 0.60; median OS, 13.9 months; 80% confidence interval (CI), 7.52-14.32] for patients treated with HER-Vaxx plus chemotherapy compared with OS of 8.31 months (80% CI, 6.01-9.59) in patients that received chemotherapy alone. A 20% PFS difference was obtained for the vaccination arm (HR, 0.80; 80% CI, 0.47, 1.38). No additional toxicity due to HER-Vaxx was observed. The vaccine-induced high levels of HER2-specific total IgG and IgG1 antibodies (P < 0.001 vs. controls) that significantly correlated with tumor reduction (IgG, P = 0.001; IgG1, P = 0.016), had a significant capacity in inhibiting phosphorylation of the intracellular HER2-signaling pathways, mediated antibody-dependent cellular cytotoxicity, and decreased immunosuppressive FOXP3+ regulatory T cells., Conclusions: HER-Vaxx plus standard chemotherapy exhibits an excellent safety profile and improves OS. Furthermore, vaccine-induced immune response was significantly associated with reduced tumor size compared with standard-of-care chemotherapy. The presented vaccination approach may substitute for treatment with trastuzumab, upon unavailability or toxicity, based on further evidence of equivalent treatment efficacy., (©2024 The Authors; Published by the American Association for Cancer Research.)

Background: Tryptophan Metabolism-associated Genes (TMGs), such as ECHS1 and ALDH2, are crucial in cancer progression through immunosuppressive mechanisms, particularly in Gastric Cancer (GC). This study explores their effects on the Tumor Microenvironment (TME). Additionally, it examines their potential as novel immunotherapy targets., Methods: We utilized single-cell and bulk transcriptomic technologies to analyze the heterogeneity of GC. Non-negative Matrix Factorization (NMF) clustering identified key TMGs, and extensive RNA-seq analyses were performed to pinpoint prognostic genes and potential immunotherapy targets. Furthermore, through PCR analyses we found that ECHS1 and ALDH2 gene expression plays a regulatory role in the migration, invasion and inflammatory factor in AGS and SNU-1 cell lines. The interference effect of si-ECHS1 and ad-ALDH2 was validated using cell scratch assay in AGS and SNU-1 cell line., Results: We observed a statistically significant correlation between ECHS1 and ALDH2 expression and increased TME heterogeneity. Our findings also revealed that ECHS1 down-regulation and ALDH2 up-regulation contribute to reduced TME heterogeneity, decreased inflammation, and inhibited AGS and SNU-1 tumor cells migration and proliferation. GSVA enrichment analysis highlighted the NF-kappa B(NF-κB) signaling pathway as specifically regulated by TMGs. Furthermore,ECHS1 and ALDH2 modulated CD8+ and CD4+ T cell activities, impacting GC progression. In vitro experiments further solidified our conclusions by showcasing the inhibitory effects of Si-ECHS1 and ad-ALDH2 on the invasive and proliferative capabilities of AGS and SNU-1 cells. Moreover, Si-ECHS1 and ad-ALDH2 gene expression effectively reduced the expression of inflammatory factors IL-10,IL-7,CXCL8 and IL-6, leading to a remarkable alleviation of chronic inflammation and the heterogeneous nature of the TME., Conclusion: This research highlights the importance of ECHS1 and ALDH2 in GC progression and immune modulation, suggesting that targeted therapies focusing on these genes offer promising avenues for personalized immunotherapy in GC. These findings hold potential for improving patient survival and quality of life. Future studies on the NF-κB signaling pathway's role in this context are warranted to further elucidate the mechanisms underlying TMG-mediated immune modulation in GC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Zhou, Yan, Miao, Wang, Gu, Fan, Xu, Huang and Liu.)

We aimed to determine the prognostic significance of ZFP1 in gastric cancer (GC), its role in the immune microenvironment, and its potential as a therapeutic target using data from The Cancer Genome Atlas (TCGA) database. ZFP1 overexpression was closely associated with tumour T stage and histological grade. Patients with GC and high ZFP1 expression had poor outcomes. Lower ZFP1 expression was associated with longer symptom-free intervals and disease-specific survival. Subgroup analyses of T3 and T4, N0, N1, and M0 patients showed that overall survival (OS), disease-specific survival, and progression-free interval (PFI) were worse in those with high ZFP1 expression. ZFP1 expression in GC was moderately to strongly positively correlated with the infiltration levels of effector central memory T cells and T helper cells and negatively correlated with Th17 cells and NK CD56bright cells. The lncRNA-miRNA-ZFP1 axis was predicted using a public database. CCK8, colony formation, and wound healing assays were conducted to investigate whether ZFP1 promoted the proliferation and migration of GC cells. Our study suggests that ZFP1 plays a key role in the prognosis, immune response, and progression of GC and is a significant factor in the diagnosis and treatment of this disease., (© 2024. The Author(s).)

Multiple investigations have demonstrated the crucial involvement of T-cell exhaustion (TEX) in anti-tumor immune response and their strong correlation with prognosis. This study aimed at creating a strong signature using TEX for gastric cancer through bioinformatics analysis and experimental validation. We utilized data from The Cancer Genome Atlas (TCGA) databases to retrieve RNA-seq data from patients with stomach adenocarcinoma (STAD). Genes related to TEX were discovered using gene set variance analysis (GSVA) and weighted gene correlation network analysis (WGCNA). Subsequently, prognostic signature based on TEX was developed using LASSO-Cox analysis. Relationship between key genes and immune cells were examined. Finally, biological function of a key TEX-related gene PTPRT in gastric cancer was verified by in vivo experiment. A total of 29 TEX-related biomarkers were screened by WGCNA and random forest. Among them, five core signatures (PTPRT, CAV2, PPIH, PRDM2, and FGF1), further identified by LASSO-Cox, were considered as strong predictors of prognosis for gastric cancer and associated with immune infiltration. PTPRT gene had the largest number of SNPs, with the most mutation types. In vivo experiments revealed that PTPRT overexpression significantly inhibited tumor malignant progression and accelerated apoptosis through stimulating the secretion of killer cytokines such as TNF-α and IFN-γ. In addition, flow cytometry revealed that PTPRT overexpression alleviated TEX by increasing the abundance of CD8+ T cells, with inhibition of cell surface PD-1 and Tim-3. The predictive prognostic value of TEX gene expression levels was evaluated in patients with gastric cancer, providing a new perspective for precision immuno-oncology studies., (© 2024. The Author(s).)

Mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) gastric cancer (GC) exhibits an immune-active tumor microenvironment (TME) compared to MMR proficient (pMMR)/microsatellite stable/Epstein-Barr virus-negative [EBV (-)] GC. The tumor cell-intrinsic cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been considered a key regulator of immune cell activation in the TME. However, its significance in regulating the immune-active TME in dMMR/MSI-H GC remains unclear. Here, we demonstrated that tumor cell-intrinsic cGAS-STING was highly expressed in dMMR GC compared to pMMR/EBV (-) GC. The expression of tumor cell-intrinsic STING was significantly and positively associated with the number of CD8 + tumor-infiltrating lymphocytes in GC. Analysis of TCGA datasets revealed that the expression of interferon-stimulated genes and STING downstream T-cell attracting chemokines was significantly higher in MSI-H GC compared to other subtypes of GC with EBV (-). These results suggest that tumor cell-intrinsic STING signaling plays a key role in activating immune cells in the dMMR/MSI-H GC TME and might serve as a novel biomarker predicting the efficacy of immunotherapy for GC treatment., (© 2024. The Author(s).)

Background: Stage IV gastric cancer is a highly heterogeneous and lethal tumor with few therapeutic strategies. The combination of programmed cell death protein 1 inhibitors and chemotherapy is currently the standard frontline treatment regimen for advanced gastric cancer. Nevertheless, it remains a great challenge to screen the beneficiaries of immunochemotherapy and expand indications for this treatment regimen., Methods: We conducted a pathological assessment to ascertain the importance of tertiary lymphoid structures based on the tissue samples collected from patients with stage IV gastric cancer (n=15) both prior to and following immunochemotherapy treatment. Additionally, we used spatial (n=10) and single-cell transcriptional analysis (n=97) to investigate the key regulators of tertiary lymphoid structures (TLSs). Multiplex immunofluorescence and image analysis (n=34) were performed to explore the association between tumor-infiltrating CXCL13 + CD160 + CD8 + T cells and TLSs. The relationship between CXCL13 + CD160 + CD8 + T cells and the responsiveness to immunotherapy was also evaluated by multiplex immunofluorescence and image analysis approaches (n=15). Furthermore, we explored the intrinsic characteristics of CXCL13 + CD160 + CD8 + T cells through various experimental techniques, including quantitative reverse transcription-PCR, western blot, and flow cytometry., Results: We found that responders exhibited higher levels of TLSs and CXCL13 + CD160 + CD8 + T cells in biopsy tissues prior to immunochemotherapy compared with non-responders. Following conversion therapy, responders also had a higher percentage of mature TLSs and a higher number of CXCL13 + CD160 + CD8 + T cells in surgical resections. Moreover, we discovered that vitamin B 6 in CD160 + CD8 + T cells could reduce the ubiquitination modification of HIF-1α by MDM2, thereby attenuating the degradation of HIF-1α. Consequently, this led to the transcriptional upregulation of CXCL13 expression, facilitating the recruitment of CXCR5 + B cells and the formation of TLSs., Conclusion: The number and maturity of TLSs, along with the extent of CXCL13 + CD160 + CD8 + T-cell infiltration, might function as potential indicators for assessing the effectiveness of immunotherapy in treating gastric malignancies. Furthermore, our research suggests that vitamin B 6 could enhance the secretion of CXCL13 by CD160 + CD8 + T cells by reducing the degradation of HIF-1α. Additionally, we demonstrate that vitamin B 6 supplementation or targeting pyridoxal kinase could substantially improve the efficacy of immunotherapies for gastric cancer., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Immunotherapy has profoundly changed the treatment of gastric cancer, but only a minority of patients benefit from immunotherapy. Therefore, numerous studies have been devoted to clarifying the mechanisms underlying resistance to immunotherapy or developing biomarkers for patient stratification. However, previous studies have focused mainly on the tumor microenvironment. Systemic immune perturbations have long been observed in patients with gastric cancer, and the involvement of the peripheral immune system in effective anticancer responses has attracted much attention in recent years. Therefore, understanding the distinct types of systemic immune organization in gastric cancer will aid personalized treatment designed to pair with traditional therapies to alleviate their detrimental effects on systemic immunity or to directly activate the anticancer response of systemic immunity. Herein, this review aims to comprehensively summarize systemic immunity in gastric cancer, including perturbations in systemic immunity induced by cancer and traditional therapies, and the potential clinical applications of systemic immunity in the detection, prediction, prognosis and therapy of gastric cancer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhang, Li, Li and Wang.)

HER2, a member of the human epidermal growth factor receptor(HER)family, exhibits gene amplification, protein overexpression, or both in 13-27% of gastric cancer(GC)cases. Through the activation of downstream Akt and ERK pathways, HER2 promotes the survival and proliferation of gastric cancer cells. The impact of HER2 signaling on the tumor microenvironment(TME)in GC remains unclear, and the heterogeneity of HER2 overexpression in GC tissues is considered a contributing factor. In this study, we focused on differences in the TME between HER2-positive and HER2-negative areas in HER2-positive GC and found that HER2 signaling, particularly the HER2-Akt cascade, may suppress stimulator of interferon genes (STING)expression and reduce CD8+ T cell infiltration in tumor cells. Overall, our findings suggest the potential for a novel therapeutic approach to activate the anti-tumor immune response in HER2-positive GC.

Backgroud: According to the 2020 statistics from the World Health Organization's International Agency for Research on Cancer (IARC), it is projected that there will be over 1 million new cases of gastric cancer (GC) patients worldwide in 2020, resulting in approximately 770 000 deaths. Gastric cancer ranks fifth in terms of incidence rate and forth in death rate among malignant tumors. Despite advancements in early diagnostic techniques, the incidence of GC has exhibited a marginal decline; nevertheless, the mortality rate remains elevated for advanced inoperable patients with no currently available efficacious treatment options., Recent Finding: Chinese medicine (CM) has emerged as an efficacious treatment for GC, gradually gaining acceptance and widespread usage in China. It exhibits distinctive advantages in the prevention and treatment of metastasis. CM and natural medicine possess the ability to elicit antitumor effects by augmenting immune cell population, enhancing immune cell activity, and improving the tumor immune microenvironment. CMs and natural remedies encompass a diverse range of types, characterized by multiple targets, pathways, and extensive pharmacological effects. Consequently, they have become a prominent research area among oncologists worldwide. Numerous studies have demonstrated that CM and natural medicine can directly or indirectly enhance innate immune system components (including macrophages, natural killer cells, and myeloid suppressor cells), adaptive immune system elements (such as T lymphocytes and regulatory T cells), relevant cytokines (e.g., IL-2, IL-4, IL-10, TNF-α), and PD-1/PD-L1 axis regulation, thereby bolstering the cytotoxicity of immune cells against tumor cells., Conclusions: This ultimately leads to an improved tumor immune microenvironment facilitating superior antitumor efficacy. This paper critically examines the role of CM and natural medicine in regulating immunotherapy for GC, aiming to establish a new theoretical framework for the clinical treatment and prevention of gastric cancer within the realm of CM., (© 2024 The Author(s). Cancer Reports published by Wiley Periodicals LLC.)

The CLDN18-ARHGAP fusion gene is an oncogenic driver newly discovered in gastric cancer. It was detected in 9% (8/87) of gastric cancer patients in our center. An immunogenic peptide specifically targeting CLDN18-ARHGAP fusion gene was generated to induce neoantigen-reactive T cells, which was proved to have specific and robust anti-tumor capacity both in in vitro coculture models and in vivo xenograft gastric cancer models. Apart from the immunogenic potential, CLDN18-ARHGAP fusion gene was also found to contribute to immune suppression by inducing a regulatory T (Treg) cell-enriched microenvironment. Mechanistically, gastric cancer cells with CLDN18-ARHGAP fusion activate PI3K/AKT-mTOR-FAS signaling, which enhances free fatty acid production of gastric cancer cells to favor the survival of Treg cells. Furthermore, PI3K inhibition could effectively reverse Treg cells upregulation to enhance anti-tumor cytotoxicity of neoantigen-reactive T cells in vitro and reduce tumor growth in the xenograft gastric cancer model. Our study identified the CLDN18-ARHGAP fusion gene as a critical source of immunogenic neoepitopes, a key regulator of the tumor immune microenvironment, and immunotherapeutic applications specific to this oncogenic fusion., (© 2024. The Author(s).)

Introduction: Immunochemotherapy with PD-1 blockade has been established as the current standard first-line therapy for patients with mGEA. Reviewing the history of clinical trials offers valuable insight into the evolution of immune oncology in mGEA, paving the way for future advancements in this field., Areas Covered: This review summarizes the findings of previous clinical trials related to immunotherapy for patients with GEA in the metastatic and locally advanced setting. We also introduce ongoing clinical trials to address the current challenging issues in clinical practice., Expert Opinion: In general, GEA exhibits intermediate immunogenic characteristics with heterogeneous expressions, and responders to anti-PD-(L)1 therapy are mostly enriched to patients with specific genomic profiles such as MSI-H, high PD-L1 expression, high TMB, and EBV-associated type. Co-administration with anti-angiogenic agents or simultaneous blockade of immune checkpoint molecules is being explored to offer benefit of immunotherapy for more patients. We hope that CLDN18.2 and upcoming targets like FGFR2b will complement the treatment niche of immunotherapy in the field of mGEA. Bispecific antibodies, antibody drug conjugates, CAR-T, and vaccine are anticipated to enhance efficacy and expand the scope of immunotherapy.

Background: The pattern of cell death known as disulfidptosis was recently discovered. Disulfidptosis, which may affect the growth of tumor cells, represents a potential new approach to treating tumors. Glycolysis affects tumor proliferation, invasion, chemotherapy resistance, the tumor microenvironment (TME), and immune evasion. However, the efficacy and therapeutic significance of disulfidptosis-related glycolysis genes (DRGGs) in stomach adenocarcinoma (STAD) remain uncertain., Methods: STAD clinical data and RNA sequencing data were downloaded from the TCGA database. DRGGs were screened using Cox regression and Lasso regression analysis to construct a prognostic risk model. The accuracy of the model was verified using survival studies, receiver operating characteristic (ROC) curves, column plots, and calibration curves. Additionally, our study investigated the relationships between the risk scores and immune cell infiltration, tumor mutational burden (TMB), and anticancer drug sensitivity., Results: We have successfully developed a prognosis risk model with 4 DRGGs (NT5E, ALG1, ANKZF1, and VCAN). The model showed excellent performance in predicting the overall survival of STAD patients. The DRGGs prognostic model significantly correlated with the TME, immune infiltrating cells, and treatment sensitivity., Conclusions: The risk model developed in this work has significant clinical value in predicting the impact of immunotherapy in STAD patients and assisting in the choice of chemotherapeutic medicines. It can correctly estimate the prognosis of STAD patients., (© 2024. The Author(s), under exclusive licence to Federación de Sociedades Españolas de Oncología (FESEO).)

Objective: NK cells play a vital role in tumor immune resistance. Various factors affect NK cell activity. While NK cell dysfunction has been observed in numerous malignancies, the underlying mechanisms in gastric cancer remain unclear., Method: Flow cytometry was used to identify the phenotypic distribution and expression of activated receptors on NK cells. ELISA was used to determine the expression of cytokines. We examined the expression of NK cell-related genes and explored their association with survival and prognosis. Additionally, we conducted PCR detection of miR-552-5p expression levels in plasma exosomes of patients and investigated its correlation with phenotypic distribution and activated receptors. We used flow cytometry and ELISA to verify the role of miR-552-5p in NK cell dysfunction. Furthermore, we investigated the potential role of PD-1/PD-L1 in regulating NK cell dysfunction in patients' cells., Results: We observed a significant decrease in the percentage of NKG2D and NKp30 and IFN-γ and TNF-α in patients than in healthy volunteers. Patients with low levels of CD56, CD16, NKG2D, and NKP46 exhibited poorer survival prognoses. Moreover, increased expression levels of plasma exosomal miR-552-5p in patients were negatively associated with NK cell phenotypic distribution and activated receptor expression. MiR-552-5p downregulated the secretion of perforin, granzyme, and IFN-γ as well as the expression of NKp30, NKp46, and NKG2D. Additionally, it suppressed the cytotoxicity of NK cells. The inhibitory effect of miR-552-5p, on NK cell function was reversed when anti-PD-L1 antibodies were used., Conclusion: Exosomal miR-552-5p targets the PD-1/PD-L1 axis, leading to impaired NK cell function., (© 2024. The Author(s).)

The infiltration of CD8 + T cells in the tumor microenvironment is associated with better survival and immunotherapy response. However, their roles in gastric cancer have not been explored so far. In here, the profiles of GC gene expression were collected from The Cancer Genome Atlas database. Single-cell transcriptomic data originated from GSE134520. Cell clustering, annotation, and CD8 + T-cell differential genes were from the TISCH database. We determined 896 CD8 + T-cell differential genes by scRNA-seq analysis. After integrating immune-related genes, 174 overlapping genes were obtained and a novel risk model was subsequently built. The performance of CD8 + T-cell-associated gene signature was assessed in the training and external validation sets. The gene signature showed independent risk factors of overall survival for GC. A quantitative nomogram was built to enhance the clinical efficacy of this signature. Furthermore, low-risk individuals showed higher mutation status, higher immune checkpoint expression, low Tumour Immune Dysfunction and Exclusion (TIDE) scores, and higher IPS-PD-1 combined IPS-CTLA4 scores, indicating a greater response to immunotherapy. In addition, analysis of IMvigor210 immunotherapy cohort demonstrated that low-risk individuals had a favorable response to prognosis and immunotherapy. In conclusion, we generated a CD8 + T-cell-related signature that can serve as a promising tool for personalized prognosis prediction and guiding decisions regarding immunotherapy in GC patients., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Enormous patients with gastric cancer (GC) are insensitive to chemotherapy and targeted therapy without the chance of radical surgery, so immunotherapy may supply a novel choice for them. Chimeric antigen receptor (CAR)-T cell therapy has the advantages of higher specificity, stronger lethality, and longer-lasting efficacy, and it has the potential for GC in the future. However, its application still faces numerous obstacles in terms of accuracy, efficacy, and safety. Cytokines can mediate the migration, proliferation, and survival of immune cells, regulate the duration and strength of immune responses, and are involved in the occurrence of severe side effects in CAR-T cell therapy. The expression levels of specific cytokines are associated with the genesis, invasion, metastasis, and prognosis of GC. Applications of cytokines and their receptors in CAR-T cell therapy have emerged, and various cytokines and their receptors have contributed to improving CAR-T cell anti-tumor capabilities. Large amounts of central cytokines in this therapy include chemokines, interleukins (ILs), transforming growth factor-β (TGF-β), and colony-stimulating factors (CSFs). Meanwhile, researchers have explored the combination therapy in treating GC, and several approaches applied to other malignancies can also be considered as references. Therefore, our review comprehensively outlines the biological functions and clinical significance of cytokines and summarizes current advances and innovative strategies for harnessing cytokines to optimize CAR-T cell therapy for GC., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The immune microenvironment plays a critical regulatory role in the pathogenesis of Helicobacter pylori (H. pylori). Understanding the mechanisms that drive the transition from chronic inflammation to cancer may provide new insights for early detection of gastric cancer. Although chronic inflammation is frequent in precancerous gastric conditions, the monitoring function of the inflammatory microenvironment in the progression from H. pylori-induced chronic inflammation to gastric cancer remains unclear. This literature review summarizes significant findings on how H. pylori triggers inflammatory responses and facilitates cancer development through the immune microenvironment. Furthermore, the implications for future research and clinical applications are also addressed. The review is divided into four main sections: inflammatory response and immune evasion mechanisms induced by H. pylori, immune dysregulation associated with gastric cancer, therapeutic implications, and future perspectives on H. pylori-induced gastric carcinogenesis with a focus on the immune microenvironment., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Immune escape is a major obstacle to T-cell-based immunotherapy for cancers such as gastric cancer (GC). Mesoderm-specific transcript (MEST) is a tumor-promoting factor that regulates multiple oncogenic signaling pathways. However, the role of MEST-mediated immune escape is unclear., Methods: Bioinformatics analysis of MEST expression and enrichment pathways were performed Quantitative reverse transcription PCR (qPCR) or western blot was used to detect the expression of MEST, Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2), Major histocompatibility class I (MHCI)-related genes. Cell function was assessed by Cell Counting Kit (CCK)-8, Transwell, Lactate dehydrogenase (LDH) kit, flow cytometry, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry (IHC). Xenograft nude mice and immune-reconstructed mice were used to test the effects of different treatments on tumor growth and immune escape in vivo., Results: MEST was upregulated in GC and promoted tumor proliferation, migration, and invasion. Rescue experiments revealed that TNO155 treatment or knockdown of SHP2 promoted the killing ability of CD8 + T cells and the expression of granzyme B (GZMB) and interferon-gamma (IFN-γ), and MEST overexpression reversed the effect. In vivo experiments confirmed that MEST promoted tumor growth, knockdown of MEST inhibited immune escape in GC, and that combination treatment with anti-PD-1 improved anti-tumor activity., Conclusion: In this study, we demonstrated that MEST inhibited IFN-γ secretion from CD8+ T cells by up-regulating SHP2, thereby downregulating MHCI expression in GC cells to promote immune escape and providing a new T cell-based therapeutic potential for GC., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024. Published by Elsevier Ltd.)

The aim of this study was to observe the therapeutic effect of sintilimab combined with a modified docetaxel + cisplatin + fluorouracil (DCF) regimen on advanced gastric cancer and its effect on Th1/Th2 immune balance. Ninety-eight cases of advanced gastric cancer patients who visited our hospital from April 2020 to May 2022 were selected and divided into 48 cases each in the conventional group and the research group by random number table method; the DCF regimen was adopted in the conventional group, and sintilimab combined with modified DCF regimen was adopted in the research group, and the therapeutic effects of the patients in the two groups and the changes of Th1/Th2 immune indexes were compared. CEA, CA199, CA242, CD168 AQ3, and IL-4 in the study group were lower than those in the conventional group at the end of three cycles of treatment, and the difference was statistically significant ( P  < 0.001). The levels of IFN-γ and IL-4 in the study group at the end of three cycles of treatment were higher than those in the conventional group ( P  < 0.001). The incidence of adverse reactions during treatment in the study group was lower than that in the conventional group ( P  < 0.001), and the grading of adverse reactions in the study group was milder than that in the conventional group. Sintilimab combined with a modified DCF regimen in the treatment of advanced gastric cancer not only improves the therapeutic effect but also positively affects the Th1/Th2 immune balance, which provides better immune regulation for patients with advanced gastric cancer., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Cancer immunotherapy aims to unleash the immune system's potential against cancer cells, providing sustained relief for tumors responsive to immune checkpoint inhibitors (ICIs). While promising in gastric cancer (GC) trials, the efficacy of ICIs diminishes in the context of peritoneal dissemination. Our objective is to identify strategies to enhance the impact of ICI treatment specifically for cases involving peritoneal dissemination in GC., Methods: The therapeutic efficacy of anti-PD1, CTLA4 treatment alone, or in combination was assessed using the YTN16 peritoneal dissemination tumor model. Peritoneum and peritoneal exudate cells were collected for subsequent analysis. Immunohistochemical staining, flow cytometry, and bulk RNA-sequence analyses were conducted to evaluate the tumor microenvironment (TME). A Janus kinase inhibitor (JAKi) was introduced based on the pathway analysis results., Results: Anti-PD1 and anti-CTLA4 combination treatment (dual ICI treatment) demonstrated therapeutic efficacy in certain mice, primarily mediated by CD8 + T cells. However, in mice resistant to dual ICI treatment, even with CD8 + T cell infiltration, most of the T cells exhibited an exhaustion phenotype. Notably, resistant tumors displayed abnormal activation of the Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) pathway compared to the untreated group, with observed infiltration of macrophages, neutrophils, and Tregs in the TME. The concurrent administration of JAKi rescued CD8 + T cells function and reshaped the immunosuppressive TME, resulting in enhanced efficacy of the dual ICI treatment., Conclusion: Dual ICI treatment exerts its anti-tumor effects by increasing tumor-specific CD8 + T cell infiltration, and the addition of JAKi further improves ICI resistance by reshaping the immunosuppressive TME., (© 2024. The Author(s).)