Low-dose radiotherapy synergizes with iRGD-antiCD3-modified T cells by facilitating T cell infiltration.

BACKGROUND AND PURPOSE: Poor penetration of transferred T cells represents a critical factor impeding the development of adoptive cell therapy in solid tumors. We demonstrated that iRGD-antiCD3 modification promoted both T cell infiltration and activation in our previous work. Interest in low-dose radiotherapy has recently been renewed due to its immuno-stimulatory effects including T cell recruitment. This study aims to explore the synergistic effects between low-dose radiotherapy and iRGD-antiCD3-modified T cells. MATERIALS AND METHODS: Flow cytometry was performed to assess the expression of iRGD receptors and chemokines. T cell infiltration was evaluated by immunohistofluorescence and in vivo real-time fluorescence imaging and antitumor effects were investigated by in vivo bioluminescence imaging in the gastric cancer peritoneal metastasis mouse model. RESULTS: We found that 2 Gy irradiation upregulated the expression of all three iRGD receptors and T-cell chemokines. The addition of 2 Gy low-dose irradiation boosted the accumulation and penetration of iRGD-antiCD3-modified T cells in peritoneal tumor nodules. Combining 2 Gy low-dose irradiation with iRGD-antiCD3-modified T cells significantly inhibited tumor growth and prolonged survival in the peritoneal metastasis mouse model with a favorable safety profile. CONCLUSION: Altogether, we demonstrated that low-dose radiotherapy could improve the antitumor potency of iRGD-antiCD3-modified T cells by promoting T cell infiltration, providing a rationale for exploring low-dose radiotherapy in combination of other adoptive T cell therapies in solid tumors.

Exploration of signature based on T cell-related genes in stomach adenocarcinoma by analysis of single cell sequencing data.

BACKGROUND: Gastric cancer (GC) is a leading reason for the death of cancer around the world. The immune microenvironment counts a great deal in immunotherapy of advanced tumors, in which T cells exert an indispensable function. METHODS: Single-cell RNA sequencing data were utilized to characterize the expression profile of T cells, followed by T cell-related genes (TCRGs) to construct signature and measure differences in survival time, enrichment pathways, somatic mutation status, immune status, and immunotherapy between groups. RESULTS: The complex tumor microenvironment was analyzed by scRNA-seq data of GC patients. We screened for these T cell signature expression genes and the TCRGs-based signature was successfully constructed and relied on the riskscore grouping. In gene set enrichment analysis, it was shown that pro-tumor and suppressive immune pathways were more abundant in the higher risk group. We also found different infiltration of immune cells in two groups, and that the higher risk samples had a poorer response to immunotherapy. CONCLUSION: Our study established a prognostic model, in which different groups had different prognosis, immune status, and enriched features. These results have provided additional insights into prognostic evaluation and the development of highly potent immunotherapies in GC.

The necroptosis-related signature and tumor microenvironment immune characteristics associated with clinical prognosis and drug sensitivity analysis in stomach adenocarcinoma.

PURPOSE: Necroptosis plays an important role in the tumorigenesis, development, metastasis, and drug resistance of malignant tumors. This study explored the new model for assessing stomach adenocarcinoma (STAD) prognosis and immunotherapy by combining long noncoding RNAs associated with necroptosis. METHODS: Patient clinical data and STAD gene expression profiles were curated from The Cancer Genome Atlas (TCGA). Immune-related genes were sourced from a specialized molecular database. Perl software and R software were used for data processing and analysis. Necroptosis-related lncRNAs in STAD were pinpointed via R's correlation algorithms. These lncRNAs, in conjunction with clinical data, informed the construction of a prognostic lncRNA-associated risk score model using univariate and multivariate Cox regression analyses. The model's prognostic capacity was evaluated by Kaplan-Meier survival curves and validated as an independent prognostic variable. Further, a nomogram incorporating this model with clinical parameters was developed, offering refined individual survival predictions. Subsequent analyses of immune infiltration and chemosensitivity within necroptosis-related lncRNA clusters utilized an arsenal of bioinformatic tools, culminating in RT-PCR validation of lncRNA expression. RESULTS: Through rigorous Cox regression, 21 lncRNAs were implicated in the risk score model. Stratification by median risk scores delineated patients into high- and low-risk cohorts, with the latter demonstrating superior prognostic outcomes. The risk model was corroborated as an independent prognostic indicator for STAD. The integrative nomogram displayed high concordance between predicted and observed survival rates, as evidenced by calibration curves. Differential immune infiltration in risk-defined groups was illuminated by the single sample GSEA (ssGSEA), indicating pronounced immune presence in higher-risk patients. Tumor microenvironment (TME) analysis showed that cluster-C3 had the highest score in the analysis of the three TMEs. Through the differential analysis of immune checkpoints, it was found that almost all immune checkpoint-related genes were expressed differently in various tumor clusters. Among them, CD44 expression was the highest. By comparing all drug sensitivities, we screened out 29 drugs with differences in drug sensitivity across different clusters. Risk score gene expression identification results showed that these lncRNAs were abnormally expressed in gastric cancer cell lines. CONCLUSIONS: This investigation provides a robust methodological advance in prognosticating and personalizing immunotherapy for STAD, leveraging quantitatively derived tumor cluster risk scores. It posits the use of necroptosis-related lncRNAs as pivotal molecular beacons for guiding therapeutic strategies and enhancing clinical outcomes in STAD.

KIF3C: an emerging biomarker with prognostic and immune implications across pan-cancer types and its experiment validation in gastric cancer.

Kinesin Family Member 3C (KIF3C) assumes a crucial role in various biological processes of specific human cancers. Nevertheless, there exists a paucity of systematic assessments pertaining to the contribution of KIF3C in human malignancies. We conducted an extensive analysis of KIF3C, covering its expression profile, prognostic relevance, molecular function, tumor immunity, and drug sensitivity. Functional enrichment analysis was also carried out. In addition, we conducted in vitro experiments to substantiate the role of KIF3C in gastric cancer (GC). KIF3C expression demonstrated consistent elevation in various tumors compared to their corresponding normal tissues. We further unveiled that heightened KIF3C expression served as a prognostic indicator, and its elevated levels correlated with unfavorable clinical outcomes, encompassing reduced OS, DSS, and PFS in several cancer types. Notably, KIF3C expression exhibited positive associations with the pathological stages of several cancers. Moreover, KIF3C demonstrated varying relationships with the infiltration of various distinct immune cell types in gastric cancer. Functional analysis outcomes indicated that KIF3C played a role in the PI3K-AKT signaling pathway. Drug sensitivity unveiled a positive relationship between KIF3C in gastric cancer and the IC50 values of the majority of identified anti-cancer drugs. Additionally, KIF3C knockdown reduced the proliferation, migration, and invasion capabilities, increased apoptosis, and led to alterations in the cell cycle of gastric cancer cells. Our research has revealed the significant and functional role of KIF3C as a tumorigenic gene in diverse cancer types. These findings indicate that KIF3C may serve as a promising target for the treatment of gastric cancer.

Análisis coste-efectividad de una vacuna para Helicobacter pylori en el sur de Europa / Cost-effectiveness analysis of a vaccine for Helicobacter pylori in southern Europe

Fundamentos: existen pruebas de la factibilidad de una vacuna para prevenir la infección por helicobacter pylori. Modelizacio-nes en entornos de baja prevalencia informan de una muy probable coste-efectividad a largo plazo. El objetivo de este estudio fue cuantificar su eficiencia en un contexto local.métodos: se simuló la evolución de una cohorte de nacidos a través de un modelo compartimental representativo de varios estados clínicos en relación a la infección por h. Pylori. Se ejecutó dicho modelo bajo las premisas de vacunación en el periodo de lactante y de no intervención. El horizonte temporal fue equivalente a la esperanza de vida y se tuvo en cuenta la perspectiva del sistema de salud.resultados: la vacunación frente a h. Pylori costaría de media 2.168 €/persona más que la no intervención. Con ello se obten-drían 0,32 años de vida ganados ajustados por calidad (avac), lo que implicaría una razón de coste-efectividad incremental (rcei) media de 7.196 €/avac. Para una disposición a pagar de 24.506 €/avac, el 99,96% de las simulaciones resultaron coste-efectivas al alcanzar el horizonte temporal y se cruzó dicho umbral a partir de los treinta años de la vacunación. Las variables que más peso tuvieron para explicar la variabilidad de la rcei fueron, en este orden, la efectividad vacunal, la incidencia de la infección en la primera infancia y el precio de la vacuna. La vacunación dejaría de ser coste-efectiva con un precio mayor de 3.634€/vial o con una cobertura poblacional efectiva menor del 11%.conclusiones: una vacunación frente a la infección por h. Pylori administrada en la infancia sería coste-efectiva a largo plazo en un entorno con las características epidemiológicas y económicas del sur de europa.(AU)

Background: there is sufficient evidence on the feasibility of a vaccine to prevent helicobacter pylori infection. Modeling studies in low prevalence environments report a very probable long-term cost-effectiveness. The objective of this study was to quantify its efficiency in a local context.methods: the evolution of a cohort of newborns was simulated through a compartmental model representing a series of clinical situations regarding h. Pylori infection and related diseases. The model was run under the assumption of both vaccination in the first year of life and no intervention. The time horizon was set as equivalent to the life expectancy and the perspective of the health system was taken into account.results: vaccination against h. Pylori would cost an average of €2,168/person more than no intervention. This would yield an average additional 0.32 quality-adjusted life years gained (qaly), which would entail an incremental cost-effectiveness ratio (icer) of €7,196/qaly. For a willingness to pay of €24,506/qaly, 99.96% of the simulations were cost-effective at eighty-four years old. This threshold was crossed thirty years after vaccination. The variables that carried the most weight in explaining the variability of the icer were, in this order, vaccine effectiveness, the incidence of infection in young children, and the price of the vaccine. Vaccination would cease to be cost-effective with a price greater than €3,634/dose or with effective population coverage less than 11%.(AU)

CLCA1 is Poorly Expressed in Stomach Adenocarcinoma and Correlates with Immune Infiltration / CLCA1 se Expresa Deficientemente en el Adenocarcinoma de Estómago y se Correlaciona con la Infiltración Inmune

SUMMARY: Calcium-activated chloride channel regulator 1 (CLCA1) is associated with cancer progression. The expression and immunologic function of CLCA1 in stomach adenocarcinoma (STAD) remain unclear. In this investigation, the expression of CLCA1 in STAD tissues and its involvement in the progression and immune response of STAD were examined using databases such as cBioPortal, TISIDB, and UALCAN. In order to validate the expression level of CLCA1 protein in gastric adenocarcinoma, thirty clinical tissue specimens were gathered for immunohistochemical staining. The findings indicated a downregulation of CLCA1 in STAD patients, which was correlated with race, age, cancer grade, Helicobacter pylori infection, and molecular subtype. Through the examination of survival analysis, it was identified that diminished levels of CLCA1 within gastric cancer cases were linked to decreased periods of post-progression survival (PPS), overall survival (OS), and first progression (FP) (P<0.05). The CLCA1 mutation rate was lower in STAD, but the survival rate was higher in the variant group. The correlation between the expression level of CLCA1 and the levels of immune infiltrating cells in STAD, as well as the immune activating molecules, immunosuppressive molecules, MHC molecules, chemokines, and their receptor molecules, was observed. Gene enrichment analysis revealed that CLCA1 may be involved in STAD progression through systemic lupus erythematosus (SLE), proteasome, cell cycle, pancreatic secretion, and PPAR signaling pathways. In summary, CLCA1 is anticipated to function as a prognostic marker for patients with STAD and is linked to the immunization of STAD.

El regulador 1 del canal de cloruro activado por calcio (CLCA1) está asociado con la progresión del cáncer. La expresión y la función inmunológica de CLCA1 en el adenocarcinoma de estómago (STAD) aún no están claras. En esta investigación, se examinó la expresión de CLCA1 en tejidos STAD y su participación en la progresión y respuesta inmune de STAD utilizando bases de datos como cBioPortal, TISIDB y UALCAN. Para validar el nivel de expresión de la proteína CLCA1 en el adenocarcinoma gástrico, se recolectaron treinta muestras de tejido clínico para tinción inmunohistoquímica. Los hallazgos indicaron una regulación negativa de CLCA1 en pacientes con STAD, que se correlacionó con la raza, la edad, el grado del cáncer, la infección por Helicobacter pylori y el subtipo molecular. Mediante el examen del análisis de supervivencia, se identificó que los niveles reducidos de CLCA1 en los casos de cáncer gástrico estaban relacionados con períodos reducidos de supervivencia posterior a la progresión (PPS), supervivencia general (OS) y primera progresión (FP) (P <0,05). La tasa de mutación CLCA1 fue menor en STAD, pero la tasa de supervivencia fue mayor en el grupo variante. Se observó la correlación entre el nivel de expresión de CLCA1 y los niveles de células inmunes infiltrantes en STAD, así como las moléculas activadoras inmunes, moléculas inmunosupresoras, moléculas MHC, quimiocinas y sus moléculas receptoras. El análisis de enriquecimiento genético reveló que CLCA1 puede estar involucrado en la progresión de STAD a través del lupus eritematoso sistémico (LES), el proteasoma, el ciclo celular, la secreción pancreática y las vías de señalización de PPAR. En resumen, se prevé que CLCA1 funcione como un marcador de pronóstico para pacientes con STAD y está vinculado a la inmunización de STAD.

Sintilimab Plus Chemotherapy for Unresectable Gastric or Gastroesophageal Junction Cancer: The ORIENT-16 Randomized Clinical Trial.

Importance: Gastric and gastroesophageal junction cancers are diagnosed in more than 1 million people worldwide annually, and few effective treatments are available. Sintilimab, a recombinant human IgG4 monoclonal antibody that binds to programmed cell death 1 (PD-1), in combination with chemotherapy, has demonstrated promising efficacy. Objective: To compare overall survival of patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction cancers who were treated with sintilimab with chemotherapy vs placebo with chemotherapy. Also compared were a subset of patients with a PD ligand 1 (PD-L1) combined positive score (CPS) of 5 or more (range, 1-100). Design, Setting, and Participants: Randomized, double-blind, placebo-controlled, phase 3 clinical trial conducted at 62 hospitals in China that enrolled 650 patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma between January 3, 2019, and August 5, 2020. Final follow-up occurred on June 20, 2021. Interventions: Patients were randomized 1:1 to either sintilimab (n = 327) or placebo (n = 323) combined with capecitabine and oxaliplatin (the XELOX regimen) every 3 weeks for a maximum of 6 cycles. Maintenance therapy with sintilimab or placebo plus capecitabine continued for up to 2 years. Main Outcomes and Measures: The primary end point was overall survival time from randomization. Results: Of the 650 patients (mean age, 59 years; 483 [74.3%] men), 327 were randomized to sintilimab plus chemotherapy and 323 to placebo plus chemotherapy. Among the randomized patients, 397 (61.1%) had tumors with a PD-L1 CPS of 5 or more; 563 (86.6%) discontinued study treatment and 388 (59.7%) died; 1 patient (<0.1%) was lost to follow-up. Among all randomized patients, sintilimab improved overall survival compared with placebo (median, 15.2 vs 12.3 months; stratified hazard ratio [HR], 0.77 [95% CI, 0.63-0.94]; P = .009). Among patients with a CPS of 5 or more, sintilimab improved overall survival compared with placebo (median, 18.4 vs 12.9 months; HR, 0.66 [95% CI, 0.50-0.86]; P = .002). The most common grade 3 or higher treatment-related adverse events were decreased platelet count (sintilimab, 24.7% vs placebo, 21.3%), decreased neutrophil count (sintilimab, 20.1% vs placebo, 18.8%), and anemia (sintilimab, 12.5% vs placebo, 8.8%). Conclusions and Relevance: Among patients with unresectable locally advanced or metastatic gastric and gastroesophageal junction adenocarcinoma treated with first-line chemotherapy, sintilimab significantly improved overall survival for all patients and for patients with a CPS of 5 or more compared with placebo. Trial Registration: ClinicalTrials.gov Identifier: NCT03745170.

Preclinical characterization of an mRNA-encoded anti-Claudin 18.2 antibody.

IMAB362/Zolbetuximab, a first-in-class IgG1 antibody directed against the cancer-associated gastric-lineage marker CLDN18.2, has recently been reported to have met its primary endpoint in two phase 3 trials as a first-line treatment in combination with standard of care chemotherapy in CLDN18.2-positive Her2 negative advanced gastric cancer. Here we characterize the preclinical pharmacology of BNT141, a nucleoside-modified RNA therapeutic encoding the sequence of IMAB362/Zolbetuximab, formulated in lipid nanoparticles (LNP) for liver uptake. We show that the mRNA-encoded antibody displays a stable pharmacokinetic profile in preclinical animal models, mediates CLDN18.2-restricted cytotoxicity comparable to IMAB362 recombinant protein and inhibits human tumor xenograft growth in immunocompromised mice. BNT141 administration did not perpetrate mortality, clinical signs of toxicity, or gastric pathology in animal studies. A phase 1/2 clinical trial with BNT141 mRNA-LNP has been initiated in advanced CLDN18.2-expressing solid cancers (NCT04683939).

Prior antibiotic administration disrupts anti-PD-1 responses in advanced gastric cancer by altering the gut microbiome and systemic immune response.

Evidence on whether prior antibiotic (pATB) administration modulates outcomes of programmed cell death protein-1 (PD-1) inhibitors in advanced gastric cancer (AGC) is scarce. In this study, we find that pATB administration is consistently associated with poor progression-free survival (PFS) and overall survival (OS) in multiple cohorts consisting of patients with AGC treated with PD-1 inhibitors. In contrast, pATB does not affect outcomes among patients treated with irinotecan. Multivariable analysis of the overall patients treated with PD-1 inhibitors confirms that pATB administration independently predicts worse PFS and OS. Administration of pATBs is associated with diminished gut microbiome diversity, reduced abundance of Lactobacillus gasseri, and disproportional enrichment of circulating exhaustive CD8+ T cells, all of which are associated with worse outcomes. Considering the inferior treatment response and poor survival outcomes by pATB administration followed by PD-1 blockade, ATBs should be prescribed with caution in patients with AGC who are planning to receive PD-1 inhibitors.

Tiliroside Combined with Anti-MUC1 Monoclonal Antibody as Promising Anti-Cancer Strategy in AGS Cancer Cells.

Specific changes in mucin-type O-glycosylation are common for many cancers, including gastric ones. The most typical alterations include incomplete synthesis of glycan structures, enhanced expression of truncated O-glycans (Tn, T antigens and their sialylated forms), and overexpression of fucosylation. Such altered glycans influence many cellular activities promoting cancer development. Tiliroside is a glycosidic dietary flavonoid with pharmacological properties, including anti-cancer. In this study, we aim to assess the effect of the combined action of anti-MUC1 and tiliroside on some cancer-related factors in AGS gastric cancer cells. Cancer cells were treated with 40, 80, and 160 µM tiliroside, 5 µg/mL anti-MUC1, and flavonoid together with mAb. Real-Time PCR, ELISA, and Western blotting were applied to examine MUC1 expression, specific, tumor-associated antigens, enzymes taking part in their formation, Gal-3, Akt, and NF-κB. MUC1 expression was significantly reduced by mAb action. The combined action of anti-MUC1 and tiliroside was more effective in comparison with monotherapy in the case of C1GalT1, ST3GalT1, FUT4, Gal-3, NF-κB, Akt mRNAs, and Tn antigen, as well as sialyl T antigen expression. The results of our study indicate that applied combined therapy may be a promising anti-gastric cancer strategy.

Analysis of genomic and immune intratumor heterogeneity in linitis plastica via multiregional exome and T-cell receptor sequencing.

The molecular landscape and the intratumor heterogeneity (ITH) architecture of gastric linitis plastica (LP) are poorly understood. We performed whole-exome sequencing (WES) and T-cell receptor (TCR) sequencing on 40 tumor regions from four LP patients. The landscape and ITH at the genomic and immunological levels in LP tumors were compared with multiple cancers that have previously been reported. The lymphocyte infiltration was further assessed by immunohistochemistry (IHC) in LP tumors. In total, we identified 6339 non-silent mutations from multi-samples, with a median tumor mutation burden (TMB) of 3.30 mutations per Mb, comparable to gastric adenocarcinoma from the Cancer Genome Atlas (TCGA) cohort (P = 0.53). An extremely high level of genomic ITH was observed, with only 12.42%, 5.37%, 5.35%, and 30.67% of mutations detectable across 10 regions within the same tumors of each patient, respectively. TCR sequencing revealed that TCR clonality was substantially lower in LP than in multi-cancers. IHC using antibodies against CD4, CD8, and PD-L1 demonstrated scant T-cell infiltration in the four LP tumors. Furthermore, profound TCR ITH was observed in all LP tumors, with no T-cell clones shared across tumor regions in any of the patients, while over 94% of T-cell clones were restricted to individual tumor regions. The Morisita overlap index (MOI) ranged from 0.21 to 0.66 among multi-regions within the same tumors, significantly lower than that of lung cancer (P = 0.002). Our results show that LP harbored extremely high genomic and TCR ITH and suppressed T-cell infiltration, suggesting a potential contribution to the frequent recurrence and poor therapeutic response of this adenocarcinoma.

Prognostic role and clinical significance of tumor-infiltrating lymphocyte (TIL) and programmed death ligand 1 (PD-L1) expression in gastric cancer: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: This study intended to evaluate the prognostic effects of programmed death-ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in survival and their associations with clinicopathological characteristics in patients with gastric cancer. METHODS: PubMed, Scopus, ProQuest, Web of Science, and Ovid databases were searched to obtain the relevant studies. Eleven studies with 2298 patients were included in this study. RESULTS: Like the level of TILs, there were no significant associations between PD-L1 expression and TNM stage, lymph node metastasis, vascular invasion, and tumor location (All p values ≥ 0.05). Furthermore, there was no significant association between PD-L1 expression with overall survival (OS) (HR = 0.76, 95% CI: 0.55 to 1.05, p value = 0.10) and disease-free survival (DFS) (HR = 0.62, 95% CI: 0.10 to 3.68, p value = 0.59). In the assessment of TILs presence and survival association, the analysis showed no association between TILs presence and overall survival (OS) (HR = 0.95, 95% CI: 0.62 to 1.45). CONCLUSIONS: In conclusion, the study has revealed no prognostic effect of PD-L1 and TILs in gastric cancer patients.

TRIM44 regulates tumor immunity in gastric cancer through LOXL2-dependent extracellular matrix remodeling.

PURPOSE: Gastric cancer is a gastrointestinal malignancy with high mortality and poor prognosis, and the molecular mechanism of gastric tumorigenesis remains unclear. TRIM44 has been reported to be involved in tumor development. However, the role of TRIM44 in tumor immunity is largely unknown. METHODS: We analyzed TRIM44 expression in clinical gastric cancer tissues and normal tissues by using western blot, quantitative real-time PCR and bioinformatics analyses. We further investigated the involvement of TRIM44 in tumor immunity in vivo and found that it was dependent on extracellular matrix remodeling. We detected the interaction between TRIM44 and LOXL2 by using immunofluorescence staining and coimmunoprecipitation assays. We observed that TRIM44 mediates the stability of LOXL2 by ubiquitination assays. RESULTS: TRIM44 expression is high and is correlated with T-cell infiltration in gastric cancer. TRIM44 inhibits gastric tumorigenicity by regulating T-cell-mediated antitumor immunity and modulating the protein level of LOXL2. Mechanistically, TRIM44 directly binds to LOXL2 and affects the stability of LOXL2 to change extracellular matrix remodeling and influence tumor immunity. CONCLUSION: These findings demonstrate that TRIM44 regulates the stability of LOXL2 to remodel the tumor extracellular matrix to modulate tumor immunity in gastric cancer and that the TRIM44/LOXL2 complex is a promising biomarker for gastric cancer prognosis and might be a novel immunotherapy target.

The Correlation of Ten Immune Checkpoint Gene Expressions and Their Association with Gastric Cancer Development.

In the immunotherapy based on immune checkpoint inhibition (IC), additional ICs are being studied to increase its effectiveness. An almost unstudied feature is the possible co-expression of ICs, which can determine the therapeutic efficacy of their inhibition. For the selection of promising ICs, information on the association of their expression with cancer development may be essential. We have obtained data on the expression correlation of ADAM17, PVR, TDO2, CD274, CD276, CEACAM1, IDO1, LGALS3, LGALS9, and HHLA2 genes in gastric cancer (GC). All but one, TDO2, have other IC genes with co-expression at some stage. At the metastatic stage, the expression of the IDO1 does not correlate with any other gene. The correlations are positive, but the expressions of the CD276 and CEACAM1 genes are negatively correlated. The expression of TDO2 and LGALS3 is associated with GC metastasis. The expression of TDO2 four-fold higher in metastatic tumors than in non-metastatic tumors, but LGALS3 was two-fold lower. The differentiation is associated with IDO1. The revealed features of TDO2, with a significant increase in expression at the metastatic stage and the absence of other IC genes with correlated expression indicates that the prospect of inhibiting TDO2 in metastatic GC. IDO1 may be considered for inhibition in low-differentiated tumors.

Identification of the ferroptosis-related ceRNA network related to prognosis and tumor immunity for gastric cancer.

Gastric cancer (GC) is a highly invasive course and has a very poor prognosis. Because there are no obvious symptoms in the early stage, most patients with GC are diagnosed in the late stage. The effective diagnosis, prognosis biomarkers and treatment targets of GC can solve this problem to a great extent. Although researchers have done a lot of research on GC in recent years, the relationship between the competing endogenous RNA (ceRNA) network of ferroptosis-related genes and the GC remains to be explored. Therefore, the research done in this paper has become particularly important. Download the expression data and clinical survival data about stomach adenocarcinoma from UCSC Xena and The Cancer Genome Atlas (TCGA) platform. Using bioinformatics tools to screen lncRNAs, miRNAs and mRNAs that are differentially expressed in GC samples and normal samples and related to the prognosis of GC. Then, screening lncRNAs, miRNAs and mRNAs with targeted relationships from the Starbase database. Subsequently, correlation analysis and survival analysis were carried out respectively. Finally, we get a ceRNA network related to the prognosis of GC patients. Cell experiments confirmed the results obtained by bioinformatics. This is critical for the discovery of the diagnosis, prognosis biomarkers and treatment targets.

Comprehensive Analyses of Immune Subtypes of Stomach Adenocarcinoma for mRNA Vaccination.

Background: Although messenger RNA (mRNA) vaccines have unique advantages against multiple tumors, mRNA vaccine targets in stomach adenocarcinoma (STAD) remain unknown. The potential effectiveness of mRNA vaccines is closely associated with the tumor immune infiltration microenvironment. The present study aimed to identify tumor antigens of STAD as mRNA vaccine targets and systematically determine immune subtypes (ISs) of STAD that might be suitable for immunotherapy. Methods: Gene expression profiles and clinical data of patients with gastric cancer were downloaded from The Cancer Genome Atlas (TCGA; n = 409) and the Gene Expression Omnibus (GEO; n = 433), and genomic data were extracted from cBioPortal. Differential gene expression was analyzed using the limma package, genetic alterations were visualized using maftools, and prognosis was analyzed using ToPP. Correlations between gene expression and immune infiltration were calculated using TIMER software, and potential ISs were identified using ConsensusClusterPlus. Functional enrichment was analyzed in clusterProfiler, and r co-expression networks were analyzed using the weighted gene co-expression network analysis (WGCNA) package in R. Results: Overexpression of the prognostic and highly mutated antigens ADAMTS18, COL10A1, PPEF1, and STRA6 was associated with infiltration by antigen-presenting cells in STAD. Five ISs (IS1-IS5) in STAD with distinct prognoses were developed and validated in TCGA and GEO databases. The tumor mutational burden and molecular and clinical characteristics significantly differed among IS1-IS5. Both IS1 and IS2 were associated with a high mutational burden, massive infiltration by immune cells, especially antigen-presenting cells, and better survival compared with the other subtypes. Both IS4 and IS5 were associated with cold immune infiltration and correlated with advanced pathological stages. We analyzed the immune microenvironments of five subtypes of immune modulators and biomarkers to select suitable populations for mRNA vaccination and established four co-expressed key modules to validate the characteristics of the ISs. Finally, the correlation of these four mRNA vaccine targets with the transcription factors of DC cells, including BATF3, IRF4, IRF8, ZEB2, ID2, KLF4, E2-2, and IKZF1, were explored to reveal the underlying mechanisms. Conclusions: ADAMTS18, COL10A1, PPEF1, and STRA6 are potential mRNA vaccine candidates for STAD. Patients with IS1 and IS2 are suitable populations for mRNA vaccination immunotherapy.

Prognostic and Immunological Value of GNB4 in Gastric Cancer by Analyzing TCGA Database.

Background: Gastric cancer (GC) represents a universal malignant tumor of the digestive system. Stromal and immune cells belong to two main nontumor components exerting a vital function in the tumor microenvironment. Methods: Based on TCGA database, this study downloaded clinical information and gene profiles of GC. The ESTIMATE algorithm was adopted for evaluating the score of immune-infiltrating cells. This work employed Sangerbox to explore the differentially denoted genes (DEGs) related to stromal, immunity, and prognosis. Besides, the STRING database was involved in order to detect the association among the proteins. The MCODE module of Cytoscape software was used to screen key genes. Oncomine and GEPIA databases were used, aiming to study the differences in key genes in healthy gastric mucosa and GC. At last, we adopted TISDIB and TIMER databases for analyzing the association of guanine nucleotide binding protein subunit-4 (GNB4) between gastric cancer and tumor immune cells. qRT-PCR was applied for exploring differential GNB4 expression between GC and normal gastric mucosa and investigating the relation of GNB4 with tumor-infiltrating lymphocytes (TILs). Results: Patients undergoing a great stromal score exhibited worse prognostic outcome, and cases having a low immune score had better prognosis. Overall, altogether 656 genes were upregulated with 5 genes being downregulated, which were matrix immune-related differential genes. Furthermore, 18 genes were screened as hub genes on the basis of the univariate Cox risk model of TCGA database (82 differential genes predicted poor GC survival). Oncomine and GEPIA databases revealed that GNB4 expression in gastric cancer was obviously higher in comparison with that in normal gastric mucosa. The GSEA, TISDIB, and TIMER databases revealed that GNB4 is involved in various tumor signal pathways and immune and metabolic processes. qRT-PCR demonstrated that GNB4 expression in gastric cancer was notably higher in comparison with that in normal gastric mucosa, showing significant association with matrix TILs. Conclusion: The selected key gene GNB4 is a potential biomarker to guide the immunotherapy of gastric cancer.

Therapeutic strategies targeting uPAR potentiate anti-PD-1 efficacy in diffuse-type gastric cancer.

The diffuse-type gastric cancer (DGC) is a subtype of gastric cancer (GC) associated with low HER2 positivity rate and insensitivity to chemotherapy and immune checkpoint inhibitors. Here, we identify urokinase-type plasminogen activator receptor (uPAR) as a potential therapeutic target for DGC. We have developed a novel anti-uPAR monoclonal antibody, which targets the domains II and III of uPAR and blocks the binding of urokinase-type plasminogen activator to uPAR. We show that the combination of anti-uPAR and anti-Programmed cell death protein 1 (PD-1) remarkably inhibits tumor growth and prolongs survival via multiple mechanisms, using cell line-derived xenograft and patient-derived xenograft mouse models. Furthermore, uPAR chimeric antigen receptor-expressing T cells based on the novel anti-uPAR effectively kill DGC patient-derived organoids and exhibit impressive survival benefit in the established mouse models, especially when combined with PD-1 blockade therapy. Our study provides a new possibility of DGC treatment by targeting uPAR in a unique manner.

Immunological Perspective: Helicobacter pylori Infection and Gastritis.

Helicobacter pylori is a spiral-shaped gram-negative bacterium. Its infection is mainly transmitted via oral-oral and fecal-oral routes usually during early childhood. It can achieve persistent colonization by manipulating the host immune responses, which also causes mucosal damage and inflammation. H. pylori gastritis is an infectious disease and results in chronic gastritis of different severity in near all patients with infection. It may develop from acute/chronic inflammation, chronic atrophic gastritis, intestinal metaplasia, dysplasia, and intraepithelial neoplasia, eventually to gastric cancer. This review attempts to cover recent studies which provide important insights into how H. pylori causes chronic inflammation and what the characteristic is, which will immunologically explain H. pylori gastritis.