Gastric cancer

The clinical significance assessment of the transverse lymph node metastasis in gastric cancer: The establishment and validation of nomogram from a single clinical medical center

BACKGROUND

Lymph node metastasis is an important route for gastric cancer metastasis. The clinical significance of transverse lymph node metastasis (TLNM) is still unclear.

AIMS

This study investigates effects of TLNM on the prognosis of GC patients and establishes two nomograms for evaluating the prognosis of GC patients and for predicting the risk clinicopathological factors to TLNM based on a Chinese medical database.

METHODS

A total of 902 GC patients with lymph node metastasis (LNM) who underwent R0 gastrectomy was included in this study. According to results of Cox proportional hazards analyses and logistic regression analyses, the prognostic and the predictive nomograms were established and validated.

RESULTS

The overall survival of patients with TLNM was significantly worse than those without TLNM (P < 0.001) and similar to patients with extra-gastric LNM (P > 0.05). TLNM independently influenced prognosis of GC patients. Prognostic and predictive nomograms were established and validated. Both nomograms were proven that have high accuracy by calculating each AUC (Area Under Cure) value. Calibration curves aligned well with actual outcomes. DCA (Decision Curve Analyses) analyses indicated the high clinical utility.

CONCLUSION

These nomograms offer precise survival and TLNM occurrence predictions, which may aid clinical decisions.

Construction and validation of a TTN mutation associated immune prognostic model for evaluating immune microenvironment and outcomes of gastric cancer: An observational study

Gastric cancer (GC) is a prevalent form of cancer worldwide, and TTN (titin) mutations are frequently observed in GC. However, the association between TTN mutations and immunotherapy for GC remains unclear, necessitating the development of novel prognostic models. The prognostic value and potential mechanisms of TTN in stomach adenocarcinoma were evaluated by TCGA (The Cancer Genome Atlas)-stomach adenocarcinoma cohort analysis, and an immune prognostic model was constructed based on TTN status. We validated it using the GSE84433 dataset. We performed Gene Set Enrichment Analysis and screened for differentially expressed genes, and used lasso (least absolute shrinkage and selection operator) regression analysis to screen for survival genes to construct a multifactorial survival model. In addition, we evaluated the relative proportions of 22 immune cells using the CIBERSORT algorithm for immunogenicity analysis. Finally, we constructed the nomogram integrating immune prognostic model and other clinical factors. GESA showed enrichment of immune-related phenotypes in patients with TTN mutations. We constructed an immune prognostic model based on 16 genes could identify gastric cancer patients with higher risk of poor prognosis. Immuno-microenvironmental analysis showed increased infiltration of naive B cells, plasma cells, and monocyte in high-risk patients. In addition, Nomo plots predicted the probability of 1-year, 3-year, and 5-year OS (overall survival) in GC patients, showing good predictive performance. In this study, we identified that TTN gene may be a potential clinical biomarker for GC and TTN mutations may be a predictor of immunotherapy in patients. We constructed and validated a new model for prognosis of GC patients based on immune characteristics associated with TTN mutations. This study may provide potential therapeutic strategies for gastric cancer.

Sample Collection and Processing in Volatile Organic Compound Analysis for Gastrointestinal Cancers

Volatile organic compounds have drawn significant attention in recent years as a novel tool for non-invasive detection of a wide range of diseases, including gastrointestinal cancers, for which the need for effective, affordable, and non-invasive screening methods is substantial. Sample preparation is a fundamental step that greatly influences the quality of results and the feasibility of wide-range applications. This review summarizes sampling methods used in studies aiming at testing the diagnostic value of volatile organic compounds in gastrointestinal cancers, discussing in detail some of the recent advancements in automated sampling techniques. Finally, we propose some directions in which sample collection and processing can improve for VOC analysis to be popularized in clinical settings.

Causality between six psychiatric disorders and digestive tract cancers risk: a two-sample Mendelian randomization study

Associations between psychiatric disorders and digestive tract cancers have been proposed. However, the causal link between these factors remains unclear. This study pioneers Mendelian randomization (MR) analysis to explore the genetic link between psychiatric disorders and digestive tract cancers risk. We analysed data on six psychiatric disorders [schizophrenia, bipolar disorder, major depressive disorder (MDD), attention deficit hyperactivity disorder, autism spectrum disorder, and panic disorder (PD)] and digestive tract cancers [esophagus cancer (EC), gastric cancer (GC), and colorectal cancer (CRC)] from genome-wide association studies databases. Using instrumental variables identified from significant single nucleotide polymorphism associations, we employed the inverse variance weighted (IVW) method alongside the weighted median (WM) method and MR-Egger regression. The results revealed no causal link between psychiatric disorders and the risk of EC or GC. Psychiatric disorders were not identified as risk factors for CRC. Notably, PD demonstrated a lower CRC risk (OR = 0.79, 95% CI 0.66-0.93, P = 0.01). This MR analysis underscores the lack of a causal association between psychiatric disorders and digestive tract cancers risk while suggesting a potential protective effect of PD against CRC.

Influence of acupuncture and moxibustion on gastrointestinal function and adverse events in gastric cancer patients after surgery and chemotherapy: a meta-analysis

OBJECTIVE

The impact of acupuncture and moxibustion on postoperative complications and adverse events (AEs) of chemotherapy in patients with gastric cancer (GC) has been investigated. Through a meta-analysis of existing randomized controlled trials (RCTs), this study sought to strengthen the evidentiary basis to help investigators further understand the effects of moxibustion and acupuncture on postoperative complications and AEs of chemotherapy among GC patients.

METHODS

Embase, Web of Science, PubMed, The Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Database, and VIP Database for Chinese Technical Periodicals were searched to collect RCTs on effects of acupuncture and moxibustion on gastrointestinal function and AEs among GC patients undergoing surgery and chemotherapy. Outcome measures included postoperative gastrointestinal recovery (bowel sound recovery time, time to first flatus/defecation/feeding), the incidence of AEs (nausea and vomiting, abdominal distension, and diarrhea), myelosuppression (white blood cells, hemoglobin, and platelet), and immune function indicators (CD3+ and CD4+). To assess quality, the Cochrane Risk of Bias Tool was utilized. Review Manager 5.4 was implemented to do the meta-analysis.

RESULTS

Fifteen eligible RCTs involved 1259 patients. Meta-analysis results showed that the experimental group had a significantly shorter bowel sound recovery time (MD =  - 14.57, 95% CI = [- 18.97, - 10.18], P < 0.00001), time to first flatus (MD =  - 17.56, 95% CI = [- 22.23, - 12.88], P < 0.00001), time to first defecation (MD =  - 17.05, 95% CI = [- 21.02, - 13.09], P < 0.00001), and time to first feeding (MD =  - 23.49, 95% CI = [- 28.81, - 18.17], P < 0.00001) than the control group. There were significant decreases in the incidence of nausea and vomiting (RR = 0.46, 95% CI = [0.21, 1.02], P = 0.05) and abdominal distension (RR = 0.45, 95% CI = [0.27, 0.75], P = 0.002) observed in the experimental group in comparison with the control group. The experimental group demonstrated a significant increase in white blood cell counts in comparison with to the control group (MD = 0.89, 95% CI = [0.23, 1.55], P = 0.008). The experimental group showed significantly higher levels of CD3+ (MD = 7.30, 95% CI = [1.86, 12.74], P = 0.009) and CD4+ (MD = 2.75, 95% CI = [1.61, 3.90], P < 0.00001) than the control group.

CONCLUSION

Among GC patients, acupuncture and moxibustion can aid in gastrointestinal function recovery, reduce the incidence of AEs of surgery and chemotherapy, and improve immune function.

Comprehensive landscape of integrator complex subunits and their association with prognosis and tumor microenvironment in gastric cancer

Backgrounds

The integrator complex (INT) is a multiprotein assembly in gene transcription. Although several subunits of INT complex have been implicated in multiple cancers, the complex's role in gastric cancer (GC) is poorly understood.

Methods

The gene expressions, prognostic values, and the associations with microsatellite instability (MSI) of INT subunits were confirmed by GEO and The Cancer Genome Atlas (TCGA) databases. cBioPortal, GeneMANIA, TISIDB, and MCPcounter algorithm were adopted to investigate the mutation frequency, protein-protein interaction network, and the association with immune cells of INT subunits in GC. Additionally, in vitro experiments were performed to confirm the role of INTS11 in pathogenesis of GC.

Results

The mRNA expression levels of INTS2/4/5/7/8/9/10/11/12/13/14 were significantly elevated both in GSE183904 and TCGA datasets. Through functional enrichment analysis, the functions of INT subunits were mainly associated with snRNA processing, INT, and DNA-directed 5'-3' RNA polymerase activity. Moreover, these INT subunit expressions were associated with tumor-infiltrating lymphocytes and MSI in GC. In vitro experiments demonstrated that knockdown of the catalytic core INTS11 in GC cells inhibits cell proliferation ability. INTS11 overexpression showed opposite effects.

Conclusions

Our data demonstrate that the INT complex might act as an oncogene and can be used as a prognosis biomarker for GC.

Personalized drug screening using patient-derived organoid and its clinical relevance in gastric cancer

The efficacy of chemotherapy varies significantly among patients with gastric cancer (GC), and there is currently no effective strategy to predict chemotherapeutic outcomes. In this study, we successfully establish 57 GC patient-derived organoids (PDOs) from 73 patients with GC (78%). These organoids retain histological characteristics of their corresponding primary GC tissues. GC PDOs show varied responses to different chemotherapeutics. Through RNA sequencing, the upregulation of tumor suppression genes/pathways is identified in 5-fluorouracil (FU)- or oxaliplatin-sensitive organoids, whereas genes/pathways associated with proliferation and invasion are enriched in chemotherapy-resistant organoids. Gene expression biomarker panels, which could distinguish sensitive and resistant patients to 5-FU and oxaliplatin (area under the dose-response curve [AUC] >0.8), are identified. Moreover, the drug-response results in PDOs are validated in patient-derived organoids-based xenograft (PDOX) mice and are consistent with the actual clinical response in 91.7% (11/12) of patients with GC. Assessing chemosensitivity in PDOs can be utilized as a valuable tool for screening chemotherapeutic drugs in patients with GC.

Construction and Identification of Eukaryotic Expression Vector pEGFP-N1-MIC-1 for Mouse MIC-1 Gene and Its Effect on Gastric Cancer Cells

This study aimed to construct an eukaryotic expression vector, pEGFP-N1-MIC-1, for overexpressing the mouse macrophage inhibitory cytokine-1 (MIC-1) gene. Additionally, we transfected the MFC cell line to observe the upregulation of MIC-1 gene expression and assess its impact on macrophage phenotype conversion. Enzyme digestion and DNA sequencing confirmed the successful construction of the pEGFP-N1-MIC-1 vector. The transfected MFC cells exhibited a significant increase in MIC-1 protein expression levels. Furthermore, transfection with pEGFP-N1-MIC-1 increased the migration and colony formation capabilities of MFC cells. These results may contribute to future research and the development of therapeutic interventions targeting MIC-1 in macrophages, particularly in the context of gastric cancer.

Identification of cancer-associated fibroblast-related Ectodysplasin-A as a novel indicator for prognosis and immune response in gastric cancer

Studies have indicated cancer-associated fibroblasts (CAFs) could have a significant impact in gastric cancer (GC) progression and chemotherapy resistance. However, the gene related to cancer fibroblasts that can be used as biomarkers to judge the occurrence of gastric cancer has not been fully explored. Based on two Gene Expression Omnibus (GEO) datasets, we focus on differentially expressed genes which may act as CAFs markers related to GC. Through COX regression, LASSO regression and Kaplan-Meier survival analysis, we discovered three upregulated genes (GLT8D2, GNAS and EDA) associated with poor GC patients' survival. By single-cell analysis and nomogram, we found that EDA may affect fibroblast production and disease prognosis in GC patients. EDA expression showed a positive correlation with 5-Fluorouracil IC50 values. Immunohistochemistry (IHC) and real time PCR indicated elevated EDA levels in GC tissues and cells. Enrichment analysis revealed that EDA was closely linked to immune system regulation. IHC and single-cell analysis indicated that EDA gene was associated with cancer fibroblasts marker FGF12 and influence cell interferon-gamma response, which may play a role in regulating immune-related characteristics. In summary, we concluded that EDA may be used as a new therapeutic CAFs marker for GC.

Exploring the effect of NK-cell related molecules on the prognosis and tumor microenvironment of gastric cancer patients: Evidence from large sample populations

Background

Natural killer (NK) cells play a significant role in anti-tumor immunity, and their involvement has been documented in various cancers. However, a deeper understanding of the mechanisms by which NK cells influence gastric cancer progression remains necessary.

Methods

We utilized the Cancer Genome Atlas (TCGA) database to acquire transcriptional profiles, clinical information, and mutation data for gastric cancer patients. R software and associated packages were employed for all analyses of this publicly available data.

Results

We used multiple algorithms to evaluate the tumor microenvironment in gastric cancer samples. We performed differential expression analysis to pinpoint genes related to NK cells. Utilizing this data, we developed a prognostic model featuring three crucial NK cell-related genes: MAB21L2, ARPP21, and MUCL1. This model showed strong predictive performance in the training and validation groups. Consistently, patients identified as high-risk according to our model had worse overall survival rates. To further elucidate the biological differences between high-risk and low-risk patients, we performed enrichment analyses focusing on biological pathways and immune-related factors. Additionally, we observed a correlation between higher risk scores and non-responsiveness to treatment. Interestingly, high-risk patients were found to be potentially more sensitive to axitinib. We selected MUCL1 for further investigation due to its potential role in the model. While MUCL1 mRNA levels were elevated in both gastric cancer and paired normal tissues, protein expression analysis using the Human Protein Atlas database revealed a decrease in MUCL1 protein levels within tumor tissues.

Conclusions

Our findings contribute to a more comprehensive understanding of the role of NK cells in gastric cancer and highlight MUCL1 as a promising therapeutic target.

PDE4B promotes the progression of gastric cancer via the PI3K/AKT/MYC pathway and immune infiltration

Phosphodiesterase 4B (PDE4B) is a key enzyme involved in regulating intracellular cyclic adenosine monophosphate levels and plays a significant role in the diagnosis, classification, treatment, and prognosis of various cancers. However, the role of PDE4B in gastric cancer (GC) remains unclear. We used the GEPIA2 (Gene Expression Profiling Interactive Analysis 2) database to analyze the differential expression level of PDE4B across tumor samples and verified our findings via qPCR and immunohistochemical analysis. We also analyzed the correlation between PDE4B expression levels and clinical pathological parameters, and prognosis, in the database. The effects of PDE4B on GC proliferation, migration, and invasion were evaluated through in vitro and in vivo experiments. Enrichment analysis was performed using bioinformatic tools, and results were validated by western blot analysis. The correlation between PDE4B expression and immune cell infiltration was investigated using bioinformatics tools. PDE4B is highly expressed in GC and is significantly associated with deep infiltration, distant metastasis, tumor, node, metastasis (TNM) stage, and preoperative CA199 levels. Over-expression of PDE4B promotes proliferation, clonal formation, migration, and invasion of GC cells and is associated with poor prognosis. PDE4B promotes the infiltration of immune cells into the tumor microenvironment (TME) and the phosphorylation of PI3K/AKT pathway, increasing MYC expression. PDE4B can serve as an independent prognostic biomarker for GC. We found that PDE4B can promote immune cell infiltration of the TME and mediate malignancy in gastric cancer through the PI3K/AKT/MYC pathway.

Identification of a novel apoptosis-related genes signature to improve gastric cancer prognosis prediction

Dysregulation of apoptosis occurs in different types of malignant tumors and is likely to influence the tumor evolution, as well as clinical prognosis. However, the limited number of studies investigating the predictive power of apoptosis-related genes (ARGs) in gastric cancer indicates a gap in the current research. 174 ARGs who differentially expressed were screened using public databases, including the Gene Expression Omnibus and the Molecular Signatures Database. Univariate and LASSO regression analyses were rigorous approaches to recognize the 12 optimal genes (CTHRC1, PDGFRL, VCAN, GJA1, LOX, UPP1, ANGPT2, CRIM1, HIF1A, APOD, RNase1, and ID1) that make up the prognostic risk model. Molecular mutations, related signaling pathways, and immune system characteristics in different subgroups defined by the risk model were analyzed using different R packages. Moreover, based on the database of Genomics of Drug Sensitivity in Cancer, chemotherapy sensitivity was predicted among the risk subgroups. As a result, there were differences in mutation profiles, signaling pathways, and infiltrated immune cells between patients in various risk groups. Moreover, the low-risk group displayed greater sensitivity to chemotherapy than the high-risk group. Risk model provided a better prognostic value than the T, N, and M stages, according to the receiver operating characteristic curve. Finally, in a nomogram, the risk model and clinical factors were combined to visualize the survival rates of patients with GC. In response to the differential expression of apoptosis-related genes, a novel model for predicting the prognosis of GC patients was developed. This model may be highly valuable for guiding doctors to deliver treatment plans tailored to the need of patients with GC.

Adipocytes impact on gastric cancer progression: Prognostic insights and molecular features

BACKGROUND

Adipocytes, especially adipocytes within tumor tissue known as cancer-associated adipocytes, have been increasingly recognized for their pivotal role in the tumor microenvironment of gastric cancer (GC). Their influence on tumor progression and patient prognosis has sparked significant interest in recent research. The main objectives of this study were to investigate adipocyte infiltration, assess its correlation with clinical pathological features, develop a prognostic prediction model based on independent prognostic factors, evaluate the impact of adipocytes on immune cell infiltration and tumor invasiveness in GC, and identify and validate genes associated with high adipocyte expression, exploring their potential diagnostic and prognostic value.

AIM

To explore the relationship between increased adipocytes within tumor tissue and prognosis in GC patients as well as the associated mechanisms and potential biomarkers, using public databases and clinical data.

METHODS

Using mRNA microarray datasets from the Gene Expression Omnibus database and clinical samples from Jiangsu Provincial Hospital, survival and regression analyses were conducted to determine the relevant prognostic factors in GC. Feature gene selection was performed using least absolute shrinkage and selection operator and support vector machine recursive feature elimination algorithms, followed by differential gene expression analysis, gene ontology, pathway analysis, and Gene Set Enrichment Analysis. Immune cell infiltration was analyzed using the CIBERSORT algorithm.

RESULTS

Tumor adipocyte infiltration correlated with poor prognosis in GC, leading to the development of a highly accurate and discriminative prognostic prediction model. Key genes, ADH1B, SFRP1, PLAC9, and FABP4, were identified as associated with high adipocyte expression in GC. The diagnostic and prognostic potential of these identified genes was validated using independent datasets. Downregulation of immune cells was observed in GC with high adipocyte expression.

CONCLUSION

GC with high intratumoral adipocyte expression demonstrated aggressive tumor biology and a poorer prognosis. The genes ADH1B, SFRP1, PLAC9, and FABP4 have been identified as holding diagnostic and prognostic significance in GC. These findings strongly support the use of adipocyte expression as a valuable indicator of tumor invasiveness and anticipated patient outcomes in GC.

Interpretable deep learning model to predict lymph node metastasis in early gastric cancer using whole slide images

In early gastric cancer (EGC), the presence of lymph node metastasis (LNM) is a crucial factor for determining the treatment options. Endoscopic resection is used for treatment of EGC with minimal risk of LNM. However, owing to the lack of definitive criteria for identifying patients who require additional surgery, some patients undergo unnecessary additional surgery. Considering that histopathologic patterns are significant factor for predicting lymph node metastasis in gastric cancer, we aimed to develop a machine learning algorithm which can predict LNM status using hematoxylin and eosin (H&E)-stained images. The images were obtained from several institutions. Our pipeline comprised two sequential approaches including a feature extractor and a risk classifier. For the feature extractor, a segmentation network (DeepLabV3+) was trained on 243 WSIs across three datasets to differentiate each histological subtype. The risk classifier was trained with XGBoost using 70 morphological features inferred from the trained feature extractor. The trained segmentation network, the feature extractor, achieved high performance, with pixel accuracies of 0.9348 and 0.8939 for the internal and external datasets in patch level, respectively. The risk classifier achieved an overall AUC of 0.75 in predicting LNM status. Remarkably, one of the datasets also showed a promising result with an AUC of 0.92. This is the first multi-institution study to develop machine learning algorithm for predicting LNM status in patients with EGC using H&E-stained histopathology images. Our findings have the potential to improve the selection of patients who require surgery among those with EGC showing high-risk histological features.

Construction of a TAN-associated risk score model with integrated multi-omics data analysis and clinical validation in gastric cancer

AIMS

An increasing number of studies have highlighted the biological significance of neutrophil activation and polarization in tumor progression. However, the characterization of tumor-associated neutrophils (TANs) is inadequately investigated.

MATERIALS AND METHODS

Patients' expression profiles were obtained from TCGA, GEO, and IMvigor210 databases. Six algorithms were used to assess immune cell infiltration. RNA sequencing was conducted to evaluate the differentially expressed genes between induced N1- and N2-like neutrophils. A TAN-associated risk score (TRS) model was established using a combination of weighted gene co-expression network analysis (WGCNA) and RNA-seq data and further assessed in pan-cancer. A clinical cohort of 117 GC patients was enrolled to assess the role of TANs in GC via immunohistochemistry (IHC).

KEY FINDINGS

A TRS signature was built with 10 TAN-related genes (TRGs) and most TRGs were highly abundant in the TANs of the GC microenvironment. The TRS model could accurately predict patients' prognosis, as well as their responses to chemotherapy and immunotherapy. The TRS was positively correlated with pro-tumor immune cells and exhibited negative relationship with anti-tumor immune cells. Additional functional analyses revealed that the signature was positively related to pro-tumor and immunosuppression pathways, such as the hypoxia pathway, across pan-cancer. Furthermore, our clinical cohort demonstrated TANs as an independent prognostic factor for GC patients.

SIGNIFICANCE

This study constructed and confirmed the value of a novel TRS model for prognostic prediction of GC and pan-cancer. Further evaluation of TRS and TANs will help strengthen the understanding of the tumor microenvironment and guide more effective therapeutic strategies.

Increased ONECUT2 induced by Helicobacter pylori promotes gastric cancer cell stemness via an AKT-related pathway

Helicobacter pylori (HP) infection initiates and promotes gastric carcinogenesis. ONECUT2 shows promise for tumor diagnosis, prognosis, and treatment. This study explored ONECUT2's role and the specific mechanism underlying HP infection-associated gastric carcinogenesis to suggest a basis for targeting ONECUT2 as a therapeutic strategy for gastric cancer (GC). Multidimensional data supported an association between ONECUT2, HP infection, and GC pathogenesis. HP infection upregulated ONECUT2 transcriptional activity via NFκB. In vitro and in vivo experiments demonstrated that ONECUT2 increased the stemness of GC cells. ONECUT2 was also shown to inhibit PPP2R4 transcription, resulting in reduced PP2A activity, which in turn increased AKT/β-catenin phosphorylation. AKT/β-catenin phosphorylation facilitates β-catenin translocation to the nucleus, initiating transcription of downstream stemness-associated genes in GC cells. HP infection upregulated the reduction of AKT and β-catenin phosphorylation triggered by ONECUT2 downregulation via ONECUT2 induction. Clinical survival analysis indicated that high ONECUT2 expression may indicate poor prognosis in GC. This study highlights a critical role played by ONECUT2 in promoting HP infection-associated GC by enhancing cell stemness through the PPP2R4/AKT/β-catenin signaling pathway. These findings suggest promising therapeutic strategies and potential targets for GC treatment.

Inflammation-Related Gene ADH1A Regulates the Polarization of Macrophage M1 and Influences the Malignant Progression of Gastric Cancer

Background

Gastric cancer (GC) is a malignant tumor originating from the gastric mucosa epithelium, and there is a low survival rate of GC patients after treatment, with a poor prognostic outcome. The inflammatory response within the tumor microenvironment plays an important role in GC progression.

Methods

We downloaded GC-related datasets and inflammation-related genes from GEO, TCGA and MSigDB databases, performed differential analysis, protein-protein interaction analysis, immunoinfiltration analysis and Lasso analysis to screen inflammation-related hub genes affecting GC progression, and carried out qRT-PCR for validation. In order to explore the role of ADH1A, we constructed overexpressed plasmids, treated GC cells with cGMP/PKG pathway agonist 8-Br-cGMP, and tested cell functions with CCK8, EdU, Transwell, scratch assay and other experiments. On this basis, GC cells were co-cultured with monocyte THP-1 to explore the effect of ADH1A on the polarization of macrophages.

Results

ADH1A was significantly decreased in GC cells, and its expression trend was consistent with the results of bioinformatics analysis. Therefore, we chose ADH1A for subsequent functional validation. Overexpression of ADH1A in GC cells revealed ADH1A's role in inhibiting the activity, proliferation, migration and invasion of GC cells, promoting apoptosis and secretion of IL-6, IFN-γ, CCL5 and CSF2, and facilitating the transformation of macrophages to a pro-inflammatory M1 phenotype. ssGSEA results demonstrated the potential involvement of ADH1A in the cGMP/PKG signaling pathway, and significant changes in the expression of proteins related to the cGMP/PKG signaling pathway. The use of the cGMP/PKG signaling pathway agonist 8-Br-cGMP in ADH1A-overexpressing GC cells substantiated ADH1A's capacity to inhibit the cGMP/PKG signaling pathway, thereby suppressing the malignant progression of GC and promoting the transformation of macrophages to a pro-inflammatory M1 phenotype.

Conclusion

ADH1A is able to influence the malignant progression of GC and the transformation of macrophages to the pro-inflammatory M1 phenotype through the cGMP/PKG signaling pathway.

Hyperactivation of mTOR/eIF4E Signaling Pathway Promotes the Production of Tryptophan-To-Phenylalanine Substitutants in EBV-Positive Gastric Cancer

Although messenger RNA translation is tightly regulated to preserve protein synthesis and cellular homeostasis, chronic exposure to interferon-γ (IFN-γ) in several cancers can lead to tryptophan (Trp) shortage via the indoleamine-2,3-dioxygenase (IDO)- kynurenine pathway and therefore promotes the production of aberrant peptides by ribosomal frameshifting and tryptophan-to-phenylalanine (W>F) codon reassignment events (substitutants) specifically at Trp codons. However, the effect of Trp depletion on the generation of aberrant peptides by ribosomal mistranslation in gastric cancer (GC) is still obscure. Here, it is shows that the abundant infiltrating lymphocytes in EBV-positive GC continuously secreted IFN-γ, upregulated IDO1 expression, leading to Trp shortage and the induction of W>F substitutants. Intriguingly, the production of W>F substitutants in EBV-positive GC is linked to antigen presentation and the activation of the mTOR/eIF4E signaling pathway. Inhibiting either the mTOR/eIF4E pathway or EIF4E expression counteracted the production and antigen presentation of W>F substitutants. Thus, the mTOR/eIF4E pathway exposed the vulnerability of gastric cancer by accelerating the production of aberrant peptides and boosting immune activation through W>F substitutant events. This work proposes that EBV-positive GC patients with mTOR/eIF4E hyperactivation may benefit from anti-tumor immunotherapy.

Pembrolizumab combined with chemotherapy versus placebo combined with chemotherapy for HER2-negative advanced gastric cancer in China: a cost-effectiveness analysis

OBJECTIVE

This study aims to conduct a cost-effectiveness analysis of pembrolizumab in combination with chemotherapy for HER2-negative advanced gastric cancer in China.

METHODS

A partitioned survival approach model was constructed to simulate the progression of HER2-negative advanced gastric cancer and evaluate the outcomes of different treatment strategies. We calculated incremental cost-effectiveness ratios (ICER) to assess the cost associated with each quality-adjusted life-year (QALY) gained. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to assess robustness and reliability.

RESULTS

The analysis conducted in the base case demonstrated that the ICER associated with pembrolizumab was $177405.83/QALY gained in all population. In the subgroup analysis, it was found that individuals with a PD-L1 CPS ≥ 1 and those with a PD-L1 CPS ≥ 10 had ICERs of $152397.06/QALY and $109534.13/QALY, respectively. All ICER values for both the all population groups and the subgroups exceeded the WTP threshold in China. Our analysis shows the robustness of these results, as they remained consistent when input parameters were varied within a ± 25% range.

CONCLUSION

The findings of this cost-effectiveness analysis suggest that pembrolizumab in combination with chemotherapy is not a cost-effective treatment option for HER2-negative advanced gastric cancer in China.

Establishment of a trastuzumab-resistant extramammary Paget disease model: loss of PTEN as a potential mechanism

BACKGROUND/OBJECTIVES

Extramammary Paget disease (EMPD) is a rare, cutaneous intraepithelial adenocarcinoma typically treated with wide local excision. Unfortunately, a number of patients with metastases show poor responses to chemotherapy. While some studies have explored trastuzumab's effectiveness against EMPD positive for human epidermal growth factor receptor 2 (HER2), trastuzumab resistance (TR) may emerge after anti-HER2 therapy.

METHODS/SUBJECTS

In this study, we established TR EMPD patient-derived xenografts (PDX) that replicated the histological and HER2 expression traits of naive EMPD tumours.

RESULTS

Cancer gene analyses revealed a loss of the PTEN gene in TR tumours, which was further confirmed by immunohistochemical staining and immunoblotting to test for protein expression levels. Reduced PTEN levels correlated with increased protein kinase B (Akt) phosphorylation and p27 downregulation, suggesting a potential mechanism for trastuzumab resistance in EMPD cells. In the trastuzumab-sensitive EMPD-PDX mouse model, PTEN inhibitors partially restored trastuzumab-mediated tumour regression. The TR EMPD-PDX responded favourably to targeted therapy (lapatinib, abemaciclib, palbociclib) and chemotherapy (eribulin, docetaxel, trastuzumab deruxtecan).

CONCLUSIONS

This study demonstrates an innovative TR EMPD-PDX model and introduces promising antineoplastic effects with various treatments for TR EMPD tumours.

The role of cGAS in epithelial dysregulation in inflammatory bowel disease and gastrointestinal malignancies

The gastrointestinal tract is lined by an epithelial monolayer responsible for selective permeability and absorption, as well as protection against harmful luminal contents. Recognition of foreign or aberrant DNA within these epithelial cells is, in part, regulated by pattern recognition receptors such as cyclic GMP-AMP synthase (cGAS). cGAS binds double-stranded DNA from exogenous and endogenous sources, resulting in the activation of stimulator of interferon genes (STING) and a type 1 interferon response. cGAS is also implicated in non-canonical pathways involving the suppression of DNA repair and the upregulation of autophagy via interactions with PARP1 and Beclin-1, respectively. The importance of cGAS activation in the development and progression of inflammatory bowel disease and gastrointestinal cancers has been and continues to be explored. This review delves into the intricacies of the complex role of cGAS in intestinal epithelial inflammation and gastrointestinal malignancies, as well as recent therapeutic advances targeting cGAS pathways.

The cGAS/STING Pathway-A New Potential Biotherapeutic Target for Gastric Cancer?

Gastric cancer ranks among the top five deadliest tumors worldwide, both in terms of prevalence and mortality rates. Despite mainstream treatments, the efficacy in treating gastric cancer remains suboptimal, underscoring the urgency for novel therapeutic approaches. The elucidation of tumor immunosuppressive microenvironments has shifted focus towards cancer biotherapeutics, which leverage the patient's immune system or biologics to target tumor cells. Biotherapy has emerged as a promising alternative for tumors resistant to traditional chemotherapy, radiation, and immunotherapy. Central to this paradigm is the cGAS-STING pathway, a pivotal component of the innate immune system. This pathway recognizes aberrant DNA, such as that from viral infections or tumor cells, and triggers an immune response, thereby reshaping the immunosuppressive tumor microenvironment into an immune-stimulating milieu. In the context of gastric cancer, harnessing the cGAS-STING pathway holds significant potential for biotherapeutic interventions. This review provides a comprehensive overview of the latest research on cGAS-STING in gastric cancer, including insights from clinical trials involving STING agonists. Furthermore, it assesses the prospects of targeting the cGAS-STING pathway as a novel biotherapeutic strategy for gastric cancer.

The Sources, Structures and Cytotoxicity of Animal-Derived Bisindole Compounds

Bisindole compounds constitute a significant class of natural compounds distinguished by their characteristic bisindole structure and renowned for their anticancer properties. Over the past four decades, researchers have isolated 229 animal-derived bisindole compounds (ADBCs) from various animals. These compounds demonstrate a wide range of pharmacological properties, including cytotoxicity, antibacterial, antifungal, antiviral, and other activities. Notably, among these activities, cytotoxicity emerges as the most prominent characteristic of ADBCs. This review also summarizes the structureactivity relationship (SAR) studies associated with the cytotoxicity of these compounds and explores the druggability of these compounds. In summary, our objective is to provide an overview of the research progress concerning ADBCs, with the aim of fostering their continued development and utilization.

Gastric cancer fibroblasts affect the effect of immunotherapy and patient prognosis by inducing micro-vascular production

Introduction

Immunotherapy is critical for treating many cancers, and its therapeutic success is linked to the tumor microenvironment. Although anti-angiogenic drugs are used to treat gastric cancer (GC), their efficacy remains limited. Cancer-associated fibroblast (CAF)-targeted therapies complement immunotherapy; however, the lack of CAF-specific markers poses a challenge. Therefore, we developed a CAF angiogenesis prognostic score (CAPS) system to evaluate prognosis and immunotherapy response in patients with GC, aiming to improve patient stratification and treatment efficacy.

Methods

We assessed patient-derived GC CAFs for promoting angiogenesis using EdU, cell cycle, apoptosis, wound healing, and angiogenesis analysis.

Results

We then identified CAF-angiogenesis-associated differentially-expressed genes, leading to the development of CAPS, which included THBS1, SPARC, EDNRA, and VCAN. We used RT-qPCR to conduct gene-level validation, and eight GEO datasets and the HPA database to validate the CAPS system at the gene and protein levels. Six independent GEO datasets were utilized for validation. Overall survival time was shorter in the high- than the low-CAPS group. Immune microenvironment and immunotherapy response analysis showed that the high-CAPS group had a greater tendency toward immune escape and reduced immunotherapy efficacy than the low-CAPS group.

Discussion

CAPS is closely associated with GC prognosis and immunotherapy outcomes. It is therefore an independent predictor of GC prognosis and immunotherapy efficacy.

Predictive modeling of lower extreme deep vein thrombosis following radical gastrectomy for gastric cancer: based on multiple machine learning methods

Postoperative venous thromboembolic events (VTEs), such as lower extremity deep vein thrombosis (DVT), are major risk factors for gastric cancer (GC) patients following radical gastrectomy. Accurately predicting and managing these risks is crucial for optimal patient care. This retrospective case‒control study involved 693 GC patients from our hospital who underwent radical gastrectomy. We collected plentiful and comprehensive clinical indicators including a total of 49 baseline, preoperative, surgical and pathological clinical data. Using univariate logistic regression, we identified potential risk factors, followed by feature selection through the Boruta algorithm. We then constructed the final predictive model using multivariate logistic regression and evaluated it using receiver operating characteristic (ROC) curve analysis, calibration plots, decision curve analysis, and other methods. Additionally, we applied various machine learning techniques, including decision trees and random forests, to assess our model's predictive strength. This retrospective case‒control study involved 693 GC patients from our hospital who underwent radical gastrectomy. We collected plentiful and comprehensive clinical indicators including a total of 49 baseline, preoperative, surgical and pathological clinical data. Using univariate logistic regression, we identified potential risk factors, followed by feature selection through the Boruta algorithm. We then constructed the final predictive model using multivariate logistic regression and evaluated it using receiver operating characteristic (ROC) curve analysis, calibration plots, decision curve analysis, and other methods. Additionally, we applied various machine learning techniques, including decision trees and random forests, to assess our model's predictive strength. Univariate logistic analysis revealed 14 risk factors associated with postoperative lower limb DVT. Based on the Boruta algorithm, six significant clinical factors were selected, namely, age, D-dimer (D-D) level, low-density lipoprotein, CA125, and calcium and chloride ion levels. A nomogram was developed using the outcomes from the multivariate logistic regression analysis. The predictive model showed high accuracy, with an area under the curve of 0.936 in the training set and 0.875 in the validation set. Various machine learning algorithms confirmed its strong predictive capacity. MR analysis revealed meaningful causal relationships between key clinical factors and DVT risk. Based on various machine learning methods, we developed an effective predictive diagnostic model for postoperative lower extremity DVT in GC patients. This model demonstrated excellent predictive value in both the training and validation sets. This novel model is a valuable tool for clinicians to use in identifying and managing thrombotic risks in this patient population.

Comparison between Glasgow prognostic criteria and O-POSSUM/ P-POSSUM physiological indices in patients undergoing gastrectomy for gastric adenocarcinoma and the occurrency of early postoperative complications

INTRODUCTION

Gastric cancer is still the third cause of death worldwide due to malignant neoplasms. Its prognostic indices have not yet been well defined for surgical intervention in terms of stratifying the intensity of chronic inflammation. The Glasgow Prognostic Score (GPS) and O-POSSUM and P-POSSUM Indices may constitute these standardizations and were tested to assess the association between them and the prognosis after curative gastrectomy.

METHOD

Retrospective observational study, analysing medical records of patients with gastric adenocarcinoma who underwent gastrectomy, from 2015 to 2021, in two hospitals in Rio de Janeiro. Surgical extension, pre, peri and postoperative clinical and laboratory data were observed, up to 30 days after surgery. Patients were layered by GPS and compared according to the Clavien-Dindo (CD) classification. Logistic regression was performed to test the association between the outcome and independent variables.

RESULTS

Of the 48 patients, 56.25% were female. There was difference between the groups regarding surgical extension and GPS (both with p<0.001), while O-POSSUM, P-POSSUM and age showed no difference. Factors associated with CD ≥ III-a complication in the univariate analysis were GPS (OR: 85,261; CI: 24,909- 291,831) and P-POSSUM (OR: 1,211; CI:1,044-1,404). In the multivariate analysis, the independent factors associated with CD ≥ III-a were GPS (OR:114,865; CI: 15,430-855,086), P-POSSUM (OR: 1,133; CI: 1,086-1,181) and O-POSSUM (OR: 2,238; CI: 1,790-2,797).

CONCLUSION

In this model, GPS, P-POSSUM and O-POSSUM predicted serious surgical complications. There is a need for further studies to establish strategies to minimize the inflammatory response in the preoperative period.

Yiqi Wenyang Jiedu prescription for preventing and treating postoperative recurrence and metastasis of gastric cancer: a randomized controlled trial protocol

Introduction

Postoperative recurrence and metastasis of gastric cancer (GC) are primary factors that contribute to poor prognosis. GC recurs at a rate of approximately 70%-80% within 2 years after local treatment and approximately 90% within 5 years. "Yang-deficient toxic node" is the core pathogenesis of GC recurrence and metastasis. The Yiqi Wenyang Jiedu prescription (YWJP), a form of complementary and alternative medicine in China, is an empirical remedy to prevent postoperative recurrence and metastasis of GC. Taking the main therapeutic principles of "nourishing Qi and warming Yang, strengthening Zhengqi, and detoxifying" can aid in preventing the recurrence and metastasis of GC in patients during the watchful waiting period after surgery and adjuvant chemotherapy. This approach aims to enhance the quality of life of patients. However, high-quality evidence to support this hypothesis is lacking. This study will aim to investigate the efficacy and safety of YWJP to prevent and treat postoperative metastasis and GC recurrence.

Methods

The study will be a multicenter, randomized, double-blind, placebo-parallel-controlled clinical trial. A total of 212 patients who completed adjuvant chemotherapy within 8 months of radical gastrectomy will be enrolled. Patients in the intervention group will receive the YWJP, whereas those in the control group will receive a placebo. The main outcome was the disease-free survival (DFS) rate 2 years after surgery. The secondary outcomes included DFS time, overall survival, annual cumulative recurrence and rate of metastasis after 1-3 years, cumulative annual survival after 1-3 years, fat distribution-related indicators, tumor markers, peripheral blood inflammatory indicators, prognostic nutritional index, symptoms and quality of life evaluation, medication compliance, and adverse reaction rate.

Discussion

There is a lack of effective therapy after the completion of adjuvant therapy during the postoperative period of watchful waiting. This study will be the first randomized clinical trial to evaluate whether complementary and alternative medical interventions can effectively prevent recurrence and metastasis during the watchful waiting period after GC surgery and to provide evidence for surveillance treatment management after GC surgery.

Clinical trial registration

ClinicalTrials.gov, identifier NCT05229809.

Prognostic Relevance of the Proximal Resection Margin Distance in Distal Gastrectomy for Gastric Adenocarcinoma

BACKGROUND

The risk for recurrence in patients with distal gastric cancer can be reduced by surgical radicality. However, dispute exists about the value of the proposed minimum proximal margin distance (PMD). Here, we assess the prognostic value of the safety distance between the proximal resection margin and the tumor.

PATIENTS AND METHODS

This is a single-center cohort study of patients undergoing distal gastrectomy for gastric adenocarcinoma (2001-2021). Cohorts were defined by adequacy of the PMD according to the European Society for Medical Oncology (ESMO) guidelines (≥ 5 cm for intestinal and ≥ 8 cm for diffuse Laurén's subtypes). Overall survival (OS) and time to progression (TTP) were assessed by log-rank and multivariable Cox-regression analyses.

RESULTS

Of 176 patients, 70 (39.8%) had a sufficient PMD. An adequate PMD was associated with cancer of the intestinal subtype (67% vs. 45%, p = 0.010). Estimated 5-year survival was 63% [95% confidence interval (CI) 51-78] and 62% (95% CI 53-73) for adequate and inadequate PMD, respectively. Overall, an adequate PMD was not prognostic for OS (HR 0.81, 95% CI 0.48-1.38) in the multivariable analysis. However, in patients with diffuse subtype, an adequate PMD was associated with improved oncological outcomes (median OS not reached versus 131 months, p = 0.038, median TTP not reached versus 88.0 months, p = 0.003).

CONCLUSION

Patients with diffuse gastric cancer are at greater risk to undergo resection with an inadequate PMD, which in those patients is associated with worse oncological outcomes. For the intestinal subtype, there was no prognostic association with PMD, indicating that a distal gastrectomy with partial preservation of the gastric function may also be feasible in the setting where an extensive PMD is not achievable.

Periodontal pathogens and cancer development

Increasing evidence suggests a significant association between periodontal disease and the occurrence of various cancers. The carcinogenic potential of several periodontal pathogens has been substantiated in vitro and in vivo. This review provides a comprehensive overview of the diverse mechanisms employed by different periodontal pathogens in the development of cancer. These mechanisms induce chronic inflammation, inhibit the host's immune system, activate cell invasion and proliferation, possess anti-apoptotic activity, and produce carcinogenic substances. Elucidating these mechanisms might provide new insights for developing novel approaches for tumor prevention, therapeutic purposes, and survival improvement.

RUNX1, FUS, and ELAVL1-induced circPTPN22 promote gastric cancer cell proliferation, migration, and invasion through miR-6788-5p/PAK1 axis-mediated autophagy

BACKGROUND

An increasing number of studies have demonstrated the association of circular RNAs (circRNAs) with the pathological processes of various diseases and their involvement in the onset and progression of multiple cancers. Nevertheless, the functional roles and underlying mechanisms of circRNAs in the autophagy regulation of gastric cancer (GC) have not been fully elucidated.

METHODS

We used transmission electron microscopy and the mRFP-GFP-LC3 dual fluorescent autophagy indicator to investigate autophagy regulation. The cell counting kit-8 assay, colony formation assay, 5-ethynyl-2'-deoxyuridine incorporation assay, Transwell assay, and Western blot assay were conducted to confirm circPTPN22's influence on GC progression. Dual luciferase reporter assays validated the binding between circPTPN22 and miR-6788-5p, as well as miR-6788-5p and p21-activated kinase-1 (PAK1). Functional rescue experiments assessed whether circPTPN22 modulates PAK1 expression by competitively binding miR-6788-5p, affecting autophagy and other biological processes in GC cells. We investigated the impact of circPTPN22 on in vivo GC tumors using a nude mouse xenograft model. Bioinformatics tools predicted upstream regulatory transcription factors and binding proteins of circPTPN22, while chromatin immunoprecipitation and ribonucleoprotein immunoprecipitation assays confirmed the binding status.

RESULTS

Upregulation of circPTPN22 in GC has been shown to inhibit autophagy and promote cell proliferation, migration, and invasion. Mechanistically, circPTPN22 directly binds to miR-6788-5p, subsequently regulating the expression of PAK1, which activates protein kinase B (Akt) and extracellular signal-regulated kinase (Erk) phosphorylation. This modulation ultimately affects autophagy levels in GC cells. Additionally, runt-related transcription factor 1 (RUNX1) negatively regulates circPTPN22 expression, while RNA-binding proteins such as FUS (fused in sarcoma) and ELAVL1 (recombinant ELAV-like protein 1) positively regulate its expression. Inhibition of the autophagy pathway can increase FUS expression, further upregulating circPTPN22 in GC cells, thereby exacerbating the progression of GC.

CONCLUSION

Under the regulation of the transcription factor RUNX1 and RNA-binding proteins FUS and ELAVL1, circPTPN22 activates the phosphorylation of Akt and Erk through the miR-6788-5p/PAK1 axis, thereby modulating autophagy in GC cells. Inhibition of autophagy increases FUS, which in turn upregulates circPTPN22, forming a positive feedback loop that ultimately accelerates the progression of GC.

RNA demethylase FTO participates in malignant progression of gastric cancer by regulating SP1-AURKB-ATM pathway

Gastric cancer (GC) is the 5th most prevalent cancer and the 4th primary cancer-associated mortality globally. As the first identified m6A demethylase for removing RNA methylation modification, fat mass and obesity-associated protein (FTO) plays instrumental roles in cancer development. Therefore, we study the biological functions and oncogenic mechanisms of FTO in GC tumorigenesis and progression. In our study, FTO expression is obviously upregulated in GC tissues and cells. The upregulation of FTO is associated with advanced nerve invasion, tumor size, and LNM, as well as the poor prognosis in GC patients, and promoted GC cell viability, colony formation, migration and invasion. Mechanistically, FTO targeted specificity protein 1 and Aurora Kinase B, resulting in the phosphorylation of ataxia telangiectasia mutated and P38 and dephosphorylation of P53. In conclusion, the m6A demethylase FTO promotes GC tumorigenesis and progression by regulating the SP1-AURKB-ATM pathway, which may highlight the potential of FTO as a diagnostic biomarker for GC patients' therapy response and prognosis.

Effect of anti-claudin 18.2 monoclonal antibody zolbetuximab alone or combined with chemotherapy or programmed cell death-1 blockade in syngeneic and xenograft gastric cancer models

The development of targeted cancer therapies based on monoclonal antibodies against tumor-associated antigens has progressed markedly over recent decades. This approach is dependent on the identification of tumor-specific, normal tissue-sparing antigenic targets. The transmembrane protein claudin-18 splice variant 2 (CLDN18.2) is frequently and preferentially displayed on the surface of primary gastric adenocarcinomas, making it a promising monoclonal antibody target. Phase 3 studies of zolbetuximab, a chimeric immunoglobulin G1 monoclonal antibody targeting CLDN18.2, combined with 5-fluorouracil/leucovorin plus oxaliplatin (modified FOLFOX6) or capecitabine plus oxaliplatin (CAPOX) in advanced or metastatic first-line gastric or gastroesophageal junction (G/GEJ) adenocarcinoma have demonstrated favorable clinical results with zolbetuximab. In studies using xenograft or syngeneic models with gastric cancer cell lines, zolbetuximab mediated death of CLDN18.2-positive human cancer cell lines via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity in vitro and demonstrated anti-tumor efficacy as monotherapy and combined with chemotherapy in vivo. Mice treated with zolbetuximab plus chemotherapy displayed a significantly higher frequency of tumor-infiltrating CD8+ T cells versus vehicle/isotype control-treated mice. Furthermore, zolbetuximab combined with an anti-mouse programmed cell death-1 antibody more potently inhibited tumor growth compared with either agent alone. These results support the potential of zolbetuximab as a novel treatment option for G/GEJ adenocarcinoma.

HDAC inhibitors activate lipid peroxidation and ferroptosis in gastric cancer

Gastric cancer remains among the deadliest neoplasms worldwide, with limited therapeutic options. Since efficacies of targeted therapies are unsatisfactory, drugs with broader mechanisms of action rather than a single oncogene inhibition are needed. Preclinical studies have identified histone deacetylases (HDAC) as potential therapeutic targets in gastric cancer. However, the mechanism(s) of action of HDAC inhibitors (HDACi) are only partially understood. This is particularly true with regard to ferroptosis as an emerging concept of cell death. In a panel of gastric cancer cell lines with different molecular characteristics, tumor cell inhibitory effects of different HDACi were studied. Lipid peroxidation levels were measured and proteome analysis was performed for the in-depth characterization of molecular alterations upon HDAC inhibition. HDACi effects on important ferroptosis genes were validated on the mRNA and protein level. Upon HDACi treatment, lipid peroxidation was found increased in all cell lines. Class I HDACi (VK1, entinostat) showed the same toxicity profile as the pan-HDACi vorinostat. Proteome analysis revealed significant and concordant alterations in the expression of proteins related to ferroptosis induction. Key enzymes like ACSL4, POR or SLC7A11 showed distinct alterations in their expression patterns, providing an explanation for the increased lipid peroxidation. Results were also confirmed in primary human gastric cancer tissue cultures as a relevant ex vivo model. We identify the induction of ferroptosis as new mechanism of action of class I HDACi in gastric cancer. Notably, these findings were independent of the genetic background of the cell lines, thus introducing HDAC inhibition as a more general therapeutic principle.

Mechanisms and clinical landscape of N6-methyladenosine (m6A) RNA modification in gastrointestinal tract cancers

Epigenetics encompasses reversible and heritable chemical modifications of non-nuclear DNA sequences, including DNA and RNA methylation, histone modifications, non-coding RNA modifications, and chromatin rearrangements. In addition to well-studied DNA and histone methylation, RNA methylation has emerged as a hot topic in biological sciences over the past decade. N6-methyladenosine (m6A) is the most common and abundant modification in eukaryotic mRNA, affecting all RNA stages, including transcription, translation, and degradation. Advances in high-throughput sequencing technologies made it feasible to identify the chemical basis and biological functions of m6A RNA. Dysregulation of m6A levels and associated modifying proteins can both inhibit and promote cancer, highlighting the importance of the tumor microenvironment in diverse biological processes. Gastrointestinal tract cancers, including gastric, colorectal, and pancreatic cancers, are among the most common and deadly malignancies in humans. Growing evidence suggests a close association between m6A levels and the progression of gastrointestinal tumors. Global m6A modification levels are substantially modified in gastrointestinal tumor tissues and cell lines compared to healthy tissues and cells, possibly influencing various biological behaviors such as tumor cell proliferation, invasion, metastasis, and drug resistance. Exploring the diagnostic and therapeutic potential of m6A-related proteins is critical from a clinical standpoint. Developing more specific and effective m6A modulators offers new options for treating these tumors and deeper insights into gastrointestinal tract cancers.

The most recent progress of baicalein in its anti-neoplastic effects and mechanisms

Problems, such as toxic side effects and drug resistance of chemoradiotherapy, target therapy and immunotherapy accompanying the current anti-cancer treatments, have become bottlenecks limiting the clinical benefit for patients. Therefore, it is urgent to find promising anti-cancer strategies with higher efficacy and lesser side effects. Baicalein, a flavonoid component derived from the Chinese medicine scutellaria baicalensis, has been widely studied for its remarkable anti-cancer activity in multiple types of malignancies both at the molecular and cellular levels. Baicalein exerts its anti-tumor effects by inhibiting angiogenesis, invasion and migration, inducing cell apoptosis and cell cycle arrest, as well as regulating cell autophagy, metabolism, the tumor microenvironment and cancer stem cells with no obvious toxic side effects. The role of classic signaling pathways, such as PI3K/AKT/mTOR, MAPK, AMPK, Wnt/β-catenin, JAK/STAT3, MMP-2/-9, have been highlighted as the major targets for baicalein exerting its anti-malignant potential. Besides, baicalein can regulate the relevant non-coding RNAs, such as lncRNAs, miRNAs and circ-RNAs, to inhibit tumorigenesis and progression. In addition to the mentioned commonalities, baicalein shows some specific anti-tumor characteristics in some specific cancer types. Moreover, the preclinical studies of the combination of baicalein and chemoradiotherapy pave the way ahead for developing baicalein as an adjunct treatment with chemoradiotherapy. Our aim is to summary the role of baicalein in different types of cancer with its mechanisms based on in vitro and in vivo experiments, hoping providing proof for baicalein serving as an effective and safe compound for cancer treatment in clinic in the future.

The tumor immune microenvironment remodeling and response to HER2-targeted therapy in HER2-positive advanced gastric cancer

Combination therapy with anti-HER2 agents and immunotherapy has demonstrated significant clinical benefits in gastric cancer (GC), but the underlying mechanism remains unclear. In this study, we used multiplex immunohistochemistry to assess the changes of the tumor microenvironment in 47 advanced GC patients receiving anti-HER2 therapy. Additionally, we performed single-cell transcriptional sequencing to investigate potential cell-to-cell communication and molecular mechanisms in four HER2-positive GC baseline samples. We observed that post-treated the infiltration of NK cells, CD8+ T cells, and B lymphocytes were significantly higher in patients who benefited from anti-HER2 treatment than baseline. Further spatial distribution analysis demonstrated that the interaction scores between NK cells and CD8+ T cells, B lymphocytes and M2 macrophages, B lymphocytes and Tregs were also significantly higher in benefited patients. Cell-cell communication analysis from scRNA sequencing showed that NK cells utilized CCL3/CCL4-CCR5 to recruit CD8+ T cell infiltration. B lymphocytes employed CD74-APP/COPA/MIF to interact with M2 macrophages, and utilized TNF-FAS/ICOS/TNFRSR1B to interact with Tregs. These cell-cell interactions contribute to inhibit the immune resistance of M2 macrophages and Tregs. Our research provides potential guidance for the use of anti-HER2 therapy in combination with immune therapy.

MRI versus Dual-Energy CT in Local-Regional Staging of Gastric Cancer

Background Preoperative local-regional tumor staging of gastric cancer (GC) is critical for appropriate treatment planning. The comparative accuracy of multiparametric MRI (mpMRI) versus dual-energy CT (DECT) for staging of GC is not known. Purpose To compare the diagnostic accuracy of personalized mpMRI with that of DECT for local-regional T and N staging in patients with GC receiving curative surgical intervention. Materials and Methods Patients with GC who underwent gastric mpMRI and DECT before gastrectomy with lymphadenectomy were eligible for this single-center prospective noninferiority study between November 2021 and September 2022. mpMRI comprised T2-weighted imaging, multiorientational zoomed diffusion-weighted imaging, and extradimensional volumetric interpolated breath-hold examination dynamic contrast-enhanced imaging. Dual-phase DECT images were reconstructed at 40 keV and standard 120 kVp-like images. Using gastrectomy specimens as the reference standard, the diagnostic accuracy of mpMRI and DECT for T and N staging was compared by six radiologists in a pairwise blinded manner. Interreader agreement was assessed using the weighted κ and Kendall W statistics. The McNemar test was used for head-to-head accuracy comparisons between DECT and mpMRI. Results This study included 202 participants (mean age, 62 years ± 11 [SD]; 145 male). The interreader agreement of the six readers for T and N staging of GC was excellent for both mpMRI (κ = 0.89 and 0.85, respectively) and DECT (κ = 0.86 and 0.84, respectively). Regardless of reader experience, higher accuracy was achieved with mpMRI than with DECT for both T (61%-77% vs 50%-64%; all P < .05) and N (54%-68% vs 51%-58%; P = .497-.005) staging, specifically T1 (83% vs 65%) and T4a (78% vs 68%) tumors and N1 (41% vs 24%) and N3 (64% vs 45%) nodules (all P < .05). Conclusion Personalized mpMRI was superior in T staging and noninferior or superior in N staging compared with DECT for patients with GC. Clinical trial registration no. NCT05508126 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Méndez and Martín-Garre in this issue.

Surgical Techniques and Related Perioperative Outcomes After Robot-assisted Minimally Invasive Gastrectomy (RAMIG): Results From the Prospective Multicenter International Ugira Gastric Registry

OBJECTIVE

To gain insight into the global practice of robot-assisted minimally invasive gastrectomy (RAMIG) and evaluate perioperative outcomes using an international registry.

BACKGROUND

The techniques and perioperative outcomes of RAMIG for gastric cancer vary substantially in the literature.

METHODS

Prospectively registered RAMIG cases for gastric cancer (≥10 per center) were extracted from 25 centers in Europe, Asia, and South-America. Techniques for resection, reconstruction, anastomosis, and lymphadenectomy were analyzed and related to perioperative surgical and oncological outcomes. Complications were uniformly defined by the Gastrectomy Complications Consensus Group.

RESULTS

Between 2020 and 2023, 759 patients underwent total (n=272), distal (n=465), or proximal (n=22) gastrectomy (RAMIG). After total gastrectomy with Roux-en-Y-reconstruction, anastomotic leakage rates were 8% with hand-sewn (n=9/111) and 6% with linear stapled anastomoses (n=6/100). After distal gastrectomy with Roux-en-Y (67%) or Billroth-II-reconstruction (31%), anastomotic leakage rates were 3% with linear stapled (n=11/433) and 0% with hand-sewn anastomoses (n=0/26). Extent of lymphadenectomy consisted of D1+ (28%), D2 (59%), or D2+ (12%). Median nodal harvest yielded 31 nodes (interquartile range: 21-47) after total and 34 nodes (interquartile range: 24-47) after distal gastrectomy. R0 resection rates were 93% after total and 96% distal gastrectomy. The hospital stay was 9 days after total and distal gastrectomy, and was median 3 days shorter without perianastomotic drains versus routine drain placement. Postoperative 30-day mortality was 1%.

CONCLUSIONS

This large multicenter study provided a worldwide overview of current RAMIG techniques and their respective perioperative outcomes. These outcomes demonstrated high surgical quality, set a quality standard for RAMIG, and can be considered an international reference for surgical standardization.

SNHG15-mediated feedback loop interplays with HNRNPA1/SLC7A11/GPX4 pathway to promote gastric cancer progression

Dysregulation of long noncoding RNA (lncRNA) expression plays a pivotal role in the initiation and progression of gastric cancer (GC). However, the regulation of lncRNA SNHG15 in GC has not been well studied. Mechanisms for ferroptosis by SNHG15 have not been revealed. Here, we aimed to explore SNHG15-mediated biological functions and underlying molecular mechanisms in GC. The novel SNHG15 was identified by analyzing RNA-sequencing (RNA-seq) data of GC tissues from our cohort and TCGA dataset, and further validated by qRT-PCR in GC cells and tissues. Gain- and loss-of-function assays were performed to examine the role of SNHG15 on GC both in vitro and in vivo. SNHG15 was highly expressed in GC. The enhanced SNHG15 was positively correlated with malignant stage and poor prognosis in GC patients. Gain- and loss-of-function studies showed that SNHG15 was required to affect GC cell growth, migration and invasion both in vitro and in vivo. Mechanistically, the oncogenic transcription factors E2F1 and MYC could bind to the SNHG15 promoter and enhance its expression. Meanwhile, SNHG15 increased E2F1 and MYC mRNA expression by sponging miR-24-3p. Notably, SNHG15 could also enhance the stability of SLC7A11 in the cytoplasm by competitively binding HNRNPA1. In addition, SNHG15 inhibited ferroptosis through an HNRNPA1-dependent regulation of SLC7A11/GPX4 axis. Our results support a novel model in which E2F1- and MYC-activated SNHG15 regulates ferroptosis via an HNRNPA1-dependent modulation of the SLC7A11/GPX4 axis, which serves as the critical effectors in GC progression, and provides a new therapeutic direction in the treatment of GC.

Metabolomic profiling of upper GI malignancies in blood and tissue: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of case-control and cohort human studies evaluating metabolite markers identified using high-throughput metabolomics techniques on esophageal cancer (EC), cancer of the gastroesophageal junction (GEJ), and gastric cancer (GC) in blood and tissue.

BACKGROUND

Upper gastrointestinal cancers (UGC), predominantly EC, GEJ, and GC, are malignant tumour types with high morbidity and mortality rates. Numerous studies have focused on metabolomic profiling of UGC in recent years. In this systematic review and meta-analysis, we have provided a collective summary of previous findings on metabolites and metabolomic profiling associated with EC, GEJ and GC.

METHODS

Following the PRISMA procedure, a systematic search of four databases (Embase, PubMed, MEDLINE, and Web of Science) for molecular epidemiologic studies on the metabolomic profiles of EC, GEJ and GC was conducted and registered at PROSPERO (CRD42023486631). The Newcastle-Ottawa Scale (NOS) was used to benchmark the risk of bias for case-controlled and cohort studies. QUADOMICS, an adaptation of the QUADAS-2 (Quality Assessment of Diagnostic Accuracy) tool, was used to rate diagnostic accuracy studies. Original articles comparing metabolite patterns between patients with and without UGC were included. Two investigators independently completed title and abstract screening, data extraction, and quality evaluation. Meta-analysis was conducted whenever possible. We used a random effects model to investigate the association between metabolite levels and UGC.

RESULTS

A total of 66 original studies involving 7267 patients that met the required criteria were included for review. 169 metabolites were differentially distributed in patients with UGC compared to healthy patients among 44 GC, 9 GEJ, and 25 EC studies including metabolites involved in glycolysis, anaerobic respiration, tricarboxylic acid cycle, and lipid metabolism. Phosphatidylcholines, eicosanoids, and adenosine triphosphate were among the most frequently reported lipids and metabolites of cellular respiration, while BCAA, lysine, and asparagine were among the most commonly reported amino acids. Previously identified lipid metabolites included saturated and unsaturated free fatty acids and ketones. However, the key findings across studies have been inconsistent, possibly due to limited sample sizes and the majority being hospital-based case-control analyses lacking an independent replication group.

CONCLUSION

Thus far, metabolomic studies have provided new opportunities for screening, etiological factors, and biomarkers for UGC, supporting the potential of applying metabolomic profiling in early cancer diagnosis. According to the results of our meta-analysis especially BCAA and TMAO as well as certain phosphatidylcholines should be implicated into the diagnostic procedure of patients with UGC. We envision that metabolomics will significantly enhance our understanding of the carcinogenesis and progression process of UGC and may eventually facilitate precise oncological and patient-tailored management of UGC.

YAP inhibition overcomes adaptive resistance in HER2-positive gastric cancer treated with trastuzumab via the AKT/mTOR and ERK/mTOR axis

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC) is a heterogeneous GC subtype characterized by the overexpression of HER2. To date, few specific targeted therapies have demonstrated durable efficacy in HER2-positive GC patients, with resistance to trastuzumab typically emerging within 1 year. However, the mechanisms of resistance to trastuzumab remain incompletely understood, presenting a significant challenge to clinical practice.

METHODS

In this study, we integrated genetic screening and bulk transcriptome and epigenomic profiling to define the mechanisms mediating adaptive resistance to HER2 inhibitors and identify potential effective therapeutic strategies for treating HER2-positive GCs.

RESULTS

We revealed a potential association between adaptive resistance to trastuzumab in HER2-positive GC and the expression of YES-associated protein (YAP). Notably, our investigation revealed that long-term administration of trastuzumab triggers extensive chromatin remodeling and initiates YAP gene transcription in HER2-positive cells characterized by the initial inhibition and subsequent reactivation. Furthermore, treatment of HER2-positive GC cells and cell line-derived xenografts (CDX) models with YAP inhibitors in combination with trastuzumab was found to induce synergistic effects through the AKT/mTOR and ERK/mTOR pathways.

CONCLUSION

These findings underscore the pivotal role of reactivated YAP and mTOR signaling pathways in the development of adaptive resistance to trastuzumab and may serve as a promising joint target to overcome resistance to trastuzumab.

Cuproptosis-related gene DLAT is a biomarker of the prognosis and immune microenvironment of gastric cancer and affects the invasion and migration of cells

OBJECTIVE

Cuproptosis is a novel cell death dependent on mitochondrial respiration and regulated by copper. This study aimed to investigate the cuproptosis-related gene DLAT potential value in gastric cancer (GC).

METHODS

Bioinformatics was used to analyze DLAT expression. DLAT expression in GC cell lines was detected using qRT-PCR. Cell proliferation ability was assessed using CCK8 and cell cycle assay. Cell migration and invasion were assessed using wound healing and transwell assay. A prognostic assessment was performed through survival and Cox regression analysis. DLAT protein expression was analyzed through HPA immunohistochemistry. Biological functions and processes were analyzed through GO and KEGG enrichment analysis and PPI. Correlation with immune cell infiltration and immune checkpoint genes was analyzed for DLAT.

RESULTS

DLAT expression was upregulated in GC tissues and cells and correlated with shorter survival for patients. Age, gender, histological typing, lymph node metastasis, and distant metastasis were identified as independent prognostic factors affecting OS in GC. DLAT protein was upregulated in GC. The biological functions and pathways enriched in DLAT were mainly linked to mitochondrial respiration and the TCA cycle. The expression of DLAT was found to be positively correlated with the infiltration of Th and Th2 immune cells and only positively correlated with the expression of the BTN2A1 immune checkpoint gene.

CONCLUSION

DLAT has the potential to serve as a prognostic assessment factor in GC. The expression of DLAT was correlated with immune infiltration and tumor immune escape, providing a new target for immunotherapy of GC.

Mortality from upper gastrointestinal tumors in colorectal cancer screening patients

Background and study aims Currently, gastric cancer screening is only cost-effective in countries with high incidence. Integrated screening, in which gastroscopy is performed in conjunction with colonoscopy, could help reduce the gastric cancer screening procedure burden in countries with low or intermediate incidence. However, there is a lack of population-based studies to identify high-risk groups. Methods In this retrospective analysis of a colorectal cancer (CRC) screening program database, we used Cox proportional hazards model to identify an association of high- and low-risk finding (polyps ≥ 10 mm or with high-grade dysplasia) with time to death from upper gastrointestinal cancer (esophageal and gastric). We estimated the 10-year mortality of upper gastrointestinal tumors in different 10-year age groups, stratified by sex and polyp finding at colonoscopy. Results We included 349,856 CRC screening colonoscopies in our study. The median follow-up time was 5.22 years (95% confidence interval [CI] 5.21-5.24 years). Of the participants, 4.5% had polyps ≥ 10 mm or with high-grade dysplasia (HGD). At the end of the study period, 384 deaths from upper gastrointestinal cancer had occurred. Aside from age and sex, we found the presence of high-risk polyps to be significantly associated with upper gastrointestinal cancer death (hazard ratio 1.54, 95% CI 1.06-2.25, P = 0.025). Conclusions CRC screening participants with polyps < 10 mm and no HGD have a lower risk for mortality from upper gastrointestinal cancers compared with participants with polyps > 10 mm and HGD. Future studies will demonstrate whether integrated screening with additional gastroscopy is effective in CRC screening participants with large or highly dysplastic polyps.

Prognostic Relevance of Recurrent Sites of Gastric Cancer Treated With Curative Resection: A Single Center Retrospective Study

PURPOSE

Gastric cancer treated with curative resection exhibits several recurrence patterns. The peritoneum is the most common site of recurrence. Some reports have indicated different prognostic influences according to the recurrence sites in other cancers, such as esophageal and colorectal cancers. This study investigated whether the recurrence sites influenced the prognosis of patients with recurrent gastric cancer.

MATERIALS AND METHODS

The data of 115 patients who experienced tumor recurrence after curative gastrectomy were retrospectively reviewed. The sites of recurrence were divided into 4 groups: lymph node (LN), peritoneum, other single organs, and multiple lesions. Clinicopathological features were compared between the sites of recurrence. Prognosis after resection and recurrence were also compared.

RESULTS

The peritoneum was the primary site of recurrence in 38 patients (33%). The tumor differentiation and pathological stages were significantly different. Survival after surgery did not show a statistically significant difference (hazard ratio [HR] of LN: 1, peritoneum: 1.083, other single organs: 1.025, and multiple lesions: 1.058; P=1.00). Survival after recurrence was significantly different (HR of LN, 1; peritoneum, 2.164; other single organs, 1.092; multiple lesions, 1.554; P=0.01), and patients with peritoneal and multiple lesion recurrences had worse prognosis. Furthermore, peritoneal recurrence seemed to occur later than that at other sites; the median times to recurrence in LN, peritoneal, other single-organ, and multiple lesions were 265, 722, 372, and 325 days, respectively.

CONCLUSIONS

The sites of gastric cancer recurrence may have different prognostic effects. Peritoneal recurrence may be less sensitive to chemotherapy and occur during the late phase of recurrence.

Gastric cancer immunosuppressive microenvironment heterogeneity: implications for therapy development

Although immunotherapy has revolutionized solid tumor treatment, durable responses in gastric cancer (GC) remain limited. The heterogeneous tumor microenvironment (TME) facilitates immune evasion, contributing to resistance to conventional and immune therapies. Recent studies have highlighted how specific TME components in GC acquire immune escape capabilities through cancer-specific factors. Understanding the underlying molecular mechanisms and targeting the immunosuppressive TME will enhance immunotherapy efficacy and patient outcomes. This review summarizes recent advances in GC TME research and explores the role of the immune-suppressive system as a context-specific determinant. We also provide insights into potential treatments beyond checkpoint inhibition.

Clinical feasibility of the preoperative C-reactive protein-albumin-lymphocyte index to predict short- and long-term outcomes of patients with gastric cancer

BACKGROUND

Gastric cancer (GC) is a major leading cause of cancer-related death worldwide. Systemic inflammation and the nutrition-based score are feasible prognostic markers for malignancies. Emerging evidence has also revealed the C-reactive protein-albumin-lymphocyte (CALLY) index to be a prognostic marker for several cancer types. However, its clinical significance to predict surgical and oncologic outcomes of patients with GC remains unclear.

METHODS

We assessed the preoperative CALLY index in 426 patients with GC who received gastrectomy.

RESULTS

A low preoperative CALLY index was significantly correlated to all well-established clinicopathologic factors for disease development, including an advanced T stage, the presence of venous invasion, lymphatic vessel invasion, lymph node metastasis, distant metastasis, and an advanced TNM stage. A low preoperative CALLY index was also an independent prognostic factor for overall survival (hazard ratio [HR], 2.64; 95 % CI, 1.66-4.2; P < .0001) and disease-free survival (HR, 1.76; 95 % CI, 1.01-3.05; P = .045). In addition, a low preoperative CALLY index was an independent predictive factor for postoperative surgical site infection (odds ratio, 2.64; 95 % CI, 1.42-4.89; P = .002).

CONCLUSION

The preoperative CALLY index is valuable for perioperative and oncologic management of patients with GC.

Galectin-1 Promotes Gastric Carcinoma Progression and Cisplatin Resistance Through the NRP-1/c-JUN/Wee1 Pathway

PURPOSE

Gastric cancer (GC) is among the deadliest malignancies and the third leading cause of cancer-related deaths worldwide. Galectin-1 (Gal-1) is a primary protein secreted by cancer-associated fibroblasts (CAFs); however, its role and mechanisms of action of Gal-1 in GC remain unclear. In this study, we stimulated GC cells with exogenous human recombinant galectin-1 protein (rhGal-1) to investigate its effects on the proliferation, migration, and resistance to cisplatin.

MATERIALS AND METHODS

We used simulated rhGal-1 protein as a paracrine factor produced by CAFs to induce GC cells and investigated its promotional effects and mechanisms in GC progression and cisplatin resistance. Immunohistochemical (IHC) assay confirmed that Gal-1 expression was associated with clinicopathological parameters and correlated with the expression of neuropilin-1 (NRP-1), c-JUN, and Wee1.

RESULTS

Our study reveals Gal-1 expression was significantly associated with poor outcomes. Gal-1 boosts the proliferation and metastasis of GC cells by activating the NRP-1/C-JUN/Wee1 pathway. Gal-1 notably increases GC cell resistance to cisplatin The NRP-1 inhibitor, EG00229, effectively counteracts these effects.

CONCLUSIONS

These findings revealed a potential mechanism by which Gal-1 promotes GC growth and contributes to chemoresistance, offering new therapeutic targets for the treatment of GC.

Liposome-based in situ antigen-modification strategy for "universal" T-cell-receptor engineered T cell in cancer immunotherapy

T-cell receptor (TCR) engineered T-cell therapy, unlike chimeric antigen receptor T-cell therapy, relies on the inherent ability of TCRs to detect a wider variety of antigenic epitopes, such as protein fragments found internally or externally on cells. Hence, TCR-T-cell therapy offers broader possibilities for treating solid tumors. However, because of the complicated process of identifying specific antigenic peptides, their clinical application still encounters significant challenges. Thus, we aimed to establish a novel "universal" TCR-T "artificial antigen expression" technique that involves the delivery of the antigen to tumor cells using DSPE-PEG-NY-ESO-1157-165 liposomes (NY-ESO-1 Lips) to express TCR-T-cell-specific recognition targets. In vitro as well as in vivo studies revealed that they could accumulate efficiently in the tumor area and deliver target antigens to activate the tumor-specific cytotoxic T-cell immune response. NY-ESO-1 TCR-T therapy, when used in combination, dramatically curbed tumor progression and extended the longevity of mice. Additionally, PD-1 blockage enhanced the therapeutic effect of the aforementioned therapy. In conclusion, NY-ESO-1 Lips "cursed" tumor cells by enabling antigenic target expression on their surface. This innovative technique presents a groundbreaking approach for the widespread utilization of TCR-T in solid tumor treatment.

Tumour cell-derived serglycin promotes IL-8 secretion of CAFs in gastric cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs)-derived IL-8 plays important roles in chemoresistance, immunosuppression, and lymph node metastasis of gastric cancer. However, the mechanisms underlying IL-8 production in CAFs remains unclear.

METHODS

DNA pulldown assay was performed to identify the transcription factors responsible for IL-8 expression in CAFs, which was further verified using CHIP-qPCR and DNA agarose gel electrophoresis assays. The cellular localisation of IL-8 was analysed using multiplex immunofluorescence (MxIF).

RESULTS

MxIF demonstrated that IL-8 was mainly produced by CAFs in gastric cancer. Lysine[K]-specific demethylase 5B (KDM5B) was identified as an IL-8 transcription factor in CAFs, and the binding of KDM5B to phosphorylated RB1 limited the transcriptional regulation of IL-8 in gastric cancer cells. Serglycin (SRGN) secreted by tumour cells activated the CD44/c-Myc pathway to upregulate KDM5B expression, thereby promoting IL-8 production in CAFs. Furthermore, tumour-associated neutrophils (TANs)-derived regenerating family member 4 (REG4) upregulates SRGN expression by activating cAMP-responsive element binding protein 1 (CREB1) in gastric cancer cells. Thus, the SRGN-IL-8-TANs-SRGN loop, which facilitates tumour progression, has been explored in gastric cancer.

CONCLUSIONS

This study revealed the mechanisms of the preferential production of IL-8 by CAFs in gastric cancer, and paves the way for potential new therapeutic strategies for gastric cancer.