Tumor-infiltrating mast cells stimulate ICOS+ regulatory T cells through an IL-33 and IL-2 axis to promote gastric cancer progression

ICOS+ CD4+ T cells promote antitumor immunity through Akt/STAT1/T-bet axis in MSS/pMMR colorectal cancer

Inducible Co-Stimulator (ICOS), as a T-cell-specific costimulatory receptor that enhances T-cell responses to foreign antigens, plays a crucial role in cancer immunity. However, its role in MSS/pMMR colorectal cancer (CRC) remains unclear. In this study, we demonstrated that ICOS expression decreases as the tumor stages advance and that high ICOS expression is associated with a favorable prognosis in MSS/pMMR CRC. Mechanistically, ICOS promoted the secretion of IFN-γ, TNF-α, and IL-12 in CD4+ T cells through the Akt/STAT1/T-bet axis, leading to the inhibition of MSS/pMMR-CRC-cell proliferation. Importantly, ICOS+ CD4+ T cells enhanced tumor responses to anti-PD-1 therapy in MSS/pMMR CRC. In conclusion, this study revealed that ICOS mediates antitumor immunity by promoting the secretion of cancer-suppressive cytokines. It also suggests that activation of ICOS serves a potential therapeutic strategy for MSS/pMMR CRC.

The role of the tumor microenvironment and inflammatory pathways in driving drug resistance in gastric cancer: A systematic review and meta-analysis

Tumor microenvironment (TME) plays a pivotal role in progression and low responsiveness to chemotherapy of gastric cancer (GC). The cascade of events that culminate with a sustained and chronic activation of inflammatory pathways underlies gastric tumorigenesis. Infiltrating immune cells enrolling in crosstalk with cancer cells that regulate inflammatory and immune status, generating an immunosuppressive TME that influences the response to therapy. Here we discuss the role of TME and the activation of inflammatory pathways to comprehend strategies to improve drug response. Furthermore, we provides systematic insight the role of TME cytotypes and related signatures reinforcing the critical roles of TAMs and Tregs, in promoting GC chemoresistance and tumor progression.

Development of a prognostic oxidative stress-immune-inflammation score and online calculators for predicting survival and recurrence in gastric cancer: a multicenter study

BACKGROUND

Oxidative stress, immune response, and inflammation play an important role in the occurrence and progression of gastric cancer (GC). This study is to develop a novel prognostic oxidative stress-immune-inflammation score (POSII score) and to explore the clinical value of the novel nomograms incorporating this factor in survival and recurrence risk.

METHODS

This study included 3612 GC patients who underwent radical gastrectomy at three tertiary hospitals from 2009 to 2020. One hospital formed the training and internal validation cohorts, while the other two constituted the external validation cohort. Twelve hematological markers were collected and analyzed to develop the POSII score via LASSO regression. Two online calculators were developed and validated.

RESULTS

The POSII score categorized patients into low and high POSII groups, with the low POSII group showing significantly improved 5-year overall survival (OS) and disease-free survival (DFS) rates, as well as a markedly reduced risk of recurrence (all P < 0.05). Multivariate COX regression showed that the POSII score was an independent prognostic factor. Based on the POSII score, two nomograms (OS: AUC = 0.837; DFS: AUC = 0.834, respectively) for individualized prognostic prediction were constructed. To enhance clinical usability, we further developed two user-friendly online calculators. The high-risk group had an earlier, more persistent peak of recurrence and a high incidence of multiple recurrence patterns.

CONCLUSION

Two novel online calculators based on the POSII score can be used as reliable tools for predicting survival and recurrence after radical gastrectomy. Our findings provide new insights into the role of cancer-related immune dysregulation, inflammation, and oxidative stress imbalances.

Role and mechanism of IL-33 in bacteria infection related gastric cancer continuum: From inflammation to tumor progression

Gastric cancer, a globally prevalent malignant tumor, is characterized by low early diagnosis rate, high metastasis rate, and poor prognosis, particularly in East Asia, Eastern Europe, and South America. Helicobacter pylori (H. pylori) is recognized as the primary risk factor for gastric cancer. However, the fact that fewer than 3 % of infected individuals develop cancer suggests that other bacteria may also influence gastric carcinogenesis. A diverse community of microorganisms may interact with H. pylori, thereby driving disease progression. Here, the role of the cytokine IL-33, a member of the IL-1 family, is scrutinized. Its production can be induced by H. pylori through the activation of specific signaling pathways, and it contributes to the inflammatory environment by promoting the release of pro-inflammatory cytokines. This article reviews the conflicting evidence regarding IL-33's role in the progression from gastritis to gastric cancer and discusses the potential therapeutic implications of targeting the IL-33/ST2 axis, with various antibodies and inhibitors in development or undergoing clinical trials for inflammatory diseases. However, the role of IL-33 in gastric cancer treatment remains to be fully elucidated, with its effects potentially dependent on the cellular context and stage of cancer progression. In summary, this review provides a comprehensive overview of the intricate relationship between gastric microbiota, IL-33, and gastritis - gastric cancer transition, offering insights into potential therapeutic targets and the development of novel treatment strategies.

Unveiling a novel model of cell senescence-related genes for prognostic assessment and immunotherapeutic insights in gastric cancer

Recent studies have shed light on the dysregulated nature of cell senescence in many cancers, with implications for tumor immunity and prognosis. However, it is still unclear what role cellular senescence plays in stomach adenocarcinoma (STAD). To address this gap, we investigated the impact of cellular senescence on gastric cancer and its potential prognostic and therapeutic significance. The mRNA expression patterns, gene mutations, and clinical information of STAD were obtained from the cancer genome atlas (TCGA) and gene expression omnibus (GEO). Differentially expressed senescence-related genes were identified between gastric cancer tissues and normal tissues, then the prognostic value and functional roles of these genes in immunotherapy were systematically investigated by bioinformatics approaches. To authenticate the dysregulated genes identified within our prognostic signature, we conducted real-time quantitative PCR. Moreover, we verified gene expression patterns in both normal and tumor samples and performed in vitro experiments to modulate gene expression, assessing its impact on cell proliferation and invasion. Leveraging least absolute shrinkage and selection operator (LASSO) regression analysis, we successfully established a prognostic signature based on cell senescence-related genes. This signature categorized patients into high and low-risk groups, with the high-risk group exhibiting decreased overall survival likelihood compared to the low-risk group. Notably, these groups demonstrated distinct tumor microenvironment features and immune cell infiltration. Furthermore, patients in the high-risk group exhibited poorer responses to treatment compared to those in the low-risk group. To facilitate clinical application, we developed a nomogram for STAD prognosis prediction. By employing this cell senescence-related signature, we could accurately predict prognosis in STAD and tailor individualized therapeutic strategies, including chemotherapy and immunotherapy.

IL-33/ST2 axis in diverse diseases: regulatory mechanisms and therapeutic potential

Interleukin-33 (IL-33) is a nuclear factor and member of the IL-1 cytokine family. IL-33 is mainly expressed by epithelial and endothelial cells and exerts its function through interaction with various immune cells, and binding to its receptor can form the IL-33/Suppression of tumorigenicity 2 (ST2) signaling pathway. While most cytokines are actively synthesized within cells, IL-33 is produced passively in response to tissue damage or cell necrosis, indicating its role as a signaling molecule following cellular infection, stress, or trauma. IL-33/ST2 signaling pathway has been proved to play diverse role in the pathological process of central nervous system disorders, cancer, fibrosis, autoimmune diseases, etc. Although research on the IL-33/ST2 signaling pathway has deepened recently, relevant treatment strategies have been proposed, and even targeted drugs are in the preclinical stage; further research on the effect of the IL-33/ST2 signaling pathway in different diseases is still necessary, to provide a clearer understanding of the different roles of IL-33/ST2 in disease progression and to develop new drugs and treatment strategies. Because IL-33/ST2 plays an important role in the occurrence and progression of diseases, the study of therapeutic drugs targeting this pathway is also necessary. This review focused on recent studies on the positive or negative role of IL-33/ST2 in different diseases, as well as the current related drugs targeting IL-33/ST2 in the preclinical and clinical stage. The mechanism of IL-33/ST2 in different diseases and its mediating effect on different immune cells have been summarized, as well as the antibody drugs targeting IL-33 or ST2, natural compounds with a mediating effect, and small molecule substances targeting relative pathway. We aim to provide new ideas and treatment strategies for IL-33/ST2-related drugs to treat different diseases.

Mast cells: key players in digestive system tumors and their interactions with immune cells

Mast cells (MCs) are critical components of both innate and adaptive immune processes. They play a significant role in protecting human health and in the pathophysiology of various illnesses, including allergies, cardiovascular diseases and autoimmune diseases. Recent studies in tumor-related research have demonstrated that mast cells exert a substantial influence on tumor cell behavior and the tumor microenvironment, exhibiting both pro- and anti-tumor effects. Specifically, mast cells not only secrete mediators related to pro-tumor function such as trypsin-like enzymes, chymotrypsin, vascular endothelial cell growth factor and histamine, but also mediators related to anti-tumor progression such as cystatin C and IL-17F. This dual role of mast cells renders them an under-recognized but very promising target for tumor immunotherapy. Digestive system tumors, characterized by high morbidity and associated mortality rates globally, are increasingly recognized as a significant healthcare burden. This paper examines the influence of mast cell-derived mediators on the development of tumors in the digestive system. It also explores the prognostic significance of mast cells in patients with various gastrointestinal cancers at different stages of the disease. Additionally, the article investigates the interactions between mast cells and immune cells, as well as the potential relationships among intratumoral bacteria, immune cells, and mast cell within digestive system microenvironment. The aim is to propose new strategies for the immunotherapy of digestive system tumors by targeting mast cells.

Interleukin-33 and Obesity-Related Inflammation and Cancer

Interleukin-33 (IL-33) is a cytokine belonging to the IL-1 family. It is primarily associated with type 2 immune responses. It interacts with a receptor complex on immune cells in reaction to tissue damage or cellular injury. IL-33 is crucial in immune responses and is involved in various autoimmune and inflammatory diseases. Obesity is marked by chronic inflammation and is a known risk factor for several types of cancer. Recent studies have shown that IL-33 and its receptor complex are expressed in adipose (fat) tissue, suggesting they may play a role in obesity. While inflammation connects obesity and cancer, it is not yet clear whether IL-33 contributes to cancer associated with obesity. Depending on the cellular context, inflammatory environment, expression levels, and bioactivity, IL-33 can exhibit both protumorigenic and antitumorigenic effects. This review will explore the various functions of IL-33 in the inflammation linked to obesity and its relationship with cancer.

IL-10+CD19+ regulatory B cells induce CD4+Foxp3+regulatory T cells in serum of cervical cancer patients

Increase of regulatory T cells (Tregs) in the tumour microenvironment predicts worse survival of patients with various types of cancer. Recently, B cells play a significant role in the maintenance of Treg cells. However, the relevance of regulatory B cells (Bregs) to tumour immunity in humans remains elusive. Flow cytometry analysis was used to detect the Bregs and Tregs. Double staining results illustrated that the proportion of Bregs and Tregs were prominently higher in cervical cancer than normal tissues. Increase of Bregs and Tregs in cervical cancer microenvironment was associated with poor survival. Furthermore, Bregs cocultured with cervical cancer cell lines increased and induced Tregs. To sum up, the increased expression of Bregs contributes to the differentiation of CD4+ T cells into Tregs in the cervical cancer.

IL-33 in cancer immunotherapy: Pleiotropic functions and biological strategies

Interleukin-33 (IL-33) belongs to the IL-1 cytokine superfamily and plays a critical role in regulating immune responses and maintaining host homeostasis. IL-33 is essential for driving and enhancing type 2 immune responses and is closely associated with the pathogenesis of various inflammatory diseases, infections, and the progression and metastasis of cancers. This study aimed to provide an overview of the anti-tumor effects of IL-33 by examining its complex immunomodulatory functions within the tumor microenvironment and how it regulates immune cells to mediate these effects. We also provided perspectives on the pleiotropic roles of IL-33 in immunomodulation, its potential use in cancer immunotherapies, and possible adverse effects associated with its therapeutic application. Understanding these mechanisms is crucial for developing more effective IL-33-based diagnostic and therapeutic strategies.

Harnessing cytokines to optimize chimeric antigen receptor-T cell therapy for gastric cancer: Current advances and innovative strategies

Enormous patients with gastric cancer (GC) are insensitive to chemotherapy and targeted therapy without the chance of radical surgery, so immunotherapy may supply a novel choice for them. Chimeric antigen receptor (CAR)-T cell therapy has the advantages of higher specificity, stronger lethality, and longer-lasting efficacy, and it has the potential for GC in the future. However, its application still faces numerous obstacles in terms of accuracy, efficacy, and safety. Cytokines can mediate the migration, proliferation, and survival of immune cells, regulate the duration and strength of immune responses, and are involved in the occurrence of severe side effects in CAR-T cell therapy. The expression levels of specific cytokines are associated with the genesis, invasion, metastasis, and prognosis of GC. Applications of cytokines and their receptors in CAR-T cell therapy have emerged, and various cytokines and their receptors have contributed to improving CAR-T cell anti-tumor capabilities. Large amounts of central cytokines in this therapy include chemokines, interleukins (ILs), transforming growth factor-β (TGF-β), and colony-stimulating factors (CSFs). Meanwhile, researchers have explored the combination therapy in treating GC, and several approaches applied to other malignancies can also be considered as references. Therefore, our review comprehensively outlines the biological functions and clinical significance of cytokines and summarizes current advances and innovative strategies for harnessing cytokines to optimize CAR-T cell therapy for GC.

CXCL6-CXCR2 axis-mediated PD-L2+ mast cell accumulation shapes the immunosuppressive microenvironment in osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy and has a high propensity for local invasion and metastasis. The tumour microenvironment of OS is infiltrated by a large number of immune cells, which play a crucial role in its progression and prognosis. Mast cells are important innate immune cells in the tumour stroma and exhibit different phenotypes in diverse tumour microenvironments. However, the underlying mechanisms of mast cell accumulation and the phenotypic characteristics of mast cells in OS remain poorly understood. In this article, we found for the first time that mast cell accumulation in osteosarcoma tissue was modulated by the CXCL6-CXCR2 axis and that the number of infiltrating mast cells was significantly greater in tumour tissues than in adjacent nontumour tissues. These tumour-infiltrating mast cells express high levels of the immunosuppressive molecule PD-L2, and survival analyses revealed that patients in the PD-L2+ high-expression group had a worse prognosis. In vitro, mast cells were induced to express PD-L2 in a time- and dose-dependent manner using OS tissue culture supernatants to mimic the tumour microenvironment. Mechanistic studies revealed that tumour cell-derived G-CSF significantly induced mast cell PD-L2 expression by activating STAT3. Importantly, mast cells overexpressing PD-L2 inhibit tumour-specific CD8+ T-cell proliferation and tumour-killing cytokine secretion, which is reversed by blocking PD-L2 on mast cells. Therefore, our findings provide new insight into the immunosuppressive and tumorigenic roles of mast cells, as well as a novel mechanism by which PD-L2-expressing mast cells mediate immune tolerance.

IL-33 and IL-33-derived DC-based tumor immunotherapy

Interleukin-33 (IL-33), a member of the IL-1 family, is a cytokine released in response to tissue damage and is recognized as an alarmin. The multifaceted roles of IL-33 in tumor progression have sparked controversy within the scientific community. However, most findings generally indicate that endogenous IL-33 has a protumor effect, while exogenous IL-33 often has an antitumor effect in most cases. This review covers the general characteristics of IL-33 and its effects on tumor growth, with detailed information on the immunological mechanisms associated with dendritic cells (DCs). Notably, DCs possess the capability to uptake, process, and present antigens to CD8+ T cells, positioning them as professional antigen-presenting cells. Recent findings from our research highlight the direct association between the tumor-suppressive effects of exogenous IL-33 and a novel subset of highly immunogenic cDC1s. Exogenous IL-33 induces the development of these highly immunogenic cDC1s through the activation of other ST2+ immune cells both in vivo and in vitro. Recognizing the pivotal role of the immunogenicity of DC vaccines in DC-based tumor immunotherapy, we propose compelling methods to enhance this immunogenicity through the addition of IL-33 and the promotion of highly immunogenic DC generation.

Clinical and basic science aspects of innate lymphoid cells as novel immunotherapeutic targets in cancer treatment

Immunotherapy has revolutionised cancer treatment over the past decade, demonstrating remarkable efficacy across a broad range of cancer types. However, not all patients or cancer types respond to contemporary clinically-utilised immunotherapeutic strategies, which largely focus on harnessing adaptive immune T cells for cancer treatment. Accordingly, it is increasingly recognised that upstream innate immune pathways, which govern and orchestrate the downstream adaptive immune response, may prove critical in overcoming cancer immunotherapeutic resistance. Innate lymphoid cells (ILCs) are the most recently discovered major innate immune cell population. They have overarching roles in homeostasis and orchestrating protective immunity against pathogens. As innate immune counterparts of adaptive immune T cells, ILCs exert effector functions through the secretion of cytokines and direct cell-to-cell contact, with broad influence on the overall immune response. Importantly, dysregulation of ILC subsets have been associated with a range of diseases, including immunodeficiency disorders, allergy, autoimmunity, and more recently, cancer. ILCs may either promote or inhibit cancer initiation and progression depending on the cancer type and the specific ILC subsets involved. Critically, therapeutic targeting of ILCs and their associated cytokines shows promise against a wide range of cancer types in both preclinical models and early phase oncology clinical trials. This chapter provides a comprehensive overview of the current understanding of ILC subsets and the associated cytokines they produce in cancer pathogenesis, with specific focus on how these innate pathways are, or can be targeted, therapeutically to overcome therapeutic resistance and ultimately improve patient care.

Analyzing the associations between tertiary lymphoid structures and postoperative prognosis, along with immunotherapy response in gastric cancer: findings from pooled cohort studies

BACKGROUND

The clinical significance of tertiary lymphoid structure (TLS) in gastric cancer (GC) was uncertain.

METHODS

A systematic search was performed in public databases for eligible studies as of April 2, 2023. Meta-analyses were performed to interrogate the associations between TLS levels and prognosis and immunotherapy response of GC. Bioinformatic analyses based on the nine-gene signature of TLS were further conducted to capture the biological underpinnings.

RESULTS

Eleven studies containing 4224 GC cases were enrolled in the meta-analysis. TLS levels positively correlated with smaller tumor size, earlier T stage and N stage. Moreover, higher TLS levels were detected in diffuse and mix subtypes of GC (P < 0.001). Higher TLS levels strongly predicted favorable postoperative overall survival of GC, with HR of 0.36 (95%CI 0.26-0.50, P < 0.001) and 0.55 (95%CI 0.45-0.68, P < 0.001) of univariate and multivariate Cox analysis, respectively. Higher TLS levels were also in favor of the treatment response of anti-PD-1 inhibitors as later-line therapy of GC. TLS levels positively correlated with immune effector cells infiltration, diversity and richness of T cell receptor and B cell receptor repertoire, immune checkpoint genes expression, and immune-related genes mutation of GC in the TCGA-STAD cohort, representing higher immunogenicity and immunoactivity. Moreover, moderate accuracy of TLS levels in predicting benefit from anti-PD-1 inhibitors in the PRJEB25780 cohort was also validated (AUC 0.758, 95%CI 0.583-0.933), higher than the microsatellite instability-score and Epstein-Barr virus status.

CONCLUSIONS

TLS levels demonstrated potential in predicting the postoperative prognosis and immunotherapy response of GC.

The Importance of Th2 Immune Responses in Mediating the Progression of Gastritis-Associated Metaplasia to Gastric Cancer

Gastric cancer is one of the leading causes of cancer deaths worldwide, with chronic gastritis representing the main predisposing factor initiating the cascade of events leading to metaplasia and eventually progressing to cancer. A widely accepted classification distinguishes between autoimmune and environmental atrophic gastritis, mediated, respectively, by T cells promoting the destruction of the oxyntic mucosa, and chronic H. pylori infection, which has also been identified as the major risk factor for gastric cancer. The original dogma posits Th1 immunity as a main causal factor for developing gastritis and metaplasia. Recently, however, it has become evident that Th2 immune responses play a major role in the events causing chronic inflammation leading to tumorigenesis, and in this context, many different cell types and cytokines are involved. In particular, the activity of cytokines, such as IL-33 and IL-13, and cell types, such as mast cells, M2 macrophages and eosinophils, are intertwined in the process, promoting chronic gastritis-dependent and more diffuse metaplasia. Herein, we provide an overview of the critical events driving the pathology of this disease, focusing on the most recent findings regarding the importance of Th2 immunity in gastritis and gastric metaplasia.

Reanalysis of single-cell data reveals macrophage subsets associated with the immunotherapy response and prognosis of patients with endometrial cancer

Endometrial cancer (EC) is an aggressive gynecological malignancy with an increased incidence rate. The immune landscape crucially affects immunotherapy efficacy and prognosis in EC patients. Here, we characterized the distinct tumor microenvironment signatures of EC tumors by analyzing single-cell RNA sequencing data from Gene Expression Omnibus and bulk RNA sequencing data from The Cancer Genome Atlas, which were compared with normal endometrium. Three macrophage subsets were identified, and two of them showed tissue-specific distribution. One of the macrophage subsets was dominant in macrophages derived from EC and exhibited characteristic behaviors such as promoting tumor growth and metastasis. One of the other macrophage subsets was mainly found in normal endometrium and served functions related to antigen presentation. We also identified a macrophage subset that was found in both EC and normal endometrial tissue. However, the pathway and cellular cross-talk of this subset were completely different based on the respective origin, suggesting a tumor-related differentiation mechanism of macrophages. Additionally, the tumor-enriched macrophage subset was found to predict immunotherapy responses in EC. Notably, we selected six genes from macrophage subset markers that could predict the survival of EC patients, SCL8A1, TXN, ANXA5, CST3, CD74 and NANS, and constructed a prognostic signature. To verify the signature, we identified immunohistochemistry for the tumor samples of 83 EC patients based on the selected genes and further followed up with the survival of the patients. Our results provide strong evidence that the signature can effectively predict the prognosis of EC patients.

Interleukin-33 as a Potential Therapeutic Target in Gastric Cancer Patients: Current Insights

Gastric cancer is a significant global health problem as it is the fifth most prevalent cancer worldwide and the fourth leading cause of cancer-related mortality. While cytotoxic chemotherapy remains the primary treatment for advanced GC, response rates are limited. Recent progresses, focused on molecular signalling within gastric cancer, have ignited new hope for potential therapeutic targets that may improve survival and/or reduce the toxic effects of traditional therapies. Carcinomas are generally initiated when critical regulatory genes get mutated, but the progression to malignancy is usually supported by the non-neoplastic cells that create a conducive environment for transformation and progression to occur. Interleukin 33 (IL-33) functions as a dual activity cytokine as it is also a nuclear factor. IL-33 is usually present in the nuclei of the cells. Upon tissue damage, it is released into the extracellular space and binds to its receptor, suppression of tumorigenicity 2 (ST2) L, which is expressed on the membranes of the target cells. IL-33 signalling activates the T Helper 2 (Th2) immune response among other responses. Although the studies on the role of IL-33 in gastric cancer are still in the early stages, they have revealed potentially important (though sometimes conflicting) functions or roles in cancer development and progression. The pro-tumorigenic roles include induction and the recruitment of tumor-associated immune cells, promoting metaplasia progression, and inducing stem cell like and EMT properties in gastric cancer cells. Therapeutic interventions to disrupt these functions may provide a unique strategy for gastric cancer prevention and treatment. This review aims to provide a summary of the role of IL-33 in GC, state its multiple functions in relation to GC, and show potential avenues for promising therapeutic investigation.