Distribution of circulating follicular helper T cells and expression of interleukin-21 and chemokine C-X-C ligand 13 in gastric cancer

Engineered murine IL-21-secreting leukemia cells induce granzyme B+ T cells and CD4+CD44+CD62L- effector memory cells while suppressing regulatory T cells, leading to long-term survival

We have explored the use of an IL-21 cell-based anti-leukemia treatment in a mouse model of acute lymphoblastic leukemia. 70Z/3 leukemia cells, engineered to secrete IL-21 and injected into the peritoneum of syngeneic mice, induced a strong anti-leukemia response resulting in 100% survival. Mice that mounted an IL-21-induced anti-leukemia immune response were immune to the parent cell line (no IL-21) when rechallenged.Above a certain threshold, IL-21 secretion correlated with improved survival compared to mice injected with parent 70Z/3 cells. IL-21 was detected in serum with peak levels on day 7, correlating with the maximum expansion of IL-21-secreting 70Z/3 cells which subsequently were eliminated. Mice injected with IL-21-secreting leukemia cells had elevated numbers of granzyme B⁺ CD4⁺ and CD8⁺ T cells in the peritoneum, compared to mice injected with the parent cell line. Regulatory T cells, which increased greatly in 70Z/3-injected mice, failed to do so in mice injected with IL-21-secreting cells. Upon rechallenge, IL-21-primed mice went through a secondary immune response, primarily requiring CD4⁺ T cells, triggering a significant increase of CD4⁺CD44⁺CD62L^- effector memory T cells. Adoptive transfer of T cells from IL21-primed/rechallenged hosts into naïve mice was successful, indicating that IL-21-primed antigen-experienced T cells convey immunity to naïve mice.Our study shows that delivery of IL-21 in a cell-based anti-leukemia protocol has the potential to induce a potent immune response leading to cancer elimination and long-term immunity-properties which make IL-21 an attractive candidate for cancer immunotherapy. Protecting against tumor antigens as well as improving cancer immunity is justified, as current strategies are limited.

A novel pyroptosis gene expression-based risk score for survival in gastric cancer

BACKGROUND

Gastric cancer (GC) is a highly heterogeneous disease, which makes treatment and prognosis prediction difficult. Pyroptosis plays a vital role in the development of GC and influence the prognosis of GC. Long non-coding RNAs (lncRNAs), as regulators of gene expressions, are among putative biomarkers and therapeutic targets. However, the importance of pyroptosis-associated lncRNAs is still unclear in predicting prognosis in gastric cancer.

METHODS

In this study, the mRNA expression profiles and clinical data of GC patients were obtained from The Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database. A pyroptosis-related lncRNA signature was constructed based on TCGA databases by using the Least Absolute Shrinkage and Selection Operator (LASSO) method Cox regression model. GC patients from the GSE62254 database cohort were used for validation. Univariate and multivariate Cox analyses were used to determine the independent predictors for OS. Gene set enrichment analyses were performed to explore the potential regulatory pathways. The immune cell infiltration level was analyzed via CIBERSORT.

RESULTS

A four-pyroptosis-related lncRNA (ACVR2B-AS1, PRSS30P, ATP2B1-AS1, RMRP) signature was constructed using LASSO Cox regression analysis. GC patients were stratified into high- and low-risk groups, and patients in the high-risk group showed significant worse prognosis in TNM stage, gender, and age. The risk score was an independent predictor for OS by multivariate Cox analysis. Functional analysis indicated that the immune cell infiltrate was different between high- and low-risk groups.

CONCLUSION

The pyroptosis-related lncRNA prognostic signature can be used for predicting prognosis in GC. Moreover, the novel signature might provide clinical therapeutic intervention for GC patients.

The Regulation between CD4+CXCR5+ Follicular Helper T (Tfh) Cells and CD19+CD24hiCD38hi Regulatory B (Breg) Cells in Gastric Cancer

Purpose

T follicular helper (Tfh) cells and regulatory B (Breg) cells are reported to play essential roles in humoral immunity, especially in inflammation, autoimmune diseases, and cancer. Hence, we sought to investigate the involvement of CXCR5⁺CD4⁺ Tfh cells and CD19⁺CD24^hiCD38^hi Breg cells in gastric cancer.

Methods

The blood samples were obtained from 36 gastric cancer patients and 18 healthy individuals. The percentage of Tfh cells (Tfh%) and Breg cells (Breg%) was detected via flow cytometry, while IL-21, IL-10, and CXCL13 levels were examined with ELISA. The association between them and clinical parameters of patients was also assessed. The in vitro Tfh-B cell coculture experiments were performed for six days, and then, Tfh%, Breg%, and cytokines were valued by flow cytometry and ELISA, respectively.

Results

Tfh%, Breg%, and CXCL13 level were significantly increased among gastric cancer patients. Moreover, higher Tfh% was associated with lymphatic metastasis, patients' worse outcomes and Breg%. Tfh differentiation and CXCL13 were upregulated by cocultured B cells in vitro, while Tfh cells seem to not participate in Breg cell differentiation from B cells.

Conclusion

Altogether, increased Tfh and Breg cells could be involved in immune suppression in gastric cancer. Moreover, B cell may be a potential regulator for Tfh differentiation, while Tfh cells had no significant effects on the regulation of Breg cells.

Serum Levels of CXCL-13, RBP-4, and IL-6, and Correlation Analysis of Patients with Graves' Disease

Objective

To investigate the serum levels of CXC chemokine 13 (CXCL-13), retinol binding protein-4 (RBP-4), and interleukin 6 (IL-6) in patients with Graves' disease (GD). The correlation between CXCL-13, RBP-4, and IL-6 levels and the basal metabolic rate (BMR) was analyzed.

Methods

118 GD patients diagnosed in our hospital were selected as the observation group from March 2017 to December 2018. According to the measured BMR value, 118 GD patients were divided into the mild group (n = 39), the moderate group (n = 47), and the severe group (n = 32), three subgroups. 60 healthy subjects were selected as the control group. The serum levels of CXCL-13, RBP-4, IL-6, TSH, FT3, and FT4 in every group were measured. Pearson correlation analysis was used to observe the correlation of serum CXCL-13, RBP-4, and IL-6 levels with TSH, FT3, FT4, and BMR.

Results

The levels of serum CXCL-13, RBP-4, and IL-6 in the observation group were higher than those of the control group, and the differences were statistically significant (P < 0.05). The levels of serum CXCL-13, RBP-4, and IL-6 in the moderate and severe groups were higher than those in the mild group, and the differences were statistically significant (P < 0.05). The levels of serum CXCL-13, RBP-4, and IL-6 in the severe group were higher than those in the moderate group, and the differences were statistically significant (P < 0.05). Pearson correlation analysis showed that the serum levels of CXCL-13, RBP-4, and IL-6 in GD patients were negatively correlated with TSH levels and positively correlated with FT3 and FT4 levels. Serum CXCL-13, RBP-4, and IL-6 levels in GD patients were positively correlated with BMR (r = 0.915, r = 0.942, r = 0.926, P < 0.001).

Conclusion

Serum CXCL-13, RBP-4, and IL-6 levels are elevated in patients with GD, and with the aggravation of the disease, the serum CXCL-13, RBP-4, and IL-6 levels also increase, showing a positive correlation, which can be used as indicators to reflect the degree of GD.

CXCL13 in Cancer and Other Diseases: Biological Functions, Clinical Significance, and Therapeutic Opportunities

The development of cancer is a multistep and complex process involving interactions between tumor cells and the tumor microenvironment (TME). C-X-C chemokine ligand 13 (CXCL13) and its receptor, CXCR5, make crucial contributions to this process by triggering intracellular signaling cascades in malignant cells and modulating the sophisticated TME in an autocrine or paracrine fashion. The CXCL13/CXCR5 axis has a dominant role in B cell recruitment and tertiary lymphoid structure formation, which activate immune responses against some tumors. In most cancer types, the CXCL13/CXCR5 axis mediates pro-neoplastic immune reactions by recruiting suppressive immune cells into tumor tissues. Tobacco smoke and haze (smohaze) and the carcinogen benzo(a)pyrene induce the secretion of CXCL13 by lung epithelial cells, which contributes to environmental lung carcinogenesis. Interestingly, the knockout of CXCL13 inhibits benzo(a)pyrene-induced lung cancer and azoxymethane/dextran sodium sulfate-induced colorectal cancer in mice. Thus, a better understanding of the context-dependent functions of the CXCL13/CXCR5 axis in tumor tissue and the TME is required to design an efficient immune-based therapy. In this review, we summarize the molecular events and TME alterations caused by CXCL13/CXCR5 and briefly discuss the potentials of agents targeting this axis in different malignant tumors.

Comprehensive analysis of prognostic genes in gastric cancer

Background: Gastric cancer is associated with high mortality, and effective methods for predicting prognosis are lacking. We aimed to identify potential prognostic markers associated with the development of gastric cancer through bioinformatic analyses.

Methods: Gastric cancer-associated gene expression profiles were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases. The key genes involved in the development of gastric cancer were obtained by differential expression analysis, coexpression analysis, and short time-series expression miner (STEM) analysis. The potential prognostic value of differentially expressed genes was further evaluated using a Cox regression model and risk scores. Hierarchical clustering was applied to validate the impact of key genes on the overall survival of gastric cancer patients.

Results: A total of 1381 genes were consistently dysregulated in the development of gastric cancer. Among them, 186 genes affected the overall survival of gastric cancer patients. The following genes had areas under the receiver operating characteristic curve greater than 0.9 in both datasets and were therefore considered key genes: ADAM12, CEP55, LRFN4, INHBA, ADH1B, DPT, FAM107A, and LOC100506388. LRFN4, DPT, and LOC100506388 were identified as potential prognostic genes for gastric cancer through a nomogram. Overexpression of LRFN4 and LOC100506388 was associated with a higher risk of gastric cancer. Finally, we found that tumors were infiltrated with high levels of Th2 cells and mast cells, and the infiltration levels were associated with overall survival in gastric cancer patients.

Conclusions: We found that key dysregulated genes may have a prognostic value for the development of gastric cancer.

CXCL13 Signaling in the Tumor Microenvironment

Chemokines have emerged as important players in tumorigenic process. An extensive body of literature generated over the last two or three decades strongly implicate abnormally activated or functionally disrupted chemokine signaling in liaising most-if not all-hallmark processes of cancer. It is well-known that chemokine signaling networks within the tumor microenvironment are highly versatile and context-dependent: exert both pro-tumoral and antitumoral activities. The C-X-C motif chemokine ligand 13 (CXCL13), and its cognate receptor CXCR5, represents an emerging example of chemokine signaling axes, which express the ability to modulate tumor growth and progression in either way. Collateral evidence indicate that CXCL13-CXCR5 axis may directly modulate tumor growth by inducing proliferation of cancer cells, as well as promoting invasive phenotypes and preventing their apoptosis. In addition, CXCL13-CXCR5 axis may also indirectly modulate tumor growth by regulating noncancerous cells, particularly the immune cells, within the tumor microenvironment. Here, we review the role of CXCL13, together with CXCR5, in the human tumor microenvironment. We first elaborate their patterns of expression, regulation, and biological functions in normal physiology. We then consider how their aberrant activity, as a result of differential overexpression or co-expression, may directly or indirectly modulate the growth of tumors through effects on both cancerous and noncancerous cells.

Impact of Immunotherapy on CD4 T Cell Phenotypes and Function in Cancer

Immunotherapy has become a standard treatment in many cancers and it is based on three main therapeutic axes: immune checkpoint blockade (ICB), vaccination and adoptive cell transfer (ACT). If originally these therapies mainly focused on exploiting CD8 T cells given their role in the direct elimination of tumor cells, increasing evidence highlights the crucial role CD4 T cells play in the antitumor immune response. Indeed, these cells can profoundly modulate the tumor microenvironment (TME) by secreting different types of cytokine or by directly eliminating cancer cells. In this review, we describe how different CD4 T cell subsets can contribute to tumor immune responses during immunotherapy and the novel high-throughput immune monitoring tools that are expected to facilitate the study of CD4 T cells, at antigen-specific and single cell level, thus accelerating bench-to-bed translational research in cancer.

Poor clinical outcomes and immunoevasive contexture in CXCL13+CD8+ T cells enriched gastric cancer patients

As an adverse survival prognosticator, chemokine (C-X-C motif) ligand 13 (CXCL13) has been studied in several types of malignancies. The secretion and physiological roles of CXCL13 in follicular helper T cells (T_FH) cells have been well described, while the clinical significance of CD8⁺ tumor-infiltrating lymphocytes (TILs)-associated CXCL13 remains unknown. This study aims to investigate the clinical significance of CXCL13⁺CD8⁺ T cells in survival and chemotherapeutic responsiveness prediction in gastric cancer. In this study, 440 patients enrolled from Zhongshan Hospital with tumor microarray (TMA) specimens were randomly divided into testing set (n = 220) and validation set (n = 220) for analysis. CXCL13⁺CD8⁺ T cells were detected by multicolor immunohistochemistry. Fresh tumor tissue samples from another 60 gastric cancer patients were collected to detect CXCL13⁺CD8⁺ T cells functional status by flow cytometry (FCM). We found that high intratumoral CXCL13⁺CD8⁺ T cells infiltration predicted poor overall survival and inferior chemotherapeutic responsiveness in gastric cancer. CXCL13⁺CD8⁺T cells were associated with immunoevasive contexture with increased regulatory T (T_reg) cells and dysfunctional cytotoxic T lymphocytes (CTLs). Moreover, the combinational analysis of CXCL13⁺CD8⁺ T cells and CD8⁺ T cells infiltration stratified patients into distinct risk groups with different clinical outcomes and chemotherapeutic responsiveness. Conclusively, intratumoral CXCL13⁺CD8⁺ T cells infiltration could be an independent prognostic and predictive marker for gastric cancer patients. CXCL13⁺CD8⁺ T cells represented an exhausted CD8⁺ T cell subset, and might be a potential immunotherapeutic target in gastric cancer.

Serum CXCL13 Level is Associated with Tumor Progression and Unfavorable Prognosis in Penile Cancer

Background

Chemokine (C-X-C motif) ligands (CXCLs) are important regulators of tumor progression in many cancers and could serve as potential cancer biomarkers. However, the expression patterns as well as functions of CXCLs remain unclear in penile cancer (PC). The aim of this study was to evaluate the usefulness of serum CXCL13 as a potential cancer biomarker for PC.

Patients and Methods

This retrospective study enrolled 76 patients diagnosed with PC between 2016 and 2018. Serum CXCL13 level was detected by enzyme-linked immunosorbent assay. Univariable and multivariable Cox regression analyses were conducted to identify the prognostic factors that influence disease-free survival. Human penile cancer cell lines Penl1, Penl2, 149RCa and LM156 were used as in vitro models. The expression of CXCL13 protein in PC cell lines was analyzed by Western blotting.

Results

Our initial analysis on GSE57955 dataset identified CXCL13 as a top CXCL gene enriched in PC. Higher preoperative serum CXCL13 level was detected in PC cohorts than in healthy male controls (P<0.001). The area under the curve was 0.911 with the sensitivity of 84.2% and specificity of 87.0% to distinguish PC. Preoperative serum CXCL13 level was associated with pathological grade (P=0.048), T stage (P=0.009), nodal status (P<0.001) and pelvic lymph node metastasis (P=0.005) in PC. Serum CXCL13 level could serve as an independent prognostic factor for disease-free survival with a HR of 3.818 (95%CI: 1.126–12.946). Furthermore, autocrine expression of CXCL13 was detected in PC tissues and cell lines. Knockdown of CXCL13 expression suppressed malignant phenotypes (cell proliferation, clonogenesis, apoptosis escape, migration and invasion), attenuated STAT3 and ERK1/2 signaling and reduced MMP2/9 secretion in PC cell lines.

Conclusion

Serum CXCL13 could serve as a novel diagnostic and prognostic biomarker for PC. CXCL13 signaling might activate oncogenic signaling pathways to promote malignant progression of PC.

Potential Prognostic Value and Mechanism of Stromal-Immune Signature in Tumor Microenvironment for Stomach Adenocarcinoma

Stomach adenocarcinoma (STAD) is one of the most common malignancies. But the molecular mechanism is unknown. In this study, we downloaded the transcriptional profiles and clinical data of 344 STAD and 30 normal samples from The Cancer Genome Atlas (TCGA) database. Stromal and immune scores of STAD were calculated by the Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) algorithm, and association of stromal/immune scores with tumor differentiation/T/N/M stage and survival was investigated. The differentially expressed genes (DEGs) between high and low score groups (based on media) were identified, and prognostic genes over-/underexpressed in both STAD and stromal/immune signature were retrieved. Furthermore, proportions of 22 infiltrating immune cells for the cohort from TCGA were estimated by the Cell-type Identification By Estimating Relative Subsets Of RNA Transcripts (CIBERSORT) algorithm, and association of 22 immune cells with tumor differentiation/T/N/M stage and survival was investigated. Next, coexpression analysis of 22 immune cells and intersection genes over-/underexpressed in both STAD and stromal signature was conducted. We found high stromal and immune scores and macrophage infiltration predicting poor tumor differentiation and severe local invasion, obtained a list of prognostic genes based on stromal-immune signature, and explored the interaction of collagen, chemokines such as CXCL9, CXCL10, and CXCL11, and macrophage through coexpression analysis and may provide novel prognostic biomarkers and immunotherapeutic targets for STAD.

Serum CXCL13 and PECAM-1 can be used as diagnostic and prognostic markers in elderly patients with gastric cancer

PURPOSE

To investigate the application value of serum CXC Chemokine-13 (CXCL-13) and platelet endothelial cell adhesion molecule-1 (PECAM-1) in elderly patients with gastric cancer (GC).

METHODS

Ninety-eight elderly GC patients admitted to the Affiliated Hexian Memorial Hospital of Southern Medical University were selected as a research group, and 60 healthy subjects of the same age and in relatively good health who underwent physical examination at the same period were selected as a control group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of CXCL13 and PECAM-1 in serum. The clinical diagnosis and prognostic value of serum CXCL13 and PECAM-1 in elderly GC patients were analyzed.

RESULTS

The levels of CXCL13 and PECAM-1 in serum of the research group were significantly higher than those of the control group (P < 0.001). The AUC value of combined diagnosis of elderly GC patients by serum CXCL13 and PECAM-1 was 0.950, and that of combined evaluation of prognosis of patients was 0.849. Serum CXCL13 and PECAM-1 were significantly related to TNM staging, differentiation degree and tumor diameter in elderly GC patients (P < 0.05). High levels of CXCL13 and PECAM-1 were significantly associated with lower 5-year OS (P < 0.05).

CONCLUSION

Elderly GC patients with higher TNM staging, longer tumor diameters, high levels of CXCL13 and PECAM-1 had an increased risk of poor prognosis. Serum CXCL13 and PECAM-1 can be used as effective indicators for diagnosis and prognosis of elderly patients with GC, and can predict the 5-year OS in patients.

Association between interleukin-21 gene rs907715 polymorphism and gastric precancerous lesions in a Chinese population

BACKGROUND

The single nucleotide polymorphisms of interleukin-21 (IL-21) gene were confirmed to be related to various diseases, but no studies have examined the possible role of IL-21 single nucleotide polymorphisms (SNPs) (rs907715, rs2221903, and rs12508721) in gastric precancerous lesions.

AIM

To explore the associations between SNPs of IL-21 gene (rs907715, rs2221903, and rs12508721) and gastric precancerous lesions in a Chinese population.

METHODS

Three SNPs of IL-21 were genotyped using polymerase chain reaction–ligase detection reaction in 588 cases and 290 healthy controls from May 2013 to December 2016 in northwestern China. Gastric precancerous lesions were confirmed by endoscopic examination and categorized as non-atrophic gastritis, atrophic gastritis, and intestinal metaplasia. Descriptive statistic and logistic regression were used for data analyses.

RESULTS

IL-21 rs907715 genotype CC and C frequencies were higher in in patients with gastric precancerous lesions than in the controls (OR = 1.59, 95%CI: 1.06-2.38, P = 0.013; OR = 1.28, 95%CI: 1.01-2.22, P = 0.044, respectively) after adjusting for confounding factors. For SNP rs907715 in intestinal metaplasia patients, significant differences between cases and controls were observed in the frequencies of genotype CC and C (OR = 1.92, 95%CI: 1.24-2.98, P = 0.004; OR = 1.53, 95%CI: 1.04-2.24, P = 0.028, respectively); for non-atrophic gastritis and atrophic gastritis patients, the CC and C genotypes showed no significant association with risk in all models. No association between either rs2221903 or rs12508721 and gastric precancerous lesions was found in the present study. In the haplotype analysis, the TC haplotype (rs907715 and rs12508721) and TT haplotype (rs2221903 and rs907715) were more frequent in the case group than control group (P < 0.05).

CONCLUSION

Our findings indicate that SNP rs907715 of IL-21 gene is associated with gastric precancerous lesions. The TC haplotype (rs907715 and rs12508721) and TT haplotype (rs2221903 and rs907715) increased the risk of gastric precancerous lesions. If confirmed, these findings will shed light on the etiology of precancerous lesions.

Th17 Cells in Helicobacter pylori Infection: a Dichotomy of Help and Harm

Helicobacter pylori is a Gram-negative bacterium that infects the gastric epithelia of its human host. Everyone who is colonized with these pathogenic bacteria can develop gastric inflammation, termed gastritis. Additionally, a small proportion of colonized people develop more adverse outcomes, including gastric ulcer disease, gastric adenocarcinoma, or gastric mucosa-associated lymphoid tissue lymphoma. The development of these adverse outcomes is dependent on the establishment of a chronic inflammatory response. The development and control of this chronic inflammatory response are significantly impacted by CD4⁺ T helper cell activity. Noteworthy, T helper 17 (Th17) cells, a proinflammatory subset of CD4⁺ T cells, produce several proinflammatory cytokines that activate innate immune cell antimicrobial activity, drive a pathogenic immune response, regulate B cell responses, and participate in wound healing. Therefore, this review was written to take an intricate look at the involvement of Th17 cells and their affiliated cytokines (interleukin-17A [IL-17A], IL-17F, IL-21, IL-22, and IL-26) in regulating the immune response to H. pylori colonization and carcinogenesis.

CXCL13 and Its Receptor CXCR5 in Cancer: Inflammation, Immune Response, and Beyond

It is well-established that the chemokine C-X-C motif ligand 13 (CXCL13) and its receptor, the G-protein coupled receptor (GPCR) CXCR5, play fundamental roles in inflammatory, infectious and immune responses. Originally identified as a B-cell chemoattractant, CXCL13 exerts important functions in lymphoid neogenesis, and has been widely implicated in the pathogenesis of a number of autoimmune diseases and inflammatory conditions, as well as in lymphoproliferative disorders. Current evidence also indicates that the CXCL13:CXCR5 axis orchestrates cell-cell interactions that regulate lymphocyte infiltration within the tumor microenvironment, thereby determining responsiveness to cytotoxic and immune-targeted therapies. In this review, we provide a comprehensive perspective of the involvement of CXCL13 and its receptor in cancer progression. Studies in recent years postulated novel roles for this chemokine in controlling the cancer cell phenotype, and suggest important functions in the growth and metastatic dissemination of solid tumors. Carcinogens have been found to induce CXCL13 production, and production of this chemokine within the tumor milieu has been shown to impact the proliferation, migration, and invasive properties of cancer cells. Thus, the complex networks of cellular interactions involving tumoral CXCL13 and CXCR5 integrate to promote cancer cell autonomous and non-autonomous responses, highlighting the relevance of autocrine and paracrine interactions in dictating the cancer phenotype. Dissecting the molecular and signaling events regulated by CXCL13 and how this chemokine dynamically controls the interaction between the cancer cell and the tumor microenvironment is key to identify novel effectors and therapeutic targets for cancer treatment.

Mast Cells, Angiogenesis and Lymphangiogenesis in Human Gastric Cancer

Gastric cancer is diagnosed in nearly one million new patients each year and it remains the second leading cause of cancer-related deaths worldwide. Although gastric cancer represents a heterogeneous group of diseases, chronic inflammation has been shown to play a role in tumorigenesis. Cancer development is a multistep process characterized by genetic and epigenetic alterations during tumour initiation and progression. The stromal microenvironment is important in maintaining normal tissue homeostasis or promoting tumour development. A plethora of immune cells (i.e., lymphocytes, macrophages, mast cells, monocytes, myeloid-derived suppressor cells, Treg cells, dendritic cells, neutrophils, eosinophils, natural killer (NK) and natural killer T (NKT) cells) are components of gastric cancer microenvironment. Mast cell density is increased in gastric cancer and there is a correlation with angiogenesis, the number of metastatic lymph nodes and the survival of these patients. Mast cells exert a protumorigenic role in gastric cancer through the release of angiogenic (VEGF-A, CXCL8, MMP-9) and lymphangiogenic factors (VEGF-C and VEGF-F). Gastric mast cells express the programmed death ligands (PD-L1 and PD-L2) which are relevant as immune checkpoints in cancer. Several clinical undergoing trials targeting immune checkpoints could be an innovative therapeutic strategy in gastric cancer. Elucidation of the role of subsets of mast cells in different human gastric cancers will demand studies of increasing complexity beyond those assessing merely mast cell density and microlocalization.