Mast cells as therapeutic target in cancer

From neglect to necessity: the role of innate immunity in cutaneous squamous cell carcinoma therapy

As the second most common non-melanoma skin cancer, cutaneous squamous cell carcinoma (cSCC) has experienced a significant increase in incidence. Although clinical detection is relatively easy, a considerable number of patients are diagnosed at an advanced stage, featuring local tissue infiltration and distant metastasis. Cemiplimab, along with other immune checkpoint inhibitors, enhances T cell activation by blocking the PD-1 pathway, resulting in notable improvements in clinical outcomes. Nonetheless, approximately 50% of the patients with advanced cSCC remain unresponsive to this therapeutic approach. It emphasizes the importance of finding innovative therapeutic targets and strategies to boost the success of immunotherapy across a wider range of patients. Therefore, we focused on frequently neglected functions of innate immune cells. Emerging evidence indicates that innate immune cells exhibit considerable heterogeneity and plasticity, fundamentally contributing to tumor initiation and development. The identification and eradication of cancer cells, along with the modulation of adaptive immune responses, are essential roles of these cells. Consequently, targeting innate immune cells to activate anti-tumor immune responses presents significant potential for enhancing immunotherapeutic strategies in cSCC.

Mast cell proteases and metastasis

Mast cells exert multiple roles beyond their classical role in IgE-mediated allergic reactions. These cells secrete pro-inflammatory and anti-inflammatory agents and change from protective immune cells to pro-inflammatory cells, capable of influencing the progression of different pathological conditions, including tumors, in which they exert anti-tumorigenic and pro-tumorigenic roles. In this context, this article analyzes the potential role played by mast cell-derived proteases in tumor progression and more specifically in driving metastatic process and the potential therapeutic approaches that inhibiting the activation of these cells could help faith cancer spreading.

Different subpopulations of macrophages, neutrophils, mast cells, and fibroblasts are involved in the control of tumor angiogenesis

The tumor microenvironment comprises diverse cell types, including T and B lymphocytes, macrophages, dendritic cells, natural killer cells, myeloid-derived suppressor cells, neutrophils, eosinophils, mast cells, and fibroblasts. Cells in the tumor microenvironment can be either tumor-suppressive or tumor-supporting cells. In this review article, we analyze the double role played by tumor macrophages, tumor neutrophils, tumor mast cells, and tumor fibroblasts, in promoting angiogenesis during tumor progression. Different strategies to target the tumor microenvironment have been developed in this context, including the depletion of tumor-supporting cells, or their "re-education" as tumor-suppressor cells.

New insights into the role of mast cells as a therapeutic target in cancer through the blockade of immune checkpoint inhibitors

Mast cells release different anti-and pro-inflammatory agents changing their role from protective to pro-inflammatory cells involved in the progression of different pathological conditions, including autoimmune diseases and tumors. Different mediators released by mast cells are involved in their biological activities which may be anti-tumorigenic and/or pro-tumorigenic. For these reasons, tumor mast cells have been considered a novel therapeutic target to prevent tumor progression and metastatic process. Many different agents have been suggested and used in the past pre-clinical and clinical settings. Among the novel immunotherapeutic approaches to cancer treatment, different immune checkpoint inhibitors targeting PD-1/PDL-1 have been used in the treatment of many human tumors improving overall survival. In this context, inhibition of mast cell activity may be considered a novel strategy to improve the efficacy of anti-PD-1/PDL-1 therapy. The blockade of the PD-1/PD-L1 interaction may be suggested as a useful and novel therapeutic approach in the treatment of tumors in which mast cells are involved.

Role of mast cells activation in the tumor immune microenvironment and immunotherapy of cancers

The mast cell is an important cellular component that plays a crucial role in the crosstalk between innate and adaptive immune responses within the tumor microenvironment (TME). Recently, numerous studies have indicated that mast cells related to tumors play a dual role in regulating cancers, with conflicting results seemingly determined by the degranulation medium. As such, mast cells are an ignored but very promising potential target for cancer immunotherapy based on their immunomodulatory function. In this review, we present a comprehensive overview of the roles and mechanisms of mast cells in diverse cancer types. Firstly, we evaluated the infiltration density and location of mast cells on tumor progression. Secondly, mast cells are activated by the TME and subsequently release a range of inflammatory mediators, cytokines, chemokines, and lipid products that modulate their pro-or anti-tumor functions. Thirdly, activated mast cells engage in intercellular communication with other immune or stromal cells to modulate the immune status or promote tumor development. Finally, we deliberated on the clinical significance of targeting mast cells as a therapeutic approach to restrict tumor initiation and progression. Overall, our review aims to provide insights for future research on the role of mast cells in tumors and their potential as therapeutic targets for cancer treatment.

Post-Implantation Inflammatory Responses to Xenogeneic Tissue-Engineered Cartilage Implanted in Rabbit Trachea: The Role of Cultured Chondrocytes in the Modification of Inflammation

Immune responses to tissue-engineered grafts made of xenogeneic materials remain poorly studied. The scope of current investigations is limited by the lack of information on orthotopically implanted grafts. A deeper understanding of these processes is of great importance since innovative surgical approaches include the implantation of xenogeneic decellularized scaffolds seeded by cells. The purpose of our work is to study the immunological features of tracheal repair during the implantation of tissue-engineered constructs based on human xenogeneic scaffolds modified via laser radiation in rabbits. The samples were stained with hematoxylin and Safranin O, and they were immunostained with antibodies against tryptase, collagen II, vimentin, and CD34. Immunological and inflammatory responses were studied by counting immune cells and evaluating blood vessels and collagen. Leukocyte-based inflammation prevailed during the implantation of decellularized unseeded scaffolds; meanwhile, plasma cells were significantly more abundant in tissue-engineered constructs. Mast cells were insignificantly more abundant in tissue-engineered construct samples. Conclusions: The seeding of decellularized xenogeneic cartilage with chondrocytes resulted in a change in immunological reactions upon implantation, and it was associated with plasma cell infiltration. Tissue-engineered grafts widely differed in design, including the type of used cells. The question of immunological response depending on the tissue-engineered graft composition requires further investigation.

Comparative analysis of single-cell transcriptome reveals heterogeneity in the tumor microenvironment of lung adenocarcinoma and brain metastases

PURPOSE

Solid tumors such as lung adenocarcinoma include not only the tumor cells but also the microenvironment in which the tumor cells continuously interact with each other. An in-depth understanding of the oncological features and tumor microenvironment (TME) of lung adenocarcinoma and brain metastases at the single-cell level could provide new therapeutic strategies for brain metastases from lung adenocarcinoma.

METHODS

To solve this problem, we performed single-cell RNA sequencing (scRNA-seq) analysis on 15 lung adenocarcinoma samples and 10 brain metastasis samples.

RESULTS

A total of 86,282 single cells were obtained and divided into 8 cell types, including epithelial cells, endothelial cells, fibroblasts, oligodendrocytes, T/NK cells, B cells, mast cells, and macrophages. In brain metastases, we found a significantly lower proportion of T/NK cells and mast cells, and more severe immune dysregulation. In addition, we found a subpopulation of macrophages with high expression of metastasis-promoting-related genes enriched in brain metastatic tissues. Moreover, in brain metastases, we found a significantly increased proportion of myofibroblastic cancer-associated fibroblasts (myCAFs) and a higher angiogenic capacity of endothelial cells. Epithelial cells in brain metastases were more malignant and underwent genomic reprogramming. Next, we found that DNA damage-inducible transcript 4 (DDIT4) expression was upregulated in epithelial cells in brain metastases and was associated with poor prognosis. Finally, we experimentally validated that the downregulation of DDIT4 inhibited the proliferation, migration, and invasion of lung cancer cells.

CONCLUSIONS

This study depicts a single-cell atlas of lung adenocarcinoma and brain metastases by scRNA-seq and paves the way for the development of future therapeutic targets for brain metastases from lung cancer.

Visualizing mast cell migration to tumor sites using sodium iodide symporter of nuclear medicine reporter gene

PURPOSE

Owing to the close relationship between mast cells and cancer progression, an imaging technique that can be applied in a clinical setting to explore the biological behavior of mast cells in the tumor microenvironment is needed. In this study, we visualized mast cell migration to lung tumor lesions in live mice using sodium iodide symporter (NIS) as a nuclear medicine reporter gene.

EXPERIMENTAL DESIGN

The murine mast cell line MC-9 was infected with retrovirus including NIS, luciferase (as a surrogate marker for NIS), and Thy1.1 to generate MC-9/NFT cells. Radioiodine uptake was measured in MC-9/NFT cells, and an inhibition assay of radioiodine uptake using KCLO4 was also performed. Cell proliferation and FcεRI expression was examined in MC-9 and MC-9/NFT cells. The effect of mast cell-conditioned media (CM) on the proliferation of Lewis lung cancer (LLC) cells was examined. The migration level of MC-9/NFT cells was confirmed in the presence of serum-free media (SFM) and CM of cancer cells. After intravenous injection of MC-9/NFT cells into mice with an LLC tumor, I-124 PET/CT and biodistribution analysis was performed.

RESULTS

MC-9/NFT cells exhibited higher radioiodine avidity compared to parental MC-9 cells; this increased radioiodine avidity in MC-9/NFT cells was reduced to basal level by KCLO4. Levels of FcεRI expression and cell proliferation were not different in parental MC-9 cell and MC-9/ NFT cells. The CM of MC-9/NFT cells increased cancer cell proliferation relative to that of the SFM. The migration level of MC-9/NFT cells was higher in the CM than the SFM of LLC cells. PET/CT imaging with I-124 clearly showed infiltration of reporter mast cells in lung tumor at 24 h after transfer, which was consistent with the findings of the biodistribution examination.

CONCLUSION

These findings suggest that the sodium iodide symporter can serve as a reliable nuclear medicine reporter gene for non-invasively imaging the biological activity of mast cells in mice with lung tumors. Visualizing mast cells in the tumor microenvironment via a nuclear medicine reporter gene would provide valuable insights into their biological functions.

Single-cell dissection of cervical cancer reveals key subsets of the tumor immune microenvironment

The tumor microenvironment (TME) directly determines patients' outcomes and therapeutic efficiencies. An in-depth understanding of the TME is required to improve the prognosis of patients with cervical cancer (CC). This study conducted single-cell RNA and TCR sequencing of six-paired tumors and adjacent normal tissues to map the CC immune landscape. T and NK cells were highly enriched in the tumor area and transitioned from cytotoxic to exhaustion phenotypes. Our analyses suggest that cytotoxic large-clone T cells are critical effectors in the antitumor response. This study also revealed tumor-specific germinal center B cells associated with tertiary lymphoid structures. A high-germinal center B cell proportion in patients with CC is predictive of improved clinical outcomes and is associated with elevated hormonal immune responses. We depicted an immune-excluded stromal landscape and established a joint model of tumor and stromal cells to predict CC patients' prognosis. The study revealed tumor ecosystem subsets linked to antitumor response or prognosis in the TME and provides information for future combinational immunotherapy.

Mast Cells as a Target-A Comprehensive Review of Recent Therapeutic Approaches

Mast cells (MCs) are the immune cells distributed throughout nearly all tissues, mainly in the skin, near blood vessels and lymph vessels, nerves, lungs, and the intestines. Although MCs are essential to the healthy immune response, their overactivity and pathological states can lead to numerous health hazards. The side effect of mast cell activity is usually caused by degranulation. It can be triggered by immunological factors, such as immunoglobulins, lymphocytes, or antigen-antibody complexes, and non-immune factors, such as radiation and pathogens. An intensive reaction of mast cells can even lead to anaphylaxis, one of the most life-threatening allergic reactions. What is more, mast cells play a role in the tumor microenvironment by modulating various events of tumor biology, such as cell proliferation and survival, angiogenesis, invasiveness, and metastasis. The mechanisms of the mast cell actions are still poorly understood, making it difficult to develop therapies for their pathological condition. This review focuses on the possible therapies targeting mast cell degranulation, anaphylaxis, and MC-derived tumors.

Novel strategies for cancer immunotherapy: counter-immunoediting therapy

The advent of immunotherapy has made an indelible mark on the field of cancer therapy, especially the application of immune checkpoint inhibitors in clinical practice. Although immunotherapy has proven its efficacy and safety in some tumors, many patients still have innate or acquired resistance to immunotherapy. The emergence of this phenomenon is closely related to the highly heterogeneous immune microenvironment formed by tumor cells after undergoing cancer immunoediting. The process of cancer immunoediting refers to the cooperative interaction between tumor cells and the immune system that involves three phases: elimination, equilibrium, and escape. During these phases, conflicting interactions between the immune system and tumor cells result in the formation of a complex immune microenvironment, which contributes to the acquisition of different levels of immunotherapy resistance in tumor cells. In this review, we summarize the characteristics of different phases of cancer immunoediting and the corresponding therapeutic tools, and we propose normalized therapeutic strategies based on immunophenotyping. The process of cancer immunoediting is retrograded through targeted interventions in different phases of cancer immunoediting, making immunotherapy in the context of precision therapy the most promising therapy to cure cancer.

Human C1q Tumor Necrosis Factor 8 (CTRP8) defines a novel tryptase+ mast cell subpopulation in the prostate cancer microenvironment

The adipokine C1q Tumor Necrosis Factor 8 (CTRP8) is the least known member of the 15 CTRP proteins and a ligand of the relaxin receptor RXFP1. We previously demonstrated the ability of the CTRP8-RXFP1 interaction to promote motility, matrix invasion, and drug resistance. The lack of specific tools to detect CTRP8 protein severely limits our knowledge on CTRP8 biological functions in normal and tumor tissues. Here, we have generated and characterized the first specific antiserum to human CTRP8 which identified CTRP8 as a novel marker of tryptase+ mast cells (MC_T) in normal human tissues and in the prostate cancer (PC) microenvironment. Using human PC tissue microarrays composed of neoplastic and corresponding tumor-adjacent prostate tissues, we have identified a significantly higher number of CTRP8+ MC_T in the peritumor versus intratumor compartment of PC tissues of Gleason scores 6 and 7. Higher numbers of CTRP8+ MC_T correlated with the clinical parameter of biochemical recurrence. We showed that the human MC line ROSA^{KIT WT} expressed RXFP1 transcripts and responded to CTRP8 treatment with a small but significant increase in cell proliferation. Like the cognate RXFP1 ligand RLN-2 and the small molecule RXFP1 agonist ML-290, CTRP8 reduced degranulation of ROSA^{KIT WT} MC stimulated by the Ca²⁺-ionophore A14187. In conclusion, this is the first report to identify the RXFP1 agonist CTRP8 as a novel marker of MC_T and autocrine/paracrine oncogenic factor within the PC microenvironment.

Mast cells inhibit colorectal cancer development by inducing ER stress through secreting Cystatin C

Mast cells (MCs) are abundantly distributed in the human intestinal mucosa and submucosa. However, their roles and mechanisms in the development of colorectal cancer (CRC) are still unclear. In the present research, we found that the infiltration density of MCs in CRC tissues was positively correlated with improved patients' prognoses. Moreover, MCs suppressed the growth and induced the apoptosis of CRC cells in vitro and in vivo but had no effect on normal colonic epithelial cells. The present study revealed that MCs specifically induced endoplasmic reticulum stress (ERS) and activated the unfolded protein response (UPR) in CRC cells but not in normal cells, which led to the suppression of CRC development in vivo. Furthermore, we found that the secreted Cystatin C protein was the key factor for the MC-induced ERS in CRC cells. This work is of significance for uncovering the antitumor function of MCs in CRC progression and identifying the potential of CRC to respond to MC-targeted immunotherapy.

Controversial role of mast cells in NSCLC tumor progression and angiogenesis

Mast cells (MCs) are multifunctional immune cells implicated in both physiological and pathological processes. Among the latter, MCs play a crucial role in cancer. Many studies have shown a correlation between MCs and tumor progression in several solid and hematological malignancies. In particular, MCs can directly promote tumor growth via c-kit/stem cell factor-dependent signaling and via the release of histamine, which modulate tumor growth through H1 and H2 receptors. At the same time, MCs can increase tumor progression by stimulating angiogenesis via both proangiogenic cytokines stored in their cytoplasm, and by acting on the tumor microenvironment and extracellular matrix. With regard to NSCLC, the role of MCs has not yet been established, with studies showing a correlation with a poor prognosis on the one hand and suggesting a protective effect of MCs on the other hand. These controversial evidences are at least, in part, due to the heterogeneity of the studies exploring the role of MCs in NSCLC, with some studies describing only the MC count without specification of the activation and degranulation state, and without reporting the intratumoral localization and the proximity to other immune and cancer cells. A better knowledge of the role of MCs in NSCLC is mandatory, not only to define their prognostic and predictive proprieties but also because targeting them could be a possible therapeutic strategy.

Mapping and Validation of scRNA-Seq-Derived Cell-Cell Communication Networks in the Tumor Microenvironment

Recent advances in single-cell technologies, particularly single-cell RNA-sequencing (scRNA-seq), have permitted high throughput transcriptional profiling of a wide variety of biological systems. As scRNA-seq supports inference of cell-cell communication, this technology has and continues to anchor groundbreaking studies into the efficacy and mechanism of novel immunotherapies for cancer treatment. In this review, we will highlight methods developed to infer inter- and intracellular signaling from scRNA-seq and discuss how they have contributed to studies of immunotherapeutic intervention in the tumor microenvironment (TME). However, a central challenge remains in validating the hypothesized cell-cell interactions. Therefore, this review will also cover strategies for integration of these scRNA-seq-derived interaction networks with existing experimental and computational approaches. Integration of these networks with imaging, protein secretion measurements, and network analysis and mathematical modeling tools addresses challenges that remain with scRNA-seq to enhance studies of immunosuppressive and immunotherapy-altered signaling in the TME.

Few, but Efficient: The Role of Mast Cells in Breast Cancer and Other Solid Tumors

Tumor outcome is determined not only by cancer cell-intrinsic features but also by the interaction between cancer cells and their microenvironment. There is great interest in tumor-infiltrating immune cells, yet mast cells have been less studied. Recent work has highlighted the impact of mast cells on the features and aggressiveness of cancer cells, but the eventual effect of mast cell infiltration is still controversial. Here, we review multifaceted findings regarding the role of mast cells in cancer, with a particular focus on breast cancer, which is further complicated because of its classification into subtypes characterized by different biological features, outcome, and therapeutic strategies.

A Novel Immune-Related Gene Signature Predicts Prognosis of Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the most common form of lung cancer, accounting for 30% of all cases and 40% of all non-small-cell lung cancer cases. Immune-related genes play a significant role in predicting the overall survival and monitoring the status of the cancer immune microenvironment. The present study was aimed at finding an immune-related gene signature for predicting LUAD patient outcomes.

Methods

First, we chose the TCGA-LUAD project in the TCGA database as the training cohort for model training. For model validating, we found the datasets of GSE72094 and GSE68465 in the GEO database and took them as the candidate cohorts. We obtained 1793 immune-related genes from the ImmPort database and put them into a univariate Cox proportional hazard model to initially look for the genes with potential prognostic ability using the data of the training cohort. These identified genes then entered into a random survival forests-variable hunting algorithm for the best combination of genes for prognosis. In addition, the LASSO Cox regression model tested whether the gene combination can be further shrinkage, thereby constructing a gene signature. The Kaplan-Meier, Cox model, and ROC curve were deployed to examine the gene signature's prognosis in both cohorts. We conducted GSEA analysis to study further the mechanisms and pathways that involved the gene signature. Finally, we performed integrating analyses about the 22 TICs, fully interpreted the relationship between our signature and each TIC, and highlighted some TICs playing vital roles in the signature's prognostic ability.

Results

A nine-gene signature was produced from the data of the training cohort. The Kaplan-Meier estimator, Cox proportional hazard model, and ROC curve confirmed the independence and predictive ability of the signature, using the data from the validation cohort. The GSEA analysis results illustrated the gene signature's mechanism and emphasized the importance of immune-related pathways for the gene signature. 22 TICs immune infiltration analysis revealed resting mast cells' key roles in contributing to gene signature's prognostic ability.

Conclusions

This study discovered a novel immune-related nine-gene signature (BTK, CCR6, S100A10, SEMA3C, GPI, SCG2, TNFRSF11A, CCL20, and DKK1) that predicts LUAD prognosis precisely and associates with resting mast cells strongly.

Carboxypeptidase A3—A Key Component of the Protease Phenotype of Mast Cells

Carboxypeptidase A3 (CPA3) is a specific mast cell (MC) protease with variable expression. This protease is one of the preformed components of the secretome. During maturation of granules, CPA3 becomes an active enzyme with a characteristic localization determining the features of the cytological and ultrastructural phenotype of MC. CPA3 takes part in the regulation of a specific tissue microenvironment, affecting the implementation of innate immunity, the mechanisms of angiogenesis, the processes of remodeling of the extracellular matrix, etc. Characterization of CPA3 expression in MC can be used to refine the MC classification, help in a prognosis, and increase the effectiveness of targeted therapy.

Low Tumor Infiltrating Mast Cell Density Reveals Prognostic Benefit in Cervical Carcinoma

Objectives: Research on the role of mast cells (MCs) in cervical tumor immunity is more limited. Therefore, our study aimed to evaluate the prognostic value of MCs and their correlation with the immune microenvironment of cervical carcinoma (CC). Methods: The Cancer Genome Atlas (TCGA) data was utilized to obtain the degree of immune infiltration of MCs in CC. Meanwhile, this study retrospectively collected patient clinical characteristic data and tissue specimens to further verify the relevant conclusions. Mast cell density (MCD) was measured by the CIBERSORT algorithm in TCGA data and immunohistochemical staining of tryptase in CC tissues. Finally, differentially expressed genes (DEGs) of TCGA data were performed using "limma" packages and key gene modules were identified using the MCODE application in Cytoscape. Results: The results showed MCs were diffusely distributed in CC tissues. Moreover, we found that low tumor-infiltrating MCD was beneficial for overall survival (OS) in the TCGA cohort. Consistent conclusions were also obtained in a clinical cohort. In addition, a total of 305 DEGs were analyzed between the high tumor-infiltrating MCD and low tumor-infiltrating MCD group. Seven key modules, a total of 34 genes, were screened through the MCODE plug-in, which was mainly related to inflammatory response and immune response and closely correlated with cytokines including CSF2, CCL20, IL1A, IL1B, and CXCL8. Conclusion: In short, high tumor-infiltration MCs in CC tissue was associated with worse OS in patients. Furthermore, MCs were closely related to cytokines in the tumor microenvironment, suggesting that they collectively played a role in the immune response of the tumor. Therefore, MCD may be a potential prognostic indicator and immunotherapy target of CC.

Metabolic syndrome related gene signature predicts the prognosis of patients with pancreatic ductal carcinoma. A novel link between metabolic dysregulation and pancreatic ductal carcinoma

Background

Pancreatic cancer is one of the most common malignancies worldwide. In recent years, specific metabolic activities, which involves the development of tumor, caused wide public concern. In this study, we wish to explore the correlation between metabolism and progression of tumor.

Methods

A retrospective analysis including 95 patients with pancreatic ductal adenocarcinoma (PDAC) and PDAC patients from The Cancer Genome Atlas (TCGA), the International Cancer Genome Consortium (ICGC), and The Gene Expression Omnibus (GEO) database were involved in our study. Multivariate Cox regression analysis was used to construct the prognosis model. The potential connection between metabolism and immunity of PDAC was investigated through a weighted gene co-expression network analysis (WGCNA). 22 types of Tumor-infiltrating immune cells (TIICs) between high-risk and low-risk groups were estimated through CIBERSORT. Moreover, the potential immune-related signaling pathways between high-risk and low-risk groups were explored through the gene set enrichment analysis (GSEA). The role of key gene GMPS in developing pancreatic tumor was further investigated through CCK-8, colony-information, and Transwell.

Results

The prognostic value of the MetS factors was analyzed using the Cox regression model, and a clinical MetS-based nomogram was established. Then, we established a metabolism-related signature to predict the prognosis of PDAC patients based on the TCGA databases and was validated in the ICGC database and the GEO database to find the distinct molecular mechanism of MetS genes in PDAC. The result of WGCNA showed that the blue module was associated with risk score, and genes in the blue module were found to be enriched in the immune-related signaling pathway. Furthermore, the result of CIBERSORT demonstrated that proportions of T cells CD8, T cells Regulatory, Tregs NK cells Activated, Dendritic cells Activated, and Mast cells Resting were different between high-risk and low-risk groups. These differences are potential causes of different prognoses of PDAC patients. GSEA and the protein–protein interaction network (PPI) further revealed that our metabolism-related signature was significantly enriched in immune‐related biological processes. Moreover, knockdown of GMPS in PDAC cells suppressed proliferation, migration, and invasion of tumor cells, whereas overexpression of GMPS performed oppositely.

Conclusion

The results shine light on fundamental mechanisms of metabolic genes on PDAC and establish a reliable and referable signature to evaluate the prognosis of PDAC. GMPS was identified as a potential candidate oncogene with in PDAC, which can be a novel biomarker and therapeutic target for PDAC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02378-w.

Development and validation of the immune signature to predict distant metastasis in patients with nasopharyngeal carcinoma

BACKGROUND

The tumor immune microenvironment has clinicopathological significance in predicting prognosis and therapeutic efficacy. We aimed to develop an immune signature to predict distant metastasis in patients with nasopharyngeal carcinoma (NPC).

METHODS

Using multiplexed quantitative fluorescence, we detected 17 immune biomarkers in a primary screening cohort of 54 NPC tissues presenting with/without distant metastasis following radical therapy. The LASSO (least absolute shrinkage and selection operator) logistic regression model used statistically significant survival markers in the training cohort (n=194) to build an immune signature. The prognostic and predictive accuracy of it was validated in an external independent group of 304 patients.

RESULTS

Eight statistically significant markers were identified in the screening cohort. The immune signature consisting of four immune markers (PD-L1+ CD163+, CXCR5, CD117) in intratumor was adopted to classify patients into high and low risk in the training cohort and it showed a high level of reproducibility between different batches of samples (r=0.988 for intratumor; p<0.0001). High-risk patients had shorter distant metastasis-free survival (HR 5.608, 95% CI 2.619 to 12.006; p<0.0001) and progression-free survival (HR 2.798, 95% CI 1.498 to 5.266; p=0·001). The C-indexes which reflected the predictive capacity in training and validation cohort were 0.703 and 0.636, respectively. Low-risk patients benefited from induction chemotherapy plus concurrent chemoradiotherapy (IC+CCRT) (HR 0.355, 95% CI 0.147 to 0.857; p=0·021), while high-risk patients did not (HR 1.329, 95% CI 0.543 to 3.253; p=0·533). To predict the individual risk of distant metastasis, nomograms with the integration of both immune signature and clinicopathological risk factors were developed.

CONCLUSIONS

The immune signature provided a reliable estimate of distant metastasis risk in patients with NPC and might be applied to identify the cohort which benefit from IC+CCRT.

Therapeutic Targets and Tumor Microenvironment in Colorectal Cancer

Colorectal cancer (CRC) is a genetically, anatomically, and transcriptionally heterogeneous disease. The prognosis for a CRC patient depends on the stage of the tumor at diagnosis and widely differs accordingly. The tumor microenvironment (TME) in CRC is an important factor affecting targeted cancer therapy. The TME has a dynamic composition including various cell types, such as cancer-associated fibroblasts, tumor-associated macrophages, regulatory T cells, and myeloid-derived suppressor cells, as well as extracellular factors that surround cancer cells and have functional and structural roles under physiological and pathological conditions. Moreover, the TME can limit the efficacy of therapeutic agents through high interstitial pressure, fibrosis, and the degradation of the therapeutic agents by enzymatic activity. For this reason, the TME is a fertile ground for the discovery of new drugs. The aim of this narrative review is to present current knowledge and future perspectives regarding the TME composition based on strategies for patients with CRC.

Aloe-emodin, a naturally occurring anthraquinone, is a highly potent mast cell stabilizer through activating mitochondrial calcium uniporter

Mast cells play a fundamental role in immune system. Upon stimulation, they are activated via IgE dependent or independent pathway and then release granules which contain plenty of preformed constituents. Mast cell stabilizers are commonly used clinically for inhibiting the degranulation of mast cells. In the current study, we firstly identified aloe-emodin, a naturally occurring anthraquinone, was a prominent mast cell stabilizer. It could strikingly dampen IgE/FcεRI- and MAS-related G protein coupled receptor (Mrgpr)-mediated mast cell degranulation in vitro and in vivo. Mechanism study indicated that aloe-emodin rapidly and reversibly decreased cytosolic Ca²⁺ (Ca²⁺_[c]) concentration through enhancing the mitochondrial Ca²⁺ (Ca²⁺_[m]) uptake. After genetically silencing or pharmacologic inhibiting mitochondrial calcium uniporter (MCU), the effects of aloe-emodin on the Ca²⁺_[c] level and mast cell degranulation were significantly weakened. In contrast to six clinical drugs with mast cell stabilizing properties (amlexanox, tranilast, ketotifen, cromolyn disodium salt, dexamethasone and pimecrolimus), aloe-emodin showed an impressive and potent inhibitory action on the mast cell degranulation. Collectively, aloe-emodin is a highly potent mast cell stabilizer. By directly activating MCU, it decreases Ca²⁺_[c] level to suppress mast cell degranulation. Our study may provide a promising candidate for the treatment of mast cell activation-related diseases.

The role of mast cells in human skin cancers

Mast cells (MCs) are immune cells derived from myeloid lineage present in all classes of vertebrates and have emerged preceding much time the development of adaptive immunity. MCs are involved in inflammatory processes, allergic reactions, and host responses to parasites and bacteria infectious diseases. MCs are located at the host-environment interface, at many sites of initial antigen entry, including skin, lung and gastrointestinal tract, and have part of a protective mechanism. Skin has an important role in protecting the host from invasion both as physical barriers and by employing an intricate network of resident immune and non-immune cells include macrophages, T and B lymphocytes, MCs, neutrophils, eosinophils, and Langerhans cells. In this review we discussed the role of MCs in human skin cancers.

Immune Microenvironment: New Insight for Familial Adenomatous Polyposis

Currently, the main treatment for familial adenomatous polyposis (FAP) is surgery, however, surgery is far from ideal as there are many complications such as uncontrollable bowel movements, pouch inflammation, anastomotic stricture, and secondary fibroids. Therefore, it is necessary to further expand the understanding of FAP and develop new treatments for FAP. The immune microenvironment including immune cells and cytokines, plays an important role in FAP and the progression of FAP to adenocarcinoma, thus it may be a promising treatment for FAP. In the current review, we summarized the recent progress in the immune microenvironment of FAP.

A pan-cancer single-cell transcriptional atlas of tumor infiltrating myeloid cells

Tumor-infiltrating myeloid cells (TIMs) are key regulators in tumor progression, but the similarity and distinction of their fundamental properties across different tumors remain elusive. Here, by performing a pan-cancer analysis of single myeloid cells from 210 patients across 15 human cancer types, we identified distinct features of TIMs across cancer types. Mast cells in nasopharyngeal cancer were found to be associated with better prognosis and exhibited an anti-tumor phenotype with a high ratio of TNF+/VEGFA+ cells. Systematic comparison between cDC1- and cDC2-derived LAMP3+ cDCs revealed their differences in transcription factors and external stimulus. Additionally, pro-angiogenic tumor-associated macrophages (TAMs) were characterized with diverse markers across different cancer types, and the composition of TIMs appeared to be associated with certain features of somatic mutations and gene expressions. Our results provide a systematic view of the highly heterogeneous TIMs and suggest future avenues for rational, targeted immunotherapies.

Evaluation of Mast Cell Density using CD117 antibody and Microvessel Density Using CD34 Antibody in Different Grades of Oral Squamous Cell Carcinoma

Objective:

To compare mast cell and microvessel densities among histologic grades of oral squamous cell carcinoma.

Setting:

Armed Forces Institute of Pathology. Materials and Methods: A total of 60 specimens of OSCC comprising 20 each of well, moderately and poorly differentiated were evaluated. Immunohistochemical analysis was performed to measure MCD and MVD by applying monoclonal CD117 antibody and monoclonal CD34 antibody, on formalin fixed and paraffin embedded sections. ANOVA and Post Hoc Tukey test was employed to assess the densities and to compare the differences between different grades of OSCC. A p-value <0.05 was considered to as significant.

Results:

There were 67% males and 33% females with a mean age of 60.1±16.0years. Immunohistochemical analysis revealed MCD to be 31.0±5.5 25.05±5.2, 10.90±3.5 in well, moderately and poorly differentiated OSCC. The intergroup comparison of decrease in MCD was also found to be statistically significant. The mean MVD was found to be 17.55±4.2, 20.35±3.6 and 28.60±3.2 in WDOSCC, MDOSCC and PDOSCC respectively. The pair wise result of MVD was found insignificant between well and moderately differentiated OSCC (p=0.057). However, the results of MVD was significant for well versus poorly differentiated and moderately versus poorly differentiated OSCC (p<0.001).

Conclusion:

The protective role of mast cells in OSCC is favored as a decrease in MCD is observed with the advancing histological grade of tumor. Significant results of MCD and MVD reveal that they can be used as an indicator for the disease progression in oral tumors This outcome might help delineating tumor population to get advantage from novel treatment modalities like mast cell degranulation blocking agents and anti-angiogenic therapy.

Identification of the key genes and characterizations of Tumor Immune Microenvironment in Lung Adenocarcinoma (LUAD) and Lung Squamous Cell Carcinoma (LUSC)

This study aimed to investigate the key genes and immune microenvironment involved in different TNM stages of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). The gene expression and clinical characteristics data were downloaded from the genomic data commons (GDC) database. After initial data processing, the characteristics of the immune microenvironment were analyzed. The differentially expressed genes (DEGs) in tumor vs. normal, and in early vs. advanced stages were screened, followed by Spearman correlation test for tumor infiltrating immune cells (TIICs) to identify immune-related genes. Finally, functional enrichment, protein-protein interaction, and survival analyses were performed. In LUAD, early stage was with higher immune scores, greater number of memory B cells and M0 macrophages compared to advanced stage. M0 and M2 macrophages, and resting memory CD4+ T cells accounted for a large proportion of TIICs in LUAD. The abundance of M0 macrophage infiltration was significantly correlated with the TNM stage and survival. In LUSC, early stage was with higher cytolytic activity and neoantigen burden compared to advanced stage. M0 and M2 macrophages, and plasma cells accounted for a large proportion of TIICs in LUSC. The abundance of resting and activated mast cells was significantly correlated with TNM stage, while resting dendritic cells, eosinophils, activated memory CD4 T cells, and mast cells were significantly correlated with prognosis. Tumor mutation burden analysis revealed that the median of variants per sample decreased from stage I to IV in LUAD, while it increased in LUSC. Further, 83 and 9 immune-related DEGs were identified in LUAD and LUSC, respectively, of which 23 genes in LUAD and 2 genes in LUSC correlated with survival. In conclusion, we identified the key genes, and characterized the tumor immune microenvironment in LUAD and LUSC which may provide therapeutic targets for the treatment of NSCLC.

Role of Mast Cells in Shaping the Tumor Microenvironment

Early mast cell (MC) infiltration has been reported in a wide range of human and animal tumors particularly malignant melanoma and breast and colorectal cancer. The consequences of their presence in the tumor microenvironment (TME) or at their margins still remain unclear as it is associated with a good or poor prognosis based on the type and anatomical site of the tumor. Within the tumor, MC interactions occur with infiltrated immune cells, tumor cells, and extracellular matrix (ECM) through direct cell-to-cell interactions or release of a broad range of mediators capable of remodeling the TME. MCs actively contribute to angiogenesis and induce neovascularization by releasing the classical proangiogenic factors including VEGF, FGF-2, PDGF, and IL-6, and nonclassical proangiogenic factors mainly proteases including tryptase and chymase. MCs support tumor invasiveness by releasing a broad range of matrix metalloproteinases (MMPs). MC presence within the tumor gained additional significance when it was assumed that controlling its activation by tyrosine kinase inhibitors (imatinib and masitinib) and tryptase inhibitors (gabexate and nafamostat mesylate) or controlling their interactions with other cell types may have therapeutic benefit.

CMA1 is potent prognostic marker and associates with immune infiltration in gastric cancer

Background: Chymase 1 (CMA1), a gene known to be expressed in mast cells (MCs), is largely linked to immunity. However, the relationship between CMA1 and prognosis of multiple tumours and tumour-infiltrating lymphocytes (TILs) remains elusive.Methods: The differential expressions of CMA1 in different tumours and their corresponding normal tissues were evaluated via exploring Tumour Immune Estimation Resource (TIMER) and Oncomine database; the correlation within expression level of CMA1 and outcome of cancer patients was evaluated via Kaplan-Meier plotter and Gene Expression Profiling Interactive Analysis (GEPIA) database; the correlation between CMA1 and tumour immune cell infiltration was further investigated by TIMER; additionally, the correlation between CMA1 and gene signature pattern of immune infiltration were checked using TIMER and GEPIA.Results: There were significant differences in CMA1 expression levels between gastric cancer (GC) tissues and adjacent normal tissues. The high expression of CMA1 was closed related to poor overall survival (OS) and progression-free survival (PFS) in patients with GC (OS HR = 1.50, p = .00015; PFS HR = 1.33, p = .016). Especially, in GC patients at N1, N2 and N3 stages, high CMA1 expression was correlated with poor OS and PFS, but not with NO (p = .15, .09). The expression of CMA1 was positively associated with the levels of infiltrated CD4+, CD8+ T cells, neutrophils, macrophages, and dendritic cells (DCs) in GC. Whereas, CMA1 expression was considerably associated with various immune markers.Conclusion: CMA1 is a key gene whose expression level is significantly correlated with GC prognosis and infiltration levels of CD8+, CD4+ T cells, neutrophils, macrophages, and DCs in GC. In addition, the expression of CMA1 may be involved in regulating tumour-associated macrophages (TAMs), dendritic cells, exhausted T cells and regulatory T cells in GC. It suggests that CMA1 could be utilized as a prognostic marker and a sign of immune infiltration in GC.

High infiltration of mast cells is associated with improved response to adjuvant chemotherapy in gallbladder cancer

Recent studies have reported that tumor-infiltrating mast cells (TIM) play an important role in tumor regression, but the effect of TIM in gallbladder cancer (GBC) remains unclear. The present study aims to investigate the prognostic value of TIM in GBC patients and its responsiveness to gemcitabine-based adjuvant chemotherapy (ACT). A total of 298 GBC patients from Zhongshan Hospital were recruited for this study. TIM infiltration was measured by immunohistochemical staining. Accumulation of TIM is significantly associated with prolonged overall survival in GBC patients. The benefit from gemcitabine-based ACT was superior among patients with high infiltration of TIM with GBC. Multivariate analysis identified TIM infiltration as an independent prognostic factor for overall survival. A heatmap showed that TIM-activated gene signatures were positively correlated with CD8+ T cells' gene signatures. Gene set enrichment analysis (GSEA) suggested that TIM was related to multiple T cell-related processes and signaling pathways, including the interferon gamma signaling pathway and the leukocyte migration signaling pathway. It was confirmed that CD8+ T cell infiltration was positively correlated with high TIM infiltration in tissue microarray (TMA), suggesting that TIM infiltration was linked to the immune surveillance in GBC. TIM can be used as an independent prognostic factor and a predictor of therapeutic response of gemcitabine-based ACT in GBC patients, which may mediate immune surveillance by recruiting and activating CD8+ T cells in GBC.

Mast cell tryptase - Marker and maker of cardiovascular diseases

Mast cells are tissue-resident cells, which have been proposed to participate in various inflammatory diseases, among them the cardiovascular diseases (CVDs). For mast cells to be able to contribute to an inflammatory process, they need to be activated to exocytose their cytoplasmic secretory granules. The granules contain a vast array of highly bioactive effector molecules, the neutral protease tryptase being the most abundant protein among them. The released tryptase may act locally in the inflamed cardiac or vascular tissue, so contributing directly to the pathogenesis of CVDs. Moreover, a fraction of the released tryptase reaches the systemic circulation, thereby serving as a biomarker of mast cell activation. Actually, increased levels of circulating tryptase have been found to associate with CVDs. Here we review the biological relevance of the circulating tryptase as a biomarker of mast cell activity in CVDs, with special emphasis on the relationship between activation of mast cells in their tissue microenvironments and the pathophysiological pathways of CVDs. Based on the available in vitro and in vivo studies, we highlight the potential molecular mechanisms by which tryptase may contribute to the pathogenesis of CVDs. Finally, the synthetic and natural inhibitors of tryptase are reviewed for their potential utility as therapeutic agents in CVDs.

Human Skin-Derived Mast Cells Spontaneously Secrete Several Angiogenesis-Related Factors

Mast cells are classically recognized as cells that cause IgE-mediated allergic reactions. However, their ability to store and secrete vascular endothelial growth factor (VEGF) suggests a role in vascular development and tumorigenesis. The current study sought to determine if other angiogenesis-related factors, in addition to VEGF, were also secreted by human tissue-derived mast cells. Using proteome array analysis and ELISA, we found that human skin-derived mast cells spontaneously secrete CXCL16, DPPIV, Endothelin-1, GM-CSF, IL-8, MCP-1, Pentraxin 3, Serpin E1, Serpin F1, TIMP-1, Thrombospondin-1, and uPA. We identified three groups based on their dependency for stem cell factor (SCF), which is required for mast cell survival: Endothelin-1, GM-CSF, IL-8, MCP-1, and VEGF (dependent); Pentraxin 3, Serpin E1, Serpin F1, TIMP-1, and Thrombospondin-1 (partly dependent); and CXCL16, DPPIV, and uPA (independent). Crosslinking of FcεRI with multivalent antigen enhanced the secretion of GM-CSF, Serpin E1, IL-8, and VEGF, and induced Amphiregulin and MMP-8 expression. Interestingly, FcεRI signals inhibited the spontaneous secretion of CXCL16, Endothelin-1, Serpin F1, Thrombospondin-1, MCP-1 and Pentraxin-3. Furthermore, IL-6, which we previously showed could induce VEGF, significantly enhanced MCP-1 secretion. Overall, this study identified several angiogenesis-related proteins that, in addition to VEGF, are spontaneously secreted at high concentrations from human skin-derived mast cells. These findings provide further evidence supporting an intrinsic role for mast cells in blood vessel formation.

Recent advances in our understanding of mast cell activation - or should it be mast cell mediator disorders?

INTRODUCTION

An increasing number of patients present with multiple symptoms affecting many organs including the brain due to multiple mediators released by mast cells. These unique tissue immune cells are critical for allergic reactions triggered by immunoglobulin E (IgE), but are also stimulated (not activated) by immune, drug, environmental, food, infectious, and stress triggers, leading to secretion of multiple mediators often without histamine and tryptase. The presentation, diagnosis, and management of the spectrum of mast cell disorders are very confusing. As a result, neuropsychiatric symptoms have been left out, and diagnostic criteria made stricter excluding most patients. Areas covered: A literature search was performed on papers published between January 1990 and November 2018 using MEDLINE. Terms used were activation, antihistamines, atopy, autism, brain fog, heparin, KIT mutation, IgE, inflammation, IL-6, IL-31, IL-37, luteolin, mast cells, mastocytosis, mediators, mycotoxins, release, secretion, tetramethoxyluteolin, and tryptase. Expert opinion: Conditions associated with elevated serum or urine levels of any mast cell mediator, in the absence of comorbidities that could explain elevated levels, should be considered 'Mast Cell Mediator Disorders (MCMD).' Emphasis should be placed on the identification of unique mast cell mediators, and development of drugs or supplements that inhibit their release.

Tumor infiltrating mast cells determine oncogenic HIF-2α-conferred immune evasion in clear cell renal cell carcinoma

PURPOSE

Hypoxia-inducible factor 2α (HIF-2α) overexpression leads to activation of angiogenic pathways. However, little is known about the association between HIF-2α expression and anti-tumor immunity in clear cell renal cell carcinoma (ccRCC). We aimed to explore how HIF-2α influenced the microenvironment and the underlying mechanisms.

EXPERIMENTAL DESIGN

We immunohistochemically evaluated immune cells infiltrations and prognostic value of HIF-2α expression in a retrospective Zhongshan Hospital cohort of 280 ccRCC patients. Fresh tumor samples, non-tumor tissues and autologous peripheral blood for RT-PCR, ELISA and flow cytometry analyses were collected from patients who underwent nephrectomy in Zhongshan Hospital from September 2017 to April 2018. The TCGA KIRC cohort and SATO cohort were assessed to support our findings.

RESULTS

We demonstrated that ccRCC patients with HIF-2αhigh tumors exhibited reduced overall survival (p = 0.025) and recurrence-free survival (p < 0.001). Functions of CD8+ T cells were impaired in HIF-2αhigh patients. In ccRCC patients, HIF-2α induced the expression of stem cell factor (SCF), which served as chemoattractant for mast cells. Tumor infiltrating mast cells impaired anti-tumor immunity partly by secreting IL-10 and TGF-β. HIF-2α mRNA level adversely associated with immunostimulatory genes expression in KIRC and SATO cohorts.

CONCLUSIONS

HIF-2α contributed to evasion of anti-tumor immunity via SCF secretion and subsequent recruitment of mast cells in ccRCC patients.

Tumor⁻Microenvironment Interaction: Analysis of Mast Cell Populations in Normal Tissue and Proliferative Disorders of the Canine Prostate

Mast cells (MCs) are involved in angiogenesis, tissue remodeling and immunomodulation in several human and animal tumors, although their exact role is still controversial. Since no information is available in canine prostate carcinoma (PC) and normal prostate tissues, the aims of this study were to evaluate the possible correlations between MC distribution, molecular expression and microvessel density (MVD) in normal prostatic tissue and proliferative disorders of the canine prostate. All samples (6 normal, 15 benign prostate hyperplasia-BPH, 8 PC) were stained with Toluidine Blue and immunohistochemically evaluated for tryptase, c-Kit (CD117) and CD31. Mast cell density (MCD) and MVD were quantified by the hot-spot method. MCD was significantly increased in periglandular/peritumoral areas, when compared with intraglandular/intratumoral areas, in all groups (p = 0.03). C-Kit expression was strongly associated with PC (ρ = 0.75 p = 0.03), whereas positive correlation between tryptase and c-Kit expression (ρ = 0.64 p = 0.01) was observed in periglandular areas of BPH. MVD showed a correlation with MCD in BPH (ρ = 0.54 p = 0.04). Our data support the importance of c-Kit in regulating MC proliferation. The predominant location of MCs in peritumoral areas of canine PC was similar to the human counterpart, in which PC cells are supposed to produce substances attracting MCs to the tumor microenvironment.

Mast cell disorders: From infancy to maturity

Mast cells are typically linked to immediate hypersensitivity and anaphylaxis. This review looks beyond this narrow role, focusing on how these cells have evolved and diversified via natural selection promoting serine protease gene duplication, augmenting their innate host defense function against helminths and snake envenomation. Plasticity of mast cell genes has come at a price. Somatic activating mutations in the mast cell growth factor KIT gene cause cutaneous mastocytosis in young children and systemic mastocytosis with a more guarded prognosis in adults who may also harbor other gene mutations with oncogenic potential as they age. Allelic TPSAB1 gene duplication associated with higher basal mast cell tryptase is possibly one of the commonest autosomal dominantly inherited multi-system diseases affecting the skin, gastrointestinal tract, circulation and musculoskeletal system. Mast cells are also establishing a new-found importance in severe asthma, and in remodeling of blood vessels in cancer and atherosclerotic vascular disease. Furthermore, recent evidence suggests that mast cells sense changes in oxygen tension, particularly in neonates, and that subsequent degranulation may contribute to common lung, eye, and brain diseases of prematurity classically associated with hypoxic insults. One hundred and forty years since Paul Ehrlich's initial description of "mastzellen," this review collates and highlights the complex and diverse roles that mast cells play in health and disease.

Immunohistochemical analysis of lymphatic vessel density and mast cells in oral tongue squamous cell carcinoma

The aim of this study was to analyze lymphangiogenesis and the presence of mast cells in oral tongue squamous cell carcinoma (OTSCC), correlating the findings with clinicopathological parameters (clinical stage, tumor size, nodal metastasis, histological grade of malignancy, local recurrence, and clinical outcome). Fifty-six cases of primary OTSCC were selected. Lymphatic vessels and mast cells were identified by immunostaining with anti-podoplanin (D2-40) and anti-tryptase antibody, respectively. Lymphatic vessel density (LVD) and mast cell density (MCD) were determined in the intratumoral and peritumoral areas. Intratumoral LVD was higher in advanced clinical stages (III/IV) when compared to early-stage (p = 0.017) and in metastatic cases compared to non-metastatic tumors (p = 0.013). Peritumoral LVD and intratumoral or peritumoral MCD did not differ significantly according to the clinicopathological parameters of OTSCCs (p > 0.05). No significant correlations between LVD and MCD were observed at the intratumoral (r = -0.014; p = 0.918) or peritumoral level (r = 0.156; p = 0.251). Our findings suggest that intratumoral lymphatic vessels, compared to peritumoral lymphatic vessels, appear to be more related to the progression of OTSCC. MCD alone does not seem to be determinant for lymphangiogenesis or for the biological behavior of OTSCC, indicating multiple pro- and antitumor effects of these inflammatory cells.

Tumor-infiltrating mast cells predict prognosis and gemcitabine-based adjuvant chemotherapeutic benefit in biliary tract cancer patients

BACKGROUND

Recent studies have reported TIMs play an important role in tumors progression or regression, but the effect of TIMs in biliary tract cancer remains unclear. The aim of this study is to investigate the prognostic value of tumor infiltrating mast cells (TIMs) and its influence on gemcitabine-based adjuvant chemotherapy (ACT) benefits in biliary tract cancer patients after surgery.

METHODS

TIMs were evaluated by immunohistochemical staining of tryptase in 250 patients with resected gallbladder carcinoma (GBC) or extrahepatic bile duct carcinoma (EBDC) from Zhongshan Hospital. The relationships between TIMs and clinicopathological factors and postoperative prognosis were analyzed respectively.

RESULTS

High TIMs infiltration was significantly correlated with prolonged overall survival (OS). Furthermore, multivariate analysis indicated TNM stage and TIMs as independent prognostic factors for OS. Patients with high TIMs infiltration appeared to significantly benefit from Gemcitabine-based ACT in the discovery and validation cohorts. Spearman analysis identified that TIMs infiltration were positively correlated with anti-tumor CD8+ T cells.

CONCLUSION

TIMs infiltration is an independent favorable prognostic factor in GBC and EBDC patients, which could better stratify patients with different prognosis and predict benefit from gemcitabine-based ACT.

Tryptase as a polyfunctional component of mast cells

Mast cells are haematopoietic cells that arise from pluripotent precursors of the bone marrow. They play immunomodulatory roles in both health and disease. When appropriately activated, mast cells undergo degranulation, and preformed granule compounds are rapidly released into the surroundings. In many cases, the effects that mast cells have on various inflammatory settings are closely associated with the enzymatic characteristics of tryptase, the main granule compound of mast cells. Tryptase degranulation is often linked with the development of an immune response, allergy, inflammation, and remodelling of tissue architecture. Tryptase also represents an informative diagnostic marker of certain diseases and a prospective target for pharmacotherapy. In this review, we discuss the current knowledge about mast cell tryptase as one of the mast cell secretome proteases. The main points of the reviewed publications are highlighted with our microscopic images of mast cell tryptases visualized using immunohistochemical staining.

Diverse exocytic pathways for mast cell mediators

Mast cells play pivotal roles in innate and adaptive immunities but are also culprits in allergy, autoimmunity, and cardiovascular diseases. Mast cells respond to environmental changes by initiating regulated exocytosis/secretion of various biologically active compounds called mediators (e.g. proteases, amines, and cytokines). Many of these mediators are stored in granules/lysosomes and rely on intricate degranulation processes for release. Mast cell stabilizers (e.g. sodium cromoglicate), which prevent such degranulation processes, have therefore been clinically employed to treat asthma and allergic rhinitis. However, it has become increasingly clear that different mast cell diseases often involve multiple mediators that rely on overlapping but distinct mechanisms for release. This review illustrates existing evidence that highlights the diverse exocytic pathways in mast cells. We also discuss strategies to delineate these pathways so as to identify unique molecular components which could serve as new drug targets for more effective and specific treatments against mast cell-related diseases.

Interleukin-6 potentiates FcεRI-induced PGD2 biosynthesis and induces VEGF from human in situ-matured skin mast cells

BACKGROUND

Interleukin-6 is a gp130 utilizing cytokine that is consistently associated with allergic diseases like asthma and urticaria in humans where mast cells are known to play a critical role. However, the role of IL-6 in allergic disease in not known. IL-6 was reported to enhance degranulation of in vitro-derived mast cells, but the effect of IL-6 on mediator release from human in situ-matured tissue-isolated mast cells had not been reported.

METHODS

Human mature mast cells were isolated and purified from normal skin tissue from different donors. The expression of surface-expressed IL-6 receptors was demonstrated by flow cytometry. The effect of IL-6 on FcεRI-induced degranulation, PGD₂ biosynthesis, and cytokine production was determined with β‑hexosaminidase release assay, Western blotting, quantitative real-time PCR, and ELISA. The small molecule inhibitor of STAT-3, C188-9, was used to demonstrate STAT3 dependency.

RESULTS

IL-6 significantly potentiated FcεRI-induced PGD₂ biosynthesis, but had no effect on degranulation. IL-6 also induced VEGF gene expression and protein secretion, and enhanced FcεRI-induced IL-8 production. Mechanistically, IL-6 enhanced FcεRI-induced COX‑2 expression, PGD2 biosynthesis, and VEGF production in a STAT3 dependent manner.

CONCLUSION

Here, we demonstrate that IL-6 is a potentiator of FcεRI-induced PGD₂ biosynthesis, and can induce or enhance production of pro-angiogenesis factors VEGF and IL-8 from human in situ-matured skin mast cells.

GENERAL SIGNIFICANCE

These findings from this study indicate that IL-6 contributes to human allergic disease by enhancing the production of inflammatory PGD₂ from tissue-resident mast cells. Moreover, the data suggest a novel role for IL-6 in mast cell-mediated angiogenesis.

AllergoOncology: Opposite outcomes of immune tolerance in allergy and cancer

While desired for the cure of allergy, regulatory immune cell subsets and nonclassical Th2-biased inflammatory mediators in the tumour microenvironment can contribute to immune suppression and escape of tumours from immunological detection and clearance. A key aim in the cancer field is therefore to design interventions that can break immunological tolerance and halt cancer progression, whereas on the contrary allergen immunotherapy exactly aims to induce tolerance. In this position paper, we review insights on immune tolerance derived from allergy and from cancer inflammation, focusing on what is known about the roles of key immune cells and mediators. We propose that research in the field of AllergoOncology that aims to delineate these immunological mechanisms with juxtaposed clinical consequences in allergy and cancer may point to novel avenues for therapeutic interventions that stand to benefit both disciplines.

C-Kit receptor and tryptase expressing mast cells correlate with angiogenesis in breast cancer patients

C-Kit protein is a transmembrane tyrosine kinase (TK) receptor (c-KitR-TK), which is predominantly expressed on mast cells (MCs) playing a role in tumor angiogenesis. It could be also expressed on epithelial breast cancer cells (EBCCs), but no data have been published regarding the correlation between mast cells positive to c-KitR (MCs-c-KitR), EBCCs positive to c-KitR (EBCCs-c-KitR), BC angiogenesis in terms of microvessel density (MVD) and the main clinic-pathological features. This study aims to evaluate the above parameters and their correlations in a series of selected 121 female early BC patients. It has been found a strong correlation between MVD and MCDPT, and MCs-c-KitR, MVD and MCs density positive to tryptase (MCDPT), and MCs-c-KitR and MCDPT by Pearson correlation. These data suggest an involvement of both MCDPT and MCs-c-KitR in BC tumor angiogenesis. Furthermore, BC tissue expressing c-KitR could be a putative predictive factor to c-KitR-TK inhibitors. In this way, selected patients with higher MCs-c-KitR could be candidate to receive c-KitR-TK inhibitors (e.g. masitinib, sunitinib) or tryptase inhibitors (e.g. nafamostat mesilate, gabexate mesilate).

High mast cell density indicates a longer overall survival in oral squamous cell carcinoma

This study evaluates the effects of tumour-associated mast cells on the prognosis of patients suffering from oral squamous cell carcinoma (OSCC). Tryptase-positive (MCT⁺) and CD117-positive (CD117⁺) mast cells were immunohistochemically evaluated in tissue samples of 118 OSCC patients. Besides, various clinicopathological parameters, the influence of the MCT⁺ and CD117⁺ mast cell density on overall survival and the incidence of first local recurrence was analysed by Cox regression and competing risk regression. Among all investigated parameters, multiple Cox regression revealed a significant influence of the MCT⁺ (cut-off at 14.87 mast cells/mm² stroma; p = 0.0027) and CD117⁺ mast cell density (cut-off at 33.19 mast cells/mm² stroma; p = 0.004), the age at primary diagnosis, and the T and N stage (all p-values < 0.05) on overall survival. Patients with a low mast cell density showed a significantly poorer overall survival rate compared to those with a high mast cell density in the tumour-associated stroma. Competing risk regression revealed a significant influence of the resection status (R) on the incidence of first local recurrence (p = 0.0023). A high mast cell density in the tumour-associated stroma of oral squamous cell carcinoma indicates a longer patient survival.

Tumor-infiltrating tryptase+ mast cells predict unfavorable clinical outcome in solid tumors

The prognostic role of tumor-infiltrating tryptase⁺ mast cells in human solid tumors remains controversial. Herein, we conducted a meta-analysis including 28 published studies with 4224 patients identified from PubMed and EBSCO to assess the prognostic impact of tumor-infiltrating tryptase⁺ mast cells in human solid tumors. We found that tryptase⁺ mast cell infiltration significantly decreased overall survival (OS) and disease-free survival (DFS) in all types of solid tumors. In stratified analyses, tryptase⁺ mast cell infiltration was significantly associated with worse OS in non-small cell lung cancer, hepatocellular carcinoma and 5-year survival in colorectal cancer. And these cells were inversely associated with DFS in hepatocellular and colorectal cancer. In addition, high density of intratumoral tryptase⁺ mast cells significantly correlated with lymph node metastasis of solid tumor. In conclusion, Tryptase⁺ mast cell infiltration leads to an unfavorable clinical outcome in solid tumors, implicating that it is a valuable biomarker for prognostic prediction for human solid malignances and targeting it may have a potential for effective treatment.

Tryptase expression as a prognostic marker in patients with resected gastric cancer

BACKGROUND

Mast cells play important roles in the progression of various malignancies, but their prognostic value in gastric cancer is unknown. Tryptase expression, as an indicator of mast cell activity, was therefore evaluated to see whether this could be incorporated usefully into a prognostic nomogram after surgery in patients with gastric cancer.

METHODS

Tissue microarrays from patients with gastric cancer were created from formalin-fixed, paraffin-embedded resection specimens. Tryptase density was assessed by immunohistochemistry, and the association between tryptase expression and prognosis was evaluated. Semiquantitative scoring was devised to determine an optimal cut-off value that correlated with survival. A prognostic nomogram was then developed incorporating tryptase expression scores along with other variables known to be related to survival.

RESULTS

Tissue microarrays were generated from 419 patients having surgery for gastric cancer. Increased tryptase expression was associated with better overall and recurrence-free survival (both P < 0·001). Tryptase expression was an independent favourable prognostic factor for overall (HR 0·72; P = 0·027) and recurrence-free (HR 0·74; P = 0·044) survival. The accuracy of an established prognostic model was improved when tryptase expression was added.

CONCLUSION

Tryptase expression is an independent prognostic factor for overall and recurrence-free survival in patients with gastric cancer after surgical resection.