Tryptase serum levels in patients suffering from hepatocellular carcinoma undergoing intra-arterial chemoembolization: Possible predictive role of response to treatment

Ultrastructural features of tumor-associated mast cells in parasympathetic paragangliomas (chemodectomas) of the neck

The mechanisms of the pathogenesis of neck paraganglioma (PGL) and the possible role of mast cells (MCs) in its development and metastasis are still poorly understood. We analyzed MCs' morphologic characterization, activation, and the properties of their cytoplasmic/released granules in PGLs, using light and transmission electron microscopy. Paragangliomas showed a large tumor-associated MC population both in the connective tissue layers of the tumor and between the tumor cells. Notably, MCs were presented by a high expression of specific proteases, size variation, polymorphism, and variable ultrastructural phenotype of granules. A massive number of granules were released surrounding the degranulated MCs while the integrity of MC membrane was maintained. Granules were electron-dense with or without a membrane, ranging from 0.2 to 0.8 μm in diameter. MC plasmalemma was not found at the site of MC-collagen fibrils contact, whereas the secretome and fibrils were directly contacted. We observed direct and mediator-based interactions between MCs and paraganglioma cells. The latter preserved their membrane integrity when MC granules were not in proximity. The effects of the MC secretome on the paraganglioma microenvironment demonstrated its pathogenetic role in tumor progression and allow its application to new diagnostic criteria and the development of protocols for personalized therapy. RESEARCH HIGHLIGHTS: Ultrastructural analysis reveals novel regulatory effects of mast cells via diverse secretory pathways on the pathogenesis of parasympathetic paraganglioma, including fibrous extracellular matrix remodeling and mediator-based interactions between MCs and cells of the tumor microenvironment.

The Role of GNMT and MMP12 Expression in Determining TACE Efficacy: Validation at Transcription and Protein Levels

Purpose

Transarterial chemoembolization (TACE) represents a significant therapeutic modality for hepatocellular carcinoma (HCC). We aimed to develop a gene signature to accurately predict patient TACE response and explore the underlying mechanisms.

Methods

Three independent datasets were utilized, including GSE104580, GSE14520 and external validation from the Cancer Hospital Chinese Academy of Medical Sciences. GSE104580 was randomly partitioned into a training set and a validation set, whereas GSE14520 was categorized into a resection group and a TACE group. Logistic regression was used to develop a TACE effectiveness model. Immunohistochemistry is utilized to confirm the protein expression trends of the signature genes. Immune infiltration and functional enrichment analyses were conducted to investigate the potential underlying mechanisms.

Results

A 2-gene signature consisting of glycine N-methyltransferase (GNMT) and matrix metalloproteinase-12 (MMP12) was constructed, and based on this, all the patients were assigned TACE effectiveness scores and categorized into high effectiveness (HE) and low effectiveness (LE) groups. The HE group exhibited a better prognosis than the LE group in the various cohorts (p < 0.05). In the external validation set, immunohistochemistry confirmed the expression of the signature genes exhibiting an upregulated trend of GNMT in the HE group and MMP12 in the LE group, the LE group also exhibited a poorer prognosis [for overall survival (OS), HE group: 881 days vs LE group: 273 days (p < 0.05), and for progression-free survival (PFS), HE group: 458 days vs LE group: 136 days (p < 0.05)]. Multivariate analysis in all the datasets identified LE status as an independent risk factor for OS, disease-free survival (DFS) and PFS. The infiltration level of M0 macrophages and activated mast cells in the LE group was significantly higher than in the HE group. The hypoxia signaling pathway and glycolysis pathway were significantly enriched in the LE group.

Conclusion

The loss of GNMT and the overexpression of MMP12 may be critical factors influencing TACE efficacy.

Immunotherapy and the Combination with Targeted Therapies for Advanced Hepatocellular Carcinoma

One of the most important abilities of a tumor is to establish a state of immunosuppression inside the tumor microenvironment. This is made possible through numerous mechanisms of tumor immune escape that have been identified in experimental studies during the last decades. In addition, the hepatic microenvironment is commonly oriented towards a state of immune tolerance because the liver receives blood from the hepatic arteries and portal veins containing a variety of endogenous antigens. Therefore, the hepatic microenvironment establishes an autoimmune tolerance, preventing an autoimmune reaction in the liver. On this basis, hepatic tumor cells may escape the immune system, avoiding being recognized and destroyed by immune cells. Moreover, since the etiology of Hepatocellular Carcinoma (HCC) is often related to cirrhosis, and hepatitis B or C, this tumor develops in the context of chronic inflammation. Thus, the HCC microenvironment is characterized by important immune cell infiltration. Given these data and the poor prognosis of advanced HCC, different immunotherapeutic strategies have been developed and evaluated for these patients. In this review, we describe all the clinical applications of immunotherapy for advanced HCC, from the drugs that have already been approved to the ongoing clinical trials.

Intra-Arterial Infusion Chemotherapy in Advanced Pancreatic Cancer: A Comprehensive Review

Simple Summary

Pancreatic cancer has a very poor prognosis. The few available therapeutic options are characterized by low efficacy and high toxicity due to the intrinsic chemoresistance of this tumor type. To improve clinical results, some clinical trials have evaluated regional chemotherapy as a treatment option for PC. The pancreatic arterial infusion of chemotherapeutics has the aim of obtaining higher local concentrations of drugs and, at the same time, of limiting systemic toxicity. This therapeutic approach has already been successfully evaluated for the treatment of several types of tumors. Regarding advanced pancreatic cancers, only a few clinical studies have investigated the safety and efficacy of this treatment, with very promising results. Therefore, in this review, we summarize literature data on the clinical approaches to pancreatic arterial drug administration for the treatment of advanced PC to deepen knowledge on this topic.

Abstract

Advanced pancreatic cancer (PC) has a very poor prognosis due to its chemoresistant nature. Nowadays, only a few therapeutic options are available for PC, and the most effective ones are characterized by low response rates (RRs), short progression-free survival and overall survival, and severe toxicity. To improve clinical results, small series studies have evaluated loco-regional chemotherapy as a treatment option for PC, demonstrating its dose-dependent sensitivity towards the tumor. In fact, pancreatic arterial infusion (PAI) chemotherapy allows higher local concentrations of chemotherapeutic agents, sparing healthy tissues with a lower rate of adverse events compared to systemic chemotherapy. This therapeutic approach has already been evaluated in different types of tumors, especially in primary and metastatic liver cancers, with favourable results. With regard to advanced PC, a few clinical studies have investigated the safety and efficacy of PAI with promising results, especially in terms of RRs compared to systemic chemotherapy. However, clear evidence about its efficacy has not been established yet nor have the underlying mechanisms leading to its success. In this review, we aim to summarize the literature data on the clinical approaches to pancreatic arterial drug administration in terms of techniques, drug pharmacokinetics, and clinical outcomes for advanced PC.

Mast Cells Positive for c-Kit Receptor and Tryptase Correlate with Angiogenesis in Cancerous and Adjacent Normal Pancreatic Tissue

Background: Mast cells (MCs) contain proangiogenic factors, in particular tryptase, associated with increased angiogenesis in several tumours. With special reference to pancreatic cancer, few data have been published on the role of MCs in angiogenesis in both pancreatic ductal adenocarcinoma tissue (PDAT) and adjacent normal tissue (ANT). In this study, density of mast cells positive for c-Kit receptor (MCDP-c-KitR), density of mast cells positive for tryptase (MCDPT), area of mast cells positive for tryptase (MCAPT), and angiogenesis in terms of microvascular density (MVD) and endothelial area (EA) were evaluated in a total of 45 PDAT patients with stage T_2–3N_0–1M₀. Results: For each analysed tissue parameter, the mean ± standard deviation was evaluated in both PDAT and ANT and differences were evaluated by Student’s t-test (p ranged from 0.001 to 0.005). Each analysed tissue parameter was then correlated to each other one by Pearson t-test analysis (p ranged from 0.01 to 0.03). No other correlation among MCDP-c-KitR, MCDPT, MCAPT, MVD, EA and the main clinical–pathological characteristics was found. Conclusions: Our results suggest that tissue parameters increased from ANT to PDAT and that mast cells are strongly associated with angiogenesis in PDAT. On this basis, the inhibition of MCs through tyrosine kinase inhibitors, such as masitinib, or inhibition of tryptase by gabexate mesylate may become potential novel antiangiogenetic approaches in pancreatic cancer therapy.

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.

Mast cells and cancer

Mast cells (MCs) are a potent proangiogenic factor in tumors, they product several pro-angiogenic factors such as fibroblast growth factor 2 (FGF-2), vascular epithelial growth factor (VEGF), tryptase and chymase. Tryptase is a serine protease classified as α-tryptase and β-tryptase, both produced by MCs. Tryptase degrades the tissues, playing an important role in angiogenesis and in the development of metastases. Serum tryptase increases with age, with increased damage to cells and risk of developing a malignancy and it could be considered the expression of a fundamental role of MCs in tumor growth or, on the contrary, in the antitumor response. Many biomarkers have been developed in clinical practice for improving diagnosis and prognosis of some neoplasms. Elevated tryptase levels are found in subgroups of patients with haematologic and solid cancers. In the current review, we want to update the perspectives of tryptase as a potential biomarker in daily practice in different neoplasms.

The emerging role of mast cells in liver disease

The depth of our knowledge regarding mast cells has widened exponentially in the last 20 years. Once thought to be only important for allergy-mediated events, mast cells are now recognized to be important regulators of a number of pathological processes. The revelation that mast cells can influence organs, tissues, and cells has increased interest in mast cell research during liver disease. The purpose of this review is to refresh the reader's knowledge of the development, type, and location of mast cells and to review recent work that demonstrates the role of hepatic mast cells during diseased states. This review focuses primarily on liver diseases and mast cells during autoimmune disease, hepatitis, fatty liver disease, liver cancer, and aging in the liver. Overall, these studies demonstrate the potential role of mast cells in disease progression.

Mast cells positive to tryptase, endothelial cells positive to protease-activated receptor-2, and microvascular density correlate among themselves in hepatocellular carcinoma patients who have undergone surgery

BACKGROUND

Mast cells (MCs) can stimulate angiogenesis, releasing several proangiogenic cytokines stored in their cytoplasm. In particular MCs can release tryptase, a potent in vivo and in vitro proangiogenic factor via proteinase-activated receptor-2 (PAR-2) activation and mitogen-activated protein kinase phosphorylation. Nevertheless, no data are available concerning the relationship between MC density positive to tryptase (MCDPT), endothelial cells positive to PAR-2 forming microvascular density (PAR-2-MVD), and classical MVD (C-MVD) in hepatocellular carcinoma (HCC) angiogenesis. This study analyzed the correlation between MCDPT, PAR-2-MVD, and C-MVD, each correlated to the others and to the main clinicopathological features, in early HCC patients who underwent surgery.

METHODS

A series of 53 HCC patients with early stage (stage 0 according to the Barcelona Clinic Liver Cancer Staging Classification) were selected and then underwent surgery. Tumor tissue samples were evaluated by means of immunohistochemistry and image analysis methods in terms of number of MCDPT, PAR-2-MVD, and C-MVD.

RESULTS

A significant correlation between MCDPT, PAR-2-MVD, and C-MVD groups, each correlated to the others, was found by Pearson t-test analysis (r ranged from 0.67 to 0.81; P-value ranged from 0.01 to 0.03). No other significant correlation was found.

CONCLUSION

Our in vivo pilot data suggest that MCDPT and PAR-2-MVD may play a role in HCC angiogenesis and could be further evaluated as a target of antiangiogenic therapy.

Mast Cell Targeted Chimeric Toxin Can Be Developed as an Adjunctive Therapy in Colon Cancer Treatment

The association of colitis with colorectal cancer has become increasingly clear with mast cells being identified as important inflammatory cells in the process. In view of the relationship between mast cells and cancer, we studied the effect and mechanisms of mast cells in the development of colon cancer. Functional and mechanistic insights were gained from ex vivo and in vivo studies of cell interactions between mast cells and CT26 cells. Further evidence was reversely obtained in studies of mast cell targeted Fcε-PE40 chimeric toxin. Experiments revealed mast cells could induce colon tumor cell proliferation and invasion. Cancer progression was found to be related to the density of mast cells in colonic submucosa. The activation of MAPK, Rho-GTPase, and STAT pathways in colon cancer cells was triggered by mast cells during cell-to-cell interaction. Lastly, using an Fcε-PE40 chimeric toxin we constructed, we confirmed the promoting effect of mast cells in development of colon cancer. Mast cells are a promoting factor of colon cancer and thus also a potential therapeutic target. The Fcε-PE40 chimeric toxin targeting mast cells could effectively prevent colon cancer in vitro and in vivo. Consequently, these data may demonstrate a novel immunotherapeutic approach for the treatment of tumors.

The Role of Mast Cell Specific Chymases and Tryptases in Tumor Angiogenesis

An association between mast cells and tumor angiogenesis is known to exist, but the exact role that mast cells play in this process is still unclear. It is thought that the mediators released by mast cells are important in neovascularization. However, it is not known how individual mediators are involved in this process. The major constituents of mast cell secretory granules are the mast cell specific proteases chymase, tryptase, and carboxypeptidase A3. Several previous studies aimed to understand the way in which specific mast cell granule constituents act to induce tumor angiogenesis. A body of evidence indicates that mast cell proteases are the pivotal players in inducing tumor angiogenesis. In this review, the likely mechanisms by which tryptase and chymase can act directly or indirectly to induce tumor angiogenesis are discussed. Finally, information presented here in this review indicates that mast cell proteases significantly influence angiogenesis thus affecting tumor growth and progression. This also suggests that these proteases could serve as novel therapeutic targets for the treatment of various types of cancer.

Tryptase, a novel angiogenic factor stored in mast cell granules

Human mast cells (MCs) are a rich reservoir of neutral proteases, packed in large amounts in their granules and comprising a high fraction of all cellular proteins. Among these proteases, tryptase is involved in angiogenesis after its release from activated MC granules, as it has been demonstrated in different in vitro and in vivo assays. Moreover, tryptase-positive MCs increase in number and vascularization increases in a linear fashion in different solid and hematological tumors. This complex interplay between MCs and tumor angiogenesis have led to consider the therapeutic use of angiogenesis inhibitors, which specifically target the angiogenic activity of tryptase, such as gabexate mesilate and nafamostat mesilate, two inhibitors of trypsin-like serine proteases.

The serum tryptase test: an emerging robust biomarker in clinical hematology

During the past few years, a number of molecular markers have been developed in clinical hematology, most of them related to specific gene defects. However, there is also an unmet need to develop novel serologic parameters to improve diagnostics and prognostication in daily practice. Among these, the serum tryptase appears to be a most reliable biomarker of myeloid neoplasms. Elevated tryptase levels are found in subgroups of patients with mastocytosis, myelodysplastic syndrome, myeloproliferative neoplasm, acute myeloid leukemia, chronic myeloid leukemia and chronic eosinophilic leukemia. In these patients, the tryptase level is of diagnostic and/or prognostic significance. In mastocytosis, an elevated tryptase level is a minor criterion of systemic disease and in BCR-ABL1(+) chronic myeloid leukemia, elevated tryptase at diagnosis correlates with treatment responses and overall survival. In patients with elevated tryptase, the enzyme also serves as follow-up parameter and can be employed to measure treatment-responses. In the current article, we review and update the perspectives of tryptase and provide recommendations for use of this conventional biomarker in daily practice.

Mast cells density positive to tryptase correlates with angiogenesis in pancreatic ductal adenocarcinoma patients having undergone surgery

Background. Literature data suggest that cells such as mast cells (MCs), are involved in angiogenesis. MCs can stimulate angiogenesis by releasing of several proangiogenic cytokines stored in their cytoplasm. In particular MCs can release tryptase, a potent in vivo and in vitro proangiogenic factor. Nevertheless few data are available concerning the role of MCs positive to tryptase in primary pancreatic cancer angiogenesis. This study analyzed MCs and angiogenesis in primary tumour tissue from patients affected by pancreatic ductal adenocarcinoma (PDAC). Method. A series of 31 PDAC patients with stage T_2-3N_0-1M₀ (by AJCC for Pancreas Cancer Staging 7th Edition) was selected and then underwent surgery. Tumour tissue samples were evaluated by means of immunohistochemistry and image analysis methods in terms of number of MCs positive to tryptase (MCDPT), area occupied by MCs positive to tryptase (MCAPT), microvascular density (MVD), and endothelial area (EA). The above parameters were related to each other and to the main clinicopathological features. Results. A significant correlation between MCDPT, MCAPT, MVD, and EA group was found by Pearson's t-test analysis (r ranged from 0.69 to 0.81; P value ranged from 0.001 to 0.003). No other significant correlation was found. Conclusion. Our pilot data suggest that MCs positive to tryptase may play a role in PDAC angiogenesis and they could be further evaluated as a novel tumour biomarker and as a target of antiangiogenic therapy.