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

Tryptase and tumor angiogenesis

Tryptases represent the most abundant constituent of human mast cells, involved in extracellular matrix degradation, contributing to wound healing and metastasis. Moreover, most recently, it has been demonstrated that tryptase is angiogenic both in vitro and in vivo. Tryptase-positive mast cell number increases parallelly with increased microvascular density in both solid and hematological tumors. The objective and the scope of this review article are to emphasize the important role of tryptase as one of the principal effectors of tumor angiogenesis mediated by mast cells. In this context, tryptase inhibitors may be considered a novel therapeutic approach in cancer treatment.

Autotaxin-Lysophosphatidate Axis: Promoter of Cancer Development and Possible Therapeutic Implications

Autotaxin (ATX) is a member of the ectonucleotide pyrophosphate/phosphodiesterase (ENPP) family; it is encoded by the ENPP2 gene. ATX is a secreted glycoprotein and catalyzes the hydrolysis of lysophosphatidylcholine to lysophosphatidic acid (LPA). LPA is responsible for the transduction of various signal pathways through the interaction with at least six G protein-coupled receptors, LPA Receptors 1 to 6 (LPAR1-6). The ATX-LPA axis is involved in various physiological and pathological processes, such as angiogenesis, embryonic development, inflammation, fibrosis, and obesity. However, significant research also reported its connection to carcinogenesis, immune escape, metastasis, tumor microenvironment, cancer stem cells, and therapeutic resistance. Moreover, several studies suggested ATX and LPA as relevant biomarkers and/or therapeutic targets. In this review of the literature, we aimed to deepen knowledge about the role of the ATX-LPA axis as a promoter of cancer development, progression and invasion, and therapeutic resistance. Finally, we explored its potential application as a prognostic/predictive biomarker and therapeutic target for tumor treatment.

Unbiasedly decoding the tumor microenvironment with single-cell multiomics analysis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a poor prognosis and limited therapeutic options. Research on the tumor microenvironment (TME) of PDAC has propelled the development of immunotherapeutic and targeted therapeutic strategies with a promising future. The emergence of single-cell sequencing and mass spectrometry technologies, coupled with spatial omics, has collectively revealed the heterogeneity of the TME from a multiomics perspective, outlined the development trajectories of cell lineages, and revealed important functions of previously underrated myeloid cells and tumor stroma cells. Concurrently, these findings necessitated more refined annotations of biological functions at the cell cluster or single-cell level. Precise identification of all cell clusters is urgently needed to determine whether they have been investigated adequately and to identify target cell clusters with antitumor potential, design compatible treatment strategies, and determine treatment resistance. Here, we summarize recent research on the PDAC TME at the single-cell multiomics level, with an unbiased focus on the functions and potential classification bases of every cellular component within the TME, and look forward to the prospects of integrating single-cell multiomics data and retrospectively reusing bulk sequencing data, hoping to provide new insights into the PDAC TME.

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.

Factors Influencing Marker Expressions of Cultured Human Cord Blood-Derived Mast Cells

Mast cells (MCs) are tissue-resident immune cells of a hematopoietic origin that play vital roles in innate and adaptive immunity. Human MCs can be isolated and differentiated from various tissue sources, including cord blood, when supplemented with cytokines such as stem cell factor, interleukin 3, and interleukin 6. Our current research study has shown significant differences in the marker expressions of human cord blood-derived mast cells (hCBMCs) based on donor dependency and the type of medium used for culturing and differentiation. These findings are particularly relevant given the challenges of obtaining specialty media influencing MC phenotypic marker expressions. We found that hCBMCs cultured in StemSpanTM-XF medium had a moderate expression of mast/stem cell growth factor receptor Kit (c-KIT) (mRNA and protein), low expressions of FcεRI (mRNA) and TLR2 (mRNA and protein) but had high levels of MRGPRX2 (mRNA and protein) expressions. In contrast, hCBMCs cultured in Stem Line II medium expressed FcεRI and TLR2 (mRNA and protein) with higher c-KIT but had lower MRGPRX2 expressions compared to the hCBMCs cultured in the StemSpanTM-XF medium. These results suggest that it is crucial to consider both donor dependency and the medium when investigating MC functions and that further research is needed to fully understand the impact of these factors on the hCBMC marker expressions.

Clinical Updates for Gastrointestinal Malignancies

Gastrointestinal (GI) cancers include hepatobiliary tumors, pancreatic cancer (PC), neuroendocrine tumors of the gastrointestinal tract, small bowel carcinomas, gastric cancer (GC), anal canal cancer, primary gastric and intestinal lymphomas, gastrointestinal stromal tumors (GISTs) and the most frequent colorectal cancer (CRC) [...].

Immunotherapy and Pancreatic Cancer: A Lost Challenge?

Although immunotherapy has proved to be a very efficient therapeutic strategy for many types of tumors, the results for pancreatic cancer (PC) have been very poor. Indeed, chemotherapy remains the standard treatment for this tumor in the advanced stage. Clinical data showed that only a small portion of PC patients with high microsatellite instability/mismatch repair deficiency benefit from immunotherapy. However, the low prevalence of these alterations was not sufficient to lead to a practice change in the treatment strategy of this tumor. The main reasons for the poor efficacy of immunotherapy probably lie in the peculiar features of the pancreatic tumor microenvironment in comparison with other malignancies. In addition, the biomarkers usually evaluated to define immunotherapy efficacy in other cancers appear to be useless in PC. This review aims to describe the main features of the pancreatic tumor microenvironment from an immunological point of view and to summarize the current data on immunotherapy efficacy and immune biomarkers in PC.

Innate immunity in pancreatic cancer: Lineage tracing and function

Increasingly, patients with gastrointestinal tumors can benefit from immunotherapy, but not patients with pancreatic cancer. While this lack of benefit has been attributed to lower T-cell infiltration in pancreatic cancer, other studies have demonstrated the presence of numerous T cells in pancreatic cancer, suggesting another mechanism for the poor efficacy of immunotherapy. Single-cell RNA sequencing studies on the pancreatic cancer immune microenvironment have demonstrated the predominance of innate immune cells (e.g., macrophages, dendritic cells, mast cells, and innate immune lymphoid cells). Therefore, in-depth research on the source and function of innate immune lymphocytes in pancreatic cancer could guide pancreatic cancer immunotherapy.

Focus on mast cells in the tumor microenvironment: Current knowledge and future directions

Mast cells (MCs) are crucial cells participating in both innate and adaptive immune processes that play important roles in protecting human health and in the pathophysiology of various diseases, such as allergies, cardiovascular diseases, and autoimmune diseases. In the context of tumors, MCs are a non-negligible population of immune cells in the tumor microenvironment (TME). In most tumor types, MCs accumulate in both the tumor tissue and the surrounding tissue. MCs interact with multiple components of the TME, affecting TME remodeling and the tumor cell fate. However, controversy persists regarding whether MCs contribute to tumor progression or trigger an anti-tumor immune response. This review focuses on the context of the TME to explore the specific properties and functions of MCs and discusses the crosstalk that occurs between MCs and other components of the TME, which affect tumor angiogenesis and lymphangiogenesis, invasion and metastasis, and tumor immunity through different mechanisms. We also anticipate the potential role of MCs in cancer immunotherapy, which might expand upon the success achieved with existing cancer therapies.

Hypoxia-Regulated Tumor-Derived Exosomes and Tumor Progression: A Focus on Immune Evasion

Tumor cells express a high quantity of exosomes packaged with unique cargos under hypoxia, an important characteristic feature in solid tumors. These hypoxic tumor-derived exosomes are, crucially, involved in the interaction of cancer cells with their microenvironment, facilitating not only immune evasion, but increased cell growth and survival, enhanced angiogenesis, epithelial–mesenchymal transition (EMT), therapeutic resistance, autophagy, pre-metastasis, and metastasis. This paper explores the tumor microenvironment (TME) remodeling effects of hypoxic tumor-derived exosome towards facilitating the tumor progression process, particularly, the modulatory role of these factors on tumor cell immune evasion through suppression of immune cells, expression of surface recognition molecules, and secretion of antitumor soluble factor. Tumor-expressed exosomes educate immune effector cells, including macrophages, monocytes, T cells, natural killer (NK) cells, dendritic cells (DCs), γδ T lymphocytes, regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), mast cells, and B cells, within the hypoxic TME through the release of factors that regulate their recruitment, phenotype, and function. Thus, both hypoxia and tumor-derived exosomes modulate immune cells, growth factors, cytokines, receptor molecules, and other soluble factors, which, together, collaborate to form the immune-suppressive milieu of the tumor environment. Exploring the contribution of exosomal cargos, such as RNAs and proteins, as indispensable players in the cross-talk within the hypoxic tumor microenvironmental provides a potential target for antitumor immunity or subverting immune evasion and enhancing tumor therapies.

Anatabine attenuates ovalbumin-induced asthma via oxidative stress and inflammation mitigation and Nrf2/HO-1 signaling upregulation in rats

AIMS

Asthma affects a large number of people worldwide and is characterized by chronic allergic airway inflammation. Anatabine is a natural alkaloid that is structurally similar to nicotine and found in the Solanaceae family of plants, with anti-inflammatory properties. Consequently, this study aimed to evaluate the potential therapeutic effect of anatabine against asthma.

MAIN METHODS

Ovalbumin was used to induce asthma in rats. Two asthmatic groups were treated with low and high doses of anatabine.

KEY FINDINGS

Asthmatic animals experienced increased total leukocyte count and inflammatory cytokines in bronchoalveolar lavage fluid (BALF), bronchitis, and bronchopneumonia associated with mast cell infiltration. Additionally, inducible nitric oxide synthase immunostaining was observed, with decreased pulmonary antioxidant capacity and enzymes and decreased Nrf2 and HO-1 gene expression while increased NFκB-P65 expression. Interestingly, asthmatic animals treated with anatabine at both doses showed dose-dependently decreased inflammatory cells and cytokine levels within BALF reduced inflammation in the airways through decreased mast cell infiltration within lung tissues and increased antioxidant enzymes and Nrf2 and Ho-1 expression levels.

SIGNIFICANCE

Our results highlight the potential beneficial effect of anatabine against asthma through anti-inflammatory and antioxidant mechanisms. Therefore, anatabine is a promising candidate for pulmonary asthma treatment.

Targeted Therapy for Hepatocellular Carcinoma: Old and New Opportunities

Simple Summary

Hepatocellular carcinoma (HCC) is the most frequent primitive cancer of the liver, accounting for 90% of all recorded cases. HCC is the third most common cause of cancer-related death, with a 5-year survival rate of just 3%. In terms of the advanced stages, systemic treatments have allowed patients to achieve clinical benefits, although the prognosis remains very poor. In the past few decades, new molecular targeted therapies have been developed and clinically evaluated with interesting results. However, on the basis of the poor prognoses and the meager benefits deriving from the available systemic therapies, research into new treatments is extremely necessary. In this review, we focus on the available systemic therapies for advanced HCC, with a look toward the future.

Abstract

Hepatocellular carcinoma (HCC) is the most frequent primitive cancer of the liver, accounting for 90% of all recorded cases. HCC is the third most common cause of cancer-related death, with a 5-year survival rate of just 3%. In the advanced stages, systemic treatments allow doctors to obtain clinical benefits, although the prognosis remains very poor. In the past few decades, new molecular targeted therapies against receptor tyrosine kinases have been developed and clinically evaluated. Sorafenib was the first oral tyrosine kinase inhibitor (TKI) approved for the treatment of advanced HCC in 2007. Subsequently, other TKIs, including Cabozantinib, Regorafenib, Lenvatinib, and vascular endothelial growth factor receptor (VEGFR) inhibitors such as Ramucirumab and VEGF inhibitors such as Bevacizumab have been approved as first- or second-line treatments. More recently, the combination of immune checkpoint inhibitors and VEGF inhibitors (Atezolizumab plus Bevacizumab) have been analyzed and approved for the treatment of advanced HCC. On the basis of the poor prognoses and the meager benefits deriving from the available systemic therapies, research into new treatments is extremely necessary. In this review, we focus on the available systemic therapies for advanced HCC, with a look toward the future.

Targeting the PDGF/PDGFR signaling pathway for cancer therapy: A review

Platelet-derived growth factors (PDGFs) and PDGF receptors (PDGFRs) are expressed in a variety of tumors. Activation of the PDGF/PDGFR signaling pathway is associated with cancer proliferation, metastasis, invasion, and angiogenesis through modulating multiple downstream pathways, including phosphatidylinositol 3 kinase/protein kinase B pathway and mitogen-activated protein kinase/extracellular signal-regulated kinase pathway. Therefore, targeting PDGF/PDGFR signaling pathway has been demonstrated to be an effective strategy for cancer therapy, and accordingly, some great progress has been made in this field in the past few decades. This review will focus on the PDGF isoforms and their binding with the related PDGFRs, the PDGF/PDGFR signaling and regulation, and especially present strategies and inhibitors developed for cancer therapy, and the related clinical benefits and side effects.

A Patient With Stage III Locally Advanced Pancreatic Adenocarcinoma Treated With Intra-Arterial Infusion FOLFIRINOX: Impressive Tumoral Response and Death due to Legionella pneumophila Infection: A Unique Case Report

Patients affected by pancreatic ductal adenocarcinoma (PDAC) have very poor prognosis, whereby at a follow-up of 5 years, the mortality rate is very similar to the incidence rate. Globally, around 10% of patients are amenable to radical surgery at the time of diagnosis, which represents the only chance of cure or long-term survival for these patients. Almost 40% of patients with PDAC show locally advanced pancreatic cancer (LAPC). LAPC is not a metastatic disease, although it is not amenable to radical surgery. For these patients, systemic induction chemotherapy with intravenous FOLFIRINOX (5-fluorouracil, folic acid, irinotecan, oxaliplatin) regimen is administered, with the aim of conversion to surgery, although the conversion rate remains low, at approximately 10% to 15%. Pancreatic arterial chemotherapy has been explored to overcome the intrinsic tumor pancreatic resistance to systemic chemotherapy, where an intra-arterial port-a-cath is placed by means of interventional oncology techniques under angiographic guidance in the operating theater. Here, we treated a patient with an intra-arterially modified FOLFIRINOX regimen. Three courses were administered, and the patient experienced no adverse events. At the end of the third course, the patient rapidly developed lung failure due to nosocomial Legionella pneumophila infection, despite the impressive pathological tumor response shown in the autopsy report. This is a first and unique report that demonstrates that pancreatic intra-arterial FOLFIRINOX can be safe and efficacious. We believe that this preliminary result will be confirmed in the next patients to be enrolled and that it provides a glimmer of hope for patients with this lethal disease.

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.