Soluble IL-33 receptor sST2 inhibits colorectal cancer malignant growth by modifying the tumour microenvironment

The potential impact of RNA splicing abnormalities on immune regulation in endometrial cancer

RNA splicing controls the post-transcriptional level of gene expression, allowing for the synthesis of many transcripts with various configurations and roles. Variations in RNA splicing regulatory factors, including splicing factors, signaling pathways, epigenetic modifications, and environmental factors, are typically the origin of tumor-associated splicing anomalies. Furthermore, thorough literature assessments on the intricate connection between tumor-related splicing dysregulation and tumor immunity are currently lacking. Therefore, we also thoroughly discuss putative targets associated with RNA splicing in endometrial cancer (EC) and the possible impacts of aberrant RNA splicing on the immune control of tumor cells and tumor microenvironment (TME), which contributes to enhancing the utilization of immunotherapy in the management of EC and offers an alternative viewpoint for the exploration of cancer therapies and plausible prognostic indicators.

The periosteum provides a stromal defence against cancer invasion into the bone

The periosteum is the layer of cells that covers nearly the entire surface of every bone. Upon infection, injury or malignancy the bone surface undergoes new growth-the periosteal reaction-but the mechanism and physiological role of this process remain unknown1,2. Here we show that the periosteal reaction protects against cancer invasion into the bone. Histological analyses of human lesions of head and neck squamous cell carcinomas (HNSCCs) show that periosteal thickening occurs in proximity to the tumour. We developed a genetically dissectible mouse model of HNSCC and demonstrate that inducible depletion of periosteal cells accelerates cancerous invasion of the bone. Single-cell RNA sequencing reveals that expression of the gene encoding the protease inhibitor TIMP1 is markedly increased in the periosteum at the pre-invasive stage. This increase is due to upregulation of HIF1α expression in the tumour microenvironment, and increased TIMP1 inactivates matrix-degrading proteases, promoting periosteal thickening to inhibit cancer invasion. Genetic deletion of Timp1 impairs periosteal expansion, exacerbating bone invasion and decreasing survival in tumour-bearing mice. Together, these data show that the periosteal reaction may act as a functional stromal barrier against tumour progression, representing a unique example of tissue immunity mediated by stromal cells.

Unveiling the contribution of tumor-associated macrophages in driving epithelial-mesenchymal transition: a review of mechanisms and therapeutic Strategies

Tumor-associated macrophages (TAMs), fundamental constituents of the tumor microenvironment (TME), significantly influence cancer development, primarily by promoting epithelial-mesenchymal transition (EMT). EMT endows cancer cells with increased motility, invasiveness, and resistance to therapies, marking a pivotal juncture in cancer progression. The review begins with a detailed exposition on the origins of TAMs and their functional heterogeneity, providing a foundational understanding of TAM characteristics. Next, it delves into the specific molecular mechanisms through which TAMs induce EMT, including cytokines, chemokines and stromal cross-talking. Following this, the review explores TAM-induced EMT features in select cancer types with notable EMT characteristics, highlighting recent insights and the impact of TAMs on cancer progression. Finally, the review concludes with a discussion of potential therapeutic targets and strategies aimed at mitigating TAM infiltration and disrupting the EMT signaling network, thereby underscoring the potential of emerging treatments to combat TAM-mediated EMT in cancer. This comprehensive analysis reaffirms the necessity for continued exploration into TAMs' regulatory roles within cancer biology to refine therapeutic approaches and improve patient outcomes.

Colorectal cancer subtyping and prognostic model construction based on interleukin-related genes

Members of the interleukin (IL) family are closely linked to cancer development and progression. However, research on the prognosis of colorectal cancer (CRC) related to IL is still lacking. This study investigated new CRC prognostic markers and offered new insights for CRC prognosis and treatment. CRC-related data and IL gene data were collected from public databases. Sample clustering was done with the NMF package to divide samples into different subtypes. Differential, enrichment, survival, and immune analyses were conducted on subtypes. A prognostic model was constructed using regression analysis. Drug sensitivity analysis was performed using GDSC database. Western blot analysis was performed to assess the effect of IL-7 on the JAK/STAT signaling pathway. Flow cytometry was used to examine the impact of IL-7 on CD8+ T cell apoptosis. Two CRC subtypes based on IL-associated genes were obtained. Cluster 1 had a higher survival rate than cluster 2, and they showed differences in some immune levels. The two clusters were mainly enriched in the JAK-STAT signaling pathway, T helper 17 cell differentiation, and the IL-17 signaling pathway. An 11-gene signature was built, and risk score was an independent prognosticator for CRC. The low-risk group showed a higher sensitivity to nine common targeted anticancer drugs. Western blot and flow cytometry results demonstrated that IL-7 could phosphorylate STAT5 and promote survival of CD8+ T cells. In conclusion, this study divided CRC samples into two IL-associated subtypes and obtained an 11-gene signature. In addition, targeted drugs that may improve the prognosis of patients with CRC were identified. These findings are of paramount importance for patient prognosis and CRC treatment.NEW & NOTEWORTHY We identified two clusters with significant survival differences in colorectal cancer (CRC) based on interleukin-related genes, constructed an 11-gene risk score model that can independently predict the prognosis of CRC, and explored some targeted drugs that may improve the prognosis of patients with CRC. The results of this study have important implications for the prognosis and treatment of CRC.

Interleukin 33 supports squamous cell carcinoma growth via a dual effect on tumour proliferation, migration and invasion, and T cell activation

Interleukin (IL)-33 is an important cytokine in the tumour microenvironment; it is known to promote the growth and metastasis of solid cancers, such as gastric, colorectal, ovarian and breast cancer. Our group demonstrated that the IL-33/ST2 pathway enhances the development of squamous cell carcinoma (SCC). Conversely, other researchers have reported that IL-33 inhibits tumour progression. In addition, the crosstalk between IL-33, cancer cells and immune cells in SCC remains unknown. The aim of this study was to investigate the effect of IL-33 on the biology of head and neck SCC lines and to evaluate the impact of IL-33 neutralisation on the T cell response in a preclinical model of SCC. First, we identified epithelial and peritumoural cells as a major local source of IL-33 in human SCC samples. Next, in vitro experiments demonstrated that the addition of IL-33 significantly increased the proliferative index, motility and invasiveness of SCC-25 cells, and downregulated MYC gene expression in SCC cell lines. Finally, IL-33 blockade significantly delayed SCC growth and led to a marked decrease in the severity of skin lesions. Importantly, anti-IL-33 monoclonal antibody therapy increase the percentage of CD4+IFNγ+ T cells and decreased CD4+ and CD8+ T cells secreting IL-4 in tumour-draining lymph nodes. Together, these data suggest that the IL-33/ST2 pathway may be involved in the crosstalk between the tumour and immune cells by modulating the phenotype of head and neck SCC and T cell activity. IL-33 neutralisation may offer a novel therapeutic strategy for SCC.

Unveiling the immune symphony: decoding colorectal cancer metastasis through immune interactions

Colorectal cancer (CRC), known for its high metastatic potential, remains a leading cause of cancer-related death. This review emphasizes the critical role of immune responses in CRC metastasis, focusing on the interaction between immune cells and tumor microenvironment. We explore how immune cells, through cytokines, chemokines, and growth factors, contribute to the CRC metastasis cascade, underlining the tumor microenvironment's role in shaping immune responses. The review addresses CRC's immune evasion tactics, especially the upregulation of checkpoint inhibitors like PD-1 and CTLA-4, highlighting their potential as therapeutic targets. We also examine advanced immunotherapies, including checkpoint inhibitors and immune cell transplantation, to modify immune responses and enhance treatment outcomes in CRC metastasis. Overall, our analysis offers insights into the interplay between immune molecules and the tumor environment, crucial for developing new treatments to control CRC metastasis and improve patient prognosis, with a specific focus on overcoming immune evasion, a key aspect of this special issue.

Tumor-mesothelium HOXA11-PDGF BB/TGF β1-miR-181a-5p-Egr1 feedforward amplifier circuity propels mesothelial fibrosis and peritoneal metastasis of gastric cancer

A proportion of gastric cancer (GC) patients suffer from peritoneal metastasis (PM) in the late stage of tumor and these patients have a poor prognosis. To provide more care for GC patient with PM, a deeper exploration of the molecular characteristics of GC-PM is needed. Here we performed the in vitro and in vivo study to illustrate the effect of HOXA11 over-expressed GC cells on peritoneal mesothelial cells (HMrSV5), transcriptomics analyses of HMrSV5 cells co-cultured with HOXA11 over-expressed GC cells, counterparts or alone, cytokine array analyses of serum-free culture medium of HOXA11 over-expressed GC cells, we validated our findings through genetic manipulation of HMrSV5 cells and neutralizing antibodies targeting cytokines secreted by HOXA11 over-expressed GC cells in vitro, as well as utilized human peritoneal metastatic lesions to validate expression of potential targets. We identified that HOXA11 over-expressed GC cells strongly propelled mesothelial fibrosis in vivo and in vitro, and HOXA11 regulated paracrine and autocrine of PDGF BB and TGF β1 in GC cells to propel mesothelial fibrosis. Meanwhile, HOXA11 over-expressed GC cells drove PDGF BB and TGF β1 secretion to activate developmental-process related genes in HMrSV5 cells, including Egr1, which processes dependent on miR-181a-5p. Then, Egr1 could mediate peritoneal mesothelial fibrosis. Correspondingly, Egr1 over-expressed HMrSV5 cells supported migration and peritoneal dissemination of GC cells. Together our results suggest that a feedforward amplifier circuity governing GC cells and mesothelial cells in peritoneum contribute to peritoneal metastasis of GC cells.

Colorectal Liver Metastasis: Can Cytokines Make the Difference?

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. Metastasis is the prime driver of CRC-related mortality, and the liver is the organ most frequently involved. Despite the overall success of current treatments, colorectal liver metastasis (CRLM) is associated with poor prognoses and a survival rate of only 14%. Recent studies have highlighted the importance of the tumor microenvironment (TME) and the crosstalk within it in determining the invasion of distant organs by circulating cancer cells. In the TME, cellular communication is mediated via soluble molecules, among which cytokines have recently emerged as key regulators, involved in every aspect of tumor progression and the metastatic cascade. Indeed, in the serum of CRC patients elevated levels of several cytokines are associated with cancer development and progression. The current review evaluates the role of different cytokines during CRLM development. Additionally, considering the increasing amount of data concerning the importance of cytokine complex networks, we outline the potential of combination treatments using targeted cytokines together with other well-established therapies, such as immune checkpoint blockades, chemotherapy, or gene therapy, to improve therapeutic outcomes.

The updates on metastatic mechanism and treatment of colorectal cancer

Colorectal cancer (CRC) is a main cause of cancer death worldwide. Metastasis is a major cause of cancer-related death in CRC. The treatment of metastatic CRC has progressed minimally. However, the potential molecular mechanisms involved in CRC metastasis have remained to be comprehensively clarified. An improved understanding of the CRC mechanistic determinants is needed to better prevent and treat metastatic cancer. In this review, based on evidence from a growing body of research in metastatic cancers, we discuss the cellular and molecular mechanisms involved in CRC metastasis. This review reveals both the molecular mechanisms of metastases and identifies new opportunities for developing more effective strategies to target metastatic relapse and improve CRC patient outcomes.

Biomarkers of aging in frailty and age-associated disorders: State of the art and future perspective

According to the Geroscience concept that organismal aging and age-associated diseases share the same basic molecular mechanisms, the identification of biomarkers of age that can efficiently classify people as biologically older (or younger) than their chronological (i.e. calendar) age is becoming of paramount importance. These people will be in fact at higher (or lower) risk for many different age-associated diseases, including cardiovascular diseases, neurodegeneration, cancer, etc. In turn, patients suffering from these diseases are biologically older than healthy age-matched individuals. Many biomarkers that correlate with age have been described so far. The aim of the present review is to discuss the usefulness of some of these biomarkers (especially soluble, circulating ones) in order to identify frail patients, possibly before the appearance of clinical symptoms, as well as patients at risk for age-associated diseases. An overview of selected biomarkers will be discussed in this regard, in particular we will focus on biomarkers related to metabolic stress response, inflammation, and cell death (in particular in neurodegeneration), all phenomena connected to inflammaging (chronic, low-grade, age-associated inflammation). In the second part of the review, next-generation markers such as extracellular vesicles and their cargos, epigenetic markers and gut microbiota composition, will be discussed. Since recent progresses in omics techniques have allowed an exponential increase in the production of laboratory data also in the field of biomarkers of age, making it difficult to extract biological meaning from the huge mass of available data, Artificial Intelligence (AI) approaches will be discussed as an increasingly important strategy for extracting knowledge from raw data and providing practitioners with actionable information to treat patients.

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

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

Modelling the Tumour Microenvironment, but What Exactly Do We Mean by "Model"?

The Oxford English Dictionary includes 17 definitions for the word "model" as a noun and another 11 as a verb. Therefore, context is necessary to understand the meaning of the word model. For instance, "model railways" refer to replicas of railways and trains at a smaller scale and a "model student" refers to an exemplary individual. In some cases, a specific context, like cancer research, may not be sufficient to provide one specific meaning for model. Even if the context is narrowed, specifically, to research related to the tumour microenvironment, "model" can be understood in a wide variety of ways, from an animal model to a mathematical expression. This paper presents a review of different "models" of the tumour microenvironment, as grouped by different definitions of the word into four categories: model organisms, in vitro models, mathematical models and computational models. Then, the frequencies of different meanings of the word "model" related to the tumour microenvironment are measured from numbers of entries in the MEDLINE database of the United States National Library of Medicine at the National Institutes of Health. The frequencies of the main components of the microenvironment and the organ-related cancers modelled are also assessed quantitatively with specific keywords. Whilst animal models, particularly xenografts and mouse models, are the most commonly used "models", the number of these entries has been slowly decreasing. Mathematical models, as well as prognostic and risk models, follow in frequency, and these have been growing in use.

Hypoxia induces downregulation of the tumor-suppressive sST2 in colorectal cancer cells via the HIF-nuclear IL-33-GATA3 pathway

As a decoy receptor, soluble ST2 (sST2) interferes with the function of the inflammatory cytokine interleukin (IL)-33. Decreased sST2 expression in colorectal cancer (CRC) cells promotes tumor growth via IL-33-mediated bioprocesses in the tumor microenvironment. In this study, we discovered that hypoxia reduced sST2 expression in CRC cells and explored the associated molecular mechanisms, including the expression of key regulators of ST2 gene transcription in hypoxic CRC cells. In addition, the effect of the recovery of sST2 expression in hypoxic tumor regions on malignant progression was investigated using mouse CRC cells engineered to express sST2 in response to hypoxia. Our results indicated that hypoxia-dependent increases in nuclear IL-33 interfered with the transactivation activity of GATA3 for ST2 gene transcription. Most importantly, hypoxia-responsive sST2 restoration in hypoxic tumor regions corrected the inflammatory microenvironment and suppressed tumor growth and lung metastasis. These results indicate that strategies targeting sST2 in hypoxic tumor regions could be effective for treating malignant CRC.

Interleukin-33 Mediates Cardiomyopathy After Acute Kidney Injury by Signaling to Cardiomyocytes

BACKGROUND

Acute kidney injury (AKI) is a short-term life-threatening condition that, if survived, can lead to renal insufficiency and development of chronic kidney disease. The pathogenesis of AKI and chronic kidney disease involves direct effects on the heart and the development of hypertrophy and cardiomyopathy.

METHODS

We used mouse models of ischemia/reperfusion AKI and unilateral ureteral obstruction to investigate the role of IL-33 (interleukin-33) and its receptor-encoding gene Il1rl1 (also called ST2L [suppression of tumorigenicity 2]) in cardiac remodeling after AKI. Mice with cell type-specific genetic disruption of the IL-33/ST2L axis were used, and IL-33 monoclonal antibody, adeno-associated virus encoding IL-33 or ST2L, and recombinant IL-33, as well.

RESULTS

Mice deficient in Il33 were refractory to cardiomyopathy associated with 2 models of kidney injury. Treatment of mice with monoclonal IL-33 antibody also protected the heart after AKI. Moreover, overexpression of IL-33 or injection of recombinant IL-33 induced cardiac hypertrophy or cardiomyopathy, but not in mice lacking Il1rl1. AKI-induced cardiomyopathy was also reduced in mice with cardiac myocyte-specific deletion of Il1rl1 but not in endothelial cell- or fibroblast-specific deletion of Il1rl1. Last, overexpression of the ST2L receptor in cardiac myocytes recapitulated induction of cardiac hypertrophy.

CONCLUSIONS

These results indicate that IL-33 released from the kidney during AKI underlies cardiorenal syndrome by directly signaling to cardiac myocytes, suggesting that antagonism of IL-33/ST2 axis would be cardioprotective in patients with kidney disease.

Dual Immune Regulatory Roles of Interleukin-33 in Pathological Conditions

Interleukin-33 (IL-33), a member of the IL-1 cytokine family and a multifunctional cytokine, plays critical roles in maintaining host homeostasis and in pathological conditions, such as allergy, infectious diseases, and cancer, by acting on multiple types of immune cells and promoting type 1 and 2 immune responses. IL-33 is rapidly released by immune and non-immune cells upon stimulation by stress, acting as an “alarmin” by binding to its receptor, suppression of tumorigenicity 2 (ST2), to trigger downstream signaling pathways and activate inflammatory and immune responses. It has been recognized that IL-33 displays dual-functioning immune regulatory effects in many diseases and has both pro- and anti-tumorigenic effects, likely depending on its primary target cells, IL-33/sST2 expression levels, cellular context, and the cytokine microenvironment. Herein, we summarize our current understanding of the biological functions of IL-33 and its roles in the pathogenesis of various conditions, including inflammatory and autoimmune diseases, infections, cancers, and cases of organ transplantation. We emphasize the nature of context-dependent dual immune regulatory functions of IL-33 in many cells and diseases and review systemic studies to understand the distinct roles of IL-33 in different cells, which is essential to the development of more effective diagnoses and therapeutic approaches for IL-33-related diseases.

Human differentiated eosinophils release IL-13 in response to IL-33 stimulation

Objective

Eosinophils are hallmarks in allergic type 2 inflammation and are known to release cytotoxic granule proteins that contribute to inflammation. Eosinophils develop in the bone marrow from hematopoietic stem cells and once mature, have a limited lifespan in culture, making them difficult to study ex vivo. IL-33 has increasingly been shown as a key regulator of type 2 inflammation via signaling through its receptor, ST2. The present study was conducted to detail a method of eosinophil differentiation from hematopoietic stem cells and determine the response to IL-33.

Methods

CD34+ and CD14+ cells were isolated from donor apheresis cones and differentiated into eosinophils or macrophage controls, respectively. Morphologic, transcriptional and protein analyses were performed to validate this method of eosinophil differentiation. The effect of IL-33 on differentiated eosinophils was assessed using qPCR, immunofluorescence, and multiplex cytokine array.

Results

CD34 differentiated eosinophils appear morphologically similar by H&E and express eosinophil peroxidase (EPX) protein as well as the conventional eosinophil transcripts EPX, CLC, and MBP. In addition, differentiated eosinophils expressed both isoforms of the IL-33 receptor, ST2L and sST2 throughout the differentiation process. Transcript levels of both IL-33 receptors were up-regulated by treatment with IL-33 at earlier timepoints in the differentiation. These cells also expressed IL-4 and IL-13 mRNA which were up-regulated by IL-33 as well. Notably, IL-13 expression was significantly higher with IL-33 treatment compared to media control at every timepoint measured. IL-33 significantly increased cellular secretion of IL-13 protein at most timepoints throughout differentiation. IL-8, LIF, CCL1, CCL5, CCL7, and CCL8 were also significantly secreted after IL-33 stimulation.

Conclusions

Our findings suggest that CD34 differentiated eosinophils are morphologically and phenotypically similar to peripheral eosinophils. The release of specific cytokines in direct response to IL-33 may contribute to the pathogenesis of type 2 inflammation and facilitates new avenues for studying eosinophils as effector cells in vitro.

Cytokine- and chemokine-induced inflammatory colorectal tumor microenvironment: Emerging avenue for targeted therapy

Colorectal cancer (CRC) is a predominant life-threatening cancer, with liver and peritoneal metastases as the primary causes of death. Intestinal inflammation, a known CRC risk factor, nurtures a local inflammatory environment enriched with tumor cells, endothelial cells, immune cells, cancer-associated fibroblasts, immunosuppressive cells, and secretory growth factors. The complex interactions of aberrantly expressed cytokines, chemokines, growth factors, and matrix-remodeling enzymes promote CRC pathogenesis and evoke systemic responses that affect disease outcomes. Mounting evidence suggests that these cytokines and chemokines play a role in the progression of CRC through immunosuppression and modulation of the tumor microenvironment, which is partly achieved by the recruitment of immunosuppressive cells. These cells impart features such as cancer stem cell-like properties, drug resistance, invasion, and formation of the premetastatic niche in distant organs, promoting metastasis and aggressive CRC growth. A deeper understanding of the cytokine- and chemokine-mediated signaling networks that link tumor progression and metastasis will provide insights into the mechanistic details of disease aggressiveness and facilitate the development of novel therapeutics for CRC. Here, we summarized the current knowledge of cytokine- and chemokine-mediated crosstalk in the inflammatory tumor microenvironment, which drives immunosuppression, resistance to therapeutics, and metastasis during CRC progression. We also outlined the potential of this crosstalk as a novel therapeutic target for CRC. The major cytokine/chemokine pathways involved in cancer immunotherapy are also discussed in this review.

Signaling and functions of interleukin-33 in immune regulation and diseases

Interleukin-33 (IL-33) which belongs to the interleukin-1 (IL-1) family is an alarmin cytokine with critical roles in tissue homeostasis, pathogenic infection, inflammation, allergy and type 2 immunity. IL-33 transmits signals through its receptor IL-33R (also called ST2) which is expressed on the surface of T helper 2 (Th2) cells and group 2 innate lymphoid cells (ILC2s), thus inducing transcription of Th2-associated cytokine genes and host defense against pathogens. Moreover, the IL-33/IL-33R axis is also involved in development of multiple types of immune-related diseases. In this review, we focus on current progress on IL-33-trigggered signaling events, the important functions of IL-33/IL-33R axis in health and diseases as well as the promising therapeutic implications of these findings.

IL-33 biology in cancer: An update and future perspectives

Interleukin-33 (IL-33) is a member of the IL-1 family of cytokines that is constitutively expressed in the nucleus of epithelial, endothelial and fibroblast-like cells. Upon cell stress, damage or necrosis, IL-33 is released into the cytoplasm to exert its prime role as an alarmin by binding to its specific receptor moiety, ST2. IL-33 exhibits pleiotropic function in inflammatory diseases and particularly in cancer. IL-33 may play a dual role as both a pro-tumorigenic and anti-tumorigenic cytokine, dependent on tumor and cellular context, expression levels, bioactivity and the nature of the inflammatory environment. In this review, we discuss the differential contribution of IL-33 to malignant or inflammatory conditions, its multifaceted effects on the tumor microenvironment, while providing possible explanations for the discrepant findings described in the literature. Additionally, we examine the emerging and divergent functions of IL-33 in the nucleus, and aspects of IL-33 biology that are currently under-addressed.

Bidirectional Relationship Between Cancer and Heart Failure: Insights on Circulating Biomarkers

Cancer and heart failure are the two leading causes of death in developed countries. These two apparently distinct clinical entities share similar risk factors, symptoms, and pathophysiological mechanisms (inflammation, metabolic disturbances, neuro-hormonal and immune system activation, and endothelial dysfunction). Beyond the well-known cardiotoxic effects of oncological therapies, cancer and heart failure are thought to be tied by a bidirectional relationship, where one disease favors the other and vice versa. In this context, biomarkers represent a simple, reproducible, sensitive and cost-effective method to explore such relationship. In this review, we recapitulate the evidence on cardiovascular and oncological biomarkers in the field of cardioncology, focusing on their role in treatment-naïve cancer patients. Cardioncological biomarkers are useful tools in risk stratification, early detection of cardiotoxicity, follow-up, and prognostic assessment. Intriguingly, these biomarkers might contribute to better understand the common pathophysiology of cancer and heart failure, thus allowing the implementation of preventive and treatment strategies in cardioncological patients

Role of ILC2s in Solid Tumors: Facilitate or Inhibit?

Group 2 innate lymphoid cells (ILC2s) are important mediators of type 2 immunity and play an important role in allergic diseases, helminth infections, and tissue fibrosis. However, the role of ILC2s in tumor immunity requires further elucidation. Studies over the past decade have reported that ILC2s play a promoting or suppressing role in different tumors. Here we reviewed the role of ILC2s in solid tumors demonstrating that ILC2s act as a crucial regulator in tumor immunity. We proposed that ILC2s could be an important predictor for tumor prognosis and a new therapeutic target after immunotherapy resistance. In conclusion, our study shed new light on modifying and targeting ILC2s for anti-tumor immunotherapy.

IL-33 promotes gastric tumour growth in concert with activation and recruitment of inflammatory myeloid cells

Interleukin-33 (IL-33) is an IL-1 family cytokine known to promote T-helper (Th) type 2 immune responses that are often deregulated in gastric cancer (GC). IL-33 is overexpressed in human gastric tumours suggesting a role in driving GC progression although a causal link has not been proven. Here, we investigated the impact of IL-33 genetic deficiency in the well-characterized gp130^F/F mouse model of GC. Expression of IL-33 (and it’s cognate receptor, ST2) was increased in human and mouse GC progression. IL-33 deficient gp130^F/F/Il33^−/− mice had reduced gastric tumour growth and reduced recruitment of pro-tumorigenic myeloid cells including key mast cell subsets and type-2 (M2) macrophages. Cell sorting of gastric tumours revealed that IL-33 chiefly localized to gastric (tumour) epithelial cells and was absent from tumour-infiltrating immune cells (except modest IL-33 enrichment within CD11b⁺ CX3CR1⁺CD64⁺MHCII⁺ macrophages). By contrast, ST2 was absent from gastric epithelial cells and localized exclusively within the (non-macrophage) immune cell fraction together with mast cell markers, Mcpt1 and Mcpt2. Collectively, we show that IL-33 is required for gastric tumour growth and provide evidence of a likely mechanism by which gastric epithelial-derived IL-33 drives mobilization of tumour-promoting inflammatory myeloid cells.

Roles for macrophage-polarizing interleukins in cancer immunity and immunotherapy

Macrophages are the most abundant and one of the most critical cells of tumor immunity. They provide a bridge between innate and adaptive immunity through releasing cytokines into the tumor microenvironment (TME). A number of interleukin (IL) cytokine family members is involved in shaping the final phenotype of macrophages toward either a classically-activated pro-inflammatory M1 state with anti-tumor activity or an alternatively-activated anti-inflammatory M2 state with pro-tumor activity. Shaping TME macrophages toward the M1 phenotype or recovering this phenotypic state may offer a promising therapeutic approach in patients with cancer. Here, we focus on the impact of macrophage-polarizing ILs on immune cells and IL-mediated cellular cross-interactions within the TME. The key aim of this review is to define therapeutic schedules for addressing ILs in cancer immunotherapy based on their multi-directional impacts in such a milieu. Gathering more knowledge on this area is also important for defining adverse effects related to cytokine therapy and addressing them for reinforcing the efficacy of immunotherapy against cancer.

Role of Cytokines and Chemokines in Angiogenesis in a Tumor Context

Simple Summary

Tumor growth in solid cancers requires adequate nutrient and oxygen supply, provided by blood vessels created by angiogenesis. Numerous studies have demonstrated that this mechanism plays a crucial role in cancer development and appears to be a well-defined hallmark of cancer. This process is carefully regulated, notably by cytokines with pro-angiogenic or anti-angiogenic features. In this review, we will discuss the role of cytokines in the modulation of angiogenesis. In addition, we will summarize the therapeutic approaches based on cytokine modulation and their clinical approval.

Abstract

During carcinogenesis, tumors set various mechanisms to help support their development. Angiogenesis is a crucial process for cancer development as it drives the creation of blood vessels within the tumor. These newly formed blood vessels insure the supply of oxygen and nutrients to the tumor, helping its growth. The main factors that regulate angiogenesis are the five members of the vascular endothelial growth factor (VEGF) family. Angiogenesis is a hallmark of cancer and has been the target of new therapies this past few years. However, angiogenesis is a complex phenomenon with many redundancy pathways that ensure its maintenance. In this review, we will first describe the consecutive steps forming angiogenesis, as well as its classical regulators. We will then discuss how the cytokines and chemokines present in the tumor microenvironment can induce or block angiogenesis. Finally, we will focus on the therapeutic arsenal targeting angiogenesis in cancer and the challenges they have to overcome.

[METTL27 is a prognostic biomarker of colon cancer and associated with immune invasion]

OBJECTIVE

To investigate the expression and gene function of methyltransferase-like protein 27 (METTL27) in colon cancer, its association with immune infiltration and its prognostic significance.

METHODS

We analyzed the expression levels of METTL27 in 33 cancers using R language and identified METTL27 as a differential gene in colon cancer. The related signaling pathways of METTL27 were analyzed by gene functional annotation and enrichment. SsGSEA algorithm was used to analyze immune infiltration, and logistic analysis was used to evaluate the correlation between METTL27 expression and clinicopathological features of the patients. Kaplan-meier analysis, univariate and multivariate Cox regression analysis were performed to construct a nomogram for evaluating the correlation between METTL27 expression and clinical prognosis. The expression level of METTL27 was further verified in colorectal cancer cell lines and 16 clinical specimens of colorectal cancer tissues using qPCR and Western blotting.

RESULTS

METTL27 was highly expressed in 21 cancers, and its expression was significantly higher in colon cancer than in adjacent tissues (P < 0.001). METTL27-related genes were identified by differential analysis, and functional annotation revealed that METTL27 was significantly enriched in transmembrane transport and lipid metabolism, and 5 related signaling pathways were identified by GSEA. METTL27 expression was negatively correlated with different T helper cells and central memory T cells (P < 0.001). The patients with a high METTL27 mRNA expression had a poor survival outcome. Cox regression analysis showed that METTL27 expression was an independent prognostic factor of the overall survival. The expression level of METTL27 was significantly higher in the colorectal cancer cell line than in normal cells (P < 0.05).

CONCLUSION

METTL27 is overexpressed in colon cancer and is associated with a poor prognosis of the patients. A high expression of METTL27 showed is associated less T cell immune infiltration, suggesting the potential of METTL27 as a prognostic marker of colon cancer.

Alternative Splicing in Cancer and Immune Cells

Splicing is a phenomenon enabling the excision of introns from pre-mRNA to give rise to mature mRNA. All the 20,000 genes of the human genome are concerned by this mechanism. Nevertheless, it is estimated that the proteome is composed of more than 100,000 proteins. How to go from 20,000 genes to more than 100,000 proteins? Alternative splicing (AS) is in charge of this diversity of proteins. AS which is found in most of the cells of an organism, participates in normal cells and in particular in immune cells, in the regulation of cellular behavior. In cancer, AS is highly dysregulated and involved in almost all of the hallmarks that characterize tumor cells. In view of the close link that exists between tumors and the immune system, we present in this review the literature relating to alternative splicing and immunotherapy. We also provide a global but not exhaustive view of AS in the immune system and tumor cells linked to the events that can lead to AS dysregulation in tumors.

Intestinal IL-33 promotes platelet activity for neutrophil recruitment during acute inflammation

Peripheral serotonin (5-HT) is mainly generated from the gastrointestinal tract and taken up and stored by platelets in the circulation. Although the gut is recognized as a major immune organ, how intestinal local immune responses control whole-body physiology via 5-HT remains unclear. Here, we show that intestinal inflammation enhances systemic platelet activation and blood coagulation. Intestinal epithelium damage induces elevated levels of the alarm cytokine interleukin-33 (IL-33), leading to platelet activation via promotion of gut-derived 5-HT release. More importantly, we found that loss of intestinal epithelial-derived IL-33 lowers peripheral 5-HT levels, resulting in compromised platelet activation and hemostasis. Functionally, intestinal IL-33 contributes to the recruitment of neutrophils to sites of acute inflammation by enhancing platelet activities. Genetic deletion of intestinal IL-33 or neutralization of peripheral IL-33 protects animals from lipopolysaccharide endotoxic shock through attenuated neutrophil extravasation. Therefore, our data establish a distinct role of intestinal IL-33 in activating platelets by promoting 5-HT release for systemic physiology and inflammation.

Circulating Levels of the Cardiovascular Biomarkers ST2 and Adrenomedullin Predict Outcome within a Randomized Phase III Lung Cancer Trial (RASTEN)

Cardiovascular comorbidity is common in small cell lung cancer (SCLC) and may significantly affect treatment tolerability and patient outcome. Still, there are no established biomarkers for objective and dynamic assessment as a tool for improved treatment decisions. We have investigated circulating levels of midregional-pro-adrenomedullin (MR-proADM), midregional-pro-atrial-natriuretic peptide (MR-proANP), copeptin (surrogate for vasopressin) and suppression-of-tumorigenicity-2 (ST2), all known to correlate with various aspects of cardiovascular function, in a SCLC cohort (N = 252) from a randomized, controlled trial (RASTEN). For all measured biomarkers, protein levels were inversely associated with survival, particularly with ST2 and MR-proADM, where the top versus bottom quartile was associated with an adjusted hazard ratio of 2.40 (95% CI 1.44−3.98; p = 0.001) and 2.18 (95% CI 1.35−3.51; p = 0.001), respectively, in the entire cohort, and 3.43 (95% CI 1.73−6.79; p < 0.001) and 3.49 (95% CI 1.84−6.60; p < 0.001), respectively, in extensive disease patients. A high combined score of MR-proADM and ST2 was associated with a significantly reduced median OS of 7.0 months vs. 14.9 months for patients with a low combined score. We conclude that the cardiovascular biomarkers MR-proADM and ST2 strongly correlate with survival in SCLC, warranting prospective studies on the clinical utility of MR-proADM and ST2 for improved, individualized treatment decisions.

Functional and Therapeutic Significance of Tumor-Associated Macrophages in Colorectal Cancer

The role of the tumor microenvironment (TME) in the progression of colorectal cancer (CRC) and its acquisition of resistance to treatment become the research hotspots. As an important component of TME, the tumor-associated macrophages (TAMs) regulate multiple critical oncogenic processes, namely, occurrence, proliferation, metastasis, and drug resistance in CRC. In this review, we have discussed the functional and therapeutic significance of TAMs in CRC. M1 macrophages act as the tumor suppressor while M2 macrophages promote CRC. The polarization of TAMs is mainly regulated by the pathways such as NFKB1 pathways, STAT3 pathways, WNT5A pathways, and PI3K pathways in CRC. Furthermore, the M2 polarization of TAMs is not only controllable but also reversible. Finally, we provide insights into the TAMs-targeted therapeutic strategies.

Paradoxical role of interleukin-33/suppressor of tumorigenicity 2 in colorectal carcinogenesis: Progress and therapeutic potential

Colorectal cancer (CRC) is presently the second most prevalent global mortality-inducing cancer. CRC carcinogenesis is a multifactorial process involving internal genetic mutations and the external environment. In addition, non-neoplastic cell activities within tumor microenvironments for CRC development have been established. However, interleukin (IL)-33, secreted by such cell types, plays a pivotal role in cancer progression due to interaction with cellular constituents within the tumor-inflammation microenvironment. IL-33 belongs to the IL-1 cytokine family and acts as binding attachments for the suppressor of tumorigenicity (ST)2 receptor. Therefore, how to coordinate tumor microenvironment, design and optimize treatment strategies suitable for CRC, based on IL-33/ST2 signal is a challenge. Even though it has established influences upon immunity-linked conditions, IL-33 effects on CRC progression and prevention and related mechanisms are still controversial. Our review depicts controversial activities for IL-33/ST2 within carcinogenesis and cancer prevention. Moreover, IL-33/ST2 signaling is a potential therapeutic target for CRC.

The role of alternative splicing in human cancer progression

In eukaryotes, alternative splicing refers to a process via which a single precursor RNA (pre-RNA) is transcribed into different mature RNAs. Thus, alternative splicing enables the translation of a limited number of coding genes into a large number of proteins with different functions. Although, alternative splicing is common in normal cells, it also plays an important role in cancer development. Alteration in splicing mechanisms and even the participation of non-coding RNAs may cause changes in the splicing patterns of cancer-related genes. This article reviews the latest research on alternative splicing in cancer, with a view to presenting new strategies and guiding future studies related to pathological mechanisms associated with cancer.

Serum soluble suppression of tumorigenicity 2 as a novel inflammatory marker predicts the severity of acute pancreatitis

BACKGROUND

Acute pancreatitis (AP) is an inflammatory disease in which the regulatory pathway is complex and not well understood. Soluble suppression of tumorigenicity 2 (sST2) protein receptor functions as a decoy receptor for interleukin (IL)-33 to prevent IL-33/suppression of tumorigenicity 2L (ST2L)-pathway-mediated T helper (Th)2 immune responses.

AIM

To investigate the role of sST2 in AP.

METHODS

We assessed the association between sST2 and severity of AP in 123 patients enrolled in this study. The serum levels of sST2, C-reactive protein (CRP) and Th1- and Th2-related cytokines, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-2, IL-4, IL-5 and IL-13, were measured by highly sensitive ELISA, and the severity of AP in patients was evaluated by the 2012 Atlanta Classification Criteria.

RESULTS

Serum sST2 levels were significantly increased in AP patients, and further, these levels were significantly elevated in severe AP (SAP) patients compared to moderately severe AP (MSAP) and mild AP (MAP) patients. Logistic regression showed sST2 was a predictor of SAP [odds ratio (OR): 1.003 (1.001–1.006), P = 0.000]. sST2 cutoff point was 1190 pg/mL, and sST2 above this cutoff was associated with SAP. sST2 was also a predictor of any organ failure and mortality during AP [OR: 1.006 (1.003–1.009), P = 0.000, OR: 1.002 (1.001–1.004), P = 0.012, respectively]. Additionally, the Th1-related cytokines IFN-γ and TNF-α in the SAP group were higher and the Th2-related cytokine IL-4 in the SAP group was significantly lower than those in MSAP and MAP groups.

CONCLUSION

sST2 may be used as a novel inflammatory marker in predicting AP severity and may regulate the function and differentiation of IL-33/ST2-mediated Th1 and Th2 Lymphocytes in AP homeostasis.

Intercellular transfer of mitochondrial DNA carrying metastasis-enhancing pathogenic mutations from high- to low-metastatic tumor cells and stromal cells via extracellular vesicles

Background

Mitochondrial DNA (mtDNA) carrying certain pathogenic mutations or single nucleotide variants (SNVs) enhances the invasion and metastasis of tumor cells, and some of these mutations are homoplasmic in tumor cells and even in tumor tissues. On the other hand, intercellular transfer of mitochondria and cellular components via extracellular vesicles (EVs) and tunneling nanotubes (TNTs) has recently attracted intense attention in terms of cell-to-cell communication in the tumor microenvironment. It remains unclear whether metastasis-enhancing pathogenic mutant mtDNA in tumor cells is intercellularly transferred between tumor cells and stromal cells. In this study, we investigated whether mtDNA with the NADH dehydrogenase subunit 6 (ND6) G13997A pathogenic mutation in highly metastatic cells can be horizontally transferred to low-metastatic cells and stromal cells in the tumor microenvironment.

Results

When MitoTracker Deep Red-labeled high-metastatic Lewis lung carcinoma A11 cells carrying the ND6 G13997A mtDNA mutation were cocultured with CellLight mitochondria-GFP-labeled low-metastatic P29 cells harboring wild-type mtDNA, bidirectional transfer of red- and green-colored vesicles, probably mitochondria-related EVs, was observed in a time-dependent manner. Similarly, intercellular transfer of mitochondria-related EVs occurred between A11 cells and α-smooth muscle actin (α-SMA)-positive cancer-associated fibroblasts (CAFs, WA-mFib), macrophages (RAW264.7) and cytotoxic T cells (CTLL-2). Intercellular transfer was suppressed by inhibitors of EV release. The large and small EV fractions (L-EV and S-EV, respectively) prepared from the conditioned medium by differential ultracentrifugation both were found to contain mtDNA, although only S-EVs were efficiently incorporated into the cells. Several subpopulations had evidence of LC3-II and contained degenerated mitochondrial components in the S-EV fraction, signaling to the existence of autophagy-related S-EVs. Interestingly, the S-EV fraction contained a MitoTracker-positive subpopulation, which was inhibited by the respiration inhibitor antimycin A, indicating the presence of mitochondria with membrane potential. It was also demonstrated that mtDNA was transferred into mtDNA-less ρ⁰ cells after coculture with the S-EV fraction. In syngeneic mouse subcutaneous tumors formed by a mixture of A11 and P29 cells, the mitochondria-related EVs released from A11 cells reached distantly positioned P29 cells and CAFs.

Conclusions

These results suggest that metastasis-enhancing pathogenic mtDNA derived from metastatic tumor cells is transferred to low-metastatic tumor cells and stromal cells via S-EVs in vitro and in the tumor microenvironment, inferring a novel mechanism of enhancement of metastatic potential during tumor progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-021-00391-5.

Targeting cancer stem cells in medulloblastoma by inhibiting AMBRA1 dual function in autophagy and STAT3 signalling

Medulloblastoma (MB) is a childhood malignant brain tumour comprising four main subgroups characterized by different genetic alterations and rate of mortality. Among MB subgroups, patients with enhanced levels of the c-MYC oncogene (MB_Group3) have the poorest prognosis. Here we identify a previously unrecognized role of the pro-autophagy factor AMBRA1 in regulating MB. We demonstrate that AMBRA1 expression depends on c-MYC levels and correlates with Group 3 patient poor prognosis; also, knockdown of AMBRA1 reduces MB stem potential, growth and migration of MB_Group3 stem cells. At a molecular level, AMBRA1 mediates these effects by suppressing SOCS3, an inhibitor of STAT3 activation. Importantly, pharmacological inhibition of autophagy profoundly affects both stem and invasion potential of MB_Group3 stem cells, and a combined anti-autophagy and anti-STAT3 approach impacts the MB_Group3 outcome. Taken together, our data support the c-MYC/AMBRA1/STAT3 axis as a strong oncogenic signalling pathway with significance for both patient stratification strategies and targeted treatments of MB_Group3.

Macrophages, as a Promising Strategy to Targeted Treatment for Colorectal Cancer Metastasis in Tumor Immune Microenvironment

The tumor immune microenvironment plays a vital role in the metastasis of colorectal cancer. As one of the most important immune cells, macrophages act as phagocytes, patrol the surroundings of tissues, and remove invading pathogens and cell debris to maintain tissue homeostasis. Significantly, macrophages have a characteristic of high plasticity and can be classified into different subtypes according to the different functions, which can undergo reciprocal phenotypic switching induced by different types of molecules and signaling pathways. Macrophages regulate the development and metastatic potential of colorectal cancer by changing the tumor immune microenvironment. In tumor tissues, the tumor-associated macrophages usually play a tumor-promoting role in the tumor immune microenvironment, and they are also associated with poor prognosis. This paper reviews the mechanisms and stimulating factors of macrophages in the process of colorectal cancer metastasis and intends to indicate that targeting macrophages may be a promising strategy in colorectal cancer treatment.

The Janus Face of IL-33 Signaling in Tumor Development and Immune Escape

Simple Summary

Interleukin-33 (IL-33) is often released from damaged cells, acting as a danger signal. IL-33 exerts its function by interacting with its receptor suppression of tumorigenicity 2 (ST2) that is constitutively expressed on most immune cells. Therefore, IL-33/ST2 signaling can modulate immune responses to participate actively in a variety of pathological conditions, such as cancer. Like a two-faced Janus, which faces opposite directions, IL-33/ST2 signaling may play contradictory roles on its impact on cancer progression through both immune and nonimmune cellular components. Accumulating evidence demonstrates both pro- and anti-tumorigenic properties of IL-33, depending on the complex nature of different tumor immune microenvironments. We summarize and discuss the most recent studies on the contradictory effects of IL-33 on cancer progression and treatment, with a goal to better understanding the various ways for IL-33 as a therapeutic target.

Abstract

Interleukin-33 (IL-33), a member of the IL-1 cytokine family, plays a critical role in maintaining tissue homeostasis as well as pathological conditions, such as allergy, infectious disease, and cancer, by promoting type 1 and 2 immune responses. Through its specific receptor ST2, IL-33 exerts multifaceted functions through the activation of diverse intracellular signaling pathways. ST2 is expressed in different types of immune cells, including Th2 cells, Th1 cells, CD8⁺ T cells, regulatory T cells (T_reg), cytotoxic NK cells, group 2 innate lymphoid cells (ILC2s), and myeloid cells. During cancer initiation and progression, the aberrant regulation of the IL-33/ST2 axis in the tumor microenvironment (TME) extrinsically and intrinsically mediates immune editing via modulation of both innate and adaptive immune cell components. The summarized results in this review suggest that IL-33 exerts dual-functioning, pro- as well as anti-tumorigenic effects depending on the tumor type, expression levels, cellular context, and cytokine milieu. A better understanding of the distinct roles of IL-33 in epithelial, stromal, and immune cell compartments will benefit the development of a targeting strategy for this IL-33/ST2 axis for cancer immunotherapy.

Interference of LPS H. pylori with IL-33-Driven Regeneration of Caviae porcellus Primary Gastric Epithelial Cells and Fibroblasts

Background: Lipopolysaccharide (LPS) of Helicobacter pylori (Hp) bacteria causes disintegration of gastric tissue cells in vitro. It has been suggested that interleukin (IL)-33 is involved in healing gastric injury. Aim: To elucidate whether Hp LPS affects regeneration of gastric barrier initiated by IL-33. Methods: Primary gastric epithelial cells or fibroblasts from Caviae porcellus were transfected with siRNA IL-33. Such cells, not exposed or treated with LPS Hp, were sub-cultured in the medium with or without exogenous IL-33. Then cell migration was assessed in conjunction with oxidative stress and apoptosis, activation of extracellular signal-regulated kinase (Erk), production of collagen I and soluble ST2 (IL-33 decoy). Results: Control cells not treated with LPS Hp migrated in the presence of IL-33. The pro-regenerative activity of IL-33 was related to stimulation of cells to collagen I production. Wound healing by cells exposed to LPS Hp was inhibited even in the presence of IL-33. This could be due to increased oxidative stress and apoptosis in conjunction with Erk activation, sST2 elevation and modulation of collagen I production. Conclusions: The recovery of gastric barrier cells during Hp infection potentially can be affected due to downregulation of pro-regenerative activity of IL-33 by LPS Hp.

The Tumor Microenvironment in SCC: Mechanisms and Therapeutic Opportunities

Squamous cell carcinoma (SCC) is the second most common skin cancer worldwide and, despite the relatively easy visualization of the tumor in the clinic, a sizeable number of SCC patients are diagnosed at advanced stages with local invasion and distant metastatic lesions. In the last decade, immunotherapy has emerged as the fourth pillar in cancer therapy via the targeting of immune checkpoint molecules such as programmed cell-death protein-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). FDA-approved monoclonal antibodies directed against these immune targets have provide survival benefit in a growing list of cancer types. Currently, there are two immunotherapy drugs available for cutaneous SCC: cemiplimab and pembrolizumab; both monoclonal antibodies (mAb) that block PD-1 thereby promoting T-cell activation and/or function. However, the success rate of these checkpoint inhibitors currently remains around 50%, which means that half of the patients with advanced SCC experience no benefit from this treatment. This review will highlight the mechanisms by which the immune checkpoint molecules regulate the tumor microenvironment (TME), as well as the ongoing clinical trials that are employing single or combinatory therapeutic approaches for SCC immunotherapy. We also discuss the regulation of additional pathways that might promote superior therapeutic efficacy, and consequently provide increased survival for those patients that do not benefit from the current checkpoint inhibitor therapies.

Increased IL-33 and IL-17 in Colorectal Carcinoma Patients with Severe Disease

Colorectal cancer (CRC) represents one of the most common cancers. It is frequently diagnosed at advanced stages, indicating on need for new diagnostic markers. The aim of this study was to determine systemic and fecal values of IL-17 and IL-33 in patients with CRC and the relationship with clinicopathological aspects of disease.

The blood samples and feces liquid fraction of 50 patients with CRC were analyzed. Serum and fecal levels of IL-33 and IL-17 were measured using sensitive enzyme-linked immunosorbent assay (ELISA) kits.

Fecal levels of Il-33 and IL-17 were increased in CRC patients with poor tumor tissue differentiation. Serum IL-33 and fecal IL-17 were increased in patients with presence of lung/liver metastasis or peritoneal carcinomatosis, respectively, while enhanced fecal IL-33 was detected only in patients with peritoneal carcinomatosis.

Positive correlation between IL-33 and IL-17 values in sera and feces, respectively was also observed.

We believe that increased local values of IL-33 and IL-17, reflected trough higher fecal concentration, in CRC patients with poor tumor tissue differentiation and with presence of lung/liver metastasis or peritoneal carcinomatosis may be considered as a sign of the tumor’s malignant progression and, consequently, of a poor prognosis for patients.

Tumor-Infiltrating Regulatory T-cell Accumulation in the Tumor Microenvironment Is Mediated by IL33/ST2 Signaling

Regulatory T cells (Treg) are enriched in the tumor microenvironment (TME) and suppress antitumor immunity; however, the molecular mechanism underlying the accumulation of Tregs in the TME is poorly understood. In various tumor models, tumor-infiltrating Tregs were highly enriched in the TME and had significantly higher expression of immune checkpoint molecules. To characterize tumor-infiltrating Tregs, we performed bulk RNA sequencing (RNA-seq) and found that proliferation-related genes, immune suppression-related genes, and cytokine/chemokine receptor genes were upregulated in tumor-infiltrating Tregs compared with tumor-infiltrating CD4+Foxp3- conventional T cells or splenic Tregs from the same tumor-bearing mice. Single-cell RNA-seq and T-cell receptor sequencing also revealed active proliferation of tumor infiltrating Tregs by clonal expansion. One of these genes, ST2, an IL33 receptor, was identified as a potential factor driving Treg accumulation in the TME. Indeed, IL33-directed ST2 signaling induced the preferential proliferation of tumor-infiltrating Tregs and enhanced tumor progression, whereas genetic deletion of ST2 in Tregs limited their TME accumulation and delayed tumor growth. These data demonstrated the IL33/ST2 axis in Tregs as one of the critical pathways for the preferential accumulation of Tregs in the TME and suggests that the IL33/ST2 axis may be a potential therapeutic target for cancer immunotherapy.

The Contradictory Role of Interleukin-33 in Immune Cells and Tumor Immunity

Interleukin (IL)-33 is a member of the IL-1 superfamily and is a crucial cytokine playing the role of a dual-function molecule. IL-33 mediates its function by interacting with its receptor suppression of tumorigenicity 2 (ST2), which is constitutively expressed on T helper (Th)1 cells, Th2 cells, and other immune cells. Previously, we summarized findings on IL-33 and performed an intensive study of the correlation between IL-33 and tumor. IL-33 enables anti-tumor immune responses through Th1 cells and natural killer (NK) cells and plays a role in tumor immune escape in cancers via Th2 cells and regulatory T cells. Herein, we discuss the contradictory role of IL-33 in immune cells in different cancer, and our summaries may be helpful for better understanding of the development of research on IL-33 and tumor immunity.

Combinatorial Immunotherapies for Metastatic Colorectal Cancer

Colorectal cancer (CRC) is one of the most frequent and deadly forms of cancer. About half of patients are affected by metastasis, with the cancer spreading to e.g., liver, lungs or the peritoneum. The majority of these patients cannot be cured despite steady advances in treatment options. Immunotherapies are currently not widely applicable for this disease, yet show potential in preclinical models and clinical translation. The tumour microenvironment (TME) has emerged as a key factor in CRC metastasis, including by means of immune evasion-forming a major barrier to effective immuno-oncology. Several approaches are in development that aim to overcome the immunosuppressive environment and boost anti-tumour immunity. Among them are vaccination strategies, cellular transplantation therapies, and targeted treatments. Given the complexity of the system, we argue for rational design of combinatorial therapies and consider the implications of precision medicine in this context.

IL-33 reduces tumor growth in models of colorectal cancer with the help of eosinophils

In many types of cancer, presence of eosinophils in tumors correlate with an improved disease outcome. In line with this, activated eosinophils have been shown to reduce tumor growth in colorectal cancer (CRC). Interleukin (IL)-33 has recently emerged as a cytokine that is able to inhibit the development of tumors through eosinophils and other cells of the tumor microenvironment thereby positively influencing disease progress. Here, we asked whether eosinophils are involved in the effects of IL-33 on tumor growth in CRC.

In models of CT26 cell engraftment and colitis-associated CRC, tumor growth was reduced after IL-33 treatment. The growth reduction was absent in eosinophil-deficient ΔdblGATA-1 mice but was restored by adoptive transfer of ex vivo-activated eosinophils indicating that the antitumor effect of IL-33 depends on the presence of eosinophils. In vitro, IL-33 increased the expression of markers of activation and homing in eosinophils, such as CD11b and Siglec-F, and the degranulation markers CD63 and CD107a. Increased expression of Siglec-F, CD11b and CD107a was also seen in vivo in eosinophils after IL-33 treatment. Viability and cytotoxic potential of eosinophils and their migration properties toward CCL24 were enhanced indicating direct effects of IL-33 on eosinophils. IL-33 treatment led to increased levels of IL-5 and CCL24 in tumors.

Our data show that the presence of eosinophils is mandatory for IL-33-induced tumor reduction in models of CRC and that the mechanisms include eosinophil recruitment, activation and degranulation. Our findings also emphasize the potential use of IL-33 as an adjuvants in CRC immunotherapy.

Abbreviations

AOM: azoxymethane; bmRPMI: bone marrow RPMI; CRC: colorectal cancer; CFSE: carboxyfluorescein succinimidyl ester; DSS: dextran sulfate sodium; EPX: eosinophil peroxidase; INF-γ: interferon gamma; ILC: innate lymphoid cell; IL-33: interleukin-33; IL-5: interleukin-5; MDSC: myeloid derived suppressor cells; NK cells: natural killer cells; P/S: penicillin/streptomycin; rm: recombinant mouse; T regs: regulatory T cells; TATE: tumor associated tissue eosinophilia; TNF-α: tumor necrosis factor alpha

The Role of Interleukins in Colorectal Cancer

Despite great progress has been made in treatment strategies, colorectal cancer (CRC) remains the predominant life-threatening malignancy with the feature of high morbidity and mortality. It has been widely acknowledged that the dysfunction of immune system, including aberrantly expressed cytokines, is strongly correlated with the pathogenesis and progression of colorectal cancer. As one of the most well-known cytokines that were discovered centuries ago, interleukins are now uncovering new insights into colorectal cancer therapy. Herein, we divide currently known interleukins into 6 families, including IL-1 family, IL-2 family, IL-6 family, IL-8 family, IL-10 family and IL-17 family. In addition, we comprehensively reviewed the oncogenic or antitumour function of each interleukin involved in CRC pathogenesis and progression by elucidating the underlying mechanisms. Furthermore, by providing interleukins-associated clinical trials, we have further driven the profound prospect of interleukins in the treatment of colorectal cancer.

Cancer cell-derived interleukin-33 decoy receptor sST2 enhances orthotopic tumor growth in a murine pancreatic cancer model

Background

Proinflammatory interleukin-33 (IL-33) binds to its receptor ST2L and is involved in inflammation and the malignant behavior of cancer cells. However, the role of IL-33-ST2L and the IL-33 decoy receptor sST2 in the tumor microenvironment of pancreatic cancer is unclear. Because we previously reported that sST2 derived from colon cancer cells profoundly influences malignant tumor growth, we hypothesized that sST2 released from pancreatic cancer cells also modulates IL-33-ST2L signaling in the tumor microenvironment, thereby influencing tumor growth.

Methods

ST2 (ST2L and sST2) expression in mouse pancreatic cancer Panc02 cells was downregulated by shRNAs. mRNA expression levels of IL-33, ST2, cytokines and chemokines in the cells and tumor tissues were examined using real-time PCR. sST2 secretion and the amount of CXCL3 in tumor tissues were measured using ELISA. Tumor growth was investigated after injection of the cells into the pancreas of C57BL/6 mice. MPO⁺, F4/80⁺ and CD20⁺ cells in tumor tissues were detected using immunohistochemistry.

Results

Some but not all human and mouse pancreatic cancer cell lines preferentially expressed sST2. Then, we investigated the role of sST2 in orthotopic tumor growth of sST2-expressing mouse pancreatic cancer Panc02 cells in immunocompetent mice. shRNA-mediated knockdown of sST2 expression in the cells suppressed orthotopic tumor growth, which was partially recovered by overexpression of shRNA-resistant sST2 mRNA but was not evident in IL-33 knockout mice. This was associated with decreases in Cxcl3 expression, vessel density and accumulation of cancer-associated neutrophils but not cancer-associated macrophages. Administration of SB225002, an inhibitor of the CXCL3 receptor CXCR2, induced similar effects.

Conclusions

Cancer cell-derived sST2 enhances tumor growth through upregulation of CXCL3 via inhibition of IL-33-ST2L signaling in the tumor microenvironment of pancreatic cancer. These results suggest that the sST2 and the CXCL3-CXCR2 axis could be therapeutic targets.

The Effects of Interleukin-33 (IL-33) on Osteosarcoma Cell Viability, Apoptosis, and Epithelial-Mesenchymal Transition are Mediated Through the PI3K/AKT Pathway

Background

Osteosarcoma is the most common primary tumor of bone. Interleukin-33 (IL-33) is a pro-inflammatory cytokine that also participates in tumor progression. This study aimed to investigate the role of IL-33 in human osteosarcoma cell viability, proliferation, apoptosis, and epithelial-mesenchymal transition (EMT) in vitro and the molecular mechanisms involved.

Material/Methods

The normal osteoblast cell line, hFOB 1.19, and the human osteosarcoma cell lines SOSP-9607, SAOS2, MG63, and U2OS were studied. The expression of IL-33 mRNA and protein in human osteosarcoma cell lines were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. The effects of IL-33 on human osteosarcoma cell viability, apoptosis, EMT, and the signaling pathways were studied using the MTT assay, flow cytometry, qRT-PCR, and Western blot.

Results

IL-33 was upregulated in human osteosarcoma cell lines, including U2OS cells. The use of an IL-33 gene plasmid promoted osteosarcoma cell viability, inhibited cell apoptosis, increased the expression of Bcl-2, and reduced the expression of Bax. IL-33 reduced the level of E-cadherin and increased the levels of N-cadherin and matrix metalloproteinase-9 (MMP-9) in osteosarcoma cells at the mRNA and protein level. The use of the IL-33 plasmid increased the protein expression levels of p-AKT and the p-AKT/AKT ratio in osteosarcoma cells, and IL-33 siRNA reversed these findings.

Conclusions

IL-33 was highly expressed in human osteosarcoma cells. Down-regulation of IL-33 reduced cell viability and EMT of osteosarcoma cells, and induced cell apoptosis through activation of the PI3K/AKT signaling pathway.

Soluble ST2: A complex and diverse role in several diseases

The Suppression of Tumorigenicity 2 protein (ST2) is a member of the interleukin (IL) 1 receptor family with transmembrane (ST2L) and soluble (sST2) isoforms that are (over)expressed in several cells in different conditions and following various triggers (e.g. inflammation, stress). The ligand of ST2 is IL-33, which on binding to ST2L results in nuclear signalling and immunomodulatory action in various cells (tumour, immune, heart). sST2, that is released in the circulation, functions as a »decoy« receptor of IL-33 and inhibits IL-33/ST2L signalling and beneficial effects. The importance and role of the ST2/IL-33 axis and sST2 have been evaluated and confirmed in several inflammatory, cancer and cardiac diseases. sST2 is involved in homeostasis/pathogenesis of these diseases, as the counterbalance/response on IL-33/ST2L axis activation, which is triggered and expressed during developing fibrosis, tissue damage/inflammation and remodelling. In clinical studies, sST2 has been recognised as an important prognostic marker in patients with cardiac disease, including patients with chronic kidney disease where specific characteristics of sST2 enable better assessment of the risk of End-Stage Renal Disease patients on dialysis. sST2 is also recognised as an important marker for monitoring treatment in heart failure patients. However, accurate measurement and interpretation of ST2 concentration in serum/plasma samples for routine and research applications require the use of appropriate methods and recognition of essential characteristics of both the methods and the analyte that may influence the result. sST2, as one of the most promising disease biomarkers, is deserving of further study and wider application in clinical practice.

Epithelial cells expressed IL-33 to promote degranulation of mast cells through inhibition on ST2/PI3K/mTOR-mediated autophagy in allergic rhinitis

Nasal epithelial cells are the first barrier against allergen infiltration in allergic rhinitis (AR), and the relationship between nasal epithelial cells and mast cell-mediated hypersensitivity remains unclear. This study aimed to investigate the possible association between allergen-challenged nasal epithelial cells (AR-HNEpC) and mast cell degranulation in AR. Our data revealed that calcium influx and degranulation were increased in AR-HNEpC-co-cultured mast cells. Expression of IL-33, a factor that binds to ST2 receptors on mast cells and regulates their degranulation, was elevated in AR-HNEpC. Blocking IL-33/ST2 pathway activated autophagy and inhibited degranulation and inflammatory factor release in mast cells. Furthermore, PI3K/mTOR was increased in IL-33-treated mast cells. Inhibition on PI3K/mTOR pathway enhanced autophagy and inhibited degranulation. Analysis using an in vivo AR model supported the above findings. In conclusion, IL-33 from epithelial cells promotes degranulation of mast cells in AR through inhibition on ST2/PI3K/mTOR-mediated autophagy, which provides a potential therapeutic target for the disease.Abbreviations: AR: allergic rhinitis; IL: interleukin; TNF-α: tumor necrosis factor-alpha; INF-γ: interferon-gamma; HNEpC: human nasal epithelial cell line; ATCC: American Type Culture Collection; C48/80: compound 48/80; 3-MA: 3-methyladenine; qPCR: quantitative PCR; AR-HNEpC: dust mite allergen-treated nasal epithelial cells; IgE: immunoglobulin E; Atg7: autophagy-related gene 7.