Role of Cyclooxygenase-2 Pathway in Creating an Immunosuppressive Microenvironment and in Initiation and Progression of Wilms' Tumor

Identification of m6A-associated genes as prognostic and immune-associated biomarkers in Wilms tumor

OBJECTIVES

Wilms tumor (WT) is a common renal malignant tumor in children. We aimed to investigate the potential prognostic value of m6A-related genes and their relationship to the immune microenvironment in WT.

METHODS

RNA-seq data and clinical information from 121 WT and 6 normal samples were obtained from the University of California Santa Cruz Xena database. We used various bioinformatics analysis tools to analyze these data and verify the expression level of m6A-related genes by experiments.

RESULTS

Four m6A-related genes were successfully screened, including ADGRG2, CPD, CTHRC1, and LRTM2. Kaplan-Meier survival curves showed that the four genes were closely related to the prognosis of WT, which was also confirmed by receiver operator characteristic curves. Subsequently, in the immune microenvironment of WT, we discovered that Th1_cells were positively correlated with ADGRG2, CCR was negatively correlated with CPD, CCR was positively correlated with CTHRC1, APC_co_stimulation, CCR, Macrophages, inflammation-promoting cells, Treg, and Type_II_IFN_Reponse were negatively correlated with LRTM2. Finally, qRT-PCR showed that expression levels of the four genes were upregulated in the nephroblastoma cell lines (G-401, SK-NEP-1, and WT-CLS1) compared with the human embryonic kidney cell lines (293T).

CONCLUSIONS

Taken together, our study first time screened the m6A-related genes and revealed that ADGRG2, CPD, CTHRC1, and LRTM2 are the prognostic and immune-associated biomarkers in WT.

Hormone Receptor Signaling and Breast Cancer Resistance to Anti-Tumor Immunity

Breast cancers regroup many heterogeneous diseases unevenly responding to currently available therapies. Approximately 70-80% of breast cancers express hormone (estrogen or progesterone) receptors. Patients with these hormone-dependent breast malignancies benefit from therapies targeting endocrine pathways. Nevertheless, metastatic disease remains a major challenge despite available treatments, and relapses frequently ensue. By improving patient survival and quality of life, cancer immunotherapies have sparked considerable enthusiasm and hope in the last decade but have led to only limited success in breast cancers. In addition, only patients with hormone-independent breast cancers seem to benefit from these immune-based approaches. The present review examines and discusses the current literature related to the role of hormone receptor signaling (specifically, an estrogen receptor) and the impact of its modulation on the sensitivity of breast cancer cells to the effector mechanisms of anti-tumor immune responses and on the capability of breast cancers to escape from protective anti-cancer immunity. Future research prospects related to the possibility of promoting the efficacy of immune-based interventions using hormone therapy agents are considered.

The innate effects of plant secondary metabolites in preclusion of gynecologic cancers: Inflammatory response and therapeutic action

Gynecologic cancers can make up the bulk of cancers in both humans and animals. The stage of diagnosis and the type of tumor, its origin, and its spread are a few of the factors that influence how effectively a treatment modality works. Currently, radiotherapy, chemotherapy, and surgery are the major treatment options recommended for the eradication of malignancies. The use of several anti-carcinogenic drugs increases the chance of harmful side effects, and patients might not react to the treatments as expected. The significance of the relationship between inflammation and cancer has been underscored by recent research. As a result, it has been shown that a variety of phytochemicals with beneficial bioactive effects on inflammatory pathways have the potential to act as anti-carcinogenic medications for the treatment of gynecologic cancer. The current paper reviews the significance of inflammatory pathways in gynecologic malignancies and discusses the role of plants-derived secondary metabolites that are useful in the treatment of cancer.

Sertoli Cells Express Accommodation, Survival, and Immunoregulatory Factors When Exposed to Normal Human Serum

Transplantation is a clinical procedure that treats a variety of diseases yet is unattainable for many patients due to a nationwide organ shortage and the harsh side effects of chronic immune suppression. Xenografted pig organs are an attractive alternative to traditional allografts and would provide an endless supply of transplantable tissue, but transplants risk rejection by the recipient's immune system. An essential component of the rejection immune response is the complement system. Sertoli cells, an immunoregulatory testicular cell, survive complement as xenografts long term without any immune suppressants. We hypothesized that exposure to the xenogeneic complement influences Sertoli cell gene expression of other accommodation factors that contribute to their survival; thus, the purpose of this study was to describe these potential changes in gene expression. RNA sequencing of baseline neonatal pig Sertoli cells (NPSC) as compared to NPSC after exposure to normal human serum (NHS, containing complement) revealed 62 significantly differentially expressed genes (DEG) that affect over 30 pathways involved in immune regulation, cell survival, and transplant accommodation. Twelve genes of interest were selected for further study, and Sertoli cell protein expression of CCL2 and the accommodation factor A20 were confirmed for the first time. Functional pathway analyses were conducted in NPSC and three biological clusters were revealed as being considerably affected by NHS exposure: innate immune signaling, cytokine signaling, and T cell regulation. Better understanding of the interaction of Sertoli cells with complement in a xenograft environment may reveal the mechanisms behind immune-privileged systems to increase graft viability.

Artesunate targets cellular metabolism to regulate the Th17/Treg cell balance

INTRODUCTION

Metabolic reprogramming is one of the important mechanisms of cell differentiation, and different cells have different preferences for energy sources. During the differentiation of naive CD4 + T cells into Th17 and Treg cells, these cells show specific energy metabolism characteristics. Th17 cells depend on enhanced glycolysis, fatty acid synthesis, and glutaminolysis. In contrast, Treg cells are dependent on oxidative phosphorylation, fatty acid oxidation, and amino acid depletion. As a potent antimalarial drug, artesunate has been shown to modulate the Th17/Treg imbalance and regulate cell metabolism.

METHODOLOGY

Relevant literatures on ART, cellular metabolism, glycolysis, lipid metabolism, amino acid metabolism, CD4 + T cells, Th17 cells, and Treg cells published from January 1, 2010 to now were searched in PubMed database.

CONCLUSION

In this review, we will highlight recent advances in which artesunate can restore the Th17/Treg imbalance in disease states by altering T-cell metabolism to influence differentiation and lineage selection. Data from the current study show that few studies have focused on the effect of ART on cellular metabolism. ART can affect the metabolic characteristics of T cells (glycolysis, lipid metabolism, and amino acid metabolism) and interfere with their differentiation lineage, thereby regulating the balance of Th17/Treg and alleviating the symptoms of the disease.

The immunotherapy advancement targeting malignant blastomas in early childhood

Malignant blastomas develop relentlessly in all functional body organs inflicting severe health ailments in younger children. Malignant blastomas exhibit diverse clinical characteristics in compliance with their emergence in functional body organs. Surprisingly, neither of these preferred treatment types (surgery, radiotherapy, and chemotherapy) showed promise or were effective in treating malignant blastomas among child patients. N ew, innovative immunotherapeutic procedures including monoclonal antibodies and chimeric-antigen based receptor (CAR) cell therapy, coupled with the clinical study of reliable therapeutic targets and immune regulatory pathways targeting malignant blastomas, have attracted the attention of clinicians recently.

The tumor microenvironment and immune targeting therapy in pediatric renal tumors

This review highlights the role of several immunomodulating elements contributing to the tumor microenvironment of various pediatric renal tumors including Wilms tumor. The roles of innate and adaptive immune cells in renal tumors are summarized as well as immunomodulatory cytokines and other proteins. The expression and the predictive role of checkpoint modulators like PD-L1 and immunomodulating proteins like glypican-3, B7-H3, COX-2 are highlighted with a translational view toward potential therapeutic innovations. We further discuss the current state of preclinical models in advancing this field of study. Finally, examples of clinical trials of immunomodulating strategies such as monoclonal antibodies and chimeric antigen receptor T (CAR-T) cells for relapsed/refractory/progressive pediatric renal tumors are described.

A Novel Inflammation-Related Gene Signature for Overall Survival Prediction and Comprehensive Analysis in Pediatric Patients with Wilms Tumor

Wilms tumor (WT) is a common pediatric renal cancer, with a poor prognosis and high-risk recurrence in some patients. The inflammatory microenvironment is gradually gaining attention in WT. In this study, novel inflammation-related signatures and prognostic model were explored and integrated using bioinformatics analysis. The mRNA profile of pediatric patients with WT and inflammation-related genes (IRGs) were acquired from Therapeutically Available Research to Generate Effective Treatments (TARGET) and Gene Set Enrichment Analysis (GSEA) databases, respectively. Then, a novel prognostic model founded on 7-IRGs signature (BICC1, CSPP1, KRT8, MYCN, NELFA, NXN, and RNF113A) was established by the least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression to stratify pediatric patients with WT into high- and low-risk groups successfully. And a stable performance of the prognostic risk model was verified in predicting overall survival (OS) by receiver-operating characteristic (ROC) curves, Kaplan-Meier (KM) curves, and independent prognostic analysis (p < 0.05). In addition, a novel nomogram integrating risk scores with good robustness was developed and validated by C-index, ROC, and calibration plots. The potential function and pathway were explored via Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and GSEA, with mainly inflammation and immune-related biological processes. The higher-risk scores, the lower immune infiltration, as shown in the single-sample GSEA (ssGSEA) and tumor microenvironment (TME) analysis. The drug sensitivity analysis showed that regulating 7-IRGs signature has a significant correlation with the chemotherapy drugs of WT patients. In summary, this study defined a prognostic risk model and nomogram based on 7-IRGs signature, which may provide novel insights into clinical prognosis and inflammatory study in WT patients. Besides, enhancing immune infiltration based on inflammatory response and regulating 7-IRGs signature are beneficial to ameliorating the efficacy in WT patients.

Bioactive phenolics fraction of Hedera helix L. (Common Ivy Leaf) standardized extract ameliorates LPS-induced acute lung injury in the mouse model through the inhibition of proinflammatory cytokines and oxidative stress

Hedera helix L. (family Araliaceae) is classified as a conventional plant used as a medicinal product in the cure and prevention of upper respiratory tract inflammation and infection due to its secretolytic and broncholytic effects. Our research was conducted to authenticate the anti-inflammatory effect of ivy leaves extract in the prevention of acute lung injury (ALI) caused by intranasal administration of lipopolysaccharides (LPS). In-vitro antimicrobial, anti-inflammatory, and anti-oxidant were evaluated, in addition to the in-vivo acute lung inflammation model induced by LPS in mice. The animals were divided into seven groups randomly (each group containing 10 mice): control negative (saline only), control positive (LPS group), standard (Dexamethasone 2 mg/kg), ethanolic ivy leaves extract (EIE, 100 mg/kg), ethanolic ivy leaves extract (EIE, 200 mg/kg), saponin rich fraction (SRF, 100 mg/kg) and phenolic rich fraction (PRF, 100 mg/kg). Right lungs were homogenized to determine the levels of SOD, MDA, catalase, IL-10, TNF-α, NO, IL-1β, IL-6, PGE2, and MPO. Left lungs were excised for histopathology and histomorphometry. Immunohistochemistry of Cox-2 and TNF-α levels were measured. Additionally, Western blotting was used to determine the levels of phosphorylated MAPK. Also, the ethanolic extract was also standardized through HPLC analysis for its content of rutin.The data showed that the oral supplementation with EIE, 200 mg/kg significantly (P < 0.05) decreased the pro-inflammatory mediators, and oxidative stress biomarkers induced by LPS. Interestingly, the phenolics showed promising activity, therefore they are responsible for the action. In conclusion, the standardized ivy leaf extract could be advised for acute lung injury for its antimicrobial, anti-oxidant, and anti-inflammatory activities.

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Ivy leaf is a traditional perennial edible herb used as an anti-inflammatory agent for respiratory disorders.

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The plant significantly reduced the serum oxidative stress biomarkers and inflammatory cytokines in the in-vivo acute lung inflammation model induced by LPS.

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Also, it had antimicrobial activity.

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Phenolics not saponins are responsible for the activity of the plant.

Meloxicam Inhibits Hepatocellular Carcinoma Progression and Enhances the Sensitivity of Immunotherapy via the MicroRNA-200/PD-L1 Pathway

Background. Hepatocellular carcinoma (HCC) has become the sixth most common cancer and the third leading cause of cancer death in the world. Although the research achievements of tumor immunotherapy have made great progress, especially the combination of immune targeted therapy has achieved good curative effect in HCC, but only a few patients are suitable for it and benefit from it. Therefore, there is an urgent need to find new effective drugs to treat HCC or to enhance the sensitivity of immunotherapy. Methods. Meloxicam, a COX2 inhibitor with strong anti-HCC potential, was screened from 800 small molecules approved by FDA. The effect of meloxicam on the proliferation, invasion, and migration of HCC cell lines was evaluated by cell phenotype analysis. The Human Protein Atlas database and the TISCH database were used to analyze COX2 data in single cells, and the TISIDB database was used to analyze the correlation of COX2 with immune function. The real-time quantitative polymerase chain reaction (qRT-PCR) and western blot were used to evaluate the level of PD-L1 and CD155 in HCC cell lines treated with meloxicam and further explore its possible mechanism. In vivo experiments were applied to verify the effect of meloxicam combined with anti-PD1 therapy on HCC tumor growth in mice. Results. Meloxicam can significantly inhibit the proliferation, invasion, and migration of HCC cells. The TISIDB database indicated that the COX2 was strongly associated with immunoinhibitors and immunostimulators. Meloxicam upregulated the level of PD-L1 in HCC cell lines and animal models. In terms of mechanism, meloxicam inhibited microRNA-200, thereby upregulating PD-L1. In vitro experiments showed that both meloxicam and anti-PD1 had inhibitory effects on the growth of HCC tumors. Compared with meloxicam and anti-PD1 alone, the combination therapy showed stronger antitumor properties. Immunohistochemical analysis confirmed that meloxicam enhanced the antitumor immune activity in the tumor microenvironment. Conclusion. Our study showed meloxicam inhibited HCC progression and enhanced the sensitivity of immunotherapy via the microRNA-200/PD-L1 pathway.

Research advances in the targeted therapy and immunotherapy of Wilms tumor: a narrative review

Wilms tumor is the most common pediatric abdominal solid tumor, and its treatment has been a focus of research. For now, the 5-year survival rate of children with Wilms tumor is about 90%. It is difficult to make further progress simply by the improvement of the existing treatments (multi-modal therapy). Therefore, targeted therapy and immunotherapy which have high accuracy and few side effects began to be considered for the treatment of Wilms tumor. At present, though targeted therapy and immunotherapy are rarely used in the treatment of Wilms tumor except in clinical trials, there are dozens of clinical trials research them around the world. The sites in targeted therapy research are mainly focused on insulin-like growth factor 2 (IGF2) pathway, anti-angiogenesis, phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, and some miRNAs, etc. And there are three types of study in Wilms tumor immunotherapy, which are inhibition of the COX-2 pathway, chimeric antigen receptor (CAR)-T cell therapy, and multi-tumor associated antigen (TAA)-specific cytotoxic T lymphocytes (CTL) therapy. Among them, the phase I clinical trial of multi-TAA-specific CTL (MTAA-CTL) therapy has been completed, and the results are very satisfactory. In this narrative review, we review the basic research and relevant clinical research on targeted therapy and immunotherapy for Wilms tumor.

Myelin and lymphocyte protein serves as a prognostic biomarker and is closely associated with the tumor microenvironment in the nephroblastoma

Nephroblastoma, also known as Wilms' tumor (WT), is the most common renal tumor that occurs in children. Although the efficacy of treatment has been significantly improved by a series of comprehensive treatments, some patients still have poor prognosis. Myelin and lymphocyte (MAL) protein, a highly hydrophobic integrated membrane‐bound protein, has been implicated in many tumors and is also closely linked to kidney development. However, the relationship between MAL and WT has not yet been elucidated. Therefore, we attempted to evaluate the feasibility of MAL as a promising prognosis factor for WT. The differential expression of MAL was investigated using TARGET database and was verified using the Gene Expression Omnibus database and real‐time quantitative PCR. The prognostic ability of MAL was determined using Kaplan–Meier and Cox regression analyses. Pearson correlation analysis was applied to explore the relationship between MAL expression and methylation sites. The ESTIMATE and CIBERSORT algorithms showed that MAL expression was associated with the WT tumor microenvironment. Gene Set Enrichment Analysis (GSEA) indicated that multiple signaling pathways closely associated with tumorigenesis were differentially enriched between the high‐ and low‐MAL groups. In conclusion, our study comprehensively explored the potential of MAL as a prognosis factor for WT. Meanwhile, we also demonstrated that MAL, as a prognostic factor for WT, may be closely related to the tumor microenvironment.

DNA Methylation Data-Based Classification and Identification of Prognostic Signature of Children With Wilms Tumor

Background: As an epigenetic alteration, DNA methylation plays an important role in early Wilms tumorigenesis and is possibly used as marker to improve the diagnosis and classification of tumor heterogeneity.

Methods: Methylation data, RNA-sequencing (RNA-seq) data, and corresponding clinical information were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. The prognostic values of DNA methylation subtypes in Wilms tumor were identified.

Results: Four prognostic subtypes of Wilms tumor patients were identified by consensus cluster analysis performed on 312 independent prognostic CpG sites. Cluster one showed the best prognosis, whereas Cluster two represented the worst prognosis. Unique CpG sites identified in Cluster one that were not identified in other subtypes were assessed to construct a prognostic signature. The prognostic methylation risk score was closely related to prognosis, and the area under the curve (AUC) was 0.802. Furthermore, the risk score based on prognostic signature was identified as an independent prognostic factor for Wilms tumor in univariate and multivariate Cox regression analyses. Finally, the abundance of B cell infiltration was higher in the low-risk group than in the high-risk group, based on the methylation data.

Conclusion: Collectively, we divided Wilms tumor cases into four prognostic subtypes, which could efficiently identify high-risk Wilms tumor patients. Prognostic methylation risk scores that were significantly associated with the adverse clinical outcomes were established, and this prognostic signature was able to predict the prognosis of Wilms tumor in children, which may be useful in guiding clinicians in therapeutic decision-making. Further independent studies are needed to validate and advance this hypothesis.

Systemic inflammatory markers and serum lactate dehydrogenase predict survival in patients with Wilms tumour

INTRODUCTION

Markers of inflammation such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) have been found to be associated with survival in cancer patients. The aim of the current study was to establish the prognostic significance of simple laboratory markers of systemic inflammation in paediatric patients diagnosed with Wilms tumour (WT). Additionally, we aimed to compare the complete blood count (CBC) parameters of WT patients and the non-oncological control group.

MATERIAL AND METHODS

The study group included 88 children diagnosed with WT. Clinicopathological data, as well as CBC, C-reactive protein (CRP) and lactate dehydrogenase (LDH) levels at diagnosis, were obtained. Additionally, the laboratory results of 62 healthy control paediatric patients were collected. Uni- and multivariate proportional Cox's hazard analyses were computed to create a model predicting relapse-free survival (RFS) and overall survival (OS) in the study group.

RESULTS

High CRP, LDH, and NLR were associated with a higher stage of WT and shorter RFS, whereas all parameters correlated with OS. In multivariate analysis, only LDH levels had adverse significance in predicting RFS. C-reactive protein and LMR retained their prognostic value in the multivariate model predicting OS. Comparing the WT group with controls, high LDH, high CRP, high NLR, and high PLR were associated with WT presence.

CONCLUSIONS

Preoperative LDH, CRP, NLR, PLR, and LMR have significant prognostic value in patients with WT independently of age and stage. Combined low CRP and high LMR identified the group of patients with excellent OS. Patients with high LDH were characterized by the highest risk of relapse.

Knockdown of SENP1 inhibits HIF-1α SUMOylation and suppresses oncogenic CCNE1 in Wilms tumor

Based on our initial bioinformatics finding of the upregulated expression of sentrin-specific protease 1 (SENP1) and cyclin E1 (CCNE1) in Wilms tumor, this study aimed to illustrate the molecular mechanism of SENP1 in Wilms tumor, which involved the hypoxia-inducible factor 1α (HIF-1α)/stanniocalcin-1 (STC1)/CCNE1 axis. Wilms tumor and adjacent normal tissues were clinically collected. Gain- and loss-of-function assays were performed to evaluate the effects of the regulatory axis on malignant phenotypes of Wilms tumor cells. A mouse model of Wilms tumor xenografts was further established for in vivo substantiation. Overexpression of CCNE1 and SENP1 occurred in Wilms tumor tissues and cells. Silencing SENP1 inhibited viability and enhanced cell-cycle arrest of Wilms tumor cells. SENP1 promoted STC1 expression and upregulated CCNE1 by driving the small ubiquitin-like modifier (SUMO)ylation of HIF-1α, which ultimately promoted the malignant phenotypes of Wilms tumor cells. It was further confirmed that silencing SENP1 downregulated the expression of CCNE1 and restricted tumorigenicity of Wilms tumor cells in vivo. Taken together, SENP1 elevated STC1 expression by driving the SUMOylation of HIF-1α, thereby upregulating the expression of CCNE1 and ultimately promoting the development of Wilms tumor.

Recent Advances in Pediatric Cancer Research

Over the past few years, the field of pediatric cancer has experienced a shift in momentum, and this has led to new and exciting findings that have relevance beyond pediatric malignancies. Here we present the current status of key aspects of pediatric cancer research. We have focused on genetic and epigenetic drivers of disease, cellular origins of different pediatric cancers, disease models, the tumor microenvironment, and cellular immunotherapies.

Systematic review of the immunological landscape of Wilms tumors

Results of immunotherapy in childhood solid cancer have been so far, with the exception of neuroblastoma, quite disappointing. Lack of knowledge of the immune contexture of these tumors may have contributed to the failure of immunotherapies so far. Here, we systematically reviewed the literature regarding the immunology of Wilms tumor (WT), one of the most frequent pediatric solid tumors of the abdomen. In Wilms tumor patients the high cure rate of >90%, achieved by the combination of surgery and radio-chemotherapy, is at the expense of a high early and late toxicity. Moreover, treatment-resistant entities, such as diffuse anaplastic tumors or recurrent disease, still pose unsolved clinical problems. Successful immunotherapy could represent a novel and possibly less-toxic treatment option. Employing the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) method of literature search, we analyzed the current knowledge of the immunological landscape of Wilms tumors in terms of tumor microenvironment, prognostic implications of single biomarkers, and immunotherapy response.

Recent advances in the role of Th17/Treg cells in tumor immunity and tumor therapy

Th17 and Treg cells play an important role in regulating tissue inflammation and maintaining the stability of the immune system. They regulate inflammatory responses, participate in the occurrence and development of autoimmune diseases and tumors, and determine the disease progress. Malignant tumor is one of the diseases with the highest mortality rate in the world. However, the efficacy of traditional treatment is limited, so it is necessary to find safe and efficient treatment methods. Studies have shown that the balance of Th17/Treg cells plays a critical role in tumor progression. In this paper, we review the antitumor and tumor-suppressing effects of Th17/Treg cells, and new strategies for tumor therapy, combined with new research hotspots such as immune checkpoint therapy, miRNA-related gene therapy, and metabolic pathway regulation of Th17/Treg cell differentiation and tumor generation. The synergistic therapy is expected to be widely used in the future clinical practice, providing a new choice for the prevention and treatment of malignant tumors.

Pediatric Tumors-Mediated Inhibitory Effect on NK Cells: The Case of Neuroblastoma and Wilms' Tumors

Simple Summary

Neuroblastoma (NB) and Wilms’ tumor (WT) are the most common childhood solid extracranial tumors. The current treatments consist of a combination of surgery and chemotherapy or radiotherapy in high-risk patients. Such treatments are responsible for significant adverse events requiring long-term monitoring. Thus, a main challenge in NB and WT treatment is the development of novel therapeutic strategies to eliminate or minimize the adverse effects. The characterization of the immune environment could allow for the identification of new therapeutic targets. Herein, we described the interaction between these tumors and innate immune cells, in particular natural killer cells and monocytes. The detection of the immunosuppressive activity of specific NB and WT tumor cells on natural killer cells and on monocytes could offer novel cellular and molecular targets for an effective immunotherapy of NB and WT.

Abstract

Natural killer (NK) cells play a key role in the control of cancer development, progression and metastatic dissemination. However, tumor cells develop an array of strategies capable of impairing the activation and function of the immune system, including NK cells. In this context, a major event is represented by the establishment of an immunosuppressive tumor microenvironment (TME) composed of stromal cells, myeloid-derived suppressor cells, tumor-associated macrophages, regulatory T cells and cancer cells themselves. The different immunoregulatory cells infiltrating the TME, through the release of several immunosuppressive molecules or by cell-to-cell interactions, cause an impairment of the recruitment of NK cells and other lymphocytes with effector functions. The different mechanisms by which stromal and tumor cells impair NK cell function have been particularly explored in adult solid tumors and, in less depth, investigated and discussed in a pediatric setting. In this review, we will compare pediatric and adult solid malignancies concerning the respective mechanisms of NK cell inhibition, highlighting novel key data in neuroblastoma and Wilms’ tumor, two of the most frequent pediatric extracranial solid tumors. Indeed, both tumors are characterized by the presence of stromal cells acting through the release of immunosuppressive molecules. In addition, specific tumor cell subsets inhibit NK cell cytotoxic function by cell-to-cell contact mechanisms likely controlled by the transcriptional coactivator TAZ. These findings could lead to a more performant diagnostic approach and to the development of novel immunotherapeutic strategies targeting the identified cellular and molecular targets.

Stromal-like Wilms tumor cells induce human Natural Killer cell degranulation and display immunomodulatory properties towards NK cells

The similarity of stromal-like Wilms tumor (str-WT) cells with mesenchymal stem cells (MSC), suggests their relevant role in the interplay with immune cells in the tumor microenvironment. We investigated the interaction between str-WT cells and NK cells. We observed that str-WT cells expressed some major ligands for activating and inhibitory NK cell receptors. Moreover, they expressed inhibitory checkpoint molecules involved in the negative regulation of anti-tumor immune response. The analysis of the interaction between str-WT cells and NK lymphocytes revealed that activated NK cells could efficiently degranulate upon interaction with str-WT cells. On the other hand, str-WT cells could exert potent inhibitory effects on cytokine-induced activation of NK cell proliferation and phenotype, which were mediated by the production of IDO and PGE2 inhibitory factors. Our data provide insight into the molecular interactions between str-WT cells and NK lymphocytes that may result in different outcomes possibly occurring in the WT microenvironment.

Immuno-Metabolism: The Role of Cancer Niche in Immune Checkpoint Inhibitor Resistance

The use of immune checkpoint inhibitors (ICI) in treating cancer has revolutionized the approach to eradicate cancer cells by reactivating immune responses. However, only a subset of patients benefits from this treatment; the majority remains unresponsive or develops resistance to ICI therapy. Increasing evidence suggests that metabolic machinery in the tumor microenvironment (TME) plays a role in the development of ICI resistance. Within the TME, nutrients and oxygen are scarce, forcing immune cells to undergo metabolic reprogramming to adapt to harsh conditions. Cancer-induced metabolic deregulation in immune cells can attenuate their anti-cancer properties, but can also increase their immunosuppressive properties. Therefore, targeting metabolic pathways of immune cells in the TME may strengthen the efficacy of ICIs and prevent ICI resistance. In this review, we discuss the interactions of immune cells and metabolic alterations in the TME. We also discuss current therapies targeting cellular metabolism in combination with ICIs for the treatment of cancer, and provide possible mechanisms behind the cellular metabolic rewiring that may improve clinical outcomes.

COX-2 Signaling in the Tumor Microenvironment

Tumorigenesis is a multistep, complicated process, and many studies have been completed over the last few decades to elucidate this process. Increasingly, many studies have shifted focus toward the critical role of the tumor microenvironment (TME), which consists of cellular players, cell-cell communications, and extracellular matrix (ECM). In the TME, cyclooxygenase-2 (COX-2) has been found to be a key molecule mediating the microenvironment changes. COX-2 is an inducible form of the enzyme that converts arachidonic acid into the signal transduction molecules (thromboxanes and prostaglandins). COX-2 is frequently expressed in many types of cancers and has been closely linked to its occurrence, progression, and prognosis. For example, COX-2 has been shown to (1) regulate tumor cell growth, (2) promote tissue invasion and metastasis, (3) inhibit apoptosis, (4) suppress antitumor immunity, and (5) promote sustainable angiogenesis. In this chapter, we summarize recent advances of studies that have evaluated COX-2 signaling in TME.

Tumor-intrinsic signaling pathways: key roles in the regulation of the immunosuppressive tumor microenvironment

Immunotherapy is a currently popular treatment strategy for cancer patients. Although recent developments in cancer immunotherapy have had significant clinical impact, only a subset of patients exhibits clinical response. Therefore, understanding the molecular mechanisms of immunotherapy resistance is necessary. The mechanisms of immune escape appear to consist of two distinct tumor characteristics: a decrease in effective immunocyte infiltration and function and the accumulation of immunosuppressive cells in the tumor microenvironment. Several host-derived factors may also contribute to immune escape. Moreover, inter-patient heterogeneity predominantly results from differences in somatic mutations between cancers, which has led to the hypothesis that differential activation of specific tumor-intrinsic pathways may explain the phenomenon of immune exclusion in a subset of cancers. Increasing evidence has also shown that tumor-intrinsic signaling plays a key role in regulating the immunosuppressive tumor microenvironment and tumor immune escape. Therefore, understanding the mechanisms underlying immune avoidance mediated by tumor-intrinsic signaling may help identify new therapeutic targets for expanding the efficacy of cancer immunotherapies.

Screening and isolation of cyclooxygenase-2 inhibitors from Trifolium pratense L. via ultrafiltration, enzyme-immobilized magnetic beads, semi-preparative high-performance liquid chromatography and high-speed counter-current chromatography

Nonsteroidal anti-inflammatory drugs reportedly reduce the risk of developing cancer. One mechanism by which they reduce carcinogenesis involves the inhibition of the activity of cyclooxygenase-2, an enzyme that is overexpressed in various cancer tissues. Its overexpression increases cell proliferation and inhibits apoptosis. However, selected cyclooxygenase-2 inhibitors can also act through cyclooxygenase-independent mechanisms. In this study, using ultrafiltration, enzyme-immobilized magnetic beads, high-performance liquid chromatography, and electrospray-ionization mass spectrometry, several isoflavonoids in Trifolium pratense L. extracts were screened and identified. Semi-preparative high-performance liquid chromatography and high-speed counter-current chromatography were then applied to separate the active constituents. Using these methods, seven major compounds were identified in Trifolium pratense L. As cyclooxygenase-2 inhibitors: rothindin, ononin, daidzein, trifoside, pseudobaptigenin, formononetin, and biochanin A, which were then isolated with >92% purity. This is the first report of the presence of potent cyclooxygenase-2 inhibitors in Trifolium pratense L. extracts. The results of this study demonstrate that the systematic isolation of bioactive components from Trifolium pratense L., by using ultrafiltration, enzyme-immobilized magnetic beads, semi-preparative high-performance liquid chromatography, and high-speed counter-current chromatography, represents a feasible and efficient technique that could be extended for the identification and isolation of other enzyme inhibitors.

Clinopodium vulgare L. (wild basil) extract and its active constituents modulate cyclooxygenase-2 expression in neutrophils

Clinopodium vulgare L. (wild basil) has a wide range of ethnopharmacological applications and accumulates a broad spectrum of phenolic compounds, recognized for their anti-inflammatory and anticancer properties. The triggered cyclooxygenase-2 (COX-2) expression is creating an immunosuppressive microenvironment in the inflamed tissue and considered to be the main cause of failure of even new anticancer-/immune-therapies. Nowadays, selective and novel plant-derived COX-2 inhibitors with safe profile are subject of profound research interest. This study aimed to analyze the metabolic profile of C. vulgare and search for phenolic molecules with potential biological properties. By application of ¹H and 2D-NMR (Nuclear Magnetic Resonance) profiling, caffeic, chlorogenic acids and catechin were identified along with a bunch of primary and secondary metabolites. Further, the biological effect of C. vulgare extract (CVE) and its constituents on zymosan-induced COX-2 expression and apoptosis of murine neutrophils have been studied. The CVE, caffeic and chlorogenic acids inhibited zymosan-induced COX-2 expression in bone marrow neutrophils, in vitro and in vivo activated. The obtained data indicate that CVE may have a good potential to manipulate neutrophil functions, however, its action may depend on the cellular state, the inflammatory milieu and the relative content of caffeic and chlorogenic acid in the extract.

Tumor microenvironment: Interactions and therapy

Tumor microenvironment (TME) is a host for a complex network of heterogeneous stromal cells with overlapping or opposing functions depending on the dominant signals within this milieu. Reciprocal paracrine interactions between cancer cells with cells within the tumor stroma often reshape the TME in favor of the promotion of tumor. These complex interactions require more sophisticated approaches for cancer therapy, and, therefore, advancing knowledge about dominant drivers of cancer within the TME is critical for designing therapeutic schemes. This review will provide knowledge about TME architecture, multiple signaling, and cross communications between cells within this milieu, and its targeting for immunotherapy of cancer.

Cyclooxygenase-2 in cancer: A review

Cyclooxygenase-2 (COX-2) is frequently expressed in many types of cancers exerting a pleiotropic and multifaceted role in genesis or promotion of carcinogenesis and cancer cell resistance to chemo- and radiotherapy. COX-2 is released by cancer-associated fibroblasts (CAFs), macrophage type 2 (M2) cells, and cancer cells to the tumor microenvironment (TME). COX-2 induces cancer stem cell (CSC)-like activity, and promotes apoptotic resistance, proliferation, angiogenesis, inflammation, invasion, and metastasis of cancer cells. COX-2 mediated hypoxia within the TME along with its positive interactions with YAP1 and antiapoptotic mediators are all in favor of cancer cell resistance to chemotherapeutic drugs. COX-2 exerts most of the functions through its metabolite prostaglandin E2. In some and limited situations, COX-2 may act as an antitumor enzyme. Multiple signals are contributed to the functions of COX-2 on cancer cells or its regulation. Members of mitogen-activated protein kinase (MAPK) family, epidermal growth factor receptor (EGFR), and nuclear factor-κβ are main upstream modulators for COX-2 in cancer cells. COX-2 also has interactions with a number of hormones within the body. Inhibition of COX-2 provides a high possibility to exert therapeutic outcomes in cancer. Administration of COX-2 inhibitors in a preoperative setting could reduce the risk of metastasis in cancer patients. COX-2 inhibition also sensitizes cancer cells to treatments like radio- and chemotherapy. Chemotherapeutic agents adversely induce COX-2 activity. Therefore, choosing an appropriate chemotherapy drugs along with adjustment of the type and does for COX-2 inhibitors based on the type of cancer would be an effective adjuvant strategy for targeting cancer.

Contribution of regulatory T cells to cancer: A review

Regulatory T cells (Tregs) represent a low number of T-cell population under normal conditions, and they play key roles for maintaining immune system in homeostasis. The number of these cells is extensively increased in nearly all cancers, which is for dampening responses from immune system against cancer cells, metastasis, tumor recurrence, and treatment resistance. The interesting point is that apoptotic Tregs are stronger than their live counterparts for suppressing responses from immune system. Tregs within the tumor microenvironment have extensive positive cross-talks with other immunosuppressive cells including cancer-associated fibroblasts, cancer cells, macrophage type 2 cells, and myeloid-derived suppressor cells, and they have negative interactions with immunostimulatory cells including cytotoxic T lymphocytes (CTL) and natural killer cells. A wide variety of markers are expressed in Tregs, among them forkhead box P3 (FOXP3) is the most specific marker and the master regulator of these cells. Multiple signals are activated by Tregs including transforming growth factor-β, signal transducer and activator of transcription, and mTORC1. Treg reprogramming from an immunosuppressive to immunostimulatory proinflammatory phenotype is critical for increasing the efficacy of immunotherapy. This would be applicable through selective suppression of tumor-bearing receptors in Tregs, including FOXP3, programmed death-1, T-cell immunoglobulin mucin-3, and CTL-associated antigen-4, among others. Intratumoral Tregs can also be targeted by increasing the ratio for CTL/Treg.

Transforming growth factor-β and peripheral regulatory cells are negatively correlated with the overall survival of hepatocellular carcinoma

AIM

To understand the cellular and molecular changes in peripheral blood that can lead to the development of hepatocellular carcinoma (HCC) and provide new methods for its diagnosis and treatment.

METHODS

Peripheral blood mononuclear cells were isolated from the peripheral blood of HCC patients and normal controls and then analyzed by flow cytometry. The percentage of transforming growth factor-β (TGF-β)+ regulatory cells (Tregs) in the peripheral blood was measured, and the expression of TGF-β was also determined. Then, the relationship between the changes and the 5-year survival of patients was analyzed. In addition, recombinant human TGF-β (rhTGF-β) and recombinant human interleukin-6 were added to stimulate the cultured cells, and their effects on HCC were evaluated.

RESULTS

The expression of TGF-β and the percentage of TGF-β+ Tregs in the peripheral blood of HCC patients increased significantly compared with normal controls. Compared with the low TGF-β expression group, the high TGF-β expression group had a significantly lower 5-year survival rate, and the same result was found in the two TGF-β+ Treg groups, suggesting that TGF-β and TGF-β+ Tregs were negatively correlated with the overall survival of the patients. In addition, rhTGF-β promoted the growth of tumor cells and induced high expression levels of IL-6, which further promoted tumor proliferation.

CONCLUSION

The results showed that TGF-β may promote tumor growth and proliferation by inducing the production of IL-6, and TGF-β and TGF-β+ Tregs may serve as new markers for predicting a poor prognosis in HCC.

Mechanisms of Phytonutrient Modulation of Cyclooxygenase-2 (COX-2) and Inflammation Related to Cancer

The link between chronic inflammation and cancer involves cytokines and mediators of inflammatory pathways. Cyclooxygenase-2 (COX-2), a key enzyme in fatty acid metabolism, is upregulated during both inflammation and cancer. COX-2 is induced by pro-inflammatory cytokines at the site of inflammation and enhanced COX-2-induced synthesis of prostaglandins stimulates cancer cell proliferation, promotes angiogenesis, inhibits apoptosis, and increases metastatic potential. As a result, COX-2 inhibitors are a subject of intense research interest toward potential clinical applications. Epidemiological studies highlight the potential benefits of diets rich in phytonutrients for cancer prevention. Plants contain numerous phytonutrient secondary metabolites shown to modulate COX-2. Studies have shown that these metabolites, some of which are used in traditional medicine, can reduce inflammation and carcinogenesis. This review describes the molecular mechanisms by which phytonutrients modulate inflammation, including studies of carotenoids, phenolic compounds, and fatty acids targeting various inflammation-related molecules and pathways associated with cancer. Examples of pathways include those of COX-2, mitogen-activated protein kinase kinase kinase, mitogen-activated protein kinase, pro-inflammatory cytokines, and transcription factors like nuclear factor kappa B. Such phytonutrient modulation of COX-2 and inflammation continue to be explored for applications in the prevention and treatment of cancer.

The Role of Secondary Metabolites on Gynecologic Cancer Therapy: Some Pathways and Mechanisms

Gynecologic cancers are among the most common cancers in humans and animals. Treatment success depends on several factors including stage at diagnosis, tumor type, origin and metastasis. Currently, surgery, chemotherapy, and radiotherapy are preferred in the treatment of these cancers. However, many anticarcinogenic drugs can cause severe adverse effects and also the expected response to treatment may not be obtained. In recent studies, the importance of the relationship between cancer and inflammation has been emphasized. Therefore, several phytochemicals that exhibit beneficial bioactive effects towards inflammatory pathways were proven to have anticarcinogenic potential for gynecologic cancer therapy. This review summarizes the role of inflammatory pathways in gynecologic cancers and effective secondary metabolites for cancer therapy.

miR-29a-3p suppresses cell proliferation and migration by downregulating IGF1R in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common primary tumor of the liver, has a poor prognosis and rapid progression. MicroRNAs (miRNAs) play important roles in carcinogenesis and tumor progression. Insulin-like growth factor 1 receptor (IGF1R) is a transmembrane heterotetrameric protein that has been reported to promote transformation to malignancy and cancer cell proliferation and survival. In this study, we found that the expression of miR-29a-3p was downregulated in HCC patients, resulting in poor survival rates. Contrastingly, the overexpression of miR-29a-3p significantly inhibited proliferation and migration in HepG2 cells. miR-29a-3p directly targeted IGF1R and down-regulated its expression. Moreover, knockdown of IGF1R led to the increased production of chemokine ligand 5 (CCL5). In tumor lesions, the local expression of CCL5 negatively affected the expression of IGF1R. Transwell analysis showed that CCL5 was important for the chemotactic movement of CD8⁺ T lymphocytes. The expression of CCL5 in HCC tissues positively correlated with the expression of CD8⁺ T lymphocyte surface marker, CD8. Patients with high CCL5 expression exhibited better survival. Our results revealed that miR-29a-3p is a tumor suppressor gene that acts by directly repressing the oncogene IGF1R, which takes part in immunoregulation in tumor microenvironments in HCC, implying that miR-29a-3p could be a potential target for HCC treatment.

The Role of Tumor Microenvironment in Chemoresistance: To Survive, Keep Your Enemies Closer

Chemoresistance is a leading cause of morbidity and mortality in cancer and it continues to be a challenge in cancer treatment. Chemoresistance is influenced by genetic and epigenetic alterations which affect drug uptake, metabolism and export of drugs at the cellular levels. While most research has focused on tumor cell autonomous mechanisms of chemoresistance, the tumor microenvironment has emerged as a key player in the development of chemoresistance and in malignant progression, thereby influencing the development of novel therapies in clinical oncology. It is not surprising that the study of the tumor microenvironment is now considered to be as important as the study of tumor cells. Recent advances in technological and analytical methods, especially ‘omics’ technologies, has made it possible to identify specific targets in tumor cells and within the tumor microenvironment to eradicate cancer. Tumors need constant support from previously ‘unsupportive’ microenvironments. Novel therapeutic strategies that inhibit such microenvironmental support to tumor cells would reduce chemoresistance and tumor relapse. Such strategies can target stromal cells, proteins released by stromal cells and non-cellular components such as the extracellular matrix (ECM) within the tumor microenvironment. Novel in vitro tumor biology models that recapitulate the in vivo tumor microenvironment such as multicellular tumor spheroids, biomimetic scaffolds and tumor organoids are being developed and are increasing our understanding of cancer cell-microenvironment interactions. This review offers an analysis of recent developments on the role of the tumor microenvironment in the development of chemoresistance and the strategies to overcome microenvironment-mediated chemoresistance. We propose a systematic analysis of the relationship between tumor cells and their respective tumor microenvironments and our data show that, to survive, cancer cells interact closely with tumor microenvironment components such as mesenchymal stem cells and the extracellular matrix.