IL-8/CXCR1/2 signalling promotes tumor cell proliferation, invasion and vascular mimicry in glioblastoma

ARF4-mediated retrograde trafficking as a driver of chemoresistance in glioblastoma

BACKGROUND

Cellular functions hinge on the meticulous orchestration of protein transport, both spatially and temporally. Central to this process is retrograde trafficking, responsible for targeting proteins to the nucleus. Despite its link to many diseases, the implications of retrograde trafficking in glioblastoma (GBM) are still unclear.

METHODS

To identify genetic drivers of TMZ resistance, we conducted comprehensive CRISPR-knockout screening, revealing ADP-ribosylation factor 4 (ARF4), a regulator of retrograde trafficking, as a major contributor.

RESULTS

Suppressing ARF4 significantly enhanced TMZ sensitivity in GBM patient-derived xenograft (PDX) models, leading to improved survival rates (P < .01) in both primary and recurrent lines. We also observed that TMZ exposure stimulates ARF4-mediated retrograde trafficking. Proteomics analysis of GBM cells with varying levels of ARF4 unveiled the influence of this pathway on EGFR signaling, with increased nuclear trafficking of EGFR observed in cells with ARF4 overexpression and TMZ treatment. Additionally, spatially resolved RNA-sequencing of GBM patient tissues revealed substantial correlations between ARF4 and crucial nuclear EGFR (nEGFR) downstream targets, such as MYC, STAT1, and DNA-PK. Decreased activity of DNA-PK, a DNA repair protein downstream of nEGFR signaling that contributes to TMZ resistance, was observed in cells with suppressed ARF4 levels. Notably, treatment with DNA-PK inhibitor, KU-57788, in mice with a recurrent PDX line resulted in prolonged survival (P < .01), highlighting the promising therapeutic implications of targeting proteins reliant on ARF4-mediated retrograde trafficking.

CONCLUSIONS

Our findings demonstrate that ARF4-mediated retrograde trafficking contributes to the development of TMZ resistance, cementing this pathway as a viable strategy to overcome chemoresistance in GBM.

An update to experimental and clinical aspects of tumor-associated macrophages in cancer development: hopes and pitfalls

Tumor-associated macrophages (TAMs) represent one of the most abundant tumor-infiltrating stromal cells, and their normal function in tumor microenvironment (TME) is to suppress tumor cells by producing cytokines which trigger both direct cell cytotoxicity and antibody-mediated immune response. However, upon prolonged exposure to TME, the classical function of these so-called M1-type TAMs can be converted to another type, "M2-type," which are recruited by tumor cells so that they promote tumor growth and metastasis. This is the reason why the accumulation of TAMs in TME is correlated with poor prognosis in cancer patients. Both M1- and M2-types have high degree of plasticity, and M2-type cells can be reprogrammed to M1-type for therapeutic purposes. This characteristic introduces TAMs as promising target for developing novel cancer treatments. In addition, inhibition of M2-type cells and blocking their recruitment in TME, as well as their depletion by inducing apoptosis, are other approaches for effective immunotherapy of cancer. In this review, we summarize the potential of TAMs to be targeted for cancer immunotherapy and provide an up-to-date about novel strategies for targeting TAMs.

Impact and potential value of immunosenescence on solid gastrointestinal tumors

Solid gastrointestinal tumors often respond poorly to immunotherapy for the complex tumor microenvironment (TME), which is exacerbated by immune system alterations. Immunosenescence is the process of increased diversification of immune genes due to aging and other factors, leading to a decrease in the recognition function of the immune system. This process involves immune organs, immune cells, and the senescence-associated secretory phenotype (SASP). The most fundamental change is DNA damage, resulting in TME remodeling. The main manifestations are worsening inflammation, increased immunosuppressive SASP production, decreased immune cell antitumor activity, and the accumulation of tumor-associated fibroblasts and myeloid-derived suppressor cells, making antitumor therapy less effective. Senotherapy strategies to remove senescent cells and block key senescence processes can have synergistic effects with other treatments. This review focuses on immunoenescence and its impact on the solid TME. We characterize the immunosenescent TME and discuss future directions for antitumor therapies targeting senescence.

Pan-cancer dissection of vasculogenic mimicry characteristic to provide potential therapeutic targets

Introduction

Vasculogenic mimicry (VM) represents a novel form of tumor angiogenesis that is associated with tumor invasiveness and drug resistance. However, the VM landscape across cancer types remains poorly understood. In this study, we elucidate the characterizations of VM across cancers based on multi-omics data and provide potential targeted therapeutic strategies.

Methods

Multi-omics data from The Cancer Genome Atlas was used to conduct comprehensive analyses of the characteristics of VM related genes (VRGs) across cancer types. Pan-cancer vasculogenic mimicry score was established to provide a depiction of the VM landscape across cancer types. The correlation between VM and cancer phenotypes was conducted to explore potential regulatory mechanisms of VM. We further systematically examined the relationship between VM and both tumor immunity and tumor microenvironment (TME). In addition, cell communication analysis based on single-cell transcriptome data was used to investigate the interactions between VM cells and TME. Finally, transcriptional and drug response data from the Genomics of Drug Sensitivity in Cancer database were utilized to identify potential therapeutic targets and drugs. The impact of VM on immunotherapy was also further clarified.

Results

Our study revealed that VRGs were dysregulated in tumor and regulated by multiple mechanisms. Then, VM level was found to be heterogeneous among different tumors and correlated with tumor invasiveness, metastatic potential, malignancy, and prognosis. VM was found to be strongly associated with epithelial-mesenchymal transition (EMT). Further analyses revealed cancer-associated fibroblasts can promote EMT and VM formation. Furthermore, the immune-suppressive state is associated with a microenvironment characterized by high levels of VM. VM score can be used as an indicator to predict the effect of immunotherapy. Finally, seven potential drugs targeting VM were identified.

Conclusion

In conclusion, we elucidate the characteristics and key regulatory mechanisms of VM across various cancer types, underscoring the pivotal role of CAFs in VM. VM was further found to be associated with the immunosuppressive TME. We also provide clues for the research of drugs targeting VM. Our study provides an initial overview and reference point for future research on VM, opening up new avenues for therapeutic intervention.

IL-8 Instructs Macrophage Identity in Lateral Ventricle Contacting Glioblastoma

Adult IDH-wildtype glioblastoma (GBM) is a highly aggressive brain tumor with no established immunotherapy or targeted therapy. Recently, CD32+ HLA-DRhi macrophages were shown to have displaced resident microglia in GBM tumors that contact the lateral ventricle stem cell niche. Since these lateral ventricle contacting GBM tumors have especially poor outcomes, identifying the origin and role of these CD32+ macrophages is likely critical to developing successful GBM immunotherapies. Here, we identify these CD32+ cells as M_IL-8 macrophages and establish that IL-8 is sufficient and necessary for tumor cells to instruct healthy macrophages into CD32+ M_IL-8 M2 macrophages. In ex vivo experiments with conditioned medium from primary human tumor cells, inhibitory antibodies to IL-8 blocked the generation of CD32+ M_IL-8 cells. Finally, using a set of 73 GBM tumors, IL-8 protein is shown to be present in GBM tumor cells in vivo and especially common in tumors contacting the lateral ventricle. These results provide a mechanistic origin for CD32+ macrophages that predominate in the microenvironment of the most aggressive GBM tumors. IL-8 and CD32+ macrophages should now be explored as targets in combination with GBM immunotherapies, especially for patients whose tumors present with radiographic contact with the ventricular-subventricular zone stem cell niche.

Intrinsic and Microenvironmental Drivers of Glioblastoma Invasion

Gliomas are diffusely infiltrating brain tumors whose prognosis is strongly influenced by their extent of invasion into the surrounding brain tissue. While lower-grade gliomas present more circumscribed borders, high-grade gliomas are aggressive tumors with widespread brain infiltration and dissemination. Glioblastoma (GBM) is known for its high invasiveness and association with poor prognosis. Its low survival rate is due to the certainty of its recurrence, caused by microscopic brain infiltration which makes surgical eradication unattainable. New insights into GBM biology at the single-cell level have enabled the identification of mechanisms exploited by glioma cells for brain invasion. In this review, we explore the current understanding of several molecular pathways and mechanisms used by tumor cells to invade normal brain tissue. We address the intrinsic biological drivers of tumor cell invasion, by tackling how tumor cells interact with each other and with the tumor microenvironment (TME). We focus on the recently discovered neuronal niche in the TME, including local as well as distant neurons, contributing to glioma growth and invasion. We then address the mechanisms of invasion promoted by astrocytes and immune cells. Finally, we review the current literature on the therapeutic targeting of the molecular mechanisms of invasion.

Chronic inflammation and cancer; the two sides of a coin

The correlation between chronic inflammation and cancer was initially identified in the 19th century. Biomolecules like interleukins, chemokines, tumor necrosis factors, growth factors, and adhesion molecules, which regulate inflammation, are recognized contributors to neoplastic transformation through various mechanisms, including oncogenic mutations, resistance to apoptosis, and adaptive responses like angiogenesis. This review aims to establish connections between the intricate and complex mechanisms of chronic inflammation and cancer. We illuminate implicit signaling mechanisms that drive the association between chronic inflammation and the initiation/progression of cancer, exploring potential impacts on other diseases. Additionally, we discuss the modalities of currently available therapeutic options for chronic inflammation and cancer, emphasizing the dual nature of such therapies. A thorough understanding of the molecular basis of chronic inflammation is crucial for developing novel approaches in the prevention and treatment of cancer.

Inhalant Cannabidiol Inhibits Glioblastoma Progression Through Regulation of Tumor Microenvironment

Introduction: Glioblastoma (GBM) is the most common invasive brain tumor composed of diverse cell types with poor prognosis. The highly complex tumor microenvironment (TME) and its interaction with tumor cells play important roles in the development, progression, and durability of GBM. Angiogenic and immune factors are two major components of TME of GBM; their interplay is a major determinant of tumor vascularization, immune profile, as well as immune unresponsiveness of GBM. Given the ineffectiveness of current standard therapies (surgery, radiotherapy, and concomitant chemotherapy) in managing patients with GBM, it is necessary to develop new ways of treating these lethal brain tumors. Targeting TME, altering tumor ecosystem may be a viable therapeutic strategy with beneficial effects for patients in their fight against GBM. Materials and Methods: Given the potential therapeutic effects of cannabidiol (CBD) in a wide spectrum of diseases, including malignancies, we tested, for the first time, whether inhalant CBD can inhibit GBM tumor growth using a well-established orthotopic murine model. Optical imaging, histology, immunohistochemistry, and flow cytometry were employed to describe the outcomes such as tumor progression, cancer cell signaling pathways, and the TME. Results: Our findings showed that inhalation of CBD was able to not only limit the tumor growth but also to alter the dynamics of TME by repressing P-selectin, apelin, and interleukin (IL)-8, as well as blocking a key immune checkpoint-indoleamine 2,3-dioxygenase (IDO). In addition, CBD enhanced the cluster of differentiation (CD) 103 expression, indicating improved antigen presentation, promoted CD8 immune responses, and reduced innate Lymphoid Cells within the tumor. Conclusion: Overall, our novel findings support the possible therapeutic role of inhaled CBD as an effective, relatively safe, and easy to administer treatment adjunct for GBM with significant impacts on the cellular and molecular signaling of TME, warranting further research.

Using Proteome Microarray and Gene Expression Omnibus Database to Screen Tumour-Associated Antigens to Construct the Optimal Diagnostic Model of Oesophageal Squamous Cell Carcinoma

AIMS

Autoantibodies against tumour-associated antigens (TAAs) are promising biomarkers for early immunodiagnosis of cancers. This study was designed to screen and verify autoantibodies against TAAs in sera as diagnostic biomarkers for oesophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

The customised proteome microarray based on cancer driver genes and the Gene Expression Omnibus database were used to identify potential TAAs. The expression levels of the corresponding autoantibodies in serum samples obtained from 243 ESCC patients and 243 healthy controls were investigated by enzyme-linked immunosorbent assay (ELISA). In total, 486 serum samples were randomly divided into the training set and the validation set in the ratio of 2:1. Logistic regression analysis, recursive partition analysis and support vector machine were performed to establish different diagnostic models.

RESULTS

Five and nine candidate TAAs were screened out by proteome microarray and bioinformatics analysis, respectively. Among these 14 anti-TAAs autoantibodies, the expression level of nine (p53, PTEN, GNA11, SRSF2, CXCL8, MMP1, MSH6, LAMC2 and SLC2A1) anti-TAAs autoantibodies in the cancer patient group was higher than that in the healthy control group based on the results from ELISA. In the three constructed models, a logistic regression model including four anti-TAA autoantibodies (p53, SLC2A1, GNA11 and MMP1) was considered to be the optimal diagnosis model. The sensitivity and specificity of the model in the training set and the validation set were 70.4%, 72.8% and 67.9%, 67.9%, respectively. The area under the receiver operating characteristic curve for detecting early patients in the training set and the validation set were 0.84 and 0.85, respectively.

CONCLUSIONS

This approach to screen novel TAAs is feasible, and the model including four autoantibodies could pave the way for the diagnosis of ESCC.

The origin of brain malignancies at the blood-brain barrier

Despite improvements in extracranial therapy, survival rate for patients suffering from brain metastases remains very poor. This is coupled with the incidence of brain metastases continuing to rise. In this review, we focus on core contributions of the blood-brain barrier to the origin of brain metastases. We first provide an overview of the structure and function of the blood-brain barrier under physiological conditions. Next, we discuss the emerging idea of a pre-metastatic niche, namely that secreted factors and extracellular vesicles from a primary tumor site are able to travel through the circulation and prime the neurovasculature for metastatic invasion. We then consider the neurotropic mechanisms that circulating tumor cells possess or develop that facilitate disruption of the blood-brain barrier and survival in the brain's parenchyma. Finally, we compare and contrast brain metastases at the blood-brain barrier to the primary brain tumor, glioma, examining the process of vessel co-option that favors the survival and outgrowth of brain malignancies.

The driving mechanism and targeting value of mimicry between vascular endothelial cells and tumor cells in tumor progression

The difficulty and poor prognosis of malignant tumor have always been a difficult problem to be solved. The internal components of solid tumor are complex, including tumor cells, stromal cells and immune cells, which play an important role in tumor proliferation, migration, metastasis and drug resistance. Hence, targeting of only the tumor cells will not likely improve survival. Various studies have reported that tumor cells and endothelial cells have high plasticity, which is reflected in the fact that they can simulate each other's characteristics by endothelial-mesenchymal transition (EndMT) and vasculogenic mimicry (VM). In this paper, this mutual mimicry concept was integrated and reviewed for the first time, and their similarities and implications for tumor development are discussed. At the same time, possible therapeutic methods are proposed to provide new directions and ideas for clinical targeted therapy and immunotherapy of tumor.

GDNF triggers proliferation of rat C6 glioma cells via the NF-κB/CXCL1 signaling pathway

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor that is characterized by its high proliferative and migratory potential, leading to a high invasiveness of this tumor type. However, the underlying mechanism of GBM proliferation and migration has not been fully elucidated. In this study, at first, we used RNA-seq together with bioinformatics technology to screen for C-X-C motif ligand 1 (CXCL1) as a proliferation-related gene. And exogenous glial cell line-derived neurotrophic factor (GDNF) induced proliferation and up-regulated the level of CXCL1 in rat C6 glioma cells determined by sqPCR and ELISA. Then, we manipulated the CXCL1 expression by using a lentiviral vector (CXCL1-RNAi) approach. By this, the proliferation of C6 cells was decreased, suggesting that CXCL1 plays a key role in proliferation in these cells. We hypothesized that exogenous GDNF promoted NF-κB nuclear translocation and therefore, analyzed the interaction of CXCL1 with NF-κB by Western Blot and immunofluorescence. Additionally, we used BAY 11-7082, a phosphorylation inhibitor of NF-κB, to elucidate NF-κB mediated the effect of GDNF on CXCL1. These results demonstrated that GDNF enhanced the proliferation of rat C6 glioma cells through activating the NF-κB/CXCL1 signaling pathway. In summary, these studies not only revealed the mechanism of action of exogenous GDNF in promoting the proliferation of C6 glioma cells but may also provide a new biological target for the treatment of malignant glioma.

Cellular senescence in glioma

INTRODUCTION

Glioma is the most common primary brain tumor and is often associated with treatment resistance and poor prognosis. Standard treatment typically involves radiotherapy and temozolomide-based chemotherapy, both of which induce cellular senescence-a tumor suppression mechanism.

DISCUSSION

Gliomas employ various mechanisms to bypass or escape senescence and remain in a proliferative state. Importantly, senescent cells remain viable and secrete a large number of factors collectively known as the senescence-associated secretory phenotype (SASP) that, paradoxically, also have pro-tumorigenic effects. Furthermore, senescent cells may represent one form of tumor dormancy and play a role in glioma recurrence and progression.

CONCLUSION

In this article, we delineate an overview of senescence in the context of gliomas, including the mechanisms that lead to senescence induction, bypass, and escape. Furthermore, we examine the role of senescent cells in the tumor microenvironment and their role in tumor progression and recurrence. Additionally, we highlight potential therapeutic opportunities for targeting senescence in glioma.

FAK/IL-8 axis promotes the proliferation and migration of gastric cancer cells

Gastric cancer (GC) is one of the most common malignancies in China and is associated with high mortality. The occurrence and development of gastric cancer are related to genetic and environmental factors. Focal adhesion kinase (FAK) is a cytoplasmic nonreceptor protein tyrosine kinase that is activated by the extracellular matrix and growth factors. FAK is highly expressed in cancer and promotes its development by regulating cancer cell proliferation, migration, and angiogenesis. The expression of IL-8 is increased in many types of malignant tumor cells and is linked to their proliferation, migration, invasion, angiogenesis, and EMT. In this study, we found FAK to be essential for the proliferation, migration, and peritoneal metastasis of gastric cancer cells. To examine the molecular regulatory mechanisms of FAK in the peritoneal dissemination of gastric cancer, we performed RNA-seq analysis of MKN-45-FAK-/- and MKN45 cells and demonstrated that IL-8 was downregulated in FAK-deficient cells. Conversely, we confirmed that IL-8 activates FAK activity. We established that IL-8 promotes the proliferation, colony formation, and migration of gastric cancer cells that are partially mediated by FAK. Thus, we propose that an IL-8-FAK-IL-8 positive feedback loop effects the proliferation and migration of gastric cancer cells.

Mechanisms of neutrophil extracellular trap in chronic inflammation of endothelium in atherosclerosis

Cardiovascular diseases are a primary cause of morbidity and mortality around the world. In addition, atherosclerosis (AS)-caused cardiovascular disease is the primary cause of death in human diseases, and almost two billion people suffer from carotid AS worldwide. AS is caused by chronic inflammation of the arterial vessel and is initiated by dysfunction of vascular endothelial cells. Neutrophils protect against pathogen invasion because they function as a component of the innate immune system. However, the contribution of neutrophils to cardiovascular disease has not yet been clarified. Neutrophil extracellular traps (NETs) represent an immune defense mechanism that is different from direct pathogen phagocytosis. NETs are extracellular web-like structures activated by neutrophils, and they play important roles in promoting endothelial inflammation via direct or indirect pathways. NETs consist of DNA, histones, myeloperoxidase, matrix metalloproteinases, proteinase 3, etc. Most of the components of NETs have no direct toxic effect on endothelial cells, such as DNA, but they can damage endothelial cells indirectly. In addition, NETs play a critical role in the process of AS; therefore, it is important to clarify the mechanisms of NETs in AS because NETs are a new potential therapeutic target AS. This review summarizes the possible mechanisms of NETs in AS.

NET-(works) in arterial and venous thrombo-occlusive diseases

Formation of Neutrophil Extracellular Traps (NETosis), accompanied by the release of extracellular decondensed chromatin and pro-inflammatory as well as pro-thrombotic factors, is a pivotal element in the development and progression of thrombo-occlusive diseases. While the process of NETosis is based on complex intracellular signalling mechanisms, it impacts a wide variety of cells including platelets, leukocytes and endothelial cells. Consequently, although initially mainly associated with venous thromboembolism, NETs also affect and mediate atherothrombosis and its acute complications in the coronary, cerebral and peripheral arterial vasculature. In this context, besides deep vein thrombosis and pulmonary embolism, NETs in atherosclerosis and especially its acute complications such as myocardial infarction and ischemic stroke gained a lot of attention in the cardiovascular research field in the last decade. Thus, since the effect of NETosis on platelets and thrombosis in general is extensively discussed in other review articles, this review focusses on the translational and clinical relevance of NETosis research in cardiovascular thrombo-occlusive diseases. Consequently, after a brief summary of the neutrophil physiology and the cellular and molecular mechanisms underlying NETosis are presented, the role of NETosis in atherosclerotic and venous thrombo-occlusive diseases in chronic and acute settings are discussed. Finally, potential prevention and treatment strategies of NET-associated thrombo-occlusive diseases are considered.

Ribonucleotide reductase regulatory subunit M2 drives glioblastoma TMZ resistance through modulation of dNTP production

During therapy, adaptations driven by cellular plasticity are partly responsible for driving the inevitable recurrence of glioblastoma (GBM). To investigate plasticity-induced adaptation during standard-of-care chemotherapy temozolomide (TMZ), we performed in vivo single-cell RNA sequencing in patient-derived xenograft (PDX) tumors of GBM before, during, and after therapy. Comparing single-cell transcriptomic patterns identified distinct cellular populations present during TMZ therapy. Of interest was the increased expression of ribonucleotide reductase regulatory subunit M2 (RRM2), which we found to regulate dGTP and dCTP production vital for DNA damage response during TMZ therapy. Furthermore, multidimensional modeling of spatially resolved transcriptomic and metabolomic analysis in patients' tissues revealed strong correlations between RRM2 and dGTP. This supports our data that RRM2 regulates the demand for specific dNTPs during therapy. In addition, treatment with the RRM2 inhibitor 3-AP (Triapine) enhances the efficacy of TMZ therapy in PDX models. We present a previously unidentified understanding of chemoresistance through critical RRM2-mediated nucleotide production.

HDAC1 mediates epithelial-mesenchymal transition and promotes cancer cell invasion in glioblastoma

Glioblastoma multiforme (GBM) is one of the most malignant tumors of the central nervous system, and its treatment has always been a difficult clinical problem. Here, we evaluated HDAC1 expression patterns and their effect on prognosis based on GBM cases from TCGA and CGGA databases. Expression was compared between GBM samples and normal controls. High HDAC1 expression was found to be an indicator of poor prognosis in glioblastoma. We also established a protein-protein interaction network to explore HDAC1-related interacting proteins, including the epithelial-mesenchymal transition (EMT)-related protein VIM, which is closely associated with HDAC1. Consistently, functional enrichment analysis showed that several GBM tissues with high HDAC1 were enriched in the expression of cancer markers, such as those involved in glycolysis, hypoxia, inflammation, and some signaling pathways. Next, this study analyzed the effect of HDAC1 on invasive ability and the EMT signaling pathway in GBM cells in vitro. The results showed that an HDAC1 inhibitor (RGFP109) could inhibit the EMT process in glioma cells in vitro, thereby affecting the invasion and migration of cells. Similar results were obtained based on in vivo studies. Our data suggest that HDAC1 has the potential to be a powerful prognostic biomarker, which might provide a basis for developing therapeutic targets for GBM.

A systematic pan-cancer analysis reveals the clinical prognosis and immunotherapy value of C-X3-C motif ligand 1 (CX3CL1)

It is now widely known that C-X3-C motif ligand 1 (CX3CL1) plays an essential part in the process of regulating pro-inflammatory cells migration across a wide range of inflammatory disorders, including a number of malignancies. However, there has been no comprehensive study on the correlation between CX3CL1 and cancers on the basis of clinical features. In order to investigate the potential function of CX3CL1 in the clinical prognosis and immunotherapy, I evaluated the expression of CX3CL1 in numerous cancer types, methylation levels and genetic alterations. I found CX3CL1 was differentially expressed in numerous cancer types, which indicated CX3CL1 may plays a potential role in tumor progression. Furthermore, CX3CL1 was variably expressed in methylation levels and gene alterations in most cancers according to The Cancer Genome Atlas (TCGA). CX3CL1 was robustly associated with clinical characteristics and pathological stages, suggesting that it was related to the degree of tumor malignancy and the physical function of patients. As determined by the Kaplan-Meier method of estimating survival, high CX3CL1 expression was associated with either favorable or unfavorable outcomes depending on the different types of cancer. It suggests the correlation between CX3CL1 and tumor prognosis. Significant positive correlations of CX3CL1 expression with CD4⁺ T cells, M1 macrophage cells and activated mast cells have been established in the majority of TCGA malignancies. Which indicates CX3CL1 plays an important role in tumor immune microenvironment. Gene Ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis suggested that the chemokine signaling pathway may shed light on the pathway for CX3CL1 to exert function. In a conclusion, our study comprehensively summarizes the potential role of CX3CL1 in clinical prognosis and immunotherapy, suggesting that CX3CL1 may represent a promising pharmacological treatment target of tumors.

Current perspectives on diffuse midline glioma and a different role for the immune microenvironment compared to glioblastoma

Diffuse midline glioma (DMG), formerly called diffuse intrinsic pontine glioma (DIPG), is a high-grade malignant pediatric brain tumor with a near-zero survival rate. To date, only radiation therapy provides marginal survival benefit; however, the median survival time remains less than a year. Historically, the infiltrative nature and sensitive location of the tumor rendered surgical removal and biopsies difficult and subsequently resulted in limited knowledge of the disease, as only post-mortem tissue was available. Therefore, clinical decision-making was based upon experience with the more frequent and histologically similar adult glioblastoma (GBM). Recent advances in tissue acquisition and molecular profiling revealed that DMG and GBM are distinct disease entities, with separate tissue characteristics and genetic profiles. DMG is characterized by heterogeneous tumor tissue often paired with an intact blood–brain barrier, possibly explaining its resistance to chemotherapy. Additional profiling shed a light on the origin of the disease and the influence of several mutations such as a highly recurring K27M mutation in histone H3 on its tumorigenesis. Furthermore, early evidence suggests that DMG has a unique immune microenvironment, characterized by low levels of immune cell infiltration, inflammation, and immunosuppression that may impact disease development and outcome. Within the tumor microenvironment of GBM, tumor-associated microglia/macrophages (TAMs) play a large role in tumor development. Interestingly, TAMs in DMG display distinct features and have low immune activation in comparison to other pediatric gliomas. Although TAMs have been investigated substantially in GBM over the last years, this has not been the case for DMG due to the lack of tissue for research. Bit by bit, studies are exploring the TAM–glioma crosstalk to identify what factors within the DMG microenvironment play a role in the recruitment and polarization of TAMs. Although more research into the immune microenvironment is warranted, there is evidence that targeting or stimulating TAMs and their factors provide a potential treatment option for DMG. In this review, we provide insight into the current status of DMG research, assess the knowledge of the immune microenvironment in DMG and GBM, and present recent findings and therapeutic opportunities surrounding the TAM–glioma crosstalk.

Combining TMZ and SB225002 induces changes of CXCR2 and VEGFR signalling in primary human endothelial cells in vitro

Standard of care therapy for glioblastoma (GBM) consisting of surgical removal, temozolomide (TMZ) and radiotherapy fails to cure the disease and median survival is limited to 15 months. Therapeutic approaches targeting vascular endothelial growth factor (VEGF)-mediated angiogenesis, one of the major drivers of tumour growth, have not prolonged patient survival as reported in clinical studies. Apart from VEGFR signalling, proangiogenic C-X-C motif chemokine receptor 2 (CXCR2) is of special interest as its ligands C-X-C motif chemokine ligand 2 (CXCL2) and interleukin-8 (IL8) are upregulated and associated with reduced survival in GBM patients. As CXCR2 is also expressed by endothelial cells, the aim of the present study was to elucidate the effect of combination therapy on gene and protein expression of primary human endothelial cells (HUVECs). To mimic the GBM specific CXCL2/IL8 oversupply environment [referred to as stimulation (STIM)], HUVECs were treated with a cocktail of CXCL2/IL8 and/or TMZ and/or CXCR2-antagonist SB225002 (SB). In brief, six treatment conditions were utilized: i) Control, ii) STIM (CXCL2/IL8), iii) TMZ + SB, iv) STIM + TMZ, v) STIM + SB, vi) STIM + TMZ + SB followed by either RNA-isolation and RT-qPCR for BAX, BCL2, vascular endothelial growth receptor (VEGFR)1/2, VEGF, CXCR1/2, CXCL2 and IL8 or immunofluorescence staining for VEGFR2 and CXCR2. SB and TMZ led to morphological changes of HUVECs and downregulated antiapoptotic BCL2 in vitro. In addition, gene expression of the alternative proangiogenic CXCL2/IL8/CXCR2 signalling pathway was significantly altered by the combination therapy, while the VEGF/VEGFR1/2 axis was only mildly affected. Furthermore, VEGFR2 and CXCR2 gene and protein expression regulation differed. VEGFR2 was not altered at the gene expression level, while combination therapy with TMZ and SB led to a 74% upregulation of VEGFR2 at the protein level. By contrast, CXCR2 was upregulated 5-fold by the combination therapy at the gene expression level and downregulated by 72.5% at the protein expression level. The present study provided first insights into the molecular changes of two major proangiogenic pathways in primary endothelial cells during treatment with TMZ and SB. Different gene and protein expression levels of the proangiogenic receptors CXCR2 and VEGFR2 in vitro must be taken into consideration in future studies.

Immunotherapy checkpoints in ovarian cancer vasculogenic mimicry: Tumor immune microenvironments, and drugs

Vasculogenic mimicry (VM), a vessel-like structure independent of endothelial cells, commonly exists in solid tumors which requires blood vessels to grow. As a special source of blood supply for tumor progression to a more aggressive state, VM has been observed in a variety of human malignant tumors and is tightly associated with tumor proliferation, invasion, metastasis, and poor patient prognosis. So far, various factors, including immune cells and cytokines, were reported to regulate ovarian cancer progression by influencing VM formation. Herein, we review the mechanisms that regulate VM formation in ovarian cancer and the effect of cells, cytokines, and signaling molecules in the tumor microenvironment on VM formation, Furthermore, we summarize the current clinical application of drugs targeting VM formation.

Ascendancy of unfolded protein response over glioblastoma: estimating progression, prognosis and survival

Glioblastoma (GBM) is presented with a poor prognosis. The endoplasmic reticulum stress (ERS) has been implicated as a major contributor to disease progression and chemoresistance in GBM. Triggering ERS by chemical agents or genetic modulations is identified as some of the reasons for regulating gene expression and the pathogenesis of GBM. ERS initiates unfolded protein response (UPR), an integrated system useful in restoring homeostasis or inducing apoptosis. Modulation of UPR might have positive outcomes in GBM treatment as UPR inducers have been shown to alter cell survival and migration. In the current review, we have utilized GSE7806, a publicly available dataset from Gene Expression Omnibus (GEO), to evaluate the genes expressed during 6.5 hr and 18 hr, which can be comparable to the early and late-onset of the disease. Subsequently, we have elucidated the prognosis and survival information whilst the expression of these genes in the GBM was noted in previous studies. This is the first of its kind review summarizing the most recent gene information correlating UPR and GBM.

Glioblastoma multiforme in patients with human immunodeficiency virus: an integrated review and analysis

INTRODUCTION

As lifespans for persons living with HIV (PLWH) have improved over the last decade, there has been a simultaneous increase in non-AIDS-related cancer in that group. However, there is a paucity of data regarding the incidence of glioblastoma multiforme (GBM) in PLWH. Better understanding of the oncogenesis, natural history, and treatment outcomes of GBM in PLWH should lead to improved treatment strategies.

METHODS

We performed a comprehensive literature search of six electronic databases to identify eligible cases of GBM among PLWH. Kaplan-Meier estimates, Fisher's exact test, and logistic regression were used to interrogate the data. Epidemiologic data on global HIV prevalence was obtained from the 2016 UNAIDS incidence report, and CNS cancer incidence was obtained from the GDB 2016 Brain and Other CNS Cancer Collaborators.

RESULTS

There is an inverse relationship between the incidence of HIV and CNS cancer globally. Median overall survival (OS) from GBM diagnosis was 8 months. Estimates for survival at 1 and 2 years were 28 and 5%, respectively. There were no statistically significant predictors of OS in this setting. There was a significant difference (p < 0.01) in OS in PLWH and GBM when compared to TCGA age matched cohorts.

CONCLUSION

The diagnosis of GBM in PLWH is severely underreported in the literature. Despite maximal treatment, OS in this patient population is significantly less than in HIV-negative people. There was a poor prognosis of GBM in PLWH, which is inconsistent with previous reports. Further investigation is required for PLWH and concomitant GBM. Analyses must consider if HAART is maintained in PLWH during GBM treatment.

Annexin-1 is an oncogene in glioblastoma and causes tumour immune escape through the indirect upregulation of interleukin-8

Annexin‐1 (ANXA1) is widely reported to be deregulated in various cancers and is involved in tumorigenesis. However, its effects on glioblastoma (GBM) remain unclear. Using immunohistochemistry with tissue microarrays, we showed that ANXA1 was overexpressed in GBM, positively correlated with higher World Health Organization (WHO) grades of glioma, and negatively associated with poor survival. To further explore its role and the underlying molecular mechanism in GBM, we constructed ANXA1shRNA U87 and U251 cell lines for further experiments. ANXA1 downregulation suppressed GBM cell proliferation, migration, and invasion and enhanced their radiosensitivity. Furthermore, we determined that ANXA1 was involved in dendritic cell (DC) maturation in patients with GBM and that DC infiltration was inversely proportional to GBM prognosis. Considering that previous reports have shown that Interleukin‐8 (IL‐8) is associated with DC migration and maturation and is correlated with NF‐κB transcriptional regulation, we examined IL‐8 and p65 subunit expressions and p65 phosphorylation levels in GBM cells under an ANXA1 knockdown. These results suggest that ANXA1 significantly promotes IL‐8 production and p65 phosphorylation levels. We inferred that ANXA1 is a potential biomarker and a candidate therapeutic target for GBM treatment and may mediate tumour immune escape through NF‐kB (p65) activation and IL‐8 upregulation.

Dynamic Interactions between Tumor Cells and Brain Microvascular Endothelial Cells in Glioblastoma

Simple Summary

In glioblastoma (GBM), tumor cells develop a symbiotic relation with brain microvascular endothelial cells (BMECs) to shift tissue homeostasis toward a tumor-supporting context. Disentangling the molecular mechanisms that govern this dynamic interaction in the context of GBM represents an exciting challenge for the update of conventional treatment and for the development of novel therapeutic targets for this aggressive and lethal brain tumor.

Abstract

GBM is the most aggressive brain tumor among adults. It is characterized by extensive vascularization, and its further growth and recurrence depend on the formation of new blood vessels. In GBM, tumor angiogenesis is a multi-step process involving the proliferation, migration and differentiation of BMECs under the stimulation of specific signals derived from the cancer cells through a wide variety of communication routes. In this review, we discuss the dynamic interaction between BMECs and tumor cells by providing evidence of how tumor cells hijack the BMECs for the formation of new vessels. Tumor cell–BMECs interplay involves multiple routes of communication, including soluble factors, such as chemokines and cytokines, direct cell–cell contact and extracellular vesicles that participate in and fuel this cooperation. We also describe how this interaction is able to modify the BMECs structure, metabolism and physiology in a way that favors tumor growth and invasiveness. Finally, we briefly reviewed the recent advances and the potential future implications of some high-throughput 3D models to better understanding the complexity of BMECs–tumor cell interaction.

Human endothelial cells promote arsenic-transformed lung epithelial cells to induce tumor growth and angiogenesis through interleukin-8 induction

Arsenic exposure is associated with lung cancer. Angiogenesis is essential for tumor development. However, the role and mechanism of human vascular endothelial cells in tumor growth and angiogenesis induced by arsenic-transformed bronchial epithelial (As-T) cells remain to be elucidated. In this study, we found that endothelial cells significantly increased As-T cell-induced tumor growth compared to those induced by As-T cells alone. To understand the molecular mechanism, we found that endothelial cells co-cultured with As-T cells or cultured in conditioned medium (CM) prepared from As-T cells showed much higher cell migration, proliferation, and tube formation compared to those co-cultured with BEAS-2B (B2B) cells or cultured in CM from B2B. We identified that higher levels of intracellular interleukin 8 (IL-8) were secreted by As-T cells, which activated IL-8/IL-8R signaling to promote endothelial cells migration and tube formation. IL-8 silencing and knockout (KO) in As-T cells, or IL-8 neutralizing antibody dramatically suppressed endothelial cell proliferation, migration, tube formation in vitro, and tumor growth and angiogenesis in vivo, suggesting a key role of IL-8 in As-T cells to induce angiogenesis via a paracrine effect. Finally, blocking of IL-8 receptors C-X-C chemokine receptor type 1 (CXCR1) and CXCR2 with neutralizing antibodies and chemical inhibitors inhibited tube formation, indicating that IL-8Rs on endothelial cells are necessary for As-T cell-induced angiogenesis. Overall, this study reveals an important molecular mechanism of arsenic-induced carcinogenesis, and suggests a new option to prevent and treat arsenic-induced angiogenesis.

Necrotic reshaping of the glioma microenvironment drives disease progression

Glioblastoma is the most common primary brain tumor and has a dismal prognosis. The development of central necrosis represents a tipping point in the evolution of these tumors that foreshadows aggressive expansion, swiftly leading to mortality. The onset of necrosis, severe hypoxia and associated radial glioma expansion correlates with dramatic tumor microenvironment (TME) alterations that accelerate tumor growth. In the past, most have concluded that hypoxia and necrosis must arise due to "cancer outgrowing its blood supply" when rapid tumor growth outpaces metabolic supply, leading to diffusion-limited hypoxia. However, growing evidence suggests that microscopic intravascular thrombosis driven by the neoplastic overexpression of pro-coagulants attenuates glioma blood supply (perfusion-limited hypoxia), leading to TME restructuring that includes breakdown of the blood-brain barrier, immunosuppressive immune cell accumulation, microvascular hyperproliferation, glioma stem cell enrichment and tumor cell migration outward. Cumulatively, these adaptations result in rapid tumor expansion, resistance to therapeutic interventions and clinical progression. To inform future translational investigations, the complex interplay among environmental cues and myriad cell types that contribute to this aggressive phenotype requires better understanding. This review focuses on contributions from intratumoral thrombosis, the effects of hypoxia and necrosis, the adaptive and innate immune responses, and the current state of targeted therapeutic interventions.

Gas Plasma Exposure of Glioblastoma Is Cytotoxic and Immunomodulatory in Patient-Derived GBM Tissue

Simple Summary

Despite treatment advances, glioblastoma multiforme (GBM) remains an often-fatal disease, motivating novel therapeutic avenues. Gas plasma is a technology that has been recently employed in preclinical oncology research and acts primarily via reactive oxygen-species-induced cell death. In addition, the modulation of immune processes and inflammation have been ascribed to gas plasma exposure. This is the first study that extends those observations from in vitro investigations to a set of 16 patient-derived GBM tumor biopsies analyzed after gas plasma treatment ex vivo. Besides cell culture results showing cell cycle arrest and apoptosis induction, an immunomodulatory potential was identified for gas plasma exposure in vitro and cultured GBM tissues. The proapoptotic action shown in this study might be an important step forward to the first clinical observational studies on the future discovery of gas plasma technology’s potential in neurosurgery and neuro-oncology.

Abstract

Glioblastoma multiforme (GBM) is the most common primary malignant adult brain tumor. Therapeutic options for glioblastoma are maximal surgical resection, chemotherapy, and radiotherapy. Therapy resistance and tumor recurrence demand, however, new strategies. Several experimental studies have suggested gas plasma technology, a partially ionized gas that generates a potent mixture of reactive oxygen species (ROS), as a future complement to the existing treatment arsenal. However, aspects such as immunomodulation, inflammatory consequences, and feasibility studies using GBM tissue have not been addressed so far. In vitro, gas plasma generated ROS that oxidized cells and led to a treatment time-dependent metabolic activity decline and G2 cell cycle arrest. In addition, peripheral blood-derived monocytes were co-cultured with glioblastoma cells, and immunomodulatory surface expression markers and cytokine release were screened. Gas plasma treatment of either cell type, for instance, decreased the expression of the M2-macrophage marker CD163 and the tolerogenic molecule SIGLEC1 (CD169). In patient-derived GBM tissue samples exposed to the plasma jet kINPen ex vivo, apoptosis was significantly increased. Quantitative chemokine/cytokine release screening revealed gas plasma exposure to significantly decrease 5 out of 11 tested chemokines and cytokines, namely IL-6, TGF-β, sTREM-2, b-NGF, and TNF-α involved in GBM apoptosis and immunomodulation. In summary, the immuno-modulatory and proapoptotic action shown in this study might be an important step forward to first clinical observational studies on the future discovery of gas plasma technology’s potential in neurosurgery and neuro-oncology especially in putative adjuvant or combinatory GBM treatment settings.

Overexpression of BQ323636.1 Modulated AR/IL-8/CXCR1 Axis to Confer Tamoxifen Resistance in ER-Positive Breast Cancer

NCOR2 is a co-repressor for estrogen receptor (ER) and androgen receptor (AR). Our group previously identified a novel splice variant of NCOR2, BQ323636.1 (BQ), that mediates tamoxifen resistance via interference of NCOR2 repression on ER. Luciferase reporter assay showed BQ overexpression could enhance the transcriptional activity of androgen response element (ARE). We proposed that BQ employs both AR and ER to confer tamoxifen resistance. Through in silico analysis, we identified interleukin-8 (IL-8) as the sole ERE and ARE containing gene responsiveness to ER and AR activation. We confirmed that BQ overexpression enhanced the expression of IL-8 in ER+ve breast cancer cells, and AR inhibition reduced IL-8 expression in the BQ overexpressing cell lines, suggesting that AR was involved in the modulation of IL-8 expression by BQ. Moreover, we demonstrated that IL-8 could activate both AKT and ERK1/2 via CXCR1 to confer tamoxifen resistance. Targeting CXCR1/2 by a small inhibitor repertaxin reversed tamoxifen resistance of BQ overexpressing breast cancer cells in vitro and in vivo. In conclusion, BQ overexpression in ER+ve breast cancer can enhance IL-8 mediated signaling to modulate tamoxifen resistance. Targeting IL-8 signaling is a promising approach to overcome tamoxifen resistance in ER+ve breast cancer.

Enhanced expression of pentraxin-3 in glioblastoma cells correlates with increased invasion and IL8-VEGF signaling axis

Glioblastoma (GB) is highly invasive and resistant to multimodal treatment partly due to distorted vasculature and exacerbated inflammation. The aggressiveness of brain tumors may be attributed to the dysregulated release of angiogenic and inflammatory factors. The glycoprotein pentraxin-3 (PTX3) is correlated with the severity of some cancers. However, the mechanism responsible for the invasive oncogenic role of PTX3 in GB malignancy remains unclear. In this study, we examined the role of PTX3 in GB growth, angiogenesis, and invasion using in vitro and in vivo GB models, proteomic profiling, molecular and biochemical approaches. Under in vitro conditions, PTX3 over-expression in U87 cells correlated with cell cycle progression, increased migratory potential, and proliferation under hypoxic conditions. Conditioned media containing PTX3 enhanced the angiogenic potential of endothelial cells. While silencing of PTX3 by siRNA decreased the proliferation, migration, and angiogenic potential of U87 cells in vitro. Importantly, PTX3 over-expression increased tumor growth, angiogenesis, and invasion in an orthotopic mouse model. Higher levels of PTX3 in these tumors were associated with the upregulation of inflammatory and angiogenic markers including interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF), but decreased levels of thrombospondin-1, an anti-angiogenic factor. Mechanistically, exogenous production of PTX3 triggered an IKK/NFκB signaling pathway that enhances the expression of the motility genes AHGEF7 and Rac1. Taken together, PTX3 expression is dysregulated in GB. PTX3 may augment invasion through enhanced angiogenesis in the GB microenvironment through the IL8-VEGF axis. Thus, PTX3 may represent a potential therapeutic target to mitigate the aggressive behavior of gliomas.

The emerging roles of circular RNAs in vessel co-option and vasculogenic mimicry: clinical insights for anti-angiogenic therapy in cancers

Unexpected resistance to anti-angiogenic treatment prompted the investigation of non-angiogenic tumor processes. Vessel co-option (VC) and vasculogenic mimicry (VM) are recognized as primary non-angiogenic mechanisms. In VC, cancer cells utilize pre-existing blood vessels for support, whereas in VM, cancer cells channel and provide blood flow to rapidly growing tumors. Both processes have been implicated in the development of tumor and resistance to anti-angiogenic drugs in many tumor types. The morphology, but rare molecular alterations have been investigated in VC and VM. There is a pressing need to better understand the underlying cellular and molecular mechanisms. Here, we review the emerging circular RNA (circRNA)-mediated regulation of non-angiogenic processes, VC and VM.

Tumor-Associated Microglia/Macrophages as a Predictor for Survival in Glioblastoma and Temozolomide-Induced Changes in CXCR2 Signaling with New Resistance Overcoming Strategy by Combination Therapy

Tumor recurrence is the main challenge in glioblastoma (GBM) treatment. Gold standard therapy temozolomide (TMZ) is known to induce upregulation of IL8/CXCL2/CXCR2 signaling that promotes tumor progression and angiogenesis. Our aim was to verify the alterations on this signaling pathway in human GBM recurrence and to investigate the impact of TMZ in particular. Furthermore, a combi-therapy of TMZ and CXCR2 antagonization was established to assess the efficacy and tolerability. First, we analyzed 76 matched primary and recurrent GBM samples with regard to various histological aspects with a focus on the role of TMZ treatment and the assessment of predictors of overall survival (OS). Second, the combi-therapy with TMZ and CXCR2-antagonization was evaluated in a syngeneic mouse tumor model with in-depth immunohistological investigations and subsequent gene expression analyses. We observed a significantly decreased infiltration of tumor-associated microglia/macrophages (TAM) in recurrent tumors, while a high TAM infiltration in primary tumors was associated with a reduced OS. Additionally, more patients expressed IL8 in recurrent tumors and TMZ therapy maintained CXCL2 expression. In mice, enhanced anti-tumoral effects were observed after combi-therapy. In conclusion, high TAM infiltration predicts a survival disadvantage, supporting findings of the tumor-promoting phenotype of TAMs. Furthermore, the combination therapy seemed to be promising to overcome CXCR2-mediated resistance.

Initial Liver Copper Status in Finishing Beef Steers Fed Three Dietary Concentrations of Copper Affects Beta Agonist Performance, Carcass Characteristics, Lipolysis Response, and Muscle Inflammation Markers

Simple Summary

Beta agonists are commonly used in the United States beef industry, offering improved performance in the days leading up to harvest by influencing energy metabolism. Copper has been shown to regulate the biological pathway leading to increased lipid mobilization. However, this connection has not been evaluated in cattle. Therefore, the objective of this study was to determine how Cu influences beta agonist-induced performance, energy metabolism and inflammation in feedlot cattle. Supplementation of Cu resulted in increased liver Cu concentrations, while cattle performance, lipolysis, and some markers of inflammation responded to Cu supplementation differently, depending on whether or not cattle were fed a beta agonist. Therefore, strategic supplementation of Cu may help optimize growth of cattle receiving a beta agonist.

Abstract

Ninety-three Angus-crossbred steers (470 ± 35 kg) were assigned to a 3 × 2 factorial to determine the effects of Cu status and beta agonist (BA) on performance, carcass characteristics, lipolytic rate, and muscle inflammation. Factors included Cu supplementation (mg Cu/kg dry matter (DM)) at: 0 (LO), 10 (MED), or 20 (HI) from Cu amino acid complex (Availa Cu; Zinpro) with no BA (NoRAC) or 300 mg·steer⁻¹·day⁻¹ of ractopamine hydrochloride (RAC; Optaflexx; Elanco) for final 28 days of 88-day trial. Linear and quadratic effects of Cu status within BA treatment were tested. Pre-BA gain was not affected by Cu supplementation (p ≥ 0.57), although day 53 liver Cu quadratically increased (p = 0.01). Average daily gain and muscle IL-8 gene expression quadratically increased (p ≤ 0.01), with MED having greatest gain and gene expression. Ribeye area tended to quadratically increase with Cu supplementation within RAC (p = 0.08). In vitro basal lipolytic rate tended to quadratically increase with Cu supplementation within RAC (p = 0.11), while stimulated lipolytic rate tended to linearly increase within NoRAC (p = 0.10). These data suggest lipolysis and the BA response of steers are influenced by dietary and liver Cu concentrations.

Targeting Tumor Immunosuppressive Microenvironment for the Prevention of Hepatic Cancer: Applications of Traditional Chinese Medicines in Targeted Delivery

Traditional Chinese Medicine (TCM) is one of the ancient and most accepted alternative medicinal systems in the world for the treatment of health ailments. World Health Organization recognizes TCM as one of the primary healthcare practices followed across the globe. TCM utilizes a holistic approach for the diagnosis and treatment of cancers. The tumor microenvironment (TME) surrounds cancer cells and plays pivotal roles in tumor development, growth, progression, and therapy resistance. TME is a hypoxic and acidic environment that includes immune cells, pericytes, fibroblasts, endothelial cells, various cytokines, growth factors, and extracellular matrix components. Targeting TME using targeted drug delivery and nanoparticles is an attractive strategy for the treatment of solid tumors and recently has received significant research attention under precise medicine concept. TME plays a pivotal role in the overall survival and metastasis of a tumor by stimulating cell proliferation, preventing the tumor clearance by the immune cells, enhancing the oncogenic potential of the cancer cells, and promoting tumor invasion. Hepatocellular Carcinoma (HCC) is one of the major causes of cancer-associated deaths affecting millions of individuals worldwide each year. TCM herbs contain several bioactive phytoconstituents with a broad range of biological, physiological, and immunological effects on the system. Several TCM herbs and their monomers have shown inhibitory effects in HCC by controlling the TME. This study reviews the fundamentals and applications of targeting strategies for immunosuppressing TME to treat cancers. This study focuses on TME targeting strategies using TCM herbs and the molecular mechanisms of several TCM herbs and their monomers on controlling TME.

Advances in Chemokine Signaling Pathways as Therapeutic Targets in Glioblastoma

With a median patient survival of 15 months, glioblastoma (GBM) is still one of the deadliest malign tumors. Despite immense efforts, therapeutic regimens fail to prolong GBM patient overall survival due to various resistance mechanisms. Chemokine signaling as part of the tumor microenvironment plays a key role in gliomagenesis, proliferation, neovascularization, metastasis and tumor progression. In this review, we aimed to investigate novel therapeutic approaches targeting various chemokine axes, including CXCR2/CXCL2/IL-8, CXCR3/CXCL4/CXCL9/CXCL10, CXCR4/CXCR7/CXCL12, CXCR6/CXCL16, CCR2/CCL2, CCR5/CCL5 and CX3CR1/CX3CL1 in preclinical and clinical studies of GBM. We reviewed targeted therapies as single therapies, in combination with the standard of care, with antiangiogenic treatment as well as immunotherapy. We found that there are many antagonist-, antibody-, cell- and vaccine-based therapeutic approaches in preclinical and clinical studies. Furthermore, targeted therapies exerted their highest efficacy in combination with other established therapeutic applications. The novel chemokine-targeting therapies have mainly been examined in preclinical models. However, clinical applications are auspicious. Thus, it is crucial to broadly investigate the recently developed preclinical approaches. Promising preclinical applications should then be investigated in clinical studies to create new therapeutic regimens and to overcome therapy resistance to GBM treatment.

Plasma IL-8 and ICOSLG as prognostic biomarkers in glioblastoma

Background

CNS immune privilege has been challenged in recent years. Glioblastoma (GBM) immune dysfunction includes complex interactions with the immune system outside the CNS. The aim of this study was to determine diagnostic and prognostic potential of immune-related proteins in plasma in GBM and interrogate biomarker presence in the brain tumor microenvironment (TME).

Methods

One hundred and fifty-eight patients with glioma WHO grade II–IV were included. Plasma collected at surgery was screened for 92 proteins using proximity extension assay technology and related to clinical outcome. Secretion and expression of candidate prognostic biomarkers were subsequently analyzed in 8 GBM cell lines and public RNAseq data.

Results

Plasma levels of 20 out of 92 screened proteins were significantly different in patients with GBM compared to patients with astrocytoma WHO grade II–III. High plasma interleukin-8 (IL-8) (hazard ratio [HR] = 1.52; P = .0077) and low CD244 (HR = 0.36; P = .0004) were associated with short progression-free survival and high plasma IL-8 (HR = 1.40; P = .044) and low ICOS ligand (ICOSLG) (HR = 0.17; P = .0003) were associated with short overall survival (OS) in newly diagnosed patients with GBM. A similar trend was found for ICOSLG (HR = 0.34; P = .053) in recurrent GBM. IL-8 was mostly secreted and expressed by mesenchymal GBM cell lines and expressed by vascular cells and immune cells in the TME. This was also the case for ICOSLG, although less consistent, and with additional expression in tumor-associated oligodendrocytes.

Conclusions

High plasma IL-8 and low ICOSLG at surgery are associated with short OS in newly diagnosed GBM. Source of plasma ICOSLG may be found outside the TME.

IL-1β Promotes Vasculogenic Mimicry of Breast Cancer Cells Through p38/MAPK and PI3K/Akt Signaling Pathways

Vasculogenic mimicry (VM), a micro vessel-like structure formed by the cancer cells, plays a pivotal role in cancer malignancy and progression. Interleukin-1 beta (IL-1β) is an active pro-inflammatory cytokine and elevated in many tumor types, including breast cancer. However, the effect of IL-1β on the VM of breast cancer has not been clearly elucidated. In this study, breast cancer cells (MCF-7 and MDA-MB-231) were used to study the effect of IL-1β on the changes that can promote VM. The evidence for VM stimulated by IL-1β was acquired by analyzing the expression of VM-associated biomarkers (VE-cadherin, VEGFR-1, MMP-9, MMP-2, c-Fos, and c-Jun) via western blot, immunofluorescent staining, and Immunohistochemistry (IHC). Additionally, morphological evidence was collected via Matrigel-based cord formation assay under normoxic/hypoxic conditions and microvessel examination through Hematoxylin and Eosin staining (H&E). Furthermore, the STRING and Gene Ontology database was also used to analyze the VM-associated interacting molecules stimulated by IL-β. The results showed that the expression of VM biomarkers was increased in both MCF-7 and MDA-MB-231 cells after IL-1β treatment. The increase in VM response was observed in IL-1β treated cells under both normoxia and hypoxia. IL-1β also increased the activation of transcription factor AP-1 complex (c-Fos/c-Jun). The bioinformatics data indicated that p38/MAPK and PI3K/Akt signaling pathways were involved in the IL-1β stimulation. It was further confirmed by the downregulated expression of VM biomarkers and reduced formation of the intersections upon the addition of the signaling pathway inhibitors. The study suggests that IL-1β stimulates the VM and its associated events in breast cancer cells via p38/MAPK and PI3K/Akt signaling pathways. Aiming the VM-associated molecular targets promoted by IL-1β may offer a novel anti-angiogenic therapeutic strategy to control the aggressiveness of breast cancer cells.

Anti-angiogenic and macrophage-based therapeutic strategies for glioma immunotherapy

As a new concept of glioma therapy, immunotherapy combined with standard therapies is a promising modality to improve glioma patient survival. VEGF and its signaling pathway molecules not only inhibit angiogenesis but also may reinforce the immunosuppressive tumor microenvironment, including promotion of the accumulation of immunosuppressive tumor-associated macrophages (TAMs). In this review, we discuss VEGF-targeted therapy as a new treatment option of the TAM-targeted therapy for high-grade gliomas, as well as other TAM-targeted therapies. The authors also discuss the potential of these therapies combined with conventional immunotherapies.

Tyro3, Axl, Mertk receptor-mediated efferocytosis and immune regulation in the tumor environment

Three structurally related tyrosine receptor cell surface kinases, Tyro3, Axl, and Mertk (TAM) have been recognized to modulate immune function, tissue homeostasis, cardiovasculature, and cancer. The TAM receptor family appears to operate in adult mammals across multiple cell types, suggesting both widespread and specific regulation of cell functions and immune niches. TAM family members regulate tissue homeostasis by monitoring the presence of phosphatidylserine expressed on stressed or apoptotic cells. The detection of phosphatidylserine on apoptotic cells requires intermediary molecules that opsonize the dying cells and tether them to TAM receptors on phagocytes. This complex promotes the engulfment of apoptotic cells, also known as efferocytosis, that leads to the resolution of inflammation and tissue healing. The immune mechanisms dictating these processes appear to fall upon specific family members or may involve a complex of different receptors acting cooperatively to resolve and repair damaged tissues. Here, we focus on the role of TAM receptors in triggering efferocytosis and its consequences in the regulation of immune responses in the context of inflammation and cancer.

The Cell Line-Dependent Diversity in Initial Morphological Dynamics of Pancreatic Cancer Cell Peritoneal Metastasis Visualized by an Artificial Human Peritoneal Model

BACKGROUND

Pancreatic ductal adenocarcinoma is considered as one of the most malignant types of cancer with rapid metastasis and invasion of the cancer cells, having peritoneal metastasis (PM) as a dominant factor of poor prognosis. Although the prevention of peritoneal dissemination would result in the inhibition of the initial metastatic process and contribute in improving the poor prognosis of the pancreatic cancer, the initial dynamics of PM are still unclear because of the lack of adequate models in studying the morphological and molecular details of pancreatic cancer cells.

MATERIALS AND METHODS

The artificial human peritoneal tissue (AHPT) that can be applied in studying for the spatial dynamics of cancer PM in vitro has been established previously. In this study, the initial dynamics of the three pancreatic cell lines, undifferentiated carcinoma MIA PaCa-2, poorly differentiated adenocarcinoma Panc-1, and moderately differentiated adenocarcinoma BxPC3 on AHPT are examined.

RESULTS

In a morphological analysis using light and electron microscopy, MIA PaCa-2 cells spread on the mesothelial layer with disruption of the sheet structure and infiltrated into the stroma-like tissue in AHPT. On the other hand, BxPC3 cells changed shapes from round into flat ones with rapid proliferation and formed sheet structure at the surface of the tissue replacing the mesothelial layer without vertical invasion into the tissue. Panc-1 cells demonstrated the intermediate characteristics of MIA PaCa-2 and BxPC3 on AHPT. These diverse morphological characteristics were verified by the correspondence with the results in a mouse model and were reflected by the profile of secreted oncogenic proteins of the three pancreatic cell lines.

CONCLUSIONS

The initial dynamics in the peritoneal dissemination of these pancreatic cancer cell lines were demonstrated by AHPT, showing the morphological and molecular diversity depending on the degree of differentiation or the properties of oncogenic protein secretion.

Paracrine interleukin-8 affects mesenchymal stem cells through the Akt pathway and enhances human umbilical vein endothelial cell proliferation and migration

Interleukin-8 (IL-8) promotes cell homing and angiogenesis, but its effects on activating human bone marrow mesenchymal stem cells (BMSCs) and promoting angiogenesis are unclear. We used bioinformatics to predict these processes. In vitro, BMSCs were stimulated in a high-glucose (HG) environment with 50 or 100 μg/ml IL-8 was used as the IL-8 group. A total of 5 μmol/l Triciribine was added to the two IL-8 groups as the Akt inhibitor group. Cultured human umbilical vein endothelial cells (HUVECs) were cultured in BMSCs conditioned medium (CM). The changes in proliferation, apoptosis, migration ability and levels of VEGF and IL-6 in HUVECs were observed in each group. Seventy processes and 26 pathways were involved in vascular development, through which IL-8 affected BMSCs. Compared with the HG control group, HUVEC proliferation absorbance value (A value), Gap closure rate, and Transwell cell migration rate in the IL-8 50 and IL-8 100 CM groups were significantly increased (P<0.01, n=30). However, HUVEC apoptosis was significantly decreased (P<0.01, n=30). Akt and phospho-Akt (P-Akt) protein contents in lysates of BMSCs treated with IL-8, as well as VEGF and IL-6 protein contents in the supernatant of BMSCs treated with IL-8, were all highly expressed (P<0.01, n=15). These analyses confirmed that IL-8 promoted the expression of 41 core proteins in BMSCs through the PI3K Akt pathway, which could promote the proliferation and migration of vascular endothelial cells. Therefore, in an HG environment, IL-8 activated the Akt signaling pathway, promoted paracrine mechanisms of BMSCs, and improved the proliferation and migration of HUVECs.

Residual Disease in Glioma Recurrence: A Dangerous Liaison with Senescence

With a dismally low median survival of less than two years after diagnosis, Glioblastoma (GBM) is the most lethal type of brain cancer. The standard-of-care of surgical resection, followed by DNA-damaging chemo-/radiotherapy, is often non-curative. In part, this is because individual cells close to the resection border remain alive and eventually undergo renewed proliferation. These residual, therapy-resistant cells lead to rapid recurrence, against which no effective treatment exists to date. Thus, new experimental approaches need to be developed against residual disease to prevent GBM survival and recurrence. Cellular senescence is an attractive area for the development of such new approaches. Senescence can occur in healthy cells when they are irreparably damaged. Senescent cells develop a chronic secretory phenotype that is generally considered pro-tumorigenic and pro-migratory. Age is a negative prognostic factor for GBM stage, and, with age, senescence steadily increases. Moreover, chemo-/radiotherapy can provide an additional increase in senescence close to the tumor. In light of this, we will review the importance of senescence in the tumor-supportive brain parenchyma, focusing on the invasion and growth of GBM in residual disease. We will propose a future direction on the application of anti-senescence therapies against recurrent GBM.

The CXCL2/IL8/CXCR2 Pathway Is Relevant for Brain Tumor Malignancy and Endothelial Cell Function

We aimed to evaluate the angiogenic capacity of CXCL2 and IL8 affecting human endothelial cells to clarify their potential role in glioblastoma (GBM) angiogenesis. Human GBM samples and controls were stained for proangiogenic factors. Survival curves and molecule correlations were obtained from the TCGA (The Cancer Genome Atlas) database. Moreover, proliferative, migratory and angiogenic activity of peripheral (HUVEC) and brain specific (HBMEC) primary human endothelial cells were investigated including blockage of CXCR2 signaling with SB225502. Gene expression analyses of angiogenic molecules from endothelial cells were performed. Overexpression of VEGF and CXCL2 was observed in GBM patients and associated with a survival disadvantage. Molecules of the VEGF pathway correlated but no relation for CXCR1/2 and CXCL2/IL8 was found. Interestingly, receptors of endothelial cells were not induced by addition of proangiogenic factors in vitro. Proliferation and migration of HUVEC were increased by VEGF, CXCL2 as well as IL8. Their sprouting was enhanced through VEGF and CXCL2, while IL8 showed no effect. In contrast, brain endothelial cells reacted to all proangiogenic molecules. Additionally, treatment with a CXCR2 antagonist led to reduced chemokinesis and sprouting of endothelial cells. We demonstrate the impact of CXCR2 signaling on endothelial cells supporting an impact of this pathway in angiogenesis of glioblastoma.

VE-cadherin fusion protein substrate enhanced the vasculogenic mimicry capability of hepatocellular carcinoma cells

To investigate the VE-cadherin-based intercellular crosstalk in tumor cells, a fusion protein consisting of a human VE-cadherin extracellular domain and an immunoglobulin G Fc region (hVE-cad-Fc) was prepared as an artificial extracellular matrix (ECM) for the culture of hepatocellular carcinoma cells (Bel7402 cells). Compared with cells cultured on TCPS and collagen coated plates, the Bel7402 cells cultured on a series concentration of hVE-cad-Fc coated plates showed elongated morphology, inhibited proliferation, and significantly enhanced migration and secretion of ECM compounds and cytokines in a concentration-dependent manner. When the concentration of hVE-cad-Fc reached 15 μg mL-1, the Bel7402 cells formed a patterned network with positive-staining of PAS. The high-density hVE-cad-Fc substrate markedly elevated the expression of endogenous VE-cadherin and EphA2, and subsequently activated the intracellular signal transduction pathways including VE-cadherin/PI3K/MMPs and VE-cadherin/EphA2/FAK/p-VE-cadherin axes as well as epithelial-mesenchymal transition (EMT). Therefore, the high-density hVE-cad-Fc substrate was able to induce the vasculogenic mimicry (VM) formation of Bel7402 cells, and exhibit the potential for the construction of an in vitro tumor model of VM. Moreover, hVE-cad-Fc appeared to be a promising candidate for the investigation of VE-cadherin mediated cell-cell interactions in tumor development.

Research Supporting a Pilot Study of Metronomic Dapsone during Glioblastoma Chemoirradiation

This short note presents previous research data supporting a pilot study of metronomic dapsone during the entire course of glioblastoma treatment. The reviewed data indicate that neutrophils are an integral part of human glioblastoma pathophysiology, contributing to or facilitating glioblastoma growth and treatment resistance. Neutrophils collect within glioblastoma by chemotaxis along several chemokine/cytokine gradients, prominently among which is interleukin-8. Old data from dermatology research has shown that the old and inexpensive generic drug dapsone inhibits neutrophils' chemotaxis along interleukin-8 gradients. It is on that basis that dapsone is used to treat neutrophilic dermatoses, for example, dermatitis herpetiformis, bullous pemphigoid, erlotinib-related rash, and others. The hypothesis of this paper is that dapsone will reduce glioblastomas' neutrophil accumulations by the same mechanisms by which it reduces dermal neutrophil accumulations in the neutrophilic dermatoses. Dapsone would thereby reduce neutrophils' contributions to glioblastoma growth. Dapsone is not an ideal drug, however. It generates methemoglobinemia that occasionally is symptomatic. This generation is reduced by concomitant use of the antacid drug cimetidine. Given the uniform lethality of glioblastoma as of 2020, the risks of dapsone 100 mg twice daily and cimetidine 400 mg twice daily is low enough to warrant a judicious pilot study.

Mesenchymal Transformation: The Rosetta Stone of Glioblastoma Pathogenesis and Therapy Resistance

Despite decades of research, glioblastoma (GBM) remains invariably fatal among all forms of cancers. The high level of inter- and intratumoral heterogeneity along with its biological location, the brain, are major barriers against effective treatment. Molecular and single cell analysis identifies different molecular subtypes with varying prognosis, while multiple subtypes can reside in the same tumor. Cellular plasticity among different subtypes in response to therapies or during recurrence adds another hurdle in the treatment of GBM. This phenotypic shift is induced and sustained by activation of several pathways within the tumor itself, or microenvironmental factors. In this review, the dynamic nature of cellular shifts in GBM and how the tumor (immune) microenvironment shapes this process leading to therapeutic resistance, while highlighting emerging tools and approaches to study this dynamic double-edged sword are discussed.

Expression and clinical significance of CXC chemokines in the glioblastoma microenvironment

BACKGROUND

Glioblastoma (GBM) is the most common subtype of brain cancer, encompassing 16% of all primary brain cancers. The prognosis of GBM is poor, with a 5-year-survial of approximately 5%. Increasing evidence has revealed that chemokines in the tumor microenvironment (TME) are often altered, thus affecting tumor proliferation and metastasis.

METHOD

Multi-omics and bioinformatics tools were utilized to clarify the role of CXC chemokine in GBM.

RESULT

Most CXC chemokines were found to be differentially regulated in GBM, which correlated with patient prognosis. CXC chemokines were found to activate cancer-related signaling pathways, thus affecting immune infiltration. Interestingly, this was found to be associated with drug resistance. Most CXC chemokines were significantly correlated with abundance of B cells, CD8+ cells and dendritic cells. Furthermore, somatic copy number alterations of CXC chemokines can inhibit dendritic cell infiltration. Moreover, CXCL1 was selected as a hub gene, and several kinase, miRNA and transcription factor targets of CXCL1 were identified.

CONCLUSION

our study provides novel insights into CXC chemokine expression and their role in the GBM microenvironment. These results are able to provide more data about prognostic biomarkers and therapeutic targets of GBM.

Biological evaluation of pyrazolyl-urea and dihydro-imidazo-pyrazolyl-urea derivatives as potential anti-angiogenetic agents in the treatment of neuroblastoma

Pyrazolyl-urea and dihydro-imidazo-pyrazolyl-urea compounds (STIRUR 13, STIRUR 41 and BUR 12) have been demonstrated to exert a strong inhibitory effect on interleukin 8 or N-formyl-methionyl-leucyl-phenylalanine-induced chemotaxis of human neutrophils. Since the migration of cancer cells is comparable to that of neutrophils, the purpose of this study is to evaluate the biological effect of STIRUR 13, STIRUR 41 and BUR 12 on ACN and HTLA-230, two neuroblastoma (NB) cell lines with different degree of malignancy. HTLA-230 cells, stage-IV NB cells, have high plasticity and can serve as progenitors of endothelial cells. The results herein reported show that the three tested compounds were not cytotoxic for both NB cells and did not alter their clonogenic potential. However, all compounds were able to inhibit the ability of HTLA-230 to form vascular-like structures. On the basis of these findings, pyrazolyl-urea and dihydro-imidazo-pyrazolyl-urea derivatives could be proposed as agents potentially effective in counteracting NB malignancy by inhibiting cell migration and tumor angiogenesis which represent important hallmarks responsible for cancer survival and progression.