Pancreatic cancer cell-derived microRNA-155-5p-containing extracellular vesicles promote immune evasion by triggering EHF-dependent activation of Akt/NF-κB signaling pathway

MiRNA-155: A double-edged sword in colorectal cancer progression and drug resistance mechanisms

Colorectal cancer (CRC) is a leading cause of death worldwide due to its aggressive nature and drug resistance, which limit traditional treatment effectiveness. Recent studies highlight the role of microRNAs (miRNAs) in tumorigenesis, metastasis, and chemotherapy resistance, with miRNA-155 emerging as a key player in CRC. miRNA-155 exerts dual effects, inducing drug resistance while serving as a potential therapeutic target. It regulates a wide array of mRNA transcripts associated with apoptosis, cell cycle regulation, and DNA repair, impacting various cellular pathways. Overexpression of miRNA-155 is linked to resistance against multiple chemotherapeutic drugs, promoting tumor cell survival, proliferation, and the epithelial-mesenchymal transition (EMT) process by repressing tumor suppressors and activating oncogenes. Additionally, miRNA-155 holds promise as a diagnostic and prognostic marker due to its association with CRC patient survival rates. However, its regulatory mechanisms across CRC subtypes remain unclear. This study provides insights into miRNA-155's role in CRC, focusing on its involvement in therapeutic resistance and potential as a therapeutic target. We also explore its significance as a prognostic biomarker and emphasize its therapeutic applications based on evidence from human, in vivo, in vitro, and clinical studies.

Extracellular vesicles in cancers: mechanisms, biomarkers, and therapeutic strategies

Extracellular vesicles (EVs) composed of various biologically active constituents, such as proteins, nucleic acids, lipids, and metabolites, have emerged as a noteworthy mode of intercellular communication. There are several categories of EVs, including exosomes, microvesicles, and apoptotic bodies, which largely differ in their mechanisms of formation and secretion. The amount of evidence indicated that changes in the EV quantity and composition play a role in multiple aspects of cancer development, such as the transfer of oncogenic signals, angiogenesis, metabolism remodeling, and immunosuppressive effects. As EV isolation technology and characteristics recognition improve, EVs are becoming more commonly used in the early diagnosis and evaluation of treatment effectiveness for cancers. Actually, EVs have sparked clinical interest in their potential use as delivery vehicles or vaccines for innovative antitumor techniques. This review will focus on the function of biological molecules contained in EVs linked to cancer progression and their participation in the intricate interrelationship within the tumor microenvironment. Furthermore, the potential efficacy of an EV-based liquid biopsy and delivery cargo for treatment will be explored. Finally, we explicitly delineate the limitations of EV-based anticancer therapies and provide an overview of the clinical trials aimed at improving EV development.

ETS homologous factor, controlled by lysine-specific demethylase 5B, suppresses clear cell renal cell carcinoma by inducing Filamin-B

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) remains a deadly disease with a poor prognosis. Here, we identified the ETS homologous factor (EHF) and its target Filamin-B (FLNB) as molecules related to immune evasion in ccRCC. We also explored the upstream modifier that manipulates EHF in ccRCC.

DESIGN

Cell proliferation and apoptosis assay, wound healing assay, and Transwell assay were designed to analyze the effects of EHF or FLNB knockdown on the biological activity of ccRCC cells. The growth of differently treated ccRCC cells was assessed by orthotopic tumors. ccRCC cells with different treatments were co-cultured with macrophages, and the role of the lysine-specific demethylase 5B (KDM5B)/EHF/FLNB axis on macrophage polarization or ccRCC progression was characterized by detecting the expression of M2 macrophage markers in the co-culture system or tumor tissues of tumor-bearing mice.

RESULTS

The expression of EHF and FLNB was higher, while KDM5B was lower in HK2 cells than in ccRCC cells. EHF overexpression inhibited the biological behavior of ccRCC cells and tumor growth in mice. EHF activated FLNB transcription. Knockdown of FLNB supported the biological activity of ccRCC cells and tumor growth and reversed M2 macrophage polarization in tumor tissues of mice in the presence of EHF. KDM5B inhibited EHF expression by H3K4me3 demethylation, and EHF knockdown potentiated M2 macrophage polarization and tumor growth in vivo repressed by KDM5B knockdown.

CONCLUSIONS

KDM5B inhibited the expression of EHF by repressing H3K4me3 modification and the transcription of FLNB by EHF to promote immune evasion and progression of ccRCC.

Deciphering the role of NcRNAs in Pancreatic Cancer immune evasion and drug resistance: a new perspective for targeted therapy

Pancreatic cancer (PC) is a very aggressive digestive system tumor, known for its high mortality rate, low cure rate, low survival rate and poor prognosis. In particular, pancreatic ductal adenocarcinoma (PADC), which accounts for more than 90% of PC cases, has an overall 5-year survival rate of only 5%, which is an extremely critical situation. Early detection and effective treatment of PC is extremely difficult, which leads many patients to despair. In the current medical context, targeted therapy, as an important strategy for cancer treatment, is expected. However, the problems of immune escape and drug resistance in PC have become two major obstacles that are difficult to be overcome by targeted therapy. How to break through these two difficulties has become a key issue to be solved in the field of PC therapy. In recent years, non-coding RNAs (ncRNAs) have continued to heat up in the field of cancer research. NcRNAs play a pivotal role in gene regulation, cell differentiation, development, and disease processes, and their important roles in the genesis, development, and therapeutic response of PC have been gradually revealed. More importantly, ncRNAs have many advantages as therapeutic targets, such as high specificity and low side effects, making them a new favorite in the field of PC therapy. Therefore, the aim of this paper is to provide new ideas and methods for the targeted therapy of PC by reviewing the mechanism of action of four major ncRNAs (circRNAs, lncRNAs, miRNAs, siRNAs) in both immune escape and drug resistance of PC. It is expected that an effective way to overcome immune escape and drug resistance can be found through in-depth study of ncRNA, bringing a ray of hope to PC patients.

MicroRNA-enriched exosome as dazzling dancer between cancer and immune cells

Exosomes are widely recognized for their roles in numerous biological processes and as intercellular communication mediators. Human cancerous and normal cells can both produce massive amounts of exosomes. They are extensively dispersed in tumor-modeling animals' pleural effusions, ascites, and plasma from people with cancer. Tumor cells interact with host cells by releasing exosomes, which allow them to interchange various biological components. Tumor growth, invasion, metastasis, and even tumorigenesis can all be facilitated by this delicate and complex system by modifying the nearby and remote surroundings. Due to the existence of significant levels of biomolecules like microRNA, exosomes can modulate the immune system's stimulation or repression, which in turn controls tumor growth. However, the role of microRNA in exosome-mediated communication between immunological and cancer cells is still poorly understood. This study aims to get the most recent information on the "yin and yang" of exosomal microRNA in the regulation of tumor immunity and immunotherapy, which will aid current cancer treatment and diagnostic techniques.

Extracellular vesicles reshape the tumor microenvironment to improve cancer immunotherapy: Current knowledge and future prospects

Tumor immunotherapy has revolutionized cancer treatment, but limitations remain, including low response rates and immune complications. Extracellular vesicles (EVs) are emerging as a new class of therapeutic agents for various diseases. Recent research shows that changes in the amount and composition of EVs can reshape the tumor microenvironment (TME), potentially improving the effectiveness of immunotherapy. This exciting discovery has sparked clinical interest in using EVs to enhance the immune system's response to cancer. In this Review, we delve into the world of EVs, exploring their origins, how they're generated, and their complex interactions within the TME. We also discuss the crucial role EVs play in reshaping the TME during tumor development. Specifically, we examine how their cargo, including molecules like PD-1 and non-coding RNA, influences the behavior of key immune cells within the TME. Additionally, we explore the current applications of EVs in various cancer therapies, the latest advancements in engineering EVs for improved immunotherapy, and the challenges faced in translating this research into clinical practice. By gaining a deeper understanding of how EVs impact the TME, we can potentially uncover new therapeutic vulnerabilities and significantly enhance the effectiveness of existing cancer immunotherapies.

Noncoding Ribonucleic Acids (RNAs) May Improve Response to Immunotherapy in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is the seventh most common cause of cancer-related mortality. Despite different methods of treatment, nearly more than 90% of patients with PDAC die shortly after diagnosis. Contrary to promising results in other cancers, immune checkpoint inhibitors (ICIs) showed limited success in PDAC. Recent studies have shown that noncoding RNAs (ncRNAs) are extensively involved in PDAC cell-immune cell interaction and mediate immune evasion in this vicious cancer. PDAC cells recruit numerous ncRNAs to widely affect the phenotype and function of immune cells through various mechanisms. For instance, PDAC cells upregulate miR-301a and downregulate miR-340 to induce M2 polarization of macrophages or overexpress miR-203, miR-146a, and miR-212-3p to downregulate toll-like receptor 4 (TLR4), CD80, CD86, CD1a, major histocompatibility complex (MHC) II, and CD83, thereby evading recognition by dendritic cells. By downregulating miR-4299 and miR-153, PDAC cells can decrease the expression of NK group 2D (NKG2D) and MHC class I chain-related molecules A and B (MICA/B) to blunt the natural killer (NK) cell response. PDAC cells also highly express lncRNA AL137789.1, hsa_circ_0046523, lncRNA LINC00460, and miR-155-5p to upregulate immune checkpoint proteins and escape T cell cytotoxicity. On the other hand, ncRNAs derived from suppressive immune cells promote proliferation, invasion, and drug resistance in PDAC cells. ncRNAs can be applied to overcome resistance to ICIs, monitor the immune microenvironment of PDAC, and predict response to ICIs. This Review article comprehensively discusses recent findings regarding the roles of ncRNAs in the immune evasion of PDAC.

Development of a Diagnostic Model for Pancreatic Ductal Adenocarcinoma Using Machine Learning and Blood-Based miRNAs

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) has the lowest survival rate among all major cancers due to a lack of symptoms in early stages, early detection tools, and optimal therapies for late-stage patients. Thus, effective and non-invasive diagnostic tests are greatly needed. Recently, circulating miRNAs have been reported to be altered in PDAC. They are promising biomarkers because of stability in the blood, ease of non-invasive detection, and convenient screening methods. This study aimed to use blood-based miRNA biomarkers and various analysis methods in the development of a machine-learning (ML) model for PDAC.

METHODS

Blood-based miRNAs associated with PDAC were collected from open sources. miRNA sequences, targeted genes, and involved pathways were used to construct a set of descriptors for an ML model.

RESULTS

Bioinformatics analysis revealed that most genes in pancreatic cancer and insulin signaling pathways were targeted by the PDAC-related miRNAs. The best-performing ML model with the Random Forest classifier was able to achieve an accuracy of 88.4%. Model evaluations of an independent PDAC-associated miRNAs test set had 100% accuracy while non-cancer miRNAs had 52.4% accuracy, indicating specificity to PDAC.

CONCLUSIONS

Our results suggest an ML model developed using blood-based miRNA biomarkers' target gene, pathway, and sequence features could be potentially implicated in PDAC diagnostics.

MicroRNAs in extracellular vesicles: A potential role in cancer progression

Intercellular communication, an essential biological process in multicellular organisms, is mediated by direct cell-to-cell contact and cell secretary molecules. Emerging evidence identifies a third mechanism of intercellular communication- the release of extracellular vesicles (EVs). EVs are membrane-enclosed nanosized bodies, released from cells into the extracellular environment, often found in all biofluids. The growing body of research indicates that EVs carry bioactive molecules in the form of proteins, DNA, RNAs, microRNAs (miRNAs), lipids, metabolites, etc., and upon transferring them, alter the phenotypes of the target recipient cells. Interestingly, the abundance of EVs is found to be significantly higher in different diseased conditions, most importantly cancer. In the past few decades, numerous studies have identified EV miRNAs as an important contributor in the pathogenesis of different types of cancer. However, the underlying mechanism behind EV miRNA-associated cancer progression and how it could be used as a targeted therapy remain ill-defined. The present review highlights how EV miRNAs influence essential processes in cancer, such as growth, proliferation, metastasis, angiogenesis, apoptosis, stemness, immune evasion, resistance to therapy, etc. A special emphasis has been given to the potential role of EV miRNAs as cancer biomarkers. The final section of the review delineates the ongoing clinical trials on the role of miRNAs in the progression of different types of cancer. Targeting EV miRNAs could be a potential therapeutic means in the treatment of different forms of cancer alongside conventional therapeutic approaches.

Airway epithelial-derived exosomes induce acute asthma exacerbation after respiratory syncytial virus infection

Acute asthma exacerbation refers to the progressive deterioration of asthma symptoms that is always triggered by virus infection represented by respiratory syncytial virus (RSV). After RSV infection, exaggerated Th2-mediated pulmonary inflammation is the critical pathological response of asthmatic patients with acute exacerbation. Significantly, airway epithelial cells, being the primary targets of RSV infection, play a crucial role in controlling the pulmonary inflammatory response by releasing airway epithelial cell-derived exosomes (AEC-Exos), which potentially influence the development of asthma. However, the specific role of AEC-Exos in acute asthma exacerbation after RSV infection remains obscure. The purpose of this study was to determine the distinct function of AEC-Exos in exacerbating acute asthma following RSV infection. Blockade of exosomes by GW reduce the enhanced pulmonary inflammation significantly. Specifically, the enhanced Th2 inflammation was induced by AEC-Exos thorough transportation of hsa-miR-155-5p-Sirtuin 1 (SIRT1) pathway during acute asthma exacerbation. Targeted inhibition of hsa-miR-155-5p blocks the exaggerated Th2 inflammation effectively in mice with acute asthma exacerbation. In summary, our study showed that during acute asthma exacerbation after RSV infection, AEC-Exos promote the enhanced Th2 inflammation through transportation of increased hsa-miR-155-5p, which was mediated partly through SIRT1-mediated pathway. hsa-miR-155-5p is a potential biomarker for early prediction of acute asthma exacerbation.

Extracellular vesicles as modulators of monocyte and macrophage function in tumors

The tumor microenvironment (TME) harbors several cell types, such as tumor cells, immune cells, and non-immune cells. These cells communicate through several mechanisms, such as cell-cell contact, cytokines, chemokines, and extracellular vesicles (EVs). Tumor-derived vesicles are known to have the ability to modulate the immune response. Monocytes are a subset of circulating innate immune cells and play a crucial role in immune surveillance, being recruited to tissues where they differentiate into macrophages. In the context of tumors, it has been observed that tumor cells can attract monocytes to the TME and induce their differentiation into tumor-associated macrophages with a pro-tumor phenotype. Tumor-derived EVs have emerged as essential structures mediating this process. Through the transfer of specific molecules and signaling factors, tumor-derived EVs can shape the phenotype and function of monocytes, inducing the expression of cytokines and molecules by these cells, thus modulating the TME towards an immunosuppressive environment.

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

Immunosuppressive microvesicles-mimetic derived from tolerant dendritic cells to target T-lymphocytes for inflammation diseases therapy

The utilization of extracellular vesicles (EV) in immunotherapy, aiming at suppressing peripheral immune cells responsible for inflammation, has demonstrated significant efficacy in treating various inflammatory diseases. However, the clinical application of EV has faced challenges due to their inadequate targeting ability. In addition, most of the circulating EV would be cleared by the liver, resulting in a short biological half-life after systemic administration. Inspired by the natural microvesicles (MV, as a subset of large size EV) are originated and shed from the plasma membrane, we developed the immunosuppressive MV-mimetic (MVM) from endotoxin tolerant dendritic cells (DC) by a straightforward and effective extrusion approach, in which DC surface proteins were inherited for providing the homing ability to the spleen, while αCD3 antibodies were conjugated to the MVM membranes for specific targeting of T cells. The engineered MVM carried a large number of bioactive cargos from the parental cells, which exhibited a remarkable ability to promote the induction of regulatory T cells (Treg) and polarization of anti-inflammatory M2 macrophages. Mechanistically, the elevated Treg level by MVM was mediated due to the upregulation of miR-155-3p. Furthermore, it was observed that systemic and local immunosuppression was induced by MVM in models of sepsis and rheumatoid arthritis through the improvement of Treg and M2 macrophages. These findings reveal a promising cell-free strategy for managing inflammatory responses to infections or tissue injury, thereby maintaining immune homeostasis.

Tumor-derived extracellular vesicles regulate macrophage polarization: role and therapeutic perspectives

Extracellular vesicles (EVs) are important cell-to-cell communication mediators. This paper focuses on the regulatory role of tumor-derived EVs on macrophages. It aims to investigate the causes of tumor progression and therapeutic directions. Tumor-derived EVs can cause macrophages to shift to M1 or M2 phenotypes. This indicates they can alter the M1/M2 cell ratio and have pro-tumor and anti-inflammatory effects. This paper discusses several key points: first, the factors that stimulate macrophage polarization and the cytokines released as a result; second, an overview of EVs and the methods used to isolate them; third, how EVs from various cancer cell sources, such as hepatocellular carcinoma, colorectal carcinoma, lung carcinoma, breast carcinoma, and glioblastoma cell sources carcinoma, promote tumor development by inducing M2 polarization in macrophages; and fourth, how EVs from breast carcinoma, pancreatic carcinoma, lungs carcinoma, and glioblastoma cell sources carcinoma also contribute to tumor development by promoting M2 polarization in macrophages. Modified or sourced EVs from breast, pancreatic, and colorectal cancer can repolarize M2 to M1 macrophages. This exhibits anti-tumor activities and offers novel approaches for tumor treatment. Therefore, we discovered that macrophage polarization to either M1 or M2 phenotypes can regulate tumor development. This is based on the description of altering macrophage phenotypes by vesicle contents.

A Current Synopsis of the Emerging Role of Extracellular Vesicles and Micro-RNAs in Pancreatic Cancer: A Forward-Looking Plan for Diagnosis and Treatment

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies worldwide, while it persists as the fourth most prevalent cause of cancer-related death in the United States of America. Although there are several novel therapeutic strategies for the approach of this intensely aggressive tumor, it remains a clinical challenge, as it is hard to identify in early stages, due to its asymptomatic course. A diagnosis is usually established when the disease is already in its late stages, while its chemoresistance constitutes an obstacle to the optimal management of this malignancy. The discovery of novel diagnostic and therapeutic tools is considered a necessity for this tumor, due to its low survival rates and treatment failures. One of the most extensively investigated potential diagnostic and therapeutic modalities is extracellular vesicles (EVs). These vesicles constitute nanosized double-lipid membraned particles that are characterized by a high heterogeneity that emerges from their distinct biogenesis route, their multi-variable sizes, and the particular cargoes that are embedded into these particles. Their pivotal role in cell-to-cell communication via their cargo and their implication in the pathophysiology of several diseases, including pancreatic cancer, opens new horizons in the management of this malignancy. Meanwhile, the interplay between pancreatic carcinogenesis and short non-coding RNA molecules (micro-RNAs or miRs) is in the spotlight of current studies, as they can have either a role as tumor suppressors or promoters. The deregulation of both of the aforementioned molecules leads to several aberrations in the function of pancreatic cells, leading to carcinogenesis. In this review, we will explore the role of extracellular vesicles and miRNAs in pancreatic cancer, as well as their potent utilization as diagnostic and therapeutic tools.

Extracellular vesicles associated microRNAs: Their biology and clinical significance as biomarkers in gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, esophageal, pancreatic, and liver, are associated with high mortality and morbidity rates worldwide. One of the underlying reasons for the poor survival outcomes in patients with these malignancies is late disease detection, typically when the tumor has already advanced and potentially spread to distant organs. Increasing evidence indicates that earlier detection of these cancers is associated with improved survival outcomes and, in some cases, allows curative treatments. Consequently, there is a growing interest in the development of molecular biomarkers that offer promise for screening, diagnosis, treatment selection, response assessment, and predicting the prognosis of these cancers. Extracellular vesicles (EVs) are membranous vesicles released from cells containing a repertoire of biological molecules, including nucleic acids, proteins, lipids, and carbohydrates. MicroRNAs (miRNAs) are the most extensively studied non-coding RNAs, and the deregulation of miRNA levels is a feature of cancer cells. EVs miRNAs can serve as messengers for facilitating interactions between tumor cells and the cellular milieu, including immune cells, endothelial cells, and other tumor cells. Furthermore, recent years have witnessed considerable technological advances that have permitted in-depth sequence profiling of these small non-coding RNAs within EVs for their development as promising cancer biomarkers -particularly non-invasive, liquid biopsy markers in various cancers, including GI cancers. Herein, we summarize and discuss the roles of EV-associated miRNAs as they play a seminal role in GI cancer progression, as well as their promising translational and clinical potential as cancer biomarkers as we usher into the area of precision oncology.

From inflammation to metastasis: The central role of miR-155 in modulating NF-κB in cancer

Cancer is a multifaceted, complex disease characterized by unchecked cell growth, genetic mutations, and dysregulated signalling pathways. These factors eventually cause evasion of apoptosis, sustained angiogenesis, tissue invasion, and metastasis, which makes it difficult for targeted therapeutic interventions to be effective. MicroRNAs (miRNAs) are essential gene expression regulators linked to several biological processes, including cancer and inflammation. The NF-κB signalling pathway, a critical regulator of inflammatory reactions and oncogenesis, has identified miR-155 as a significant participant in its modulation. An intricate network of transcription factors known as the NF-κB pathway regulates the expression of genes related to inflammation, cell survival, and immunological responses. The NF-κB pathway's dysregulation contributes to many cancer types' development, progression, and therapeutic resistance. In numerous cancer models, the well-studied miRNA miR-155 has been identified as a crucial regulator of NF-κB signalling. The p65 subunit and regulatory molecules like IκB are among the primary targets that miR-155 directly targets to alter NF-κB activity. The molecular processes by which miR-155 affects the NF-κB pathway are discussed in this paper. It also emphasizes the miR-155's direct and indirect interactions with important NF-κB cascade elements to control the expression of NF-κB subunits. We also investigate how miR-155 affects NF-κB downstream effectors in cancer, including inflammatory cytokines and anti-apoptotic proteins.

Extracellular vesicles remodel tumor environment for cancer immunotherapy

Tumor immunotherapy has transformed neoplastic disease management, yet low response rates and immune complications persist as major challenges. Extracellular vesicles including exosomes have emerged as therapeutic agents actively involved in a diverse range of pathological conditions. Mounting evidence suggests that alterations in the quantity and composition of extracellular vesicles (EVs) contribute to the remodeling of the immune-suppressive tumor microenvironment (TME), thereby influencing the efficacy of immunotherapy. This revelation has sparked clinical interest in utilizing EVs for immune sensitization. In this perspective article, we present a comprehensive overview of the origins, generation, and interplay among various components of EVs within the TME. Furthermore, we discuss the pivotal role of EVs in reshaping the TME during tumorigenesis and their specific cargo, such as PD-1 and non-coding RNA, which influence the phenotypes of critical immune cells within the TME. Additionally, we summarize the applications of EVs in different anti-tumor therapies, the latest advancements in engineering EVs for cancer immunotherapy, and the challenges encountered in clinical translation. In light of these findings, we advocate for a broader understanding of the impact of EVs on the TME, as this will unveil overlooked therapeutic vulnerabilities and potentially enhance the efficacy of existing cancer immunotherapies.

Extracellular vesicles as next generation immunotherapeutics

Extracellular vesicles (EVs) function as a mode of intercellular communication and molecular transfer to elicit diverse biological/functional response. Accumulating evidence has highlighted that EVs from immune, tumour, stromal cells and even bacteria and parasites mediate the communication of various immune cell types to dynamically regulate host immune response. EVs have an innate capacity to evade recognition, transport and transfer functional components to target cells, with subsequent removal by the immune system, where the immunological activities of EVs impact immunoregulation including modulation of antigen presentation and cross-dressing, immune activation, immune suppression, and immune surveillance, impacting the tumour immune microenvironment. In this review, we outline the recent progress of EVs in immunorecognition and therapeutic intervention in cancer, including vaccine and targeted drug delivery and summarise their utility towards clinical translation. We highlight the strategies where EVs (natural and engineered) are being employed as a therapeutic approach for immunogenicity, tumoricidal function, and vaccine development, termed immuno-EVs. With seminal studies providing significant progress in the sequential development of engineered EVs as therapeutic anti-tumour platforms, we now require direct assessment to tune and improve the efficacy of resulting immune responses - essential in their translation into the clinic. We believe such a review could strengthen our understanding of the progress in EV immunobiology and facilitate advances in engineering EVs for the development of novel EV-based immunotherapeutics as a platform for cancer treatment.

Five plus Three for the Pancreas

Preneoplastic high-risk lesions in the pancreas need to be differentiated from low-risk lesions warranting surveillance and eventually surgical intervention. Imaging is used so far; however, certain imaging features are subject to interpretation and hence have their intrinsic flaws. In a recent article, a liquid biopsy with protein and RNA markers demonstrates differentiation based on a blood test. See related article by Zhang et al., p. 1535.

Diagnostic and Prognostic Role of Extracellular Vesicles in Pancreatic Cancer: Current Evidence and Future Perspectives

Pancreatic cancer is one of the most aggressive tumors, with a dismal prognosis due to poor detection rates at early stages, rapid progression, post-surgical complications, and limited effectiveness of conventional oncologic therapies. There are no consistently reliable biomarkers or imaging modalities to accurately diagnose, classify, and predict the biological behavior of this tumor. Therefore, it is imperative to develop new and improved strategies to detect pancreatic lesions in the early stages of cancerization with greater sensitivity and specificity. Extracellular vesicles, including exosome and microvesicles, are membrane-coated cellular products that are released in the outer environment. All cells produce extracellular vesicles; however, this process is enhanced by inflammation and tumorigenesis. Based on accumulating evidence, extracellular vesicles play a crucial role in pancreatic cancer progression and chemoresistance. Moreover, they may represent potential biomarkers and promising therapy targets. The aim of the present review is to review the current evidence on the role of extracellular vesicles in pancreatic cancer.

Extracellular Vesicles and Their Roles in the Tumor Immune Microenvironment

Tumor cells actively incorporate molecules (e.g., proteins, lipids, RNA) into particles named extracellular vesicles (EVs). Several groups have demonstrated that EVs can be transferred to target (recipient) cells, making EVs an important means of intercellular communication. Indeed, EVs are able to modulate the functions of target cells by reprogramming signaling pathways. In a cancer context, EVs promote the formation of a supportive tumor microenvironment (TME) and (pre)metastatic niches. Recent studies have revealed that immune cells, tumor cells and their secretome, including EVs, promote changes in the TME and immunosuppressive functions of immune cells (e.g., natural killer, dendritic cells, T and B cells, monocytes, macrophages) that allow tumor cells to establish and propagate. Despite the growing knowledge on EVs and on their roles in cancer and as modulators of the immune response/escape, the translation into clinical practice remains in its early stages, hence requiring improved translational research in the EVs field. Here, we comprehensively review the current knowledge and most recent research on the roles of EVs in tumor immune evasion and immunosuppression in both solid tumors and hematological malignancies. We also highlight the clinical utility of EV-mediated immunosuppression targeting and EV-engineering. Importantly, we discuss the controversial role of EVs in cancer biology, current limitations and future perspectives to further the EV knowledge into clinical practice.

Extracellular vesicles in pancreatic cancer immune escape: Emerging roles and mechanisms

Pancreatic cancer (PC) is the most lethal malignancy worldwide due to its delayed diagnosis and limited treatment options. Despite great progress in clinical trials of immunotherapies for various cancers, their effectiveness in PC is very low, indicating that immune evasion is still a major obstacle to immunotherapy in PC. However, the mechanism of immune escape in PC is not fully understood, which substantially restricts the development of immunotherapy. As an important component of intercellular communication networks, extracellular vesicles (EVs) have attracted increasing attention in relation to immune escape. This review aims to provide a better understanding of the roles of EVs in tumor immune escape and the potential to expand their application in cancer immunotherapy. The relationship between PC and the tumor immune microenvironment is briefly introduced. Then, the mechanism by which EVs are involved in immune regulation is summarized, and the latest progress in determining the role of EVs in regulating PC immune escape is highlighted.

The Anti-Tumor Efficacy of Verbascoside on Ovarian Cancer via Facilitating CCN1-AKT/NF-κB Pathway-Mediated M1 Macrophage Polarization

Background

Ovarian cancer (OC) is the leading cause of gynecological cancer-related mortality. Verbascoside (VB) is a phenylpropanoid glycoside from Chinese herbs, with anti-tumour activities. This study aimed to investigate the effects and mechanism of VB on OC.

Methods

OC cell lines SKOV3 and A2780 were used in this study. Cell viability, proliferation, and migration were measured using CCK-8, clonogenic, and transwell assays, respectively. Apoptosis and M1/M2 macrophages were detected using flow cytometry. The interaction between VB and CCN1 was predicted by molecular docking. The mRNA expression of CCN1 was detected by RT-qPCR. The protein levels of CCN1, AKT, p-AKT, p65, and p-p65 were determined by western blotting. A xenograft mice model was established for in vivo validation.

Results

VB inhibited OC cell proliferation and migration in a dose-dependent manner, and promoted apoptosis and M1 macrophage polarization. VB downregulated CCN1 and inhibited the AKT/NF-κB pathway. LY294002, an AKT inhibitor, potentiated the anti-tumour effects of VB. CCN1 overexpression weakened the anti-tumour effects of VB and VB + LY294002. In vivo experiments verified that VB inhibited tumour growth and promoted M1 polarization, which is regulated by the CCN1-mediated AKT/NF-κB pathway.

Conclusion

VB triggers the CCN1-AKT/NF-κB pathway-mediated M1 macrophage polarization for protecting against OC.