Extracellular vesicle-mediated communication between hepatocytes and natural killer cells promotes hepatocellular tumorigenesis

The role of extracellular vesicles in immune cell exhaustion and resistance to immunotherapy

INTRODUCTION

Extracellular vesicles (EVs) are membrane-bound nanoparticles for intercellular communication. Subtypes of EVs, namely exosomes and microvesicles transfer diverse, bioactive cargo to their target cells and eventually interfere with immune responses. Despite being a promising approach, cancer immunotherapy currently faces several challenges including immune resistance. EVs secreted from various sources in the tumor microenvironment provoke immune cell exhaustion and lower the efficacy of immunological treatments, such as CAR T cells and immune checkpoint inhibitors.

AREAS COVERED

This article goes through the mechanisms of action of various types of EVs in inhibiting immune response and immunotherapies, and provides a comprehensive review of EV-based treatments.

EXPERT OPINION

By making use of the distinctive features of EVs, natural or modified EVs are innovatively utilized as novel cancer therapeutics. They are occasionally coupled with currently established treatments to overcome their inadequacies. Investigating the properties and interactions of EVs and EV-based treatments is crucial for determining future steps in cancer therapeutics.

Extracellular vesicle dynamics in COPD: understanding the role of miR-422a, SPP1 and IL-17 A in smoking-related pathology

BACKGROUND

Chronic obstructive pulmonary disease (COPD) induced by smoking poses a significant global health challenge. Recent findings highlight the crucial role of extracellular vesicles (EVs) in mediating miRNA regulatory networks across various diseases. This study utilizes the GEO database to uncover distinct expression patterns of miRNAs and mRNAs, offering a comprehensive understanding of the pathogenesis of smoking-induced COPD. This study aims to investigate the mechanisms by which extracellular vesicles (EVs) mediate the molecular network of miR-422a-SPP1 to delay the onset of COPD caused by smoking.

METHODS

The smoking-related miRNA chip GSE38974-GPL7723 was obtained from the GEO database, and candidate miRs were retrieved from the Vesiclepedia database. Downstream target genes of the candidate miRs were predicted using mRNA chip GSE38974-GPL4133, TargetScan, miRWalk, and RNA22 databases. This prediction was integrated with COPD-related genes from the GeneCards database, downstream target genes predicted by online databases, and key genes identified in the core module of WGCNA analysis to obtain candidate genes. The candidate genes were subjected to KEGG functional enrichment analysis using the "clusterProfiler" package in R language, and a protein interaction network was constructed. In vitro experiments involved overexpressing miRNA or extracting extracellular vesicles from bronchial epithelial cell-derived exosomes, co-culturing them with myofibroblasts to observe changes in the expression levels of the miR-422a-SPP1-IL-17 A regulatory network, and assessing protein levels of fibroblast differentiation-related factors α-SMA and collagen I using Western blot analysis.

RESULTS

The differential gene analysis of chip GSE38974-GPL7723 and the retrieval results from the Vesiclepedia database identified candidate miRs, specifically miR-422a. Subsequently, an intersection was taken among the prediction results from TargetScan, miRWalk, and RNA22 databases, the COPD-related gene retrieval results from GeneCards database, the WGCNA analysis results of chip GSE38974-GPL4133, and the differential gene analysis results. This intersection, combined with KEGG functional enrichment analysis, and protein-protein interaction analysis, led to the final screening of the target gene SPP1 and its upstream regulatory gene miR-422a. KEGG functional enrichment analysis of mRNAs correlated with SPP1 revealed the IL-17 signaling pathway involved. In vitro experiments demonstrated that miR-422a inhibition targets suppressed the expression of SPP1 in myofibroblasts, inhibiting differentiation phenotype. Bronchial epithelial cells, under cigarette smoke extract (CSE) stress, could compensate for myofibroblast differentiation phenotype by altering the content of miR-422a in their Extracellular Vesicles (EVs).

CONCLUSION

The differential gene analysis of Chip GSE38974-GPL7723 and the retrieval results from the Vesiclepedia database identified candidate miRs, specifically miR-422a. Further analysis involved the intersection of predictions from TargetScan, miRWalk, and RNA22 databases, gene search on COPD-related genes from the GeneCards database, WGCNA analysis from Chip GSE38974-GPL4133, and differential gene analysis, combined with KEGG functional enrichment analysis and protein interaction analysis. Ultimately, the target gene SPP1 and its upstream regulatory gene miR-422a were selected. KEGG functional enrichment analysis on mRNAs correlated with SPP1 revealed the involvement of the IL-17 signaling pathway. In vitro experiments showed that miR-422a targeted inhibition suppressed the expression of SPP1 in myofibroblast cells, inhibiting differentiation phenotype. Furthermore, bronchial epithelial cells could compensate for myofibroblast differentiation phenotype under cigarette smoke extract (CSE) stress by altering the miR-422a content in their extracellular vesicles (EVs).

The causality between CD8+NKT cells and CD16-CD56 on NK cells with hepatocellular carcinoma: a Mendelian randomization study

BACKGROUND

Hepatocellular carcinoma (HCC), which is featured with high morbidity and mortality worldwide, is a primary malignant tumor of the liver. Recently, there is a wealth of supporting evidence revealing that NK cell-related immune traits are strongly associated with the development of HCC, but the causality between them has not been proven.

METHODS

Two-sample Mendelian randomization (MR) study was performed to probe the causal correlation between NK cell-related immune traits and HCC. Genetic variations in NK cell-related immune traits were extracted from recent genome-wide association studies (GWAS) of individuals with European blood lineage. HCC data were derived from the UK Biobank Consortium's GWAS summary count data, including a total of 372,184 female and male subjects, with 168 cases and 372,016 controls, all of whom are of European ancestry. Sensitivity analysis was mainly used for heterogeneity and pleiotropy testing.

RESULTS

Our research indicated the causality between NK cell-related immune traits and HCC. Importantly, CD8+NKT cells had protective causal effects on HCC (OR = 0.9996;95%CI,0.9993-0.9999; P = 0.0489). CD16-CD56 caused similar effects on NK cells (OR = 0.9997;95%CI,0.9996-0.9999; P = 0.0117) as CD8+NKT cells. Intercepts from Egger showed no pleiotropy and confounding factors. Furthermore, insufficient evidence was found to support the existence of heterogeneity by Cochran's Q test.

CONCLUSION

MR analysis suggested that low CD8+NKT cells and CD16-CD56 expression on NK cells were linked with a higher risk of HCC.

EZH2 in hepatocellular carcinoma: progression, immunity, and potential targeting therapies

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death. The accumulation of genetic and epigenetic changes is closely related to the occurrence and development of HCC. Enhancer of zeste homolog 2 (EZH2, a histone methyltransferase) is suggested to be one of the principal factors that mediates oncogenesis by acting as a driver of epigenetic alternation. Recent studies show that EZH2 is widely involved in proliferation and metastasis of HCC cells. In this review, the functions of EZH2 in HCC progression, the role of EZH2 in tumor immunity and the application of EZH2-related inhibitors in HCC therapy are summarized.

Role of Small Extracellular Vesicles in Liver Diseases: Pathogenesis, Diagnosis, and Treatment

Extracellular vesicles (EVs) are vesicular bodies that bud off from the cell membrane or are secreted virtually by all cell types. Small EVs (sEVs or exosomes) are key mediators of cell-cell communication by delivering their cargo, including proteins, lipids, or RNAs, to the recipient cells where they induce changes in signaling pathways and phenotypic properties. Tangible findings have revealed the pivotal involvement of sEVs in the pathogenesis of various diseases. On the bright side, they are rich sources of biomarkers for diagnosis, prognosis, treatment response, and disease monitoring. sEVs have high stability, biocompatibility, targetability, low toxicity, and are immunogenic in nature. Their intrinsic properties make sEVs an ideal delivery vehicle to be loaded with cargo for therapeutic interventions. Liver diseases are a major global health problem. This review aims to focus on the roles and mechanisms of sEVs in the pathogenesis of liver diseases, liver injury, liver failure, and liver cancer. sEVs are released not only by hepatocytes but also by stromal and immune cells in the microenvironment. Early detection of liver disease determines the chance for curative treatment and high survival of patients. This review focuses on the potential of circulating sEV cargo as specific and sensitive noninvasive biomarkers for the early detection and prognosis of liver diseases. In addition, the therapeutic use of sEVs derived from various cell types is discussed. Although sEVs hold promise for clinical applications, there are still challenges to be overcome by further research to bring utilization of sEVs into clinical practice.

Extracellular vesicles: catching the light of intercellular communication in fibrotic liver diseases

The increasing prevalence of fibrotic liver diseases resulting from different etiologies has become a major global problem for public health. Fibrotic liver diseases represent a redundant accumulation of extracellular matrix, dysregulation of immune homeostasis and angiogenesis, which eventually contribute to the progression of cirrhosis and liver malignancies. The concerted actions among liver cells including hepatocytes, hepatic stellate cells, kupffer cells, liver sinusoidal endothelial cells and other immune cells are essential for the outcome of liver fibrosis. Recently, a growing body of literature has highlighted that extracellular vesicles (EVs) are critical mediators of intercellular communication among different liver cells either in local or distant microenvironments, coordinating a variety of systemic pathological and physiological processes. Despite the increasing interests in this field, there are still relatively few studies to classify the contents and functions of EVs in intercellular transmission during hepatic fibrogenesis. This review aims to summarize the latest findings with regards to the cargo loading, release, and uptake of EVs in different liver cells and clarify the significant roles of EVs played in fibrotic liver diseases.