Small Membrane Vesicles Research Articles

Urinary Biomarkers in Bladder Cancer: Where Do We Stand and Potential Role of Extracellular Vesicles.

Extracellular vesicles (EVs) are small membrane vesicles released by all cells and involved in intercellular communication. Importantly, EVs cargo includes nucleic acids, lipids, and proteins constantly transferred between different cell types, contributing to autocrine and paracrine signaling. In recent years, they have been shown to play vital roles, not only in normal biological functions, but also in pathological conditions, such as cancer. In the multistep process of cancer progression, EVs act at different levels, from stimulation of neoplastic transformation, proliferation, promotion of angiogenesis, migration, invasion, and formation of metastatic niches in distant organs, to immune escape and therapy resistance. Moreover, as products of their parental cells, reflecting their genetic signatures and phenotypes, EVs hold great promise as diagnostic and prognostic biomarkers. Importantly, their potential to overcome the current limitations or the present diagnostic procedures has created interest in bladder cancer (BCa). Indeed, cystoscopy is an invasive and costly technique, whereas cytology has poor sensitivity for early staged and low-grade disease. Several urine-based biomarkers for BCa were found to overcome these limitations. Here, we review their potential advantages and downfalls. In addition, recent literature on the potential of EVs to improve BCa management was reviewed and discussed.

Exosomes: Potential Therapies for Disease via Regulating TLRs.

Exosomes are small membrane vesicles that retain various substances such as proteins, nucleic acids, and small RNAs. Exosomes play crucial roles in many physiological and pathological processes, including innate immunity. Innate immunity is an important process that protects the organism through activating pattern recognition receptors (PRRs), which then can induce inflammatory factors to resist pathogen invasion. Toll-like receptor (TLR) is one member of PRRs and is important in pathogen clearance and nervous disease development. Although exosomes and TLRs are two independent materials, abundant evidences imply exosomes can regulate innate immunity through integrating with TLRs. Herein, we review the most recent data regarding exosome regulation of TLR pathways. Specifically, exosome-containing materials can regulate TLR pathways through the interaction with TLRs. This is a new strategy regulating immunity to resist pathogens and therapy diseases, which provide a potential method to cure diseases.

Exosomes as drug delivery vehicle and contributor of resistance to anticancer drugs.

Exosomes are small membranous vesicles implicated in intercellular signalling. Through their uncanny ability to carry and deliver donor cellular cargo (biomolecules) to target cells, they exert a profound effect on the regular functioning of healthy cells and play a significant role in pathogenesis and progression of several diseases, including cancer. The composition and number of endogenously circulating exosomes frequently vary, which is often reflective of the pathophysiological status of the cell. Applicability of exosomes derived from normal cells as a drug carrier with or without modifying their intraluminal and surface components are generally tested. Conversely, exosomes also are reported to contribute to resistance towards several anti-cancer therapies. Therefore, it is necessary to carefully evaluate the role of exosomes in cancer progression, resistance and the potential use of exosomes as a delivery vehicle of cancer therapeutics. In this review, we summarize the recent advancements in the exploitation of exosomes as a drug delivery vehicle. We also discuss the role of exosomes in conferring resistance to anti-cancer therapeutics. While this review is focused on cancer, the exosome-based drug delivery and resistance is also applicable to other human diseases.

Lung CSC-derived exosomal miR-210-3p contributes to a pro-metastatic phenotype in lung cancer by targeting FGFRL1.

Lung cancer has the highest mortality rate among human cancers, and the majority of deaths can be attributed to metastatic spread. Lung cancer stem cells (CSCs) are a component of the tumour microenvironment that contributes to this process. Exosomes are small membrane vesicles secreted by all types of cells that mediate cell interactions, including cancer metastasis. Here, we show that lung CSC‐derived exosomes promote the migration and invasion of lung cancer cells, up‐regulate expression levels of N‐cadherin, vimentin, MMP‐9 and MMP‐1, and down‐regulate E‐cadherin expression. Moreover, we verified that these exosomes contribute to a pro‐metastatic phenotype in lung cancer cells via miR‐210‐3p transfer. The results of bioinformatics analysis and dual‐luciferase reporter assays further indicated that miR‐210‐3p may bind to fibroblast growth factor receptor‐like 1 (FGFRL1); silencing FGFRL1 enhanced the metastatic ability of lung cancer cells, whereas overexpressing FGFRL1 suppressed metastasis. Taken together, our results provide new insights into a potential molecular mechanism whereby lung CSC‐derived exosomal miR‐210‐3p targets FGFRL1 to promote lung cancer metastasis. FGFRL1 may be a promising therapeutic target in lung cancer.

Circulating Biomarkers for Tumor Angiogenesis: Where Are We?

In recent years, several anti-angiogenic drugs have been developed and their addition to standard treatment has been associated with clinical benefits. However, the response to anti-angiogenic therapy is characterized by considerable variability. In this context, the development of dynamic non-invasive biomarkers would be helpful to elucidate the emergence of anti-angiogenic resistance as well as to correctly address the treatment. The purpose of this review is to describe current reports on circulating diagnostic and prognostic biomarkers related to angiogenesis. We further discuss how this non-invasive strategy could improve the monitoring of tumor treatment and help clinical strategy. We discuss the latest evidence in the literature regarding circulating anti-angiogenic markers. Besides growth factor proteins, different circulating miRNAs could exert a pro- or anti-angiogenic activity so as to represent suitable candidates for a non-invasive strategy. Recent reports indicate that tumor-derived exosomes, which are small membrane vesicles abundant in biological fluids, also have an impact on vascular remodeling. Numerous circulating biomarkers related to angiogenesis have been recently identified. Their use will allow identifying patients who are more likely to benefit from a specific anti-angiogenic treatment, as well as detecting those who will develop resistance and/or adverse effects. Nonetheless, further studies are required to elucidate the role of these biomarkers in clinical settings.

Paper-Based Preconcentration and Isolation of Microvesicles and Exosomes.

Microvesicles and exosomes are small membranous vesicles released to the extracellular environment and circulated throughout the body. Because they contain various parental cell-derived biomolecules such as DNA, mRNA, miRNA, proteins, and lipids, their enrichment and isolation are critical steps for their exploitation as potential biomarkers for clinical applications. However, conventional isolation methods (e.g., ultracentrifugation) cause significant loss and damage to microvesicles and exosomes. These methods also require multiple repetitive steps of ultracentrifugation, loading, and wasting of reagents. This article describes a detailed method to fabricate an origami-paper-based device (Exo-PAD) designed for the effective enrichment and isolation of microvesicles and exosomes in a simple manner. The unique design of the Exo-PAD, consisting of accordion-like multifolded layers with convergent sample areas, is integrated with the ion concentration polarization technique, thereby enabling fivefold enrichment of the microvesicles and exosomes on specific layers. In addition, the enriched microvesicles and exosomes are isolated by simply unfolding the Exo-PAD.

Circulating Exosomal miRNA as Diagnostic Biomarkers of Neurodegenerative Diseases.

Neurodegenerative diseases (NDDs) are a group of diseases caused by chronic and progressive degeneration of neural tissue. The main pathological manifestations are neuronal degeneration and loss in the brain and/or spinal cord. Common NDDs include Alzheimer disease (AD), Parkinson disease (PD), Huntington disease (HD), and amyotrophic lateral sclerosis (ALS). The complicated pathological characteristics and different clinical manifestations of NDDs result in a lack of sensitive and efficient diagnostic methods. In addition, no sensitive biomarkers are available to monitor the course of NDDs, predict their prognosis, and monitor the therapeutic response. Despite extensive research in recent years, analysis of amyloid β (Aβ) and α-synuclein has failed to effectively improve NDD diagnosis. Although recent studies have indicated circulating miRNAs as promising diagnostic biomarkers of NDDs, the miRNA in the peripheral circulation is susceptible to interference by other components, making circulating miRNA results less consistent. Exosomes are small membrane vesicles with a diameter of approximately 30–100 nm that transport proteins, lipids, mRNA, and miRNA. Because recent studies have shown that exosomes have a double-membrane structure that can resist ribonuclease in the blood, giving exosomal miRNA high stability and making them resistant to degradation, they may become an ideal biomarker of circulating fluids. In this review, we discuss the applicability of circulating exosomal miRNAs as biomarkers, highlight the technical aspects of exosomal miRNA analysis, and review studies that have used circulating exosomal miRNAs as candidate diagnostic biomarkers of NDDs.

The Fibroblast-Like Synoviocyte Derived Exosomal Long Non-coding RNA H19 Alleviates Osteoarthritis Progression Through the miR-106b-5p/TIMP2 Axis.

Osteoarthritis (OA) is a common degenerative joint disease that affects people worldwide. The interaction between fibroblast-like synoviocytes (FLSs) and chondrocytes may play a vital role in OA disease pathology. However, the underlying mechanisms by which FLSs exert regulatory effects on chondrocytes still need to be elucidated. Exosomes, small membrane vesicles secreted from living cells, are known to play a variety of roles in mediating cell-to-cell communication through the transferring of biological components such as non-coding RNAs and proteins. Here, we investigate the cellular processes of chondrocytes regulated by FLS-derived exosomes and the mechanisms of action underlying the functions of exosomes in OA pathogenesis. We observed that exosome-mediated cartilage repair was characterized by increased cell viability and migration as well as alleviated matrix degradation. Using chondrocyte cultures, the enhanced cellular proliferation and migration during exosome-mediated cartilage repair was linked to the exosomal lncRNA H19-mediated regulation of the miR-106b-5p/TIMP2 axis. Transfection of miR-106-5p mimics in chondrocytes significantly decreased cell proliferation and migration, promoted matrix degradation characterized by elevated MMP13 and ADAMTS5 expression, and reduced the expression of COL2A1 and ACAN in chondrocytes. Furthermore, we found that TIMP2 was directly regulated by miR-106-5p. Co-transfections of miR-106-5p mimics and TIMP2 resulted in higher levels of COL2A1 and ACAN, but lower levels of MMP13 and ADAMTS5. Together, these observations demonstrated that the lncRNA H19 may promote chondrocyte proliferation and migration and inhibit matrix degradation in OA possibly by targeting the miR-106b-5p/TIMP2 axis. In the future, H19 may serve as a potential therapeutic target for the treatment of OA.

Circulating Exosomes from Human Lung Transplant Recipients with Rejection Induces IL-6 by Rab27A Signaling and Promotes Epithelial Mesenchymal Transition of Airway Epithelial Cells In Vitro

Exosomes are small membrane vesicles that regulate intracellular function and cell-to-cell communication. Our report has shown circulating exosomes are induced during lung allograft rejection (Am J Transplant, 2017; 17:474-484). Rab27, a member of the Rab subfamily of GTPases, is essential for exosome secretion. The aim of this study is to determine the role of Rab27A signaling in human bronchial epithelial cells (BEAS-2B) stimulated with exosomes from human lung transplant recipients (LTxRs) diagnosed with acute rejection, bronchiolitis obliterans syndrome (BOS), or stable. Exosomes were isolated using ultracentrifugation and 100µg of exosomes were added to BEAS-2B and incubated for 24hrs. Supernatants collected were analyzed for IL-6 using luminex platform. Epithelial mesenchymal transformation was determined using vimentin and α-SMA by Western blot. Protein band in western blot was normalized with β-Actin and densitometry was performed using Image-J software. Supernatants of BEAS-2B cells, stimulated with BOS-exosome, showed significantly higher production of IL-6 (2927, 4592 MFI p=<0.01) as compared to stable-exosome. Rab27A siRNA knockdown decreased the production of IL-6 (2998 MFI vs 1307 MFI p=<0.01) in supernatants. Further, Rab27A knockdown significantly reduced fibronectin protein in BOS (50% reduction) exosome treated BEAS-2B cells compared to stable (p=<0.01). Vimentin and α-SMA were significantly higher (p=<0.01) in BOS-exosome treated BEAS-2B cells compared to stable-exosome. Rab27A signaling plays an important role in the production of pro-inflammatory cytokine IL-6 by airway epithelial cells following incubation with exosomes isolated from LTxRs with rejection. In addition, Rab27A signaling plays a role in exosome mediated upregulation of fibronectin protein production resulting in epithelia mesenchymal transition of the airway epithelial cells.

Hepatocellular carcinoma-derived exosomes in organotropic metastasis, recurrence and early diagnosis application.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, despite improvements in the clinical trial and diagnosis, HCC still remains high mortality due to the 70% recurrence and lung metastasis after surgical resection. Exosomes are small membrane vesicles, which are shuttled from donor cells to recipient cells, contributing to the recruitment and reprogramming of constituents via an autocrine or paracrine fashion. HCC derived exosomes could redirect metastasis of tumor cells which lack the capacity to metastasize to a specific organ via generating pre-metastatic niche. These findings emphasize a practical and potentially feasible role of exosomes in the treatment of patients with HCC, both as a target and a vehicle for drug design. We herein summarize recent findings that implicate oncogenes and non-canonical signaling of HCC exosomes, as well as the impact of exosomal bioactive molecules in high recurrence induced by organ-specific metastasis. The aim of review is to illustrate the underlying mechanism of exosomes in tumor metastasis, immune evasion, and the potential application of prognostic biomarker in HCC process.

Abstract WP158: Maximum Tolerated Dose of Exosomes Derived From Mesenchymal Stem Cells via Intra-Arterial Dosing in a Rat Stroke Model

Background: Recent preclinical studies of stroke recovery have explored the possibility of utilizing exosomes (ES) instead of complete cells as therapeutic agents. ES are endosomal origin small-membrane vesicles with a size of 40 to 100nm in diameter, secreted from many types of cells including mesenchymal stem cells (MSCs). ES-encapsulated transfer of miRNAs promotes neurite remodeling and functional recovery of stroke in rats. The optimal route of delivery of ES in stroke is not established. While a few studies have shown efficacy of intra-venous exosomes administration for stroke, there is one study exploring intra-arterial exosome therapy (IAX) with single dose of 100ug exosomes. We propose intra-arterial delivery of exosomes in a dose escalation study to establish safety and early efficacy. Methods: Female ovariectomized Sprague-Dawley rats were exposed to MCAo for 90 min. Rats were treated with IAX (10, 50 and 100ug/0.5mL), IAMSCs (1x10 5 cells/0.5mL) or IA phosphate-buffered saline (IAPBS) at 1 day (1D) after MCAo. To test neurological and motor function, the standardized neurobehavioral test battery and the rotarod test were performed. The mean duration (in seconds) on the device was recorded from 3 rotarod measurements. The rats were tested at pre-surgery, 7, 15 and 30 days post-MCAo. Results: There was no neurological worsening or mortality post IA exosome delivery at any dose tier. The Neurological deficit score of IAX 10ug treatment group at POD 7, 15 and 30, and IAX 50ug treatment at POD 15 were significantly improved in comparison to IA PBS. IAX 10ug treatment group showed trend of improvement in motor coordination compared to the IA PBS/MSC/higher doses of exosome treatment groups. Conclusions: The Neurological deficit scores of IAX 10ug treatment group were significantly improved in comparison to IA PBS. Lower dose than previously published might be most effective, and noninferior to IA-MSCs.

Value of detection of extracellular vesicles in the diagnosis of nonalcoholic fatty liver disease

Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells, and hence participate in the variety of diseases including the occurrence and development of liver diseases. In recent years, the prevalence of nonalcoholic fatty liver disease (NAFLD) has increased. Currently there is no reliable method except invasive liver biopsy for the diagnosis of liver inflammation or fibrosis staging. Therefore, the search for the corresponding markers of noninvasive circulation continues to be active, and extracellular vesicles are one of the most concerned. To this end, we reviewed current knowledge about the physical characteristics, biological components, and isolation methods of extracellular vesicles, and introduced the concept of using circulating cell-derived vesicles as a new diagnostic marker for nonalcoholic fatty liver disease.

DEF Cell-Derived Exosomal miR-148a-5p Promotes DTMUV Replication by Negative Regulating TLR3 Expression.

Duck tembusu virus (DTMUV) is a single-stranded, positive-polarity RNA flavivirus that has caused considerable economic losses in China in recent years. Innate immunity represents the first line of defense against invading pathogens and serves as an important role in resisting viral infections. In this study, we found that the infection of ducks by DTMUV triggers Toll-like receptors (TLRs) and (RIG-I)-like receptors (RLRs) signaling pathways and inducing abundant of pro-inflammatory factors and type I interferons (IFNs), in which melanoma differentiation-associated gene 5 (MDA5) and Toll-like receptor 3 (TLR3) play important immunity roles, they can inhibit the replication process of DTMUV via inducing type I IFNs. Moreover, we demonstrated that type I IFNs can inhibit the DTMUV replication process in a time- and dose-dependent manner. Exosomes are small membrane vesicles that have important roles in intercellular communication. MicroRNAs (miRNAs) are small non-coding RNAs that can modulate gene expression and are common substances in exosomes. In our experiment, we successfully isolated DEF cells derived exosome for the first time and explored its function. Firstly, we found the expression of miR-148a-5p is significantly decreased following DTMUV infect. Then we found miR-148a-5p can target TLR3 and down-regulate the expression of TLR3, serving as a negative factor in innate immunity. Unfortunately, we cannot find miRNAs with different expression changes that can target MDA5. Lastly, our experimental results showed that TLR3 was one of the causes of miR-148a-5p reduction, suggesting that the high level of TLR3 after DTMUV infect can both trigger innate immunity and suppress miR-148a-5p to resist DTMUV.

Ca2+ mediates extracellular vesicle biogenesis through alternate pathways in malignancy

ABSTRACT Extracellular vesicles (EVs) are small membrane vesicles that serve as important intercellular signalling intermediaries in both malignant and non-malignant cells. For EVs formed by the plasma membrane, their biogenesis is characterized by an increase in intracellular calcium followed by successive membrane and cytoskeletal changes. EV-production is significantly higher in malignant cells relative to non-malignant cells and previous work suggests this is dependent on increased calcium mobilization and activity of calpain. However, calcium-signalling pathways involved in malignant and non-malignant EV biogenesis remain unexplored. Here we demonstrate; malignant cells have high basal production of plasma membrane EVs compared to non-malignant cells and this is driven by a calcium–calpain dependent pathway. Resting vesiculation in malignant cells occurs via mobilization of calcium from endoplasmic reticulum (ER) stores rather than from the activity of plasma membrane calcium channels. In the event of ER store depletion however, the store-operated calcium entry (SOCE) pathway is activated to restore ER calcium stores. Depleting both ER calcium stores and blocking SOCE, inhibits EV biogenesis. In contrast, calcium signalling pathways are not activated in resting non-malignant cells. Consequently, these cells are relatively low vesiculators in the resting state. Following cellular activation however, an increase in cytosolic calcium and activation of calpain increase in EV biogenesis. These findings contribute to furthering our understanding of extracellular vesicle biogenesis. As EVs are key mediators in the intercellular transfer of deleterious cancer traits such as cancer multidrug resistance (MDR), understanding the molecular mechanisms governing their biogenesis in cancer is the crucial first step in finding novel therapeutic targets that circumvent EV-mediated MDR.

Extracellular vesicles as biomarkers and therapeutic targets for cancer.

Extracellular vesicles (EVs) are small lipid membrane vesicles that are secreted from almost all kinds of cells into the extracellular space. EVs are widely accepted to be involved in various cellular processes; in particular, EVs derived from cancer cells have been reported to play important roles in modifying the tumor microenvironment and promoting tumor progression. In addition, EVs derived from cancer cells encapsulate various kinds of tumor-specific molecules, such as proteins and RNAs, which contribute to cancer malignancy. Therefore, the unveiling of the precise mechanism of intercellular communication via EVs in cancer patients will provide a novel strategy for cancer treatment. Furthermore, a focus on the contents of EVs could promote the use of EVs in body fluids as clinically useful diagnostic and prognostic biomarkers. In this review, we summarize the current research knowledge on EVs as biomarkers and therapeutic targets and discuss their potential clinical applications.

Role of Microparticles in the Pathogenesis of Inflammatory Joint Diseases.

Rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) make up a group of chronic immune-mediated inflammatory diseases (IMIDs). The course of these diseases involves chronic inflammation of joints and enthesopathies, which can result in joint damage and disability. Microparticles (MPs) are a group of small spherical membranous vesicles. The structure and cellular origin of MPs, mechanisms that stimulate their secretion and the place of their production, determine their biological properties, which could become manifest in the pathogenesis of immune-mediated inflammatory diseases. Microparticles can stimulate synovitis with proinflammatory cytokines and chemokines. MPs may also contribute to the pathogenesis of rheumatic diseases by the formation of immune complexes and complement activation, pro-coagulation activity, activation of vascular endothelium cells, and stimulation of metalloproteinase production. It seems that in the future, microparticles can become a modern marker of disease activity, a response to treatment, and, possibly, they can be used in the prognosis of the course of arthritis. The knowledge of the complexity of MPs biology remains incomplete and it requires further comprehensive studies to explain how they affect the development of rheumatic diseases. This review focuses on the immunopathogenic and therapeutic role of MPs in chronic immune-mediated inflammatory joint diseases.

1924P - Exosomes in NSCLC as a source of biomarkers

BackgroundExosomes are small membranous vesicles (around 40-130nm), that have been detected in different biological samples, that play a key role in NSCLC and being relevant in stem cell differentiation as well. The main objective of this study was to analyze the exosomes cargo from NSCLC cell cultures growth in monolayer (2D) and suspension conditions (3D, lung tumorespheres). MethodsCultures were established from NSCLC resected patients and cell lines. Exosomes isolation was performed by ultracentrifugation. Characterization was carried out by NTA, electron microscopy, immunoblot and flow cytometry. Mutational status of EGFR and RAS genes was analyzed by BEAMing dPCR. Transcriptomic analysis has been carried out from exosomal RNA with microarrays, (p≤0.01). Consequently, XAGE1B (significantly expressed gene in exosomes) was analyzed by RTqPCR in 189 paired fresh-frozen tumor and normal tissue samples of resected NSCLC. Prognostic value was assessed by Kaplan‐Meier curves (log rank‐test), considering significant p<0.05. ResultsExosomal characterization through NTA and electron microscopy showed an exosomes size from 108-125nm. Specific markers were detected by IB and FC. Mutational analysis of EGFR and RAS genes in exosomes shown the same pattern displayed by the origin cells. Transcriptomic analysis showed that the expression of mRNAs, miRNAs and precursors were significantly different between 3D and 2D-derived exosomes. A pathway enrichment was carried out to know in which processes (cancer-related) are involved. Significant differential expression was also found between ADC vs SCC–derived exosomes. Concretely, XAGE1B is overexpressed in ADC-derived exosomes (p=0.00003). This overexpression in ADC was validated in NSCLC cohort (p=0.002). Furthermore, it has revealed a significant association with patient prognosis for overall survival in the ADC group (n=74)(OS 49.8 vs. NR months, p=0.043). ConclusionsDifferences in exosomal cargo have been observed between: i) 3D vs. 2D cultures and ii) ADC vs. SCC. In addition, the same mutational pattern was detected in exosomes as compared with parental cells. Therefore, exosomes can be a useful source of biomarkers in NSCLC analysis. Supported by grant GV/2018/026, PI18/00266, & AECC Valencia. Legal entity responsible for the studyFundación de Investigación del Hospital General Universitario de Valencia. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Differentially expressed miRNAs in circulating exosomes between atrial fibrillation and sinus rhythm.

Exosomes are small (30-150 nm) membrane vesicles released by cells that transmit intercellular information. As one of the contents of exosomes, microRNAs (miRNAs) may play an important role in the pathogenesis of atrial fibrillation (AF). Exosomal miRNAs potentially function as biomarkers in AF, as shown in many other diseases. To identify the different expression level of plasma exosomal miRNAs between persistent AF and sinus rhythm (SR) patients, we performed high-throughput sequencing of small RNAs in the exosomes of AF (n=4) and SR (n=4) patients. Target genes of the DE miRNAs were predicted and put into gene ontology analysis and pathway analysis. In the validation phase, we performed quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) of 6 of the DE miRNAs in AF (n=40) and SR (n=20) patients. Univariate and multivariate logistic analysis were used to analyze risk factors of AF. With high-throughput sequencing, we revealed 39 differentially expressed (DE) miRNAs in circulating exosomes. We validated 4 of the DE plasma exosomal miRNAs (miR-483-5p, miR-142-5p, miR-223-3p, miR-223-5p) using qRT-PCR. Univariate logistic analysis shows miR-483-5p, miR-142-5p, miR-223-3p are related with AF, while multivariate logistic analysis suggests miR-483-5p is independently in correlation with AF. This discovery opens up a new perspective in the complicated mechanism underlying AF and the DE plasma exosomal miRNAs exert enormous potential of acting as biomarkers in assessing severity or prognostic of AF and help selecting therapeutic strategy.

Exosomes in Head and Neck Squamous Cell Carcinoma.

Exosomes are small membranous vesicles that contain proteins, lipids, genetic material, and metabolites with abundant information from parental cells. Exosomes carry and deliver bioactive contents that can reprogram the functions of recipient cells and modulate the tumor microenvironment to induce pathological events through cell-to-cell communication and signal transduction. Tumor-derived exosomes (TDEs) in head and neck squamous cell carcinoma (HNSCC) are involved in most aspects of cancer initiation, invasion, progression, immunoregulation, therapeutic applications, and treatment resistance. In addition, HNSCC-derived exosomes can be used to obtain information on diagnostic and therapeutic biomarkers in circulating blood and saliva. Currently, the biology, mechanisms, and applications of TDEs in HNSCC are still unclear, and further research is required. In this review, we discuss various aspects of exosome biology, including exosomal components, exosomal biomarkers, and molecular mechanisms involved in immunoregulation, cancer metastasis, and therapy resistance. We also describe recent applications to update our understanding of exosomes in HNSCC.

Rasal2 suppresses breast cancer cell proliferation modulated by secretory autophagy.

Rasal2, a Ras-GTPase-activating protein (RasGAP), is a tumor suppressor in Luminal B breast cancer, frequently metastatic and recurrent. Exosomes (Exos) are small membrane vesicles secreted by various cell types, including tumor cells, recognized as vehicles for cell-to-cell communication. Our study aimed to investigate whether Rasal2 regulates breast cancer cell growth via affecting this process. In this paper, we described that Rasal2 knockout (KO) in MCF-7 cells enhanced exosomal release and increased autophagy-related proteins in exosomal fraction, while attenuated by exosome release inhibitor GW4869. Moreover, MCF-7 cells with chloroquine (CQ) treatment boosted Rasal2 KO-induced secretory autophagy. In addition, we presented that exosomes derived from KO MCF-7 cells (KO-exo) significantly promoted breast cancer cell proliferation compared to those from MCF-7 cells transfected with an empty crispr-cas9 plasmid serving as controls (sgNT-exo); however, exosomes purified from KO MCF-7 cells co-cultured with 3-methyladenine ((3-MA + KO)-exo)/CQ ((CQ + KO)-exo) dramatically inhibited/facilitated MCF-7 cell proliferation in contrast to KO-exo group, separately. In conclusion, our findings revealed a new mechanism of Rasal2 in the regulation of breast cancer cell proliferation via autophagy-exo-mediated pathway.