Isolation and identification of potential urinary microparticle biomarkers of bladder cancer

Exosomes, Circadian Rhythms, and Cancer Precision Medicine: New Frontiers

"The environment shapes people's actions," a well-known proverb, strongly dictates that a change in our way of life changes our behavior. Circadian rhythms have been identified as a mechanism for maintaining homeostasis in the body, which, if disrupted by sleeping patterns, could result in significant metabolic alterations that adversely affect our health. The changes induced by circadian rhythm alter the secretion and cargo selection in exosomes which are nanovesicles important for intercellular communication. Exosomes were formerly known as "junk particles" but are now recognized as miniature copies of a cell's genetic material. Dysregulation of circadian rhythm has shown that it changes the gene expression of a cell to some extent and significantly alters the exosomal release. Meanwhile, cells secrete exosomes continuously to align the rhythmicity of the biological clock. In this study, we integrate circadian rhythms and exosomes with precision medicines to find better approaches to early diagnosis and treatment of disease.

Mesenchymal stem cell-derived exosomes for management of prostate cancer: An updated view

Prostate cancer represents the second most prevalent form of cancer found in males, and stands as the fifth primary contributor to cancer-induced mortality on a global scale. Research has shown that transplanted mesenchymal stem cells (MSCs) can migrate by homing to tumor sites in the body. In prostate cancer, researchers have explored the fact that MSC-based therapies (including genetically modified delivery vehicles or vectors) and MSC-derived exosomes are emerging as attractive options to improve the efficacy and safety of traditional cancer therapies. In addition, researchers have reported new insights into the application of extracellular vesicle (EV)-MSC therapy as a novel treatment option that could provide a more effective and targeted approach to prostate cancer treatment. Moreover, the new generation of exosomes, which contain biologically functional molecules as signal transducers between cells, can simultaneously deliver different therapeutic agents and induce an anti-tumor phenotype in immune cells and their recruitment to the tumor site. The results of the current research on the use of MSCs in the treatment of prostate cancer may be helpful to researchers and clinicians working in this field. Nevertheless, it is crucial to emphasize that although dual-role MSCs show promise as a therapeutic modality for managing prostate cancer, further investigation is imperative to comprehensively grasp their safety and effectiveness. Ongoing clinical trials are being conducted to assess the viability of MSCs in the management of prostate cancer. The results of these trials will help determine the viability of this approach. Based on the current literature, engineered MSCs-EV offer great potential for application in targeted tumor therapy.

Improved recovery of urinary small extracellular vesicles by differential ultracentrifugation

Extracellular vesicles (EVs) are lipid-membrane enclosed structures that are associated with several diseases, including those of genitourinary tract. Urine contains EVs derived from urinary tract cells. Owing to its non-invasive collection, urine represents a promising source of biomarkers for genitourinary disorders, including cancer. The most used method for urinary EVs separation is differential ultracentrifugation (UC), but current protocols lead to a significant loss of EVs hampering its efficiency. Moreover, UC protocols are labor-intensive, further limiting clinical application. Herein, we sought to optimize an UC protocol, reducing the time spent and improving small EVs (SEVs) yield. By testing different ultracentrifugation times at 200,000g to pellet SEVs, we found that 48 min and 60 min enabled increased SEVs recovery compared to 25 min. A step for pelleting large EVs (LEVs) was also evaluated and compared with filtering of the urine supernatant. We found that urine supernatant filtering resulted in a 1.7-fold increase on SEVs recovery, whereas washing steps resulted in a 0.5 fold-decrease on SEVs yield. Globally, the optimized UC protocol was shown to be more time efficient, recovering higher numbers of SEVs than Exoquick-TC (EXO). Furthermore, the optimized UC protocol preserved RNA quality and quantity, while reducing SEVs separation time.

Prognostic significance of EGFR, AREG and EREG amplification and gene expression in muscle invasive bladder cancer

Introduction

Muscle invasive bladder cancer (MIBC) remains a prevalent cancer with limited therapeutic options, obviating the need for innovative therapies. The epidermal growth factor receptor (EGFR) is a linchpin in tumor progression and presents a potential therapeutic target in MIBC. Additionally, the EGFR ligands AREG and EREG have shown associations with response to anti-EGFR therapy and improved progression-free survival in colorectal carcinoma.

Materials and methods

We investigated the prognostic significance of EGFR, AREG, and EREG in MIBC. Gene expression and copy number analyses were performed via qRT-PCR on tissue samples from 100 patients with MIBC who underwent radical cystectomy at the University Hospital Mannheim (MA; median age 72, interquartile range [IQR] 64-78 years, 25% female). Results were validated in 361 patients from the 2017 TCGA MIBC cohort (median age 69, IQR 60-77 years, 27% female), in the Chungbuk and MDACC cohort. Gene expressions were correlated with clinicopathologic parameters using the Mann-Whitney test, Kruskal-Wallis- test and Spearman correlation. For overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) gene expression was analyzed with Kaplan-Meier and Cox-proportional hazard models.

Results

Significant gene expression differences in EGFR, AREG, and EREG could be detected in all cohorts. In the TCGA cohort, EGFR expression was significantly elevated in patients with EGFR amplification and KRAS wildtype. High AREG expression independently predicted longer OS (HR = 0.35, CI 0.19 - 0.63, p = 0.0004) and CSS (HR = 0.42, CI 0.18 - 0.95, p = 0.0378) in the MA cohort. In the TCGA cohort, high EGFR, AREG, and EREG expression correlated with shorter OS (AREG: HR = 1.57, CI 1.12 - 2.20, p = 0.0090) and DFS (EGFR: HR = 1.91, CI 1.31 - 2.8, p = 0.0008). EGFR amplification was also associated with reduced DFS.

Discussion

High EGFR and EREG indicate worse survival in patients with MIBC. The prognostic role of AREG should further be investigated in large, prospective series. Divergent survival outcomes between the four cohorts should be interpreted cautiously, considering differences in analysis methods and demographics. Further in vitro investigations are necessary to elucidate the functional mechanisms underlying the associations observed in this study.

The incorporation of extracellular vesicle markers varies among vesicles with distinct surface charges

Extracellular vesicles (EVs) are important mediators of intercellular communication. However, the methods available for distinguishing the heterogeneity of secreted EVs and isolating and purifying them are limited. This study introduced a HiBiT-tag to detect various EV markers, including CD63, CD9, Epidermal Growth Factor Receptor (EGFR), Flotilin1, and Syndecan-1, and investigated whether these marker-containing vesicles were capable of binding to differently charged column carriers. Four column carriers, Diethylaminoethyl (DEAE), Capto Adhere, Blue and Heparin, showed affinity for CD63 containing EVs, but their elution patterns varied. Furthermore, we observed that the elution patterns of the EV markers differed among vesicles with distinct surface charges when a DEAE column was used. This suggests that the incorporation of EV markers varied between these vesicles. The markers showed different subcellular localizations, indicating that the site of vesicle formation may contribute to the production of vesicles with varying charges and marker incorporation. These findings may have implications for the development of methods to purify homogeneous EVs, which could be useful in EV-mediated drug delivery systems.

Urinary markers for bladder cancer diagnosis: A review of current status and future challenges

Bladder cancer is a common urological cancer with a high recurrence rate that requires long-term follow-up, and early detection positively affects prognosis. To date, the initial diagnosis and follow-up for bladder cancer rely on cystoscopy, which is an invasive and expensive procedure. Therefore, urinary markers for the detection of bladder cancer have attracted research attention for decades to reduce unnecessary cystoscopies. Urine, which is in continuous contact with bladder cancer, is considered a suitable fluid for providing tumor information. Urinary cytology is the only widely used urinary marker in clinical practice; however, it has poor sensitivity for low-grade tumors; indicating the need for novel urinary markers. Considerable research has been conducted on this topic over the years, resulting in a complex landscape with a wide range of urinary markers, including protein-, exfoliated cell-, RNA-, DNA-, and extracellular vesicle-based markers. Although some of these markers have been approved by the U.S. Food and Drug Administration and are commercially available, their use in clinical practice is limited. To facilitate clinical application, potential urinary markers must withstand prospective clinical trials and be easy for patients and clinicians to understand and utilize in a clinical context. This review provides a comprehensive overview of currently available and recently reported promising urinary markers for bladder cancer. Additionally, the challenges and the prospects of these urinary markers for clinical implementation in bladder cancer treatment were discussed.

Advances and challenges in clinical applications of tumor cell-derived extracellular vesicles

Extracellular vesicles (EVs) are a class of substances that feature vesicle-like structures. Initially deemed to be "biological waste", recent studies have highlighted the crucial role of EVs in mediating information communication between cells by transporting bioactive components. Specifically, tumor cell-derived extracellular vesicles (TEVs) contain components that can be utilized for disease diagnosis and as vaccines to activate the immune system. Moreover, since TEVs have a phospholipid bilayer shell and can transport exogenous substances, they are being increasingly explored as drug delivery vehicles in anti-tumor therapy. TEVs have proven highly compatible with their corresponding tumor cells, allowing for efficient drug delivery and exerting killing effects on tumor cells through various mechanisms such as domino effects, lysosomal pathways, and inhibition of drug efflux from tumor tissues. Despite these promising developments, challenges remain in the clinical applications of EVs derived from tumor cells. This paper outlines the current advances and limitations in this field, highlighting the potential of TEVs as a powerful tool for combating cancer.

Recent Progress in Prompt Molecular Detection of Exosomes Using CRISPR/Cas and Microfluidic-Assisted Approaches Toward Smart Cancer Diagnosis and Analysis

Exosomes are essential indicators of molecular mechanisms involved in interacting with cancer cells and the tumor environment. As nanostructures based on lipids and nucleic acids, exosomes provide a communication pathway for information transfer by transporting biomolecules from the target cell to other cells. Importantly, these extracellular vesicles are released into the bloodstream by the most invasive cells, i. e., cancer cells; in this way, they could be considered a promising specific biomarker for cancer diagnosis. In this matter, CRISPR-Cas systems and microfluidic approaches could be considered practical tools for cancer diagnosis and understanding cancer biology. CRISPR-Cas systems, as a genome editing approach, provide a way to inactivate or even remove a target gene from the cell without affecting intracellular mechanisms. These practical systems provide vital information about the factors involved in cancer development that could lead to more effective cancer treatment. Meanwhile, microfluidic approaches can also significantly benefit cancer research due to their proper sensitivity, high throughput, low material consumption, low cost, and advanced spatial and temporal control. Thereby, employing CRISPR-Cas- and microfluidics-based approaches toward exosome monitoring could be considered a valuable source of information for cancer therapy and diagnosis. This review assesses the recent progress in these promising diagnosis approaches toward accurate cancer therapy and in-depth study of cancer cell behavior.

Drug target therapy and emerging clinical relevance of exosomes in meningeal tumors

Meningioma is the most common central nervous system (CNS) tumor. In recent decades, several efforts have been made to eradicate this disease. Surgery and radiotherapy remain the standard treatment options for these tumors. Drug therapy comes to play its role when both surgery and radiotherapy fail to treat the tumor. This mostly happens when the tumors are close to vital brain structures and are nonbenign. Although a wide variety of chemotherapeutic drugs and molecular targeted drugs such as tyrosine kinase inhibitors, alkylating agents, endocrine drugs, interferon, and targeted molecular pathway inhibitors have been studied, the roles of numerous drugs remain unexplored. Recent interest is growing toward studying and engineering exosomes for the treatment of different types of cancer including meningioma. The latest studies have shown the involvement of exosomes in the theragnostic of various cancers such as the lung and pancreas in the form of biomarkers, drug delivery vehicles, and vaccines. Proper attention to this new emerging technology can be a boon in finding the consistent treatment of meningioma.

Isolation of Extracellular Vesicles Using Titanium Dioxide Microspheres

Extracellular vesicles (EVs) are bilayer membrane particles released from several cell types to the extracellular environment. EVs have a crucial role in cell-cell communication, involving different biological processes in health and diseases. Due to the potential of biomarkers for several diseases as diagnostic and therapeutic tools, it is relevant to understand the biology of the EVs and their content. One of the current challenges involving EVs is regarding the purification method, which is a critical step for EV's functional and characterization studies. Ultracentrifugation is the most used method for EV isolation, where the nanoparticles are separated in sequential centrifugation to isolate the EVs based on their size. However, for viscous biofluids such as plasma, there is a co-isolation of the most abundant proteins, which can impair the EV's protein identification due to the low abundance of these proteins and signal suppression by the most abundant plasma proteins. Emerging techniques have gained attention in recent years. Titanium dioxide (TiO2) is one of the most promising techniques due to its property for selective isolation based on the interaction with phospholipids in the EV membrane. Using a small amount of TiO2 beads and a low volume of plasma, it is possible to isolate EVs with reduced plasma protein co-isolation. This study describes a comprehensive workflow for the isolation and characterization of plasma extracellular vesicles (EVs) using mass spectrometry-based proteomics techniques. The aim of this chapter is describe the EV isolation using TiO2 beads enrichment and high-throughput mass spectrometry techniques to efficiently identify the protein composition of EVs in a fast and straightforward manner.

Deciphering Urogenital Cancers through Proteomic Biomarkers: A Systematic Review and Meta-Analysis

Urogenital cancers, which include prostate, bladder, and kidney malignancies, exert a substantial impact on global cancer-related morbidity and mortality. Proteomic biomarkers, emerging as valuable tools, aim to enhance early detection, prognostic accuracy, and the development of personalized therapeutic strategies. This study undertook a comprehensive systematic review and meta-analysis of the existing literature investigating the role and potential of proteomic biomarkers in plasma, tissue, and urine samples in urogenital cancers. Our extensive search across several databases identified 1879 differentially expressed proteins from 37 studies, signifying their potential as unique biomarkers for these cancers. A meta-analysis of the significantly differentially expressed proteins was executed, accentuating the findings through visually intuitive volcano plots. A functional enrichment analysis unveiled their significant involvement in diverse biological processes, including signal transduction, immune response, cell communication, and cell growth. A pathway analysis highlighted the participation of key pathways such as the nectin adhesion pathway, TRAIL signaling pathway, and integrin signaling pathways. These findings not only pave the way for future investigations into early detection and targeted therapeutic approaches but also underscore the fundamental role of proteomics in advancing our understanding of the molecular mechanisms underpinning urogenital cancer pathogenesis. Ultimately, these findings hold remarkable potential to significantly enhance patient care and improve clinical outcomes.

The Role of Longevity Assurance Homolog 2/Ceramide Synthase 2 in Bladder Cancer

The human CERS2 gene encodes a ceramide synthase enzyme, known as CERS2 (ceramide synthase 2). This protein is also known as LASS2 (LAG1 longevity assurance homolog 2) and TMSG1 (tumor metastasis-suppressor gene 1). Although previously described as a tumor suppressor for different types of cancer, such as prostate or liver cancer, it has also been observed to promote tumor growth in adenocarcinoma. In this review, we focus on the influence of CERS2 in bladder cancer (BC), approaching the existing literature about its structure and activity, as well as the miRNAs regulating its expression. From a mechanistic point of view, different explanations for the role of CERS2 as an antitumor protein have been proposed, including the production of long-chain ceramides, interaction with vacuolar ATPase, and its function as inhibitor of mitochondrial fission. In addition, we reviewed the literature specifically studying the expression of this gene in both BC and biopsy-derived tumor cell lines, complementing this with an analysis of public gene expression data and its association with disease progression. We also discuss the importance of CERS2 as a biomarker and the presence of CERS2 mRNA in extracellular vesicles isolated from urine.

Liquid biopsy in urothelial carcinoma: Detection techniques and clinical applications

The types of urothelial carcinoma (UC) include urothelial bladder cancer and upper tract urothelial carcinoma. Current diagnostic techniques cannot meet the needs of patients. Liquid biopsy is an accurate method of determining the molecular profile of UC and is a cutting-edge and popular technique that is expected to complement existing detection techniques and benefit patients with UC. Circulating tumor cells, cell-free DNA, cell-free RNA, extracellular vesicles, proteins, and metabolites can be found in the blood, urine, or other bodily fluids and are examined during liquid biopsies. This article focuses on the components of liquid biopsies and their clinical applications in UC. Liquid biopsies have tremendous potential in multiple aspects of precision oncology, from early diagnosis and treatment monitoring to predicting prognoses. They may therefore play an important role in the management of UC and precision medicine.

Proteomic Research of Extracellular Vesicles in Clinical Biofluid

Extracellular vesicles (EVs), the lipid bilayer membranous structures of particles, are produced and released from almost all cells, including eukaryotes and prokaryotes. The versatility of EVs has been investigated in various pathologies, including development, coagulation, inflammation, immune response modulation, and cell-cell communication. Proteomics technologies have revolutionized EV studies by enabling high-throughput analysis of their biomolecules to deliver comprehensive identification and quantification with rich structural information (PTMs, proteoforms). Extensive research has highlighted variations in EV cargo depending on vesicle size, origin, disease, and other features. This fact has sparked activities to use EVs for diagnosis and treatment to ultimately achieve clinical translation with recent endeavors summarized and critically reviewed in this publication. Notably, successful application and translation require a constant improvement of methods for sample preparation and analysis and their standardization, both of which are areas of active research. This review summarizes the characteristics, isolation, and identification approaches for EVs and the recent advances in EVs for clinical biofluid analysis to gain novel knowledge by employing proteomics. In addition, the current and predicted future challenges and technical barriers are also reviewed and discussed.

Extracellular Vesicles as Potential Bladder Cancer Biomarkers: Take It or Leave It?

Bladder cancer (BC) is the 10th most frequently diagnosed cancer worldwide. Although urine cytology and cystoscopy are current standards for BC diagnosis, both have limited sensitivity to detect low-grade and small tumors. Moreover, effective prognostic biomarkers are lacking. Extracellular vesicles (EVs) are lipidic particles that contain nucleic acids, proteins, and metabolites, which are released by cells into the extracellular space, being crucial effectors in intercellular communication. These particles have emerged as potential tools carrying biomarkers for either diagnosis or prognosis in liquid biopsies namely urine, plasma, and serum. Herein, we review the potential of liquid biopsies EVs’ cargo as BC diagnosis and prognosis biomarkers. Additionally, we address the emerging advantages and downsides of using EVs within this framework.

Exosomes and ultrasound: The future of theranostic applications

Biomaterials and pertaining formulations have been very successful in various diagnostic and therapeutic applications because of its ability to overcome pharmacological limitations. Some of them have gained significant focus in the recent decade for their theranostic properties. Exosomes can be grouped as biomaterials, since they consist of various biological micro/macromolecules and possess all the properties of a stable biomaterial with size in nano range. Significant research has gone into isolation and exploitation of exosomes as potential theranostic agent. However, the limitations in terms of yield, efficacy, and target specificity are continuously being addressed. On the other hand, several nano/microformulations are responsive to physical or chemical alterations and were successfully stimulated by tweaking the physical characteristics of the surrounding environment they are in. Some of them are termed as photodynamic, sonodynamic or thermodynamic therapeutic systems. In this regard, ultrasound and acoustic systems were extensively studied for its ability towards altering the properties of the systems to which they were applied on. In this review, we have detailed about the diagnostic and therapeutic applications of exosomes and ultrasound separately, consisting of their conventional applications, drawbacks, and developments for addressing the challenges. The information were categorized into various sections that provide complete overview of the isolation strategies and theranostic applications of exosomes in various diseases. Then the ultrasound-based disease diagnosis and therapy were elaborated, with special interest towards the use of ultrasound in enhancing the efficacy of nanomedicines and nanodrug delivery systems, Finally, we discussed about the ability of ultrasound in enhancing the diagnostic and therapeutic properties of exosomes, which could be the future of theranostics.

Exosomes─Nature's Lipid Nanoparticles, a Rising Star in Drug Delivery and Diagnostics

Exosomes are a subgroup of nanosized extracellular vesicles enclosed by a lipid bilayer membrane and secreted by most eukaryotic cells. They represent a route of intercellular communication and participate in a wide variety of physiological and pathological processes. The biological roles of exosomes rely on their bioactive cargos, including proteins, nucleic acids, and lipids, which are delivered to target cells. Their distinctive properties─innate stability, low immunogenicity, biocompatibility, and good biomembrane penetration capacity─allow them to function as superior natural nanocarriers for efficient drug delivery. Another notably favorable clinical application of exosomes is in diagnostics. They hold various biomolecules from host cells, which are indicative of pathophysiological conditions; therefore, they are considered vital for biomarker discovery in clinical diagnostics. Here, we use data from the CAS Content Collection and provide a landscape overview of the current state and delineate trends in research advancement on exosome applications in therapeutics and diagnostics across time, geography, composition, cargo loading, and development pipelines. We discuss exosome composition and pathway, from their biogenesis and secretion from host cells to recipient cell uptake. We assess methods for exosome isolation and purification, their clinical applications in therapy and diagnostics, their development pipelines, the exploration goals of the companies, the assortment of diseases they aim to treat, development stages of their research, and publication trends. We hope this review will be useful for understanding the current knowledge in the field of medical applications of exosomes, in an effort to further solve the remaining challenges in fulfilling their potential.

Urine exosomes as biomarkers in bladder cancer diagnosis and prognosis: From functional roles to clinical significance

Bladder cancer is one of the top ten most common cancers and top ten causes of cancer death globally. 5-year survival rates have decreased in Australia from 66% to 55% in the past three decades. The current gold standard for diagnosis is cystoscopy. However, cystoscopies are an invasive and health-resource intensive procedure which has sub-optimal sensitivity for flat lesions such as CIS (carcinoma in situ) and low specificity for differentiating inflammation from cancer - hence requiring biopsies under anesthesia. Frequent and life-long surveillance cystoscopy is required for most patients since there are high rates of progression and local recurrence in high-risk non-muscle invasive cancer (NMIBC) as well as poor outcomes associated with delayed detection of muscle-invasive bladder cancer (MIBC). There is an unmet need for a non-invasive test to provide better discrimination and risk-stratification of bladder cancer which could aid clinicians by improving patient selection for cystoscopy; enhanced risk stratification methods may guide the frequency of surveillance cystoscopies and inform treatment choices. Exosomes, which are nano-sized extracellular vesicles containing genetic material and proteins, have been shown to have functional roles in the development and progression of bladder cancer. Exosomes have also been demonstrated to be a robust source of potential biomarkers for bladder cancer diagnosis and prognosis and may also have roles as therapeutic agents. In this review, we summarize the latest evidence of biological roles of exosomes in bladder cancer and highlight their clinical significance in bladder cancer diagnosis, surveillance and treatment.

Alternative splicing patterns reveal prognostic indicator in muscle-invasive bladder cancer

Background

Bladder cancer is one of the most lethal malignancy in urological system, and 20–25% of bladder cancer patients are muscle invasive with unfavorable prognosis. However, the role of alternative splicing (AS) in muscle-invasive bladder cancer (MIBC) remains to be elucidated.

Methods

Percent spliced in (PSI) data obtained from the Cancer Genome Atlas (TCGA) SpliceSeq database (n = 394) were utilized to evaluate the AS events in MIBC. Prognosis-associated AS events were screened out by univariate Cox regression. LASSO Cox regression was used to identify reliable prognostic patterns in a training set and further validated in a test set. Splicing regulatory networks were constructed by correlations between PSI of AS events and RNA expression of splicing factors.

Results

As a result, a total of 2589 prognosis-related AS events in MIBC were identified. Pathways of spliceosomal complex (FDR = 0.017), DNA-directed RNA polymerase II, core complex (FDR = 0.032), and base excision repair (FDR = 0.038) were observed to be significantly enriched. Additionally, we noticed that most of the prognosis-related AS events were favorable factors. According to the LASSO and multivariate Cox regression analyses, 15-AS-based signature was established with the area under curve (AUC) of 0.709, 0.823, and 0.857 at 1-, 3-, and 5- years, respectively. The MIBC patients were further divided into high- and low-risk groups based on median risk sores. Interestingly, we observed that the prevalence of FGFR3 with mutations and focal amplification was significantly higher in low-risk group. Functional and immune infiltration analysis suggested potential signaling pathways and distinct immune states between these two groups. Moreover, splicing correlation network displayed a regulatory mode of prognostic splicing factors (SF) in MIBC patients.

Conclusions

This study not only provided novel insights into deciphering the possible mechanism of tumorgenesis and pathogenesis but also help refine risk stratification systems and potential treatment of decision-making for MIBC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02685-0.

EphA2 on urinary extracellular vesicles as a novel biomarker for bladder cancer diagnosis and its effect on the invasiveness of bladder cancer

BACKGROUND

Urinary extracellular vesicles (uEVs) secreted from bladder cancer contain cancer-specific proteins that are potential diagnostic biomarkers. We identified and evaluated a uEV-based protein biomarker for bladder cancer diagnosis and analysed its functions.

METHODS

Biomarker candidates, selected by shotgun proteomics, were validated using targeted proteomics of uEVs obtained from 49 patients with and 48 individuals without bladder cancer, including patients with non-malignant haematuria. We developed an enzyme-linked immunosorbent assay (ELISA) for quantifying the uEV protein biomarker without ultracentrifugation and evaluated urine samples from 36 patients with and 36 patients without bladder cancer.

RESULTS

Thirteen membrane proteins were significantly upregulated in the uEVs from patients with bladder cancer in shotgun proteomics. Among them, eight proteins were validated by target proteomics, and Ephrin type-A receptor 2 (EphA2) was the only protein significantly upregulated in the uEVs of patients with bladder cancer, compared with that of patients with non-malignant haematuria. The EV-EphA2-CD9 ELISA demonstrated good diagnostic performance (sensitivity: 61.1%, specificity: 97.2%). We showed that EphA2 promotes proliferation, invasion and migration and EV-EphA2 promotes the invasion and migration of bladder cancer cells.

CONCLUSIONS

We established EV-EphA2-CD9 ELISA for uEV-EphA2 detection for the non-invasive early clinical diagnosis of bladder cancer.

Integrated view of molecular diagnosis and prognosis of dengue viral infection: future prospect of exosomes biomarkers

Dengue viruses (DENVs) are the viruses responsible for dengue infection which affects lungs, liver, heart and also other organs of individuals. DENVs consist of the group of four serotypically diverse dengue viruses transmitted in tropical and sub-tropical countries of world. Aedes mosquito is the principal vector which spread the infection from infected person to healthy humans. DENVs can cause different syndromes depending on serotype of virus which range from undifferentiated mild fever to dengue hemorrhagic fever resulting in vascular leakage due to release of cytokine and Dengue shock syndrome with fluid loss and hypotensive shock, or other severe manifestations such as bleeding and organ failure. Increase in dengue cases in pediatric population is a major concern. Transmission of dengue depends on various factors like temperature, rainfall, and distribution of Aedes aegypti mosquitoes. The present review describes a comprehensive overview of dengue, pathophysiology, diagnosis, treatment with an emphasis on potential of exosomes as biomarkers for early prediction of dengue in pediatrics.

Roles of Microvesicles in Tumor Progression and Clinical Applications

Microvesicles are extracellular vesicles with diameter ranging from 100 to 1000 nm that are secreted by tumor cells or other cells in the tumor microenvironment. A growing number of studies demonstrate that tumor-derived microvesicles are involved in tumor initiation and progression, as well as drug resistance. In addition, tumor-derived microvesicles carry a variety of immunogenic molecules and inhibit tumor response to immunotherapy; therefore, they can be exploited for use in tumor vaccines. Moreover, because of their high stability, tumor-derived microvesicles extracted from body fluids can be used as biomarkers for cancer diagnosis or assessment of prognosis. Tumor-derived microvesicles can also be deployed to reverse drug resistance of tumor regenerative cells, or to deliver chemotherapeutic drugs and oncolytic adenovirus for the treatment of cancer patients. This review summarizes the general characteristics of tumor-derived microvesicles, focusing on their biological characteristics, their involvement in tumor progression, and their clinical applications.

Comprehensive overview of extracellular vesicle proteomics in meningioma: future strategy

Background

Meningioma arising from meninges is one among the various types of brain tumors. Others are, astrocytomas originating from astrocyte, oligodendrogliomas originating from oligodendrocyte, Ependymomas originating from ependymal cells and medulloblastomas originating from neurons. Current knowledge of molecular biology, genetics and epigenetics of meningioma is not sufficient. Therefore, In depth understanding of the mechanism of meningioma formation and progression is needed for its treatment and management. Grade I Grade I meningiomas are majorly classified as grade I, grade II and grade III. Meningioma can be indolent, slow growing or can be invasive and metastatic which can recurre. Grade I meningioma can be removed by surgery in comparison to invasive meningioma which may recurre with high propensity. This property of recurrence is responsible for high morbidity and mortality. Meningioma are majorly classified into three classes namely grade I, grade II, grade III. Protein biomarkers are considered as promising candidates for the diagnosis of meningioma.

Study

Various studies done on differential expression of proteins have shown increased expression of EGFR, NEK9, EPS812, CKAP4, SET and STAT2, in all the three grades of meningioma. Additionally, some proteins like HK2 are overexpressed in grade II and grade III meningioma than in grade I meningioma. Protein Markers, found on extracellular vesicles of different grades of meningioma can serve the same purpose. A test done on a sample of any kind of body fluid like blood, tear, saliva, urine etc. for recognizing the circulating cancer cells or DNA and extracellular vesicles released from them to help detecting the early stage of cancer is known as liquid biopsy. Solid biopsy has several limitations as compared to liquid biopsy. This is because the samples can be easily collected and studied in case of liquid biopsy. Exosomes are related with liquid biopsy and hence provide platform for better diagnosis, prognosis and treatment of any type of cancer including meningioma. Exosomal tetraspanin are important example of exosomal biomarkers. The tetraspanin network is a molecular scaffold which connects various proteins for signal transduction.

Conclusion

This study tells about the utility of proper knowledge of extracellular vesicle proteins and their profiles in different grades, which can help in better understanding of pathogenesis, diagnosis, prognosis and treatment of meningioma. In Addition to use of these proteins as biomarkers, role of exosomes in currently available therapeutic approaches has been discussed.

The Immunomodulation Potential of Exosomes in Tumor Microenvironment

Exosomes are lipid bilayer particles that originated from almost all types of cells and play an important role in intercellular communication. Tumor-derived exosomes contain large amounts of noncoding RNA, DNA, and proteins, which can be transferred into recipient cells as functional components in exosomes. These exosomal functional constituents depend on the originating cells, and it has been proved that types and numbers of exosomal components differ in cancer patients and healthy individuals. This review summarizes the role of tumor-derived exosomes in immunomodulation and discusses the application of exosomes in immunotherapy in cancers. Overall, exosomes isolated from cancer cells are turned out to promote immune evasion and interfere with immune responses in tumors through inducing apoptosis of CD8+ T cells, facilitating generation of Tregs, suppressing natural killer (NK) cell cytotoxicity, inhibiting maturation and differentiation of monocyte, and enhancing suppressive function of myeloid-derived suppressor cells (MDSCs). Mechanistically, exosomal functional components play a significant role in the immunomodulation in cancers. Moreover, based on the existing studies, exosomes could potentially serve as therapeutic delivery vehicles, noninvasive biomarkers, and immunotherapeutic vaccines for various types of cancers.

Isolation and analysis methods of extracellular vesicles (EVs)

Extracellular vesicles (EVs) have been recognized as an evolving biomarker within the liquid biopsy family. While carrying both host cell proteins and different types of RNAs, EVs are also present in sufficient quantities in biological samples to be tested using many molecular analysis platforms to interrogate their content. However, because EVs in biological samples are comprised of both disease and non-disease related EVs, enrichment is often required to remove potential interferences from the downstream molecular assay. Most benchtop isolation/enrichment methods require > milliliter levels of sample and can cause varying degrees of damage to the EVs. In addition, some of the common EV benchtop isolation methods do not sort the diseased from the non-diseased related EVs. Simultaneously, the detection of the overall concentration and size distribution of the EVs is highly dependent on techniques such as electron microscopy and Nanoparticle Tracking Analysis, which can include unexpected variations and biases as well as complexity in the analysis. This review discusses the importance of EVs as a biomarker secured from a liquid biopsy and covers some of the traditional and non-traditional, including microfluidics and resistive pulse sensing, technologies for EV isolation and detection, respectively.

Urinary Exosomal CA9 mRNA as a Novel Liquid Biopsy for Molecular Diagnosis of Bladder Cancer

Objective

The objective of this study was to assess the possibility of using urinary exosomal CA9 mRNA as a novel liquid biopsy for the molecular diagnosis of bladder cancer.

Patients and Methods

A total of 168 bladder cancer patients and 90 control subjects were included in the study. An isolation kit was used to isolate urinary exosomes. Transmission electron microscopy (TEM) was used to examine the presence of exosomes. Flow cytometry was used to examine the exosomal marker CD63. The expression level of exosomal CA9 mRNA was detected by RT-qPCR. The diagnostic performance of urinary urinary exosomal CA9 mRNA was evaluated.

Results

TEM confirmed the enriched exosomes from urinary bladder patients. Flow cytometry indicated a strong positive expression of exosome marker CD63. Successful extraction of RNA was performed from exosome samples. The level of urinary exosomal CA9 mRNA was significantly higher in bladder cancer group than in control group (p<0.001). The area under the ROC curve was 0.837 (95% CI: 0.743–0.859) with a sensitivity of 85.18% and a specificity of 83.15% for the diagnosis of bladder cancer.

Conclusion

We found that the urinary exosomes were abundant in the urine of bladder cancer patients. CA9 mRNA could be detectable in urinary exosomes. The urinary exosomal CA9 mRNA may present a new liquid biopsy for the diagnosis of bladder cancer.

Proteomic Profiling of Ectosomes Derived from Paired Urothelial Bladder Cancer and Normal Cells Reveals the Presence of Biologically-Relevant Molecules

Protein content of extracellular vesicles (EVs) can modulate different processes during carcinogenesis. Novel proteomic strategies have been applied several times to profile proteins present in exosomes released by urothelial bladder cancer (UBC) cells. However, similar studies have not been conducted so far on another population of EVs, i.e., ectosomes. In the present study we used a shotgun nanoLC-MS/MS proteomic approach to investigate the protein content of ectosomes released in vitro by T-24 UBC cells and HCV-29 normal ureter epithelial cells. In addition, cancer-promoting effects exerted by UBC-derived ectosomes on non-invasive cells in terms of cell proliferation and migratory properties were assessed. In total, 1158 proteins were identified in T-24-derived ectosomes, while HCV-29-derived ectosomes contained a lower number of 259 identified proteins. Qualitative analysis revealed 938 proteins present uniquely in T-24-derived ectosomes, suggesting their potential applications in bladder cancer management as diagnostic and prognostic biomarkers. In addition, T-24-derived ectosomes increased proliferation and motility of recipient cells, likely due to the ectosomal transfer of the identified cancer-promoting molecules. The present study provided a focused identification of biologically relevant proteins in UBC-derived ectosomes, confirming their role in UBC development and progression, and their applicability for further biomarker-oriented studies in preclinical or clinical settings.

Clinical applications for exosomes: Are we there yet?

Exosomes are a subset of extracellular vesicles essential for cell-cell communication in health and disease with the ability to transport nucleic acids, functional proteins and other metabolites. Their clinical use as diagnostic biomarkers and therapeutic carriers has become a major field of research over recent years, generating rapidly expanding scientific interest and financial investment. Their reduced immunogenicity compared to liposomes or viral vectors and their ability to cross major physiological barriers like the blood-brain barrier make them an appealing and innovative option as biomarkers and therapeutic agents. Here, we review the latest clinical developments of exosome biotechnology for diagnostic and therapeutic purposes, including the most recent COVID-19-related exosome-based clinical trials. We present current exosome engineering strategies for optimal clinical safety and efficacy, and assess the technology developed for good manufacturing practice compliant scaling up and storage approaches along with their limitations in pharmaceutical industry.

Proteomic analysis of urinary and tissue-exudative extracellular vesicles to discover novel bladder cancer biomarkers

Proteomic analysis of urinary extracellular vesicles (EVs) is a powerful approach to discover potential bladder cancer (BCa) biomarkers, however urine contains numerous EVs derived from the kidney and normal urothelial epithelium, which can obfuscate information related to BCa cell-derived EVs. In this study, we combined proteomic analysis of urinary EVs and tissue-exudative EVs (Te-EVs), which were isolated from culture medium of freshly resected viable BCa tissues. Urinary EVs were isolated from urine samples of 11 individuals (7 BCa patients and 4 healthy individuals), and Te-EVs were isolated from 7 BCa tissues. We performed tandem mass tag (TMT)-labeling liquid chromatography (LC-MS/MS) analysis for both urinary EVs and Te-EVs and identified 1960 proteins in urinary EVs and 1538 proteins in Te-EVs. Most of the proteins identified in Te-EVs were also present in urinary EVs (82.4%), with 55 of these proteins showing upregulated levels in the urine of BCa patients (fold change > 2.0; P < .1). Among them, we selected 22 membrane proteins as BCa biomarker candidates for validation using selected reaction monitoring/multiple reaction monitoring (SRM/MRM) analysis on urine samples from 70 individuals (40 BCa patients and 30 healthy individuals). Six urinary EV proteins (heat-shock protein 90, syndecan-1, myristoylated alanine-rich C-kinase substrate (MARCKS), MARCKS-related protein, tight junction protein ZO-2, and complement decay-accelerating factor) were quantified using SRM/MRM analysis and validated as significantly upregulated in BCa patients (P < .05). In conclusion, the novel strategy that combined proteomic analysis of urinary EVs and Te-EVs enabled selective detection of urinary BCa biomarkers.

Specimen-specific drift of densities defines distinct subclasses of extracellular vesicles from human whole saliva

Extracellular vesicles (EVs) in body fluids constitute heterogenous populations, which mirror their diverse parental cells as well as distinct EV-generation pathways. Various methodologies have been proposed to differentiate EVs in order to deepen the current understanding of EV biology. Equilibrium density-gradient centrifugation has often been used to separate EVs based on their buoyant densities; however, the standard conditions used for the method do not necessarily allow all EVs to move to their equilibrium density positions, which complicates the categorization of EVs. Here, by prolonging ultracentrifugation time to 96 h and fractionating EVs both by floating up or spinning down directions, we allowed 111 EV-associated protein markers from the whole saliva of three healthy volunteers to attain equilibrium. Interestingly, the determined buoyant densities of the markers drifted in a specimen-specific manner, and drift patterns differentiated EVs into at least two subclasses. One class carried classical exosomal markers, such as CD63 and CD81, and the other was characterized by the molecules involved in membrane remodeling or vesicle trafficking. Distinct patterns of density drift may represent the differences in generation pathways of EVs.

Urinary extracellular vesicles: a rising star in bladder cancer management

Clinically, the detection of bladder cancer (BCa) typically requires cystoscopy, which is potentially harmful and sometimes accompanied by adverse effects. Thus, new biomarkers are desirable for improving the management of BCa. Recently, “liquid biopsy” has received enormous attentions and has been extensively studied due to its promising clinical implication for precise medicine. Especially, extracellular vesicles (EVs) have attracted strong interest as a potential source of biomarkers. EVs have been reported to be found in almost all types of body fluids and are easy to collect. In addition, EVs tightly reflect the current state of the disease by inheriting specific biomolecules from their parental cells. Urinary EVs have gained great scientific interest in the field of BCa biomarker research since urine is in direct contact with BCa and can contain large amounts of EVs from the tumour microenvironment. To date, various kinds of biomolecules, including noncoding RNAs, mRNAs, and proteins, have been investigated as biomarkers in urinary EVs. In this narrative review, we summarize the recent advances regarding urinary EVs as non-invasive biomarkers in patients with BCa. The current hurdles in the clinical implications of EV-based liquid biopsy and the potential applications of EV research are also discussed.

Urinary Extracellular Vesicles as Potential Biomarkers for Urologic Cancers: An Overview of Current Methods and Advances

Urologic cancers are a heterogeneous group of tumors, some of which have poor prognosis. This is partly due to the unavailability of specific and sensitive diagnostic techniques and monitoring tests, ideally non- or minimally invasive. Hence, liquid biopsies are promising tools that have been gaining significant attention over the last decade. Among the different classes of biomarkers that can be isolated from biofluids, urinary extracellular vesicles (uEVs) are a promising low-invasive source of biomarkers, with the potential to improve cancer diagnosis and disease management. Different techniques have been developed to isolate and characterize the cargo of these vesicles; however, no consensus has been reached, challenging the comparison among studies. This results in a vast number of studies portraying an extensive list of uEV-derived candidate biomarkers for urologic cancers, with the potential to improve clinical outcome; however, without significant validation. Herein, we review the current published research on miRNA and protein-derived uEV for prostate, bladder and kidney cancers, focusing on different uEV isolation methods, and its implications for biomarker studies.

Exosomes as Emerging Biomarker Tools in Neurodegenerative and Neuropsychiatric Disorders-A Proteomics Perspective

Exosomes are synthesized and secreted by different cell types and contain proteins, lipids, metabolites and RNA species that reflect the physiological status of the cell of origin. As such, exosomes are increasingly being used as a novel reservoir for disease biomarker discovery. However, isolation of exosomes can be challenging due to their nonuniformity of shape and variable tissue of origin. Moreover, various analytical techniques used for protein detection and quantitation remain insensitive to the low amounts of protein isolated from exosomes. Despite these challenges, techniques to improve proteomic yield and increase protein dynamic range continue to improve at a rapid rate. In this review, we highlight the importance of exosome proteomics in neurodegenerative and neuropsychiatric disorders and the associated technical difficulties. Furthermore, current progress and technological advancements in exosome proteomics research are discussed with an emphasis on disease-associated protein biomarkers.

Extracellular vesicles in cancer nanomedicine

To date, a lot of nanotechnological optitions are available for targeted drug delivery. Extracellular vesicles (EVs) are membrane structures that cells use for storage, transport, communication, and signaling. Recent research has focused on EVs as natural nanoparticles for drug delivery. This review sheds light on the application of EVs in cancer therapy, such as targeted chemotherapy, gene therapy, and vaccine development. Aspects of biogenesis, isolation, targeting, and loading of EVs are discussed in detail.

Emerging Roles of Urine-Derived Components for the Management of Bladder Cancer: One Man's Trash Is Another Man's Treasure

Simple Summary

Urinary bladder cancer (UBC) is one of the most common and deadly cancers worldwide, with many patients not responding to chemotherapy, or presenting with serious adverse effects after chemotherapy. Yet, current bench side assays provide limited accuracy for predicting therapeutic response to chemotherapeutic drugs. The aim of this review is to demonstrate the potential of urinary-derived extracellular vesicles and UBC-organoids to serve as predictive biomarkers for this cancer. Specifically, molecular subtyping of urine-derived extracellular vesicles has the potential to provide insights into the molecular stratification of the tumor, while urinary organoids will allow for individualized chemotherapy testing in the context of precision medicine.

Abstract

Urinary bladder cancer (UBC) is the most common malignancy of the urinary tract in humans, with an estimated global prevalence of 1.1 million cases over 5 years. Because of its high rates of recurrence and resistance to chemotherapy, UBC is one of the most expensive cancers to treat, resulting in significant health care costs. The development of innovative molecular and cellular tools is necessary to refine patient stratification and help predict response to treatment. Urine is an underused resource of biological components shed from bladder tumors, such as exfoliated cells and extracellular vesicles, that could serve as molecular fingerprints and provide valuable biological insights into tumor phenotype and mechanisms of resistance to chemotherapy. Additionally, characterization of urine-derived extracellular vesicles and cells could be used as reliable biomarkers for prediction of response to neoadjuvant therapy.

Comprehensive Proteomic Profiling of Urinary Exosomes and Identification of Potential Non-invasive Early Biomarkers of Alzheimer's Disease in 5XFAD Mouse Model

Background

Alzheimer’s disease (AD) is an incurable neurodegenerative disease characterized by irreversible progressive cognitive deficits. Identification of candidate biomarkers, before amyloid-β-plaque deposition occurs, is therefore of great importance for early intervention of AD.

Objective

To investigate the potential non-invasive early biomarkers of AD in 5XFAD mouse model, we investigate the proteome of urinary exosomes present in 1-month-old (before amyloid-β accumulation) 5XFAD mouse models and their littermate controls. Another two groups of 2 and 6 months-old urinary samples were collected for monitoring the dynamic change of target proteins during AD progression.

Methods

Proteomic, bioinformatics analysis, multiple reaction monitoring (MRM), western blotting (WB) or ELISA were performed for analyzing these urinary exosomes.

Results

A total of 316 proteins including 44 brain cell markers were identified using liquid chromatography tandem mass spectrometry. Importantly, 18 proteins were unique to the 5XFAD group. Eighty-eight proteins including 11 brain cell markers were differentially expressed. Twenty-two proteins were selected to be verified by WB. Furthermore, based on an independent set of 12 urinary exosomes samples, five in these proteins were further confirmed significant difference. Notably, Annexin 2 and Clusterin displayed significant decreased in AD model during the course detected by ELISA. AOAH, Clusterin, and Ly86 are also brain cell markers that were first reported differential expression in urinary exosomes of AD model.

Conclusion

Our data demonstrated that some urinary exosome proteins, especially Annexin 2 and Clusterin, as nanometer-sized particles, enable detection of differences before amyloid-β-plaque deposition in 5XFAD mouse model, which may present an ideal non-invasive source of biomarkers for prevention of AD.

The Biological Function and Therapeutic Potential of Exosomes in Cancer: Exosomes as Efficient Nanocommunicators for Cancer Therapy

Cancer therapeutics must be delivered to their targets for improving efficacy and reducing toxicity, though they encounter physiological barriers in the tumor microenvironment. They also face limitations associated with genetic instability and dynamic changes of surface proteins in cancer cells. Nanosized exosomes generated from the endosomal compartment, however, transfer their cargo to the recipient cells and mediate the intercellular communication, which affects malignancy progression, tumor immunity, and chemoresistance. In this review, we give an overview of exosomes' biological aspects and therapeutic potential as diagnostic biomarkers and drug delivery vehicles for oncotherapy. Furthermore, we discuss whether exosomes could contribute to personalized cancer immunotherapy drug design as efficient nanocommunicators.

Exosomes: A Source for New and Old Biomarkers in Cancer

Clinical oncology needs reliable tumor biomarkers to allow a follow-up of tumor patients who do not necessarily need invasive approaches. To date, the existing biomarkers are not sufficiently reliable, and many of them have generated more problems than facilitating the commitment of clinical oncologists. Over the last decades, a broad family of extracellular vesicles, with size ranging between micro to nano, has been raised as a new hope for potential sources of new tumor biomarkers. However, while knowledge in the field is increasing, we do not currently have definitive information allowing a clinical use of extracellular vesicles in cancer clinics. Recent evidence provides new perspective in clinical oncology, based on data showing that circulating nanovesicles called exosomes may represent a valuable source of tumor biomarkers. In this review, we discuss the existing clinical data supporting a key role of exosomes as a source of tumor biomarkers, including proteins and miRNAs, but also discuss the importance of the expression of known tumor biomarkers when expressed on exosomes.

Selectively-Packaged Proteins in Breast Cancer Extracellular Vesicles Involved in Metastasis

Cancer-derived extracellular vesicles are known to play a role in the progression of the disease. In this rapidly-growing field, there are many reports of phenotypic changes in cells following exposure to cancer-derived extracellular vesicles. This study examines the protein contents of vesicles derived from three well-known breast cancer cell lines, MCF-7, MDA-MB-231 and T47D, using peptide-centric LC-MS/MS and cytokine multiplex immunoassay analysis to understand the molecular basis of these changes. Through these techniques a large number of proteins within these vesicles were identified. A large proportion of these proteins are known to be important in cancer formation and progression and associated with cancer signaling, angiogenesis, metastasis and invasion and immune regulation. This highlights the importance of extracellular vesicles (EVs) in cancer communications and shows some of the mechanisms the vesicles use to assist in cancer progression.

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.

Increased urinary exosomal SYT17 levels in chronic active antibody-mediated rejection after kidney transplantation via the IL-6 amplifier

Chronic active antibody-mediated rejection (CAAMR) is a particular problem in kidney transplantation (KTx), and ~25% of grafts are lost by CAAMR. Further, the pathogenesis remains unclear, and there is no effective cure or marker. We previously found that a hyper NFκB-activating mechanism in non-immune cells, called the IL-6 amplifier, is induced by the co-activation of NFκB and STAT3, and that this activation can develop various chronic inflammatory diseases. Here, we show that synaptotagmin-17 (SYT17) is increased in an exosomal fraction of the urine from CAAMR patients, and that this increase is associated with activation of the IL-6 amplifier. Immunohistochemistry showed that SYT17 protein expression was increased in renal tubule cells of the CAAMR group. While SYT17 protein was not detectable in whole-urine samples by western blotting, urinary exosomal SYT17 levels were significantly elevated in the CAAMR group compared to three other histology groups (normal, interstitial fibrosis and tubular atrophy, and calcineurin inhibitors toxicity) after KTx. On the other hand, current clinical laboratory data could not differentiate the CAAMR group from these groups. These data suggest that urinary exosomal SYT17 is a potential diagnostic marker for CAAMR.

Urinary Exosomes from Bladder Cancer Patients Show a Residual Cancer Phenotype despite Complete Pathological Downstaging

Invasive urinary bladder cancer shows high recurrence rates after cystectomy even with apparent complete downstaging at cystectomy. Exosomes are nano-sized vesicles important in cell-cell communication, which have been hypothesized to contribute to cancer dissemination and recurrence. The aim of this study was to investigate if pro-carcinogenic exosomes could be detected in urine from histologically downstaged bladder cancer patients. 13 Patients were included in this study. Paired ureter and urine samples from nine patients underwent mass spectrometry, while samples from the remaining patients were used for exosome characterization. At cystectomy, exosomes were isolated from bladder and ureter urine, whereafter quantitative proteome profiling was performed. Urinary exosomes clustered based on whether they came from the bladder, with tumour contact, or the ureters, without tumour contact, even though all came from completely downstaged patients. Proteins overexpressed in exosomes derived from bladder urine contained several oncogenes and were mainly associated with tumour metabolism pathways. Although patients were histologically tumour-free at cystectomy, the bladder urine contained exosomes with a carcinogenic metabolic profile. This suggests a continuous release of exosomes from the bladder, which may promote recurrence at distant sites through metabolic rewiring, even after apparent complete downstaging. These exosomes, coming from either undetected cancer cells or partly transformed cells, are likely to increase the risk of metastasis and encourages cystectomy even in completely downstaged patients.

Extracellular vesicle-associated proteins as potential biomarkers

Every cell in the body secretes extracellular vesicles (EVs) possibly as cellular signaling components and these cell-derivatives can be found in multiple numbers in biological fluids. EVs have in the scientific field received great attention in relation to pathophysiology and disease diagnostics. Altered protein expressions associated with circulating EVs in diseased individuals can serve as biomarkers for different disease states. This capacity paves the way for non-invasive screening tools and early diagnostic markers. However, no isolation method of EVs has been acknowledged as the "golden standard," thus reproducibility of the studies remains inadequate. Increasing interest in EV proteins as disease biomarkers could give rise to more scientific knowledge with diagnostic applicability. In this chapter, studies of proteins believed to be associated with EVs within cancer, autoimmunity, metabolic and neurodegenerative diseases have been outlined.

Unravelling the proteomic landscape of extracellular vesicles in prostate cancer by density-based fractionation of urine

Extracellular vesicles (EV) are increasingly being recognized as important vehicles of intercellular communication and promising diagnostic and prognostic biomarkers in cancer. Despite this enormous clinical potential, the plethora of methods to separate EV from biofluids, providing material of highly variable purity, and lacking knowledge regarding methodological repeatability pose a barrier to clinical translation. Urine is considered an ideal proximal fluid for the study of EV in urological cancers due to its direct contact with the urogenital system. We demonstrate that density-based fractionation of urine by bottom-up Optiprep density gradient centrifugation separates EV and soluble proteins with high specificity and repeatability. Mass spectrometry-based proteomic analysis of urinary EV (uEV) in men with benign and malignant prostate disease allowed us to significantly expand the known human uEV proteome with high specificity and identifies a unique biological profile in prostate cancer not uncovered by the analysis of soluble proteins. In addition, profiling the proteome of EV separated from prostate tumour conditioned medium and matched uEV confirms the specificity of the identified uEV proteome for prostate cancer. Finally, a comparative proteomic analysis with uEV from patients with bladder and renal cancer provided additional evidence of the selective enrichment of protein signatures in uEV reflecting their respective cancer tissues of origin. In conclusion, this study identifies hundreds of previously undetected proteins in uEV of prostate cancer patients and provides a powerful toolbox to map uEV content and contaminants ultimately allowing biomarker discovery in urological cancers.

Rigorous characterization of urinary extracellular vesicles (uEVs) in the low centrifugation pellet - a neglected source for uEVs

Urinary extracellular vesicles (uEVs) provide bio-markers for kidney and urogenital diseases. Centrifugation is the most common method used to enrich uEVs. However, a majority of studies to date have focused on the ultracentrifugation pellet, potentially losing a novel source of important biomarkers that could be obtained at lower centrifugation. Thus, the aim of this study is to rigorously characterize for the first time uEVs in the low speed pellet and determine the minimal volume of urine required for proteomic analysis (≥9.0 mL urine) and gene ontology classification identified 75% of the protein as extracellular exosomes. Cryo-Transmission Electron Microscopy (≥3.0 mL urine) provided evidence of a heterogeneous population of EVs for size and morphology independent of uromodulin filaments. Western blot detected several specific uEV kidney and EV markers (≥4.5 mL urine per lane). microRNAs quantification by qPCR was possible with urine volume as low as 0.5 mL. Particle enumeration with tunable resistive pulse sensing, nano particles tracking analysis and single EV high throughput imaging flow cytometry are possible starting from 0.5 and 3.0 mL of urine respectively. This work characterizes a neglected source of uEVs and provides guidance with regard to volume of urine necessary to carry out multi-omic studies and reveals novel aspects of uEV analysis such as autofluorescence of podocyte origin.

Inside(sight) of tiny communicator: exosome biogenesis, secretion, and uptake

Discovered in the late 1980s as an extracellular vesicle of endosomal origin secreted from reticulocytes, exosomes recently gained scientific attention due to its role in intercellular communication. Exosomes have now been identified to carry cell-specific cargo of nucleic acids, proteins, lipids, and other biologically active molecules. Exosomes can be selectively taken up by neighboring or distant cells, which has shown to result in structural and functional responses in the recipient cells. Recent advances indicate the regulation of exosomes at various steps, including their biogenesis, selection of their cargo, as well as cell-specific uptake. This review will shed light on the differences between the type of extracellular vesicles. In this review, we discuss the recent progress in our understanding of the regulation of exosome biogenesis, secretion, and uptake.

Characterization and function of medium and large extracellular vesicles from plasma and urine by surface antigens and Annexin V

Background

Extracellular vesicles (EVs) are released by most cell types and are involved in multiple basic biological processes. Medium/large EVs (m/lEVs), which are of a different size from exosomes, play an important role in the coagulation in blood, and are secreted from cancer cells, etc., suggesting functions related to malignant transformation. The m/lEVs levels in blood or urine may help unravel pathophysiological findings in many diseases. However, it remains unclear how many naturally-occurring m/lEV subtypes exist as well as how their characteristics and functions differ from one another.

Methods

We used the blood and urinal sample from each 10 healthy donors for analysis. Using a flow cytometer, we focus on characterization of EVs with large sizes (>200 nm) that are different from exosomes. We also searched for a membrane protein for characterization with a flow cytometer using shotgun proteomics. We then identified m/lEVs pelleted from plasma and urine samples by differential centrifugation and characterized by flow cytometry.

Results

Using proteomic profiling, we identified several proteins involved in m/lEV biogenesis including adhesion molecules, peptidases and exocytosis regulatory proteins. In healthy human plasma, we could distinguish m/lEVs derived from platelets, erythrocytes, monocytes/macrophages, T and B cells, and vascular endothelial cells with more than two positive surface antigens. The ratio of phosphatidylserine appearing on the membrane surface differed depending on the cell-derived m/lEVs. In urine, 50% of m/lEVs were Annexin V negative but contained various membrane peptidases derived from renal tubular villi. Urinary m/lEVs, but not plasma m/lEVs, showed peptidase activity. The knowledge of the new characteristics is considered to be useful as a diagnostic material and the newly developed method suggests the possibility of clinical application.

Non-Exosomal and Exosomal Circulatory MicroRNAs: Which Are More Valid as Biomarkers?

MicroRNAs (miRNAs) are a group of small non-coding RNAs with approximately 19–25 nucleotides that are involved in regulating a range of developmental and physiological processes. Non-exosomal circulating and exosomal miRNAs have also been proposed to be useful in diagnostics as biomarkers for diseases and different types of cancer. In this review, the quantity of miRNAs and of reliable experimental data analyses of miRNAs that come from exosomal and non-exosomal sources are discussed from the perspective of their use as biomarkers for cancer and other diseases, including viral infections, nervous system disorders, cardiovascular disorders, and diabetes. We summarize other research findings regarding the use of miRNA from these two sources as biomarkers in diagnostics and clinical use. The challenges in using miRNA from these two sources in cancer and disease diagnostics are evaluated and discussed. Validation of specific miRNA signatures as biomarkers is a critical milestone in diagnostics.