Differentiation of tumour-promoting stromal myofibroblasts by cancer exosomes. Oncogene. 2015;34:290-302. [PMID: 24441045 DOI: 10.1038/onc.2013.560]

Prostate Cancer Tumor Stroma: Responsibility in Tumor Biology, Diagnosis and Treatment

Simple Summary

The crosstalk between prostate stroma and its epithelium is essential to tissue homeostasis. Likewise, reciprocal signaling between tumor cells and the stromal compartment is required in tumor progression to facilitate or stimulate key processes such as cell proliferation and invasion. The aim of the present work was to review the current state of knowledge on the significance of tumor stroma in the genesis, progression and therapeutic response of prostate carcinoma. Additionally, we addressed the future therapeutic opportunities.

Abstract

Prostate cancer (PCa) is a common cancer among males globally, and its occurrence is growing worldwide. Clinical decisions about the combination of therapies are becoming highly relevant. However, this is a heterogeneous disease, ranging widely in prognosis. Therefore, new approaches are needed based on tumor biology, from which further prognostic assessments can be established and complementary strategies can be identified. The knowledge of both the morphological structure and functional biology of the PCa stroma compartment can provide new diagnostic, prognostic or therapeutic possibilities. In the present review, we analyzed the aspects related to the tumor stromal component (both acellular and cellular) in PCa, their influence on tumor behavior and the therapeutic response and their consideration as a new therapeutic target.

Radiation induces ESCRT pathway dependent CD44v3+ extracellular vesicle production stimulating pro-tumor fibroblast activity in breast cancer

Despite recent advances in radiotherapeutic strategies, acquired resistance remains a major obstacle, leading to tumor recurrence for many patients. Once thought to be a strictly cancer cell intrinsic property, it is becoming increasingly clear that treatment-resistance is driven in part by complex interactions between cancer cells and non-transformed cells of the tumor microenvironment. Herein, we report that radiotherapy induces the production of extracellular vesicles by breast cancer cells capable of stimulating tumor-supporting fibroblast activity, facilitating tumor survival and promoting cancer stem-like cell expansion. This pro-tumor activity was associated with fibroblast production of the paracrine signaling factor IL-6 and was dependent on the expression of the heparan sulfate proteoglycan CD44v3 on the vesicle surface. Enzymatic removal or pharmaceutical inhibition of its heparan sulfate side chains disrupted this tumor-fibroblast crosstalk. Additionally, we show that the radiation-induced production of CD44v3⁺ vesicles is effectively silenced by blocking the ESCRT pathway using a soluble pharmacological inhibitor of MDA-9/Syntenin/SDCBP PDZ1 domain activity, PDZ1i. This population of vesicles was also detected in the sera of human patients undergoing radiotherapy, therefore representing a potential biomarker for radiation therapy and providing an opportunity for clinical intervention to improve treatment outcomes.

CD9 mediates the uptake of extracellular vesicles from cancer-associated fibroblasts that promote pancreatic cancer cell aggressiveness

In pancreatic ductal adenocarcinoma (PDAC), signaling from stromal cells is implicated in metastatic progression. Tumor-stroma cross-talk is often mediated through extracellular vesicles (EVs). We previously reported that EVs derived from cancer-associated stromal fibroblasts (CAFs) that are abundant in annexin A6 (ANXA6⁺ EVs) support tumor cell aggressiveness in PDAC. Here, we found that the cell surface glycoprotein and tetraspanin CD9 is a key component of CAF-derived ANXA6⁺ EVs for mediating this cross-talk. CD9 was abundant on the surface of ANXA6⁺ CAFs isolated from patient PDAC samples and from various mouse models of PDAC. CD9 colocalized with CAF markers in the tumor stroma, and CD9 abundance correlated with tumor stage. Blocking CD9 impaired the uptake of ANXA6⁺ EVs into cultured PDAC cells. Signaling pathway arrays and further analyses revealed that the uptake of CD9⁺ANXA6⁺ EVs induced mitogen-activated protein kinase (MAPK) pathway activity, cell migration, and epithelial-to-mesenchymal transition (EMT). Blocking either CD9 or p38 MAPK signaling impaired CD9⁺ANXA6⁺ EV-induced cell migration and EMT in PDAC cells. Analysis of bioinformatic datasets indicated that CD9 abundance was an independent marker of poor prognosis in patients with PDAC. Our findings suggest that CD9-mediated stromal cell signaling promotes PDAC progression.

Selective Internal Radiotherapy Changes the Immune Profiles of Extracellular Vesicles and Their Immune Origin in Patients with Inoperable Cholangiocarcinoma

The incidence of cholangiocellular carcinoma (CCA) is rising worldwide. As there are no specific early symptoms or specific markers of CCA, it is often diagnosed in later inoperable stages. Accumulating evidence underlines the importance of radiation therapy in the induction of antitumor immunity. The surface protein composition on extracellular vesicles (EVs) relates to originating cells and thus may play a role in vesicle function. We assessed immune profiles of EVs and their immune origin in patients with inoperable CCA prior and after selective internal radiotherapy (SIRT). A total of 47 CCA patients receiving SIRT and 12 healthy volunteers (HV) were included. Blood was withdrawn before therapy (pre T) and after T. EVs were purified from plasma by cluster of differentiation (CD)9-, CD63-, and CD81-immunobead isolation. To detect differently abundant surface markers, dynamic range and EVs input quality were assessed. A total of 37 EVs surface markers were measured by flow cytometry and correlated either with the administered activity dose (MBq) or with the interval until death (month). EVs phenotyping identified lymphocytes, B cells, NK cells, platelets, endothelial cells, leukocyte activation, B cell activation, T and B cell adhesion markers, stem/progenitor cells, and antigen-presenting cells (APC) as EVs-parenteral cells. CD4 and CD8 significantly declined, while other markers significantly increased in CCA patients pre T vs. HV. Platelets-deriving EVs significantly decreased, normalizing to levels of HV but still significantly increasing vs. HV post SIRT. B cells-deriving EVs significantly increased pre T vs. HV, positively correlating with administered activity dose. MHCII and CD40 EVs significantly increased pre SIRT and negatively correlated with administered activity dose, while EVs from antigen presenting cells and CD49e pre SIRT positively correlated with survival time after therapy. Increased levels of CD24 and CD44 in cancer pre T were significantly decreased post T. Among the heterogeneity of EVs that was demonstrated, in particular, B cells-deriving, MHCII, and CD40 positive or APC-deriving EVs need to be further studied for their diagnostic or prognostic relevance in clinical scenarios.

Scalable Production of Extracellular Vesicles and Its Therapeutic Values: A Review

Extracellular vesicles (EVs) are minute vesicles with lipid bilayer membranes. EVs are secreted by cells for intercellular communication. Recently, EVs have received much attention, as they are rich in biological components such as nucleic acids, lipids, and proteins that play essential roles in tissue regeneration and disease modification. In addition, EVs can be developed as vaccines against cancer and infectious diseases, as the vesicle membrane has an abundance of antigenic determinants and virulent factors. EVs for therapeutic applications are typically collected from conditioned media of cultured cells. However, the number of EVs secreted by the cells is limited. Thus, it is critical to devise new strategies for the large-scale production of EVs. Here, we discussed the strategies utilized by researchers for the scalable production of EVs. Techniques such as bioreactors, mechanical stimulation, electrical stimulation, thermal stimulation, magnetic field stimulation, topographic clue, hypoxia, serum deprivation, pH modification, exposure to small molecules, exposure to nanoparticles, increasing the intracellular calcium concentration, and genetic modification have been used to improve the secretion of EVs by cultured cells. In addition, nitrogen cavitation, porous membrane extrusion, and sonication have been utilized to prepare EV-mimetic nanovesicles that share many characteristics with naturally secreted EVs. Apart from inducing EV production, these upscaling interventions have also been reported to modify the EVs' cargo and thus their functionality and therapeutic potential. In summary, it is imperative to identify a reliable upscaling technique that can produce large quantities of EVs consistently. Ideally, the produced EVs should also possess cargo with improved therapeutic potential.

Liquid Biopsy in Pre-Metastatic Niche: From Molecular Mechanism to Clinical Application

Metastatic dissemination represents a hallmark of cancer that is responsible for the high mortality rate. Recently, emerging evidence demonstrates a time-series event—pre-metastatic niche (PMN) has a profound impact on cancer metastasis. Exosomes, cell-free DNA (cfDNA), circulating tumor cells (CTC), and tumor microenvironment components, as critical components in PMN establishment, could be monitored by liquid biopsy. Intensive studies based on the molecular profile of liquid biopsy have made it a viable alternative to tissue biopsy. Meanwhile, the complex molecular mechanism and intercellular interaction are great challenges for applying liquid biopsy in clinical practice. This article reviews the cellular and molecular components involved in the establishment of the PMN and the promotion of metastasis, as well as the mechanisms of their interactions. Better knowledge of the characteristics of the PMN may facilitate the application of liquid biopsy for clinical diagnosis, prognosis, and treatment.

The Potential Role of Exosomal Proteins in Prostate Cancer

Prostate cancer is the most prevalent malignant tumor in men across developed countries. Traditional diagnostic and therapeutic methods for this tumor have become increasingly difficult to adapt to today’s medical philosophy, thus compromising early detection, diagnosis, and treatment. Prospecting for new diagnostic markers and therapeutic targets has become a hot topic in today’s research. Notably, exosomes, small vesicles characterized by a phospholipid bilayer structure released by cells that is capable of delivering different types of cargo that target specific cells to regulate biological properties, have been extensively studied. Exosomes composition, coupled with their interactions with cells make them multifaceted regulators in cancer development. Numerous studies have described the role of prostate cancer-derived exosomal proteins in diagnosis and treatment of prostate cancer. However, so far, there is no relevant literature to systematically summarize its role in tumors, which brings obstacles to the later research of related proteins. In this review, we summarize exosomal proteins derived from prostate cancer from different sources and summarize their roles in tumor development and drug resistance.

Comprehensive insight into endothelial progenitor cell-derived extracellular vesicles as a promising candidate for disease treatment

Endothelial progenitor cells (EPCs), which are a type of stem cell, have been found to have strong angiogenic and tissue repair capabilities. Extracellular vesicles (EVs) contain many effective components, such as cellular proteins, microRNAs, messenger RNAs, and long noncoding RNAs, and can be secreted by different cell types. The functions of EVs depend mainly on their parent cells. Many researchers have conducted functional studies of EPC-derived EVs (EPC-EVs) and showed that they exhibit therapeutic effects on many diseases, such as cardiovascular disease, acute kidney injury, acute lung injury, and sepsis. In this review article, we comprehensively summarized the biogenesis and functions of EPCs and EVs and the potent role of EPC-EVs in the treatment of various diseases. Furthermore, the current problems and future prospects have been discussed, and further studies are needed to compare the therapeutic effects of EVs derived from various stem cells, which will contribute to the accelerated translation of these applications in a clinical setting.

Exosomes Derived From Hypoxia-Conditioned Stem Cells of Human Deciduous Exfoliated Teeth Enhance Angiogenesis via the Transfer of let-7f-5p and miR-210-3p

Physiological root resorption of deciduous teeth is a normal phenomenon. How the angiogenesis process is regulated to provide adequate levels of oxygen and nutrients in hypoxic conditions when the dental pulp tissue is reduced at the stage of root resorption is not fully understood. In this study, we designed hypoxic preconditioning (2%) to mimic the physiological conditions. We isolated exosomes from hypoxic-preconditioned SHED (Hypo-exos) cells and from normally cultured SHED cells (Norm-exos). We found that treatment with Hypo-exos significantly enhanced the growth, migration and tube formation of endothelial cells in vitro compared with Norm-exos. We also performed matrigel plug assays in vivo and higher expression of VEGF and higher number of lumenal structures that stained positive for CD31 were found in the Hypo-exos treated group. To understand the potential molecular mechanism responsible for the positive effects of Hypo-exos, we performed exosomal miRNA sequencing and validated that Hypo-exos transferred both let-7f-5p and miR-210-3p to promote the tube formation of endothelial cells. Further study revealed that those two miRNAs regulate angiogenesis via the let-7f-5p/AGO1/VEGF and/or miR-210-3p/ephrinA3 signal pathways. Finally, we found that the increased release of exosomes regulated by hypoxia treatment may be related to Rab27a. Taking these data together, the present study demonstrates that exosomes derived from hypoxic-preconditioned SHED cells promote angiogenesis by transferring let-7f-5p and miR-210-3p, which suggests that they can potentially be developed as a novel therapeutic approach for pro-angiogenic therapy in tissue regeneration engineering.

Extracellular Vesicles and Transforming Growth Factor β Signaling in Cancer

Complexity in mechanisms that drive cancer development and progression is exemplified by the transforming growth factor β (TGF-β) signaling pathway, which suppresses early-stage hyperplasia, yet assists aggressive tumors to achieve metastasis. Of note, several molecules, including mRNAs, non-coding RNAs, and proteins known to be associated with the TGF-β pathway have been reported as constituents in the cargo of extracellular vesicles (EVs). EVs are secreted vesicles delimited by a lipid bilayer and play critical functions in intercellular communication, including regulation of the tumor microenvironment and cancer development. Thus, this review aims at summarizing the impact of EVs on TGF-β signaling by focusing on mechanisms by which EV cargo can influence tumorigenesis, metastatic spread, immune evasion and response to anti-cancer treatment. Moreover, we emphasize the potential of TGF-β-related molecules present in circulating EVs as useful biomarkers of prognosis, diagnosis, and prediction of response to treatment in cancer patients.

Graphene-Based Electrochemical Sensor for Detection of Hepatocellular Carcinoma Markers

Hepatocellular carcinoma (HCC) is a group of highly lethal malignant tumors that seriously threaten human health. The main way to improve the survival quality and reduce the mortality of HCC is early diagnosis and treatment. Therefore, it will be of great significance to explore new quantitative detection methods for HCC markers. With the rapid development of electrochemical biosensors and nanomaterials, electrochemical sensors based on graphene can detect tumor markers, with the advantages of simple operation, high detection sensitivity, and specificity. Combined with the published literature in recent years, the article briefly reviews the application of graphene-based electrochemical biosensors in the detection of HCC markers, including alpha-fetoprotein (AFP), Golgi protein-73 (GP73), exosomes, and microRNA-122 (miR-122).

The biogenesis and secretion of exosomes and multivesicular bodies (MVBs): Intercellular shuttles and implications in human diseases

Exosomes carry and transmit signaling molecules used for intercellular communication. The generation and secretion of exosomes is a multistep interlocking process that allows simultaneous control of multiple regulatory sites. Protein molecules, mainly RAB GTPases, cytoskeletal proteins and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE), are specifically regulated in response to pathological conditions such as altered cellular microenvironment, stimulation by pathogenic factors, or gene mutation. This interferes with the smooth functioning of endocytosis, translocation, degradation, docking and fusion processes, leading to changes in the secretion of exosomes. Large numbers of secreted exosomes are disseminated by the flow of body fluids and absorbed by the recipient cells. By transmitting characteristic functional proteins and genetic information produced under disease conditions, exosomes can change the physiological state of the recipient cells and their microenvironment. The microenvironment, in turn, affects the occurrence and development of disease. Therefore, this review will discuss the mechanism by which exosome secretion is regulated in cells following the formation of mature secretory multivesicular bodies (MVBs). The overall aim is to find ways to eliminate disease-derived exosomes at their source, thereby providing an important new basis for the clinical treatment of disease.

The Role of Tumor Stem Cell Exosomes in Cancer Invasion and Metastasis

Exosomes are lipid membrane bilayer-encapsulated vesicles secreted by cells into the extracellular space. They carry abundant inclusions (such as nucleic acids, proteins, and lipids) that play pivotal roles in intercellular communication. Tumor stem cells are capable of self-renewal and are crucial for survival, proliferation, drug resistance, metastasis, and recurrence of tumors. The miRNAs (microRNAs) in exosomes have various functions, such as participating in inflammatory response, cell migration, proliferation, apoptosis, autophagy, and epithelial-mesenchymal transition. Tumor stem cells secrete exosomes that act as important messengers involved in various tumor processes and several studies provide increasing evidence supporting the importance of these exosomes in tumor recurrence and metastasis. This review primarily focuses on the production and secretion of exosomes from tumors and tumor stem cells and their effects on cancer progression. Cancer stem cancer derived exosome play an important massager in the tumor microenvironment. It also emphasizes on the study of tumor stem cell exosomes in the light of cancer metastasis and recurrence aiming to provide valuable insights and novel perspectives, which could be beneficial for developing effective diagnostic and treatment strategies.

Cancer-Derived Extracellular Vesicles: Their Role in Sarcoma

Soft tissue sarcomas (STS) are rare malignancies with limited responses to anticancer therapy. Extracellular vesicles (EVs) are a heterogeneous group of bi-lipid layer sacs secreted by cells into extracellular space. Investigations of tumor-derived EVs have revealed their functional capabilities, including cell-to-cell communication and their impact on tumorigenesis, progression, and metastasis; however information on the roles of EVs in sarcoma is currently limited. In this review we investigate the role of various EV cargos in sarcoma and the mechanisms by which those cargos can affect the recipient cell phenotype and the aggressivity of the tumor itself. The study of EVs in sarcoma may help establish novel therapeutic approaches that target specific sarcoma subtypes or biologies, thereby improving sarcoma therapeutics in the future.

Tumor-Derived Extracellular Vesicles Activate Normal Human Fibroblasts to a Cancer-Associated Fibroblast-Like Phenotype, Sustaining a Pro-Tumorigenic Microenvironment

Fibroblasts in the tumor microenvironment have been proven to actively participate in tumor progression; they can be "educated" by cancer cells acquiring an activated state and, as such, are identified as cancer-associated fibroblasts (CAFs); CAFs, in turn, remodel tumor stroma to be more advantageous for cancer progression by modulating several processes, including angiogenesis, immunosuppression, and drug access, presumably driving the chemoresistance. That is why they are believed to hamper the response to clinical therapeutic options. The communication between cancer cells and fibroblasts can be mediated by extracellular vesicles (EVs), composed of both exosomes (EXOs) and microvesicles (MVs). To verify the role of different subpopulations of EVs in this cross-talk, a nearly pure subpopulation of EXO-like EVs and the second one of mixed EXO- and MV-like EVs were isolated from ovarian cancer cells and administered to fibroblasts. It turned out that EVs can activate fibroblasts to a CAF-like state, supporting their proliferation, motility, invasiveness, and enzyme expression; EXO-like EV subpopulation seems to be more efficient in some of those processes, suggesting different roles for different EV subpopulations. Moreover, the secretome of these "activated" fibroblasts, composed of both soluble and EV-associated molecules, was, in turn, able to modulate the response of bystander cells (fibroblasts, tumor, and endothelial cells), supporting the idea that EVs sustain the mutual cross-talk between tumor cells and CAFs.

Analysis of 5-Methylcytosine Regulators and DNA Methylation-Driven Genes in Colon Cancer

Background: Epigenetic-driven events are important molecular mechanisms of carcinogenesis. The 5-methylcytosine (5mC) regulators play important roles in the methylation-driven gene expression. However, the effect of the 5mC regulators on the oncogenic pathways in colon cancer (CC) remains unclear. Also, the clinical value of such epigenetic-driven events needs further research.

Methods: The transcriptome and matching epigenetic data were obtained from The Cancer Genome Atlas dataset. The gene set variation analysis identified the oncogenic pathways adjusted by 5mC regulators. The “edgeR” and “methylmix” package identified the differential expression genes of DNA methylation-driven genes. The correlation between 5mC regulators or transcription factors and shortlisted genes was investigated by calculating the Spearman's rank correlation coefficient. Among them, the genes related to diagnosis were screened out based on differential gene expression in extracellular vesicles (EVs) by the “limma” package and histology by immunohistochemistry. Then, a risk signature was constructed by fitting the generalized linear model and validated by the receiver operating characteristic curve.

Results: MYC targets pathway and phosphatidylinositol-3-kinase–AKT–mammalian target of rapamycin signaling pathway were identified as the hallmark-related pathways associated with 5mC regulators. Also, the P53 pathway was subject to the influence of regulators' expression. A five methylation-driven gene signature (FIRRE, MYBL2, TGFBI, AXIN2, and SLC35D3) was developed as the biomarker for CC diagnosis. Meanwhile, those genes positively related to 5mC regulators and interacted with their relevant or transcription factors.

Conclusion: In general, 5mC regulators are positively related to each other and DNA methylation-driven genes, with the relationship of multiple active and inhibitory pathways related to cancer. Meanwhile, the signature (FIRRE, MYBL2, TGFBI, AXIN2, and SLC35D3) can prefigure prospective diagnosis in CC.

In Vitro and In Vivo Analysis of Extracellular Vesicle-Mediated Metastasis Using a Bright, Red-Shifted Bioluminescent Reporter Protein

Cancer cells produce heterogeneous extracellular vesicles (EVs) as mediators of intercellular communication. This study focuses on a novel method to image EV subtypes and their biodistribution in vivo. A red-shifted bioluminescence resonance energy transfer (BRET) EV reporter is developed, called PalmReNL, which allows for highly sensitive EV tracking in vitro and in vivo. PalmReNL enables the authors to study the common surface molecules across EV subtypes that determine EV organotropism and their functional differences in cancer progression. Regardless of injection routes, whether retro-orbital or intraperitoneal, PalmReNL positive EVs, isolated from murine mammary carcinoma cells, localized to the lungs. The early appearance of metastatic foci in the lungs of mammary tumor-bearing mice following multiple intraperitoneal injections of the medium and large EV (m/lEV)-enriched fraction derived from mammary carcinoma cells is demonstrated. In addition, the results presented here show that tumor cell-derived m/lEVs act on distant tissues through upregulating LC3 expression within the lung.

Extracellular vesicles released by non-small cell lung cancer cells drive invasion and permeability in non-tumorigenic lung epithelial cells

Extracellular vesicles (EVs) released from non-small cell lung cancer (NSCLC) cells are known to promote cancer progression. However, it remains unclear how EVs from various NSCLC cells differ in their secretion profile and their ability to promote phenotypic changes in non-tumorigenic cells. Here, we performed a comparative analysis of EV release from non-tumorigenic cells (HBEC/BEAS-2B) and several NSCLC cell lines (A549, H460, H358, SKMES, and Calu6) and evaluated the potential impact of NSCLC EVs, including EV-encapsulated RNA (EV-RNA), in driving invasion and epithelial barrier impairment in HBEC/BEAS-2B cells. Secretion analysis revealed that cancer cells vary in their secretion level, with some cell lines having relatively low secretion rates. Differential uptake of NSCLC EVs was also observed, with uptake of A549 and SKMES EVs being the highest. Phenotypically, EVs derived from Calu6 and H358 cells significantly enhanced invasion, disrupted an epithelial barrier, and increased barrier permeability through downregulation of E-cadherin and ZO-1. EV-RNA was a key contributing factor in mediating these phenotypes. More nuanced analysis suggests a potential correlation between the aggressiveness of NSCLC subtypes and the ability of their respective EVs to induce cancerous phenotypes.

Microfluidic Approaches and Methods Enabling Extracellular Vesicle Isolation for Cancer Diagnostics

Advances in cancer research over the past half-century have clearly determined the molecular origins of the disease. Central to the use of molecular signatures for continued progress, including rapid, reliable, and early diagnosis is the use of biomarkers. Specifically, extracellular vesicles as biomarker cargo holders have generated significant interest. However, the isolation, purification, and subsequent analysis of these extracellular vesicles remain a challenge. Technological advances driven by microfluidics-enabled devices have made the challenges for isolation of extracellular vesicles an emerging area of research with significant possibilities for use in clinical settings enabling point-of-care diagnostics for cancer. In this article, we present a tutorial review of the existing microfluidic technologies for cancer diagnostics with a focus on extracellular vesicle isolation methods.

Exosomes: the key of sophisticated cell-cell communication and targeted metastasis in pancreatic cancer

Pancreatic cancer is one of the most common malignancies. Unfortunately, the lack of effective methods of treatment and diagnosis has led to poor prognosis coupled with a very high mortality rate. So far, the pathogenesis and progression mechanisms of pancreatic cancer have been poorly characterized. Exosomes are small vesicles secreted by most cells, contain lipids, proteins, and nucleic acids, and are involved in diverse functions such as intercellular communications, biological processes, and cell signaling. In pancreatic cancer, exosomes are enriched with multiple signaling molecules that mediate intercellular communication with control of immune suppression, mutual promotion between pancreas stellate cells and pancreatic cancer cells, and reprogramming of normal cells. In addition, exosomes can regulate the pancreatic cancer microenvironment and promote the growth and survival of pancreatic cancer. Exosomes can also build pre-metastatic micro-ecological niches and facilitate the targeting of pancreatic cancer. The ability of exosomes to load cargo and target allows them to be of great clinical value as a biomarker mediator for targeted drugs in pancreatic cancer. Video Abstract.

In sickness and in health: The functional role of extracellular vesicles in physiology and pathology in vivo: Part II: Pathology: Part II: Pathology

It is clear from Part I of this series that extracellular vesicles (EVs) play a critical role in maintaining the homeostasis of most, if not all, normal physiological systems. However, the majority of our knowledge about EV signalling has come from studying them in disease. Indeed, EVs have consistently been associated with propagating disease pathophysiology. The analysis of EVs in biofluids, obtained in the clinic, has been an essential of the work to improve our understanding of their role in disease. However, to interfere with EV signalling for therapeutic gain, a more fundamental understanding of the mechanisms by which they contribute to pathogenic processes is required. Only by discovering how the EV populations in different biofluids change-size, number, and physicochemical composition-in clinical samples, may we then begin to unravel their functional roles in translational models in vitro and in vivo, which can then feedback to the clinic. In Part II of this review series, the functional role of EVs in pathology and disease will be discussed, with a focus on in vivo evidence and their potential to be used as both biomarkers and points of therapeutic intervention.

Overcoming TGFβ-mediated immune evasion in cancer

Transforming growth factor-β (TGFβ) signalling controls multiple cell fate decisions during development and tissue homeostasis; hence, dysregulation of this pathway can drive several diseases, including cancer. Here we discuss the influence that TGFβ exerts on the composition and behaviour of different cell populations present in the tumour immune microenvironment, and the context-dependent functions of this cytokine in suppressing or promoting cancer. During homeostasis, TGFβ controls inflammatory responses triggered by exposure to the outside milieu in barrier tissues. Lack of TGFβ exacerbates inflammation, leading to tissue damage and cellular transformation. In contrast, as tumours progress, they leverage TGFβ to drive an unrestrained wound-healing programme in cancer-associated fibroblasts, as well as to suppress the adaptive immune system and the innate immune system. In consonance with this key role in reprogramming the tumour microenvironment, emerging data demonstrate that TGFβ-inhibitory therapies can restore cancer immunity. Indeed, this approach can synergize with other immunotherapies - including immune checkpoint blockade - to unleash robust antitumour immune responses in preclinical cancer models. Despite initial challenges in clinical translation, these findings have sparked the development of multiple therapeutic strategies that inhibit the TGFβ pathway, many of which are currently in clinical evaluation.

Hallmarks of exosomes

Exosomes are a new horizon in modern therapy, presenting exciting new opportunities for advanced drug delivery and targeted release. Exosomes are small extracellular vesicles with a size range of 30-100 nm, secreted by all cell types in the human body and carrying a unique collection of DNA fragments, RNA species, lipids, protein biomarkers, transcription factors and metabolites. miRNAs are one of the most common RNA species in exosomes, and they play a role in a variety of biological processes including exocytosis, hematopoiesis and angiogenesis, as well as cellular communication via exosomes. Exosomes can act as cargo to transport this information from donor cells to near and long-distance target cells, participating in the reprogramming of recipient cells.

Advances on biological functions of exosomal non-coding RNAs in osteoarthritis

Exosomes can be secreted by various cells and function as intercellular communication vehicles by delivering specific cargoes from the donor cells to the recipient cells through their paracrine activity. Recently, an increasing number of studies have shown that non-coding RNAs (ncRNAs) could be entrapped in and transferred between cartilage-related cells as exosomal cargoes to modulate the expression of various target genes by regulation at post-transcriptional and post-translational levels. They are mainly comprised of microRNAs, long non-coding RNAs, and circular RNAs. Articular cartilage degeneration is one of the main pathological features of osteoarthritis. Exosomal ncRNAs are involved in pathological processes of osteoarthritis, such as proliferation, migration, chondrogenesis, chondrocyte differentiation induction, extracellular matrix formation, apoptosis, and inflammation. In this review, we summarize the biological functions of exosomal ncRNAs in cartilage homeostasis and osteoarthritis progression and discuss the perspectives and challenges of exosomal ncRNAs application for osteoarthritis patients in the future. Exosomal ncRNA has an important regulatory role in the pathogenesis of osteoarthritis, but more evidence is needed for clinical application.

Role of cell-free network communication in alcohol-associated disorders and liver metastasis

The aberrant use of alcohol is a major factor in cancer progression and metastasis. Contributing mechanisms include the systemic effects of alcohol and the exchange of bioactive molecules between cancerous and non-cancerous cells along the brain-gut-liver axis. Such interplay leads to changes in molecular, cellular, and biological functions resulting in cancer progression. Recent investigations have examined the role of extracellular vesicles (EVs) in cancer mechanisms in addition to their contribution as diagnostic biomarkers. Also, EVs are emerging as novel cell-free mediators in pathophysiological scenarios including alcohol-mediated gut microbiome dysbiosis and the release of nanosized EVs into the circulatory system. Interestingly, EVs in cancer patients are enriched with oncogenes, miRNA, lipids, and glycoproteins whose delivery into the hepatic microenvironment may be enhanced by the detrimental effects of alcohol. Proof-of-concept studies indicate that alcohol-associated liver disease is impacted by the effects of exosomes, including altered immune responses, reprogramming of stromal cells, and remodeling of the extracellular matrix. Moreover, the culmination of alcohol-related changes in the liver likely contributes to enhanced hepatic metastases and poor outcomes for cancer patients. This review summarizes the numerous aspects of exosome communications between organs with emphasis on the relationship of EVs in alcohol-associated diseases and cancer metastasis. The potential impact of EV cargo and release along a multi-organ axis is highly relevant to the promotion of tumorigenic mechanisms and metastatic disease. It is hypothesized that EVs target recipient tissues to initiate the formation of prometastatic niches and cancer progression. The study of alcohol-associated mechanisms in metastatic cancers is expected to reveal a better understanding of factors involved in the growth of secondary malignancies as well as novel approaches for therapeutic interventions.

Natural Products for the Management of Castration-Resistant Prostate Cancer: Special Focus on Nanoparticles Based Studies

Prostate cancer is the most common type of cancer among men and the second most frequent cause of cancer-related mortality around the world. The progression of advanced prostate cancer to castration-resistant prostate cancer (CRPC) plays a major role in disease-associated morbidity and mortality, posing a significant therapeutic challenge. Resistance has been associated with the activation of androgen receptors via several mechanisms, including alternative dehydroepiandrosterone biosynthetic pathways, other androgen receptor activator molecules, oncogenes, and carcinogenic signaling pathways. Tumor microenvironment plays a critical role not only in the cancer progression but also in the drug resistance. Numerous natural products have shown major potential against particular or multiple resistance pathways as shown by in vitro and in vivo studies. However, their efficacy in clinical trials has been undermined by their unfavorable pharmacological properties (hydrophobic molecules, instability, low pharmacokinetic profile, poor water solubility, and high excretion rate). Nanoparticle formulations can provide a way out of the stalemate, employing targeted drug delivery, improved pharmacokinetic drug profile, and transportation of diagnostic and therapeutic agents via otherwise impermeable biological barriers. This review compiles the available evidence regarding the use of natural products for the management of CRPC with a focus on nanoparticle formulations. PubMed and Google Scholar search engines were used for preclinical studies, while ClinicalTrials.gov and PubMed were searched for clinical studies. The results of our study suggest the efficacy of natural compounds such as curcumin, resveratrol, apigenin, quercetin, fisetin, luteolin, kaempferol, genistein, berberine, ursolic acid, eugenol, gingerol, and ellagic acid against several mechanisms leading to castration resistance in preclinical studies, but fail to set the disease under control in clinical studies. Nanoparticle formulations of curcumin and quercetin seem to increase their potential in clinical settings. Using nanoparticles based on betulinic acid, capsaicin, sintokamide A, niphatenones A and B, as well as atraric acid seems promising but needs to be verified with preclinical and clinical studies.

Application of extracellular vesicles in the diagnosis and treatment of prostate cancer: Implications for clinical practice

Extracellular vesicles (EV) are cell-derived lipid bilayer-delimited structures providing an important means of intercellular communication. Recent studies have shown that EV, particularly exosomes and large-oncosomes contain miRNA and proteins crucial in prostate cancer (PCa) progression, metastasis and treatment resistance. This includes not just EV released from PCa cells, but also from other cells in the tumor microenvironment. PCa patient derived EV have a unique composition compared to healthy and benign prostatic diseases. As such, EV show promise as diagnostic liquid biopsy biomarkers, both as an adjunct and alternative to the invasive current gold-standard. EV could also be utilized to stratify patients' risk and predict response to hormonal, chemo, immune- and targeted therapy, which will direct future treatment decisions in PCa. We present a summary of the current evidence on the role of EV in PCa and the application of EV in PCa diagnosis and treatment to optimize patient outcomes.

New Advances in Liquid Biopsy Technologies for Anaplastic Lymphoma Kinase (ALK)-Positive Cancer

Cancer cells are characterized by high genetic instability, that favors tumor relapse. The identification of the genetic causes of relapse can direct next-line therapeutic choices. As tumor tissue rebiopsy at disease progression is not always feasible, noninvasive alternative methods are being explored. Liquid biopsy is emerging as a non-invasive, easy and repeatable tool to identify specific molecular alterations and monitor disease response during treatment. The dynamic follow-up provided by this analysis can provide useful predictive information and allow prompt therapeutic actions, tailored to the genetic profile of the recurring disease, several months before radiographic relapse. Oncogenic fusion genes are particularly suited for this type of analysis. Anaplastic Lymphoma Kinase (ALK) is the dominant driver oncogene in several tumors, including Anaplastic Large-Cell Lymphoma (ALCL), Non-Small Cell Lung Cancer (NSCLC) and others. Here we review recent findings in liquid biopsy technologies, including ctDNA, CTCs, exosomes, and other markers that can be investigated from plasma samples, in ALK-positive cancers.

Extracellular Vesicles in Reprogramming of the Ewing Sarcoma Tumor Microenvironment

Ewing sarcoma (EwS) is a highly aggressive cancer and the second most common malignant bone tumor of children and young adults. Although patients with localized disease have a survival rate of approximately 75%, the prognosis for patients with metastatic disease remains dismal (<30%) and has not improved in decades. Standard-of-care treatments include local therapies such as surgery and radiotherapy, in addition to poly-agent adjuvant chemotherapy, and are often associated with long-term disability and reduced quality of life. Novel targeted therapeutic strategies that are more efficacious and less toxic are therefore desperately needed, particularly for metastatic disease, given that the presence of metastasis remains the most powerful predictor of poor outcome in EwS. Intercellular communication within the tumor microenvironment is emerging as a crucial mechanism for cancer cells to establish immunosuppressive and cancer-permissive environments, potentially leading to metastasis. Altering this communication within the tumor microenvironment, thereby preventing the transfer of oncogenic signals and molecules, represents a highly promising therapeutic strategy. To achieve this, extracellular vesicles (EVs) offer a candidate mechanism as they are actively released by tumor cells and enriched with proteins and RNAs. EVs are membrane-bound particles released by normal and tumor cells, that play pivotal roles in intercellular communication, including cross-talk between tumor, stromal fibroblast, and immune cells in the local tumor microenvironment and systemic circulation. EwS EVs, including the smaller exosomes and larger microvesicles, have the potential to reprogram a diversity of cells in the tumor microenvironment, by transferring various biomolecules in a cell-specific manner. Insights into the various biomolecules packed in EwS EVs as cargos and the molecular changes they trigger in recipient cells of the tumor microenvironment will shed light on various potential targets for therapeutic intervention in EwS. This review details EwS EVs composition, their potential role in metastasis and in the reprogramming of various cells of the tumor microenvironment, and the potential for clinical intervention.

Small Extracellular Vesicles: Functions and Potential Clinical Applications as Cancer Biomarkers

Cancer, as the second leading cause of death worldwide, is a major public health concern that imposes a heavy social and economic burden. Effective approaches for either diagnosis or therapy of most cancers are still lacking. Dynamic monitoring and personalized therapy are the main directions for cancer research. Cancer-derived extracellular vesicles (EVs) are potential disease biomarkers. Cancer EVs, including small EVs (sEVs), contain unique biomolecules (protein, nucleic acid, and lipids) at various stages of carcinogenesis. In this review, we discuss the biogenesis of sEVs, and their functions in cancer, revealing the potential applications of sEVs as cancer biomarkers.

Stroma-derived extracellular vesicle mRNA signatures inform histological nature of prostate cancer

Histological assessment of prostate cancer is the key diagnostic test and can predict disease outcome. This is however an invasive procedure that carries associated risks, hence non-invasive assays to support the diagnostic pathway are much needed. A key feature of disease progression, and subsequent poor prognosis, is the presence of an altered stroma. Here we explored the utility of prostate stromal cell-derived vesicles as indicators of an altered tumour environment. We compared vesicles from six donor-matched pairs of adjacent-normal versus disease-associated primary stromal cultures. We identified 19 differentially expressed transcripts that discriminate disease from normal stromal extracellular vesicles (EVs). EVs isolated from patient serum were investigated for these putative disease-discriminating mRNA. A set of transcripts including Caveolin-1 (CAV1), TMP2, THBS1, and CTGF were found to be successful in discriminating clinically insignificant (Gleason = 6) disease from clinically significant (Gleason > 8) prostate cancer. Furthermore, correlation between transcript expression and progression-free survival suggests that levels of these mRNA may predict disease outcome. Informed by a machine learning approach, combining measures of the five most informative EV-associated mRNAs with PSA was shown to significantly improve assay sensitivity and specificity. An in-silico model was produced, showcasing the superiority of this multi-modal liquid biopsy compared to needle biopsy for predicting disease progression. This proof of concept highlights the utility of serum EV analytics as a companion diagnostic test with prognostic utility, which may obviate the need for biopsy.

Exosomes and organ-specific metastasis

The transmission of information between tumor cells and other cell types in the tumor microenvironment plays an important role in tumor metastasis and is critically modulated by exosomes and other mediators. Tumor-derived exosomes can promote epithelial-mesenchymal transition, angiogenesis, immune escape, formation of the pre-metastatic microenvironment, and transmission of drug-resistant molecules, thereby promoting tumor growth, invasion, and metastasis. Integrins are important regulatory molecules on exosomes that can locate metastatic cells at the initial stage of metastasis and show good organotropism. This fact suggests that a clear understanding of the roles of exosomal integrins will be beneficial for future clinical applications. Follow-up studies on exosomes using continuously updated purification techniques and identification methods are extremely important. In addition to their potential as cancer biomarkers, exosomes also provide new research directions for precision medicine. Currently, exosomes have potential value in disease treatment and provide clinicians with more meaningful judgment standards.

Dissecting esophageal squamous-cell carcinoma ecosystem by single-cell transcriptomic analysis

Esophageal squamous-cell carcinoma (ESCC), one of the most prevalent and lethal malignant disease, has a complex but unknown tumor ecosystem. Here, we investigate the composition of ESCC tumors based on 208,659 single-cell transcriptomes derived from 60 individuals. We identify 8 common expression programs from malignant epithelial cells and discover 42 cell types, including 26 immune cell and 16 nonimmune stromal cell subtypes in the tumor microenvironment (TME), and analyse the interactions between cancer cells and other cells and the interactions among different cell types in the TME. Moreover, we link the cancer cell transcriptomes to the somatic mutations and identify several markers significantly associated with patients’ survival, which may be relevant to precision care of ESCC patients. These results reveal the immunosuppressive status in the ESCC TME and further our understanding of ESCC.

Esophageal squamous-cell carcinomas (ESCC) have poor prognosis, and detailed molecular profiles are necessary to identify prognostic markers. Here the authors analyse 60 ESCC patient samples using scRNA-seq, TCR-seq and genomics; they find mucosal immunity markers associated with survival and immunosuppressive microenvironments.

Pro-angiogenic effect of PC-3 exosomes in endothelial cells in vitro

The progression to a castration-resistant prostate cancer can occur after treatment with androgen deprivation therapy, resulting in poor prognosis and ineffective therapy response. Hormone dependence transition has been associated with increased tumor vascularization. Considering that exosomes are important components in communication between tumor cells and the microenvironment, we examined the angiogenic potential of exosomes released from Pca cell lines with distinctive profiles of androgen response through exosomes isolation, microscopy and uptake, functional assays follow up by microarray, RT-qPCR and bioinformatics analysis. HUVEC cells treated with PC-3 exosomes (androgen independent) showed increased invasion and tube formation ability. In order to identify microRNAs (miRNAs) related to the angiogenic response, the characterization of exosomal miRNA profile was performed. As result we suggest that the miR-27a-3p could be involved in the pro-angiogenic effect of PC-3 exosomes.

Therapeutic effect of co-culture of rat bone marrow mesenchymal stem cells and degenerated nucleus pulposus cells on intervertebral disc degeneration

BACKGROUND

After non-contact co-culture of bone marrow mesenchymal stem cells (BMSCs) with nucleus pulposus cells (NPCs), exosomes secreted by BMSCs were able to ameliorate the degree of disc degeneration. The reason for this is, at least in part, that exosomes from BMSCs achieve by affecting the level of autophagy in NPCs, while the components in exosomes are diverse and their specific mechanism of action is still unclear.

PURPOSE

Here, we aimed to explore the therapeutic effect of co-culture of BMSCs and NPCs on NPCs and explore its specific mechanism of action.

STUDY DESIGN/SETTING

In vitro study.

METHODS

Rat NPCs and BMSCs were isolated and cultured in vitro. The serum deprivation experiment (using oxygen, glucose, and serum deprivation [OGD]) simulates the pathological state of low blood supply of the intervertebral disc in vivo. We used apoptotic cell staining and flow cytometry to study the effect of BMSCs on the apoptosis rate of rat NPCs, and the apoptotic proteins active-caspase-3, active-caspase-9, autophagy marker proteins LC3 and Beclin 1 were further detected using Western blot analysis. The expression levels of the pro-apoptotic protein Bax and the apoptosis-inhibiting protein Bcl2 were measured. The differentially expressed miRNAs were screened in a gene expression profiling chip. Then qRT-PCR was used to detect the effect of different treatment methods on miR-155 expression. The effect of anti-miR-155 antibodies on autophagy was studied by flow cytometry and transmission electron microscopy. A luciferase reporter assay was used to study the direct interaction between miR-155 and BACH1 mRNA, which was analyzed by TargetScan software, and the results were verified by Western blotting.

RESULTS

Compared with the OGD group, the expression level of miR-155 and the NPC autophagy level significantly increased; the HO-1 protein expression increased; and the Bach1 protein expression, degeneration index, and apoptosis index all significantly decreased in the co-culture group. After BMSCs transfected with anti-miR-155 were co-cultured with NPCs, the miR-155 expression in the cells was significantly reduced, the HO-1 protein expression and the level of cell autophagy was reduced. However, Bach1 protein expression, NPC degeneration index, and apoptosis index increased. After being inhibited by the autophagy inhibitor wortmannin, the cell degeneration index and apoptosis rate significantly improved.

CONCLUSION

In the OGD model, BMSCs can significantly increase the viability, the level of autophagy, and reduce the level of apoptosis in rat NPCs. BMSC exosomes increase miR-155 expression in NPCs, which targets Bach1 and in turn upregulates HO-1 expression, activates autophagy in NPCs, inhibits the apoptosis level, and improves intervertebral disc degeneration.

CLINICAL SIGNIFICANCE

Our experiment shows that it is maybe feasible to treat disc degeneration with drugs. At the same time, compared with BMSC injection method of treatment, side effects of drug therapy are smaller, and can be controlled, it also provides a new way for intervertebral disc degeneration drug treatment.

The power of imaging to understand extracellular vesicle biology in vivo

Extracellular vesicles (EVs) are nano-sized lipid bilayer vesicles released by virtually every cell type. EVs have diverse biological activities, ranging from roles in development and homeostasis to cancer progression, which has spurred the development of EVs as disease biomarkers and drug nanovehicles. Owing to the small size of EVs, however, most studies have relied on isolation and biochemical analysis of bulk EVs separated from biofluids. Although informative, these approaches do not capture the dynamics of EV release, biodistribution, and other contributions to pathophysiology. Recent advances in live and high-resolution microscopy techniques, combined with innovative EV labeling strategies and reporter systems, provide new tools to study EVs in vivo in their physiological environment and at the single-vesicle level. Here we critically review the latest advances and challenges in EV imaging, and identify urgent, outstanding questions in our quest to unravel EV biology and therapeutic applications.

Ovarian-Cancer-Associated Extracellular Vesicles: Microenvironmental Regulation and Potential Clinical Applications

Ovarian cancer (OC) is one of the most diagnosed gynecological cancers in women. Due to the lack of effective early stage screening, women are more often diagnosed at an advanced stage; therefore, it is associated with poor patient outcomes. There are a lack of tools to identify patients at the highest risk of developing this cancer. Moreover, early detection strategies, therapeutic approaches, and real-time monitoring of responses to treatment to improve survival and quality of life are also inadequate. Tumor development and progression are dependent upon cell-to-cell communication, allowing cancer cells to re-program cells not only within the surrounding tumor microenvironment, but also at distant sites. Recent studies established that extracellular vesicles (EVs) mediate bi-directional communication between normal and cancerous cells. EVs are highly stable membrane vesicles that are released from a wide range of cells, including healthy and cancer cells. They contain tissue-specific signaling molecules (e.g., proteins and miRNA) and, once released, regulate target cell phenotypes, inducing a pro-tumorigenic and immunosuppressive phenotype to contribute to tumor growth and metastasis as well as proximal and distal cell function. Thus, EVs are a “fingerprint” of their cell of origin and reflect the metabolic status. Additionally, via the capacity to evade the immune system and remain stable over long periods in circulation, EVs can be potent therapeutic agents. This review examines the potential role of EVs in the different aspects of the tumor microenvironment in OC, as well as their application in diagnosis, delivery of therapeutic agents, and disease monitoring.

Small Extracellular Vesicles and Metastasis-Blame the Messenger

Simple Summary

Due to their systemic nature, metastatic lesions are a major problem for curative cancer treatment. According to a common model for metastasis, tumor cells disseminate by local invasion, survival in the blood stream and extravasation into suitable tissue environments. At secondary sites, metastatic cells adapt, proliferate and foster vascularization to satisfy nutrient and oxygen demand. In recent years, tumors were shown to extensively communicate with cells in the local microenvironment and future metastatic sites by secreting small extracellular vesicles (sEVs, exosomes). sEVs deliver bioactive cargos, e.g., proteins, and in particular, several nucleic acid classes to reprogram target cells, which in turn facilitate tumor growth, cell motility, angiogenesis, immune evasion and establishment of pre-metastatic niches. sEV-cargos also act as biomarkers for diagnosis and prognosis. This review discusses how tumor cells utilize sEVs with nucleic acid cargos to progress through metastasis, and how sEVs may be employed for prognosis and treatment.

Abstract

Cancer is a complex disease, driven by genetic defects and environmental cues. Systemic dissemination of cancer cells by metastasis is generally associated with poor prognosis and is responsible for more than 90% of cancer deaths. Metastasis is thought to follow a sequence of events, starting with loss of epithelial features, detachment of tumor cells, basement membrane breakdown, migration, intravasation and survival in the circulation. At suitable distant niches, tumor cells reattach, extravasate and establish themselves by proliferating and attracting vascularization to fuel metastatic growth. These processes are facilitated by extensive cross-communication of tumor cells with cells in the primary tumor microenvironment (TME) as well as at distant pre-metastatic niches. A vital part of this communication network are small extracellular vesicles (sEVs, exosomes) with a size of 30–150 nm. Tumor-derived sEVs educate recipient cells with bioactive cargos, such as proteins, and in particular, major nucleic acid classes, to drive tumor growth, cell motility, angiogenesis, immune evasion and formation of pre-metastatic niches. Circulating sEVs are also utilized as biomarker platforms for diagnosis and prognosis. This review discusses how tumor cells facilitate progression through the metastatic cascade by employing sEV-based communication and evaluates their role as biomarkers and vehicles for drug delivery.

Bispecific antibody CD73xEpCAM selectively inhibits the adenosine-mediated immunosuppressive activity of carcinoma-derived extracellular vesicles

Tumor-derived extracellular vesicles (EVs) carry potent immunosuppressive factors that affect the antitumor activities of immune cells. A significant part of the immunoinhibitory activity of EVs is attributable to CD73, a GPI-anchored ecto-5'-nucleotidase involved in the conversion of tumor-derived proinflammatory extracellular ATP (eATP) to immunosuppressive adenosine (ADO). The CD73-antagonist antibody oleclumab inhibits cell surface-exposed CD73 and is currently undergoing clinical testing for cancer immunotherapy. However, a strategy to selectively inhibit CD73 exposed on EVs is not available. Here, we present a novel bispecific antibody (bsAb) CD73xEpCAM designed to bind with high affinity the common EV surface marker EpCAM and concurrently inhibit CD73. Unlike oleclumab, bsAb CD73xEpCAM potently inhibited the immunosuppressive activity of EVs from CD73pos/EpCAMpos carcinoma cell lines and patient-derived colorectal cancer cells. Taken together, selective blockade of EV-exposed CD73 by bsAb CD73xEpCAM may be useful as an alternate or complementary targeted approach in cancer immunotherapy.

Exosomes and prostate cancer management

Exosomes (and other extracellular vesicles) are now part of the cancer research landscape, involved both as players in pathophysiological mechanisms, as biomarkers of the cancer process and as therapeutic tools. One step they have yet to take is to move into routine clinical practice and management of prostate cancer is an example of this necessary maturation. More than for many other cancers and because a possible alternative is active surveillance (neither removal nor destruction), the diagnosis of prostate cancer does not only involve the detection of cancerous cells but also the determination of its true aggressiveness. By measuring TRMPRSS2:ERG fusion and PCA3 transcripts in urine exosomes, the EPI assay seems able to help prostate biopsy decision. Results from clinical studies showed that it can reduce the proportion of unnecessary biopsies while missing only a minimal proportion of clinically significant cancers. In metastatic prostate cancer, after failure of a first step androgen deprivation therapy, when a choice has to be made between a second-generation androgen receptor (AR) signaling inhibitor and taxane-based chemotherapy, detection of the AR splicing variant AR-V7 in circulating tumor cells (CTCs) has appeared promising. Whether exosomes could be a better material (simpler to isolate from the bloodstream than CTCs?) to detect AR-V7 has been suggested by some studies and remains to be confirmed. At last, a couple of exploratory studies either targeted or used exosomes to treat prostate cancer, by respectively inhibiting their secretion (to prevent exosome-mediated transfer of biologically active oncogenic actors), or loading them with immunogenic cancer-specific proteins (to generate anticancer vaccine) or with pharmacologic agents. Overall efforts are however still needed to confirm these results and generalize exosome-based diagnostic, prognostic or therapeutic strategies in prostate cancer management.

Repurposing macitentan with nanoparticle modulates tumor microenvironment to potentiate immune checkpoint blockade

Immune checkpoint therapy (ICT), which reinvigorates cytotoxic T cells, provides clinical benefits as an alternative to conventional cancer therapies. However, its clinical response rate is too low to treat an immune-excluded tumor, owing to the presence of abundant stromal elements impeding the penetration of immune cells. Here, we report that macitentan, a dual endothelin receptor antagonist approved by the FDA to treat pulmonary arterial hypertension, can be repositioned to modulate the desmoplastic tumor microenvironment (TME). In the 4T1 orthotopic tumor model, the polymeric nanoparticles bearing macitentan (M-NPs) prevent fibrotic progression by regulating the function of cancer-associated fibroblasts, attenuate the biogenesis of cancer cell-derived exosomes, and modulate the T cell subsets and distribution in TME. These results demonstrate that the M-NPs effectively reorganize the immunosuppressive TME by targeting the endothelin-1 axis and consequently exhibit synergistic antitumor effects in combination with ICT.

Extracellular vesicles in urological malignancies

Extracellular vesicles (EVs) are small lipid bound structures released from cells containing bioactive cargoes. Both the type of cargo and amount loaded varies compared to that of the parent cell. The characterisation of EVs in cancers of the male urogenital tract has identified several cargoes with promising diagnostic and disease monitoring potential. EVs released by cancers of the male urogenital tract promote cell-to-cell communication, migration, cancer progression and manipulate the immune system promoting metastasis by evading the immune response. Their use as diagnostic biomarkers represents a new area of screening and disease detection, potentially reducing the need for invasive biopsies. Many validated EV cargoes have been found to have superior sensitivity and specificity than current diagnostic tools currently in use. The use of EVs to improve disease monitoring and develop novel therapeutics will enable clinicians to individualise patient management in the exciting era of personalised medicine.

The Role of Extracellular Vesicles as Shuttles of RNA and Their Clinical Significance as Biomarkers in Hepatocellular Carcinoma

Extracellular vesicles (EVs) have attracted interest as mediators of intercellular communication following the discovery that EVs contain RNA molecules, including non-coding RNA (ncRNA). Growing evidence for the enrichment of peculiar RNA species in specific EV subtypes has been demonstrated. ncRNAs, transferred from donor cells to recipient cells, confer to EVs the feature to regulate the expression of genes involved in differentiation, proliferation, apoptosis, and other biological processes. These multiple actions require accuracy in the isolation of RNA content from EVs and the methodologies used play a relevant role. In liver, EVs play a crucial role in regulating cell-cell communications and several pathophysiological events in the heterogeneous liver class of cells via horizontal transfer of their cargo. This review aims to discuss the rising role of EVs and their ncRNAs content in regulating specific aspects of hepatocellular carcinoma development, including tumorigenesis, angiogenesis, and tumor metastasis. We analyze the progress in EV-ncRNAs' potential clinical applications as important diagnostic and prognostic biomarkers for liver conditions.

Cancer stem cell marker DCLK1 reprograms small extracellular vesicles toward migratory phenotype in gastric cancer cells

Doublecortin-like kinase 1 (DCLK1) is a putative cancer stem cell marker, a promising diagnostic and prognostic maker for malignant tumors and a proposed driver gene for gastric cancer (GC). DCLK1 overexpression in a majority of solid cancers correlates with lymph node metastases, advanced disease and overall poor-prognosis. In cancer cells, DCLK1 expression has been shown to promote epithelial-to-mesenchymal transition (EMT), driving disruption of cell-cell adhesion, cell migration and invasion. Here, we report that DCLK1 influences small extracellular vesicle (sEV/exosome) biogenesis in a kinase-dependent manner. sEVs isolated from DCLK1 overexpressing human GC cell line MKN1 (MKN1^OE -sEVs), promote the migration of parental (non-transfected) MKN1 cells (MKN1^PAR ). Quantitative proteome analysis of MKN1^OE -sEVs revealed enrichment in migratory and adhesion regulators (STRAP, CORO1B, BCAM, COL3A, CCN1) in comparison to MKN1^PAR -sEVs. Moreover, using DCLK1-IN-1, a specific small molecule inhibitor of DCLK1, we reversed the increase in sEV size and concentration in contrast to other EV subtypes, as well as kinase-dependent cargo selection of proteins involved in EV biogenesis (KTN1, CHMP1A, MYO1G) and migration and adhesion processes (STRAP, CCN1). Our findings highlight a specific role of DCLK1-kinase dependent cargo selection for sEVs and shed new light on its role as a regulator of signaling in gastric tumorigenesis.

Stromal-Derived Extracellular Vesicles Suppress Proliferation of Bone Metastatic Cancer Cells Mediated By ERK2

Bone is a common site of cancer metastasis, including cancers such as breast, prostate, and multiple myeloma. Disseminated tumor cells (DTC) shed from a primary tumor may travel to bone and can survive undetected for years before proliferating to form overt metastatic lesions. This period of time can be defined as metastatic latency. Once in the metastatic microenvironment, DTCs engage in intercellular communication with surrounding stromal cells, which can influence cancer cell survival, proliferation, and ultimately disease progression. The role of the surrounding tumor microenvironment in regulating DTC fate is becoming increasingly recognized. We have previously shown that in the bone microenvironment, osteoblasts are "educated" by interactions with breast cancer cells, and these "educated" osteoblasts (EO) produce soluble factors that regulate cancer cell proliferation. In this study, we provide evidence indicating that EOs produce small extracellular vesicles (sEV) that suppress breast cancer proliferation, in part through regulation of ERK1/2 signaling. In addition, using EdU-incorporation assays and propidium iodide staining we demonstrate that exposure to EO-derived sEVs decreases breast cancer cell entry to S-phase of cell cycle. We also have evidence that particular microRNAs, including miR-148a-3p, are enriched in EO-derived sEVs, and that miR-148a-3p is capable of regulating breast cancer proliferation. IMPLICATIONS: These findings underscore the importance of sEV-mediated communication in the earlier stages of cancer progression, and suggest that EO-derived sEVs may be one mechanism by which the bone microenvironment suppresses breast cancer cell proliferation.

Secretion rates and protein composition of extracellular vesicles released by cancer-associated fibroblasts after radiation

Reciprocal communication between the malignant and non-malignant cellular elements in tumors is essential for cancer sustainability and plays an important role in the response of cancers to treatments. Some of this cellular crosstalk takes place via secretion of vesicles that are actively released into the extracellular space by most cell types in tumors. Recent studies have demonstrated radiation-induced changes in the secretion rate and composition of extracellular vesicles (EVs), with impact on radiation-related cellular communication. However, little is known about the effects of different radiation regimens on the release of EVs by cells of the tumor microenvironment. In this study, we provide a comprehensive molecular characterization of EVs released by cultured primary lung tumor fibroblasts. We explore the quantitative and morphological changes triggered by ionizing radiation (IR), delivered as a single dose of 18 Gy or three consecutive daily medium-doses of 6 Gy. Cancer-associated fibroblasts (CAFs) secrete EVs with sizes ranging from 80 to 200 nm, expressing some of the classical exosome markers. Exposing CAFs to a single-high radiation dose (1 × 18 Gy) or fractionated medium-dose did not alter the release of CAF-EVs. The protein composition of CAF-EVs was analyzed by LC-MS/MS proteomics and revealed that CAF-EVs are enriched with heat shock proteins, integrins, tetraspanins, proteinases, collagens, growth factors and an array of molecules involved in the regulation of cell migration and the immune system. Quantitative proteomic analyses revealed minor changes in the protein composition of CAF-EVs after radiation exposure. Taken together, this study presents original data on lung tumor CAF-EV composition and reveals that release and protein cargo of CAF-EVs are largely unaltered after exposing CAFs to IR.

Emerging Role of Exosomes in Liquid Biopsy for Monitoring Prostate Cancer Invasion and Metastasis

Prostate cancer (PCa) is the most common solid tumor in men. While patients with local PCa have better prognostic survival, patients with metastatic PCa have relatively high mortality rates. Existing diagnostic methods for PCa rely on tissue biopsy and blood prostate-specific antigen (PSA) detection; however, the PSA test does not detect aggressive PCa. Liquid biopsy is a promising technique to overcome tumor heterogeneity in diagnosis, provide more comprehensive information, and track tumor progression over time, allowing for the development of treatment options at all stages of PCa. Exosomes containing proteins and nucleic acids are potential sources of tumor biomarkers. Accumulating evidence indicates that exosomes play important roles in cell communication and tumor progression and are suitable for monitoring PCa progression and metastasis. In this review, we summarize recent advances in the use of exosomal proteins and miRNAs as biomarkers for monitoring PCa invasion and metastasis and discuss their feasibility in clinical diagnosis.

The role of galectin-3 and its genetic variants in tumor risk and survival of patients with surgically resected early-stage non-small cell lung cancer

Background

The aim of this study was to investigate the possible relationship between galectin-3 gene variants, serum level, gene expression level, and the risks and survivals of resectable non-small cell lung cancer patients.

Methods

The rs4644 and rs4652 variants of galectin-3 were genotyped by TaqMan single nucleotide polymorphism assay using genomic deoxyribonucleic acid isolated from the peripheral blood of 65 (54 males, 11 females; mean age: 60.1±11.9 years; range, 34 to 83 years) with Stage IA-IIIA non-small cell lung cancer who underwent primary surgical treatment and 95 healthy individuals (48 males, 47 females; mean age: 53.9±13.5 years; range, 32 to 87 years) between March 2017 and September 2018. Circulating galectin-3 levels in serum samples of the patient and control groups were assessed by enzyme-linked immunosorbent assay. Messenger ribonucleic acid expression of galectin-3 in tumor and surrounding tissues of the patient group was examined by real-time quantitative polymerase chain reaction. Both predictive and prognostic significance of the results were analyzed.

Results

The presence of angiolymphatic invasion was significant in the patients with rs4652 AA genotype (p=0.04). Serum galectin-3 levels were significantly higher in the patients than the controls (p<0.0001). The patients with rs4644 CA/CC (p<0.0001 and p<0.0001) and rs4652 AA/AC (p=0.001 and p<0.0001) genotypes had higher serum galectin-3 levels than their corresponding controls. Serum galectin-3 levels increased in the presence of vascular invasion in patients with both rs4644 AC (p=0.03) and rs4652 AC (p=0.019) genotypes. The receiver operating characteristic curve suggested serum galectin-3 level as a strong predictive marker for the patient group with a cut-off value of 17.089 ng/mL (area under the curve: 0.910±0.04; 95% confidence interval: 0.832-0.988; p<0.001). Univariate analysis revealed the association of lower serum galectin-3 levels with better survival (p=0.048). Multivariate survival analysis showed that only high serum galectin-3 levels tended to be related to survival of the patients (hazard ratio: 5.106; 95% confidence interval: 0.956-27.267; p=0.056).

Conclusion

The presence of galectin-3 gene variants may lead to histopathological differences among patients with non-small cell lung cancer. Serum galectin-3 level may be a valuable diagnostic biomarker and be associated with survival of these patients.

The roles of small extracellular vesicles in lung cancer: Molecular pathology, mechanisms, diagnostics, and therapeutics

Small extracellular vesicles (sEVs) are submicron-sized, lipid-bilayer-enclosed particles that are released from cells. A variety of tissue-specific molecules, including proteins, DNA fragments, RNA, lipids, and metabolites, can be selectively encapsulated into sEVs and delivered to nearby and distant recipient cells. Incontestable and growing evidence shows the important biological roles and the clinical relevance of sEVs in tumors. In particular, recent studies validate sEVs can be used for early tumor diagnostics, staging, and treatment monitoring. Moreover, sEVs have been used as drug delivery nanocarriers, cancer vaccines, and antigen conferrers. While still in its infancy, the field of sEV-based fundamental and translational studies has been rapidly advancing. This review comprehensively examines the latest sEV-related studies in lung cancers, encompassing extracellular vesicles and their roles in lung cancer pathophysiology, diagnostics, and therapeutics. The state-of-the-art technologies for sEV isolation, downstream molecular analyses, and sEV-based therapies indicate their potency as tools for understanding the pathology and promising clinical management of lung cancers.

Centrosome amplification mediates small extracellular vesicle secretion via lysosome disruption

Bidirectional communication between cells and their surrounding environment is critical in both normal and pathological settings. Extracellular vesicles (EVs), which facilitate the horizontal transfer of molecules between cells, are recognized as an important constituent of cell-cell communication. In cancer, alterations in EV secretion contribute to the growth and metastasis of tumor cells. However, the mechanisms underlying these changes remain largely unknown. Here, we show that centrosome amplification is associated with and sufficient to promote small extracellular vesicle (SEV) secretion in pancreatic cancer cells. This is a direct result of lysosomal dysfunction, caused by increased reactive oxygen species (ROS) downstream of extra centrosomes. We propose that defects in lysosome function could promote multivesicular body fusion with the plasma membrane, thereby enhancing SEV secretion. Furthermore, we find that SEVs secreted in response to amplified centrosomes are functionally distinct and activate pancreatic stellate cells (PSCs). These activated PSCs promote the invasion of pancreatic cancer cells in heterotypic 3D cultures. We propose that SEVs secreted by cancer cells with amplified centrosomes influence the bidirectional communication between the tumor cells and the surrounding stroma to promote malignancy.