Microvesicles secreted by macrophages shuttle invasion-potentiating microRNAs into breast cancer cells

Tumor-derived miRNAs as tumor microenvironment regulators for synergistic therapeutic options

MicroRNAs (miRNAs) are a class of non-coding RNAs that perform post-transcriptional gene regulation. This review focuses on the role of tumor cell-derived miRNAs in the regulation of the tumor microenvironment (TME) via receptor cell recoding, including angiogenesis, expression of immunosuppressive molecules, formation of radiation resistance, and chemoresistance. Furthermore, we discuss the potential of these molecules as adjuvant therapies in combination with chemotherapy, radiotherapy, or immunotherapy, as well as their advantages as efficacy predictors for personalized therapy. MiRNA-based therapeutic agents for tumors are currently in clinical trials, and while challenges remain, additional research on tumor-derived miRNAs is warranted, which may provide significant clinical benefits to cancer patients.

Crosstalk between extracellular vesicles and tumor-associated macrophage in the tumor microenvironment

In concert with hijacking key genes to drive tumor progression, cancer cells also have the unique ability to dynamically interact with host microenvironment and discreetly manipulate the surrounding stroma, also known as the tumor microenvironment (TME), to provide optimal conditions for tumor cells to thrive and evade host immunity. Complex cellular crosstalk and molecular signaling between cancer cells, surrounding non-malignant cells, and non-cellular components are involved in this process. While intercellular communication traditionally centers around chemokines, cytokines, inflammatory mediators, and growth factors, emerging pathways involving extracellular vesicles (EVs) are gaining increasing attention. The immunosuppressive TME is created and maintained in part by the large abundance of tumor-associated macrophages (TMAs), which are associated with drug resistance, poor prognosis, and have emerged as potential targets for cancer immunotherapy. TMAs are highly dynamic, and can be polarized into either M1 or M2-like macrophages. EVs are efficient cell-cell communication molecules that have been catapulted to the center of TMA polarization. In this article, we provide detailed examination of the determinative role of EVs in sustaining the TME through mediating crosstalk between tumor cells and tumor-associated macrophages.

Macrophage - tumor cell interaction beyond cytokines

Tumor cells communication with tumor associated macrophages is a highly important factor of tumor malignant potential development. For a long time, studies of this interaction were focused on a cytokine- and other soluble factors -mediated processes. Discovery of exosomes and regulatory RNAs as their cargo opened a broad field of research. Non-coding RNAs (ncRNAs) were demonstrated to contribute significantly to the development of macrophage phenotype, not only by regulating expression of certain genes, but also by providing for feedback loops of macrophage activation. Being a usual cargo of macrophage- or tumor cell-derived exosomes ncRNAs provide an important mechanism of tumor-stromal cell interaction that contributes significantly to the pathogenesis of various types of tumors. Despite the volume of ongoing research there are still many gaps that must be filled before the practical use of ncRNAs will be possible. In this review we discuss the role of regulatory RNAs in the development of macrophage phenotype. Further we review recent studies supporting the hypothesis that macrophages may affect the properties of tumor cells and vice versa tumor cells influence macrophage phenotype by miRNA and lncRNA transported between these cells by exosomes. We suggest that this mechanism of tumor cell - macrophage interaction is highly promising for the development of novel diagnostic and therapeutic strategies, though many problems are still to be solved.

Role of the Hypoxic-Secretome in Seed and Soil Metastatic Preparation

During tumor growth, the delivery of oxygen to cells is impaired due to aberrant or absent vasculature. This causes an adaptative response that activates the expression of genes that control several essential processes, such as glycolysis, neovascularization, immune suppression, and the cancer stemness phenotype, leading to increased metastasis and resistance to therapy. Hypoxic tumor cells also respond to an altered hypoxic microenvironment by secreting vesicles, factors, cytokines and nucleic acids that modify not only the immediate microenvironment but also organs at distant sites, allowing or facilitating the attachment and growth of tumor cells and contributing to metastasis. Hypoxia induces the release of molecules of different biochemical natures, either secreted or inside extracellular vesicles, and both tumor cells and stromal cells are involved in this process. The mechanisms by which these signals that can modify the premetastatic niche are sent from the primary tumor site include changes in the extracellular matrix, recruitment and activation of different stromal cells and immune or nonimmune cells, metabolic reprogramming, and molecular signaling network rewiring. In this review, we will discuss how hypoxia might alter the premetastatic niche through different signaling molecules.

Pro-tumoral functions of tumor-associated macrophage EV-miRNA

MicroRNAs (miRNAs) are central players in cancer biology. Their relevance in cancer development, progression and resistance to therapy has been further emphasized by the discovery that they are important cargo component of extracellular vesicles (EVs), which represent a prominent means of inter-cellular communication within the tumor microenvironment (TME). This review article focuses on the interaction between cancer cells and tumor-associated macrophages (TAMs) and in particular on the pro-tumoral phenotype elicited by EV-contained miRNAs released by TAMs and transferred to cancer cells. All main hallmarks of the malignant phenotype are affected by TAM-derived vesicular miRNAs, paving the road to the identification of such miRNAs as promising upcoming novel anti-cancer agents.

Exosomes in bone remodeling and breast cancer bone metastasis

Exosomes are endosome-derived microvesicles that carry cell-specific biological cargo, such as proteins, lipids, and noncoding RNAs (ncRNAs). They play a key role in bone remodeling by enabling the maintenance of a balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Recent evidence indicates that exosomes disrupt bone remodeling that occurs during breast cancer (BC) progression. The bone is a preferred site for BC metastasis owing to its abundant osseous reserves. In this review, we aimed to highlight the roles of exosomes derived from bone cells and breast tumor in bone remodeling and BC bone metastasis (BCBM). We also briefly outline the mechanisms of action of ncRNAs and proteins carried by exosomes secreted by bone and BCBM. Furthermore, this review highlights the potential of utilizing exosomes as biomarkers or delivery vehicles for the diagnosis and treatment of BCBM.

Extracellular vesicles in cancer therapy

Extracellular vesicles (EVs), including a variety of membrane-enclosed nanosized particles carrying cell-derived cargo, mediate a major type of intercellular communication in physiological and pathological processes. Both cancer and non-cancer cells secrete EVs, which can travel to and influence various types of cells at the primary tumor site as well as in distant organs. Tumor-derived EVs contribute to cancer cell plasticity and resistance to therapy, adaptation of tumor microenvironment, local and systemic vascular remodeling, immunomodulation, and establishment of pre-metastatic niches. Therefore, targeting the production, uptake, and function of tumor-derived EVs has emerged as a new strategy for stand-alone or combinational therapy of cancer. On the other hand, as EV cargo partially reflects the genetic makeup and phenotypic properties of the secreting cell, EV-based biomarkers that can be detected in biofluids are being developed for cancer diagnosis and for predicting and monitoring tumor response to therapy. Meanwhile, EVs from presumably safe sources are being developed as delivery vehicles for anticancer therapeutic agents and as anticancer vaccines. Numerous reviews have discussed the biogenesis and characteristics of EVs and their functions in cancer. Here, I highlight recent advancements in translation of EV research outcome towards improved care of cancer, including developments of non-invasive EV-based biomarkers and therapeutic agents targeting tumor-derived EVs as well as engineering of therapeutic EVs.

Crosstalk between Tumor-Associated Macrophages and MicroRNAs: A Key Role in Tumor Microenvironment

As an in-depth understanding of immunotherapy continues to grow, current anticancer therapy research is increasingly focused on the tumor microenvironment (TME). MicroRNAs (miRNAs) play crucial roles in the regulation of genetic information and expression and mediate interactions between tumor cells and components in the TME, such as tumor-associated macrophages (macrophages). Macrophages are abundant in the TME, and their different polarization directions can promote or inhibit tumor growth and progression. By regulating biological behaviors, such as macrophage recruitment, infiltration, and polarization, miRNAs can affect various molecular pathways to regulate tumor progression and treatment response. In this review, we discuss in detail the effects of macrophages on tumors and the multifaceted effects of miRNAs on macrophages. We also discuss the potential clinical applications and prospects of targeted therapy based on miRNAs, novel clinical biomarkers, and drug delivery systems.

Towards extracellular vesicle delivery systems for tissue regeneration: material design at the molecular level

The discovery and development of extracellular vesicles in tissue engineering have shown great potential for tissue regenerative therapies. However, their vesicle nature requires dosage-dependent administration and efficient interactions with recipient cells. Researchers have resorted to biomaterials for localized and sustained delivery of extracellular vesicles to the targeted cells, but not much emphasis has been paid on the design of the materials, which deeply impacts their molecular interactions with the loaded extracellular vesicles and subsequent delivery. Therefore, we present in this review a comprehensive survey of extracellular vesicle delivery systems from the viewpoint of material design at the molecular level. We start with general requirements of the materials and delve into different properties of delivery systems as a result of different designs, from material selections to processing strategies. Based on these differences, we analyzed the performance of extracellular vesicle delivery and tissue regeneration in representative studies. In light of the current missing links within the relationship of material structures, physicochemical properties and delivery performances, we provide perspectives on the interactions of materials and extracellular vesicles and the possible extension of materials. This review aims to be a strategic enlightenment for the future design of extracellular vesicle delivery systems to facilitate their translation from basic science to clinical applications.

Role of exosomal non-coding RNAs from tumor cells and tumor-associated macrophages in the tumor microenvironment

Exosomes have a crucial role in intercellular communication and mediate interactions between tumor cells and tumor-associated macrophages (TAMs). Exosome-encapsulated non-coding RNAs (ncRNAs) are involved in various physiological processes. Tumor-derived exosomal ncRNAs induce M2 macrophage polarization through signaling pathway activation, signal transduction, and transcriptional and post-transcriptional regulation. Conversely, TAM-derived exosomal ncRNAs promote tumor proliferation, metastasis, angiogenesis, chemoresistance, and immunosuppression. MicroRNAs induce gene silencing by directly targeting mRNAs, whereas lncRNAs and circRNAs act as miRNA sponges to indirectly regulate protein expressions. The role of ncRNAs in tumor-host interactions is ubiquitous. Current research is increasingly focused on the tumor microenvironment. On the basis of the "cancer-immunity cycle" hypothesis, we discuss the effects of exosomal ncRNAs on immune cells to induce T cell exhaustion, overexpression of programmed cell death ligands, and create a tumor immunosuppressive microenvironment. Furthermore, we discuss potential applications and prospects of exosomal ncRNAs as clinical biomarkers and drug delivery systems.

miR-aculous new avenues for cancer immunotherapy

The rising toll of cancer globally necessitates ingenuity in early detection and therapy. In the last decade, the utilization of immune signatures and immune-based therapies has made significant progress in the clinic; however, clinical standards leave many current and future patients without options. Non-coding RNAs, specifically microRNAs, have been explored in pre-clinical contexts with tremendous success. MicroRNAs play indispensable roles in programming the interactions between immune and cancer cells, many of which are current or potential immunotherapy targets. MicroRNAs mechanistically control a network of target genes that can alter immune and cancer cell biology. These insights provide us with opportunities and tools that may complement and improve immunotherapies. In this review, we discuss immune and cancer cell-derived miRNAs that regulate cancer immunity and examine miRNAs as an integral part of cancer diagnosis, classification, and therapy.

The roles of small extracellular vesicles in cancer and immune regulation and translational potential in cancer therapy

Extracellular vesicles (EVs) facilitate the extracellular transfer of proteins, lipids, and nucleic acids and mediate intercellular communication among multiple cells in the tumour environment. Small extracellular vesicles (sEVs) are defined as EVs range in diameter from approximately 50 to 150 nm. Tumour-derived sEVs (TDsEVs) and immune cell-derived sEVs have significant immunological activities and participate in cancer progression and immune responses. Cancer-specific molecules have been identified on TDsEVs and can function as biomarkers for cancer diagnosis and prognosis, as well as allergens for TDsEVs-based vaccination. Various monocytes, including but not limited to dendritic cells (DCs), B cells, T cells, natural killer (NK) cells, macrophages, and myeloid-derived suppressor cells (MDSCs), secrete sEVs that regulate immune responses in the complex immune network with either protumour or antitumour effects. After engineered modification, sEVs from immune cells and other donor cells can provide improved targeting and biological effects. Combined with their naïve characteristics, these engineered sEVs hold great potential as drug carriers. When used in a variety of cancer therapies, they can adjunctly enhance the safety and antitumor efficacy of multiple therapeutics. In summary, both naïve sEVs in the tumour environment and engineered sEVs with effector cargoes are regarded as showing promising potential for use in cancer diagnostics and therapeutics.

Extracellular Vesicles: A Novel Tool in Nanomedicine and Cancer Treatment

Simple Summary

Extracellular vesicles (EVs) are plasma-membrane-encased particles with various biomolecules. Recent studies have demonstrated that EVs play a role in homeostasis and disease progression, and therefore may be important disease biomarkers. In cancer, EVs mediate inflammatory responses, oxidative stress, and contribute to altering the microenvironment. Additionally, EVs function as mediators in neurodegenerative diseases. Interestingly, EVs also promote stem cell differentiation, intercellular communication, and wound healing. These functions suggest that EVs can be utilized in medicine as therapeutic tools. Moreover, their endogenous nature and ability to carry intact biomolecules of different sizes to their target site due to their lipid bilayer makes them perfect drug transport systems that can be utilized in the treatment of many diseases, with higher efficacy and fewer side effects than other treatments as they can only target diseased cells and not healthy nearby cells, which occurs in conventional chemotherapy, for example. As such, their role in drug delivery has great potential.

Abstract

Extracellular vesicles are membrane-bound vesicles released by cells to mediate intercellular communication and homeostasis. Various external stimuli as well as inherent abnormalities result in alterations in the extracellular vesicle milieu. Changes to cells result in alterations in the content of the extracellular vesicle biogenesis, which may affect proximal and distal cells encountering these altered extracellular vesicles. Therefore, the examination of changes in the extracellular vesicle signature can be used to follow disease progression, reveal possible targets to improve therapy, as well as to serve as mediators of therapy. Furthermore, recent studies have developed methods to alter the cargo of extracellular vesicles to restore normal function or deliver therapeutic agents. This review will examine how extracellular vesicles from cancer cells differ from normal cells, how these altered extracellular vesicles can contribute to cancer progression, and how extracellular vesicles can be used as a therapeutic agent to target cancer cells and cancer-associated stroma. Here we present extracellular vesicles as a novel tool in nanomedicine.

The potential applications of microparticles in the diagnosis, treatment, and prognosis of lung cancer

Microparticles (MPs) are 100–1000 nm heterogeneous submicron membranous vesicles derived from various cell types that express surface proteins and antigenic profiles suggestive of their cellular origin. MPs contain a diverse array of bioactive chemicals and surface receptors, including lipids, nucleic acids, and proteins, which are essential for cell-to-cell communication. The tumour microenvironment (TME) is enriched with MPs that can directly affect tumour progression through their interactions with receptors. Liquid biopsy, a minimally invasive test, is a promising alternative to tissue biopsy for the early screening of lung cancer (LC). The diverse biomolecular information from MPs provides a number of potential biomarkers for LC risk assessment, early detection, diagnosis, prognosis, and surveillance. Remodelling the TME, which profoundly influences immunotherapy and clinical outcomes, is an emerging strategy to improve immunotherapy. Tumour-derived MPs can reverse drug resistance and are ideal candidates for the creation of innovative and effective cancer vaccines. This review described the biogenesis and components of MPs and further summarised their main isolation and quantification methods. More importantly, the review presented the clinical application of MPs as predictive biomarkers in cancer diagnosis and prognosis, their role as therapeutic drug carriers, particularly in anti-tumour drug resistance, and their utility as cancer vaccines. Finally, we discussed current challenges that could impede the clinical use of MPs and determined that further studies on the functional roles of MPs in LC are required.

Emerging innovations on exosome-based onco-therapeutics

Exosomes, nano-sized extracellular vesicles for intercellular communications, are gaining rapid momentum as a novel strategy for the diagnosis and therapeutics of a spectrum of diseases including cancers. Secreted by various cell sources, exosomes pertain numerous functionalities from their parental cells and have enhanced stability that enable them with many features favorable for clinical use and commercialization. This paper focuses on the possible roles of exosomes in cancer therapeutics and reviews current exosome-based innovations toward enhanced cancer management and challenges that limit their clinical translation. Importantly, this paper casts insights on how cold atmospheric plasma, an emerging anticancer strategy, may aid in innovations on exosome-based onco-therapeutics toward improved control over cancers.

Tumor associated macrophages-derived exosomes facilitate hepatocellular carcinoma malignance by transferring lncMMPA to tumor cells and activating glycolysis pathway

BACKGROUND

Tumor-associated macrophages (TAMs), which form a large part of the tumor microenvironment, are normally regulated by metabolic reprogramming. However, the potential mechanisms of the immune-metabolism interaction between hepatocellular carcinoma (HCC) cells and TAMs remain unclear.

METHODS

The candidate long non-coding RNAs (lncRNAs) were screened by Smart-seq based scRNA-seq method and then validated by qPCR. Immunostaining analysis was done to examine the levels of markers for TAMs and glycolysis. Exosomes from primary TAMs of human HCC tissues were isolated by centrifugation, and their internalization with lncRNAs was confirmed by immunofluorescence. The underlying mechanism of TAMs-derived exosomal lncRNA to HCC was confirmed by luciferase reporter assay and RNA immunoprecipitation. Metabolism regulation was evaluated through glucose consumption, lactate productions and extracellular acidification rates (ECARs). Mouse xenograft models were used to elucidate the in vivo effect of candidate lncRNAs on tumor growth.

RESULTS

TAMs augment the aerobic glycolysis in HCC cells and their proliferation by the extracellular exosome transmission of a myeloid-derived lncRNA, M2 macrophage polarization associated lncRNA (lncMMPA). Mechanistically, lncMMPA not only could polarize M2 macrophage, but also could act as an microRNA sponge to interact with miR-548 s and increase the mRNA level of ALDH1A3, then further promote glucose metabolism and cell proliferation in HCC. Moreover, lncMMPA increased HCC cell multiplication through interacting with miR-548 s in vivo. Clinically, lncMMPA expression associates with glycolysis in TAMs and reduced survival of HCC patients.

CONCLUSION

LncMMPA plays an important role in regulating HCC malignancy and metabolic reprogramming of miR-548 s/ALDH1A3 pathway.

Modes of action and diagnostic value of miRNAs in sepsis

Sepsis is a clinical syndrome defined as a dysregulated host response to infection resulting in life-threatening organ dysfunction. Sepsis is a major public health concern associated with one in five deaths worldwide. Sepsis is characterized by unbalanced inflammation and profound and sustained immunosuppression, increasing patient susceptibility to secondary infections and mortality. microRNAs (miRNAs) play a central role in the control of many biological processes, and deregulation of their expression has been linked to the development of oncological, cardiovascular, neurodegenerative and metabolic diseases. In this review, we discuss the role of miRNAs in sepsis pathophysiology. Overall, miRNAs are seen as promising biomarkers, and it has been proposed to develop miRNA-based therapies for sepsis. Yet, the picture is not so straightforward because of the versatile and dynamic features of miRNAs. Clearly, more research is needed to clarify the expression and role of miRNAs in sepsis, and to promote the use of miRNAs for sepsis management.

The Exosome Journey: From Biogenesis to Regulation and Function in Cancers

Exosomes are a type of small endosomal-derived vesicles ranging from 30 to 150 nm, which can serve as functional mediators in cell-to-cell communication and various physiological and pathological processes. In recent years, exosomes have emerged as crucial mediators of intracellular communication among tumor cells, immune cells, and stromal cells, which can shuttle bioactive molecules, such as proteins, lipids, RNA, and DNA. Exosomes exhibit the high bioavailability, biological stability, targeting specificity, low toxicity, and immune characteristics, suggesting their potentials in the diagnosis and treatment of cancers. They can be applied as an effective tool in the diagnostics, therapeutics, and drug delivery in cancers. This review summarizes the regulation and functions of exosomes in various cancers to augment our understanding of exosomes, which paves the way for parallel advancements in the therapeutic approach of cancers. In this review, we also discuss the challenges and prospects for clinical application of exosome-based diagnostics and therapeutics for cancers.

Tumor-Derived Membrane Vesicles: A Promising Tool for Personalized Immunotherapy

Tumor-derived membrane vesicles (TDMVs) are non-invasive, chemotactic, easily obtained characteristics and contain various tumor-borne substances, such as nucleic acid and proteins. The unique properties of tumor cells and membranes make them widely used in drug loading, membrane fusion and vaccines. In particular, personalized vectors prepared using the editable properties of cells can help in the design of personalized vaccines. This review focuses on recent research on TDMV technology and its application in personalized immunotherapy. We elucidate the strengths and challenges of TDMVs to promote their application from theory to clinical practice.

The Significance of MicroRNAs in the Molecular Pathology of Brain Metastases

Brain metastases are the most frequent intracranial tumors in adults and the cause of death in almost one-fourth of cases. The incidence of brain metastases is steadily increasing. The main reason for this increase could be the introduction of new and more efficient therapeutic strategies that lead to longer survival but, at the same time, cause a higher risk of brain parenchyma infiltration. In addition, the advances in imaging methodology, which provide earlier identification of brain metastases, may also be a reason for the higher recorded number of patients with these tumors. Metastasis is a complex biological process that is still largely unexplored, influenced by many factors and involving many molecules. A deeper understanding of the process will allow the discovery of more effective diagnostic and therapeutic approaches that could improve the quality and length of patient survival. Recent studies have shown that microRNAs (miRNAs) are essential molecules that are involved in specific steps of the metastatic cascade. MiRNAs are endogenously expressed small non-coding RNAs that act as post-transcriptional regulators of gene expression and thus regulate most cellular processes. The dysregulation of these molecules has been implicated in many cancers, including brain metastases. Therefore, miRNAs represent promising diagnostic molecules and therapeutic targets in brain metastases. This review summarizes the current knowledge on the importance of miRNAs in brain metastasis, focusing on their involvement in the metastatic cascade and their potential clinical implications.

Exosomal MicroRNAs Signature Acts as Efficient Biomarker for Non-Invasive Diagnosis of Gallbladder Carcinoma

Through a three-step study that relies on biomarker discovery, training, and validation, we identified a set of five exosomal microRNAs (miRNAs) that can be used to evaluate the risk of gallbladder carcinoma (GBC), including miR-552-3p, miR-581, miR-4433a-3p, miR-496, and miR-203b-3p. When validated in 102 GBC patients and 112 chronic cholecystitis patients from multiple medical centers, the AUC of this combinatorial biomarker was 0.905, with a sensitivity of 81.37% and a specificity of 86.61%. The performance of this biomarker is superior to that of the standard biomarkers CA199 and CEA and is suited for GBC early diagnosis. The multi-clinicopathological features and prognosis of GBC patients were significantly associated with this biomarker. After building a miRNA-target gene regulation network, cell functions and signaling pathways regulated by these five miRNAs were examined. This biomarker signature can be used in the development of a noninvasive tool for GBC diagnosis, screening and prognosis prediction.

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A five exosomal miRNAs-set is identified to diagnose GBC through a three-step study

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The efficacy of this noninvasive biomarker is superior to that of conventional ones

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This biomarker is correlated with multiple GBC clinical features and the prognosis

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The functions and signal pathways that this biomarker may affect were estimated

Macrophage-Derived Small Extracellular Vesicles in Multiple Diseases: Biogenesis, Function, and Therapeutic Applications

Macrophages (Mφs), as immune cells, play a pivotal role against pathogens and many diseases, such as cancer, inflammation, cardiovascular diseases, orthopedic diseases, and metabolic disorders. In recent years, an increasing number of studies have shown that small extracellular vesicles (sEVs) derived from Mφs (M-sEVs) play important roles in these diseases, suggesting that Mφs carry out their physiological functions through sEVs. This paper reviews the mechanisms underlying M-sEVs production via different forms of polarization and their biological functions in multiple diseases. In addition, the prospects of M-sEVs in disease diagnosis and treatment are described.

An Eleven-microRNA Signature Related to Tumor-Associated Macrophages Predicts Prognosis of Breast Cancer

The dysregulation of microRNAs (miRNAs) has been known to play important roles in tumor development and progression. However, the understanding of the involvement of miRNAs in regulating tumor-associated macrophages (TAMs) and how these TAM-related miRNAs (TRMs) modulate cancer progression is still in its infancy. This study aims to explore the prognostic value of TRMs in breast cancer via the construction of a novel TRM signature. Potential TRMs were identified from the literature, and their prognostic value was evaluated using 1063 cases in The Cancer Genome Atlas Breast Cancer database. The TRM signature was further validated in the external Gene Expression Omnibus GSE22220 dataset. Gene sets enrichment analyses were performed to gain insight into the biological functions of this TRM signature. An eleven-TRM signature consisting of mir-21, mir-24-2, mir-125a, mir-221, mir-22, mir-501, mir-365b, mir-660, mir-146a, let-7b and mir-31 was constructed. This signature significantly differentiated the high-risk group from the low-risk in terms of overall survival (OS)/ distant-relapse free survival (DRFS) (p value < 0.001). The prognostic value of the signature was further enhanced by incorporating other independent prognostic factors in a nomogram-based prediction model, yielding the highest AUC of 0.79 (95% CI: 0.72−0.86) at 5-year OS. Enrichment analyses confirmed that the differentially expressed genes were mainly involved in immune-related pathways such as adaptive immune response, humoral immune response and Th1 and Th2 cell differentiation. This eleven-TRM signature has great potential as a prognostic factor for breast cancer patients besides unravelling the dysregulated immune pathways in high-risk breast cancer.

Extracellular Vesicles and Cancer Therapy: Insights into the Role of Oxidative Stress

Oxidative stress plays a significant role in cancer development and cancer therapy, and is a major contributor to normal tissue injury. The unique characteristics of extracellular vesicles (EVs) have made them potentially useful as a diagnostic tool in that their molecular content indicates their cell of origin and their lipid membrane protects the content from enzymatic degradation. In addition to their possible use as a diagnostic tool, their role in how normal and diseased cells communicate is of high research interest. The most exciting area is the association of EVs, oxidative stress, and pathogenesis of numerous diseases. However, the relationship between oxidative stress and oxidative modifications of EVs is still unclear, which limits full understanding of the clinical potential of EVs. Here, we discuss how EVs, oxidative stress, and cancer therapy relate to one another; how oxidative stress can contribute to the generation of EVs; and how EVs’ contents reveal the presence of oxidative stress. We also point out the potential promise and limitations of using oxidatively modified EVs as biomarkers of cancer and tissue injury with a focus on pediatric oncology patients.

Insights Into Platelet-Derived MicroRNAs in Cardiovascular and Oncologic Diseases: Potential Predictor and Therapeutic Target

Non-communicable diseases (NCDs), represented by cardiovascular diseases and cancer, have been the leading cause of death globally. Improvements in mortality from cardiovascular (CV) diseases (decrease of 14%/100,000, United States) or cancers (increase 7.5%/100,000, United States) seem unsatisfactory during the past two decades, and so the search for innovative and accurate biomarkers of early diagnosis and prevention, and novel treatment strategies is a valuable clinical and economic endeavor. Both tumors and cardiovascular system are rich in angiological systems that maintain material exchange, signal transduction and distant regulation. This pattern determines that they are strongly influenced by circulating substances, such as glycolipid metabolism, inflammatory homeostasis and cyclic non-coding RNA and so forth. Platelets, a group of small anucleated cells, inherit many mature proteins, mRNAs, and non-coding RNAs from their parent megakaryocytes during gradual formation and manifest important roles in inflammation, angiogenesis, atherosclerosis, stroke, myocardial infarction, diabetes, cancer, and many other diseases apart from its classical function in hemostasis. MicroRNAs (miRNAs) are a class of non-coding RNAs containing ∼22 nucleotides that participate in many key cellular processes by pairing with mRNAs at partially complementary binding sites for post-transcriptional regulation of gene expression. Platelets contain fully functional miRNA processors in their microvesicles and are able to transport their miRNAs to neighboring cells and regulate their gene expression. Therefore, the importance of platelet-derived miRNAs for the human health is of increasing interest. Here, we will elaborate systematically the roles of platelet-derived miRNAs in cardiovascular disease and cancer in the hope of providing clinicians with new ideas for early diagnosis and therapeutic strategies.

Harnessing anti-tumor and tumor-tropism functions of macrophages via nanotechnology for tumor immunotherapy

Reprogramming the immunosuppressive tumor microenvironment by modulating macrophages holds great promise in tumor immunotherapy. As a class of professional phagocytes and antigen-presenting cells in the innate immune system, macrophages can not only directly engulf and clear tumor cells, but also play roles in presenting tumor-specific antigen to initiate adaptive immunity. However, the tumor-associated macrophages (TAMs) usually display tumor-supportive M2 phenotype rather than anti-tumor M1 phenotype. They can support tumor cells to escape immunological surveillance, aggravate tumor progression, and impede tumor-specific T cell immunity. Although many TAMs-modulating agents have shown great success in therapy of multiple tumors, they face enormous challenges including poor tumor accumulation and off-target side effects. An alternative solution is the use of advanced nanostructures, which not only can deliver TAMs-modulating agents to augment therapeutic efficacy, but also can directly serve as modulators of TAMs. Another important strategy is the exploitation of macrophages and macrophage-derived components as tumor-targeting delivery vehicles. Herein, we summarize the recent advances in targeting and engineering macrophages for tumor immunotherapy, including (1) direct and indirect effects of macrophages on the augmentation of immunotherapy and (2) strategies for engineering macrophage-based drug carriers. The existing perspectives and challenges of macrophage-based tumor immunotherapies are also highlighted.

Role of Biological Mediators of Tumor-Associated Macrophages in Breast Cancer Progression

BACKGROUND

Breast cancer (BRCA) has become the most common cancer worldwide. The tumor microenvironment (TME) in the breast exerts a crucial role in promoting BRCA initiation, progression, and metastasis. Tumor-associated macrophages (TAMs) are the primary component of tumor-infiltrating immune cells through biological mediators which convert TME into malignant tumors. Combinations of these biological mediators can promote tumor growth, metastasis, angiogenesis, immune suppression, and limit the anti-tumor activity of conventional chemotherapy and radiotherapy.

OBJECTIVES

The present study aimed to highlight the functions of several biological mediators in the breast which generate TME into malignant tumors. Furthermore, this review offers a rationale for TAM-targeted therapy as a novel treatment strategy for BRCA Results: this review emphasizes TAM-associated biological mediators of TME viz., cancer-associated fibroblasts, endothelial cells, adipocytes, tumor-derived exosomes, extracellular matrix, and other immune cells, which facilitates TME into malignant tumors. Evidence suggests that the increased infiltration of TAMs and elevated expression of TAM-related genes are associated with a poor prognosis of BRCA. Based on these findings, TAM-targeted therapeutic strategies, including inhibitors of CSF-1/CSF-1R, CCL2/CCR2, CCL5-CCR5, bisphosphonate, nanoparticle, and exosomal-targeted delivery have been developed, and are currently being employed in intervention trials.

CONCLUSION

This review concludes the roles of biological mediators of TME interact with TAMs in BRCA that provide a rationale for TAM-targeted therapy as a novel treatment approach for BRCA.

Exosomal microRNAs shuttling between tumor cells and macrophages: cellular interactions and novel therapeutic strategies

Extracellular vesicles secreted by tumor microenvironment (TME) cells are vital players in tumor progression through transferring nucleic acids and proteins. Macrophages are the main immune cells in TME and tumor associated macrophages (TAM) express M2 phenotype, which induce tumor proliferation, angiogenesis, invasion, metastasis and immune elimination, resulting in the subsequent evolution of malignancies. There are a high number of studies confirmed that tumor cells and TAM interact with each other through extracellular vesicles in various cancers, like pancreatic ductal adenocarcinoma, gastric cancer, breast cancer, ovarian cancer, colon cancer, glioblastoma, hepatocellular cancer, and lung cancer. Herein, this review summarizes the current knowledge on mechanisms of communications between tumor cells and TAM via extracellular vesicles, mainly about microRNAs, and targeting these events might represent a novel approach in the clinical implications of this knowledge into successful anti-cancer strategies.

Immune cells-derived exosomes function as a double-edged sword: role in disease progression and their therapeutic applications

Exosomes, ranging in size from 30 to 150 nm as identified initially via electron microscopy in 1946, are one of the extracellular vesicles (EVs) produced by many cells and have been the subject of many studies; initially, they were considered as cell wastes with the belief that cells produced exosomes to maintain homeostasis. Nowadays, it has been found that EVs secreted by different cells play a vital role in cellular communication and are usually secreted in both physiological and pathological conditions. Due to the presence of different markers and ligands on the surface of exosomes, they have paracrine, endocrine and autocrine effects in some cases. Immune cells, like other cells, can secrete exosomes that interact with surrounding cells via these vesicles. Immune system cells-derived exosomes (IEXs) induce different responses, such as increasing and decreasing the transcription of various genes and regulating cytokine production. This review deliberate the function of innate and acquired immune cells derived exosomes, their role in the pathogenesis of immune diseases, and their therapeutic appliances.

Exosomal and Non-Exosomal MicroRNAs: New Kids on the Block for Cancer Therapy

MicroRNAs have been projected as promising tools for diagnostic and prognostic purposes in cancer. More recently, they have been highlighted as RNA therapeutic targets for cancer therapy. Though miRs perform a generic function of post-transcriptional gene regulation, their utility in RNA therapeutics mostly relies on their biochemical nature and their assembly with other macromolecules. Release of extracellular miRs is broadly categorized into two different compositions, namely exosomal (extracellular vesicles) and non-exosomal. This nature of miRs not only affects the uptake into target cells but also poses a challenge and opportunity for RNA therapeutics in cancer. By virtue of their ability to act as mediators of intercellular communication in the tumor microenvironment, extracellular miRs perform both, depending upon the target cell and target landscape, pro- and anti-tumor functions. Tumor-derived miRs mostly perform pro-tumor functions, whereas host cell- or stroma-derived miRs are involved in anti-tumor activities. This review deals with the recent understanding of exosomal and non-exosomal miRs in the tumor microenvironment, as a tool for pro- and anti-tumor activity and prospective exploit options for cancer therapy.

Tumor-promoting mechanisms of macrophage-derived extracellular vesicles-enclosed microRNA-660 in breast cancer progression

INTRODUCTION

Breast cancer metastasis is the main cause of cancer-related death in women worldwide. Current therapies have remarkably improved the prognosis of breast cancer patients but still fail to manage metastatic breast cancer. Here, the present study was set to explore the role of microRNA (miR)-660 from tumor-associated macrophages (TAMs) in breast cancer, particularly in metastasis.

MATERIALS AND METHODS

We collected breast cancer tissues and isolated their polarized macrophages as well as extracellular vesicles (EVs), in which we measured the expression of miR-660, Kelch-like Protein 21 (KLHL21), and nuclear factor-κB (NF-κB) p65. Breast cancer cells were transfected with miR-660 mimic, miR-660 inhibitor, and sh-KLHL21 and then the cells were co-cultured with EVs or TAMs followed by detection of invasion and migration. Finally, mouse model of breast cancer was established to detect the effect of miR-660 or KLHL21 on metastasis by measuring the lymph node metastasis (LNM) foci in femur and lung.

RESULTS

KLHL21 was poorly expressed, whereas miR-660 was highly expressed in breast cancer tissues and cells. Of note, low KLHL21 expression or high miR-660 expression was related to poor overall survival. EVs-contained miR-660 was identified to bind to KLHL21, reducing the binding between KLHL21 and inhibitor kappa B kinase β (IKKβ) to activate the NF-κB p65 signaling pathway. Interestingly, EV-loaded miR-660 from TAMs could be internalized by breast cancer cells. Moreover, silencing of KLHL21 increased the number of lung LNM foci in vivo, while EVs-contained miR-660 promoted cancerous cell invasion and migration.

DISCUSSION

Taken altogether, our work shows that TAMs-EVs-shuttled miR-660 promotes breast cancer progression through KLHL21-mediated IKKβ/NF-κB p65 axis.

Oxidative Stress and Inflammation in Cardiovascular Diseases and Cancer: Role of Non-coding RNAs

High oxidative stress, Th1/Th17 immune response, M1 macrophage inflammation, and cell death are associated with cardiovascular diseases. Controlled oxidative stress, Th2/Treg anti-tumor immune response, M2 macrophage inflammation, and survival are associated with cancer. MiR-21 protects against cardiovascular diseases but may induce tumor growth by retaining the anti-inflammatory M2 macrophage and Treg phenotypes and inhibiting apoptosis. Down-regulation of let-7, miR-1, miR-9, miR-16, miR-20a, miR-22a, miR-23a, miR-24a, miR-26a, miR-29, miR-30a, miR-34a, miR-124, miR-128, miR-130a, miR-133, miR-140, miR-143-145, miR-150, miR-153, miR-181a, miR-378, and miR-383 may aid cancer cells to escape from stresses. Upregulation of miR-146 and miR-223 may reduce anti-tumor immune response together with miR-21 that also protects against apoptosis. MiR-155 and silencing of let-7e, miR-125, and miR-126 increase anti-tumor immune response. MiR expression depends on oxidative stress, cytokines, MYC, and TGF-β, and expression of silencing lncRNAs and circ-RNAs. However, one lncRNA or circ-RNA may have opposite effects by targeting several miRs. For example, PVT1 induces apoptosis by targeting miR-16a and miR-30a but inhibits apoptosis by silencing miR-17. In addition, levels of a non-coding RNA in a cell type depend not only on expression in that cell type but also on an exchange of microvesicles between cell types and tumors. Although we got more insight into the function of a growing number of individual non-coding RNAs, overall, we do not know enough how several of them interact in functional networks and how their expression changes at different stages of disease progression.

Exosome-derived noncoding RNAs: Function, mechanism, and application in tumor angiogenesis

Exosomes are extracellular vesicles released by various cell types that perform various biological functions, mainly mediating communication between different cells, especially those active in cancer. Noncoding RNAs (ncRNAs), of which there are many types, were recently identified as enriched and stable in the exocrine region and play various roles in the occurrence and progression of cancer. Abnormal angiogenesis has been confirmed to be related to human cancer. An increasing number of studies have shown that exosome-derived ncRNAs play an important role in tumor angiogenesis. In this review, we briefly outline the characteristics of exosomes, ncRNAs, and tumor angiogenesis. Then, the mechanism of the impact of exosome-derived ncRNAs on tumor angiogenesis is analyzed from various angles. In addition, we focus on the regulatory role of exosome-derived ncRNAs in angiogenesis in different types of cancer. Furthermore, we emphasize the potential role of exosome-derived ncRNAs as biomarkers in cancer diagnosis and prognosis and therapeutic targets in the treatment of tumors.

Exosomal non-coding RNAs: Emerging roles in bilateral communication between cancer cells and macrophages

The tumor microenvironment (TME) is a dynamic network of cellular organization that comprises diverse cell types and significantly contributes to cancer development. As pivotal immune stromal cells in the TME, macrophages are extensively heterogeneous and exert both antitumor and protumor functions. Exosomes are nanosized extracellular membranous vesicles with diameters between 30 and 150 nm. By transferring multiple bioactive substances such as proteins, lipids, and nucleic acids, exosomes play an important role in the communication between cells. Recently, growing evidence has demonstrated that non-coding RNAs (ncRNAs) are enriched in exosomes and that exosomal ncRNAs are involved in the crosstalk between cancer cells and macrophages. Furthermore, circulating exosomal ncRNAs can be detected in biofluids, serving as promising noninvasive biomarkers for the early diagnosis and prognostic prediction of cancer. Exosome-based therapies are emerging as potent strategies that can be utilized to alleviate tumor progression. Herein, the present knowledge of exosomal ncRNAs and their vital roles in regulating the interplay between cancer cells and macrophages, as well as their clinical applications are summarized.

Circulating microRNA biomarkers in melanoma and non-melanoma skin cancer

INTRODUCTION

Skin cancer is the most common type of cancer and is classified in melanoma and non-melanoma cancers, which include basal cell, squamous cell and Merkel cell carcinoma. Specific microRNAs are dysregulated in each skin cancer type. MicroRNAs act as oncogene or tumor suppressor gene regulators and are actively released from tumor cells in the circulation. Cell-free microRNAs serve many, and possibly yet unexplored, functional roles, but their presence and abundance in the blood has been investigated as disease biomarker. Indeed, specific microRNAs can be isolated and quantified in the blood, usually in serum or plasma fractions, where they are uncommonly stable. MicroRNA levels reflect underlying conditions and have been associated with skin cancer presence, stage, evolution, or therapy efficacy.

AREAS COVERED

In this review, we summarize the state of the art on circulating microRNAs detectable in skin cancer patients including all the studies that performed microRNA identification and quantification in the circulation using appropriate sample size and statistics and providing detailed methodology, with a specific focus on diagnostic and prognostic biomarkers.

EXPERT OPINION

Circulating microRNAs display a relevant biomarker potential. We expect the development of methodological guidelines and standardized protocols for circulating miRNA quantification in clinical settings.

The Immuno-Modulation Effect of Macrophage-Derived Extracellular Vesicles in Chronic Inflammatory Diseases

As natural nanocarriers and intercellular messengers, extracellular vesicles (EVs) control communication among cells. Under physiological and pathological conditions, EVs deliver generic information including proteins and nucleic acids to recipient cells and exert regulatory effects. Macrophages help mediate immune responses, and macrophage-derived EVs may play immunomodulatory roles in the progression of chronic inflammatory diseases. Furthermore, EVs derived from various macrophage phenotypes have different biological functions. In this review, we describe the pathophysiological significance of macrophage-derived extracellular vesicles in the development of chronic inflammatory diseases, including diabetes, cancer, cardiovascular disease, pulmonary disease, and gastrointestinal disease, and the potential applications of these EVs.

Exosome-derived miR-200a promotes esophageal cancer cell proliferation and migration via the mediating Keap1 expression

Previous studies have reported that exosomes bearing certain microRNAs (miRNAs) are related to the physiological functions of different types of cancer cells. Our study aimed to elucidate the role of miR-200a in esophageal squamous cell carcinoma (ESCC). We observed that miR-200a expression is higher in esophageal carcinoma cells, tissues, and exosomes than in normal cells and healthy tissues. We showed that exosome-shuttled miR-200a promotes the proliferation, migration, and invasion of esophageal cells and inhibits apoptosis, thereby leading to the progression of ESCC. We showed that miR-200a exerts its effects through its interaction with Keap1, thus altering the Keap1/Nrf2 signaling pathway. Our results suggest that exosome-shuttled miR-200a might be useful as a biomarker for prognosis in patients with ESCC.

Tumor hijacks macrophages and microbiota through extracellular vesicles

The tumor microenvironment (TME) is a biological system with sophisticated constituents. In addition to tumor cells, tumor-associated macrophages (TAMs) and microbiota are also dominant components. The phenotypic and functional changes of TAMs are widely considered to be related to most tumor progressions. The chronic colonization of pathogenic microbes and opportunistic pathogens accounts for the generation and development of tumors. As messengers of cell-to-cell communication, tumor-derived extracellular vesicles (TDEVs) can transfer various malignant factors, regulating physiological and pathological changes in the recipients and affecting TAMs and microbes in the TME. Despite the new insights into tumorigenesis and progress brought by the above factors, the crosstalk among tumor cells, macrophages, and microbiota remain elusive, and few studies have focused on how TDEVs act as an intermediary. We reviewed how tumor cells recruit and domesticate macrophages and microbes through extracellular vehicles and how hijacked macrophages and microbiota interact with tumor-promoting feedback, achieving a reciprocal coexistence under the TME and working together to facilitate tumor progression. It is significant to seek evidence to clarify those specific interactions and reveal therapeutic targets to curb tumor progression and improve prognosis.

Tumor-associated macrophages promote cholangiocarcinoma progression via exosomal Circ_0020256

This study investigated the exosomal circular RNAs (CircRNAs) produced by tumor-associated macrophages and delivered into the microenvironment of cholangiocarcinoma cells in order to use them as molecular targets for clinical therapy. Tumor-associated M2 macrophages (TAMs) were induced from THP-1 cells and identified by flow cytometry. The TAM-secreted exosomes were isolated from conditioned medium and a CircRNA microarray assay was performed to identify CircRNAs that were uniquely expressed in the isolated exosomes. Circ_0020256 was especially identified based on having the highest differential expression level among all of the CircRNA candidates. In vitro and in vivo experiments were performed to assess the effects of TAMs, exosomes, and Circ_0020256 on the growth and migration of cholangiocarcinoma (CCA) cells. The induced TAMs promoted the proliferation, migration, and invasion of CCA cells and those effects were mediated by exosomes secreted by the TAMs. In CCA cells (RBE and HCCC-9810), Circ_0020256 significantly promoted cellular activity by interacting with its intra-cellular microRNA target, miR-432-5p. In contrast, overexpression of transcription factor E2F3 in CCA cells restored the CCA cellular activities that were inhibited by miR-432-5p. On the other hand, treatment with small interference RNA (siRNA) for Circ_0020256 inhibited CCA cell proliferation, migration, and invasion both in vitro and in vivo. In conclusion, Circ_0020256 in TAM-secreted exosomes promoted the proliferation, migration, and invasion of CCA cells, and that promotional activity was regulated via a Circ_0020256/miR-432-5p/E2F3 axis.

Exosomes in breast cancer management. Where do we stand? A literature review

BACKGROUND

Exosomes constitute cellular molecular fingertips that participate in intercellular communication both in health and disease states. Hence, exosomes emerge as critical mediators of cancer development and progression, as well as potential biomarkers and novel therapeutic targets.

OBJECTIVE

To review literature data regarding applications of circulating exosomes in breast cancer management.

METHODS

This is a literature review of relevant published studies until April 2020 in PubMed and Google Scholar databases. Original papers in the English language concerning exosome related studies were included.

RESULTS

Exosomes represent molecular miniatures of their parent cells. Several homeostatic mechanisms control exosomal secretion and synthesis. Exosomal exchange among cells creates an intricate intercellular crosstalk orchestrating almost every tissue process, as well as carcinogenesis. Available data highlight exosomes as major mediators of cancer development and progression. The secretion of specific exosomal molecules, particularly miRNAs, correlates with the underlying processes and can be used as a means of tumor detection and prognostic assessment.

CONCLUSIONS

Exosomal miRNAs expression profiles and levels closely relate to cancer extent, type and prognosis. Deep comprehension of such correlations and systematization of experimental outcomes will offer a novel approach in cancer detection and management. This article is protected by copyright. All rights reserved.

Applications of Extracellular Vesicles in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive and refractory subtype of breast cancer, often occurring in younger patients with poor clinical prognosis. Given the current lack of specific targets for effective intervention, the development of better treatment strategies remains an unmet medical need. Over the last decade, the field of extracellular vesicles (EVs) has grown tremendously, offering immense potential for clinical diagnosis/prognosis and therapeutic applications. While TNBC-EVs have been shown to play an important role in tumorigenesis, chemoresistance and metastasis, they could be repurposed as potential biomarkers for TNBC diagnosis and prognosis. Furthermore, EVs from various cell types can be utilized as nanoscale drug delivery systems (NDDS) for TNBC treatment. Remarkably, EVs generated from specific immune cell subsets have been shown to delay solid tumour growth and reduce tumour burden, suggesting a new immunotherapy approach for TNBC. Intrinsically, EVs can cross the blood-brain barrier (BBB), which holds great potential to treat the brain metastases diagnosed in one third of TNBC patients that remains a substantial clinical challenge. In this review, we present the most recent applications of EVs in TNBC as diagnostic/prognostic biomarkers, nanoscale drug delivery systems and immunotherapeutic agents, as well as discuss the associated challenges and future directions of EVs in cancer immunotherapy.

Tumor associated macrophage and microbe: The potential targets of tumor vaccine delivery

The occurrence and development of tumors depend on the tumor microenvironment (TME), which is made of various immune cells, activated fibroblasts, basement membrane, capillaries, and extracellular matrix. Tumor associated macrophages (TAMs) and microbes are important components in TME. Tumor cells can recruit and educate TAMs and microbes, and the hijacked TAMs and microbes can promote the progression of tumor reciprocally. Tumor vaccine delivery remodeling TME by targeting TAM and microbes can not only enhance the specificity and immunogenicity of antigens, but also contribute to the regulation of TME. Tumor vaccine design benefits from nanotechnology which is a suitable platform for antigen and adjuvant delivery to catalyze new candidate vaccines applying to clinical therapy at unparalleled speed. In view of the characteristics and mechanisms of TME development, vaccine delivery targeting and breaking the malignant interactions among tumor cells, TAMs, and microbes may serve as a novel strategy for tumor therapy.

Exosome-based delivery nanoplatforms: Next-generation theranostic platforms for breast cancer

Breast cancer is the most frequent type of malignancy, and the leading cause of cancer-related death in women across the globe. Exosomes are naturally derived 50-150 nm nanovesicles with a...

Role of Exosomal MicroRNAs in Cell-to-Cell Communication

Exosomes, a type of extracellular vesicle, are small vesicles (30-100 nm) secreted into extracellular space from almost all types of cells. Exosomes mediate cell-to-cell communication carrying various biologically active molecules including microRNAs. Studies have shown that exosomal microRNAs play fundamental roles in healthy and pathological conditions such as immunity, cancer, and inflammation. In this chapter, we introduce the current knowledge on exosome biogenesis, techniques used in exosome research, and exosomal miRNA and their functions in biological and pathological processes.

The role of RNA processing and regulation in metastatic dormancy

Tumor dormancy is a major contributor to the lethality of metastatic disease, especially for cancer patients who develop metastases years-to-decades after initial diagnosis. Indeed, tumor cells can disseminate during early disease stages and persist in new microenvironments at distal sites for months, years, or even decades before initiating metastatic outgrowth. This delay between primary tumor remission and metastatic relapse is known as "dormancy," during which disseminated tumor cells (DTCs) acquire quiescent states in response to intrinsic (i.e., cellular) and extrinsic (i.e., microenvironmental) signals. Maintaining dormancy-associated phenotypes requires DTCs to activate transcriptional, translational, and post-translational mechanisms that engender cellular plasticity. RNA processing is emerging as an essential facet of cellular plasticity, particularly with respect to the initiation, maintenance, and reversal of dormancy-associated phenotypes. Moreover, dysregulated RNA processing, particularly that associated with alternative RNA splicing and expression of noncoding RNAs (ncRNAs), can occur in DTCs to mediate intrinsic and extrinsic metastatic dormancy. Here we review the pathophysiological impact of alternative RNA splicing and ncRNAs in promoting metastatic dormancy and disease recurrence in human cancers.

Exosomes in triple negative breast cancer: From bench to bedside

Exosomes are lipid bilayer extracellular vesicles with a size of 30-150 nm, which can be released by various types of cells including breast cancer cells. Exosomes are enriched with multiple nucleic acids, lipids, proteins and play critical biological roles by binding to recipient cells and transmitting various biological cargos. Studies have reported that tumor-derived exosomes are involved in cancer initiation and progression, such as promoting cancer invasion and metastasis, accelerating angiogenesis, contributing to epithelial-mesenchymal transition, and enhancing drug resistance in tumors. Recently the dysregulating of exosomes has been found in triple-negative breast cancer (TNBC), relating to the clinicopathological characteristics and prognosis of TNBC patients. Considering the poor prognosis and lack of adequate response to conventional therapy of TNBC, the discovery of certain exosomes as a new target for diagnosis and treatment of TNBC may be a good choice that provides new opportunities for the early diagnosis, clinical treatment of TNBC. Here, we first discuss the innovative prognostic and predictive effects of exosomes on TNBC, as well as the practical clinical problems. Secondly, we focus on the new therapeutic areas represented by exosomes, especially the impact of introducing exosomes in TNBC treatment in the future.

miRNAs in the Regulation of Cancer Immune Response: Effect of miRNAs on Cancer Immunotherapy

In the last few decades, carcinogenesis has been extensively explored and substantial research has identified immunogenic involvement in various types of cancers. As a result, immune checkpoint blockers and other immune-based therapies were developed as novel immunotherapeutic strategies. However, despite being a promising therapeutic option, immunotherapy has significant constraints such as a high cost of treatment, unpredictable toxicity, and clinical outcomes. miRNAs are non-coding, small RNAs actively involved in modulating the immune system's multiple signalling pathways by binding to the 3'-UTR of target genes. miRNAs possess a unique advantage in modulating multiple targets of either the same or different signalling pathways. Therefore, miRNA follows a 'one drug multiple target' hypothesis. Attempts are made to explore the therapeutic promise of miRNAs in cancer so that it can be transported from bench to bedside for successful immunotherapeutic results. Therefore, in the current manuscript, we discussed, in detail, the mechanism and role of miRNAs in different types of cancers relating to the immune system, its diagnostic and therapeutic aspect, the effect on immune escape, immune-checkpoint molecules, and the tumour microenvironment. We have also discussed the existing limitations, clinical success and the prospective use of miRNAs in cancer.

Advances of Exosomal miRNAs in Breast Cancer Progression and Diagnosis

Breast cancer is one of the most commonly diagnosed malignancies and the leading cause of cancer death in women worldwide. Although many factors associated with breast cancer have been identified, the definite etiology of breast cancer is still unclear. In addition, early diagnosis of breast cancer remains challenging. Exosomes are membrane-bound nanovesicles secreted by most types of cells and contain a series of biologically important molecules, such as lipids, proteins, and miRNAs, etc. Emerging evidence shows that exosomes can affect the status of cells by transmitting substances and messages among cells and are involved in various physiological and pathological processes. In breast cancer, exosomes play a significant role in breast tumorigenesis and progression through transfer miRNAs which can be potential biomarkers for early diagnosis of breast cancer. This review discusses the potential utility of exosomal miRNAs in breast cancer progression such as tumorigenesis, metastasis, immune regulation and drug resistance, and further in breast cancer diagnosis.

The Advancing Roles of Exosomes in Breast Cancer

Breast cancer (BC) develops from breast tissue and is the most common aggressive malignant tumor in women worldwide. Although advanced treatment strategies have been applied and reduced current mortality rates, BC control remains unsatisfactory. It is essential to elucidate the underlying molecular mechanisms to assist clinical options. Exosomes are a type of extracellular vesicles and mediate cellular communications by delivering various biomolecules (oncogenes, oncomiRs, proteins, and even pharmacological compounds). These bioactive molecules can be transferred to change the transcriptome of target cells and influence tumor-related signaling pathways. Extensive studies have implicated exosomes in BC biology, including therapeutic resistance and the surrounding microenvironment. This review focuses on discussing the functions of exosomes in tumor treatment resistance, invasion and metastasis of BC. Moreover, we will also summarize multiple interactions between exosomes and the BC tumor microenvironment. Finally, we propose promising clinical applications of exosomes in BC.