Chemokine-containing exosomes are released from heat-stressed tumor cells via lipid raft-dependent pathway and act as efficient tumor vaccine

Exosome-based anticancer vaccines: From Bench to bedside

Exosomes, a subset of extracellular vesicles, are released by all active cells and play a crucial role in intercellular communications. Exosomes could facilitate the transfer of various biologically active molecules, such as DNA, non-coding RNAs, and proteins, from donor to recipient cells, thereby participating in diverse biological and pathological processes. Besides, exosomes possess unique characteristics, including non-toxicity, low-immunogenicity, and stability within biological systems, rendering them highly advantageous for cancer drug development. Meanwhile, accumulating evidence suggests that exosomes originating from tumor cells and immune cells possess distinct composition profiles that play a direct role in anticancer immunotherapy. Of note, exosomes can transport their contents to specific cells, thereby exerting an impact on the phenotype and immune-regulatory functions of targeted cells. Therapeutic cancer vaccines, an emerging therapeutics of immunotherapy, could enhance antitumor immune responses by delivering a large number of tumor antigens, thereby augmenting the immune response against tumor cells. Therefore, the therapeutic rationale of cancer vaccines and exosome-based immunotherapy are almost similar to some extent, but some challenges have hindered their application in the clinical setting. Here, in this review, we first summarized the biogenesis, structure, compositions, and biological functions of exosomes. Then we described the roles of exosomes in cancer biology, particularly in tumor immunity. We also comprehensively reviewed current exosome-based anticancer vaccine development and we divided them into three types. Finally, we give some insights into clinical translation and clinical trial progress of exosome-based anticancer vaccines for future direction.

Exosomes, and the potential for exosome-based interventions against COVID-19

Since late 2019, the world has been devastated by the coronavirus disease 2019 (COVID-19) induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with more than 760 million people affected and ∼seven million deaths reported. Although effective treatments for COVID-19 are currently limited, there has been a strong focus on developing new therapeutic approaches to address the morbidity and mortality linked to this disease. An approach that is currently being investigated is the use of exosome-based therapies. Exosomes are small, extracellular vesicles that play a role in many clinical diseases, including viral infections, infected cells release exosomes that can transmit viral components, such as miRNAs and proteins, and can also include receptors for viruses that facilitate viral entry into recipient cells. SARS-CoV-2 has the ability to impact the formation, secretion, and release of exosomes, thereby potentially facilitating or intensifying the transmission of the virus among cells, tissues and individuals. Therefore, designing synthetic exosomes that carry immunomodulatory cargo and antiviral compounds are proposed to be a promising strategy for the treatment of COVID-19 and other viral diseases. Moreover, exosomes generated from mesenchymal stem cells (MSC) might be employed as cell-free therapeutic agents, as MSC-derived exosomes can diminish the cytokine storm and reverse the suppression of host anti-viral defences associated with COVID-19, and boost the repair of lung damage linked to mitochondrial activity. The present article discusses the significance and roles of exosomes in COVID-19, and explores potential future applications of exosomes in combating this disease. Despite the challenges posed by COVID-19, exosome-based therapies could represent a promising avenue for improving patient outcomes and reducing the impact of this disease.

Extracellular Vesicles in Lung Cancer: Implementation in Diagnosis and Therapeutic Perspectives

Lung cancer represents the leading cause of cancer-related mortality worldwide, with around 1.8 million deaths in 2020. For this reason, there is an enormous interest in finding early diagnostic tools and novel therapeutic approaches, one of which is extracellular vesicles (EVs). EVs are nanoscale membranous particles that can carry proteins, lipids, and nucleic acids (DNA and RNA), mediating various biological processes, especially in cell-cell communication. As such, they represent an interesting biomarker for diagnostic analysis that can be performed easily by liquid biopsy. Moreover, their growing dataset shows promising results as drug delivery cargo. The aim of our work is to summarize the recent advances in and possible implications of EVs for early diagnosis and innovative therapies for lung cancer.

Anticancer Therapy Targeting Cancer-Derived Extracellular Vesicles

Extracellular vesicles (EVs) are natural lipid nanoparticles secreted by most types of cells. In malignant cancer, EVs derived from cancer cells contribute to its progression and metastasis by facilitating tumor growth and invasion, interfering with anticancer immunity, and establishing premetastasis niches in distant organs. In recent years, multiple strategies targeting cancer-derived EVs have been proposed to improve cancer patient outcomes, including inhibiting EV generation, disrupting EVs during trafficking, and blocking EV uptake by recipient cells. Developments in EV engineering also show promising results in harnessing cancer-derived EVs as anticancer agents. Here, we summarize the current understanding of the origin and functions of cancer-derived EVs and review the recent progress in anticancer therapy targeting these EVs.

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Exosome-mediated tumor metastasis: Biology, molecular targets and immuno-therapeutic options

Small extracellular vesicles called exosomes play a crucial part in promoting intercellular communication. They act as intermediaries for the exchange of bioactive chemicals between cells, released into the extracellular milieu by a variety of cell types. Within the context of cancer progression, metastasis is a complex process that plays a significant role in the spread of malignant cells from their main site of origin to distant anatomical locations. This complex process plays a key role in the domain of cancer-related deaths. In summary, the trajectory of current research in the field of exosome-mediated metastasis is characterized by its unrelenting quest for more profound understanding of the molecular nuances, the development of innovative diagnostic tools and therapeutic approaches, and the unwavering dedication to transforming these discoveries into revolutionary clinical applications. This unrelenting pursuit represents a shared desire to improve the prognosis for individuals suffering from metastatic cancer and to nudge the treatment paradigm in the direction of more effective and customized interventions.

The role of extracellular vesicles in cholangiocarcinoma tumor microenvironment

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor that originates from the biliary system. With restricted treatment options at hand, the challenging aspect of early CCA diagnosis leads to a bleak prognosis. Besides the intrinsic characteristics of tumor cells, the generation and progression of CCA are profoundly influenced by the tumor microenvironment, which engages in intricate interactions with cholangiocarcinoma cells. Of notable significance is the role of extracellular vesicles as key carriers in enabling communication between cancer cells and the tumor microenvironment. This review aims to provide a comprehensive overview of current research examining the interplay between extracellular vesicles and the tumor microenvironment in the context of CCA. Specifically, we will emphasize the significant contributions of extracellular vesicles in molding the CCA microenvironment and explore their potential applications in the diagnosis, prognosis assessment, and therapeutic strategies for this aggressive malignancy.

Exosome Mediated Cell-Cell Crosstalk in Tissue Injury and Repair

The landscape of exosome research has undergone a significant paradigm shift, with a departure from early conceptions of exosomes as vehicles for cellular waste disposal towards their recognition as integral components of cellular communication with therapeutic potential. This chapter presents an exhaustive elucidation of exosome biology, detailing the processes of exosome biogenesis, release, and uptake, and their pivotal roles in signal transduction, tissue repair, regeneration, and intercellular communication. Additionally, the chapter highlights recent innovations and anticipates future directions in exosome research, emphasizing their applicability in clinical settings. Exosomes have the unique ability to navigate through tissue spaces to enter the circulatory system, positioning them as key players in tissue repair. Their contributory role in various processes of tissue repair, although in the nascent stages of investigation, stands out as a promising area of research. These vesicles function as a complex signaling network for intracellular and organ-level communication, critical in both pathological and physiological contexts. The chapter further explores the tissue-specific functionality of exosomes and underscores the advancements in methodologies for their isolation and purification, which have been instrumental in expanding the scope of exosome research. The differential cargo profiles of exosomes, dependent on their cellular origin, position them as prospective diagnostic biomarkers for tissue damage and regenerative processes. Looking ahead, the trajectory of exosome research is anticipated to bring transformative changes to biomedical fields. This includes advancing diagnostic and prognostic techniques that utilize exosomes as non-invasive biomarkers for a plethora of diseases, such as cancer, neurodegenerative, and cardiovascular conditions. Additionally, engineering exosomes through alterations of their native content or surface properties presents a novel frontier, including the synthesis of artificial or hybrid variants with enhanced functional properties. Concurrently, the ethical and regulatory frameworks surrounding exosome research, particularly in clinical translation, will require thorough deliberation. In conclusion, the diverse aspects of exosome research are coalescing to redefine the frontiers of diagnostic and therapeutic methodologies, cementing its importance as a discipline of considerable consequence in the biomedical sciences.

A review on the use of extracellular vesicles for the delivery of drugs and biological therapeutics

INTRODUCTION

Exosomes, a type of extracellular vesicles, are effective tools for delivering small-molecule drugs and biological therapeutics into cells and tissues. Surface modifications with targeting ligands ensure precise delivery to specific cells, minimizing accumulation in healthy organs and reducing the side effects. This is a rapidly growing area in drug delivery research and this review aims to comprehensively discuss the recent advances in the field.

AREA COVERED

Recent studies have presented compelling evidence supporting the application of exosomes as efficient delivery vehicles that escape endosome trapping, achieving effective in vivo delivery in animal models. This review provides a systemic discussion on the exosome-based delivery technology, with topics covering exosome purification, surface modification, and targeted delivery of various cargos ranging from siRNAs, miRNAs, and proteins, to small molecule drugs.

EXPERT OPINION

Exosome-based gene and drug delivery has low toxicity and low immunogenicity. Surface modifications of the exosomes can effectively avoid endosome trapping and increase delivery efficiency. This exciting technology can be applied to improve the treatments for a wide variety of diseases.

Ultrasound-Driven Healing: Unleashing the Potential of Chondrocyte-Derived Extracellular Vesicles for Chondrogenesis in Adipose-Derived Stem Cells

Repairing cartilage defects represents a significant clinical challenge. While adipose-derived stem cell (ADSC)-based strategies hold promise for cartilage regeneration, their inherent chondrogenic potential is limited. Extracellular vesicles (EVs) derived from chondrocytes (CC-EVs) have shown potential in enhancing chondrogenesis, but their role in promoting chondrogenic differentiation of ADSCs remains poorly understood. Moreover, the clinical application of EVs faces limitations due to insufficient quantities for in vivo use, necessitating the development of effective methods for extracting significant amounts of CC-EVs. Our previous study demonstrated that low-intensity ultrasound (LIUS) stimulation enhances EV secretion from mesenchymal stem cells. Here, we identified a specific LIUS parameter for chondrocytes that increased EV secretion by 16-fold. CC-EVs were found to enhance cell activity, proliferation, migration, and 21-day chondrogenic differentiation of ADSCs in vitro, while EVs secreted by chondrocytes following LIUS stimulation (US-CC-EVs) exhibited superior efficacy. miRNA-seq revealed that US-CC-EVs were enriched in cartilage-regeneration-related miRNAs, contributing to chondrogenesis in various biological processes. In conclusion, we found that CC-EVs can enhance the chondrogenesis of ADSCs in vitro. In addition, our study introduces ultrasound-driven healing as an innovative method to enhance the quantity and quality of CC-EVs, meeting clinical demand and addressing the limited chondrogenic potential of ADSCs. The ultrasound-driven healing unleashes the potential of CC-EVs for chondrogenesis possibly through the enrichment of cartilage-regeneration-associated miRNAs in EVs, suggesting their potential role in cartilage reconstruction. These findings hold promise for advancing cartilage regeneration strategies and may pave the way for novel therapeutic interventions in regenerative medicine.

The therapeutic potential of exosomes in lung cancer

BACKGROUND

Lung cancer (LC) is one of the most common malignancies globally. Besides early detection and surgical resection, there is currently no effective curative treatment for metastatic advanced LC. Exosomes are endogenous nano-extracellular vesicles produced by somatic cells that play an important role in the development and maintenance of normal physiology. Exosomes can carry proteins, peptides, lipids, nucleic acids, and various small molecules for intra- and intercellular material transport or signal transduction. LC cells can maintain their survival, proliferation, migration, invasion, and metastasis, by producing or interacting with exosomes. Basic and clinical data also show that exosomes can be used to suppress LC cell proliferation and viability, induce apoptosis, and enhance treatment sensitivity. Due to the high stability and target specificity, good biocompatibility, and low immunogenicity of exosomes, they show promise as vehicles of LC therapy.

CONCLUSION

We have written this comprehensive review to communicate the LC treatment potential of exosomes and their underlying molecular mechanisms. We found that overall, LC cells can exchange substances or crosstalk with themselves or various other cells in the surrounding TME or distant organs through exosomes. Through this, they can modulate their survival, proliferation, stemness, migration, and invasion, EMT, metastasis, and apoptotic resistance.

In Vitro Insights Into the Influence of Marrow Mesodermal/Mesenchymal Progenitor Cells on Acute Myelogenous Leukemia and Myelodysplastic Syndromes

The study of marrow-resident mesodermal progenitors can provide important insight into their role in influencing normal and aberrant hematopoiesis as occurs in acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS). In addition, the chemokine competency of these cells provides links to the inflammatory milieu of the marrow microenvironment with additional implications for normal and malignant hematopoiesis. While in vivo studies have elucidated the structure and function of the marrow niche in murine genetic models, corollary human studies have not been feasible, and thus the use of culture-adapted mesodermal cells has provided insights into the role these rare endogenous niche cells play in physiologic, malignant, and inflammatory states. This review focuses on culture-adapted human mesenchymal stem/stromal cells (MSCs) as they have been utilized in understanding their influence in AML and MDS as well as on their chemokine-mediated responses to myeloid malignancies, injury, and inflammation. Such studies have intrinsic limitations but have provided mechanistic insights and clues regarding novel druggable targets.

Extracellular Vesicle Heterogeneity and Its Impact for Regenerative Medicine Applications

Extracellular vesicles (EVs) are cell-derived membrane-enclosed particles that are involved in physiologic and pathologic processes. EVs are increasingly being studied for therapeutic applications in the field of regenerative medicine. Therapeutic application of stem cell-derived EVs has shown great potential to stimulate tissue repair. However, the exact mechanisms through which they induce this effect have not been fully clarified. This may to a large extent be attributed to a lack of knowledge on EV heterogeneity. Recent studies suggest that EVs represent a heterogeneous population of vesicles with distinct functions. The heterogeneity of EVs can be attributed to differences in their biogenesis, and as such, they can be classified into distinct populations that can then be further subcategorized into various subpopulations. A better understanding of EV heterogeneity is crucial for elucidating their mechanisms of action in tissue regeneration. This review provides an overview of the latest insights on EV heterogeneity related to tissue repair, including the different characteristics that contribute to such heterogeneity and the functional differences among EV subtypes. It also sheds light on the challenges that hinder clinical translation of EVs. Additionally, innovative EV isolation techniques for studying EV heterogeneity are discussed. Improved knowledge of active EV subtypes would promote the development of tailored EV therapies and aid researchers in the translation of EV-based therapeutics to the clinic. SIGNIFICANCE STATEMENT: Within this review we discuss the differences in regenerative properties of extracellular vesicle (EV) subpopulations and implications of EV heterogeneity for development of EV-based therapeutics. We aim to provide new insights into which aspects are leading to heterogeneity in EV preparations and stress the importance of EV heterogeneity studies for clinical applications.

Immunotherapeutic effect of photothermal-mediated exosomes secreted from breast cancer cells

Aim: Exosomal damage-associated molecular patterns can play a key role in immunostimulation and changing the cold tumor microenvironment to hot. Materials & methods: This study examined the immunostimulation effect of photothermal and hyperthermia-treated 4T1 cell-derived exosomes on 4T1 cell-induced breast tumors in BALB/c animal models. Exosomes were characterized for HSP70, HSP90 and HMGB-1 before injection into mice and tumor tissues were analyzed for IL-6, IL-12 and IL-1β, CD4 and CD8 T-cell permeability, and PD-L1 expression. Results: Thermal treatments increased high damage-associated molecular patterns containing exosome secretion and the permeability of T cells to tumors, leading to tumor growth inhibition. Conclusion: Photothermal-derived exosomes showed higher damage-associated molecular patterns than hyperthermia with a higher immunostimulation and inhibiting tumor growth effect.

Manufacture of extracellular vesicles derived from mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) are a promising therapy for various diseases ranging from ischemic stroke to wound healing and cancer. Their therapeutic effects are mainly mediated by secretome-derived paracrine factors, with extracellular vesicles (EVs) proven to play a key role. This has led to promising research on the potential of MSC-EVs as regenerative, off-the-shelf therapeutic agents. However, the translation of MSC-EVs into the clinic is hampered by the poor scalability of their production. Recently, new advanced methods have been developed to upscale MSC cultivation and EV production yields, ranging from new cell culture devices to priming procedures. This review gives an overview of these innovative strategies for manufacturing MSC-EVs.

Combining energy-based focal ablation and immune checkpoint inhibitors: preclinical research and clinical trials

Energy-based focal therapy (FT) uses targeted, minimally invasive procedures to destroy tumors while preserving normal tissue and function. There is strong emerging interest in understanding how systemic immunity against the tumor can occur with cancer immunotherapy, most notably immune checkpoint inhibitors (ICI). The motivation for combining FT and ICI in cancer management relies on the synergy between the two different therapies: FT complements ICI by reducing tumor burden, increasing objective response rate, and reducing side effects of ICI; ICI supplements FT by reducing local recurrence, controlling distal metastases, and providing long-term protection. This combinatorial strategy has shown promising results in preclinical study (since 2004) and the clinical trials (since 2011). Understanding the synergy calls for understanding the physics and biology behind the two different therapies with distinctive mechanisms of action. In this review, we introduce different types of energy-based FT by covering the biophysics of tissue-energy interaction and present the immunomodulatory properties of FT. We discuss the basis of cancer immunotherapy with the emphasis on ICI. We examine the approaches researchers have been using and the results from both preclinical models and clinical trials from our exhaustive literature research. Finally, the challenges of the combinatory strategy and opportunities of future research is discussed extensively.

Tumour-derived extracellular vesicle based vaccines for melanoma treatment

The interest of extracellular vesicles (EVs) in cancer immunotherapy is increasing every day. EVs are lipid bilayer vesicles released by most cells, which contain the molecular signature of their parent cell. Melanoma-derived EVs present antigens specific to this aggressive type of cancer, but they also exert immunomodulatory and pro-metastatic activity. Until now, most reviews focus on the immunoevasive characteristics of tumour-derived EVs, but do not help to overcome the issues related to them. In this review, we describe isolation methods of EVs from melanoma patients and most interesting markers to oversee their effect if they are used as antigen carriers. We also discuss the methods developed so far to overcome the lack of immunogenicity of melanoma-derived EVs, which includes EV modification or adjuvant co-administration. In summary, we conclude that EVs can be an interesting antigen source for immunotherapy development once EV obtaining is optimised and the understanding of the mechanisms behind their multiple effects is further understood.

S100A10 promotes HCC development and progression via transfer in extracellular vesicles and regulating their protein cargos

OBJECTIVE

Growing evidence indicates that tumour cells exhibit characteristics similar to their lineage progenitor cells. We found that S100 calcium binding protein A10 (S100A10) exhibited an expression pattern similar to that of liver progenitor genes. However, the role of S100A10 in hepatocellular carcinoma (HCC) progression is unclear. Furthermore, extracellular vesicles (EVs) are critical mediators of tumourigenesis and metastasis, but the extracellular functions of S100A10, particularly those related to EVs (EV-S100A10), are unknown.

DESIGN

The functions and mechanisms of S100A10 and EV-S100A10 in HCC progression were investigated in vitro and in vivo. Neutralising antibody (NA) to S100A10 was used to evaluate the significance of EV-S100A10.

RESULTS

Functionally, S100A10 promoted HCC initiation, self-renewal, chemoresistance and metastasis in vitro and in vivo. Of significance, we found that S100A10 was secreted by HCC cells into EVs both in vitro and in the plasma of patients with HCC. S100A10-enriched EVs enhanced the stemness and metastatic ability of HCC cells, upregulated epidermal growth factor receptor (EGFR), AKT and ERK signalling, and promoted epithelial-mesenchymal transition. EV-S100A10 also functioned as a chemoattractant in HCC cell motility. Of significance, S100A10 governed the protein cargos in EVs and mediated the binding of MMP2, fibronectin and EGF to EV membranes through physical binding with integrin αⅤ. Importantly, blockage of EV-S100A10 with S100A10-NA significantly abrogated these enhancing effects.

CONCLUSION

Altogether, our results uncovered that S100A10 promotes HCC progression significantly via its transfer in EVs and regulating the protein cargoes of EVs. EV-S100A10 may be a potential therapeutic target and biomarker for HCC progression.

Tumor-Derived Extracellular Vesicles in Cancer Immunoediting and Their Potential as Oncoimmunotherapeutics

The tumor microenvironment (TME) within and around a tumor is a complex interacting mixture of tumor cells with various stromal cells, including endothelial cells, fibroblasts, and immune cells. In the early steps of tumor formation, the local microenvironment tends to oppose carcinogenesis, while with cancer progression, the microenvironment skews into a protumoral TME and the tumor influences stromal cells to provide tumor-supporting functions. The creation and development of cancer are dependent on escape from immune recognition predominantly by influencing stromal cells, particularly immune cells, to suppress antitumor immunity. This overall process is generally called immunoediting and has been categorized into three phases; elimination, equilibrium, and escape. Interaction of tumor cells with stromal cells in the TME is mediated generally by cell-to-cell contact, cytokines, growth factors, and extracellular vesicles (EVs). The least well studied are EVs (especially exosomes), which are nanoparticle-sized bilayer membrane vesicles released by many cell types that participate in cell/cell communication. EVs carry various proteins, nucleic acids, lipids, and small molecules that influence cells that ingest the EVs. Tumor-derived extracellular vesicles (TEVs) play a significant role in every stage of immunoediting, and their cargoes change from immune-activating in the early stages of immunoediting into immunosuppressing in the escape phase. In addition, their cargos change with different treatments or stress conditions and can be influenced to be more immune stimulatory against cancer. This review focuses on the emerging understanding of how TEVs affect the differentiation and effector functions of stromal cells and their role in immunoediting, from the early stages of immunoediting to immune escape. Consideration of how TEVs can be therapeutically utilized includes different treatments that can modify TEV to support cancer immunotherapy.

Production and Biological Effects of Extracellular Vesicles from Adipose-Derived Stem Cells Were Markedly Increased by Low-Intensity Ultrasound Stimulation for Promoting Diabetic Wound Healing

Diabetic wound treatment has posed a significant challenge in clinical practice. As a kind of cell-derived nanoparticles, extracellular vesicles produced by adipose-derived stem cells (ADSC-EVs) have been reported to be potential agents for diabetic wound treatment. However, ADSC-EV yield is insufficient to meet the demands of clinical therapy. In this study, a novel method involving the use of low-intensity ultrasound stimulation on ADSCs is developed to promote EV secretion for clinical use. A proper low-intensity ultrasound stimulation parameter which significantly increases ADSC-EV quantity has been found. In addition, EVs secreted by ADSCs following low-intensity ultrasound stimulation (US-EVs) are enriched in wound healing-related miRNAs. Moreover, US-EVs promote the biological functions of fibroblasts, keratinocytes, and endothelial cells in vitro, and promote diabetic wound healing in db/db mice in vivo through re-epithelialization, collagen production, cell proliferation, keratinocyte differentiation and migration, and angiogenesis. This study proposes low-intensity ultrasound stimulation as a new method for promoting significant EV secretion by ADSCs and for improving the diabetic wound-healing potential of EVs, which will meet the clinical needs for these nanoparticles. The production of extracellular vesicles of adipose-derived stem cells is obviously promoted by a low-intensity ultrasound stimulation method, and the biological effects of promoting diabetic wound healing were markedly increased in vitro and in vivo.

Engineered tumor cell-derived vaccines against cancer: The art of combating poison with poison

Tumor vaccination is a promising approach for tumor immunotherapy because it presents high specificity and few side effects. However, tumor vaccines that contain only a single tumor antigen can allow immune system evasion by tumor variants. Tumor antigens are complex and heterogeneous, and identifying a single antigen that is uniformly expressed by tumor cells is challenging. Whole tumor cells can produce comprehensive antigens that trigger extensive tumor-specific immune responses. Therefore, tumor cells are an ideal source of antigens for tumor vaccines. A better understanding of tumor cell-derived vaccines and their characteristics, along with the development of new technologies for antigen delivery, can help improve vaccine design. In this review, we summarize the recent advances in tumor cell-derived vaccines in cancer immunotherapy and highlight the different types of engineered approaches, mechanisms, administration methods, and future perspectives. We discuss tumor cell-derived vaccines, including whole tumor cell components, extracellular vesicles, and cell membrane-encapsulated nanoparticles. Tumor cell-derived vaccines contain multiple tumor antigens and can induce extensive and potent tumor immune responses. However, they should be engineered to overcome limitations such as insufficient immunogenicity and weak targeting. The genetic and chemical engineering of tumor cell-derived vaccines can greatly enhance their targeting, intelligence, and functionality, thereby realizing stronger tumor immunotherapy effects. Further advances in materials science, biomedicine, and oncology can facilitate the clinical translation of tumor cell-derived vaccines.

Advances in Nanotechnology for Cancer Immunoprevention and Immunotherapy: A Review

One of the most effective cancer therapies, cancer immunotherapy has produced outstanding outcomes in the field of cancer treatment. However, the cost is excessive, which limits its applicability. A smart way to address this issue would be to apply the knowledge gained through immunotherapy to develop strategies for the immunoprevention of cancer. The use of cancer vaccines is one of the most popular methods of immunoprevention. This paper reviews the technologies and processes that support the advantages of cancer immunoprevention over traditional cancer immunotherapies. Nanoparticle drug delivery systems and nanoparticle-based nano-vaccines have been employed in the past for cancer immunotherapy. This paper outlines numerous immunoprevention strategies and how nanotechnology can be applied in immunoprevention. To comprehend the non-clinical and clinical evaluation of these cancer vaccines through clinical studies is essential for acceptance of the vaccines.

Exosomal MicroRNAs as Novel Cell-Free Therapeutics in Tissue Engineering and Regenerative Medicine

Extracellular vesicles (EVs) are membrane-bound vesicles (50-1000 nm) that can be secreted by all cell types. Microvesicles and exosomes are the major subsets of EVs that exhibit the cell-cell communications and pathological functions of human tissues, and their therapeutic potentials. To further understand and engineer EVs for cell-free therapy, current developments in EV biogenesis and secretion pathways are discussed to illustrate the remaining gaps in EV biology. Specifically, microRNAs (miRs), as a major EV cargo that exert promising therapeutic results, are discussed in the context of biological origins, sorting and packing, and preclinical applications in disease progression and treatments. Moreover, advanced detection and engineering strategies for exosomal miRs are also reviewed. This article provides sufficient information and knowledge for the future design of EVs with specific miRs or protein cargos in tissue repair and regeneration.

Methods of the Large-Scale Production of Extracellular Vesicles

To date, extracellular vesicles (EVs) have been extensively investigated as potential substitutes for cell therapy. Research has suggested their ability to overcome serious risks associated with the application of these cells. Although, the translation of EVs into clinical practice is hampered by the lack of a cheap reasonable way to obtain a clinically relevant number of EVs, an available method for the large-scale production of EVs ensures vesicles’ integrity, preserves their biological activity, and ensures they are well reproducible, providing homogeneity of the product from batch to batch. In this review, advances in the development of methods to increase EVs production are discussed. The existing approaches can be divided into the following: (1) those based on increasing the production of natural EVs by creating and using high capacity “cell factories”, (2) those based on the induction of EVs secretion under various cell stressors, and (3) those based on cell fragmentation with the creation of biomimetic vesicles. The aim of this review is to stimulate the introduction of EVs into clinical practice and to draw attention to the development of new methods of EVs production on a large scale.

Tumor-polarized GPX3+ AT2 lung epithelial cells promote premetastatic niche formation

The cellular and molecular components required for the formation of premetastatic niche (PMN) to promote lung metastasis need to be further investigated. Lung epithelial cells have been reported to exhibit immunomodulatory roles in lung homeostasis and also to mediate immunosuppressive PMN formation in lung metastasis. Here, by single-cell sequencing, we identified a tumor-polarized subpopulation of alveolar type 2 (AT2) epithelial cells with increased expression of glutathione peroxidase 3 (GPX3) and high production of interleukin (IL)-10 in the PMN. IL-10-producing GPX3⁺ AT2 cells inhibited CD4⁺ T cell proliferation but enhanced regulatory T cell generation. Mechanistically, tumor exosome-inducing GPX3 expression is required for GPX3⁺ AT2 cells to preferentially produce IL-10 by stabilizing hypoxia-inducible factor 1 (HIF-1α) and promoting HIF-1α-induced IL-10 production. Accordingly, conditional knockout of GPX3 in AT2 cells suppressed lung metastasis in spontaneous metastatic models. Together, our findings reveal a role of tumor-polarized GPX3⁺ AT2 cells in promoting lung PMN formation, adding insights into immune evasion in lung metastasis and providing potential targets for the intervention of tumor metastasis.

Interplay between purinergic signalling and extracellular vesicles in health and disease

Purinergic signalling is a receptor-mediated process characterized by the binding of extracellular nucleotides and nucleosides to purinergic receptors, which results in the activation intracellular signalling pathways, and, ultimately, leads to changes in cell physiology. Purinergic signalling has been related to the regulation of important physiological processes (e.g., renal electrolyte reabsorption; platelet aggregation; immune response). In addition, it has been associated with pathophysiological situations such as cancer and inflammation. Extracellular vesicles (EVs) are nanoparticles released by all cells of the organism, which play a key role in cell-cell communication. In this regard, EVs can mediate effects on target cells located at distant locations. Within their cargo, EVs contain molecules with the potential to affect purinergic signalling at the target cells and tissues. Here, we review the studies addressing the regulation of purinergic signalling by EVs based on the cell type or tissue where the regulation takes place. In this regard, EVs are found to play a major role in modulating the extracellular ATP levels and, specially, adenosine. This has a clear impact on, for instance, the inflammatory and immune response against cancer cells. Furthermore, we discuss the data available on the regulation of EV secretion and its cargo by purinergic signalling. Here, a major role of the purinergic receptor P2X7 and again, an impact on processes such as inflammation, immune response and cancer pathogenesis has been established. Finally, we highlight uninvestigated aspects of these two regulatory networks and address their potential as therapeutic targets.

Current Status, Opportunities, and Challenges of Exosomes in Oral Cancer Diagnosis and Treatment

Oral cancer is one of the most common cancers in the world, with more than 300,000 cases diagnosed each year, of which oral squamous cell carcinoma accounts for more than 90%, with a 5-year survival rate of only 40–60%, and poor prognosis. Exploring new strategies for the early diagnosis and treatment of oral cancer is key to improving the survival rate. Exosomes are nanoscale lipid bilayer membrane vesicles that are secreted by almost all cell types. During the development of oral cancer, exosomes can transport their contents (DNA, RNA, proteins, etc) to target cells and promote or inhibit the proliferation, invasion, and metastasis of oral cancer cells by influencing the host immune response, drug-resistant metastasis, and tumour angiogenesis. Therefore, exosomes have great potential and advantages as biomarkers for oral cancer diagnosis, and as drug delivery vehicles or targets for oral cancer therapy. In this review, we first describe the biogenesis, biological functions, and isolation methods of exosomes, followed by their relationship with oral cancer. Here, we focused on the potential of exosomes as oral cancer biomarkers, drug carriers, and therapeutic targets. Finally, we provide an insightful discussion of the opportunities and challenges of exosome application in oral cancer diagnosis and treatment, intending to offer new ideas for the clinical management of oral cancer.

Laser ablation: Heating up the anti-tumor response in the intracranial compartment

Immunotherapies, such as immune checkpoint inhibition (ICI), have had limited success in treating intracranial malignancies. These failures are due partly to the restrictive blood-brain-barrier (BBB), the profound tumor-dependent induction of local and systemic immunosuppression, and immune evasion exhibited by these tumors. Therefore, novel approaches must be explored that aim to overcome these stringent barriers. LITT is an emerging treatment for brain tumors that utilizes thermal ablation to kill tumor cells. LITT provides an additional therapeutic benefit by synergizing with ICI and systemic chemotherapies to strengthen the anti-tumor immune response. This synergistic relationship involves transient disruption of the BBB and local augmentation of immune function, culminating in increased CNS drug penetrance and improved anti-tumor immunity. In this review, we will provide an overview of the challenges facing immunotherapy for brain tumors, and discuss how LITT may synergize with the endogenous anti-tumor response to improve the efficacy of ICI.

Exosomal Proteins and Lipids as Potential Biomarkers for Lung Cancer Diagnosis, Prognosis, and Treatment

Simple Summary

Exosomes (or extracellular vesicles) are known to mediate intercellular communication and to transmit molecular signals between cells. Molecules carried by exosomes have their own molecular roles in affecting surrounding and distant environment, as well as recipient cells. Molecular components of exosomes can be used as cancer biomarkers for diagnosis and prognosis, being promising therapeutic targets for the interruption of cellular signals. Therefore, the understanding of the molecular compositions and their functional indications of exosomes has the potential to help doctors to diagnose and monitor diseases and to allow researchers to design and develop potential targeted therapies. This review aims to provide a comprehensive protein and lipid characterization of lung cancer exosomes and to explore their molecular functions and mechanisms regulating physiological and pathological processes. This organization offers informative insight for lung cancer diagnosis and treatment.

Abstract

Exosomes participate in cell–cell communication by transferring molecular components between cells. Previous studies have shown that exosomal molecules derived from cancer cells and liquid biopsies can serve as biomarkers for cancer diagnosis and prognosis. The exploration of the molecules transferred by lung cancer-derived exosomes can advance the understanding of exosome-mediated signaling pathways and mechanisms. However, the molecular characterization and functional indications of exosomal proteins and lipids have not been comprehensively organized. This review thoroughly collected data concerning exosomal proteins and lipids from various lung cancer samples, including cancer cell lines and cancer patients. As potential diagnostic and prognostic biomarkers, exosomal proteins and lipids are available for clinical use in lung cancer. Potential therapeutic targets are mentioned for the future development of lung cancer therapy. Molecular functions implying their possible roles in exosome-mediated signaling are also discussed. Finally, we emphasized the importance and value of lung cancer stem cell-derived exosomes in lung cancer therapy. In summary, this review presents a comprehensive description of the protein and lipid composition and function of lung cancer-derived exosomes for lung cancer diagnosis, prognosis, and treatment.

Cancer exosomes and natural killer cells dysfunction: biological roles, clinical significance and implications for immunotherapy

Tumor-derived exosomes (TDEs) play pivotal roles in several aspects of cancer biology. It is now evident that TDEs also favor tumor growth by negatively affecting anti-tumor immunity. As important sentinels of immune surveillance system, natural killer (NK) cells can recognize malignant cells very early and counteract the tumor development and metastasis without a need for additional activation. Based on this rationale, adoptive transfer of ex vivo expanded NK cells/NK cell lines, such as NK-92 cells, has attracted great attention and is widely studied as a promising immunotherapy for cancer treatment. However, by exploiting various strategies, including secretion of exosomes, cancer cells are able to subvert NK cell responses. This paper reviews the roles of TDEs in cancer-induced NK cells impairments with mechanistic insights. The clinical significance and potential approaches to nullify the effects of TDEs on NK cells in cancer immunotherapy are also discussed.

Exogenous and Endogenous Dendritic Cell-Derived Exosomes: Lessons Learned for Immunotherapy and Disease Pathogenesis

Immune therapeutic exosomes, derived exogenously from dendritic cells (DCs), the 'directors' of the immune response, are receiving favorable safety and tolerance profiles in phase I and II clinical trials for a growing number of inflammatory and neoplastic diseases. DC-derived exosomes (EXO), the focus of this review, can be custom tailored with immunoregulatory or immunostimulatory molecules for specific immune cell targeting. Moreover, the relative stability, small size and rapid uptake of EXO by recipient immune cells offer intriguing options for therapeutic purposes. This necessitates an in-depth understanding of mechanisms of EXO biogenesis, uptake and routing by recipient immune cells, as well as their in vivo biodistribution. Against this backdrop is recognition of endogenous exosomes, secreted by all cells, the molecular content of which is reflective of the metabolic state of these cells. In this regard, exosome biogenesis and secretion is regulated by cell stressors of chronic inflammation and tumorigenesis, including dysbiotic microbes, reactive oxygen species and DNA damage. Such cell stressors can promote premature senescence in young cells through the senescence associated secretory phenotype (SASP). Pathological exosomes of the SASP amplify inflammatory signaling in stressed cells in an autocrine fashion or promote inflammatory signaling to normal neighboring cells in paracrine, without the requirement of cell-to-cell contact. In summary, we review relevant lessons learned from the use of exogenous DC exosomes for immune therapy, as well as the pathogenic potential of endogenous DC exosomes.

Secretions from hypochlorous acid-treated tumor cells delivered in a melittin hydrogel potentiate cancer immunotherapy

Autologous tumor cells and cell-derived secretions (CDS) can induce antitumor immune responses. The conditions in which cells are cultured and treated impact CDS, and cellular insults alter their composition and function. In this study, we generated CDS from tumor cells exposed to normal culture conditions, hypoxia, cisplatin, radiotherapy, photodynamic therapy, or hypochlorous acid (HOCl). In vitro HOCl-CDS showed the strongest stimulatory effects on dendritic cells and macrophages compared to CDS generated by hypoxia, cisplatin, radiotherapy or photodynamic therapy. To improve HOCl-CDS activity at the tumor site, we loaded HOCl-CDS into a melittin-encapsulated hydrogel scaffold. When injected intratumorally, the HOCl-CDS hydrogel promoted tumor cell death, cytotoxic T lymphocyte infiltration, and tumor-associated macrophage reprogramming towards an M1 phenotype. The hydrogel inhibited tumor growth and prolonged the survival of mice bearing B16–F10 melanoma. Furthermore, hydrogel-delivered HOCl-CDS augmented the antitumor effects of immune checkpoint blockade. These results underscore the importance of the CDS generation method and delivery approach for improving cancer immunotherapy.

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HOCl-treated tumor cell-derived secretions (HOCl-CDS) is a robust immune-stimulator on dendritic cells and macrophages.

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A multifunctional HOCl-CDS hydrogel was developed by loading HOCl-CDS into a melittin-encapsulated hydrogel scaffold.

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HOCl-CDS hydrogel promoted tumor cell death, cytotoxic T lymphocyte infiltration and M1-TAM polarization in mice.

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HOCl-CDS hydrogel synergistically augmented the therapeutic effect of anti-PD-1 and further potentiated cancer immunotherapy.

Supplementation with Serum-Derived Extracellular Vesicles Reinforces Antitumor Immunity Induced by Cryo-Thermal Therapy

Effective cancer therapies should reshape immunosuppression and trigger antitumor immunity. Previously, we developed a novel cryo-thermal therapy through applying local rapid cooling followed by rapid heating of tumor tissue. It could not only ablate local tumors, but also, subsequently, induce systemic long-term antitumor immunity. Hyperthermia can induce the release of extracellular vesicles (EVs) to stimulate antitumor immunity. We examine whether EVs are released after cryo-thermal therapy and whether they could improve the efficacy of cryo-thermal therapy in the 4T1 model. In this study, serum extracellular vesicles (sEVs) are isolated and characterized 3 h after cryo-thermal therapy of subcutaneous tumors. sEV phagocytosis is observed in vitro and in vivo by using laser confocal microscopy and flow cytometry. After cryo-thermal therapy, sEVs are administered to mice via the tail vein, and changes in immune cells are investigated by using flow cytometry. After cryo-thermal therapy, a large number of sEVs are released to the periphery carrying danger signals and tumor antigens, and these sEVs could be phagocytosed by peripheral blood monocytes and differentiated macrophages. After cryo-thermal therapy, supplementation with sEVs released after treatment promotes the differentiation of myeloid-derived suppressor cells (MDSCs), monocytes into macrophages and CD4⁺ T cells into the Th1 subtype, as well as prolonging the long-term survival of the 4T1 subcutaneous tumor-bearing mice. sEVs released after cryo-thermal tumor treatment could clinically serve as an adjuvant in subsequent cryo-thermal therapy to improve the therapeutic effects on malignant tumors.

The Recruitment of Neutrophils to the Tumor Microenvironment Is Regulated by Multiple Mediators

Neutrophils sense and migrate towards chemotactic factors released at sites of infection/inflammation and contain the affected area using a variety of effector mechanisms. Aside from these established immune defense functions, neutrophils are emerging as one of the key tumor-infiltrating immune cells that influence cancer progression and metastasis. Neutrophil recruitment to the tumor microenvironment (TME) is mediated by multiple mediators including cytokines, chemokines, lipids, and growth factors that are secreted from cancer cells and cancer-associated stromal cells. However, the molecular mechanisms that underlie the expression and secretion of the different mediators from cancer cells and how neutrophils integrate these signals to reach and invade tumors remain unclear. Here, we discuss the possible role of the epithelial to mesenchymal transition (EMT) program, which is a well-established promoter of malignant potential in cancer, in regulating the expression and secretion of these key mediators. We also summarize and review our current understanding of the machineries that potentially control the secretion of the mediators from cancer cells, including the exocytic trafficking pathways, secretory autophagy, and extracellular vesicle-mediated secretion. We further reflect on possible mechanisms by which different mediators collaborate by integrating their signaling network, and particularly focus on TGF-β, a cytokine that is highly expressed in invasive tumors, and CXCR2 ligands, which are crucial neutrophil recruiting chemokines. Finally, we highlight gaps in the field and the need to expand current knowledge of the secretory machineries and cross-talks among mediators to develop novel neutrophil targeting strategies as effective therapeutic options in the treatment of cancer.

Extracellular Vesicles in Lung Cancer: Prospects for Diagnostic and Therapeutic Applications

Extracellular vesicles (EVs) are nano-sized lipid-bound particles containing proteins, nucleic acids and metabolites released by cells. They have been identified in body fluids including blood, saliva, sputum and pleural effusions. In tumors, EVs derived from cancer and immune cells mediate intercellular communication and exchange, and can affect immunomodulatory functions. In the context of lung cancer, emerging evidence implicates EV involvement during various stages of tumor development and progression, including angiogenesis, epithelial to mesenchymal transformation, immune system suppression, metastasis and drug resistance. Additionally, tumor-derived EVs (TDEs) have potential as a liquid biopsy source and as a means of therapeutic targeting, and there is considerable interest in developing clinical applications for EVs in these contexts. In this review, we consider the biogenesis, components, biological functions and isolation methods of EVs, and the implications for their clinical utility for diagnostic and therapeutic applications in lung cancer.

Macrophages at the nexus of mesenchymal stromal cell potency: The emerging role of chemokine cooperativity

Pharmacological depletion of macrophages in vivo with liposomal clodronate renders mice unresponsive to adoptive transfer of mesenchymal stromal cells (MSCs) for affecting outcomes of acute inflammatory pathology. This experimental observation identifies host macrophages as necessary in mediating the salutary anti-inflammatory properties of MSCs as a cellular pharmaceutical. This theory is supported by the observation that transfusion of MSCs leads to the prompt phagocytosis of nearly half of lung entrapped MSCs by lung resident macrophages, triggering an interleukin (IL)-10 suppressive efferocytotic response. In addition, non-phagocytosed MSCs with COX2 competency shape the immune milieu by inducing tissue macrophages to express IL-10. Additional experimental evidence identifies MSC-borne IL-6, IDO and TSG-6 as directly involved in macrophage polarization. Along similar lines of functional convergence, implantation of CCL2⁺ MSCs in the extravascular space where interaction with lung resident perivascular macrophages is not operative, also leads to IL-10 polarization of CCR2⁺ macrophages within acute injured tissue far removed from MSC depot. Intriguingly, MSC-derived CCL2 on its own is not sufficient to polarize macrophages and requires heterodimerization with MSC-borne CXCL12 to trigger macrophage IL-10 polarization via CCR2, but not CXCR4. Such chemokine cooperativity opens a new venue for analysis of MSC potency especially considering the rich chemokine secretome of MSC exposed to inflammatory stimulus. As an aggregate, these data highlight a necessary MSC and host macrophage functional dyad that may inform potency attribute analysis of MSCs-including the chemokine interactome-that may be directly linked to in vivo clinical anti-inflammatory and regenerative response.

Tumor-Derived Extracellular Vesicles: Their Role in Immune Cells and Immunotherapy

Nowadays, tumor has been the serious threat to human health and life. To further explore the mechanism of tumor genesis and development is necessarily for developing the effective treatment strategy. Extracellular vesicles are the vesicles secreted by almost all types of cells, and they play an important part in intercellular communication by transporting their cargoes. Immune cells are the vital components of the human defense system, which defense against infection and tumor through cytotoxicity, immune surveillance, and clearance. However, via release tumor-derived extracellular vesicles, tumor could induce immune cells dysfunction to facilitate its proliferation and metastasis. Studies have shown that tumor-derived extracellular vesicles play dual role on immune cells by their specific cargoes. Here, we reviewed the effects of tumor-derived extracellular vesicles on immune cells in recent years and also summarized their research progress in the tumor immunotherapy and diagnosis.

Magnetic systems for cancer immunotherapy

Immunotherapy is a rapidly developing area of cancer treatment due to its higher specificity and potential for greater efficacy than traditional therapies. Immune cell modulation through the administration of drugs, proteins, and cells can enhance antitumoral responses through pathways that may be otherwise inhibited in the presence of immunosuppressive tumors. Magnetic systems offer several advantages for improving the performance of immunotherapies, including increased spatiotemporal control over transport, release, and dosing of immunomodulatory drugs within the body, resulting in reduced off-target effects and improved efficacy. Compared to alternative methods for stimulating drug release such as light and pH, magnetic systems enable several distinct methods for programming immune responses. First, we discuss how magnetic hyperthermia can stimulate immune cells and trigger thermoresponsive drug release. Second, we summarize how magnetically targeted delivery of drug carriers can increase the accumulation of drugs in target sites. Third, we review how biomaterials can undergo magnetically driven structural changes to enable remote release of encapsulated drugs. Fourth, we describe the use of magnetic particles for targeted interactions with cellular receptors for promoting antitumor activity. Finally, we discuss translational considerations of these systems, such as toxicity, clinical compatibility, and future opportunities for improving cancer treatment.

The principles of directed cell migration

Cells have the ability to respond to various types of environmental cues, and in many cases these cues induce directed cell migration towards or away from these signals. How cells sense these cues and how they transmit that information to the cytoskeletal machinery governing cell translocation is one of the oldest and most challenging problems in biology. Chemotaxis, or migration towards diffusible chemical cues, has been studied for more than a century, but information is just now beginning to emerge about how cells respond to other cues, such as substrate-associated cues during haptotaxis (chemical cues on the surface), durotaxis (mechanical substrate compliance) and topotaxis (geometric features of substrate). Here we propose four common principles, or pillars, that underlie all forms of directed migration. First, a signal must be generated, a process that in physiological environments is much more nuanced than early studies suggested. Second, the signal must be sensed, sometimes by cell surface receptors, but also in ways that are not entirely clear, such as in the case of mechanical cues. Third, the signal has to be transmitted from the sensing modules to the machinery that executes the actual movement, a step that often requires amplification. Fourth, the signal has to be converted into the application of asymmetric force relative to the substrate, which involves mostly the cytoskeleton, but perhaps other players as well. Use of these four pillars has allowed us to compare some of the similarities between different types of directed migration, but also to highlight the remarkable diversity in the mechanisms that cells use to respond to different cues provided by their environment.

Role of Extracellular Vesicles in Compromising Cellular Resilience to Environmental Stressors

Extracellular vesicles (EVs), like exosomes, are nanosized membrane-enveloped vesicles containing different bioactive cargo, such as proteins, lipids, mRNA, miRNA, and other small regulatory RNAs. Cell-derived EVs, including EVs originating from stem cells, may capture components from damaged cells or cells impacted by therapeutic treatments. Interestingly, EVs derived from stem cells can be preconditioned to produce and secrete EVs with different therapeutic properties, particularly with respect to heat-shock proteins and other molecular cargo contents. This behavior is consistent with stem cells that also respond differently to various microenvironments. Heat-shock proteins play roles in cellular protection and mediate cellular resistance to radiotherapy, chemotherapy, and heat shock. This review highlights the possible roles EVs play in mediating cellular plasticity and survival when exposed to different physical and chemical stressors, with a special focus on the respiratory distress due to the air pollution.

Exosomes in the lung cancer microenvironment: biological functions and potential use as clinical biomarkers

Lung cancer is one of the most common malignant tumours worldwide. however, emerging immunotherapy and targeted therapies continue to show limited efficacy. In the search for new targets for lung cancer treatment, exosomes have become a major focus of research. Exosomes play an important role in the tumour microenvironment (TME) of lung cancer and affect invasion, metastasis, and treatment responses. This review describes our current understanding of the release of exosomes derived from different cells in the TME, the effects of exosomes on T/Tregs, myeloid-derived suppressor cells, tumour-associated macrophages, dendritic cells, and natural killer cells, and the role of exosomes in the endothelial–mesenchymal transition, angiogenesis, and cancer-associated fibroblasts. In particular, this review focuses on the potential clinical applications of exosomes in the lung cancer microenvironment and their prognostic and diagnostic value.

Exosomes as Naturally Occurring Vehicles for Delivery of Biopharmaceuticals: Insights from Drug Delivery to Clinical Perspectives

Exosomes as nanosized vesicles are emerging as drug delivery systems for therapeutics owing to their natural origin, their ability to mediate intercellular communication, and their potential to encapsulate various biological molecules such as proteins and nucleic acids within the lipid bilayer membrane or in the lumen. Exosomes contain endogenous components (proteins, lipids, RNA) that could be used to deliver cargoes to target cells, offering an opportunity to diagnose and treat various diseases. Owing to their ability to travel safely in extracellular fluid and to transport cargoes to target cells with high efficacy, exosomes offer enhanced delivery of cargoes in vivo. However, several challenges related to the stabilization of the exosomes, the production of sufficient amounts of exosomes with safety and efficacy, the efficient loading of drugs into exosomes, the clearance of exosomes from circulation, and the transition from the bench scale to clinical production may limit their development and clinical use. For the clinical use of exosomes, it is important to understand the molecular mechanisms behind the transport and function of exosome vesicles. This review exploits techniques related to the isolation and characterization of exosomes and their drug delivery potential to enhance the therapeutic outcome and stabilization methods. Further, routes of administration, clinical trials, and regulatory aspects of exosomes will be discussed in this review.

Hyperthermia by near infrared radiation induced immune cells activation and infiltration in breast tumor

Breast cancer is the most common cancer that causes death in women. Conventional therapies, including surgery and chemotherapy, have different therapeutic effects and are commonly associated with risks and side effects. Near infrared radiation is a technique with few side effects that is used for local hyperthermia, typically as an adjuvant to other cancer therapies. The understanding of the use of near NIR as a monotherapy, and its effects on the immune cells activation and infiltration, are limited. In this study, we investigate the effects of HT treatment using NIR on tumor regression and on the immune cells and molecules in breast tumors. Results from this study demonstrated that local HT by NIR at 43 °C reduced tumor progression and significantly increased the median survival of tumor-bearing mice. Immunohistochemical analysis revealed a significant reduction in cells proliferation in treated tumor, which was accompanied by an abundance of heat shock protein 70 (Hsp70). Increased numbers of activated dendritic cells were observed in the draining lymph nodes of the mice, along with infiltration of T cells, NK cells and B cells into the tumor. In contrast, tumor-infiltrated regulatory T cells were largely diminished from the tumor. In addition, higher IFN-γ and IL-2 secretion was observed in tumor of treated mice. Overall, results from this present study extends the understanding of using local HT by NIR to stimulate a favourable immune response against breast cancer.

Synaptic Activity and (Neuro)Inflammation in Alzheimer's Disease: Could Exosomes be an Additional Link?

Nanosized extracellular vesicles, known as exosomes, are produced by all cell types in mammalian organisms and have been recently involved in neurodegeneration. In the brain, both glia and neurons give rise to exosomes, which contribute to their intercellular communication. In addition, brain-derived exosomes have a remarkable property to cross the blood-brain-barrier bi-directionally. In this line, exosomes of central origin have been identified in peripheral circulation and already considered as putative blood biomarkers of neurodegenerative diseases, including Alzheimer's disease (AD). Moreover, tentative use of exosomes as vehicle for the clearance of brain-born toxic proteins or, conversely, neuroprotective drug delivery, was also envisaged. However, little is known about the precise role of exosomes in the control and regulation of neuronal functions. Based on the presence of subunits of glutamate receptors in neuron-derived exosomes on one hand, and complement proteins in astrocyte-derived exosomes on the other hand, we hypothesize that exosomes may participate in the control of neuronal excitability via inflammatory-like mechanisms both at the central level and from the periphery. In this review, we will focus on AD and discuss the mechanisms by which exosomes of neuronal, glial, and/or peripheral origin could impact on neuronal excitability either directly or indirectly.

Triple-Negative Breast Cancer Cells Recruit Neutrophils by Secreting TGF-β and CXCR2 Ligands

Tumor associated neutrophils (TANs) are frequently detected in triple-negative breast cancer (TNBC). Recent studies also reveal the importance of neutrophils in promoting tumor progression and metastasis during breast cancer. However, the mechanisms regulating neutrophil trafficking to breast tumors are less clear. We sought to determine whether neutrophil trafficking to breast tumors is determined directly by the malignant potential of cancer cells. We found that tumor conditioned media (TCM) harvested from highly aggressive, metastatic TNBC cells induced a polarized morphology and robust neutrophil migration, while TCM derived from poorly aggressive estrogen receptor positive (ER+) breast cancer cells had no activity. In a three-dimensional (3D) type-I collagen matrix, neutrophils migrated toward TCM from aggressive breast cancer cells with increased velocity and directionality. Moreover, in a neutrophil-tumor spheroid co-culture system, neutrophils migrated with increased directionality towards spheroids generated from TNBC cells compared to ER+ cells. Based on these findings, we next sought to characterize the active factors secreted by TNBC cell lines. We found that TCM-induced neutrophil migration is dependent on tumor-derived chemokines, and screening TCM elution fractions based on their ability to induce polarized neutrophil morphology revealed the molecular weight of the active factors to be around 12 kDa. TCM from TNBC cell lines contained copious amounts of GRO (CXCL1/2/3) chemokines and TGF-β cytokines compared to ER+ cell-derived TCM. TCM activity was inhibited by simultaneously blocking receptors specific to GRO chemokines and TGF-β, while the activity remained intact in the presence of either single receptor inhibitor. Together, our findings establish a direct link between the malignant potential of breast cancer cells and their ability to induce neutrophil migration. Our study also uncovers a novel coordinated function of TGF-β and GRO chemokines responsible for guiding neutrophil trafficking to the breast tumor.

Extracellular vesicles: Critical players during cell migration

Cell migration is essential for the development and maintenance of multicellular organisms, contributing to embryogenesis, wound healing, immune response, and other critical processes. It is also involved in the pathogenesis of many diseases, including immune deficiency disorders and cancer metastasis. Recently, extracellular vesicles (EVs) have been shown to play important roles in cell migration. Here, we review recent studies describing the functions of EVs in multiple aspects of cell motility, including directional sensing, cell adhesion, extracellular matrix (ECM) degradation, and leader-follower behavior. We also discuss the role of EVs in migration during development and disease and the utility of imaging tools for studying the role of EVs in cell migration.

M2-Like TAMs Function Reversal Contributes to Breast Cancer Eradication by Combination Dual Immune Checkpoint Blockade and Photothermal Therapy

Immune checkpoint inhibitor (ICI) therapy is considered to be a revolutionary anti-tumor strategy that may surpass other traditional therapies. Breast cancer is particularly suitable for it theoretically due to upregulation of programmed cell death 1 (PD-1) / programmed cell death ligand 1 (PD-L1) immune checkpoint pathway which exhausts the adaptive immune response mediated by T lymphocytes. However, its blockades exhibit very little effect in breast cancer, owing to the lack of T lymphocytes pre-infiltration and co-existing of intricate immune negative microenvironment including the macrophage-suppressed "Don't eat me" CD47 signal overexpression. Herein, a stimuli-responsive multifunctional nanoplatform (ZIF-PQ-PDA-AUN) is built. Its photothermal therapy can promote the infiltration of T lymphocytes in addition to ablating tumor cells and AUNP-12 and PQ912 further boost both the innate and adaptive immune reactions by cutting off PD-L1 and CD47 signals, respectively. In contrast to earlier single immunotherapy, the nanocomposites exhibit a stronger anti-tumor immune effect without obvious autoimmune side effects, promoting infiltration of T lymphocyte into the tumor site and strengthening phagocytosis of macrophages, even more exciting, significantly reversing pro-tumor M2-like tumor-associated macrophages (TAMs) to anti-tumor M1-like TAMs. The research may provide a promising strategy to develop high-efficient and low-toxic immunotherapy based on nanotechnology.

Modulating the Heat Stress Response to Improve Hyperthermia-Based Anticancer Treatments

Simple Summary

Hyperthermia is a method to expose a tumor to elevated temperatures. Heating of the tumor promotes the effects of various treatment regimens that are based on chemo and radiotherapy. Several aspects, however, limit the efficacy of hyperthermia-based treatments. This review provides an overview of the effects and limitations of hyperthermia and discusses how current drawbacks of the therapy can potentially be counteracted by inhibiting the heat stress response—a mechanism that cells activate to defend themselves against hyperthermia.

Abstract

Cancer treatments based on mild hyperthermia (39–43 °C, HT) are applied to a widening range of cancer types, but several factors limit their efficacy and slow down more widespread adoption. These factors include difficulties in adequate heat delivery, a short therapeutic window and the acquisition of thermotolerance by cancer cells. Here, we explore the biological effects of HT, the cellular responses to these effects and their clinically-relevant consequences. We then identify the heat stress response—the cellular defense mechanism that detects and counteracts the effects of heat—as one of the major forces limiting the efficacy of HT-based therapies and propose targeting this mechanism as a potentially universal strategy for improving their efficacy.

Membrane vesicles nanotheranostic systems: sources, engineering methods, and challenges

Extracellular vesicles (EVs) are cell secretory native components with long-circulation, good biocompatibility, and physiologic barriers cross ability. EVs derived from different donor cells inherit varying characteristics and functions from their original cells and are favorable to serve as vectors for diagnosing and treating various diseases. However, EVs nanotheranostics are still in their infancy because of their limited accumulation at lesion sites and compromised therapy efficiency. Hence, engineering modification of EVs is usually needed to further enhance their stability, biological activity, and lesion-targeting capacity. Herein, we overview the characteristics of EVs from different sources, as well as the latest developments of surface engineering and cargo loading methods. We also focus especially on advances in EVs-based disease theranostics. At the end of the review, we predict the obstacles and prospects of the future clinical application of EVs.

Immunogenic Hybrid Nanovesicles of Liposomes and Tumor-Derived Nanovesicles for Cancer Immunochemotherapy

Exploring a rational delivery system of integrating chemotherapy with immunotherapy to broaden benefits of cancer immunochemotherapy is still under challenge. Herein, we developed doxorubicin (DOX)-loaded biomimetic hybrid nanovesicles (DOX@LINV) via fusing artificial liposomes (LIPs) with tumor-derived nanovesicles (TNVs) for combinational immunochemotherapy. DOX@LINV with a homologous targeting ability could deliver DOX to tumor tissue and elicit an effective immunogenic cell death response to improve the immunogenicity of a tumor. Meanwhile, the preserved tumor antigens and endogenous danger signals in DOX@LINV activated dendritic cells and induced a subsequent antigen-specific T cell immune response. DOX@LINV displayed a specific antitumor effect on murine melanoma, Lewis lung cancer, and 4T1 breast cancer based on the infiltration of effector immune cells and improvement of the immunosuppressive tumor microenvironment. Furthermore, the combination of DOX@LINV with immune checkpoint inhibitor amplified antitumor efficacy with 33.3% of the mice being tumor-free. Therefore, the hybrid LINV is a promising drug delivery platform with a boosted antitumor immune response for effective immunochemotherapy.