Extracellular Vesicles: An Emerging Nanoplatform for Cancer Therapy

Engineering therapeutical extracellular vesicles for clinical translation

Cell-based therapies are revolutionizing medicine by replacing or modifying dysfunctional cells with healthy cells or engineered derivatives, offering disease reversal and cure. One promising approach is using cell-derived extracellular vesicles (EVs), which offer therapeutic benefits similar to cell transplants without the biosafety risks. Although EV applications face challenges like limited production, inadequate therapeutic loading, and poor targeting efficiency, recent advances in bioengineering have enhanced their effectiveness. Herein, we summarize technological breakthroughs in EV bioengineering over the past 5 years, highlighting their improved therapeutic functionalities and potential clinical prospects. We also discuss biomanufacturing processes, regulation, and safety considerations for bioengineered EV therapies, emphasizing the significance of establishing robust frameworks to ensure translation capability, safety, and therapeutic effectiveness for successful clinical adoption.

Exploring the potential of the convergence between extracellular vesicles and CAR technology as a novel immunotherapy approach

Cancer therapy is a dynamically evolving field, witnessing the emergence of innovative approaches that offer a promising outlook for patients grappling with persistent disease. Within the realm of therapeutic exploration, chimeric antigen receptor (CAR) T cells as well as CAR NK cells, have surfaced as novel approaches, each possessing unique attributes and transformative potential. Immune cells engineered to express CARs recognizing tumour-specific antigens, have shown remarkable promise in treating terminal cancers by combining the precision of antibody specificity with the potent cytotoxic function of T cells. However, their application in solid tumours is still in its nascent stages, presenting unique major challenges. On the same note, CAR NK cells offer a distinct immunotherapeutic approach, utilizing CARs on NK cells, providing advantages in safety, manufacturing simplicity, and a broader scope for cancer treatment. Extracellular vesicles (EVs) have emerged as promising therapeutic agents due to their ability to carry crucial biomarkers and biologically active molecules, serving as vital messengers in the intercellular communication network. In the context of cancer, the therapeutic potential of EVs lies in delivering tumour-suppressing proteins, nucleic acid components, or targeting drugs with precision, thereby redefining the paradigm of precision medicine. The fusion of CAR technology with the capabilities of EVs has given rise to a new therapeutic frontier. CAR T EVs and CAR NK EVs, leveraging the power of EVs, have the potential to alleviate challenges associated with live-cell therapies. EVs are suggested to reduce the side effects linked to CAR T cell therapy and hold the potential to revolutionize the penetrance in solid tumours. EVs act as carriers of pro-apoptotic molecules and RNA components, enhancing immune responses and thereby expanding their therapeutic potential. In this review article, we navigate dynamic landscapes, with our objective being to evaluate comparative efficacy, safety profiles, manufacturing complexities, and clinical applicability.

Harnessing exosomes as a platform for drug delivery in breast cancer: A systematic review for in vivo and in vitro studies

Breast cancer remains a significant global health concern, emphasizing the critical need for effective treatment strategies, especially targeted therapies. This systematic review summarizes the findings from in vitro and in vivo studies regarding the therapeutic potential of exosomes as drug delivery platforms in the field of breast cancer treatment. A comprehensive search was conducted across bibliographic datasets, including Web of Science, PubMed, and Scopus, using relevant queries from several related published articles and the Medical Subject Headings Database. Then, all morphological, biomechanical, histopathological, and cellular-molecular outcomes were systematically collected. A total of 30 studies were identified based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. These studies underwent assessment using the Systematic Review Centre for Laboratory Animal Experimentation risk of bias assessment tool. The results indicate that exosomes exhibit promise as effective drug delivery platforms, capable of hindering cancer cell viability, proliferation, migration, and angiogenesis. However, a comprehensive assessment is challenging due to some studies deviating from guidelines and having incomplete methodology. Addressing these, future studies should detail methodologies, optimize dosing, and enhance exosome production. Standardization in reporting, consistent protocols, and exploration of alternative sources are crucial.

Nano-Proteolysis Targeting Chimeras (Nano-PROTACs) in Cancer Therapy

Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that have the capability to induce specific protein degradation. While playing a revolutionary role in effectively degrading the protein of interest (POI), PROTACs encounter certain limitations that impede their clinical translation. These limitations encompass off-target effects, inadequate cell membrane permeability, and the hook effect. The advent of nanotechnology presents a promising avenue to surmount the challenges associated with conventional PROTACs. The utilization of nano-proteolysis targeting chimeras (nano-PROTACs) holds the potential to enhance specific tissue accumulation, augment membrane permeability, and enable controlled release. Consequently, this approach has the capacity to significantly enhance the controllable degradation of target proteins. Additionally, they enable a synergistic effect by combining with other therapeutic strategies. This review comprehensively summarizes the structural basis, advantages, and limitations of PROTACs. Furthermore, it highlights the latest advancements in nanosystems engineered for delivering PROTACs, as well as the development of nano-sized PROTACs employing nanocarriers as linkers. Moreover, it delves into the underlying principles of nanotechnology tailored specifically for PROTACs, alongside the current prospects of clinical research. In conclusion, the integration of nanotechnology into PROTACs harbors vast potential in enhancing the anti-tumor treatment response and expediting clinical translation.

Extracellular Vesicles in Breast Cancer: From Intercellular Communication to Therapeutic Opportunities

Breast cancer, a multifaceted and heterogeneous disease, poses significant challenges in terms of understanding its intricate resistance mechanisms and devising effective therapeutic strategies. This review provides a comprehensive overview of the intricate landscape of extracellular vesicles (EVs) in the context of breast cancer, highlighting their diverse subtypes, biogenesis, and roles in intercellular communication within the tumour microenvironment (TME). The discussion spans various aspects, from EVs and stromal cells in breast cancer to their influence on angiogenesis, immune response, and chemoresistance. The impact of EV production in different culture systems, including two dimensional (2D), three dimensional (3D), and organoid models, is explored. Furthermore, this review delves into the therapeutic potential of EVs in breast cancer, presenting emerging strategies such as engineered EVs for gene delivery, nanoplatforms for targeted chemotherapy, and disrupting tumour derived EVs as a treatment approach. Understanding these complex interactions of EV within the breast cancer milieu is crucial for identifying resistance mechanisms and developing new therapeutic targets.

MicroRNAs as regulators of immune checkpoints in cancer immunotherapy: targeting PD-1/PD-L1 and CTLA-4 pathways

Immunotherapy has revolutionized cancer treatment by harnessing the power of the immune system to eliminate tumors. Immune checkpoint inhibitors (ICIs) block negative regulatory signals that prevent T cells from attacking cancer cells. Two key ICIs target the PD-1/PD-L1 pathway, which includes programmed death-ligand 1 (PD-L1) and its receptor programmed death 1 (PD-1). Another ICI targets cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). While ICIs have demonstrated remarkable efficacy in various malignancies, only a subset of patients respond favorably. MicroRNAs (miRNAs), small non-coding RNAs that regulate gene expression, play a crucial role in modulating immune checkpoints, including PD-1/PD-L1 and CTLA-4. This review summarizes the latest advancements in immunotherapy, highlighting the therapeutic potential of targeting PD-1/PD-L1 and CTLA-4 immune checkpoints and the regulatory role of miRNAs in modulating these pathways. Consequently, understanding the complex interplay between miRNAs and immune checkpoints is essential for developing more effective and personalized immunotherapy strategies for cancer treatment.

Smart Nanoscale Extracellular Vesicles in the Brain: Unveiling their Biology, Diagnostic Potential, and Therapeutic Applications

Information exchange is essential for the brain, where it communicates the physiological and pathological signals to the periphery and vice versa. Extracellular vesicles (EVs) are a heterogeneous group of membrane-bound cellular informants actively transferring informative calls to and from the brain via lipids, proteins, and nucleic acid cargos. In recent years, EVs have also been widely used to understand brain function, given their "cell-like" properties. On the one hand, the presence of neuron and astrocyte-derived EVs in biological fluids have been exploited as biomarkers to understand the mechanisms and progression of multiple neurological disorders; on the other, EVs have been used in designing targeted therapies due to their potential to cross the blood-brain-barrier (BBB). Despite the expanding literature on EVs in the context of central nervous system (CNS) physiology and related disorders, a comprehensive compilation of the existing knowledge still needs to be made available. In the current review, we provide a detailed insight into the multifaceted role of brain-derived extracellular vesicles (BDEVs) in the intricate regulation of brain physiology. Our focus extends to the significance of these EVs in a spectrum of disorders, including brain tumors, neurodegenerative conditions, neuropsychiatric diseases, autoimmune disorders, and others. Throughout the review, parallels are drawn for using EVs as biomarkers for various disorders, evaluating their utility in early detection and monitoring. Additionally, we discuss the promising prospects of utilizing EVs in targeted therapy while acknowledging the existing limitations and challenges associated with their applications in clinical scenarios. A foundational comprehension of the current state-of-the-art in EV research is essential for informing the design of future studies.

Engineered exosomes derived from stem cells: a new brain-targeted strategy

INTRODUCTION

Using engineered exosomes produced from stem cells is an experimental therapeutic approach for treating brain diseases. According to reports, preclinical research has demonstrated notable neurogenesis and angiogenesis effects using modified stem cell-derived exosomes. These biological nanoparticles have a variety of anti-apoptotic, anti-inflammatory, and antioxidant properties that make them very promising for treating nervous system disorders.

AREAS COVERED

This review examines different ways to enhance the delivery of modified stem cell-derived exosomes, how they infiltrate the blood-brain barrier (BBB), and how they facilitate their access to the brain. We would also like to determine whether these nanoparticles have the most significant transmission rates through BBB when targeting brain lesions.

EXPERT OPINION

Using engineered stem cell-derived exosomes for treating brain disorders has generated considerable attention toward clinical research and application. However, stem cell-derived exosomes lack consistency, and their mechanisms of action are uncertain. Therefore, upcoming research needs to prioritize examining the underlying mechanisms and strategies via which these nanoparticles combat neurological disorders.

CRISPR-Cas9 delivery strategies with engineered extracellular vesicles

Therapeutic genome editing has the potential to cure diseases by directly correcting genetic mutations in tissues and cells. Recent progress in the CRISPR-Cas9 systems has led to breakthroughs in gene editing tools because of its high orthogonality, versatility, and efficiency. However, its safe and effective administration to target organs in patients is a major hurdle. Extracellular vesicles (EVs) are endogenous membranous particles secreted spontaneously by all cells. They are key actors in cell-to-cell communication, allowing the exchange of select molecules such as proteins, lipids, and RNAs to induce functional changes in the recipient cells. Recently, EVs have displayed their potential for trafficking the CRISPR-Cas9 system during or after their formation. In this review, we highlight recent developments in EV loading, surface functionalization, and strategies for increasing the efficiency of delivering CRISPR-Cas9 to tissues, organs, and cells for eventual use in gene therapies.

Ergolide mediates anti-cancer effects on metastatic uveal melanoma cells and modulates their cellular and extracellular vesicle proteomes

Background

Uveal melanoma is a poor prognosis cancer. Ergolide, a sesquiterpene lactone isolated from Inula Brittanica, exerts anti-cancer properties. The objective of this study was to 1) evaluate whether ergolide reduced metastatic uveal melanoma (MUM) cell survival/viability in vitro and in vivo; and 2) to understand the molecular mechanism of ergolide action.

Methods

Ergolide bioactivity was screened via long-term proliferation assay in UM/MUM cells and in zebrafish MUM xenograft models. Mass spectrometry profiled proteins modulated by ergolide within whole cell or extracellular vesicle (EVs) lysates of the OMM2.5 MUM cell line. Protein expression was analyzed by immunoblots and correlation analyses to UM patient survival used The Cancer Genome Atlas (TCGA) data.

Results

Ergolide treatment resulted in significant, dose-dependent reductions (48.5 to 99.9%; p<0.0001) in OMM2.5 cell survival in vitro and of normalized primary zebrafish xenograft fluorescence (56%; p<0.0001) in vivo, compared to vehicle controls. Proteome-profiling of ergolide-treated OMM2.5 cells, identified 5023 proteins, with 52 and 55 proteins significantly altered at 4 and 24 hours, respectively ( p<0.05; fold-change >1.2). Immunoblotting of heme oxygenase 1 (HMOX1) and growth/differentiation factor 15 (GDF15) corroborated the proteomic data. Additional proteomics of EVs isolated from OMM2.5 cells treated with ergolide, detected 2931 proteins. There was a large overlap with EV proteins annotated within the Vesiclepedia compendium. Within the differentially expressed proteins, the proteasomal pathway was primarily altered. Interestingly, BRCA2 and CDKN1A Interacting Protein (BCCIP) and Chitinase Domain Containing 1 (CHID1), were the only proteins significantly differentially expressed by ergolide in both the OMM2.5 cellular and EV isolates and they displayed inverse differential expression in the cells versus the EVs.

Conclusions

Ergolide is a novel, promising anti-proliferative agent for UM/MUM. Proteomic profiling of OMM2.5 cellular/EV lysates identified candidate pathways elucidating the action of ergolide and putative biomarkers of UM, that require further examination.

Ergolide mediates anti-cancer effects on metastatic uveal melanoma cells and modulates their cellular and extracellular vesicle proteomes

BACKGROUND

Uveal melanoma is a poor prognosis cancer. Ergolide, a sesquiterpene lactone isolated from Inula Brittanica, exerts anti-cancer properties. The objective of this study was to 1) evaluate whether ergolide reduced metastatic uveal melanoma (MUM) cell survival/viability in vitro and in vivo; and 2) to understand the molecular mechanism of ergolide action.

METHODS

Ergolide bioactivity was screened via long-term proliferation assay in UM/MUM cells and in zebrafish MUM xenograft models. Mass spectrometry profiled proteins modulated by ergolide within whole cell or extracellular vesicle (EVs) lysates of the OMM2.5 MUM cell line. Protein expression was analyzed by immunoblots and correlation analyses to UM patient survival used The Cancer Genome Atlas (TCGA) data.

RESULTS

Ergolide treatment resulted in significant, dose-dependent reductions (48.5 to 99.9%; p<0.0001) in OMM2.5 cell survival in vitro and of normalized primary zebrafish xenograft fluorescence (56%; p<0.0001) in vivo, compared to vehicle controls. Proteome-profiling of ergolide-treated OMM2.5 cells, identified 5023 proteins, with 52 and 55 proteins significantly altered at 4 and 24 hours, respectively ( p<0.05; fold-change >1.2). Immunoblotting of heme oxygenase 1 (HMOX1) and growth/differentiation factor 15 (GDF15) corroborated the proteomic data. Additional proteomics of EVs isolated from OMM2.5 cells treated with ergolide, detected 2931 proteins. There was a large overlap with EV proteins annotated within the Vesiclepedia compendium. Within the differentially expressed proteins, the proteasomal pathway was primarily altered. Interestingly, BRCA2 and CDKN1A Interacting Protein (BCCIP) and Chitinase Domain Containing 1 (CHID1), were the only proteins significantly differentially expressed by ergolide in both the OMM2.5 cellular and EV isolates and they displayed inverse differential expression in the cells versus the EVs.

CONCLUSIONS

Ergolide is a novel, promising anti-proliferative agent for UM/MUM. Proteomic profiling of OMM2.5 cellular/EV lysates identified candidate pathways elucidating the action of ergolide and putative biomarkers of UM, that require further examination.

Exosomal mRNAs for Angiogenic-Osteogenic Coupled Bone Repair

Regenerative medicine in tissue engineering often relies on stem cells and specific growth factors at a supraphysiological dose. These approaches are costly and may cause severe side effects. Herein, therapeutic small extracellular vesicles (t-sEVs) endogenously loaded with a cocktail of human vascular endothelial growth factor A (VEGF-A) and human bone morphogenetic protein 2 (BMP-2) mRNAs within a customized injectable PEGylated poly (glycerol sebacate) acrylate (PEGS-A) hydrogel for bone regeneration in rats with challenging femur critical-size defects are introduced. Abundant t-sEVs are produced by a facile cellular nanoelectroporation system based on a commercially available track-etched membrane (TM-nanoEP) to deliver plasmid DNAs to human adipose-derived mesenchymal stem cells (hAdMSCs). Upregulated microRNAs associated with the therapeutic mRNAs are enriched in t-sEVs for enhanced angiogenic-osteogenic regeneration. Localized and controlled release of t-sEVs within the PEGS-A hydrogel leads to the retention of therapeutics in the defect site for highly efficient bone regeneration with minimal low accumulation in other organs.

Cellular organelles as drug carriers for disease treatment

Organelles not only constitute the basic structure of the cell but also are important in maintaining the normal physiological activities of the cell. With the development of biomimetic nanoscience, researchers have developed technologies to use organelles as drug carriers for disease treatment. Compared with traditional drug carriers, organelle drug carriers have the advantages of good biocompatibility, high drug loading efficiency, and modifiability, and the surface biomarkers of organelles can also participate in intracellular signal transduction to enhance intracellular and intercellular communication, and assist in enhancing the therapeutic effect of drugs. Among different types of organelles, extracellular vesicles, lipid droplets, lysosomes, and mitochondria have been used as drug carriers. This review briefly reviews the biogenesis, isolation methods, and drug-loading methods of four types of organelles, and systematically summarizes the research progress in using organelles as drug-delivery systems for disease treatment. Finally, the challenges faced by organelle-based drug delivery systems are discussed. Although the organelle-based drug delivery systems still face challenges before they can achieve clinical translation, they offer a new direction and vision for the development of next-generation drug carriers.

Transcriptome profiling of patient-derived tumor xenografts suggests novel extracellular matrix-related signatures for gastric cancer prognosis prediction

BACKGROUND

A major obstacle to the development of personalized therapies for gastric cancer (GC) is the prevalent heterogeneity at the intra-tumor, intra-patient, and inter-patient levels. Although the pathological stage and histological subtype diagnosis can approximately predict prognosis, GC heterogeneity is rarely considered. The extracellular matrix (ECM), a major component of the tumor microenvironment (TME), extensively interacts with tumor and immune cells, providing a possible proxy to investigate GC heterogeneity. However, ECM consists of numerous protein components, and there are no suitable models to screen ECM-related genes contributing to tumor growth and prognosis. We constructed patient-derived tumor xenograft (PDTX) models to obtain robust ECM-related transcriptomic signatures to improve GC prognosis prediction and therapy design.

METHODS

One hundred twenty two primary GC tumor tissues were collected to construct PDTX models. The tumorigenesis rate and its relationship with GC prognosis were investigated. Transcriptome profiling was performed for PDTX-originating tumors, and least absolute shrinkage and selection operator (LASSO) Cox regression analysis was applied to extract prognostic ECM signatures and establish PDTX tumorigenicity-related gene (PTG) scores. The predictive ability of the PTG score was validated using two independent cohorts. Finally, we combined PTG score, age, and pathological stage information to establish a robust nomogram for GC prognosis prediction.

RESULTS

We found that PDTX tumorigenicity indicated a poor prognosis in patients with GC, even at the same pathological stage. Transcriptome profiling of PDTX-originating GC tissues and corresponding normal controls identified 383 differentially expressed genes, with enrichment of ECM-related genes. A robust prognosis prediction model using the PTG score showed robust performance in two validation cohorts. A high PTG score was associated with elevated M2 polarized macrophage and cancer-associated fibroblast infiltration. Finally, combining the PTG score with age and TNM stage resulted in a more effective prognostic model than age or TNM stage alone.

CONCLUSIONS

We found that ECM-related signatures may contribute to PDTX tumorigenesis and indicate a poor prognosis in GC. A feasible survival prediction model was built based on the PTG score, which was associated with immune cell infiltration. Together with patient ages and pathological TNM stages, PTG score could be a new approach for GC prognosis prediction.

Pathological and Therapeutic Significance of Tumor-Derived Extracellular Vesicles in Cancer Cell Migration and Metastasis

The infiltration of primary tumors and metastasis formation at distant sites strongly impact the prognosis and the quality of life of cancer patients. Current therapies including surgery, radiotherapy, and chemotherapy are limited in targeting the complex cell migration mechanisms responsible for cancer cell invasiveness and metastasis. A better understanding of these mechanisms and the development of new therapies are urgently needed. Extracellular vesicles (EVs) are lipid-enveloped particles involved in inter-tissue and inter-cell communication. This review article focuses on the impact of EVs released by tumor cells, specifically on cancer cell migration and metastasis. We first introduce cell migration processes and EV subtypes, and we give an overview of how tumor-derived EVs (TDEVs) may impact cancer cell migration. Then, we discuss ongoing EV-based cancer therapeutic approaches, including the inhibition of general EV-related mechanisms as well as the use of EVs for anti-cancer drug delivery, focusing on the harnessing of TDEVs. We propose a protein-EV shuttle as a route alternative to secretion or cell membrane binding, influencing downstream signaling and the final effect on target cells, with strong implications in tumorigenesis. Finally, we highlight the pitfalls and limitations of therapeutic EV exploitation that must be overcome to realize the promise of EVs for cancer therapy.

The Fatal Role of Enterohaemorrhagic Escherichia coli Shiga Toxin-associated Extracellular Vesicles in Host Cells

Enterohemorrhagic Escherichia coli (EHEC) is a specific subset of Shiga toxin-producing Escherichia coli (STEC) strains that are characterized by their ability to cause bloody diarrhea (hemorrhagic colitis) and potentially life-threatening, extraintestinal complications such as hemolytic uremic syndrome (HUS), which is associated with acute renal failure., contributing to severe clinical outcomes. The Shiga toxins (Stxs), produced by EHEC, are primary virulence factors. These potent cytotoxins are composed of one enzymatically active A subunit (StxA) and five receptor-binding B subunits (StxB). Although the toxins are primarily associated with cytotoxic effects, they also elicit other pathogenic consequences due to their induction of a number of biological processes, including apoptosis through ER-stress, pro-inflammatory responses, autophagy, and post-translational modification (PTM). Moreover, several studies have reported the association between Stxs and extracellular vesicles (EVs), including microvesicles and exosomes, demonstrating that Stx-containing EVs secreted by intoxicated macrophages are taken up by recipient cells, such as toxin-sensitive renal proximal tubular epithelial cells. This mechanism likely contributes to the spreading of Stxs within the host, and may exacerbate gastrointestinal illnesses and kidney dysfunction. In this review, we summarize recent findings relating to the host responses, in different types of cells in vitro and in animal models, mediated by Stxs-containing exosomes. Due to their unique properties, EVs have been explored as therapeutic agents, drug delivery systems, and diagnostic tools. Thus, potential therapeutic applications of EVs in EHEC Stxs-mediated pathogenesis are also briefly reviewed.

Optimization of extracellular vesicle isolation and their separation from lipoproteins by size exclusion chromatography

Interest in the use of extracellular vesicles (EVs) as biomarkers of disease is rapidly growing. However, one main unsolved issue in the EV field is finding a technique able to eliminate non-EV contaminants present in biofluid samples in a one-step isolation protocol. Due to the expansion and value of size exclusion chromatography (SEC) as one of the best EV isolation methods, we have tested several agarose resins with different agarose percentages, bead sizes and crosslinking features to optimize EV isolation. For this optimization of SEC, we first employed conditioned media from a melanoma cell culture, a simpler sample in comparison to biological fluids, but which also contains abundant contaminants such as soluble protein and lipoproteins (LPPs). The distinct agaroses and the combinations of resins with different agarose percentages in the same column were tested. Soluble protein, EVs and LPPs levels from the different eluted fractions were quantitated by immunodetection or absorbance measurements. Samples were also analysed by NTA and TEM to verify the yield and the LPP contamination. Different percentages of agarose resins (2%, 4% and 6%) yielded samples with increasing LPP contamination respectively, which was not improved in the columns that combined them. Crosslinking of the agarose did not affect EV isolation yield nor the LPP contamination. In contrast, reducing the bead size greatly improved EV purity. We thus selected 4% Rapid Run Fine agarose beads as the resin that more efficiently isolated EVs with almost no contamination of other particles. Using blood plasma samples, this resin also demonstrated an improved capacity in the isolation of EVs from LPPs in comparison to the agaroses most commonly used in the field and differential ultracentrifugation.

Surface-Engineered Extracellular Vesicles in Cancer Immunotherapy

Extracellular vesicles (EVs) are lipid bilayer-enclosed bodies secreted by all cell types. EVs carry bioactive materials, such as proteins, lipids, metabolites, and nucleic acids, to communicate and elicit functional alterations and phenotypic changes in the counterpart stromal cells. In cancer, cells secrete EVs to shape a tumor-promoting niche. Tumor-secreted EVs mediate communications with immune cells that determine the fate of anti-tumor therapeutic effectiveness. Surface engineering of EVs has emerged as a promising tool for the modulation of tumor microenvironments for cancer immunotherapy. Modification of EVs' surface with various molecules, such as antibodies, peptides, and proteins, can enhance their targeting specificity, immunogenicity, biodistribution, and pharmacokinetics. The diverse approaches sought for engineering EV surfaces can be categorized as physical, chemical, and genetic engineering strategies. The choice of method depends on the specific application and desired outcome. Each has its advantages and disadvantages. This review lends a bird's-eye view of the recent progress in these approaches with respect to their rational implications in the immunomodulation of tumor microenvironments (TME) from pro-tumorigenic to anti-tumorigenic ones. The strategies for modulating TME using targeted EVs, their advantages, current limitations, and future directions are discussed.

Exosomal MicroRNA Levels Associated with Immune Checkpoint Inhibitor Therapy in Clear Cell Renal Cell Carcinoma

Immunotherapy with immune checkpoint inhibitors (ICIs) has shown high efficiency in clear cell renal cell carcinoma (ccRCC) treatment. However, the response to therapy among patients varies greatly. Modern studies demonstrate the high potential of exosomal miRNAs as diagnostic and prognostic markers in oncopathology. This study aimed to evaluate exosomal miRNA expression profiles of miRNAs-144, -146a, -149, -126, and -155 in patients with clear cell renal cell carcinoma treated with immune checkpoint inhibitors. The study included 35 patients whose venous blood samples were taken before and after ICI therapy. Expression analysis was performed using real-time quantitative PCR. It was demonstrated that the level of microRNA-146a increased after therapy (median(IQR) 12.92(4.06–18.90)) compared with the level before it (median(IQR) 7.15(1.90–10.50); p-value = 0.006). On the contrary, microRNA-126 was reduced after therapy with immune checkpoint inhibitors (median(IQR) 0.85(0.55–1.03) vs. 0.48(0.15–0.68) before and after therapy, respectively; p-value = 0.0001). In addition, miRNA-146a expression was shown to be reduced in patients with a higher grade of immune-related adverse events (p-value = 0.020). The AUC value for the miRNA-146a and miRNA-126 combination was 0.752 (95% CI 0.585–0.918), with the sensitivity at 64.3% and the specificity at 78.9%. Thus, while it can be assumed that miRNA-146a and miRNA-126 can be used as predictors for ICI therapy effectiveness, additional in-depth studies are required.

Detection of Breast Cancer-Specific Extracellular Vesicles with Fiber-Optic SPR Biosensor

Extracellular vesicles (EVs) have attracted great attention as potential biomarkers for cancer diagnostics. Although several technologies have been developed for EV detection, many of them are still not applicable to clinical settings as they rely on complex EV isolation processes, while lacking sensitivity, specificity or standardization. To solve this problem, we have developed a sensitive breast cancer-specific EV detection bioassay directly in blood plasma using a fiber-optic surface plasmon resonance (FO-SPR) biosensor, previously calibrated with recombinant EVs. First, we established a sandwich bioassay to detect SK-BR-3 EVs by functionalizing the FO-SPR probes with anti-HER2 antibodies. A calibration curve was built using an anti-HER2/^Banti-CD9 combination, resulting in an LOD of 2.1 × 10⁷ particles/mL in buffer and 7 × 10⁸ particles/mL in blood plasma. Next, we investigated the potential of the bioassay to detect MCF7 EVs in blood plasma using an anti-EpCAM/^Banti-mix combination, obtaining an LOD of 1.1 × 10 ⁸ particles/mL. Finally, the specificity of the bioassay was proven by the absence of signal when testing plasma samples from 10 healthy people unknown to be diagnosed with breast cancer. The remarkable sensitivity and specificity of the developed sandwich bioassay together with the advantages of the standardized FO-SPR biosensor highlight outstanding potential for the future of EV analysis.

Engineered mesenchymal stem cell-derived extracellular vesicles: A state-of-the-art multifunctional weapon against Alzheimer's disease

With the increase of population aging, the number of Alzheimer's disease (AD) patients is also increasing. According to current estimates, approximately 11% of people over 65 suffer from AD, and that percentage rises to 42% among people over 85. However, no effective treatment capable of decelerating or stopping AD progression is available. Furthermore, AD-targeted drugs composed of synthetic molecules pose concerns regarding biodegradation, clearance, immune response, and neurotoxicity. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) are essential intercellular communication mediators holding great promise as AD therapeutics owing to their biocompatibility, versatility, effortless storage, superior safety, and the ability to transport messenger and noncoding RNAs, proteins, lipids, DNAs, and other bioactive compounds derived from cells. The functionalisation and engineering strategies of MSC-EVs are highlighted (e.g. preconditioning, drug loading, surface modification, and artificial EV fabrication), which could improve AD treatment by multiple therapeutic effects, including clearing abnormal protein accumulation and achieving neuroprotection and immunomodulatory effects. Herein, this review summarises state-of-the-art strategies to engineer MSC-EVs, discusses progress in their use as AD therapeutics, presents the perspectives and challenges associated with the related clinical applications, and concludes that engineered MSC-EVs show immense potential in AD therapy.

Cellular and molecular basis of therapeutic approaches to breast cancer

In recent decades, there has been a significant amount of research into breast cancer, with some important breakthroughs in the treatment of both primary and metastatic breast cancers. It's a well-known fact that treating breast cancer is still a challenging endeavour even though physicians have a fantastic toolset of the latest treatment options at their disposal. Due to limitations of current clinical treatment options, traditional chemotherapeutic drugs, and surgical options are still required to address this condition. In recent years, there have been several developments resulting in a wide range of treatment options. This review article discusses the cellular and molecular foundation of chemotherapeutic drugs, endocrine system-based treatments, biological therapies, gene therapy, and innovative techniques for treating breast cancer.

Advances in the Lung Cancer Immunotherapy Approaches

Despite the progress in the comprehension of LC progression, risk, immunologic control, and treatment choices, it is still the primary cause of cancer-related death. LC cells possess a very low and heterogeneous antigenicity, which allows them to passively evade the anticancer defense of the immune system by educating cytotoxic lymphocytes (CTLs), tumor-infiltrating lymphocytes (TILs), regulatory T cells (Treg), immune checkpoint inhibitors (ICIs), and myeloid-derived suppressor cells (MDSCs). Though ICIs are an important candidate in first-line therapy, consolidation therapy, adjuvant therapy, and other combination therapies involving traditional therapies, the need for new predictive immunotherapy biomarkers remains. Furthermore, ICI-induced resistance after an initial response makes it vital to seek and exploit new targets to benefit greatly from immunotherapy. As ICIs, tumor mutation burden (TMB), and microsatellite instability (MSI) are not ideal LC predictive markers, a multi-parameter analysis of the immune system considering tumor, stroma, and beyond can be the future-oriented predictive marker. The optimal patient selection with a proper adjuvant agent in immunotherapy approaches needs to be still revised. Here, we summarize advances in LC immunotherapy approaches with their clinical and preclinical trials considering cancer models and vaccines and the potential of employing immunology to predict immunotherapy effectiveness in cancer patients and address the viewpoints on future directions. We conclude that the field of lung cancer therapeutics can benefit from the use of combination strategies but with comprehension of their limitations and improvements.

Extracellular Vesicles and Membrane Protrusions in Developmental Signaling

During embryonic development, cells communicate with each other to determine cell fate, guide migration, and shape morphogenesis. While the relevant secreted factors and their downstream target genes have been characterized extensively, how these signals travel between embryonic cells is still emerging. Evidence is accumulating that extracellular vesicles (EVs), which are well defined in cell culture and cancer, offer a crucial means of communication in embryos. Moreover, the release and/or reception of EVs is often facilitated by fine cellular protrusions, which have a history of study in development. However, due in part to the complexities of identifying fragile nanometer-scale extracellular structures within the three-dimensional embryonic environment, the nomenclature of developmental EVs and protrusions can be ambiguous, confounding progress. In this review, we provide a robust guide to categorizing these structures in order to enable comparisons between developmental systems and stages. Then, we discuss existing evidence supporting a role for EVs and fine cellular protrusions throughout development.

Cancer Immunotherapy and Delivery System: An Update

With an understanding of immunity in the tumor microenvironment, immunotherapy turns out to be a powerful tool in the clinic to treat many cancers. The strategies applied in cancer immunotherapy mainly include blockade of immune checkpoints, adoptive transfer of engineered cells, such as T cells, natural killer cells, and macrophages, cytokine therapy, cancer vaccines, and oncolytic virotherapy. Many factors, such as product price, off-target side effects, immunosuppressive tumor microenvironment, and cancer cell heterogeneity, affect the treatment efficacy of immunotherapies against cancers. In addition, some treatments, such as chimeric antigen receptor (CAR) T cell therapy, are more effective in treating patients with lymphoma, leukemia, and multiple myeloma rather than solid tumors. To improve the efficacy of targeted immunotherapy and reduce off-target effects, delivery systems for immunotherapies have been developed in past decades using tools such as nanoparticles, hydrogel matrix, and implantable scaffolds. This review first summarizes the currently common immunotherapies and their limitations. It then synopsizes the relative delivery systems that can be applied to improve treatment efficacy and minimize side effects. The challenges, frontiers, and prospects for applying these delivery systems in cancer immunotherapy are also discussed. Finally, the application of these approaches in clinical trials is reviewed.

NFκB activation by hypoxic small extracellular vesicles drives oncogenic reprogramming in a breast cancer microenvironment

Small extracellular vesicles (sEV) contribute to the crosstalk between tumor cells and stroma, but the underlying signals are elusive. Here, we show that sEV generated by breast cancer cells in hypoxic (sEVHYP), but not normoxic (sEVNORM) conditions activate NFκB in recipient normal mammary epithelial cells. This increases the production and release of inflammatory cytokines, promotes mitochondrial dynamics leading to heightened cell motility and disrupts 3D mammary acini architecture with aberrant cell proliferation, reduced apoptosis and EMT. Mechanistically, Integrin-Linked Kinase packaged in sEVHYP via HIF1α is sufficient to activate NFκB in the normal mammary epithelium, in vivo. Therefore, sEVHYP activation of NFκB drives multiple oncogenic steps of inflammation, mitochondrial dynamics, and mammary gland morphogenesis in a breast cancer microenvironment.

Modification of Lipid-Based Nanoparticles: An Efficient Delivery System for Nucleic Acid-Based Immunotherapy

Lipid-based nanoparticles (LBNPs) are biocompatible and biodegradable vesicles that are considered to be one of the most efficient drug delivery platforms. Due to the prominent advantages, such as long circulation time, slow drug release, reduced toxicity, high transfection efficiency, and endosomal escape capacity, such synthetic nanoparticles have been widely used for carrying genetic therapeutics, particularly nucleic acids that can be applied in the treatment for various diseases, including congenital diseases, cancers, virus infections, and chronic inflammations. Despite great merits and multiple successful applications, many extracellular and intracellular barriers remain and greatly impair delivery efficacy and therapeutic outcomes. As such, the current state of knowledge and pitfalls regarding the gene delivery and construction of LBNPs will be initially summarized. In order to develop a new generation of LBNPs for improved delivery profiles and therapeutic effects, the modification strategies of LBNPs will be reviewed. On the basis of these developed modifications, the performance of LBNPs as therapeutic nanoplatforms have been greatly improved and extensively applied in immunotherapies, including infectious diseases and cancers. However, the therapeutic applications of LBNPs systems are still limited due to the undesirable endosomal escape, potential aggregation, and the inefficient encapsulation of therapeutics. Herein, we will review and discuss recent advances and remaining challenges in the development of LBNPs for nucleic acid-based immunotherapy.

Role of the Mediator Complex and MicroRNAs in Breast Cancer Etiology

Transcriptional coactivators play a key role in RNA polymerase II transcription and gene regulation. One of the most important transcriptional coactivators is the Mediator (MED) complex, which is an evolutionary conserved large multiprotein complex. MED transduces the signal between DNA-bound transcriptional activators (gene-specific transcription factors) to the RNA polymerase II transcription machinery to activate transcription. It is known that MED plays an essential role in ER-mediated gene expression mainly through the MED1 subunit, since estrogen receptor (ER) can interact with MED1 by specific protein–protein interactions; therefore, MED1 plays a fundamental role in ER-positive breast cancer (BC) etiology. Additionally, other MED subunits also play a role in BC etiology. On the other hand, microRNAs (miRNAs) are a family of small non-coding RNAs, which can regulate gene expression at the post-transcriptional level by binding in a sequence-specific fashion at the 3′ UTR of the messenger RNA. The miRNAs are also important factors that influence oncogenic signaling in BC by acting as both tumor suppressors and oncogenes. Moreover, miRNAs are involved in endocrine therapy resistance of BC, specifically to tamoxifen, a drug that is used to target ER signaling. In metazoans, very little is known about the transcriptional regulation of miRNA by the MED complex and less about the transcriptional regulation of miRNAs involved in BC initiation and progression. Recently, it has been shown that MED1 is able to regulate the transcription of the ER-dependent miR-191/425 cluster promoting BC cell proliferation and migration. In this review, we will discuss the role of MED1 transcriptional coactivator in the etiology of BC and in endocrine therapy-resistance of BC and also the contribution of other MED subunits to BC development, progression and metastasis. Lastly, we identified miRNAs that potentially can regulate the expression of MED subunits.

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...

Emerging Role of Extracellular Vesicles and Cellular Communication in Metastasis

Communication between cancer cells and the surrounding stromal cells of the tumor microenvironment (TME) plays a key role in promoting metastasis, which is the major cause of cancer death. Small membrane-bound particles called extracellular vesicles (EVs) are released from both cancer and stromal cells and have a key role in mediating this communication through transport of cargo such as various RNA species (mRNA, miRNA, lncRNA), proteins, and lipids. Tumor-secreted EVs have been observed to induce a pro-tumorigenic phenotype in non-malignant cells of the stroma, including fibroblasts, endothelial cells, and local immune cells. These cancer-associated cells then drive metastasis by mechanisms such as increasing the invasiveness of cancer cells, facilitating angiogenesis, and promoting the formation of the pre-metastatic niche. This review will cover the role of EV-mediated signaling in the TME during metastasis and highlight the therapeutic potential of targeting these pathways to develop biomarkers and novel treatment strategies.

Extracellular Vesicles in Lung Cancer Metastasis and Their Clinical Applications

Extracellular vesicles (EVs) are heterogenous membrane-encapsulated vesicles secreted by every cell into the extracellular environment. EVs carry bioactive molecules, including proteins, lipids, DNA, and different RNA forms, which can be internalized by recipient cells, thus altering their biological characteristics. Given that EVs are commonly found in most body fluids, they have been widely described as mediators of communication in several physiological and pathological processes, including cancer. Moreover, their easy detection in biofluids makes them potentially useful candidates as tumor biomarkers. In this manuscript, we review the current knowledge regarding EVs and non-coding RNAs and their role as drivers of the metastatic process in lung cancer. Furthermore, we present the most recent applications for EVs and non-coding RNAs as cancer therapeutics and their relevance as clinical biomarkers.

Mitochondrial Extracellular Vesicles - Origins and Roles

Extracellular vesicles (EVs) have emerged in the last decade as critical cell-to-cell communication devices used to carry nucleic acids and proteins between cells. EV cargo includes plasma membrane and endosomal proteins, but EVs also contain material from other cellular compartments, including mitochondria. Within cells, mitochondria are responsible for a large range of metabolic reactions, but they can also produce damaging levels of reactive oxygen species and induce inflammation when damaged. Consistent with this, recent evidence suggests that EV-mediated transfer of mitochondrial content alters metabolic and inflammatory responses of recipient cells. As EV mitochondrial content is also altered in some pathologies, this could have important implications for their diagnosis and treatment. In this review, we will discuss the nature and roles of mitochondrial EVs, with a special emphasis on the nervous system.

Exosomes as Efficient Nanocarriers in Osteosarcoma: Biological Functions and Potential Clinical Applications

Osteosarcoma is the most common bone tumor affecting both adolescents and children. Although localized osteosarcoma has an overall survival of >70% in the clinic, metastatic, refractory, and recurrent osteosarcoma have poorer survival rates. Exosomes are extracellular vesicles released by cells and originally thought to be a way for cells to discard unwanted products. Currently, exosomes have been reported to be involved in intercellular cross-talk and induce changes in cellular behavior by transferring cargoes (proteins, DNA, RNA, and lipids) between cells. Exosomes regulate osteosarcoma progression, and processes such as tumorigenesis, proliferation, metastasis, angiogenesis, immune evasion, and drug resistance. Increasing evidences shows that exosomes have significant potential in promoting osteosarcoma progression and development. In this review, we describe the current research status of exosomes in osteosarcoma, focusing on the biological functions of osteosarcoma exosomes as well as their application in osteosarcoma as diagnostic biomarkers and therapeutic targets.

Biomimetic Nanostructure Platform for Cancer Diagnosis Based on Tumor Biomarkers

Biomarker discovery and its clinical use have attracted considerable attention since early cancer diagnosis can significantly decrease mortality. Cancer biomarkers include a wide range of biomolecules, such as nucleic acids, proteins, metabolites, sugars, and cytogenetic substances present in human biofluids. Except for free-circulating biomarkers, tumor-extracellular vesicles (tEVs) and circulating tumor cells (CTCs) can serve as biomarkers for the diagnosis and prognosis of various cancers. Considering the potential of tumor biomarkers in clinical settings, several bioinspired detection systems based on nanotechnologies are in the spotlight for detection. However, tremendous challenges remain in detection because of massive contamination, unstable signal-to-noise ratios due to heterogeneity, nonspecific bindings, or a lack of efficient amplification. To date, many approaches are under development to improve the sensitivity and specificity of tumor biomarker isolation and detection. Particularly, the exploration of natural materials in biological frames has encouraged researchers to develop new bioinspired and biomimetic nanostructures, which can mimic the natural processes to facilitate biomarker capture and detection in clinical settings. These platforms have substantial influence in biomedical applications, owing to their capture ability, significant contrast increase, high sensitivity, and specificity. In this review, we first describe the potential of tumor biomarkers in a liquid biopsy and then provide an overview of the progress of biomimetic nanostructure platforms to isolate and detect tumor biomarkers, including in vitro and in vivo studies. Capture efficiency, scale, amplification, sensitivity, and specificity are the criteria that will be further discussed for evaluating the capability of platforms. Bioinspired and biomimetic systems appear to have a bright future to settle obstacles encountered in tumor biomarker detection, thus enhancing effective cancer diagnosis.

Mesenchymal Stem Cells Do Not Lose Direct Labels Including Iron Oxide Nanoparticles and DFO-89Zr Chelates through Secretion of Extracellular Vesicles

Rapidly ageing populations are beset by tissue wear and damage. Stem cell-based regenerative medicine is considered a solution. Years of research point to two important aspects: (1) the use of cellular imaging to achieve sufficient precision of therapeutic intervention, and the fact that (2) many therapeutic actions are executed through extracellular vesicles (EV), released by stem cells. Therefore, there is an urgent need to interrogate cellular labels in the context of EV release. We studied clinically applicable cellular labels: superparamagnetic iron oxide nanoparticles (SPION), and radionuclide detectable by two main imaging modalities: MRI and PET. We have demonstrated effective stem cell labeling using both labels. Then, we obtained EVs from cell cultures and tested for the presence of cellular labels. We did not find either magnetic or radioactive labels in EVs. Therefore, we report that stem cells do not lose labels in released EVs, which indicates the reliability of stem cell magnetic and radioactive labeling, and that there is no interference of labels with EV content. In conclusion, we observed that direct cellular labeling seems to be an attractive approach to monitoring stem cell delivery, and that, importantly, labels neither locate in EVs nor affect their basic properties.