Tumor-derived small extracellular vesicles in cancer invasion and metastasis: molecular mechanisms, and clinical significance

Salivary adenoid cystic carcinoma-derived α2,6-sialylated extracellular vesicles increase vascular permeability by triggering ER-stress in endothelial cells and promote lung metastasis

Salivary adenoid cystic carcinoma (SACC) tends to metastasize to the lungs in the early stages of the disease. Factors secreted by the primary tumor can induce the formation of a supportive microenvironment in distant organs prior to metastasis, a process known as pre-metastatic niche (PMN) formation. Extracellular vesicles (EVs) participate in PMN formation. In this study, α2,6-sialylation of EVs derived from SACC cells with high metastatic potential increased vascular permeability, thereby facilitating tumor metastasis to the lungs. Mechanistic studies indicated that EV α2,6-sialylation triggers protein kinase R-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2α (eIF2α)-dependent activation of endoplasmic reticulum (ER) stress in the endothelium, leading to the disruption of vascular endothelial cadherin membrane expression. Sialidase or an ER stress inhibitor rescued vascular permeability induced by SACC EVs, which decreased the number of SACC cells extravasating into the lungs both in vitro and in vivo. This study identified a critical role of α2,6-sialylation of SACC EVs in lung metastasis. The findings indicate that EV α2,6-sialylation-induced ER stress in endothelial cells might be a therapeutic target for preventing SACC lung metastasis.

A catalytic assembly triggered DNAzyme motor on spherical nucleic acids for sensitive small extracellular vesicle detection

The expression levels of small extracellular vesicles (sEVs) are closely associated with several significant biological processes, which can be used as a crucial biomarker for cancer diagnosis, such as colorectal cancer. More efforts are still necessary to amplify sEV detection sensitivity, as their expression is minimal during the early stages of colorectal cancer. Through the integration of a catalytic assembly-triggered DNAzyme motor and gold nanoparticle (AuNP) aggregation, we have developed a triple signal amplified biosensor for the detection of sEVs. In this method, the catalytic assembly triggered DNAzyme motor continuously cleaved on the hairpin probe which is fixed on the surface of AuNPs, leaving a single-stranded sequence on the surface of AuNPs to induce the aggregation. This approach employs a triple signal amplification process to enhance the efficiency of the reaction and circumvent the issue of expensive and readily degradable proteases. The signal output system is based on dynamic light scattering technology, which enables ultra-sensitive detection of sEVs with a detection limit of 3.08 particles per μL. The present strategy exhibits significant potential for the analysis of a variety of additional analytes in clinical research disciplines due to its appealing analytical capabilities.

Microfluidic Nanoparticle Separation for Precision Medicine

A deeper understanding of disease heterogeneity highlights the urgent need for precision medicine. Microfluidics, with its unique advantages, such as high adjustability, diverse material selection, low cost, high processing efficiency, and minimal sample requirements, presents an ideal platform for precision medicine applications. As nanoparticles, both of biological origin and for therapeutic purposes, become increasingly important in precision medicine, microfluidic nanoparticle separation proves particularly advantageous for handling valuable samples in personalized medicine. This technology not only enhances detection, diagnosis, monitoring, and treatment accuracy, but also reduces invasiveness in medical procedures. This review summarizes the fundamentals of microfluidic nanoparticle separation techniques for precision medicine, starting with an examination of nanoparticle properties essential for separation and the core principles that guide various microfluidic methods. It then explores passive, active, and hybrid separation techniques, detailing their principles, structures, and applications. Furthermore, the review highlights their contributions to advancements in liquid biopsy and nanomedicine. Finally, it addresses existing challenges and envisions future development spurred by emerging technologies such as advanced materials science, 3D printing, and artificial intelligence. These interdisciplinary collaborations are anticipated to propel the platformization of microfluidic separation techniques, significantly expanding their potential in precision medicine.

TYROBP promotes the spread of pancreatic cancer by causing M2 TAM polarization

BACKGROUND AND AIM

M2-polarized tumor-associated macrophages (M2 TAMs) are known to promote cancer progression, and exosomes are crucial mediators of communication within the tumor microenvironment (TME). However, the specific role of exosomes derived from M2 TAMs in pancreatic cancer (PC) progression remains poorly understood. Tyrosine kinase binding protein (TYROBP, also known as DAP12 for DNAX activating protein-12) is a transmembrane signal transduction polypeptide that interacts with immune cell receptors, influencing cellular functions via signal transduction pathways. TYROBP is prominently found in M2 TAMs exosomes, facilitating its transfer to PC cells and suggesting a potential role in PC pathogenesis.

METHODS

This study initially confirmed the presence of TYROBP in M2 TAMs exosomes and its transfer to PC cells via exosomes. The impact of TYROBP on PC proliferation, apoptosis, migration, and invasion was investigated. Special attention was given to TYROBP's influence on PC metastasis and its underlying mechanisms, focusing particularly on the CD44/AKT/ERK signaling pathway.

RESULTS

TYROBP expression in PC cells did not significantly affect tumor cell proliferation or apoptosis but demonstrated a notable inhibitory effect on migration and invasion, which was mediated through the CD44/AKT/ERK pathway. Both in vivo and in vitro experiments consistently showed that TYROBP enhanced PC metastasis.

CONCLUSIONS

This study elucidates that TYROBP plays a direct role in promoting PC metastasis through its association with M2 TAMs polarization. Therefore, TYROBP represents a potential novel therapeutic target for interventions aimed at combatting PC progression.

Soluble and EV-bound CD27 act as antagonistic biomarkers in patients with solid tumors undergoing immunotherapy

BACKGROUND

The major breakthrough in cancer therapy with immune checkpoint inhibitors (ICIs) has highlighted the important role of immune checkpoints in antitumoral immunity. However, most patients do not achieve durable responses, making biomarker research in this setting essential. CD27 is a well known costimulatory molecule, however the impact of its soluble form in ICI is poorly investigated. Therefore, we aimed at testing circulating concentrations of soluble CD27 (sCD27) and CD27 bound to extracellular vesicles (EVs) as potential biomarkers to predict response and overall survival (OS) in patients undergoing ICI.

METHODS

Serum and plasma levels of sCD27 were assessed by immunoassay in three patient cohorts (n = 187) with advanced solid malignancies including longitudinal samples (n = 126): a training (n = 84, 210 specimens, Aachen ICI) and validation cohort (n = 70, 70 specimens, Hamburg ICI), both treated with ICI therapy, and a second independent validation cohort (n = 33, 33 specimens, Hamburg non-ICI) undergoing systemic therapy without any ICI. In a subset (n = 36, 36 baseline and 108 longitudinal specimens), EV-bound CD27 from serum was measured, while EV characterization studies were conducted on a fourth cohort (n = 45).

RESULTS

In the Aachen and Hamburg ICI cohorts, patients with lower circulating sCD27 levels before and during ICI therapy had a significantly longer progression-free survival (PFS) and OS compared to patients with higher levels, a finding that was confirmed by multivariate analysis (MVA) (Aachen ICI: pPFS = 0.012, pOS = 0.001; Hamburg ICI: pPFS = 0.040, pOS = 0.004) and after randomly splitting both cohorts into training and validation. This phenomenon was not observed in the Hamburg non-ICI cohort, providing a rationale for the predictive biomarker role of sCD27 in immune checkpoint blockade. Remarkably, EV-bound CD27 baseline levels and dynamics during ICI therapy also emerged as potent predictive biomarkers, acting however antagonistically to soluble sCD27, i.e. higher levels were associated with PFS and OS benefit. Combining both molecules ("multi-CD27" score) enhanced the predictive ability (HRPFS: 17.21 with p < 0.001, HROS: 6.47 with p = 0.011).

CONCLUSION

Soluble and EV-bound CD27 appear to have opposing immunomodulatory functions and may represent easily measurable, non-invasive prognostic markers to predict response and survival in patients undergoing ICI therapy.

The Biological Roles of ZKSCAN3 (ZNF306) in the Hallmarks of Cancer: From Mechanisms to Therapeutics

ZKSCAN3 (also known as ZNF306) plays a pivotal role in the regulation of various cellular processes that are fundamental to the development of cancer. It has been widely acknowledged as a key contributor to cancer progression, with its overexpression consistently reported in a broad spectrum of malignancies. Importantly, clinical studies have demonstrated a significant association between elevated ZKSCAN3 levels and adverse prognosis, as well as resistance to therapeutic drugs. Specifically, ZKSCAN3 promotes tumor progression by enhancing multiple hallmark features of cancer and promoting the acquisition of cancer-specific phenotypes. These effects manifest as increased tumor cell proliferation, invasion, and metastasis, accompanied by inhibiting tumor cell apoptosis and modulating autophagy. Consequently, ZKSCAN3 emerges as a promising prognostic marker, and targeting its inhibition represents a potential strategy for anti-tumor therapy. In this review, we provide an updated perspective on the role of ZKSCAN3 in governing tumor characteristics and the underlying molecular mechanisms. Furthermore, we underscore the clinical relevance of ZKSCAN3 and its potential implications for tumor prognosis and therapeutic strategies.

Nanoparticle Tracking Analysis: An Effective Tool to Characterize Extracellular Vesicles

Extracellular vesicles (EVs) are membrane-enclosed particles that have attracted much attention for their potential in disease diagnosis and therapy. However, the clinical translation is limited by the dosing consistency due to their heterogeneity. Among various characterization techniques, nanoparticle tracking analysis (NTA) offers distinct benefits for EV characterization. In this review, we will discuss the NTA technique with a focus on factors affecting the results; then, we will review the two modes of the NTA techniques along with suitable applications in specific areas of EV studies. EVs are typically characterized by their size, size distribution, concentration, protein markers, and RNA cargos. The light-scattering mode of NTA offers accurate size, size distribution, and concentration information in solution, which is useful for comparing EV isolation methods, storage conditions, and EV secretion conditions. In contrast, fluorescent mode of NTA allows differentiating EV subgroups based on specific markers. The success of fluorescence NTA heavily relies on fluorescent tags (e.g., types of dyes and labeling methods). When EVs are labeled with disease-specific markers, fluorescence NTA offers an effective tool for disease detection in biological fluids, such as saliva, blood, and serum. Finally, we will discuss the limitations and future directions of the NTA technique in EV characterization.

Elucidating the role of FOS in modulating the immune microenvironment through fibroblast and myeloid cell regulation in locoregional recurrent HNSCC

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) presents a significant clinical challenge, particularly due to its high propensity for locoregional recurrence. Current research underscores the need to unravel the complex interactions within the tumor microenvironment. This study addresses the critical gap in understanding how FOS modulates the immune landscape in HNSCC, with a focus on its influence on fibroblast and myeloid cell dynamics.

METHODS

Employing a comprehensive approach, we analyzed tissue samples from HNSCC patients and adjacent non-cancerous tissues using bulk RNA sequencing complemented by in-depth bioinformatics analyses, including gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, and immune infiltration assessment. A pivotal aspect of our research involved dissecting single-cell RNA-seq data from GSE234933 to elucidate the cell-type-specific expression of FOS.

RESULTS

We found that FOS expression varies significantly in different cell populations in the HNSCC tumor microenvironment, especially in fibroblasts and myeloid cells. This expression difference may reflect the different roles of these cells in tumor progression and their impact on the tumor microenvironment.

CONCLUSION

Our results uncover a significant correlation between FOS expression and key immune and hypoxia-related pathways, suggesting its integral role in the tumor microenvironment. These findings not only enhance our understanding of HNSCC pathogenesis but also highlight FOS as a potential therapeutic target. This study marks a significant step towards addressing the urgent need for targeted interventions in HNSCC, particularly in the context of locoregional recurrence.

Prospects and Current Challenges of Extracellular Vesicle-Based Biomarkers in Cancer

Cancer continues to impose a substantial global health burden, particularly among the elderly, where the ongoing global demographic shift towards an ageing population underscores the growing need for early cancer detection. This is essential for enabling personalised cancer care and optimised treatment throughout the disease course to effectively mitigate the increasing societal impact of cancer. Liquid biopsy has emerged as a promising strategy for cancer diagnosis and treatment monitoring, offering a minimally invasive method for the isolation and molecular profiling of circulating tumour-derived components. The expansion of the liquid biopsy approach to include the detection of tumour-derived extracellular vesicles (tdEVs) holds significant therapeutic opportunity. Evidence suggests that tdEVs carry cargo reflecting the contents of their cell-of-origin and are abundant within the blood, exhibiting superior stability compared to non-encapsulated tumour-derived material, such as circulating tumour nucleic acids and proteins. However, despite theoretical promise, several obstacles hinder the translation of extracellular vesicle-based cancer biomarkers into clinical practice. This critical review assesses the current prospects and challenges facing the adoption of tdEV biomarkers in clinical practice, offering insights into future directions and proposing strategies to overcome translational barriers. By addressing these issues, EV-based liquid biopsy approaches could revolutionise cancer diagnostics and management.

Exosomes: Key Factors in Ovarian Cancer Peritoneal Metastasis and Drug Resistance

Ovarian cancer remains a leading cause of death among gynecological cancers, largely due to its propensity for peritoneal metastasis and the development of drug resistance. This review concentrates on the molecular underpinnings of these two critical challenges. We delve into the role of exosomes, the nano-sized vesicles integral to cellular communication, in orchestrating the complex interactions within the tumor microenvironment that facilitate metastatic spread and thwart therapeutic efforts. Specifically, we explore how exosomes drive peritoneal metastasis by promoting epithelial-mesenchymal transition in peritoneal mesothelial cells, altering the extracellular matrix, and supporting angiogenesis, which collectively enable the dissemination of cancer cells across the peritoneal cavity. Furthermore, we dissect the mechanisms by which exosomes contribute to the emergence of drug resistance, including the sequestration and expulsion of chemotherapeutic agents, the horizontal transfer of drug resistance genes, and the modulation of critical DNA repair and apoptotic pathways. By shedding light on these exosome-mediated processes, we underscore the potential of exosomal pathways as novel therapeutic targets, offering hope for more effective interventions against ovarian cancer's relentless progression.

Role of Extracellular Vesicles in the Progression of Brain Tumors

Brain tumors, and, in particular, glioblastoma (GBM), are among the most aggressive forms of cancer. In spite of the advancement in the available therapies, both diagnosis and treatments are still unable to ensure pathology-free survival of the GBM patients for more than 12-15 months. At the basis of the still poor ability to cope with brain tumors, we can consider: (i) intra-tumor heterogeneity; (ii) heterogeneity of the tumor properties when we compare different patients; (iii) the blood-brain barrier (BBB), which makes difficult both isolation of tumor-specific biomarkers and delivering of therapeutic drugs to the brain. Recently, it is becoming increasingly clear that cancer cells release large amounts of extracellular vesicles (EVs) that transport metabolites, proteins, different classes of RNAs, DNA, and lipids. These structures are involved in the pathological process and characterize any particular form of cancer. Moreover, EVs are able to cross the BBB in both directions. Starting from these observations, researchers are now evaluating the possibility to use EVs purified from organic fluids (first of all, blood and saliva), in order to obtain, through non-invasive methods (liquid biopsy), tumor biomarkers, and, perhaps, also for obtaining nanocarriers for the targeted delivering of drugs.

Extracellular Vesicle Preparation and Analysis: A State-of-the-Art Review

In recent decades, research on Extracellular Vesicles (EVs) has gained prominence in the life sciences due to their critical roles in both health and disease states, offering promising applications in disease diagnosis, drug delivery, and therapy. However, their inherent heterogeneity and complex origins pose significant challenges to their preparation, analysis, and subsequent clinical application. This review is structured to provide an overview of the biogenesis, composition, and various sources of EVs, thereby laying the groundwork for a detailed discussion of contemporary techniques for their preparation and analysis. Particular focus is given to state-of-the-art technologies that employ both microfluidic and non-microfluidic platforms for EV processing. Furthermore, this discourse extends into innovative approaches that incorporate artificial intelligence and cutting-edge electrochemical sensors, with a particular emphasis on single EV analysis. This review proposes current challenges and outlines prospective avenues for future research. The objective is to motivate researchers to innovate and expand methods for the preparation and analysis of EVs, fully unlocking their biomedical potential.

NIR-II Light-Driven Genetically Engineered Exosome Nanocatalysts for Efficient Phototherapy against Glioblastoma

Glioblastoma (GBM) poses a significant therapeutic challenge due to its invasive nature and limited drug penetration through the blood-brain barrier (BBB). In response, here we present an innovative biomimetic approach involving the development of genetically engineered exosome nanocatalysts (Mn@Bi2Se3@RGE-Exos) for efficient GBM therapy via improving the BBB penetration and enzyme-like catalytic activities. Interestingly, a photothermally activatable multiple enzyme-like reactivity is observed in such a nanosystem. Upon NIR-II light irradiation, Mn@Bi2Se3@RGE-Exos are capable of converting hydrogen peroxide into hydroxyl radicals, oxygen, and superoxide radicals, providing a peroxidase (POD), oxidase (OXD), and catalase (CAT)-like nanocatalytic cascade. This consequently leads to strong oxidative stresses to damage GBM cells. In vitro, in vivo, and proteomic analysis further reveal the potential of Mn@Bi2Se3@RGE-Exos for the disruption of cellular homeostasis, enhancement of immunological response, and the induction of cancer cell ferroptosis, showcasing a great promise in anticancer efficacy against GBM with a favorable biosafety profile. Overall, the success of this study provides a feasible strategy for future design and clinical study of stimuli-responsive nanocatalytic medicine, especially in the context of challenging brain cancers like GBM.

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.

Exosomal lncRNA XIST promotes perineural invasion of pancreatic cancer cells via miR-211-5p/GDNF

Perineural invasion (PNI) is an essential form of tumor metastasis in multiple malignant cancers, such as pancreatic cancer, prostate cancer, and head and neck cancer. Growing evidence has revealed that pancreatic cancer recurrence and neuropathic pain positively correlate with PNI. Therefore, targeting PNI is a proper strategy for pancreatic cancer treatment. Exosomal lncRNA derived from pancreatic cancer cells is an essential component of the tumor microenvironment. However, whether exosomal lncXIST derived from pancreatic cancer cells can promote PNI and its exact mechanism remains to be elucidated. We show that lncXIST mediates nerve-tumor crosstalk via exosomal delivery. Our data reveal that exosomal lncXIST derived from pancreatic cancer cells is delivered to neural cells and promotes their release of glial-cell-line-derived neurotrophic factor (GDNF), essential in facilitating the PNI of pancreatic cancer. Mechanistically, microRNA-211-5p negatively regulates GDNF, and lncXIST serves as a miR-211-5p sponge. The function of exosomes in the dynamic interplay between nerves and cancer is confirmed in both in vivo and in vitro PNI models. Therefore, targeting pancreatic cancer cell-derived exosomal lncXIST may provide clues for a promising approach for developing a new strategy to combat PNI of pancreatic cancer.

Cytokines and soluble mediators as architects of tumor microenvironment reprogramming in cancer therapy

Navigating the intricate landscape of the tumor microenvironment (TME) unveils a pivotal arena for cancer therapeutics, where cytokines and soluble mediators emerge as double-edged swords in the fight against cancer. This review ventures beyond traditional perspectives, illuminating the nuanced interplay of these elements as both allies and adversaries in cancer dynamics. It critically evaluates the evolving paradigms of TME reprogramming, spotlighting innovative strategies that target the sophisticated network of cytokines and mediators. Special focus is placed on unveiling the therapeutic potential of novel cytokines and mediators, particularly their synergistic interactions with extracellular vesicles, which represent underexplored conduits for therapeutic targeting. Addressing a significant gap in current research, we explore the untapped potential of these biochemical players in orchestrating immune responses, tumor proliferation, and metastasis. The review advocates for a paradigm shift towards exploiting these dynamic interactions within the TME, aiming to transcend conventional treatments and pave the way for a new era of precision oncology. Through a critical synthesis of recent advancements, we highlight the imperative for innovative approaches that harness the full spectrum of cytokine and mediator activities, setting the stage for breakthrough therapies that offer heightened specificity, reduced toxicity, and improved patient outcomes.