Pancreatic cancer exosomes initiate pre-metastatic niche formation in the liver

Visual and fluorescence dual mode platform for sensitive and accurate screening of breast carcinoma

Compared to single-mode detection, dual-mode sensing strategies have garnered increasing attention from researchers due to their superior detection accuracy and reliability. Exosomes, as non-invasive biomarkers, hold significant potential for disease diagnosis. However, sensitive and precise detection of exosomes still presents considerable technical challenges. Inspired by the advantages of dual-mode detection, we developed a visual and fluorescence dual-mode platform (VFDMP) based on an aptamer strategy for exosome detection using enzyme-free nucleic acid amplification and nanomaterial-assisted cation exchange reactions (CERs). The Aptamer-ssDNA complexes capture tumor-derived exosomes, releasing abundant single-stranded DNA (ssDNAs), which then triggers the catalytic hairpin assembly (CHA) cycle, leading to the release of Ag+. The introduced CdTe quantum dots (QDs) act as signal reporters, interacting with Ag+ through CERs, and switching both fluorescence and visual signals from "on" to "off" to achieve exosome detection. Based on this innovative sensing principle, the developed FL/visual dual-mode aptasensor demonstrated excellent sensitivity and accuracy, achieving a low detection limit of 1.1 particles/μL by fluorometer, while exosome concentrations as low as 300 particles/mL could be visually distinguished by naked eye. Furthermore, this dual-mode platform can directly detect exosomes in clinical human serum samples, with only a small volume (10 μL) required. It can accurately differentiate between healthy individuals and breast cancer patients, as well as identify cancer stages (Stage II and Stage III) and subtypes (triple-negative, luminal B, and HER2+). These results suggest that the developed dual-mode detection strategy holds great promise as a sensitive, accurate method for biomarker analysis in clinical samples.

Immunological Pre-Metastatic Niche in Dogs With Naturally Occurring Osteosarcoma

Pre-metastatic niche (PMN) formation is essential for metastatic development and drives organotropism. Tumour-derived extracellular vesicles and soluble factors remodel the microenvironment of distant metastatic organs before subsequent metastasis. Dogs with osteosarcoma (OS) have proven to be excellent disease models for their human companions. Here, we show evidence of PMN formation in dogs with OS before metastasis. We necropsied and sampled lung tissues from dogs with naturally occurring treatment-naïve OS (n = 15) and control dogs without cancer (n = 10). We further divided dogs with OS into those having lung metastases (n = 5) and those without (n = 10). We stained formalin-fixed paraffin-embedded tissues using multiplex immunofluorescence to quantify the number of bone marrow-derived cells, monocytes and macrophages in the lung samples from each dog. The numbers of CD204+ macrophages, CD206+ macrophages and monocytes and CD11d+ bone marrow-derived cells (BMDCs) were significantly higher in the pre-metastatic lung of dogs with OS (n = 10) than in control dogs without cancer (n = 10). Furthermore, the total nucleated cell (DAPI+) density was higher before metastasis than in healthy lungs. In dogs with established metastases, the number of CD11d+ BMDCs was significantly lower than in the pre-metastatic lung, suggesting this recruitment is transient. Our study provides evidence of PMN existence in a naturally occurring cancer model similar to those observed in pre-clinical murine models. BMDCs are recruited to the lungs before metastases have developed. Dogs with OS may represent ideal candidates for assessing new PMN-targeting therapies.

Exosomes: a double-edged sword in cancer immunotherapy

Over the past few decades, immunotherapy has emerged as a powerful strategy to overcome the limitations of conventional cancer treatments. The use of extracellular vesicles, particularly exosomes, which carry cargoes capable of modulating the immune response, has been extensively explored as a potential therapeutic approach in cancer immunotherapy. Exosomes can deliver their cargo to target cells, thereby influencing their phenotype and immunomodulatory functions. They exhibit either immunosuppressive or immune-activating characteristics, depending on their internal contents. These exosomes originate from diverse cell sources, and their internal contents can vary, suggesting that there may be a delicate balance between immune suppression and stimulation when utilizing them for immunotherapy. Therefore, a thorough understanding of the molecular mechanisms underlying the role of exosomes in cancer progression is essential. This review focuses on the molecular mechanisms driving exosome function and their impact on the tumor microenvironment (TME), highlighting the intricate balance between immune suppression and activation that must be navigated in exosome-based therapies. Additionally, it underscores the challenges and ongoing efforts to optimize exosome-based immunotherapies, thereby making a significant contribution to the advancement of cancer immunotherapy research.

Extracellular vesicles from pancreatic cancer and its tumour microenvironment promote increased Schwann cell migration

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) exhibits a high frequency of neural invasion (NI). Schwann cells (SCs) have been shown to be reprogrammed to facilitate cancer cell migration and invasion into nerves. Since extracellular vesicles (EVs) affect the tumour microenvironment and promote metastasis, the present study analysed the involvement of EVs from pancreatic cancer cells and their microenvironment in altering SC phenotype as part of the early events in the process of NI.

METHODS

EVs were isolated from human/murine PDAC cells, pancreatic stellate cells (PSCs), human tissues and plasma to perform a novel 3D migration assay, qRT-PCR and western blot. Kaplan-Meier and Cox regression analyses were employed to evaluate the clinical potential of plasma EV-derived candidate from 165 PDAC patients.

RESULTS

The EVs from PDAC cells, PSCs derived from human tumour tissues, other cell types in the tumour microenvironment from tumour tissues and circulating plasma act as drivers of a pro-migratory phenotype of SCs by inducing dedifferentiation in SCs. Notably, p75NTR expression was upregulated in the plasma-derived EVs from patients with NI (Pn1) relative to those without NI (Pn0). High expression of plasma-derived EV p75NTR correlated with reduced overall survival and was identified as an independent prognostic factor.

CONCLUSIONS

These findings suggest that EV-mediated SC migration underlies the interactions contributing to PDAC-associated NI with implications for improved outcome and therapeutic strategy.

Invasion and metastasis in cancer: molecular insights and therapeutic targets

The progression of malignant tumors leads to the development of secondary tumors in various organs, including bones, the brain, liver, and lungs. This metastatic process severely impacts the prognosis of patients, significantly affecting their quality of life and survival rates. Research efforts have consistently focused on the intricate mechanisms underlying this process and the corresponding clinical management strategies. Consequently, a comprehensive understanding of the biological foundations of tumor metastasis, identification of pivotal signaling pathways, and systematic evaluation of existing and emerging therapeutic strategies are paramount to enhancing the overall diagnostic and treatment capabilities for metastatic tumors. However, current research is primarily focused on metastasis within specific cancer types, leaving significant gaps in our understanding of the complex metastatic cascade, organ-specific tropism mechanisms, and the development of targeted treatments. In this study, we examine the sequential processes of tumor metastasis, elucidate the underlying mechanisms driving organ-tropic metastasis, and systematically analyze therapeutic strategies for metastatic tumors, including those tailored to specific organ involvement. Subsequently, we synthesize the most recent advances in emerging therapeutic technologies for tumor metastasis and analyze the challenges and opportunities encountered in clinical research pertaining to bone metastasis. Our objective is to offer insights that can inform future research and clinical practice in this crucial field.

Cancer-secreted exosomal miR-1246 promotes colorectal cancer liver metastasis by activating hepatic stellate cells

Colorectal cancer liver metastases (CRLM) are the primary cause of mortality in colorectal cancer (CRC) patients, highlighting the importance of understanding the underlying mechanisms. The tumor microenvironment (TME) and its interaction with tumor cells play a crucial role in CRLM progression. Notably, the stability and peak levels of tumor-derived exosomal miRNAs facilitate intercellular communication in the TME. Hepatic stellate cells (HSCs), key liver mesenchymal cells, constitute about 33% of the liver's nonsolid cell population and exhibit plasticity. However, the specific role of tumor-derived exosomal miRNAs in the crosstalk between HSCs and tumor cells during the CRLM process remains unclear. We studied CRC-secreted exosomal miR-1246 and its impact on HSCs, as well as its effects on CRC cell proliferation and metastasis. Our findings demonstrate that CRC-secreted exosomal miR-1246 can be internalized by HSCs, leading to their activation and facilitating the metastatic potential of CRC cells. Mechanistically, exosomal miR-1246 targets INSIG1, resulting in SREBP2 nucleation and cholesterol metabolism alterations. This accumulation of free cholesterol (FC) regulates the TLR4/NF-κB/TGF-β pathway, promoting HSC activation. Activated HSCs, in turn, enhance liver metastasis of CRC cells through the TNFSF13/TNFRSF13B axis. Our study reveals the role of CRC-secreted exosomal miR-1246 in triggering HSC activation and reprogramming the TME, ultimately facilitating liver metastasis in CRC patients. Exosomal miR-1246 could serve as a potential non-invasive biomarker for predicting colorectal cancer liver metastasis, enhancing our understanding of CRC-associated liver metastases.

Intratumoral microbiome: implications for immune modulation and innovative therapeutic strategies in cancer

Recent advancements have revealed the presence of a microbiome within tumor tissues, underscoring the crucial role of the tumor microbiome in the tumor ecosystem. This review delves into the characteristics of the intratumoral microbiome, underscoring its dual role in modulating immune responses and its potential to both suppress and promote tumor growth. We examine state-of-the-art techniques for detecting and analyzing intratumoral bacteria, with a particular focus on their interactions with the immune system and the resulting implications for cancer prognosis and treatment. By elucidating the intricate crosstalk between the intratumoral microbiome and the host immune system, we aim to uncover novel therapeutic strategies that enhance the efficacy of cancer treatments. Additionally, this review addresses the existing challenges and future prospects within this burgeoning field, advocating for the integration of microbiome research into comprehensive cancer therapy frameworks.

The lncRNA MIR181A1HG in extracellular vesicles derived from highly metastatic colorectal cancer cells promotes liver metastasis by remodeling the extracellular matrix and recruiting myeloid-derived suppressor cells

BACKGROUND

Colorectal liver metastasis (CRLM) is the main cause of death in colorectal cancer (CRC) patients worldwide. In the initial stage of metastasis, primary tumors provide the necessary conditions for metastasis by shaping the local microenvironment of the target organ, forming "premetastatic niches" (PMNs), and extracellular vesicles (EVs) play important roles in shaping PMNs. Therefore, investigating the EVs involved in the regulation of PMNs and their mechanism is highly valuable for the further understanding of CRLM.

METHODS

Transmission electron microscopy and differential ultracentrifugation were used to verify the existence of exosomes. In vivo and in vitro assays were used to identify the roles of MIR181A1HG in EVs in CRLM. RNA pull-down and dual-luciferase reporter assays were used to clarify the mechanism by which MIR181A1HG in EVs regulated the crosstalk between CRC cells and hepatic stellate cells (HSCs).

RESULTS

We demonstrated that the lncRNA MIR181A1HG was progressively upregulated in tissues, serum EVs from healthy normal controls to CRC and paired liver metastatic groups. Additionally, we verified that HNRNPA2B1 mediated the packaging of MIR181A1HG into CRC cell-derived EVs, which in turn functioned as a ceRNA by sponging miR373-3p to activate HSCs via the TGFβRII/Smad2/3 signaling pathway. Furthermore, activated HSCs could secrete the chemokine CXCL12 to promote CRLM by remodeling the extracellular matrix and recruiting myeloid-derived suppressor cells in the liver, which resulted in liver metastasis.

CONCLUSIONS

MIR181A1HG in EVs from highly metastatic CRC cells promoted CRLM by activating HSCs to form PMNs in the liver, which contributes to the further understanding of the mechanism of CRLM and provides potential predictive markers for CRLM.

Extracellular vesicle biomarkers redefine prostate cancer radiotherapy

Radiotherapy (RT) remains a cornerstone in the treatment of prostate cancer (PCa). Extracellular vesicles (EVs), nano-sized particles secreted by cells, play important roles in intercellular communication within the tumour microenvironment (TME) and contribute to tumour growth, metastasis, and therapy resistance. Recent advancements demonstrate the potential of EVs as biomarkers for cancer diagnosis, prognosis, and treatment monitoring. Accumulating evidence supports the role of EVs in modulating RT outcomes by shaping the TME, mediating radioresistance, and influencing cancer metastasis. Despite substantial progress, challenges remain, including the heterogeneity of EV biogenesis, variability in cargo composition, and the absence of standardised methods for EV isolation and characterisation. While the therapeutic and diagnostic prospects of EVs in PCa management are promising, further research is needed to clarify the mechanisms through which EVs impact RT and to translate these findings into clinical practice. Incorporating EV research into PCa treatment paradigms could enhance diagnostic accuracy, enable real-time monitoring of RT responses, and support the development of new targeted therapeutic strategies. This review discusses recent progress in understanding EVs in the context of RT for PCa, focuses on their roles in modulating tumour growth, contributing to radioresistance within the TME, and facilitating the monitoring of RT efficacy and recurrence. In addition, the potential of EVs as biomarkers for liquid biopsy and their applications in enhancing radiosensitivity or overcoming radioresistance is also explored.

Revolutionizing HER-2 assessment: multidimensional radiomics in breast cancer diagnosis

OBJECTIVE

To explore the application value of multidimensional radiomics based on ultrasound imaging in assessing the HER-2 status of breast cancer.

METHODS

We retrospectively analyzed the ultrasound imaging, clinical, and laboratory data of 850 breast cancer patients from two centers. During the study, we first utilized automation technology to accurately delineate the tumor region of interest (ROI) in breast ultrasound imaging. Subsequently, the intra-tumoral ROI was automatically expanded by 1 cm and 2 cm to obtain larger areas including the peritumoral tissues, and further generated three-dimensional volumes of interest (VOI) within and around the tumor. Through the K-means clustering method, we identified the sub-regions of interest within the ROI and extracted corresponding radiomic features using the pyradiomics toolkit. Additionally, we employed an advanced Vision Transformer (VIT) model to perform deep radiomic feature extraction on the ROI. Based on feature selection, we utilized various machine learning algorithms for modeling and analysis to assess the HER-2 status of breast cancer.

RESULTS

After comprehensive comparison and evaluation of multiple models, we found that the diagnostic model based on multidimensional feature fusion exhibited excellent diagnostic performance in assessing the HER-2 status of breast cancer. In the training set, the model achieved an accuracy of 0.949 and an AUC value of 0.990 (95% CI: 0.986-0.995), with outstanding key performance indicators such as sensitivity, specificity, positive predictive value, negative predictive value, and F1 score. The model showed good generalization in the test set, with accuracy 0.747, AUC 0.848 (95% CI: 0.791-0.904), and sensitivity 0.911. Specificity was slightly lower, but other indicators remained high, and the F1 score was 0.703. Calibration and clinical decision curves further confirmed the model's effectiveness and reliability.

CONCLUSION

This study fully demonstrates that multidimensional breast ultrasonography-based radiomic features can effectively assess the HER-2 status of breast cancer. This finding not only provides new evidence for early diagnosis of breast cancer but also offers new ideas and methods for personalized treatment planning and prognosis assessment.

Towards understanding cancer dormancy over strategic hitching up mechanisms to technologies

Delving into cancer dormancy has been an inherent task that may drive the lethal recurrence of cancer after primary tumor relief. Cells in quiescence can survive for a short or long term in silence, may undergo genetic or epigenetic changes, and can initiate relapse through certain contextual cues. The state of dormancy can be induced by multiple conditions including cancer drug treatment, in turn, undergoes a life cycle that generally occurs through dissemination, invasion, intravasation, circulation, immune evasion, extravasation, and colonization. Throughout this cascade, a cellular machinery governs the fate of individual cells, largely affected by gene regulation. Despite its significance, a precise view of cancer dormancy is yet hampered. Revolutionizing advanced single cell and long read sequencing through analysis methodologies and artificial intelligence, the most recent stage in the research tool progress, is expected to provide a holistic view of the diverse aspects of cancer dormancy.

Exosomes play a crucial role in remodeling the tumor microenvironment and in the treatment of gastric cancer

Gastric cancer (GC) is a common and frequent malignant cancer of the digestive system with a poor prognosis. In addition to common therapies such as surgical resection and chemotherapy, novel biological interventions are quite valuable for research. Exosomes are extracellular vesicles (EVs) that originate from various cell types and contain proteins, RNA, DNA, and other components that transmit biological signals and mediate intercellular communication. Numerous studies have shown that exosomes shape the tumor microenvironment (TME) by affecting hypoxia, inflammation, immunity, metabolism, and interstitial changes in the tumor, playing a crucial role in the development and metastasis of GC. This article reviews the important role of exosomes in the TME of GC and explores their potential clinical applications in GC treatment.

Selective removal of proteins and microvesicles ex vivo from blood of pancreatic cancer patients using bioengineered adsorption filters

Metastatic pancreatic ductal adenocarcinoma (PDAC) is a deadly disease with limited efficacious therapeutic options. Recent investigations have provided proof of concept that circulating tumor cells (CTCs) are reduced by purification of PDAC patient blood samples through ExThera Seraph100™ adsorption filters. Whether additional tumorigenic factors are also removed remains inadequately studied. Here, matched whole blood and purified blood samples from seven PDAC patients were analyzed for microparticle and soluble protein content. For microparticle analysis, patient samples were stratified by abundance. Filters markedly reduced ∼200-nm particles when in high abundance. Exosomes, or vesicles ranging from ∼50 to 150-nm were not significantly affected by the purification process. Proteomic analysis of plasma from the whole and purified blood revealed only a limited number of differentially expressed proteins. The complement C1Q proteins were reduced by the purification process, likely due to their heparin binding affinity. In contrast, there was an elevation in cytoplasmic proteins after purification, which may be due to cell destruction. Taken together, this study shows the selective removal of a subfraction of larger (>200 nm) microvesicles and C1Q during blood purification by the Seraph100™. The clinical significance of these findings requires further study.

Advances in Vaccine-Based Therapies for Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers, with a 5-year survival rate that has improved only marginally over the past 30 years, despite numerous clinical trials. PDAC poses several unique challenges, including early metastatic spread and a predilection for liver metastasis. It is also highly resistant to anti-tumor immunity and immunotherapy due to its dense and immunosuppressive tumor microenvironment, low immunogenicity, and systemic immune suppression. PDAC has a low mutational burden, defective antigen presentation, and immune checkpoint molecule upregulation, which reduce immune recognition. Together, these factors leave PDAC as an "immune cold" tumor with minimal cytotoxic T-cell activity. Novel therapeutic approaches are urgently needed to reinvigorate anti-tumor immunity. Recent advances, such as adjuvant personalized mRNA neoantigen vaccines and mutant-KRAS targeted vaccines, have demonstrated sustained vaccine-induced T cell responses that are associated with improved recurrence-free survival in surgically resected PDAC. Combining different vaccine approaches with optimal sequencing of chemotherapy, surgery, radiotherapy, and other immunotherapies may further enhance outcomes. PDAC vaccines represent a promising strategy for overcoming PDAC's resistance to conventional therapies, with ongoing trials exploring their potential to improve long-term survival.

Clinical Impact of Exosome Chemistry in Cancer

As we progress into the 21st century, cancer stands as one of the most dreaded diseases. With approximately one in every four individuals facing a lifetime risk of developing cancer, cancer remains one of the most serious health challenges worldwide. Its multifaceted nature makes it an arduous and tricky problem to diagnose and treat. Over the years, researchers have explored plenty of approaches and avenues to improve cancer management. One notable strategy includes the study of extracellular vesicles (EVs) as potential biomarkers and therapeutics. Among these EVs, exosomes have emerged as particularly promising candidates due to their unique characteristic properties and functions. They are small membrane-bound vesicles secreted by cells carrying a cargo of biomolecules such as proteins, nucleic acids, and lipids. These vesicles play crucial roles in intercellular communication, facilitating the transfer of biological information between cell-to-cell communication. Exosomes transport cargoes such as DNA, RNA, proteins, and lipids involved in cellular reprogramming and promoting cancer. In this review, we explore the molecular composition of exosomes, significance of exosomes chemistry in cancer development, and its theranostic application as well as exosomes research complications and solutions.

Harnessing extracellular vesicle-mediated crosstalk between T cells and cancer cells for therapeutic applications

Small extracellular vesicles (EVs) are a diverse group of lipid-based particles that are ≤200 nm in diameter and contain an aqueous core. EVs have been shown to mediate intercellular communications between a wide array of immune cells; the downstream effects are diverse and have potential implications for the development of novel immunotherapeutic treatments. Despite a high volume of studies addressing the role EVs play in the immune system, our understanding of the crosstalk between T cells and cancer cells remains limited. Here, we discuss how EVs derived from cancer cells modulate T cell functions and conversely, how T cell derived EVs are crucial in modulating adaptive immune functions. In the context of cancer, tumor derived EVs (TD-EVs) halt T cell-mediated immunity by interfering with effector functions and enhancing regulatory T cell (Treg) functions. In contrast, EVs derived from effector T cells can serve to stimulate anticancer immunity, curbing metastasis and tumor growth. These findings highlight important aspects of how EVs can both mediate the therapeutic effects of T cells as well as impair T cell-mediated immunity. This calls for a deeper understanding of EV-mediated effects in order to advance them as next-generation therapeutics and nanocarriers.

Extracellular vesicles from the lung pro-thrombotic niche drive cancer-associated thrombosis and metastasis via integrin beta 2

Cancer is a systemic disease with complications beyond the primary tumor site. Among them, thrombosis is the second leading cause of death in patients with certain cancers (e.g., pancreatic ductal adenocarcinoma [PDAC]) and advanced-stage disease. Here, we demonstrate that pro-thrombotic small extracellular vesicles (sEVs) are secreted by C-X-C motif chemokine 13 (CXCL13)-reprogrammed interstitial macrophages in the non-metastatic lung microenvironment of multiple cancers, a niche that we define as the pro-thrombotic niche (PTN). These sEVs package clustered integrin β2 that dimerizes with integrin αX and interacts with platelet-bound glycoprotein (GP)Ib to induce platelet aggregation. Blocking integrin β2 decreases both sEV-induced thrombosis and lung metastasis. Importantly, sEV-β2 levels are elevated in the plasma of PDAC patients prior to thrombotic events compared with patients with no history of thrombosis. We show that lung PTN establishment is a systemic consequence of cancer progression and identify sEV-β2 as a prognostic biomarker of thrombosis risk as well as a target to prevent thrombosis and metastasis.

The Evolutionary Forest of Pancreatic Cancer

SIGNIFICANCE

Although the pancreatic cancer genome has been described, it has not been explored with respect to stages of diagnosis or treatment bottlenecks. We now describe and quantify the genomic features of PDAC in the context of evolutionary metrics and in doing so have identified a novel prognostic biomarker.

Small extracellular vesicles (sEVs) in pancreatic cancer progression and diagnosis

Pancreatic cancer is one of the most aggressive malignancies with poor prognostic outcomes, necessitating the exploration of novel biomarkers and therapeutic targets for early detection and effective treatment. Small extracellular vesicles (sEVs) secreted by cells, have gained considerable attention in cancer research due to their role in intercellular communication and their potential as non-invasive biomarkers. This review focuses on the role of sEVs in the progression of pancreatic cancer and their application as biomarkers. We delve into the biogenesis, composition, and functional implications of sEVs in pancreatic tumor biology, emphasizing their involvement in processes such as tumor growth, metastasis, immune modulation, and chemotherapy resistance. In addition, we discuss the challenges in isolating and characterizing sEVs. The review also highlights recent advances in the utilization of sEV-derived biomarkers for the early diagnosis, prognosis, and monitoring of pancreatic cancer. By synthesizing the latest findings, we aim to underscore the significance of sEVs in pancreatic cancer and their potential to revolutionize patient management through improved diagnostics and targeted therapies.

MIF/CD74 axis in hepatic stellate cells mediates HBV-related liver fibrosis

Chronic hepatitis B virus (HBV) infection is a major risk factor for liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Despite advances in understanding HBV-related liver diseases, effective therapeutic strategies remain limited. Macrophage migration inhibitory factor (MIF) has been implicated in various inflammatory and fibrotic conditions, but its role in HBV-induced liver fibrosis has not been fully explored. This study investigates the involvement of MIF in liver fibrosis and evaluates its potential as a therapeutic target. We found that MIF expression was significantly elevated in hepatic stellate cells (HSCs) following stimulation with HBVcc (HBV cell culture) or HBV surface antigen (HBsAg). Through its receptor CD74, MIF enhanced the TGF-β/SMAD signaling pathway, promoting HSC activation and liver fibrosis progression. Histological analysis revealed higher MIF and CD74 expression in HBsAg-positive individuals compared to HBsAg-negative controls. Moreover, MIF expression correlated with the activation of fibrosis markers, including α-SMA and TGF-β-related proteins. Inhibition of MIF with the specific inhibitor ISO-1 attenuated fibrosis progression, suggesting that targeting MIF could offer a promising approach for treating HBV-related liver fibrosis. Our findings underscore the critical role of the MIF/CD74 axis in liver fibrosis and provide a basis for future therapeutic strategies targeting MIF in chronic liver diseases.

Inflammation and Immunity in Liver Neoplasms: Implications for Future Therapeutic Strategies

Over the past two decades, the "hallmarks of cancer" have revolutionized cancer research and highlighted the crucial roles of inflammation and immunity. Protumorigenic inflammation promotes cancer development along with inhibition of antitumor immunity, shaping the tumor microenvironment (TME) toward a tumor-permissive state and further enhancing the malignant potential of cancer cells. This immunosuppressive TME allows tumors to evade immunosurveillance. Thus, understanding the complex interplay between tumors and the immune system within the TME has become pivotal, especially with the advent of immunotherapy. Although immunotherapy has achieved notable success in many malignancies, primary liver cancer, particularly hepatocellular carcinoma, presents unique challenges. The hepatic immunosuppressive environment poses obstacles to the effectiveness of immunotherapy, along with high mortality rates and limited treatment options for patients with liver cancer. In this review, we discuss current understanding of the complex immune-mediated mechanisms underlying liver neoplasms, focusing on hepatocellular carcinoma and liver metastases. We describe the molecular and cellular heterogeneity within the TME, highlighting how this presents unique challenges and opportunities for immunotherapy in liver cancers. By unraveling the immune landscape of liver neoplasms, this review aims to contribute to the development of more effective therapeutic interventions, ultimately improving clinical outcomes for patients with liver cancer.

Exosomal signaling in cancer metastasis: Molecular insights and therapeutic opportunities

Exosomes are membrane-bound extracellular vesicles that play a role in exchanging biological products across membranes and serve as intermediaries in intercellular communication to maintain normal homeostasis. Numerous molecules, including lipids, proteins, and nucleic acids are enclosed in exosomes. Exosomes are constantly released into the extracellular environment and exhibit distinct characteristics based on the secreted cells that produce them. Exosome-mediated cell-to-cell communication has reportedly been shown to affect multiple cancer hallmarks, such as immune response modulation, pre-metastatic niche formation, angiogenesis, stromal cell reprogramming, extracellular matrix architecture remodeling, or even drug resistance, and eventually the development and metastasis of cancer cells. Exosomes can be used as therapeutic targets and possible diagnostic biomarkers by selectively loading oncogenic molecules into them. We highlight the important roles that exosomes play in cancer development in this review, which may lead to the development of fresh approaches for future clinical uses.

Organoids, tissue slices and organotypic cultures: Advancing our understanding of pancreatic ductal adenocarcinoma through in vitro and ex vivo models

Pancreatic ductal adenocarcinoma (PDAC) has one of the worst prognoses of all common solid cancers. For the large majority of PDAC patients, only systemic therapies with very limited efficacy are indicated. In addition, immunotherapies have not brought the advances seen in other cancer types. Several key characteristics of PDAC contribute to poor treatment outcomes, and in this review, we will discuss how these characteristics are best captured in currently available ex vivo or in vitro model systems. For instance, PDAC is hallmarked by a highly desmoplastic and immune-suppressed tumor microenvironment that impacts disease progression and therapy resistance. Also, large differences in tumor biology exist between and within tumors, complicating treatment decisions. Furthermore, PDAC has a very high propensity for locally invasive and metastatic growth. The use of animal models is often not desirable or feasible and several in vitro and ex vivo model systems have been developed, such as organotypic cocultures and tissue slices, among others. However, the absence of a full host organism impacts the ability of these models to accurately capture the characteristics that contribute to poor outcomes in PDAC. We will discuss the caveats and advantages of these model systems in the context of PDAC's key characteristics and provide recommendations on model choice and the possibilities for optimization. These considerations should be of use to researchers aiming to study PDAC in the in vitro setting.

Roles of gastric cancer-derived exosomes in the occurrence of metastatic hepatocellular carcinoma

Gastric cancer (GC), particularly in East Asia, is among the most prevalent cancers with high mortality rates. According to recent epidemiological data, patients with GC account for over a quarter of all cancer incidences and approximately one third of cancer-related deaths in East Asia. Liver metastasis (LM) is not only a common form of GC distant metastasis but also poses a major challenge to the prognosis and treatment of patients with advanced GC. Increasing evidence has shown that the gut-liver axis plays a pivotal role in maintaining the stomach-liver-gut homeostasis. Exosomes are small secreted vesicles enriched with specific proteins, lipids, and nucleic acids. These vesicles exhibit significant activities in signal transmission to adjacent or distant cells in the gut-liver axis, as well as in remodeling the tumor microenvironment. Some research have pointed out that exosomes promote LM of various cancers. However, there still lack of complete and systematic review on how exosomes affect GC-LM. In this article, we present a comprehensive description to explore the role of GC-derived exosomes in the occurrence and development of metastatic hepatocellular carcinoma (HCC).

Extracellular vesicles-a new player in the development of urinary bladder cancer

Bladder cancer was the 10th most commonly diagnosed cancer worldwide in 2020. Extracellular vesicles (EVs) are nano-sized membranous structures secreted by all types of cells into the extracellular space. EVs can transport proteins, lipids, or nucleic acids to specific target cells. What brings more attention and potential implications is the fact that cancer cells secrete more EVs than non-malignant cells. EVs are widely studied for their role in cancer development. This publication summarizes the impact of EVs secreted by urinary bladder cancer cells on urinary bladder cancer development and metastasis. EVs isolated from urinary bladder cancer cells affect other lower-grade cancer cells or normal cells by inducing different metabolic pathways (transforming growth factor β/Smads pathway; phosphoinositide 3-kinase/Akt pathway) that promote epithelial-mesenchymal transition. The cargo carried by EVs can also induce angiogenesis, another critical element in the development of bladder cancer, and modulate the immune system response in a tumor-beneficial manner. In summary, the transfer of substances produced by tumor cells via EVs to the environment influences many stages of tumor progression. An in-depth understanding of the role EVs play in the development of urinary bladder cancer is crucial for the development of future anticancer therapies.

Labeling tumor-associated extracellular vesicles with antibody-DNA conjugates for quantitative analysis

Introduction

Extracellular vesicles (EVs) shed from tumor cells into peripheral circulation or other body fluids are promising biomarkers for cancer diagnosis with enormously long circulation. Consequently, precise methods for differentiating normal and tumor-associated EVs (TAEs) are required.

Methods

This study used quantifiable antibody-DNA conjugate-assisted quantitative methods combined with proximity ligation technology to detect TAEs. The antibody-DNA conjugate contained one antibody associated with three oligonucleotides for signal amplification. The antibody in the conjugate can recognize the surface tumor antigens of TAEs. Simultaneously, DNA in the conjugate is attached to the surfaces of TAEs and holds the signal amplification post, converting protein identities to DNA amplification for protein detection, even at the molecular level.

Results

These findings revealed that TAEs can be quantitatively detected using DNA-mediated quantitative polymerase chain reaction (qPCR). Antibody-DNA conjugates were used to recognize the epithelial cell adhesion molecule (EpCAM) antigen on the TAE surface and quantify the antigen using qPCR for cancer analysis.

Discussion

This method proposed a new quantitative detection approach for TAEs, which aim to identify specific EV-associated markers for diagnostic or therapeutic, this method could inspire a new idea for tumor diagnosis and detection of other diseases.

Exosomes in Ocular Health: Recent Insights into Pathology, Diagnostic Applications and Therapeutic Functions

Exosomes are extracellular vesicles ranging from 30 to 150 nm in diameter that contain proteins, nucleic acids and other molecules. Produced by virtually all cell types, they travel throughout the body until they reach their target, where they can trigger a wide variety of effects by transferring the molecular cargo to recipient cells. In the context of ocular physiology, exosomes play a very important role in embryological development, the regulation of homeostasis and the immune system, which is crucial for normal vision. Consequently, in pathological situations, exosomes also undergo modifications in terms of quantity, composition and content, depending on the etiology of the disease. However, the mechanisms by which exosomes contribute to ocular pathology has not yet been studied in depth, and many questions remain unanswered. This review aims to summarize the most recent knowledge on the function of exosomes in the ocular system in healthy individuals and the role they play during pathological processes of a degenerative, infectious, neurodegenerative, vascular and inflammatory nature, such as keratoconus, keratitis, glaucoma, diabetic retinopathy and uveitis. Furthermore, given their unique characteristics, their potential as diagnostic biomarkers or therapeutic agents and their application in clinical ophthalmology are also explored, along with the main limitations that researchers face today in the field.

Matrix stiffness modulated release of spheroid-derived extracellular vesicles and discovery of Piezo1 cargo

Augmented extracellular matrix (ECM) stiffness is a mechanical hallmark of cancer. Mechanotransduction studies have extensively probed the mechanisms by which ECM stiffness regulates intracellular communication. However, the influence of stiffness on intercellular communication aiding tumor progression in three-dimensional microenvironments remains unknown. Small extracellular vesicles (EVs) are communicators of altered biophysical cues to distant sites through EV-ECM interactions and EV-mediated recipient cell-ECM interactions. Here we demonstrate stiffness-mediated modulation of small EVs secretion and cargo from three-dimensional oral squamous cell carcinoma spheroids. Using a spheroid culture platform with varying matrix stiffness properties, we show that small EVs carry parental biomolecular cargo, including mechanosensitive Piezo1 ion channel and adhesion molecule CD44. We comprehensively validate the presence of both markers in our EV populations using proteomic and genetic analysis. Transcriptomic analysis of microRNA and long non-coding RNA cargo of small EVs released from soft and stiff ECM spheroids revealed enrichment of tumorigenic and metastatic profiles in EVs from stiff ECM cultures compared to that of soft ones. Gene set enrichment analysis of a comparative dataset obtained by overlaying spheroid mRNA and EV miRNA profiles identified key oncogenic pathways involved in cell-EV crosstalk in the spheroid model.

Exosomal Galectin-3 promotes peritoneal metastases in gastric adenocarcinoma via microenvironment alterations

Peritoneal carcinomatosis (PC) in gastric adenocarcinoma (GAC) is the most common metastatic site and leads to a short median survival. Exosomes have been shown to remodel the microenvironment, facilitating tumor metastases. However, the functional component in GAC cell-derived exosomes that remodel the landscape in the peritoneal cavity remains unclear. To address this, we performed in-depth proteomic profiling of ascites-derived exosomes from patients with PC, and we found that Galectin-3 was highly enriched in exosomes derived from malignant ascites. exosomal Galectin-3 was the crucial regulator of PC. Blockage of exosomal Galectin-3 significantly inhibited tumor metastases and prolonged overall survival. Exosomal Galectin-3 activated cancer-associated fibroblasts through integrin α1β1/FAK/Akt/mTOR/CXCL12 signaling. Combined inhibition of the CXCL12-CXCR4 axis and exosomal Galectin-3 enhanced the efficacy of anti-PD-1 immunotherapy, leading to significantly diminished PC progression and durable antitumor responses. These findings provide a rationale for clinical strategy of targeting exosomal Galectin-3 to treat PC.

Phenotypic diversity of CTCs and tdEVs in liquid biopsies of tumour-draining veins is linked to poor prognosis in colorectal cancer

BACKGROUND

Circulating tumour cells (CTCs) and tumour-derived extracellular vesicles (tdEVs) have great potential for monitoring therapy response and early detection of tumour relapse, facilitating personalized adjuvant therapeutic strategies. However, their low abundance in peripheral blood limits their informative value. In this study, we explored the presence of CTCs and tdEVs collected intraoperatively from a tumour-draining vein (DV) and via a central venous catheter (CVC) prior to tumour resection.

METHODS

CellSearch analyses of 395 blood samples from 306 patients with gastrointestinal tumours and 93 blood samples from healthy donors were used to establish and validate gates for the automated detection of CTCs and tdEVs with ACCEPT software and R scripts. The selected gate settings were applied to 227 samples of 142 patients with colorectal cancer (CRC) from two independent collectives. Phenotypic features were obtained via numeric analysis of their fluorescence signals (e.g. size, shape, and intensity) and were used for calculating diversity using Shannon index (SI) of clusters generated via the k-means algorithm after Uniform Manifold Approximation and Projection (UMAP) pre-processing, and standard deviation (SD).

RESULTS

CTCs and tdEVs were more abundant in the DV samples compared to CVC samples (p < 0.05). tdEVs were detected in higher numbers than CTCs in both compartments. Importantly, tdEVs in CVCs were associated with tumor spread, whereas CTCs in DVs were linked to tumor size. In both compartments, the prognostic value of tdEVs for overall survival (OS) surpassed that of CTCs, as demonstrated by univariate, multivariate, and Kaplan-Meier analyses. CTCs and tdEVs in DVs were phenotypically distinct, being larger, more eccentric, and displaying stronger cytokeratin intensities (p < 0.05) compared to those in CVC samples. Furthermore, increased diversity in CTC and tdEV phenotypes was significantly associated with shorter survival, validating the prognostic relevance of the SD-diversity metric.

CONCLUSION

Our study demonstrates that DV sampling significantly enhances the detection of prognostically relevant CTCs and tdEVs in CRC patients, underscoring the superior prognostic significance of tdEVs compared to CTCs. Importantly, the combined phenotypic diversity of both markers emerges as a more powerful biomarker than their enumeration alone. These findings suggest that comprehensive, automated analysis of CTCs and tdEVs in DVs may open new avenues for tailoring individualized therapies in CRC patients.

Breaking boundaries: role of the brain barriers in metastatic process

Brain metastases (BMs) are the most common intracranial tumors in adults and occur 3-10 times more frequently than primary brain tumors. Despite intensive multimodal therapies, including resection, radiotherapy, and chemotherapy, BMs are associated with poor prognosis and remain challenging to treat. BMs predominantly originate from primary lung (20-56%), breast (5-20%), and melanoma (7-16%) tumors, although they can arise from other cancer types less frequently. The metastatic cascade is a multistep process involving local invasion, intravasation into the bloodstream or lymphatic system, extravasation into normal tissue, and colonization of the distal site. After reaching the brain, circulating tumor cells (CTCs) breach the blood-brain barrier (BBB).The selective permeability of the BBB poses a significant challenge for therapeutic compounds, limiting the treatment efficacy of BMs. Understanding the mechanisms of tumor cell interactions with the BBB is crucial for the development of effective treatments. This review provides an in-depth analysis of the brain barriers, including the BBB, blood-spinal cord barrier, blood-meningeal barrier, blood-arachnoid barrier, and blood-cerebrospinal fluid barrier. It explores the molecular and cellular components of these barriers and their roles in brain metastasis, highlighting the importance of this knowledge for identifying druggable targets to prevent or limit BM formation.

The Roles of Myeloid Cells in Breast Cancer Progression

This chapter reviews tumor-associated myeloid cells, including macrophages, neutrophils, and other innate immune cells, and their multifaceted roles in supporting breast cancer progression and metastasis. In primary tumors, myeloid cells play key roles in promoting tumor epithelial-mesenchymal transition (EMT) and invasion. They can facilitate intravasation (entry into the bloodstream) and colonization, disrupting the endothelial cell layer and reshaping the extracellular matrix. They can also stimulate angiogenesis, suppress immune cell responses, and enhance cancer cell adaptability. In the bloodstream, circulating myeloid cells enable the survival of disseminated tumor cells via immunosuppressive effects and physical shielding. At the metastatic sites, they prime the premetastatic niche, facilitate tumor cell extravasation, and support successful colonization and outgrowth. Mechanistically, myeloid cells enhance cancer cell survival, dormancy escape, proliferation, and mesenchymal-epithelial transition (MET). Nonetheless, substantial gaps in our understanding persist regarding the functional and spatiotemporal diversity, as well as the evolutionary patterns, of myeloid cells during metastatic progression. Myeloid cell plasticity and differential responses to therapies present key barriers to successful treatments. Identifying specific pro-tumoral myeloid cell subpopulations and disrupting their interactions with cancer cells represent promising therapeutic opportunities. Emerging evidence suggests combining immunomodulators or stromal normalizers with conventional therapies could help overcome therapy-induced immunosuppression and improve patient outcomes. Overall, further elucidating myeloid cell heterogeneity and function throughout the process of breast cancer progression and metastasis will enable more effective therapeutic targeting of these critical stromal cells.

Exosome applications for the diagnosis and treatment of pancreatic ductal adenocarcinoma: An update (Review)

Pancreatic ductal adenocarcinoma (PDAC) is a malignant neoplasm that typically manifests with subtle clinical manifestations in its early stages and frequently eludes diagnosis until the advanced phases of the disease. The limited therapeutic options available for PDAC significantly contribute to its high mortality rate, highlighting the urgent need for novel biomarkers capable of effectively identifying early clinical manifestations and facilitating precise diagnosis. The pivotal role of cellular exosomes in both the pathogenesis and therapeutic interventions for PDAC has been underscored. Furthermore, researchers have acknowledged the potential of exosomes as targeted drug carriers against regulatory cells in treating PDAC. The present article aims to provide a comprehensive review encompassing recent advancements in utilizing exosomes for elucidating mechanisms underlying disease development, patterns of metastasis, diagnostic techniques and treatment strategies associated with PDAC.

Increased levels of extracellular matrix proteins associated with extracellular vesicles from brains of aged mice

Extracellular vesicles (EVs) are secreted by all major cell types of the brain, providing a mode of intercellular communication and a pathway for disposal of cellular debris. EVs help maintain healthy brain function, but may also contribute to diseases affecting the brain. EVs might contribute to aging of the brain, as aging-related processes such as inflammation and cellular senescence may alter EV cargo, promoting further inflammation and senescence. However, the effects of aging on brain EVs and the function of EVs in the aging brain remain poorly understood. To address this question, we measured the levels and protein cargo of EVs isolated from the brains of 4-, 12-, and 22-month-old C57BL/6J mice. We detected no changes in EV levels, but observed age-dependent changes in EV proteins. EV fractions from aged (22 month old) brains contained higher levels of extracellular matrix proteins than EV fractions from young (4 month old) brains, with intermediate levels in 12-month-old brains. Specifically, EV fractions from aged mice contained elevated levels of hyaluronan and proteoglycan link proteins 1 and 2 and several chondroitin sulfate proteoglycans (CSPGs). Analysis of extracellular matrix in several brain regions of aged mice revealed increased immunolabeling for the CSPG aggrecan, but reduced labeling with Wisteria floribunda agglutinin, which binds to chondroitin sulfate side chains of CSPGs. These data are consistent with prior studies showing changes to the composition of extracellular matrix in aged brains, and indicate a novel association of EVs with changes in the extracellular matrix of the aging brain.

Relationship between exosomes and cancer: formation, diagnosis, and treatment

Exosomes are a member of extracellular vesicles. However, their biological characteristics differ from those of other vesicles, and recently, their powerful functions as information molecules, biomarkers, and carriers have been demonstrated. Malignancies are the leading cause of high morbidity and mortality worldwide. The cure rate of malignancies can be improved by improving early screening rates and therapy. Moreover, a close correlation between exosomes and malignancies has been observed. An in-depth study of exosomes can provide new methods for diagnosing and treating tumors. Therefore, this study aimed to review, sort, and summarize such achievements, and present ideas and opinions on the application of exosomes in tumor treatment.

Reprogramming tumor-associated macrophages with lipid nanosystems reduces PDAC tumor burden and liver metastasis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) requires innovative therapeutic strategies to counteract its progression and metastatic potential. Since the majority of patients are diagnosed with advanced metastatic disease, treatment strategies targeting not only the primary tumor but also metastatic lesions are needed. Tumor-Associated Macrophages (TAMs) have emerged as central players, significantly influencing PDAC progression and metastasis. Our objective was to validate an innovative therapeutic strategy involving the reprogramming of TAMs using lipid nanosystems to prevent the formation of a pro-metastatic microenvironment in the liver.

RESULTS

In vitro results demonstrate that M2-polarized macrophages lose their M2-phenotype following treatment with lipid nanoemulsions composed of vitamin E and sphingomyelin (VitE:SM), transitioning to an M0/M1 state. Specifically, VitE:SM nanoemulsion treatment decreased the expression of macrophage M2 markers such as Arg1 and Egr2, while M1 markers such as Cd86, Il-1b and Il-12b increased. Additionally, the TGF-βR1 inhibitor Galunisertib (LY2157299) was loaded into VitE:SM nanoemulsions and delivered to C57BL/6 mice orthotopically injected with KPC PDAC tumor cells. Treated mice showed diminished primary tumor growth and reduced TAM infiltration in the liver. Moreover, we observed a decrease in liver metastasis with the nanoemulsion treatment in an intrasplenic model of PDAC liver metastasis. Finally, we validated the translatability of our VitE:SM nanosystem therapy in a human cell-based 3D co-culture model in vivo, underscoring the pivotal role of macrophages in the nanosystem's therapeutic effect in the context of human PDAC metastasis.

CONCLUSIONS

The demonstrated effectiveness and safety of our nanosystem therapy highlights a promising therapeutic approach for PDAC, showcasing its potential in reprogramming TAMs and mitigating the occurrence of liver metastasis.

Neuroblastoma-derived hypoxic extracellular vesicles promote metastatic dissemination in a zebrafish model

The zebrafish (Danio rerio) is a valuable model organism for studying human biology due to its easy genetic manipulation and small size. It is optically transparent and shares genetic similarities with humans, making it ideal for studying developmental processes, diseases, and drug screening via imaging-based approaches. Solid malignant tumors often contain hypoxic areas that stimulate the release of extracellular vesicles (EVs), lipid-bound structures released by cells into the extracellular space, that facilitate short- and long-range intercellular communication and metastatization. Here we investigate the effects of EVs derived from neuroblastoma (NB), a pediatric solid tumor, on metastatic niche formation using the zebrafish as an in vivo model. Intravascular injection in zebrafish embryos allows a non-invasive visualization of EVs dispersion, uptake, and interactions with host cells. To improve repeatability of our results and ease the injection steps, we used an agarose device replica molded from a custom designed micromilled aluminum mold. We first demonstrated that EVs released under hypoxic conditions promote angiogenesis and are more easily internalized by endothelial cells than those purified from normoxic cells. We also showed that injection of with hypoxic EVs increased macrophages mobilization. We then focused on the caudal hematopoietic tissue (CHT) region of the embryo as a potential metastatic site. After hypoxic EVs injection, we highlighted changes in the expression of mmp-9 and cxcl8b genes. Furthermore, we investigated the ability of NB-derived EVs to prime a metastatic niche by a two-step injection of EVs first, followed by NB cells. Interestingly, we found that embryos injected with hypoxic EVs had more proliferating NB cells than those injected with normoxic EVs. Our findings suggest that EVs released by hypoxic NB cells alter the behavior of recipient cells in the zebrafish embryo and promote metastatic outgrowth. In addition, we demonstrated the ability of the zebrafish embryo to be a suitable model for studying the interactions between EVs and recipient cells in the metastatic process.

Biogenesis and functional implications of extracellular vesicles in cancer metastasis

Extracellular vesicles (EVs) play a crucial role in the complex process of cancer metastasis by facilitating cellular communication and influencing the microenvironment to promote the spread and establishment of cancer cells in distant locations. This paper explores the process of EV biogenesis, explaining their various sources that range from endosomal compartments to plasma membrane shedding. It also discusses the complex mechanisms that control the sorting of cargo within EVs, determining their chemical makeup. We investigate the several functions of EVs in promoting the spread of cancer to other parts of the body. These functions include influencing the immune system, creating environments that support the formation of metastases before they occur, and aiding in the transformation of cells from an epithelial to a mesenchymal state. Moreover, we explore the practical consequences of EV cargo, such as nucleic acids, proteins, and lipids, in influencing the spread of cancer cells, from the beginning of invasion to the creation of secondary tumor sites. Examining recent progress in the field of EV-based diagnostics and treatments, we explore the potential of EVs as highly promising biomarkers for predicting the course of cancer and as targets for therapeutic intervention. This review aims to provide a complete understanding of the biology of EVs in the context of cancer metastasis. By unravelling the nuances of EV biology, it seeks to pave the way for new tactics in cancer detection, treatment, and management.

Development of Liver-Targeting αVβ5+ Exosomes as Anti-TGF-β Nanocarriers for the Treatment of the Pre-Metastatic Niche

Liver metastases frequently occur in pancreatic and colorectal cancer. Their development is promoted by tumor-derived exosomes with the integrin αVβ5 on their membrane. This integrin directs exosomes to the liver, where they promote a TGF-β-dependent pre-metastatic niche. We proposed the development of αVβ5+ exosomes to deliver anti-TGF-β therapy to the liver. This study demonstrates that the overexpression of αVβ5 in 293T cells allows its transfer to the secreted exosomes. αVβ5 overexpression increases exosome delivery to the liver, and αVβ5+ exosomes accumulate more in the liver compared to the lungs, kidneys, and brain in mice. We then sought 293T cells to directly produce and load an anti-TGF-β agent in their exosomes. First, we transduced 293T cells to express shRNAs against Tgfb1; however, the exosomes isolated from these cells did not knock down Tgfb1 in treated macrophages in vitro. However, when 293T expressed an mRNA coding a soluble form of betaglycan (sBG), a TGF-β inhibitor, this mRNA was detected in the isolated exosomes and the protein in the conditioned media of macrophages treated in vitro. In turn, this conditioned media decreased the TGF-β-induced phosphorylation of SMAD2/3 in hepatic cells in vitro. Our findings suggest that αVβ5+ exosomes could serve as nanocarriers for liver-targeted anti-TGF-β therapies.

Oncolytic viruses alter the biogenesis of tumor extracellular vesicles and influence their immunogenicity

Extracellular vesicles (EVs) are mediators of intercellular communication in the tumor microenvironment. Tumor EVs are commonly associated with metastasis, immunosuppression or drug resistance. Viral infections usually increase EV secretion, but little is known about the effect of oncolytic viruses (OVs) on tumor EVs. Here, we investigated the impact of oncolytic vesicular stomatitis virus (VSV) and vaccinia virus on EVs secreted by human melanoma and thoracic cancer cells. We found that OV infection increases the production of EVs by tumor cells. These EVs contain proteins of viral origin, such as VSV-G, thus creating a continuum of particles sharing markers of both canonical EVs and viruses. As such, the presence of VSV-G on EVs improves the transfer of their protein content to cell types commonly found in the tumor microenvironment. A proteomic analysis also revealed that EVs-OV secreted during VSV infection are enriched in immunity-related proteins. Finally, CD8+ T cells incubated with EVs-OV from infected cells display slightly enhanced cytotoxic functions. Taken together, these data suggest that OVs enhance the communication mediated by tumor EVs, which could participate in the therapeutic efficacy of OVs. These results also provide rationale for engineering OVs to exploit EVs and disseminate therapeutic proteins within the tumor microenvironment.

Tumor-derived exosomes: Unravelling the pathogenesis of pancreatic cancer with liver metastases and exploring the potential for clinical translation

Pancreatic cancer (PC) is one of the most malignant solid cancers, and PC metastasis, particularly liver metastasis, is a major cause of cancer mortality. A key event in tumor metastasis is the formation of pre-metastatic niche (PMN), which provides a microenvironment conducive to tumor cells colonization and progression. Various molecules loaded in tumor-derived exosomes (TDEs) contribute to PMN formation and distant tumor metastasis, by regulating immune and stromal cell function, inducing angiogenesis, and promoting metabolic reprogramming. Therefore, therapies targeting PMN may offer novel advantages to prevent tumor metastasis at an earlier stage. In this review, we summarize multifaceted mechanisms underlying hepatic PMN formation, with a focus on how PC TDEs participate in angiogenesis and vascular permeability, create immune suppressive microenvironment, remodel the extracellular matrix, and regulate metabolic reprogramming. In addition, we highlight the promise of TDEs for early diagnosis and effective therapy of PC liver metastases.

A large-scale proteomics resource of circulating extracellular vesicles for biomarker discovery in pancreatic cancer

Pancreatic cancer has the worst prognosis of all common tumors. Earlier cancer diagnosis could increase survival rates and better assessment of metastatic disease could improve patient care. As such, there is an urgent need to develop biomarkers to diagnose this deadly malignancy. Analyzing circulating extracellular vesicles (cEVs) using 'liquid biopsies' offers an attractive approach to diagnose and monitor disease status. However, it is important to differentiate EV-associated proteins enriched in patients with pancreatic ductal adenocarcinoma (PDAC) from those with benign pancreatic diseases such as chronic pancreatitis and intraductal papillary mucinous neoplasm (IPMN). To meet this need, we combined the novel EVtrap method for highly efficient isolation of EVs from plasma and conducted proteomics analysis of samples from 124 individuals, including patients with PDAC, benign pancreatic diseases and controls. On average, 912 EV proteins were identified per 100 µL of plasma. EVs containing high levels of PDCD6IP, SERPINA12, and RUVBL2 were associated with PDAC compared to the benign diseases in both discovery and validation cohorts. EVs with PSMB4, RUVBL2, and ANKAR were associated with metastasis, and those with CRP, RALB, and CD55 correlated with poor clinical prognosis. Finally, we validated a seven EV protein PDAC signature against a background of benign pancreatic diseases that yielded an 89% prediction accuracy for the diagnosis of PDAC. To our knowledge, our study represents the largest proteomics profiling of circulating EVs ever conducted in pancreatic cancer and provides a valuable open-source atlas to the scientific community with a comprehensive catalogue of novel cEVs that may assist in the development of biomarkers and improve the outcomes of patients with PDAC.

Macrophages promote pre-metastatic niche formation of breast cancer through aryl hydrocarbon receptor activity

Macrophages that acquire an immunosuppressive phenotype play a crucial role in establishing the pre-metastatic niche (PMN), which is essential for facilitating breast cancer metastasis to distant organs. Our study showed that increased activity of the aryl hydrocarbon receptor (AHR) in lung macrophages plays a crucial role in establishing the immunosuppressive PMN in breast cancer. Specifically, AHR activation led to high expression of PD-L1 on macrophages by directly binding to the promoter of Pdl1. This upregulation of PD-L1 promoted the differentiation of regulatory T cells (Tregs) within the PMN, further enhancing immunosuppressive conditions. Mice with Ahr conditional deletion in macrophages had reduced lung metastasis of breast cancer. The elevated AHR levels in PMN macrophages were induced by GM-CSF, which was secreted by breast cancer cells. Mechanistically, the activated STAT5 signaling pathway induced by GM-CSF prevented AHR from being ubiquitinated, thereby sustaining its activity in macrophages. In breast cancer patients, the expression of AHR and PD-L1 was correlated with increased Treg cell infiltration, and higher levels of AHR were associated with a poor prognosis. These findings reveal that the crosstalk of breast cancer cells, lung macrophages, and Treg cells via the GM-CSF-STAT5-AHR-PD-L1 cascade modulates the lung pre-metastatic niche during breast cancer progression.

Mutant p53-Mediated Tumor Secretome: Bridging Tumor Cells and Stromal Cells

The tumor secretome comprises the totality of protein factors secreted by various cell components within the tumor microenvironment, serving as the primary medium for signal transduction between tumor cells and between tumor cells and stromal cells. The deletion or mutation of the p53 gene leads to alterations in cellular secretion characteristics, contributing to the construction of the tumor microenvironment in a cell non-autonomous manner. This review discusses the critical roles of mutant p53 in regulating the tumor secretome to remodel the tumor microenvironment, drive tumor progression, and influence the plasticity of cancer-associated fibroblasts (CAFs) as well as the dynamics of tumor immunity by focusing on both secreted protein expression and secretion pathways. The aim is to provide new insights for targeted cancer therapies.

Disruption of cellular plasticity by repeat RNAs in human pancreatic cancer

Aberrant expression of repeat RNAs in pancreatic ductal adenocarcinoma (PDAC) mimics viral-like responses with implications on tumor cell state and the response of the surrounding microenvironment. To better understand the relationship of repeat RNAs in human PDAC, we performed spatial molecular imaging at single-cell resolution in 46 primary tumors, revealing correlations of high repeat RNA expression with alterations in epithelial state in PDAC cells and myofibroblast phenotype in cancer-associated fibroblasts (CAFs). This loss of cellular identity is observed with dosing of extracellular vesicles (EVs) and individual repeat RNAs of PDAC and CAF cell culture models pointing to cell-cell intercommunication of these viral-like elements. Differences in PDAC and CAF responses are driven by distinct innate immune signaling through interferon regulatory factor 3 (IRF3). The cell-context-specific viral-like responses to repeat RNAs provide a mechanism for modulation of cellular plasticity in diverse cell types in the PDAC microenvironment.

Breast cancer stem cell-derived exosomal lnc-PDGFD induces fibroblast-niche formation and promotes lung metastasis

Triple-negative breast cancer (TNBC) is the most aggressive subtype with high metastatic potential and lack of therapeutic targets. Breast cancer stem cells (BCSCs) are enriched in TNBC and contribute to its metastatic propensity. Accumulating evidence suggests that cancer-derived exosomes are key drivers of premetastatic niche formation in distal organs. However, the function and underlying mechanism of BCSC-derived exosomes in TNBC metastasis remain elusive. Here, we demonstrated that BCSC-derived exosomes exhibit a greater capacity to activate fibroblasts and promote TNBC cell metastasis to the lung than non-BCSC-derived exosomes. Additionally, we found that upregulation of exosomal long non-coding RNA platelet derived growth factor D (lnc-PDGFD) expression in BCSCs is responsible for fibroblast activation through YBX1/NF-kB signaling in the lung. Activated fibroblasts further promote tumor progression by secreting IL-11. Taken together, BCSC-derived exosomes enriched with lnc-PDGFD could activate fibroblasts, thereby facilitating lung metastasis in TNBC patients. These results provide new insights into the mechanism of TNBC metastasis to the lung.

How the bone microenvironment shapes the pre-metastatic niche and metastasis

The bone is a frequent metastatic site, with changes in the mineralized bone and the bone marrow milieu that can also prime other sites for metastasis by educating progenitor cells to support metastatic spread. Stromal and immune populations cooperatively maintain the organizationally complex bone niches and are dysregulated in the presence of a distant primary tumor and metastatic disease. Interrogating the bone niches that facilitate metastatic spread using innovative technologies holds the potential to aid in preventing metastasis in and mediated by the bone. Here, we review recent advances in bone niche biology and its adaptations in the context of cancer.

A Multicellular Mechanochemical Model to Investigate Tumor Microenvironment Remodeling and Pre-Metastatic Niche Formation

Introduction

Colorectal cancer (CRC) is a major cause of cancer related deaths in the United States, with CRC metastasis to the liver being a common occurrence. The development of an optimal metastatic environment is essential process prior to tumor metastasis. This process, called pre-metastatic niche (PMN) formation, involves activation of key resident liver cells, including fibroblast-like stellate cells and macrophages such as Kupffer cells. Tumor-mediated factors introduced to this environment transform resident cells that secrete additional growth factors and remodel the extracellular matrix (ECM), which is thought to promote tumor colonization and metastasis in the secondary environment.

Methods

To investigate the underlying mechanisms of these dynamics, we developed a multicellular computational model to characterize the spatiotemporal dynamics of the PMN formation in tissue. This modeling framework integrates intracellular and extracellular signaling, and traction and junctional forces into a Cellular Potts model, and represents multiple cell types with varying levels of cellular activation. We perform numerical experiments to investigate the role of key factors in PMN formation and tumor invasiveness, including growth factor concentration, timing of tumor arrival, relative composition of resident cells, and the size of invading tumor cluster.

Results

These parameter studies identified growth factor availability and ECM concentration in the environment as two of the key determinants of tumor invasiveness. We further predict that both the ECM concentration potential and growth factor sensitivity of the stellate cells are key drivers of the PMN formation and associated ECM concentration.

Conclusions

Overall, this modeling framework represents a significant step towards simulating cancer metastasis and investigating the role of key factors on PMN formation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-024-00831-0.

Unique structural configuration of EV-DNA primes Kupffer cell-mediated antitumor immunity to prevent metastatic progression

Extracellular vesicles (EVs) transport biomolecules that mediate intercellular communication. We previously showed that EVs contain DNA (EV-DNA) representing the entire genome. However, the mechanism of genomic EV-DNA packaging and its role in cancer remain elusive. We now demonstrate that EV-DNA is predominantly localized on the vesicle surface and associated with uniquely modified and cleaved histones. Moreover, a genome-wide clustered regularly interspaced short palindromic repeats knockout screen revealed that immune developmental pathways and genes, including apoptotic peptidase activating factor 1 (APAF1) and neutrophil cytosolic factor 1 (NCF1), regulate EV-DNA packaging. Furthermore, in colorectal cancer models, uptake of EV-DNA by pre-metastatic liver Kupffer cells (KCs) activated DNA damage responses. This activation rewired KC cytokine production and promoted the formation of tertiary lymphoid structures, thereby suppressing liver metastasis. Conversely, loss of APAF1 decreased EV-DNA packaging and promoted liver metastasis. Importantly, colorectal cancer biopsy EV-DNA secretion could serve as a predictive biomarker for postoperative metastasis. Taken together, our findings indicate that uniquely chromatinized EV-DNA induces antitumor immunity.

Exosomal integrins in tumor progression, treatment and clinical prediction (Review)

Integrins are a large family of cell adhesion molecules involved in tumor cell differentiation, migration, proliferation and neovascularization. Tumor cell‑derived exosomes carry a large number of integrins, which are closely associated with tumor progression. As crucial mediators of intercellular communication, exosomal integrins have gained attention in the field of cancer biology. The present review examined the regulatory mechanisms of exosomal integrins in tumor cell proliferation, migration and invasion, and emphasized their notable roles in tumor initiation and progression. The potential of exosomal integrins as drug delivery systems in cancer treatment was explored. Additionally, the potential of exosomal integrins in clinical tumor prediction was considered, while summarizing their applications in diagnosis, prognosis assessment and treatment response prediction. Thus, the present review aimed to provide guidance and insights for future basic research and the clinical translation of exosomal integrins. The study of exosomal integrins is poised to offer new perspectives and methods for precise cancer treatment and clinical prediction.