ECM stiffness-tuned exosomes drive breast cancer motility through thrombospondin-1

Asymmetric crowders and membrane morphology at the nexus of intracellular trafficking and oncology

A definitive understanding of the interplay between protein binding/migration and membrane curvature evolution is emerging but needs further study. The mechanisms defining such phenomena are critical to intracellular transport and trafficking of proteins. Among trafficking modalities, exosomes have drawn attention in cancer research as these nano-sized naturally occurring vehicles are implicated in intercellular communication in the tumor microenvironment, suppressing anti-tumor immunity and preparing the metastatic niche for progression. A significant question in the field is how the release and composition of tumor exosomes are regulated. In this perspective article, we explore how physical factors such as geometry and tissue mechanics regulate cell cortical tension to influence exosome production by co-opting the biophysics as well as the signaling dynamics of intracellular trafficking pathways and how these exosomes contribute to the suppression of anti-tumor immunity and promote metastasis. We describe a multiscale modeling approach whose impact goes beyond the fundamental investigation of specific cellular processes toward actual clinical translation. Exosomal mechanisms are critical to developing and approving liquid biopsy technologies, poised to transform future non-invasive, longitudinal profiling of evolving tumors and resistance to cancer therapies to bring us one step closer to the promise of personalized medicine.

The role of SPI1/VSIG4/THBS1 on glioblastoma progression through modulation of the PI3K/AKT pathway

INTRODUCTION

Glioblastoma multiforme (GBM) poses a significant challenge in terms of treatment due to its high malignancy, necessitating the identification of additional molecular targets. VSIG4, an oncogenic gene participates in tumor growth and migration in various cancer types. Nevertheless, the precise process through which VSIG4 facilitates the malignant progression of glioma remains to be elucidated.

OBJECTIVES

This research aims to explore the function and molecular mechanism involving VSIG4 in the malignant progression of glioma.

METHODS

The amount of VSIG4 was measured using qPCR, western blotting, and immunohistochemistry. Lentivirus infections were applied for upregulating or downregulating molecules within glioma cells. The incorporation of 5-ethynyl-20-deoxyuridine, Transwell, cell counting kit-8, and clone formation experiments, were applied to assess the biological functions of molecules on glioma cells. Dual luciferase reporter gene, RNA immunoprecipitation, and chromatin immunoprecipitation assays were used to explore the functional relationship among relevant molecules.

RESULTS

The upregulation of VSIG4 was observed in GBM tissues, indicating an adverse prognosis. Silencing VSIG4 in glioma cells resulted in a decrease in cell viability, invasion, proliferation, and tumorigenesis, an increase in cell apoptosis, and a stagnation in the cell cycle progression at the G0/G1 phase. Mechanistically, SPI1-mediated upregulation of VSIG4 expression led to binding between VSIG4 and THBS1 protein, ultimately facilitating the malignant progression of glioma cells through the activation of the PI3K/AKT pathway. The inhibited proliferative and invasive capabilities of glioma cells were reversed by overexpressing THBS1 following the knockdown of VSIG4.

CONCLUSION

Our findings provide evidence for the role of VSIG4 as an oncogene and reveal the previously unidentified contribution of the SPI1/VSIG4/THBS1 axis in the malignant progression of glioma. This signaling cascade enhances tumor growth and invasion by modulating the PI3K/AKT pathway. VSIG4 as a potential biomarker may be a viable strategy in the development of tailored molecular therapies for GBM.

Growing Role of 3D In Vitro Cell Cultures in the Study of Cellular and Molecular Mechanisms: Short Focus on Breast Cancer, Endometriosis, Liver and Infectious Diseases

Over the past decade, the development of three-dimensional (3D) models has increased exponentially, facilitating the unravelling of fundamental and essential cellular mechanisms by which cells communicate with each other, assemble into tissues and organs and respond to biochemical and biophysical stimuli under both physiological and pathological conditions. This section presents a concise overview of the most recent updates on the significant contribution of different types of 3D cell cultures including spheroids, organoids and organ-on-chip and bio-printed tissues in advancing our understanding of cellular and molecular mechanisms. The case studies presented include the 3D cultures of breast cancer (BC), endometriosis, the liver microenvironment and infections. In BC, the establishment of 3D culture models has permitted the visualization of the role of cancer-associated fibroblasts in the delivery of exosomes, as well as the significance of the physical properties of the extracellular matrix in promoting cell proliferation and invasion. This approach has also become a valuable tool in gaining insight into general and specific mechanisms of drug resistance. Given the considerable heterogeneity of endometriosis, 3D models offer a more accurate representation of the in vivo microenvironment, thereby facilitating the identification and translation of novel targeted therapeutic strategies. The advantages provided by 3D models of the hepatic environment, in conjunction with the high throughput characterizing various platforms, have enabled the elucidation of complex molecular mechanisms underlying various threatening hepatic diseases. A limited number of 3D models for gut and skin infections have been developed. However, a more profound comprehension of the spatial and temporal interactions between microbes, the host and their environment may facilitate the advancement of in vitro, ex vivo and in vivo disease models. Additionally, it may pave the way for the development of novel therapeutic approaches in diverse research fields. The interested reader will also find concluding remarks on the challenges and prospects of using 3D cell cultures for discovering cellular and molecular mechanisms in the research areas covered in this review.

Cell-Specific Impacts of Surface Coating Composition on Extracellular Vesicle Secretion

Biomaterial properties have recently been shown to modulate extracellular vesicle (EV) secretion and cargo; however, the effects of substrate composition on EV production remain underexplored. This study investigates the impacts of surface coatings composed of collagen I (COLI), fibronectin (FN), and poly l-lysine (PLL) on EV secretion for applications in therapeutic EV production and to further understanding of how changes in the extracellular matrix microenvironment affect EVs. EV secretion from primary bone marrow-derived mesenchymal stromal cells (BMSCs), primary adipose-derived stem cells (ASCs), HEK293 cells, NIH3T3 cells, and RAW264.7 cells was characterized on the different coatings. Expression of EV biogenesis genes and cellular adhesion genes was also analyzed. COLI coatings significantly decreased EV secretion in RAW264.7 cells, with associated decreases in cell viability and changes in EV biogenesis-related and cell adhesion genes at day 4. FN coatings increased EV secretion in NIH3T3 cells, while PLL coatings increased EV secretion in ASCs. Surface coatings had significant effects on the capacity of EVs derived from RAW264.7 and NIH3T3 cells to impact in vitro macrophage proliferation. Overall, surface coatings had different cell-specific effects on EV secretion and in vitro functional capacity, thus highlighting the potential of substrate coatings to further the development of clinical EV production systems.

Procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 promotes collagen cross-linking and ECM stiffening to induce liver fibrosis

Procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (Plod2) is a key collagen lysyl hydroxylase mediating the formation of collagen fiber and stabilized collagen cross-links, and has been identified in several forms of fibrosis. However, the potential role and regulatory mechanism of Plod2 in liver fibrosis remain unclear yet. Mouse liver fibrosis models were induced by injecting carbon tetrachloride (CCl4) intraperitoneally. The morphology and alignment of collagen was observed under transmission and scanning electron microscopy, and extracellular matrix (ECM) stiffness was measured by atomic force microscopy. Large amounts of densely packed fibrillar collagen fibers produced by myofibroblasts (MFs) were deposited in fibrotic liver of mice reaching very large diameters in the cross section, accompanied with ECM stiffening, which was positively correlated with collagen-crosslinking. The expression of Plod2 was dynamically up-regulated in fibrotic liver of mouse and human. In MFs transfection of Plod2 siRNA made collagen fibers more orderly and linear aligned which can be easily degraded and protected from ECM stiffness. Administration of Plod2 siRNA preventatively or therapeutically in CCl4 mice reduced the average size of collagen bundles in transverse section, increased collagen solubility, decreases the levels of crosslinking products hydroxylysylpyridinoline and lysylpyridinoline, prevented ECM stiffening and alleviated liver fibrosis. Altogether, Plod2 mediates the formation of stabilized profibrotic collagen cross-links in MFs, leading to the alteration of collagen solubility and ECM stiffness, and eventually aggravates liver fibrosis, which provide potential target for the treatment of liver disease.

Astragaloside IV inhibits colorectal cancer metastasis by reducing extracellular vesicles release and suppressing M2-type TAMs activation

Ethnopharmacological relevance

Tumour-derived extracellular vesicles (TEVs) have been confirmed to facilitate colorectal cancer (CRC) metastasis by remodelling the tumour microenvironment (TME). Drugs targeted TEVs is considered as a promising therapeutic strategy for cancer treatment. Traditional Chinese medicine (TCM) plays a vital role in improving the prognosis of CRC patients and eventually CRC patients with distant metastasis. Although the anti-tumour effects of active compounds from TCM prescriptions are observed widely, the molecular mechanisms remain unknown.

Aim of the study

This study aims to investigate the effects of active compounds in our library of TCM on preventing CRC metastasis, and also explore the potential mechanisms from the perspective of TEVs. Materials and methods: The effects of active compounds on the proliferation of CRC cells were determined by CCK-8 assay. TEVs were extracted from MC38 cells by ultracentrifugation and characterized by electron microscopy, Nanosight NS300 and western blotting. The TEV particles were quantified by Nanosight NS300. The potential mechanism by which astragaloside IV (ASIV) reduced TEV secretion was determined by western blotting. RAW264.7 cells were cocultured with the conditioned medium (CM) of MC38 cells treated with or without ASIV, and the activation of tumour-associated macrophages (TAMs) was assessed by immunofluorescence and quantitative polymerase chain reaction (qPCR). The migration of CRC cells was measured by wound healing and Transwell assay. A spleen-to-liver metastasis model of colorectal cancer was used to confirm the efficiency of ASIV in vivo. Liver metastatic tumours of the mice were used for liver weight measures and H&E staining. Immunofluorescence was applied to observe the infiltration of TAMs, the expression of neutral sphingomyelinase 2 (nSMase2) and Rab27a.

Results

By screening our TCM monomer library, we found that ASIV, which is mainly extracted from Radix Astragali, reduced the release of TEVs from CRC cells in a time- and concentration-dependent manner. Mechanistically, ASIV inhibited the production and secretion of TEVs by downregulating nSMase2 and Rab27a expression in CRC cells. CM from ASIV-treated CRC cells reshaped the polarization of TAMs by decreasing M2-type polarization, increasing M1-type polarization. Consequently, the repolarization of M2-type to M1-type macrophages led to reduced invasion and migration of CRC cells. Moreover, we confirmed that ASIV inhibited the liver metastasis of CRC, reduced M2-type macrophage infiltration and decreased the expression of nSMase2 and Rab27a in liver metastases.

Conclusions

ASIV inhibited CRC metastasis by reducing EVs release and suppressing M2-type TAMs activation. All these findings reveal a new insight into the mechanisms of ASIV in preventing CRC progression and provide a promising approach for anti-tumour therapy.

Matrix stiffening promotes chondrocyte senescence and the osteoarthritis development through downregulating HDAC3

Extracellular matrix (ECM) stiffening is a typical characteristic of cartilage aging, which is a quintessential feature of knee osteoarthritis (KOA). However, little is known about how ECM stiffening affects chondrocytes and other molecules downstream. This study mimicked the physiological and pathological stiffness of human cartilage using polydimethylsiloxane (PDMS) substrates. It demonstrated that epigenetic Parkin regulation by histone deacetylase 3 (HDAC3) represents a new mechanosensitive mechanism by which the stiffness matrix affected chondrocyte physiology. We found that ECM stiffening accelerated cultured chondrocyte senescence in vitro, while the stiffness ECM downregulated HDAC3, prompting Parkin acetylation to activate excessive mitophagy and accelerating chondrocyte senescence and osteoarthritis (OA) in mice. Contrarily, intra-articular injection with an HDAC3-expressing adeno-associated virus restored the young phenotype of the aged chondrocytes stimulated by ECM stiffening and alleviated OA in mice. The findings indicated that changes in the mechanical ECM properties initiated pathogenic mechanotransduction signals, promoted the Parkin acetylation and hyperactivated mitophagy, and damaged chondrocyte health. These results may provide new insights into chondrocyte regulation by the mechanical properties of ECM, suggesting that the modification of the physical ECM properties may be a potential OA treatment strategy.

Small Extracellular Vesicles Promote Stiffness-mediated Metastasis

Tissue stiffness is a critical prognostic factor in breast cancer and is associated with metastatic progression. Here we show an alternative and complementary hypothesis of tumor progression whereby physiologic matrix stiffness affects the quantity and protein cargo of small extracellular vesicles (EV) produced by cancer cells, which in turn aid cancer cell dissemination. Primary patient breast tissue released by cancer cells on matrices that model human breast tumors (25 kPa; stiff EVs) feature increased adhesion molecule presentation (ITGα2β1, ITGα6β4, ITGα6β1, CD44) compared with EVs from softer normal tissue (0.5 kPa; soft EVs), which facilitates their binding to extracellular matrix proteins including collagen IV, and a 3-fold increase in homing ability to distant organs in mice. In a zebrafish xenograft model, stiff EVs aid cancer cell dissemination. Moreover, normal, resident lung fibroblasts treated with stiff and soft EVs change their gene expression profiles to adopt a cancer-associated fibroblast phenotype. These findings show that EV quantity, cargo, and function depend heavily on the mechanical properties of the extracellular microenvironment.

SIGNIFICANCE

Here we show that the quantity, cargo, and function of breast cancer-derived EVs vary with mechanical properties of the extracellular microenvironment.

The role of THBS1 and PDGFD in the immune microenvironment of Helicobacter pylori-associated gastric cancer

BACKGROUND AND STUDY AIMS

Immunotherapy has emerged as a hot topic in cancer treatment in recent years and has also shown potential in the treatment of Helicobacter pylori-associated gastric cancer. However, there is still a need to identify potential immunotherapy targets.

MATERIAL AND METHODS

We used the GSE116312 dataset of Helicobacter pylori-associated gastric cancer to identify differentially expressed genes, which were then overlapped with immune genes from the ImmPort database. The identified immune genes were used to classify gastric cancer samples and evaluate the relationship between classification and tumor mutations, as well as immune infiltration. An immune gene-based prognostic model was constructed, and the expression levels of the genes involved in constructing the model were explored in the tumor immune microenvironment.

RESULTS

We successfully identified 60 immune genes and classified gastric cancer samples into two subtypes, which showed differences in prognosis, tumor mutations, immune checkpoint expression, and immune cell infiltration. Subsequently, we constructed an immune prognostic model consisting of THBS1 and PDGFD, which showed significant associations with macrophages and fibroblasts.

CONCLUSION

We identified abnormal expression of THBS1 and PDGFD in cancer-associated fibroblasts (CAFs) within the tumor immune microenvironment, suggesting their potential as therapeutic targets.

Mechanoelectronic stimulation of autologous extracellular vesicle biosynthesis implant for gut microbiota modulation

Pathogenic gut microbiota is responsible for a few debilitating gastrointestinal diseases. While the host immune cells do produce extracellular vesicles to counteract some deleterious effects of the microbiota, the extracellular vesicles are of insufficient doses and at unreliable exposure times. Here we use mechanical stimulation of hydrogel-embedded macrophage in a bioelectronic controller that on demand boost production of up to 20 times of therapeutic extracellular vesicles to ameliorate the microbes' deleterious effects in vivo. Our miniaturized wireless bioelectronic system termed inducible mechanical activation for in-situ and sustainable generating extracellular vesicles (iMASSAGE), leverages on wireless electronics and responsive hydrogel to impose mechanical forces on macrophages to produce extracellular vesicles that rectify gut microbiome dysbiosis and ameliorate colitis. This in vivo controllable extracellular vesicles-produced system holds promise as platform to treat various other diseases.

Breast cancer derived exosomes: Theragnostic perspectives and implications

Breast cancer (BC) is the most prevalent malignancy affecting women worldwide. Although conventional treatments such as chemotherapy, surgery, hormone therapy, radiation therapy, and biological therapy are commonly used, they often entail significant side effects. Therefore, there is a critical need to investigate more cost-effective and efficient treatment modalities in BC. Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, play a crucial role in modulating recipient cell behaviour and driving cancer progression. Among the EVs, exosomes provide valuable insights into cellular dynamics under both healthy and diseased conditions. In cancer, exosomes play a critical role in driving tumor progression and facilitating the development of drug resistance. BC-derived exosomes (BCex) dynamically influence BC progression by regulating cell proliferation, immunosuppression, angiogenesis, metastasis, and the development of treatment resistance. Additionally, BCex serve as promising diagnostic markers in BC which are detectable in bodily fluids such as urine and saliva. Targeted manipulation of BCex holds significant therapeutic potential. This review explores the therapeutic and diagnostic implications of exosomes in BC, underscoring their relevance to the disease. Furthermore, it discusses future directions for exosome-based research in BC, emphasizing the necessity for further exploration in this area.

Distinct spectral signatures unfold ECM stiffness-triggered biochemical changes in breast cancer cells

Cancer progression often accompanies the stiffening of extracellular matrix (ECM) in and around the tumor, owing to extra deposition and cross-linking of collagen. Stiff ECM has been linked with poor prognosis and is known to fuel invasion and metastasis, notably in breast cancer. However, the underlying biochemical or metabolic changes and the cognate molecular signatures remain elusive. Here, we explored Raman spectroscopy to unveil the spectral fingerprints of breast cancer cells in response to extracellular mechanical cues. Using stiffness-tuneable hydrogels, we showed that cells grown on stiff ECM displayed morphological changes with high proliferation. We further demonstrated that Raman Spectroscopy, a label-free and non-invasive technique, could provide comprehensive information about the biochemical environment of breast cancer cells in response to varying ECM stiffness. Raman spectroscopic analysis classified the cells into distinct clusters based on principal component-based linear discriminant analysis (PC-LDA). Multivariate curve resolution-alternating least squares (MCR-ALS) analysis indicated that cells cultured on stiff ECM exhibited elevated nucleic acid content and lesser lipids. Interestingly, increased intensity of Raman bands corresponding to cytochrome-c was also observed in stiff ECM conditions, suggesting mitochondrial modulation. The key findings harboured by spectral profiles were also corroborated by transmission electron microscopy, confirming altered metabolic status as reflected by increased mitochondria number and decreased lipid droplets in response to ECM stiffening. Collectively, these findings not only give the spectral signatures for mechanoresponse but also provide the landscape of biochemical changes in response to ECM stiffening.

Emerging role of lncRNAs as mechanical signaling molecules in mechanotransduction and their association with Hippo-YAP signaling: a review

Cells within tissues are subject to various mechanical forces, including hydrostatic pressure, shear stress, compression, and tension. These mechanical stimuli can be converted into biochemical signals through mechanoreceptors or cytoskeleton-dependent response processes, shaping the microenvironment and maintaining cellular physiological balance. Several studies have demonstrated the roles of Yes-associated protein (YAP) and its homolog transcriptional coactivator with PDZ-binding motif (TAZ) as mechanotransducers, exerting dynamic influence on cellular phenotypes including differentiation and disease pathogenesis. This regulatory function entails the involvement of the cytoskeleton, nucleoskeleton, integrin, focal adhesions (FAs), and the integration of multiple signaling pathways, including extracellular signal-regulated kinase (ERK), wingless/integrated (WNT), and Hippo signaling. Furthermore, emerging evidence substantiates the implication of long non-coding RNAs (lncRNAs) as mechanosensitive molecules in cellular mechanotransduction. In this review, we discuss the mechanisms through which YAP/TAZ and lncRNAs serve as effectors in responding to mechanical stimuli. Additionally, we summarize and elaborate on the crucial signal molecules involved in mechanotransduction.

Exosomes Derived from Human Palatal Mesenchymal Cells Mediate Intercellular Communication During Palatal Fusion by Promoting Oral Epithelial Cell Migration

Purpose

Exosomes are important "messengers" in cell-cell interactions, but their potential effects on palatal fusion are still unknown. This study aimed to explore the role and mechanism of exosomes derived from palatal mesenchymal cells in epithelial-mesenchymal communication during palatogenesis.

Methods

The expression of exosome marker CD63 and CD81 in palatal cells during palatogenesis was detected by immunofluorescence staining. After being purified from the supernatant of human embryonic palatal mesenchymal (HEPM) cells, exosomes (HEPM-EXO) were characterized by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western blot. HEPM-EXO were co-cultured with human immortalized oral epithelial cells (HIOEC). The effects of HEPM-EXO on the cell proliferation, migration, apoptosis and epithelial-mesenchymal transition (EMT) of HIOEC were evaluated. The proteins encapsulated in HEPM-EXO were analyzed by proteomic analysis.

Results

The extensive expression of CD63 and CD81 in palatal epithelial and mesenchymal cells were continuously detected during E12.5~E14.5, suggesting that exosomes were involved in the process of palatal fusion. The expression of CD63 was also observed in the acellular basement membrane between the palatal epithelium and the mesenchyme in vivo, and HEPM-EXO could be internalized by HIOEC in vitro, suggesting that exosomes are potent to diffuse through the cellular tissue boundary to mediate palatal cell-cell communication. Exposure of HEPM-EXO to HIOEC substantially inhibited the proliferation and stimulated the migration of HIOEC, but had no significant effect on cell apoptosis and EMT. Proteomic analysis revealed the basic characteristics of the proteins in HEPM-EXO and that exosomal THBS1 may potentially regulate the cell behaviors of HIOEC, which needs further verification. Gene ontology (GO) analysis uncovered that the proteins highly expressed in HEPM-EXO are closely related to wound healing, implying a promising therapeutic opportunity of HEPM-EXO in tissue injury treatment with future studies.

Conclusion

HEPM-EXO mediated cell-cell communication by regulating cell proliferation and migration of oral epithelial cells during palatogenesis.

ECM stiffness affects cargo sorting into MSC-EVs to regulate their secretion and uptake behaviors

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have garnered extensive attention as natural product-based nanomedicines and potential drug delivery vehicles. However, the specific mechanism for regulating MSC-EVs secretion and delivery remains unclear. Here, we demonstrate that extracellular matrix (ECM) stiffness regulates the secretion and delivery of EVs by affecting MSCs' cargo sorting mechanically. Using multi-omics analysis, we found that a decrease in ECM stiffness impeded the sorting of vesicular transport-related proteins and autophagy-related lipids into MSC-EVs, impairing their secretion and subsequent uptake by macrophages. Hence, MSC-EVs with different secretion and uptake behaviors can be produced by changing the stiffness of culture substrates. This study provides new insights into MSC-EV biology and establishes a connection between MSC-EV behaviors and ECM from a biophysical perspective, providing a basis for the rational design of biomedical materials.

Exosome Heterogeneity Affects the Distal "Barrier-Crossing" Trafficking of Exosome Encapsulated Quantum Dots

The biological activities of nanoparticles (NPs), which include endocytosis by macrophages and subsequent intracellular degradation and/or release, transfer to other cells, or translocation across tissue barriers, highly depend on their fate in living organisms. Yet, translocation across barriers, especially the distal "barrier-crossing" trafficking of NPs, is still unclear. The exosome (Exo) plays a crucial role in intercellular communication and biological barrier trafficking. Here, we report that ZnCdSe@ZnS quantum dots (QDs), as a representation of NPs in biomedical applications, could cross the blood-brain barrier and approach the mouse brain via active Exo encapsulation. By employing multiple techniques, we demonstrated that QDs were internalized by macrophages (J774A.1) and tumor cells (HeLa) and then released to the extracellular environment along with Exo. Exo encapsulation facilitates the distal barrier-crossing trafficking of QDs in vivo, while Exo biogenesis inhibitor GW4869 suppressed the QDs enriched in the brains of mice with a 4T1-Luc breast cancer xenograft. Interestingly, Exo heterogeneity affects the distal trafficking of enveloped QDs. Exo derived from tumorous HeLa cells, not macrophages, that were enriched in functional proteins with cell adhesion, cell migration, axon guidance, and cell motility, showed a better capacity for the remote trafficking of QDs. This study proposes Exo as a vehicle to deliver exogenous NPs to translocate across the distal barrier and provides further information for biomedical application and the risk assessment of NPs.

Physical modulation of mesenchymal stem cell exosomes: A new perspective for regenerative medicine

Mesenchymal stem cell-derived exosomes (MSC-Exo) offer promising therapeutic potential for various refractory diseases, presenting a novel therapeutic strategy. However, their clinical application encounters several obstacles, including low natural secretion, uncontrolled biological functions and inherent heterogeneity. On the one hand, physical stimuli can mimic the microenvironment dynamics where MSC-Exo reside. These factors influence not only their secretion but also, significantly, their biological efficacy. Moreover, physical factors can also serve as techniques for engineering exosomes. Therefore, the realm of physical factors assumes a crucial role in modifying MSC-Exo, ultimately facilitating their clinical translation. This review focuses on the research progress in applying physical factors to MSC-Exo, encompassing ultrasound, electrical stimulation, light irradiation, intrinsic physical properties, ionizing radiation, magnetic field, mechanical forces and temperature. We also discuss the current status and potential of physical stimuli-affected MSC-Exo in clinical applications. Furthermore, we address the limitations of recent studies in this field. Based on this, this review provides novel insights to advance the refinement of MSC-Exo as a therapeutic approach in regenerative medicine.

The molecular mechanism of thrombospondin family members in cardiovascular diseases

Cardiovascular diseases have been identified as vital factors in global morbidity and mortality in recent years. The available evidence suggests that various cytokines and pathological proteins participate in these complicated and changeable diseases. The thrombospondin (TSP) family is a series of conserved, multidomain calcium-binding glycoproteins that cause cell-matrix and cell-cell effects via interactions with other extracellular matrix components and cell surface receptors. The TSP family has five members that can be divided into two groups (Group A and Group B) based on their different structures. TSP-1, TSP-2, and TSP-4 are the most studied proteins. Among recent studies and findings, we investigated the functions of several family members, especially TSP-5. We review the basic concepts of TSPs and summarize the relevant molecular mechanisms and cell interactions in the cardiovascular system. Targeting TSPs in CVD and other diseases has a remarkable therapeutic benefit.

Scleral remodeling during myopia development in mice eyes: a potential role of thrombospondin-1

BACKGROUND

Scleral extracellular matrix (ECM) remodeling plays a crucial role in the development of myopia, particularly in ocular axial elongation. Thrombospondin-1 (THBS1), also known as TSP-1, is a significant cellular protein involved in matrix remodeling in various tissues. However, the specific role of THBS1 in myopia development remains unclear.

METHOD

We employed the HumanNet database to predict genes related to myopic sclera remodeling, followed by screening and visualization of the predicted genes using bioinformatics tools. To investigate the potential target gene Thbs1, we utilized lens-induced myopia models in male C57BL/6J mice and performed Western blot analysis to detect the expression level of scleral THBS1 during myopia development. Additionally, we evaluated the effects of scleral THBS1 knockdown on myopia development through AAV sub-Tenon's injection. The refractive status and axial length were measured using a refractometer and SD-OCT system.

RESULTS

During lens-induced myopia, THBS1 protein expression in the sclera was downregulated, particularly in the early stages of myopia induction. Moreover, the mice in the THBS1 knockdown group exhibited alterations in myopia development in both refraction and axial length changed compared to the control group. Western blotting analysis confirmed the effectiveness of AAV-mediated knockdown, demonstrating a decrease in COLA1 expression and an increase in MMP9 levels in the sclera.

CONCLUSION

Our findings indicate that sclera THBS1 levels decreased during myopia development and subsequent THBS1 knockdown showed a decrease in scleral COLA1 expression. Taken together, these results suggest that THBS1 plays a role in maintaining the homeostasis of scleral extracellular matrix, and the reduction of THBS1 may promote the remodeling process and then affect ocular axial elongation during myopia progression.

mTORC1 Mediates Biphasic Mechano-Response to Orchestrate Adhesion-Dependent Cell Growth and Anoikis Resistance

Cells constantly sense and respond to not only biochemical but also biomechanical changes in their microenvironment, demanding for dynamic metabolic adaptation. ECM stiffening is a hallmark of cancer aggressiveness, while survival under substrate detachment also associates with poor prognosis. Mechanisms underlying this, non-linear mechano-response of tumor cells may reveal potential double-hit targets for cancers. Here, an integrin-GSK3β-FTO-mTOR axis is reported, that can integrate stiffness sensing to ensure both the growth advantage endowed by rigid substrate and cell death resistance under matrix detachment. It is demonstrated that substrate stiffening can activate mTORC1 and elevate mTOR level through integrins and GSK3β-FTO mediated mRNA m6 A modification, promoting anabolic metabolism. Inhibition of this axis upon ECM detachment enhances autophagy, which in turn conveys resilience of tumor cells to anoikis, as it is demonstrated in human breast ductal carcinoma in situ (DCIS) and mice malignant ascites. Collectively, these results highlight the biphasic mechano-regulation of cellular metabolism, with implications in tumor growth under stiffened conditions such as fibrosis, as well as in anoikis-resistance during cancer metastasis.

[Hepatocellular Carcinoma-Derived Exosomes: Key Players in Intercellular Communication Within the Tumor Microenvironment]

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths in the world. Due to the insidious onset and rapid progression and a lack of effective treatments, the prognosis of patients with HCC is extremely poor, with the average 5-year survival rate being less than 10%. The tumor microenvironment (TME), the internal environment in which HCC develops, can regulate the oncogenesis, development, invasion, and metastasis of HCC. During the process of cancer progression, HCC cells can regulate the biological behaviors of tumor cells, cancer-associated fibroblasts, cancer-associated immune cells, and other cells in the TME by releasing exosomes containing specific signals, thereby promoting cancer progression. However, the exact molecular mechanisms and the roles of exosomes in the specific cellular regulation of these processes are not fully understood. Herein, we summarized the TME components of HCC, the sources and the biological traits of exosomes in the TME, and the impact of mechanical factors on exosomes. In addition, special attention was given to the discussion of the effects of HCC-exosomes on different types of cells in the microenvironment. There are still many difficulties to be overcome before exosomes can be applied as carriers in clinical cancer treatment. First of all, the homogeneity of exosomes is difficult to ensure. Secondly, exosomes are mainly administered through subcutaneous injection. Although this method is simple and easy to implement, the absorption efficiency is not ideal. Thirdly, exosome extraction methods are limited in number and inefficient, making it difficult to prepare exosomes in large quantities. It is important to ensure that exosomes are used in sufficient quantities to trigger an effective tumor immune response, especially for exosome-mediated tumor immunotherapy. With the improvement in identification, isolation, and purification technology, exosomes are expected to be successfully used in the clinical diagnosis of early-stage HCC and the clinical treatment of liver cancer.

Preparation and Characterization of Collagen-Hyaluronic Acid (Col-HA) Matrices: In Vitro Mimics of the Tumor Microenvironment

Collagen-I (Col) and hyaluronic acid (HA) are two of the most important extracellular matrix (ECM) components. While collagen serves as the main structural feature of the ECM and is an important ligand for integrin-based adhesions, HA acts as a ligand for the transmembrane glycoprotein CD44. However, most studies on cancer invasion utilize 3D collagen matrices, thereby ignoring the importance of HA-CD44 interactions. Here, we describe the process of fabricating Col-HA gels with varying Col/HA ratios, which can be used to suitably mimic the tumor microenvironment.

Distinguished biomimetic dECM system facilitates early detection of metastatic breast cancer cells

Breast cancer is the most prevalent malignant tumor affecting women's health. Bone is the most common distant metastatic organ, worsening the quality of life and increasing the mortality of patients. Early detection of breast cancer bone metastasis is urgent for halting disease progression and improving tumor prognosis. Recently, extracellular matrix (ECM) with biomimetic tissue niches opened a new avenue for tumor models in vitro. Here, we developed a biomimetic decellularized ECM (dECM) system to recapitulate bone niches at different situations, bone mimetic dECM from osteoblasts (BM-ECM) and bone tumor mimetic dECM from osteosarcoma cells (OS-ECM). The two kinds of dECMs exhibited distinct morphology, protein composition, and distribution. Interestingly, highly metastatic breast cancer cells tended to adhere and migrate on BM-ECM, while lowly metastatic breast cancer cells preferred the OS-ECM niche. Epithelial-to-mesenchymal transition was a potential mechanism to initiate the breast cancer cell migration on different biomimetic dECMs. Importantly, in the nude mice model, the dECM system captured metastatic breast cancer cells as early as 10 days after orthotopic transplantation in mammary gland pads, with higher signal on BM-ECM than that on OS-ECM. Collectively, the biomimetic dECM system might be a promising tumor model to distinguish the metastatic ability of breast cancer cells in vitro and to facilitate early detection of metastatic breast cancer cells in vivo, contributing to the diagnosis of breast cancer bone metastasis.

Stiffness-dependent MSC homing and differentiation into CAFs - implications for breast cancer invasion

Cellular heterogeneity and extracellular matrix (ECM) stiffening have been shown to be drivers of breast cancer invasiveness. Here, we examine how stiffness-dependent crosstalk between cancer cells and mesenchymal stem cells (MSCs) within an evolving tumor microenvironment regulates cancer invasion. By analyzing previously published single-cell RNA sequencing datasets, we establish the existence of a subpopulation of cells in primary tumors, secondary sites and circulatory tumor cell clusters of highly aggressive triple-negative breast cancer (TNBC) that co-express MSC and cancer-associated fibroblast (CAF) markers. By using hydrogels with stiffnesses of 0.5, 2 and 5 kPa to mimic different stages of ECM stiffening, we show that conditioned medium from MDA-MB-231 TNBC cells cultured on 2 kPa gels, which mimic the pre-metastatic stroma, drives efficient MSC chemotaxis and induces stable differentiation of MSC-derived CAFs in a TGFβ (TGFB1)- and contractility-dependent manner. In addition to enhancing cancer cell proliferation, MSC-derived CAFs on 2 kPa gels maximally boost local invasion and confer resistance to flow-induced shear stresses. Collectively, our results suggest that homing of MSCs at the pre-metastatic stage and their differentiation into CAFs actively drives breast cancer invasion and metastasis in TNBC.

Potential therapeutic effects of milk-derived exosomes on intestinal diseases

Exosomes are extracellular vesicles with the diameter of 30 ~ 150 nm, and are widely involved in intercellular communication, disease diagnosis and drug delivery carriers for targeted disease therapy. Therapeutic application of exosomes as drug carriers is limited due to the lack of sources and methods for obtaining adequate exosomes. Milk contains abundant exosomes, several studies have shown that milk-derived exosomes play crucial roles in preventing and treating intestinal diseases. In this review, we summarized the biogenesis, secretion and structure, current novel methods used for the extraction and identification of exosomes, as well as discussed the role of milk-derived exosomes in treating intestinal diseases, such as inflammatory bowel disease, necrotizing enterocolitis, colorectal cancer, and intestinal ischemia and reperfusion injury by regulating intestinal immune homeostasis, restoring gut microbiota composition and improving intestinal structure and integrity, alleviating conditions such as oxidative stress, cell apoptosis and inflammation, and reducing mitochondrial reactive oxygen species (ROS) and lysosome accumulation in both humans and animals. In addition, we discussed future prospects for the standardization of milk exosome production platform to obtain higher concentration and purity, and complete exosomes derived from milk. Several in vivo clinical studies are needed to establish milk-derived exosomes as an effective and efficient drug delivery system, and promote its application in the treatment of various diseases in both humans and animals.

Targeting cancer stem cell plasticity in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer subtype with limited treatment options. Cancer stem cells (CSCs) are thought to play a crucial role in TNBC progression and resistance to therapy. CSCs are a small subpopulation of cells within tumors that possess self-renewal and differentiation capabilities and are responsible for tumor initiation, maintenance, and metastasis. CSCs exhibit plasticity, allowing them to switch between states and adapt to changing microenvironments. Targeting CSC plasticity has emerged as a promising strategy for TNBC treatment. This review summarizes recent advances in understanding the molecular mechanisms underlying CSC plasticity in TNBC and discusses potential therapeutic approaches targeting CSC plasticity.

Exploring the dual role of circRNA and PI3K/AKT pathway in tumors of the digestive system

The interactions among circRNAs, the PI3K/AKT pathway, and their downstream effectors are intricately linked to their functional roles in tumorigenesis. Furthermore, the circRNAs/PI3K/AKT axis has been significantly implicated in the context of digestive system tumors. This axis is frequently abnormally activated in digestive cancers, including gastric cancer, colorectal cancer, pancreatic cancer, and others. Moreover, the overactivation of the circRNAs/PI3K/AKT axis promotes tumor cell proliferation, suppresses apoptosis, enhances invasive and metastatic capabilities, and contributes to drug resistance. In this regard, gaining crucial insights into the complex interaction between circRNAs and the PI3K/AKT pathway holds great potential for elucidating disease mechanisms, identifying diagnostic biomarkers, and designing targeted therapeutic interventions.

Extracellular Vesicles: Biological Packages That Modulate Tumor Cell Invasion

Tumor progression, from early-stage invasion to the formation of distal metastases, relies on the capacity of tumor cells to modify the extracellular matrix (ECM) and communicate with the surrounding stroma. Extracellular vesicles (EVs) provide an important means to regulate cell invasion due to the selective inclusion of cargoes such as proteases and matrix proteins into EVs that can degrade or modify the ECM. EVs have also been shown to facilitate intercellular communication in the tumor microenvironment through paracrine signaling, which can impact ECM invasion by cancer cells. Here, we describe the current knowledge of EVs as facilitators of tumor invasion by virtue of their effects on proteolytic degradation and modification of the ECM, their ability to educate the stromal cells in the tumor microenvironment, and their role as mediators of long-range communication aiding in cell invasion and matrix remodeling at secondary sites.

Breast tumor-on-chip: from the tumor microenvironment to medical applications

With the development of microfluidic technology, tumor-on-chip models have gradually become a new tool for the study of breast cancer because they can simulate more key factors of the tumor microenvironment compared with traditional models in vitro. Here, we review up-to-date advancements in breast tumor-on-chip models. We summarize and analyze the breast tumor microenvironment (TME), preclinical breast cancer models for TME simulation, fabrication methods of tumor-on-chip models, tumor-on-chip models for TME reconstruction, and applications of breast tumor-on-chip models and provide a perspective on breast tumor-on-chip models. This review will contribute to the construction and design of microenvironments for breast tumor-on-chip models, even the development of the pharmaceutical field, personalized/precision therapy, and clinical medicine.

Circ_0058063 regulates cell vitality and proliferation in oesophageal squamous-cell carcinomas

Oesophageal squamous-cell carcinoma (ESCC) is a malignant tumor of the digestive system with a poor prognosis. Recent studies have shown the promoting effect of hsa_circ_0058063 (circ_0058063) on ESCC, but the potential regulatory mechanisms of circ_0058063 in ESCC remain largely unclear. The levels of circ_0058063, microRNA-4319 (miR-4319) and mRNA of thrombospondin-1 (THBS1) were indicated by quantitative real-time polymerase chain reaction in ESCC tissues and cells. Meanwhile, the level of THBS1 was quantified by western blot analysis. In addition, the cell functions were examined by CCK8 assay, Edu assay, flow cytometry assay and transwell assay. Furthermore, the interplay between miR-4319 and circ_0058063 or THBS1 was detected by dual-luciferase reporter assay. Finally, an in vivo experiment was implemented to confirm the effect of circ_0058063. The level of circ_0058063 and THBS1 were increased, and the miR-4319 level was decreased in ESCC tissues in contrast to that in normal tissues and cells. For functional analysis, circ_0058063 deficiency inhibited cell vitality, cell proliferation, migration and invasion in ESCC cells, whereas promoted cell apoptosis. Moreover, miR-4319 was confirmed to repress the progression of ESCC cells by suppressing THBS1. In mechanism, circ_0058063 acted as a miR-4319 sponge to regulate the level of THBS1. Besides, circ_0058063 knockdown also attenuated tumour growth in vivo. Circ_0058063 facilitates the development of ESCC through increasing THBS1 expression by regulating miR-4319, which also offered an underlying targeted therapy for ESCC treatment.

Recent progress on the effect of extracellular matrix on occurrence and progression of breast cancer

Breast cancer (BC) metastasis is an enormous challenge targeting BC therapy. The extracellular matrix (ECM), the principal component of the BC metastasis niche, is the pivotal driver of breast tumor development, whose biochemical and biophysical characteristics have attracted widespread attention. Here, we review the biological effects of ECM constituents and the influence of ECM stiffness on BC metastasis and drug resistance. We provide an overview of the relative signal transduction mechanisms, existing metastasis models, and targeted drug strategies centered around ECM stiffness. It will shed light on exploring more underlying targets and developing specific drugs aimed at ECM utilizing biomimetic platforms, which are promising for breast cancer treatment.

Insight into extracellular vesicles in vascular diseases: intercellular communication role and clinical application potential

BACKGROUND

Cells have been increasingly known to release extracellular vesicles (EVs) to the extracellular environment under physiological and pathological conditions. A plethora of studies have revealed that EVs contain cell-derived biomolecules and are found in circulation, thereby implicating them in molecular trafficking between cells. Furthermore, EVs have an effect on physiological function and disease development and serve as disease biomarkers.

MAIN BODY

Given the close association  between EV circulation and vascular disease, this review aims to provide a brief introduction to EVs, with a specific focus on the EV cargoes participating in pathological mechanisms, diagnosis, engineering, and clinical potential, to highlight the emerging evidence suggesting promising targets in vascular diseases. Despite the expansion of research in this field, some noticeable limitations remain for clinical translational research.

CONCLUSION

This review makes a novel contribution to a summary of recent advances and a perspective on the future of EVs in vascular diseases. Video Abstract.

Decoding Hidden Messengers: Proteomic Profiling of Exosomes in Mammary Cancer Research

Cancer is a complex and heterogeneous disease, influenced by various factors that affect its progression and response to treatment. Although a histopathological diagnosis is crucial for identifying and classifying cancer, it may not accurately predict the disease's development and evolution in all cases. To address this limitation, liquid biopsy has emerged as a valuable tool, enabling a more precise and non-invasive analysis of cancer. Liquid biopsy can detect tumor DNA fragments, circulating tumor cells, and exosomes released by cancer cells into the bloodstream. Exosomes attracted significant attention in cancer research because of their specific protein composition, which can provide valuable insights into the disease. The protein profile of exosomes often differs from that of normal cells, reflecting the unique molecular characteristics of cancer. Analyzing these proteins can help identify cancer-associated markers that play important roles in tumor progression, invasion, and metastasis. Ongoing research and clinical validation are essential to advance and effectively utilize protein biomarkers in cancer. Nevertheless, their potential to improve diagnosis and treatment is highly promising. This review discusses several exosome proteins of interest in breast cancer, particularly focusing on studies conducted in mammary tissue and cell lines in humans and experimental animals. Unfortunately, studies conducted in canine species are scarce. This emphasis sheds light on the limited research available in this field. In addition, we present a curated selection of studies that explored exosomal proteins as potential biomarkers, aiming to achieve benefits in breast cancer diagnosis, prognosis, monitoring, and treatment.

The role of matrix stiffness in breast cancer progression: a review

The significance of matrix stiffness in cancer development has been investigated in recent years. The gradual elastic force the extracellular matrix imparts to cells, known as matrix stiffness, is one of the most important types of mechanical stimulation. Increased matrix stiffness alters the biological activity of cells, which promotes the growth of numerous malignancies, including breast cancer. Comprehensive studies have demonstrated that increasing matrix stiffness activates molecular signaling pathways that are closely linked to breast cancer progression. There are many articles exploring the relationship between mechanism hardness and breast cancer, so we wanted to provide a systematic summary of recent research advances. In this review, we briefly introduce the mechanism of matrix stiffness in breast cancer, elaborate on the effect of extracellular matrix stiffness on breast cancer biological behavior and signaling pathways, and finally, we will talk about breast cancer treatment that focuses on matrix stiffness.

Exosomes-regulated lipid metabolism in tumorigenesis and cancer progression

Increasing evidence highlights the role of lipid metabolism in tumorigenesis and tumor progression. Targeting the processes of lipid metabolism, including lipogenesis, lipid uptake, fatty acid oxidation, and lipolysis, is an optimal strategy for anti-cancer therapy. Beyond cell-cell membrane surface interaction, exosomes are pivotal factors that transduce intercellular signals in the tumor microenvironment (TME). Most research focuses on the role of lipid metabolism in regulating exosome biogenesis and extracellular matrix (ECM) remodeling. The mechanisms of exosome and ECM-mediated reprogramming of lipid metabolism are currently unclear. We summarize several mechanisms associated with the regulation of lipid metabolism in cancer, including transport of exosomal carriers and membrane receptors, activation of the PI3K pathway, ECM ligand-receptor interactions, and mechanical stimulation. This review aims to highlight the significance of these intercellular factors in TME and to deepen the understanding of the functions of exosomes and ECM in the regulation of lipid metabolism.

Microcarriers promote the through interface movement of mouse trophoblast stem cells by regulating stiffness

Mechanical force is crucial in the whole process of embryonic development. However, the role of trophoblast mechanics during embryo implantation has rarely been studied. In this study, we constructed a model to explore the effect of stiffness changes in mouse trophoblast stem cells (mTSCs) on implantation: microcarrier was prepared by sodium alginate using a droplet microfluidics system, and mTSCs were attached to the microcarrier surface with laminin modifications, called T(micro). Compared with the spheroid, formed by the self-assembly of mTSCs (T(sph)), we could regulate the stiffness of the microcarrier, making the Young's modulus of mTSCs (367.70 ± 79.81 Pa) similar to that of the blastocyst trophoblast ectoderm (432.49 ± 151.90 Pa). Moreover, T(micro) contributes to improve the adhesion rate, expansion area and invasion depth of mTSCs. Further, T(micro) was highly expressed in tissue migration-related genes due to the activation of the Rho-associated coiled-coil containing protein kinase (ROCK) pathway at relatively similar modulus of trophoblast. Overall, our study explores the embryo implantation process with a new perspective, and provides theoretical support for understanding the effect of mechanics on embryo implantation.

Actomyosin-dependent cell contractility orchestrates Zika virus infection

Emerging pathogen infections, such as Zika virus (ZIKV), pose an increasing threat to human health, but the role of mechanobiological attributes of host cells during ZIKV infection is largely unknown. Here, we reveal that ZIKV infection leads to increased contractility of host cells. Importantly, we investigated whether host cell contractility contributes to ZIKV infection efficacy, from both the intracellular and extracellular perspective. By performing drug perturbation and gene editing experiments, we confirmed that disruption of contractile actomyosin compromises ZIKV infection efficiency, viral genome replication and viral particle production. By culturing on compliant matrix, we further demonstrate that a softer substrate, leading to less contractility of host cells, compromises ZIKV infection, which resembles the effects of disrupting intracellular actomyosin organization. Together, our work provides evidence to support a positive correlation between host cell contractility and ZIKV infection efficacy, thus unveiling an unprecedented layer of interplay between ZIKV and the host cell.

Tumor matrix stiffness provides fertile soil for cancer stem cells

Matrix stiffness is a mechanical characteristic of the extracellular matrix (ECM) that increases from the tumor core to the tumor periphery in a gradient pattern in a variety of solid tumors and can promote proliferation, invasion, metastasis, drug resistance, and recurrence. Cancer stem cells (CSCs) are a rare subpopulation of tumor cells with self-renewal, asymmetric cell division, and differentiation capabilities. CSCs are thought to be responsible for metastasis, tumor recurrence, chemotherapy resistance, and consequently poor clinical outcomes. Evidence suggests that matrix stiffness can activate receptors and mechanosensor/mechanoregulator proteins such as integrin, FAK, and YAP, modulating the characteristics of tumor cells as well as CSCs through different molecular signaling pathways. A deeper understanding of the effect of matrix stiffness on CSCs characteristics could lead to development of innovative cancer therapies. In this review, we discuss how the stiffness of the ECM is sensed by the cells and how the cells respond to this environmental change as well as the effect of matrix stiffness on CSCs characteristics and also the key malignant processes such as proliferation and EMT. Then, we specifically focus on how increased matrix stiffness affects CSCs in breast, lung, liver, pancreatic, and colorectal cancers. We also discuss how the molecules responsible for increased matrix stiffness and the signaling pathways activated by the enhanced stiffness can be manipulated as a therapeutic strategy for cancer.

The Roles of Extracellular Vesicles in the Progression of Renal Cell Carcinoma and Their Potential for Future Clinical Application

Renal cell carcinoma (RCC) is the most common type of kidney cancer and is thought to originate from renal tubular epithelial cells. Extracellular vesicles (EVs) are nanosized lipid bilayer vesicles that are secreted into extracellular spaces by nearly all cell types, including cancer cells and non-cancerous cells. EVs are involved in multiple steps of RCC progression, such as local invasion, host immune modulation, drug resistance, and metastasis. Therefore, EVs secreted from RCC are attracting rapidly increasing attention from researchers. In this review, we highlight the mechanism by which RCC-derived EVs lead to disease progression as well as the potential and challenges related to the clinical implications of EV-based diagnostics and therapeutics.

ECM stiffness-regulated exosomal thrombospondin-1 promotes tunneling nanotubes-based cellular networking in breast cancer cells

Intercellular communication is pivotal in various stages of cancer progression. For smart and effective communication, cancer cells employ diverse modes of messaging that may be further fine-tuned by the microenvironmental changes. Extracellular matrix (ECM) stiffening due to excess deposition and crosslinking of collagen is one of the crucial tumor-microenvironmental changes that influence a plethora of cellular processes, including cell-cell communication. We herein studied the crosstalk between exosomes and tunneling nanotubes (TNT), the two distinct means of cell-cell communication under varying ECM-stiffness conditions. We show that exosomes promote the formation of tunneling nanotubes in breast cancer cells, which results in cellular internet. Interestingly, exosomes drastically increased the fraction of cells connected by TNT; however, they elicited no effect on the number of TNTs per pair of connected cells or the length of TNT. The observed pro-TNT effects of exosomes were found to be ECM-stiffness dependent. ECM-stiffness tuned exosomes were found to promote TNT formation predominantly via the 'cell dislodgment model'. At the molecular level, exosomal thrombospondin-1 was identified as a critical pro-TNT factor. These findings underline the influence of ECM stiffening on two diverse modes of cell communication and their interdependence, which may have significant implications in cancer biomedical research.

The role of biomechanical stress in extracellular vesicle formation, composition and activity

Extracellular vesicles (EVs) are cornerstones of intercellular communication with exciting fundamental, clinical, and more broadly biotechnological applications. However, variability in EV composition, which results from the culture conditions used to generate the EVs, poses significant fundamental and applied challenges and a hurdle for scalable bioprocessing. Thus, an understanding of the relationship between EV production (and for clinical applications, manufacturing) and EV composition is increasingly recognized as important and necessary. While chemical stimulation and culture conditions such as cell density are known to influence EV biology, the impact of biomechanical forces on the generation, properties, and biological activity of EVs remains poorly understood. Given the omnipresence of these forces in EV preparation and in biomanufacturing, expanding the understanding of their impact on EV composition-and thus, activity-is vital. Although several publications have examined EV preparation and bioprocessing and briefly discussed biomechanical stresses as variables of interest, this review represents the first comprehensive evaluation of the impact of such stresses on EV production, composition and biological activity. We review how EV biogenesis, cargo, efficacy, and uptake are uniquely affected by various types, magnitudes, and durations of biomechanical forces, identifying trends that emerge both generically and for individual cell types. We also describe implications for scalable bioprocessing, evaluating processes inherent in common EV production and isolation methods, and propose a path forward for rigorous EV quality control.

Extracellular Vesicles in Breast Cancer: From Biology and Function to Clinical Diagnosis and Therapeutic Management

Breast cancer (BC) is the first worldwide most frequent cancer in both sexes and the most commonly diagnosed in females. Although BC mortality has been thoroughly declining over the past decades, there are still considerable differences between women diagnosed with early BC and when metastatic BC is diagnosed. BC treatment choice is widely dependent on precise histological and molecular characterization. However, recurrence or distant metastasis still occurs even with the most recent efficient therapies. Thus, a better understanding of the different factors underlying tumor escape is mainly mandatory. Among the leading candidates is the continuous interplay between tumor cells and their microenvironment, where extracellular vesicles play a significant role. Among extracellular vesicles, smaller ones, also called exosomes, can carry biomolecules, such as lipids, proteins, and nucleic acids, and generate signal transmission through an intercellular transfer of their content. This mechanism allows tumor cells to recruit and modify the adjacent and systemic microenvironment to support further invasion and dissemination. By reciprocity, stromal cells can also use exosomes to profoundly modify tumor cell behavior. This review intends to cover the most recent literature on the role of extracellular vesicle production in normal and cancerous breast tissues. Specific attention is paid to the use of extracellular vesicles for early BC diagnosis, follow-up, and prognosis because exosomes are actually under the spotlight of researchers as a high-potential source of liquid biopsies. Extracellular vesicles in BC treatment as new targets for therapy or efficient nanovectors to drive drug delivery are also summarized.

Novel thrombospondin-1 transcript exhibits distinctive expression and activity in thyroid tumorigenesis

Thrombospondin 1 (TSP1) is known for its cell-specific functions in cancer progression, such as proliferation and migration. It contains 22 exons that may potentially produce several different transcripts. Here, we identified TSP1V as a novel TSP1-splicing variant produced by intron retention (IR) in human thyroid cancer cells and tissues. We observed that TSP1V functionally inhibited tumorigenesis contrary to TSP1 wild-type, as identified in vivo and in vitro. These activities of TSP1V are caused by inhibiting phospho-Smad and phospho-focal adhesion kinase. Reverse transcription polymerase chain reaction and minigene experiments revealed that some phytochemicals/non-steroidal anti-inflammatory drugs enhanced IR. We further found that RNA-binding motif protein 5 (RBM5) suppressed IR induced by sulindac sulfide treatment. Additionally, sulindac sulfide reduced phospho-RBM5 levels in a time-dependent manner. Furthermore, trans-chalcone demethylated TSP1V, thereby preventing methyl-CpG-binding protein 2 binding to TSP1V gene. In addition, TSP1V levels were significantly lower in patients with differentiated thyroid carcinoma than in those with benign thyroid nodule, indicating its potential application as a diagnostic biomarker in tumor progression.

Extracellular-matrix mechanics regulate cellular metabolism: A ninja warrior behind mechano-chemo signaling crosstalk

Mechanical forces are the indispensable constituent of environmental cues, such as gravity, barometric pressure, vibration, and contact with bodies, which are involved in pattern and organogenesis, providing mechanical input to tissues and determining the ultimate fate of cells. Extracellular matrix (ECM) stiffness, the slow elastic force, carries the external physical force load onto the cell or outputs the internal force exerted by the cell and its neighbors into the environment. Accumulating evidence illustrates the pivotal role of ECM stiffness in the regulation of organogenesis, maintenance of tissue homeostasis, and the development of multiple diseases, which is largely fulfilled through its systematical impact on cellular metabolism. This review summarizes the establishment and regulation of ECM stiffness, the mechanisms underlying how ECM stiffness is sensed by cells and signals to modulate diverse cell metabolic pathways, and the physiological and pathological significance of the ECM stiffness-cell metabolism axis.

Extracellular matrix remodeling in tumor progression and immune escape: from mechanisms to treatments

The malignant tumor is a multi-etiological, systemic and complex disease characterized by uncontrolled cell proliferation and distant metastasis. Anticancer treatments including adjuvant therapies and targeted therapies are effective in eliminating cancer cells but in a limited number of patients. Increasing evidence suggests that the extracellular matrix (ECM) plays an important role in tumor development through changes in macromolecule components, degradation enzymes and stiffness. These variations are under the control of cellular components in tumor tissue via the aberrant activation of signaling pathways, the interaction of the ECM components to multiple surface receptors, and mechanical impact. Additionally, the ECM shaped by cancer regulates immune cells which results in an immune suppressive microenvironment and hinders the efficacy of immunotherapies. Thus, the ECM acts as a barrier to protect cancer from treatments and supports tumor progression. Nevertheless, the profound regulatory network of the ECM remodeling hampers the design of individualized antitumor treatment. Here, we elaborate on the composition of the malignant ECM, and discuss the specific mechanisms of the ECM remodeling. Precisely, we highlight the impact of the ECM remodeling on tumor development, including proliferation, anoikis, metastasis, angiogenesis, lymphangiogenesis, and immune escape. Finally, we emphasize ECM "normalization" as a potential strategy for anti-malignant treatment.

Production and Utility of Extracellular Vesicles with 3D Culture Methods

In recent years, extracellular vesicles (EVs) have emerged as promising biomarkers, cell-free therapeutic agents, and drug delivery carriers. Despite their great clinical potential, poor yield and unscalable production of EVs remain significant challenges. When using 3D culture methods, such as scaffolds and bioreactors, large numbers of cells can be expanded and the cell environment can be manipulated to control the cell phenotype. This has been employed to successfully increase the production of EVs as well as to enhance their therapeutic effects. The physiological relevance of 3D cultures, such as spheroids, has also provided a strategy for understanding the role of EVs in the pathogenesis of several diseases and to evaluate their role as tools to deliver drugs. Additionally, 3D culture methods can encapsulate EVs to achieve more sustained therapeutic effects as well as prevent premature clearance of EVs to enable more localised delivery and concentrated exosome dosage. This review highlights the opportunities and drawbacks of different 3D culture methods and their use in EV research.

Pirfenidone suppressed triple-negative breast cancer metastasis by inhibiting the activity of the TGF-β/SMAD pathway

Among breast cancer patients, metastases are the leading cause of death. Despite decades of effort, little progress has been made to improve the treatment of breast cancer metastases, especially triple-negative breast cancer (TNBC). The extracellular matrix plays an important role in tumour growth and metastasis by causing its deposition, remodelling, and signalling. As we know, the process of fibrosis results in excessive amounts of extracellular matrix being deposited within the cells. So, it will be interesting to study if the use of anti-fibrotic drugs in combination with conventional chemotherapy drugs can produce synergistic antitumor effects. In this study, we assessed the efficacy of Pirfenidone (PFD), an FDA-approved medication for the treatment of idiopathic pulmonary fibrosis, on TNBC cells as well as its anti-tumour effects in xenograft tumour model. PFD inhibited in a dose-dependent manner breast cancer cell proliferation, migration, and invasion, while promoted their apoptosis in vitro. PFD also suppressed TGF-β-induced activation of Smad signalling pathway and expression level of EMT-inducing transcription factors (e.g. SNAI2, TWIST1, ZEB1) as well as the mesenchymal genes such as VIMENTIN and N-Cadherin. On the contrary, the expression level of epithelial marker gene E-Cadherin was up-regulated in the presence of PFD. In vivo, PFD alone exerted a milder but significant anti-tumour effect than the chemotherapy drug nanoparticle albumin-bound paclitaxel (nab-PTX) did in the breast cancer xenograft mouse model. Interestingly, PFD synergistically boosted the cancer-killing effect of nab-PTX. Furthermore, Our data suggest that PFD suppressed breast cancer metastasis by inhibiting the activity of the TGFβ/SMAD pathway.

Spatial transcriptomics reveals the heterogeneity and FGG+CRP+ inflammatory cancer-associated fibroblasts replace islets in pancreatic ductal adenocarcinoma

Background

Understanding the spatial heterogeneity of the tumor microenvironment (TME) in pancreatic cancer (PC) remains challenging.

Methods

In this study, we performed spatial transcriptomics (ST) to investigate the gene expression features across one normal pancreatic tissue, PC tissue, adjacent tumor tissue, and tumor stroma. We divided 18,075 spatial spots into 22 clusters with t-distributed stochastic neighbor embedding based on gene expression profiles. The biological functions and signaling pathways involved in each cluster were analyzed with gene set enrichment analysis.

Results

The results revealed that KRT13+FABP5+ malignant cell subpopulation had keratinization characteristics in the tumor tissue. Fibroblasts from adjacent tumor tissue exhibited a tumor-inhibiting role such as "B-cell activation" and "positive regulation of leukocyte activation." The FGG+CRP+ inflammatory cancer-associated fibroblasts replaced the islets in tumor stroma. During PC progression, the damage to pancreatic structure and function was heavier in the pancreatic exocrine (AMYA2+PRSS1+) than in the endocrine (INS+GCG+).

Conclusion

Our results revealed the spatial heterogeneity of dynamic changes and highlighted the significance of impaired exocrine function in PC.

Exosomes-mediated tumor metastasis through reshaping tumor microenvironment and distant niche

Tumor-derived exosomes (TDEs) are the particular communicator and messenger between tumor cells and other cells containing cancer-associated genetic materials and proteins. And TDEs who are also one of the important components consisting of the tumor microenvironment (TME) can reshape and interact with TME to promote tumor development and metastasis. Moreover, due to their long-distance transmission by body fluids, TDEs can facilitate the formation of pre-metastatic niche to support tumor colonization. We discuss the main characteristics and mechanism of TDE-mediated tumor metastasis by reshaping TME and pre-metastatic niche as well as the potential of TDEs for diagnosing tumor and predicting future metastatic development.