β-Catenin promotes long-term survival and angiogenesis of peripheral blood mesenchymal stem cells via the Oct4 signaling pathway

DON-Apt19S bioactive scaffold transplantation promotes in situ spinal cord repair in rats with transected spinal cord injury by effectively recruiting endogenous neural stem cells and mesenchymal stem cells

The spinal cord's limited regeneration is attributed to the scarcity of endogenous stem cells and a poor post-injury microenvironment in adult mammals. To overcome these challenges, we transplanted a DNA aptamer 19S (Apt19S) sustained-release decellularized optic nerve (DON) scaffold (DON-A) into completely transected spinal cord injury (SCI) site in rats and investigated its effect on endogenous stem cell recruitment and differentiation, which subsequently contributed to in situ SCI repair. It has been demonstrated that Apt19S specifically binds to the membrane receptor alkaline phosphatase highly expressed on neural stem cells (NSCs) and mesenchymal stem cells (MSCs), and our study further proved that Apt19S can simultaneously recruit endogenous NSCs and MSCs to the lesion of SCI. In our study, the DON-A promoted stem cell proliferation in the early stage of the injury, followed by the rapid neurogenesis through NSCs and revascularization via MSCs. Synaptic connections between corticospinal tracts and calcitonin gene-related peptide positive nerve fibers with newborn neurons confirmed the formation of endogenous neuronal relays at the injury site, which improved the rats' motor and sensory functions. This study offers a new strategy for recruiting both NSCs and MSCs to synergistically overcome low spinal cord self-repair ability, holding a high potential for clinical translation.

Exosome-transmitted HSPA9 facilitates bortezomib resistance by targeting TRIP13/USP1 signaling in multiple myeloma

BACKGROUND

Resistance to the proteasome inhibitor bortezomib (BTZ) poses a formidable therapeutic challenge in multiple myeloma (MM). Our study aims to analyze the mechanism by which exosomes heat shock 70 kDa protein 9 (HSPA9) secreted by BTZ-resistant MM cells disseminate resistance to BTZ-sensitive MM cells.

METHODS

The serum exosomes were identified by nanoparticle tracking analysis and transmission electron microscopy. Liquid chromatography-mass spectrometry and public databases were performed to screen exosomes HSPA9. Cell counting kit-8, western blotting and colony formation assay were used to detected the role of HSPA9 protein in vitro. Co-immunoprecipitation, immunofluorescence and protein truncation test experiments were used to determine the regulatory network of the HSPA9-USP1-TRIP13 complex. Optical imaging in vivo and xenograft mouse models were performed to investigate that exosomes HSPA9 promoted MM proliferation and BTZ resistance.

RESULTS

We demonstrated that HSPA9 was highly expressed in serum exosomes and BTZ-resistant MM patients. Knockdown of HSPA9 significantly suppressed tumorigenesis and reversed BTZ resistance in vitro. As a downstream molecular of HSPA9, thyroid hormone receptor-interacting protein 13 (TRIP13) was also highly expressed in BTZ-resistant MM patients. Mechanistically, the carboxyl-terminal peptide-binding domain of HSPA9, provides a platform for recruiting the deubiquitinating enzyme ubiquitin-specific peptidase 1 (USP1), which prevents TRIP13 protein degradation. The HSPA9-USP1-TRIP13 complex exhibits stability in the cytoplasm, and its inhibition remarkably enhances BTZ resistance in vito.

CONCLUSION

Our findings propose a pioneering molecular regulatory network in which MM-cell-derived exosomes HSPA9 transmitted BTZ resistance through the USP1/TRIP13 signaling pathway. This research highlights exosomes HSPA9 as a promising target to overcome MM BTZ resistance.

Extracellular vesicles in cancer´s communication: messages we can read and how to answer

Extracellular vesicles (EVs) are emerging as critical mediators of intercellular communication in the tumor microenvironment (TME), profoundly influencing cancer progression. These nano-sized vesicles, released by both tumor and stromal cells, carry a diverse cargo of proteins, nucleic acids, and lipids, reflecting the dynamic cellular landscape and mediating intricate interactions between cells. This review provides a comprehensive overview of the biogenesis, composition, and functional roles of EVs in cancer, highlighting their significance in both basic research and clinical applications. We discuss how cancer cells manipulate EV biogenesis pathways to produce vesicles enriched with pro-tumorigenic molecules, explore the specific contributions of EVs to key hallmarks of cancer, such as angiogenesis, metastasis, and immune evasion, emphasizing their role in shaping TME and driving therapeutic resistance. Concurrently, we submit recent knowledge on how the cargo of EVs can serve as a valuable source of biomarkers for minimally invasive liquid biopsies, and its therapeutic potential, particularly as targeted drug delivery vehicles and immunomodulatory agents, showcasing their promise for enhancing the efficacy and safety of cancer treatments. By deciphering the intricate messages carried by EVs, we can gain a deeper understanding of cancer biology and develop more effective strategies for early detection, targeted therapy, and immunotherapy, paving the way for a new era of personalized and precise cancer medicine with the potential to significantly improve patient outcomes.

Dandelion extract suppresses the stem-like properties of triple-negative breast cancer cells by regulating CUEDC2/β-catenin/OCT4 signaling axis

ETHNOPHARMACOLOGICAL RELEVANCE

Triple-negative breast cancer (TNBC) represents the most aggressive subtype of breast cancer, featuring a high proportion of cancer stem cells (CSCs) and the poorest clinical outcomes. Taraxacum mongolicum Hand. -Mazz., widely recognized as dandelion, is a traditional medicinal herb that has demonstrated promising anti-TNBC potential. However, the efficacy of dandelion in anti-TNBC stem-like properties remains to be elucidated.

AIM OF THE STUDY

The aim was to examine the impact of dandelion extract on the stemness properties of TNBC and to delineate the underlying mechanisms.

MATERIALS AND METHODS

UHPLC-Q-Orbitrap HRMS was employed to characterize the components present in dandelion extract. Network pharmacology was utilized to explore the impact of dandelion-derived compounds on the molecular pathways associated with TNBC. The assessment of TNBC stem-like properties was conducted through mammosphere formation assays and flow cytometry analysis. Western blotting, qRT-PCR, and immunofluorescence were employed to investigate the mechanisms of dandelion extract. 4T1-luc xenograft tumor model was used to assess the anti-tumor effect of dandelion extract in vivo. IVIS imaging technology was used to monitor lung metastasis.

RESULTS

In this study, pharmacological network analysis revealed the potential regulatory effects of dandelion extract on TNBC stemness. Dandelion extract disrupts the stem-like properties in MDA-MB-231 and MDA-MB-468 cell lines via reducing ALDH + cells proportion, impeding mammosphere formation, and downregulating CSC-related markers, including SOX2, SOX9, NANOG, and FOXM1. Furthermore, CUE domain containing protein 2 (CUEDC2) promotes the maintenance of TNBC stemness and contributes to the anti-stemness effects of dandelion extract. Mechanistically, dandelion extract inhibits CUEDC2-mediated nuclear translocation of β-catenin, thereby reducing the transcriptional activity of OCT4. In vivo, dandelion extract suppresses tumor growth, lung metastasis, and decreases the expression of CSC-related markers.

CONCLUSION

These findings suggest that dandelion extract inhibits TNBC stem-like properties via modulating the CUEDC2/β-catenin/OCT4 signaling axis, highlighting its potential as a therapeutic option for TNBC.

Methionine Modulates the Growth and Development of Heat-Stressed Dermal Papilla Cells via the Wnt/β-Catenin Signaling Pathway

This study furnishes insights into how methionine mitigates heat-stress-induced impairments in hair follicle development in Rex rabbits at the cellular level. Dermal papilla cells from the dorsal skin of Rex rabbits were isolated, cultured in vitro, and divided into six groups, i.e., control (37 °C; 0 mM methionine), heat stress (45 °C; 0 mM methionine), and heat stress + methionine (45 °C; 15 mM, 30 mM, 45 mM, and 60 mM methionine), with six replicates per group. The heat stress groups were exposed to 45 °C, 5% CO2, and 95% humidity for 30 min, followed by recovery at 37 °C, repeated three times over three days. On the third day, samples were collected post-heat stress. The results show that methionine markedly fortified HSP70, MSRA, and SOD expression (p < 0.01); augmented proliferation (p < 0.01); ameliorated cell cycle progression; and lessened apoptosis (p < 0.05). Adding Wnt signaling pathway activators and inhibitors manifested that these effects were associated with diminished β-catenin phosphorylation and aggrandized expression of the Wnt10b, β-catenin (p < 0.001), and LEF/TCF nuclear transcription factors (p < 0.01). Thus, this study demonstrates that methionine regulates the growth and development of heat-stressed hair papilla cells via the Wnt signaling pathway, remitting heat-stress trauma.

Wnt/β-catenin pathway as a link between therapy resistance-driven epithelial-mesenchymal transition and stemness in colorectal cancer

The high plasticity of cells undergoing epithelial-mesenchymal transition (EMT) promotes increased tumor heterogeneity, and its interaction with tumor-associated stromal cells appears to contribute to developing a stemness phenotype. Cells with these characteristics exhibit increased resistance to chemotherapy and radiotherapy, leading to disease relapse and metastasis. Here, we discuss the activation of the Wnt/β-catenin pathway in promoting EMT and stemness within the context of cellular resistance to these therapies. We discuss whether EMT and cancer stem cells (CSCs) function in conjunction, independently, or if a link is connecting their development. We further propose that this pathway is necessary to establish a connection between these two phenotypes. And suggest that it could hinder the rise of CSCs from treatment-induced EMT cells when inhibited. Understanding this cellular phenomenon might allow the development of new targeted therapies to improve clinical responses, particularly in colorectal cancer.

Mesenchymal stem cells derived exosomes: a new era in cardiac regeneration

Despite significant strides in medical treatments and surgical procedures for cardiovascular diseases, these conditions continue to be a major global health concern. The persistent need for innovative therapeutic approaches to mend damaged heart tissue highlights the complexity and urgency of this medical challenge. In recent years, stem cells have emerged as a promising tool for tissue regeneration, but challenges such as graft rejection and tumor formation have limited their clinical application. Exosomes, extracellular vesicles containing a diverse array of biomolecules, have garnered significant attention for their potential in regenerative medicine. The cardioprotective and reparative properties of mesenchymal stem cell-derived exosomes hold promise for the treatment of heart diseases. These exosomes can modulate various cellular processes, including angiogenesis, apoptosis, and inflammation, thereby enhancing cardiac function. Despite the growing interest, there remains a lack of comprehensive reviews synthesizing the molecular mechanisms, preclinical, and clinical evidence related to the specific role of MSC-derived exosomes in cardiac therapies. This review aims to fill that gap by exploring the potential of MSC-derived exosomes as a therapeutic strategy for cardiac diseases. This review explores the potential of mesenchymal stem cell-derived exosomes as a therapeutic strategy for cardiac diseases. We discuss the molecular mechanisms underlying their cardioprotective effects, summarize preclinical and clinical studies investigating their efficacy, and address the challenges and future perspectives of exosome-based therapies. The collective evidence suggests that MSC-derived exosomes hold promise as a novel and effective therapeutic approach for cardiac diseases.

iTRAQ proteomic analysis of exosomes derived from synovial fluid reveals disease patterns and potential biomarkers of Osteoarthritis

Exosomes extracted from synovial fluid (SF-exo) reflect the status of their originating cells. The proteomic profiles of SF-exo are important for the diagnosis of osteoarthritis (OA). To delineate the proteomic differences between SF-exo from OA patients and healthy individuals, a quantitative proteomic study based on iTRAQ technology was performed. In this study, a total of 439 proteins were identified, with 20 proteins exhibiting increased expression in the OA patient group, while 5 showed decreased expression levels. Bioinformatic analysis showed these differentially expressed proteins (DEPs) were involved in a variety of immune-related processes, including complement activation and antigen binding. For further screening, we downloaded a publicly available dataset of synovial fluid (PXD023708) and compared it with our dataset. The comparative Results identified that 5 DEPs overlapped in two datasets, and protein-protein interaction revealed that C3, C4B and APOM were key members of a tightly interactive network. Through receiver operating characteristic (ROC) curve analysis and enzyme-linked immunosorbent assay (ELISA), we confirmed 5 DEPs (C3, C4B, APOM, MMP3, DPYSL2) as potential diagnostic biomarkers for OA. And Pearson correlation analysis confirmed that most of these biomarkers had no significant linear correlation with age. Overall, our study provides the first comprehensive description of the proteomic landscape of SF-exo in OA and identifies several potential biomarkers. These findings are expected to provide valuable insights into the diagnosis and treatment of OA.

Genetically modified mesenchymal stromal cells: a cell-based therapy offering more efficient repair after myocardial infarction

Myocardial infarction (MI) is a serious complication of coronary artery disease. This condition is common worldwide and has a profound impact on patients' lives and quality of life. Despite significant advances in the treatment of heart disease in modern medicine, the efficient treatment of MI still faces a number of challenges. Problems such as scar formation and loss of myocardial function after a heart attack still limit patients' recovery. Therefore, the search for a new therapeutic tool that can promote repair and regeneration of myocardial tissue has become crucial. In this context, mesenchymal stromal cells (MSCs) have attracted much attention as a potential therapeutic tool. MSCs are a class of adult stem cells with multidirectional differentiation potential, derived from bone marrow, fat, placenta and other tissues, and possessing properties such as self-renewal and immunomodulation. The application of MSCs may provide a new direction for the treatment of MI. These stem cells have the potential to differentiate into cardiomyocytes and vascular endothelial cells in damaged tissue and to repair and protect myocardial tissue through anti-inflammatory, anti-fibrotic and pro-neovascularization mechanisms. However, the clinical results of MSCs transplantation for the treatment of MI are less satisfactory due to the limitations of the native function of MSCs. Genetic modification has overcome problems such as the low survival rate of transplanted MSCs in vivo and enhanced their functions of promoting neovascularization and differentiation into cardiomyocytes, paving the way for them to become an effective tool for repair therapy after MI. In previous studies, MSCs have shown some therapeutic potential in experimental animals and preliminary clinical trials. This review aims to provide readers with a comprehensive and in-depth understanding to promote the wider application of engineering MSCs in the field of MI therapy, offering new hope for recovery and improved survival of cardiac patients.

Tackling exosome and nuclear receptor interaction: an emerging paradigm in the treatment of chronic diseases

Nuclear receptors (NRs) function as crucial transcription factors in orchestrating essential functions within the realms of development, host defense, and homeostasis of body. NRs have garnered increased attention due to their potential as therapeutic targets, with drugs directed at NRs demonstrating significant efficacy in impeding chronic disease progression. Consequently, these pharmacological agents hold promise for the treatment and management of various diseases. Accumulating evidence emphasizes the regulatory role of exosome-derived microRNAs (miRNAs) in chronic inflammation, disease progression, and therapy resistance, primarily by modulating transcription factors, particularly NRs. By exploiting inflammatory pathways such as protein kinase B (Akt)/mammalian target of rapamycin (mTOR), nuclear factor kappa-B (NF-κB), signal transducer and activator of transcription 3 (STAT3), and Wnt/β-catenin signaling, exosomes and NRs play a pivotal role in the panorama of development, physiology, and pathology. The internalization of exosomes modulates NRs and initiates diverse autocrine or paracrine signaling cascades, influencing various processes in recipient cells such as survival, proliferation, differentiation, metabolism, and cellular defense mechanisms. This comprehensive review meticulously examines the involvement of exosome-mediated NR regulation in the pathogenesis of chronic ailments, including atherosclerosis, cancer, diabetes, liver diseases, and respiratory conditions. Additionally, it elucidates the molecular intricacies of exosome-mediated communication between host and recipient cells via NRs, leading to immunomodulation. Furthermore, it outlines the implications of exosome-modulated NR pathways in the prophylaxis of chronic inflammation, delineates current limitations, and provides insights into future perspectives. This review also presents existing evidence on the role of exosomes and their components in the emergence of therapeutic resistance.

ST8SIA6-AS1, a novel lncRNA star in liver cancer

Liver cancer is one of the most lethal gastrointestinal malignancies. Emerging evidence has underscored the pivotal role of long non-coding RNAs (lncRNAs) in tumorigenesis, with ST8SIA6-AS1 identified as a novel oncogenic lncRNA contributing to liver cancer progression. ST8SIA6-AS1 is consistently upregulated in hepatic cancer tissues and is strongly associated with unfavorable prognosis. Moreover, it demonstrates high diagnostic efficacy in detecting HCC. ST8SIA6-AS1 is involved in various cellular processes including proliferation, migration, and invasion, primarily through its function as a competing endogenous RNA (ceRNA), thereby facilitating hepatocarcinogenesis and disease advancement. This review provides a detailed examination of the molecular functions and regulatory mechanisms of ST8SIA6-AS1 in hepatocellular carcinoma (HCC) and highlights its potential as a promising biomarker for liver cancer, aiming to propel the development of innovative therapeutic strategies for HCC management.

Role of Protein Phosphatases in Tumor Angiogenesis: Assessing PP1, PP2A, PP2B and PTPs Activity

Tumor angiogenesis, the formation of new blood vessels to support tumor growth and metastasis, is a complex process regulated by a multitude of signaling pathways. Dysregulation of signaling pathways involving protein kinases has been extensively studied, but the role of protein phosphatases in angiogenesis within the tumor microenvironment remains less explored. However, among angiogenic pathways, protein phosphatases play critical roles in modulating signaling cascades. This review provides a comprehensive overview of the involvement of protein phosphatases in tumor angiogenesis, highlighting their diverse functions and mechanisms of action. Protein phosphatases are key regulators of cellular signaling pathways by catalyzing the dephosphorylation of proteins, thereby modulating their activity and function. This review aims to assess the activity of the protein tyrosine phosphatases and serine/threonine phosphatases. These phosphatases exert their effects on angiogenic signaling pathways through various mechanisms, including direct dephosphorylation of angiogenic receptors and downstream signaling molecules. Moreover, protein phosphatases also crosstalk with other signaling pathways involved in angiogenesis, further emphasizing their significance in regulating tumor vascularization, including endothelial cell survival, sprouting, and vessel maturation. In conclusion, this review underscores the pivotal role of protein phosphatases in tumor angiogenesis and accentuate their potential as therapeutic targets for anti-angiogenic therapy in cancer.

Exosome-derived circUPF2 enhances resistance to targeted therapy by redeploying ferroptosis sensitivity in hepatocellular carcinoma

BACKGROUND

Advanced hepatocellular carcinoma (HCC) can be treated with sorafenib, which is the primary choice for targeted therapy. Nevertheless, the effectiveness of sorafenib is greatly restricted due to resistance. Research has shown that exosomes and circular RNAs play a vital role in the cancer's malignant advancement. However, the significance of exosomal circular RNAs in the development of resistance to sorafenib in HCC remains uncertain.

METHODS

Ultracentrifugation was utilized to isolate exosomes (Exo-SR) from the sorafenib-resistant HCC cells' culture medium. Transcriptome sequencing and differential expression gene analysis were used to identify the targets of Exo-SR action in HCC cells. To identify the targets of Exo-SR action in HCC cells, transcriptome sequencing and analysis of differential expression genes were employed. To evaluate the impact of exosomal circUPF2 on resistance to sorafenib in HCC, experiments involving gain-of-function and loss-of-function were conducted. RNA pull-down assays and mass spectrometry analysis were performed to identify the RNA-binding proteins interacting with circUPF2. RNA immunoprecipitation (RIP), RNA pull-down, electrophoretic mobility shift assay (EMSA), immunofluorescence (IF) -fluorescence in situ hybridization (FISH), and rescue assays were used to validate the interactions among circUPF2, IGF2BP2 and SLC7A11. Finally, a tumor xenograft assay was used to examine the biological functions and underlying mechanisms of Exo-SR and circUPF2 in vivo.

RESULTS

A novel exosomal circRNA, circUPF2, was identified and revealed to be significantly enriched in Exo-SR. Exosomes with enriched circUPF2 enhanced sorafenib resistance by promoting SLC7A11 expression and suppressing ferroptosis in HCC cells. Mechanistically, circUPF2 acts as a framework to enhance the creation of the circUPF2-IGF2BP2-SLC7A11 ternary complex contributing to the stabilization of SLC7A11 mRNA. Consequently, exosomal circUPF2 promotes SLC7A11 expression and enhances the function of system Xc- in HCC cells, leading to decreased sensitivity to ferroptosis and resistance to sorafenib.

CONCLUSIONS

The resistance to sorafenib in HCC is facilitated by the exosomal circUPF2, which promotes the formation of the circUPF2-IGF2BP2-SLC7A11 ternary complex and increases the stability of SLC7A11 mRNA. Focusing on exosomal circUPF2 could potentially be an innovative approach for HCC treatment.

Kynurenine in IDO1high cancer cell-derived extracellular vesicles promotes angiogenesis by inducing endothelial mitophagy in ovarian cancer

BACKGROUND

Mitophagy, a prominent cellular homeostasis process, has been implicated in modulating endothelial cell function. Emerging evidence suggests that extracellular vesicles (EVs) participate in intercellular communication, which could modulate tumor angiogenesis, a hallmark of ovarian cancer (OC) progression. However, the underlying mechanisms through how EVs regulate endothelial mitophagy associated with tumor angiogenesis during OC development remain obscure.

METHODS

The effect of cancer cell-derived EVs on endothelial mitophagy and its correlation with tumor angiogenesis and OC development were explored by in vitro and in vivo experiments. Multi-omics integration analysis was employed to identify potential regulatory mechanisms of cancer cell-derived EVs on endothelial mitophagy, which is involved in tumor angiogenesis associated with OC development. These insights were then further corroborated through additional experiments. An orthotopic OC mouse model was constructed to assess the antiangiogenic and therapeutic potential of the Indoleamine 2,3 dioxygenase-1 (IDO1) inhibitor.

RESULTS

Cancer cell-derived EVs promoted tumor angiogenesis via the activation of endothelial mitophagy, contributing to the growth and metastasis of OC. The aberrantly high expression of IDO1 mediated abnormal tryptophan metabolism in cancer cells and promoted the secretion of L-kynurenine (L-kyn)-enriched EVs, with associated high levels of L-kyn in EVs isolated from both the tumor tissues and patient plasma in OC. EVs derived from IDO1high ovarian cancer cells elevated nicotinamide adenine dinucleotide (NAD +) levels in endothelial cells via delivering L-kyn. Besides, IDO1high ovarian cancer cell-derived EVs upregulated sirt3 expression in endothelial cells by increasing acetylation modification. These findings are crucial for promoting endothelial mitophagy correlated with tumor angiogenesis. Notably, both endothelial mitophagy and tumor angiogenesis could be suppressed by the IDO1 inhibitor in the orthotopic OC mouse model.

CONCLUSIONS

Together, our findings unveil a mechanism of mitophagy in OC angiogenesis and indicate the clinical relevance of EV enriched L-kyn as a potential biomarker for tumorigenesis and progression. Additionally, IDO1 inhibitors might become an alternative option for OC adjuvant therapy.

Nkx2.5: a crucial regulator of cardiac development, regeneration and diseases

Cardiomyocytes fail to regenerate after birth and respond to mitotic signals through cellular hypertrophy rather than cellular proliferation. Necrotic cardiomyocytes in the infarcted ventricular tissue are eventually replaced by fibroblasts, generating scar tissue. Cardiomyocyte loss causes localized systolic dysfunction. Therefore, achieving the regeneration of cardiomyocytes is of great significance for cardiac function and development. Heart development is a complex biological process. An integral cardiac developmental network plays a decisive role in the regeneration of cardiomyocytes. During this process, genetic epigenetic factors, transcription factors, signaling pathways and small RNAs are involved in regulating the developmental process of the heart. Cardiomyocyte-specific genes largely promote myocardial regeneration, among which the Nkx2.5 transcription factor is one of the earliest markers of cardiac progenitor cells, and the loss or overexpression of Nkx2.5 affects cardiac development and is a promising candidate factor. Nkx2.5 affects the development and function of the heart through its multiple functional domains. However, until now, the specific mechanism of Nkx2.5 in cardiac development and regeneration is not been fully understood. Therefore, this article will review the molecular structure, function and interaction regulation of Nkx2.5 to provide a new direction for cardiac development and the treatment of heart regeneration.

Asymmetrically split DNAzyme-based colorimetric and electrochemical dual-modal biosensor for detection of breast cancer exosomal surface proteins

Exosomal surface proteins are potentially useful for breast cancer diagnosis and awareness of risk. However, some detection techniques involving complex operations and expensive instrumentation are limited to advance to clinical applications. To solve this problem, we develop a dual-modal sensor combining naked-eye detection and electrochemical assay of exosomal surface proteins from breast cancer. Most of existing sensors rely on aptamers recognizing exosomes and generating amplified signals at the same time, which require well-designed aptamer probes to avoid difficulties in identifying exosomes. In our work, aptamers not bound by the exosomes can serve as complete templates to induce formation of G quadruplexes. The peroxidase activity of the G-quadruplex/hemin DNAzyme catalyze substrates can generate both color and electrochemical signals. The developed dual-modal sensor offers a remarkable capability to differentiate nonmetastatic, metastatic breast cancer patients, and healthy individuals through the analysis of exosomal surface proteins. The sensor's distinctive features, including its universality, simplicity, and cost-effectiveness, position it as a promising diagnostic tool in breast cancer research and clinical practice.

Emerging integrated SERS-microfluidic devices for analysis of cancer-derived small extracellular vesicles

Cancer-derived small extracellular vesicles (sEVs) are specific subgroups of lipid bilayer vesicles secreted from cancer cells to the extracellular environment. They carry distinct biomolecules (e.g., proteins, lipids and nucleic acids) from their parent cancer cells. Therefore, the analysis of cancer-derived sEVs can provide valuable information for cancer diagnosis. However, the use of cancer-derived sEVs in clinics is still limited due to their small size, low amounts in circulating fluids, and heterogeneous molecular features, making their isolation and analysis challenging. Recently, microfluidic technology has gained great attention for its ability to isolate sEVs in minimal volume. In addition, microfluidics allows the isolation and detection of sEVs to be integrated into a single device, offering new opportunities for clinical application. Among various detection techniques, surface-enhanced Raman scattering (SERS) has emerged as a promising candidate for integrating with microfluidic devices due to its ultra-sensitivity, stability, rapid readout, and multiplexing capability. In this tutorial review, we start with the design of microfluidics devices for isolation of sEVs and introduce the key factors to be considered for the design, and then discuss the integration of SERS and microfluidic devices by providing descriptive examples of the currently developed platforms. Lastly, we discuss the current limitations and provide our insights for utilising integrated SERS-microfluidics to isolate and analyse cancer-derived sEVs in clinical settings.