Age-related macular degeneration is a leading cause of vision loss in aging populations, driven by complex interactions between genetic, environmental, and molecular factors. MicroRNAs have emerged as crucial regulators of cellular processes such as oxidative stress, inflammation, and angiogenesis, all of which contribute to AMD pathogenesis. This narrative review aims to summarize the involvement of peripheral blood microRNAs in the pathogenesis of AMD, focusing on key pathways such as oxidative stress, inflammation, and angiogenesis. Additionally, it explores their potential as biomarkers for predicting treatment response, particularly to anti-VEGF therapies. The potential of miRNAs as noninvasive biomarkers for early diagnosis and personalized treatment strategies is also explored, highlighting future directions for research.

Tumor microenvironment (TME) refers to the local environment in which various cancer cells grow, encompassing tumor cells, adjacent non-tumor cells, and associated non-cellular elements, all of which collectively promote cancer occurrence and progression. As a principal immune component in the TME, tumor-associated macrophages (TAMs) exert a considerable influence on cancer behaviors via their interactions with cancer cells. The interactive loops between cancer cells and TAMs, including secretory factors derived from both cancer cells and TAMs, are crucial for the proliferation, stemness, drug resistance, invasion, migration, metastasis, and immune escape of various cancers. Cancer cells release paracrine proteins (HMGB1, AREG etc.), cytokines (IL-6, CCL2 etc.), RNAs (miR-21-5p, circPLEKHM1, LINC01812 etc.), and metabolites (lactic acid, succinate etc.) to regulate the polarization phenotype, mediator secretion and function of TAMs. In turn, mediators (TGF-β, IL-10, IL-6 etc.) from TAMs promote cancer progression. This review summarizes recent advancements in the interactive loops between cancer cells and TAMs in TME. Inhibiting the recruitment and M2 polarization of TAMs, reprogramming TAMs from M2 to M1 phenotype, blocking TAMs-mediated immunosuppression and immune escape, and combining with existing immunotherapy can target TAMs to overcome immunotherapy resistance in various cancers. The new breakthroughs lie in identifying effective targets for drug development, improving the drug delivery system to enhance the drug delivery efficiency, and adopting combined therapy. Interventions targeting secretory factors, cell surface receptors, intracellular signaling pathways, and metabolic modulation in the interactive loops between cancer cells and TAMs are expected to suppress cancer progression and improve therapeutic effects.

Most eukaryotic cells secrete extracellular vesicles called exosomes, which are involved in intercellular communication. Exosomes play a role in tumor development and metastasis by transporting bioactive chemicals from cancerous cells to other cells in local and distant microenvironments. However, the potential of exosomes can be used by engineering them and considering different therapeutic approaches to overcome tumors. Exosomes are a promising drug delivery approach that can help decrease side effects from traditional treatments like radiation and chemotherapy by acting as targeted agents at the tumor site. The present review provides an overview of exosomes and various aspects of the role of exosomes in cancer development, which include these items: exosomes in cancer diagnosis, exosomes and drug delivery, exosomes and drug resistance, exosomal microRNAs and exosomes in tumor microenvironment, etc. Cancer stem cells release exosomes that nurture tumors, promoting unwanted growth and regeneration, and these types of exosomes should be inhibited. Ironically, exosomes from other cells, such as hepatocytes or mesenchymal stem cells (MSCs), are vital for healing organs like the liver and repairing gastric ulcers. Without proper treatment, this healing process can backfire, potentially leading to disease progression or even cancer. What can be found from various studies about the role of exosomes in the field of cancer is that exosomes act like a double-edged sword; on the other hand, natural exosomes in the body may play an important role in the process and progression of cancer, but by engineering exosomes, they can be directed towards target therapy and targeted delivery of drugs to tumor cells. By examining the role and application of exosomes in various mechanisms of cancer, it is possible to help treat this disease more efficiently and quickly in preclinical and clinical research.

The study aimed to investigate the effect and mechanism of monotropein on renal cell carcinoma (RCC).

After monotropein and NF-κB receptor activator (RANKL) treatment, cell proliferation, invasion, and apoptosis were evaluated using CCK-8, Transwell, and flow cytometry. Primary macrophages co-cultured with monotropein-treated RCC cells were analyzed to evaluate macrophage polarization using qRT-PCR, western blot, and ELISA assays by detecting the expression of M2 markers (CD206, CD168) and cytokines (IL-10, TGF-β). Additionally, the therapeutic efficacy of monotropein was examined using an RCC mouse xenograft model.

Monotropein could inhibit the proliferation, invasion, and M2 macrophage polarization and accelerate the apoptosis of RCC cells. Mechanistically, monotropein suppressed NF-κB pathway activation in RCC cells and reduced the expression of NF-κB downstream targets, including Bcl-2, c-Myc, and MMP9. RANKL could eliminate the effect of monotropein on RCC progression. In primary macrophages co-cultured with monotropein-treated RCC cells, monotropein downregulated M2 polarization markers and cytokines, further supporting its role in modulating the tumor microenvironment. In mouse models, monotropein reduced RCC tumor growth, induced apoptosis, and blocked NF-κB pathway.

Monotropein prevents RCC malignant progression and reduces M2 macrophage polarization by suppressing the NF-κB pathway, suggesting that monotropein may serve as a potential therapeutic agent for RCC by targeting both tumor cells and the tumor microenvironment.

Despite the significant advances in the development of immune checkpoint inhibitors (ICI), primary and acquired ICI resistance remains the primary impediment to effective cancer immunotherapy. Residing in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play a pivotal role in tumor progression by regulating diverse signaling pathways. Notably, accumulating evidence has confirmed that TAMs interplay with various cellular components within the TME directly or indirectly to maintain the dynamic balance of the M1/M2 ratio and shape an immunosuppressive TME, consequently conferring immune evasion and immunotherapy tolerance. Detailed investigation of the communication network around TAMs could provide potential molecular targets and optimize ICI therapies. In this review, we systematically summarize the latest advances in understanding the origin and functional plasticity of TAMs, with a focus on the key signaling pathways driving macrophage polarization and the diverse stimuli that regulate this dynamic process. Moreover, we elaborate on the intricate interplay between TAMs and other cellular constituents within the TME, that is driving tumor initiation, progression and immune evasion, exploring novel targets for cancer immunotherapy. We further discuss current challenges and future research directions, emphasizing the need to decode TAM-TME interactions and translate preclinical findings into clinical breakthroughs. In conclusion, while TAM-targeted therapies hold significant promise for enhancing immunotherapy outcomes, addressing key challenges-such as TAM heterogeneity, context-dependent plasticity, and therapeutic resistance-remains critical to achieving optimal clinical efficacy.

Exosomes play an important role in the metastatic microenvironment, acting as a transmission belt that facilitates intercellular communication. By delivering proteins, nucleic acids, and other substances in the exosomes, they can change the function of the receptor target cells, change the microenvironment of the metastatic site, and promote the colonization of the tumor cells, thus promoting cancer metastasis. The interaction between tumor cells and the surrounding microenvironment is complex, with exosomes serving as key facilitators of crosstalk between the primary tumor microenvironment and the pre-metastasis microenvironment. Despite many current studies to explore exosomes, we still do not have a detailed understanding of the role and mechanism of exosomes in the pre-metastatic immune microenvironment, and there are many challenges in the clinical application of exosomes. In this paper, we summarize the role of exosomes in regulating the pre-metastatic immune microenvironment and its mechanism, focusing on how exosomes regulate the function of immune cells in the pre-metastatic microenvironment to promote tumor metastasis. In addition, the potential application of exosomes in tumor immunotherapy and strategies for targeting exosomes are discussed. This will contribute to the immunotherapy of cancer metastasis and promote the clinical application of exosomes.

Macrophages are innate immune cells distributed throughout the body that play vital roles in organ development, tissue homeostasis, and immune surveillance. Macrophages acquire a binary M1/M2 polarized phenotype through signaling cascades upon sensing different signaling molecules in the environment, thereby playing a core role in a series of immune tasks, rendering precise regulation essential. M1/M2 macrophage phenotypes regulate inflammatory responses, while controlled activation of inflammatory signaling pathways is involved in regulating macrophage polarization. Among the relevant signaling pathways, we focus on the six well-characterized NF-κB, MAPK, JAK-STAT, PI3K/AKT, inflammasome, and cGAS-STING inflammatory pathways, and elucidate their roles and crosstalk in macrophage polarization. Furthermore, the effects of many environmental signals that influence macrophage polarization are investigated by modulating these pathways in vivo and in vitro. We thus detail the physiological and pathophysiological status of these six inflammatory signaling pathways and involvement in regulating macrophage polarization in cancer and beyond, as well as describe potential therapeutic approaches targeting these signaling pathways. In this review, the latest research advances in inflammatory signaling pathways regulating macrophage polarization are reviewed, as targeting these inflammatory signaling pathways provides suitable strategies to intervene in macrophage polarization and various tumor and non-tumor diseases.

Cancer metastasis is a complicated biological process that critically affects cancer progression, patient outcomes, and treatment plans. A significant step in metastasis is the formation of a pre-metastatic niche (PMN). A small subset of cells within tumors, known as cancer stem cells (CSCs), possess unique characteristics including, differentiation into different cell types within the tumor, self-renewal, and resistance to conventional therapies, that enable them to initiate tumors and drive metastasis. PMN plays an important role in preparing secondary organs for the arrival and proliferation of CSCs, thereby facilitating metastasis. CSC-derived exosomes are crucial components in the complex interplay between CSCs and the tumor microenvironment. These exosomes function as transporters of various substances that can promote cancer progression, metastasis, and modulation of pre-metastatic environments by delivering microRNA (miRNA, miR) cargo. This review aims to illustrate how exosomal miRNAs (exo-miRs) secreted by CSCs can predispose PMN and promote angiogenesis and metastasis.

Colorectal cancer (CRC) is the second most common malignant tumor in the world. With its increasing incidence and younger age trend, its impact on human health has been paid more and more attention. Currently, we have a variety of chemotherapy drugs that can be used to treat colorectal cancer. However, the drug resistance of colorectal cancer has become a significant factor affecting its cure rate. Some studies have reported that exosomes are related to the occurrence of drug resistance. However, the exact mechanism is not precise. Therefore, we focused on the role of cancer associated-fibroblast-derived (CAFs-derived) exosomes in colorectal progression. It was found that cancer cells transmit information through exosome interaction and induce chemotherapy resistance by promoting epithelial-mesenchymal transition (EMT), up-regulating the Wnt/β-catenin signaling pathway, transforming growth factor-β1 (TGF-β1) pathway, promoting angiogenesis and other possible molecular mechanisms. In addition, in terms of clinical significance and therapeutic strategies, we explore the clinical relevance of CAFs-derived exosomes in colorectal cancer patients and their potential as potential biomarkers for predicting chemotherapy response. We also provide a new possible direction for overcoming chemotherapy resistance in colorectal cancer by targeting CAFs-derived exosomes.

Digestive system tumors constitute a major subset of malignancies, consistently ranking among the leading causes of mortality globally. Despite limitations inherent in current therapeutic modalities, recent advancements in targeted therapy and drug delivery systems have led to significant improvements in the efficacy of pharmacotherapy for digestive system tumors. In this context, exosomes - naturally occurring nanoscale vesicles - have emerged as promising drug delivery candidates due to their intrinsic molecular transport capabilities, superior biocompatibility, and targeted recognition of tumor cells. The integration of exosomes into cancer therapeutics represents a novel and potentially transformative approach for treating digestive system tumors, which may drive further progress in this field. This review comprehensively examines the sources, loading mechanisms, and therapeutic efficacy of exosomes in the context of digestive system tumor treatment. Furthermore, it discusses the opportunities and challenges associated with exosomes, offering insights into their future role within the therapeutic armamentarium against digestive tumors.

Recent advancements in tumor immunotherapy have highlighted the importance of the tumor microenvironment in modulating immune responses against cancer cells. Within the TME, macrophages - particularly the M2 phenotype - serve pivotal regulatory functions through cytokine/chemokine secretion to modulate tumor progression. Elucidating the molecular crosstalk between gastric cancer (GC) cells and tumor-associated macrophages (TAMs) remains imperative for developing targeted therapeutic interventions. In this study, we identified Biglycan (BGN), a small leucine-rich proteoglycan, as a key mediator in GC progression. Exosomal BGN derived from GC cell is delivered to macrophages, where it binds to NONO protein, thereby driving M2 polarization and upregulating CXCL10 expression. Elevated CXCL10 levels activate the JAK/STAT1 signaling pathways, thereby potentiating GC cell proliferation, invasion, and metastatic dissemination. Clinically, elevated BGN expression correlates with advanced tumor stage and poor prognosis in GC patients, positioning it as a promising therapeutic target. Our findings reveal a previously unrecognized mechanism of exosomal BGN-mediated M2 macrophage reprogramming and CXCL10-driven oncogenic signaling in the GC microenvironment. These insights establish a novel therapeutic paradigm for GC management through disruption of tumor-macrophage communication.

Simultaneous abuse of ethanol and methamphetamine (METH) causes severe liver damage through oxidative stress and inflammation. This study evaluated the antifibrotic effects of gold nanoparticles (AuNPs) coadministered with the β-blocker carvedilol (CARV) against liver damage in rats. Male Wistar rats received 30% ethanol (7 g/kg) daily for 28 days, with METH (10 mg/kg) administered on the 22nd and 28th days. Liver damage was assessed using serum hepatic enzymes, glutathione (GSH) levels, malondialdehyde (MDA) formation, myeloperoxidase (MPO) inhibition, and histopathological analysis, including H&E, Picrosirius Red staining, immunofluorescence, and transmission electron microscopy. Cytokine levels were measured in liver tissue samples. In vitro, RAW 264.7 macrophages were induced to polarize into M1 and M2 phenotypes and cocultured with AuNPs + CARV-treated 3T3 cells, analyzed by rtPCR. AuNPs + CARV effectively protected the liver by modulating interactions between hepatic stellate cells (HSCs) and Kupffer cells, promoting an antifibrotic immune response driven by M1 macrophages. This was indicated by downregulation of profibrotic M2 macrophages and upregulation of M1 macrophages, shown by an increased CD86/CD163 ratio and reduced levels of IL-1β, TNF-α, TGFβ, AKT, and PI3K., pointing an attenuated liver inflammation. These results suggest that AuNPs combined with CARV could potentially serve as a therapy for alcohol and METH-induced liver fibrosis by targeting M2 macrophages.

MicroRNAs (miRNAs) are a class of non-coding RNAs approximately 20-24 nucleotides in length, which play a crucial role during gene regulation in plant-pathogen interaction. They negatively regulate the expression of target genes, primarily at the transcriptional or post-transcriptional level, through complementary base pairing with target gene sequences. Recent studies reveal that during pathogen infection, miRNAs produced by plants and miRNA-like RNAs (milRNAs) produced by fungi can regulate the expression of endogenous genes in their respective organisms and undergo trans-kingdom transfer. They can thereby negatively regulate the expression of target genes in recipient cells. These findings provide novel perspectives for deepening our understanding of the regulatory mechanisms underlying plant-pathogen interactions. Here, we summarize and discuss the roles of miRNAs and milRNAs in mediating plant-pathogen interactions via multiple pathways, providing new insights into the functions of these RNAs and their modes of action. Collectively, these insights lay a theoretical foundation for the targeted management of crop diseases.

Globally, drug-induced hepatotoxicity or drug-induced liver injury (DILI) is a serious clinical concern. Knowing the processes and patterns of cell death is essential for finding new therapeutic targets since there are not many alternatives to therapy for severe liver lesions. Excessive lipid peroxidation is a hallmark of ferroptosis, an iron-reliant non-apoptotic cell death linked to various liver pathologies. When iron is pathogenic, concomitant inflammation may exacerbate iron-mediated liver injury, and the hepatocyte necrosis that results is a key element in the fibrogenic response. The idea that dysregulated metabolic pathways and compromised iron homeostasis contribute to the development of liver injury by ferroptosis is being supported by new data. Various ferroptosis-linked genes and pathways have been linked to liver injury, although the molecular processes behind ferroptosis's pathogenicity are not well known. Here, we delve into the features of ferroptosis, the processes governing ferroptosis, and our current knowledge of iron metabolism. We also provide an overview of ferroptosis's involvement in the pathophysiology of liver injury, particularly DILI. Lastly, the therapeutic possibilities of ferroptosis targeting for liver injury management have been provided. Natural products, nanoparticles (NPs), mesenchymal stem cell (MSC), and their exosomes have attracted increasing attention among such therapeutics.

Macrophages, polarized into pro-inflammatory M1 or anti-inflammatory M2 states, are essential cellular elements of innate immunity. In the tumor microenvironment, owing to a paracrine manipulative program by cancerous cells, tumor-associated macrophages (TAMs) evolve, which can shift between M1-like and M2-like phenotypes. Since it is fairly unknown how the promising anticancer agents, silver (AgNPs) and gold nanoparticles (AuNPs) affect the bidirectional communication and reprogramming in the tumor stroma, we examined the behavior, the tumor-supporting functions, and the expression of polarization and functional marker genes of TAMs to reveal how these are modulated upon interaction with nanoparticle-exposed cancer cells.

We established co-cultures of murine immortalized J774 or primary bone marrow-derived macrophages with 4T1 breast cancer cells treated with AuNPs or AgNPs or with none of the nanoparticles. We assessed the expression of macrophage polarization and functional markers using RT-qPCR and Proteome Profiler Array and evaluated macrophage migration and matrix metalloproteinase activity by specific assays.

Protein and mRNA levels of most examined factors - except tumor necrosis factor-alpha - such as C-C-motif chemokine ligands 2 and 22, interleukin-23, inducible nitric oxide synthase, cyclooxygenase-2, the macrophage mannose receptor CD206, transforming growth factor-beta, and chitinase-like-3 protein decreased, and the expression of polarization markers revealed a shift towards M1-like phenotype in macrophages co-cultured with AgNP- or AuNP-treated 4T1 cells. Both nanoparticle treatments reduced the levels and activity of cell migration-related factors, such as C-C motif chemokine ligand 3, matrix metalloproteinases, and suppressed macrophage migration.

Both AuNPs and AgNPs showed a remarkable ability to influence macrophage-cancer cell communication, suppressed indirectly M2-like TAM polarization, and perturbed the migration behavior of TAMs that is critical for tumor invasion, indicating modulated immunological functions and debilitated cancer-promoting capabilities of TAMs in this microenvironment.

Colorectal cancer (CRC) is prone to metastasis, leading to a poor prognosis. miR-411-3p exhibits a tumor-suppressive function in CRC, but its exact mechanism is unclear. The malignant biological properties of CRC cells were detected by Carboxyfluorescein diacetate succinimidyl ester (CFSE) staining, scratch-wound and transwell assay. Levels of markers associated with macrophage polarization were evaluated by flow cytometry and ELISA kits. Bioinformatics analysis to screen whether the downstream target mRNA of miR-411-3p is matrix metalloproteinase 7 (MMP7), and Dual-Luciferase reporter assay verified the targeting relationship between the two. qRT-PCR tested miR-411-3p and MMP7 levels. MMP7 level was quantified by Western blot. Additionally, a nude mouse subcutaneous graft tumor model was constructed, Ki-67 expression was detected by immunohistochemistry, and the impact of miR-411-3p/MMP7 on the polarization of M2 macrophages was explored. miR-411-3p expression is downregulated in CRC. Knockdown of miR-411-3p elevated the amount of CFSE-positive, migrating, and invading cells, decreased apoptosis, and elevated the levels of M2 macrophage polarization markers. After overexpression of miR-411-3p, all of the above metrics were reversed in CRC cells. miR-411-3p targeted negative regulation of MMP7 expression, and MMP7 overexpression further enhanced the promotional effect of knockdown of miR-411-3p on the malignant progression of CRC and M2 macrophage polarization. Furthermore, knockdown of miR-411-3p upregulated the MMP7 level, elevated Ki-67-positive cells count, and induced M2 macrophage polarization in vivo. Knockdown of miR-411-3p upregulates MMP7 and induces M2 macrophage polarization, which in turn promotes malignant biological progression of CRC.

This study aimed to investigate the crosstalk mechanism between pancreatic cancer (PAC) cells and M2 tumor-associated macrophages induced by tumor-derived exosomal miR-34a. MicroRNA and mRNA expression levels were detected using RT-qPCR. Cell Counting Kit-8, wound-healing, transwell assays and flow cytometry were respectively employed to assess cell proliferation, migration, invasion and apoptosis. Enzyme-linked immunosorbent assay was utilized to determine cytokine secretion. Transmission electron microscopy and nanoparticle tracking analyses were performed to detect the exosome morphology and particle size. Phagocytosis of exosomes by macrophages was verified by PKH26 labeling. The effects of exosome-treated macrophages on the epithelial-mesenchymal transition, invasion, and migration of PANC-1 cells were investigated using coculture experiments. The identification of miR-34a's potential targets were determined with TargetScan and validated by a dual-luciferase reporter assay. miR-34a was expressed at low levels in PAC tissues, cells, and exosomes. The overexpression of miR-34a restrains the malignant progression of PANC-1 cells. After miR-34a-overexpressed PANC-1-derived exosomes were phagocytosed by macrophages, the process of M2 polarization in macrophages was obstructed, leading to the suppression of epithelial-mesenchymal transition, migration, and invasion of the cocultured PANC-1 cells. Suppressor of cytokine signaling 3 is a direct target of miR-34a. MiR-34a negatively modulates the suppressor of cytokine signaling 3 to prevent the M2 polarization of macrophages by engaging the Janus kinase/signal transducers and activators of the transcription pathway and influencing the malignancy of PAC cells.  miR-34a in cancer cell-derived exosomes inhibits the malignant progression of pancreatic cancer cells by restraining M2 polarization of macrophages.

Our team previously reported that MACC1 levels are closely related to a variety of tumors and the efficacy of immune checkpoint blockade (ICB) therapy. However, the predictive value of MACC1 levels for lung adenocarcinoma (LUAD) immunotherapy has not been studied. This study aimed to investigate the predictive effect of the oncogene MACC1 on ICB reactivity in patients with LUAD. First, the expression patterns and clinical features of MACC1 in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were comprehensively evaluated using R packages. We subsequently assessed the correlations between MACC1 and immunological characteristics in the LUAD tumor microenvironment (TME) using the CIBERSORT algorithm. The results revealed that MACC1 overexpression was significantly correlated with 3 immune checkpoints, 14 tumor-infiltrating immune cells (TIICs), 9 immunomodulators, 5 anticancer immune process activities, and 3 effector genes of TIICs in LUAD. Additionally, on the basis of the prognostic genes from LASSO analysis, we developed the MACC1-related Risk Score (MRRS), which can accurately predict the prognosis and response to cancer immunotherapy in LUAD patients (HR = 3.50, AUC at 1, 2, and 3 years = 0.737, 0.744, and 0.724, respectively). Finally, in vivo experiments revealed that the combination of MACC1 silencing and PD-L1 inhibitors significantly inhibits tumor progression. These findings increase our understanding of MACC1 as a potential prognostic biomarker and potential therapeutic target for cancer immunotherapy. The MRRS may play a critical role in predicting the response of LUAD patients to ICB therapy.

Cisplatin (DDP) is a key chemotherapeutic agent in the treatment of gastric cancer; however, its efficacy is often limited by chemoresistance, a notable challenge in clinical oncology. The present study aimed to investigate the influence of exosomes derived from M2‑polarized macrophages, which promote this resistance, on the response of gastric cancer cells to DDP, examining both the effects and the underlying mechanisms. M2 macrophages, differentiated from mouse bone marrow cells with interleukin (IL)‑13 and IL‑4, were identified using immunofluorescence staining for CD206 and CD163. Exosomes derived from these macrophages were characterized using transmission electron microscopy and protein markers, including calnexin, tumor susceptibility gene 101 and CD9. The role of exosomal microRNA (miR)‑3681‑3p in DDP resistance was assessed using Cell Counting Kit‑8 and apoptosis assays, while a luciferase reporter assay was used to elucidate the interaction between miR‑3681‑3p and MutL protein homolog 1 (MLH1). Co‑culturing gastric cancer cells with M2 macrophages enhanced DDP resistance, an effect amplified by exosomes from M2 macrophages enriched with miR‑3681‑3p. This microRNA directly targeted and reduced MLH1 protein expression. Overexpression of miR‑3681‑3p through mimic transfection, along with MLH1 silencing by small interfering RNA transfection, significantly increased DDP resistance, as evidenced by elevated IC50 values in AGS cells. By contrast, the overexpression of MLH1 effectively reversed the drug resistance of AGS cells to DDP caused by miR‑3681‑3p mimic transfection, as evidenced by a decrease in the IC50 value. In conclusion, exosomal miR‑3681‑3p from M2 macrophages may have a key role in conferring DDP resistance to gastric cancer by suppressing MLH1, offering a new therapeutic target for overcoming chemoresistance.

Papillary thyroid carcinoma (PTC), comprising 85% of all thyroid cancers, is an epithelial malignancy. The potential for malignant transformation in normal cells by thyroid cancer cells via exosomal Annexin A1 (ANXA1) delivery is investigated in this study. Our aim is to determine the impact of PTC cells on macrophage polarization through exosomal ANXA1 secretion and its implications for tumor progression. Exosomes in PTC cells were examined using transmission electron microscopy, exosome labeling, and nanoparticle tracking analysis. Real-time quantitative polymerase chain reaction was employed to quantify gene expression levels. Protein levels were determined through Western blot analysis. The interplay between genes was assessed using luciferase reporter and RNA pull-down assays. Functional experiments were conducted to investigate PTC cell proliferation and apoptosis. Our findings reveal that ANXA1 promotes PTC cell proliferation and inhibits apoptosis. Exosomes derived from PTC cells were found to promote macrophage M2 polarization. ANXA1 stimulates M2 polarization through the activation of the PI3K/AKT pathway. MicroRNA-374a-5p (miR-374a-5p) and microRNA-374b-5p (miR-374b-5p) were identified as inhibitors of ANXA1 expression and PI3K/AKT pathway activity, thereby inhibiting macrophage M2 polarization. Furthermore, miR-374a-5p and miR-374b-5p were observed to suppress PTC cell proliferation through their regulatory action on ANXA1. Our study suggests that miR-374a/b-5p inhibits PTC cell growth by blocking the macrophage M2 polarization induced by exosomal ANXA1.

Lung cancer is a common cancer. Exosomes are emerging mediators of intercellular communication, and miRNAs serve a crucial position in cancer progression. This project intends to discover whether exosomal miR-454-3p affects tumor progression and its underlying mechanisms.

Exosomes were isolated utilizing ultracentrifugation. The exosomal biomarkers level was monitored by western blot (WB). The miR-454-3p levels were assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR), and HHEX expression were detected by qRT-PCR and WB. Cell growth and metastasis were detected through CCK-8, colony formation assay and transwell. Meanwhile, the dual luciferase reporter system and immunoprecipitation (RIP) assay was applied to clarify the interactions between miR-454-3p and HHEX.

We successfully isolated serum exosomes from NSCLC patients. Then, our team discovered that miR-454-3p was elevated in serum-derived exosomes from NSCLC patients. Functional analysis disclosed that exosomes accelerated NSCLC cell proliferation and metastasis. Silencing of exosomal miR-454-3p hindered NSCLC cell proliferation and metastasis. Subsequently, the starbase database declared that miR-454-3p was interacted with HHEX. HHEX overexpression reversed the promotion of NSCLC cell proliferation and metastasis by exosomal miR-454-3p.

Exosomal miR-454-3p enhanced the progression of NSCLC cells through HHEX. miR-454-3p may be a therapeutic target for NSCLC.

Colorectal cancer (CRC) ranks among the most prevalent cancers worldwide and is the fourth leading cause of cancer-related deaths. Metastasis poses a significant obstacle in CRC treatment, as distant metastasis, particularly to the liver, remains the primary cause of mortality. Colorectal liver metastasis (CRLM) occurs frequently due to the liver's direct vascular connection to the colorectal region via the portal vein. Standard treatment approaches for CRLM are limited; only a few patients qualify for surgical intervention, resulting in a persistently low survival rate. Additionally, resistance to chemotherapy is common, emphasizing the need for more effective targeted therapies. Emerging evidence highlights the pivotal role of microRNAs (miRNAs) in modulating critical pathways associated with CRLM, including tumor invasion, epithelial-mesenchymal transition, and angiogenesis. MiRNAs exhibit dual functions as tumor suppressors and oncogenes by targeting multiple genes, thus playing a complex role in both the initiation and progression of metastasis. The regulatory mechanisms of miRNAs could help to identify novel biomarkers for early diagnosis and prognosis of CRLM, as well as promising therapeutic targets to overcome chemoresistance. Despite numerous studies on miRNA involvement in CRC metastasis, dedicated reviews focusing on miRNAs and CRLM remain scarce. This review aims to approach targeted therapies by examining the current understanding of miRNA involvement in CRLM and exploring their potential as diagnostic, prognostic, and therapeutic agents. Through an integrative approach, we aim to provide insights that could transform CRLM management and improve patient outcomes.

Tumor-associated macrophages (TAM) have been shown to regulate colon cancer (CC) progression. However, it is not clear whether tumor-derived exosomal circular RNA (circRNA) regulates TAM to influence CC progression. The expression levels of circ_0020095, M1 macrophage markers, M2 macrophage markers, and interleukin-1 receptor-associated kinase 1 (IRAK1) were determined by qRT-PCR. Cell proliferation, migration and invasion were examined by EdU assay, wound healing assay and transwell assay. Exosomes derived from CC cells were used to treat M0 macrophages. M1 macrophage surface marker CD86 was detected by flow cytometry, and protein expression was examined by western blot. Then, the medium of exosome-treated M0 macrophages was used to culture CC cells to determine CC cell functions. RNA pull-down assay, RIP assay and dual-luciferase reporter assay were performed to validate interaction. Circ_0020095 had elevated expression in CC tissues and cells, and its knockdown repressed CC cell proliferation and metastasis. M0 macrophages could take by CC cell-derived exosomes to regulate circ_0020095 expression. Exosomal circ_0020095 restrained M1 macrophage polarization and increased M2 macrophage polarization to enhance CC cell progression. Besides, IRAK1 silencing could promote CC cell proliferation and metastasis by inhibiting M1 macrophage polarization, and its overexpression also abolished the effect of exosomal circ_0020095. Mechanistically, circ_0020095 could competitively bind to IGF2BP1 and then reduced the binding ability of IGF2BP1 and IRAK1 3'UTR. Tumor-derived exosomal circ_0020095 promoted CC cell progression via inhibiting M1 macrophage polarization through IGF2BP1/IRAK1 axis.

Tumor-associated macrophages (TAMs) are one type of the most abundant immune cells within tumor, resulting in immunosuppresive tumor microenvironment and tumor resistance to immunotherapy. Thus, targeting TAMs is a promising therapeutic strategy for boosting cancer immunotherapy. This study provides an overview of current therapeutic strategies targeting TAMs, which focus on blocking the recruitment of TAMs by tumors, regulating the polarization of TAMs, and directly eliminating TAMs using various nanodrugs, especially with a new categorization based on the specific signaling pathways, such as NF-κB, HIF-1α, ROS, STAT, JNK, PI3K, and Notch involved in their regulatory mechanism. The latest developments of nanodrugs modulating these pathways are discussed in determining the polarization of TAMs and their role in the tumor microenvironment. Despite the challenges in clinical translation and the complexity of nanodrug synthesis, the potential of nanodrugs in enhancing the effectiveness of cancer immunotherapy is worthy of expecting.

The molecular basis for the disparities between primary ovarian cancer (POC) and ovarian cancer secondary to breast cancer (OCSTBC) remains poorly understood. This study aimed to explore the different characteristics between them through genomic analysis.

We performed differentially expressed genes (DEGs) analysis between POC (n=96) and OCSTBC (n=44) groups with transcriptome data and revealed the enriched biological pathways with Kyoto Encyclopedia of Genes and Genomes (KEGG) and Hallmark gene sets between these two groups. Then, the Microenvironment Cell Populations (MCP)-counter and Cell-type Identification by Estimating Relative Subsets of RNA Transcript (CIBERSORT) algorithms were applied to evaluate the immune infiltration in tumor microenvironment (TME) between them. Finally, we performed the association analysis within single nucleotide polymorphism (SNP) data and obtained some meaningful SNPs and candidate genes for further transcriptomic analysis.

We identified a total of 13 cancer-related genes including GATA3, FOXA1, CCND1, and TTK between POC (n=96) and OCSTBC (n=44) groups with DEGs analysis. Integrated analysis revealed more significant immune-enriched pathways in the POC than in the OCSTBC group. Most immune cells had higher infiltration abundance in POC, except M2 macrophages, which was higher in OCSTBC. In SNP analysis, four SNP regions (8q12.1, 11q21, 11q24.3, and 17q25.3) were found to be significantly correlated with phenotypes (POC/OCSTBC), and importantly, some new susceptibility genes such as ETS1, CWC15, and XKR4 were revealed to potentially be associated with distinction between POC and OCSTBC.

Our study provides a systematic molecular characteristic between POC and OCSTBC and suggests a pressing need to develop some specific therapeutic strategies in certain types of ovarian cancer.

In recent years, natural compounds have attracted wide attention for the treatment of liver cancer due to their therapeutic potential and reduced toxicity. Among these, Schisandrin B (Sch B), a primary bioactive component derived from Schisandra chinensis, has shown notable antitumor activity; however, its specific mechanism remains unclear.

The effect of Sch B on the growth of hepatocellular carcinoma(HCC) cells were assessed using CCK-8 assay, colony formation assay and EdU assay, and apoptosis was detected by flow cytometry. The co-culture system of macrophages and HCC cells was established to detect the effect of Sch B on the cell viability and cell cycle changes of HCC cells in the co-culture system. Then, the migration of HCC cells in the co-culture system was studied using a subtoxic concentration of Sch B. Exosomes of the co-culture system with or without Sch B effect were collected for identification and protein spectrum analysis. The differential protein was analyzed by KEGG enrichment analysis and protein interaction network, which was verified by western blotting. Meanwhile, the expression changes of macrophage polarization markers were detected. Finally, the inhibitory effect of Sch B on HCC and the changes of FN1 were verified by in vivo experiments.

Sch B inhibited HCC cell growth; moreover, it significantly suppressed HCC cell proliferation in the co-culture system and induced S-phase cell cycle arrest by downregulating CDK4, CDK2, and cyclin A2 while upregulating p27 Kip1. Additionally, Sch B inhibited the migration of HCC cells in the co-culture system.The differentially expressed protein fibronectin 1(FN1) in liver cancer patients was higher than that in healthy people. Moreover, after SchB treatment, the expression of FN1 protein in exosomes decreased and the macrophages exhibited M1 polarization. In vivo experiments also verified that Sch B inhibited HCC growth and downregulated the expression of FN1 protein in tumor tissues.

Sch B may inhibit the development of HCC by inhibiting the expression of exosomal FN1during interactions between macrophages and HCC cells.

Exosomes (Exos) are extracellular vesicles secreted by cells and serve as crucial mediators of intercellular communication. They play a pivotal role in the pathogenesis and progression of various diseases and offer promising avenues for therapeutic interventions. Exos derived from mesenchymal stem cells (MSCs) have significant immunomodulatory properties. They effectively regulate immune responses by modulating both innate and adaptive immunity. These Exos can inhibit excessive inflammatory responses and promote tissue repair. Moreover, they participate in antigen presentation, which is essential for activating immune responses. The cargo of these Exos, including ligands, proteins, and microRNAs, can suppress T cell activity or enhance the population of immunosuppressive cells to dampen the immune response. By inhibiting lymphocyte proliferation, acting on macrophages, and increasing the population of regulatory T cells, these Exos contribute to maintaining immune and metabolic homeostasis. Furthermore, they can activate immune-related signaling pathways or serve as vehicles to deliver microRNAs and other bioactive substances to target tumor cells, which holds potential for immunotherapy applications. Given the immense therapeutic potential of MSC-derived Exos, this review comprehensively explores their mechanisms of immune regulation and therapeutic applications in areas such as infection control, tumor suppression, and autoimmune disease management. This article aims to provide valuable insights into the mechanisms behind the actions of MSC-derived Exos, offering theoretical references for their future clinical utilization as cell-free drug preparations.

The liver is the most commonly metastasized organ in colorectal cancer (CRC), and distant metastasis is the primary cause of mortality from CRC. In recent years, researchers have discovered that tumor cells create a "pre-metastatic niche (PMN)" favorable to metastasis before reaching the metastatic location. This review discusses the many processes and mechanisms that lead to PMN formation in CRC, including gut microbiota, stem cell stimulation, immunocyte interactions, and the induction of extracellular vesicles that carry important information. It examines research methods and diagnostic and therapeutic approaches for treating metastatic CRC with PMN. The crucial significance of PMN formation in metastatic CRC is also highlighted.

In this article, we revisit an article, which specifically focuses on the utilization of exosomes derived from human bone marrow mesenchymal stem cells (MSCs) for targeted delivery of gemcitabine in pancreatic cancer treatment. The experimental results demonstrated that the exosome-based drug delivery system derived from MSCs significantly augmented apoptosis in pancreatic cancer cells. The biocompatibility, targeting specificity, and low immunogenicity of exosomes render them as optimal carriers for drug delivery, enabling precise administration of therapeutics to diseased tissues while mitigating adverse effects, thereby achieving targeted treatment of cancer cells and significantly enhancing anti-tumor efficacy. However, the clinical application of exosome drug delivery platforms in oncology still presents challenges, necessitating further optimization to ensure their stability and efficacy. This study focuses on elucidating the advantages of exosomes as a drug delivery platform, exploring the utilization of MSC-derived exosomes in oncology therapy, and discussing their potential and future directions in cancer treatment.

Buzhong Yiqi Decoction (BZYQD) is a traditional Chinese medicine renowned for its anti-colorectal cancer (CRC) properties. However, the bioactive components and mechanisms of BZYQD against CRC remain unknown. In this study, LC-MS was used to analyze the chemical composition of BZYQD. Next, the network pharmacology and molecular docking was used to investigate the core components and targets of BZYQD against CRC. Finally, we experimentally validated the potential mechanism of BZYQD against CRC through in vitro studies. Our results identified 26 chemical components in the BZYQD; 75 "hithubs" targets were screened by network pharmacology, and mainly involving pathways such as including pathways in cancer, P13K-Akt signaling pathway, proteoglycans in cancer, kaposi sarcoma-associated herpesvirus, and lipid and atherosclerosis signaling pathways. Based on the number of "hithubs" targets in the key pathways, the two most critical targets including AKT1 and PIK3CA were selected. The component-target network results indicated that astragaloside IV, gancaonin A, quercetin, poricoic acid A, and licoisoflavanone are key anti-CRC components in BZYQD. Molecular docking showed a strong binding affinity between these components and targets. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway emerged as the primary target of BZYQD. Further in vitro studies confirmed that BZYQD's anti-CRC activity is mediated through the PI3K/AKT/mTOR axis and influences macrophage polarization. BZYQD exerts its therapeutic effects on CRC through multiple components, targets, and pathways. Our study elucidates the effective components and molecular mechanisms of BZYQD in CRC treatment and provides preliminary validation through molecular docking and experimental studies.

Colorectal cancer (CRC) is one of the most prevalent malignant neoplasms globally. Its development and metastasis are closely associated with the polarization of macrophages within the tumor microenvironment (TME). In particular, the polarization of M2-type macrophages has been demonstrated to be related to the promotion of tumor growth, migration, and angiogenesis. This study aims to investigate the role of miR-92a-3p in colon cancer-derived exosomes in regulating M2-type macrophage polarization by targeting EID2B and to elucidate the impact of this process on tumor migration and angiogenesis. MicroRNAs that were differentially expressed in plasma exosomes from CRC patients were initially identified through a search of the GEO database. The results were then verified by RT-qPCR using miR-92a-3p. The uptake of exosomes was observed via laser confocal microscopy, and the impact of miR-92a-3p on the polarization of exosomes and macrophages was examined through the use of RT-qPCR and WB. A bioinformatics analysis and a dual-luciferase reporter assay were employed to identify the downstream target of miR-92a-3p and to investigate its effect on the MAPK/ERK pathway. miR-92a-3p was upregulated in plasma exosomes of colon cancer patients and exhibited a positive correlation with lymph node metastasis. The results demonstrated that miR-92a-3p was capable of promoting M0 macrophage polarization toward the M2 phenotype, and of enhancing the migratory and invasive capacities of CRC cells, as well as their angiogenic potential in vitro. Bioinformatic analysis and experimental validation demonstrated that miR-92a-3p targeted EID2B and that this target gene was negatively correlated with M2-type macrophage polarization. The results demonstrated that miR-92a-3p promotes macrophage M2 polarization by activating the MAPK/ERK pathway. miR-92a-3p activates the MAPK/ERK pathway and induces macrophage M2 polarization by targeting EID2B, thereby promoting migration and angiogenesis in CRC. These findings offer new potential targets for the treatment of colon cancer.

The tumor microenvironment (TME) plays an important role in tumorigenesis and development. Tumor-associated macrophages (TAMs) are essential members of the TME, the exosomes and miRNAs they secrete are crucial in tumor regulation. Our previous study showed that GRP78-induced macrophages infinitely tend to be M2-type TAMs. In this study, the exosomes of M0 and GRP78-induced macrophage were collected and co-incubated with colorectal cancer (CRC) cells. The results implied that macrophage exosomes induced by GRP78 (GRP78-exos) significantly promoted stemness and chemoresistance in CRC in vitro and in vivo. Further, the top 5 miRNAs upregulated in GRP78-exos were obtained from miRNA sequencing data. The qRT-PCR validation revealed that miR-769-5p was the most observably upregulated and could be directly transferred into CRC cells via GRP78-exos. Mechanistically, the study indicated that miR-769-5p targeted MAPK1 to regulate the cell cycle-related proteins RB1, cyclin D1, and cyclin E1. This contributes to CRC cells entering a quiescent state, which leads to the development of chemoresistance. Moreover, miR-769-5p is also expressed higher in the tissues of 5-FU-resistant CRC patients. In summary, the findings indicate a novel function of miR-769-5p as a potential marker for the diagnosis and treatment of chemotherapy resistance in CRC.

Prior studies have demonstrated the association between immune cells and colorectal cancer (CRC). However, the causal link to specific immunophenotypes is limited. This study intends to elucidate the causal relationship of immune cell signatures on CRC.

We performed a bi-directional and two-sample mendelian randomization (MR) study, utilizing GWAS summary data of 731 immune cell traits (n = 3,757) and CRC statistics (n = 470,002). The primary MR methodology was inverse-variance weighted (IVW) method. Furthermore, heterogeneity was evaluated by Cochran's Q test. MR-PRESSO and MR-Egger were employed to assess horizontal and vertical pleiotropy respectively. Sensitivity analysis and FDR correction were conducted in our results. These results were validated in both the UK Biobank and FinnGen cohorts. We also extracted transcriptomic data of CRC and adjacent non-tumor tissues from TCGA, and used CIBERSORT to compare the infiltration patterns of 22 immune cell panels between normal tissues and the tumor microenvironment (TME).

Our study indicated nine immune cell signatures had significant causality with the risk of CRC after sensitivity analysis and FDR correction. The positive results covered four panels: B cell, CD8 + T cell, Treg, and monocyte. IgD- CD38br and IgD + CD38br B cell, CD8dim and CD28 + CD45RA- CD8dim T cell, and CD14 on CD14 + CD16- monocyte were the protective factors of CRC. However, CD39 + resting Treg, CX3CR1 on CD14- CD16 + monocyte, FSC-A on HLA DR + T cell, and BAFF-R on B cell increased the risk of CRC. The results were validated in the UK Biobank data and FinnGen cohorts. The data from the TCGA database also confirmed the infiltration of B cell, CD8 + T cell, Treg, and monocyte panels in the TME.

This study highlights the causal link between specific immune cell phenotypes and CRC, providing valuable insights into the immune microenvironment's role in CRC. The validation of our findings using large-scale datasets (UK Biobank, FinnGen) and TCGA underscores the robustness of our results, offering new potential therapeutic targets for CRC treatment.

The crosstalk between immunity and cancer in the regulation of tumor growth is considered a hallmark of cancer. Antitumor immunity refers to the innate and adaptive immune responses that regulate cancer development and proliferation. Tumor immune evasion represents a major hindrance to effective anticancer treatment. Extracellular vesicles (EVs) are nano-sized and lipid-bilayer-enclosed particles that are secreted to the extracellular space by all cell types. They are critically involved in numerous biological functions including intercellular communication. Tumor-derived extracellular vesicles (TEVs) can transport a variety of cargo to modulate immune cells in the tumor microenvironment (TME). This review provides the latest update about how tumor cells evade immune surveillance by exploiting TEVs. First, the biogenesis of EVs and the cargo-sorting machinery are discussed. Second, how tumor cells modulate immune cell differentiation, activation, and function via TEVs to evade immune surveillance is illustrated. Last but not least, the novel antitumor strategies that can reverse immune escape are summarized.

Exosomes can be modified and designed for various therapeutic goals because of their unique physical and chemical characteristics. Researchers have identified tumor-derived exosomes (TEXs) as significant players in cancer by influencing tumor growth, immune response evasion, angiogeneis, and drug resistance. TEXs promote the production of specific proteins important for cancer progression. Due to their easy accessibility, TEXs are being modified through genetic, drug delivery, membrane, immune system, and chemical alterations to be repurposed as vehicles for delivering drugs to improve cancer treatment outcomes. In the complex in vivo environment, the clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR/Cas9) system encounters challenges from degradation, neutralization, and immune responses, emphasizing the need for strategic distribution strategies for effective genome editing. Engineered exosomes present a promising avenue for delivering CRISPR/Cas9 in vivo. In this review, we will explore different techniques for enhancing TEXs using various engineering strategies. Additionally, we will discuss how these exosomes can be incorporated into advanced genetic engineering systems like CRISPR/Cas9 for possible therapeutic uses.

The Bushen Jiedu Formula (BSJDF) is a traditional and effective chemical prescription of traditional Chinese medicine (TCM) administered due to its anti-cancer properties, particularly in colorectal cancer (CRC).

This study proposes to explore the therapeutic benefits of BSJDF against metastasis in CRC and unravel its regulatory mechanisms related to the tumor microenvironment.

The combination of mass spectrometry and network pharmacology was used to analyze the involvement of BSJDF in anti-tumor progression. In vitro and in vivo experiments were conducted to measure the regulatory effect of BSJDF on tumor-derived extracellular vesicles (EVs), which induce the M2 polarization of macrophages and CRC metastasis. Flow cytometry, immunofluorescence, and RT-qPCR assays were employed to elucidate the mechanisms by which tumor-derived EVs induce macrophage M2-type polarization.

Network pharmacology illuminated that immune and inflammatory response pathways were involved in the beneficial effects of BSJDF on CRC. In vivo experiments indicated that BSJDF suppressed the metastasis of CRC to the liver by modulating macrophage immune infiltration. Mechanically, BSJDF inhibited CRC metastasis via modulating tumor-derived EVs that facilitate the polarization of M2 macrophages. Moreover, BSJDF suppressed the metastasis of CRC and the polarization of M2 macrophages by reducing lncRPPH1 in tumor-derived EVs.

BSJDF blocked the M2-type polarization of macrophages and prevented CRC metastasis by decreasing the expression levels of lncRPPH1 in tumor-derived EVs.

Liver metastasis is the leading cause of colorectal cancer (CRC)‑related mortality. Microbiota dysbiosis serves a role in the pathogenesis of colorectal liver metastases. Bile acids (BAs), cholesterol metabolites synthesized by intestinal bacteria, contribute to the metastatic cascade of CRC, encompassing colorectal invasion, migration, angiogenesis, anoikis resistance and the establishment of a hepatic pre‑metastatic niche. BAs impact inflammation and modulate the immune landscape within the tumor microenvironment by activating signaling pathways, which are used by tumor cells to facilitate metastasis. Given the widespread distribution of BA‑activated receptors in both tumor and immune cells, strategies aimed at restoring BA homeostasis and blocking metastasis‑associated signaling are of importance in cancer therapy. The present study summarizes the specific role of BAs in each step of colorectal liver metastasis, elucidating the association between BA and CRC progression to highlight the potential of BAs as predictive biomarkers for colorectal liver metastasis and their therapeutic potential in developing novel treatment strategies.

Liver metastasis is a leading cause of mortality from malignant tumors and significantly impairs the efficacy of therapeutic interventions. In recent years, both preclinical and clinical research have made significant progress in understanding the molecular mechanisms and therapeutic strategies of liver metastasis. Metastatic tumor cells from different primary sites undergo highly similar biological processes, ultimately achieving ectopic colonization and growth in the liver. In this review, we begin by introducing the inherent metastatic-friendly features of the liver. We then explore the panorama of liver metastasis and conclude the three continuous, yet distinct phases based on the liver's response to metastasis. This includes metastatic sensing stage, metastatic stress stage, and metastasis support stage. We discuss the intricate interactions between metastatic tumor cells and various resident and recruited cells. In addition, we emphasize the critical role of spatial remodeling of immune cells in liver metastasis. Finally, we review the recent advancements and the challenges faced in the clinical management of liver metastasis. Future precise antimetastatic treatments should fully consider individual heterogeneity and implement different targeted interventions based on stages of liver metastasis.

Small extracellular vesicles (sEVs) facilitate intercellular communication and play a pivotal role in tumor progression. Accumulated evidence has indicated the diversity of sEVs but with limited results revealing the landscape of heterogeneity of sEVs. The heterogeneity of cargo RNA in sEVs presents the different cell origins and indicates different functions. Here, we analyzed the heterogeneity of sEVs at droplet levels from single-cell RNA sequencing results of head and neck squamous cell carcinoma (HNSCC) with the previously reported algorithm SEVtras. With the sEVs secretion activity calculated by SEVtras, we also found that the T cells held the major role of sEVs secretion. In addition, we found these sEVs secreted by T cells increased the cytotoxic ability of natural killer cells (NK cells), which illustrated an indirect manner for the anti-tumor function of T cells. These results revealed the heterogeneity of cargo RNA of sEVs in HNSCC and underlined a sEVs-dependent manner in which T cells act on NK cells and anti-tumor immunity.