Involvement of extracellular vesicles in the macrophage-tumor cell communication in head and neck squamous cell carcinoma.
ABSTRACT: BACKGROUND:Exosomes are cell-derived vesicles that mediate cellular communication in health and multiple diseases, including cancer. However, its role in head and neck cancer has been poorly defined. Here, we investigated the relevance of exosomes in the signaling between larynx cancer cells and macrophages. METHODS:Exosomes from THP1 macrophages and BICR18 cells (a larynx squamous cell carcinoma cell line) were purified and their role in the cancer cell migration, macrophage phenotype and immunosuppressive activity was evaluated. The activation of STAT3 signal transduction in macrophages in response to exosomes obtained from cancer cells was also evaluated. RESULTS:Macrophages foster the cancer cell migration and this effect is mediated by exosome signaling. On the other hand, exosomes also induce the expression of IL-10 in macrophages and PD-L1 in cancer cells, thus resulting in the promotion of an immunosuppressive environment. Moreover, we observed that the effects induced in cancer cells are mediated by the exosome-depending activation of STAT-3 signal transduction pathway. CONCLUSIONS:Our study indicates that exosomes released by both macrophages and cancer cells plays a critical role in tumor progression in larynx cancer and might be a potential target for therapeutic intervention in head and neck cancer.
Project description:Exosomes are small membranous vesicles that contain proteins, lipids, genetic material, and metabolites with abundant information from parental cells. Exosomes carry and deliver bioactive contents that can reprogram the functions of recipient cells and modulate the tumor microenvironment to induce pathological events through cell-to-cell communication and signal transduction. Tumor-derived exosomes (TDEs) in head and neck squamous cell carcinoma (HNSCC) are involved in most aspects of cancer initiation, invasion, progression, immunoregulation, therapeutic applications, and treatment resistance. In addition, HNSCC-derived exosomes can be used to obtain information on diagnostic and therapeutic biomarkers in circulating blood and saliva. Currently, the biology, mechanisms, and applications of TDEs in HNSCC are still unclear, and further research is required. In this review, we discuss various aspects of exosome biology, including exosomal components, exosomal biomarkers, and molecular mechanisms involved in immunoregulation, cancer metastasis, and therapy resistance. We also describe recent applications to update our understanding of exosomes in HNSCC.
Project description:Tumor-associated macrophages are major contributors to malignant progression and resistance to immunotherapy, but the mechanisms governing their differentiation from immature myeloid precursors remain incompletely understood. In this study, we demonstrate that exosomes secreted by human and mouse tumor-educated mesenchymal stem cells (MSCs) drive accelerated breast cancer progression by inducing differentiation of monocytic myeloid-derived suppressor cells into highly immunosuppressive M2-polarized macrophages at tumor beds. Mechanistically, MSC-derived exosomes but not exosomes from tumor cells contain TGF-?, C1q, and semaphorins, which promote myeloid tolerogenic activity by driving PD-L1 overexpression in both immature myelomonocytic precursors and committed CD206+ macrophages and by inducing differentiation of MHC class II+ macrophages with enhanced l-Arginase activity and IL-10 secretion at tumor beds. Accordingly, administration of tumor-associated murine MSC-derived exosomes accelerates tumor growth by dampening antitumor immunity, and macrophage depletion eliminates exosome-dependent differences in malignant progression. Our results unveil a new role for MSC-derived exosomes in the differentiation of myeloid-derived suppressor cells into macrophages, which governs malignant growth.
Project description:<h4>Background</h4>Exosomes mediated crosstalk between tumor cells and other stromal cells including tumor associated macrophages plays an essential role in reprogramming tumor microenvironment (TME) to facilitate tumor progression. However, the mechanism of tumor derived exosomes promotes bladder cancer progression have not been defined.<h4>Methods</h4>Exosomes were extracted from bladder cancer cells MB49 conditioned medium by ultracentrifugation. The effects of MB49-derived exosomes on macrophages polarization were analyzed by qPCR, flow cytometry, and Western blot. The immunosuppressive phenotype and function of MB49-derived exosomes stimulated macrophages were verified by tumor xenograft assays and T cell co-culture experiments. Exosomal miRNAs were analyzed by microarray to identify potential targets regulating macrophage polarization.<h4>Results</h4>MB49-derived exosomes could be ingested by macrophages, consequently promoting macrophages immunosuppressive polarization. Mechanically, the MB49-derived exosomes induced macrophage M2 polarization was mediated by down-regulation of PTEN and activation of AKT/STAT3/6 signaling. Moreover, hindrance of the generation or secretion of exosomes by GW4869 inhibited macrophages differentiation into immunosuppressive phenotype and function, thereby suppressed tumor growth in a mouse subcutaneous tumor model.<h4>Conclusion</h4>Our study confirmed the contribution of bladder cancer derived exosomes on the establishment of immunosuppressive TME and provided a potential therapeutic target for bladder cancer treatment. Video Abstract.
Project description:Pancreatic ductal adenocarcinoma (PDAC) tumor growth is enhanced by tumor-associated macrophages (TAMs), yet the mechanisms by which tumor cells and TAMs communicate are not fully understood. Here we show that exosomes secreted by PDAC cell lines differed in their surface proteins, lipid composition, and efficiency of fusing with THP-1-derived macrophages in vitro. Exosomes from AsPC-1, an ascites-derived human PDAC cell line, were enriched in ICAM-1, which mediated their docking to macrophages through interactions with surface-exposed CD11c on macrophages. AsPC-1 exosomes also contained much higher levels of arachidonic acid (AA), and they fused at a higher rate with THP-1-derived macrophages than did exosomes from other PDAC cell lines or from an immortalized normal pancreatic ductal epithelial cell line (HPDE) H6c7. Phospholipase A2 enzymatic cleavage of arachidonic acid from AsPC-1 exosomes reduced fusion efficiency. PGE2 secretion was elevated in macrophages treated with AsPC-1 exosomes but not in macrophages treated with exosomes from other cell lines, suggesting a functional role for the AsPC-1 exosome-delivered arachidonic acid in macrophages. Non-polarized (M0) macrophages treated with AsPC-1 exosomes had increased levels of surface markers indicative of polarization to an immunosuppressive M2-like phenotype (CD14hi CD163hi CD206hi). Furthermore, macrophages treated with AsPC-1 exosomes had significantly increased secretion of pro-tumoral, bioactive molecules including VEGF, MCP-1, IL-6, IL-1?, MMP-9, and TNF?. Together, these results demonstrate that compared to exosomes from other primary tumor-derived PDAC cell lines, AsPC-1 exosomes alter THP-1-derived macrophage phenotype and function. AsPC-1 exosomes mediate communication between tumor cells and TAMs that contributes to tumor progression.
Project description:<b>Purpose</b>: Exosomes, small extracellular vesicles (EVs) derived from the endocytic compartment of their parent cells, are present in plasma of cancer patients and may serve as non-invasive biomarkers of disease outcome. Here, we asked whether tumor-derived (TEX) and/or T-cell derived exosomes can predict outcome in head and neck squamous cell carcinoma (HNSCC) patients treated with oncological therapy. <b>Materials and Methods</b>: 18 HNSCC patients enrolled in phase I clinical trial and receiving a combination of cetuximab, ipilimumab and radiation therapy were serially monitored for TEX and T cell-derived exosomes. Exosomes isolated from plasma by size exclusion chromatography were fractionated into TEX and CD3 + T cell-derived exosomes by immunocapture. Exosome-associated proteins were quantified by on-bead flow cytometry. Exosome molecular cargos of patients whose tumors recurred within 2 years (N = 5) were compared to cargos of patients who remained disease free at 2 years (N = 13) after therapy. <b>Results</b>: The predictive value of the exosome molecular cargo for disease recurrence was evaluated pre-, during and post therapy. In patients whose disease recurred, total exosome proteins, TEX/total exosome ratios, total CD3+, CD3(-)PD-L1+ and CD3 + 15s+ (Treg-derived) exosomes increased from the baseline levels. In patients who remained disease free, total exosome protein and TEX levels decreased, CD3+ and CD3+ CD15s+ exosomes stabilized and CD3+ CTLA4+ exosomes declined after ipilimumab therapy. <b>Conclusion</b>: TEX and T cell-derived circulating exosomes instead of immune cells were used for monitoring of patients' responses to oncological therapy. The results support the potential role of exosomes as a non-invasive tumor and immune cell biomarkers in cancer.
Project description:Exosomes are nanometer-sized extracellular vesicles that are believed to function as intercellular communicators. Here, we report that exosomes are able to modify the radiation response of the head and neck cancer cell lines BHY and FaDu. Exosomes were isolated from the conditioned medium of irradiated as well as non-irradiated head and neck cancer cells by serial centrifugation. Quantification using NanoSight technology indicated an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response of other cells the exosomes were transferred to non-irradiated and irradiated recipient cells. We found an enhanced uptake of exosomes isolated from both irradiated and non-irradiated cells by irradiated recipient cells compared to non-irradiated recipient cells. Functional analyses by exosome transfer indicated that all exosomes (from non-irradiated and irradiated donor cells) increase the proliferation of non-irradiated recipient cells and the survival of irradiated recipient cells. The survival-promoting effects are more pronounced when exosomes isolated from irradiated compared to non-irradiated donor cells are transferred. A possible mechanism for the increased survival after irradiation could be the increase in DNA double-strand break repair monitored at 6, 8 and 10 h after the transfer of exosomes isolated from irradiated cells. This is abrogated by the destabilization of the exosomes. Our results demonstrate that radiation influences both the abundance and action of exosomes on recipient cells. Exosomes transmit prosurvival effects by promoting the proliferation and radioresistance of head and neck cancer cells. Taken together, this study indicates a functional role of exosomes in the response of tumor cells to radiation exposure within a therapeutic dose range and encourages that exosomes are useful objects of study for a better understanding of tumor radiation response.
Project description:<h4>Background</h4>Tumor-derived exosomes (TEXs) are involved in tumor progression and the immune modulation process and mediate intercellular communication in the tumor microenvironment. Although exosomes are considered promising liquid biomarkers for disease diagnosis, it is difficult to discriminate TEXs and to develop TEX-based predictive biomarkers.<h4>Methods</h4>In this study, the gene expression profiles and clinical information were collected from The Cancer Genome Atlas (TCGA) database, IMvigor210 cohorts, and six independent Gene Expression Omnibus datasets. A TEXs-associated signature named TEXscore was established to predict overall survival in multiple cancer types and in patients undergoing immune checkpoint blockade therapies.<h4>Results</h4>Based on exosome-associated genes, we first constructed a tumor-derived exosome signature named TEXscore using a principal component analysis algorithm. In single-cell RNA-sequencing data analysis, ascending TEXscore was associated with disease progression and poor clinical outcomes. In the TCGA Pan-Cancer cohort, TEXscore was elevated in tumor samples rather than in normal tissues, thereby serving as a reliable biomarker to distinguish cancer from non-cancer sources. Moreover, high TEXscore was associated with shorter overall survival across 12 cancer types. TEXscore showed great potential in predicting immunotherapy response in melanoma, urothelial cancer, and renal cancer. The immunosuppressive microenvironment characterized by macrophages, cancer-associated fibroblasts, and myeloid-derived suppressor cells was associated with high TEXscore in the TCGA and immunotherapy cohorts. Besides, TEXscore-associated miRNAs and gene mutations were also identified. Further experimental research will facilitate the extending of TEXscore in tumor-associated exosomes.<h4>Conclusions</h4>TEXscore capturing tumor-derived exosome features might be a robust biomarker for prognosis and treatment responses in independent cohorts.
Project description:Plasma-derived exosomes of head and neck squamous cell carcinoma (HNSCC) patients carry inhibitory factors mediating immune suppression. Separation of tumor-derived exosomes (TEX) and non-TEX may assist in a better understanding of their respective parental cells. Here, we evaluate the impact of TEX or hematopoietic-derived exosomes on immune suppression. We evaluated apoptosis in CD8+ T cells, conversion of CD4+ T cells to regulatory T cells (Treg), and adenosine production by TEX, non-TEX, or total exosomes. Exosome protein cargo was significantly higher in total and CD45(-) exosomes from high stage compared to low stage patients. Furthermore, total and CD45(-) exosomes of high stage patients induced more apoptosis in CD8+ T cells than their low stage counterparts. CD69 suppression, a marker of reduced CD8+ T cell activation, was only mediated by CD45(-) exosomes. All fractions induced Treg differentiation, defined by CD39 expression, but only CD45(-) exosomes showed a stage-dependent conversion. CD45(-) exosomes produced higher adenosine concentrations than CD45(+) exosomes, concluding that adenosine production measured in total exosomes mainly derives from TEX. The presented results show significant induction of immune suppression by TEX in HNSCC. This immunosuppressive effect supports the potential role of exosomes as liquid biomarkers for disease stage and level of immune suppression.