New roles of tumor-derived exosomes in tumor microenvironment

Throughout tumorigenesis, the co-evolution of tumor cells and their surrounding microenvironment leads to the development of malignant phenotypes. Cellular communication within the tumor microenvironment(TME) plays a critical role in influencing various aspects of tumor progression, including invasion and metastasis. The release of exosomes, a type of extracellular vesicle, by most cell types in the body, is an essential mediator of intercellular communication. A growing body of research indicates that tumor-derived exosomes(TDEs) significantly expedite tumor progression through multiple mechanisms, inducing epithelial-mesenchymal transition and macrophage polarization, enhancing angiogenesis, and aiding in the immune evasion of tumor cells. Herein, we describe the formation and characteristics of the TME, and summarize the contents of TDEs and their diverse functions in modulating tumor development. Furthermore, we explore potential applications of TDEs in tumor diagnosis and treatment.

Epigenetic changes of pituitary tumor-derived transforming gene 1 in pancreatic cancer

BACKGROUND: Pancreatic cancer is a devastating disease with abnormal genetic changes. The pituitary tumor-derived transforming gene (PTTG) is considered to be implicated in the tumorigenesis of cancers when the gene is epigenetically transformed. In this study, we investigated the relationships between aberrant expression and epigenetic changes of the PTTG1 gene in pancreatic cancer. METHODS: We chose 4 cell lines (PANC-1, Colo357, T3M-4 and PancTu I) and pancreatic ductal adenocarcinoma (PDAC) tissues. After using restriction isoschizomer endonucleases (Msp I /Hpa II) to digest the DNA sequence (5'-CCGG-3'), we performed PCR reaction to amplify the product. And RT-PCR was applied to determine the gene expression. RESULTS: The mRNA expression of the PTTG1 gene was higher in pancreatic tumor than in normal tissue. The gene was also expressed in the 4 PDAC cell lines. The methylation states of the upstream regions of the PTTG1 gene were almost identical in normal, tumor pancreatic tissues and the 4 PDAC cell lines. Some (5'-CCGG-3') areas in the upstream region of PTTG1 were methylated, while some others were unmethylated. CONCLUSIONS: The oncogene PTTG1 was overexpressed in pancreatic tumor tissues and verified by RT-PCR detection. The methylation status of DNA in promoter areas was involved in the gene expression with the help of other factors in pancreatic cancer.

Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of CD19-specific CAR T-cells via TGF-βsignaling

Tumor-derived exosomes (TEXs) enriched in immune suppressive molecules predominantly drive T-cell dysfunction and impair antitumor immunity. Chimeric antigen receptor (CAR) T-cell therapy has emerged as a promising treatment for refractory and relapsed hematological malignancies, but whether lymphoma TEXs have the same impact on CAR T-cell remains unclear. Here, we demonstrated that B-cell lymphoma-derived exosomes induce the initial activation of CD19-CAR T-cells upon stimulation with exosomal CD19. However, lymphoma TEXs might subsequently induce CAR T-cell apoptosis and impair the tumor cytotoxicity of the cells because of the upregulated expression of the inhibitory receptors PD-1, TIM3, and LAG3 upon prolonged exposure. Similar results were observed in the CAR T-cells exposed to plasma exosomes from patients with lymphoma. More importantly, single-cell RNA sequencing revealed that CAR T-cells typically showed differentiated phenotypes and regulatory T-cell (Treg) phenotype conversion. By blocking transforming growth factor β (TGF-β)-Smad3 signaling with TGF-β inhibitor LY2109761, the negative effects of TEXs on Treg conversion, terminal differentiation, and immune checkpoint expression were rescued. Collectively, although TEXs lead to the initial activation of CAR T-cells, the effect of TEXs suppressed CAR T-cells, which can be rescued by LY2109761. A treatment regimen combining CAR T-cell therapy and TGF-β inhibitors might be a novel therapeutic strategy for refractory and relapsed B-cell lymphoma.

Tumor-derived exosomes:Nanovesicles made by cancer cells to promote cancer metastasis

Nanomedicine usually refers to nanoparticles that deliver the functional drugs and siRNAs to treat cancer.Recent research has suggested that cancer cells can also make nanoparticles that also deliver functional molecules in promoting cancer metastasis,which is the leading cause of various cancer mortalities.This nanoparticle is called tumor-derived vesicles,or better-known as tumor-derived exosomes(TEXs).TEXs are nanoscale membrane vesicles(30 e140 nm)that are released continuously by various types of cancer cells and contain tumor-derived functional biomolecules,including lipids,proteins,and genetic molecules.These endogenous TEXs can interact with host immune cells and epithelial cells locally and systemically.More importantly,they can reprogram the recipient cells in favor of promoting metastasis through facilitating tumor cell local invasion,intravasation,immune evasion,extravasation,and survival and growth in distant organs.Growing evidence suggests that TEXs play a key role in cancer metastasis.Here,we will review the most recent findings of how cancer cells harness TEXs to promote cancer metastasis through modulating vascular permeability,suppressing systemic immune surveillance,and creating metastatic niches.We will also summarize recent research in targeting TEXs to treat cancer metastasis.

Tumor-derived exosomes:immune properties and clinical application in lung cancer

Lung cancer is the leading cause of cancer-related death worldwide.Despite advances in diagnosis and treatment of lung cancer,the overall survival remains poor.Evidence indicates that lung cancer development is a complex and dynamic process that involves interactions between tumor cells and their microenvironments,including immune cells.Exosomes are small extracellular vesicles secreted by most cell types;they contain functional molecules that allow intercellular communication.Tumor-derived exosomes(TEXs)carry both immunosuppressive and immunostimulatory mediators and may be involved in various immunomodulatory effects.TEXs,which partially mimic profiles of the parent cells,are a potential source of cancer biomarkers for prognosis,diagnosis,and prediction of response to therapy.In addition,TEXs may interfere with immunotherapies,but they also could be used as adjuvants and antigenic components in vaccines against lung cancer.In the context of lung cancer,identifying TEXs and understanding their contribution to tumorigenesis and the response to immunotherapies represents a challenging research area.

Effect of Diallyl Trisulfide on the Activation of T Cell and Macrophage－mediated Cytotoxicity

At high concentration (50 μg/ml), diallyl trisulfide (DATS) had an inhibitory effect on T cell activation (compared with control group, P<0.05). But at appropriate concentrations(3.125-12. 5 μg/ml). DATS augmented the activation of T lymphocytes by Con A (compared with control group, P<0. 01). The augmentation of T cell activation by DATS was related to its inhibitory effect on the production of nitric oxide (NO) by macrophages.In a wide range of concentrations (1-100 μg/ml) , DATS can inhibit the production of NO by macrophas,es (P<0.05,P<0.01). In addition, DATS can antagonize the inhibition of tumor-derived immunosuppressive factors produced by S180 cells and Ehrlich ascitic cancer cells on the activation of T cells, and reduce the inhibitory rate significantly (P<0.01). DATS, despite its inhibition of the production of NO by macrophages, can significantly enhance the production of hydrogen peroxide (H2O2 by macrophages.When macrophages were pretreated with DATS for 24 h, the cytotoxicity % of macrophages to three tumor cell lines was significantly higher than that in corresponding control group (P<0.05,P<0.01). In the presence of both DATS and LPS, the cytotoxicity of macrophages was further enhanced so that the cytotoxicity % of macrophages to tumor cells was significantly higher than either that in the presence of DAIS alone or that in the presence of LPS alone(P<0.05, P<0.01). These results indicate that DATS can augment the activation of T cells and enhance the anti-tumor function of macrophage, suggesting that DATS may be potentially useful in tumor therapy.

Dendritic cell subsets in cancer immunity and tumor antigen sensing

Dendritic cells(DCs)exhibit a specialized antigen-presenting function and play crucial roles in both innate and adaptive immune responses.Due to their ability to cross-present tumor cell-associated antigens to naïve T cells,DCs are instrumental in the generation of specific T-cell-mediated antitumor effector responses in the control of tumor growth and tumor cell dissemination.Within an immunosuppressive tumor microenvironment,DC antitumor functions can,however,be severely impaired.In this review,we focus on the mechanisms of DC capture and activation by tumor cell antigens and the role of the tumor microenvironment in shaping DC functions,taking advantage of recent studies showing the phenotype acquisition,transcriptional state and functional programs revealed by scRNA-seq analysis.The therapeutic potential of DC-mediated tumor antigen sensing in priming antitumor immunity is also discussed.

Glioblastoma cell-derived exosomes functionalized with peptides as efficient nanocarriers for synergistic chemotherapy of glioblastoma with improved biosafety

Glioblastoma(GBM)has been regarded as one of the most deadly and challenging cancers to treat with extremely poor prognosis.The limited efficacy of current chemotherapies might be attributed to the presence of glioma stem cells(GSCs)as well as the difficulties in passing through the blood–brain barrier(BBB)and targeting tumor cells.Tumor-derived exosomes are emerging as novel and promising drug delivery systems.However,great concerns regarding the biosafety and BBB penetrability remain to be addressed.Herein,we have developed a simple and feasible strategy to engineer GBM cell-derived exosomes with improved biosafety termed“Exo@TDPs”to deliver the cargos of chemotherapeutic agents temozolomide(TMZ)and doxorubicin(DOX)into GBM tissues.Exo@TDPs decorated with angiopep-2(Ang-2)and CD133-targeted peptides improve the capacity to penetrate the BBB and target tumor cells.Both in vitro and in vivo studies demonstrate that Exo@TDPs can cross the BBB,target GBM cells,penetrate into deep tumor parenchyma,and release the therapeutic cargos effectively.Synergistic delivery of TMZ and DOX by Exo@TDPs exerts therapeutic effects to suppress the tumor growth and prolong the survival time of orthotopic syngeneic mouse GBM models.These findings suggest that our developed Exo@TDPs loaded with chemotherapeutic drugs may bring new possibilities for the application of tumor cell-derived exosomes for brain tumor treatment.

Repurposing vitamin D for treatment of human malignancies via targeting tumor microenvironment

Tumor cells along with a small proportion of cancer stem cells exist in a stromal microenvironment consisting of vasculature, cancer-associated fibroblasts, immune cells and extracellular components.Recent epidemiological and clinical studies strongly support that vitamin D supplementation is associated with reduced cancer risk and favorable prognosis. Experimental results suggest that vitamin D not only suppresses cancer cells, but also regulates tumor microenvironment to facilitate tumor repression. In this review, we have outlined the current knowledge on epidemiological studies and clinical trials of vitamin D. Notably, wesummarized and discussed the anticancer action of vitamin D in cancer cells, cancer stem cells and stroma cells in tumor microenvironment, providing a better understanding of the role of vitamin D in cancer. We presently re-propose vitamin D to be a novel and economical anticancer agent.

Cholangiocarcinoma-derived exosomes inhibit the antitumor activity of cytokine-induced killer cells by down-regulating the secretion of tumor necrosis factor-α and perforin

Objective： The aim of our study is to observe the impact of cholangiocarcinoma-derived exosomes on the antitumor activities of cytokine-induced killer （CIK） cells and then demonstrate the appropriate mechanism. Methods： Tumor-derived exosomes （TEXs）, which are derived from RBE cells （human cholangiocarcinoma line）, were collected by ultracentrifugation. CIK cells induced from peripheral blood were stimulated by TEXs. Fluorescence-activated cell sorting （FACS） was performed to determine the phenotypes of TEX-CIK and N-CIK （normal CIK） cells. The concen- trations of tumor necrosis factor-a （TNF-a） and perforin in the culture medium supematant were examined by using an enzyme-linked immunosorbent assay （ELISA） kit. A CCK-8 kit was used to evaluate the cytotoxic activity of the CIK cells to the RBE cell line. Results： The concentrations of TNF-a and perforin of the group TEX-CIK were 138.61 pg/ml and 2.41 ng/ml, respectively, lower than those of the group N-CIK 194.08 pg/ml （P〈0.01） and 3.39 ng/ml （P〈0.05）. The killing rate of the group TEX-CIK was 33.35%, lower than that of the group N-CIK （47,35% （P〈0.01））. The population of CD3＋, CD8＋, NK （CD56＋）, and CD3＋CD56＋ cells decreased in the TEX-CIK group （63.2±6.8）%, （2.5±1.0）%, （0.53±0.49）%, （0.45±0.42）%） compared with the N-CIK group （（90.3±7.3）%, （65.7±3.3）%, （4.2±1.2）%, （15.2±2.7）%）, P〈0.01. Conclusions： Our results suggest that RBE cells-derived exosomes inhibit the antitumor activity of CIK cells by down-regulating the population of CD3＋, CD8＋, NK （CD56＋）, and CD3＋CD56＋ cells and the secretion of TNF-a and perforin. TEX may play an important role in cholangiocarcinoma immune escape.

Hyperthermia based individual in situ recombinant vaccine enhances lymph nodes drainage for de novo antitumor immunity

The continuing challenges that limit effectiveness of tumor therapeutic vaccines were high heterogeneity of tumor immunogenicity, low bioactivity of antigens, as well as insufficient lymph nodes(LNs) drainage of antigens and adjuvants. Transportation of in situ neoantigens and adjuvants to LNs may be an effective approach to solve the abovementioned problems. Therefore, an FA-TSL/AuNCs/SV nanoplatform was constructed by integrating simvastatin(SV) adjuvant loaded Au nanocages(AuNCs)as cores(AuNCs/SV) and folic acid modified thermal-sensitive liposomes(FA-TSL) as shells to enhance de novo antitumor immunity. After accumulation in tumor guided by FA, AuNCs mediated photothermal therapy(PTT) induced the release of tumor-derived protein antigens(TDPAs) and the shedding of FATSL. Exposed AuNCs/SV soon captured TDPAs to form in situ recombinant vaccine(AuNCs/SV/TDPAs). Subsequently, AuNCs/SV/TDPAs could efficiently transport to draining LNs owing to the hyperthermia induced vasodilation effect and small particle size, achieving co-delivery of antigens and adjuvant for initiation of specific T cell response. In melanoma bearing mice, FA-TSL/AuNCs/SV and laser irradiation effectively ablated primary tumor, against metastatic tumors and induced immunological memory. This approach served a hyperthermia enhanced platform drainage to enable robust personalized cancer vaccination.

Exosomes as a promising diagnostic tool in head and neck squamous cell carcinoma?

Head and neck squamous cell carcinoma(HNSCC)is the 6th most frequently diagnosed malignancy and accounts for about 5%of all malignancies worldwide.There is a lack of biomarkers to monitor the status and progress of the disease.Therefore,it is of great importance to develop non-invasive diagnostic tools such as exosomes that monitor tumor changes and provide molecular information about the malignancy to identify the metastatic disease earlier and allow better therapeutic management.Thus,we aimed to review whether tumor-derived exosomes can predict disease progression in HNSCC and if and especially how they can be used as a diagnostic tool.