Regulation of Macrophage Activation and Polarization by HCC-Derived Exosomal lncRNA TUC339. Int J Mol Sci. 2018;19. [PMID: 30274167 PMCID: PMC6213212 DOI: 10.3390/ijms19102958]

Tumor immune microenvironment lncRNAs

Long non-coding ribonucleic acids (RNAs) (lncRNAs) are key players in tumorigenesis and immune responses. The nature of their cell type-specific gene expression and other functional evidence support the idea that lncRNAs have distinct cellular functions in the tumor immune microenvironment (TIME). To date, the majority of lncRNA studies have heavily relied on bulk RNA-sequencing data in which various cell types contribute to an averaged signal, limiting the discovery of cell type-specific lncRNA functions. Single-cell RNA-sequencing (scRNA-seq) is a potential solution for tackling this limitation despite the lack of annotations for low abundance yet cell type-specific lncRNAs. Hence, updated annotations and further understanding of the cellular expression of lncRNAs will be necessary for characterizing cell type-specific functions of lncRNA genes in the TIME. In this review, we discuss lncRNAs that are specifically expressed in tumor and immune cells, summarize the regulatory functions of the lncRNAs at the cell type level and highlight how a scRNA-seq approach can help to study the cell type-specific functions of TIME lncRNAs.

Identification of hepatocellular carcinoma-related genes associated with macrophage differentiation based on bioinformatics analyses

Macrophage differentiation is associated with tumorigenesis, including the tumorigenesis of hepatocellular carcinoma (HCC). Herein, we explored the value of macrophage differentiation-associated genes (MDGs) in the prognosis of HCC using data from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) databases. We performed multivariate Cox regression analyses to identify the hub genes affecting HCC patient prognoses. The correlations between hub genes and macrophage differentiation and immune checkpoint inhibitors (PD-1, PD-L1, and CTLA4) were investigated. Finally, the potential mechanism was examined with gene set enrichment analysis (GSEA). In total, seventeen differentially expressed MDGs were obtained after intersecting data from the two databases. Multivariate analysis indicated that CDC42 expression was an independent prognostic indicator in both databases. Furthermore, CDC42 showed a strong correlation with the tumor infiltration levels of immune cells in HCC tissue. Correlation analysis revealed that CDC42 expression was positively associated with M2 macrophage markers and immune checkpoint inhibitors, which indicated that CDC42 expression might be related to M2 macrophage differentiation and HCC cell immune tolerance. Finally, GSEA showed that CDC42 expression was most significantly related to the Wnt signaling pathway. In conclusion, this study showed that CDC42 expression might be an important MDG in HCC and may prove to be a new gene for studying macrophage differentiation in HCC. Abbreviations: HCC: hepatocellular carcinoma; TCGA: The Cancer Genome Atlas; ICGC: International Cancer Genome Consortium; GSEA: gene set enrichment analysis; GO: Gene Ontology; KEGG: Kyoto Encyclopedia of Genes and Genomes; ROC: receiver operating characteristic; K-M: Kaplan-Meier; AUC: the area under the ROC curve; TNM: Tumor size/lymph nodes/distance metastasis.

Long Non-Coding RNAs (lncRNAs) in Response and Resistance to Cancer Immunosurveillance and Immunotherapy

Long non-coding RNAs (lncRNAs) are critical regulatory elements in cellular functions in states of both normalcy and disease, including cancer. LncRNAs can influence not only tumorigenesis but also cancer features such as metastasis, angiogenesis and resistance to chemo-and immune-mediated apoptotic signals. Several lncRNAs have been demonstrated to control directly or indirectly the number, type and activities of distinct immune cell populations of adaptive and innate immunities within and without the tumor microenvironment. The disruption of lncRNA expression in both cancer and immune cells may reflect alterations in tumor responses to cancer immunosurveillance and immunotherapy, thus providing new insights into lncRNA biomarker-based prognostic and therapeutic cancer assessment. Here we present an overview on lncRNAs’ functions and underlying molecular mechanisms related to cancer immunity and conventional immunotherapy, with the expectation that any elucidations may lead to a better understanding and management of cancer immune escape and response to current and future immunotherapeutics.

The role of exosomal lncRNAs in cancer biology and clinical management

Exosomes play a vital role in cell–cell communication within the cancer microenvironment. Exosomal long noncoding RNAs (lncRNAs) are important regulators in cancer development and are involved in multiple processes, including cancer cell proliferation, angiogenesis, metastasis, drug resistance, and immunomodulation. Changes in the levels of exosomal lncRNAs often appear with the occurrence and development of cancer. Therefore, exosomal lncRNAs can be used as biomarkers for cancer diagnosis and prognosis. Exosomal lncRNAs can also indicate the treatment response of patients receiving chemotherapy. Moreover, exosomal lncRNAs are potential therapeutic targets for cancer treatment. In this review, we summarize the role of exosomal lncRNAs in cancer biology as well as in clinical management. A more comprehensive and in-depth understanding of the role of exosomal lncRNAs in cancer may help us better understand the mechanism of cancer development and clinically manage cancer patients.

Cancer cells routinely release tiny membrane vesicles laden with RNAs that help promote tumor progression, but which could also offer useful biomarkers for diagnosis and reveal new drug targets. Many cells secrete such vesicles, known as exosomes, as a mode of intercellular communication. Researchers led by Tongbao Feng at Nanjing Medical University, Changzhou, China, have reviewed the evidence linking exosome-borne RNAs to tumor cell function. The authors focus on a class of molecules known as ‘long noncoding RNAs’ (lncRNAs), and show that exosomal lncRNAs are relayed as messages between tumor cells, promoting proliferation, metastatic spread, and acquisition of drug resistance. These RNAs can therefore also offer a useful window into the progress of disease and interventions that block such exosomally transmitted messages, and could potentially inhibit malignant growth and spread.

Roles and mechanisms of exosomal non-coding RNAs in human health and diseases

Exosomes play a role as mediators of cell-to-cell communication, thus exhibiting pleiotropic activities to homeostasis regulation. Exosomal non-coding RNAs (ncRNAs), mainly microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are closely related to a variety of biological and functional aspects of human health. When the exosomal ncRNAs undergo tissue-specific changes due to diverse internal or external disorders, they can cause tissue dysfunction, aging, and diseases. In this review, we comprehensively discuss the underlying regulatory mechanisms of exosomes in human diseases. In addition, we explore the current knowledge on the roles of exosomal miRNAs, lncRNAs, and circRNAs in human health and diseases, including cancers, metabolic diseases, neurodegenerative diseases, cardiovascular diseases, autoimmune diseases, and infectious diseases, to determine their potential implication in biomarker identification and therapeutic exploration.

A novel immune-related ceRNA network that predicts prognosis and immunotherapy response in lung adenocarcinoma

Background

The tumor microenvironment plays an important role in the progression and malignancy of lung adenocarcinoma and affects the immunotherapy response. There is increasing evidence that long non-coding RNAs (lncRNAs) as competing endogenous RNAs (ceRNAs) have significant functions in the development and treatment response of various kinds of cancer. This study aimed to explore the association between immune-related lncRNA-microRNA (miRNA)-messenger RNA (mRNA)-ceRNA networks, and the prognosis of and immunotherapy response in lung adenocarcinoma.

Methods

RNA-sequencing (RNA-seq) and miRNA-seq data from The Cancer Genome Atlas (TCGA) were used to evaluate the infiltration of immune cells in lung adenocarcinoma samples by undertaking a single-sample gene set enrichment analysis (ssGSEA) to divide the cells into high and low immune cell infiltration groups. The differentially expressed mRNA (DEmRNA) was further analyzed by a weighted gene co-expression network analysis (WGCNA), search tool for recurring instances of neighboring genes (STRING), and Cytoscape to select hub genes. The ceRNA network was constructed using Cytoscape. Additionally, survival analyses were conducted to screen out prognostic candidate genes.

Results

Seven thousand five hundred and thirty-eight mRNAs, 540 lncRNAs, and 138 miRNAs were found to be differentially expressed between the high and low immune cell infiltration groups. The two DEmRNA modules most significantly associated with immune cell infiltration were further analyzed, and four clusters, including 179 DEmRNAs, were selected based on Molecular Complex Detection (MCODE) scores. The selected DEmRNAs in the four clusters were mainly enriched in pathways involved in regulating the immune response. Ultimately, a ceRNA network of SNHG6-hsa-miR-30e-5p-CYSLTR1 was identified as being associated with the prognosis of and immunotherapy response in lung adenocarcinoma.

Conclusions

The present study extends understandings of immune-related lncRNA-miRNA-mRNA-ceRNA networks and identifies novel targets and a regulatory pathway for anti-tumor immunotherapy.

Exosome-Mediated Crosstalk Between Tumor and Tumor-Associated Macrophages

Exosomes are nanosized vesicles, derived from the endolysosomal compartment of cells and can shuttle diverse biomolecules such as nucleic acids, proteins, lipids, amino acids, and metabolites, which can reflect their origin cells. Delivery of these cargoes to recipient cells enables exosomes to influence diverse cellular functions. As one of the most abundant immune cells in the tumor microenvironment, tumor-associated macrophages (TAMs) are educated by the tumor milieu, which is rich in cancer cells and stroma components, to exert functions such as the promotion of tumor growth, immunosuppression, angiogenesis, and cancer cell dissemination. Herein, we focus on exosomes-mediated intercellular communication between tumor cells and TAM in the tumor microenvironment, which may provide new targets for anti-tumor treatment. In this review, we highlight the most recent studies on the effect of tumor/macrophage-derived exosomes on macrophage/tumor function in different cancer types.

Tumor-Derived Extracellular Vesicles: A Means of Co-opting Macrophage Polarization in the Tumor Microenvironment

Extracellular vesicles (EVs) are a heterogeneous population of membrane-bound parcels of bioactive proteins, nucleic acids, and lipids released from almost all cell types. The diversity of cargo packaged into EVs proffer the induction of an array of effects on recipient cells. EVs released from tumor cells have emerged as a vital means of communication and immune modulation within the tumor microenvironment (TME). Macrophages are an important contributor to the TME with seemingly paradoxical roles promoting either pro- or anti-tumoral immune function depending on their activated phenotypes. Here, we discuss the influence of tumor-derived extracellular vesicles on the functional plasticity of macrophages in tumor progression.

Diverse roles of EV-RNA in cancer progression

Extracellular vesicles (EVs) have emerged as important players in all aspects of cancer biology. Their function is mediated by their cargo and surface molecules including proteins, lipids, sugars and nucleic acids. RNA in particular is a key mediator of EV function both in normal and cancer cells. This statement is supported by several lines of evidence. First, cells do not always randomly load RNA in EVs, there seems to be a specific manner in which cells populate their EVs with certain RNA molecules. Moreover, cellular uptake of EV-RNA and the secondary compartmentalization of EV-RNA in recipient cells is widely reported, and these RNAs have an impact on all aspects of cancer growth and the anti-tumoral immune response. Additionally, EV-RNA seems to work through various mechanisms of action, highlighting the intricacies of EVs and their RNA cargo as prominent means of inter-cellular communication.

The Role of Long Non-Coding RNA and microRNA Networks in Hepatocellular Carcinoma and Its Tumor Microenvironment

Hepatocellular carcinoma (HCC) is a common liver malignancy with high morbidity and poor prognosis. Long non-coding RNAs (lncRNAs) are involved in crucial biological processes of tumorigenesis and progression, and play four major regulatory roles, namely signal, decoy, guide, and scaffold, to regulate gene expression. Through these processes, lncRNAs can target microRNAs (miRNAs) to form lncRNA and miRNA networks, which regulate cancer cell proliferation, metastasis, drug resistance, and the tumor microenvironment. Here, we summarize the multifaceted functions of lncRNA and miRNA networks in the pathogenesis of HCC, the potential use of diagnostic or prognostic biomarkers, and novel therapeutic targets in HCC. This review also highlights the regulatory effects of lncRNA and miRNA networks in the tumor microenvironment of HCC.

LncRNA RP11-465B22.8 triggers esophageal cancer progression by targeting miR-765/KLK4 axis

LncRNAs play an important role in tumorigenesis and progression; however, the function and mechanisms of lncRNAs in esophageal cancer (EC) remain largely unclear. In this study, we screened the differentially expressed lncRNAs in EC by using RNA-seq and one of the most upregulated lncRNAs, lncRNA RP11-465B22.8, was further characterized. LncRNA RP11-465B22.8 was upregulated in EC tissues and high lncRNA RP11-465B22.8 expression was associated with poor survival of EC patients. Ectopic expression of lncRNA RP11-465B22.8 enhanced the proliferation, migration, and invasion of EC cells, whereas knockdown of lncRNA RP11-465B22.8 led to the opposite effects. Mechanistically, lncRNA RP11-465B22.8 sponged miR-765 to increase the expression of KLK4. Moreover, LncRNA RP11-465B22.8 could be delivered from EC cells to macrophages via exosomes and subsequently induced M2 macrophage-induced cell migration and invasion. Our findings revealed a novel lncRNA RP11-465B22.8/miR-765/KLK4 pathway in EC and indicated that lncRNA RP11-465B22.8 might be a potential target for EC therapy.

New insights into exosome mediated tumor-immune escape: Clinical perspectives and therapeutic strategies

Recent advances in extracellular vesicle biology have uncovered a substantial role in maintaining cell homeostasis in health and disease conditions by mediating intercellular communication, thus catching the scientific community's attention worldwide. Extracellular microvesicles, some called exosomes, functionally transfer biomolecules such as proteins and non-coding RNAs from one cell to another, influencing the local environment's biology. Although numerous advancements have been made in treating cancer patients with immune therapy, controlling the disease remains a challenge in the clinic due to tumor-driven interference with the immune response and inability of immune cells to clear cancer cells from the body. The present review article discusses the recent findings and knowledge gaps related to the role of exosomes derived from tumors and the tumor microenvironment cells in tumor escape from immunosurveillance. Further, we highlight examples where exosomal non-coding RNAs influence immune cells' response within the tumor microenvironment and favor tumor growth and progression. Therefore, exosomes can be used as a therapeutic target for the treatment of human cancers.

Exosomal non-coding RNAs in Hepatobiliary Cancer: A Rising Star

Hepatobiliary cancers are a heterogeneous group of malignancies with a dismal prognosis. Despite intensive research efforts focused on these tumors, methods for early diagnosis and effective targeted therapies are still lacking. Exosomes, released by most cells, exist in all kinds of body fluids and play an important role in cell-to-cell communication. They are small membranous vesicles containing biological molecules, such as noncoding RNAs (ncRNAs), which are not translated into proteins, but they exert effects on the regulation of gene transcription and translation. There is growing evidence for the essential roles of ncRNAs in exosomes in both physiological and pathological conditions of hepatobiliary cancers. They have been identified as sensitive diagnostic biomarkers as well as potential therapeutic targets. The present review discusses recent findings in the crosstalk between hepatobiliary cancers cells and the surrounding cells of the microenvironment and discuss their potential clinical usage.

Prognostic Impact of MITD1 and Associates With Immune Infiltration in Kidney Renal Clear Cell Carcinoma

Kidney renal clear cell carcinoma (KIRC) is one of the most malignant diseases with poor survival rate over the world. The tumor microenvironment (TME) is highly related to the oncogenesis, development, and prognosis of KIRC. Thus, making the identification of KIRC biomarkers and immune infiltrates critically important. Microtubule Interacting and Trafficking Domain containing 1(MITD1) was reported to participate in cytokinesis of cell division. In the present study, multiple bioinformatics tools and databases were applied to investigate the expression level and clinical value of MITD1 in KIRC. We found that the expression of MITD1 was significantly increased in KIRC tissues. Further, the KIRC patients with high MITD1 levels showed a worse overall survival (OS) rate and disease free survival (DFS) rate. Otherwise, we found a significant correlation MITD1 expression and the abundance of CD8+ T cells. Functional enrichment analyses revealed that immune response and cytokine-cytokine receptor are very critical signaling pathways which associated with MITD1 in KIRC. In conclusion, our findings indicated that MITD1 may be a potential biomarker and associated with immune infiltration in KIRC.

An immunotherapeutic approach to decipher the role of long non-coding RNAs in cancer progression, resistance and epigenetic regulation of immune cells

Immunotherapeutic treatments are gaining attention due to their effective anti-tumor response. Particularly, the revolution of immune checkpoint inhibitors (ICIs) produces promising outcomes for various cancer types. However, the usage of immunotherapy is limited due to its low response rate, suggesting that tumor cells escape the immune surveillance. Rapid advances in transcriptomic profiling have led to recognize immune-related long non-coding RNAs (LncRNAs), as regulators of immune cell-specific gene expression that mediates immune stimulatory as well as suppression of immune response, indicating LncRNAs as targets to improve the efficacy of immunotherapy against tumours. Moreover, the immune-related LncRNAs acting as epigenetic modifiers are also under deep investigation. Thus, herein, is a summarised knowledge of LncRNAs and their regulation in the adaptive and innate immune system, considering their importance in autophagy and predicting putative immunotherapeutic responses.

Tumor-Associated Macrophages in Hepatocellular Carcinoma: Friend or Foe?

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, and it has diverse etiologies with multiple mechanisms. The diagnosis of HCC typically occurs at advanced stages when there are limited therapeutic options. Hepatocarcinogenesis is considered a multistep process, and hepatic macrophages play a critical role in the inflammatory process leading to HCC. Emerging evidence has shown that tumor-associated macrophages (TAMs) are crucial components defining the HCC immune microenvironment and represent an appealing option for disrupting the formation and development of HCC. In this review, we summarize the current knowledge of the polarization and function of TAMs in the pathogenesis of HCC, as well as the mechanisms underlying TAM-related anti-HCC therapies. Eventually, novel insights into these important aspects of TAMs and their roles in the HCC microenvironment might lead to promising TAM-focused therapeutic strategies for HCC.

Exosomal long non-coding RNA SOX2 overlapping transcript enhances the resistance to EGFR-TKIs in non-small cell lung cancer cell line H1975

Crosstalk between cancer cells and macrophages plays a crucial role in the development of cancer. In this study, our data showed that M1 macrophages attenuate, while M2 macrophages and tumor-associated macrophages enhance the EGFR-TKIs resistance in non-small cell lung cancer (NSCLC) cell line H1975. Next, long non-coding RNA SOX2 overlapping transcript (SOX2-OT) is highly expressed in NSCLC cells-derived exosomes. NSCLC cells-derived exosomes promote macrophages M2 polarization and inhibit M1 polarization through transferring SOX2-OT to macrophages. Subsequently, our results indicated that NSCLC cells-induced M2-polarized macrophages enhance the EGFR-TKIs resistance in H1975 cells. Furthermore, our data revealed that NSCLC cells-derived exosomes inhibit the expression of miR-627-3p, while promote Smads expression in THP-1 cells. SOX2-OT acts as miR-627-3p sponge to facilitate Smad2, Smad3 and Smad4 expression. Finally, our results indicated that NSCLC cells promote macrophages M2 polarization and suppress M1 polarization through targeting miR-627-3p/Smads signaling pathway by transferring exosomes to THP-1 cells. In conclusion, our data revealed that NSCLC cells promote macrophages M2 polarization through transferring exosomal SOX2-OT, thus to enhance its own EGFR-TKIs resistance. Mechanismly, NSCLC cells-derived exosomal SOX2-OT promotes macrophages M2 polarization via promoting Smads by sponging miR-627-3p. Our data provide a novel therapeutic target for EGFR-TKIs resistance in NSCLC.

The Emerging Role of Exosomes in the Treatment of Human Disorders With a Special Focus on Mesenchymal Stem Cells-Derived Exosomes

Extracellular vesicles (EVs) are produced by diverse eukaryotic and prokaryotic cells. They have prominent roles in the modulation of cell-cell communication, inflammation versus immunomodulation, carcinogenic processes, cell proliferation and differentiation, and tissue regeneration. These acellular vesicles are more promising than cellular methods because of the lower risk of tumor formation, autoimmune responses and toxic effects compared with cell therapy. Moreover, the small size and lower complexity of these vesicles compared with cells have made their production and storage easier than cellular methods. Exosomes originated from mesenchymal stem cells has also been introduced as therapeutic option for a number of human diseases. The current review aims at summarization of the role of EVs in the regenerative medicine with a focus on their therapeutic impacts in liver fibrosis, lung disorders, osteoarthritis, colitis, myocardial injury, spinal cord injury and retinal injury.

Long Non-Coding RNAs in the Tumor Immune Microenvironment: Biological Properties and Therapeutic Potential

Cancer immunotherapy (CIT) is considered a revolutionary advance in the fight against cancer. The complexity of the immune microenvironment determines the success or failure of CIT. Long non-coding RNA (lncRNA) is an extremely versatile molecule that can interact with RNA, DNA, or proteins to promote or inhibit the expression of protein-coding genes. LncRNAs are expressed in many different types of immune cells and regulate both innate and adaptive immunity. Recent studies have shown that the discovery of lncRNAs provides a novel perspective for studying the regulation of the tumor immune microenvironment (TIME). Tumor cells and the associated microenvironment can change to escape recognition and elimination by the immune system. LncRNA induces the formation of an immunosuppressive microenvironment through related pathways, thereby controlling the escape of tumors from immune surveillance and promoting the development of metastasis and drug resistance. Using lncRNA as a therapeutic target provides a strategy for studying and improving the efficacy of immunotherapy.

The Role of Extracellular Vesicles in Disease Progression and Detection of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and one of the leading causes of cancer-related death worldwide. Despite the improvements in surveillance and treatment, the prognosis of HCC remains poor. Extracellular vesicles (EVs) are a heterogeneous group of phospholipid bilayer-enclosed particles circulating in the bloodstream and mediating intercellular communication. Emerging studies have shown that EVs play a crucial role in regulating the proliferation, immune escape, and metastasis of HCC. In addition, because EVs are present in the circulation at relatively early stages of disease, they are getting attention as an attractive biomarker for HCC detection. Over the past decade, dedicated efforts have been made to isolate EVs more efficiently and make them useful tools in different clinical settings. In this review article, we provide an overview of the EVs isolation methods and highlight the role of EVs as mediators in the pathogenesis and progression of HCC. Lastly, we summarize the potential applications of EVs in early-stage HCC detection.

The Role of Extracellular Vesicles as Shuttles of RNA and Their Clinical Significance as Biomarkers in Hepatocellular Carcinoma

Extracellular vesicles (EVs) have attracted interest as mediators of intercellular communication following the discovery that EVs contain RNA molecules, including non-coding RNA (ncRNA). Growing evidence for the enrichment of peculiar RNA species in specific EV subtypes has been demonstrated. ncRNAs, transferred from donor cells to recipient cells, confer to EVs the feature to regulate the expression of genes involved in differentiation, proliferation, apoptosis, and other biological processes. These multiple actions require accuracy in the isolation of RNA content from EVs and the methodologies used play a relevant role. In liver, EVs play a crucial role in regulating cell-cell communications and several pathophysiological events in the heterogeneous liver class of cells via horizontal transfer of their cargo. This review aims to discuss the rising role of EVs and their ncRNAs content in regulating specific aspects of hepatocellular carcinoma development, including tumorigenesis, angiogenesis, and tumor metastasis. We analyze the progress in EV-ncRNAs' potential clinical applications as important diagnostic and prognostic biomarkers for liver conditions.

Interaction of long non-coding RNAs and circular RNAs with microRNAs for the regulation of immunological responses in human cancers

Advancements in single-cell RNA sequencing technologies have enabled us to deconvolve immune system heterogeneity by identification of functionally distinct immune cell subsets in disease and health. Discovery of non-coding RNAs has opened new horizons for re-interpretation of regulatory roles of myriad of cell signaling pathways in immunology and oncology. Role of miRNAs, circular RNAs and long non-coding RNAs (lncRNAs) in the context of immunomodulation has just begun to be uncovered and future studies may further expand the repertoire of non-coding RNAs implicated in the regulatory circuits. One of the most recent and exciting aspect in molecular immunology is the delivery of non-coding RNAs through exosomes to the recipient cells which results in the re-wiring of different pathways and protein networks in recipient cells. Broader understanding of all of the layers of regulation in this system can provide useful information that could be harnessed to rationally translate laboratory findings into clinically effective therapeutics.

Exosomal LINC00161 promotes angiogenesis and metastasis via regulating miR-590-3p/ROCK axis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a lethal malignancy with few effective options for therapeutic treatment in its advanced stages. While exosomal LINC00161 has been identified as a potential biomarker for HCC, its regulatory function and clinical values remain largely unknown. LINC00161 expressions in serum-derived exosomes from HCC patients and HCC cells were determined by qRT-PCR. The ability of proliferation, migration, and angiogenesis in HUVECs was assessed by MTT, Transwell, and tube formation. Luciferase reporter assay and AGO2-RIP assay were conducted to explore the interactions among LINC00161, miR-590-3p, and ROCK2. The level of ROCK signal-related proteins was examined by Western blotting and immunohistochemistry (IHC) assay. Subcutaneous tumor growth was observed in nude mice, in which in vivo metastasis was observed following tail vein injection of HCC cells. High levels of LINC00161 were detected in both serum-derived exosomes from HCC patients and the supernatants of HCC cell lines and were significantly associated with poor survival. Functional study demonstrated that exosomal LINC00161 derived from HCC-cells were significantly associated with enhanced proliferation, migration, and angiogenesis in HUVECs in vitro, all of which were effectively inhibited when LINC00161 was sliced with shRNA in HCC-cells. In vivo experiment showed that LINC00161 loss inhibited tumorigenesis and metastasis of HCC. Mechanistic study revealed that exosome-carried LINC00161 directly targeted miR-590-3p and induced its downstream target ROCK2, finally activating growth/metastasis-related signals in HCC. Exosome-carried LINC00161 promotes HCC tumorigenesis through inhibiting miR-590-3p to activate the ROCK2 signaling pathway, suggesting that LINC00161 may be used as potential targets to improve HCC treatment efficiency.

Exosomes Isolated From Bone Marrow Mesenchymal Stem Cells Exert a Protective Effect on Osteoarthritis via lncRNA LYRM4-AS1-GRPR-miR-6515-5p

Objectives

The aim of this study was to investigate the effects of exosomes isolated from human bone marrow mesenchymal stem cells (BMSCs) on osteoarthritis (OA) and a competitive endogenous RNA (ceRNA) network.

Methods

Exosomes were isolated from human BMSCs and characterized by transmission electron microscopy (TEM), Nanosight (NTA), and western blotting. Chondrocytes were treated with interleukin-1β (IL-1β) and then transfected with exosomes. Cell viability and apoptosis were determined using Cell Counting Kit-8 (CCK-8) and flow cytometry, respectively. Cells with IL-1β and exosomes were sequenced, and differentially expressed lncRNAs (DE-lncRNAs) and miRNAs (DE-miRNAs) were identified. Thereafter, a ceRNA network (LYRM4-AS1-GRPR-miR-6515-5p) was chosen for further validation.

Results

TEM, NTA, and western blotting showed that exosomes were successfully isolated, and PKH67 staining showed that exosomes could be taken up by IL-1β-induced chondrocytes. Compared with the control group, IL-1β significantly decreased cell viability and promoted apoptosis (P < 0.05), while exosomes reversed the changes induced by IL-1β. For MMP3, AKT, and GRPR, IL-1β upregulated their expression, while exosomes downregulated their expression. For PTEN, there was no significant difference in PTEN expression between the control and IL-1β groups; however, exosomes markedly upregulated PTEN expression. By sequencing, 907 DE-lncRNAs and 25 DE-miRNAs were identified, and a ceRNA network was constructed. The dual-luciferase reporter gene indicated that LYRM4-AS1, miR-6515-5, and GRPR interacted with each other. The results of cell experiments showed that LYRM4-AS1 regulated the growth of IL-1β-induced chondrocytes by GRPR/miR-6515-5p.

Conclusion

Exosomes may alleviate OA inflammation by regulating the LYRM4-AS1/GRPR/miR-6515-5p signaling pathway.

Exosomal DLX6-AS1 from hepatocellular carcinoma cells induces M2 macrophage polarization to promote migration and invasion in hepatocellular carcinoma through microRNA-15a-5p/CXCL17 axis

Background

Hepatocellular carcinoma (HCC) cells-secreted exosomes (exo) could stimulate M2 macrophage polarization and promote HCC progression, but the related mechanism of long non-coding RNA distal-less homeobox 6 antisense 1 (DLX6-AS1) with HCC-exo-mediated M2 macrophage polarization is largely ambiguous. Thereafter, this research was started to unearth the role of DLX6-AS1 in HCC-exo in HCC through M2 macrophage polarization and microRNA (miR)-15a-5p/C-X-C motif chemokine ligand 17 (CXCL17) axis.

Methods

DLX6-AS1, miR-15a-5p and CXCL17 expression in HCC tissues and cells were tested. Exosomes were isolated from HCC cells with overexpressed DLX6-AS1 and co-cultured with M2 macrophages. MiR-15a-5p/CXCL17 down-regulation assays were performed in macrophages. The treated M2 macrophages were co-cultured with HCC cells, after which cell migration, invasion and epithelial mesenchymal transition were examined. The targeting relationships between DLX6-AS1 and miR-15a-5p, and between miR-15a-5p and CXCL17 were explored. In vivo experiment was conducted to detect the effect of exosomal DLX6-AS1-induced M2 macrophage polarization on HCC metastasis.

Results

Promoted DLX6-AS1 and CXCL17 and reduced miR-15a-5p exhibited in HCC. HCC-exo induced M2 macrophage polarization to accelerate migration, invasion and epithelial mesenchymal transition in HCC, which was further enhanced by up-regulated DLX6-AS1 but impaired by silenced DLX6-AS1. Inhibition of miR-15a-5p promoted M2 macrophage polarization to stimulate the invasion and metastasis of HCC while that of CXCL17 had the opposite effects. DLX6-AS1 mediated miR-15a-5p to target CXCL17. DLX6-AS1 from HCC-exo promoted metastasis in the lung by inducing M2 macrophage polarization in vivo.

Conclusion

DLX6-AS1 from HCC-exo regulates CXCL17 by competitively binding to miR-15a-5p to induce M2 macrophage polarization, thus promoting HCC migration, invasion and EMT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01973-z.

Role of exosomes in the immune microenvironment of ovarian cancer

Exosomes are excretory vesicles that can deliver a variety of bioactive cargo molecules to the extracellular environment. Accumulating evidence demonstrates exosome participation in intercellular communication, immune response, inflammatory response and they even play an essential role in affecting the tumor immune microenvironment. The role of exosomes in the immune microenvironment of ovarian cancer is mainly divided into suppression and stimulation. On one hand exosomes can stimulate the innate and adaptive immune systems by activating dendritic cells (DCs), natural killer cells and T cells, allowing these immune cells exert an antitumorigenic effect. On the other hand, ovarian cancer-derived exosomes initiate cross-talk with immunosuppressive effector cells, which subsequently cause immune evasion; one of the hallmarks of cancer. Exosomes induce the polarization of macrophages in M2 phenotype and induce apoptosis of lymphocytes and DCs. Exosomes further activate additional immunosuppressive effector cells (myeloid-derived suppressor cells and regulatory T cells) that induce fibroblasts to differentiate into cancer-associated fibroblasts. Exosomes also induce the tumorigenicity of mesenchymal stem cells to exert additional immune suppression. Furthermore, besides mediating the intercellular communication, exosomes carry microRNAs (miRNAs), proteins and lipids to the tumor microenvironment, which collectively promotes ovarian cancer cells to proliferate, invade and tumors to metastasize. Studying proteins, lipids and miRNAs carried by exosomes could potentially be used as an early diagnostic marker of ovarian cancer for designing treatment strategies.

An Immune-Related lncRNA Expression Profile to Improve Prognosis Prediction for Lung Adenocarcinoma: From Bioinformatics to Clinical Word

Background

Lung cancer is still the top-ranked cancer-related deaths all over the world. Now immunotherapy has emerged as a promising option for treating lung cancer. Recent evidence indicated that lncRNAs were also key regulators in immune system. We aimed to develop a novel prognostic signature based on the comprehensive analysis of immune-related lncRNAs to predict survival outcome of LUAD patients.

Methods

The gene expression profiles of 491 LUAD patients were downloaded from TCGA. 1047 immune-related lncRNAs were obtained through Pearson correlation analysis of immune genes and lncRNAs using statistical software R language. Univariate and multivariate Cox regression analysis were performed to determine the optimal immune-related lncRNAs prognostic signature (ITGCB-DT, ABALON, TMPO-AS1 and VIM-AS1). Finally, we validated the immune-related lncRNAs prognostic signature in The First Affiliated Hospital of Xi'an Jiaotong University cancer center cohort.

Results

A four immune-related lncRNAs prognostic signature was constructed to predict the survival outcome of LUAD patients. Statistical significance were found that the LUAD patients in high-risk group suffered shorter overall survival than those in low-risk group (P <0.001). ROC curve analysis shown that the four immune-related lncRNAs prognostic signature had the best predictive effect compared with age, gender, AJCC-stage, T stage, N stage, M stage (AUC = 0.756). More importantly, clinical cohort studies proved that the signature could predict the overall survival of LUAD patients with an AUC = 0.714.

Conclusions

In summary, we demonstrated that the novel immune-related lncRNAs signature had the ability to predict the prognosis of LUAD patients, which might serve as potential prognostic biomarkers and guide the individualized treatment strategies for LUAD patients.

LncRNA GNAS-AS1 facilitates ER+ breast cancer cells progression by promoting M2 macrophage polarization via regulating miR-433-3p/GATA3 axis

Objective: ER⁺ breast cancer is the most common type of breast cancer, which seriously affects the physical and mental health of women. Recently, lncRNAs mediated tumor-associated macrophages (TAM) were identified to involve in tumorigenesis. Therefore, the present study aimed at demonstrating the regulatory network of GNAS-AS1 in TAM-mediated ER⁺ breast cancer progress.

Methods: The expression levels of genes were evaluated using qRT-PCR. The proportions of polarized macrophages (M1, M2) were assessed by flow cytometry. Cell proliferation, migration and invasion were evaluated by CCK-8, wound healing and transwell assay, respectively. Double-luciferase reporter system was used to detect the interaction between molecules. Western blot was applied to test protein levels.

Results: The expression of GNAS-AS1 was obviously increased in ER⁺ breast cancer tissues and cell lines, as well as M2 macrophages. GNAS-AS1 facilitated the capabilities of proliferation, migration and invasion of ER⁺ breast cancer cells by accelerating M2 macrophage polarization via directly sponging miR-433-3p. GATA3, as a target of miR-433-3p, could positively regulate by GNAS-AS1. Furthermore, either miR-433-3p overexpression or GATA3 knockdown impaired the effects of GNAS-AS1 on M2 macrophage polarization and ER⁺ breast cancer cells progression.

Conclusion: GNAS-AS1/miR-433-3p/GATA3 axis promoted proliferation, metastasis of ER⁺ breast cancer cells by accelerating M2 macrophage polarization. The mechanism may provide a new strategy and target for ER⁺ breast cancer treatment.

Current perspectives on exosomes in the diagnosis and treatment of hepatocellular carcinoma (review)

The prognosis of hepatocellular carcinoma (HCC), a malignant tumor, is poor. Tumor recurrence and metastasis are the major challenges for the treatment of HCC. Various studies have demonstrated that exosomes, which are loaded with various biomolecules including nucleic acids, lipids, and proteins are involved in the recurrence and metastasis of HCC. Additionally, exosomes mediate various biological processes, such as immune response, cell apoptosis, angiogenesis, thrombosis, autophagy, and intercellular signal transduction. In cancer, exosomes regulate cancer cell differentiation, development, and drug resistance. Circular RNAs, microRNAs, and proteins in the exosomes can serve as early diagnostic and prognostic markers for HCC. As exosomes are characterized by low immunogenicity and high stability in the tissues and circulation, they can be used to deliver the drugs in cancer therapies.

M2 Macrophage-Derived Exosomes Facilitate HCC Metastasis by Transferring αM β2 Integrin to Tumor Cells

BACKGROUND AND AIMS

The development and progression of hepatocellular carcinoma (HCC) is dependent on its local microenvironment. Tumor-associated macrophages (TAMs) are deemed a key factor for the tumor microenvironment and attribute to contribute to tumor aggressiveness. However, the detailed mechanism underlying the pro-metastatic effect of TAMs on HCC remains undefined.

APPROACH AND RESULTS

The present study proved that TAMs were enriched in HCC. TAMs were characterized by an M2-polarized phenotype and accelerated the migratory potential of HCC cells in vitro and in vivo. Furthermore, we found that M2-derived exosomes induced TAM-mediated pro-migratory activity. With the use of mass spectrometry, we identified that integrin, α_M β₂ (CD11b/CD18), was notably specific and efficient in M2 macrophage-derived exosomes (M2 exos). Blocking either CD11b and/or CD18 elicited a significant decrease in M2 exos-mediated HCC cell metastasis. Mechanistically, M2 exos mediated an intercellular transfer of the CD11b/CD18, activating the matrix metalloproteinase-9 signaling pathway in recipient HCC cells to support tumor migration.

CONCLUSIONS

Collectively, the exosome-mediated transfer of functional CD11b/CD18 protein from TAMs to tumor cells may have the potency to boost the migratory potential of HCC cells, thus providing insights into the mechanism of tumor metastasis.

Alarming Cargo: The Role of Exosomes in Trauma-Induced Inflammation

Severe polytraumatic injury initiates a robust immune response. Broad immune dysfunction in patients with such injuries has been well-documented; however, early biomarkers of immune dysfunction post-injury, which are critical for comprehensive intervention and can predict the clinical course of patients, have not been reported. Current circulating markers such as IL-6 and IL-10 are broad, non-specific, and lag behind the clinical course of patients. General blockade of the inflammatory response is detrimental to patients, as a certain degree of regulated inflammation is critical and necessary following trauma. Exosomes, small membrane-bound extracellular vesicles, found in a variety of biofluids, carry within them a complex functional cargo, comprised of coding and non-coding RNAs, proteins, and metabolites. Composition of circulating exosomal cargo is modulated by changes in the intra- and extracellular microenvironment, thereby serving as a homeostasis sensor. With its extensively documented involvement in immune regulation in multiple pathologies, study of exosomal cargo in polytrauma patients can provide critical insights on trauma-specific, temporal immune dysregulation, with tremendous potential to serve as unique biomarkers and therapeutic targets for timely and precise intervention.

Exosomes in hepatocellular carcinoma microenvironment and their potential clinical application value

Hepatocellular carcinoma (HCC) has become a challenging disease in the world today. Due to the limitations on the current diagnosis and treatment as well as its high metastatic ability and high recurrence rate, HCC gradually becomes the second deadliest tumor. Exosomes are one of the types of cell-derived vesicles and can carry intracellular materials such as genetic materials, lipids, and proteins. In recent years, it has been verified that exosomes are linked to numerous physiological and pathological processes, including HCC. However, how exosomes affect HCC progression remains largely unknown. In this review, the exosome-mediated cellular material transfer between cells of different types in the HCC microenvironment and their effects on the behaviors and functions of recipient cells are studied. Furthermore, we also addressed the underlying molecular mechanisms. We believe that new light on the diagnosis of this cancer as well as its treatment strategies will be shed after a collation of literature in this area.

Exosomal Non-Coding RNAs: Regulatory and Therapeutic Target of Hepatocellular Carcinoma

Exosomes are small extracellular vesicles secreted by most somatic cells, which can carry a variety of biologically active substances to participate in intercellular communication and regulate the pathophysiological process of recipient cells. Recent studies have confirmed that non-coding RNAs (ncRNAs) carried by tumor cell/non-tumor cell-derived exosomes have the function of regulating the cancerous derivation of target cells and remodeling the tumor microenvironment (TME). In addition, due to the unique low immunogenicity and high stability, exosomes can be used as natural vehicles for the delivery of therapeutic ncRNAs in vivo. This article aims to review the potential regulatory mechanism and the therapeutic value of exosomal ncRNAs in hepatocellular carcinoma (HCC), in order to provide promising targets for early diagnosis and precise therapy of HCC.

lncRNA Gm16410 Mediates PM2.5-Induced Macrophage Activation via PI3K/AKT Pathway

PM₂.₅ refers to atmospheric particulate matters with a diameter of less than 2.5 μm. The deposit of PM₂.₅ in lung cells can cause oxidative stress, leading to changes in macrophage polarity, which can subsequently cause pulmonary inflammation. Long-chain non-coding RNA (lncRNA) is a class of transcripts that regulate biological processes through multiple mechanisms. However, the role of lncRNA in PM₂.₅-induced lung inflammation has not been established. In this study, the biological effects and associated mechanism of lncRNA in PM₂.₅-induced change in macrophage polarity were investigated. The lncRNA-mediated PM₂.₅-induced macrophage inflammation and lung inflammation-associated injury were also determined. Mice were exposed to chronic levels of PM₂.₅, and changes in the expression of lncRNA in the lung were measured by lncRNA microarray. lncRNAs that showed significant changes in expression in response to PM₂.₅ were identified. lncRNA showing the biggest change was subjected to further analysis to determine its functional roles and mechanisms with respect to macrophage activation. The result showed that a significant reduction in expression of one lncRNA, identified as lncGm16410, was observed in the lung of mice and RAW264.7 cells following exposure to PM₂.₅. lncGm16410 suppressed PM₂.₅-induced macrophage activation via the SRC protein-mediated PI3K/AKT signaling pathway. PM₂.₅ promoted lung inflammation by downregulating the expression of lncGm16410, enhancing the activation of macrophages. Thus, lncGm16410 might provide new insight into the prevention of PM₂.₅ injury.

Remodeling of Stromal Cells and Immune Landscape in Microenvironment During Tumor Progression

The molecular understanding of carcinogenesis and tumor progression rests in intra and inter-tumoral heterogeneity. Solid tumors confined with vast diversity of genetic abnormalities, epigenetic modifications, and environmental cues that differ at each stage from tumor initiation, progression, and metastasis. Complexity within tumors studied by conventional molecular techniques fails to identify different subclasses in stromal and immune cells in individuals and that affects immunotherapies. Here we focus on diversity of stromal cell population and immune inhabitants, whose subtypes create the complexity of tumor microenvironment (TME), leading primary tumors towards advanced-stage cancers. Recent advances in single-cell sequencing (epitope profiling) approach circumscribes phenotypic markers, molecular pathways, and evolutionary trajectories of an individual cell. We discussed the current knowledge of stromal and immune cell subclasses at different stages of cancer development with the regulatory role of non-coding RNAs. Finally, we reported the current therapeutic options in immunotherapies, advances in therapies targeting heterogeneity, and possible outcomes.

Exosome-mediated communication between tumor cells and tumor-associated macrophages: implications for tumor microenvironment

Exosomes are extracellular vesicles released from numerous types of cells that are involved in multiple tumors development. Exosomes contribute to the modulation of tumor microenvironment (TME) through intercellular communication. As essential immune stromal cells in the TME, tumor-associated macrophages (TAMs) participate in tumor development by mediating angiogenesis, metastasis, chemoresistance, and immune escape. Due to communication with multiple cells in the TME, they exhibit plasticity and heterogeneity during the progress of polarization from monocytes to macrophages. Previous studies suggest that targeting TAMs is a promising therapeutic strategy; however, the detailed mechanism by which TAMs regulate tumor development still remains unclear. In this review, we provide an overview of the roles of exosomes as messengers in the communication between tumor cells and polarization of TAMs; we also describe the effects of their interaction on tumor development. Finally, we comprehensively discussed the potential application of exosomes as the promising tumor immunotherapy strategy.

Non-coding RNAs regulation of macrophage polarization in cancer

Noncoding RNA (ncRNA) transcripts that did not code proteins but regulate their functions were extensively studied for the last two decades and the plethora of discoveries have instigated scientists to investigate their dynamic roles in several diseases especially in cancer. However, there is much more to learn about the role of ncRNAs as drivers of malignant cell evolution in relation to macrophage polarization in the tumor microenvironment. At the initial stage of tumor development, macrophages have an important role in directing Go/No-go decisions to the promotion of tumor growth, immunosuppression, and angiogenesis. Tumor-associated macrophages behave differently as they are predominantly induced to be polarized into M2, a pro-tumorigenic type when recruited with the tumor tissue and thereby favoring the tumorigenesis. Polarization of macrophages into M1 or M2 subtypes plays a vital role in regulating tumor progression, metastasis, and clinical outcome, highlighting the importance of studying the factors driving this process. A substantial number of studies have demonstrated that ncRNAs are involved in the macrophage polarization based on their ability to drive M1 or M2 polarization and in this review we have described their functions and categorized them into oncogenes, tumor suppressors, Juggling tumor suppressors, and Juggling oncogenes.

Tumor exosome promotes Th17 cell differentiation by transmitting the lncRNA CRNDE-h in colorectal cancer

The T helper 17 (Th17) cells in tumor microenvironment play an important role in colorectal cancer (CRC) progression. This study investigated the mechanism of Th17 cell differentiation in CRC with a focus on the role of tumor exosome-transmitted long noncoding RNA (lncRNA). Exosomes were isolated from the CRC cells and serum of CRC patients. The role and mechanism of the lncRNA CRNDE-h transmitted by CRC exosomes in Th17 cell differentiation were assessed by using various molecular biological methods. The serum exosomal CRNDE-h level was positively correlated with the proportion of Th17 cells in the tumor-infiltrating T cells in CRC patients. CRC exosomes contained abundant CRNDE-h and transmitted them to CD4⁺ T cells to increase the Th17 cell proportion, RORγt expression, and IL-17 promoter activity. The underlying mechanism is that, CRNDE-h bound to the PPXY motif of RORγt and impeded the ubiquitination and degradation of RORγt by inhibiting its binding with the E3 ubiquitin ligase Itch. The in vivo experiments confirmed that the targeted silence of CRNDE-h in CD4⁺ T cells attenuated the CRC tumor growth in mice. The present findings demonstrated that the tumor exosome transmitted CRNDE-h promoted Th17 cell differentiation by inhibiting the Itch-mediated ubiquitination and degradation of RORγt in CRC, expanding our understanding of Th17 cell differentiation in CRC.

Exosomal Long Non-Coding RNA: Interaction Between Cancer Cells and Non-Cancer Cells

Exosomes are small membranous vesicles released by many kinds of cells, and are indispensable in cell-to-cell communication by delivering functional biological components both locally and systemically. Long non-coding RNAs (lncRNAs) are long transcripts over 200 nucleotides that exhibit no or limited protein-coding potentials. LncRNAs are dramatic gene expression regulators, and can be selectively sorted into exosomes. Exosomal lncRNAs derived from cancer cells and stromal cells can mediate the generation of pre-metastatic niches (PMNs) and thus promote the progression of cancer. In this review, we summarized the fundamental biology and characteristics of exosomal lncRNAs. Besides, we provided an overview of current research on functions of exosomal lncRNAs between cancer cells and non-cancer cells. A deep understanding of exosomal lncRNAs' role in cancer will be facilitated to find important implications for cancer development and treatment.

Exosomes in Immune Regulation

Exosomes, small extracellular vesicles mediate intercellular communication by transferring their cargo including DNA, RNA, proteins and lipids from cell to cell. Notably, in the immune system, they have protective functions. However in cancer, exosomes acquire new, immunosuppressive properties that cause the dysregulation of immune cells and immune escape of tumor cells supporting cancer progression and metastasis. Therefore, current investigations focus on the regulation of exosome levels for immunotherapeutic interventions. In this review, we discuss the role of exosomes in immunomodulation of lymphoid and myeloid cells, and their use as immune stimulatory agents to elicit specific cytotoxic responses against the tumor.

Long Non-Coding RNAs: Potential Biomarkers and Targets for Hepatocellular Carcinoma Therapy and Diagnosis

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Increasing studies showed that long non-coding RNAs (lncRNAs), a novel class of RNAs that are greater than 200 nucleotides in length but lack the ability to encode proteins, exert crucial roles in the occurrence and progression of HCC. LncRNAs promote the proliferation, migration, invasion, autophagy, and apoptosis of tumor cells by regulating downstream target gene expression and cancer-related signaling pathways. Meanwhile, lncRNA can be used as biomarkers to predict the efficacy of HCC treatment strategies, such as surgery, radiotherapy, chemotherapy, and immunotherapy, and as a potential individualized tool for HCC diagnosis and treatment. In this review, we overview up-to-date findings on lncRNAs as potential biomarkers for HCC surgery, radiotherapy, chemotherapy resistance, target therapy, and immunotherapy, and discuss the potential clinical application of lncRNA as tools for HCC diagnosis and treatment.

Exosomal linc-FAM138B from cancer cells alleviates hepatocellular carcinoma progression via regulating miR-765

Exosomes are small vesicles with a diameter of 30-150 nm secreted by cells, which can be used as signal carriers to transfer nucleic acids, proteins, lipids and other functional substances to the recipient cells and play a role in cell communication. Hepatocellular carcinoma is the fourth most common cause of cancer-related death worldwide. Studies have shown that long non-coding RNAs (lncRNAs) are involved in the development and progression of many types of tumors. Our present study found that linc-FAM138B was reduced in HCC tissues and cell lines, low expression of linc-FAM138B indicated a poor prognosis in HCC patients. Interestingly, linc-FAM138B could be packaged into cancer cells. And exo-FAM138B inhibited the proliferation, migration and invasion of HCC cells. Furthermore, linc-FAM138B sponged miR-765 levels. And exo-si-FAM138B promoted HCC progression, while deletion of miR-765 reversed the role of exo-si-FAM138B. In vivo tumorigenesis experiments showed that exo-FAM138B suppressed HCC growth via modulating miR-765. In conclusion, exo-linc-FAM138B secreted by cancer cells inhibited HCC development via targeting miR-765, which provided a new idea and perspective for in-depth understanding of the complex signal regulation in HCC process.

Immune Regulation by Dendritic Cell Extracellular Vesicles in Cancer Immunotherapy and Vaccines

Extracellular vesicles (EVs) play a crucial role in intercellular communication as vehicles for the transport of membrane and cytosolic proteins, lipids, and nucleic acids including different RNAs. Dendritic cells (DCs)-derived EVs (DEVs), albeit variably, express major histocompatibility complex (MHC)-peptide complexes and co-stimulatory molecules on their surface that enable the interaction with other immune cells such as CD8⁺ T cells, and other ligands that stimulate natural killer (NK) cells, thereby instructing tumor rejection, and counteracting immune-suppressive tumor microenvironment. Malignant cells oppose this effect by secreting EVs bearing a variety of molecules that block DCs function. For instance, tumor-derived EVs (TDEVs) can impair myeloid cell differentiation resulting in myeloid-derived suppressor cells (MDSCs) generation. Hence, the unique composition of EVs makes them suitable candidates for the development of new cancer treatment approaches including prophylactic vaccine targeting oncogenic pathogens, cancer vaccines, and cancer immunotherapeutics. We offer a perspective from both cell sides, DCs, and tumor cells, on how EVs regulate the antitumor immune response, and how this translates into promising therapeutic options by reviewing the latest advancement in DEV-based cancer therapeutics.

Long non-coding RNAs: Emerging regulators for chemo/immunotherapy resistance in cancer stem cells

Cancer stem cells (CSCs) are a small subpopulation of tumor cells critical for tumor development. Their unique abilities, such as self-renewal, have resulted in tumor resistance to various cancer treatments, including traditional chemotherapy and latest immunotherapy. CSCs-targeting therapy is a promising treatment to overcome the therapeutic resistances to different tumors. However, despite their significance, the regulatory mechanism generating therapy-resistant CSCs is still obscure. Long non-coding RNAs (lncRNAs) are key regulators in various biological processes, including cell proliferation, apoptosis, migration, and invasion. Recent studies have revealed that lncRNAs play an important role in the therapeutic resistance of CSCs. Here we summarize the latest studies on the regulatory role of lncRNAs in sustaining the stemness of CSCs, and discuss the associated mechanisms behind these behavior changes in CSCs-related chemo- and immune-resistance. Future research implications are also discussed, shedding light on the potential CSCs-targeted strategies to break through the resistance of current therapies.

Impact of Long Non-coding RNAs Associated With Microenvironment on Survival for Bladder Cancer Patients

Background

Cumulative evidence from several tumor studies, including bladder cancer, emphasizes the importance of the tumor microenvironment (TME) in tumorigenesis, development, and metastasis, which can be regulated by long non-coding RNAs (lncRNAs). This study aims to identify bladder cancer (BC) microenvironment-associated lncRNAs for their prognostic value predicting the survival of BC patients.

Methods

The data of BC patients regarding lncRNA expression and corresponding clinical characteristics were obtained from The Cancer Genome Atlas (TCGA). The Cox regression analysis and the least absolute shrinkage and selection operator (LASSO) regression analysis were performed to screen lncRNAs following the calculation of the immune score for each sample. For the screened lncRNAs, a risk score model was constructed to predict the survival, and 3- and 5-year overall survival (OS) rates were assessed using a nomogram. The calibration curve and concordance index (C-index) validated the performance of the nomogram. Finally, to explore the potential function related to the screened lncRNAs, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed.

Results

The multivariate Cox regression analysis screened five TME-associated lncRNAs regarded as independent factors influencing the tumor progression. The corresponding risk score model was established as follows: (-0.15816 AC064805.1) + (0.10015 AC084033.3) + (-0.17977 AC092112.1) + (-0.05673AC103691.1) + (0.17789 AL391704.1) + (-0.16258 LINC00892). The C-index for the nomogram was 0.63 (95% CI: 0.625-0.635). Also, the calibration curve verified the predictive effectiveness by showing a good concordance between the nomogram prediction and the actual observation. GO and KEGG analysis demonstrated that six TME-associated lncRNAs were most likely linked to tumor metastasis and progression.

Conclusion

The present study determined six lncRNAs as independent immuno-biomarkers in the TME, constructed a nomogram to predict their prognostic value, and investigated the potential biological processes to understand their regulatory roles in the progression of BC.

Non-coding RNA derived from extracellular vesicles in cancer immune escape: Biological functions and potential clinical applications

The tumor microenvironment represents a dynamically composed matrix into which cancer cells and many other cell types are embedded to form organ-like structures. The tumor immune microenvironment (TIME), composed of immune cells, is an inseparable part of the tumor microenvironment. Extracellular vesicles (EVs) participate in the occurrence and development of tumors by delivering various biologically active molecules between cells; their role in cancer immune escape in particular has been widely proven. EVs can carry a wide array of cargo, such as non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, which are selectively loaded by EVs, secreted, and transported to participate in the proliferation of immune cells. Hence, strategies to specifically target EV-ncRNAs could be attractive therapeutic options. In this review, we summarize the current research on the role of EV-ncRNAs in cancer immune escape, and discuss the latest research on the function and regulation mechanism of EV-ncRNAs in cancer immune escape, highlighting and elucidating the potential clinical applications of EV-ncRNAs, including in diagnosis and immunotherapy.

Long noncoding RNA: a dazzling dancer in tumor immune microenvironment

Long noncoding RNAs (lncRNAs) are a class of endogenous, non-protein coding RNAs that are highly linked to various cellular functions and pathological process. Emerging evidence indicates that lncRNAs participate in crosstalk between tumor and stroma, and reprogramming of tumor immune microenvironment (TIME). TIME possesses distinct populations of myeloid cells and lymphocytes to influence the immune escape of cancer, the response to immunotherapy, and the survival of patients. However, hitherto, a comprehensive review aiming at relationship between lncRNAs and TIME is missing. In this review, we focus on the functional roles and molecular mechanisms of lncRNAs within the TIME. Furthermore, we discussed the potential immunotherapeutic strategies based on lncRNAs and their limitations.

Exosomal cargoes in OSCC: current findings and potential functions

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy in head and neck cancer, with high recurrence and mortality. Early diagnosis and efficient therapeutic strategies are vital for the treatment of OSCC patients. Exosomes can be isolated from a broad range of different cell types, implicating them as important factors in the regulation of human physiological and pathological processes. Due to their abundant cargo including proteins, lipids, and nucleic acids, exosomes have played a valuable diagnostic and therapeutic role across multiple diseases, including cancer. In this review, we summarize recent findings concerning the content within and participation of exosomes relating to OSCC and their roles in tumorigenesis, proliferation, migration, invasion, metastasis, and chemoresistance. We conclude this review by looking ahead to their potential utility in providing new methods for treating OSCC to inspire further research in this field.

LncRNA NEAT1: Shedding light on mechanisms and opportunities in liver diseases

With advances in genome and transcriptome research technology, the function and mechanism of lncRNAs in physiological and pathological states have been gradually revealed. Nuclear Enriched Abundant Transcript 1 (NEAT1, a long non-coding RNA), a vital component of paraspeckles, plays an indispensable role in the formation and integrity of paraspeckles. Throughout the research history, NEAT1 is mostly aberrantly upregulated in various cancers, and high expression of NEAT1 often contributes to poor prognosis of patients. Notably, the role and mechanism of NEAT1 in liver diseases have been increasingly reported. NEAT1 accelerates the progression of non-alcoholic fatty liver disease (NAFLD), liver fibrosis and hepatocellular carcinoma, while exerting a protective role in the pathogenesis of acute-on-chronic liver failure by inhibiting the inflammatory response. In this review, we will elaborate on relevant studies on the different casting of NEAT1 in liver diseases, especially focusing on its regulatory mechanisms and new opportunities for alcoholic liver disease.