Long noncoding RNA LINC00662 promotes M2 macrophage polarization and hepatocellular carcinoma progression via activating Wnt/β-catenin signaling

Inhibition of BCL9 Modulates the Cellular Landscape of Tumor-Associated Macrophages in the Tumor Immune Microenvironment of Colorectal Cancer

Tumor-associated macrophages (TAMs) are an indispensable part of the tumor microenvironment (TME), and they likely play a negative rather than positive role in cancer treatment. However, the cellular landscape and transcriptional profile regulation of TAMs in the case of tumor gene inactivation or chemical interference remains unclear. The B-cell lymphoma 9/B-cell lymphoma 9-like (BCL9/BCL9L) is a critical transcription co-factor of β-catenin. Suppression of Bcl9 inhibits tumor growth in mouse models of colorectal cancer (CRC). Here, we studied the TAMs of CRC by single-cell sequencing. Bcl9 depletion caused macrophage polarization inhibition from M0 to M2 and changed the CRC TME, which further interferes with the inflammation of M0 and M1. The transcription factor regulating these processes may be related to the Wnt signaling pathway from multiple levels. Furthermore, we also found that the cells delineated from monocyte to NK-like non-functioning cells were significantly different in the BCL9-deprived population. Combining these data, we proposed a TAM-to-NK score to evaluate the dynamic balance in TME of monocyte/TAM cells and NK-like non-functioning cells in The Cancer Genome Atlas (TCGA) clinical samples to verify the clinical significance. We demonstrated that the cell type balance and transcription differences of TAMs regulated by BCL9-driven Wnt signaling affected immune surveillance and inflammation of cancer, ultimately affecting patients' prognosis. We thereby highlighted the potential of targeting Wnt signaling pathway through cancer immunotherapy.

P53 suppresses the progression of hepatocellular carcinoma via miR-15a by decreasing OGT expression and EZH2 stabilization

Existing literature has highlighted the tumour suppressive capacity of microRNA-15a (miR-15a); however, its role in hepatocellular carcinoma (HCC) remains relatively unknown. This study aimed to investigate the role of miR-15a in HCC and the associated underlying mechanism. Initially, RT-qPCR was performed to detect the expression of miR-15a in HCC tissues and cells. Bioinformatics analysis, Pearson correlation coefficient, dual-luciferase reporter assay, and molecular approaches were all conducted to ascertain the interaction between miR-15a and O-linked N-acetylglucosamine (GlcNAc) transferase (OGT). PUGNAc treatment and cycloheximide (CHX) assay were performed to evaluate O-GlcNAc and the stabilization of the enhancer of zeste homolog 2 (EZH2). Finally, gain- and loss-of-function studies were employed to elucidate the role of P53 and the miR-15a/OGT/EZH2 axis in the progression of HCC, followed by in vivo experiments based on tumour-bearing nude mice. Our results demonstrated that the miR-15a expression was decreased in the HCC tissues and cells. P53 upregulated miR-15a expression, which inhibited the proliferation, migration and invasion of HCC cells, while inducing apoptosis and triggering a G0/G1 cell cycle phase arrest. OGT stabilized EZH2 via catalysing O-GlcNAc, which reversed the effect of P53 and miR-15a. The results of our in vivo study provided evidence demonstrating that P53 could suppress the development of HCC via the miR-15a/OGT/EZH2 axis. P53 was found to inhibit the OGT expression by promoting the expression of miR-15a, which destabilized EZH2 and suppressed the development of HCC. The key findings of our study highlight a promising novel therapeutic strategy for the treatment of HCC.

MiR-145-5p modulates lipid metabolism and M2 macrophage polarization by targeting PAK7 and regulating β-catenin signaling in hyperlipidemia

The present study aims to explore the role of microRNA 145-5p (miR-145-5p) in hyperlipidemia. Using bioinformatics tools and a wide range of function and mechanism assays, we attempted to understand the specific function and potential mechanism of miR-145-5p in hyperlipidemia. A cholesterol-enriched diet induced an increase of serum cholesterol and triacylglycerol but a decrease of serum high-density lipoprotein. MiR-145-5p level was decreased in hyperlipidemia rat models. MiR-145-5p regulated lipid metabolism by antagonizing the alteration of high-density lipoprotein, cholesterol, and triacylglycerol in serum mediated by a cholesterol-enriched diet. In mechanism, miR-145-5p directly bound with p21 protein (RAC1)-activated kinase 7 (PAK7) and negatively regulated mRNA and protein levels of PAK7 in THP-1 cells. Furthermore, miR-145-5p level was negatively associated with PAK7 level in rat cardiac tissues. Finally, overexpression of PAK7 reversed the effects of miR-145-5p on β-catenin activation and M2 macrophages polarization in THP-1 cells. In conclusion, MiR-145-5p modulated lipid metabolism and M2 macrophage polarization by targeting PAK7 and regulating β-catenin signaling in hyperlipidemia, which may provide a potential biomarker for the treatment of hyperlipidemia-induced cardiovascular diseases.

Hidden Treasures: Macrophage Long Non-Coding RNAs in Lung Cancer Progression

Ever since RNA sequencing of whole genomes and transcriptomes became available, numerous RNA transcripts without having the classic function of encoding proteins have been discovered. Long non-coding RNAs (lncRNAs) with a length greater than 200 nucleotides were considered as "junk" in the beginning, but it has increasingly become clear that lncRNAs have crucial roles in regulating a variety of cellular mechanisms and are often deregulated in several diseases, such as cancer. Lung cancer is the leading cause of cancer-related deaths and has a survival rate of less than 10%. Immune cells infiltrating the tumor microenvironment (TME) have been shown to have a great effect on tumor development with macrophages being the major cell type within the TME. Macrophages can inherit an inflammatory M1 or an anti-inflammatory M2 phenotype. Tumor-associated macrophages, which are predominantly polarized to M2, favor tumor growth, angiogenesis, and metastasis. In this review, we aimed to describe the complex roles and functions of lncRNAs in macrophages and their influence on lung cancer development and progression through the TME.

Macrophage polarization-associated lnc-Ma301 interacts with caprin-1 to inhibit hepatocellular carcinoma metastasis through the Akt/Erk1 pathway

Background

Epithelial–mesenchymal transition (EMT) promotes migration, invasion, and metastasis of hepatocellular carcinoma (HCC) cells. The molecular mechanisms behind EMT and metastasis in HCC remain unclear.

Methods

Microarray analysis was used to identify lncRNAs expression during polarization of U937 macrophages from M2 to M1 phenotype. The expression of the identified lncRNA was compared between clinical samples of HCC tissues or adjacent normal tissues, as well as between HCC and normal liver cell lines. lnc-Ma301 was overexpressed or knocked-down in HCC cell lines, and the effects were assessed in vitro and in vivo. Interactions among lnc-Ma301 and its potential downstream targets caprin-1 were investigated in HCC cell lines. Effects of lnc-Ma301 over- and underexpression on the Akt/Erk1 signaling pathways were examined.

Results

Microarray analyses identified lnc-Ma301 as one of the most overexpressed long non-coding RNAs during polarization of U937 macrophages from M2 to M1 phenotype. Lnc-Ma301 showed lower expression in HCC tissues than in adjacent normal tissues, and lower expression was associated with worse prognosis. Activation of lnc-Ma301 inhibited cell proliferation, migration and EMT in HCC cell cultures, and it inhibited lung metastasis of HCC tumors in mice. Mechanistic studies suggested that lnc-Ma301 interacts with caprin-1 to inhibit HCC metastasis and EMT through Akt/Erk1 pathway.

Conclusions

Lnc-Ma301 may help regulate onset and metastasis of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02133-1.

The Vital Roles of LINC00662 in Human Cancers

Long non-coding RNAs (lncRNAs) play crucial roles in many human diseases, particularly in tumorigenicity and progression. Although lncRNA research studies are increasing rapidly, our understanding of lncRNA mechanisms is still incomplete. The long intergenic non-protein coding RNA 662 (LINC00662) is a novel lncRNA, and accumulating evidence suggests that it is related to a variety of tumors in multiple systems, including the respiratory, reproductive, nervous, and digestive systems. LINC00662 has been shown to be upregulated in malignant tumors and has been confirmed to promote the development of malignant tumors. LINC00662 has also been reported to facilitate a variety of cellular events, such as tumor-cell proliferation, invasion, and migration, and its expression has been correlated to clinicopathological characteristics in patients with tumors. In terms of mechanisms, LINC00662 regulates gene expression by interacting with both proteins and with RNAs, so it may be a potential biomarker for cancer diagnosis, prognosis, and treatment. This article reviews the expression patterns, biological functions, and underlying molecular mechanisms of LINC00662 in tumors.

M2 macrophage-derived extracellular vesicles facilitate CD8+T cell exhaustion in hepatocellular carcinoma via the miR-21-5p/YOD1/YAP/β-catenin pathway

Hepatocellular carcinoma (HCC) is a common malignancy. CD8⁺ T cell-mediated immune response is critical for the inhibition of HCC progression. M2 macrophages participate in HCC progression. This study set out to investigate the effect of M2 macrophage-derived extracellular vesicles (EVs) on CD8⁺ T cell exhaustion in HCC. M2 macrophage-derived EVs were isolated and identified. The murine model of primary HCC was established through DEN/CCl₄ induction, and model mice were injected with EVs. Peripheral blood mononuclear cells (PBMCs) were isolated from the mouse liver and CD8⁺ T cells were sorted. The expressions of immune checkpoint inhibitory receptors and effector cytokines on CD8⁺ T cells were detected, followed by the evaluation of CD8⁺ T cell proliferation and killing function. miR-21-5p expression in M2 macrophage-derived EVs was detected. The binding relationship between miR-21-5p and YOD1 was verified. The activation of the YAP/β-catenin pathway was detected. Consequently, M2 macrophage-derived EVs promoted CD8⁺ T cell exhaustion in HCC mice. miR-21-5p expression was upregulated in M2 macrophage-derived EVs, and EVs carried miR-21-5p into HCC tissues. miR-21-5p targeted YOD1. Inhibition of miR-21-5p or overexpression of YOD1 annulled the promoting effect of EVs on CD8⁺ T cell exhaustion. YOD1 inactivated the YAP/β-catenin pathway. In conclusion, M2 macrophage-derived EVs facilitated CD8⁺ T cell exhaustion via the miR-21-5p/YOD1/YAP/β-catenin axis. This study may confer novel insights into the immunotherapy of HCC.

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.

Clinical Value and Underlying Mechanisms of Upregulated LINC00485 in Hepatocellular Carcinoma

Aims

This study aimed to reveal the functional role of LINC00485 in hepatocellular carcinoma (HCC).

Materials & Methods

210 serum samples from Zhongnan Hospital of Wuhan University were employed to evaluate clinical value of LINC00485. Bioinformatics analysis was adopted to explore its potential mechanisms.

Results

LINC00485 was confirmed to be upregulated in HCC tissues and serum samples. Survival analysis and receiver operating characteristic curve revealed its prognostic and diagnostic roles. The combination of serum LINC00485 with AFP can remarkably improve diagnostic ability of HCC. Exploration of the underlying mechanism demonstrated that LINC00485 might exert pro-oncogenic activity by LINC00485—three miRNAs—four mRNAs network.

Conclusions

Our study unveiled that upregulated LINC00485 could act as a potential diagnostic and prognostic biomarker and provide a novel insight into the molecular mechanisms of LINC00485 in HCC pathogenesis.

HNRNPH1-stabilized LINC00662 promotes ovarian cancer progression by activating the GRP78/p38 pathway

Numerous studies suggest an important role for copy number alterations (CNAs) in cancer progression. However, CNAs of long intergenic noncoding RNAs (lincRNAs) in ovarian cancer (OC) and their potential functions have not been fully investigated. Here, based on analysis of The Cancer Genome Atlas (TCGA) database, we identified in this study an oncogenic lincRNA termed LINC00662 that exhibited a significant correlation between its CNA and its increased expression. LINC00662 overexpression is highly associated with malignant features in OC patients and is a prognostic indicator. LINC00662 significantly promotes OC cell proliferation and metastasis in vitro and in vivo. Mechanistically, LINC00662 is stabilized by heterogeneous nuclear ribonucleoprotein H1 (HNRNPH1). Moreover, LINC00662 exerts oncogenic effects by interacting with glucose-regulated protein 78 (GRP78) and preventing its ubiquitination in OC cells, leading to activation of the oncogenic p38 MAPK signaling pathway. Taken together, our results define an oncogenic role for LINC00662 in OC progression mediated via GRP78/p38 signaling, with potential implications regarding therapeutic targets for OC.

Roles of long noncoding RNAs on tumor immune escape by regulating immune cells differentiation and function

A long noncoding RNA (lncRNA) transcript is generally more than 200 nucleotides in length and rarely codes for any protein. Currently, many lncRNAs have been identified among mammalian genomes, and their known functions are associated with various physiological activities or pathological processes. Some lncRNAs are dysregulated in a variety of malignant tumors, while increasing evidence indicates that abnormal expression can contribute to the regulation of immune cells in tumors and to shaping the immune response. More specifically, lncRNAs participate in regulating the differentiation of immune cells, also known as myeloid and lymphoid cells, as well as recruiting various immunosuppressive factors to influence the tumor microenvironment, thereby promoting tumor cell immune escape. However, we still know very little about the specific mechanism of lncRNAs in immune escape of cancer. Nonetheless, although unprecedented achievements have allowed the development of a new generation of anti-tumor immune therapies to be applied in clinical trials, the drug resistance caused by immune escape has become a major clinical challenge. The focus of this review is to describe the relationship among lncRNAs, immune cells, and tumor immune escape, in order to identify novel diagnostic and therapeutic targets in human cancers.

Diving into the Pleural Fluid: Liquid Biopsy for Metastatic Malignant Pleural Effusions

Simple Summary

Malignant pleural effusion is a common complication arising as the natural progression of many tumors, such as lung cancer. When this occurs, the common protocol consists of analyzing the pleural fluid for the presence of malignant cells. However, on many occasions no malignant cells are found despite a clear suspicion of cancer. Thus, the current diagnostic methodology is imperfect and more precise methods for the identification of malignancy are needed. Nonetheless, these methods are often invasive, which may be counterproductive, especially for patients with poor health condition. These concerns have made clinicians consider alternative non-invasive strategies to diagnose cancer using the generally abundant pleural fluid (e.g., liquid biopsy). Thus, a liquid sample can be analyzed for the presence of cancer footprints, such as circulating malignant cells and tumor nucleic acids. Herein, we review the literature for studies considering pleural fluid as a successful source of liquid biopsy.

Abstract

Liquid biopsy is emerging as a promising non-invasive diagnostic tool for malignant pleural effusions (MPE) due to the low sensitivity of conventional pleural fluid (PF) cytological examination and the difficulty to obtain tissue biopsies, which are invasive and require procedural skills. Currently, liquid biopsy is increasingly being used for the detection of driver mutations in circulating tumor DNA (ctDNA) from plasma specimens to guide therapeutic interventions. Notably, malignant PF are richer than plasma in tumor-derived products with potential clinical usefulness, such as ctDNA, micro RNAs (miRNAs) and long non-coding RNAs (lncRNAs), and circulating tumor cells (CTC). Tumor-educated cell types, such as platelets and macrophages, have also been added to this diagnostic armamentarium. Herein, we will present an overview of the role of the preceding biomarkers, collectively known as liquid biopsy, in PF samples, as well as the main technical approaches used for their detection and quantitation, including a proper sample processing. Technical limitations of current platforms and future perspectives in the field will also be addressed. Using PF as liquid biopsy shows promise for use in current practice to facilitate the diagnosis and management of metastatic MPE.

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.

Identifying Dendritic Cell-Related Genes Through a Co-Expression Network to Construct a 12-Gene Risk-Scoring Model for Predicting Hepatocellular Carcinoma Prognosis

The prognostic prediction of hepatocellular carcinoma (HCC) is still challenging. Immune cells play a crucial role in tumor initiation, progression, and drug resistance. However, prognostic value of immune-related genes in HCC remains to be further clarified. In this study, the mRNA expression profiles and corresponding clinical information of HCC patients were downloaded from public databases. Then, we estimated the abundance of immune cells and identified the differentially infiltrated and prognostic immune cells. The weighted gene co-expression network analysis (WGCNA) was performed to identify immune-related genes in TCGA cohort and GEO cohort. The least absolute shrinkage and selection operator (LASSO) Cox regression model was applied to establish a risk-scoring model in the TCGA cohort. HCC patients from the GSE14520 datasets were utilized for risk model validation. Our results found that high level of dendritic cell (DC) infiltration was associated with poor prognosis. Over half of the DC-related genes (58.2%) were robustly differentially expressed between HCC and normal specimens in the TCGA cohort. 17 differentially expressed genes (DEGs) were found to be significantly associated with overall survival (OS) by univariate Cox regression analysis. A 12-gene risk-scoring model was established to evaluate the prognosis of HCC. The high-risk group exhibits significantly lower OS rate of HCC patients than the low-risk group. The risk-scoring model shows benign predictive capacity in both GEO dataset and TCGA dataset. The 12-gene risk-scoring model may independently perform prognostic value for HCC patients. Receiver operating characteristic (ROC) curve analysis of the risk-scoring model in GEO cohort and TCGA cohort performed well in predicting OS. Taken together, the 12-gene risk-scoring model could provide prognostic and potentially predictive information for HCC. SDC3, NCF2, BTN3A3, and WARS were noticed as a novel prognostic factor for HCC.

LINC00467 Promotes Prostate Cancer Progression via M2 Macrophage Polarization and the miR-494-3p/STAT3 Axis

Background

The long non-coding RNA LINC00467 plays a vital role in many malignancies. Nevertheless, the role of LINC00467 in prostate carcinoma (PC) is unknown. Herein, we aimed to explore the mechanism by which LINC00467 regulates PC progression.

Methods

We used bioinformatics analyses and RT-qPCR to investigate the expression of LINC00467 in PC tissues and cells. The function of LINC00467 in the progression of PC was confirmed by loss-of-function experiments. PC cell proliferation was assessed by CCK-8 and EdU assays. The cell cycle progression of PC cells was examined by flow cytometry. Moreover, Transwell assays were used to investigate the migration and invasion of PC cells. Western blot assays were used to detect the expression of factors associated with epithelial–mesenchymal transition. The interactions of LINC00467 with prostate cancer progression and M2 macrophage polarization were confirmed by RT-qPCR. The subcellular localization of LINC00467 was investigated via the fractionation of nuclear and cytoplasmic RNA. Bioinformatics data analysis was used to predict the correlation of LINC00467 expression with miR-494-3p expression. LINC00467/miR-494-3p/STAT3 interactions were identified by using a dual-luciferase reporter system. Finally, the influence of LINC00467 expression on PC progression was investigated with an in vivo nude mouse model of tumorigenesis.

Results

We established that LINC00467 expression was upregulated in PC tissues and cells. Downregulated LINC00467 expression inhibited PC cell growth, cell cycle progression, migration, and invasion. Downregulated LINC00467 expression similarly inhibited PC cell migration via M2 macrophage polarization. Western blot analysis showed that LINC00467 could regulate the STAT3 pathway. We established that LINC00467 is mainly localized to the cytoplasm. Bioinformatics analysis and rescue experiments indicated that LINC00467 promotes PC progression via the miR-494-3p/STAT3 axis. Downregulated LINC00467 expression was also able to suppress PC tumor growth in vivo.

Conclusions

Our study reveals that LINC00467 promotes prostate cancer progression via M2 macrophage polarization and the miR-494-3p/STAT3 axis.

Long non-coding RNA: An immune cells perspective

Long non-coding RNAs (lncRNAs) were considered as accumulated genetic waste until they were found to be gene expression regulators by highly sensitive modern genomics platforms. It is a huge class of non-coding transcripts with an arbitrary length of >200 nucleotides, which has gained much attention in the past few years. Increasing evidence from several experimental studies unraveled the expression of lncRNA linked to immune response and disease progression. However, only a small number of lncRNAs have robust evidence of their function. Differential expression of lncRNAs in different immune cells is also evident. In this review, we focused on how lncRNAs expression assist in shaping immune cells (Macrophages, Dendritic cells, NK cells, T cells, B cells, eosinophils, neutrophils, and microglial cells) function and their response to the diseased conditions. Emerging evidence revealed lncRNAs may serve as key regulators in the innate and adaptive immune response system. So, the molecular mechanism insight into the function of lncRNAs in immune response may contribute to the development of potential therapeutic targets for various disease treatments. Therefore, it is imperative to explore the expression of lncRNAs and understand its relevance associated with the immune system.

MIRLET7BHG promotes hepatocellular carcinoma progression by activating hepatic stellate cells through exosomal SMO to trigger Hedgehog pathway

Hepatocellular carcinoma (HCC), commonly caused by liver fibrosis, is a global challenge with high morbidity. Activation of hepatic stellate cells (HSCs) contributes to hepatic fibrosis. Exosomes are small vesicles that play a significant role in cell-to-cell communication. Smoothened (SMO) is the key signal transducer for Hedgehog pathway. This study was designed to study the function and underlying mechanism of SMO in HSC activation. Functional assays including 5-Ethynyl-2´-deoxyuridine, colony formation, wound healing, transwell, and sphere formation assays disclosed the function of SMO. Western blot analysis of exosome biomarkers, immunofluorescence staining assay, electron microscope, and flow cytometry revealed the existence of exosomes. Bioinformatics analyses and mechanistic assays uncovered the interplays between RNAs. Nude mice xenograft model was established to evaluate HCC tumor growth. We uncovered that SMO was an oncogene in HCC cells and was low-expressed in quiescent HSCs. Then, SMO was upregulated in HSCs cultured with HCC cells-conditioned medium. Next, it was revealed that HCC cells-derived exosomes activated HSCs by transmitting SMO to HSCs. Subsequently, we recognized that microRNA let-7b host gene (MIRLET7BHG) served as the competing endogenous RNA against miR-330-5p to upregulate SMO. In turn, SMO induced hedgehog pathway to promote GLI family zinc finger 1 (Gli1), leading to transcriptional activation of MIRLET7BHG in activated HSCs. In summary, this study demonstrated that Gli1-induced MIRLET7BHG facilitated HCC by activating HSCs through exosomal SMO to stimulate hedgehog pathway, providing a new road for HCC treatment.

Rapid Arc-SBRT: Non-invasive immune adjuvant for advanced stage Non-Small Cell Lung Carcinoma

In conjunction with Radio-chemotherapy, pulmonary resection is recommended for early-stage Non-small-cell lung carcinoma but not for advanced-stage NSCLC patients with having high-grade metastatic lesions. In these cases, Rapid Arc-Stereotactic body radiotherapy (Ra-SBRT) technique offers a therapeutic advantage by delivering focal irradiation to metastatic lung lesions and reduces the bystander toxicity to normal tissues. We have previously demonstrated that Ra-SBRT ablates metastatic lesions and induces tumor immune rejection of metastatic tumors by promoting in situ programming of M2 TAM towards M1-TAM and infiltration of Siglec-8+ Eosinophils. Most interestingly, Ra SBRT has very low abscopal impact and spares normal tissues, which are the significant limitations with conventional radiotherapy. In view of this and Immune adjuvant potential of Ra SBRT, it promotes normalization of aberrant vasculature and inhibits the metastatic potential of NSCLC lesions. In view of this we here propose that Ra-SBRT indeed represents an immunogenic approach for the effective management of advanced-stage NSCLC.

KLHDC7B-DT aggravates pancreatic ductal adenocarcinoma development via inducing cross-talk between cancer cells and macrophages

Tumor microenvironment (TME) exerts key roles in pancreatic ductal adenocarcinoma (PDAC) development. However, the factors regulating the cross-talk between PDAC cells and TME are largely unknown. In the present study, we identified a long noncoding RNA (lncRNA) KLHDC7B divergent transcript (KLHDC7B-DT), which was up-regulated in PDAC and correlated with poor survival of PDAC patients. Functional assays demonstrated that KLHDC7B-DT enhanced PDAC cell proliferation, migration, and invasion. Mechanistically, KLHDC7B-DT was found to directly bind IL-6 promoter, induce open chromatin structure at IL-6 promoter region, activate IL-6 transcription, and up-regulate IL-6 expression and secretion. The expression of KLHDC7B-DT was positively correlated with IL-6 in PDAC tissues. Via inducing IL-6 secretion, KLHDC7B-DT activated STAT3 signaling in PDAC cells in an autocrine manner. Furthermore, KLHDC7B-DT also activated STAT3 signaling in macrophages in a paracrine manner, which induced macrophage M2 polarization. KLHDC7B-DT overexpressed PDAC cells-primed macrophages promoted PDAC cell proliferation, migration, and invasion. Blocking IL-6/STAT3 signaling reversed the effects of KLHDC7B-DT on macrophage M2 polarization and PDAC cell proliferation, migration, and invasion. In conclusion, KLHDC7B-DT enhanced malignant behaviors of PDAC cells via IL-6-induced macrophage M2 polarization and IL-6-activated STAT3 signaling in PDAC cells. The cross-talk between PDAC cells and macrophages induced by KLHDC7B-DT represents potential therapeutic target for PDAC.

Potential therapeutic targets in the tumor microenvironment of hepatocellular carcinoma: reversing the protumor effect of tumor-associated macrophages

In hepatocellular carcinoma patients, due to the microenvironmental specificity of liver, the tumor microenvironment exhibits high immunosuppression and drug resistance, resulting in excessive or insufficient responses to immunotherapy. The dynamic interactions between tumor cells and immune modulators in the TME significantly impact the occurrence and development of tumors, efficacy, and drug resistance, which can create a much more positive response to immunotherapy. Moreover, with the wide application of single-cell sequencing technology in the TME, increasing evidence shows an interaction network among cells. Sequencing results suggest that specific tumor-associated macrophages are a hub node, connecting different cell populations in the cell interaction network, and can could regulate tumor generation and antitumor immunity. This review focused on therapeutic targets that could be targeted to remodel the tumor microenvironment and reprogram the tumor-associated macrophage phenotype in hepatocellular carcinoma patients, thereby improving immunotherapeutic efficacy.

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.

Long non-coding RNAs as the regulators and targets of macrophage M2 polarization

Macrophages are immune cells with high heterogeneity and plasticity. M2 polarization is one extreme of the well-established phenotypes of macrophage polarization, and involves in diverse biological processes. The polarization process is initiated at the command of numerous components. Long non-coding RNAs (lncRNAs) are RNAs longer than 200 nucleotides with limited protein-coding capacity. Recent studies have revealed a newly found subset of lncRNAs engaged in the M2 polarization and their potent and multifunctional roles in developing diseases. By interfering with specific signaling pathways and altering the active mode, acting as the sponges of microRNAs or decoys of transcription factors, lncRNAs prompted macrophages to an M2 phenotype. Further, lncRNAs can bind to the genome to regulate the chromatin dynamics or work as a platform for protein complexes tether. Exosomal lncRNAs can also orchestrate the polarization in a paracrine way. To make it easier to interpret the roles of lncRNAs in the M2 polarization, we review the reported lncRNAs according to the underlying mechanisms. Moreover, we discuss the possibilities of targeting macrophages' M2 polarization using the oligonucleotides drugs or clustered regularly interspaced palindromic repeats (CRISPR) technologies to provoke wisdom on the therapeutic strategies.

Promotion of epithelial-mesenchymal transformation by hepatocellular carcinoma-educated macrophages through Wnt2b/β-catenin/c-Myc signaling and reprogramming glycolysis

Background

Tumour-associated macrophages (TAMs) in the tumour microenvironment (TME) can promote the progression of hepatocellular carcinoma (HCC). Some tumours can be suppressed by targeting Wnt2b in tumour cells. However, the role of Wnt2b in HCC is still unknown. In particular, the role of Wnt2b-mediated signal activation in macrophage polarization in the HCC microenvironment, and the regulatory effect between Wnt and glycolysis in TAMs has not been described.

Methods

The expression of Wnt2b in TAMs was detected by qPCR and immunofluorescence. Wnt2b/β-catenin interference in HCC-TAMs was performed by lentivirus carrying targeted shRNA or TLR9 agonist. Markers related to macrophage polarization and the changes of key glycolytic enzymes expression were detected by flow cytometry and qPCR. ECAR was analysed by Seahorse analyser. MTT assay, wound healing assay, western blotting were used to evaluate the promoting effect of different HCC-TAMs on the proliferation, migration and EMT of HCC in vitro. Tumour cells and different HCC-TAMs were injected via subcutaneously into immunodeficient mice to assess the effects of CpG ODN, Wnt2b, or β-catenin on HCC-TAMs in tumour growth in vivo.

Results

Polarization-promoting factors derived from HCC cells upregulated the expression of Wnt2b in macrophages, which promoted the polarization of TAMs to M2-like macrophages by activating Wnt2b/β-catenin/c-Myc signalling. Furthermore, this process was associated with the activation of glycolysis in HCC-TAMs. These HCC-TAMs could promote the development of EMT, proliferation, and migration of HCC. In addition to silencing Wnt2b or β-catenin expression, TLR9 agonist CpG ODN downregulated the level of glycolysis and inhibited the M2 polarization of HCC-TAMs, reversing the tumour-promoting effects of TAMs in vitro and vivo.

Conclusions

As a potential target for HCC therapy, Wnt2b may play an important regulatory role for the functions of TAMs in the TME. Moreover, the TLR9 agonist CpG ODN might act as a Wnt2b signal inhibitor and can potentially be employed for HCC therapy by disturbing Wnt2b/β-catenin/c-Myc and inhibiting glycolysis in HCC-TAMs.

Integrated analysis of the molecular mechanisms in idiopathic pulmonary fibrosis

Rationale: Idiopathic pulmonary fibrosis (IPF) is one of the most aggressive forms of idiopathic interstitial pneumonia. Some miRNAs may be associated with IPF and may affect the occurrence and development of IPF in various pathways. Many miRNAs and genes that may be involved in the development of IPF have been discovered using chip and high throughput technologies. Methods: We analyzed one miRNA and four mRNA databases. We identified hub genes and pathways related to IPF using GO, KEGG enrichment analysis, gene set variation analysis (GSVA), PPI network construction, and hub gene analysis. A comprehensive analysis of differentially expressed miRNAs (DEMs), predicted miRNA target genes, and differentially expressed genes (DEGs) led to the creation of a miRNA-mRNA regulatory network in IPF. Results: We found 203 DEGs and 165 DEMs that were associated with IPF. The findings of enrichment analyses showed that these DEGs were mainly involved in antimicrobial humoral response, antimicrobial humoral immune response mediated by antimicrobial peptide, extracellular matrix organization, cell killing, and organ or tissue specific immune response. The VEGFA, CDH5, and WNT3A genes overlapped between hub genes and the miRNA-mRNA regulatory network. The miRNAs including miR-199b-5p, miR-140-5p, miR-199a-5p, miR-125A-5p, and miR-107 that we predicted would regulate the VEGFA, CDH5, and WNT3A genes, which were also associated with IPF or other fibrosis-related diseases. GSVA indicated that metabolic processes of UTP and IMP, immune response, regulation of Th2 cell cytokine production, and positive regulation of NK cell-mediated immunity are associated with the pathogenesis and treatment of IPF. These pathways also interact with VEGFA, CDH5, and WNT3A. Conclusion: These findings provide a new research direction for the diagnosis and treatment of IPF.

Wnt/β-Catenin Signaling as a Driver of Hepatocellular Carcinoma Progression: An Emphasis on Molecular Pathways

Liver cancers cause a high rate of death worldwide and hepatocellular carcinoma (HCC) is considered as the most common primary liver cancer. HCC remains a challenging disease to treat. Wnt/β-catenin signaling pathway is considered a tumor-promoting factor in various cancers; hence, the present review focused on the role of Wnt signaling in HCC, and its association with progression and therapy response based on pre-clinical and clinical evidence. The nuclear translocation of β-catenin enhances expression level of genes such as c-Myc and MMPs in increasing cancer progression. The mutation of CTNNB1 gene encoding β-catenin and its overexpression can lead to HCC progression. β-catenin signaling enhances cancer stem cell features of HCC and promotes their growth rate. Furthermore, β-catenin prevents apoptosis in HCC cells and increases their migration via triggering EMT and upregulating MMP levels. It is suggested that β-catenin signaling participates in mediating drug resistance and immuno-resistance in HCC. Upstream mediators including ncRNAs can regulate β-catenin signaling in HCC. Anti-cancer agents inhibit β-catenin signaling and mediate its proteasomal degradation in HCC therapy. Furthermore, clinical studies have revealed the role of β-catenin and its gene mutation (CTNBB1) in HCC progression. Based on these subjects, future experiments can focus on developing novel therapeutics targeting Wnt/β-catenin signaling in HCC therapy.

Decoding Immune Heterogeneity of Melanoma and identifying immune-prognostic hub genes

Melanoma is an aggressive skin cancer that has gained attention worldwide. Growing evidence has highlighted that the tumor microenvironment (TME) is an important feature of carcinogenesis and contributes to therapeutic efficacy in melanoma. However, additional advances in melanoma immuno-oncology are necessary to achieve a comprehensive knowledge of the immune infiltrate population and to identify accurate and readily measurable biomarkers. In this study, we analyzed gene expression of 468 melanoma cases from the TCGA database, which led to the identification of three melanoma clusters (representedby low, median and high infiltration) that display unique immune features. We found that the microenvironment clusters had substantial prognostic efficacy. The median cluster was characterized by an inability to draw immune cells, highlighting possible immune escape mechanisms, and lower CXCL9 and CXCL10 expression, which was correlated to poor prognosis. Deep molecular characterization of immune cells, cytolytic-activity and tumor-inflammatory status revealed diversity of the local immune infiltration landscape in the melanoma clusters. Differentially expressed genes related to TME were extracted from each infiltration cluster. Functional annotations revealed that these genes were mainly related to immune system activation and the processes of immunoreaction. The top ten hub genes in immune infiltration-related protein-protein interaction (PPI) networks were selected for further prognostic investigation. Further validation showed that five of ten hub genes were good prognostic biomarkers for melanoma in two independent groups from the Gene Expression Omnibus database. In brief, these data highlight that systemic characterization of melanoma could uncover tumor infiltrate characteristics, which can help select the most adequate treatment and identify consistent and important indicators of the local immune tumor microenvironment in melanoma patients.

The novel target of esophageal squamous cell carcinoma: lncRNA GASL1 regulates cell migration, invasion and cell cycle stagnation by inactivating the Wnt3a/β-catenin signaling

Long non-coding RNA (lncRNA) Growth-Arrest Associated LncRNA 1 (GASL1) is a lncRNA with a suppressive role in glioma, prostate carcinoma and gastric carcinoma, whereas its involvement in esophageal cancer is unknown. In the present study, we used RT-qPCR to detect the expression of GASL1 in esophageal cancer cell carcinoma (ESCC) cell lines, and constructed the overexpression and interference plasmids of GASL1 and the interference plasmid of DKK1. CCK8 was used to detect the cell proliferation level, clone formation experiment was used to detect the cell clonal formation ability, flow cytometry was used to detect the cell cycle level, and wound healing and Transwell experiments were respectively used to detect the cell invasion and migration. The interference and overexpression plasmids of GASL1 were injected into mice subcutaneously for tumor-bearing experiment. The body weight, tumor growth curve, and tumor weight of mice were recorded, and western blot was used to detect the expression of proliferation-, invasion-, and migration-related proteins and the expression of Wnt3a/β-catenin signal-related proteins in tumor tissues. LncRNA GASL1 was down-regulated in ESCC cell lines, and GASL1 inhibited ESCC cell progression and regulated cell cycle arrest in ESCC cells. In vivo, GASL1 inhibited tumor growth. GASL1 decreased the protein levels of DDK1, Wnt3a, β-catenin, and c-MYC in ESCC cell lines. Interfering DKK1 activates Wnt3a/β--catenin signal to reverse the inhibitory effects of GASL1 on proliferation, cell cycle acceleration, invasion, and migration. In conclusion, lncRNA GASL1 regulates cell migration, invasion and cell cycle stagnation by inactivating the wnt/β-catenin signaling.

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.

Long Noncoding RNA PRR34-AS1 Aggravates the Progression of Hepatocellular Carcinoma by Adsorbing microRNA-498 and Thereby Upregulating FOXO3

Purpose

Long noncoding RNAs are differentially expressed in hepatocellular carcinoma (HCC) and have been validated as essential regulators in HCC. However, there is limited knowledge regarding the detailed roles and mechanisms of most lncRNAs in HCC cells. In this study, the expression profiles of PRR34 antisense RNA 1 (PRR34-AS1) in HCC tissues and cell lines were determined. In addition, the detailed roles and underlying mechanisms of PRR34-AS1 in HCC cells were comprehensively elucidated.

Methods

Reverse transcription-quantitative polymerase chain reaction (PCR) was performed to measure PRR34-AS1 expression in HCC cells. Cell proliferation, apoptosis, and migration and invasion were evaluated in vitro using the cell counting kit-8 (CCK-8) assay, flow cytometric analysis, and transwell cell migration and invasion assays, respectively. In vivo tumor growth was determined using tumor xenograft experiments. The potential miRNA targets of PRR34-AS1 were predicted via bioinformatic analysis and further confirmed using the luciferase reporter assay, RNA immunoprecipitation assay, and reverse transcription-quantitative PCR.

Results

PRR34-AS1 was highly expressed in HCC tissues and cell lines, and its interference suppressed HCC cell proliferation, migration, and invasion but promoted cell apoptosis in vitro. In addition, loss of PRR34-AS1 decreased tumor growth in HCC cells in vivo. Mechanistically, PRR34-AS1 functions as a miR-498 sponge and subsequently increases forkhead box O3 (FOXO3) expression in HCC cells. Rescue experiments revealed that the suppressive effects triggered by PRR34-AS1 knockdown on the malignant characteristics of HCC cells could be abrogated by inhibiting miR-498 or restoring FOXO3 expression.

Conclusion

The depletion of PRR34-AS1 suppresses the oncogenicity of HCC cells by targeting the miR-498/FOXO3 axis. Therefore, the PRR34-AS1/miR-498/FOXO3 pathway may offer a basis for HCC treatment.

LncRNA PSMB8-AS1 contributes to pancreatic cancer progression via modulating miR-382-3p/STAT1/PD-L1 axis

Background

Accumulating evidence demonstrates the essential role of long non-coding RNA (lncRNA) in various types of cancers, including pancreatic cancer. However, the functions and regulation mechanism of lncRNA PMSB8-AS1 in pancreatic cancer are largely unclear.

Methods

Quantitative reverse transcription PCR (qRT-PCR) is used to examine the expression of PMSB8-AS1 in PC tissues and PC cell lines. The effect of PMSB8-AS1 on the proliferation of PC cells was detected using CCK8 assay, colony assay, and flow cytometry. The effect of PMSB8-AS1 on the migration and invasion of pancreatic cancer cells was detected using a wound-healing assay and transwell migration assay. Bioinformatic analysis, double luciferase reporting assay, western blot, and rescue experiments were used to detect the regulatory relationship between PMSB8-AS1, miR-382–3p, STAT1, and PD-L1.

Results

PMSB8-AS1 expression was upregulated in PC tissues and cell lines and positively associated with the worst survival in patients with PC. The in vitro and in vivo assays demonstrated that overexpression of PMSB8-AS1 significantly promoted pancreatic cancer cell proliferation, migration, and invasion, whereas knockdown of PMSB8-AS1 suppressed cell proliferation, migration, invasion, and EMT, and decreased apoptosis of PC cells. Besides, PMSB8-AS1 directly bound to miR-382–3p downregulated its expression. Besides, PMSB8-AS1 reversed the effect of miR-382–3p on the growth and metastasis of PC cells, which might be targeted on STAT1. Furthermore, STAT1 is the transcriptional factor that activates the expression of PD-L1.

Conclusion

lncRNA PMSB8-AS1 promotes pancreatic cancer progression via STAT1 by sponging miR-382–3p involving regulation PD-L1.

LINC00662 Long Non-Coding RNA Knockdown Attenuates the Proliferation, Migration, and Invasion of Osteosarcoma Cells by Regulating the microRNA-15a-5p/Notch2 Axis

Purpose

Osteosarcoma (OS) is a frequently occurring malignancy in children and adolescents. In this study, we aimed to investigate the effects of the long non-coding RNA (lncRNA) LINC00662 (LINC00662) in OS and the underlying molecular mechanism.

Methods

The expression of LINC00662, microRNA-15a-5p (miR-15a-5p), and Notch2 in OS was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration, and invasion of OS cells were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound-healing, and transwell assay. The interactions among LINC00662, miR-15a-5p, and Notch2 were determined by dual-luciferase reporter assays. A tumor xenograft model was established in mice for evaluating tumor growth in vivo.

Results

The expression of LINC00662 and Notch2 was found to be upregulated in OS, but the expression of miR-15a-5p was downregulated. The results demonstrated that LINC00662 knockdown attenuated the proliferation, migration, and invasion of OS cells and suppressed tumor growth in mice. The study further demonstrated that LINC00662 directly interacted with miR-15a-5p, and that Notch2 was a target of miR-15a-5p. The inhibition of miR-15a-5p or Notch2 overexpression markedly reversed the suppressive effect of sh-LINC00662 on the proliferation, migration, and invasion of OS cells.

Conclusion

The study demonstrated that LINC00662 could be a potential biomarker for OS therapy, and LINC00662 knockdown suppressed the proliferation, migration, and invasion of OS cells by regulating the miR-15a-5p/Notch2 axis.

Role of long noncoding RNA-mediated competing endogenous RNA regulatory network in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are noncoding RNAs (ncRNAs) that occupy over 90% of the human genome, and their main function is to directly or indirectly regulate messenger RNA (mRNA) expression and participate in the tumorigenesis and progression of malignances. In particular, some lncRNAs can interact with miRNAs as competing endogenous RNAs (ceRNAs) to modulate mRNA expression. Accordingly, these RNA molecules are interrelated and coordinate to form a dynamic lncRNA-mediated ceRNA regulatory network. Mounting evidence has revealed that lncRNAs that act as ceRNAs are closely related to tumorigenesis. To date, numerous studies have established many different regulatory networks in hepatocellular carcinoma (HCC), and perturbations in these ceRNA interactions may result in the initiation and progression of HCC. Herein, we emphasize recent advances concerning the biological function of lncRNAs as ceRNAs in HCC, with the aim of elucidating the molecular mechanism underlying these HCC-related RNA molecules and providing novel insights into the diagnosis and treatment of HCC.

Emerging neo adjuvants for harnessing therapeutic potential of M1 tumor associated macrophages (TAM) against solid tumors: Enusage of plasticity

Macrophages are a major component of the tumor microenvironment (TME) of most tumors. They are characterized by a high degree of functional plasticity which enable these cells to both promote and eliminate established tumors. Under the influence of immunosuppressive TME, tumor infiltrating iNOS+ and CD11b+ M-1 effector macrophages get polarized towards tumor associated macrophages (TAM) which are tropic to variety of tumors. Increased infiltration and density of TAM is associated with tumor progression and poor prognosis in the plethora of tumors due to their angiogenetic and tissue re-modelling nature. Importantly, TAMs are also responsible for developing endothelium anergy, a major physical barrier for majority of cancer directed immune/chemotherapies. Therefore, functional retuning/re-educating TAM to M-1 phenotypic macrophages is paramount for effective immunotherapy against established tumors. In this review, we discuss and provide comprehensive update on TAM-targeted approaches for enhancing immunity against various solid tumors.

Knockdown of LINC00662 represses AK4 and attenuates radioresistance of oral squamous cell carcinoma

Background

LncRNAs play crucial roles in the development of carcinomas. However, the investigation of LINC00662 in Oral squamous cell carcinoma (OSCC) is still elusive.

Methods

qRT-PCR assay tested the expression levels of LINC00662, hnRNPC and AK4. With exposure to irradiation, CCK-8, colony formation, flow cytometry and western blot experiments, respectively determined the function of LINC00662 in the radiosensitivity of OSCC cells. Then RIP and western blot assays affirmed the interaction between hnRNPC protein and LINC00662 or AK4. Finally, rescue assays validated the regulation mechanism of LINC00662 in the radioresistance of OSCC.

Results

In the present report, LINC00662 was overexpressed in OSCC and its silencing could alleviate radioresistance of OSCC. Furthermore, the interaction between hnRNPC protein and LINC00662 or AK4 was uncovered. Besides, LINC00662 regulated AK4 mRNA stability through binding to hnRNPC protein. To sum up, LINC00662 modulated the radiosensitivity of OSCC cells via hnRNPC-modulated AK4.

Conclusion

The molecular mechanism of the LINC00662/hnRNPC/AK4 axis was elucidated in OSCC, which exhibited a promising therapeutic direction for patients with OSCC.

Emerging Roles of Long non-coding RNAs in The Tumor Microenvironment

Long non-coding RNAs (lncRNAs) are a diverse class of longer than 200 nucleotides RNA transcripts that have limited protein coding capacity. LncRNAs display diverse cellular functions and widely participate in both physiological and pathophysiological processes. Aberrant expressions of lncRNAs are correlated with tumor progression, providing sound rationale for their targeting as attractive anti-tumor therapeutic strategies. Emerging evidences support that lncRNAs participate in tumor-stroma crosstalk and stimulate a distinctive and suitable tumor microenvironment (TME). The TME comprises several stromal cells such as cancer stem cells (CSCs), cancer-associated endothelial cells (CAEs), cancer-associated fibroblasts (CAFs) and infiltrated immune cells, all of which are involved in the complicated crosstalk with tumor cells to affect tumor progression. In this review, we summarize the essential properties and functional roles of known lncRNAs in related to the TME to validate lncRNAs as potential biomarkers and promising anti-cancer targets.