Epstein-Barr Virus miRNA BART2-5p Promotes Metastasis of Nasopharyngeal Carcinoma by Suppressing RND3

Predicting the overall survival and progression-free survival of nasopharyngeal carcinoma patients based on hemoglobin, albumin, and globulin ratio and classical clinicopathological parameters

BACKGROUND

Serum biomarkers have a significant impact on the prediction of treatment outcomes in patients diagnosed with nasopharyngeal carcinoma (NPC). The primary aim of this study was to develop and validate a nomogram that incorporates hemoglobin, albumin, and globulin ratio (HAGR) and clinical data to accurately forecast treatment outcomes in patients with NPC.

METHODS

A total of 796 patients diagnosed with NPC were included in the study.

RESULTS

The results of the multivariate Cox analysis revealed that TNM stage and HAGR were found to be significant independent prognostic factors for OS and PFS. Furthermore, the utilization of the nomogram demonstrated a significant improvement in the evaluation of OS, PFS compared with the eighth TNM staging system. Additionally, the implementation of Kaplan-Meier curves and decision curve analysis curves further confirmed the discriminability and clinical effectiveness of the nomogram.

CONCLUSIONS

The HAGR, an innovative prognostic factor grounded in the realm of immunonutrition, has emerged as a promising prognostic marker for both OS and PFS in individuals afflicted with NPC.

KIAA1429 facilitates metastasis via m6A-YTHDC1-dependent RND3 down-regulation in hepatocellular carcinoma cells

N6-methyladenosine (m6A), a dynamically reversible modification in eukaryotic RNAs, modulates gene expression and pathological processes in various tumors. KIAA1429, the largest component of the m6A methyltransferase complex, plays an important role in m6A modification. However, the underlying mechanism of KIAA1429 in hepatocellular carcinoma (HCC) remains largely unknown. Immunohistochemical assay was performed to examine the expression of KIAA1429 in HCC tissues. Transwell, wound healing and animal experiments were used to investigate the influence of KIAA1429 on cell migration and invasion. The mRNA high-throughput sequencing (RNA-seq) and methylated RNA immunoprecipitation sequencing (MeRIP-seq) were performed to screen the downstream target of KIAA1429. RNA stability assays, RNA immunoprecipitation assay (RIP), MeRIP-qPCR and luciferase assay were used to evaluate the relationship between KIAA1429 and the m6A-modified genes. Results showed that the expression level of KIAA1429 was significantly higher in HCC tissues than in adjacent tissues, and the upregulation of KIAA1429 could promote HCC metastasis in vitro and in vivo. Mechanistically, we confirmed that KIAA1429 negatively regulated the tumor suppressor, Rho family GTPase 3 (RND3), by decreasing its mRNA stability in coordination with the m6A reader YTHDC1. Moreover, we demonstrated that KIAA1429 could regulate the m6A modification of RND3 mRNA via its RNA binding domain. Our data indicated that KIAA1429 exerted its oncogenic role by inhibiting RND3 expression in an m6A-dependent manner, suggesting that KIAA1429 might be a potential prognostic biomarker and therapeutic target in HCC.

Oncoviruses: Induction of cancer development and metastasis by increasing anoikis resistance

The phenomenon of cell death is a vital aspect in the regulation of aberrant cells such as cancer cells. Anoikis is a kind of cell death that occurs when cells get separated from the extracellular matrix. Some cancer cells can inhibit anoikis in order to progress metastasis. One of the key variables that might be implicated in anoikis resistance (AR) is viral infections. The most important viruses involved in this process are Epstein-Barr virus, human papillomavirus, hepatitis B virus, human herpes virus 8, human T-cell lymphotropic virus type 1, and hepatitis C virus. A better understanding of how carcinogenic viruses suppress anoikis might be helpful in developing an effective treatment for virus-associated cancers. In the current study, we review the role of the mentioned viruses and their gene products in anoikis inhibition.

Epstein-Barr virus microRNA miR-BART2-5p accelerates nasopharyngeal carcinoma metastasis by suppressing RNase Ⅲ endonuclease DICER1

The development and progression of nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) infection. NPC is usually asymptomatic until it spreads to other sites, and more than 70% of cases are classified as locally advanced disease at diagnosis. EBV-positive nasopharyngeal cancer tissues express only limited viral latent proteins, but express high levels of the EBV-encoded BamHI-A rightward transcript (BART) miRNA molecules. Here, we report that EBV-miRNA-BART2-5p (BART2-5p) promotes NPC cell invasion and metastasis in vivo and in vitro but has no effect on NPC cell proliferation and apoptosis. In addition, BART2-5p altered the mRNA and miRNA expression profiles of NPC cells. The development of human tumors has been reported to be associated with altered miRNAs expression, and overall miRNAs expression is reduced in many types of tumors. We found that BART2-5p downregulated the expression of several miRNAs that could exert oncogenic functions. Mechanistically, BART2-5p directly targets the RNase III endonuclease DICER1, inhibiting its function of cleaving double-stranded stem-loop RNA into short double-stranded RNA, which in turn causes altered expression of a series of key epithelial-mesenchymal transition molecules, and reverting DICER1 expression can rescue this phenotype. Furthermore, analysis from clinical samples showed a negative correlation between BART2-5p and DICER1 expression. According to our study, high expression of BART2-5p in tissues and plasma of patients with NPC is associated with poor prognosis. Our results suggest that, BART2-5p can accelerate NPC metastasis through modulating miRNA profiles which are mediated by DICER1, implying a novel role of EBV miRNAs in the pathogenesis of NPC.

Hypoxic nasopharyngeal carcinoma-derived exosomal miR-455 increases vascular permeability by targeting ZO-1 to promote metastasis

Nasopharyngeal carcinoma (NPC), the most frequent reason for treatment failure in head and neck tumors, has the greatest incidence of distant metastases. Increased vascular permeability facilitates metastasis. Exosomal microRNAs (miRNAs) have been implicated in the development of the premetastatic niche and are emerging as prospective biomarkers in cancer patients. We discovered that a higher level of miR-455 was connected to a larger propensity for NPC metastasis based on deep sequencing and RT-qPCR. We found that hypoxia promoted NPC exosomes release and increased miR-455 expression in a way that was hypoxia-inducible factor 1-alpha (HIF-1α) dependent. Exosomes from NPC cells with high levels of miR-455 were found to specifically target zonula occludens 1 (ZO-1), increasing the permeability of endothelial monolayers in vitro vascular permeability and transendothelial invasion experiments. Additional in vivo studies showed that zebrafish with sustained miR-455-overexpressing NPC cell xenografts displayed increased tumor cell mass throughout the body. In vivo, zebrafish vascular tight junction integrity was disrupted by exosomes produced by NPC cells with elevated miR-455 expression. Mice-bearing xenografts further supported the finding that exosomes containing miR-455 might reduce ZO-1 expression in addition to promote NPC cell growth. These findings suggest that in a hypoxic microenvironment, exosomal miR-455 released by NPC cells enhances vascular permeability and promotes metastasis by targeting ZO-1. The HIF-1α-miR-455-ZO-1 signaling pathway may be a promising predictor and potential therapeutic target for NPC with metastasis.

SEVs-mediated miR-6750 transfer inhibits pre-metastatic niche formation in nasopharyngeal carcinoma by targeting M6PR

Reliable detection of circulating small extracellular vesicles (SEVs) and their miRNA cargo has been needed to develop potential specific non-invasive diagnostic and therapeutic marker for cancer metastasis. Here, we detected miR-6750, the precise molecular function of which was largely unknown, was significantly enriched in serum-SEVs from normal volunteers vs. patients with nasopharyngeal carcinoma (NPC). And we determined that miR-6750-SEVs attenuated NPC metastasis. Subsequently, miR-6750-SEVs was proven to inhibit angiogenesis and activate macrophage toward to M1 phenotype to inhibit pre-metastatic niche formation. After analyzing the expression level of miR-6750 in NPC cells, HUVECs and macrophage, we found that once miR-6750 level in NPC cells was close to or higher than normal nasopharyngeal epithelial cells (NP69), miR-6750-SEVs would be transferred from NPC cells to macrophage and then to HUVECs to modulate metastatic niche. Moreover, in vitro assays and BALB/c mouse tumor models revealed that miR-6750 directly targeted mannose 6-phosphate receptor (M6PR). Taken together, our findings revealed that miR-6750-M6PR axis can mediate NPC metastasis by remodeling tumor microenvironment (TME) via SEVs, which give novel sights to pathogenesis of NPC.

Epstein-Barr virus miR-BART2-5p and miR-BART11-5p regulate cell proliferation, apoptosis, and migration by targeting RB and p21 in gastric carcinoma

Epstein-Barr virus (EBV) was the first tumor virus discovered in humans and can cause various types of tumors. Molecular classification suggests that EBV-associated gastric cancer (EBVaGC) is a unique subtype of gastric cancer.EBV was also the first virus found to encode its own microRNAs. However, the functions of many miRNAs remain unknown. This study investigated the roles and targets of miR-BART2-5p (BART2-5p) and miR-BART11-5p (BART11-5p) in EBVaGC. The expression of RB and p21 in EBVaGC and EBV negative GC (EBVnGC) cells was evaluated by western blotting. Expression of BART2-5p and BART11-5p in EBVaGC cells was evaluated by droplet digital PCR. The effects of BART2-5p or BART11-5p and their potential mechanisms were further investigated using cell counting kit-8, colony formation assay, flow cytometry analysis, and transwell assay. BART2-5p and BART11-5p were abundantly expressed and RB and p21 were downregulated in EBVaGC cells. BART2-5p regulates RB and p21 expression by directly targeting them. BART11-5p regulates RB expression by directly targeting RB. Both BART2-5p and BART11-5p promoted proliferation and migration of gastric cancer cells, while inhibiting apoptosis and promoting S-phase arrest of the cell cycle. Thus, BART2-5p and BART11-5p play important roles in promoting proliferation and migration, and inhibiting apoptosis in EBVaGC by targeting RB and p21, thus providing new potential therapeutic targets for EBVaGC.

Screening Key Genes and Biological Pathways in Nasopharyngeal Carcinoma by Integrated Bioinformatics Analysis

The purpose of this study was to identify the hub genes and biological pathways of nasopharyngeal carcinoma (NPC) through bioinformatics analysis and potential new therapeutic targets. In this study, three datasets were downloaded from the Gene Expression Omnibus (GEO), and differentially expressed genes (DEGs) between NPC and normal tissues were analyzed using the GEO2R online tool. Volcano and heat maps of the DEGs were visualized using the hiplot database. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the upregulated and downregulated DEGs were performed using the DAVID database. Finally, we established a protein-protein interaction (PPI) network using the STRING database and showed the differential expression of hub genes between the normal and tumor tissues. In all, 109,371,221 upregulated DEGs and 139,226,520 downregulated DEGs were obtained in datasets GSE40290, GSE61218, and GSE53819, respectively, and 18 common differential genes, named co-DEGs, were screened in the three datasets. The most abundant biological GO terms of the co-DEGs were inflammatory response et al. The KEGG pathway enrichment analysis showed that co-DEGs mainly participated in the interleukin (IL)-17 signaling pathway et al. Finally, we identified four hub genes using PPI analysis and observed that three of them were highly expressed in tumor tissues. In this study, the hub genes of NPC, such as PTGS2, and pathways such as IL-17 signaling, were identified through bioinformatics analysis, which may be potential new therapeutic targets for NPC.

Epstein-Barr Virus-Encoded MicroRNA-BART18-3p Promotes Colorectal Cancer Progression by Targeting De Novo Lipogenesis

The Epstein-Barr virus (EBV) genome encodes a cluster of 22 viral microRNAs, called miR-BamHI-A rightward transcripts (miR-BARTs), which are shown to promote the development of cancer. Here, this study reports that EBV-miR-BART18-3p is highly expressed in colorectal cancer (CRC) and is closely associated with the pathological and advanced clinical stages of CRC. Ectopic expression of EBV-miR-BART18-3p leads to increased migration and invasion capacities of CRC cells in vitro and causes tumor metastasis in vivo. Mechanistically, EBV-miR-BART18-3p activates the hypoxia inducible factor 1 subunit alpha/lactate dehydrogenase A axis by targeting Sirtuin, which promotes lactate accumulation and acetyl-CoA production in CRC cells under hypoxic condition. Increased acetyl-CoA utilization subsequently leads to histone acetylation of fatty acid synthase and fatty acid synthase-dependent fat synthesis, which in turn drives de novo lipogenesis. The oncogenic role of EBV-miR-BART18-3p is confirmed in the patient-derived tumor xenograft mouse model. Altogether, the findings define a novel mechanism of EBV-miR-BART18-3p in CRC development through the lipogenesis pathway and provide a potential clinical intervention target for CRC.

Establishment of a prognostic nomogram for patients with locoregionally advanced nasopharyngeal carcinoma incorporating clinical characteristics and dynamic changes in hematological and inflammatory markers

Background

This study aims to investigate the prognostic value of changes in hematological and inflammatory markers during induction chemotherapy (IC) and concurrent chemo-radiation (CCRT), thus construct nomograms to predict progression free survival (PFS) of patients with locally advanced nasopharyngeal carcinoma (LANPC).

Methods

130 patients were included in this prospective analysis. Univariate and multivariate cox regression analyses were conducted to identify prognostic factors. Three multivariate analyses integrating different groups of variables were conducted independently. Concordance indexes (c-index), calibration plots and Kaplan-Meier curves were used to evaluate the nomograms. Bootstrap validation was performed to determine the accuracy of the nomogram using 1000 resamples. The performances of proposed nomograms and TNM staging system were compared to validate the prognostic value of hematological and inflammatory markers.

Results

Pretreatment gross tumor volume of nodal disease (GTVn), Δe/bHGB (hemoglobin count at end of treatment/baseline hemoglobin count), and stage were selected as predictors for 3-year PFS in first multivariate analysis of clinical factors. The second multivariate analysis of clinical factors and all hematological variables demonstrated that ΔminLYM (minimum lymphocyte count during CCRT/lymphocyte count post-IC), pretreatment GTVn and stage were associated with 3-year PFS. Final multivariate analysis, incorporating all clinical factors, hematological variables and inflammatory markers, identified the following prognostic factors: pretreatment GTVn, stage, ΔmaxPLR (maximum platelet-to-lymphocyte ratio (PLR) during CCRT/PLR post-IC), and ΔminPLT (minimum platelet count during CCRT/platelet count post-IC). Calibration plots showed agreement between the PFS predicted by the nomograms and actual PFS. Kaplan–Meier curves demonstrated that patients in the high-risk group had shorter PFS than those in the low-risk group (P ≤ 0.001). The c-indexes of the three nomograms for PFS were 0.742 (95% CI, 0.639-0.846), 0.766 (95% CI, 0.661-0.871) and 0.815 (95% CI,0.737-0.893) respectively, while c-index of current TNM staging system was 0.633 (95% CI, 0.531-0.736).

Conclusion

We developed and validated a nomogram for predicting PFS in patients with LANPC who received induction chemotherapy and concurrent chemo-radiation. Our study confirmed the prognostic value of dynamic changes in hematological and inflammatory markers. The proposed nomogram outperformed the current TNM staging system in predicting PFS, facilitating risk stratification and guiding individualized treatment plans.

Epstein-Barr virus-encoded microRNA BART22 serves as novel biomarkers and drives malignant transformation of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy ubiquitously associated with Epstein-Barr virus (EBV). EBV generates various viral microRNAs (miRNAs) by processing the BHRF1 and BamHI A rightward (BART) transcripts. These BART miRNAs are abundantly expressed in NPC, but their functions and molecular mechanisms remain largely unknown. Our study found that the EBV-encoded microRNA BART-22 was significantly upregulated in NPC tissues and positively correlated with tumor progression. Furthermore, we found that EBV-miR-BART-22 was a significant predictor of poor prognosis in NPC. A reliable nomogram model to predict the preoperative overall survival (OS) of NPC patients was established. The area under the receiver operating characteristic (ROC) curve value for 5-year survival was 0.91. Elevated levels of EBV-miR-BART-22 significantly promoted the epithelial-mesenchymal transition (EMT) and metastasis of NPC cells in vivo and in vitro. We found that EBV-miR-BART-22 directly targets the 3'-UTR of MOSPD2 mRNA to promote the EMT and metastasis of NPC cells by activating the Wnt/β-catenin signaling pathway. Our findings provide a potential prognostic biomarker and new insight into the molecular mechanisms of NPC metastasis.

RND3 Transcriptionally Regulated by FOXM1 Inhibits the Migration and Inflammation of Synovial Fibroblasts in Rheumatoid Arthritis Through the Rho/ROCK Pathway

Rheumatoid arthritis (RA) is a systemic immune disease. Rho family GTPase 3 (RND3) has been reported to play an important role in inflammatory diseases. In this study, the expression of RND3 in RA was analyzed by gene chips. After RND3 was overexpressed, cell counting kit-8 assay was to detect the viability of fibroblast-like synovial cells (RA-FLSs). Transwell assays were to appraise the migratory and invasive capacities of RA-FLSs. Enzyme-linked immunosorbent assay (ELISA) and Western blot analysis were to estimate inflammatory response. In addition, MMP3 and MMP9 levels were also tested by ELISA analysis. After forkhead box M1 (FOXM1) was overexpressed, RND3 expression was detected by Western blot. The transcriptional relationship between FOXM1 and RND3 was predicted by HumanTFDB and JASPAR databases. Luciferase reporter and chromatin immunoprecipitation assays verified the binding ability of FOXM1 and RND3. The role of FOXM1/RND3 axis in RA was detected again by functional experiments. Western blot detected the expression of Rho/ROCK pathway-related proteins. RND3 expression was downregulated in RA. Overexpression of RND3 reduced the proliferation, migration, invasion, and inflammation of RA-FLSs. RND3 was inhibited by FOXM1 transcription, and upregulated FOXM1 reduced the inhibitory effect of RND3 overexpression on cell growth and inflammation, which might be associated with the Rho/ROCK pathway. RND3 transcriptionally regulated by FOXM1 inhibited the migration and inflammation of RA-FLSs in RA through the Rho/ROCK pathway.

Prognostic Epstein-Barr Virus (EBV) miRNA biomarkers for survival outcome in EBV-associated epithelial malignancies: Systematic review and meta-analysis

Background

The EBV-associated epithelial tumours consist 80% of all EBV-associated cancer, where the nasopharyngeal cancer (NPC) and EBV-associated gastric carcinoma (EBVaGC) are considered as the most frequent EBV-associated epithelial tumours. It has been shown that the BART-encoded miRNAs are abundantly expressed in EBV-associated epithelial tumours, hence, these miRNAs may serve as diagnostic and prognostic biomarkers for EBV-associated epithelial tumours. Therefore, the purpose of this systematic review and meta-analysis is to assess these EBV miRNAs as prognostic biomarkers for NPC and GC.

Method

This systematic review was developed based on PRISMA guidelines and utilizing PubMed, Web of Science, Scopus, Cochrane, and Google scholar databases. The retrieved articles were thoroughly screened in accordance with the selection criteria. The hazard ratio (HR) and 95% confidence interval (CI) for patient survival outcomes were used to evaluate EBV miRNA expression levels. To assess the risk of bias, funnel plot symmetry and Egger’s bias test were employed.

Result

Eleven studies met the selection criteria for inclusion, and four were included in the meta-analysis. Most of the articles considered in this study were from China, with one study from South Korea. The overall pooled effect size estimation (HR) for upregulated EBV miRNAs was 3.168 (95% CI: 2.020–4.969), demonstrating that upregulated EBV miRNA expression enhanced the mortality risk in NPC and GC patients by three times.

Conclusion

To the best of our knowledge, this is the first meta-analysis that investigates the significance of EBV miRNAs as prognostic biomarkers in NPC and GC patients. The pooled effect estimates of HR of the various studies revealed that higher EBV miRNA expression in NPC and GC may result in a worse survival outcome. To assess the clinical significance of EBV miRNAs as prognostic biomarkers, larger-scale prospective studies are needed.

Identification of a 3-miRNA Signature Associated With the Prediction of Prognosis in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor caused by an infection of the epithelial cells of the nasopharynx, which is highly metastatic and aggressive. Due to the deep anatomical site and atypical early symptoms, the majority of NPC patients are diagnosed at terminal stages. There is growing evidence that microRNAs offer options for early detection, accurate diagnosis, and prediction of malignancy treatment response. Therefore, the purpose of this article was to identify microRNAs that predict the prognosis of patients with NPC by integrating biological information analysis. In this study, we utilized the GSE36682 dataset rooted in the Gene Expression Omnibus (GEO) data bank, including 62 cases of NPC tissues and six cases of non-cancerous tissues. The miRNAs were subjected to weighted gene co-expression network analysis, and hub miRNAs were screened for differentially upregulated miRNAs from modules highly correlated with tumor progression. We took a lot of time to calculate the risk scores of miRNA markers for 62 NPC patients, and incidentally combined the clinical survival information of patients to finally identify the three key miRNAs, and then divided the patients into low- and high-risk groups. Kaplan-Meier curve analysis revealed that the overall survival of patients in the high-risk group was obviously shorter than that of the low-risk group. Subsequently, the target genes of the three miRNAs were predicted and analyzed for functional enrichment. In summary, a prognostic predictive risk model based on three miRNA profiles may increase prognostic predictive value and provide reference information for the precise treatment of nasopharyngeal carcinoma.

MicroRNA-483-5p Predicts Poor Prognosis and Promotes Cancer Metastasis by Targeting EGR3 in Nasopharyngeal Carcinoma

Background

MicroRNAs, as small non-coding RNAs, play an important role in tumorigenesis. MiR-483-5p was found to have a significant increase as a diagnostic biomarker of nasopharyngeal carcinoma (NPC), not only in plasma from NPC patients but also in tumor cell lines and biopsy tissues in our previous study. However, its function and mechanism in NPC are still unclear.

Methods

Tissue microarray including 178 primary NPC and 35 adjacent non-cancerous nasopharyngeal mucosal tissues was used to further validate the overexpression of miR-483-5p. Wound healing and invasion assays were conducted to verify its biological function. RNA sequencing (RNA-seq) and dual-luciferase reporter assay was performed to explore its target, and it was verified in fresh biopsy tissues from 23 NPC patients and 9 patients with chronic nasopharyngitis.

Results

MiR-483-5p was highly expressed in NPC tissues than in adjacent non-cancerous tissues. It was found to have a significant correlation with poor overall survival (OS) [hazard ratio (HR) = 2.89, 95% confidence interval (CI) = 1.00-8.35, p = 0.041] and progression-free survival (PFS) (HR = 1.95, 95%CI = 1.06-3.60, p = 0.029) of NPC patients. Silencing of its expression inhibited the migratory and invasive capacities of NPC cells in vitro. EGR3 (early growth response 3) was identified as a direct target, and inhibiting miR-483-5p expression markedly enhanced the expression of EGR3 at both the mRNA and protein levels. Besides, a significant decrease of EGR3 expression was found in fresh biopsy tissues from NPC patients, in contrast to miR-483-5p expression. Furthermore, directly decreasing the expression of EGR3 could enhance the migration and invasion of NPC cells.

Conclusion

The newly identified miR-483-5p/EGR3 pathway provides further insights into the development and metastasis of NPC and may provide a potential therapeutic target for NPC treatment in order to improve survival of NPC patients.

Noncoding RNAs in tumor metastasis: molecular and clinical perspectives

Metastasis is the main culprit of cancer-associated mortality and involves a complex and multistage process termed the metastatic cascade, which requires tumor cells to detach from the primary site, intravasate, disseminate in the circulation, extravasate, adapt to the foreign microenvironment, and form organ-specific colonization. Each of these processes has been already studied extensively for molecular mechanisms focused mainly on protein-coding genes. Recently, increasing evidence is pointing towards RNAs without coding potential for proteins, referred to as non-coding RNAs, as regulators in shaping cellular activity. Since those first reports, the detection and characterization of non-coding RNA have explosively thrived and greatly enriched the understanding of the molecular regulatory networks in metastasis. Moreover, a comprehensive description of ncRNA dysregulation will provide new insights into novel tools for the early detection and treatment of metastatic cancer. In this review, we focus on discussion of the emerging role of ncRNAs in governing cancer metastasis and describe step by step how ncRNAs impinge on cancer metastasis. In particular, we highlight the diagnostic and therapeutic applications of ncRNAs in metastatic cancer.

MicroRNA and Other Non-Coding RNAs in Epstein-Barr Virus-Associated Cancers

EBV is a direct causative agent in around 1.5% of all cancers. The oncogenic properties of EBV are related to its ability to activate processes needed for cellular proliferation, survival, migration, and immune evasion. The EBV latency program is required for the immortalization of infected B cells and involves the expression of non-coding RNAs (ncRNAs), including viral microRNAs. These ncRNAs have different functions that contribute to virus persistence in the asymptomatic host and to the development of EBV-associated cancers. In this review, we discuss the function and potential clinical utility of EBV microRNAs and other ncRNAs in EBV-associated malignancies. This review is not intended to be comprehensive, but rather to provide examples of the importance of ncRNAs.

Immune Escape by Non-coding RNAs of the Epstein Barr Virus

Epstein Barr virus (EBV) is one of the most successful pathogens of humans, persistently colonizing more than 95% of the adult human population. At the same time EBV encodes oncogenes that can readily transform human B cells in culture and threaten healthy virus carriers with lymphomagenesis. Cytotoxic lymphocytes have been identified in experimental models and by primary immunodeficiencies as the main protective immune compartments controlling EBV. EBV has reached a stalemate with these cytotoxic T and innate lymphocytes to ensure persistence in most infected humans. Recent evidence suggests that the non-coding RNAs of the virus contribute to viral immune escape to prevent immune eradication. This knowledge might be used in the future to attenuate EBV for vaccine development against this human tumor virus that was discovered more than 55 years ago.

Advances in research on microRNAs related to the invasion and metastasis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), which is associated with latent Epstein-Barr virus infection in most cases, is a unique epithelial malignancy arising from the nasopharyngeal mucosal lining. Accumulating evidence provides insights into the genetic and molecular aberrations that likely drive nasopharyngeal tumor development and progression. We review recent analyses of microRNAs (miRNAs), including Epstein-Barr virus-encoded miRNAs (EBV-encoded miRNAs) and dysregulated cellular miRNAs, that may be related to the metastasis of nasopharyngeal carcinoma. The studies summarized herein have greatly expanded our knowledge of the molecular biology of NPC involving miRNAs, and they may provide new biological targets for clinical diagnosis and reveal the potential of microRNA therapeutics. However, much information remains to be uncovered.

Identification of potential plasma biomarkers in early-stage nasopharyngeal carcinoma-derived exosomes based on RNA sequencing

BACKGROUND

Early diagnosis of nasopharyngeal carcinoma (NPC) is vital to improve the prognosis of these patients. However, early diagnosis of NPC is typically challenging. Therefore, we explored the pathogenetic roles and associated mechanisms of exosomes in plasma of patients with early-stage NPC.

METHODS

Exosomes in plasma were extracted by ultra-high-speed centrifugation. Western blot and transmission electron microscopy (TEM) were used to verify the purity of exosomes. The sequencing data (6 plasma samples from healthy volunteers vs. 6 NPC plasma samples) were analyzed by principal component analysis (PCA), DESeq2, gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and TargetScan. The differentially expressed miRNAs (DEmiRNAs) were obtained from the dataset (GSE118720) downloaded from the Gene Expression Omnibus (GEO) repository. Additionally, the datasets downloaded from the GEO database (GSE12452, GSE13597, GSE53819, GSE64634) were used to predict the target genes and functions of hsa-miR-1301-3p. qPCR was applied to verify the differences in the expressions of hsa-miR-1301-3p between 10 normal plasma and 10 NPC plasma samples.

RESULTS

Western blot, TEM, and Nanoparticle Tracking Analysis showed adequate purity of the extracted exosomes. RNA-seq analysis revealed 21 upregulated miRNAs, and 10 downregulated miRNAs in plasma exosomes of early-stage NPC patients. GO analysis showed that the target genes of DEmiRNAs were mainly enriched in DNA synthesis and transcription regulation. KEGG analysis revealed that DEmiRNAs were mainly enriched in PI3K-Akt and MAPK signaling pathways. Moreover, the expression of hsa-mir-1301-3p was verified to be significantly upregulated in enlarged samples of plasma exosomes.

CONCLUSIONS

We identified several DEmiRNAs extracted from tumor-derived exosomes between normal plasma and early-stage NPC plasma. Bioinformatics analyses indicated that these DEmiRNAs may be related to NPC development. Our study may provide novel insights into underlying biomarkers and mechanisms of plasma exosomes in early-stage NPC.

Impacts of Environmental Factors on Head and Neck Cancer Pathogenesis and Progression

Epidemiological and clinical studies over the past two decades have provided strong evidence that genetic elements interacting with environmental components can individually and collectively influence one’s susceptibility to cancer. In addition to tumorigenic properties, numerous environmental factors, such as nutrition, chemical carcinogens, and tobacco/alcohol consumption, possess pro-invasive and pro-metastatic cancer features. In contrast to traditional cancer treatment, modern therapeutics not only take into account an individual’s genetic makeup but also consider gene–environment interactions. The current review sharpens the focus by elaborating on the impact that environmental factors have on the pathogenesis and progression of head and neck cancer and the underlying molecular mechanisms involved. Recent advances, challenges, and future perspectives in this area of research are also discussed. Inhibiting key environmental drivers of tumor progression should yield survival benefits for patients at any stage of head and neck cancer.

Epstein-Barr virus microRNAs in the pathogenesis of human cancers

The Epstein-Barr Virus (EBV) is a gamma-herpesvirus involved with a variety of human cancers, notably the endemic Burkitt lymphoma and nasopharyngeal carcinoma. In 2004, EBV was described as one the first known human oncoviruses to encode viral microRNAs (miRNAs), and these molecules were found to interact with viral and host targets. EBV miRNAs modulate biological processes that are critical for carcinogenesis, contributing to cell transformation and tumor progression of EBV-associated cancers. Herein we review and discuss EBV miRNAs as modulators of viral biology and carcinogenesis, as well as their usefulness as putative markers to monitor the onset, progression, and recurrence of cancers associated with the EBV infection.

EBV-encoded miRNAs can sensitize nasopharyngeal carcinoma to chemotherapeutic drugs by targeting BRCA1

Nasopharyngeal carcinoma (NPC) is an Epstein‐Barr virus (EBV)‐associated epithelial malignancy. The high expression of BART‐miRNAs (miR‐BARTs) during latent EBV infection in NPC strongly supports their pathological importance in cancer progression. Recently, we found that several BART‐miRNAs work co‐operatively to modulate the DNA damage response (DDR) by reducing Ataxia‐telangiectasia‐mutated (ATM) activity. In this study, we further investigated the role of miR‐BARTs on DDR. The immunohistochemical study showed that the DNA repair gene, BRCA1, is consistently down‐regulated in primary NPCs. Using computer prediction programs and a series of reporter assays, we subsequently identified the negative regulatory role of BART2‐3p, BART12, BART17‐5p and BART19‐3p in BRCA1 expression. The ectopic expression of these four miR‐BARTs suppressed endogenous BRCA1 expression in EBV‐negative epithelial cell lines, whereas BRCA1 expression was enhanced by repressing endogenous miR‐BARTs activities in C666‐1 cells. More importantly, suppressing BRCA1 expression in nasopharyngeal epithelial cell lines using miR‐BART17‐5p and miR‐BART19‐3p mimics reduced the DNA repair capability and increased the cell sensitivity to the DNA‐damaging chemotherapeutic drugs, cisplatin and doxorubicin. Our findings suggest that miR‐BARTs play a novel role in DDR and may facilitate the development of effective NPC therapies.

Identification and characterization of a new isoform of small GTPase RhoE

The Rho family of GTPases consists of 20 members including RhoE. Here, we discover the existence of a short isoform of RhoE designated as RhoEα, the first Rho GTPase isoform generated from alternative translation. Translation of this new isoform is initiated from an alternative start site downstream of and in-frame with the coding region of the canonical RhoE. RhoEα exhibits a similar subcellular distribution while its protein stability is higher than RhoE. RhoEα contains binding capability to RhoE effectors ROCK1, p190RhoGAP and Syx. The distinct transcriptomes of cells with the expression of RhoE and RhoEα, respectively, are demonstrated. The data propose distinctive and overlapping biological functions of RhoEα compared to RhoE. In conclusion, this study reveals a new Rho GTPase isoform generated from alternative translation. The discovery provides a new scope of understanding the versatile functions of small GTPases and underlines the complexity and diverse roles of small GTPases.

Dai et al. report the identification and characterization of a new isoform of RhoE (RhoEα), a member of the Rho GTPase family, which is generated from the same gene by alternative translation initiation at the downstream ATG codon 46. Compared to RhoE, RhoEα does not differ in the subcellular localization but has increased protein stability and distinct molecular signalling profile.