Long non-coding RNA NEAT1 overexpression is associated with unfavorable prognosis in patients with hepatocellular carcinoma after hepatectomy: A Chinese population-based study

Construction of a prognostic prediction model in liver cancer based on genes involved in integrin cell surface interactions pathway by multi-omics screening

Background: Liver cancer is a common malignant tumor with an increasing incidence in recent years. We aimed to develop a model by integrating clinical information and multi-omics profiles of genes to predict survival of patients with liver cancer. Methods: The multi-omics data were integrated to identify liver cancer survival-associated signal pathways. Then, a prognostic risk score model was established based on key genes in a specific pathway, followed by the analysis of the relationship between the risk score and clinical features as well as molecular and immunologic characterization of the key genes included in the prediction model. The function experiments were performed to further elucidate the undergoing molecular mechanism. Results: Totally, 4 pathways associated with liver cancer patients' survival were identified. In the pathway of integrin cell surface interactions, low expression of COMP and SPP1, and low CNVs level of COL4A2 and ITGAV were significantly related to prognosis. Based on above 4 genes, the risk score model for prognosis was established. Risk score, ITGAV and SPP1 were the most significantly positively related to activated dendritic cell. COL4A2 and COMP were the most significantly positively associated with Type 1 T helper cell and regulatory T cell, respectively. The nomogram (involved T stage and risk score) may better predict short-term survival. The cell assay showed that overexpression of ITGAV promoted tumorigenesis. Conclusion: The risk score model constructed with four genes (COMP, SPP1, COL4A2, and ITGAV) may be used to predict survival in liver cancer patients.

Exploring the role of lncrna neat1 knockdown in regulating apoptosis across multiple cancer types: A review

Long non-coding RNAs (lncRNAs) have emerged as pivotal regulators of gene expression, contributing significantly to a diverse range of cellular processes, including apoptosis. One such lncRNA is NEAT1, which is elevated in several types of cancer and aid in cancer growth. However, recent studies have also demonstrated that the knockdown of NEAT1 can inhibit cancer cells proliferation, movement, and infiltration while enhancing apoptosis. This article explores the function of lncRNA NEAT1 knockdown in regulating apoptosis across multiple cancer types. We explore the existing understanding of NEAT1's involvement in the progression of malignant conditions, including its structure and functions. Additionally, we investigate the molecular mechanisms by which NEAT1 modulates the cell cycle, cellular proliferation, apoptosis, movement, and infiltration in diverse cancer types, including acute myeloid leukemia, breast cancer, cervical cancer, colorectal cancer, esophageal squamous cell carcinoma, glioma, non-small cell lung cancer, ovarian cancer, prostate cancer, and retinoblastoma. Furthermore, we review the recent studies investigating the therapeutic potential of NEAT1 knockdown in cancer treatment. Targeting the lncRNA NEAT1 presents a promising therapeutic approach for treating cancer. It has shown the ability to suppress cancer cell proliferation, migration, and invasion while promoting apoptosis in various cancer types.

A New Understanding of Long Non-Coding RNA in Hepatocellular Carcinoma-From m6A Modification to Blood Biomarkers

With recent advancements in biological research, long non-coding RNAs (lncRNAs) with lengths exceeding 200 nucleotides have emerged as pivotal regulators of gene expression and cellular phenotypic modulation. Despite initial skepticism due to their low sequence conservation and expression levels, their significance in various biological processes has become increasingly apparent. We provided an overview of lncRNAs and discussed their defining features and modes of operation. We then explored their crucial function in the hepatocarcinogenesis process, elucidating their complex involvement in hepatocellular carcinoma (HCC). The influential role of lncRNAs within the HCC tumor microenvironment is emphasized, illustrating their potential as key modulators of disease dynamics. We also investigated the significant influence of N6-methyladenosine (m6A) modification on lncRNA function in HCC, enhancing our understanding of both their roles and their upstream regulators. Additionally, the potential of lncRNAs as promising biomarkers was discussed in liver cancer diagnosis, suggesting a novel avenue for future research and clinical application. Finally, our work underscored the dual potential of lncRNAs as both contributors to HCC pathogenesis and innovative tools for its diagnosis. Existing challenges and prospective trajectories in lncRNA research are also discussed, emphasizing their potential in advancing liver cancer research.

Long noncoding RNA NEAT1 promotes cardiac fibrosis in heart failure through increased recruitment of EZH2 to the Smad7 promoter region

Cardiac fibrosis, a well-known major pathological process that ultimately leads to heart failure, has attracted increasing attention and focus in recent years. A large amount of research indicates that long noncoding RNAs (lncRNAs) play an important role in cardiac fibrosis, but little is known about the specific function and mechanism of the lncRNA NEAT1 in the progression of cardiac fibrosis to heart failure. In the present study, we have demonstrated that the lncRNA NEAT1 is upregulated in patients with heart failure. Similarly, the expression of Neat1 was also increased in the left ventricular tissue of transverse aortic constriction (TAC) surgery mice and cardiac fibroblasts treated with TGF-β1. Further, gain-of-function and loss-of-function experiments showed that silencing of Neat1 attenuated cardiac fibrosis, while overexpression of Neat1 with adenovirus significantly aggravated the in vitro progression of fibrosis. With regard to the underlying mechanism, our experiments showed that Neat1 recruited EZH2 to the promoter region of Smad7 through physical binding of EZH2 to the promoter region, as a result of which Smad7 expression was inhibited and the progression of cardiac fibrosis was ultimately exacerbated. We found that the introduction of shNeat1 carried by adeno-associated virus-9 significantly ameliorated cardiac fibrosis and dysfunction caused by TAC surgery in mice. Overall, our study findings demonstrate that the lncRNA Neat1 accelerates the progression of cardiac fibrosis and dysfunction by recruiting EZH2 to suppress Smad7 expression. Thus, NEAT1 may serve as a target for the treatment of cardiac fibrosis.

The Impact of Long Non-Coding RNAs in the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the utmost deadly human malignancies. This type of cancer has been associated with several environmental, viral, and lifestyle risk factors. Among the epigenetic factors which contribute in the pathogenesis of HCC is dysregulation of long non-coding RNAs (lncRNAs). These transcripts modulate expression of several tumor suppressor genes and oncogenes and alter the activity of cancer-related signaling axes. Several lncRNAs such as NEAT1, MALAT1, ANRIL, and SNHG1 have been up-regulated in HCC samples. On the other hand, a number of so-called tumor suppressor lncRNAs namely CASS2 and MEG3 are down-regulated in HCC. The interaction between lncRNAs and miRNAs regulate expression of a number of mRNA coding genes which are involved in the pathogenesis of HCC. H19/miR-15b/CDC42, H19/miR-326/TWIST1, NEAT1/miR-485/STAT3, MALAT1/miR-124-3p/Slug, MALAT1/miR-195/EGFR, MALAT1/miR-22/SNAI1, and ANRIL/miR-144/PBX3 axes are among functional axes in the pathobiology of HCC. Some genetic polymorphisms within non-coding regions of the genome have been associated with risk of HCC in certain populations. In the current paper, we describe the recent finding about the impact of lncRNAs in HCC.

Prognostic Value of lncRNA NEAT1 as a New Biomarker in Digestive System Tumors: a Systematic Study and Meta-analysis

OBJECTIVE

Nuclear paraspeckle assembly transcript 1 (NEAT1), a newly found lncRNA, is found abnormally expressed in digestive system tumors. This meta-analysis aims to evaluate the effect of NEAT1 on digestive system tumors.

METHODS

An analysis was conducted to investigate NEAT1 expression in digestive system tumors from the PubMed, Embase, and Web of Science databases. The relationship between NEAT1 expression and patient overall survival (OS) and clinicopathology was evaluated by correlation analysis with the pooled hazard ratio (HR), 95% confidence interval (CI), and odds ratio (OR).

RESULTS

A total of 12 published studies were enrolled in this meta-analysis. The NEAT1 overexpression was significantly associated with poor OS (HR = 1.64, 95% CI:1.41-1.91, p < 0.05), lymphatic metastasis (OR = 2.70, 95% CI: 2.02-3.61, p < 0.05), distal metastasis (OR = 3.01, 95% CI: 1.97-4.59, p < 0.05) and advanced tumor stage (OR = 3.04, 95% CI: 2.32-3.99, p < 0.05). However, digestive system tumor patients with high NEAT1 expression was not related to the patients' age (OR = 0.91, 95% CI: 0.65-1.26, p = 0.561), gender (OR = 1.04, 95% CI: 0.81-1.33, p = 0.761), tumor size (OR = 1.84, 95% CI: 0.88-3.88, p = 0.106), and tumor differentiation (OR = 0.86, 95% CI: 0.51-1.44, p = 0.570).

CONCLUSION

Collectively, NEAT1 can be used as a potential biomarker to predict the prognosis of patients with digestive system tumors, which is worth verifying in clinical practice.

LncRNA Neat1 expedites the progression of liver fibrosis in mice through targeting miR-148a-3p and miR-22-3p to upregulate Cyth3

Liver fibrosis is a common response to chronic liver injury, ultimately leading to cirrhosis. The activation of hepatic stellate cells (HSCs) plays a dominant role in liver fibrosis. The regulatory roles of long noncoding RNAs (lncRNAs) in multiple human diseases have been observed. This study was dedicated to investigating the regulatory effects of the lncRNA nuclear paraspeckle assembly transcript 1 (Neat1) on liver fibrosis and HSC activation. Upregulation of Neat1 and cytohesin 3 (Cyth3) and downregulation of miR-148a-3p and miR-22-3p were observed in mouse fibrotic liver tissues. Knockdown of Neat1 or Cyth3 attenuated liver fibrosis and collagen deposition in vivo and the activation of HSCs in vitro. An miR-148a-3p and miR-22-3p inhibitor facilitated HSC activation and collagen fiber expression. Neat1 directly targeted miR-148a-3p and miR-22-3p to modulate Cyth3 expression. Knockdown of Neat1 inhibited Cyth3 expression via the competing endogenous RNA (ceRNA) mechanism of sponging miR-148a-3p and miR-22-3p to regulate liver fibrosis and HSC activation. The ceRNA regulatory network may promote a better understanding of liver fibrogenesis, contribute to an original agreement of liver fibrosis etiopathogenesis and provide insights into the development of a novel domain of lncRNA-directed therapy against liver fibrosis.

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

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

The prognostic significance of long non-coding RNAs in hepatocellular carcinoma: An updated meta-analysis

BACKGROUND

Recently, many studies have demonstrated that long non-coding RNAs (lncRNAs) are abnormally expressed in hepatocellular carcinoma (HCC) and may serve as a potential molecular biomarker to evaluate the prognosis of hepatocellular carcinoma. Therefore, we accomplished a meta-analysis built on current studies to assess the prognostic value of lncRNAs in hepatocellular carcinoma.

METHODS

The PubMed database was carefully searched to collect all eligible studies until February 20, 2019. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) of the overall survival, relapse-free survival, and progression-free survival were calculated to evaluate the prognostic significance of lncRNAs expression in hepatocellular carcinoma using Stata12.0 software. Heterogeneity, sensitivity analysis, and publication bias were also evaluated.

RESULTS

The results showed that the expression level of lncRNAs was significantly correlated with clinical outcomes. Abnormally expressed lncRNAs predicted poor overall survival (HR=2.19, 95% CI: 1.99-2.42, P<0.001; I²=44.7%, P=0.005), relapse-free survival (HR=2.68, 95% CI: 1.74-4.14, P<0.001; I²=0.0%, P=0.763) and progression-free survival of hepatocellular carcinoma patients (HR=2.44, 95% CI: 1.53-3.89, P<0.001; I²=0.0%, P=0.336). Statistical significance was also noted in subgroup meta-analyses that were stratified by follow-up time, cutoff value, and quality score. Moreover, the pooled results indicated that lncRNAs expression was significantly associated with tumor size (HR=1.48, 95% CI: 1.24-1.79), tumor number (HR=1.34, 95% CI: 1.08-1.66), and tumor node metastasis stage (HR=2.10, 95% CI: 1.48-2.99), but not liver cirrhosis and tumor differentiation (P>0.05).

CONCLUSIONS

This meta-analysis indicates that lncRNAs are strongly associated with prognosis in hepatocellular carcinoma and may serve as a promising indicator for prognostic evaluation of patients with hepatocellular carcinoma. But larger clinical studies are needed to verify its feasibility.

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

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

lncRNA NEAT1 regulates the proliferation and migration of hepatocellular carcinoma cells by acting as a miR‑320a molecular sponge and targeting L antigen family member 3

Long non‑coding RNAs (lncRNAs) serve a pivotal role in hepatocellular carcinoma (HCC) progression and have been confirmed to participate in the carcinogenesis and development of HCC. Certain studies have focused on lncRNA nuclear enriched abundant transcript 1 (NEAT1) in HCC. However, the relationship between lncRNA NEAT1 and HCC remains unclear. The present study found that NEAT1 was significantly overexpressed in HCC cell lines compared with LX‑2 hepatic stellate cells. NEAT1 expression in Huh7 and MHCC‑97H cells was increased following transfection with lentivirus (LV)‑NEAT1 but inhibited by LV‑short hairpin NEAT1. Knockdown of NEAT1 significantly repressed HCC cell viability, increased cell apoptosis, and inhibited cell migration and invasion capacity. By contrast, upregulation of NEAT1 demonstrated the reverse effects. Furthermore, microRNA‑320a (miR‑230a) was predicted to be a direct target of NEAT1 and was significantly reduced in HCC cells. Additionally, a luciferase activity reporter assay and RNA immunoprecipitation assay were performed to confirm the interaction between miR‑320a and NEAT1. Using a dual‑luciferase activity assay, L antigen family member 3 (LAGE3) was found to be a target of miR‑320a. Finally, in vivo nude mouse models were established, and the results indicated that NEAT1 suppressed HCC progression by targeting miR‑320a. In conclusion, the present findings revealed that the NEAT1/miR‑320a/LAGE3 axis participates in HCC development and that NEAT1 could be used as a biomarker for HCC.

The role of NEAT1 lncRNA in squamous cell carcinoma of the head and neck is still difficult to define

INTRODUCTION

Nuclear paraspeckle assembly transcript 1 (NEAT1) is considered an oncogene in various cancers, but the role in head and neck squamous cell carcinomas (HNSCC) is not clear.

MATERIAL AND METHODS

Expression of NEAT1 in HNSCC patients' samples and cell lines was analysed using qRT-PCR. The TCGA expression data of NEAT1 were analysed depending on the clinicopathological parameters and tumour localisation. Correlation and gene set enrichment analysis (GSEA) were conducted, and the results were analysed using the REACTOME and GeneMANIA tools. All statistical analyses were carried out using GraphPad Prism 5 and Statistica 13.

RESULTS

The NEAT1 was up-regulated in some patients' samples and HNSCC cell lines. Moreover, TCGA data analysis indicated that the expression of NEAT1 was up-regulated in tumour tissue in most of the analysed TCGA cancers, including HNSCC. There were no significant differences in levels of NEAT1 between various tumour localisations. Overall survival of individuals with high expression of NEAT1 was slightly longer than in the low-expression group (p = 0.0553). Analysis of genes that positively and negatively correlated with NEAT1 indicated that they are involved in mRNA metabolism and cellular transport. Moreover, the GSEA revealed that in patients with low NEAT1, the most up-regulated genes were in clusters associated with the cAMP-dependent pathway, the MYC pathway, unfolded protein response, the MTORC1 signalling pathway, oxidative phosphorylation, and DNA repair.

CONCLUSIONS

Patients with low expression of NEAT1 display worse overall survival, presumably due to up-regulation of certain oncogenic signalling pathways that are important for cancerogenesis.

Hypoxia-Induced lncRNA-NEAT1 Sustains the Growth of Hepatocellular Carcinoma via Regulation of miR-199a-3p/UCK2

Objective: The long noncoding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) has emerged as a novel player in hepatocellular carcinoma (HCC). Hypoxia is a common characteristic of the microenvironment of HCC. This study aimed to investigate whether lncRNA-NEAT1 is induced by hypoxia in HCC, and the mechanism that underlies LncRNA-NEAT1 function.

Methods: The expression changes of lncRNA-NEAT1 in HCC cell lines under hypoxic conditions were examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The regulatory effect of HIF-1α on lncRNA-NEAT1 was confirmed with chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The function of lncRNA-NEAT1 on HCC cell growth under hypoxic conditions was determined by CCK-8 assay and flow cytometry. lncRNA -NEAT1 was predicted to serve as a competing endogenous RNA (ceRNA) within microRNA (miRNA)/mRNA axes based on microarray data, public HCC-related datasets and integrative bioinformatics analysis, and the miR-199a-3p/UCK2 axis was selected and validated by qRT-PCR, western blotting, RNA immunoprecipitation, and luciferase reporter analyses. The role of miR-199a-3p/UCK2 in HCC and its functional association with lncRNA-NEAT1 were assessed both in vitro and in vivo.

Results: LncRNA-NEAT1 expression was significantly induced by hypoxia in SNU-182 and HUH7 cells. HIF-1α was shown to regulate lncRNA-NEAT1 transcription. Under hypoxic conditions, lncRNA-NEAT1 maintained the growth of HCC cells and inhibited apoptosis and cell cycle arrest. LncRNA-NEAT1 was predicted to regulate a panel of HCC-associated miRNA-mRNA pairs consisting of 8 miRNAs and 13 mRNAs. LncRNA-NEAT1 was shown to function as a ceRNA of miR-199a-3p/UCK2 both in HCC cells under hypoxic conditions and in an animal model.

Conclusion: LncRNA-NEAT1 is a hypoxia-responsive lncRNA in HCC cell lines Insilico evidence suggested that LncRNA-NEAT1 may sustainthe growth of HCC cells by regulating HCC-associated mRNAs that interact with tumor-suppressive miRNAs. The lncRNA-NEAT1/miR-199a-3p/UCK2 pathway may contribute to the progression of HCC cell lines in a hypoxic microenvironment and therefore may represent a novel therapeutic target for HCC.

Long Noncoding RNA NEAT1 Promotes Cell Proliferation And Invasion And Suppresses Apoptosis In Hepatocellular Carcinoma By Regulating miRNA-22-3p/akt2 In Vitro And In Vivo

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most aggressive cancers that is associated with cirrhosis and other chronic liver diseases. Although remarkable progress has been made in past decades, it is still necessary to continue exploring the pathology and development of HCC.

OBJECTIVE

In this study, we elucidated the effect of long noncoding RNA (lncRNA) NEAT1 on HCC development and underlying mechanisms.

METHODS

Clinicopathological features of HCC patients were collected and the correlations with NEAT1 expression were assessed. To determine cell activities, CCK-8, flow cytometry, invasion assays, and TUNEL assays were performed. Real-time PCR, Western blot, and luciferase reporter assays were performed to investigate the related mechanism of HCC.

RESULTS

The results revealed that NEAT1 expression was associated with tumor size and differentiation where NEAT1 was upregulated in both HCC tissues and cell lines. Overexpression of NEAT1 promoted proliferation and invasion while inhibited apoptosis in HCC cells, which was opposite to the effect of NEAT1 knockdown. Also, AKT2 was increased in HCC tissues. Downregulation of AKT2 was associated with reduced cell proliferation and invasion while increased apoptosis, while overexpression of AKT2 exerted opposite roles. In addition, the expression of miRNA-22-3p displayed an inverse association with NEAT1. miRNA-22-3p mimic and inhibitor suppressed and promoted HCC development, respectively. The luciferase assay revealed that both NEAT1 and AKT2 were direct target genes of miRNA-22-3p. Furthermore, knockdown and overexpression of NEAT1 suppressed and promoted tumor growth in the HCC mouse model, which were abolished by the miRNA-22-3p inhibitor and mimic, respectively.

CONCLUSION

In conclusion, the results demonstrate that NEAT1 promotes the development of HCC, both in vitro and in vivo, through regulating miRNA-22-3p/AKT2, and provides insight into developing a new strategy for HCC treatment.

Long Non-Coding RNA in the Pathogenesis of Cancers

The incidence and mortality rate of cancer has been quickly increasing in the past decades. At present, cancer has become the leading cause of death worldwide. Most of the cancers cannot be effectively diagnosed at the early stage. Although there are multiple therapeutic treatments, including surgery, radiotherapy, chemotherapy, and targeted drugs, their effectiveness is still limited. The overall survival rate of malignant cancers is still low. It is necessary to further study the mechanisms for malignant cancers, and explore new biomarkers and targets that are more sensitive and effective for early diagnosis, treatment, and prognosis of cancers than traditional biomarkers and methods. Long non-coding RNAs (lncRNAs) are a class of RNA transcripts with a length greater than 200 nucleotides. Generally, lncRNAs are not capable of encoding proteins or peptides. LncRNAs exert diverse biological functions by regulating gene expressions and functions at transcriptional, translational, and post-translational levels. In the past decade, it has been demonstrated that the dysregulated lncRNA profile is widely involved in the pathogenesis of many diseases, including cancer, metabolic disorders, and cardiovascular diseases. In particular, lncRNAs have been revealed to play an important role in tumor growth and metastasis. Many lncRNAs have been shown to be potential biomarkers and targets for the diagnosis and treatment of cancers. This review aims to briefly discuss the latest findings regarding the roles and mechanisms of some important lncRNAs in the pathogenesis of certain malignant cancers, including lung, breast, liver, and colorectal cancers, as well as hematological malignancies and neuroblastoma.

Long noncoding RNA Neat1 modulates myogenesis by recruiting Ezh2

Neat1 is widely expressed in many tissues and cells and exerts pro-proliferation effects on many cancer cells. However, little is known about the function of Neat1 in myogenesis. Here we characterized the roles of Neat1 in muscle cell formation and muscle regeneration. Gain- or loss-of-function studies in C2C12 cells demonstrated that Neat1 accelerates myoblast proliferation but suppresses myoblast differentiation and fusion. Further, knockdown of Neat1 in vivo increased the cross-sectional area of muscle fibers but impaired muscle regeneration. Mechanically, Neat1 physically interacted with Ezh2 mainly through the core binding region (1001–1540 bp) and recruited Ezh2 to target gene promoters. Neat1 promoted myoblast proliferation mainly by decreasing the expression of the cyclin-dependent kinase inhibitor P21 gene but inhibited myoblast differentiation by suppressing the transcription of myogenic marker genes, such as Myog, Myh4, and Tnni2. Altogether, we uncover a previously unknown function of Neat1 in muscle development and the molecular mechanism by which Neat1 regulates myogenesis.

Long Noncoding RNA Can Be a Probable Mechanism and a Novel Target for Diagnosis and Therapy in Fragile X Syndrome

Fragile X syndrome (FXS) is the most common congenital hereditary disease of low intelligence after Down syndrome. Its main pathogenic gene is fragile X mental retardation 1 (FMR1) gene associated with intellectual disability, autism, and fragile X-related primary ovarian insufficiency (FXPOI) and fragile X-associated tremor/ataxia syndrome (FXTAS). FMR1 gene transcription leads to the absence of fragile X mental retardation protein (FMRP). How to relieve or cure disorders associated with FXS has also become a clinically disturbing problem. Previous studies have recently shown that long noncoding RNAs (lncRNAs) contribute to the pathogenesis. And it has been identified that several lncRNAs including FMR4, FMR5, and FMR6 contribute to developing FXPOI/FXTAS, originating from the FMR1 gene locus. FMR4 is a product of RNA polymerase II and can regulate the expression of relevant genes during differentiation of human neural precursor cells. FMR5 is a sense-oriented transcript while FMR6 is an antisense lncRNA produced by the 3' UTR of FMR1. FMR6 is likely to contribute to developing FXPOI, and it overlaps exons 15-17 of FMR1 as well as two microRNA binding sites. Additionally, BC1 can bind FMRP to form an inhibitory complex and lncRNA TUG1 also can control axonal development by directly interacting with FMRP through modulating SnoN-Ccd1 pathway. Therefore, these lncRNAs provide pharmaceutical targets and novel biomarkers. This review will: (1) describe the clinical manifestations and traditional pathogenesis of FXS and FXTAS/FXPOI; (2) summarize what is known about the role of lncRNAs in the pathogenesis of FXS and FXTAS/FXPOI; and (3) provide an outlook of potential effects and future directions of lncRNAs in FXS and FXTAS/FXPOI researches.

Long noncoding RNA NEAT1 promotes cell proliferation, migration, and invasion in hepatocellular carcinoma through interacting with miR-384

It was reported that long non-coding RNA nuclear-enriched abundant transcript 1 (NEAT1) is involved in hepatocellular carcinoma (HCC). However, the underlying mechanism of tumorigenesis is still largely unclear. Here, we found that NEAT1 is remarkably upregulated in HCC tissues and cell lines. Overexpression of NEAT1 notably accelerated HCC cell proliferation, migration, and invasion. Knockdown of NEAT1 significantly inhibited HCC cell proliferation, migration and invasion. MiR-384 expression was lower in HCC tissues and cell lines than adjacent nontumor tissues and L02 cell. MiR-384 exhibited the functions of tumor-suppressive. The expression of miR-384 was negatively correlated with the expression of NEAT1. Overexpression of NEAT1 reduced miR-384 expression, whereas inhibition of miR-384 led to a distinct upregulation of NEAT1 expression. In addition, we provided evidence that miR-384 was directly bound to the sequence of NEAT1 by luciferase reporter and RNA-binding protein immunoprecipitation assays. Overexpression of miR-384 inhibited NEAT1 function. Thus, we demonstrated that NEAT1 promotes the malignant biological properties of hepatocellular carcinoma by negatively regulating miR-384.

NEAT1 is a potential prognostic biomarker for patients with nasopharyngeal carcinoma

Nuclear paraspeckle assembly transcript 1 (NEAT1) has been found to be dysregulated and associated with clinical progression in various human cancers. The clinical and prognostic value of NEAT1 in nasopharyngeal carcinoma (NPC) was still controversial. The aim of our study was to provide more sufficient evidence that NEAT1 expression is correlated with overall survival in patients with NPC. NEAT1 expression was detected in NPC tissue samples, and the relationship between NEAT1 expression and clinical parameters, including prognosis, was analyzed. The meta-analysis was performed to further assess the prognostic significance of NEAT1 expression in patients with NPC. In our study, we found that the levels of NEAT1 expression were increased in NPC clinical tissue specimens, and associated with advanced M classification and clinical stages. Moreover, the Kaplan-Meier analysis suggested that the levels of NEAT1 expression were negatively associated with the overall survival of patients with NPC. Furthermore, univariate and multivariate Cox regression analyses showed that NEAT1 high-expression was an independent unfavorable prognostic factor in patients with NPC. Finally, we conducted a meta-analysis including 297 patients with NPC from the three studies, and found the pooled HR (95% confidence interval [CI]) was 1.64 (95% CI: 0.68-3.93) for the random effects model and 2.04 (95% CI: 1.42-2.95) for the fixed effect model. In conclusion, NEAT1 is a potential prognostic biomarker for NPC, but more studies are needed to further verify the prognostic value of NEAT1 in patients with NPC.

Long Non-coding RNA NEAT1: A Novel Target for Diagnosis and Therapy in Human Tumors

The nuclear paraspeckle assembly transcript 1 (NEAT1, a long non-coding RNA) is frequently overexpressed in human tumors, and higher NEAT1 expression is correlated with worse survival in cancer patients. NEAT1 drives tumor initiation and progression by modulating the expression of genes involved in the regulation of tumor cell growth, migration, invasion, metastasis, epithelial-to-mesenchymal transition, stem cell-like phenotype, chemoresistance and radioresistance, indicating the potential for NEAT1 to be a novel diagnostic biomarker and therapeutic target. Mechanistically, NEAT1 functions as a scaffold RNA molecule by interacting with EZH2 (a subunit of the polycomb repressive complex) to influence the expression of downstream effectors of EZH2, it also acts as a microRNA (miRNA) sponge to suppress the interactions between miRNAs and target mRNAs, and affects the expression of miR-129 by promoting the DNA methylation of the miR-129 promoter region. Knockdown of NEAT1 via small interfering RNA or short hairpin RNA inhibits the malignant behavior of tumor cells. In this review, we highlight the latest insights into the expression pattern, biological roles and mechanisms underlying the function and regulation of NEAT1 in tumors, and especially focus on its clinical implication as a new diagnostic biomarker and an attractive therapeutic target for cancers.

NEAT1_2-SFPQ axis mediates cisplatin resistance in liver cancer cells in vitro

Background

Liver cancer is a type of malignant tumor with high morbidity and mortality in People’s Republic of China. Its occurrence and development involve the variation and expression changes of multiple genes, and the pathogenesis and related regulatory networks are complex.

Purpose

In the present research, we investigate the involvement of NEAT1_2 and SFPQ in cisplatin resistance in liver cancer. The effects of LncRNA NEAT1 and SFPQ expression on the chemotherapeutic resistance of liver cancer cells were analyzed.

Methods

The expression level of NEAT1_2 and SFPQ mRNA in tissue specimens or cell lines were examined by RT-qPCR and western blotting. CCK-8 assay was performed to evaluate cell viability. Cell proliferation was performed using the EdU cell proliferation assay.

Results

Our data showed that increase NEAT1_2 and SFPQ expressions in liver cancer specimens were associated with the development of cisplatin resistance; high SFPQ expression level impaired patients’ survival from liver cancer. Gain-and loss-of function assay using NEAT1_2 knock-in and knock-out cells constructed using CRISPER/Cas9 system revealed that NEAT1_2 is essential for liver cancer cell survival and mediates cisplatin resistance in liver cancer cells at least partially through SFPQ. Artificial change in NEAT1_2 expression level didn’t significantly influence SFPQ transcription or translation level.

Conclusion

Our data revealed NEAT1_2—SFPQ axis as a novel cisplatin resistance mechanism in liver cancer cells in vitro.

Long non-coding RNA NEAT1 promotes migration and invasion of oral squamous cell carcinoma cells by sponging microRNA-365

Long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) has been demonstrated to serve key roles in numerous human cancer types, but its function in oral squamous cell carcinoma (OSCC) and underlying regulatory mechanism have not been evaluated. The present study demonstrated that expression of NEAT1 was significantly higher in OSCC tissue and cell lines compared with adjacent non-tumour tissue and normal oral keratinocytes, respectively. Additionally, upregulation of NEAT1 was significantly associated with advanced clinical stage and shorter survival time in patients with OSCC. Bioinformatics analysis and luciferase reporter gene assay data confirmed the interaction between NEAT1 and miR-365, and it was revealed that NEAT1 may downregulate microRNA (miR)-365 expression in OSCC cells. Furthermore, inhibition of NEAT1 expression led to a significant reduction in OSCC cell migration and invasion, which was accompanied by reduced matrix metalloproteinase (MMP)-2 and MMP9 protein expression. By contrast, inhibition of miR-365 eliminated suppressive effects of NEAT1 knockdown on OSCC cell migration and invasion. miR-365 was significantly downregulated in OSCC tissue and cell lines and an inverse correlation between miR-365 and NEAT1 expression in OSCC tissue was observed. To conclude, the present study demonstrated that NEAT1 promoted migration and invasiveness of OSCC cells by sponging miR-365. The current study suggests that NEAT1 may serve as a novel therapeutic target for the treatment of OSCC.