Noncoding RNA Nuclear Paraspeckle Assembly Transcript 1 Research Articles

Isoform balance of the long noncoding RNA NEAT1 is regulated by the RNA-binding protein QKI, governs the glioma transcriptome, and impacts cell migration

The long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) is involved in a variety of human cancers. Two overlapping NEAT1 isoforms, NEAT1_1 and NEAT1_2, are produced through mutually exclusive alternative 3' end formation. Previous studies extensively investigated NEAT1 dysregulation in tumors, but often failed to achieve distinct quantification of the two NEAT1 isoforms. Moreover, molecular mechanisms governing the biogenesis of NEAT1 isoforms and the functional impacts of their dysregulation in tumorigenesis remain poorly understood. In this study, we employed an isoform-specific quantification assay and found differential dysregulation of NEAT1 isoforms in patient-derived glioblastoma multiforme cells. We further showed usage of the NEAT1 proximal polyadenylation site (PAS) is a critical mechanism that controls glioma NEAT1 isoform production. CRISPR-Cas9-mediated PAS deletion reduced NEAT1_1 and reciprocally increased NEAT1_2, which enhanced nuclear paraspeckle formation in human glioma cells. Moreover, the utilization of the NEAT1 PAS is facilitated by the RNA-binding protein quaking (QKI), which binds to the proximal QKI recognition elements. Functionally, we identified transcriptomic changes and altered biological pathways caused by NEAT1 isoform imbalance in glioma cells, including the pathway for the regulation of cell migration. Finally, we demonstrated the forced increase of NEAT1_2 upon NEAT1 PAS deletion is responsible for driving glioma cell migration and promoting the expression of genes implicated in the regulation of cell migration. Together, our studies uncovered a novel mechanism that regulates NEAT1 isoforms and their functional impacts on the glioma transcriptome, which affects pathological pathways of glioma, represented by migration.

Molecular Mechanisms of Tumorgenesis and Metastasis of Long Non-coding RNA (lncRNA) NEAT1 in Human Solid Tumors; An Update.

The expression of the nuclear paraspeckle assembly transcript 1 (NEAT1), as a well-known long non-coding RNA (lncRNA), is often upregulated in varied types of cancers and associated with poor survival outcomes in patients suffering from tumors. NEAT1 promotes the tumors growth by influencing the various genes' expression profile that regulate various aspects of tumor cell behavior, in particular tumor growth, metastasis and drug resistance. This suggests that NEAT1 are capable of serving as a new diagnostic biomarker and target for therapeutic intervention. Through interrelation with enhancer of zeste homolog 2 (EZH2), NEAT1 acts as a scaffold RNA molecule, and thus regulating the expression EZH2-associated genes. Additionally, by perform as miRNA sponge, it constrains suppressing the interactions between miRNAs-mediated degradation of target mRNAs. In light of this, NEAT1 inhibition by small interfering RNA (siRNA) hampers tumorgenesis. We summarize recent findings about the expression, biological functions, and regulatory process of NEAT1 in human tumors. It specifically emphasizes the clinical significance of NEAT1 as a novel diagnostic biomarker and a promising therapeutic mark for many types of cancers.

Long non-coding RNA NEAT1 promotes aerobic glycolysis and progression of cervical cancer through WNT/β-catenin/PDK1 axis.

Cervical cancer is one of the most common gynecological cancers. Accumulated evidence shows that long non-coding RNAs (lncRNAs) play essential roles in cervical cancer occurrence and progression, but their specific functions and mechanisms remain to be further explored. The RT-qPCR assay was used to detect the expression of NEAT1 in cervical cancer tissues and cell lines. CCK-8, colony formation, flow cytometry, western blotting, and Transwell assays were used to evaluate the impact of NEAT1 on the malignant behavior of cervical cancer cells. Glucose consumption, lactate production, ATP levels, ROS levels, MMP levels, and the mRNA expressions of glycolysis-related genes and tricarboxylic acid cycle-related genes were detected to analyze the effect of NEAT1 on metabolism reprograming in cervical cancer cells. The expressions of PDK1, β-catenin and downstream molecules of the WNT/β-catenin signaling pathway in cervical cancer cells and tissues were detected by western blotting, RT-qPCR, immunofluorescence and immunohistochemistry assays. This study investigated the role and possible molecular mechanism of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in cervical cancer. Our results showed that NEAT1 was highly expressed in cervical cancer tissues and cell lines. Downregulation of NEAT1 inhibited the proliferation, migration, invasion and glycolysis of cervical cancer cells, while overexpression of NEAT1 led to the opposite effects. Mechanistically, NEAT1 upregulated pyruvate dehydrogenase kinase (PDK1) through the WNT/β-catenin signaling pathway, which enhanced glycolysis and then facilitated cervical cancer metastasis. Furthermore, NEAT1 maintained the protein stability of β-catenin but did not affect its mRNA level. We also excluded the direct binding of NEAT1 to the β-catenin protein via RNA pull-down assay. The suppressive impact of NEAT1 knockdown on cell proliferation, invasion, and migration was rescued by β-catenin overexpression. The WNT inhibitor iCRT3 attenuated the carcinogenic effect induced by NEAT1 overexpression. In summary, these findings indicated that NEAT1 may contribute to the progression of cervical cancer by activating the WNT/β-catenin/PDK1 signaling axis.

NEAT1 regulates VSMC differentiation and calcification in as long noncoding RNA NEAT1 enhances phenotypic and osteogenic switching of vascular smooth muscle cells in atherosclerosis via scaffolding EZH2.

Atherosclerosis (AS) is a significant contributor to cardio-cerebrovascular ischemia diseases, resulting in high mortality rates worldwide. During AS, vascular smooth muscle cells (VSMCs) play a crucial role in plaque formation by undergoing phenotypic and osteogenic switching. Long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has previously been identified as a nuclear regulator that promotes tumorigenesis and metastasis, but its role in regulating VSMCs in AS remains unclear. Our study aimed to investigate the biological functions and specific mechanisms of NEAT1 in regulating VSMCs in AS. We found that NEAT1 was upregulated in the aortas of AS mouse models and dedifferentiated primary VSMCs. Silencing NEAT1 in vitro attenuated the proliferation, migration, and osteogenic differentiation of VSMCs, while NEAT1 overexpression had the opposite effect. Furthermore, NEAT1 promoted VSMC osteogenic differentiation and vascular calcification in both in vivo and in vitro vascular calcification models. We also discovered that NEAT1 directly activates enhancer of zeste homolog 2 (EZH2), an epigenetic enzyme that suppresses the expression of senescence- and antimigration-related genes, by translocating it into the nucleus. CUT&Tag assay revealed that NEAT1 guides EZH2 to the promoters of senescence-related genes (P16, P21, and TIMP3), methylating local histones to reduce their transcription. Our findings suggest that NEAT1 functions in AS by modulating the epigenetic function of EZH2, which enhances the proliferation, migration, and osteogenic differentiation of VSMCs. This study provides new insights into the molecular mechanisms underlying the pathogenesis of AS and highlights the potential of NEAT1 as a therapeutic target of AS.NEW & NOTEWORTHY Our study demonstrates that the upregulation of long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) promotes proliferation and migration during phenotypic switching of vascular smooth muscle cells in atherosclerosis. We also provide in vivo and in vitro evidence that NEAT1 accelerates vascular calcification. Our findings identified the direct interaction between enhancer of zeste homolog 2 (EZH2) and NEAT1 during atherosclerosis. NEAT1 is necessary for EZH2 to translocate from the cytoplasm to the nucleus, where EZH2 epigenetically inhibits the expression of genes related to senescence and antimigration.

Exercise Mitigates Endothelial Pyroptosis and Atherosclerosis by Downregulating NEAT1 Through N6-Methyladenosine Modifications

The benefits of exercise on the cardiovascular system are widely recognized; however, the underlying mechanisms are unknown. Here, we report the effect of the long noncoding RNA NEAT1 (nuclear paraspeckle assembly transcript 1), which is regulated by exercise, on atherosclerosis development after N6-methyladenosine (m6A) modifications. Using clinical cohorts and NEAT1-/- mice, we determined the exercise-mediated expression and role of NEAT1 in atherosclerosis. To investigate the mechanism of epigenetic modification of NEAT1 regulated by exercise, we identified METTL14 (methyltransferase-like 14)-a key m6A modification enzyme under exercise-and found that METTL14 alters the expression and role of NEAT1 through m6A modification and elucidated the specific mechanism of METTL14 in vitro and in vivo. Finally, the NEAT1 downstream regulatory network was investigated. We found that NEAT1 expression was downregulated with exercise and that downregulation of NEAT1 was an important factor in the improvement of atherosclerosis with exercise. Exercise-mediated loss of function of NEAT1 can delay atherosclerosis. Mechanistically, we showed that exercise induced a significant downregulation of m6A modification and METTL14, which binds to the m6A sites of NEAT1 and promotes NEAT1 expression through subsequent YTHDC1 (YTH domain-containing 1) recognition to promote endothelial pyroptosis. Furthermore, NEAT1 induces endothelial pyroptosis by binding KLF4 (Kruppel-like factor 4) to promote the transcriptional activation of the key pyroptotic protein NLRP3 (NOD-like receptor thermal protein domain-associated protein 3), whereas exercise can attenuate NEAT1-mediated endothelial pyroptosis to improve atherosclerosis. Our study of NEAT1 provides new insights into the improvement of atherosclerosis by exercise. This finding demonstrates the role of exercise-mediated NEAT1 downregulation in atherosclerosis while expanding our understanding of the mechanisms by which exercise regulates long noncoding RNA function through epigenetic modifications.

The lncRNA NEAT1 Inhibits miRNA-216b and Promotes Colorectal Cancer Progression by Indirectly Activating YY1.

Background Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) is commonly considered an oncogene in various cancers. The long noncoding RNA NEAT1 has been reported to be overexpressed in colorectal cancer (CRC). However, the exact role of NEAT1 in CRC remains unknown. Our research aimed to explore the function of NEAT1 in the tumorigenesis and the development of CRC. Methods Real-time quantitative PCR (qRT-PCR) was used to detect the NEAT1, miR-216b, and YIN-YANG-1 (YY1) mRNA levels in CRC tissues and cells, then immunohistochemistry (IHC) was used to detect the expression of YY1 in CRC tissues. Luciferase reporter, qPCR, western blot, and DNA pulldown assays were conducted to study the relationships between NEAT1, miR-216b, and YY1. Flow cytometry analysis was performed for cell cycle and apoptosis analyses, and a colony formation assay was performed to test cell proliferation. Transwell assays were performed to detect cell invasion and migration. Results The NEAT1 expression was significantly upregulated in CRC tissues compared with its expression in normal tissues, and downregulation of NEAT1 suppressed the proliferation, migration, and invasion of CRC cells. Moreover, we found NEAT1 decreased the miR-216b level directly, and the suppression of miR-216b could inhibit the function of downstream YY1. However, overexpression of YY1 accelerated CRC cell proliferation, migration, and invasion. Conclusion Our results indicated that NEAT1 acted as an oncogene in CRC and promoted the progression of CRC by directly sponging miR-216 b expression to activate the expression of YY1. The NEAT1/miR-216b/YY1 axis may be a novel therapeutic target for CRC.

Long non-coding RNA NEAT1 promotes angiogenesis in hepatoma carcinoma via the miR-125a-5p/VEGF pathway.

The study’s purpose was to investigate the biological function of long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) in hepatoma carcinoma (HCC). HCC tissues and cells exhibited increased levels of NEAT1 and decreased levels of miR-125a-5p. Reduction in the expression of NEAT suppressed HepG2 cell proliferation and increased apoptosis. This was accompanied by suppression of the AKT/mTOR and ERK pathways, while the opposite was observed for miR-125a-5p. Angiogenesis assay results indicated that NEAT was proangiogenic. A dual-luciferase reporter assay indicated that NEAT1 was bound to miR-125a-5p and miR-125a-5p was bound to vascular endothelial growth factor (VEGF). The proangiogenic effects of NEAT and its stimulation of AKT/mTOR and ERK were reversed by miR-125a-5p. The anti-angiogenic effects of miR-125a-5p and its inhibitory effect on AKT/mTOR and ERK pathways were reversed by co-incubation with VEGF. The conclusion was that NEAT1 enhances angiogenesis in HCC by VEGF via a competing endogenous RNA (ceRNA) of miR-125a-5p that regulates AKT/mTOR and ERK pathways.

Molecular Interactions of the Long Noncoding RNA NEAT1 in Cancer.

Simple SummaryIn this review, we present current knowledge of LncRNA NEAT1 in the development of malignant diseases. First, we illustrate the structure and functions of NEAT1 in cancer. Then we explore the interaction between NEAT1 and other molecules and analyze the impact of this interaction on cancer progression. Finally, we summarize the regulation of NEAT1 and the function of NEAT1-containing exosomes. Elucidating the molecular interaction of NEAT1 may shed light on future treatment of cancer.As one of the best-studied long noncoding RNAs, nuclear paraspeckle assembly transcript 1 (NEAT1) plays a pivotal role in the progression of cancers. NEAT1, especially its isoform NEAT1-1, facilitates the growth and metastasis of various cancers, excluding acute promyelocytic leukemia. NEAT1 can be elevated via transcriptional activation or stability alteration in cancers changing the aggressive phenotype of cancer cells. NEAT1 can also be secreted from other cells and be delivered to cancer cells through exosomes. Hence, elucidating the molecular interaction of NEAT1 may shed light on the future treatment of cancer. Herein, we review the molecular function of NEAT1 in cancer progression, and explain how NEAT1 interacts with RNAs, proteins, and DNA promoter regions to upregulate tumorigenic factors.

Withdrawal: "Long Non-coding RNA NEAT1 Drives the Development of Polycystic Ovary Syndrome via Sponging Multiple MicroRNAs" by Xia Sang and Yuzhen Zhang.

A line of evidences have validated that multiple microRNAs (including miR-16, miR-483 and miR-324-3p) were abnormally expressed in granulosa cells, which may be closely related with the pathogenesis of polycystic ovary syndrome (PCOS). Long-chain non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) has been proved to participate in the progression of various human diseases via regulating microRNAs, but its function in PCOS are not yet clear. In this work, RT-PCR was performed to detect NEAT1 expression in PCOS tissues, and human ovarian granulosa cell line KGN were taken as the model to construct the cell line with high expression and low expression of NEAT1. CCK-8 and flow cytometry were carried out to monitor cells proliferation and apoptosis, respectively. Besides, we performed luciferase reporter gene assay and RNA binding protein immunoprecipitation (RIP) assay to verify the interaction between NEAT1, miR-16, miR-483 and miR-324-3p. We demonstrated that NEAT1 was highly expressed in PCOS tissues and cells. Over-expressed NEAT1 promoted the proliferation and inhibited the apoptosis. Moreover, NEAT1 was negatively correlated with the expression levels of miR-16, miR-483 and miR-324-3p. Dual luciferase analysis and RIP assay confirmed that NEAT1 can specifically bind to miR-16, miR-483 and miR-324-3p, by which NEAT1 can reduce their expression. In conclusion, NEAT1 can promote the proliferation of ovarian granulosa cells and arrest apoptosis via impeding expressions of miR-16, miR-483 and miR-324-3p. Our research would shed new light on the molecular mechanism of ovarian granulosa cell disorder. This article is protected by copyright. All rights reserved.

Compartment-Specific Proximity Ligation Expands the Toolbox to Assess the Interactome of the Long Non-Coding RNA NEAT1

The nuclear paraspeckle assembly transcript 1 (NEAT1) locus encodes two long non-coding (lnc)RNA isoforms that are upregulated in many tumours and dynamically expressed in response to stress. NEAT1 transcripts form ribonucleoprotein complexes with numerous RNA-binding proteins (RBPs) to assemble paraspeckles and modulate the localisation and activity of gene regulatory enzymes as well as a subset of messenger (m)RNA transcripts. The investigation of the dynamic composition of NEAT1-associated proteins and mRNAs is critical to understand the function of NEAT1. Interestingly, a growing number of biochemical and genetic tools to assess NEAT1 interactomes has been reported. Here, we discuss the Hybridisation Proximity (HyPro) labeling technique in the context of NEAT1. HyPro labeling is a recently developed method to detect spatially ordered interactions of RNA-containing nuclear compartments in cultured human cells. After introducing NEAT1 and paraspeckles, we describe the advantages of the HyPro technology in the context of other methods to study RNA interactomes, and review the key findings in mapping NEAT1-associated RNA transcripts and protein binding partners. We further discuss the limitations and potential improvements of HyPro labeling, and conclude by delineating its applicability in paraspeckles-related cancer research.

Long noncoding RNA NEAT1 promotes ferroptosis by modulating the miR-362-3p/MIOX axis as a ceRNA

Ferroptosis, a novel form of regulated cell death induced by iron-dependent lipid peroxidation, plays an essential role in the development and drug resistance of tumors. Long noncoding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to be involved in the regulation of cell cycle, proliferation, apoptosis, and migration of tumor cells. However, the function and molecular mechanism of NEAT1 in regulating ferroptosis in tumors remain unclear. Here, we found that ferroptosis inducers erastin and RSL3 increased NEAT1 expression by promoting the binding of p53 to the NEAT1 promoter. Induced NEAT1 promoted the expression of MIOX by competitively binding to miR-362-3p. MIOX increased ROS production and decreased the intracellular levels of NADPH and GSH, resulting in enhanced erastin- and RSL3-induced ferroptosis. Importantly, overexpression of NEAT1 increased the anti-tumor activity of erastin and RSL3 by enhancing ferroptosis both in vitro and in vivo. Collectively, these data suggest that NEAT1 plays a novel and indispensable role in ferroptosis by regulating miR-362-3p and MIOX. Considering the clinical findings that HCC patients are insensitive to chemotherapy and immunotherapy, ferroptosis induction may be a promising therapeutic strategy for HCC patients with high NEAT1 expression.

Implication of long non-coding RNA NEAT1 in the pathogenesis of bacterial meningitis-induced blood-brain barrier damage.

Blood-brain barrier (BBB) damage is closely related to various neurological disorders, including bacterial meningitis (BM). Determining a reliable strategy to prevent BBB damage in the context of infection would be highly desirable. In the present study, we investigated the implications of the long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) in moderating BBB damage. In vitro BBB models were developed by co-culturing hCMEC/D3 cells with glioma cells, whereupon the glioma-exposed endothelial cells (GECs) were treated with a series of mimics, inhibitors, overexpression plasmids, and shRNAs for evaluating whether NEAT1, microRNA-135a (miR-135a) and hypoxia-inducible factor 1α (HIF1α) mediated BBB integrity and permeability. Furthermore, the in vivo biological function of NEAT1 was validated in a mouse model of BBB damage. NEAT1 and HIF1α were determined to be up-regulated, while miR-135a was under-expressed in GECs. As demonstrated by chromatin immunoprecipitation and dual-luciferase reporter assays, NEAT1 could bind to miR-135a, and HIF1α was confirmed as a target of miR-135a. Either overexpression of NEAT1 or depletion of miR-135a impaired the integrity and augmented the permeability of BBB. However, HIF1α silencing could reverse the BBB damage induced by NEAT1 overexpression or by inhibition of miR-135a. In vivo experiments substantiated that knockdown of NEAT1 could alleviate BBB damage in living mice. Hence, NEAT1 knockdown prevents BBB disruption and exerts promise as a potential target for BM treatment.

Long Noncoding RNA NEAT1 Knockdown Ameliorates 1-Methyl-4-Phenylpyridine–Induced Cell Injury Through MicroRNA-519a-3p/SP1 Axis in Parkinson Disease

Parkinson disease is a neurodegenerative disease and is characterized by resting tremor, dementia, and gait disorder. Previous studies have indicated that long noncoding RNA participates in the regulation of the pathogenesis of Parkinson disease. The study aimed to reveal the effects of long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) on 1-methyl-4-phenylpyridine (MPP+)-induced human neuroblastoma cell injury and the underlying mechanism. The expressions of NEAT1, microRNA (miR)-519a-3p, and transcription factor specific protein 1 (SP1) were detected by quantitative real-time polymerase chain reaction. The protein expressions of SP1 and inflammation-related factors were determined by Western blot. Cell viability was determined by 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was investigated by flow cytometry analysis. The targeting relationship between miR-519a-3p and NEAT1 or SP1 was predicted by starBase online database and verified by a dual-luciferase reporter assay. NEAT1 and SP1 expressions were significantly upregulated, whereas miR-519a-3p was downregulated in MPP+-treated neuroblastoma cells in a dose-and time-dependent manner when compared with control groups. NEAT1 knockdown restrained MPP+-induced repression of cell viability and promotion of cell apoptosis and inflammation. Additionally, NEAT1 served as a sponge of miR-519a-3p and regulated MPP+-caused cell injury by interacting with miR-519a-3p. Also, SP1, a target gene of miR-519a-3p, rescued miR-519a-3p-mediated actions under MPP+ treatment. Importantly, NEAT1 stimulated SP1 expression through interaction with miR-519a-3p. NEAT1 silencing protected against MPP+-induced neuroblastoma cell injury by regulating the miR-519a-3p/SP1 pathway. This finding provides a novel direction for the development of therapeutic strategies for Parkinson disease.

Adenosine-to-inosine Alu RNA editing controls the stability of the pro-inflammatory long noncoding RNA NEAT1 in atherosclerotic cardiovascular disease

Long non-coding RNAs (lncRNAs) have emerged as critical regulators in human disease including atherosclerosis. However, the mechanisms involved in the post-transcriptional regulation of the expression of disease-associated lncRNAs are not fully understood. Gene expression studies revealed that Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) lncRNA expression was increased by >2-fold in peripheral blood mononuclear cells (PBMCs) derived from patients with coronary artery disease (CAD) or in carotid artery atherosclerotic plaques. We observed a linear association between NEAT1 lncRNA expression and prevalence of CAD which was independent of age, sex, cardiovascular traditional risk factors and renal function. NEAT1 expression was induced by TNF-α, while silencing of NEAT1 profoundly attenuated the TNF-α-induced vascular endothelial cell pro-inflammatory response as defined by the expression of CXCL8, CCL2, VCAM1 and ICAM1. Overexpression of the RNA editing enzyme adenosine deaminase acting on RNA-1 (ADAR1), but not of its editing-deficient mutant, upregulated NEAT1 levels. Conversely, silencing of ADAR1 suppressed the basal levels and the TNF-α-induced increase of NEAT1. NEAT1 lncRNA expression was strongly associated with ADAR1 in CAD and peripheral arterial vascular disease. RNA editing mapping studies revealed the presence of several inosines in close proximity to AU-rich elements within the AluSx3+/AluJo‐ double-stranded RNA complex. Silencing of the stabilizing RNA-binding protein AUF1 reduced NEAT1 levels while silencing of ADAR1 profoundly affected the binding capacity of AUF1 to NEAT1. Together, our findings propose a mechanism by which ADAR1-catalyzed A-to-I RNA editing controls NEAT1 lncRNA stability in ASCVD.

Long Non-coding RNA NEAT1 as an Emerging Biomarker in Breast and Gynecologic Cancers: a Systematic Overview.

Long non-coding RNAs (lncRNAs) are emerging regulators of cellular pathways, especially in cancer development. Among the lncRNAs, nuclear paraspeckle assembly transcript 1 (NEAT1) forms a scaffold for a nuclear body; the paraspeckle and aberrant expression of NEAT1 have been reported in breast and gynecologic cancers (ovarian, cervical, endometrial, and vulvar). Abundantly expressed NEAT1 in breast and gynecologic cancers generally contribute to tumor development by sponging its corresponding tumor-suppressive microRNAs or interacting with various regulatory proteins. The distinct expression of NEAT1 and its contribution to tumorigenic pathways make it a promising therapeutic target in breast and gynecologic cancers. Herein, we summarize the functions and molecular mechanisms of NEAT1 in human breast, ovarian, cervical, endometrial, and vulvar cancers. Furthermore, we emphasize its critical role in the formation of paraspeckle development and its functions. Conclusively, NEAT1 is a considerable biomarker with a bright prospect and can be therapeutically targeted to manage breast and gynecologic cancers.

Delivery of Long Non-coding RNA NEAT1 by Peripheral Blood Monouclear Cells-Derived Exosomes Promotes the Occurrence of Rheumatoid Arthritis via the MicroRNA-23a/MDM2/SIRT6 Axis.

Emerging evidence has pointed out the importance of long non-coding RNAs (lncRNAs) in multiple diseases, the knowledge of rheumatoid arthritis (RA)-associated lncRNAs remains limited. In this present study, we aimed to elucidate the mechanism of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) from peripheral blood monouclear cell (PBMC)-derived exosomes (exos) on RA development by modulating the microRNA-23a (miR-23a)/murine double minute-2 (MDM2)/Sirtuin 6 (SIRT6) axis. RA was modeled in vivo by collagen induction in mice and in vitro by exposing fibroblast-like synoviocytes (FLSs) to lipopolysaccharide. Exos were isolated from human or mouse PBMCs, which were then were co-cultured with FLSs. Based on gain- and loss-of-function experiments, the cell proliferation and secretion of inflammatory factors were measured. LncRNA NEAT1 was found to be highly expressed in RA, and PBMCs-derived exos contributed to RA development by delivering lncRNA NEAT1. In lipopolysaccharide-induced FLSs, miR-23a inhibited the expression of MDM2, and overexpression of MDM2 partially rescued the inhibitory effect of miR-23a on FLS proliferation and inflammatory response. Mechanistically, MDM2 ubiquitination degraded SIRT6 in RA. LncRNA NEAT1 shuttled by PBMC-derived exos promoted FLS proliferation and inflammation through regulating the MDM2/SIRT6 axis. Furthermore, in vivo experiments suggested that downregulated lncRNA NEAT1 shuttled by PBMC-derived exos or upregulated miR-23a impeded RA deterioration in mice. This study highlights that lncRNA NEAT1 shuttled by PBMC-derived exos contributes to RA development with the involvement of the miR-23a/MDM2/SIRT6 axis.

Long noncoding RNA NEAT1 promotes progression of glioma as a ceRNA by sponging miR-185-5p to stimulate DNMT1/mTOR signaling.

Long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) is regarded as an oncogene in multiple cancers. Previous studies have shown that NEAT1 is involved in the proliferation and tumorigenesis of glioma cells, while miR-185-5p functions as a tumor suppressor in glioma. However, the underlying molecular mechanism of NEAT1 in glioma, especially in association with miR-185-5p, has not been studied. In this study, we first demonstrated that NEAT1 expression was upregulated, and miR-185-5p downregulated in glioma tissues and cells. More important, NEAT1 expression was negatively correlated with miR-185-5p expression in glioma tissues. In vitro and in vivo experiments verified that NEAT1 was a competing endogenous RNA for miR-185-5p for promoting DNA methyltransferase 1 (DNMT1) expression and activated mammalian target of rapamycin (mTOR) signaling, thus inhibiting apoptosis, and promoting glioma migration, proliferation, and epithelial-mesenchymal transition process. Furthermore, NEAT1 knockdown suppressed tumor growth and reduced the expression of proliferation antigen Ki-67, DNMT1, and mTOR, but upregulated the expression of miR-185-5p in vivo. Finally, with mTOR inhibitor rapamycin, we confirmed that NEAT1 promoted glioma activity through mTOR signaling both in vitro and in vivo. In conclusion, these results suggest that NEAT1 promotes glioma tumorigenesis via miR-185-5p/DNMT1/mTOR signaling, which may provide a new target for the diagnosis and therapy of glioma.

Long Noncoding RNA NEAT1 Regulates TGF-β2-Induced Epithelial-Mesenchymal Transition of Lens Epithelial Cells through the miR-34a/Snail1 and miR-204/Zeb1 Pathways.

The aim of this study was to explore whether the long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1)/miR-34a/Snail1 and NEAT1/miR-204/Zeb1 pathways are involved in epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs). Primary human LECs (HLECs) were separated and cultured. Our results identified that TGF-β2 induces NEAT1 overexpression in a dose-dependent manner and a time-dependent manner. Additionally, TGF-β2 induced downregulation of E-cadherin and upregulation of fibronectin in primary HLECs through a NEAT1-dependent mechanism. Microarray analysis showed that NEAT1 overexpression inhibited the miR-34a and miR-204 levels in the LECs. The expression of miR-34a and miR-204 was decreased, and the levels of Snail1 and Zeb1 were elevated in human posterior capsule opacification- (PCO-) attached LECs and the LECs obtained from anterior subcapsular cataract (ASC) by quantitative RT-PCR (qRT-PCR). Mechanistic studies revealed that NEAT1 negatively regulates miR-34a or miR-204, and miR-34a or miR-204 directly targets Snail1 or Zeb1 by luciferase assay and RNA-binding protein immunoprecipitation assay, respectively. Overall, the NEAT1/miR-34a/Snail1 and NEAT1/miR-204/Zeb1 pathways are involved in TGF-β2-induced EMT of HLECs. In summary, TGF-β2 induces NEAT1 overexpression, which in turn suggests that NEAT1 acts as a ceRNA targeting Snail1 or Zeb1 by binding miR-34a or miR-204, and promotes the progression of EMT of LECs.

<p>Long Non-Coding RNA NEAT1 Serves as Sponge for miR-365a-3p to Promote Gastric Cancer Progression via Regulating ABCC4</p>

IntroductionLong non-coding RNA (lncRNA) was reported to be a crucial regulator in cancer. In this work, our purpose is to explore the biological roles of nuclear paraspeckle assembly transcript 1 (NEAT1) in gastric cancer (GC).MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect NEAT1 expression in GC cells and normal cells. GC cell behaviors after NEAT1 overexpression or downregulation were analyzed by Cell Counting Kit-8 assay, colony formation assay, wound-healing assay, and flow cytometry assay. Bioinformatic tools were used to analyze the significance of NEAT1 in GC. The involvement of microRNA-365a-3p (miR-365a-3p) and ATP-binding cassette subfamily C member 4 (ABCC4) in the biological roles of NEAT1 in GC progression was validated by luciferase activity reporter assay and rescue experiments.ResultsWe found NEAT1 increased expression in both GC tissues and cells and correlated with poorer overall survival of cancer patients. We found NEAT1 overexpression promotes, while its knockdown inhibits GC cell proliferation, colony formation, invasion, and cell cycle progression in vitro. Mechanism analyses showed that NEAT1 serves as a ceRNA to upregulate ABCC4 expression via sponging miR-365a-3p.ConclusionIn this study, we revealed a NEAT1/miR-365a-3p/ABCC4 triplet in GC progression, which may provide novel targeted therapy markers for GC.

Long non-coding RNA NEAT1 targeting impairs the DNA repair machinery and triggers anti-tumor activity in multiple myeloma.

The biological role and therapeutic potential of long non-coding RNAs (lncRNAs) in multiple myeloma (MM) are still open questions. Herein, we investigated the functional significance of the oncogenic lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in MM. Our study demonstrates that NEAT1 expression level is higher in MM than in the majority of hematological malignancies. NEAT1 silencing by novel LNA-gapmeR antisense oligonucleotide inhibits MM cell proliferation and triggers apoptosis in vitro and in vivo murine MM model as well. By transcriptome analyses, we found that NEAT1 targeting downregulates genes involved in DNA repair processes including the Homologous Recombination pathway, which in turn results in massive DNA damage. These findings may explain the synergistic impact on apoptosis observed in MM cell lines co-treated with inhibitors of both NEAT1 and PARP. The translational significance of NEAT1 targeting is further underlined by its synergistic effects with the most common drugs administered for MM treatment, including bortezomib, carfilzomib, and melphalan. Overall, NEAT1 silencing is associated with a chemo-sensitizing effect of both conventional and novel therapies, and its targeting could therefore represent a promising strategy for novel anti-MM therapeutic options.