lncRNA NORAD Research Articles

Elevated circulating LncRNA NORAD fosters endothelial cell growth and averts ferroptosis by modulating the miR-106a/CCND1 axis in CAD patients

Atherosclerosis is a leading cause of cardiovascular diseases, characterized by endothelial dysfunction and lipid accumulation. Long non-coding RNAs (lncRNAs) are emerging as key regulators of endothelial cell behavior. This study aimed to investigate the role of lncRNA NORAD in endothelial cell proliferation and as a potential therapeutic target for atherosclerosis. A total of 75 CAD patients and 76 controls were recruited, and plasma NORAD levels were measured using qRT-PCR. HUVECs were transfected with si-NORAD to evaluate its effects on cell cycle, proliferation, migration, and apoptosis. Plasma NORAD levels were significantly elevated in CAD patients. The NORAD-miRNA-mRNA ceRNA regulatory network was constructed based on GEO database, and G1/S-specific cyclin-D1 (CCND1) was identified as one of the hub factors. NORAD deficiency suppressed cell migration and induced G1 cell cycle arrest in HUVECs by downregulating CCND1 in vitro. NORAD upregulated CCND1 in HUVECs via sponging miR-106a that inhibited cell migration. The dual-luciferase assay confirmed the direct targeting of miR-106a by NORAD, and overexpression of miR-106a inhibited HUVEC proliferation and migration. Si-NORAD transfection resulted in induced early apoptosis, increased intracellular ROS levels, decreased GSH levels, and reduced mitochondrial membrane potential. Additionally, si-NORAD decreased the expression of GPX4, FTH1, KEAP1, NCOA4, and Nrf2, while increasing Xct levels, confirming the involvement of ferroptosis. Our findings reveal that NORAD plays a critical role in endothelial cell proliferation, migration, and apoptosis, and its silencing induces ferroptosis. The regulatory network involving NORAD, miR-106a, and their target genes provides a potential therapeutic avenue for atherosclerosis.

M2 macrophage-derived lncRNA NORAD in EVs promotes NSCLC progression via miR-520g-3p/SMIM22/GALE axis

Non-small cell lung cancer (NSCLC) constitutes the majority of lung cancer cases, accounting for over 80%. RNAs in EVs play a pivotal role in various biological and pathological processes mediated by extracellular vesicle (EV). Long non-coding RNAs (lncRNAs) are widely associated with cancer-related functions, including cell proliferation, migration, invasion, and drug resistance. Tumor-associated macrophages are recognized as pivotal contributors to tumorigenesis. Given these insights, this study aims to uncover the impact of lncRNA NORAD in EVs derived from M2 macrophages in NSCLC cell lines and xenograft mouse models of NSCLC. EVs were meticulously isolated and verified based on their morphology and specific biomarkers. The interaction between lncRNA NORAD and SMIM22 was investigated using immunoprecipitation. The influence of SMIM22/GALE or lncRNA NORAD in EVs on glycolysis was assessed in NSCLC cell lines. Additionally, we evaluated the effects of M2 macrophage-derived lncRNA NORAD in EVs on cell proliferation and apoptosis through colony formation and flow cytometry assays. Furthermore, the impact of M2 macrophage-derived lncRNA NORAD in EVs on tumor growth was confirmed using xenograft tumor animal models. The results underscored the potential role of M2 macrophage-derived lncRNA NORAD in EVs in NSCLC. SMIM22/GALE promoted glycolysis and the proliferation of NSCLC cells. Furthermore, lncRNA NORAD in EVs targeted SMIM22 and miR-520g-3p in NSCLC cells. Notably, lncRNA NORAD in EVs promoted the proliferation of NSCLC cells and facilitated NSCLC tumor growth through the miR-520g-3p axis. In conclusion, M2 macrophage-derived lncRNA NORAD in EVs promotes NSCLC progression through the miR-520g-3p/SMIM22/GALE axis.

LncRNA NORAD Promotes Proliferation and Inhibits Apoptosis of Gastric Cancer by Regulating miR-214/Akt/mTOR Axis [Retraction

[This retracts the article DOI: 10.2147/OTT.S216862.].

Long non-coding RNA NORAD regulates megakaryocyte differentiation and proplatelet formation via the DUSP6/ERK signaling pathway

Megakaryopoiesis and platelet production is a complex process that is underpotential regulation at multiple stages. Many long non-coding RNAs (lncRNAs) are distributed in hematopoietic stem cells and platelets. lncRNAs may play important roles as key epigenetic regulators in megakaryocyte differentiation and proplatelet formation. lncRNA NORAD can affect cell ploidy by sequestering PUMILIO proteins, although its direct effect on megakaryocyte differentiation and thrombopoiesis is still unknown. In this study, we demonstrate NORAD RNA is highly expressed in the cytoplasm during megakaryocyte differentiation. Interestingly, we identified for the first time that NORAD has a strong inhibitory effect on megakaryocyte differentiation and proplatelet formation from cultured megakaryocytes. DUSP6/ERK1/2 pathway is activated in response to NORAD knockdown during megakaryocytopoiesis, which is achieved by sequestering PUM2 proteins. Finally, compared with the wild-type control mice, NORAD knockout mice show a faster platelet recovery after severe thrombocytopenia induced by 6 Gy total body irradiation. These findings demonstrate lncRNA NORAD has a key role in regulating megakaryocyte differentiation and thrombopoiesis, which provides a promising molecular target for the treatment of platelet-related diseases such as severe thrombocytopenia.

LncRNA NORAD alleviates dysfunction of renal proximal tubular epithelial cells during the sepsis-associated acute kidney injury by modulating the miR-155-5p-PDK1 axis.

The sepsis-associated acute kidney injury (Sa-AKI) is closely related to high mortality rates worldwide. Injury to the renal proximal tubular epithelial cells (RPTECs), caused by pathological conditions, is a major cause of acute kidney injury (AKI). The lncRNA NORAD has been reported to be positively associated with kidney cancers. However, the biological roles and underlying mechanisms of NORAD in RPTECs during AKI are still unclear. In this study, we found that NORAD was significantly downregulated in RPTECs from AKI tissues. Overexpression of NORAD alleviated RPTECs injury induced by lipopolysaccharide (LPS). Additionally, glucose metabolism was significantly impaired during AKI, and LPS treatment inhibited glucose metabolism in RPTECs. We demonstrated that NORAD rescued the LPS-induced inhibition of glucose metabolism in RPTECs. Furthermore, miRNA-155-5p was significantly upregulated in RPTECs from AKI. Through bioinformatics analysis, RNA pull-down, RNA IP, and luciferase assays, we showed that NORAD directly associated with miR-155-5p to downregulate its expression. Moreover, overexpression of miR-155-5p inhibited glucose metabolism by directly targeting the 3'UTR of the glucose metabolism enzyme, pyruvate dehydrogenase kinase 1 (PDK1). Finally, rescue experiments validated that NORAD's protective effect on RPTECs injury was mediated through modulation of the miR-155-5p-PDK1-glucose metabolism pathway. In summary, these results reveal that lncRNA NORAD can alleviate RPTECs dysfunction by targeting the miR-155-5p-PDK1 axis, suggesting that NORAD has the potential to contribute to the development of therapeutic approaches against Sa-AKI.

METTL3-mediated m6A modification of NORAD inhibits the ferroptosis of vascular smooth muscle cells to attenuate the aortic dissection progression in an YTHDF2-dependent manner.

Ferroptosis of vascular smooth muscle cells (VSMCs) is related to the incidence of aortic dissection (AD). Long non-coding RNA (lncRNA) NORAD plays a crucial role in the progression of various diseases. The present study aimed to investigate the effects of NORAD on the ferroptosis of VSMCs and the molecular mechanisms. The expression of NORAD, HUR, and GPX4 was detected using quantitative real-time PCR (qPCR) or western blot. Ferroptosis was evaluated by detecting lactate dehydrogenase (LDH) activity, lipid reactive oxygen species (ROS), malonaldehyde (MDA) content, L-Glutathione (GSH) level, Fe2+ content, and ferroptosis-related protein levels. The molecular mechanism was assessed using RNA pull-down, RNA-binding protein immunoprecipitation (RIP), and luciferase reporter assay. The histology of aortic tissues was assessed using H&E, elastic Verhoeff-Van Gieson (EVG), and Masson staining assays. The data indicated that NORAD was downregulated in patients with AD and AngII-treated VSMCs. Overexpression of NORAD promoted VSMC growth and inhibited the ferroptosis induced by AngII. Mechanistically, NORAD interacted with HUR, which promoted GPX4 mRNA stability and elevated GPX4 levels. Knockdown of GPX4 abrogated the effects of NORAD on cell growth and ferroptosis of AngII-treated VSMCs. Moreover, METTL3 promoted m6A methylation of NORAD in an YTHDF2-dependent manner. In addition, NORAD attenuated AAD symptoms, incidence, histopathology, inflammation, and ferroptosis in AAD mice. In conclusion, METTL3-mediated NORAD inhibited ferroptosis of VSMCs via the HUR/GPX4 axis and decelerated AAD progression, suggesting that NORAD may be an AD therapeutic target.

Diagnostic and prognostic potential of long non-coding RNA NORAD in patients with acute deep vein thrombosis and its role in endothelial cell function

BackgroundDeep venous thrombosis (DVT) is the common clinical cardiovascular disease, and easily develops into post-thrombotic syndrome (PTS). The study aimed to examine the clinical value of long non-coding RNA NORAD gene in the development of DVT and PTS. In vitro, the underlying mechanism was explored.MethodsSerum levels of lncRNA NORAD gene in 85 DVT cases and 85 healthy individuals were tested. The role of lncRNA NORAD gene in human umbilical vein endothelial cells (HUVECs) proliferation, migration and inflammation was examined. The candidate downstream target gene was predicted via bioinformatic analysis. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were done for the function annotation and pathway enrichment.ResultsLncRNA NORAD gene was at high expression in the serum of DVT patients, it can distinguish DVT patients from healthy controls with the area under the curve of 0.919. Elevated expression of lncRNA NORAD gene in PTS patients was detected, DVT cases with high expression of lncRNA NORAD gene were more susceptible to PTS. LncRNA NORAD gene knockdown promoted HUVECs’ proliferation, migration while suppressing cell apoptosis and inflammation. MiR-93-5p served as a target of lncRNA NORAD gene, and its overexpression reversed the role of lncRNA NORAD gene in the biological function of HUVECs. The target genes of miR-93-5p were enriched in HIF-1 signaling, TGF-beta signaling and PI3K-Akt signaling, protein-protein interaction (PPI) network indicated STAT3, MAPK1 to be the key targets.ConclusionsUpregulation of expression of lncRNA NORAD gene was a potential diagnostic biomarker for DVT and related to the development of PTS. LncRNA NORAD/miR-93-5p axis was involved in the progress of DVT through regulating endothelial cell function.

Sevoflurane preconditioning attenuates myocardial cell damage caused by hypoxia and reoxygenation via regulating the NORAD/miR-144-3p axis.

This study aimed to investigate the function and mechanism of lncRNA NORAD in Sevoflurane (Sev) protection against myocardial hypoxia-reoxygenation (H/R). Preprocess rat cardiomyocytes H9c2 cells with Sev at concentrations of 0.5%, 1.0%, and 1.5%, and subjected them to H/R treatment. qRT-PCR was used to detect levels of NORAD and miR-144-3p. Measure concentrations of the inflammatory cytokines IL-6, TNF-α, and IL-10, as well as cardiac injury markers cTnI, CK-MB, and LDH using ELISA. Assess cell proliferation and apoptosis using CCK-8 and flow cytometry. Perform dual-luciferase reporter assay and RIP assay to validate the targeting relationship between NORAD and miR-144-3p. H/R induced inhibition of cell proliferation, increase in apoptosis, and production of IL-6, TNF-α, CK-MB, LDH, and cTnI were significantly attenuated by Sev. As hypoxic treatment time lengthened, the NORAD levels in myocardial cells showed an increase, with Sev pretreatment being able to suppress the NORAD levels elevation. The overexpression of NORAD notably weakened the cardioprotective effect of Sev. NORAD targetedly binds to miR-144-3p and negatively regulates miR-144-3p. Increased miR-144-3p levels inhibited the antagonistic effect of NORAD on the cardioprotective effects of Sev. The current study confirmed that sevoflurane attenuated H/R-induced cardiomyocyte injury via the NORAD/miR-144-3p axis.

Expression of NORAD correlates with breast cancer aggressiveness and protects breast cancer cells from chemotherapy

The recently discovered human lncRNA NORAD is induced after DNA damage in a p53-dependent manner. It plays a critical role in the maintenance of genomic stability through interaction with Pumilio proteins, limiting the repression of their target mRNAs. Therefore, NORAD inactivation causes chromosomal instability and aneuploidy, which contributes to the accumulation of genetic abnormalities and tumorigenesis. NORAD has been detected in several types of cancer, including breast cancer, which is the most frequently diagnosed and the second-leading cause of cancer death in women. In the present study, we confirmed upregulated NORAD expression levels in a set of human epithelial breast cancer cell lines (MDA-MB-231, MDA-MB-436, and MDA-MB-468), which belong to the most aggressive subtypes (triple-negative breast cancer). These results are in line with previous data showing that high NORAD expression levels in basal-like tumors were associated with poor prognosis. Here, we demonstrate that NORAD downregulation sensitizes triple-negative breast cancer cells to chemotherapy, through a potential accumulation of genomic aberrations and an impaired capacity to signal DNA damage. These results show that NORAD may represent an unexploited neoadjuvant therapeutic target for chemotherapy-unresponsive breast cancer.

Impacts of LncRNA NORAD on the Proliferation, Apoptosis, and Chemosensitivity of Non-small Cell Lung Cancer Cells by Regulating ZNF217 through MiR-199a-3p

The treatment and diagnosis of non-small cell lung cancer (NSCLC) is still a difficult problem in the medical community, and exploring the molecular mechanism of the occurrence and development of NSCLC is a hot topic of the current research. Long non-coding RNA (lncRNA) NORAD is highly expressed in a variety of cancer cells. It may be a molecular target that promotes NSCLC. The aim of this study was to investigate the impacts of lncRNA NORAD on the proliferation, apoptosis, and chemosensitivity of NSCLC by regulating zinc finger protein 217 (ZNF217) through miR-199a-3p. Real-time quantitative polymerase chain reaction (qRT-PCR) method was applied to detect the expressions of NORAD, miR-199a-3p and ZNF217 genes in normal lung epithelial cells BEAS-2B, lung cancer H460 cells, and Cisplatin (DDP) resistant cell lines H460/DDP. H460/DDP cells were devided into control group, si-NC group, si-NORAD group, miR-NC group, miR-199a-3p mimic group, si-NORAD+inhibitor NC group and si-NORAD+miR-199a-3p inhibitor group. Cell proliferation, apoptosis, the expression of NORAD, miR-199a-3p and ZNF217 genes of cells in each group were detected and the expression levels of Ki-67, caspase-9 and ZNF217 proteins in different cells were also observed. The relationship between miR-199a-3p, NORAD and ZNF217 was vefified. Compared with BEAS-2B cells, the expressions of NORAD, ZNF217 mRNA were significantly increased in H460 and H460/DDP cells (P<0.05) but the expression of miR-199a-3p was significantly reduced (P<0.05). Compared with H460 cells, the expression of NORAD and ZNF217 mRNA in H460/DDP cells was significantly increased (P<0.05) and the expression of miR-199a-3p was significantly reduced (P<0.05). Compared with the control group and si-NC group, the proliferation rate, NORAD and ZNF217 mRNA expression, Ki-67 and ZNF217 protein expression of H460/DDP cells in the si-NORAD group were significantly reduced (P<0.05), but the apoptosis rate, miR-199a-3p expression and caspase-9 expression were significantly increased (P<0.05). Compared with the miR-NC group, the proliferation rate, NORAD and ZNF217 mRNA expression, Ki-67 and ZNF217 protein expression of H460/DDP cells in the miR-199a-3p mimic group were significantly reduced (P<0.05), but the apoptosis rate, miR-199a-3p expression and caspase-9 expression were significantly increased (P<0.05). Compared with the si-NORAD+inhibitor NC group, the proliferation rate, ZNF217 mRNA expression, Ki-67 and ZNF217 protein expression of H460/DDP cells in the si-NORAD+miR-199a-3p inhibitor group were significantly increased (P<0.05), the apoptosis rate, miR-199a-3p expression and caspase-9 expression were obviously increased reduced (P<0.05). Down-regulating NORAD expression can enhance miR-199a-3p expression and inhibit ZNF217 expression, thereby inhibiting H460/DDP cell proliferation, promoting apoptosis and enhancing its DDP chemotherapy sensitivity.

LncRNA NORAD, soluble ICAM1 and their correlations may be related to the regulation of the tumor immune microenvironment in laryngealsquamous cell carcinoma (LSCC).

NORAD, non-coding RNA activated by DNA damage, is a Long non-coding RNA (lncRNA) transcript that modulates genome stability and has been reported to be dysregulated in different cancers. Although it has been reported to be upregulated in tumor cells mostly for solid organ cancers, it has also been reported to be downregulated in some cancers. Although the pathophysiological mechanism is not fully understood, a negative correlation between NORAD and intercellular cell adhesion molecule-1 (ICAM-1) has been shown in experimental models, but this situation has not been evaluated in terms of cancer. We aimed to evaluate the potential roles of these two biomarker candidates together and separately in the clinicopathological axis in Laryngeal squamous cell carcinoma (LSCC) in a case-control study setting. The interactions of NORAD and ICAM1 at the RNA level were evaluated interactively by the RIblast program. sICAM1 (soluble intercellular cell adhesion molecule-1) levels were determined by ELISA in one hundred and five individuals (forty-four LSCC, sixty-one control) and lncRNA NORAD expression in eighty-eight tissues (forty-four LSCC tumors, forty-four tumor-free surrounding tissues) was determined by Real-time PCR. While the energy treesholud was -16kcal/mol between NORAD and ICAM1, the total energy was 176.33kcal/mol, and 9 base pair pairings from 4 critical points were detected. NORAD expression level was found to be higher in tumor surrounding tissue compared to tumor tissue, and sICAM1 was higher in the control group compared to LSCC (p=0.004; p=0.02). NORAD discreminte tumor surrounding tissue from tumor (AUC: 0.674; optimal sensitivity:87.50%; optimal specificity 54.55%; cut-off point as >1.58 fold change; P=0.034). The sICAM1 level was found to be higher in the control (494,814±93.64ng/L) than LSCC (432.95±93.64ng/L) (p=0.02). sICAM1 discreminte control group from LSCC (AUC: 0.624; optimal sensitivity 68,85%; optimal specificity 61,36%; cut-off point ≤115,0ng/L; (p=0.033). A very strong negative correlation was found between NORAD expression and patients' sICAM1 levels (r=-.967; n=44; p=0.033). sICAM1 levels were found to be 1.63 times higher in NORAD downregulated subjects compared to upregulated ones (p=0.031). NORAD was 3.63 times higher in those with alcohol use, and sICAM 1 was 5.77 times higher in those without distant organ metastasis (p=0.043; 0.004). The increased NORAD expression in the tumor microenvironment in LSCC, the activation of T cells via TCR signaling, and the decrease of sICAM in the control group in correlation with NORAD suggests that ICAM1 may be needed as a membrane protein in the tumor microenvironment. NORAD and ICAM1 may be functionally related to tumor microenvironment and immune control in LSCC.

LncRNA NORAD regulates the mechanism of the miR-532-3p/Nectin-4 axis in pancreatic cancer cell proliferation and angiogenesis.

Pancreatic cancer (PC) is one of the deadliest cancers worldwide, and cell proliferation and angiogenesis play an important role in its occurrence and development. High levels of lncRNANORAD have been detected in many tumors, including PC, yet the effect and mechanism of lncRNA NORAD on PC cell angiogenesis are unexplored. qRT.PCR was applied to quantify lncRNA NORAD and miR-532-3p expression in PC cells, and a dual luciferase reporter gene was used to verify the targeting effects of NORAD, miR-532-3p and Nectin-4. Then, we regulated NORAD and miR-532-3p expression in PC cells and detected their effects on PC cell proliferation and angiogenesis using cloning experiments and HUVEC tube formation experiments. LncRNA NORAD was upregulated and miR-532-3p was downregulated in PC cells compared with normal cells. Knockdown of NORAD inhibited PC cell proliferation and angiogenesis. LncRNA NORAD and miR-532-3p competitively bound to promote the expression of the miR-532-3p target gene Nectin-4, thereby promoting proliferation and angiogenesis of PC cells in vitro. LncRNA NORAD promotes the proliferation and angiogenesis of PC cells by regulating the miR-532-3p/Nectin-4 axis, which may be a potential biological target in the diagnosis and treatment of clinical PC.

Long Noncoding RNA NORAD Promotes Fracture Healing through Interacting with Osteoblast Differentiation via Targeting miR-26a.

The present study was designed to evaluate the dynamic expression of lncRNA NORAD in fracture healing of patients with brittle fractures and explore the function and mechanism of NORAD in regulating osteoblastic proliferation, differentiation, and apoptosis. The expression level of NORAD was detected by quantitative real-time PCR. The proliferation, differentiation, and apoptosis of osteoblasts were analyzed by MTT assay, ELISA, and flow cytometry. Luciferase report analysis was used to confirm the interaction between NORAD and its target ceRNA miR-26a. This study showed no significant differences in serum NORAD expression on the 7th day during fracture healing in patients, but increased expression of NORAD was certified on the 14, 21, and 28 days after fixation. Overexpression of NORAD promoted the proliferation and differentiation of osteoblasts and suppressed the apoptosis of osteoblasts. miR-26a proved to be the target gene of NORAD and was inhibited by overexpression of NORAD in osteoblasts. The enhanced expression of miR-26a was negatively linked to the lessened expression of NORAD. NORAD could accelerate the proliferation and differentiation of osteoblasts and inhibit apoptosis, thereby promoting fracture healing.

Expression and clinical significance of lncRNA NORAD in patients with gestational hypertension.

Gestational hypertension (GH), the most common type of hypertensive disorders in pregnancy, often occurs in women during pregnancy. The purpose of this study was to investigate the expression and clinical significance of lncRNA NORAD in gestational hypertension, and to discuss the possibility of lncRNA NORAD as a diagnostic marker of gestational hypertension. A total of 219 participants were involved in the study. Basic clinical information of all participants was collected, and the expression of NORAD in serum was detected by RT-qPCR. ROC curves were drawn to evaluate the diagnostic value of NORAD expression for gestational hypertension. Multiple linear regression analysis was done to explore the relationship between NORAD and clinical variables. Logistic regression analysis was conducted to analyze the independent influence of different variables on the development of gestational hypertension into preeclampsia. The expression level of NORAD in gestational hypertension was higher than that of healthy individuals, and the expression level of NORAD in preeclampsia was higher than that of gestational hypertension and healthy individuals. The ROC curve suggested that the expression of NORAD has a higher diagnostic value for gestational hypertension. Multiple linear regression analysis showed that systolic blood pressure (SBP) and diastolic blood pressure (DBP) were correlated with the expression of NORAD. SBP, DBP and NORAD were all factors that affect the development of gestational hypertension to preeclampsia, which were known by Logistic regression analysis. LncRNA NORAD may be used as a biomarker for gestational hypertension diagnosis and can influence its progression into preeclampsia.

LncRNA NORAD promotes the progression of myocardial infarction by targeting the miR-22-3p/PTEN axis.

NORAD is a newly identified long non-coding RNA (lncRNA) that plays an important role in cancers. NORAD has been found to be highly expressed in the mouse model of acute myocardial infarction (AMI). However, the role of NORAD in the regulation of AMI remains unknown. In the present study, we aimed to investigate the function of NORAD in AMI and explore the potential regulatory mechanisms. A mouse model of AMI was established and NORAD was knocked-down. The infarcted size of heart tissues and the cardiac function were evaluated. In addition, two cardiomyocyte cell lines were treated with hypoxia/re-oxygenation (H/R) to mimic AMI . Luciferase reporter assay, RNA pull-down assay, fluorescence hybridization, qRT-PCR, and western blot analysis were performed. Apoptotic cells and the levels of L-lactate dehydrogenase (LDH) and malondialdehyde (MDA) were detected. Our results show that downregulation of NORAD efficiently attenuates heart damage in the AMI mouse model. NORAD interacts with miR-22-3p. Knock-down of NORAD inhibits H/R-induced cell apoptosis and reduces LDH and MDA levels, while its effects are abolished by miR-22-3p inhibitor. MiR-22-3p interacts with PTEN and inhibits its expression. Overexpression of miR-22-3p inhibits H/R-induced cell apoptosis and reduces LDH and MDA levels, while its effects are abolished by overexpression of PTEN. Finally, overexpression of NORAD inhibits the AKT/mTOR signaling pathway, and its effects are attenuated by overexpression of miR-22-3p. Taken together, our study reveals that NORAD promotes the progression of AMI by regulating the miR-22-3p/PTEN axis, and the AKT/mTOR signaling may also be involved in the regulatory processes.

A non-coding RNA balancing act: miR-346-induced DNA damage is limited by the long non-coding RNA NORAD in prostate cancer

BackgroundmiR-346 was identified as an activator of Androgen Receptor (AR) signalling that associates with DNA damage response (DDR)-linked transcripts in prostate cancer (PC). We sought to delineate the impact of miR-346 on DNA damage, and its potential as a therapeutic agent.MethodsRNA-IP, RNA-seq, RNA-ISH, DNA fibre assays, in vivo xenograft studies and bioinformatics approaches were used alongside a novel method for amplification-free, single nucleotide-resolution genome-wide mapping of DNA breaks (INDUCE-seq).ResultsmiR-346 induces rapid and extensive DNA damage in PC cells - the first report of microRNA-induced DNA damage. Mechanistically, this is achieved through transcriptional hyperactivation, R-loop formation and replication stress, leading to checkpoint activation and cell cycle arrest. miR-346 also interacts with genome-protective lncRNA NORAD to disrupt its interaction with PUM2, leading to PUM2 stabilisation and its increased turnover of DNA damage response (DDR) transcripts. Confirming clinical relevance, NORAD expression and activity strongly correlate with poor PC clinical outcomes and increased DDR in biopsy RNA-seq studies. In contrast, miR-346 is associated with improved PC survival.INDUCE-seq reveals that miR-346-induced DSBs occur preferentially at binding sites of the most highly-transcriptionally active transcription factors in PC cells, including c-Myc, FOXA1, HOXB13, NKX3.1, and importantly, AR, resulting in target transcript downregulation. Further, RNA-seq reveals widespread miR-346 and shNORAD dysregulation of DNA damage, replication and cell cycle processes.NORAD drives target-directed miR decay (TDMD) of miR-346 as a novel genome protection mechanism: NORAD silencing increases mature miR-346 levels by several thousand-fold, and WT but not TDMD-mutant NORAD rescues miR-346-induced DNA damage. Importantly, miR-346 sensitises PC cells to DNA-damaging drugs including PARP inhibitor and chemotherapy, and induces tumour regression as a monotherapy in vivo, indicating that targeting miR-346:NORAD balance is a valid therapeutic strategy.ConclusionsA balancing act between miR-346 and NORAD regulates DNA damage and repair in PC. miR-346 may be particularly effective as a therapeutic in the context of decreased NORAD observed in advanced PC, and in transcriptionally-hyperactive cancer cells.

WTAP-mediated m6A modification of lncRNA NORAD promotes intervertebral disc degeneration

N6-methyladenosine (m6A) is the most prevalent RNA modification at the posttranscriptional level and involved in various diseases and cellular processes. However, the underlying mechanism of m6A regulation in intervertebral disc degeneration (IVDD) remains elusive. Here, we show that methylation of the lncRNA NORAD significantly increases in senescent nucleus pulposus cells (NPCs) by m6A sequencing. Subsequent loss- and gain-of-function experiments reveal WTAP is increased in senescent NPCs due to an epigenetic increase in H3K4me3 of the promoter mediated by KDM5a, and significantly promotes NORAD m6A modification. Furthermore, YTHDF2-mediated decay of NORAD is enhanced in senescent NPCs, and then deficiency of NORAD results in less sequestraion of PUMILIO proteins, contributing to the augmented activity of PUM1/2, thus repressing the expression of target E2F3 mRNAs and promoting the cellular senescence. Here, we show interruption of NORAD m6A modification or the NORAD/PUMILIO/E2F3 axis could serve as a potential therapeutic target to inhibit the senescence of NPCs and development of IVDD.

BMSC-EV-derived lncRNA NORAD Facilitates Migration, Invasion, and Angiogenesis in Osteosarcoma Cells by Regulating CREBBP via Delivery of miR-877-3p.

Bone marrow mesenchymal stem cells (BMSCs) can boost osteosarcoma (OS) cell proliferation and invasion, yet the function of extracellular vesicles (EVs) derived from BMSCs on OS is scarcely known. This study is aimed at examining the role of BMSC-EVs in OS cells. BMSCs and BMSC-EVs were isolated and identified. The effect of EVs and EVs-si-NORAD on OS cell proliferation, invasion, migration, and angiogenesis was determined. Expressions of NORAD, miR-877-3p, and CREBBP were detected. The binding relationship among NORAD, miR-877-3p, and CREBBP was verified. The miR-877-3p inhibitor or pc-CREBBP was delivered into OS cells treated with EVs-si-NORAD for in vitro analysis. The nude mouse model of the subcutaneous tumor xenograft was established for in vivo analysis. BMSC-EVs promoted OS cell proliferation, invasion, migration, and angiogenesis. BMSC-EVs carried NORAD into OS cells and upregulated CREBBP by sponging miR-877-3p. miR-877-3p downregulation or CREBBP overexpression partly inverted the inhibitory effect of EVs by silencing NORAD on OS cell proliferation, invasion, migration, and angiogenesis. In vivo experiments validated that BMSC-EV-derived NORAD facilitated tumor growth by upregulating CREBBP via miR-877-3p. To conclude, BMSC-EV-derived NORAD facilitated OS cell proliferation, invasion, migration, and angiogenesis by modulating CREBBP via miR-877-3p, which may offer new insights into OS treatment.

LncRNA NORAD facilitates oral squamous cell carcinoma progression by sponging miR-577 to enhance TPM4

BackgroundLong non-coding RNAs (lncRNAs) have been reported to be vital factors to affect the expression of genes and proteins. Also, it has been proved that the abnormal expression or mutation of lncRNAs stands as a signal of metastasis and proliferation of cancer. Nevertheless, the majority of lncRNAs still need to be explored in abundant cancers especially in oral squamous cell carcinoma (OSCC).MethodsRT-qPCR assays were applied to test the expression of RNAs. Mechanism assays were performed to verify the combination among NORAD, TPM4 and miR-577. Also, functional assays were conducted to verify the function of RNAs on OSCC cells.ResultsLncRNA NORAD was highly expressed in OSCC tissues and cells. NORAD silencing repressed the biological behaviors of OSCC cells. MiR-577 was found in OSCC with low expression, and RIP assays illustrated that NORAD, miR-577 and TPM4 coexisted in RNA-induced silencing complexes. Rescue assays proved that the overexpression of TPM4 could recover the effect of NORAD silencing on OSCC progression.ConclusionsIt was revealed that NORAD functioned as a tumor promoter to sponge miR-577 thus elevating TPM4 in OSCC, which indicated that NORAD was worthy to be studied as a target for the treatment of OSCC.

Upregulated lncRNA NORAD can diagnose acute cerebral ischemic stroke patients and predict poor prognosis.

Acute cerebral ischemic stroke (AIS) dramatically influences patients' quality of life. lncRNA NORAD (NORAD) has been studied in cerebrovascular diseases, which are potential risk factors for AIS. The specific significance of NORAD is unclear. This study aimed to assess the role of NORAD in AIS, and to provide therapeutic value for its' treatment. A total of 103 AIS patients and 95 healthy individuals (control) were enrolled into this study. Expression level of NORAD in the plasma of all participants was analyzed by PCR. Diagnostic potential of NORAD in AIS was evaluated by ROC analysis, while Kaplan-Meier and Cox regression analyses were conducted to assess its' prognostic value in AIS. A significantly increased level of NORAD was observed in AIS patients compared with healthy individuals. The upregulation of NORAD could dramatically discriminate AIS patients from healthy individuals with high sensitivity (81.60%) and specificity (88.40%). NORAD was positively correlated with patients' high-sensitivity C-reactive protein (hs CRP, r = 0.796), matrix metalloproteinase-9 (MMP9, r = 0.757), and NIHSS scores ( r = 0.840), and negatively related to pc-ASPECTS scores ( r = -0.607). Moreover, NORAD upregulation was associated with patients' unfavorable prognosis and served as an independent prognostic biomarker, together with NIHSS and pc-ASPECTS scores of AIS patients. NORAD was upregulated in AIS, which can discriminate AIS patients, and was closely correlated with severe development and poor prognosis of patients.