Rhabdomyosarcoma 2-associated Transcript Research Articles

The oxidative stress-associated long non-coding RNAs in pancreatic cancer

PurposeA lot of people are dying from pancreatic cancer (PC) annually. The early detection of this cancer is particularly challenging due to the fact that symptoms tend to appear in advanced stages. It has been suggested that oxidative stress may play a role in the development of PC. Several genes regulate this process, including long noncoding RNAs (lncRNAs). There is no comprehensive study on the expression pattern of lncRNAs related to oxidative stress in PC patients. In the present case-control study, we quantified levels of oxidative stress-associated lncRNAs in PC patients versus healthy controls. Patients and methodsIn the present study, we investigated the expression levels of lincRNA-p21, LUCAT, RMST, FOXD3-AS1, and MT1DP lncRNAs in the peripheral blood mononuclear cells (PBMCs) of 53 ​PC patients and 50 healthy controls. The association between lncRNA expression and clinical and pathological characteristics was also evaluated. ResultsThe expression of lincRNA-P21 and rhabdomyosarcoma 2-associated transcript (RMST) lncRNAs in PC patients has significantly decreased. Expression of lncRNA RMST was significantly higher in TNM stage III-IV patients in comparison to TNM stage I-II patients. In addition, a significant positive association was recognized between candidate lncRNA expression, and finally, the AUC values of the expression levels of lincRNA-p21 and RMST were 0.60 and 0.61, respectively. ConclusionsAltogether, our study suggests a possible role of lincRNA-p21 and RMST lncRNAs in the etiology of PC pathobiology, and their biomarker role may be understood in future studies.

The lncRNA RMST is drastically downregulated in anaplastic thyroid carcinomas where exerts a tumor suppressor activity impairing epithelial-mesenchymal transition and stemness

Thyroid cancer is the most prevalent endocrine malignancy and comprises a wide range of lesions subdivided into differentiated (DTC) and undifferentiated thyroid cancer (UTC), mainly represented by the anaplastic thyroid carcinoma (ATC). This is one of the most lethal malignancies in humankind leading invariably to patient death in few months. Then, a better comprehension of the mechanisms underlying the development of ATC is required to set up new therapeutic approaches. Long non-coding RNAs (lncRNAs) are transcripts over 200 nucleotides in length that do not code for proteins. They show a strong regulatory function at both transcriptional and post-transcriptional level and are emerging as key players in regulating developmental processes. Their aberrant expression has been linked to several biological processes, including cancer, making them potential diagnostic and prognostic markers. We have recently analyzed the lncRNA expression profile in ATC through a microarray technique and have identified rhabdomyosarcoma 2-associated transcript (RMST) as one of the most downregulated lncRNA in ATC. RMST has been reported to be deregulated in a series of human cancers, to play an anti-oncogenic role in triple-negative breast cancer, and to modulate neurogenesis by interacting with SOX2. Therefore, these findings prompted us to investigate the role of RMST in ATC development. In this study we show that RMST levels are strongly decreased in ATC, but only slightly in DTC, indicating that the loss of this lncRNA could be related to the loss of the differentiation and high aggressiveness. We also report a concomitant increase of SOX2 levels in the same subset of ATC, that inversely correlated with RMST levels, further supporting the RMST/SOX2 relationship. Finally, functional studies demonstrate that the restoration of RMST in ATC cells reduces cell growth, migration and the stemness properties of ATC stem cells. In conclusion, these findings support a critical role of RMST downregulation in ATC development.

Differential Expression of LncRNA in Bladder Cancer Development.

Bladder cancer (BC) is the tenth most common cancer, with urothelial carcinoma representing about 90% of all BC, including neoplasms and carcinomas of different grades of malignancy. Urinary cytology has a significant role in BC screening and surveillance, although it has a low detection rate and high dependence on the pathologist's experience. The currently available biomarkers are not implemented into routine clinical practice due to high costs or low sensitivity. In recent years, the role of lncRNAs in BC has emerged, even though it is still poorly explored. We have previously shown that the lncRNAs Metallophosphoesterase Domain-Containing 2 Antisense RNA 1 (MPPED2-AS1), Rhabdomyosarcoma-2 Associated Transcript (RMST), Kelch-like protein 14 antisense (Klhl14AS) and Prader Willi/Angelman region RNA 5 (PAR5) are involved in the progression of different types of cancers. Here, we investigated the expression of these molecules in BC, first by interrogating the GEPIA database and observing a different distribution of expression levels between normal and cancer specimens. We then measured them in a cohort of neoplastic bladder lesions, either benign or malignant, from patients with suspicion of BC undergoing transurethral resection of bladder tumor (TURBT). The total RNA from biopsies was analyzed using qRT-PCR for the expression of the four lncRNA genes, showing differential expression of the investigated lncRNAs between normal tissue, benign lesions and cancers. In conclusion, the data reported here highlight the involvement of novel lncRNAs in BC development, whose altered expression could potentially affect the regulatory circuits in which these molecules are involved. Our study paves the way for testing lncRNA genes as markers for BC diagnosis and/or follow-up.

LncRNA RMST suppresses the progression of colorectal cancer by competitively binding to miR-27a-3p/RXRα axis and inactivating Wnt signaling pathway.

Colorectal cancer (CRC) ranks the 3rd in cancer types globally. Long noncoding RNAs (lncRNAs) are related to the initiation and progression of CRC. The current study plans to reveal the action of rhabdomyosarcoma 2-associated transcript (RMST) in CRC. The results show that RMST is downregulated in CRC specimens and cell lines relative to normal specimens and a fetal normal colon cell line (FHC), respectively. Elevation of RMST represses cell proliferation and colony formation and induces cell apoptosis in CRC cells. Bioinformatic analysis reveals a binding site in RMST for miR-27a-3p. The direct association between RMST and miR-27a-3p is confirmed by dual luciferase reporter assay, RNA pull-down assay, and real time-quantitative polymerase chain reaction (RT-qPCR). miR-27a-3p is upregulated in CRC tumor specimens relative to normal specimens, and there is a negative correlation between RMST and miR-27a-3p in CRC tumor specimens. In addition, the effects of RMST overexpression are weakened by the elevation of miR-27a-3p. RMST and retinoid X receptor (RXRα) share the same complementary site with miR-27a-3p. The direct association between RXRα and miR-27a-3p is confirmed by RNA pull-down assay, RT-qPCR and western blot analysis. Overexpression of RMST induces RXRα expression and inactivates the Wnt signaling pathway by decreasing β-catenin levels in CRC cells. Collectively, our findings reveal a pivotal role of RMST in regulating miR-27a-3p/RXRα axis and counteracting Wnt signaling pathway during the progression of CRC.

Long non-coding RNA rhabdomyosarcoma 2-associated transcript contributes to neuropathic pain by recruiting HuR to stabilize DNA methyltransferase 3 alpha mRNA expression in dorsal root ganglion neuron.

Long non-coding RNAs (lncRNAs) act as key regulators in multiple human diseases. In particular, the dysfunction of lncRNAs in dorsal root ganglion (DRG) contributes to the pathogenesis of neuropathic pain (NP). Nevertheless, the role and mechanism of most lncRNAs in NP remain unclear. Two classic chronic NP models, including L4 spinal nerve ligation (SNL) model and chronic constriction injury (CCI) of the sciatic nerve, were performed. Mechanical allodynia and heat hyperalgesia were used to evaluate neuropathic pain. DRG microinjection was used to deliver agents into DRG. qRT-PCR, immunofluorescence, immunoprecipitation, western blotting, siRNA transfection, AAV transduction were performed to investigate the phenotypes and molecular basis. Here, we discovered that Rmst as a lncRNA was specifically expressed in Atf3 + injured DRG neurons and significantly upregulated following peripheral nerve damage. Rmst overexpression by direct DRG injection of AAV5-Rmst causes neuropathic symptoms in the absence of nerve damage. Conversely, blocking Rmst expression in injured DRGs alleviated nerve injury-induced pain hypersensitivities and downregulated Dnmt3a expression. Furthermore, we found peripheral nerve damage induced Rmst increase could interact with RNA-binding protein HuR to stabilize the Dnmt3a mRNA. Our findings reveal a crucial role of Rmst in damaged DRG neurons under NP condition and provide a novel target for drug development against NP.

Tumor-related Molecular Regulatory Mechanisms of Long Non-coding RNA RMST: Recent Evidence.

Long non-coding RNA rhabdomyosarcoma 2-associated transcript (LncRNA RMST) can affect every aspect of tumor progressions, such as proliferation, translocation, and apoptosis. As a result, RMST can be used as an attractive biomarker for early diagnosis and clinical therapies of different disease states. This article aims to review pathophysiological functions, molecular mechanisms as well as promising biotherapies of RMST in multiple tumors. Through the systematic induction and summary of 46 papers published in PubMed concerning this study, the molecular mechanisms of RMST in all kinds of tumors have been reviewed. LncRNA RMST is a tumor-related regulatory mediator, aberrantly expressed in diverse tumors, including medullary thyroid cancer, hepatocellular carcinoma, endometrial carcinoma, colon cancer, pancreatic cancer, glioma, Wilm's tumor, and breast cancer. Furthermore, as a mechanismbased player, RMST probably guides the translation and post-translation modification, containing DNA methylation and SUMOylation. It is capable of regulating distinct tumor cells and stem cells of biological behaviors via various molecular pathways. LncRNA RMST, potentially as an original therapeutic target, is valuable in the occurrence, development, and apoptosis of different tumors.

LncRNA-RMST Functions as a Transcriptional Co-regulator of SOX2 to Regulate miR-1251 in the Progression of Hirschsprung's Disease.

Hirschsprung's disease (HSCR) is a congenital disorder characterized by the absence of enteric neural crest cells (ENCCs). LncRNA rhabdomyosarcoma 2-associated transcript (RMST) is essential for the growth and development of neuron. This study aimed to reveal the role of RMST in the pathogenesis of HSCR. The expression level of RMST, miR-1251, SOX2, and AHNAK was evaluated with qRT-PCR or western blot. CCK-8 and transwell assays were applied to detect cell proliferation and migration. CHIP and RIP assays were applied to determine the combination relationship between SOX2 and promoter region of miR-1251 or RMST and SOX2, respectively. Dual-luciferase reporter assay was performed to confirm miR-1251 targeted AHNAK. As results have shown, RMST was downregulated in the aganglionic colon of HSCR patients. The knockdown of RMST attenuated cell proliferation and migration significantly. MiR-1251, the intronic miRNA of RMST, was also low expressed in HSCR, but RMST did not alter the expression of miR-1251 directly. Furthermore, SOX2 was found to regulate the expression of miR-1251 via binding to the promoter region of miR-1251, and RMST strengthened this function by interacting with SOX2. Moreover, AHNAK was the target gene of miR-1251, which was co-regulated by RMST and SOX2. In conclusion, our study demonstrated that RMST functioned as a transcriptional co-regulator of SOX2 to regulate miR-1251 and resulted in the upregulation of AHNAK, leading to the occurrence of HSCR. The novel RMST/SOX2/miR-1251/AHNAK axis provided potential targets for the diagnosis and treatment of HSCR during embryonic stage.

Abnormal expression of long non-coding RNA rhabdomyosarcoma 2-associated transcript (RMST) participates in the pathological mechanism of atherosclerosis by regulating miR-224-3p

ABSTRACT Study shows that long non-coding RNA (lncRNA) plays a regulatory role in cardiovascular diseases, and the mechanism of rhabdomyosarcoma 2-associated transcript (RMST) in atherosclerosis (AS) is still unclear. This study aimed to evaluate the expression of RMST and its possible role in the occurrence of AS. RMST and miR-224-3p level in serum and human umbilical vein endothelial cells (HUVECs) were determined by real-time quantitative PCR (RT-qPCR). In vitro atherosclerotic cell model was achieved by treating HUVECs with ox-LDL. Receiver operating characteristic (ROC) curve assessed the diagnostic value of RMST in AS, and Pearson correlation coefficient estimated the correlation of RMST with carotid intima-media thickness (CIMT) and carotid-femoral pulse wave velocity (cfPWV). Cell counting kit-8 (CCK-8) assay and Enzyme-linked immunosorbent assay (ELISA) were performed to evaluate the effect of RMST on cell viability and inflammatory response. The luciferase analysis was used to validate the relationship between RMST and miR-224-3p. The results showed that in serum and HUVECs, RMST levels were increased, while miR-224-3p level was decreased. ROC curve suggested that RMST had clinical diagnostic value for AS. Besides, CIMT and cfPWV were positively correlated with RMST levels, respectively. In HUVECs, RMST-knockdown notably improved the cell viability and inhibited the production of inflammatory factors. Moreover, miR-224-3p was the target of RMST. In conclusion, RMST has the potential to be a diagnostic marker for AS. RMST-knockdown contributes to the enhancement of cell viability and the inhibition of inflammatory response, which may provide new insights into the conquest of AS.

The long non-coding RNA rhabdomyosarcoma 2-associated transcript exerts anti-tumor effects on lung adenocarcinoma via ubiquitination of SOX9.

BackgroundLong non-coding RNAs (lncRNAs) play an important role in the post-translational modification of proteins, but the importance of lncRNAs in protein ubiquitination remains unclear. This study investigated to role of the lncRNA rhabdomyosarcoma 2-associated transcript (RMST) in lung adenocarcinoma (LUAD).MethodsThe expression of RMST was analyzed in LUAD samples and normal lung tissues using data from The Cancer Genome Atlas (TCGA) and The Genotype-Tissue Expression (GTEx) public databases. Colony formation and transwell assays were used to determine the anti-tumor effects of RMST in human LUAD progression. RNA pull-down assays, RNA immunoprecipitation assays, and mass spectrometry were used to determine the mechanisms by which RMST induces the ubiquitination of SRY-box transcription factor 9 (SOX9). Furthermore, animal models were used to determine the effects of RMST on LUAD tumorigenicity in vivo.ResultsCompared with normal tissues, RMST expression was significantly downregulated in LUAD samples. This abnormal expression of RMST led to significant changes in the proliferation and migration of LUAD cells both in vitro and in vivo. The experiments demonstrated that RMST binds directly to the SOX9 protein, resulting in the ubiquitination of SOX9 and this was mediated by F-box and WD repeat domain-containing 7 (FBW7). Clinically, RMST expression was shown to be positively correlated with the overall survival of LUAD patients.ConclusionsThese findings revealed that RMST suppressed the SOX9 signaling pathway to inhibit LUAD growth and metastasis. The RMST-induced ubiquitination of SOX9 via FBW7 may be a potential therapeutic target for the treatment of patients with LUAD.

Long Non-coding RNA Rhabdomyosarcoma 2-Associated Transcript Regulates Angiogenesis in Endothelial Cells.

Background: Long non-coding RNAs (lncRNAs) are non-coding RNAs that have more than 200 nucleotides. They have recently emerged as important regulators of angiogenesis. To identify novel lncRNAs that may be involved in the regulation of angiogenesis, we detected the mRNA of 84 lncRNAs in human umbilical vein endothelial cells (HUVECs) exposed to hypoxia for 24h. One of these, rhabdomyosarcoma 2-associated transcript (RMST), is significantly upregulated by hypoxia. Little is known about the presence and roles of RMST in EC function.Objective: The main objective of the study was to investigate the regulation of RMST in ECs and to determine its role in EC survival, proliferation, migration, and differentiation.Methods: Using qPCR, basal mRNA levels of 10 RMST isoforms in HUVECs were measured. Levels were then measured in response to 24h of hypoxia, 7days of differentiation in a co-culture assay, and exposure to four different angiogenesis factors. Functional roles of RMST in EC survival, migration, and differentiation were quantified by using a loss-of-function approach (transfection with single-stranded antisense LNA GapmeRs). EC survival was measured using cell counts and crystal violet assays. Cell migration and differentiation were measured using scratch wound healing and Matrigel® differentiation assays, respectively.Results: Five RMST isoforms (RMST-202, -203, -204, -206, and -207) were detected in HUVECs and human microvascular endothelial cells (HMEC-1s). Other types of vascular cells, including human aortic valve interstitial cells and human aortic smooth muscle cells, did not display this expression profile. RMST was significantly upregulated in response to 24h of hypoxia and in response to 7days of HUVEC co-culture with human lung fibroblasts. RMST was significantly downregulated by angiopoietin-2 (Ang-2), but not by VEGF, FGF-2, or angiopoietin-1 (Ang-1). Selective knockdown of RMST demonstrated that it promotes EC survival in response to serum deprivation. It is also required for VEGF- and Ang-1-induced EC survival and migration, but not for differentiation.Conclusion: We conclude that RMST is expressed in human ECs and that this expression is upregulated in response to hypoxia and during differentiation into capillary-like structures. We also conclude that RMST plays important roles in EC survival and migration.

TIGER: The gene expression regulatory variation landscape of human pancreatic islets.

SUMMARYGenome-wide association studies (GWASs) identified hundreds of signals associated with type 2 diabetes (T2D). To gain insight into their underlying molecular mechanisms, we have created the translational human pancreatic islet genotype tissue-expression resource (TIGER), aggregating >500 human islet genomic datasets from five cohorts in the Horizon 2020 consortium T2DSystems. We impute genotypes using four reference panels and meta-analyze cohorts to improve the coverage of expression quantitative trait loci (eQTL) and develop a method to combine allele-specific expression across samples (cASE). We identify >1 million islet eQTLs, 53 of which colocalize with T2D signals. Among them, a low-frequency allele that reduces T2D risk by half increases CCND2 expression. We identify eight cASE colocalizations, among which we found a T2D-associated SLC30A8 variant. We make all data available through the TIGER portal (http://tiger.bsc.es), which represents a comprehensive human islet genomic data resource to elucidate how genetic variation affects islet function and translates into therapeutic insight and precision medicine for T2D.

LncRNA RMST Regulates Neuronal Apoptosis and Inflammatory Response via Sponging miR-150-5p in Parkinson’s Disease

Introduction: LncRNA rhabdomyosarcoma 2-associated transcript (RMST) serves as a key regulator in neural stem cell fate and is involved in the progression of different neurological diseases. In this research, the serum level and clinical value of RMST in Parkinson’s disease (PD) patients were detected, and the underlying mechanism was explored. Methods: Ninety-nine PD patients and 93 healthy individuals were collected for clinical experiments. SH-SY5Y cells were treated with the dopaminergic neurotoxin 1-methyl-4-phenylpyridinium (MPP⁺) to establish PD cell models. qRT-PCR was used for the detection of mRNA levels. CCK-8 and flow cytometry were used to detect neuronal viability and apoptosis. The target relationship of RMST with miR-15a-5p was confirmed applying luciferase reporter assay. Results: RMST was present at high levels in both serum of PD patients and PD cell models. Serum RMST had a certain clinical value for the diagnosis of PD with the AUC of 0.892 at a cutoff value of 1.225. Serum RMST was positively associated with the levels of TNF-α (r = 0.421, p < 0.001) and IL-1β (r = 0.567, p < 0.001) in PD patients. Knockdown of RMST alleviated the apoptosis and inflammatory response of SH-SY5Y cells induced by MPP⁺. miR-150-5p was the target gene of RMST and less expressed in the clinical serum samples and PD cell models. Conclusion: Serum RMST serves as a promising biomarker for the diagnosis of PD. RMST downregulation may regulate the occurrence and development of PD through inhibiting neuron cell apoptosis and the release of inflammatory cytokines via targeting miR-150-5p.

Down-regulated long non-coding RNA RMST ameliorates dopaminergic neuron damage in Parkinson’s disease rats via regulation of TLR/NF-κB signaling pathway

ObjectiveCurrent treatment and prognosis of Parkinson’s disease (PD) are not ideal. This study explored the mechanism of long non-coding RNA (lncRNA) rhabdomyosarcoma 2-associated transcript (RMST) in dopaminergic (DA) neuron damage in PD rats. MethodsPD rats were modeled and injected with RMST silence or overexpression vectors to figure out its roles in oxidative stress, the apoptosis of DA neurons in brain substantia nigra (SN), and neurobehavioral activities of PD rats. Tyrosine hydroxylase (TH), synaptophysin (SYN), glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule (Iba-1) in SN were detected. RMST and Toll-like receptor (TLR)/nuclear factor kappa B (NF-κB) pathway-related factors were detected. ResultsRMST expression in brain SN of rats, TLR2, TLR4 expression in neurons and NF-κB expression in cell nucleus were increased. Silenced RMST improved the neurobehavioral activities, depressed oxidative stress and neuronal apoptosis, increased TH and SYN expression, and reduced the activation degree of glial cells in SN and the inflammatory response via reducing GFAP and Iba-1. Moreover, reduced RMST reduced TLR2 and TLR4 expression in neurons and NF-κB expression in cell nucleus in PD rats. ConclusionInhibited RMST attenuates DA neuron damage in PD rats, which may be implicated with TLR/NF-κB signaling pathway.

Long non-coding RNA RMST promotes oxygen-glucose deprivation-induced injury in brain microvascular endothelial cells by regulating miR-204-5p/VCAM1 axis

AimsMany long non-coding RNAs (lncRNAs) have been suggested to play critical roles in the pathogenesis of ischemic stroke, including lncRNA rhabdomyosarcoma 2-associated transcript (RMST). We aimed to elucidate the role and molecular mechanism of RMST in ischemic stroke. Materials and methodsThe in vitro ischemic stroke model was established by treating brain microvascular endothelial cells with oxygen-glucose deprivation (OGD). The expression of RMST, miR-204-5p and vascular cell adhesion molecule 1 (VCAM1) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The interaction between miR-204-5p and RMST or VCAM1 was confirmed using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Cell viability, migration and apoptosis were assessed by Cell Counting Kit-8 (CCK-8), wound healing assay and flow cytometry, respectively. Lactic dehydrogenase (LDH) leakage rate was determined by LDH activity assay kit. The protein level of VCAM1 was analyzed by western blot (WB) assay. Key findingsRMST was upregulated in OGD-treated HBMEC and bEnd.3 cells. MiR-204-5p was a direct target of RMST, and miR-204-5p inhibition abated the inhibitory effect of RMST knockdown on OGD-induced injury via inhibiting cell viability and migration and promoting apoptosis in HBMEC and bEnd.3 cells. Moreover, VCAM1 was identified as a direct target of miR-204-5p, and VCAM1 alleviated the effect of miR-204-5p on reduction of OGD-induced injury in HBMEC and bEnd.3 cells. In addition, RMST regulated VCAM1 expression via sponging miR-204-5p. SignificanceRMST knockdown attenuated OGD-induced injury of HBMEC and bEnd.3 cells via regulating miR-204-5p/VCAM1 axis, indicating a possible therapeutic strategy for future ischemic stroke therapy.

Knockdown of RMST Impedes Neuronal Apoptosis and Oxidative Stress in OGD/R-Induced Ischemic Stroke Via Depending on the miR-377/SEMA3A Signal Network.

Long non-coding RNAs (lncRNAs) have pivotal roles in regulating ischemic stroke (IS), including lncRNA rhabdomyosarcoma 2-associated transcript (RMST). The purpose of this report is to discover the functional mechanism of RMST. The expression detection of RMST, microRNA-377 (miR-377) and Semaphorin 3A (SEMA3A) was performed by quantitative real-time polymerase chain reaction (qRT-PCR). Oxygen and glucose deprivation/reperfusion (OGD/R) in N2a cells was used to mimic IS environment in vitro. Cell Counting Kit-8 (CCK-8) and flow cytometry were implemented to assess cell viability and apoptosis. Oxidative stress was analyzed via assaying the associated indicators. Dual-luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays were jointly administrated for binding analysis between targets. SEMA3A protein level was measured using western blot. We found in IS serum samples, RMST was upregulated while miR-377 was downregulated. After the establishment of OGD/R-induced IS model, we found that the decreased RMST abrogated the OGD/R-triggered apoptosis and oxidative stress. Through the target analysis, miR-377 was shown to be sponged by RMST and the effects of RMST knockdown on OGD/R-induced cell injuries were related to miR-377 upregulation. Besides, SEMA3A served as a target gene of miR-377 and the mitigation of miR-377 for ischemic brain damages was achieved by downregulating SEMA3A. What's more, RMST could regulate SEMA3A by playing the sponge action on miR-377. Collectively, all these findings clarified that RMST repression retarded IS progression in vitro via SEMA3A downregulation by targeting miR-377, which represented a different perspective in the pathological development of IS.

EGb761 Protects Brain Microvascular Endothelial Cells Against Oxygen-Glucose Deprivation-Induced Injury Through lncRNA Rmst/miR-150 Axis.

In the present study, we aimed to illustrate the roles and working mechanisms of long non-coding RNA (lncRNA) rhabdomyosarcoma 2-associated transcript (Rmst) and EGb761 in oxygen-glucose deprivation (OGD)-induced brain microvascular endothelial cells (BMECs). OGD exposure augmented the level of Rmst while reduced the expression of miR-150 in bEnd.3 cells. MiR-150 could directly bind to Rmst in bEnd.3 cells. Rmst silencing abrogated the inhibitory influences on the proliferation and migration and the promoting impact on the apoptosis of bEnd.3 cells caused by OGD exposure. Rmst overexpression intensified OGD-induced injury in bEnd.3 cells. OGD induced the injury of bEnd.3 cells through Rmst/miR-150 axis. EGb761 attenuated the damage in bEnd.3 cells induced by OGD through targeting Rmst/miR-150 axis. EGb761 might be an effective therapeutic agent to protect brain microvascular endothelial cells from hypoxia-ischemia induced injury.

LncRNA RMST Suppressed GBM Cell Mitophagy through Enhancing FUS SUMOylation

Long non-coding RNAs (lncRNAs) play a significant role in post-translational modifications of proteins, yet the importance of lncRNAs for SUMOylation is unknown. rhabdomyosarcoma 2 associated transcript (RMST) expression in glioma tissues and normal brain tissues was measured by quantitative real-time PCR and in situ hybridization. The functional roles of RMST in astrocytomas were demonstrated by a series of in vitro experiments. The potential mechanisms of RMST for SUMOylation were investigated by RNA immunoprecipitation, RNA pull-down, western blotting, and coimmunoprecipitation assays. We first demonstrated the oncogenic activity of lncRNA RMST by inhibiting glioma cells mitophagy. We also first determined that RMST is an enhancer of FUS SUMOylation, especially boosting SUMO1 modification at K333. SUMOylation induced by RMST contributes to the interaction between FUS and heterogeneous nuclear ribonucleoprotein D (hnRNPD) and stabilized their expression and cells mitophagy. Importantly, lncRNA RMST could serve as a promising prognostic factor for glioma patients. Our results demonstrated a previously unknown function of lncRNAs worked as an enhancer in FUS SUMOylation, and RMST will be a significant guide for the development of medications targeting gliomas.

LncRNA RMST-mediated miR-107 transcription promotes OGD-induced neuronal apoptosis via interacting with hnRNPK

The long noncoding RNA (lncRNA) rhabdomyosarcoma 2-associated transcript (RMST) silencing has been demonstrated to protect against ischemic brain injury in vivo and neuron injury in vitro. However, its underlying mechanisms in the progression of ischemic stroke have not been well explored. The expression of RMST in oxygen-glucose deprivation (OGD)-treated HT-22 hippocampal neuron cell line was examined using quantitative Real-Time PCR (qRT-PCR). CCK-8 cell viability and apoptotic cell detection using Annexin V-FITC and PI staining coupled with flow cytometry were performed to determine the pro-apoptotic role of RMST in HT-22 hippocampal neuron cell line. Furthermore, RNA pull-down, RNA immunoprecipitation (RIP), coimmunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP) and dual-Luciferase reporter assays were performed to determine the mechanism of RMST in OGD-induced HT-22 cell apoptosis. In the results, RMST was highly expressed in OGD-treated HT-22 cells. Altered RMST expression led to marked changes in HT-22 cell proliferation and apoptosis. Mechanistically, RMST indirectly activated p53/miR-107 signaling pathway via interacting with heterogeneous nuclear ribonucleoprotein K (hnRNPK) and fulfilled its pro-apoptotic function in HT-22 cells. In conclusion, our data indicated that the RMST/hnRNPK/p53/miR-107/Bcl2l2 axis plays an important role in regulating neuronal apoptosis.

RETRACTED: lncRNA RMST Enhances DNMT3 Expression through Interaction with HuR

Large bodies of studies have shown that the CRISPR/Cas9-based library screening is a very powerful tool for the identification of gene functions. However, most of these studies have focused on protein-coding genes, and, furthermore, very few studies have used gene reporters for screening. In the present study, we generated DNA methyltransferase 3B (DNMT3B) reporter and screened a CRISPR/Cas9 synergistic activation mediator (SAM) library against a focused group of lncRNAs. With this screening approach, we identified Rhabdomyosarcoma 2-Associated Transcript (RMST) as a positive regulator for DNMT3B. This was confirmed by activation of the endogenous RMST by SAM or ectopic expression of RMST. Moreover, RMST knockout (KO) suppresses DNMT3, while rescue with RMST in the KO cells restores the DNMT3 level. Finally, RMST KO suppresses global DNA methylation, leading to the upregulation of methylation-regulated genes. Mechanistically, RMST promotes the interaction between the RNA-binding protein HuR and DNMT3B 3′ UTR, increasing the DNMT3B stability. Together, these results not only provide the feasibility of a reporter system for CRISPR library screening but also demonstrate the previously uncharacterized factor RMST as an important player in the modulation of DNA methylation.

LncRNA RMST activates TAK1-mediated NF-κB signaling and promotes activation of microglial cells via competitively binding with hnRNPK.

This study aimed to explore the biological role and molecular mechanism of long noncoding RNA (lncRNA) rhabdomyosarcoma 2-associated transcript (RMST) in regulating microglial activation. Mouse microglial BV2 cells were cultured to establish the cell model of cerebral ischemic stroke by oxygen-glucose deprivation (OGD). We observed highly expressed RMST, increased expression of M1, and decreased expression of M2 markers in BV2 microglial cells stimulated with OGD. These alterations were reversed by RMST knockdown. Activation of transforming growth factor-beta-activated kinase 1 (TAK1)-mediated nuclear factor-κB (NF-κB) pathway was observed upon OGD stimulation, which was promoted by RMST through competitively binding with heterogeneous nuclear ribonucleoprotein K (hnRNPK), confirmed by RNA pull down and RNA immunoprecipitation (RIP) assays. Furthermore, RMST overexpressing-BV2 cells effectively enhanced neuronal apoptosis. In conclusion, RMST promoted OGD-induced microglial M1 polarization by competitively interacting with hnRNPK via TAK1-mediated NF-κB pathway, which will provide a basis for understanding the pathogenesis of cerebrovascular diseases.