H19 Knockdown Research Articles

LncRNA H19 downregulation confers erlotinib resistance through upregulation of PKM2 and phosphorylation of AKT in EGFR-mutant lung cancers.

First-generation EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib have significant activity in NSCLC patients with activating EGFR mutations. However, EGFR-TKI resistance inevitably occurs after approximately 12 months of treatment. Acquired mechanisms of resistance, other than secondary mutations in EGFR (T790M) which account for 50-60%, are less well understood. Here, we identified lncRNA H19 as a significantly downregulated lncRNA in vitro models and clinical specimens with acquired EGFR-TKI resistance, H19 knockdown or overexpression conferred resistance or sensitivity, respectively, both in vitro and in vivo models. H19 downregulation contributed to erlotinib resistance through interaction and upregulation of PKM2, which enhanced the phosphorylation of AKT. AKT inhibitors restored the sensitivity of erlotinib-resistant cells to erlotinib. In EGFR-mutant patients treated with EGFR-TKIs, low H19 levels were associated with a shorter progression-free survival (PFS) (P=0.021). These findings revealed a novel mechanism of low-level H19 in the regulation of erlotinib resistance in EGFR-mutant lung cancers. Combination of AKT inhibitors and EGFR-TKIs could be a rational therapeutic approach for some subgroups of EGFR-mutant lung cancer patients.

Long noncoding RNA mediates stroke-induced neurogenesis.

Neurogenesis contributes to poststroke recovery. Long noncoding RNAs (lncRNAs) participate in the regulation of stem cell self-renewal and differentiation. However, the role of lncRNAs in stroke-induced neurogenesis remains unknown. In this study, we found that H19 was the most highly upregulated lncRNA in neural stem cells (NSCs) of the subventricular zone (SVZ) of rats subjected to focal cerebral ischemia. Deletion of H19 suppressed cell proliferation, promoted cell death, and blocked NSC differentiation. RNA sequencing analysis revealed that genes deregulated by H19 knockdown were those that are involved in transcription, apoptosis, proliferation, cell cycle, and response to hypoxia. H19 knockdown significantly increased the transcription of cell cycle-related genes including p27, whereas overexpression of H19 substantially reduced expression of these genes through the interaction with chromatin remodeling proteins EZH2 and SUZ12. Moreover, H19 regulated neurogenesis-related miRNAs. Inactivation of H19 in NSCs of ischemic rats attenuated spontaneous functional recovery after stroke. Collectively, our data provide novel insights into the epigenetic regulation of lncRNAs in stroke-induced neurogenesis.

LncRNA H19 Aggravates Cerebral Ischemia/Reperfusion Injury by Functioning as a ceRNA for miR-19a-3p to Target PTEN

Long non-coding RNAs (lncRNAs) play critical roles in regulating the progression of cerebral ischemia. LncRNA H19 was significantly up-regulated under ischemia–reperfusion (I/R) damage and implicatedin I/R injury progression, but the mechanisms remain unclear. Mice were subjected to middle cerebral artery occlusion (MCAO)/R (1 h/24 h) to build an I/R injury model and the infarct volume and neurological deficit were assessed. Human neuroblastoma cell line SH-SY5Y was used in oxygen-glucose deprivation and reperfusion (OGD/R, 3 h/24 h) injury model. Expression of genes were evaluated by qRT-PCR or western blotting. Flow cytometry and TUNEL were performed to examine apoptosis. Cell viability was determined with CCK8 assay. LDH, MDA, SOD levels were evaluated using commercial detection kits. Furthermore, dual luciferase reporter assay was conducted to confirm the binding between H19 and miR-19a-3p, as well miR-19a-3p and PTEN. The results showed that H19 was up-regulated whereas miR-19a-3p was down-regulated in I/R tissues and OGD/R induced cells. H19 aggravated I/R or OGD/R caused oxidative stress and apoptosis via PTEN/Akt signaling pathway. H19 regulated PI3K/AKTsignaling through acting as a ceRNA for miR-19a-3p to target PTEN. H19 knockdown and miR-19a-3p overexpression relieved I/R or OGD/R induced neuronal cell oxidative stress and apoptosis. H19/miR-19a-3p/PTEN axis could promote cerebral I/R injury via PI3K/AKT pathway. These demonstrated a mechanism how H19 participates in I/R injury, and provided us a potential target for I/R injury diagnosis and treatment.

Long non-coding RNA H19 promotes osteogenic differentiation of human bone marrow-derived mesenchymal stem cells by regulating microRNA-140-5p/SATB2 axis

The osteogenic differentiation of mesenchymal stem cells (MSCs) has potential clinical values in the treatment of bone-related diseases. Long non-coding RNA H19 and microRNA-140-5p (miR-140-5p) have attracted much attention of researchers by virtue of their biological importance in cell differentiation and bone formation. Moreover, bioinformatics analyses suggest that miR-140-5p have the potential to bind with H19 and SATB homeobox 2 (SATB2). In this study, we further explored whether H19 could regulate osteogenic differentiation of human bone marrow-derived MSCs (BM-MSCs) by miR-140-5p/SATB2 axis. RT-qPCR assay was conducted to examine the expression of H19, miR-140-5p and SATB2. The osteogenic differentiation capacity of BM-MSCs was assessed through alkaline phosphatase (ALP) activity and osteogenic marker expression. The relationships among H19, miR-140-5p and SATB2 were examined through bioinformatics analyses, luciferase reporter assay, RIP assay and RNA pull-down assay. H19 expression was remarkably increased and miR-140-5p expression was dramatically reduced during osteogenic differentiation of BMMSCs. Functional analyses revealed that H19 overexpression or miR-140-5p depletion accelerated osteogenic differentiation of BM-MSCs. Conversely, H19 loss or miR-140-5p increase suppressed osteogenic differentiation of BM-MSCs. MiR-140-5p was confirmed as a target of H19, and miR-140-5p could bind to SATB2 as well. Moreover, H19 knockdown reduced SATB2 expression by upregulating miR-140-5p. Additionally, miR140-5p depletion antagonized the inhibitory effect of H19 knockdown on osteogenic differentiation of BMMSCs. And, miR-140-5p inhibited osteogenic differentiation of BM-MSCs by targeting SATB2. In conclusion, H19 promoted osteogenic differentiation of BM-MSCs through regulating miR-140-5p/SATB2 axis, deepening our understanding on the molecular mechanisms of H19 in coordinating osteogenesis.

Absence of Long Noncoding RNA H19 Promotes Childhood Nephrotic Syndrome through Inhibiting ADCK4 Signal.

BackgroundNephrotic syndrome (NS) is a common chronic kidney disease in children characterized by a group of clinical symptoms such as massive proteinuria, hypoproteinemia, high edema, and hyperlipidemia. Despite the tremendous efforts already made, the diagnosis for nephrotic syndrome still remains poor in children.Material/MethodsThe blood samples from 30 healthy children and 30 children with nephrotic syndrome were collected. The expression of H19 and ADCK4 (which are genes recently identified to play key roles in the development of nephrotic syndrome) in peripheral blood mononuclear cells (PBMCs), were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The expression of ADCK4 was also detected by RT-qPCR or western blot when H19 was overexpressed or knocked down in human primary renal podocytes. Luciferase activity analysis was performed to measure whether H19 could regulate the promoter activity of ADCK4. RNA pull-down. In addition, mass spectrometry assay was used to find the transcription factor which could bind with H19, and RNA immunoprecipitation assay (RIPA) analysis was done to further confirm the interaction between H19 and candidate transcription factor.ResultsLong noncoding RNA H19 (lncRNA H19) expression was downregulated in PBMCs of children with nephrotic syndrome. ADCK4 was also downregulated. In human primary renal podocytes, overexpression of H19 promoted the expression of ADCK4, while H19 knockdown inhibited it. Furthermore, our study demonstrated that H19 could regulate the promoter activity of ADCK4. Using RNA pull-down and mass spectrometry technology, we found the transcription factor-THAP1 could bind with H19, and the interaction between them was further confirmed by RIPA analysis.ConclusionsH19 expression in blood samples may be a novel marker of the diagnosis of nephrotic syndrome in children.

PIM protein kinases regulate the level of the long noncoding RNA H19 to control stem cell gene transcription and modulate tumor growth.

The proviral integration site for Moloney murine leukemia virus (PIM) serine/threonine kinases have an oncogenic and prosurvival role in hematological and solid cancers. However, the mechanism by which these kinases drive tumor growth has not been completely elucidated. To determine the genes controlled by these protein kinases, we carried out a microarray analysis in T‐cell acute lymphoblastic leukemia (T‐ALL) comparing early progenitor (ETP‐ALL) cell lines whose growth is driven by PIM kinases to more mature T‐ALL cells that have low PIM levels. This analysis demonstrated that the long noncoding RNA (lncRNA) H19 was associated with increased PIM levels in ETP‐ALL. Overexpression or knockdown of PIM in these T‐ALL cell lines controlled the level of H19 and regulated the methylation of the H19 promoter, suggesting a mechanism by which PIM controls H19 transcription. In these T‐ALL cells, the expression of PIM1 induced stem cell gene expression (SOX2, OCT‐4, and NANOG) through H19. Identical results were found in prostate cancer (PCa) cell lines where PIM kinases drive cancer growth, and both H19 and stem cell gene levels. Small molecule pan‐PIM inhibitors (PIM‐i) currently in clinical trials reduced H19 expression in both of these tumor types. Importantly, the knockdown of H19 blocked the ability of PIM to induce stem cell genes in T‐ALL cells, suggesting a novel signal transduction cascade. In PCa, increases in SOX2 levels have been shown to cause both resistance to the androgen deprivation therapy (ADT) and the induction of neuroendocrine PCa, a highly metastatic form of this disease. Treatment of PCa cells with a small molecule pan‐PIM‐i reduced stem cell gene transcription and enhanced ADT, while overexpression of H19 suppressed the ability of pan‐PIM‐i to regulate hormone blockade. Together, these results demonstrate that the PIM kinases control the level of lncRNA H19, which in turn modifies stem cell gene transcription regulating tumor growth.

Icariin affects cell cycle progression and proliferation of human retinal pigment epithelial cells via enhancing expression of H19.

BackgroundAberrant proliferation of retinal pigment epithelial (RPE) cells under pathologic condition results in the occurrence of proliferative vitreoretinopathy (PVR). Icariin (ICA)-a flavonol glucoside-has been shown to inhibit proliferation of many cell types, but the effect on RPE cells is unknown. This study aimed to clarify the inhibitory effects of ICA on RPE cells against platelet-derived growth factor (PDGF)-BB-induced cell proliferation, and discuss the regulatory function of H19 in RPE cells.MethodsMTS assay was conducted to determine the effects of ICA on cell proliferation. Flow cytometry analysis was performed to detect cell cycle progression. Quantitative real-time PCR and western blot assay were used to measure the expression patterns of genes in RPE cells.ResultsICA significantly suppressed PDGF-BB-stimulated RPE cell proliferation in a concentration-dependent manner. Moreover, since administration of ICA induced cell cycle G0/G1 phase arrest, the anti-proliferative activity of ICA may be due to G0/G1 phase arrest in RPE cells. At molecular levels, cell cycle regulators cyclin D1, CDK4, CDK6, p21 and p53 were modulated in response to treatment with ICA. Most importantly, H19 was positively regulated by ICA and H19 depletion could reverse the inhibitory effects of ICA on cell cycle progression and proliferation in PDGF-BB-stimulated RPE cells. Further mechanical explorations showed that H19 knockdown resulted in alternative expressions levels of cyclin D1, CDK4, CDK6, p21 and p53 under ICA treatment.ConclusionsOur findings revealed that ICA was an effective inhibitor of PDGF-BB-induced RPE cell proliferation through affecting the expression levels of cell cycle-associated factors, and highlighted the potential application of ICA in PVR therapy. H19 was described as a target regulatory gene of ICA whose disruption may contribute to excessive proliferation of RPE cells, suggesting that modulation of H19 expression may be a novel therapeutic approach to treat PVR.

585 nm light-emitting diodes inhibit melanogenesis through upregulating H19/miR-675 axis in LEDs-irradiated keratinocytes by paracrine effect

Background585 nm light-emitting diodes have been proven to suppress melanogenesis in melanocytes. However, whether LEDs will influence normal human epidermal keratinocytes (NHEKs) and paracrine effect of LEDs-irradiated NHEKs in melanogenesis remains unknown. ObjectiveTo elucidate the possible mechanisms in vitro of anti-melanogenic activity of 585 nm LEDs on paracrine effect of NHEKs and its exosomes. MethodsNHEKs irradiated with different fluences of 585 nm LEDs were evaluated the cell viability by CCK8 assay. Irradiated medium of NHEKs was co-cultured with melanocytes. Melanin content, tyrosinase activity and melanogenic enzymes activities were detected. Exosomes from NHEKs medium were isolated and characterized by electron microscopy and nanoparticle tracking analysis. The expression changes of H19 and its encoded exosomal miR-675 were analyzed. ResultsIrradiation with 585 nm LEDs from 0 J/cm2 to 20 J/cm2 had no cytotoxic effect on NHEKs. After co-cultured with irradiated medium of NHEKs, melanin content and tyrosinase activity were reduced and the melanogenic activities were downregulated on both mRNA and protein levels of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR) and tyrosinase-related protein 1 (TRP-1). H19 and its derived exosomal miR-675 from NHEKs, which has been proven relevant to melanogenesis, were significantly upregulated after irradiation. Furthermore, H19 knockdown and miR-675 inhibition in NHEKs could attenuate the inhibition effect of 585 nm LEDs on melanogenesis. ConclusionsThis study demonstrated that 585 nm LEDs could inhibit melanogenesis via the up-regulation of H19 and its derived exosomal miR-675 from NHEKs, which was considered as a novel paracrine factor in regulating melanogenesis.

Long Non-Coding RNA H19 Promotes Porcine Satellite Cell Differentiation by Interacting with TDP43.

Long non-coding RNAs (lncRNAs) have been implicated in fundamental and diverse biological processes, including myogenesis. However, the molecular mechanisms involved in this process remain largely unexplored. This study found that H19 affected the differentiation of porcine satellite cells (PSCs) by directly binding to the DNA/RNA-binding protein TDP43. Functional analyses showed that TDP43 knockdown decreased PSC differentiation, whereas TDP43 overexpression exerted opposite effects in vitro. Furthermore, rescue experiments demonstrated that TDP43 can rescue the decrease in PSC differentiation caused by H19 knockdown. Mechanistically, H19 may act as a scaffold to recruit TDP43 to the promoters of MYOD and thereby activate the transcription of MYOD, leading to PSC differentiation. In summary, we elucidate the molecular mechanism by which H19 and TDP43 regulate myogenesis.

Ghrelin protects against obesity-induced myocardial injury by regulating the lncRNA H19/miR-29a/IGF-1 signalling axis

BackgroundObesity is associated with the impairment of cardiac fitness and consequent ventricular dysfunction and heart failure. Ghrelin has been largely documented to be cardioprotective against ischaemia/reperfusion injury. However, the role of ghrelin in obesity-induced myocardial injury is largely unknown. This study sought to determine the cardiac effect of ghrelin against obesity-induced injury and the underlying mechanisms. MethodsThe effect of ghrelin was evaluated in a mouse model of obesity and a palmitic acid (PA)-treated cardiomyocyte cell line with or without ghrelin transfection. Gene and protein expression levels were determined by real-time PCR and western blot, respectively. Cell apoptosis was measured by flow cytometry analysis. ResultsIn the present study, we found that both a high-fat diet (HFD) and PA treatment caused myocardial injury by increasing apoptosis and the expression of inflammatory cytokines. Overexpression of ghrelin reversed the effects induced by HFD or PA treatment. Knockdown of lncRNA H19 or overexpression of miR-29a abrogated the cardioprotective effects of ghrelin against apoptosis and inflammation. We also found that IGF-1 was a target gene of miR-29a and that H19 regulated IGF-1 expression via miR-29a. Overexpression of IGF-1 partially reversed the apoptosis and inflammation promoting effects of miR-29a. ConclusionsOur findings suggested that ghrelin protected against obesity-induced myocardial injury by regulating the H19/miR-29a/IGF-1 signalling axis, providing further evidence for the clinical application of ghrelin.

Long non‑coding RNA H19 protects H9c2 cells against hypoxia‑induced injury by activating the PI3K/AKT and ERK/p38 pathways.

Myocardial ischemia/reperfusion injury often leads to adverse cardiovascular outcomes due to severe hypoxia. The present study aimed to evaluate the effects and mechanism of long non-coding RNA H19 (H19) on rat H9c2 cells with hypoxia-induced injury. H9c2 cells were infected with lentiviruses to express H19 or H19-targeting short hairpin RNA (shRNA), or their respective controls, at a multiplicity of infection of 1:100. H19 expression was determined by reverse transcription-quantitative PCR. Hypoxic injury was induced and assessed by analyzing the level of apoptosis, the cell cycle distribution and the mitochondrial membrane potential using flow cytometry in the different groups. The expression of the PI3K/AKT and the ERK/p38 signaling pathways were analyzed using western blotting. It was found that hypoxia stimulated apoptosis, induced G1 phase cell cycle arrest and increased the mitochondrial depolarization rate in H9c2 cells. When compared with the hypoxic model group, the H19 overexpression group had a significantly reduced rate of apoptosis (P=0.016), a smaller G1 population and a higher S phase population (P=0.018 and P=0.031, respectively), and a reduced mitochondrial depolarization rate (P=0.036). By contrast, the H19 shRNA group exhibited the opposite trends, suggesting that hypoxia-induced injury was alleviated by the overexpression of H19 and was aggravated by the knockdown of H19. The present mechanistic studies revealed that H19 may decrease hypoxia-induced cell injury by activating the PI3K/AKT and ERK/p38 pathways. The results of the present study suggested that H19 may alleviate hypoxia-induced myocardial cell injury through the activation of the PI3K/AKT and ERK/p38 pathways.

Abstract TMP25: Long Non-Coding RNA Mediates Stroke-Induced Neurogenesis

Background and Purpose: Adult neurogenesis contributes to functional recovery after stroke. Long non-coding RNAs (lncRNAs) regulate stem cell self-renewal and differentiation. However, the role of lncRNAs in stroke-induced neurogenesis remains unknown. Methods and Results: Using lncRNA array and in situ hybridization, we analyzed lncRNA profiles of adult neural stem cells (NSCs) isolated from the subventricular zone neurogenic region in rats subjected to middle cerebral artery occlusion. We found that H19 was the most highly upregulated lncRNA (19 fold) in ischemic NSCs compared with non-ischemic NSCs. Reduction of endogenous H19 in NSCs by CRISPR-Cas9 genome editing significantly decreased the proliferation and increased the apoptosis of ischemic NSCs, as assayed by the number of BrdU + cells (56±5% vs 22±3%, p<0.01, n=3) and Caspase-3/7 activity compared to NSCs transfected with scrambled small guide RNA (sgRNA). Knockdown of H19 significantly decreased the number of Tuj1 + neuroblasts (8±2% vs 5±0.4%, p<0.01, n=3) and NG 2 + oliogodendrocyte progenitor cells (10±1% vs 5±0.3%, p<0.01, n=3), suggesting that deletion of H19 suppresses the proliferation and survival and blocks the differentiation of NSCs into neurons and oligodendrocytes. Additional RNA-sequencing and bioinformatics analyses revealed that genes deregulated by H19 knockdown were involved in transcription, apoptosis, proliferation, cell cycle and response to hypoxia. Western blot analysis validated that loss-of-function and gain-of-function of H19 significantly increased and reduced, respectively, the transcription of cell cycle-related genes including p27. Using ChIRP assay, we found that upregulated H19 in NSCs was physically associated with EZH2 which catalyzes the repressive H3K27me3 histone marker. Knockdown of H19 significantly reduced the enrichment of H3K27me3 at the promoter of p27, leading to the upregulation of p27 expression and consequently inhibition of NSC proliferation. Conclusions: H19 mediates stroke-induced neurogenesis by regulating genes involved in cell cycle and survival through the interaction with chromatin remodeling proteins. Our data provide novel insights into epigenetic regulation of gene expression by lncRNA in neurogenesis.

Knock down of lncRNA H19 promotes axon sprouting and functional recovery after cerebral ischemic stroke

Ischemic stroke is a leading cause of irreversible brain damages and disabilities. In the past decade, much attention has been focused on exploring effective strategies to promote circuit reorganization and functional recovery post injury. Here, we showed that the expression level of a long non-coding RNA (lncRNA H19) is bilaterally increased in the sensorimotor cortex after a cerebral ischemia induced by middle cerebral artery occlusion (MCAO). Knock down of contralaterally elevated H19 robustly enhanced the midline-crossing sprouting of the intact corticospinal axons in the spinal cord. Furthermore, H19 knockdown mice showed significant improvement on the performance of the food pellet retrieval assay, a skilled, cortical dependent motor task.Mechanistically, lncRNA H19 inhibition increased IGF1R expression and activated IGF1 mediated mTOR pathway. Our research thereby provided novel insights into identifying therapeutic targets for ischemic stroke.

LncRNA H19 is involved in myocardial ischemic preconditioning via increasing the stability of nucleolin protein.

Myocardial ischemic preconditioning (IP) is defined as a brief period of myocardial ischemia/reperfusion (I/R) that significantly reduces injury during the subsequent exposure to long-term I/R. However, the underlying mechanisms of myocardial IP are yet to be elucidated. This study investigated the expression and roles of long noncoding RNA (lncRNA) H19 in myocardial IP in vitro and in vivo. LncRNA H19 expression levels were analyzed by quantitative reverse-transcription polymerase chain reaction, cell viability was determined by the Cell Counting Kit-8 assay, apoptosis was evaluated based on the caspase 3 activity, and RNA immunoprecipitation was performed to examine the interaction between lncRNA H19 and nucleolin. The results of this study showed that lncRNA H19 expression was significantly upregulated in mouse hearts subjected to myocardial IP, in rat H9C2 cells exposed to H2 O2 preconditioning (H2 O2 -PC), and in neonatal rat cardiomyocytes subjected to hypoxia preconditioning. H19 knockdown abrogated the H2 O2 -PC-mediated protection in cardiomyocytes evidenced by the decreased cell viability and increased caspase-3 activity. Conversely, H19 overexpression enhanced the protective role of H2 O2 -PC in cardiomyocytes. In addition, H19 overexpression increased the expression of nucleolin, whereas H19 ablation abrogated H2 O2 -PC-induced upregulation of nucleolin in cardiomyocytes. Furthermore, H19 overexpression increased the stabilization of nucleolin; an interaction between H19 and nucleolin was identified using the RNA-protein interaction studies. Furthermore, nucleolin small interfering RNA relieved the protective role of lncRNA H19. These findings demonstrated that the lncRNA H19 is involved in myocardial IP via increasing the stability of nucleolin protein and lncRNA H19 may represent a potential therapeutic target for the treatment of the myocardial injury.

Long Noncoding RNA H19 Promotes Tumorigenesis of Multiple Myeloma by Activating BRD4 Signaling by Targeting MicroRNA 152-3p.

Multiple myeloma (MM) accounts for over twenty percent of hematological cancer-related death worldwide. Long noncoding RNA (lncRNA) H19 is associated with multiple tumorigenesis and is increased in MM, but the underlying mechanism of H19 in MM is unclear. In this study, the expression of H19, microRNA 152-3p (miR-152-3p), and BRD4 in MM patients was evaluated by quantitative real-time PCR (qRT-PCR) and Western blotting. Colony formation and flow cytometry analysis were used to determine the effects of H19 and miR-152-3p on MM cell proliferation, apoptosis, and cell cycle. A luciferase reporter assay was conducted to confirm the interaction among H19, miR-152-3p, and BRD4. A nude mouse xenograft model was established, and the cell proliferation and apoptosis were evaluated by immunohistochemistry (IHC) staining and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay. We found that levels of H19 and BRD4 were upregulated and the expression of miR-152-3p was downregulated in MM patients. Dual luciferase reporter assay showed H19 targeted miR-152-3p to promote BRD4 expression. Knockdown of H19 repressed proliferation and enhanced apoptosis and cell cycle G1 arrest by upregulating miR-152-3p in MM cells. Furthermore, H19 knockdown suppressed the growth of xenograft tumor, reduced Ki-67 and BRD4 levels, and increased cell apoptosis in xenograft tumor tissues. Taking these results together, H19 knockdown suppresses MM tumorigenesis via inhibiting BRD4-mediated cell proliferation through targeting miR-152-3p, implying that H19 is a promising biomarker and drug target for MM.

Dexmedetomidine Postconditioning Alleviates Hypoxia/Reoxygenation Injury in Senescent Myocardial Cells by Regulating lncRNA H19 and m6A Modification

H19, a long noncoding RNA (lncRNA), reportedly protects myocardial cells (H9c2 cell line) against hypoxia-reoxygenation- (H/R-) induced injury. Dexmedetomidine (Dex) has an important myocardial protective effect, although its function and mechanism in cardiac ischemia/reperfusion (I/R) injury, especially for senile patients, requires further study. RNA N6-methyladenosine (m6A) is the most abundant endogenous RNA modification. However, the effect of Dex postconditioning on RNA m6A modification has rarely been reported. The aim of this study was to evaluate roles of H19 and m6A modification in Dex postconditioning of aged cardiomyocytes. Hydrogen peroxide (H2O2) was used to induce senescence of H9c2 cells. After 6 h of hypoxia, H9c2 cells were exposed to different concentrations of dexmedetomidine (0, 500 nM, 1 μM, and 2 μM) for 6 h. After knockdown or overexpression of H19 and its downstream gene miR-29b-3p and cellular inhibitor of apoptosis protein 1 (cIAP1), Dex postconditioning experiments were performed to examine effects on myocardial cell injury. Global m6A levels after H/R with or without Dex postconditioning were measured with a colorimetric m6A RNA Methylation Quantification Kit. The mechanism by which RNA m6A methylation regulated genes mediating H19 expression was verified by m6A RNA immunoprecipitation (MeRIP), and the function of Dex postconditioning of aged cardiomyocytes was investigated. Dex postconditioning protected against H/R-induced injury of aged myocardial cells through H19/miR-29b-3p/cIAP1, increased methylation of RNA m6A elicited by H/R, and attenuated H/R-induced injury by suppressing expression of the RNA m6A demethylase gene alkB homolog 5 (ALKBH5). In addition, AKLBH5 regulated the expression of H19, and Dex postconditioning attenuated H/R-induced injury via ALKBH5 in aged cardiomyocytes.

Long non-coding RNA H19 regulates proliferation and doxorubicin resistance in MCF-7 cells by targeting PARP1

ABSTRACT Chemoresistance is a major obstacle to effective breast cancer chemotherapy. However, the underlying molecular mechanisms remain unclear. The long noncoding RNA H19 (H19) is involved in various stages of tumorigenesis, however, its role in doxorubicin resistance remains unknown. The goal of this study was to evaluate the role of H19 in the development of doxorubicin-resistant breast cancer. Quantitative real-time PCR (qRT-PCR) analyzed H19 expression in chemotherapy-resistant and sensitive breast cancer tissues. Both knockdown and overexpression of H19 were used to assess the sensitivity to doxorubicin in breast cancer cells in vitro and in vivo. qRT-PCR and Western blot were used to explore the doxorubicin resistance mechanism of H19. We observed that the H19 expression was significantly upregulated in chemotherapy-resistant breast cancer tissues and doxorubicin-resistant breast cancer cell lines. Knockdown of H19 enhanced the sensitivity to doxorubicin both in vitro and in vivo. While H19 overexpression developed doxorubicin-resistant in breast cancer cells both in vitro and in vivo. Furthermore, it was revealed that H19 negatively regulated PARP1 expression in breast cancer cells following doxorubicin treatment. Knockdown of H19 sensitized breast cancer cells to doxorubicin by promoting PARP1 upregulation. H19 overexpression could recapitulate doxorubicin resistance by PARP1 downregulation. Our findings revealed that H19 plays a leading role in breast cancer chemoresistance development, mediated mainly through a H19-PARP1 pathway.

Long non-coding RNA H19 confers resistance to gefitinib via miR-148b-3p/DDAH1 axis in lung adenocarcinoma.

Epidermal growth factor receptor tyrosine kinase inhibitors therapy, such as gefitinib, have proven to be effective for lung adenocarcinoma with epidermal growth factor receptor-sensitive mutations. However, drug resistance remains inevitable and the underlying mechanisms are still elusive and poorly understood. In order to explore the mechanisms underlying tyrosine kinase inhibitors resistance, we used long non-coding RNA microarray analysis and found that long non-coding RNA H19 was highly expressed in gefitinib-resistant cell lines. In addition, knockdown of long non-coding RNA H19 was found to be able to decrease cell proliferation, half maximal inhibitory concentration (IC50) of gefitinib, migration and invasion. Mechanistically, we demonstrated that long non-coding RNA H19 positively regulated dimethylarginine dimethylaminohydrolase-1 expression via sponging miR-148b-3p. Furthermore, overexpression or inactivation of miR-148b-3p could enhance or reverse the inhibitory effect of long non-coding RNA H19 inhibition in lung adenocarcinoma cells, respectively. High expression of either long non-coding RNA H19 or dimethylarginine dimethylaminohydrolase-1 was associated with poorer overall survival in patients with lung adenocarcinoma, while high expression of miR-148b was associated with better overall survival. Overall, our data revealed that long non-coding RNA H19 confers resistance to gefitinib via miR-148b/dimethylarginine dimethylaminohydrolase-1 axis in lung adenocarcinoma, which offers a new insight into the epidermal growth factor receptor tyrosine kinase inhibitors therapy resistance.

Knock-down of circular RNA H19 induces human adipose-derived stem cells adipogenic differentiation via a mechanism involving the polypyrimidine tract-binding protein 1

PurposeThe metabolic syndrome (MetS) is characterized of a cluster of medical disorders. Altered function of adipose tissue has a significant impact on whole-body metabolism and represents a key driver for MetS. In this study, we aim to explore the function of human circular RNA H19 (hsa_circH19) in human adipose-derived stem cells (hADSCs). MethodsThe blood samples from MetS patients and normal subjects were used to determine the expression level of the hsa_circH19. After knock-down of hsa_circH19 in hADSCs, we measured the expression of adipogenic genes. Oil red O, Nile red staining assay and triglyceride assessment were performed to examine the role of hsa_circH19 in hADSCs differentiation. Then, RNA Pull-down and RIP assays were conducted to explore the related RNA binding protein of hsa_circH19. IF was performed to determine the potential molecular regulatory mechanism. ResultsAfter accounting for confounding factors, high levels of hsa_circH19 remained an independent risk factor for MetS. Furthermore, the knockdown of hsa_circH19 significantly increased the expression of adipogenic genes and the formation of lipid droplets. Bioinformatics analyses revealed that has_circH19 shared multiple binding sites with polypyrimidine tract-binding protein 1 (PTBP1) and their interaction was validated by circRNA pull-down and RIP assays. Mechanistically, depletion of hsa_circH19 triggered translocation of sterol-regulatory element binding proteins (SREBP1) from cytoplasm to nucleus in the presence of PTBP1. ConclusionOur experiments suggest that knockdown of hsa_circH19 promotes hADCSs adipogenic differentiation via targeting of PTBP1. In consequence, the expression of hsa_circH19 might correlated to lipid metabolism in adipose tissue from MetS.

LncRNA H19 promotes glioma angiogenesis through miR-138/HIF-1α/VEGF axis.

Glioma is one of the most common and aggressive malignant primary brain tumors with high recurrence rate and mortality rate and heavily depends on the angiogenesis. LncRNA H19 has many diverse biological functions, including the regulation of cell proliferation, differentiation and metabolism. Here, we aimed to investigate the molecular mechanism of lncRNA H19 affecting angiogenesis in glioma, which could help to uncover potential target for glioma therapy. RT-qPCR analysis was performed to detect the expression of lncRNA H19 and miR-138 in HEB, U87, A172 and U373 cell lines. MTT assay was used to evaluate the cell viability. To evaluate the migration and invasion after lncRNA H19 knockdown, Transwell and wound healing assay were employed. After lncRNA H19 knockdown, protein expression of HIF 1α and VEGF was detected by western blot and tube formation was assessed. For the prediction and validation of the interaction between lncRNA H19 and miR-138, bioinformatics and luciferase assay were performed. We investigated the regulatory roles and downstream molecular mechanisms of lncRNA H19 in glioma by knockdown H19, which inhibited the proliferation, migration and angiogenesis of glioma cells. Moreover, miR-138 acted as a target of H19 as detected by luciferase reporter assays. Meanwhile, HIF-1α was also a target of miR-138 and miR-138 could also regulate the proliferation, migration and angiogenesis of glioma cells by targeting HIF-1α and affecting the expression of VEGF in turn. Our findings identified an upregulated lncRNA H19 in glioma cells, which could promote proliferation, migration, invasion and angiogenesis via miR-138/HIF-1α axis as a ceRNA. This study provided a new opportunity to advance our understanding in the potential mechanism of lncRNA in glioma angiogenesis.