Development of gene expression signatures for miR-218 overexpression
Ontology highlight
ABSTRACT: To investigate differences in gene expression after overexpression miR-218 in U251MG 2 Samples, one transduced with miR-control and one with miR-218.
Project description:Receptor tyrosine kinase pathway signalings plays a central role in the growth and progression of glioblastoma, a highly aggressive group of brain tumors. We recently reported that miR-218 repression, an essentially uniform feature of human GBM, directly promotes RTK hyperactivation by increasing the expression of key positive signaling effectors, including EGFR, PLCr1, PIK3CA and ARAF. However, enhanced RTK signaling is known to activate compensatory inhibitory feedback mechanisms in both normal and cancer cells. We demonstrate here that miR-218 repression in GBM cells also increases the abundance of additional up stream and downstream signaling mediators, including PDGFRa, RSK2, and S6K1, which collectively funciton to alleviate inhibitory RTK feedback regulation. In turn, RTK signaling suppresses miR-218 expression via STAT3, which binds to the miR-218 locus, along with BCLAF1, to repress its expression. These data identify novel interacting feedback loops by which miR-218 repression promotes increased RTK signaling in high-grade gliomas.
Project description:The assembly of the mammalian brain is orchestrated by temporally coordinated waves of gene expression. Post-transcriptional regulation of gene expression by microRNAs (miRNAs) is a key aspect of this program. Indeed, deletion of neuron-enriched miRNAs induces strong developmental phenotypes, and miRNA levels are altered in patients with neurodevelopmental disorders. However, the mechanisms used by miRNAs to instruct brain development remain largely unexplored. Here, we identified miR-218 as a critical regulator of hippocampal assembly. MiR-218 is highly expressed in the hippocampus and enriched in both excitatory principal neurons (PNs) and GABAergic inhibitory interneurons (INs). Early life inhibition of miR-218 results in an adult brain with a predisposition to seizures. Changes in gene expression in the absence of miR-218 suggest that network assembly is impaired. Indeed, we find that miR-218 inhibition results in the disruption of early depolarizing GABAergic signaling, structural defects in dendritic spines, and altered intrinsic membrane excitability. Conditional knockout of miR-218 in INs, but not PNs, is sufficient to recapitulate long-term instability. Finally, de-repressing Kif21b and Syt13, two miR-218 targets, phenocopies the effects on early synchronous network activity induced by miR-218 inhibition. Taken together, the data suggest that miR-218 orchestrates formative events in PNs and INs to produce stable networks.
Project description:Lung cancer is the leading cause of cancer death worldwide. Brain metastasis is a major cause of morbidity and mortality in lung cancer. CDH2 (N-cadherin, a mesenchymal marker in epithelial-mesenchymal transition) and ADAM9 (a member of type I transmembrane proteins) have been reported relating to lung cancer brain metastasis, however, it is still not clear whether any interaction between them to mediate lung cancer brain metastasis. Since microRNAs were discovered to regulate many biological functions and disease processes (e.g., cancer) by down-regulating their target genes, microRNA microarrays were used to identify ADAM9 regulated miRNAs that target CDH2 in aggressive lung cancer cells. Luciferase assays and immunoblotting proved that CDH2 was a target gene of miR-218. The expression of miR-218 was generated from pri-mir-218-1, located in SLIT2, in low invasive lung adenocarcinoma while it was inhibited in aggressive lung adenocarcinoma. Down-regulation of ADAM9 could up-regulate SLIT2 and miR-218, thus down-regulate CDH2 expression. This study elucidated the mechanism of ADAM9 activating CDH2 may be due to release the inhibition of miR-218 on CDH2 in lung adenocarcinoma. For each of the cell lines bm#2, bm#7, and F4, one microarray was analyzed.
Project description:Lung cancer is the leading cause of cancer death worldwide. Brain metastasis is a major cause of morbidity and mortality in lung cancer. CDH2 (N-cadherin, a mesenchymal marker in epithelial-mesenchymal transition) and ADAM9 (a member of type I transmembrane proteins) have been reported relating to lung cancer brain metastasis, however, it is still not clear whether any interaction between them to mediate lung cancer brain metastasis. Since microRNAs were discovered to regulate many biological functions and disease processes (e.g., cancer) by down-regulating their target genes, microRNA microarrays were used to identify ADAM9 regulated miRNAs that target CDH2 in aggressive lung cancer cells. Luciferase assays and immunoblotting proved that CDH2 was a target gene of miR-218. The expression of miR-218 was generated from pri-mir-218-1, located in SLIT2, in low invasive lung adenocarcinoma while it was inhibited in aggressive lung adenocarcinoma. Down-regulation of ADAM9 could up-regulate SLIT2 and miR-218, thus down-regulate CDH2 expression. This study elucidated the mechanism of ADAM9 activating CDH2 may be due to release the inhibition of miR-218 on CDH2 in lung adenocarcinoma. For each of the cell lines bm#2, bm#7, and F4, one microarray was analyzed.
Project description:Background: UNC50 has long been recognized as a Golgi apparatus protein in yeast, and is involved in nicotinic receptor trafficking in Caenorhabditis elegans, but little is known about UNC50 gene function in human biology despite it being conserved from yeast to high eukaryotes. Objectives: We investigated the relation between UNC50 and human hepatocellular carcinoma (HCC) and the potential mechanisms underlying HCC development. Methods: UNC50 mRNA expression patterns in 12 HCC and adjacent non-cancerous tissues determined using northern blotting were confirmed by real-time PCR in another 44 paired tissues. Microarray experiments were used to screen for global effects of UNC50 knockdown in the Hep3B cell line, and were confirmed by real-time PCR, western blotting, flow cytometry, and tetrazolium assay in both UNC50 overexpression and knockdown Hep3B cells. Results: UNC50 expression levels were upregulated in HCC tissues in comparison with the adjacent non-cancerous tissues. UNC50 knockdown reduced mRNA levels of the downstream targets of the epidermal growth factor receptor (EGFR) pathway: cyclin D1 (CCND1), EGF, matrix metalloproteinase-7 (MMP7), aldose reductase-like 1 (AKR1B10), cell surfaceM-bM-^@M-^Sassociated mucin 1 (MUC1), and gastrin (GAST). Moreover, UNC50 influenced EGF, inducing cell cycle entry by affecting cell surface EGFR amounts. Conclusions: UNC50 is a potential oncogene that promotes HCC progression by affecting the EGFR pathway. To gain insight into the role UNC50 plays in HCC progression, we used microarray analyses to identify indirect evidence of UNC50 gene function via the knockdown strategy in Hep3B cells. Hep3B cells transfected with the shRNA expression plasmids shR-467, shR-554, shR-749, and shR-MOCK were purified with 1ug/ml puromycin, and the total RNA from each cell was extracted and analyzed with oligo microarrays.
Project description:Motor-neuron specific microRNA-218 (miR-218) was recently put in the spotlight because of its striking roles in mouse development. However, miR-218 relevance to human motor neuron disease was not yet explored. Here, we demonstrate by neuropathology that miR-218 is abundant in healthy human motor neurons. However, in amyotrophic lateral sclerosis (ALS) motor neurons miR-218 is downregulated and its mRNA targets are reciprocally upregulated (de-repressed). We further identify the potassium channel Kv10.1 as a new miR-218 direct target that controls neuronal activity. In addition, we screened thousands of ALS genomes and identified six rare variants in the human miR-218-2 sequence. Intriguingly, miR-218 gene variants fail to regulate neuron activity, suggesting the importance of this small endogenous RNA for neuronal robustness. The underlying mechanisms involve inhibition of miR-218 biogenesis and reduced processing by DICER. Therefore, miR-218 activity uncovers a previously unappreciated facet of motor neuron specificity that may be particularly susceptible to failure in human ALS, contributes to a view of ALS as a disease with a prominent RNA component and suggests that miR-218 is a potential therapeutic target for motor neuron disease.
Project description:Objective: Fibroblast-like synovial cells (FLS) have multilineage differentiation potential including osteoblasts. We aimed to investigate the role of microRNAs during the osteogenic differentiation of rheumatoid arthritis (RA)-FLS. Methods: MicroRNA(miRNA) array analysis was performed to investigate the differentially expressed miRNAs during the osteogenic differentiation. Expression of miR-218-5p (miR-218) during the osteogenic differentiation was determined by quantitative real-time PCR. Transfection with miR-218 precursor and inhibitor were used to confirm the targets of miR-218 and to analyse the ability of miR-218 to induce osteogenic differentiation. Results: The miRNA array revealed that 12 miRNAs were up-regulated and 24 miRNAs were down-regulated after osteogenic differentiation. We observed that miR-218 rose in the early phase of osteogenic differentiation and then decreased. Micro array analysis revealed the mir-218 modulate the expression of ROBO1 in RA-FLS. The induction of miR-218 in RA-FLS decreased ROBO1 expression, and promoted osteogenic differentiation.
Project description:Noncoding RNAs, especially microRNAs (miRNAs) have been implicated in the regulation of neuronal functions, such as learning, cognition and memory formation. However, the particular miRNAs involved in drug-induced behavioral plasticity are largely unknown. Here we report a novel regulator, miR-218, that inhibits heroin-induced behavioral plasticity. Network propagation-based method revealed several miRNAs that play key roles in drug-addiction, among which, miR-218 was decreased in nucleus accumbens (NAc) after chronic exposure to heroin. Lentiviral overexpression of miR-218 in NAc could inhibit heroin-induced reinforcement in both conditioning place preference (CPP) test and heroin self-administration (SA) experiment. Luciferase activity assay indicated miR-218 could regulate neuroplasticity related genes and directly target Mecp2 3’UTR. Consistently, Mecp2-/y mice exhibited reduced heroin seeking behavior in CPP test. These data reveal a functional role of miR-218 and its target, Mecp2, in the regulation of heroin-induced behavioral plasticity.
Project description:To identify genes hypermethylated and transcriptionally downregulated, we have employed the Illumina Infinium HumanMethylation450 BeadChip and Agilent SurePrint G3 Human Gene Expression 8x60K.And we validated selected genes in cases and controls. eventually we estalished CIMP of MDS. The gene expressions of four cases and four controls were measured.
Project description:Neural progenitor cells (NPCs) can be induced from somatic cells by defined factors. Here we report that NPCs can be generated from mouse embryonic fibroblasts by a chemical cocktail, namely VCR (V, VPA, an inhibitor of HDACs; C, CHIR99021, an inhibitor of GSK-3 kinases and R, Repsox, an inhibitor of TGF-β pathways), under a physiological hypoxic condition. These chemical-induced NPCs (ciNPCs) resemble mouse brain-derived NPCs regarding their proliferative and self-renewing abilities, gene expression profiles, and multipotency for different neuroectodermal lineages in vitro and in vivo. Further experiments reveal that alternative cocktails with inhibitors of histone deacetylation, glycogen synthase kinase, and TGF-β pathways show similar efficacies for ciNPC induction. Moreover, ciNPCs can also be induced from mouse tail-tip fibroblasts and human urinary cells with the same chemical cocktail VCR. Thus our study demonstrates that lineage-specific conversion of somatic cells to NPCs could be achieved by chemical cocktails without introducing exogenous factors. To access the exact identity of ciNPCs, we extracted mRNA from mouse brain-derived NPCs (as control NPCs), MEFs, ciNPCs at passage 5 and passage 13 and compared the global gene expression patterns of these cells by microarray analysis.