DNA methylation directs microRNA biogenesis
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE124879 | GEO | 2019/01/10
REPOSITORIES: GEO
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Project description:MicroRNA (miRNA) biogenesis is a tightly controlled multi-step process operated in the nucleus by the activity of the Large Drosha Complex (LDC). Through high resolution mass spectrometry (MS) analysis we discovered that the LDC is extensively methylated, with 82 distinct methylated sites associated to 16 out of 23 subunits of the LDC. The majority of these modifications occurs on arginine (R)- residues (61), leading to 86 methylation events, while 29 lysine (K)-methylation events occurs on 21 sites of the complex. Interestingly, the depletion and pharmacological inhibition of PRMT1 lead to a widespread alteration of the methylation state of the complex and induce global decrease of miRNA expression, as a consequence of the specific impairment of the pri-to-pre-miRNA processing step. In particular, we show that the reduced methylation of the ILF3 subunit of the complex is linked to its diminished binding to the target pri-miRNAs. Overall, our study uncovers a previously uncharacterized role of R-methylation in the regulation of the LDC activity in mammalian cells, thus effecting global miRNA levels.
2019-10-23 | PXD011617 | Pride
Project description:DEAD-box RNA-binding proteins (RBPs) play a significant role in RNA metabolism to achieve cellular homeostasis, including miRNA biogenesis and transcription. Hypoxia induces stemness cell-like characteristics in cancer cells and promotes malignant progression. Despite the fact that hypoxia can induce the changes in protein and RNA modification, thereby regulating downstream gene expressions, how modifications at different molecular layers interplay with each other are poorly understood. Here we show that hypoxia induces HectH9-mediated K63-linked polyubiquitination of the DEAD-box protein DDX17 as well as reduces N6-methyladenosine (m6A) marks in pri-miRNAs. While m6A potentiates DDX17 binding to pri-miRNAs, decreased m6A modifications of pri-miRNAs and increased polyubiquitination of DDX17 under hypoxia lead to decreased DDX17 binding to pri-miRNAs binding. These events enhance the association of DDX17 with the ubiquitin receptor p300 and lead to a decrease in miRNA biogenesis, especially for miRNAs regulating stemness and stemness-related genes. In addition, polyubiquitinated DDX17 together with p300 upregulates H3K56Ac levels on the stemness and stemness-related genes, resulting in enhancement of tumor initiating ability. Post-transcriptionally, decreased miRNA production, including those targeting stemness genes or stemness-related genes, also facilitates tumor initiation. Together, hypoxia triggers DDX17 poly-ubiquitination, which orchestrates dual mechanisms to increase tumor initiating ability and promote tumor progression.
2018-03-09 | PXD006059 | JPOST Repository
Project description:MiRNAs are key regulators of gene expression. They are processed from primary miRNA transcripts (pri-miRNAs), most of which are transcribed by DNA-dependent polymerase II (Pol II). MiRNA levels need to be precisely controlled to maintain various biological processes. In this manuscript, we report a discovery that STV1, a conserved ribosomal protein, acts in miRNA biogenesis in Arabidopsis. A portion of STV1 localizes at the nucleus and binds pri-miRNAs. Using pri-miR172b as a reporter, we show that STV1 binds the stem-loop with a short 5’ flanking sequencing within pri-miRNAs. Lack of STV1 in stv1-1 reduced the association of pri-miRNAs with their processing complex. These data suggest that STV1 promotes miRNA biogenesis through facilitating the recruitment of pri-miRNAs to their processing complex. Furthermore, we show that STV1 indirectly influence the occupancy of Pol II at the promoters of miRNA coding genes (MIR) and MIR promoter activities. Based on these results, we propose that STV1 refines the accumulation of miRNAs through its combined effects on pri-miRNA processing and transcription. This study uncovers an extra-ribsomal function of STV1.
2017-03-06 | GSE91013 | GEO
Project description:Abnormal miRNA expression has been linked to the development and progression of human cancers, and such dysregulation can result from aberrant DNA methylation. We combined the analysis of miRNA expression data deposited with empirical DNA methylation data in HCT116 and DKO colon cancer cells (SRA accession# SRP001414) to identify novel DNA methylation regulated miRNAs. ABSTRACT: Abnormal microRNA (miRNA) expression has been linked to the development and progression of several human cancers, and such dysregulation can result from aberrant DNA methylation. While a small number of miRNAs is known to be regulated by DNA methylation, we postulated that such epigenetic regulation is more prevalent. By combining MBD-isolated Genome Sequencing (MiGS) to evaluate genome-wide DNA methylation patterns and microarray analysis to determine miRNA expression levels, we systematically searched for candidate miRNAs regulated by DNA methylation in colorectal cancer cell lines. We found 64 miRNAs to be robustly methylated in HCT116 cells and/or DNMT-1 and 3B doubleknock cells (DKO); eighteen of them were located in imprinting regions or already reported to be regulated by DNA methylation. In the remaining 46 miRNAs, expression levels of 18 were consistent with their DNA methylation status. Finally, 10 miRNAs were up-regulated by 5-aza-2'-deoxycytidine treatment and identified to be novel miRNAs regulated by DNA methylation. Moreover, we demonstrated the functional relevance of these epigenetically silenced miRNAs by ectopically expressing select candidates, which resulted in inhibition of growth and migration of cancer cells. Our study also provides a reliable strategy to identify DNA methylation-regulated miRNAs by combining DNA methylation profiles and expression data.
2011-05-20 | GSE26819 | GEO
Project description:Abnormal miRNA expression has been linked to the development and progression of human cancers, and such dysregulation can result from aberrant DNA methylation. We combined the analysis of miRNA expression data deposited with empirical DNA methylation data in HCT116 and DKO colon cancer cells (SRA accession# SRP001414) to identify novel DNA methylation regulated miRNAs. ABSTRACT: Abnormal microRNA (miRNA) expression has been linked to the development and progression of several human cancers, and such dysregulation can result from aberrant DNA methylation. While a small number of miRNAs is known to be regulated by DNA methylation, we postulated that such epigenetic regulation is more prevalent. By combining MBD-isolated Genome Sequencing (MiGS) to evaluate genome-wide DNA methylation patterns and microarray analysis to determine miRNA expression levels, we systematically searched for candidate miRNAs regulated by DNA methylation in colorectal cancer cell lines. We found 64 miRNAs to be robustly methylated in HCT116 cells and/or DNMT-1 and 3B doubleknock cells (DKO); eighteen of them were located in imprinting regions or already reported to be regulated by DNA methylation. In the remaining 46 miRNAs, expression levels of 18 were consistent with their DNA methylation status. Finally, 10 miRNAs were up-regulated by 5-aza-2'-deoxycytidine treatment and identified to be novel miRNAs regulated by DNA methylation. Moreover, we demonstrated the functional relevance of these epigenetically silenced miRNAs by ectopically expressing select candidates, which resulted in inhibition of growth and migration of cancer cells. Our study also provides a reliable strategy to identify DNA methylation-regulated miRNAs by combining DNA methylation profiles and expression data. [miRNA expression]: Total RNA was extracted from 3 biological replicate sets of HCT116 and DMNT-1 and 3B double knock out HCT116 (DKO) colorectal cancer cells.
2011-05-20 | E-GEOD-26819 | biostudies-arrayexpress
Project description:The enhancer/promoter of the vitellogenin II (VTG) gene has been extensively studied as a model system of vertebrate transcriptional control. While deletion mutagenesis and in vivo footprinting identified the transcription factor (TF) binding sites governing its tissue specificity, DNase hypersensitivity- and DNA methylation studies revealed the epigenetic changes accompanying its hormone-dependent activation. Moreover, upon induction with estrogen (E2), the region flanking the estrogen-responsive element (ERE) was reported to undergo active DNA demethylation. We now show that although the VTG ERE is methylated in embryonic chicken liver and in LMH/2A hepatocytes, its induction by E2 was not accompanied by extensive demethylation. In contrast, E2 failed to activate a VTG enhancer/promoter-controlled luciferase reporter gene methylated by SssI. Surprisingly, this inducibility difference could be traced not to the ERE, but rather to a single CpG in an E-box (CACGTG) sequence upstream of the VTG TATA box, which is unmethylated in vivo, but methylated by SssI. We demonstrate that this E-box binds the upstream stimulating factor USF1/2. Selective methylation of the CpG within this binding site with an E-box-specific DNA methyltranferase Eco72IM was sufficient to attenuate USF1/2 binding in vitro and abolish the hormone-induced transcription of the VTG gene in the reporter system.
2020-05-27 | PXD015594 | Pride
Project description:During microRNA-biogenesis, stem-loop structured precursors are processed in two endonucleolytic steps, giving rise to mature microRNAs (miRNAs). This process is not only regulated at the level of transcription but also posttranscriptionally by RNA-binding proteins (RBPs). Here we have used a proteomics-based pull-down approach to map and characterize the interactome of 72 pre-miRNAs in eleven cell lines. We identify over 150 RBPs that interact specifically with distinct pre-miRNAs. To demonstrate their functional relevance, we used RNAi knockdown and CRISPR/Cas-mediated knockout experiments and analyzed changes in miRNA levels. Indeed, a large number of the investigated candidates have effects on miRNA-processing under our experimental conditions, including several C3H-zinc-finger proteins. Ultimately, we show that TRIM71/Lin41 is a potent regulator of miR-29a processing and its inactivation directly affects miR-29a targets. In summary, we provide an extended database of RBPs that interact with pre-miRNAs in different cell types helping to elucidate posttranscriptional regulation of miRNA biogenesis on a global scale.
2017-04-26 | PXD004193 | Pride
Project description:Emerging evidences indicate that microRNAs (miRNAs) are often deregulated and have fundamental roles in hepatocellular carcinoma (HCC). However, the mechanism underlying miRNA dysregulation in HCC is still elusive. In this report, we used an integrated analysis strategy combining methylated DNA immunoprecipitation chip (MeDIP-chip) and miRNA expression microarray data to study the correlation between aberrant methylation and dysregulation of miRNA in HCC. In all, we showed that global miRNA methylation profiles were significantly different between cancerous and normal hepatocytes, and abnormal methylation was an important mechanism governing miRNA expression in HCC.
2015-08-05 | GSE49554 | GEO
Project description:Methylation of N6-adenosine (me6A) has been observed in rRNA, tRNA, snoRNA, lncRNA and mRNA (ref.), but not yet miRNA. Interestingly, many mRNAs contain miRNA-binding sites and me6A in their 3'-UTR, although they do not appear to overlap (Mayer). We have investigated whether adenosine methylation affects miRNA levels and whether miRNAs are methylated. Indeed, we have obtained evidence suggesting that miRNA can be methylated and that the steady state level of certain miRNAs is affected by the level of the 6meA demethylase FTO.
2015-07-20 | GSE59767 | GEO
Project description:Purpose: The major aim of this study was to investigate the role of DNA methylation (referred to as methylation) on microRNA (miRNA) silencing in non-small cell lung cancers (NSCLC). Experimental Design: We performed microarray expression analyses of 856 miRNAs in NSCLC A549 cells before and after treatment with the DNA methyltransferase inhibitor 5-aza-2´-deoxycytidine (Aza-dC) and with a combination of Aza-dC and the histone deacetylase inhibitor trichostatin A. MiRNA methylation was determined in 11 NSCLC cell lines and in primary tumors and corresponding non-malignant lung tissue samples of 101 stage I-III NSCLC patients. Results: By comparing microarray data of untreated and drug treated A549 cells, we identified 33 miRNAs whose expression was upregulated after drug treatment and which are associated with a CpG island. Thirty (91%) of these miRNAs were found to be methylated in at least 1 of 11 NSCLC cell lines analysed. Moreover, miR-9-3 and miR-193a were found to be tumor-specifically methylated in NSCLC patients. We observed a shorter disease-free survival of miR-9-3 methylated lung squamous cell carcinoma (LSCC) patients compared to miR-9-3 unmethylated LSCC patients by multivariate analysis (HR = 3.8, 95% CI = 1.3 to 11.2, p = 0.017) and a shorter overall survival of miR-9-3 methylated LSCC patients compared to miR-9-3 unmethylated LSCC patients by univariate analysis (p = 0.013). Conclusions: Overall, our results suggest that methylation is an important mechanism for inactivation of certain miRNAs in NSCLCs and that miR-9-3 methylation may serve as a prognostic parameter in LSCC patients. MiRNA expression (LC Sciences, mirBASE12) was analyzed before and after treatment of A549 cells with 5-aza-2´-deoxycytidine (Aza-dC) and a combination of Aza-dC and trichostatin A (TSA). Experiments were performed in duplicates.
2012-03-13 | E-GEOD-31579 | biostudies-arrayexpress