Project description:Triple helix is a potential mechanism how lncRNAs interact with the genome. Our in silico method (Triplex Domain Finder) is able to predict the binding sites of lncRNA MEG3 and GATA6-AS in the genome. In order to validate these predictions, we develop DBD-Capture-Seq to capture the DNA loci where the given RNA oligo binds to via triplex. Method: Different RNA oligos are used The biotinylated RNA oligos (MEG3 TFR1, MEG3 TFR2, and GATA6-AS TFR1) were incubated with sheared genomic DNA to allow for triplex formation. After binding to streptavidin-coated beads, RNA-associated DNA was eluted and subjected to deep sequencing. Control experiments were conducted in the absence of biotinylated RNA oligos.
Project description:Long noncoding RNAs (lncRNAs) are important regulators of chromatin; however, the mechanistic roles for many lncRNAs are poorly understood in part because their direct interactions with genomic loci and proteins are difficult to assess. We used CHART-seq to map the genomic binding sites for two highly expressed human lncRNAs, NEAT1 and MALAT1, which localize within the nucleus to paraspeckles and nuclear speckles, respectively. We show that NEAT1 and MALAT1 localize to hundreds of genomic sites in human cells, primarily over active genes. NEAT1 and MALAT1 exhibit colocalization to many of these loci, but display distinct gene body binding patterns at these sites, suggesting independent but complementary functions for these RNAs. Protein mass spectrometry analysis of CHART-enriched material (CHART-MS) identified numerous proteins enriched by both lncRNAs, supporting complementary binding and function, in addition to unique associated proteins. Transcriptional inhibition or stimulation affects the localization of NEAT1 to active chromatin sites, implying that DNA sequence itself does not target NEAT1 to chromatin and that localization responds to cues involved in the transcription process. Paired-end CHART-seq was performed for a single replicate of each capture oligonucleotide in untreated MCF-7 cells to establish binding sites of these RNAs, for a total of 6 samples. To investigate the effects of transcriptional inhibition and E2 stimulation on the localization of these RNAs, we performed paired-end CHART-seq with each capture oligonucleotide for two biological replicates of flavopiridol- and vehicle (DMSO)-treated MCF-7 cells and for two biological replicates of E2- and vehicle (ethanol)-treated MCF-7 cells. To establish the overlap of NEAT1 and MALAT1 binding sites with a known component of paraspeckles (NEAT1-containing subnuclear body), we performed paired-end ChIP-seq for the paraspeckle component PSF in MCF-7 cells, as well as a single-end biological replicate.
Project description:Long noncoding RNAs (lncRNAs) are important regulators of chromatin; however, the mechanistic roles for many lncRNAs are poorly understood in part because their direct interactions with genomic loci and proteins are difficult to assess. We used CHART-seq to map the genomic binding sites for two highly expressed human lncRNAs, NEAT1 and MALAT1, which localize within the nucleus to paraspeckles and nuclear speckles, respectively. We show that NEAT1 and MALAT1 localize to hundreds of genomic sites in human cells, primarily over active genes. NEAT1 and MALAT1 exhibit colocalization to many of these loci, but display distinct gene body binding patterns at these sites, suggesting independent but complementary functions for these RNAs. Protein mass spectrometry analysis of CHART-enriched material (CHART-MS) identified numerous proteins enriched by both lncRNAs, supporting complementary binding and function, in addition to unique associated proteins. Transcriptional inhibition or stimulation affects the localization of NEAT1 to active chromatin sites, implying that DNA sequence itself does not target NEAT1 to chromatin and that localization responds to cues involved in the transcription process.
Project description:We compared the performance of conventional RNAseq with RNA Capture Sequencing (CaptureSeq) to assemble and quantify known RNA spike-Ins and human transcripts. We find CaptureSeq to be superior for the detection and quantification of the 37% lowest expressed genes, and comparable for the next 45% of moderately expressed genes. CaptureSeq contributes only minor technical variation and measures differential gene expression accurately. We demonstrate these advantages by the targeted sequencing of long noncoding RNAs across 20 human tissues, expanding previous annotations two-fold and simultaneously generating a quantitative atlas of expression. This analysis confirms the use of CaptureSeq as an important method for transcriptional profiling. Long noncoding RNA assembly and expression is analysed by targeted RNA sequencing for 20 human tissues and 4 human cell lines
Project description:Tumour DNA contains thousands of somatic single nucleotide variants (SNVs) in non-protein-coding elements, yet their functional significance remains poorly understood. Amongst the most highly mutated elements are long noncoding RNAs (lncRNAs), functional transcripts with known roles in carcinogenesis. To search for driver mutations in lncRNAs, we apply an integrative driver discovery algorithm to SNVs from 2583 primary tumours and 3527 metastases to reveal 54 potential “driver lncRNAs”. Our algorithm confirms a particularly high mutation rate in the iconic cancer lncRNA, NEAT1, which has been ascribed by recent studies to passenger effects. We directly test the functionality of NEAT1 SNVs using in cellulo mutagenesis, identifying discrete regions where mutations reproducibly increase cell proliferation in diverse cell backgrounds, both cancerous and normal. In particular, mutations in the 5’ region alter ribonucleoprotein assembly and boost the population of subnuclear paraspeckles, thus mechanistically linking mutations to cellular proliferation. We then used RNA-pull down followed by mass spectrometry to identify the protein interactor changing between the wild type and mutant form of NEAT1.
Project description:GM0637 cell were treated with or without DNA damaging agent neocarzinostatin (NCS), and cells were harvested after 4 hours and 8 hours for the microarray analyses of whole-genome long noncoding RNAs. To examine how long noncoding RNAs are regulated in the DNA damage response, we assessed the genome-wide long noncoding RNA expression in GM0637 cells treated with or without DNA damage
Project description:1. Evaluate the diagnostic value of long noncoding RNA (CCAT1) expression by RT-PCR in peripheral blood in colorectal cancer patients versus normal healthy control personal.
2. Evaluate the clinical utility of detecting long noncoding RNA (CCAT1) expression in diagnosis of colorectal cancer patients & its relation to tumor staging.
3. Evaluate the clinical utility of detecting long noncoding RNA (CCAT1) expression in precancerous colorectal diseases.
4. Compare long noncoding RNA (CCAT1) expression with traditional marker; carcinoembryonic antigen (CEA) and Carbohydrate antigen 19-9 (CA19-9) in diagnosis of colorectal cancer.