The mammalian genome contains thousands of loci that transcribe long noncoding RNAs (lncRNAs), some of which are known to play critical roles in diverse cellular processes through a variety of mechanisms. While some lncRNA loci encode RNAs that act non-locally (in trans), emerging evidence indicates that many lncRNA loci act locally (in cis) to regulate expression of nearby genes—for example, through functions of the lncRNA promoter, transcription, or transcript itself. Despite their potentially important roles, it remains challenging to identify functional lncRNA loci and distinguish among these and other mechanisms. To address these challenges, we developed a genome-scale CRISPR-Cas9 activation screen targeting more than 10,000 lncRNA transcriptional start sites (TSSs) to identify noncoding loci that influence a phenotype of interest. We found 11 novel lncRNA loci that, upon recruitment of an activator, each mediate BRAF inhibitor resistance in melanoma. Most candidate loci appear to regulate nearby genes. Detailed analysis of one candidate, termed EMICERI, revealed that its transcriptional activation results in dosage-dependent activation of four neighboring protein-coding genes, one of which confers the resistance phenotype. Our screening and characterization approach provides a CRISPR toolkit to systematically discover functions of noncoding loci and elucidate their diverse roles in gene regulation and cellular function. Overall design: RNA-seq on A375 cells overexpressing candidate lncRNA or protein-coding gene.
Genome-scale activation screen identifies a lncRNA locus regulating a gene neighbourhood.
Specimen part, Cell line, Subject
View SamplesRNA-seq and ATAC-seq data to understand how gene regulation and chromatin accessibility correlates with function enrichment in CRISPR screen for melanoma drug resistance
Genome-scale activation screen identifies a lncRNA locus regulating a gene neighbourhood.
No sample metadata fields
View SamplesA major role of NINJA is to repress root jasmonate signalling and allow normal cell elongation.
Multilayered Organization of Jasmonate Signalling in the Regulation of Root Growth.
Specimen part
View SamplesAPE1 was knocked down using siRNA in low passage patient-derived PDAC cells and the resulting cells, along with control cells were analysed using scRNA-seq to identify differentially expressed genes and pathways as a result of APE1 knock-down. Overall design: siRNA APE1 knock-down versus scrambled control, The SMARTer system was used to generate cDNA from 96 captured single cells. Unstranded 2x100bp reads were sequenced using a HiSeq2500 on rapid run mode in 1 lane.
APE1/Ref-1 knockdown in pancreatic ductal adenocarcinoma - characterizing gene expression changes and identifying novel pathways using single-cell RNA sequencing.
Subject
View SamplesDespite the approval of several anti-angiogenic therapies, clinical results remain unsatisfactory, and transient benefits are followed by rapid tumor recurrence. In the present study, we aimed to identify resistance mechanisms to the small-molecule tyrosine kinase inhibitor nintedanib in the Py2T murine breast cancer transplantation model. To identify differences in gene expression between short- and long-term nintedanib and untreaded FAC-sorted tumor and endothelial cells, we performed gene expression profiling by using affymetrix microarrays.
Targeting Metabolic Symbiosis to Overcome Resistance to Anti-angiogenic Therapy.
Specimen part, Treatment
View SamplesMetastasis is the major cause of death in cancer patients, yet the genetic/epigenetic programs that drive metastasis are poorly understood. Here, we report a novel epigenetic reprogramming pathway that is required for breast cancer metastasis. Concerted differential DNA methylation is initiated by activation of the RON receptor tyrosine kinase by its ligand, macrophage stimulating protein (MSP). Through PI3K signaling, RON/MSP promotes expression of the G:T mismatch-specific thymine glycosylase MBD4. RON/MSP and MBD4-dependent aberrant DNA methylation results in misregulation of a specific set of genes. Knockdown of MBD4 reverses methylation at these specific loci, and blocks metastasis. We also show that the MBD4 glycosylase catalytic residue is required for RON/MSP-driven metastasis. Analysis of human breast cancers using a set of specific genes that are regulated by RON/MSP through MBD4-directed aberrant DNA methylation revealed that this epigenetic program is significantly associated with poor clinical outcome. Furthermore, inhibition of Ron kinase activity with a new pharmacological agent prevents activation of the RON/MBD4 pathway and blocks metastasis of patient-derived breast tumor grafts in vivo. Overall design: Examination of 3 cell types.
The RON receptor tyrosine kinase promotes metastasis by triggering MBD4-dependent DNA methylation reprogramming.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines.
Sex, Specimen part, Disease, Cell line, Treatment
View SamplesAbstract: Epigenetic alterations are a fundamental aspect of cancer cells, and epigenetic drugs are currently used in clinical practice for hematological malignancies. Pediatric neuro-ectodermal tumors originate from neural crest cells and show epigenetic defects of apoptotic pathways, which makes the introduction of epigenetic drugs in this patient category logical. However, the young age of these patients is accompanied by ongoing developmental processes which are regulated epigenetic mechanisms, and prompted us to study molecular effects of nanomolar dosage epigenetic drugs in neuro-ectodermal tumor cell lines. Combination treatment of 5-aza-2`-deoxicytidine (DAC) and Trichostatin A (TSA) at nanomolar dosages resulted in wide-spread demethylating effects in 17 NBL and 5 PNET cell lines in vitro. This widespread demethylation had large effects on gene-expression profiles. In NBL cell lines, almost every cellular pathway (193/200) investigated demonstrated altered expression upon treatment, and resulted in upregulation of known epigenetically regulated genes such as X-chromosomal, tissue-specific, and a few imprinted genes. Integration analysis of CpG island methylation array data and whole genome gene expression data identified 30 genes potentially upregulated by gene promoter demethylation. Homeobox genes frequently showed demethylation in both short term (72 hours) and long term cultures (3 months) of NBL lines. Continuous treatment with epigenetic drugs resulted in low rates of proliferation. The low rate of proliferation that might explain limited consecutive demethylation upon prolonged exposure. In conclusion, genome-wide methylation and gene expression changes are induced DAC and TSA treatment at nanomolar dosages. These effects affected more than 97% of cellular pathways investigated. Further studies towards the effects of epigenetic drug combinations are advised before being applied in clinical trials for pediatric patients.
Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines.
Sex, Specimen part, Cell line
View SamplesThe transcriptional response of Arabidopsis thaliana cell suspensions following treatment with the stress hormone methyl jasmonate (MeJA) was monitored over time 16 hours after subcultivation. Three time points were included: 30 minutes, 2 hours and 6 hours after elicitation with 50µm MeJA or DMSO as a control.
Mapping methyl jasmonate-mediated transcriptional reprogramming of metabolism and cell cycle progression in cultured Arabidopsis cells.
Compound, Time
View SamplesDietary fat quality may influence skeletal muscle lipid handling and fat accumulation, thereby modulating insulin sensitivity. Objective: To examine acute effects of meals with various fatty acid (FA) compositions on skeletal muscle FA handling and postprandial insulin sensitivity in obese insulin resistant men. Design: In a single-blinded randomized crossover study, 10 insulin resistant men consumed three high-fat mixed-meals (2.6MJ). Meals were high in saturated FA (SFA), in monounsaturated FA (MUFA) or in polyunsaturated FA (PUFA). Fasting and postprandial skeletal muscle FA handling were examined by measuring arterio-venous concentration differences across forearm muscle. [2H2]-palmitate was infused intravenously to label endogenous triacylglycerol (TAG) and FFA in the circulation and [U-13C]-palmitate was added to the meal to label chylomicron-TAG. Skeletal muscle biopsies were taken to assess intramuscular lipid metabolism and gene expression. Results: Insulin and glucose responses (AUC) after SFA meal were significantly higher compared with PUFA meal (p=0.003 and 0.028, respectively). Uptake of TAG-derived FA was significantly lower in the early postprandial phase after PUFA meal as compared with other meals (AUC60-120, p<0.001). The PUFA meal induced less transcriptional downregulation of oxidative pathways compared with other meals. The fractional synthetic rate was higher in DAG and PL fraction after MUFA and PUFA meal. Conclusion: Intake of a PUFA meal reduced TAG-derived skeletal muscle FA uptake, which was accompanied by higher postprandial insulin sensitivity and a tendency towards a higher muscle lipid turnover. These data suggest that the effects of replacement of SFA by PUFA may contribute to less muscle lipid uptake and may be therefore protective against the development of insulin resistance.
PUFAs acutely affect triacylglycerol-derived skeletal muscle fatty acid uptake and increase postprandial insulin sensitivity.
Sex, Age, Time
View Samples