In acute myeloid leukemia, chemotherapy resistance remains prevalent and poorly understood. Using functional proteomics of patient AML specimens, we identified MEF2C S222 phosphorylation as a specific marker of primary chemoresistance. We found that transgenic Mef2cS222A/S222A mice engineered to block MEF2C phosphorylation exhibited normal hematopoiesis, but were resistant to leukemogenesis induced by MLL-AF9. MEF2C phosphorylation was required for leukemia stem cell maintenance, induced by MARK kinases in cells, and blocked by selective MARK inhibitor MRT199665, which caused apoptosis of MEF2C-activated human AML cell lines and primary patient specimens, but not those lacking MEF2C. These findings identify signaling-dependent dysregulation of transcription factor control as a determinant of therapy response in AML, with immediate potential for improved diagnosis and therapy for this disease. Overall design: RNA-sequencing of human leukemia cell line with induction of wildtype or mutant MEF2C.
MEF2C Phosphorylation Is Required for Chemotherapy Resistance in Acute Myeloid Leukemia.
Specimen part, Cell line, Treatment, Subject
View SamplesIn acute myeloid leukemia, chemotherapy resistance remains prevalent and poorly understood. Using functional proteomics of patient AML specimens, we identified MEF2C S222 phosphorylation as a specific marker of primary chemoresistance. We found that transgenic Mef2cS222A/S222A mice engineered to block MEF2C phosphorylation exhibited normal hematopoiesis, but were resistant to leukemogenesis induced by MLL-AF9. MEF2C phosphorylation was required for leukemia stem cell maintenance, induced by MARK kinases in cells, and blocked by selective MARK inhibitor MRT199665, which caused apoptosis of MEF2C-activated human AML cell lines and primary patient specimens, but not those lacking MEF2C. These findings identify signaling-dependent dysregulation of transcription factor control as a determinant of therapy response in AML, with immediate potential for improved diagnosis and therapy for this disease. Overall design: RNA-sequencing of human leukemia cell line with treatment of MARK inhibitor MRT199665.
MEF2C Phosphorylation Is Required for Chemotherapy Resistance in Acute Myeloid Leukemia.
Specimen part, Cell line, Treatment, Subject
View SamplesWe studied whether the accumulation of lipids in the fasted kidney are derived from lipoproteins or (non-esterified fatty acids) NEFAs. With overnight fasting, kidneys accumulated triglyceride, but had reduced levels of ceramide and glycosphingolipid species. Fasting led to a nearly 5-fold increase in kidney uptake of plasma [14C]oleic acid. Increasing circulating NEFAs using a ß adrenergic receptor agonist caused a 15-fold greater accumulation of lipid in the kidney, while mice with reduced NEFAs due to adipose tissue deficiency of adipose triglyceride lipase had reduced triglycerides. Cluster of differentiation (Cd)36 mRNA increased 2-fold, and angiopoietin-like 4 (Angptl4), an LPL inhibitor, increased 10-fold. Fasting-induced kidney lipid accumulation was not affected by inhibition of LPL with poloxamer 407 or by use of mice with induced genetic LPL deletion. Despite the increase in CD36 expression with fasting, genetic loss of CD36 did not alter fatty acid uptake or triglyceride accumulation. Our data demonstrate that fasting-induced triglyceride accumulation in the kidney correlates with the plasma concentrations of NEFAs, but is not due to uptake of lipoprotein lipids and does not involve the fatty acid transporter, CD36. Overall design: Mice (n=4-5/group) were either fasted for 16 hours or fed ad libitum. Kidneys were removed and snap frozen. RNA was extracted for sequencing.
Kidney triglyceride accumulation in the fasted mouse is dependent upon serum free fatty acids.
Sex, Cell line, Treatment, Subject
View SamplesVitamin A (retinol) is an essential precursor for the production of retinoic acid (RA), which in turn is a major regulator of gene expression, affecting cell differentiation throughout the body. Understanding how vitamin A nutritional status, as well as therapeutic retinoid treatment, regulates the expression of retinoid homeostatic genes is important for improving dietary recommendations and therapeutic strategies using retinoids. This study investigated genes central to processes of retinoid uptake and storage, release to plasma, and oxidation in the liver of rats under steady-state conditions after different exposures to dietary vitamin A (deficient, marginal, adequate and supplemented), and acutely after administration of a therapeutic dose of all-trans-RA. Over a very wide range of dietary vitamin A, lecithin:retinol acyltransferase (LRAT) as well as multiple cytochrome P450s (CYP26A1, CYP26B1, and CYP2C22) differed by diet and were highly correlated with one another and with vitamin A status assessed by liver retinol concentration (all correlations, P<0.05). After acute treatment with RA, the same genes were rapidly and concomitantly induced, preceding RAR, a classical direct target of RA. CYP26A1 mRNA exhibited the greatest dynamic range (change of log26 in 3 h). Moreover, CYP26A1 increased more rapidly in the liver of RA-primed rats than nave rats. By in situ hybridization, CYP26A1 mRNA was strongly regulated within hepatocytes, closely resembling RBP4 in location. Overall, whether RA is produced endogenously from retinol or administered exogenously, changes in retinoid homeostatic gene expression simultaneously favor both retinol esterification and RA oxidation, with CYP26A1 exhibiting the greatest dynamic change.
Multiple cytochrome P-450 genes are concomitantly regulated by vitamin A under steady-state conditions and by retinoic acid during hepatic first-pass metabolism.
Sex, Age, Specimen part
View SamplesmicroRNAs (miRNAs) are typically generated as ~22-nucleotide double-stranded RNAs via processing of precursor hairpins by the RNase III enzyme Dicer, after which they are loaded into Argonaute (Ago) proteins to form RNA-induced silencing complex (RISC). However, the biogenesis of miR-451, an erythropoietic miRNA conserved in vertebrates, does not require Dicer processing. Instead, the short pre-miR-451 precursor hairpin is directly loaded into Ago, followed by cleavage of the 3'' arm and trimming of the 3'' end to the mature length by PARN. Here we show the in vivo activity of miR-430 Ago2-hairpin, a canonical microRNA engineered to fit the structure of miR-451 and hence become Ago2-dependent. Moreover, we test a modified miR-430 Ago2-haipin with 3x phoshorothioate bonds that impairs trimmng. Surprisingly, our data show that trimming of Ago-cleaved pre-miRNAs is not essential for target silencing, indicating that RISC is functional with miRNAs longer than 22-nucleotides. Overall design: Rescue of MZdicer zebrafish mutant with the injection of trimmable and nontrimmable miR-430 Ago2 hairpins: Transcriptome of wild type, MZdicer mutant, and MZdicer mutant micoinjected with miR-430 duplex, miR-430 (Ago2-haripin), miR-430 (Ago2-haripin 3xPhosphorothioate)
Poly(A)-specific ribonuclease mediates 3'-end trimming of Argonaute2-cleaved precursor microRNAs.
No sample metadata fields
View SamplesTo investigate the time-dependent and coordinated sequence of inflammation-related events, and the dynamic features of macrophage polarisation/activation, we build and validated an in vitro model based on primary human monocytes
Transcriptomic profiling of the development of the inflammatory response in human monocytes in vitro.
Specimen part
View SamplesHere we identify a Dicer-independent miRNA biogenesis pathway that employs the slicer catalytic activity of Argonaute2 (Ago2). To uncover Dicer-independent miRNAs, we sequenced small RNAs in wild type, maternal-zygotic dicer (MZdicer) and MZago2 mutants, using zebrafish as a model system. We find that, in contrast to other miRNAs, miR-451 levels were increased in MZdicer but drastically reduced in the MZago2 mutants. We show that pre-miR-451 processing requires Ago2 catalytic activity in vivo. MZago2 mutant embryos display delayed erythrocyte maturation that can be rescued by wild type Ago2 or miR-451 duplex but not catalytically dead Ago2. We propose that Ago2-mediated cleavage of a subset of pre-miRNAs, followed by uridylation and trimming, generates functional miRNAs in a Dicer-independent manner. Overall design: Examination of small RNAs (18 to 35 nucleotides) in 3 different zebrafish genotypes (wild type, MZago2, MZdicer) at 48 hours post-fertilization.
A novel miRNA processing pathway independent of Dicer requires Argonaute2 catalytic activity.
No sample metadata fields
View SamplesCTCF is a master regulator that plays a role in genome architecture and gene expression. A key aspect of CTCF’s mechanism involves bringing together distant genetic elements for intra- and inter-chromosomal interactions. Evidence from epigenetic processes, such as X-chromosome inactivation (XCI), suggests that CTCF may carry out its functions through interacting RNAs. Using genome-wide approaches to investigate the relationship between CTCF’s RNA interactome and its epigenomic landscape, here we report that CTCF interacts with thousands of transcripts in mouse embryonic stem cells (mESC), many in close proximity to CTCF’s genomic binding sites. Biochemical analysis demonstrates that CTCF is a high-affinity RNA binding protein that contacts RNA directly and specifically. In the XCI model, CTCF binds the active and inactive X-chromosomes allele-specifically. At the X-inactivation center, Tsix RNA binds CTCF and targets CTCF to a region associated with X-chromosome pairing. Our work implicates CTCF-RNA interactions in long-range chromosomal interactions in trans and adds a new layer of complexity to CTCF regulation. The genome-wide datasets reported here will provide a useful resource for further study of CTCF-mediated epigenomic regulation. Overall design: CTCF RNA interactome was identified by UV-crosslinking and immunoprecipitation followed by high-throughput sequencing (CLIP-seq), and was compared to CTCF''s epigenomic landscape as obtained by chromatin immunoprecipitation (ChIP-seq).
Locus-specific targeting to the X chromosome revealed by the RNA interactome of CTCF.
No sample metadata fields
View SamplesGene expression changes in 3 human melanoma cell lines were compared to freshly isolated normal primary melanocytes Overall design: Three biological replicates for each melanoma cell line and primary melanocytes were labeled and run Illumina HiSeq2500. The transcriptome of melanocytes was compared to cell line SK-Mel-28, SK-Mel-147 or UACC-62.
Systems analysis identifies melanoma-enriched pro-oncogenic networks controlled by the RNA binding protein CELF1.
Specimen part, Subject
View SamplesPurpose: Asess the transcritpional changes induced upon RAB7 knock-down in melanoma (SK-Mel-28 and UACC-62) and in colon cancer (HCT-116) cell lines. Methods: mRNA profiles of tumor cell lines (SK-Mel-28, UACC-62, HCT-116) stably expressing scrambled shRNA or RAB7 shRNA (harvested at day 3 after lentiviral infection) were generated by deep sequencing, using three biological replicates per condition. The sequence reads that passed quality filters were analyzed with TopHat and Cufflinks. Validation of induced / silenced genes was performed by western blot. Results show a differential impact of RAB7 expression in the transcriptomic profile of melanoma vs non-melanoma cell lines, and support a lineage-specific role of this small GTPase in melanoma. Overall design: Examination of the mRNA profiles RAB7-depleted vs wild type cells, performed in parallel in 3 different tumor cell lines (Melanomas: SK-Mel-28 and UACC-62, Non-melanoma: HCT-116) harvested at day 3 after lentiviral infection.
RAB7 controls melanoma progression by exploiting a lineage-specific wiring of the endolysosomal pathway.
Cell line, Treatment, Subject, Time
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