Eicosapentaenoic acid in its free fatty acid form (EPA-FFA), 2g daily, is safe and well-tolerated in patients undergoing liver resection surgery for colorectal liver metastasis.Oral EPA incorporates into colorectal liver metastasis tissue. EPA-FFA treatment is associated with reduced vascularity of liver metastases in -3 PUFA-nave patients. Preoperative (median 30 days) EPA-FFA treatment may have prolonged benefit on postoperative overall and disease-free survival.
Anticolorectal cancer activity of the omega-3 polyunsaturated fatty acid eicosapentaenoic acid.
Specimen part, Treatment
View SamplesCdc34 is an essential E2 ubiquitin conjugating enzyme found in nearly all eukaryotes. It contains a highly conserved motif composed of S73/S97/12 amino acid insert near the active site cysteine. This motif is unique to Cdc34/Ubc7 type E2s while other E2s contain K/D/no insert at these positions. To better understand the function of this motif we mutated Cdc34 S73/S97/insert to be K/D/no insert and observed changes in transcript levels in mid-log phase yeast cells. ABSTRACT [Cdc34 is a ubiquitin conjugating enzyme necessary for the ubiquitylation of substrates by the SCF family of ubiquitin ligases. Previous work has shown that the Cdc34 protein is phosphorylated in vivo on serine residues. Cdc34 contains two serines within its catalytic domain, S73 and S97, that together with a 12 amino acid acidic loop, constitute a highly conserved motif (serine, serine, insert) among all members of the Cdc34 family of E2 enzymes. Using phosphospecific antibodies, we show that the essential serine S97 is indeed phosphorylated in vivo. Furthermore, this phosphorylation event is regulated by treatment with pheromone in yeast. Consistently, expression of a Cdc34 mutant lacking this motif (serine, serine, insert) leads to misregulation of the SCF substrates, Sic1, Far1, Cln1 and Cln2 and suppresses the cell cycle arrest brought about by an activated mating pathway. We further explored the function of this motif by microarray analysis and show that the transcripts of nearly the entire Sic1 cluster of co-transcribed genes is altered in a strain the expresses Cdc34 lacking this motif. Our data reveals that this highly conserved motif in Cdc34 and its phosphorylation are important for modulating SCF substrate abundance both transcriptionally and post-transcriptionally.]
New insight into the role of the Cdc34 ubiquitin-conjugating enzyme in cell cycle regulation via Ace2 and Sic1.
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View SamplesWe previously identified the ZTRE in genes involved in zinc homeostasis and showed that it mediates transcriptional repression in response to zinc. We now report that ZNF658 acts at the ZTRE. ZNF658 was identified by MALDI-TOF mass spectrometry of a band excised after EMSA using a ZTRE probe. The protein contains a KRAB domain and 21 zinc fingers. It has similarity with ZAP1 from Saccharomyces cerevisiae, which regulates the response to zinc restriction, including a conserved DNA binding region we show to be functional also in ZNF658. siRNA targeted to ZNF658 abrogated the zinc-induced, ZTRE-dependent reduction in SLC30A5 (ZnT5), SLC30A10 (ZnT10) and CBWD transcripts in human Caco-2 cells and the ability of zinc to repress reporter gene expression from corresponding promoter-reporter constructs. Microarray analysis of the effect of reducing ZNF658 expression by siRNA uncovered large changes in rRNA. We find that ZTREs are clustered within the 45S rRNA precursor. We also saw effects on expression of multiple ribosomal proteins. ZNF658 thus links zinc homeostasis with ribosome biogenesis, the most active transcriptional, and hence zinc-demanding, process in the cell. ZNF658 is thus a novel transcriptional regulator that plays a fundamental role in the orchestrated cellular response to zinc availability.
The zinc finger protein ZNF658 regulates the transcription of genes involved in zinc homeostasis and affects ribosome biogenesis through the zinc transcriptional regulatory element.
Cell line
View SamplesBackground: Eukaryotic cells express a complex layer of noncoding RNAs. An intriguing family of regulatory RNAs includes transcripts from the opposite strand of protein coding genes, so called natural antisense transcripts (NATs). Here, we test the hypothesis that antisense transcription triggers RNA interference and gives rise to endogenous short RNAs (endo-siRNAs). Methods/Results: We used cloned human embryonic kidney cells (HEK293) followed by short RNAseq to investigate the small genic RNA transcriptome. 378 genes gave rise to short RNA reads that mapped to exons of RefSeq genes. The length profile of short RNAs showed a broad peak of 20-24 nucleotides, indicative of endo-siRNAs. Collapsed reads mapped predominantly to the first and the last exon of genes (74%). RNAs reads were intersected with sequences occupied by RNAPolII or bound to Argonaute (AGO1 by crosslinking, ligation, and sequencing of hybrids, CLASH). In the first exon, 94% of the reads correlated with PolII occupancy with an average density of 130 (relative units); this decreased to 65%/20 in middle exons and 54%/12 in the last exon. CLASH reads mapping to multi-exon genes showed little distribution bias with an average of about 5 CLASH reads overlapping with 60% of the endo-siRNA reads. However, endo-siRNAs (21-25 nt) intersecting with CLASH reads were enriched at the 5''end and decreased towards the 3''end. We then investigated the 378 genes with particular focus on features indicative for short RNA production; however, found that endo-siRNA numbers did not correlate with gene structures that favor convergent transcription. In contrast, our gene set was found notably over-represented in the NATsDB sense/antisense group as compared to non-overlapping and non-bidirectional groups. Moreover, read counts showed no correlation with the steady-state levels of the related mRNAs and the pattern of endo-siRNAs proved reproducible after an induced mutagenic insult. Conclusions: Our results suggest that antisense transcripts contribute to low levels of endo-siRNAs in fully differentiated human cells. A characteristic endo-siRNA footprint is being produced at sites of RNAPolII transcription which is also related to AGO1. This endo-siRNA signature represents an intriguing finding and its reproducibility suggests that the production of endo-siRNAs is a regulated process with potential homoeostatic impact. Overall design: Size selected RNASeq of 3 human embryonic kidney cell (HEK293) samples. 1 control and 2 samples exposed to 100 µg/ml ethyl methanesulfonate for 24 hrs.
Contribution of natural antisense transcription to an endogenous siRNA signature in human cells.
No sample metadata fields
View SamplesThe rapid improvements in single cell sequencing technologies and analyses methods afford greater scope for dissecting organoid cultures composed of multiple cell types and create an opportunity to interrogate these models to understand tissue biology, cellular behaviour and interactions. To this end, retinal organoids generated from human embryonic stem cells (hESCs) were analysed by single cell RNA-Sequencing at three time points of differentiation. Combinatorial data from all time points revealed the presence of nine clusters, five of which corresponded to key retinal cell types, namely retinal pigment epithelium (RPE), retinal ganglion cells (RGCs), cone and rod photoreceptors and Müller glia cells. The remaining four clusters expressed genes typical of mitotic cells, extracellular matrix (ECM) components and those involved in retinal homeostasis. The cell clustering analysis revealed the decreasing presence of mitotic cells and RGCs, formation of a distinct RPE cluster, the emergence of cone and rod photoreceptors from photoreceptor precursors and an increasing number of Müller Glia cells over time. The pseudotime analysis resembled the order of cell birth during retinal development, with the mitotic cluster commencing the trajectory and the large majority of Müller glia being the latest. Together, these data demonstrate the feasibility and potential of single cell RNA-Seq to dissect the inherent complexity of the organoids and the orderly birth of key retinal cell types. Overall design: A hESC (H9) cell line harbouring a CRX-GFP reporter was differentiated to retinal organoids 25. Samples were collected at 60, 90 and 200 days, dissociated, partitioned into single cells using the Fluidigm C1 Single-Cell mRNA-Seq HT IFC and processed for scRNA-Seq.
Deconstructing Retinal Organoids: Single Cell RNA-Seq Reveals the Cellular Components of Human Pluripotent Stem Cell-Derived Retina.
Cell line, Subject, Time
View SamplesLong terminal repeat (LTR) elements are wide-spread in the human genome and have the potential to act as promoters and enhancers. Their expression is therefore under tight epigenetic control. We previously reported that a member of the THE1B class of LTR elements in classical Hodgkin Lymphoma (cHL) acted as a promoter for the growth factor receptor gene CSF1R and that expression of this gene is required for tumor survival. However, to which extent and how such elements participate in globally shaping the unique cHL gene expression program is unknown. To address this question we mapped the genome-wide activation of THE1-LTRs in cHL cells using a targeted next generation sequencing approach (RACE-Seq). Integration of these data with global gene expression data from cHL and control B cell lines showed a unique pattern of LTR activation impacting on gene expression, including genes associated with the cHL phenotype. We also show that global LTR activation is induced by strong inflammatory stimuli. Together these results demonstrate that LTR activation provides an additional layer of gene deregulation in classical Hodgkin lymphoma and highlight the potential impact of genome-wide LTR activation in other inflammatory diseases. Overall design: RNA-Seq in laser capture microdissected (LCM) tumour (TU) and non tumour cells (NTC) primary HL material from patient samples
Global long terminal repeat activation participates in establishing the unique gene expression programme of classical Hodgkin lymphoma.
Specimen part, Subject
View SamplesThe ovine Callipyge mutation causes postnatal muscle hypertrophy localized to the pelvic limbs and torso, as well as body leanness. The mechanism underpinning enhanced muscle mass is unclear, as is the systemic impact of the mutation. Using muscle fibre typing immunohistochemistry we confirmed muscle specific effects and demonstrated that affected muscles had greater prevalence and hypertrophy of type 2X fast twitch glycolytic fibres and decreased representation of types 1, 2C, 2A and/or 2AX fibres. To investigate potential systemic effects of the mutation, proton NMR spectra of plasma taken from lambs at 8 and 12 weeks of age were measured. Multivariate statistical analysis of plasma metabolite profiles demonstrated effects of development and genotype but not gender. Plasma from Callipyge lambs at 12 weeks of age, but not 8 weeks, was characterized by a metabolic profile consistent with contributions from the affected hypertrophic fast twitch glycolytic muscle fibres. Microarray analysis of the perirenal adipose tissue depot did not reveal a transcriptional effect of the mutation in this tissue. We conclude that there is an indirect systemic effect of the Callipyge mutation in skeletal muscle in the form of changes of blood metabolites, which may contribute to secondary phenotypes such as body leanness.
Impacts of the Callipyge mutation on ovine plasma metabolites and muscle fibre type.
Specimen part
View SamplesExpression data from Sheep longissimus dorsi (LD) muscle during development; fetal lambs (80, 100, 120 days gestation), new born lambs at birth (150 d) and lambs at 12 weeks (230 d)
A gene network switch enhances the oxidative capacity of ovine skeletal muscle during late fetal development.
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View SamplesLambs that inherit a callipyge allele from their dam have an up-regulation of maternally imprinted transcripts near the callipyge mutation but do not exhibit muscle hypertrophy. It is not clear what effects these maternally expressed transcripts have in the muscle or how the inheritance of a maternal callipyge allele prevents the expression of the callipyge phenotype which is seen paternal heterozygotes only.
Effect of DLK1 and RTL1 but not MEG3 or MEG8 on muscle gene expression in Callipyge lambs.
No sample metadata fields
View SamplesRUNX1 is a frequent target of translocations in acute myeloid leukemia whereby its DNA binding domain fuses to different epigenetic regulators. To assess how different RUNX1 fusion proteins interact with the epigenome we compared the global binding patterns and the chromatin landscape of t(8;21) and t(3;21) AML which express RUNX1-ETO and RUNX1-EVI-1, respectively. We found that differential prognosis for these types of AML is reflected in fundamental differences in gene expression, chromatin landscape, binding patterns of the fusion proteins and other transcription factors as identified by genome-wide digital footprinting in patients. As previously shown for RUNX1-ETO, knockdown of RUNX1-EVI-1 expression initiates differentiation of t(3;21) cells which is associated with up-regulation of genes vital for myeloid differentiation, including C/EBPa. Furthermore, by expressing either dominant-negative C/EBP or an inducible C/EBPa construct in t(3;21) cells we show that C/EBPa is necessary and sufficient for the differentiation response of these cells to RUNX1-EVI-1 knockdown. Overall design: RNA-seq expreiments have been used to study the chromatin landscape of t(8;21) and t(3;21) AML
RUNX1-ETO and RUNX1-EVI1 Differentially Reprogram the Chromatin Landscape in t(8;21) and t(3;21) AML.
Specimen part, Subject
View Samples