Current models imply that the FERM domain protein Merlin, encoded by the tumor suppressor NF2, inhibits mitogenic signaling at or near the plasma membrane. Here, we show that the closed, growth inhibitory form of Merlin accumulates in the nucleus, binds to the E3 ubiquitin ligase CRL4DCAF1, and suppresses its activity. Depletion of DCAF1 blocks the promitogenic effect of inactivation of Merlin. Conversely, enforced expression of a Merlin-insensitive mutant of DCAF1 counteracts the antimitogenic effect of Merlin. Re-expression of Merlin and silencing of DCAF1 induce a similar, tumor-suppressive program of gene expression. Tumor-derived mutations invariably disrupt Merlins ability to interact with or inhibit CRL4DCAF1. Finally, depletion of DCAF1 inhibits the hyperproliferation of Schwannoma cells from NF2 patients and suppresses the oncogenic potential of Merlin-deficient tumor cell lines. We propose that Merlin suppresses tumorigenesis by translocating to the nucleus to inhibit CRL4DCAF1.
Merlin/NF2 suppresses tumorigenesis by inhibiting the E3 ubiquitin ligase CRL4(DCAF1) in the nucleus.
Specimen part
View SamplesWe report the effect of DKK1 treatment during culture on the length and transcriptome of embryos on day 15 of development, supporting the notion that changes early in development affect later stages of development. Overall design: Bovine embryos were produced in vitro and exposed to either 0 or 100 ng/ml DKK1 from day 5 to 7 of culture. Embryos were transferred on day 7 and recovered on day 15 for evaluation of length and transciptome
Dickkopf-related protein 1 is a progestomedin acting on the bovine embryo during the morula-to-blastocyst transition to program trophoblast elongation.
Treatment, Subject
View SamplesBackground & Aims: Ursodeoxycholic acid (UDCA) attenuates chemical and colitis-induced colon carcinogenesis in animal models. We investigated its mechanism of action on normal intestinal cells, in which carcinogenesis- or inflammation-related alterations do not interfere with the result. Methods: Alterations of gene expression were identified in Affymetrix arrays in isolated colon epithelium of mice fed with a diet containing 0.4% UDCA and were confirmed in the normal rat intestinal cell line IEC-6 by RT-PCR. The effect of the insulin receptor substrate 1 (Irs-1) expression and of ERK phosphorylation on proliferation was investigated in vitro by flow cytometry, western blotting, siRNA-mediated gene suppression or by pharmacological inhibition of the kinase activity. The ERK1-effect on Irs-1 transcription was tested in a reporter system. Results: UDCA-treatment in vivo suppressed potential pro-proliferatory genes including Irs-1 and reduced cell proliferation by more than 30%. In vitro it neutralised the proliferatory signals of IGF-1 and EGF and slowed down the cell cycle. Irs-1 transcription was suppressed due to high ERK1 activation. Both Irs-1 suppression and the persistent high ERK activation inhibited proliferation. Conversely, the decrease of phosphorylation of ERK1 (but not ERK2) or of its expression partially abrogated the inhibitory effects of UDCA. Conclusions: UDCA inhibits proliferation of intestinal epithelial cells by acting upon IGF-1 and EGF pathways and targeting ERK1 and, consequently, Irs-1. The inhibition of these pathways adds a new dimension to the physiological and therapeutic action of UDCA and, since both pathways are activated in inflammation and cancer, suggests new applications of UDCA in chemoprevention and chemotherapy.
UDCA slows down intestinal cell proliferation by inducing high and sustained ERK phosphorylation.
Specimen part, Cell line
View SamplesOxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major medical problem, and predictive markers are urgently needed. Recently, miR-625-3p was reported as a promising predictive marker. Here, we have used in vitro models to show that miR-625-3p functionally induces oxPt resistance in CRC cells, and have identified signalling networks affected by miR-625-3p. The p38 MAPK activator MAP2K6 was shown to be a direct target of miR-625-3p, and, accordingly, was downregulated in patients not responding to oxPt therapy. miR-625-3p resistance could be reversed in CRC cells by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. In addition, by reducing p38 MAPK signalling using either siRNA technology, chemical inhibitors to p38 or by ectopic expression of dominant negative MAP2K6 protein we induced resistance to oxPt. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signalling as one likely mechanism a possible driving force behind of oxPt resistance. Our study shows that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks, and corroborates the predictive power of miR-625-3p
miR-625-3p regulates oxaliplatin resistance by targeting MAP2K6-p38 signalling in human colorectal adenocarcinoma cells.
Subject
View SamplesPentoxifylline attenuated hypertrophic scars by influencing the cell cycles Overall design: mRNA profiles of control hypertrophic scar fibroblasts and pentoxifylline treated cells were generated by deep sequencing, in triplicate, using Ion Proton.
The Akt/FoxO/p27<sup>Kip1</sup> axis contributes to the anti-proliferation of pentoxifylline in hypertrophic scars.
Specimen part, Treatment, Subject
View SamplesGenome-wide studies have identified abundant small, non-coding RNAs including snRNAs, snoRNAs, cryptic unstable transcripts (CUTs), and upstream regulatory RNAs (uRNAs) that are transcribed by RNA polymerase II (pol II) and terminated by a Nrd1-dependent pathway. Here, we show that the prolyl isomerase, Ess1, is required for Nrd1-dependent termination of ncRNAs. Ess1 binds the carboxy terminal domain (CTD) of pol II and is thought to regulate transcription by conformational isomerization of Ser-Pro bonds within the CTD. In ess1 mutants, expression of ~10% of the genome was altered, due primarily to defects in termination of snoRNAs, CUTs, SUTs and uRNAs. Ess1 promoted dephosphorylation of Ser5 (but not Ser2) within the CTD, most likely by the Ssu72 phosphatase, and we provide evidence for a competition between Nrd1 and Pcf11 for CTD-binding that is regulated by Ess1-dependent isomerization. This is the first example of a prolyl isomerase required for interpreting the CTD code.
The Ess1 prolyl isomerase is required for transcription termination of small noncoding RNAs via the Nrd1 pathway.
No sample metadata fields
View SamplesThe response to the presence of the ncpBVDV-infected PI or TI fetus is expected to provide information on the impact of the PI fetus on the immune response of the dam
Persistent fetal infection with bovine viral diarrhea virus differentially affects maternal blood cell signal transduction pathways.
No sample metadata fields
View SamplesSalmonella enterica serotype Typhimurium causes an acute inflammatory reaction in the cecum of streptomycin pre-treated mice. We determined global changes in gene expression elicited by serotype Typhimurium in the cecal mucosa. The gene expression profile was dominated by T cell derived cytokines and genes whose expression is known to be induced by these cytokines. Markedly increased mRNA levels of interferon (IFN-gamma), interleukin-22 (IL-22) and IL-17 were detected by quantitative real-time PCR. Furthermore, mRNA levels of genes whose expression is induced by IFN-gamma, IL-22 or IL-17, including macrophage inflammatory protein 2 (MIP-2), inducible nitric oxide synthase (Nos2), lipocalin-2, MIP-1alpha, MIP-1beta, and keratinocyte-derived cytokine (KC), were also markedly increased. To assess the importance of T cells in orchestrating this pro-inflammatory gene expression profile, we depleted T cells using a monoclonal antibody prior to investigating cecal inflammation caused by serotype Typhimurium in streptomycin pre-treated mice. Depletion of CD3+ T cells resulted in a dramatic reduction in gross pathology, a significantly reduced recruitment of neutrophils and a marked reduction in mRNA levels of IFN-gamma, IL-22, IL-17, iNOS, lipocalin-2 and KC. Our results suggest that T cells play an important role in amplifying inflammatory responses induced by serotype Typhimurium in the cecal mucosa.
T cells help to amplify inflammatory responses induced by Salmonella enterica serotype Typhimurium in the intestinal mucosa.
No sample metadata fields
View SamplesSUMMARY: This article presents a predictive molecular signature that marks the early onset of fibrosis in a translational nonalcoholic steatohepatitis mouse model. Overlap of genes and processes with human nonalcoholic steatohepatitis and a list of top candidate biomarkers for early fibrosis are described. BACKGROUND & AIMS: The incidence of nonalcoholic steatohepatitis (NASH) is increasing. The pathophysiological mechanisms of NASH and the sequence of events leading to hepatic fibrosis are incompletely understood. The aim of this study was to gain insight into the dynamics of key molecular processes involved in NASH and to rank early markers for hepatic fibrosis. METHODS: A time-course study in low-density lipoprotein–receptor knockout. Leiden mice on a high-fat diet was performed to identify the temporal dynamics of key processes contributing to NASH and fibrosis. An integrative systems biology approach was used to elucidate candidate markers linked to the active fibrosis process by combining transcriptomics, dynamic proteomics, and histopathology. The translational value of these findings were confirmed using human NASH data sets. RESULTS: High-fat-diet feeding resulted in obesity, hyperlipidemia, insulin resistance, and NASH with fibrosis in a time-dependent manner. Temporal dynamics of key molecular processes involved in the development of NASH were identified, including lipid metabolism, inflammation, oxidative stress, and fibrosis. A data-integrative approach enabled identification of the active fibrotic process preceding histopathologic detection using a novel molecular fibrosis signature. Human studies were used to identify overlap of genes and processes and to perform a network biology-based prioritization to rank top candidate markers representing the early manifestation of fibrosis. CONCLUSIONS: An early predictive molecular signature was identified that marked the active profibrotic process before histopathologic fibrosis becomes manifest. Early detection of the onset of NASH and fibrosis enables identification of novel blood-based biomarkers to stratify patients at risk, development of new therapeutics, and help shorten (pre)clinical experimental time frames. Keywords: Systems Biology; Metabolic Syndrome; Liver Disease; Diagnosis. Overall design: In total 9 treatment groups: 5 Control groups (chow = standard diet; t=0, 6, 12, 18, 24 weeks), 4 Treatment groups (HFD = High Fat diet; 6, 12, 18, 24 weeks).
Uncovering a Predictive Molecular Signature for the Onset of NASH-Related Fibrosis in a Translational NASH Mouse Model.
Specimen part, Subject
View SamplesBoar taint (BT) is an offensive odour or taste observed in pork from a proportion of non-castrated male pigs. Surgical castration is effective in avoiding BT, but animal welfare issues have created an incentive for alternatives such as genomic selection. In order to find candidate biomarkers, gene expression profiles were analysed from tissues of non-castrated pigs grouped by their genetic merit of BT. Differential expression analysis revealed substantial changes with log-transformed fold changes of liver and testis from -3.39 to 2.96 and -7.51 to 3.53, respectively. Co-expression network analysis revealed one module with a correlation of -0.27 in liver and three modules with correlations of 0.31, -0.44 and -0.49 in testis. Differential expression and co-expression analysis revealed candidate biomarkers with varying biological functions: phase I (COQ3, COX6C, CYP2J2, CYP2B6, ACOX2) and phase II metabolism (GSTO1, GSR, FMO3) of skatole and androstenone in liver to steroidgenesis (HSD17B7, HSD17B8, CYP27A1), regulation of steroidgenesis (STARD10, CYB5R3) and GnRH signalling (MAPK3, MAP2K2, MAP3K2) in testis. Overrepresented pathways included “Ribosome”, “Protein export” and “Oxidative phosphorylation” in liver and “Steroid hormone biosynthesis” and “Gap junction” in testis. Future work should evaluate the biomarkers in large populations to ensure their usefulness in genomic selection programs. Overall design: Total RNA was extracted from liver and testis of 48 Danish Landrace pigs with low- medium and high genetic merit of boar taint and sequenced by Illumina HiSeq 2500.
Systems genomics study reveals expression quantitative trait loci, regulator genes and pathways associated with boar taint in pigs.
Specimen part, Subject
View Samples