RAS oncogenic mutations are common in human cancers, but RAS proteins have been difficult to target. We sought to identify pharmacological agents to block the RAS oncogenic signaling by a distinct mechanism. Since the biological activity of RAS proteins rely upon lipid modifications and RAS regulates lipid metabolisms in cancer cells, we screened a bioactive lipid library using a RAS specific cell viability assay. We report the discovery of a new class of inhibitors for RAS transformation. Compounds in the class represented by endocannabinoid N-arachidonoyl dopamine (NADA) can induce cell oncosis, independent of its ability to engage cannabinoid receptors. Further analyses show that NADA is more active in inhibiting the NRAS transformation and signaling than that of KRAS4B. Mechanistically, NADA blocks the plasma membrane translocation of NRAS, but not that of KRAS4B. In addition, NADA inhibits the plasma membrane translocation and neoplastic transformation of oncogenic KRAS4A. Interestingly, NADA also redistributes the cytoplasmic NRAS to the Golgi apparatus in a palmitoylation-dependent manner. The results indicate that NADA inhibits NRAS and KRAS4A plasma membrane translocation by targeting a novel molecular process. The new findings would help to develop novel targeted therapies for a broad range of human cancers.
N-Arachidonoyl Dopamine Inhibits NRAS Neoplastic Transformation by Suppressing Its Plasma Membrane Translocation.
No sample metadata fields
View SamplesNeutrophil activation plays a critical role in the inflammatory response to gram-negative bacterial infections. Lipopolysaccharide (LPS) from gram-negative bacterial has been shown to be a major mediator of neutrophil activation to produce pro-inflammatory cytokines, chemokines and ROS which are important to tissue damage in LPS induced septic shock.
No associated publication
Age, Specimen part
View SamplesThe activation of different oncogenic signals may primarily contribute to the heterogeneity of cancer cells. However, the exact mechanisms underlying different oncogenic transformation are still unclear. We used the c-Myc, H-Ras and Akt transformed liver cell model to define mRNA expression profiles in the non-transformed and the three types of oncogene-transformed cells
No associated publication
No sample metadata fields
View SamplesZygotic genome activation (ZGA), which is according to the midblastula transition in zebrafish, is an important event during the maternal-zygotic transition in animals. Our preliminary study and other groups works indicate that epigenetic regulations play an essential role in ZGA.
Protein Arginine Methyltransferase 6 (Prmt6) Is Essential for Early Zebrafish Development through the Direct Suppression of gadd45αa Stress Sensor Gene.
Age, Specimen part
View SamplesThe serine threonine kinase Stk40 has been shown to involve in mouse embryonic stem cell differentiation, pulmonary maturation and adipocyte differentiation. Here we report that targeted deletion of Stk40 leads to fetal liver hypoplasia and anemia in the mouse embryos. The reduction of erythrocytes in the fetal liver is accompanied by increased apoptosis and compromised erythroid maturation. Stk40-/- fetal liver cells have significantly reduced colony forming units (CFUs) capable of erythroid differentiation, including burst forming unit-erythroid (BFU-E), colony forming unit-erythroid (CFU-E), and CFU-granulocyte, erythrocyte, megakaryocyte and macrophage (CFU-GEMM), but not CFU-granulocyte/macrophages (CFU-GM). Purified Stk40-/- megakaryocyte-erythrocyte progenitors (MEPs) produced substantially fewer CFU-E colonies compared to control cells. Moreover, Stk40-/- fetal liver erythroblasts failed to form normal erythroblastic islands in association with wild type or Stk40-/- macrophages, indicating an intrinsic defect of Stk40-/- erythroblasts. Furthermore, the hematopoietic stem and progenitor cell pool is reduced in Stk40-/- fetal livers but still retains the multi-lineage reconstitution capacity. Finally, analysis of microarray data of E14.5 fetal liver cells suggests a potential role of aberrantly activated TNF- signaling in Stk40 depletion induced dyserythropoiesis with a concomitant increase in cleaved Caspase-3 and decrease in Gata1 proteins. Altogether, the identification of Stk40 as a regulator for fetal erythroid differentiation, maturation and survival provides new clues to the molecular regulation of erythropoiesis and related diseases.
No associated publication
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
No associated publication
Specimen part, Cell line, Treatment
View SamplesInduced pluripotent stem (iPS) cells were produced from reprogramming of somatic cells, and they are shown to possess pluripotent properties similar to embryonic stem (ES) cells. Here we used microarrays to detail the global expression pattern among the ES cells and iPS cells, as well as the original mouse embryo fibroblast (MEF), to identify important players involved in the reprogramming process.
iPS cells produce viable mice through tetraploid complementation.
Specimen part, Cell line
View SamplesDNA methylation of C5-cytosine (5mC) in the mammalian genome is a key epigenetic event that is critical for various cellular processes. However, how the genome-wide 5mC pattern is dynamically regulated remains a fundamental question in epigenetic biology. The TET family of 5mC hydroxylases, which convert 5mC to 5-hydroxymethylcytosine (5hmC), have provided a new potential mechanism for the dynamic regulation of DNA methylation. The extent to which individual Tet family members contribute to the genome-wide 5mC and 5hmC patterns and associated gene network remains largely unknown. Here we report genome-wide mapping of Tet1 and 5hmC in mESCs and reveal a mechanism of action by which Tet1 controls 5hmC and 5mC levels in mESCs. In combination with microarray and mRNA-seq expression profiling, we identify a comprehensive yet intricate gene network influenced by Tet1. We propose a model whereby Tet1 controls DNA methylation both by binding to CpG-rich regions to prevent unwanted DNA methyltransferase activity, and by converting the existing 5mC to 5hmC through its enzymatic activity. This Tet1-mediated antagonism of CpG methylation imparts differential maintenance of DNA methylation status at Tet1 target loci, thereby providing a new regulatory mechanism for establishing the epigenetic landscape of mESCs, which ultimately contributes to mESC differentiation and the onset of embryonic development.
Genome-wide regulation of 5hmC, 5mC, and gene expression by Tet1 hydroxylase in mouse embryonic stem cells.
Specimen part, Treatment
View SamplesTrophoblast lineages, as the precursor of placenta, are essential for post-implantation embryo survival. However, the regulatory networks for trophoblast development remains incompletely understood. Here, we identified CITED1 as a regulator to induce trophoblast-like differentiation from mESCs. Overexpression of CITED1 in ESCs prompted differentiation towards trophoblast accompanying with elevated expression of trophoblast marker genes. To evaluate the ability of CITED1 to induce trophoblast differentiation at a genome-wide scale, we compared the global transcriptional profiles between CITED1 overexpressing cells and control ESCs by Affymetrix microarray analysis at day 1 and day 2 after transfection.
No associated publication
Specimen part, Cell line
View SamplesThe protein level of OCT4, a core pluripotency transcriptional factor, is vital for embryonic stem cell (ESC) maintenance, differentiation and somatic cell reprogramming. Although OCT4 protein is regulated at multiple scales, the role and regulatory mechanisms of OCT4 ubiquitination in reprogramming remains elusive. We identified the five lysine residues as ubiquitination sites on OCT4, and found that destruction of the ubiquitination can enhance OCT4 activity in reprogramming.
No associated publication
Specimen part
View Samples