Epigenetic events, including covalent post-translational modification of histones, have frequently been demonstrated to play critical roles in tumor development and progression. The transcriptional coactivator, p300/CBP, possesses both histone acetyltransferase (HAT) activity as well as scaffolding properties that directly influence transcriptional activation of targeted genes. We have used a recently reported small molecule inhibitor of p300 HAT activity, C646, to explore the specific contribution of p300/CBP HAT activity to tumor development and progression. We find that C646 inhibits the growth of lineage-specific tumor cell lines including human melanomas through direct transcriptional regulation of cell cycle regulatory proteins. Further evaluation of the p300 HAT transcriptome in human melanoma cells using comprehensive gene expression profiling reveals that p300 HAT activity globally promotes cell cycle progression, nucleosome assembly, and the DNA damage checkpoint through direct transcriptional regulatory mechanisms. Additionally, C646 promotes sensitivity to DNA damaging agents leading to enhanced apoptosis of melanoma cells following combination treatment with cisplatin. Together our data suggest that p300 HAT activity regulates critical growth regulatory pathways in tumors and may serve as a novel therapeutic target for melanoma and other malignancies by promoting cellular responses to DNA damaging agents.
Selective inhibition of p300 HAT blocks cell cycle progression, induces cellular senescence, and inhibits the DNA damage response in melanoma cells.
Cell line, Treatment, Time
View SamplesGraft versus host disease (GVHD) is the most common complication of hematopoietic stem cell transplant (HCT). However, our understanding of the molecular pathways that cause this disease remains incomplete, leading to inadequate treatment strategies. To address this, we measured the gene expression profile of non-human primate (NHP) T cells during acute GVHD. In this study we specifically interrogated the transcriptional signatures of animals treated with FR104 monotherapy and FR104/Sirolimus combination therapy
Combined OX40L and mTOR blockade controls effector T cell activation while preserving T<sub>reg</sub> reconstitution after transplant.
Specimen part, Subject
View SamplesGraft versus host disease (GVHD) is the most common complication of hematopoietic stem cell transplant (HCT). However, our understanding of the molecular pathways that cause this disease remains incomplete, leading to inadequate treatment strategies. To address this, we measured the gene expression profile of non-human primate (NHP) T cells during acute GVHD. In this study we specifically interrogated the transcriptional signatures of animals treated with KY1005 monotherapy and KY1005/Sirolimus combination therapy
Combined OX40L and mTOR blockade controls effector T cell activation while preserving T<sub>reg</sub> reconstitution after transplant.
No sample metadata fields
View SamplesNotch signaling is widely implicated in mouse mammary gland development and tumorigenesis. To investigate the effects of acute activation of Notch signaling in the mammary epithelial compartment, we generated bi-transgenic MMTV-rtTA; TetO-NICD1 (MTB/TICNX) mice that conditionally express a constitutively active NOTCH1 intracellular domain (NICD1) construct in the mammary epithelium upon doxycycline administration.
Notch promotes recurrence of dormant tumor cells following HER2/neu-targeted therapy.
Sex, Age, Specimen part, Treatment, Time
View SamplesWe compare the transcriptome of two different clones of multipotent adult progenitor cells (MAPCs) using Affymetrix arrays.
Hematopoietic reconstitution by multipotent adult progenitor cells: precursors to long-term hematopoietic stem cells.
No sample metadata fields
View SamplesPotassium is one of the essential macronutrients required for plant growth and development. It plays a major role in different physiological processes like cell elongation, stomatal movement, turgor regulation, osmotic adjustment, and signal transduction by acting as a major osmolyte and component of the ionic environment in the cytosol and subcellular organelles.
Gene expression analysis of rice seedling under potassium deprivation reveals major changes in metabolism and signaling components.
Specimen part, Treatment, Time
View SamplesEpigenetic regulation of gene expression by histone modification has emerged as a major facet of physiologic and disease processes. As a result, there has been intense interest in developing epigenetic therapies leading to the discovery of small molecule agents that target proteins involved in histone modification. Several histone deacetylase (HDAC) inhibitors are now approved drugs for a specialized group of hematologic malignancies but not yet for a wider range of cancer types including solid tumors. One of the conceptual challenges in targeting HDACs is that even selective class I HDAC inhibitors likely impact these deacetylase activities indiscriminately across a range of distinct HDAC-containing multiprotein complexes. Such broad cellular effects may result in a narrow therapeutic window between disease efficacy and toxicity. Among HDAC complexes, the CoREST complex, which includes HDAC1 or its close paralog HDAC2, the scaffolding protein CoREST, and lysine specific demethylase 1 (LSD1) has attracted special interest. Here we report corin2, designed to dually inhibit the CoREST complex major enzymatic activities, lysine specific demethylase 1 (LSD1) and HDACs 1/2. Corin2 is a synthetic hybrid agent derived from the class I HDAC inhibitor (entinostat) and an LSD1 inhibitor (tranylcypromine analog). Enzymologic analysis reveals that corin2 selectively targets the CoREST complex and shows more sustained inhibition of the CoREST complex HDAC activity than entinostat. Cell-based experiments demonstrate that corin2 exhibits a superior anti-proliferative profile against several melanoma lines compared to its parent monofunctional HDAC and LSD1 inhibitors (alone or in combination) but is less toxic to non-cancerous primary human melanocytes. Transcriptomics analysis shows that corin2 is a more powerful inducer of tumor suppressor genes relative to the parent HDAC and LSD1 compounds (alone or in combination). Genetic knockdown of CoREST or LSD1 in cancer cell lines abolishes the differences in potency of corin2 vs. entinostat, suggesting that corin2's favorable pharmacologic effects rely on an intact CoREST complex. Corin2 was also effective in slowing tumor growth in a melanoma mouse xenograft model. These studies highlight the promise of a new class of two-pronged hybrid agents that selectively target particular epigenetic regulatory complexes and offer unique therapeutic opportunities.
Targeting the CoREST complex with dual histone deacetylase and demethylase inhibitors.
Cell line
View SamplesIL-10 regulates anti-inflammatory signaling via the activation of STAT3, which in turn controls the induction of a gene expression program whose products execute inhibitory effects on pro-inflammatory mediator production. Here we show that IL-10 induces the expression of an ETS family transcriptional repressor, ETV3 and a helicase family co-repressor, SBNO2 (Strawberry notch homolog 2) in mouse and human macrophages. IL-10-mediated induction of ETV3 and SBNO2 expression was dependent upon both STAT3, and co-stimulus through the TLR pathway. We also observed that ETV3 expression was strongly induced by the STAT3 pathway induced by IL-10 but not STAT3 signaling activated by IL-6, which cannot activate the anti-inflammatory signaling pathway. ETV3 and SBNO2 specifically repressed NF-kB-mediated transcription and can physically interact. Collectively our data suggest that ETV3 and SBNO2 are components of the pathways that contribute to the downstream anti-inflammatory effects of IL-10.
Cutting edge: A transcriptional repressor and corepressor induced by the STAT3-regulated anti-inflammatory signaling pathway.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Knockout of G protein β5 impairs brain development and causes multiple neurologic abnormalities in mice.
Specimen part
View SamplesGb5 is a divergent, evolutionarily-conserved, member of the heterotrimeric G protein b subunit family that is expressed principally in brain and neuronal tissue. Among Gb isoforms, Gb5 is unique in its ability to heterodimerize with members of the R7 subfamily of the regulator of G protein signaling (RGS) proteins that contain G protein-g like (GGL) domains. Previous studies employing Gb5 knockout mice have shown that Gb5 is an essential stabilizer of GGL domain-containing RGS proteins and regulates the deactivation of retinal phototransduction and the proper functioning of retinal bipolar cells. The purpose of this study is to better understand the functions of Gb5 in the brain outside the visual system by employing molecular biology, immunohistochemistry and confocal imaging technologies. We show here that mice lacking Gb5 have a markedly abnormal neurologic phenotype that includes neurobehavioral developmental delay, wide-based gait, motor learning and coordination deficiencies, and hyperactivity. Using immunohistochemical analysis and a green fluorescent reporter of Purkinje cell maturation we show that the phenotype of Gb5-deficient mice includes, in part, delayed development of the cerebellar cortex, an abnormality that likely contributes to the neurobehavioral phenotype. Multiple neuronally-expressed genes are dysregulated in non-cerebellar portion of Gb5 KO mice.
Knockout of G protein β5 impairs brain development and causes multiple neurologic abnormalities in mice.
Specimen part
View Samples