Search results for "Histone"
showing 10 items of 522 documents
Id2 leaves the chromatin of the E2F4–p130-controlled c-myc promoter
2006
The Id (inhibitor of DNA binding or inhibitor of differentiation) helix–loop–helix proteins are involved in the regulation of cell growth, differentiation and cancer. The fact that the molecular mechanisms of liver regeneration are not completely understood prompted us to study the fate of Id2 in proliferating liver. Id2 increases in liver regeneration after partial hepatectomy, following the early induction of its gene. Co-immunoprecipitation shows that Id2 forms a complex with E2F4, p130 and mSin3A in quiescent liver and all these components are present at the c-myc promoter as shown using ChIP (chromatin immunoprecipitation). Activation of c-myc during hepatocyte priming (G0–G1 transitio…
The dynamic properties of neuronal chromatin are modulated by triiodothyronine.
1992
The effect of triiodothyronine (T3) on the rate of synthesis of nuclear proteins was studied during terminal differentiation of rat cortical neurons cultured in a serum-free medium. To this aim total and acid soluble nuclear proteins were analyzed by different electrophoretic techniques. Our results show that: 1) during maturation in vitro, neuronal nuclei undergo a dramatic change in the rate at which different classes of histones and high mobility group (HMG) proteins are synthesized; the synthetic activity, measured as incorporation of radioactive precursors into nuclear proteins, slows indeed down with age: especially evident is the decrease in core histones synthesis; at day 15, on the…
Cigarette smoke alters the EZH2/DAB2IP expression in bronchial epithelial cells. A risk factor for lung cancer in COPD patients
2016
Cigarette smoke is an environmental risk factor for COPD and Lung cancer, leading causes of morbidity and mortality worldwide. In cancer, enhancer of zeste homolog 2 (EZH2) silenced disabled homolog 2 interacting protein gene (DAB2IP) (tumor-suppressor gene) bytri-methylation of lysine 27 on histone H3 (H3K27me3). We studied EZH2 and DAB2IP expression in airway epithelial cells from COPD patients and their potential involvement in the progression of COPD toward lung cancer. We assessed EZH2 and DAB2IPimmunoreactivity in bronchial epithelial cells from surgical specimens of COPD patients and healthy control subjects (HC) by immunohistochemistry. Bronchial epithelial cell line (16HBE), primar…
Histone deacetylase inhibition modulates deoxyribonucleotide pools and enhances the antitumor effects of the ribonucleotide reductase inhibitor 3’-C-…
2011
Histone deacetylase (HDAC) inhibitors are a new class of epigenetic agents that were reported to enhance the cytotoxic effects of classical anticancer drugs through multiple mechanisms. However, which of the possible drug combinations would be the most effective and clinically useful are to be determined. We treated the HL60 and NB4 promyelocytic leukaemia cells with a combination of the ribonucleotide reductase (RR) inhibitor 3'-C-methyladenosine (3'-Me-Ado) and several hydroxamic acid-derived HDAC inhibitors, including two recently synthesized molecules, MC1864 and MC1879, and the reference compound trichostatin A (TSA). The results showed significant growth inhibitory and apoptotic syner…
Crosstalk between leukemia-associated proteins MOZ and MLL regulates HOX gene expression in human cord blood CD34+ cells
2010
MOZ and MLL, encoding a histone acetyltransferase (HAT) and a histone methyltransferase, respectively, are targets for recurrent chromosomal translocations found in acute myeloblastic or lymphoblastic leukemia. In MOZ (MOnocytic leukemia Zinc-finger protein)/CBP- or mixed lineage leukemia (MLL)-rearranged leukemias, abnormal levels of HOX transcription factors have been found to be critical for leukemogenesis. We show that MOZ and MLL cooperate to regulate these key genes in human cord blood CD34+ cells. These chromatin-modifying enzymes interact, colocalize and functionally cooperate, and both are recruited to multiple HOX promoters. We also found that WDR5, an adaptor protein essential fo…
Whole-body pharmacokinetics of HDAC inhibitor drugs, butyric acid, valproic acid and 4-phenylbutyric acid measured with carbon-11 labeled analogs by …
2013
The fatty acids, n-butyric acid (BA), 4-phenylbutyric acid (PBA) and valproic acid (VPA, 2-propylpentanoic acid) have been used for many years in the treatment of a variety of CNS and peripheral organ diseases including cancer. New information that these drugs alter epigenetic processes through their inhibition of histone deacetylases (HDACs) has renewed interest in their biodistribution and pharmacokinetics and the relationship of these properties to their therapeutic and side effect profiles. In order to determine the pharmacokinetics and biodistribution of these drugs in primates, we synthesized their carbon-11 labeled analogues and performed dynamic positron emission tomography (PET) in…
Selective inhibition of HDAC6 regulates expression of the oncogenic driver EWSR1-FLI1 through the EWSR1 promoter in Ewing sarcoma
2021
Ewing sarcoma (EWS) is an aggressive bone and soft tissue tumor of children and young adults in which the principal driver is a fusion gene, EWSR1-FLI1. Although the essential role of EWSR1-FLI1 protein in the regulation of oncogenesis, survival, and tumor progression processes has been described in-depth, little is known about the regulation of chimeric fusion-gene expression. Here, we demonstrate that the active nuclear HDAC6 in EWS modulates the acetylation status of specificity protein 1 (SP1), consequently regulating the SP1/P300 activator complex binding to EWSR1 and EWSR1-FLI1 promoters. Selective inhibition of HDAC6 impairs binding of the activator complex SP1/P300, thereby inducing…
SAHA induces apoptosis in hepatoma cells and synergistically interacts with the proteasome inhibitor Bortezomib.
2007
Histone deacetylase (HDAC) inhibitors represent a promising group of anticancer agents. This paper shows that the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) stimulated at 5-10 microM apoptosis in human hepatoma HepG2 and Huh6 cells, but was ineffective in primary human hepatocytes (PHH). In HepG2 cells SAHA induced the extrinsic apoptotic pathway, increasing the expression of both FasL and FasL receptor and causing the activation of caspase-8. Moreover, SAHA enhanced the level of Bim proteins, stimulated alternative splicing of the Bcl-X transcript with the expression of the proapoptotic Bcl-Xs isoform, induced degradation of Bid into the apoptotic factor t-Bid and dephosphorylat…
From a Better Understanding of the Mechanisms of Action of Histone Deacetylases Inhibitors to the Progress of the Treatment of Malignant Lymphomas an…
2017
Background Notable progress has been made in chemo- and immunotherapy of B-cell lymphomas, but less in the treatment of T-cell lymphomas. Objective Histone deacetylases inhibitors are a potentially useful therapeutic mean, as an epigenetic dysregulation is present in lymphomas, and especially in T-cell types. We aimed to study the progress made in this area. Method A mini-review was achieved using the articles published in PubMed in the last two years and the new patents made in this field. Results Histone deacetylases inhibitors are involved in the derepression of tumor suppressor genes through a histone deacetylase-mediated transcriptional process. Their inhibition is followed by cell cyc…
The Compass-like Locus, Exclusive to the Ambulacrarians, Encodes a Chromatin Insulator Binding Protein in the Sea Urchin Embryo
2013
Chromatin insulators are eukaryotic genome elements that upon binding of specific proteins display barrier and/or enhancer-blocking activity. Although several insulators have been described throughout various metazoans, much less is known about proteins that mediate their functions. This article deals with the identification and functional characterization in Paracentrotus lividus of COMPASS-like (CMPl), a novel echinoderm insulator binding protein. Phylogenetic analysis shows that the CMPl factor, encoded by the alternative spliced Cmp/Cmpl transcript, is the founder of a novel ambulacrarian-specific family of Homeodomain proteins containing the Compass domain. Specific association of CMPl…