ABSTRACT
RUNX3, runt-domain transcription factor, is a master regulator of gene expression in major developmental pathways. It acts as a tumor suppressor in many cancers but is oncogenic in certain tumors. We observed upregulation of RUNX3 mRNA and protein expression in nasal-type extranodal natural killer (NK)/T-cell lymphoma (NKTL) patient samples and NKTL cell lines compared to normal NK cells. RUNX3 silenced NKTL cells showed increased apoptosis and reduced cell proliferation. Potential binding sites for MYC were identified in the RUNX3 enhancer region. Chromatin immunoprecipitation-quantitative PCR revealed binding activity between MYC and RUNX3. Co-transfection of the MYC expression vector with RUNX3 enhancer reporter plasmid resulted in activation of RUNX3 enhancer indicating that MYC positively regulates RUNX3 transcription in NKTL cell lines. Treatment with a small-molecule MYC inhibitor (JQ1) caused significant downregulation of MYC and RUNX3, leading to apoptosis in NKTL cells. The growth inhibition resulting from depletion of MYC by JQ1 was rescued by ectopic MYC expression. In summary, our study identified RUNX3 overexpression in NKTL with functional oncogenic properties. We further delineate that MYC may be an important upstream driver of RUNX3 upregulation and since MYC is upregulated in NKTL, further study on the employment of MYC inhibition as a therapeutic strategy is warranted.
Subject(s)
Cell Transformation, Neoplastic/genetics , Core Binding Factor Alpha 3 Subunit/physiology , Gene Expression Regulation, Neoplastic , Lymphoma, Extranodal NK-T-Cell/genetics , Nose Neoplasms/genetics , Proto-Oncogene Proteins c-myc/physiology , Transcription, Genetic/genetics , Apoptosis , Azepines/pharmacology , Binding Sites , Cell Division , Cell Line, Tumor , Core Binding Factor Alpha 3 Subunit/antagonists & inhibitors , Core Binding Factor Alpha 3 Subunit/genetics , Enhancer Elements, Genetic , Genes, Reporter , Genetic Vectors , Humans , Lymphoma, Extranodal NK-T-Cell/etiology , Lymphoma, Extranodal NK-T-Cell/metabolism , Lymphoma, Extranodal NK-T-Cell/pathology , Molecular Targeted Therapy , Nose Neoplasms/etiology , Nose Neoplasms/metabolism , Nose Neoplasms/pathology , Protein Interaction Mapping , Proto-Oncogene Proteins c-myc/antagonists & inhibitors , RNA Interference , RNA, Small Interfering/genetics , Recombinant Fusion Proteins/metabolism , Triazoles/pharmacology , Up-RegulationABSTRACT
Following acute-phase infection, activated T cells are terminated to achieve immune homeostasis, failure of which results in lymphoproliferative and autoimmune diseases. We report that sterile α- and heat armadillo-motif-containing protein (SARM), the most conserved Toll-like receptors adaptor, is proapoptotic during T-cell immune response. SARM expression is significantly reduced in natural killer (NK)/T lymphoma patients compared with healthy individuals, suggesting that decreased SARM supports NK/T-cell proliferation. T cells knocked down of SARM survived and proliferated more significantly compared with wild-type T cells following influenza infection in vivo. During activation of cytotoxic T cells, the SARM level fell before rising, correlating inversely with cell proliferation and subsequent T-cell clearance. SARM knockdown rescued T cells from both activation- and neglect-induced cell deaths. The mitochondria-localized SARM triggers intrinsic apoptosis by generating reactive oxygen species and depolarizing the mitochondrial potential. The proapoptotic function is attributable to the C-terminal sterile alpha motif and Toll/interleukin-1 receptor domains. Mechanistically, SARM mediates intrinsic apoptosis via B cell lymphoma-2 (Bcl-2) family members. SARM suppresses B cell lymphoma-extra large (Bcl-xL) and downregulates extracellular signal-regulated kinase phosphorylation, which are cell survival effectors. Overexpression of Bcl-xL and double knockout of Bcl-2 associated X protein and Bcl-2 homologous antagonist killer substantially reduced SARM-induced apoptosis. Collectively, we have shown how T-cell death following infection is mediated by SARM-induced intrinsic apoptosis, which is crucial for T-cell homeostasis.
Subject(s)
Armadillo Domain Proteins/metabolism , Cytoskeletal Proteins/metabolism , Mitochondria/metabolism , T-Lymphocytes/metabolism , Animals , Apoptosis , Armadillo Domain Proteins/antagonists & inhibitors , Armadillo Domain Proteins/genetics , Caspase 9/metabolism , Cells, Cultured , Cytoskeletal Proteins/antagonists & inhibitors , Cytoskeletal Proteins/genetics , Extracellular Signal-Regulated MAP Kinases/metabolism , HEK293 Cells , Humans , Lymphocyte Activation , Lymphoma, T-Cell/metabolism , Lymphoma, T-Cell/pathology , Mice , Mice, Transgenic , Phosphorylation , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA Interference , RNA, Small Interfering/metabolism , T-Lymphocytes/immunology , Transfection , bcl-2-Associated X Protein/antagonists & inhibitors , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolism , bcl-X Protein/antagonists & inhibitors , bcl-X Protein/genetics , bcl-X Protein/metabolismABSTRACT
In this paper, the surfaces of PET/TiO(2) thin film were modified by DC glow discharge plasma as a function of discharge potentials for improving the bioactivity. The hydrophilicity of the plasma-treated PET/TiO(2) film was measured by contact angle measurement and the surface energy was estimated by using Fowkes method. The structural and chemical composition of the plasma-treated PET/TiO(2) was analysed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Immersion in a simulated body solution (SBF) solution was used to evaluate the bioactivity of the plasma-treated PET/TiO(2) samples in vitro. It was found that the plasma treatment modified the surfaces both in chemical composition and crystallinity which makes surface of the PET/TiO(2) to become more hydrophilic compared with untreated one. Analytical and microstructural investigations of SBF results, showed considerable higher rates of apatite formation on the plasma-treated PET/TiO(2) compared to the untreated films.
Subject(s)
Coated Materials, Biocompatible/chemistry , Polyethylene Glycols/chemistry , Titanium/chemistry , Apatites/chemistry , Biomimetic Materials/chemistry , Biomimetics/instrumentation , Biomimetics/methods , Body Fluids/chemistry , Humans , Hydrophobic and Hydrophilic Interactions , Photoelectron Spectroscopy , Polyethylene Terephthalates , Solutions/chemistry , Surface Properties , X-Ray DiffractionABSTRACT
Amines such as dopamine, norepinephrine and epinephrine were analysed in the brain regions of O.mossambicus exposed to quinalphos, phenthoate and their combination for 96 hr. The three types of treatments significantly (P < 0.05) altered the amines level at various intervals in the brain regions.
Subject(s)
Biogenic Amines/metabolism , Brain/metabolism , Organophosphorus Compounds/adverse effects , Stress, Physiological/chemically induced , Tilapia/metabolism , Water Pollutants, Chemical/adverse effects , AnimalsABSTRACT
An acute dose of phosalone, intraperitoneally injected to Rana tigrina alters the bioelectrical activity of the brain. The frequency levels of delta, theta, alpha, and beta waves remained similar in both control and experimental groups, while the amplitude of the waves was significantly decreased by 40 to 60% in the latter group. The total work done (TWD) was also significantly reduced. The above disturbance in the brain electrical activity may have correlation to the inhibition of cation-linked ATPase, as well as the cholinesterase activity.
Subject(s)
Brain/drug effects , Brain/physiology , Cholinesterase Inhibitors/toxicity , Insecticides/toxicity , Organothiophosphorus Compounds/toxicity , Ranidae/physiology , Adenosine Triphosphatases/antagonists & inhibitors , Animals , Brain/enzymology , Electroencephalography/drug effects , Injections, Intraperitoneal , MaleABSTRACT
An acute dose of phosalone, an organophosphate pesticide, widely used in crop fields, injected to Rana tigrina, intraperitoneally, inhibited the different inorganic ion linked ATPase enzymes of the central nervous system (CNS). Six discrete CNS compartments, namely telencephalon, mid-brain, rhombencephalon, cervical spinal cord, thoracic spinal cord and lumbar spinal cord showed markedly diminished ATPase activity. ATPases inhibition affected the neuronal activity and muscular coordination leading to moribund or comatose phase in the poisoned frogs. The specific inhibition of Mg(2+)-ATPase suggests the uncoupling action of the compound in the neuronal tissue. Increased oxygen uptake in the brain regions of phosalone-treated frogs also supports the above uncoupling action.
Subject(s)
Ca(2+) Mg(2+)-ATPase/metabolism , Calcium-Transporting ATPases/metabolism , Central Nervous System/drug effects , Cholinesterase Inhibitors/poisoning , Insecticides/poisoning , Organothiophosphorus Compounds/poisoning , Sodium-Potassium-Exchanging ATPase/metabolism , Animals , Ca(2+) Mg(2+)-ATPase/drug effects , Calcium-Transporting ATPases/drug effects , Cations/metabolism , Central Nervous System/enzymology , Cholinesterase Inhibitors/toxicity , Insecticides/toxicity , Male , Organothiophosphorus Compounds/toxicity , Oxygen Consumption/drug effects , Ranidae , Sodium-Potassium-Exchanging ATPase/drug effectsABSTRACT
The level of acetylcholinesterase (AChE) in brain regions of O. mossambicus at different intervals showed the extent of phosalone toxicity. Significant inhibition of AChE at the end of 96 hr in the brain regions was observed. In contrast to AChE inhibition, the monoamine oxidase (MAO) activity showed significant increase in the regions of cerebral hemispheres, dien/mesencephalon, cerebellum and medulla oblongata. The increase of MAO activity in the brain regions under phosalone toxicity is considered to be one of the mechanisms to maintain the amines level in O. mossambicus.
