tretinoin and Cell-Transformation--Viral

Middle East Respiratory Syndrome (MERS) is a novel respiratory illness firstly reported in Saudi Arabia in 2012. It is caused by a new corona virus, called MERS corona virus (MERS-CoV). Most people who have MERS-CoV infection developed severe acute respiratory illness.. This work is done to determine the clinical characteristics and the outcome of intensive care unit (ICU) admitted patients with confirmed MERS-CoV infection.. This study included 32 laboratory confirmed MERS corona virus infected patients who were admitted into ICU. It included 20 (62.50%) males and 12 (37.50%) females. The mean age was 43.99 ± 13.03 years. Diagnosis was done by real-time reverse transcription polymerase chain reaction (rRT-PCR) test for corona virus on throat swab, sputum, tracheal aspirate, or bronchoalveolar lavage specimens. Clinical characteristics, co-morbidities and outcome were reported for all subjects.. Most MERS corona patients present with fever, cough, dyspnea, sore throat, runny nose and sputum. The presence of abdominal symptoms may indicate bad prognosis. Prolonged duration of symptoms before patients' hospitalization, prolonged duration of mechanical ventilation and hospital stay, bilateral radiological pulmonary infiltrates, and hypoxemic respiratory failure were found to be strong predictors of mortality in such patients. Also, old age, current smoking, smoking severity, presence of associated co-morbidities like obesity, diabetes mellitus, chronic heart diseases, COPD, malignancy, renal failure, renal transplantation and liver cirrhosis are associated with a poor outcome of ICU admitted MERS corona virus infected patients.. Plasma HO-1, ferritin, p21, and NQO1 were all elevated at baseline in CKD participants. Plasma HO-1 and urine NQO1 levels each inversely correlated with eGFR (. SnPP can be safely administered and, after its injection, the resulting changes in plasma HO-1, NQO1, ferritin, and p21 concentrations can provide information as to antioxidant gene responsiveness/reserves in subjects with and without kidney disease.. A Study with RBT-1, in Healthy Volunteers and Subjects with Stage 3-4 Chronic Kidney Disease, NCT0363002 and NCT03893799.. HFNC did not significantly modify work of breathing in healthy subjects. However, a significant reduction in the minute volume was achieved, capillary [Formula: see text] remaining constant, which suggests a reduction in dead-space ventilation with flows > 20 L/min. (ClinicalTrials.gov registration NCT02495675).. 3 组患者手术时间、术中显性失血量及术后 1 周血红蛋白下降量比较差异均无统计学意义（. 对于肥胖和超重的膝关节单间室骨关节炎患者，采用 UKA 术后可获满意短中期疗效，远期疗效尚需进一步随访观察。.. Decreased muscle strength was identified at both time points in patients with hEDS/HSD. The evolution of most muscle strength parameters over time did not significantly differ between groups. Future studies should focus on the effectiveness of different types of muscle training strategies in hEDS/HSD patients.. These findings support previous adverse findings of e-cigarette exposure on neurodevelopment in a mouse model and provide substantial evidence of persistent adverse behavioral and neuroimmunological consequences to adult offspring following maternal e-cigarette exposure during pregnancy. https://doi.org/10.1289/EHP6067.. This RCT directly compares a neoadjuvant chemotherapy regimen with a standard CROSS regimen in terms of overall survival for patients with locally advanced ESCC. The results of this RCT will provide an answer for the controversy regarding the survival benefits between the two treatment strategies.. NCT04138212, date of registration: October 24, 2019.. Results of current investigation indicated that milk type and post fermentation cooling patterns had a pronounced effect on antioxidant characteristics, fatty acid profile, lipid oxidation and textural characteristics of yoghurt. Buffalo milk based yoghurt had more fat, protein, higher antioxidant capacity and vitamin content. Antioxidant and sensory characteristics of T. If milk is exposed to excessive amounts of light, Vitamins B. The two concentration of ZnO nanoparticles in the ambient air produced two different outcomes. The lower concentration resulted in significant increases in Zn content of the liver while the higher concentration significantly increased Zn in the lungs (p < 0.05). Additionally, at the lower concentration, Zn content was found to be lower in brain tissue (p < 0.05). Using TEM/EDX we detected ZnO nanoparticles inside the cells in the lungs, kidney and liver. Inhaling ZnO NP at the higher concentration increased the levels of mRNA of the following genes in the lungs: Mt2 (2.56 fold), Slc30a1 (1.52 fold) and Slc30a5 (2.34 fold). At the lower ZnO nanoparticle concentration, only Slc30a7 mRNA levels in the lungs were up (1.74 fold). Thus the two air concentrations of ZnO nanoparticles produced distinct effects on the expression of the Zn-homeostasis related genes.. Until adverse health effects of ZnO nanoparticles deposited in organs such as lungs are further investigated and/or ruled out, the exposure to ZnO nanoparticles in aerosols should be avoided or minimised.

Topics: A549 Cells; Acetylmuramyl-Alanyl-Isoglutamine; Acinetobacter baumannii; Acute Lung Injury; Adaptor Proteins, Signal Transducing; Adenine; Adenocarcinoma; Adipogenesis; Administration, Cutaneous; Administration, Ophthalmic; Adolescent; Adsorption; Adult; Aeromonas hydrophila; Aerosols; Aged; Aged, 80 and over; Aging; Agriculture; Air Pollutants; Air Pollution; Airway Remodeling; Alanine Transaminase; Albuminuria; Aldehyde Dehydrogenase 1 Family; Algorithms; AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase; Alzheimer Disease; Amino Acid Sequence; Ammonia; Ammonium Compounds; Anaerobiosis; Anesthetics, Dissociative; Anesthetics, Inhalation; Animals; Anti-Bacterial Agents; Anti-HIV Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Antibiotics, Antineoplastic; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Monoclonal, Humanized; Antifungal Agents; Antigens, Bacterial; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antimetabolites, Antineoplastic; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Antioxidants; Antitubercular Agents; Antiviral Agents; Apolipoproteins E; Apoptosis; Arabidopsis; Arabidopsis Proteins; Arsenic; Arthritis, Rheumatoid; Asthma; Atherosclerosis; ATP-Dependent Proteases; Attitude of Health Personnel; Australia; Austria; Autophagy; Axitinib; Bacteria; Bacterial Outer Membrane Proteins; Bacterial Proteins; Bacterial Toxins; Bacterial Typing Techniques; Bariatric Surgery; Base Composition; Bayes Theorem; Benzoxazoles; Benzylamines; beta Catenin; Betacoronavirus; Betula; Binding Sites; Biological Availability; Biological Oxygen Demand Analysis; Biomarkers; Biomarkers, Tumor; Biopsy; Bioreactors; Biosensing Techniques; Birth Weight; Blindness; Blood Chemical Analysis; Blood Gas Analysis; Blood Glucose; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Blood-Brain Barrier; Blotting, Western; Body Mass Index; Body Weight; Bone and Bones; Bone Density; Bone Resorption; Borates; Brain; Brain Infarction; Brain Injuries, Traumatic; Brain Neoplasms; Breakfast; Breast Milk Expression; Breast Neoplasms; Bronchi; Bronchoalveolar Lavage Fluid; Buffaloes; Cadherins; Calcification, Physiologic; Calcium Compounds; Calcium, Dietary; Cannula; Caprolactam; Carbon; Carbon Dioxide; Carboplatin; Carcinogenesis; Carcinoma, Ductal; Carcinoma, Ehrlich Tumor; Carcinoma, Hepatocellular; Carcinoma, Non-Small-Cell Lung; Carcinoma, Pancreatic Ductal; Carcinoma, Renal Cell; Cardiovascular Diseases; Carps; Carrageenan; Case-Control Studies; Catalysis; Catalytic Domain; Cattle; CD8-Positive T-Lymphocytes; Cell Adhesion; Cell Cycle Proteins; Cell Death; Cell Differentiation; Cell Line; Cell Line, Tumor; Cell Movement; Cell Nucleus; Cell Phone Use; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; Cell Transformation, Viral; Cells, Cultured; Cellulose; Chemical Phenomena; Chemoradiotherapy; Child; Child Development; Child, Preschool; China; Chitosan; Chlorocebus aethiops; Cholecalciferol; Chromatography, Liquid; Circadian Clocks; Circadian Rhythm; Circular Dichroism; Cisplatin; Citric Acid; Clinical Competence; Clinical Laboratory Techniques; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clostridioides difficile; Clostridium Infections; Coculture Techniques; Cohort Studies; Cold Temperature; Colitis; Collagen Type I; Collagen Type I, alpha 1 Chain; Collagen Type XI; Color; Connective Tissue Diseases; Copper; Coronary Angiography; Coronavirus 3C Proteases; Coronavirus Infections; Cost of Illness; Counselors; COVID-19; COVID-19 Testing; Creatine Kinase; Creatinine; Cross-Over Studies; Cross-Sectional Studies; Cryoelectron Microscopy; Cryosurgery; Crystallography, X-Ray; Cues; Cultural Competency; Cultural Diversity; Curriculum; Cyclic AMP Response Element-Binding Protein; Cyclin-Dependent Kinase Inhibitor p21; Cycloparaffins; Cysteine Endopeptidases; Cytokines; Cytoplasm; Cytoprotection; Databases, Factual; Denitrification; Deoxycytidine; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diagnosis, Differential; Diatoms; Diet; Diet, High-Fat; Dietary Exposure; Diffusion Magnetic Resonance Imaging; Diketopiperazines; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Disease Progression; Disease-Free Survival; DNA; DNA Damage; DNA Glycosylases; DNA Repair; DNA-Binding Proteins; DNA, Bacterial; DNA, Viral; Docetaxel; Dose Fractionation, Radiation; Dose-Response Relationship, Drug; Down-Regulation; Doxorubicin; Drosophila; Drosophila melanogaster; Drug Carriers; Drug Delivery Systems; Drug Liberation; Drug Repositioning; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Drug Synergism; Drug Therapy, Combination; Edema; Edible Grain; Education, Graduate; Education, Medical, Graduate; Education, Pharmacy; Ehlers-Danlos Syndrome; Electron Transport Complex III; Electron Transport Complex IV; Electronic Nicotine Delivery Systems; Emergency Service, Hospital; Empathy; Emulsions; Endothelial Cells; Endurance Training; Energy Intake; Enterovirus A, Human; Environment; Environmental Monitoring; Enzyme Assays; Enzyme Inhibitors; Epithelial Cells; Epithelial-Mesenchymal Transition; Epoxide Hydrolases; Epoxy Compounds; Erythrocyte Count; Erythrocytes; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Esophagectomy; Estrogens; Etanercept; Ethiopia; Ethnicity; Ethylenes; Exanthema; Exercise; Exercise Test; Exercise Tolerance; Extracellular Matrix; Extracorporeal Membrane Oxygenation; Eye Infections, Fungal; False Negative Reactions; Fatty Acids; Fecal Microbiota Transplantation; Feces; Female; Femur Neck; Fermentation; Ferritins; Fetal Development; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Fibroblasts; Fibroins; Fish Proteins; Flavanones; Flavonoids; Focus Groups; Follow-Up Studies; Food Handling; Food Supply; Food, Formulated; Forced Expiratory Volume; Forests; Fractures, Bone; Fruit and Vegetable Juices; Fusobacteria; G1 Phase Cell Cycle Checkpoints; G2 Phase Cell Cycle Checkpoints; Gamma Rays; Gastrectomy; Gastrointestinal Microbiome; Gastrointestinal Stromal Tumors; Gefitinib; Gels; Gemcitabine; Gene Amplification; Gene Expression; Gene Expression Regulation; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Neoplastic; Gene Expression Regulation, Plant; Gene Knockdown Techniques; Gene-Environment Interaction; Genotype; Germany; Glioma; Glomerular Filtration Rate; Glucagon; Glucocorticoids; Glycemic Control; Glycerol; Glycogen Synthase Kinase 3 beta; Glycolipids; Glycolysis; Goblet Cells; Gram-Negative Bacterial Infections; Granulocyte Colony-Stimulating Factor; Graphite; Greenhouse Effect; Guanidines; Haemophilus influenzae; HCT116 Cells; Health Knowledge, Attitudes, Practice; Health Personnel; Health Services Accessibility; Health Services Needs and Demand; Health Status Disparities; Healthy Volunteers; Heart Failure; Heart Rate; Heart Transplantation; Heart-Assist Devices; HEK293 Cells; Heme; Heme Oxygenase-1; Hemolysis; Hemorrhage; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B, Chronic; Hepatocytes; Hexoses; High-Throughput Nucleotide Sequencing; Hippo Signaling Pathway; Histamine; Histamine Agonists; Histidine; Histone Deacetylase 2; HIV Infections; HIV Reverse Transcriptase; HIV-1; Homebound Persons; Homeodomain Proteins; Homosexuality, Male; Hospice and Palliative Care Nursing; HSP70 Heat-Shock Proteins; Humans; Hyaluronan Receptors; Hydrogen; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hydrolysis; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemia; Hypoglycemic Agents; Hypoxia; Idiopathic Interstitial Pneumonias; Imaging, Three-Dimensional; Imatinib Mesylate; Immunotherapy; Implementation Science; Incidence; INDEL Mutation; Induced Pluripotent Stem Cells; Industrial Waste; Infant; Infant, Newborn; Inflammation; Inflammation Mediators; Infliximab; Infusions, Intravenous; Inhibitory Concentration 50; Injections; Insecticides; Insulin-Like Growth Factor Binding Protein 5; Insulin-Secreting Cells; Interleukin-1; Interleukin-17; Interleukin-8; Internship and Residency; Intestines; Intracellular Signaling Peptides and Proteins; Ion Transport; Iridaceae; Iridoid Glucosides; Islets of Langerhans Transplantation; Isodon; Isoflurane; Isotopes; Italy; Joint Instability; Ketamine; Kidney; Kidney Failure, Chronic; Kidney Function Tests; Kidney Neoplasms; Kinetics; Klebsiella pneumoniae; Knee Joint; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Lactate Dehydrogenase 5; Laparoscopy; Laser Therapy; Lasers, Semiconductor; Lasers, Solid-State; Laurates; Lead; Leukocyte L1 Antigen Complex; Leukocytes, Mononuclear; Light; Lipid Peroxidation; Lipopolysaccharides; Liposomes; Liver; Liver Cirrhosis; Liver Neoplasms; Liver Transplantation; Locomotion; Longitudinal Studies; Lopinavir; Lower Urinary Tract Symptoms; Lubricants; Lung; Lung Diseases, Interstitial; Lung Neoplasms; Lymphocyte Activation; Lymphocytes, Tumor-Infiltrating; Lymphoma, Mantle-Cell; Lysosomes; Macrophages; Male; Manganese Compounds; MAP Kinase Kinase 4; Mass Screening; Maternal Health; Medicine, Chinese Traditional; Melanoma, Experimental; Memantine; Membrane Glycoproteins; Membrane Proteins; Mesenchymal Stem Cell Transplantation; Metal Nanoparticles; Metalloendopeptidases; Metalloporphyrins; Methadone; Methane; Methicillin-Resistant Staphylococcus aureus; Mexico; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Knockout; Mice, Nude; Mice, SCID; Mice, Transgenic; Microarray Analysis; Microbial Sensitivity Tests; Microbiota; Micronutrients; MicroRNAs; Microscopy, Confocal; Microsomes, Liver; Middle Aged; Milk; Milk, Human; Minority Groups; Mitochondria; Mitochondrial Membranes; Mitochondrial Proteins; Models, Animal; Models, Molecular; Molecular Conformation; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular Epidemiology; Molecular Structure; Molecular Weight; Multilocus Sequence Typing; Multimodal Imaging; Muscle Strength; Muscle, Skeletal; Muscular Diseases; Mutation; Mycobacterium tuberculosis; Myocardial Stunning; Myristates; NAD(P)H Dehydrogenase (Quinone); Nanocomposites; Nanogels; Nanoparticles; Nanotechnology; Naphthalenes; Nasal Cavity; National Health Programs; Necrosis; Needs Assessment; Neoadjuvant Therapy; Neonicotinoids; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Recurrence, Local; Neoplasm Staging; Neoplasm Transplantation; Neoplasms; Neoplastic Stem Cells; Netherlands; Neuroblastoma; Neuroprotective Agents; Neutrophils; NF-kappa B; NFATC Transcription Factors; Nicotiana; Nicotine; Nitrates; Nitrification; Nitrites; Nitro Compounds; Nitrogen; Nitrogen Dioxide; North Carolina; Nuclear Magnetic Resonance, Biomolecular; Nuclear Proteins; Nucleic Acid Hybridization; Nucleosomes; Nutrients; Obesity; Obesity, Morbid; Oceans and Seas; Oncogene Protein v-akt; Oncogenes; Oocytes; Open Reading Frames; Osteoclasts; Osteogenesis; Osteoporosis; Osteoporosis, Postmenopausal; Outpatients; Ovarian Neoplasms; Ovariectomy; Overweight; Oxazines; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxides; Oxidoreductases; Oxygen; Oxygen Inhalation Therapy; Oxygenators, Membrane; Ozone; Paclitaxel; Paenibacillus; Pain Measurement; Palliative Care; Pancreatic Neoplasms; Pandemics; Parasympathetic Nervous System; Particulate Matter; Pasteurization; Patient Preference; Patient Satisfaction; Pediatric Obesity; Permeability; Peroxiredoxins; Peroxynitrous Acid; Pharmaceutical Services; Pharmacists; Pharmacy; Phaseolus; Phenotype; Phoeniceae; Phosphates; Phosphatidylinositol 3-Kinases; Phospholipid Transfer Proteins; Phospholipids; Phosphorus; Phosphorylation; Photoperiod; Photosynthesis; Phylogeny; Physical Endurance; Physicians; Pilot Projects; Piperidines; Pituitary Adenylate Cyclase-Activating Polypeptide; Plant Extracts; Plant Leaves; Plant Proteins; Plant Roots; Plaque, Atherosclerotic; Pneumonia; Pneumonia, Viral; Point-of-Care Testing; Polyethylene Glycols; Polymers; Polysorbates; Pore Forming Cytotoxic Proteins; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Postprandial Period; Poverty; Pre-Exposure Prophylaxis; Prediabetic State; Predictive Value of Tests; Pregnancy; Pregnancy Trimester, First; Pregnancy, High-Risk; Prenatal Exposure Delayed Effects; Pressure; Prevalence; Primary Graft Dysfunction; Primary Health Care; Professional Role; Professionalism; Prognosis; Progression-Free Survival; Prolactin; Promoter Regions, Genetic; Proof of Concept Study; Proportional Hazards Models; Propylene Glycol; Prospective Studies; Prostate; Protein Binding; Protein Biosynthesis; Protein Isoforms; Protein Kinase Inhibitors; Protein Phosphatase 2; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Protein Transport; Proteoglycans; Proteome; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Proto-Oncogene Proteins c-ret; Proto-Oncogene Proteins p21(ras); Proton Pumps; Protons; Protoporphyrins; Pseudomonas aeruginosa; Pseudomonas fluorescens; Pulmonary Artery; Pulmonary Disease, Chronic Obstructive; Pulmonary Gas Exchange; Pulmonary Veins; Pyrazoles; Pyridines; Pyrimidines; Qualitative Research; Quinoxalines; Rabbits; Random Allocation; Rats; Rats, Sprague-Dawley; Rats, Wistar; Receptors, Histamine H3; Receptors, Immunologic; Receptors, Transferrin; Recombinant Proteins; Recurrence; Reference Values; Referral and Consultation; Regional Blood Flow; Registries; Regulon; Renal Insufficiency, Chronic; Reperfusion Injury; Repressor Proteins; Reproducibility of Results; Republic of Korea; Research Design; Resistance Training; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Insufficiency; Resuscitation; Retinal Dehydrogenase; Retreatment; Retrospective Studies; Reverse Transcriptase Inhibitors; Rhinitis, Allergic; Ribosomal Proteins; Ribosomes; Risk Assessment; Risk Factors; Ritonavir; Rivers; RNA Interference; RNA-Seq; RNA, Messenger; RNA, Ribosomal, 16S; RNA, Small Interfering; Rosuvastatin Calcium; Rural Population; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Salivary Ducts; Salivary Gland Neoplasms; San Francisco; SARS-CoV-2; Satiation; Satiety Response; Schools; Schools, Pharmacy; Seasons; Seawater; Selection, Genetic; Sequence Analysis, DNA; Serine-Threonine Kinase 3; Sewage; Sheep; Sheep, Domestic; Shock, Hemorrhagic; Signal Transduction; Silver; Silymarin; Single Photon Emission Computed Tomography Computed Tomography; Sirolimus; Sirtuin 1; Skin; Skin Neoplasms; Skin Physiological Phenomena; Sleep Initiation and Maintenance Disorders; Social Class; Social Participation; Social Support; Soil; Soil Microbiology; Solutions; Somatomedins; Soot; Specimen Handling; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis; Spinal Fractures; Spirometry; Staphylococcus aureus; STAT1 Transcription Factor; STAT3 Transcription Factor; Streptomyces coelicolor; Stress, Psychological; Stroke; Stroke Volume; Structure-Activity Relationship; Students, Medical; Students, Pharmacy; Substance Abuse Treatment Centers; Sulfur Dioxide; Surface Properties; Surface-Active Agents; Surveys and Questionnaires; Survival Analysis; Survival Rate; Survivin; Sweden; Swine; Swine, Miniature; Sympathetic Nervous System; T-Lymphocytes, Regulatory; Talaromyces; Tandem Mass Spectrometry; tau Proteins; Telemedicine; Telomerase; Telomere; Telomere Homeostasis; Temperature; Terminally Ill; Th1 Cells; Thiamethoxam; Thiazoles; Thiophenes; Thioredoxin Reductase 1; Thrombosis; Thulium; Thyroid Cancer, Papillary; Thyroid Carcinoma, Anaplastic; Thyroid Neoplasms; Time Factors; Titanium; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; TOR Serine-Threonine Kinases; Transcription Factor AP-1; Transcription Factors; Transcription, Genetic; Transcriptional Activation; Transcriptome; Transforming Growth Factor beta1; Transistors, Electronic; Translational Research, Biomedical; Transplantation Tolerance; Transplantation, Homologous; Transportation; Treatment Outcome; Tretinoin; Tuberculosis, Multidrug-Resistant; Tuberculosis, Pulmonary; Tubulin Modulators; Tumor Microenvironment; Tumor Necrosis Factor Inhibitors; Tumor Necrosis Factor-alpha; Twins; Ultrasonic Therapy; Ultrasonography; Ultraviolet Rays; United States; Up-Regulation; Uranium; Urethra; Urinary Bladder; Urodynamics; Uromodulin; Uveitis; Vasoconstrictor Agents; Ventricular Function, Left; Vero Cells; Vesicular Transport Proteins; Viral Nonstructural Proteins; Visual Acuity; Vital Capacity; Vitamin D; Vitamin D Deficiency; Vitamin K 2; Vitamins; Volatilization; Voriconazole; Waiting Lists; Waste Disposal, Fluid; Wastewater; Water Pollutants, Chemical; Whole Genome Sequencing; Wine; Wnt Signaling Pathway; Wound Healing; Wounds and Injuries; WW Domains; X-linked Nuclear Protein; X-Ray Diffraction; Xanthines; Xenograft Model Antitumor Assays; YAP-Signaling Proteins; Yogurt; Young Adult; Zebrafish; Zebrafish Proteins; Ziziphus

A universal cellular defense mechanism against viral invasion is the elimination of infected cells through apoptotic cell death. To counteract host defenses many viruses have evolved complex apoptosis evasion strategies. The oncogenic human retrovirus HTLV-1 is the etiological agent of adult-T-cell leukemia/lymphoma (ATLL) and the neurodegenerative disease known as HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The poor prognosis in HTLV-1-induced ATLL is linked to the resistance of neoplastic T cells against conventional therapies and the immuno-compromised state of patients. Nevertheless, several studies have shown that the apoptotic pathway is largely intact and can be reactivated in ATLL tumor cells to induce specific killing. A better understanding of the molecular mechanisms employed by HTLV-1 to counteract cellular death pathways remains an important challenge for future therapies and the treatment of HTLV-1-associated diseases.

Topics: Apoptosis; Cell Transformation, Viral; Gene Products, tax; Human T-lymphotropic virus 1; Humans; I-kappa B Kinase; Janus Kinases; Leukemia-Lymphoma, Adult T-Cell; NF-kappa B; Paraparesis, Tropical Spastic; Proto-Oncogene Proteins c-akt; Receptors, Interleukin-2; Retroviridae Proteins; STAT Transcription Factors; Tretinoin; Tumor Suppressor Protein p53; Viral Regulatory and Accessory Proteins

Topics: Animals; Antigens, Viral; Canavanine; Carcinogens; Cell Line; Cell Transformation, Viral; Diterpenes; DNA, Viral; Enzyme Induction; Herpesviridae; Herpesvirus 4, Human; Humans; Ornithine Decarboxylase; Papillomaviridae; Phorbols; Polyomaviridae; Retroviridae; Structure-Activity Relationship; Tetradecanoylphorbol Acetate; Tretinoin; Virus Activation

EGF-Rs are cell membrane glycoproteins of wide distribution. They have not yet been fully characterized or purified but are probably molecules of 170-190,000 mol. wt. in most cells. The growth factor EGF binds and will saturate cell surface receptors with a KA of about 5 X 10(9) M-1 although a receptor class with an affinity in excess of 10(10) M-1 has been detected in some cells. The number of receptors on a cell does not determine the level of its response. Some cell types have receptors which bind EGF, but with no mitogenic response. The ways in which receptor affinity and/or number is modulated are described. This and other evidence is reviewed in a search for a suitable model of a mechanism of action on the cell, which best fits the current data. There is ample evidence that EGF binds to the receptor; that ligand-receptor complexes cluster or aggregate; and then are internalized and degraded, but evidence for a direct connection between internalization and the subsequent mitogenic response is lacking. Good correlations between internalization and mitogenic responses have been observed and developed into a theory of endocytic activation, but there is a body of evidence which cannot be accommodated by this theory. Instead, an alternative model is suggested.

Topics: Animals; Binding Sites; Cell Membrane; Cell Transformation, Neoplastic; Cell Transformation, Viral; DNA; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Kinetics; Models, Biological; Molecular Weight; Organ Specificity; Peptides; Pregnancy; Receptors, Cell Surface; Species Specificity; Teratoma; Tissue Distribution; Tretinoin

Middle East Respiratory Syndrome (MERS) is a novel respiratory illness firstly reported in Saudi Arabia in 2012. It is caused by a new corona virus, called MERS corona virus (MERS-CoV). Most people who have MERS-CoV infection developed severe acute respiratory illness.. This work is done to determine the clinical characteristics and the outcome of intensive care unit (ICU) admitted patients with confirmed MERS-CoV infection.. This study included 32 laboratory confirmed MERS corona virus infected patients who were admitted into ICU. It included 20 (62.50%) males and 12 (37.50%) females. The mean age was 43.99 ± 13.03 years. Diagnosis was done by real-time reverse transcription polymerase chain reaction (rRT-PCR) test for corona virus on throat swab, sputum, tracheal aspirate, or bronchoalveolar lavage specimens. Clinical characteristics, co-morbidities and outcome were reported for all subjects.. Most MERS corona patients present with fever, cough, dyspnea, sore throat, runny nose and sputum. The presence of abdominal symptoms may indicate bad prognosis. Prolonged duration of symptoms before patients' hospitalization, prolonged duration of mechanical ventilation and hospital stay, bilateral radiological pulmonary infiltrates, and hypoxemic respiratory failure were found to be strong predictors of mortality in such patients. Also, old age, current smoking, smoking severity, presence of associated co-morbidities like obesity, diabetes mellitus, chronic heart diseases, COPD, malignancy, renal failure, renal transplantation and liver cirrhosis are associated with a poor outcome of ICU admitted MERS corona virus infected patients.. Plasma HO-1, ferritin, p21, and NQO1 were all elevated at baseline in CKD participants. Plasma HO-1 and urine NQO1 levels each inversely correlated with eGFR (. SnPP can be safely administered and, after its injection, the resulting changes in plasma HO-1, NQO1, ferritin, and p21 concentrations can provide information as to antioxidant gene responsiveness/reserves in subjects with and without kidney disease.. A Study with RBT-1, in Healthy Volunteers and Subjects with Stage 3-4 Chronic Kidney Disease, NCT0363002 and NCT03893799.. HFNC did not significantly modify work of breathing in healthy subjects. However, a significant reduction in the minute volume was achieved, capillary [Formula: see text] remaining constant, which suggests a reduction in dead-space ventilation with flows > 20 L/min. (ClinicalTrials.gov registration NCT02495675).. 3 组患者手术时间、术中显性失血量及术后 1 周血红蛋白下降量比较差异均无统计学意义（. 对于肥胖和超重的膝关节单间室骨关节炎患者，采用 UKA 术后可获满意短中期疗效，远期疗效尚需进一步随访观察。.. Decreased muscle strength was identified at both time points in patients with hEDS/HSD. The evolution of most muscle strength parameters over time did not significantly differ between groups. Future studies should focus on the effectiveness of different types of muscle training strategies in hEDS/HSD patients.. These findings support previous adverse findings of e-cigarette exposure on neurodevelopment in a mouse model and provide substantial evidence of persistent adverse behavioral and neuroimmunological consequences to adult offspring following maternal e-cigarette exposure during pregnancy. https://doi.org/10.1289/EHP6067.. This RCT directly compares a neoadjuvant chemotherapy regimen with a standard CROSS regimen in terms of overall survival for patients with locally advanced ESCC. The results of this RCT will provide an answer for the controversy regarding the survival benefits between the two treatment strategies.. NCT04138212, date of registration: October 24, 2019.. Results of current investigation indicated that milk type and post fermentation cooling patterns had a pronounced effect on antioxidant characteristics, fatty acid profile, lipid oxidation and textural characteristics of yoghurt. Buffalo milk based yoghurt had more fat, protein, higher antioxidant capacity and vitamin content. Antioxidant and sensory characteristics of T. If milk is exposed to excessive amounts of light, Vitamins B. The two concentration of ZnO nanoparticles in the ambient air produced two different outcomes. The lower concentration resulted in significant increases in Zn content of the liver while the higher concentration significantly increased Zn in the lungs (p < 0.05). Additionally, at the lower concentration, Zn content was found to be lower in brain tissue (p < 0.05). Using TEM/EDX we detected ZnO nanoparticles inside the cells in the lungs, kidney and liver. Inhaling ZnO NP at the higher concentration increased the levels of mRNA of the following genes in the lungs: Mt2 (2.56 fold), Slc30a1 (1.52 fold) and Slc30a5 (2.34 fold). At the lower ZnO nanoparticle concentration, only Slc30a7 mRNA levels in the lungs were up (1.74 fold). Thus the two air concentrations of ZnO nanoparticles produced distinct effects on the expression of the Zn-homeostasis related genes.. Until adverse health effects of ZnO nanoparticles deposited in organs such as lungs are further investigated and/or ruled out, the exposure to ZnO nanoparticles in aerosols should be avoided or minimised.

Topics: A549 Cells; Acetylmuramyl-Alanyl-Isoglutamine; Acinetobacter baumannii; Acute Lung Injury; Adaptor Proteins, Signal Transducing; Adenine; Adenocarcinoma; Adipogenesis; Administration, Cutaneous; Administration, Ophthalmic; Adolescent; Adsorption; Adult; Aeromonas hydrophila; Aerosols; Aged; Aged, 80 and over; Aging; Agriculture; Air Pollutants; Air Pollution; Airway Remodeling; Alanine Transaminase; Albuminuria; Aldehyde Dehydrogenase 1 Family; Algorithms; AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase; Alzheimer Disease; Amino Acid Sequence; Ammonia; Ammonium Compounds; Anaerobiosis; Anesthetics, Dissociative; Anesthetics, Inhalation; Animals; Anti-Bacterial Agents; Anti-HIV Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Antibiotics, Antineoplastic; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Monoclonal, Humanized; Antifungal Agents; Antigens, Bacterial; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antimetabolites, Antineoplastic; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Antioxidants; Antitubercular Agents; Antiviral Agents; Apolipoproteins E; Apoptosis; Arabidopsis; Arabidopsis Proteins; Arsenic; Arthritis, Rheumatoid; Asthma; Atherosclerosis; ATP-Dependent Proteases; Attitude of Health Personnel; Australia; Austria; Autophagy; Axitinib; Bacteria; Bacterial Outer Membrane Proteins; Bacterial Proteins; Bacterial Toxins; Bacterial Typing Techniques; Bariatric Surgery; Base Composition; Bayes Theorem; Benzoxazoles; Benzylamines; beta Catenin; Betacoronavirus; Betula; Binding Sites; Biological Availability; Biological Oxygen Demand Analysis; Biomarkers; Biomarkers, Tumor; Biopsy; Bioreactors; Biosensing Techniques; Birth Weight; Blindness; Blood Chemical Analysis; Blood Gas Analysis; Blood Glucose; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Blood-Brain Barrier; Blotting, Western; Body Mass Index; Body Weight; Bone and Bones; Bone Density; Bone Resorption; Borates; Brain; Brain Infarction; Brain Injuries, Traumatic; Brain Neoplasms; Breakfast; Breast Milk Expression; Breast Neoplasms; Bronchi; Bronchoalveolar Lavage Fluid; Buffaloes; Cadherins; Calcification, Physiologic; Calcium Compounds; Calcium, Dietary; Cannula; Caprolactam; Carbon; Carbon Dioxide; Carboplatin; Carcinogenesis; Carcinoma, Ductal; Carcinoma, Ehrlich Tumor; Carcinoma, Hepatocellular; Carcinoma, Non-Small-Cell Lung; Carcinoma, Pancreatic Ductal; Carcinoma, Renal Cell; Cardiovascular Diseases; Carps; Carrageenan; Case-Control Studies; Catalysis; Catalytic Domain; Cattle; CD8-Positive T-Lymphocytes; Cell Adhesion; Cell Cycle Proteins; Cell Death; Cell Differentiation; Cell Line; Cell Line, Tumor; Cell Movement; Cell Nucleus; Cell Phone Use; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; Cell Transformation, Viral; Cells, Cultured; Cellulose; Chemical Phenomena; Chemoradiotherapy; Child; Child Development; Child, Preschool; China; Chitosan; Chlorocebus aethiops; Cholecalciferol; Chromatography, Liquid; Circadian Clocks; Circadian Rhythm; Circular Dichroism; Cisplatin; Citric Acid; Clinical Competence; Clinical Laboratory Techniques; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clostridioides difficile; Clostridium Infections; Coculture Techniques; Cohort Studies; Cold Temperature; Colitis; Collagen Type I; Collagen Type I, alpha 1 Chain; Collagen Type XI; Color; Connective Tissue Diseases; Copper; Coronary Angiography; Coronavirus 3C Proteases; Coronavirus Infections; Cost of Illness; Counselors; COVID-19; COVID-19 Testing; Creatine Kinase; Creatinine; Cross-Over Studies; Cross-Sectional Studies; Cryoelectron Microscopy; Cryosurgery; Crystallography, X-Ray; Cues; Cultural Competency; Cultural Diversity; Curriculum; Cyclic AMP Response Element-Binding Protein; Cyclin-Dependent Kinase Inhibitor p21; Cycloparaffins; Cysteine Endopeptidases; Cytokines; Cytoplasm; Cytoprotection; Databases, Factual; Denitrification; Deoxycytidine; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diagnosis, Differential; Diatoms; Diet; Diet, High-Fat; Dietary Exposure; Diffusion Magnetic Resonance Imaging; Diketopiperazines; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Disease Progression; Disease-Free Survival; DNA; DNA Damage; DNA Glycosylases; DNA Repair; DNA-Binding Proteins; DNA, Bacterial; DNA, Viral; Docetaxel; Dose Fractionation, Radiation; Dose-Response Relationship, Drug; Down-Regulation; Doxorubicin; Drosophila; Drosophila melanogaster; Drug Carriers; Drug Delivery Systems; Drug Liberation; Drug Repositioning; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Drug Synergism; Drug Therapy, Combination; Edema; Edible Grain; Education, Graduate; Education, Medical, Graduate; Education, Pharmacy; Ehlers-Danlos Syndrome; Electron Transport Complex III; Electron Transport Complex IV; Electronic Nicotine Delivery Systems; Emergency Service, Hospital; Empathy; Emulsions; Endothelial Cells; Endurance Training; Energy Intake; Enterovirus A, Human; Environment; Environmental Monitoring; Enzyme Assays; Enzyme Inhibitors; Epithelial Cells; Epithelial-Mesenchymal Transition; Epoxide Hydrolases; Epoxy Compounds; Erythrocyte Count; Erythrocytes; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Esophagectomy; Estrogens; Etanercept; Ethiopia; Ethnicity; Ethylenes; Exanthema; Exercise; Exercise Test; Exercise Tolerance; Extracellular Matrix; Extracorporeal Membrane Oxygenation; Eye Infections, Fungal; False Negative Reactions; Fatty Acids; Fecal Microbiota Transplantation; Feces; Female; Femur Neck; Fermentation; Ferritins; Fetal Development; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Fibroblasts; Fibroins; Fish Proteins; Flavanones; Flavonoids; Focus Groups; Follow-Up Studies; Food Handling; Food Supply; Food, Formulated; Forced Expiratory Volume; Forests; Fractures, Bone; Fruit and Vegetable Juices; Fusobacteria; G1 Phase Cell Cycle Checkpoints; G2 Phase Cell Cycle Checkpoints; Gamma Rays; Gastrectomy; Gastrointestinal Microbiome; Gastrointestinal Stromal Tumors; Gefitinib; Gels; Gemcitabine; Gene Amplification; Gene Expression; Gene Expression Regulation; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Neoplastic; Gene Expression Regulation, Plant; Gene Knockdown Techniques; Gene-Environment Interaction; Genotype; Germany; Glioma; Glomerular Filtration Rate; Glucagon; Glucocorticoids; Glycemic Control; Glycerol; Glycogen Synthase Kinase 3 beta; Glycolipids; Glycolysis; Goblet Cells; Gram-Negative Bacterial Infections; Granulocyte Colony-Stimulating Factor; Graphite; Greenhouse Effect; Guanidines; Haemophilus influenzae; HCT116 Cells; Health Knowledge, Attitudes, Practice; Health Personnel; Health Services Accessibility; Health Services Needs and Demand; Health Status Disparities; Healthy Volunteers; Heart Failure; Heart Rate; Heart Transplantation; Heart-Assist Devices; HEK293 Cells; Heme; Heme Oxygenase-1; Hemolysis; Hemorrhage; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B, Chronic; Hepatocytes; Hexoses; High-Throughput Nucleotide Sequencing; Hippo Signaling Pathway; Histamine; Histamine Agonists; Histidine; Histone Deacetylase 2; HIV Infections; HIV Reverse Transcriptase; HIV-1; Homebound Persons; Homeodomain Proteins; Homosexuality, Male; Hospice and Palliative Care Nursing; HSP70 Heat-Shock Proteins; Humans; Hyaluronan Receptors; Hydrogen; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hydrolysis; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemia; Hypoglycemic Agents; Hypoxia; Idiopathic Interstitial Pneumonias; Imaging, Three-Dimensional; Imatinib Mesylate; Immunotherapy; Implementation Science; Incidence; INDEL Mutation; Induced Pluripotent Stem Cells; Industrial Waste; Infant; Infant, Newborn; Inflammation; Inflammation Mediators; Infliximab; Infusions, Intravenous; Inhibitory Concentration 50; Injections; Insecticides; Insulin-Like Growth Factor Binding Protein 5; Insulin-Secreting Cells; Interleukin-1; Interleukin-17; Interleukin-8; Internship and Residency; Intestines; Intracellular Signaling Peptides and Proteins; Ion Transport; Iridaceae; Iridoid Glucosides; Islets of Langerhans Transplantation; Isodon; Isoflurane; Isotopes; Italy; Joint Instability; Ketamine; Kidney; Kidney Failure, Chronic; Kidney Function Tests; Kidney Neoplasms; Kinetics; Klebsiella pneumoniae; Knee Joint; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Lactate Dehydrogenase 5; Laparoscopy; Laser Therapy; Lasers, Semiconductor; Lasers, Solid-State; Laurates; Lead; Leukocyte L1 Antigen Complex; Leukocytes, Mononuclear; Light; Lipid Peroxidation; Lipopolysaccharides; Liposomes; Liver; Liver Cirrhosis; Liver Neoplasms; Liver Transplantation; Locomotion; Longitudinal Studies; Lopinavir; Lower Urinary Tract Symptoms; Lubricants; Lung; Lung Diseases, Interstitial; Lung Neoplasms; Lymphocyte Activation; Lymphocytes, Tumor-Infiltrating; Lymphoma, Mantle-Cell; Lysosomes; Macrophages; Male; Manganese Compounds; MAP Kinase Kinase 4; Mass Screening; Maternal Health; Medicine, Chinese Traditional; Melanoma, Experimental; Memantine; Membrane Glycoproteins; Membrane Proteins; Mesenchymal Stem Cell Transplantation; Metal Nanoparticles; Metalloendopeptidases; Metalloporphyrins; Methadone; Methane; Methicillin-Resistant Staphylococcus aureus; Mexico; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Knockout; Mice, Nude; Mice, SCID; Mice, Transgenic; Microarray Analysis; Microbial Sensitivity Tests; Microbiota; Micronutrients; MicroRNAs; Microscopy, Confocal; Microsomes, Liver; Middle Aged; Milk; Milk, Human; Minority Groups; Mitochondria; Mitochondrial Membranes; Mitochondrial Proteins; Models, Animal; Models, Molecular; Molecular Conformation; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular Epidemiology; 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Oocytes; Open Reading Frames; Osteoclasts; Osteogenesis; Osteoporosis; Osteoporosis, Postmenopausal; Outpatients; Ovarian Neoplasms; Ovariectomy; Overweight; Oxazines; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxides; Oxidoreductases; Oxygen; Oxygen Inhalation Therapy; Oxygenators, Membrane; Ozone; Paclitaxel; Paenibacillus; Pain Measurement; Palliative Care; Pancreatic Neoplasms; Pandemics; Parasympathetic Nervous System; Particulate Matter; Pasteurization; Patient Preference; Patient Satisfaction; Pediatric Obesity; Permeability; Peroxiredoxins; Peroxynitrous Acid; Pharmaceutical Services; Pharmacists; Pharmacy; Phaseolus; Phenotype; Phoeniceae; Phosphates; Phosphatidylinositol 3-Kinases; Phospholipid Transfer Proteins; Phospholipids; Phosphorus; Phosphorylation; Photoperiod; Photosynthesis; Phylogeny; Physical Endurance; Physicians; Pilot Projects; Piperidines; Pituitary Adenylate Cyclase-Activating Polypeptide; Plant Extracts; Plant Leaves; Plant Proteins; Plant Roots; Plaque, Atherosclerotic; Pneumonia; Pneumonia, Viral; Point-of-Care Testing; Polyethylene Glycols; Polymers; Polysorbates; Pore Forming Cytotoxic Proteins; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Postprandial Period; Poverty; Pre-Exposure Prophylaxis; Prediabetic State; Predictive Value of Tests; Pregnancy; Pregnancy Trimester, First; Pregnancy, High-Risk; Prenatal Exposure Delayed Effects; Pressure; Prevalence; Primary Graft Dysfunction; Primary Health Care; Professional Role; Professionalism; Prognosis; Progression-Free Survival; Prolactin; Promoter Regions, Genetic; Proof of Concept Study; Proportional Hazards Models; Propylene Glycol; Prospective Studies; Prostate; Protein Binding; Protein Biosynthesis; Protein Isoforms; Protein Kinase Inhibitors; Protein Phosphatase 2; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Protein Transport; Proteoglycans; Proteome; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Proto-Oncogene Proteins c-ret; Proto-Oncogene Proteins p21(ras); Proton Pumps; Protons; Protoporphyrins; Pseudomonas aeruginosa; Pseudomonas fluorescens; Pulmonary Artery; Pulmonary Disease, Chronic Obstructive; Pulmonary Gas Exchange; Pulmonary Veins; Pyrazoles; Pyridines; Pyrimidines; Qualitative Research; Quinoxalines; Rabbits; Random Allocation; Rats; Rats, Sprague-Dawley; Rats, Wistar; Receptors, Histamine H3; Receptors, Immunologic; Receptors, Transferrin; Recombinant Proteins; Recurrence; Reference Values; Referral and Consultation; Regional Blood Flow; Registries; Regulon; Renal Insufficiency, Chronic; Reperfusion Injury; Repressor Proteins; Reproducibility of Results; Republic of Korea; Research Design; Resistance Training; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Insufficiency; Resuscitation; Retinal Dehydrogenase; Retreatment; Retrospective Studies; Reverse Transcriptase Inhibitors; Rhinitis, Allergic; Ribosomal Proteins; Ribosomes; Risk Assessment; Risk Factors; Ritonavir; Rivers; RNA Interference; RNA-Seq; RNA, Messenger; RNA, Ribosomal, 16S; RNA, Small Interfering; Rosuvastatin Calcium; Rural Population; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Salivary Ducts; Salivary Gland Neoplasms; San Francisco; SARS-CoV-2; Satiation; Satiety Response; Schools; Schools, Pharmacy; Seasons; Seawater; Selection, Genetic; Sequence Analysis, DNA; Serine-Threonine Kinase 3; Sewage; Sheep; Sheep, Domestic; Shock, Hemorrhagic; Signal Transduction; Silver; Silymarin; Single Photon Emission Computed Tomography Computed Tomography; Sirolimus; Sirtuin 1; Skin; Skin Neoplasms; Skin Physiological Phenomena; Sleep Initiation and Maintenance Disorders; Social Class; Social Participation; Social Support; Soil; Soil Microbiology; Solutions; Somatomedins; Soot; Specimen Handling; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis; Spinal Fractures; Spirometry; Staphylococcus aureus; STAT1 Transcription Factor; STAT3 Transcription Factor; Streptomyces coelicolor; Stress, Psychological; Stroke; Stroke Volume; Structure-Activity Relationship; Students, Medical; Students, Pharmacy; Substance Abuse Treatment Centers; Sulfur Dioxide; Surface Properties; Surface-Active Agents; Surveys and Questionnaires; Survival Analysis; Survival Rate; Survivin; Sweden; Swine; Swine, Miniature; Sympathetic Nervous System; T-Lymphocytes, Regulatory; Talaromyces; Tandem Mass Spectrometry; tau Proteins; Telemedicine; Telomerase; Telomere; Telomere Homeostasis; Temperature; Terminally Ill; Th1 Cells; Thiamethoxam; Thiazoles; Thiophenes; Thioredoxin Reductase 1; Thrombosis; Thulium; Thyroid Cancer, Papillary; Thyroid Carcinoma, Anaplastic; Thyroid Neoplasms; Time Factors; Titanium; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; TOR Serine-Threonine Kinases; Transcription Factor AP-1; Transcription Factors; Transcription, Genetic; Transcriptional Activation; Transcriptome; Transforming Growth Factor beta1; Transistors, Electronic; Translational Research, Biomedical; Transplantation Tolerance; Transplantation, Homologous; Transportation; Treatment Outcome; Tretinoin; Tuberculosis, Multidrug-Resistant; Tuberculosis, Pulmonary; Tubulin Modulators; Tumor Microenvironment; Tumor Necrosis Factor Inhibitors; Tumor Necrosis Factor-alpha; Twins; Ultrasonic Therapy; Ultrasonography; Ultraviolet Rays; United States; Up-Regulation; Uranium; Urethra; Urinary Bladder; Urodynamics; Uromodulin; Uveitis; Vasoconstrictor Agents; Ventricular Function, Left; Vero Cells; Vesicular Transport Proteins; Viral Nonstructural Proteins; Visual Acuity; Vital Capacity; Vitamin D; Vitamin D Deficiency; Vitamin K 2; Vitamins; Volatilization; Voriconazole; Waiting Lists; Waste Disposal, Fluid; Wastewater; Water Pollutants, Chemical; Whole Genome Sequencing; Wine; Wnt Signaling Pathway; Wound Healing; Wounds and Injuries; WW Domains; X-linked Nuclear Protein; X-Ray Diffraction; Xanthines; Xenograft Model Antitumor Assays; YAP-Signaling Proteins; Yogurt; Young Adult; Zebrafish; Zebrafish Proteins; Ziziphus

Overexpression of wild-type MN1 is a negative prognostic factor in patients with acute myeloid leukemia (AML) with normal cytogenetics. We evaluated whether MN1 plays a functional role in leukemogenesis. We demonstrate using retroviral gene transfer and bone marrow (BM) transplantation that MN1 overexpression rapidly induces lethal AML in mice. Insertional mutagenesis and chromosomal instability were ruled out as secondary aberrations. MN1 increased resistance to all-trans retinoic acid (ATRA)-induced cell-cycle arrest and differentiation by more than 3000-fold in vitro. The differentiation block could be released by fusion of a transcriptional activator (VP16) to MN1 without affecting the ability to immortalize BM cells, suggesting that MN1 blocks differentiation by transcriptional repression. We then evaluated whether MN1 expression levels in patients with AML (excluding M3-AML) correlated with resistance to ATRA treatment in elderly patients uniformly treated within treatment protocol AMLHD98-B. Strikingly, patients with low MN1 expression who received ATRA had a significantly prolonged event-free (P = .008) and overall (P = .04) survival compared with patients with either low MN1 expression and no ATRA, or high MN1 expression with or without ATRA. MN1 is a unique oncogene in hematopoiesis that both promotes proliferation/self-renewal and blocks differentiation, and may become useful as a predictive marker in AML treatment.

Topics: Aged; Animals; Antineoplastic Agents; Biomarkers, Tumor; Bone Marrow Cells; Cell Cycle; Cell Differentiation; Cell Transformation, Viral; Chromosomal Instability; Disease-Free Survival; Drug Resistance, Neoplasm; Gene Expression Regulation, Leukemic; Hematopoiesis; Herpes Simplex Virus Protein Vmw65; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Mutagenesis, Insertional; Predictive Value of Tests; Recombinant Fusion Proteins; Repressor Proteins; Retroviridae; Risk Factors; Survival Rate; Trans-Activators; Transduction, Genetic; Tretinoin; Tumor Suppressor Proteins

The c-myb protooncogene as well as its transforming derivate, the v-myb oncogene code for transcription factors. They regulate transcription of specific target genes thus controlling proliferation, differentiation and apoptosis of hematopoietic cells. Up-regulation of the c-myb expression or rearrangement/amplification of the myb locus are often involved in leukemogenesis. Enforced myb expression blocks differentiation of various leukemic cell lines. Human promonocytes U937 can be induced to differentiate to monocyte/macrophage-like cells using phorbol esters or to granulocytes using retinoic acid. In order to investigate transforming capability of v-myb, we expressed the v-myb oncogene of avian myeloblastosis virus in U937 cells. We found that v-Myb efficiently suppressed formation of macrophages upon treatment with phorbol ester. Some features of granulocytic differentiation of retinoic acid-treated U937 cells were affected by the v-Myb protein as well. These results document that v-Myb is significantly involved in control of myeloid differentiation.

Topics: Cell Differentiation; Cell Transformation, Viral; Gene Expression; Genes, myb; Granulocytes; Humans; Macrophages; Monocytes; Phorbol Esters; Transfection; Tretinoin; U937 Cells

In uterine cervical cancer, certain oncogenic HPV types are considered as key etiologic factor. But the progression of HPV associated cervical precancerous lesions depends on many other factors such as oncogenes, immune system, anti-viral factors etc. This study is therefore focused on the effect of an important dietary anti-viral factor called All Trans Retinoic Acid (ATRA) on the development of HPV associated cervical cancer as it is found higher in poor socioeconomic people.. We analyzed a total population of 130 including control subjects who have no complaints of uterine cervical lesions and the HPV-6/11, 16/18 infected cases of low grade squamous intraepithelial lesions [SIL], high grade squamous intraepithelial lesions [HSIL], and invasive cancers, for serum ATRA level. This study also focused to find out the association of serum ATRA level with the proliferation status in terms of proliferating cell nuclear antigen (PCNA) expression as it is an anti-proliferation agent and with the grades of cervical lesions, using SPSS statistical package.. The results showed a highly significant negative association for serum ATRA level with different stages of cervical lesions (F = 3.305; P = 0.000) by one-way ANOVA and with intensity of PCNA expression (r = -0.825; P < 0.01) by Pearson's correlation test. A highly significant association was observed for the PCNA expression with the grades of cervical lesions too (F = 37.89; P = 0.000). Further, we found from our data that all the invasive cancer cases were infected with HPV-16/18 and none with HPV-6/11. Hence, we analyzed the association of serum ATRA level with HPV-16/18 infected preinvasive cases in developing invasiveness, by Fisher's Exact Test, using Graph Pad Prism as shown in Table 1. The results show an odds ratio (OR) of 36.93 and a relative risk (RR) of 4.99 with an 95% interval being 2.896 to 8.603, which is significant at the level of P = 0.0001 for the reduced [<0.6 mug/ml] serum ATRA level in developing invasive cancer in HPV-16/18 infected preinvasive cases.. All these results suggest that the serum ATRA level highly influences the progression of cervical lesions to invasive cancer and can be therefore aimed as a marker for progression in combination with HPV-16/18, which helps to enhance the modalities of therapy towards cost effectiveness.

Topics: Adult; Cell Growth Processes; Cell Transformation, Viral; Female; Humans; Middle Aged; Neoplasm Staging; Papillomaviridae; Papillomavirus Infections; Polymerase Chain Reaction; Proliferating Cell Nuclear Antigen; Tretinoin; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms

Adeno-associated virus (AAV) can infect a wide variety of mammalian cell types and is capable of infecting both dividing and non-dividing cell populations. Here we report the construction of a recombinant AAV vector which expresses the SV40 large T protein (AAV-T) and the use of this vector to immortalize primary cells from embryonic rat mesencephalon.. The AAV-T vector was constructed by introducing the BamH1 fragment of the pCMV/SVE/Neo plasmid containing T antigen and SV40 regulatory elements into the JM48 plasmid containing the inverted terminal repeats of AAV. Neuronal cultures from E-12 rat mesencephalon were grown in defined media supplemented with basic fibroblast growth factor. These cells were infected with the AAV-T vector.. A cell line (designated RMAT) and six subclones were established from these cultures through multiple passages. This cell line was immunoreactive for SV40 large T antigen and the cytoskeletal proteins nestin and vimentin. Morphological differentiation and expression of neurofilament 160 kDa were induced by exposure to dibutyrl cyclic AMP. Immunoassays performed to measure endogenous production of growth factors showed that RMAT cells produced high levels of platelet-derived growth factor (PDGF).. AAV may be a useful vector for the transduction of oncogenes to produce cell lines.

Topics: 1-Methyl-3-isobutylxanthine; Animals; Antigens, Polyomavirus Transforming; Antineoplastic Agents; Blotting, Western; Bucladesine; Cell Differentiation; Cell Size; Cell Transformation, Viral; Cells, Cultured; Dependovirus; Drug Interactions; Embryo, Mammalian; Enzyme-Linked Immunosorbent Assay; Female; Fibroblast Growth Factors; Gene Expression Regulation, Viral; Genetic Vectors; Immunohistochemistry; Intermediate Filament Proteins; Mesencephalon; Nerve Growth Factors; Nerve Tissue Proteins; Nestin; Neurons; Phosphodiesterase Inhibitors; Platelet-Derived Growth Factor; Pregnancy; Rats; Time Factors; Transduction, Genetic; Tretinoin

We showed earlier that cellular retinol-binding protein (CRBP) expression is downregulated in a subset of human breast cancers. We have now investigated the outcome of ectopic CRBP expression in MTSV1-7 cells, a SV40 T antigen-transformed human breast epithelial cell line devoid of endogenous CRBP expression. We found that: (i) CRBP did not inhibit adherent cell growth but suppressed foci formation in post-confluent cultures and colony formation in soft agar; (ii) this effect was due to CRBP inhibition of cell survival, as demonstrated by viability and TUNEL assays of cells in soft-agar or plated on polyHEMA-coated dishes; (iii) CRBP inhibited protein kinase B/Akt activation in cells in suspension but not in adherent cells and the CRBP suppression of anchorage-independent growth was mimicked by cell treatment with the phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002; (iv) CRBP enhanced retinyl ester formation and storage but did not regulate retinoic acid synthesis or retinoic acid receptor activity. Ectopic CRBP-mediated inhibition of anchorage-independent cell survival and colony formation in the absence of significantly altered responses to either retinol or retinoic acid was also documented in T47D human breast cancer cells. In conclusion, the data suggest two novel and linked CRBP functions in mammary epithelial cells: inhibition of the PI3K/Akt survival pathway and suppression of anchorage-independent growth.

Topics: Agar; Apoptosis; Breast; Breast Neoplasms; Carrier Proteins; Cell Adhesion; Cell Division; Cell Line, Transformed; Cell Transformation, Viral; Chromones; Contact Inhibition; Enzyme Activation; Enzyme Inhibitors; Fatty Acid-Binding Protein 7; Fatty Acid-Binding Proteins; Female; Humans; Morpholines; Neoplasm Proteins; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Receptors, Retinoic Acid; Retinol-Binding Proteins; Retinol-Binding Proteins, Cellular; Signal Transduction; Simian virus 40; Tretinoin; Tumor Stem Cell Assay; Tumor Suppressor Proteins; Vitamin A

We have previously demonstrated that 13-cis-retinoic acid (RA), 9-cis-RA and all-trans-RA (ATRA) powerfully inhibit the proliferation of Epstein-Barr virus-immortalized B-lymphoblastoid cell lines (LCLs). The aim of the present study was to assess whether these compounds are effective at inhibiting the growth of B cells at more advanced stages of lymphomagenesis, including fully transformed B lymphocytes. To this end, c-myc-transfected LCLs (myc-LCLs) and Burkitt's lymphoma (BL) cell lines were used. We report that 13-cis-RA, 9-cis-RA and ATRA also markedly inhibit the proliferation of myc-LCLs by inducing G(0)/G(1) growth arrest as well as enhancing rates of apoptosis. Conversely, all but 1 (DG75) of the 8 BL cell lines investigated were poorly RA-responsive. Moreover, unlike LCLs and myc-LCLs, RA-treated DG75 cells rapidly resumed proliferation upon drug removal. Analysis of cell cycle-regulatory proteins showed that, as in LCLs, strong up-regulation of p27(Kip-1) and increased levels of under-phosphorylated pRb and p130 were detected in RA-treated DG75 cells. While the catalytic activity of all 3 G(1)-associated CDKs (CDK2, CDK4 and CDK6) was strongly inhibited in RA-treated LCLs, only CDK2-associated kinase activity was reduced in DG75 cells arrested in G(0)/G(1) by RA. Moreover, RA-treated DG75 cells failed to show the down-regulation of cyclin D3 observed in LCLs. Use of receptor-selective agonists and antagonists showed that in LCLs and RA-responsive BL cells, RA-induced growth arrest is mainly mediated by RARalpha. The RARalpha-selective agonist Ro 40-6055 was also effective at very low concentrations (10(-10) M). Nevertheless, comparable levels of RARalpha mRNA were found in RA-responsive and -resistant BL cell lines, indicating that mechanisms different from transcriptional deregulation of RARalpha probably underlie the differential responsiveness of BL cells.

Topics: Antineoplastic Agents; B-Lymphocytes; Burkitt Lymphoma; Cell Division; Cell Line, Transformed; Cell Transformation, Viral; Gene Transfer Techniques; Genes, myc; Herpesvirus 4, Human; Humans; Proto-Oncogene Proteins c-myc; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Signal Transduction; Tretinoin; Tumor Cells, Cultured

In our in vitro model of human cell carcinogenesis, normal human foreskin keratinocytes (HKc) transfected with human papillomavirus type 16 DNA (HKc/HPV16) progress toward malignancy through several phenotypically defined and reproducible "steps" that include immortalization, growth factor independence (HKc/GFI), differentiation resistance (HKc/DR), and ultimately malignant conversion. While HKc/HPV16 are very sensitive to growth inhibition by all-trans-retinoic acid (RA) at early passages, they lose their sensitivity to RA during progression in culture. However, gel mobility shift assays using the retinoid response elements DR1 and DR5 showed no changes in binding activity of nuclear extracts obtained from HKc/HPV16 at different stages of in vitro progression. Similarly, Western blot analyses for retinoic acid receptor gamma-1 and the retinoid X receptors failed to reveal any decreases in the levels of these retinoid receptors throughout progression. In addition, luciferase activity driven by the SV40 promoter with a DR5 enhancer element was activated following RA treatment of HKc/DR that were resistant to growth inhibition by RA. Since RA induces transforming growth factor-beta2 (TGF-beta2) in normal HKc and HKc/HPV16, we investigated whether this response changed during progression. Again, RA induced TGF-beta2 mRNA in early and late passage HKc/HPV16, HKc/GFI, and HKc/DR approximately to the same extent, confirming that the RA signaling pathways remained intact during in vitro progression despite the fact that the cells become resistant to growth inhibition by RA. We then investigated the sensitivity of HKc/HPV16 to growth inhibition by TGF-beta. While early passage HKc/HPV16 were as sensitive as normal HKc to growth inhibition by TGF-beta1 and TGF-beta2, the cells became increasingly resistant to both TGF-beta isotypes during in vitro progression. In addition, while both RA and TGF-beta produced a decrease in the levels of mRNA for the HPV16 oncogenes E6 and E7 in early passage HKc/HPV16, this effect was also lost at later stages of progression. Finally, blocking anti-TGF-beta antibodies partially prevented RA inhibition of growth and E6/E7 expression in early passage HKc/HPV16. Taken together, these data strongly suggest that inhibition of growth and HPV16 early gene expression in HKc/HPV16 by RA is mediated by TGF-beta and that a loss of RA sensitivity is linked to TGF-beta resistance rather than alterations in RA signaling.

Topics: Antineoplastic Agents; Cell Division; Cell Transformation, Viral; Cells, Cultured; Drug Resistance, Neoplasm; Humans; Keratinocytes; Papillomaviridae; Signal Transduction; Transforming Growth Factor beta; Tretinoin

Retinoids are important agents which regulate differentiation and proliferation processes in various cell types, including cancer cells. Growth arrest and induction of terminal differentiation demonstrate the tumor-suppressive effects of retinoids on leukemic cells. We studied differentiation, proliferation, and death processes in the cell line of v-myb-transformed monoblasts BM2 and their retinoic acid receptor (RAR) alpha- and retinoid X receptor (RXR) alpha-expressing derivatives after exposure to four different retinoids: all-trans retinoic acid, 9-cis retinoic acid, TTNPB, and LG1000153. The effects of retinoids on the phenotype of BM2, BM2RAR, and BM2RXR cells were correlated with the transcription activation function of the v-Myb oncoprotein of avian myeloblastosis virus. We found that the efficiency of terminal differentiation of BM2RAR and BM2RXR cells induced by retinoids is indirectly proportional to the v-Myb transcription activation activity. In contrast, the effects of liganded retinoid receptors on growth of BM2 cells are more complex. Activated RAR protein induces growth inhibition of BM2 cells by suppression of v-Myb function. However, liganded RXR protein is less efficient in cell cycle arrest and rather decreases cellular viability. This process can occur in the presence of active v-Myb protein. These results suggest that ligand-activated RARalpha protein is primarily engaged in control of proliferation and differentiation of v-myb-transformed monoblasts, while activated RXRalpha protein controls their differentiation and death.

Topics: Alitretinoin; Animals; Benzoates; Cell Count; Cell Differentiation; Cell Division; Cell Survival; Cell Transformation, Viral; Genes, myb; Humans; Ligands; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Retinoid X Receptors; Retinoids; Transcription Factors; Transcriptional Activation; Tretinoin; Tumor Cells, Cultured

Retinoids mediate the normal growth of a variety of epithelial cells and may play an important role in the chemoprevention of breast cancer. Despite the widespread clinical use of retinoids, specific target genes that are regulated by retinoids are relatively poorly characterized. We reported previously that all-trans-retinoic acid (ATRA) mediates G1-S-phase arrest in normal human mammary epithelial cells (HMECs). The tumor suppressor gene p53 is thought to be a critical regulator of G1-S-phase arrest mediated by DNA-damaging agents such as chemotherapy and radiation. The role of p53 protein expression in G1-S-phase arrest mediated by the differentiating agent ATRA is unknown. Increased expression of p53 protein is observed in ATRA-treated HMECs at 72 h; however, initiation of G1-S-phase arrest starts at 24 h, suggesting that this observed induction of p53 is a secondary event. Using retroviral-mediated gene transfer, we expressed the E6 protein of the human papillomavirus strain 16 (HPV-16) in HMECs. The HPV-16 E6 protein binds to p53 and targets it for degradation. Western analysis confirmed that HPV-16 E6-transduced HMECs had markedly decreased levels of p53 protein expression. Suppression of cellular p53 levels in HMECs did not alter the sensitivity of HMECs to ATRA-mediated growth arrest. Our studies suggest that ATRA-mediated G1-S-phase arrest is independent of the level of p53 protein expression. We also tested the ability of estrogen and antiestrogens to induce growth arrest in HMECs lacking p53 expression and found no decrease in the sensitivity of these cells to these agents. Our results emphasize the chemotherapeutic potential of ATRA and antiestrogens, particularly for suppressing the growth of tumors lacking functional p53.

Topics: Antigens, Viral; Apoptosis; Breast; Cell Cycle; Cell Division; Cell Transformation, Viral; Cells, Cultured; Cyclin D1; Cysteine Endopeptidases; Epithelial Cells; Female; G1 Phase; Gene Expression Regulation; Genetic Vectors; Humans; Multienzyme Complexes; Oncogene Proteins, Viral; Proteasome Endopeptidase Complex; Repressor Proteins; Retroviridae; S Phase; Tretinoin; Tumor Suppressor Protein p53

Immortalization of chondrocytes by SV40 T Ag has often been reported to trigger the loss of expression of type II collagen, one of the main differentiation markers, although some immortalized chondrocyte lines maintaining a differentiated phenotype have also been described. Here, we show using transient cotransfections in differentiated chondrocytes that, in contrast to c-src, neither SV40 T Ag, nor c-myc, decreases col2a1 transcriptional activity. Then, we report the possibility of immortalizing rabbit articular chondrocytes by expression of SV40 T Ag controlled by the col2a1 promoter and enhancer (pCol2SV). This strategy allows one to select within a population of differentiated chondrocytes those which are able to maintain functional regulation of the col2a1 gene through long-term culture. In precrisis pCol2SV-transfected chondrocytes, all-trans-retinoic acid, a down-regulator of col2a1 expression, induced apoptosis, strongly suggesting the strict control of T Ag expression by col2a1 regulatory sequences. Some pCol2SV-transfected chondrocytes were definitively immortalized, after a short crisis period. However, type II collagen synthesis was restricted to a small proportion of cells, which went on to decrease with subculture, while the proportion of cells expressing T Ag was not affected. In these postcrisis cells, T Ag remained at least partially under the control of functional col2a1 regulatory elements as assessed by all-trans-retinoic acid down-regulation.

Topics: Animals; Antigens, Polyomavirus Transforming; Apoptosis; Cell Differentiation; Cell Line, Transformed; Cell Transformation, Viral; Chondrocytes; Collagen; Down-Regulation; Enhancer Elements, Genetic; Fluorescent Antibody Technique, Indirect; Gene Expression Regulation; Plasmids; Promoter Regions, Genetic; Rabbits; Rats; Simian virus 40; Transcription, Genetic; Transfection; Tretinoin

Tumor cells expressing the herpes simplex virus-thymidine kinase (HSV-tk) gene become sensitive to ganciclovir (GCV), and the phenomenon by which tumor cells surrounding the HSV-tk expressing cells also become sensitive to GCV is known as the "bystander effect." The purpose of this study was to investigate the bystander effect in human lung-cancer cell lines, and the role of gap-junctional intercellular communication as the mechanism responsible for it. Gap-junctional intercellular communication was measured both with a dye-transfer assay involving single-cell microinjection of Lucifer Yellow and with a PKH26/calcein-AM double-dye-transfer assay. Significant bystander tumoricidal effect was observed in lung-cancer cell lines when cultured cells contained only 10% HSV-tk expressing cells. This was also observed to occur with cell lines of different origin or from different species. Although gap-junctional intercellular communication characterized by rapid transfer of Lucifer Yellow was not observed, we did detect gap-junctional communication marked by the slow transfer of calcein-AM in lung-cancer cell lines. However, neither an inhibitor (1-octanol) nor an enhancer (all trans-retinoic acid [ATRA]) of gap-junctional communication affected the extent of the bystander effect. These findings suggest that low levels of gap-junctional communication may be efficient for producing the bystander effect in lung-cancer cells, or that other mechanisms may underlie this effect. Although gap-junctional communication may play an important role in generating the bystander effect in tumor cells expressing the HSV-tk gene, further knowledge of the mechanism of this effect may help improve the treatment of lung cancer with an HSV-tk system.

Topics: 1-Octanol; Animals; Antimetabolites, Antineoplastic; Carcinoma; Cell Communication; Cell Division; Cell Transformation, Viral; Coculture Techniques; Ganciclovir; Gap Junctions; Genetic Vectors; Humans; Lung Neoplasms; Mice; Moloney murine leukemia virus; Simplexvirus; Thymidine Kinase; Tretinoin; Tumor Cells, Cultured

Human papillomaviruses (HPVs) and cigarette smoking are epidemiologically associated with cervical cancer. We recently found that HEN-16 and HEN-16-2 HPV type 16-immortalized endocervical cells form tumors after treatment with cigarette smoke condensate and derived 2 tumor cell line cultures, HEN-16T and HEN-16-2T, respectively. Here, we examine the molecular pathologic effect of tumorigenesis. HEN-16T and HEN-16-2T exhibit unchanged status and expression of integrated HPV 16 DNA. However, the expression of the cytokeratin CK7 and CK13 endocervical cell markers is more homogeneous in monolayer and organotypic raft cultures after tumorigenesis. For the effect of retinoic acid on monolayers for growth inhibition, HEN-16T were significantly less sensitive than the normal and immortalized non-tumorigenic cells. HEN-16-2T were completely resistant. Moreover, the rafts from both tumorigenic cell line cultures were resistant to retinoic acid and continued to display thick rafts and homogeneous severe dysplasia/carcinoma in situ. In contrast, the non-malignant HEN-16 and HEN-16-2 rafts were thinner, and treatment with retinoic acid blocked the formation of severe dysplasia, reconstructing an epithelium resembling that of the normal endocervix. Our results support the significance of non-viral factors in the mechanism by which cigarette smoking induces tumorigenesis in the late stages of HPV-initiated progression to cervical cancer. Importantly, our data indicate that the sensitivity to retinoic acid of the HPV-containing endocervical cells is lost following tumorigenesis in vitro and possibly in women.

Topics: Cell Division; Cell Line, Transformed; Cell Transformation, Neoplastic; Cell Transformation, Viral; DNA, Viral; Drug Resistance; Female; Humans; Keratins; Keratolytic Agents; Papillomaviridae; Tretinoin; Uterine Cervical Neoplasms

We previously established a human fibroblast cell line, HFL 6-2, that contains a temperature sensitive simian virus 40 (SV40) T antigen, permitting cell growth at 35 degrees C but restricting growth at 39 degrees C. p21 (Waf1/Cip1) was significantly induced by temperature shifts in HFL 6-2 cells. Here we show that all-trans-retinoic acid (RA) treatment prevented the growth restriction of HFL 6-2 cells at 39 degrees C. In the presence of RA, HFL 6-2 cells proliferated into sizeable colonies even at 39 degrees C. [3H]Thymidine incorporation and flow cytometry analysis revealed that cells exposed to RA maintained DNA synthesis at 39 degrees C. Prevention of growth restriction by RA was correlated with a lack of induction of p21 at the transcription level. These observations suggest that RA may prevent the senescence process by repressing p21 gene expression, and perturb the growth regulation of somatic cells.

Topics: Antigens, Polyomavirus Transforming; Cell Division; Cell Line, Transformed; Cell Transformation, Viral; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Down-Regulation; Fibroblasts; Gene Expression Regulation; Hot Temperature; Humans; Promoter Regions, Genetic; Tretinoin

Natural and synthetic retinoids have proved to be effective in the treatment and prevention of various human cancers. In the present study, we investigated the effect of retinoids on Epstein-Barr virus (EBV)-infected lymphoblastoid cell lines (LCLs), since these cells closely resemble those that give rise to EBV-related lymphoproliferative disorders in the immunosuppressed host. All six compounds tested inhibited LCL proliferation with no significant direct cytotoxicity, but 9-cis-retinoic acid (RA), 13-cis-RA, and all-trans-RA (ATRA) were markedly more efficacious than Ro40-8757, Ro13-6298, and etretinate. The antiproliferative action of the three most effective compounds was confirmed in a large panel of LCLs, thus appearing as a generalized phenomenon in these cells. LCL growth was irreversibly inhibited even after 2 days of treatment at drug concentrations corresponding to therapeutically achievable plasma levels. Retinoid-treated cells showed a marked downregulation of CD71 and a decreased S-phase compartment with a parallel accumulation in Gzero/ G1 phases. These cell cycle perturbations were associated with the upregulation of p27 Kip1, a nuclear protein that controls entrance and progression through the cell cycle by inhibiting several cyclin/cyclin-dependent kinase complexes. Unlike what is observed in other systems, the antiproliferative effect exerted by retinoids on LCLs was not due to the acquisition of a terminally differentiated status. In fact, retinoid-induced modifications of cell morphology, phenotype (downregulation of CD19, HLA-DR, and s-Ig, and increased expression of CD38 and c-Ig), and IgM production were late events, highly heterogeneous, and often slightly relevant, being therefore only partially indicative of a drug-related differentiative process. Moreover, EBV-encoded EBV nuclear antigen-2 and latent membrane protein-1 proteins were inconstantly downregulated by retinoids, indicating that their growth-inhibitory effect is not mediated by a direct modulation of viral latent antigen expression. The strong antiproliferative activity exerted by retinoids in our experimental model indicates that these compounds may represent a useful tool in the medical management of EBV-related lymphoproliferative disorders of immunosuppressed patients.

Topics: Antigens, CD; Antigens, Differentiation, B-Lymphocyte; Antigens, Surface; B-Lymphocytes; Benzoates; Cell Cycle; Cell Cycle Proteins; Cell Division; Cell Line, Transformed; Cell Transformation, Viral; Cyclin-Dependent Kinase Inhibitor p27; Etretinate; Gene Expression Regulation; Growth Inhibitors; Herpesvirus 4, Human; Humans; Isotretinoin; Microtubule-Associated Proteins; Morpholines; Receptors, Transferrin; Retinoids; Tretinoin; Tumor Suppressor Proteins

Topics: Alpharetrovirus; Animals; Cell Transformation, Viral; Chick Embryo; Erythropoiesis; Gene Expression Regulation, Developmental; Oncogene Proteins v-erbA; Polymerase Chain Reaction; Receptors, Retinoic Acid; Tretinoin

Retinoids (vitamin A and its natural and synthetic derivatives) have shown potential as chemopreventive agents, and diets poor in vitamin A and/or its precursor beta-carotene have been linked to an increased risk of cancer at several sites including the cervix. Human papillomavirus (HPV) plays an important role in the etiology of cervical cancer. We have developed an in vitro model of cancer progression using human keratinocytes (HKc) immortalized by HPV16 DNA (HKc/HPV16). Although immortal, early passage HKc/HPV16, like normal HKc, require epidermal growth factor (EGF) and bovine pituitary extract (BPE) for proliferation and undergo terminal differentiation in response to serum and calcium. However, following prolonged culture, growth factor independent HKc/HPV16 lines that no longer require EGF and BPE can be selected (HKc/GFI). Further selection of HKc/GFI produces lines that are resistant to serum- and calcium- induced terminal differentiation (HKc/DR). HKc/DR, but not early passage HKc/HPV16, are susceptible to malignant conversion following transfection with viral Harvey ras or Herpes simplex virus type II DNA. We have investigated the sensitivity of low to high passage HKc/HPV16 and HKc/GFI to growth control by all-trans-retinoic acid (RA, an active metabolite of vitamin A). Early passage HKc/HPV16 are very sensitive to growth inhibition by RA, and in these cells RA decreases the expression of the HPV16 oncogenes E6 and E7. However, as the cells progress in culture they lose their sensitivity to RA. Growth inhibition by RA may be mediated through the cytokine transforming growth factor-beta (TGF-beta), a potent inhibitor of epithelial cell proliferation. RA treatment of HKc/HPV16 and HKc/GFI results in a dose-and time-dependent induction (maximal of 3-fold) in secreted levels of TGF-beta. Also, Northern blot analysis of mRNA isolated from HKc/HPV16 demonstrated that RA treatment induced TGF-beta 1 and TGF-beta 2 expression about 3- and 50-fold, respectively. We next studied the effect of TGF-beta 1 and TGF-beta 2 on the proliferation of early to late passage HKc/HPVa6, HKc/GFI and HKc/DR. While early passage HKc/HPV16 were as sensitive as normal HKc to growth inhibition by TGF-beta 1 and TGF-beta 2, the cells became increasingly resistant to TGF-beta during in vitro progression, with the proliferation of HKc/DR being virtually unaffected by TGF-beta 1 or TGF-beta 2 treatment. Overall, loss of growth inhibition by RA parallels loss of TGF-beta sensi

Topics: Cell Division; Cell Line, Transformed; Cell Transformation, Neoplastic; Cell Transformation, Viral; Female; Humans; Keratinocytes; Male; Models, Biological; Papillomaviridae; RNA, Messenger; Transforming Growth Factor beta; Tretinoin; Uterine Cervical Neoplasms

Adult T cell leukemia derived factor (ADF), which was first reported as a cytokine-like factor produced by human T lymphotropic virus I (HTLV-I)-transformed T cells, is a human homologue of thioredoxin (TRX). ADF/TRX has multiple functions including growth promoting, antiapoptotic and radical scavenging activities, and is also involved in a wide variety of intracellular processes as a dithiol reducing agent in cooperation with the NADPH-TRX reductase system. In HTLV-1(+) T cell lines, HuT 102 and MT-2, which are ADF/TRX high producing cells, we found that the expression of ADF/TRX was dependent on the cell cycle and peaked at S phase. The reducing activity of ADF/TRX in these cells was also dependent on the cell cycle and elevated in S phase as determined by NADPH-dependent insulin degradation assay. Furthermore, inhibitors of TRX reductase, 13-cis-retinoic acid (13-cis-RA) and azelaic acid, inhibited the DNA synthesis of these cells. In contrast, the residual expression and reducing activity of ADF/TRX in HTLV-I(-) T cell lines did not show any significant correlation with the cell cycle. There was no distinct inhibitory effect of 13-cis-RA or azelaic acid on the growth of these ADF/TRX low producing cells. These results indicate that a high level of reducing activity of the ADF/TRX system may be required for the cell division of these virally transformed cells. This suggests that the TRX reductase inhibitors including retinoid derivatives have a potential therapeutic utility for treatment of HTLV-1(+) T cell leukemia without any effect on HTLV-I(-) cells.

Topics: Cell Cycle; Cell Division; Cell Line, Transformed; Cell Transformation, Viral; Cytokines; Dicarboxylic Acids; Enzyme Inhibitors; Growth Substances; Human T-lymphotropic virus 1; Humans; Insulin; Neoplasm Proteins; T-Lymphocytes; Thioredoxin-Disulfide Reductase; Thioredoxins; Tretinoin; Tumor Cells, Cultured; Vitamin K

Mineralization was induced by glucocorticoid treatment in a human osteoblastic cell line derived from normal bone in vitro, designated SV-HFO, immortalized with simian virus 40 (CHIBA, H. et al. (1993). Jpn. J. Cancer Res., 84: 290-297). Mineralization was revealed by electron microscopy, von Kossa staining and electron spectroscopic analysis, which indicated that the Ca/P ratio was approximately 1.70, corresponding to the value of hydroxyapatite. The effect was dose- (10(-8)-10(-6) M) and time-dependent (days 7-28), was greatest at day 28, and was preceded by expression of alkaline phosphatase (ALP) and osteopontin (OPN). The ALP activity induced was highest at day 7, whereas OPN reached its highest level at day 28. When the induction of ALP activity was inhibited by 10(-4) M levamisole, mineralization of SV-HFO cells by glucocorticoid treatment was markedly reduced, suggesting that elevated ALP activity in the early phase is important in the mineralization of human osteoblastic cells. Glucocorticoid treatment did not alter cell proliferation. These results indicated that glucocorticoids play crucial roles in the formation of mineralized matrix in human osteoblasts by inducing differentiation of SV-HFO cells without modulating their proliferative activity.

Topics: Alkaline Phosphatase; Calcification, Physiologic; Calcitriol; Cell Division; Cell Line; Cell Transformation, Viral; Dose-Response Relationship, Drug; Fibroblast Growth Factor 2; Gene Expression; Glucocorticoids; Humans; Interleukin-4; Levamisole; Microscopy, Electron; Minerals; Osteoblasts; Protein Biosynthesis; Proteins; Simian virus 40; Spectrum Analysis; Time Factors; Transforming Growth Factor beta; Tretinoin

In a previous paper, we predicted that retinoic acid suppressed polyoma virus transformation of rat F111 fibroblasts by affecting the expression of one or more genes that are involved in signalling pathways normally activated by the viral mT oncogene (Talmage & Lackey, Oncogene 7, 1837-1845, 1992). We had identified the cellular c-fos proto-oncogene as a possible candidate target for both polyoma virus mT and retinoic acid regulated expression. In this report we present the results of experiments that demonstrate that retinoic acid does indeed inhibit transcriptional transactivation of the c-fos promoter by polyoma virus, as well as by calf serum and purified serum growth factors. Further experiments demonstrate that inhibition of c-fos expression with antisense fos RNA also prevents polyoma virus induced transformation. Restoration of c-fos expression, even in the presence of retinoic acid, restored transformation, indicating that retinoic acid inhibition of c-fos expression is sufficient to explain the retinoid suppression of transformation. These results identify the c-fos proto-oncogene as a key nuclear target for mT-dependent transformation and show that the anticarcinogenic properties of retinoic acid can be brought about by inhibiting c-fos expression.

Topics: Animals; Cell Line; Cell Transformation, Viral; Genes, fos; Polyomavirus; Proto-Oncogene Mas; Rats; RNA, Messenger; Transcription, Genetic; Tretinoin

We have used a model system of normal HKc and HKc immortalized by transfection with HPV16 DNA (HKc/HPV16) to investigate the effect of RA on the growth of HKc/HPV16 and the expression of the HPV16 oncogenes E6 and E7. These studies found that HKc/HPV16 are about 100-fold more sensitive than normal HKc to growth inhibition by RA in both clonal and mass culture growth assays. The precursor to RA, retinol, was also found to be a more potent inhibitor of growth of HKc/HPV16 than normal HKc while beta-carotene did not inhibit growth of either normal HKc or HKc/HPV16. No differences were observed in the rate of uptake of [3H]RA or [3H]retinol between normal HKc and HKc/HPV16. Northern blot analysis of mRNA extracted from HKc/HPV16 cultured in the absence or in the presence of 10(-7) M RA showed that the expression of the HPV16 oncogenes E6 and E7 as well as the early ORFs E2 and E5 is substantially reduced following RA treatment. In addition, protein levels of E6 and E7, as measured by immunofluorescence (E6 and E7) and Western blot (E7) are also decreased by RA treatment of HKc/HPV16. Since E6 and E7 are considered the oncogenes of HPV16, we explored the possibility that RA may interfere with HPV16-mediated immortalization of HKc. The RA treatment (1 nM) of normal HKc, during or immediately following transfection with HPV16 DNA, inhibited immortalization by about 95%. Overall, these results provide a direct biochemical basis for a role of dietary retinoids in the chemoprevention of HPV-induced cancers.

Topics: Cell Division; Cell Transformation, Neoplastic; Cell Transformation, Viral; Gene Expression; Humans; Keratinocytes; Oncogene Proteins, Viral; Papillomaviridae; Papillomavirus E7 Proteins; Protein-Tyrosine Kinases; Repressor Proteins; Tretinoin; Vitamin A

In the present study, we examine the effects of all-trans-retinoic acid (RA) and interferons-alpha and -gamma (IFN-alpha and IFN-gamma) on the growth of HPV16-immortalized cell lines, ECE16-1 and CaSki. Treating proliferating ECE16-1 cells with RA causes a concentration-dependent decrease in cell number. At 1 microM RA, cell growth is suppressed by 65% and the level of mRNA encoding cytokeratin K5, a biochemical marker of retinoid action, is also suppressed. In contrast, the level of transcript encoding the HPV16 oncogenes, E6 and E7, is reduced by only 5 to 10%. IFN-alpha at 1000 IU/ml or IFN-gamma at 200 IU/ml suppresses growth by 70%. This growth suppression by IFN-gamma is correlated with a > 90% reduction in E6/E7 mRNA levels. Additional growth suppression is observed upon simultaneous treatment with retinoid and interferon. Optimal suppression is observed in the presence of 200 IU/ml IFN-gamma and 1 microM RA. The rank order of effectiveness is IFN-gamma/RA > IFN-alpha/RA = IFN-gamma > RA > IFN-alpha. In contrast to the suppression of ECE16-1 cell growth, RA causes a concentration-dependent increase in CaSki cell number (50-60%) which is optimal at 1 microM RA. Cytokeratin K5 mRNA levels are markedly suppressed, and E6/E7 mRNA levels increased by 5% under these conditions. IFN-alpha at 1000 IU/ml or IFN-gamma at 200 IU/ml decreases CaSki cell growth by 20 and 45%, respectively, and 200 IU/ml of IFN-gamma reduce E6/E7 expression to undetectable levels. Addition of RA (1 microM) partially counters the IFN-dependent suppression of growth and E6/E7 mRNA levels. Our results suggest that retinoid-dependent changes in human papillomavirus-immortalized cervical cell proliferation are not always correlated with changes in E6/E7 transcript levels.

Topics: Animals; Cell Division; Cell Line; Cell Line, Transformed; Cell Transformation, Viral; Cervix Uteri; Dose-Response Relationship, Drug; Epidermal Growth Factor; Epithelial Cells; Epithelium; Female; Gene Expression; Humans; Interferon-alpha; Interferon-gamma; Kinetics; Mice; Mice, Nude; Oncogenes; Papillomaviridae; RNA, Messenger; Transcription, Genetic; Transplantation, Heterologous; Tretinoin; Uterine Cervical Neoplasms

In order to study how human papillomaviruses (HPVs) can alter normal epithelial cell differentiation, we looked at the response to retinoic acid (RA) of HPV-immortalized keratinocytes grown on organotypic cultures. Ten- to 30-fold higher concentrations of RA were required to block terminal differentiation in these cultures when compared to organotypic cultures of control cells. This resistance to RA was associated with maintained expression of differentiation-specific markers and, for keratin K1, Northern analysis showed that K1 mRNA was also detectable at 30-fold higher concentrations of RA in HPV organotypic cultures when compared to controls. These differences were reproducible and characteristic of all HPV cell lines studied, including very early passage HPV16-containing cell lines, suggesting that expression of HPV genes leads to this phenotype. Expression of epithelia-specific components of the RA response pathway was also studied by Northern analysis. At all RA concentrations, there were no detectable differences in overall levels of retinoic acid receptor gamma or cytosolic RA-binding protein II mRNA found. Retinoid X receptor alpha expression was also evaluated, and, in two of three HPV-immortalized cell lines, it was found to be 2 to 3 times as abundant as in controls. Although this difference in retinoid X receptor alpha expression could contribute to RA resistance, the mechanism involved in producing this resistance could not be fully elucidated in these studies. However, resistance to the effects of RA on epithelial differentiation is demonstrated in organotypic cultures of HPV-containing cells, and it is shown that this is associated with maintenance of RNA and protein expression of differentiation-associated genes at abnormally high concentrations of RA.

Topics: Cell Differentiation; Cell Line; Cell Transformation, Viral; Cytosol; Drug Resistance; Epithelial Cells; Epithelium; Humans; Keratinocytes; Nuclear Proteins; Organ Culture Techniques; Papillomaviridae; Phenotype; Receptors, Cytoplasmic and Nuclear; Receptors, Retinoic Acid; Retinoid X Receptors; Transcription Factors; Tretinoin

We previously reported that human keratinocytes (HKc) immortalized by transfection with human papillomavirus type 16 DNA (HKc/HPV16) are more sensitive than normal HKc to growth inhibition by retinoic acid (RA), and that RA treatment of HKc/HPV16 inhibits HPV16 E6/E7 mRNA expression (L. Pirisi et al., Cancer Res., 52: 187-193, 1992). We now demonstrate that HPV16 E2 and E5 mRNAs are also decreased by RA treatment of HKc/HPV16, indicating a general inhibition by RA on the expression of HPV16 early genes. In addition, protein levels of E6 and E7, as measured by immunofluorescence, are also decreased in a dose-dependent manner following RA treatment of HKc/HPV16. Since E6 and E7 are considered the oncogenes of HPV16, we explored the possibility that RA may interfere with HPV16-mediated immortalization of HKc. RA treatment (1 nM) of normal HKc, immediately following transfection with HPV16 DNA, inhibited immortalization by about 95%. Overall, these results provide a direct biochemical basis for a role of RA in the chemo-prevention of human papillomavirus-induced cancers.

Topics: Cell Transformation, Neoplastic; Cell Transformation, Viral; DNA-Binding Proteins; Gene Expression Regulation, Viral; Humans; Keratinocytes; Oncogene Proteins, Viral; Papillomaviridae; Papillomavirus E7 Proteins; Repressor Proteins; RNA, Messenger; Transfection; Tretinoin

Similar cellular responses are elicited by retinoic acid (RA) and transforming growth factor beta (TGF-beta). We investigated the ability of RA to modulate the production of TGF-beta in normal human keratinocytes (HKc) and HKc lines immortalized by transfection with human papillomavirus type 16 DNA (HKc/HPV16). RA treatment of both normal HKc and HKc/HPV16 resulted in a 2-3-fold induction in secreted levels of latent TGF-beta. The induction in TGF-beta secretion by RA was dose dependent, with significant increases observed with RA concentrations as low as 1-10 nM, and time dependent, with maximal induction occurring about 3 days after initiation of RA exposure. In addition, RA induced intracellular levels of TGF-beta almost 5-fold. Sandwich enzyme-linked immunosorbent assays were used to specifically quantify TGF-beta 1 and TGF-beta 2 secreted by normal HKc and HKc/HPV16 cultured in the absence or presence of RA. RA increased the secreted levels of latent TGF-beta 1 and TGF-beta 2 an average of 2- and 5-fold, respectively, with no major differences in the fold induction between normal HKc and HKc/HPV16. Northern blot analysis of mRNA isolated from HKc/HPV16 demonstrated that RA treatment induced specific transcripts for TGF-beta 1 and TGF-beta 2 about 3- and 50-fold, respectively. RA treatment of HKc had no significant effect on the binding affinity of TGF-beta for its receptors or receptor number. Normal HKc and HKc/HPV16 displayed similar dose-dependent inhibition of proliferation by TGF-beta 1. These studies indicate that RA may regulate growth control in both normal HKc and HKc/HPV16 by enhancing TGF-beta 1 and TGF-beta 2 production, which, after activation at the cell surface, could inhibit cellular proliferation in an autocrine and/or paracrine manner.

Topics: Cell Division; Cell Line, Transformed; Cell Transformation, Viral; DNA, Viral; Humans; Keratinocytes; Papillomaviridae; Transforming Growth Factor beta; Tretinoin

Human papillomavirus (HPV) type 16 (HPV16) is associated with a large percentage of cervical malignancies, and HPV16 DNA can immortalize human keratinocytes in vitro. The transforming ability of the virus resides primarily in the open reading frames E6 and E7. Retinoids are potent modulators of growth and differentiation of keratinocytes and have been shown to reverse cervical lesions resulting from HPV infection. We compared the sensitivity of normal human foreskin keratinocytes (HKc) and four immortalized HKc lines, independently obtained by transfection of different normal HKc strains with HPV16 DNA (HKc/HPV16), to growth control by retinoic acid (RA). All the HKc/HPV16 lines were 10- to 100-fold more sensitive than normal HKc to growth inhibition by RA in both clonal and mass culture growth assays. The precursor to RA, retinol, was also found to be a more potent inhibitor of growth of HKc/HPV16 than normal HKc, while beta-carotene did not inhibit growth of either normal HKc or HKc/HPV16. In addition, HKc/HPV16 lines were more sensitive than normal HKc to modulation of keratin expression by RA and retinol. No differences were observed in the rate of uptake of [3H]RA or [3H]retinol between normal HKc and HKc/HPV16. Dot blot analysis of RNA extracted from HKc/HPV16 cultured in the absence or in the presence of 10(-7) M RA showed that the expression of the HPV16 open reading frames E6 and E7 is reduced 2- to 4-fold by RA. In addition, Northern blot analysis demonstrated that RA inhibition of E6 and E7 expression was both dose and time dependent. Overall, these results suggest that the increased sensitivity of the HKc/HPV16 lines to growth control by RA may be mediated by an inhibition of the expression of HPV16 gene products which are required for the maintenance of continuous growth.

Topics: beta Carotene; Carotenoids; Cell Division; Cell Line, Transformed; Cell Transformation, Viral; Humans; Keratinocytes; Keratins; Papillomaviridae; RNA, Viral; Tretinoin; Vitamin A

Human cervical cells are a primary site of papillomavirus infection and 90% of all cervical tumors are positive for human papillomavirus (HPV) DNA. Over one-half million cases of HPV-associated cervical, vulvar, and penile cancers are reported per year. Yet, in spite of the magnitude of this problem, the effects of HPV infection on cervical cell growth and differentiation are not well characterized. To study these effects we have developed a clonal cell line of HPV-16-immortalized ectocervical epithelial cells, ECE16-1. In the present study we demonstrate that under normal growth conditions the cytokeratin content of ECE16-1 cells is dramatically altered compared to normal cervical cells; the level of K5, K6, K14, K16, and K17 is reduced and the level of K7, K8, and K19 is increased. We demonstrate that this change is largely due to a difference in the response of the cells to retinoids, as growth in retinoid-free medium produces a complete normalization of cytokeratin levels. Upon addition of natural and synthetic retinoids, the levels of cytokeratins K5, K6, K14, K16, and K17 are reduced, while the levels of cytokeratins K19, K7, and K8 are increased. Cytokeratin K13 levels are only slightly altered. The level of involucrin, a precursor of the cervical cell envelope (superficial cell), is not changed by immortalization nor is it regulated by retinoids. Transglutaminase activity is also not appreciably altered by immortalization; however, ECE16-1 cells make fewer envelopes than normal ECE cells. Our results clearly indicate that natural and synthetic retinoids suppress the differentiation of HPV transformed cervical cells. In early, low grade, cervical intraepithelial neoplasia, transcription of the HPV16 E6/E7 oncogenes is confined to the suprabasal layers. Our results suggest that retinoids, because they inhibit the differentiation of HPV16 immortalized cervical cells, may reduce the extent of viral oncogene transcription and thus be useful in slowing the neoplastic process.

Topics: Cell Differentiation; Cell Transformation, Viral; Cells, Cultured; Cervix Uteri; Epithelial Cells; Epithelium; Female; Humans; Keratins; Papillomaviridae; Phenotype; Retinoids; RNA, Messenger; Transcription, Genetic; Transfection; Tretinoin; Uterine Cervical Neoplasms; Virus Replication; Vitamin A

Proteins encoded by the adenovirus E1A oncogene are capable of positive and negative transcriptional regulation of both viral and cellular genes. E1A regulatory function is commonly thought to involve modifications of specific cellular factors that interact with responsive promoters. In this report we present evidence that E1A induces the activity of the jun/AP-1 transcription factor in three different cell types: P19, JEG-3, and HeLa. AP-1 binds to 12-O-tetradecanoylphorbol-13-acetate (TPA)-responsive elements (TREs); therefore, E1A might modulate a specific signal transduction pathway normally induced by activation of the protein kinase C. Binding of jun/AP-1 to a TRE is induced in all cell types studied when E1A is expressed. We observe that the expression of endogenous c-jun and jun B genes is induced by E1A, which directly transactivates the promoters of c-fos, c-jun, and jun B. Similar inducibility is obtained by treatment with retinoic acid and differentiation of P19-embryonal carcinoma cells. The E1A 13S product transactivates TRE sequences and cooperates with c-jun in the transcriptional stimulation. The 12S E1A product does not activate a TRE sequence, but cotransfection with c-jun circumvents this lack of stimulation. Coexpression of c-fos and E1A 12S, however, blocks the transactivation by c-jun, suggesting an important role for fos in determining the dominance of the 12S or 13S protein.

Topics: Adenovirus Early Proteins; Cell Differentiation; Cell Transformation, Viral; DNA-Binding Proteins; Gene Expression Regulation; Humans; In Vitro Techniques; Oncogene Proteins, Viral; Promoter Regions, Genetic; Protein Binding; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Regulatory Sequences, Nucleic Acid; Tetradecanoylphorbol Acetate; Transcription Factors; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured

Balb/3T3 fibroblasts were cultured in type I collagen gel and the effects of tretinoin (all-trans-retinoic acid) were examined on cell growth and the gel contraction produced by cells. Cell proliferation was suppressed and the degree of gel contraction was enhanced by the addition of 10(-7) and 10(-6) M tretinoin. Growth and gel contractility of transformed cells derived from the Balb/3T3 cells were not influenced by this agent. Addition of 12-O-tetradecanoylphorbol ester, which is known to antagonize tretinoin in several biological processes, enhanced gel contraction synergistically with tretinoin. These results suggest that tretinoin influences cell-to-collagen interactions.

Topics: Animals; Cell Division; Cell Line; Cell Transformation, Neoplastic; Cell Transformation, Viral; Collagen; Fibroblasts; Gels; Mice; Tetradecanoylphorbol Acetate; Tretinoin

Antioxidants were found to protect against the genotoxic effects of chemical and physical mutagenic and clastogenic agents. This study focused on the capacity of antioxidants to reduce an intrinsic and persistent chromosome instability. As a model system, strains of C127 cells, which were transformed by bovine papillomavirus (BPV) DNA and which carry BPV DNA varying from 20 to 160 copies, were used. Transformed cells of 10 different strains showed a persistently high incidence of mitotic irregularities detectable at anaphase and telophase (27.3-58.9%), an elevated frequency of cells with micronuclei (6.6-34.7%), and a broad spectrum of nuclear sizes, as measured by image analysis. A 3-day exposure to retinoic acid, retinol, beta-carotene, canthaxanthin, ascorbic acid and ellagic acid greatly reduced the degree of chromosome instability, whereas catechin, eugenol and pyrogallol showed a smaller inhibitory effect, and curcumin had no detectable effect on the frequency of mitotic irregularities. After withdrawal of retinoic acid treatment, the high levels of chromosome instability reappeared. The possibility that the protective effect of the retinoids and carotenoids examined in the model system points to their beneficial administration to human cells with an intrinsic or acquired chromosome instability is discussed.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Bovine papillomavirus 1; Canthaxanthin; Carotenoids; Catechin; Cell Line, Transformed; Cell Transformation, Viral; Chromosomes; Curcumin; DNA, Viral; Ellagic Acid; Eugenol; Micronucleus Tests; Mitosis; Papillomaviridae; Pyrogallol; Tretinoin; Vitamin A

Some undifferentiated F9 embryonal carcinoma cells allow adenovirus genes to be expressed independently of the E1a oncogene normally required for their activation; this has been attributed to a cellular equivalent of E1a in F9 cells. However, transcription of all early genes was low in undifferentiated OTF963 embryonic carcinoma cells during the first 48 hr after infection with adenovirus type 5 (Ad5). Transcription then increased to about the level seen 16 hr after infection of cells induced to differentiate by retinoic acid (RA) (referred to as RA-dF9 cells), but this increase did not occur in cells infected by the E1a deletion mutant dl312. Addition of E1a in trans, or of RA, had no immediate effect on viral transcription in OTF963 cells, but viral transcription increased about 48 hr after these additions. Ad5 induced transcription of several differentiation-specific genes in OTF963 cells with about the same kinetics as their induction by RA. These genes were superinduced in RA-dF9 cells by cAMP or infection by adenovirus. We suggest the small amount of E1a produced early in infection of OTF963 cells activates cellular genes, some of which are differentiation specific and required for efficient transcription of viral genes, so that E1a both induces and is induced by differentiation. The simple hypothesis of a cellular equivalent to E1a does not adequately explain the complex interactions between viral and cellular genes in OTF963 embryonic carcinoma cells.

Topics: Adenovirus Early Proteins; Adenoviruses, Human; Animals; Cell Differentiation; Cell Line; Cell Transformation, Viral; Cytomegalovirus; Gene Expression Regulation, Viral; Kinetics; Oncogene Proteins, Viral; Plasmids; Promoter Regions, Genetic; Restriction Mapping; Teratoma; Transcription, Genetic; Transfection; Tretinoin

32D C13(G) is an interleukin 3(IL3)-dependent non-tumorigenic murine hematopoietic cell line which undergoes terminal differentiation into granulocytes when exposed to granulocytic colony stimulating factor (G-CSF). Infections of 32D C13(G) cells with either Kirsten rat sarcoma virus or Balb murine sarcoma virus, both containing a v-ras oncogene, generates clones that can permanently grow in G-CSF without differentiation. 32D-Ki-ras cells show a heterogeneous morphology ranging from the promyelocytic to the myelocytic stage of differentiation, and express high levels of both myeloperoxidase (MPO) and lactoferrin (LF) mRNA. 32D-Ha-ras cells show a more immature phenotype and express MPO but no LF mRNA. The apparent differentiation block of both 32D Ki-ras and 32D Ha ras can be reversed by treatment with the chemical inducers retinoic acid, sodium butyrate or dimethylsulphoxide, which leads to terminal differentiation into granulocytes. When 32D-Ki-ras and 32D-Ha-ras cells are cultured in medium containing IL-3 they become adherent and express some monocyte-macrophage markers. Upon prolonged exposure to IL3, 32D-Ki-ras, but not 32D-Ha-ras, resume suspension growth. Both 32D-Ki-ras and 32D-Ha-ras rapidly die if grown in chemically defined medium in the absence of any growth factor and are non-tumorigenic in immunosuppressed mice. These findings indicate that ras activation may interfere with the normal response to growth and differentiation factors in cells of the granulocytic lineage. These alterations may represent a critical, although non-sufficient, step in leukemogenesis.

Topics: Butyrates; Butyric Acid; Cell Differentiation; Cell Division; Cell Transformation, Viral; Colony-Stimulating Factors; Dimethyl Sulfoxide; Gene Expression Regulation; Genes, ras; Granulocyte Colony-Stimulating Factor; Granulocytes; Harvey murine sarcoma virus; Hematopoiesis; Hematopoietic Stem Cells; Interleukin-3; Kirsten murine sarcoma virus; Lactoferrin; Peroxidase; Sarcoma Viruses, Murine; Tretinoin

Two new bone cell lines were established by immortalizing cells derived from embryonic rat calvariae with a recombinant retrovirus containing the cDNA for SV-40 large T antigen and the neomycin resistance gene. One cell line, RCT-1, isolated from early digest cells, a population which typically does not express osteoblastic features, displayed osteoblastic characteristics only after 3 days of treatment with 1 microM retinoic acid: alkaline phosphatase activity increased from 0.003 to 0.25 mumol/min.mg protein, the steady state level of type I procollagen mRNA increased 4-fold, and the cells acquired a PTH-stimulatable adenylate cyclase (EC50, 10 nM). mRNA for osteopontin, an abundant bone matrix protein, was induced in RCT-1 cells by 1,25-dihydroxyvitamin D3 (10 nM). The second cell line, RCT-3, isolated from late digest cells, a population previously shown to be enriched with differentiated osteoblasts, expressed constitutively the properties described above. In addition, RCT-3 cells responded to interleukin-1 by increased prostaglandin production (EC50, 20 pM) and to prostaglandin E2 by enhanced cAMP accumulation, features exhibited by calvarial cells in organ culture. Thus, the SV-40 immortalized cell lines we describe retained many of the characteristics of osteoblasts in primary culture, including hormonal regulation of phenotype-related genes. In RCT-1 cells the coordinate induction of several properties by retinoic acid offers a new model for the study of differentiation-related gene expression in bone cells.

Topics: 1-Methyl-3-isobutylxanthine; Adenylyl Cyclases; Animals; Antigens, Polyomavirus Transforming; Bone and Bones; Calcitonin; Cell Line; Cell Transformation, Viral; Cells, Cultured; Collagen; Isoproterenol; Osteoblasts; Osteopontin; Parathyroid Hormone; Peptide Fragments; Phosphoproteins; Rats; RNA, Messenger; Sialoglycoproteins; Simian virus 40; Teriparatide; Tretinoin

A serum-free culture system was used to compare the nutritional requirements of mouse mammary cells transformed by bovine papillomavirus type 1 (ID13 cells) and the uninfected parent line (C127 cells). The serum-free, chemically defined medium used for this study was an MCDB 151-based medium (MCDB 151+S+I), supplemented with epidermal growth factor, transferrin, hydrocortisone, ethanolamine, phosphoethanolamine, retinoic acid, trace metals, and insulin. Proliferation of either cell type in serum-free culture required the addition of 250 micrograms/ml of insulin. ID13 cells have a doubling time of greater than 96 h in MCDB 151+S+I, whereas C127 cells have a doubling time of 60 h. This is in sharp contrast to the growth characteristics of the two cell types in 10% fetal bovine serum, where doubling times for the ID13 and C127 cells are 24 and 30 h, respectively. Culture of the cells in a serum-free medium has therefore revealed that the papillomavirus-transformed cells have more stringent growth requirement than the uninfected parent line.

Topics: Animals; Cell Line, Transformed; Cell Transformation, Viral; Culture Media; Dose-Response Relationship, Drug; Epidermal Growth Factor; Ethanolamines; Female; Hydrocortisone; Insulin; Mammary Glands, Animal; Metals; Mice; Nutritional Requirements; Papillomaviridae; Transferrin; Tretinoin

To study the regulation of MHC class I gene expression during embryonic development, we have characterized a number of clonal cell lines derived from somite stage mouse embryos that were established with or without infection by several transforming retroviruses in combination with murine leukemia viruses. Unlike embryonal carcinoma (EC) cells that have been used as a model for early embryos, the cell lines derived from somite stage embryos are negative for stage specific embryonic Ag-1 and do not appear to differentiate after retinoic acid treatment. Morphology varies from clone to clone and is distinct from that of F9 and other EC cells. In agreement with previous findings in in vivo embryos, expression of surface MHC class I antigen in 57 new clones is either undetectable or low (with variability). All of the clones respond to the addition of interferons and express MHC class I antigens at high levels, but the kinetics of mRNA accumulation vary considerably. To examine the basis of the generally low or absent MHC class I gene expression in these cells, we tested promoter activity of a MHC class I gene by CAT assay after transient DNA transfection. Regardless of the basal levels of mRNA or surface Ag, CAT activity directed by various portions of the 5' flanking region of the MHC class I gene was uniformly low. The cells showed neither the negative nor the positive regulation of MHC class I genes that had been noted respectively for EC cells and for cells expressing the Ag constitutively. The pattern seen in the new cell lines suggests that there is an intermediate stage in the developmental regulation of MHC class I gene expression that may operate during the middle to late stage of fetal development.

Topics: Animals; beta 2-Microglobulin; Cell Line, Transformed; Cell Transformation, Viral; Clone Cells; Embryo, Mammalian; Female; Genes, MHC Class I; Globosides; Glycolipids; H-2 Antigens; Interferons; Laminin; Lewis X Antigen; Male; Mesoderm; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Promoter Regions, Genetic; Retroviridae; RNA, Messenger; Tretinoin

The effect of all-trans-retinoic acid (RA) was examined on (1) transformation induced in C127 cells by transfection with plasmid pdBPV-1 (142-6), which contains DNA of bovine papillomavirus (BPV), (2) the capacity of transformed BPV DNA-containing clones to form colonies with transformed properties (e.g., piling up into multilayered colonies), and (3) the number of BPV DNA copies in transformed cells. At nontoxic doses ranging from 10(-7) to 10(-5) M, RA reduced the frequency of transformed foci in a dose-dependent manner. The extent of inhibition depended on the length of RA treatment and on the time that elapsed between DNA transfection and RA treatment. RA exerted only a slight inhibitory effect during the first days after transfection. Complete inhibition was observed when the cells were continuously exposed after transfection to RA at doses ranging from 0.5 to 1 X 10(-5) M. The inhibitory effect of RA on transformation was reversible. Transformed foci started to form after withdrawal of RA treatment. In the presence of RA (5 X 10(-6) M), cells from transformed colonies were no longer able to form foci displaying transformed properties. The number of BPV DNA copies gradually decreased when the cells were grown over several generations in the presence of RA (5 X 10(-6) M). After approximately 30 cell generations, the cell cultures appeared to have less than one copy of BPV DNA.

Topics: Animals; Bovine papillomavirus 1; Cell Division; Cell Line; Cell Transformation, Viral; DNA, Viral; Papillomaviridae; Plasmids; Transfection; Tretinoin

Retinoic acid inhibits the reduction of diferric transferrin through the transplasma membrane electron transport system on fetal rat liver cells infected with a temperature-sensitive SV40 virus when the cells are in the nontransformed state cultured at 40 degrees C. When the cells are in the transformed state (grown at the permissive 33 degrees C temperature), retinoic acid does not inhibit the diferric transferrin reduction. Inhibition of activity of nontransformed cells is specific for retinoic acid with only slight inhibition by retinol and retinyl acetate at higher concentrations. Isolated rat liver plasma membrane NADH diferric transferrin reductase is also inhibited by retinoic acid. The effect of transformation with SV40 virus to decrease susceptibility to retinoic acid inhibition stands in contrast to much greater adriamycin inhibition of diferric transferrin reduction in the transformed cells than in nontransformed cells.

Topics: Animals; Cell Membrane; Cell Transformation, Viral; Cells, Cultured; Doxorubicin; Fetus; Kinetics; Liver; NADH, NADPH Oxidoreductases; Rats; Reference Values; Simian virus 40; Tretinoin

The effects of retinoic acid on the epidermal growth factor (EGF) receptor binding and cell growth of normal and simian virus 40 (SV40)-transformed BALB/c 3T3 cells were compared under identical culture conditions. Retinoic acid induced a rapid enhancement of EGF binding to SV40-transformed cells. Half-maximal enhancement occurred at about 7 h after the cells were exposed to 20 ng/ml of retinoic acid, and maximal stimulation (from 2.5- to 3.5-fold over the control) was obtained after 12 h of exposure. The kd of the control and retinoic acid-treated cells was calculated to be 8.0 X 10(-10) M and 8.2 X -10 M, respectively. However, the number of unoccupied EGF binding sites increased from 0.98 X 10(4) to 2.28 X 10(4) per cell. Normal 3T3 cells would not respond to retinoic acid unless they were cultured in serum-containing medium. After 96 h of exposure, only a 50% enhancement of EGF binding was observed. The EGF receptor number of the untreated normal cells was calculated to be 1.82 X 10(4) per cell, twice the number expressed by untreated SV40-transformed cells. The increase of EGF receptor number caused by retinoic acid in SV40-transformed cells was blocked by either actinomycin D or cycloheximide treatment. These results indicated that SV40 transformation of BALB/c 3T3 cells altered the regulatory mechanism governing the complement of cell surface EGF receptors.

Topics: Cell Division; Cell Line; Cell Transformation, Viral; Culture Media; Epidermal Growth Factor; ErbB Receptors; Simian virus 40; Tretinoin

Several lots of fetal bovine serum (FBS) were divided into 2 groups; in one group, retinoic acid (RA) suppressed the anchorage-independent growth (AIG) of spontaneously transformed BHK21/C13 cells (clone Ag8-1) dose-dependently, but in the other group, little suppression occurred. In neither group of FBS was the anchorage-dependent growth (ADG) of the cells suppressed by RA. The addition of insulin enhanced the AIG of the cells in both groups even in the presence of RA. The 2 types of AIG systems in Ag8-1 cells, one susceptible and the other resistant to RA, are discussed.

Topics: Animals; Cattle; Cell Transformation, Viral; Cells, Cultured; Cricetinae; Culture Media; Insulin; Plasma; Tretinoin

Filopodia in log and stationary phase populations of human fetal lung fibroblasts (WI-38) at low and high population doubling levels (PDLs) and of SV40 transformed WI-38 cells (VA13A), were observed and counted under different conditions of in vitro growth by scanning electron microscopy. Cells from old non-vigorously growing WI-38 populations (those at a high PDL) had more filopodia than younger populations (those at a lower PDL) at all times after seeding, and for any given population stationary phase cells (those entering, or in, quiescence), had more than log phase cells. Hydrocortisone (HC, 14 microM), which stimulates proliferation and increases life span of WI-38 cells, was associated with a marked decrease in filopodia. Conversely, retinoic acid (RA, 10 microM), which inhibits growth and decreases life span of WI-38 cells, was associated with an increase in filopodia. Since old cell populations have lower saturation densities than young, it is suggested that cell contact signaling growth cessation in these populations may be mediated by filopodia. The HC-associated decrease in filopodia may thus be possibly interpreted as a decrease in filopodia-mediated "density dependent inhibition," and the increase in filopodia with RA as a possible increase in this "inhibition." Both HC and RA inhibit growth and are associated with an increase in filopodia in VA13A cultures.

Topics: Cell Line; Cell Transformation, Viral; Fetus; Fibroblasts; Humans; Hydrocortisone; Lung; Microscopy, Electron, Scanning; Mitosis; Pseudopodia; Simian virus 40; Tretinoin

All-trans retinoic acid (10(-5) M) added at seeding reduces the growth rate and saturation density of normal human embryonic lung fibroblasts of two lines (WI-38 and IMR-90) and similarly inhibits growth of SV40-transformed WI-38 cells (VA13A). The growth inhibitory effects of retinoic acid do not show serum dependency, and the viability of treated cells is 95-99% of controls. Old populations of WI-38 cells (cells at high population doubling levels) are more sensitive to the effects of retinoic acid than are young populations (cells at low population doubling levels), and population life span is reduced by continuous exposure to retinoic acid. When retinoic acid is combined with the glucocorticoid hydrocortisone, inhibition of VA13A cell growth is increased, whereas the retinoic acid-induced inhibition of normal cells is decreased. VA13A cells treated with retinoic acid alone, or in combination with hydrocortisone, exhibit a reversion to a more elongated, fibroblast-like appearance. This paper discusses the clinical implications of the relationship between retinoic acid and hydrocortisone.

Topics: Cell Division; Cell Line; Cell Transformation, Neoplastic; Cell Transformation, Viral; Embryo, Mammalian; Fibroblasts; Humans; Hydrocortisone; Microscopy, Electron, Scanning; Simian virus 40; Tretinoin

The effect of all-trans-retinoic acid (RA) on cellular transformation and on tumorigenicity of retrovirally transformed cells was investigated. RA treatment of NRK and NIH/3T3 cells transformed by BALB/c murine sarcoma virus (MuSV), Kirsten murine sarcoma virus (K-MuSV), and simian sarcoma virus resulted in a significant reduction in anchorage-dependent growth of only K-MuSV-transformed NRK cells. A 62% reduction in cell number was observed at 10(-5) M RA. In contrast, anchorage-independent growth induced by each of the viruses tested was suppressed by RA. Balb/cMSV3T3 cells showed the greatest level of sensitivity with a significant reduction in anchorage-independent growth occurring at 10(-9) M RA. The level of cytoplasmic retinoic acid-binding protein (CRABP) was determined in both parent and transformed cell lines. CRABP was present at a high level in all 3T3 cell types but was absent in all NRK cell lines. For testing the antineoplastic activity of RA in vivo, Balb/cMSV3T3 cells were injected intradermally into nude mice. Subsequent treatment of the tumor sites of these animals by topical application of RA resulted in a significant reduction in both tumor incidence and tumor size, confirming the in vitro results. Analysis of the level of v-onc mRNA revealed that inhibition of retroviral transformation by RA was not due to a decrease in transcription of the v-onc genes.

Topics: Animals; Carrier Proteins; Cell Division; Cell Line; Cell Transformation, Viral; Mice; Mice, Nude; Oncogenes; Receptors, Retinoic Acid; RNA, Messenger; RNA, Viral; Sarcoma Virus, Woolly Monkey; Sarcoma Viruses, Murine; Skin Neoplasms; Transcription, Genetic; Tretinoin; Tumor Virus Infections

Topics: Animals; Bovine papillomavirus 1; Cell Transformation, Viral; Cells, Cultured; DNA, Viral; Fibroblasts; Mice; Papillomaviridae; Retinoids; Tretinoin

Invasion of chick chorioallantoic membrane (CAM) organ cultures by rat 3Y1 cells transformed by the highly oncogenic human adenovirus type 12 (3Y1/12-10 cells) was inhibited by several retinoids tested. The anti-invasive activity of the retinoids was dependent on retinoid concentration and continuous (4 d) exposure of the CAM. The 50% retinoid dose (dose effective in achieving a response in half of the organ cultures) that inhibited invasion was 0.85 micrograms/ml of retinol palmitate, 0.39 micrograms/ml of retinoic acid, or 0.16 micrograms/ml of retinol acetate. This dose was of the same order of magnitude as that which induced CAM differentiation, and was three- to fourfold less than the dose that caused cytotoxic damage of CAM. In addition, the retinoids inhibited 3Y1/12-10 cell growth by approximately 40% at levels over 10-fold higher than those needed for anti-invasion activity. The findings suggest that the anti-invasive activity of retinoids was at least partly due to direct induction of cell differentiation of the CAM host tissue.

Topics: Adenoviruses, Human; Allantois; Animals; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Cell Transformation, Viral; Chick Embryo; Chorion; Diterpenes; Extraembryonic Membranes; Neoplasm Invasiveness; Organ Culture Techniques; Rats; Retinoids; Retinyl Esters; Tretinoin; Vitamin A

This study examined the effects of retinoic acid (RA) on [14C]acetate incorporation and fatty acid composition of hamster embryo fibroblasts (HEF) and two cell lines derived from the same inbred strain but transformed by herpes simplex-2 virus (HSV) or polyoma virus (HFT). Cells were exposed to all trans RA, or dimethylsulfoxide (DMSO), the vehicle for RA, and the lipids labeled with [14C]acetate. Lipids were extracted from the cells, separated by paper chromatography, located by autoradiography, and acetate incorporation determined by liquid scintillation spectrometry. The distribution of fatty acids in total cell lipids was examined by gas chromatography. HEF cells incorporated more acetate into cholesterol than either transformed cell type. The HFT line incorporated more acetate into triglycerides and less into total phospholipids than either the HSV line or the HEF line. RA caused a significant decrease in incorporation of acetate into cholesterol and sphingomyelin in all three cell lines. HEF and HSV cells had decreased incorporation into phosphatidyl inositol-phosphatidyl serine and increased incorporation into triglycerides, changes not evident in the HFT cell. The control fatty acid profiles of the HEF and HSV cells were similar, while the HFT cells had a larger proportion of C16:0 and 18:1 fatty acids. Following treatment with RA all three cell types showed an increase in palmitic and a decrease in oleic acids. The three related cell types showed different [14C]acetate labeling patterns which did not respond uniformly to RA. On the other hand, exposure elicited some like responses in all cell types.

Topics: Acetates; Acetic Acid; Animals; Carbon Radioisotopes; Cell Line; Cell Transformation, Viral; Cricetinae; Embryo, Mammalian; Fatty Acids; Fibroblasts; Kinetics; Lipids; Polyomavirus; Simplexvirus; Tretinoin

To study the mode of action of human cytomegalovirus, an important teratogenic agent in human populations, the susceptibility of a pluripotent human embryonal carcinoma cell line to the virus was investigated. Viral antigens were not expressed nor was infectious virus produced by human embryonal carcinoma cells after infection, although the virus was able to penetrate these cells. In contrast, retinoic acid-induced differentiated derivatives of embryonal carcinoma cells were permissive for antigen expression and infectious virus production. Replication of human cytomegalovirus in human teratocarcinoma cells may therefore depend on cellular functions associated with differentiation.

Topics: Cell Line; Cell Transformation, Neoplastic; Cell Transformation, Viral; Cytomegalovirus; Embryonal Carcinoma Stem Cells; Humans; Neoplastic Stem Cells; Stem Cells; Teratoma; Tretinoin; Virus Replication

The effect of retinoids (Rds) on cell proliferation was studied in serum-free culture condition, using non-transformed and transformed derivatives of BALB 3T3. Cell proliferation of an SV40-transformed line was inhibited significantly by Rd treatment. However, proliferation of two cell lines that were transformed by a Kirsten and Moloney strain of murine sarcoma virus (MSV) and produced growth factor into culture medium, was remarkably stimulated by Rds. Addition of serum masked both the inhibitory and stimulatory effects of Rds.

Topics: Animals; Blood; Cell Line; Cell Transformation, Viral; Culture Media; Diterpenes; Dose-Response Relationship, Drug; Growth Substances; Kirsten murine sarcoma virus; Mice; Retinaldehyde; Retinyl Esters; Sarcoma Viruses, Murine; Simian virus 40; Tretinoin; Vitamin A

In an attempt to analyse the cause-effect relationship between anchorage-independent growth (a property which correlates best with in vivo tumorigenicity) and a set of other common transformation-related properties, the effect of retinoic acid (RA) treatment on six unrelated transformed cell lines (including DNA tumor virus, retrovirus, and spontaneously transformed cells) were studied. The data show that the changes in morphology and cellular orientation in culture, loss of cell surface fibronectin, disruption of actin microfilaments, increased hexose uptake, loss of density-dependent growth, and decreased binding of EGF, properties which are often associated with oncogenic transformation of cells, are dissociable from one another and from anchorage-independent growth. RA appears to interfere with anchorage-independent growth of all the retrovirus and spontaneously transformed cell lines (responsive cells) that we examined; however, such treatment failed to inhibit anchorage-independent growth in both of the DNA tumor virus-transformed cell lines (non-responsive cells) that we used in the present study. The presence of RA-binding proteins in both responsive and non-responsive cells suggests that the mechanism of RA action for the inhibition of anchorage-independent growth in transformed cells may be independent of the presence of such cytoplasmic proteins. Finally, the present study clearly indicates that the use of RA treatment, like partial transformation mutants of oncogenic viruses, can be a novel approach in analysing the general mechanism by which transformed cells grow without anchorage.

Topics: Actins; Animals; Carrier Proteins; Cell Adhesion; Cell Transformation, Viral; Cytoplasm; Epidermal Growth Factor; Fibronectins; Glucose; Mice; Mice, Inbred BALB C; Receptors, Retinoic Acid; Tretinoin

Cloned cells of the rat kidney fibroblast line designated NRK-49F, which requires epidermal growth factor (EGF), fibronectin, insulin, and retinoic acid for rapid multiplication in serum-free culture, were transformed by polyoma virus. Cells from two independent transformation events were isolated and cloned, as were cells from two corresponding control untransformed cultures not treated with virus. Tests in serum-free culture showed that the two transformed subclones required EGF and fibronectin but not insulin or retinoic acid for rapid multiplication, whereas the two control subclones retained the requirements for all four factors. Although EGF at 10 to 50 ng/ml stimulated the multiplication of all four subclones, EGF at 500 ng/ml strongly inhibited multiplication of the two transformed subclones but not the two control subclones.

Topics: Animals; Cell Transformation, Viral; Clone Cells; Dose-Response Relationship, Drug; Epidermal Growth Factor; Fibronectins; Insulin; Kidney; Polyomavirus; Rats; Tretinoin

F9 embryonal carcinoma cells express high levels of a 53,000-molecular-weight cellular tumor antigen called p53. When F9 cell cultures are treated with retinoic acid and dibutyryl adenosine 3',5'-phosphate, they differentiate, predominantly into endoderm-like cells. This differentiation is accompanied by a marked decrease in the levels of p53. The mechanism(s) responsible for this decline in the level of p53 in differentiated cells was investigated. The results demonstrate that the high levels of p53 in F9 cells relative to their differentiated progeny were not due to alterations in the stability or turnover of this protein. Rather, the regulation during differentiation involved a marked decrease in the amount of in vitro translatable p53 mRNA detected in the differentiated cell cultures. This mechanism is unlike the one operating during the simian virus 40 infection or transformation, where the increased levels of p53 are largely due to the increased stability of the p53 protein.

Topics: Animals; Bucladesine; Cell Differentiation; Cell Transformation, Viral; Cells, Cultured; Fibroblasts; Mice; Mice, Inbred BALB C; Phosphoproteins; RNA, Messenger; Simian virus 40; Teratoma; Tretinoin; Tumor Suppressor Protein p53

Topics: Animals; Carboxy-Lyases; Cell Adhesion; Cell Division; Cell Transformation, Viral; Cytoskeleton; Epidermal Growth Factor; Fibronectins; Mice; Ornithine Decarboxylase; Tretinoin

Several retinoids were examined for their capacity to block chemically induced expression of endogenous xenotropic retrovirus from Kirsten sarcoma virus-transformed BALB/c mouse cells. Retinoic acid (RA) was found to inhibit induction of virus by 5-iododeoxyuridine, cycloheximide, and histidinol; inhibition was concentration (10(-4) to 10(-6) M) and time dependent (1 to 7 hr) and not a consequence of cytotoxicity. Following a 6-hr treatment with 10(-4) M RA, [3H]thymidine and [3H]uridine incorporation into total cellular DNA and RNA was reduced 37 and 63%, respectively. Heteronuclear RNA synthesis was reduced 36 and 7% within 4 hr by 10(-4) and 10(-5) M RA, respectively, indicating that inhibition was not the result of a general transcriptional block. Using synchronized cells, it was found that 5 X 10(-5) M RA added in G1 phase and followed by cycloheximide or 5-iododeoxyuridine induction inhibited virus expression 60 and 84%, respectively. Little or no inhibition was observed when RA was added during S phase with the inducers or during G2 phase followed by inducers. Cells synchronized by mitotic arrest showed a RA-mediated restriction point in early-to-mid-G1 phase as indicated by a delay in the onset of DNA synthesis and an inhibition of virus induction during S phase. The results show the presence in Kirsten sarcoma virus-transformed BALB/c cells of a RA-sensitive G1 restriction point for cell progression and suggest that inhibition of retrovirus activation may be related to an extended G1 phase.

Topics: Animals; Cell Cycle; Cell Transformation, Viral; DNA; Gene Expression Regulation; Genes, Viral; Kirsten murine sarcoma virus; Mice; RNA; Sarcoma Viruses, Murine; Tretinoin; Virus Replication

The in vitro proliferation of herpesvirus-transformed marmoset lymphoblastoid cell lines (LCL) was inhibited by retinoic acid and retinyl acetate. Both Herpesvirus-ateles-and Herpesvirus-saimiri-transformed LCL with T-cell characteristics and Epstein-Barr-transformed LCL with B-cell markers were more sensitive to retinoic acid than to retinyl acetate. Inhibition of LCL proliferation was dependent on retinoid concentration and became apparent only after 3-4 days of exposure. In vitro assays for marmoset LCL sensitivity to retinoids may indicate the potential usefulness of these compounds in the chemoprevention of virus-induced lymphoma in vivo.

Topics: Animals; Callitrichinae; Cell Division; Cell Line; Cell Survival; Cell Transformation, Viral; Diterpenes; Herpesviridae; Herpesvirus 4, Human; In Vitro Techniques; Lymphocyte Activation; Lymphocytes; Retinyl Esters; Tretinoin; Vitamin A

Ultraviolet irradiation mapping techniques have previously been used to study the organization of eucaryotic gene classes and transcription units. We used the same method to probe some regulatory phenomena observed in the induction of plasminogen activator (PA) biosynthesis: PA synthesis in chicken embryo fibroblasts is induced by tumor-promoting phorbol esters and by retinoic acid; furthermore, PA induction by phorbol esters is synergistic with transformation, being 10- to 20-fold greater in virus-transformed cells than in normal cells. We found that the ultraviolet irradiation inactivation cross sections for PA induction by phorbol esters and by retinoate differed significantly, suggesting that these agents induce PA biosynthesis by different mechanisms. On the other hand, the ultraviolet irradiation sensitivity of phorbol ester induction in normal chicken embryo fibroblasts was the same as in transformed cells, indicating that the synergism of transformation and phorbol esters is probably not due to different pathways of PA induction.

Topics: Animals; Avian Sarcoma Viruses; Cell Transformation, Viral; Cells, Cultured; Chick Embryo; Enzyme Induction; Fibroblasts; Gene Expression Regulation; Phorbol Esters; Plasminogen Activators; Tretinoin; Ultraviolet Rays

Topics: Animals; Cell Line; Cell Transformation, Viral; Epidermal Growth Factor; Glycoproteins; Kirsten murine sarcoma virus; Mice; Phorbols; Protein Biosynthesis; RNA, Messenger; Sarcoma Viruses, Murine; Tetradecanoylphorbol Acetate; Tretinoin

Treatment of simian virus 40-transformed 3T3 cells with 1 microM beta-all-trans-retinoic acid (RA) resulted in a 5- to 6-fold enhancement of plasminogen activator (PA) release. Intracellular PA levels rose to twice control levels. Confluent 3T3 cells were less responsive to RA. In 6 of 10 experiments, no increase in 3T3 cell PA levels was noted, although up to a 2.5-fold enhancement of PA elaboration has been observed in some experiments at a dose of 10 microM RA. Simultaneous treatments of 3T3 cells with 10 microM RA and 2.1 to 9.3 mM Ca2+, 5 to 40 ng phorbol myristate acetate per ml, or 150 to 600 ng Fraction I from lactalbumin hydrolysate (Fl) protein per ml indicated that RA potentiated the PA stimulatory activities of these agents. Extracellular PA levels of RA-treated cells increased by 4 to 10 times the amount of increase observed for Ca2+, PMA, or Fl alone. A potentiating activity of RA was also evident when quiescent 3T3 cells were pretreated with 10 microM RA and then stimulated to synthesize DNA with Ca2+, PMA, or Fl. For RA-pretreated cells, an increased percentage of nuclei was labeled with [3H]thymidine (24 hr) in response to doses of the three mitogens which were ineffective without RA pretreatment (2.4mM Ca2+, 5 ng PMA per ml, or 150 ng Fl protein per ml). Additional experiments have indicated that, like platelet extracts, Ra renders quiescent 3T3 cells competent to synthesize DNA in response to the progression factors of human plasma as defined by Pledger et al. (Proc. Natl. Acad. Sci. U. S. A., 74: 4481-4485, 1977). Pretreatment of quiescent 3T3 cells for 6 hr with 10 microM RA resulted in a greater than 4-fold increase in the percentage of cells which incorporated [3H]thymidine in response to a 36-hr treatment with 10% human plasma, as compared to cells treated with human plasma alone. Thus, under certain conditions, RA may have cell-activating properties, and caution should be exercised with regard to its suggested use as an antitumor agent.

Topics: Animals; Calcium; Cell Division; Cell Transformation, Viral; Cells, Cultured; Dose-Response Relationship, Drug; Lactalbumin; Mice; Mice, Inbred BALB C; Phorbol Esters; Plasminogen Activators; Simian virus 40; Tretinoin

Low concentrations of Vitamin A stimulated plasminogen activator synthesis (PA) in chick embryo fibroblasts (CEF). It caused a dose dependent and reversible increase in PA synthesis in both normal CEF and CEF infected with a temperature sensitive mutant of Rous Sarcoma virus (RSV-Ts68). Both induction and deinduction of PA could be inhibited by Actinomycin D. Vitamin A also accentuated the morphological changes associated with transformation in the Rous Sarcoma virus infected cells. The effects of Vitamin A on PA synthesis were essentially similar to those of the known tumour promoter, phorbol myristate acetate (PMA). Both Vitamin A and PMA were found to act synergistically with sarcoma gene expression as far as PA synthesis was concerned.

Topics: Animals; Avian Sarcoma Viruses; Cell Transformation, Viral; Cells, Cultured; Chickens; Cholera Toxin; Nucleotides, Cyclic; Plasminogen Activators; Temperature; Tretinoin; Vitamin A

This paper reports the effect of vitamin A and its derivatives, the retinoids, on plasminogen activator (PA) synthesis in chick embryo fibroblast cultures (CEF). Low concentrations of retinoic acid (RA) (10(-6)-10(-10) M) and the retinoids stimulated PA synthesis in CEF; the maximal stimulation achieved, 9--10 fold, was somewhat lower than that obtained with optimal concentrations of the potent tumor promoter phorbol myristate acetate (PMA). This action of RA required protein and mRNA synthesis but, in contrast to enzyme induction by PMA and/or sarcoma virus transformation, retinoid effects were not significantly inhibited by elevated concentrations of cAMP. In inducing and/or stimulating PA production, the effects of RA and sarcoma virus transformation were synergistic rather than additive. Analogous synergism was observed between RA and PMA, but only at suboptimal concentrations of the latter. RA did not affect PA production in normal or transformed cultures maximally stimulated by PMA. These findings may help to elucidate the role of retinoids in promoting tumor growth, tissue remodeling and teratogenesis.

Topics: Animals; Cell Transformation, Viral; Cells, Cultured; Cyclic AMP; Cycloheximide; Dactinomycin; Dose-Response Relationship, Drug; Genes, Viral; Kinetics; Phorbols; Sarcoma, Experimental; Tetradecanoylphorbol Acetate; Tretinoin; Vitamin A