sirolimus has been researched along with Carcinogenesis* in 41 studies
4 review(s) available for sirolimus and Carcinogenesis
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Role of mammalian target of rapamycin (mTOR) signalling in oncogenesis.
The signalling system known as mammalian target of rapamycin (mTOR) is believed to be required for several biological activities involving cell proliferation. The serine-threonine kinase identified as mTOR recognises PI3K-AKT stress signals. It is well established in the scientific literature that the deregulation of the mTOR pathway plays a crucial role in cancer growth and advancement. This review focuses on the normal functions of mTOR as well as its abnormal roles in cancer development. Topics: Carcinogenesis; Cell Proliferation; Cell Transformation, Neoplastic; Humans; Neoplasms; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Sirolimus; TOR Serine-Threonine Kinases | 2023 |
Targeting Akt/PKB in pediatric tumors: A review from preclinical to clinical trials.
The serine/threonine kinase Akt is a major player in the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway, and its modulation impacts multiple cellular processes such as growth, proliferation, and survival. Several abnormalities in this pathway have been documented over the years, and these alterations were shown to have great implications in tumorigenesis and resistance to chemotherapy. Thus, multiple Akt inhibitors have been developed and tested in adult tumors, and some of them are currently undergoing phase I, II, and III clinical trials for distinct cancers that arise during adulthood. Despite that, the impact of these inhibitors is still not fully understood in pediatric tumors, and Akt-specific targeting seems to be a promising approach to treat children affected by cancers. This review summarizes recent available evidence of Akt inhibitors in pediatric cancers, from both preclinical and clinical studies. In short, we demonstrate the impact that Akt inhibition provides in tumorigenesis, and we suggest targeting the PI3K/Akt/mTOR signaling pathway, alone or in combination with other inhibitors, is a feasible tool to achieve better outcomes in pediatric tumors. Topics: Adult; Carcinogenesis; Child; Humans; Neoplasms; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Sirolimus; TOR Serine-Threonine Kinases | 2022 |
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; 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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; 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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 | 2016 |
Pleiotropic roles of mTOR complexes in haemato-lymphopoiesis and leukemogenesis.
Mammalian/mechanistic target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that responds to environmental determinants such as growth factor concentration, nutrient availability, energy sufficiency and stress. mTOR forms two different complexes, called mTOR complex 1 (mTORC1) and mTORC2, and these complexes have distinct substrate molecules that function in the regulation of protein translation and cellular metabolism. Although mTOR was originally discovered as a target protein of rapamycin, a natural macrolide immunosuppressant, rapamycin mainly inhibits the kinase activity of mTORC1, whereas mTORC2 is affected to a much lesser extent. The inhibitory effects of rapamycin on mTORC1 substrates are complex, and the use of rapamycin to investigate mTORC functions may provide misleading results. In contrast to pharmacological inhibition, studies using genetic approaches to the disruption of mTORC subunits have clearly demonstrated the physiological roles of the distinct mTOR complexes in organogenesis and tumourigenesis. In this review, we provide an overview of current knowledge about the roles of the mTOR complexes in haemato-lymphopoiesis and leukemogenesis. Topics: Animals; Carcinogenesis; Hematopoiesis; Humans; Leukemia, Myeloid, Acute; Lymphoid Progenitor Cells; Lymphopoiesis; Sirolimus; TOR Serine-Threonine Kinases | 2014 |
1 trial(s) available for sirolimus and Carcinogenesis
37 other study(ies) available for sirolimus and Carcinogenesis
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Protein Arginine Methyltransferases 5 (PRMT5) affect Multiple Stages of Autophagy and Modulate Autophagy-related Genes in Controlling Breast Cancer Tumorigenesis.
Autophagy disorders are linked to human cancer, and the details of their mechanisms remain unclear.. To investigate the regulatory role of PRMT5 in the autophagy of breast cancer cells.. Human breast adenocarcinoma cell lines (MDA-MB-231, MCF7) were cultured. Plasmids of overexpression and down-regulation of PRMT5 were transfected into MDA-MB-231 and MCF7 cells. The MTT assay was used to determine the proliferation of MDA-MB-231 and MCF7 cells. A western blotting assay was used to verify the expression of autophagy-associated molecules. Immunofluorescence was applied to observe the expression of GFP-LC3.. The expression of PRMT5 decreased the sensitivity to rapamycin and nutrient deprivation. PRMT5 acts as an oncogene to promote cell proliferation and influences migration and stamness. PRMT5 expression elevated the autophagic activity initiated by EBSS and Rapamycin. PRMT5 was necessary and sufficient to enhance stress-induced autophagy. PRMT5 could improve several autophagy- related gene expressions. Atg5 expression could be regulated by activating the PRMT5 and PDCD4 molecules. The PRMT5 molecule could mediate the regulation of ULK1 expression.. PRMT5 influenced multiple stages of autophagy in controlling autophagy and tumorigenesis. Autophagy-related PRMT5 might be a respected target for therapeutic interventions in cancers. This study would provide new ideas for treating and selecting breast cancer targets. Topics: Apoptosis Regulatory Proteins; Autophagy; Breast Neoplasms; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Female; Humans; Protein-Arginine N-Methyltransferases; RNA-Binding Proteins; Sirolimus | 2023 |
Degradation of helicase-like transcription factor (HLTF) by β-TrCP promotes hepatocarcinogenesis via activation of the p62/mTOR axis.
Helicase-like transcription factor (HLTF) has been found to be involved in the maintenance of genome stability and tumour suppression, but whether its downregulation in cancers is associated with posttranslational regulation remains unclear. Here, we observed that HLTF was significantly downregulated in hepatocellular carcinoma (HCC) tissues and positively associated with the survival of HCC patients. Mechanistically, the decreased expression of HLTF in HCC was attributed to elevated β-TrCP-mediated ubiquitination and degradation. Knockdown of HLTF enhanced p62 transcriptional activity and mammalian target of rapamycin (mTOR) activation, leading to HCC tumourigenesis. Inhibition of mTOR effectively blocked β-TrCP overexpression- or HLTF knockdown-mediated HCC tumourigenesis and metastasis. Furthermore, in clinical tissues, decreased HLTF expression was positively correlated with elevated expression of β-TrCP, p62, or p-mTOR in HCC patients. Overall, our data not only uncover new roles of HLTF in HCC cell proliferation and metastasis, but also reveal a novel posttranslational modification of HLTF by β-TrCP, indicating that the β-TrCP/HLTF/p62/mTOR axis may be a new oncogenic driver involved in HCC development. This finding provides a potential therapeutic strategy for HCC patients by targeting the β-TrCP/HLTF/p62/mTOR axis. Topics: beta-Transducin Repeat-Containing Proteins; Carcinogenesis; Carcinoma, Hepatocellular; Cell Line, Tumor; DNA-Binding Proteins; Humans; Liver Neoplasms; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors | 2023 |
CDK13 phosphorylates the translation machinery and promotes tumorigenic protein synthesis.
Cyclin-dependent kinase 13 (CDK13) has been suggested to phosphorylate RNA polymerase II and is involved in transcriptional activation. However, whether CDK13 catalyzes other protein substrates and how CDK13 contributes to tumorigenesis remain largely unclear. We here identify key translation machinery components, 4E-BP1 and eIF4B, as novel CDK13 substrates. CDK13 directly phosphorylates 4E-BP1 at Thr46 and eIF4B at Ser422; genetically or pharmacologically inhibiting CDK13 disrupts mRNA translation. Polysome profiling analysis shows that MYC oncoprotein synthesis strictly depends on CDK13-regulated translation in colorectal cancer (CRC), and CDK13 is required for CRC cell proliferation. As mTORC1 is implicated in 4E-BP1 and eIF4B phosphorylation, inactivation of CDK13 in combination with the mTORC1 inhibitor rapamycin further dephosphorylates 4E-BP1 and eIF4B and blocks protein synthesis. As a result, dual inhibition of CDK13 and mTORC1 induces more profound tumor cell death. These findings clarify the pro-tumorigenic role of CDK13 by direct phosphorylation of translation initiation factors and enhancing protein synthesis. Therefore, therapeutic targeting of CDK13 alone or in combination with rapamycin may pave a new way for cancer treatment. Topics: Carcinogenesis; CDC2 Protein Kinase; Cell Cycle Proteins; Humans; Mechanistic Target of Rapamycin Complex 1; Phosphoproteins; Phosphorylation; Protein Biosynthesis; Sirolimus | 2023 |
Gα13 loss in Kras/Tp53 mouse model of pancreatic tumorigenesis promotes tumors susceptible to rapamycin.
Gα13 transduces signals from G-protein-coupled receptors. While Gα13 functions as a tumor suppressor in lymphomas, it is not known whether Gα13 is pro-tumorigenic or tumor suppressive in genetically engineered mouse (GEM) models of epithelial cancers. Here, we show that loss of Gα13 in the Kras/Tp53 (KPC) GEM model promotes well-differentiated tumors and reduces survival. Mechanistically, tumors developing in KPC mice with Gα13 loss exhibit increased E-cadherin expression and mTOR signaling. Importantly, human pancreatic ductal adenocarcinoma (PDAC) tumors with low Gα13 expression also exhibit increased E-cadherin expression and mTOR signaling. Treatment with the mTOR inhibitor rapamycin decreases the growth of syngeneic KPC tumors with Gα13 loss by promoting cell death. This work establishes a tumor-suppressive role of Gα13 in pancreatic tumorigenesis in the KPC GEM model and suggests targeting mTOR in human PDAC tumors with Gα13 loss. Topics: Animals; Cadherins; Carcinogenesis; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Disease Models, Animal; GTP-Binding Protein alpha Subunits, G12-G13; Mice; Pancreatic Neoplasms; Proto-Oncogene Proteins p21(ras); Sirolimus; TOR Serine-Threonine Kinases | 2022 |
MAP kinase and mammalian target of rapamycin are main pathways of gallbladder carcinogenesis: results from bioinformatic analysis of next generation sequencing data from a hospital-based cohort (NCT05404347).
Gallbladder Cancer (GBC) is one of the most common cancers of the biliary tract and the third commonest gastrointestinal (GI) malignancy worldwide. The disease is characterized by the late presentation and poor outcome despite treatment, and hence, newer therapies and targets need to be identified.. The current study investigated various functionally enriched pathways in GBC pathogenesis involving the genes identified through Next Generation Sequencing (NGS) in a hospital-based cohort. The Pathway enrichment analysis and Gene Ontology (GO) were carried out after NGS, followed by the construction of the protein-protein interaction (PPI) network to discover associations among the genes.. Of the thirty-three patients with GBC who were screened through next-generation sequencing (NGS), 27somatic mutations were identified. These mutations involved a total of 14 genes. The p53 and KRAS were commonly found to be mutated, while mutations in other genes were seen in one case each, the mean number of mutations were 1.2, and maximum mutation in a single case (eight) was seen in one case. The bioinformatics analysis identified MAP kinase, PI3K-AKT, EGF/EGFR, and Focal Adhesion PI3K-AKT-mTOR signaling pathways and cross-talk between these.. The results suggest that the complex crosstalk between the mTOR, MAPK, and multiple interacting cell signaling cascades can promote GBC progression, and hence, mTOR-MAPK targeted treatment will be an attractive option. Topics: Carcinogenesis; Computational Biology; Gallbladder Neoplasms; High-Throughput Nucleotide Sequencing; Hospitals; Humans; Mitogen-Activated Protein Kinases; Mutation; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Sirolimus; TOR Serine-Threonine Kinases | 2022 |
FTO-mediated autophagy promotes progression of clear cell renal cell carcinoma via regulating SIK2 mRNA stability.
Topics: Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Animals; Autophagy; Biomarkers; Carcinogenesis; Carcinoma, Renal Cell; Cell Line, Tumor; Humans; Kidney Neoplasms; Mice; RNA Stability; RNA-Binding Proteins; RNA, Messenger; Sirolimus | 2022 |
Sirolimus diminishes the expression of GRO-α (CXCL-1) /CXCR2 axis in human keratinocytes and cutaneous squamous cell carcinoma cells.
Organ transplant recipients show a high incidence for the formation of cutaneous squamous cell carcinoma (cSCC), while sirolimus appears to reduce the risk. GRO-α is a chemokine, which is overexpressed in many tumor entities and associated with malignant transformation. However, little is known about the expression and function of GRO-α in human cSCC.. Our aim was to investigate the relevance of the GRO-α (CXCL-1)/ CXCR2 axis in human cSCC and the potential impact of sirolimus.. We analyzed the GRO-α expression in human keratinocytes, different cSCC cell lines as well as cSCC tissue and investigated its effect on cell proliferation and migration. Additionally, we incubated cells with sirolimus and measured the expression of GRO-α and its receptor CXCR2.. We showed that both constitutive as well as induced GRO-α expression is higher in in cSCC cell lines compared to keratinocytes and that GRO-α protein is detectable in human cSCC tissue. By GRO-α exposure and shRNA knock down, we identified GRO-α as a driving factor in proliferation and migration. Moreover, in a dermis equivalent GRO-α knocked down cSCC cell lines displayed a reduced capacity in tumor nest formation. Incubation with sirolimus significantly inhibited GRO-α expression in keratinocytes as well as tumor cell lines. Moreover, sirolimus decreased the expression of the corresponding receptor CXCR2.. Taken together, our results suggest that the GRO-α/CXCR2 axis plays a role in human keratinocyte carcinogenesis and might represent a molecular mechanism for the preventive effect of mTOR inhibitors in cSCC development. Topics: Carcinogenesis; Carcinoma, Squamous Cell; Cell Line, Tumor; Chemokine CXCL1; Gene Knockdown Techniques; Humans; Keratinocytes; MTOR Inhibitors; Receptors, Interleukin-8B; Signal Transduction; Sirolimus; Skin Neoplasms | 2021 |
Rapamycin Extends Life Span in Apc
We previously showed that lifelong rapamycin treatment of short-lived Apc. We asked, what effect would pretreatment of Apc. These data indicate that enteric rapamycin prevents or delays colon neoplasia in Apc Topics: Adenomatous Polyposis Coli Protein; Animals; Carcinogenesis; Colon; Colonic Neoplasms; Disease Models, Animal; Female; Heterozygote; Humans; Intestinal Mucosa; Male; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Transgenic; Sirolimus; Survival Analysis; Time Factors | 2021 |
mTOR inhibition acts as an unexpected checkpoint in p53-mediated tumor suppression.
Here, we showed that the acetylation-defective Topics: Acetylation; Animals; Carcinogenesis; Cell Cycle Checkpoints; Embryo, Mammalian; Lysine; Mice; Mutation; Neoplasms; Proto-Oncogene Proteins c-mdm2; Sirolimus; Survival Analysis; TOR Serine-Threonine Kinases; Tumor Suppressor Protein p53 | 2021 |
Long-Term Effects of Sirolimus on Human Skin TSC2-Null Fibroblast‒Like Cells.
Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder characterized by hamartomatous tumors of the skin, kidneys, brain, and lungs. TSC is caused by mutations in the TSC1 and TSC2 genes, which result in hyperactivation of the mTOR, leading to dysregulated cell growth and autophagy. Rapamycin (sirolimus) shrinks TSC tumors, but the clinical benefits of sirolimus are not sustained after its withdrawal. In this study, we studied the cellular processes critical for tumor formation and growth, including cell proliferation and cell size. TSC2 Topics: Angiofibroma; Antibiotics, Antineoplastic; Autophagy; Carcinogenesis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Size; Cellular Reprogramming; Estrogens; Fibroblasts; Humans; Mutation, Missense; Sirolimus; Skin; Skin Neoplasms; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 2 Protein | 2021 |
RAPTOR promotes colorectal cancer proliferation by inducing mTORC1 and upregulating ribosome assembly factor URB1.
Mammalian target of rapamycin complex 1 (mTORC1) is evolutionally conserved and frequently activated in various tumors, including colorectal cancer (CRC). It has been reported that the ribosome assembly factor Urb1 acts downstream of mTORC1/raptor signaling and contributes to digestive organ development in zebrafish. Previously, we highlighted that URB1 was overexpressed in CRC. Here, we assessed the mTORC1/regulatory associated protein with mTOR (RAPTOR)-URB1 axis in CRC tumorigenesis. We found that RAPTOR was overexpressed in CRC tissues and cell lines, was a favorable predictor in patients with CRC, and positively correlated with URB1. Silencing of RAPTOR suppressed CRC cell proliferation and migration and induced cell cycle arrest and apoptosis in vitro and inhibited xenograft growth in vivo. Moreover, ectopic overexpression of RAPTOR exerted an inverse biological phenotype. Knockdown of RAPTOR quenched mTORC1 activity and reduced the expression of URB1 and cyclinA2 (CCNA2). In contrast, overexpression of RAPTOR activated mTORC1 and upregulated URB1 and CCNA2. Furthermore, URB1 and CCNA2 expression were also impeded by rapamycin, which is a specific inhibitor of mTORC1. Thus, RAPTOR promoted CRC proliferation, migration, and cell cycle progression by inducing mTORC1 signaling and transcriptional activation of both URB1 and CCNA2. Taken together, we concluded that RAPTOR has the potential to serve as a novel biomarker and therapeutic target for CRC. Topics: Animals; Apoptosis; Biomarkers, Tumor; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Colon; Colorectal Neoplasms; Cyclin A2; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Kaplan-Meier Estimate; Male; Mechanistic Target of Rapamycin Complex 1; Mice; Middle Aged; Nuclear Proteins; Rectum; Regulatory-Associated Protein of mTOR; Signal Transduction; Sirolimus; Up-Regulation; Xenograft Model Antitumor Assays | 2020 |
OTULIN protects the liver against cell death, inflammation, fibrosis, and cancer.
Methionine-1 (M1)-linked polyubiquitin chains conjugated by the linear ubiquitin chain assembly complex (LUBAC) control NF-κB activation, immune homoeostasis, and prevents tumour necrosis factor (TNF)-induced cell death. The deubiquitinase OTULIN negatively regulates M1-linked polyubiquitin signalling by removing the chains conjugated by LUBAC, and OTULIN deficiency causes OTULIN-related autoinflammatory syndrome (ORAS) in humans. However, the cellular pathways and physiological functions controlled by OTULIN remain poorly understood. Here, we show that OTULIN prevents development of liver disease in mice and humans. In an ORAS patient, OTULIN deficiency caused spontaneous and progressive steatotic liver disease at 10-13 months of age. Similarly, liver-specific deletion of OTULIN in mice leads to neonatally onset steatosis and hepatitis, akin to the ORAS patient. OTULIN deficiency triggers metabolic alterations, apoptosis, and inflammation in the liver. In mice, steatosis progresses to steatohepatitis, fibrosis and pre-malignant tumour formation by 8 weeks of age, and by the age of 7-12 months the phenotype has advanced to malignant hepatocellular carcinoma. Surprisingly, the pathology in OTULIN-deficient livers is independent of TNFR1 signalling. Instead, we find that steatohepatitis in OTULIN-deficient livers is associated with aberrant mTOR activation, and inhibition of mTOR by rapamycin administration significantly reduces the liver pathology. Collectively, our results reveal that OTULIN is critical for maintaining liver homoeostasis and suggest that M1-linked polyubiquitin chains may play a role in regulation of mTOR signalling and metabolism in the liver. Topics: Animals; Animals, Newborn; Carcinogenesis; Carcinoma, Hepatocellular; Cell Death; Cell Proliferation; Endopeptidases; Fatty Liver; Female; Gene Deletion; Hematopoiesis; Humans; Inflammation; Liver; Liver Cirrhosis; Liver Neoplasms; Male; Mice; Receptors, Tumor Necrosis Factor, Type I; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2020 |
Two well-differentiated pancreatic neuroendocrine tumor mouse models.
Topics: Animals; Antibiotics, Antineoplastic; Carcinogenesis; Disease Models, Animal; Gene Deletion; Mice; Neuroendocrine Tumors; Pancreatic Neoplasms; Proto-Oncogene Proteins; PTEN Phosphohydrolase; Sirolimus | 2020 |
Short-Term Environmental Conditioning Enhances Tumorigenic Potential of Triple-Negative Breast Cancer Cells.
Tumor microenvironments expose cancer cells to heterogeneous, dynamic environments by shifting availability of nutrients, growth factors, and metabolites. Cells integrate various inputs to generate cellular memory that determines trajectories of subsequent phenotypes. Here we report that short-term exposure of triple-negative breast cancer cells to growth factors or targeted inhibitors regulates subsequent tumor initiation. Using breast cancer cells with different driver mutations, we conditioned cells lines with various stimuli for 4 hours before implanting these cells as tumor xenografts and quantifying tumor progression by means of bioluminescence imaging. In the orthotopic model, conditioning a low number of cancer cells with fetal bovine serum led to enhancement of tumor-initiating potential, tumor volume, and liver metastases. Epidermal growth factor and the mTORC1 inhibitor ridaforolimus produced similar but relatively reduced effects on tumorigenic potential. These data show that a short-term stimulus increases tumorigenic phenotypes based on cellular memory. Conditioning regimens failed to alter proliferation or adhesion of cancer cells in vitro or kinase signaling through Akt and ERK measured by multiphoton microscopy in vivo, suggesting that other mechanisms enhanced tumorigenesis. Given the dynamic nature of the tumor environment and time-varying concentrations of small-molecule drugs, this work highlights how variable conditions in tumor environments shape tumor formation, metastasis, and response to therapy. Topics: Animals; Carcinogenesis; Cell Adhesion; Cell Count; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Disease Progression; Epidermal Growth Factor; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Luminescent Measurements; Mechanistic Target of Rapamycin Complex 1; Neoplasm Metastasis; Proto-Oncogene Proteins c-akt; Serum Albumin, Bovine; Sirolimus; Triple Negative Breast Neoplasms; Tumor Microenvironment | 2019 |
Germ-free (GF). GF. Human clinical isolate Topics: Animals; Bacterial Toxins; Campylobacter jejuni; Carcinogenesis; Colorectal Neoplasms; DNA Damage; DNA, Neoplasm; Feces; Gastrointestinal Microbiome; Gene Expression; Humans; Mice; RNA, Neoplasm; Sirolimus; Transcriptome | 2019 |
Phosphodiesterase 4B is an effective therapeutic target in colorectal cancer.
Identification of new therapeutic targets may improve the survival rate of patients with colorectal cancer (CRC). Recent studies have suggested that the level of phosphodiesterase 4B (PDE4B) is elevated in fatal/refractory diffuse large B-cell lymphoma (DLBCL), and therapeutic efficacy of a PDE4 inhibitor in B-cell lymphoma has been successfully tested in clinical settings. Here, we show that PDE4B is a potential therapeutic target in CRC. Treatment with forskolin, an activator of adenylyl cyclase (AC), increased intracellular cyclic AMP (cAMP) levels in PDE4B-low, but not PDE4B-high cells, indicating that PDE4B was a major regulator of cAMP levels in CRC cells. Furthermore, cAMP modulated the activities of AKT and AMPK in a PDE4B-dependent manner, which was associated with a marked decrease in mTOR-Myc signals and oncogenic properties of CRC cells such as anchorage-independent growth and colony formation. We found that the Myc proto-oncogene was a crucial downstream target of the AKT/mTOR and AMPK/mTOR signals that mediated cAMP-induced anti-tumor effect. A natural polyphenol resveratrol that was reported to have PDE4 inhibitory effects also showed tumor suppressive effects by inhibiting the mTOR-Myc axis. Intriguingly, we identified Myc as a transcriptional activator of PDE4B in CRC cells, which maintains the intracellular cAMP levels low and promotes cell survival. These data suggest that cAMP/PDE4B signals play a significant role in regulating the malignant phenotype of CRC cells and targeting of PDE4B should be actively pursued. Topics: AMP-Activated Protein Kinases; Antineoplastic Agents; Azepines; Carcinogenesis; Cell Line, Tumor; Colorectal Neoplasms; Cyclic AMP; Cyclic Nucleotide Phosphodiesterases, Type 4; Humans; Phosphodiesterase 4 Inhibitors; Proto-Oncogene Mas; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Resveratrol; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Triazoles | 2019 |
Sirtuin 4 Depletion Promotes Hepatocellular Carcinoma Tumorigenesis Through Regulating Adenosine-Monophosphate-Activated Protein Kinase Alpha/Mammalian Target of Rapamycin Axis in Mice.
Sirtuin 4 (SIRT4) has been reported to play a vital role in the maintenance of glutamine catabolism and adenosine triphosphate (ATP) homeostasis, but its character in hepatocellular carcinomas (HCCs) remains obscure. In this study, we observed low expression of SIRT4 in both HCC cell lines and HCCs from patients. Decreased disease-free survival time is associated with low tumor levels of SIRT4 in patients. Deficiency of SIRT4 facilitated liver tumor development and lung metastasis in xenografts and knockout (KO) mice by promoting colony formation and migration of hepatoma cells and enhancing sphere formation of HCCs. Mechanistically, SIRT4 deletion augmented mammalian target of rapamycin (mTOR) signaling by inactivating adenosine-monophosphate (AMP)-activated protein kinase alpha (AMPKα) through regulation of glutamine catabolism and subsequent AM)/liver kinase B1 (LKB1) axis. Blockage of mTOR by rapamycin or inhibition of glutaminolysis abolished the discrepancy in tumorigenic capacity between SIRT4-depleted hepatoma cells and control cells. Suppression of LKB1 or promotion of AMP by metformin also abrogated the hyperproliferative phenotype caused by SIRT4 loss, which further confirmed that the LKB1/AMPKα/mTOR axis is required in SIRT4-deficiency-promoted HCC tumorigenesis. Conclusion: SIRT4 could exert its tumor suppressive function in HCC by inhibiting glutamine metabolism and thereby increasing the adenosine diphosphate (ADP)/AMP levels to phosphorylate AMPKα by LKB1, which blocks the mTOR signaling pathway. Topics: Adenosine Monophosphate; AMP-Activated Protein Kinases; Animals; Carcinogenesis; Carcinoma, Hepatocellular; Down-Regulation; Glutamine; Hep G2 Cells; Humans; Liver Neoplasms, Experimental; Mice, Knockout; Mitochondrial Proteins; Protein Serine-Threonine Kinases; Signal Transduction; Sirolimus; Sirtuins; TOR Serine-Threonine Kinases | 2019 |
Rapalog resistance is associated with mesenchymal-type changes in Tsc2-null cells.
Tuberous Sclerosis Complex (TSC) and Lymphangioleiomyomatosis (LAM) are caused by inactivating mutations in TSC1 or TSC2, leading to mTORC1 hyperactivation. The mTORC1 inhibitors rapamycin and analogs (rapalogs) are approved for treating of TSC and LAM. Due to their cytostatic and not cytocidal action, discontinuation of treatment leads to tumor regrowth and decline in pulmonary function. Therefore, life-long rapalog treatment is proposed for the control of TSC and LAM lesions, which increases the chances for the development of acquired drug resistance. Understanding the signaling perturbations leading to rapalog resistance is critical for the development of better therapeutic strategies. We developed the first Tsc2-null rapamycin-resistant cell line, ELT3-245, which is highly tumorigenic in mice, and refractory to rapamycin treatment. In vitro ELT3-245 cells exhibit enhanced anchorage-independent cell survival, resistance to anoikis, and loss of epithelial markers. A key alteration in ELT3-245 is increased β-catenin signaling. We propose that a subset of cells in TSC and LAM lesions have additional signaling aberrations, thus possess the potential to become resistant to rapalogs. Alternatively, when challenged with rapalogs TSC-null cells are reprogrammed to express mesenchymal-like markers. These signaling changes could be further exploited to induce clinically-relevant long-term remissions. Topics: Animals; Anoikis; Carcinogenesis; Cell Line; Cell Proliferation; Cell Survival; Drug Resistance; Humans; Lymphangioleiomyomatosis; Mechanistic Target of Rapamycin Complex 1; Mesoderm; Mice; Mutation; Signal Transduction; Sirolimus; Tuberous Sclerosis | 2019 |
FBXW7 deletion contributes to lung tumor development and confers resistance to gefitinib therapy.
Gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), is an effective treatment for non-small-cell lung cancer (NSCLC) with EGFR activating mutations, but inevitably, the clinical efficacy is impeded by the emergence of acquired resistance. The tumor suppressor gene FBXW7 modulates chemosensitivity in various human cancers. However, its role in EGFR-TKI therapy in NSCLC has not been well studied. Here, we demonstrate that the mice with deficient Fbxw7 have greater susceptibility to urethane-induced lung tumor development. Through analysis of The Cancer Genome Atlas data, we show that deletion of FBXW7 occurs in 30.9% of lung adenocarcinomas and 63.5% of lung squamous cell carcinomas, which significantly leads to decrease in FBXW7 mRNA expression. The reduction in FBXW7 mRNA level is associated with poor overall survival in lung cancer patients. FBXW7 knockdown dramatically promotes epithelial-mesenchymal transition, migration, and invasion in NSCLC cells. Moreover, with silenced FBXW7, EGFR-TKI-sensitive cells become resistant to gefitinib, which is reversed by the mammalian target of rapamycin inhibitor, rapamycin. Furthermore, xenograft mouse model studies show that FBXW7 knockdown enhances tumorigenesis and resistance to gefitinib. Combination of gefitinib with rapamycin treatment suppresses tumor formation of gefitinib-resistant (GR) FBXW7-knockdown cells. In conclusion, our findings suggest that loss of FBXW7 promotes NSCLC progression as well as gefitinib resistance and combination of gefitinib and rapamycin may provide an effective therapy for GR NSCLC. Topics: Animals; Carcinogenesis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Movement; Disease Susceptibility; Down-Regulation; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; F-Box-WD Repeat-Containing Protein 7; Gefitinib; Gene Deletion; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Lung Neoplasms; Mice, Inbred BALB C; Mice, Nude; Neoplasm Invasiveness; Prognosis; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome | 2018 |
Streptomyces, shared microbiome member of soil and gut, as 'old friends' against colon cancer.
Inflammation contributes to colon cancer initiation. The disease along with allergy and autoimmunity has been on the rise in Western and more recently in developing countries. This shared rise may imply a shared cause. Streptomycetes are known as soil residents and produce numerous antiproliferative, anti-inflammatory/immunosuppressive compounds, e.g. rapamycin and tacrolimus. Recently, Streptomyces has been shown in gut microbiome with a lower prevalence in humans than nonhumans whose microbiomes might be more representative of past humans' in a hunter-gatherer and farming environment. It was previously suggested that Streptomyces producing antiproliferatives/immunosuppressants would be 'old friends' against allergy and autoimmunity as well as inflammatory bowel diseases. Here, it is suggested that these streptomycetes within gut microbiome have also been evolved as 'old friends' to suppress colon tumorigenesis through their numerous antiproliferatives/immunosuppressants. Subsequently, the shortage of exposure to nature in our current lifestyle has cost us the shortage of these friends and vulnerability to colon cancer. An attractive research area in the future would be whether the shortage of Streptomyces exposure can be the underlying reason for colon cancer, allergy and autoimmunity rise, and if the restoration of these 'old friends' through probiotics or more exposure to nature can prevent colon cancer. Topics: Anti-Inflammatory Agents; Carcinogenesis; Colonic Neoplasms; Friends; Gastrointestinal Microbiome; Humans; Life Style; Microbiota; Probiotics; Sirolimus; Soil; Soil Microbiology; Streptomyces; Tacrolimus | 2018 |
The mTOR-inhibitor Sirolimus decreases the cyclosporine-induced expression of the oncogene ATF3 in human keratinocytes.
Due to their immunosuppressive therapy, organtransplant recipients (OTRs) exhibit a high incidence for the development of cutaneous squamous cell carcinoma (cSCC). Randomized studies of kidney-transplanted patients indicate a significant lower susceptibility for cSCC among patients receiving the mTOR-inhibitor Sirolimus, compared to patients without mTOR-regimen. The exact mechanism, how mTOR inhibition affects keratinocyte carcinogenesis remains unclear.. Our aim was to investigate the impact of Sirolimus on the expression level of the oncogene ATF3, which is involved in the development and progression of cSCC.. We incubated human keratinocytes, cSSC cell lines and 3D skin equivalents with Sirolimus, exposed the cells to calcineurin inhibitors (CNI) and UVA-radiation and measured the expression level of ATF3 by real-time PCR and western blot.. We show that Sirolimus downregulates the expression of ATF3 induced by cyclosporine or cyclosporine plus UV-radiation in keratinocytes. In line with this we demonstrate a decrease in ATF3 expression, by incubating 3D skin equivalents with Sirolimus prior to cyclosporine and UV-light. However, Sirolimus has no significant impact on the ATF3 expression levels of cyclosporine stimulated cSCC cell lines.. Taken together, our study demonstrates that Sirolimus downregulates the CNI or UV-induced ATF3 expression in human keratinocytes, which could be a potential molecular mechanism how Sirolimus reduces cSCC in OTRs. The lack of ATF3 suppression by Sirolimus in cSCC cell lines fits to observations from clinical studies which demonstrated a clinical benefit from the switch to a mTOR-regimen in patients with low tumor burden in early stage of disease. Topics: Activating Transcription Factor 3; Calcineurin Inhibitors; Carcinogenesis; Carcinoma, Squamous Cell; Cell Culture Techniques; Cell Line, Tumor; Cyclosporine; Down-Regulation; Humans; Immunosuppressive Agents; Keratinocytes; Oncogenes; Organ Transplantation; Sirolimus; Skin; Skin Neoplasms; TOR Serine-Threonine Kinases; Ultraviolet Rays | 2018 |
Autophagy suppresses self-renewal ability and tumorigenicity of glioma-initiating cells and promotes Notch1 degradation.
Autophagy is a vital process that involves degradation of long-lived proteins and dysfunctional organelles and contributes to cellular metabolism. Glioma-initiating cells (GICs) have the ability to self-renew, differentiate into heterogeneous types of tumor cells, and sustain tumorigenicity; thus, GICs lead to tumor recurrence. Accumulating evidence indicates that autophagy can induce stem cell differentiation and increase the lethality of temozolomide against GICs. However, the mechanism underlying the regulation of GIC self-renewal by autophagy remains uncharacterized. In the present study, autophagy induced by AZD8055 and rapamycin treatment suppressed GIC self-renewal in vitro. We found that autophagy inhibited Notch1 pathway activation. Moreover, autophagy activated Notch1 degradation, which is associated with maintenance of the self-renewal ability of GICs. Furthermore, autophagy abolished the tumorigenicity of CD133 + U87-MG neurosphere cells in an intracranial model. These findings suggest that autophagy regulating GICs self-renewal and tumorigenicity is probably bound up with Notch1 degradation. The results of this study could aid in the design of autophagy-based clinical trials for glioma treatments, which may be of great value. Topics: Animals; Antineoplastic Agents; Autophagy; Brain Neoplasms; Calcium-Binding Proteins; Carcinogenesis; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Membrane Proteins; Mice; Mice, Nude; Morpholines; Neoplastic Stem Cells; Proteolysis; Receptor, Notch1; Signal Transduction; Sirolimus; Sodium-Potassium-Exchanging ATPase; Spheroids, Cellular; Survival Analysis; Xenograft Model Antitumor Assays | 2018 |
MITA modulated autophagy flux promotes cell death in breast cancer cells.
The crosstalk between inflammation and autophagy is an emerging phenomenon observed during tumorigenesis. Activation of NF-κB and IRF3 plays a key role in the regulation of cytokines that are involved in tumor growth and progression. The genes of innate immunity are known to regulate the master transcription factors like NF-κB and IRF3. Innate immunity pathways at the same time regulate the genes of the autophagy pathway which are essential for tumor cell metabolism. In the current study, we studied the role of MITA (Mediator of IRF3 Activation), a regulator of innate immunity, in the regulation of autophagy and its implication in cell death of breast cancer cells. Here, we report that MITA inhibits the fusion of autophagosome with lysosome as evident from different autophagy flux assays. The expression of MITA induces the translocation of p62 and NDP52 to mitochondria which further recruits LC3 for autophagosome formation. The expression of MITA decreased mitochondrial number and enhances mitochondrial ROS by increasing complex-I activity. The enhancement of autophagy flux with rapamycin or TFEB expression normalized MITA induced cell death. The evidences clearly show that MITA regulates autophagy flux and modulates mitochondrial turnover through mitophagy. Topics: Autophagosomes; Autophagy; Breast Neoplasms; Carcinogenesis; Cell Line, Tumor; Female; Gene Expression Regulation, Neoplastic; Humans; Immunity, Innate; Inflammation; Interferon Regulatory Factor-3; Lysosomes; Membrane Proteins; Mitochondria; Mitophagy; NF-kappa B; Signal Transduction; Sirolimus | 2017 |
A functional mammalian target of rapamycin complex 1 signaling is indispensable for c-Myc-driven hepatocarcinogenesis.
Amplification and/or activation of the c-Myc proto-oncogene is one of the leading genetic events along hepatocarcinogenesis. The oncogenic potential of c-Myc has been proven experimentally by the finding that its overexpression in the mouse liver triggers tumor formation. However, the molecular mechanism whereby c-Myc exerts its oncogenic activity in the liver remains poorly understood. Here, we demonstrate that the mammalian target of rapamycin complex 1 (mTORC1) cascade is activated and necessary for c-Myc-dependent hepatocarcinogenesis. Specifically, we found that ablation of Raptor, the unique member of mTORC1, strongly inhibits c-Myc liver tumor formation. Also, the p70 ribosomal S6 kinase/ribosomal protein S6 and eukaryotic translation initiation factor 4E-binding protein 1/eukaryotic translation initiation factor 4E signaling cascades downstream of mTORC1 are required for c-Myc-driven tumorigenesis. Intriguingly, microarray expression analysis revealed up-regulation of multiple amino acid transporters, including solute carrier family 1 member A5 (SLC1A5) and SLC7A6, leading to robust uptake of amino acids, including glutamine, into c-Myc tumor cells. Subsequent functional studies showed that amino acids are critical for activation of mTORC1 as their inhibition suppressed mTORC1 in c-Myc tumor cells. In human hepatocellular carcinoma specimens, levels of c-Myc directly correlate with those of mTORC1 activation as well as of SLC1A5 and SLC7A6.. Our current study indicates that an intact mTORC1 axis is required for c-Myc-driven hepatocarcinogenesis; thus, targeting the mTOR pathway or amino acid transporters may be an effective and novel therapeutic option for the treatment of hepatocellular carcinoma with activated c-Myc signaling. (Hepatology 2017;66:167-181). Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Biopsy, Needle; Carcinogenesis; Carcinoma, Hepatocellular; Cell Cycle Proteins; Disease Models, Animal; Genes, myc; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Liver Neoplasms; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Knockout; Multiprotein Complexes; Phosphoproteins; Phosphorylation; Proportional Hazards Models; Proto-Oncogene Mas; Random Allocation; Signal Transduction; Sirolimus; Statistics, Nonparametric; TOR Serine-Threonine Kinases | 2017 |
c‑Myc promotes cholangiocarcinoma cells to overcome contact inhibition via the mTOR pathway.
The loss of contact inhibition is a hallmark of a wide range of human cancer cells. Yet, the precise mechanism behind this process is not fully understood. c‑Myc plays a pivotal role in carcinogenesis, but its involvement in regulating contact inhibition has not been explored to date. Here, we report that c‑Myc plays an important role in abrogating contact inhibition in human cholangiocarcinoma (CCA) cells. Our data show that the protein level of c‑Myc obviously decreased in contact-inhibited normal biliary epithelial cells. However, CCA cells sustain high protein levels of c‑Myc and keep strong proliferation ability in confluent conditions. Importantly, the suppression of c‑Myc by inhibitor or siRNA induced G0/G1 phase cell cycle arrest in confluent CCA cells. We demonstrate that the inhibition of c‑Myc suppressed the activity of mammalian target of rapamycin (mTOR) in confluent CCA cells, and mTOR inhibition induced G0/G1 phase cell cycle arrest in confluent CCA cells. In confluent CCA cells, the activity of Merlin is downregulated, and Yes-associated protein (YAP) sustains high levels of activity. Furthermore, YAP inhibition not only induced G0/G1 phase cell cycle arrest, but also decreased c‑Myc expression in confluent CCA cells. These results indicate that Merlin/YAP/c‑Myc/mTOR signaling axis promotes human CCA cell proliferation by overriding contact inhibition. We propose that overriding c‑Myc‑mediated contact inhibition is implicated in the development of CCA. Topics: Carcinogenesis; Cell Cycle Checkpoints; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cholangiocarcinoma; Contact Inhibition; Gene Expression Regulation, Neoplastic; Humans; Neurofibromin 2; Nuclear Proteins; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors | 2017 |
Everolimus exhibits anti-tumorigenic activity in obesity-induced ovarian cancer.
Everolimus inhibits mTOR kinase activity and its downstream targets by acting on mTORC1 and has anti-tumorigenic activity in ovarian cancer. Clinical and epidemiologic data find that obesity is associated with worse outcomes in ovarian cancer. In addition, obesity leads to hyperactivation of the mTOR pathway in epithelial tissues, suggesting that mTOR inhibitors may be a logical choice for treatment in obesity-driven cancers. However, it remains unclear if obesity impacts the effect of everolimus on tumor growth in ovarian cancer. The present study was aimed at evaluating the effects of everolimus on cytotoxicity, cell metabolism, apoptosis, cell cycle, cell stress and invasion in human ovarian cancer cells. A genetically engineered mouse model of serous ovarian cancer fed a high fat diet or low fat diet allowed further investigation into the inter-relationship between everolimus and obesity in vivo. Everolimus significantly inhibited cellular proliferation, induced cell cycle G1 arrest and apoptosis, reduced invasion and caused cellular stress via inhibition of mTOR pathways in vitro. Hypoglycemic conditions enhanced the sensitivity of cells to everolimus through the disruption of glycolysis. Moreover, everolimus was found to inhibit ovarian tumor growth in both obese and lean mice. This reduction coincided with a decrease in expression of Ki-67 and phosphorylated-S6, as well as an increase in cleaved caspase 3 and phosphorylated-AKT. Metabolite profiling revealed that everolimus was able to alter tumor metabolism through different metabolic pathways in the obese and lean mice. Our findings support that everolimus may be a promising therapeutic agent for obesity-driven ovarian cancers. Topics: Animals; Antibiotics, Antineoplastic; Apoptosis; Carcinogenesis; Carcinoma, Ovarian Epithelial; Cell Adhesion; Cell Cycle; Cell Movement; Cell Proliferation; Disease Models, Animal; Female; Humans; Mice; Neoplasms, Glandular and Epithelial; Obesity; Ovarian Neoplasms; Phosphorylation; Prognosis; Signal Transduction; Sirolimus; Tumor Cells, Cultured | 2016 |
mTORC1-mediated downregulation of COX2 restrains tumor growth caused by TSC2 deficiency.
Tuberous sclerosis complex (TSC), caused by loss-of-function mutations in the TSC1 or TSC2 gene, is characterized by benign tumor formation in multiple organs. Hyperactivation of mammalian target of rapamycin complex 1 (mTORC1) is the primary alteration underlying TSC tumors. By analyzing Tsc2-null mouse embryonic fibroblasts (MEFs) and rat uterine leiomyoma-derived Tsc2-null ELT3 cells, we detected evidence for the involvement of cyclooxygenase 2 (COX2) as a downstream target of mTORC1 in the development of TSC tumors. We showed that loss of TSC2 led to decreased COX2 expression through activation of an mTORC1/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Overexpression of COX2 promoted proliferation and tumoral growth of Tsc2-null cells. COX2 knockdown inhibited the proliferation of the control cells. COX2 enhanced Tsc2-null cell growth through upregulation of interleukin-6 (IL-6). In addition, rapamycin in combination with celecoxib, a COX2 inhibitor, strongly inhibited Tsc2-deficient cell growth. We conclude that downregulation of COX2 exerts a protective effect against hyperactivated mTORC1-mediated tumorigenesis caused by the loss of TSC2, and the combination of rapamycin and celecoxib may be an effective new approach to treating TSC. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Carcinogenesis; Celecoxib; Cell Proliferation; Cyclooxygenase 2; Down-Regulation; Mechanistic Target of Rapamycin Complex 1; Mice; Neoplasms; Rats; Sirolimus; Tuberous Sclerosis; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins | 2016 |
mTORC1 is a critical mediator of oncogenic Semaphorin3A signaling.
Aberration of signaling pathways by genetic mutations or alterations in the surrounding tissue environments can result in tumor development or metastasis. However, signaling molecules responsible for these processes have not been completely elucidated. Here, we used mouse Lewis lung carcinoma cells (LLC) to explore the mechanism by which the oncogenic activity of Semaphorin3A (Sema3A) signaling is regulated. Sema3A knockdown by shRNA did not affect apoptosis, but decreased cell proliferation in LLCs; both the mammalian target of rapamycin complex 1 (mTORC1) level and glycolytic activity were also decreased. In addition, Sema3A knockdown sensitized cells to inhibition of oxidative phosphorylation by oligomycin, but conferred resistance to decreased cell viability induced by glucose starvation. Furthermore, recombinant SEMA3A rescued the attenuation of cell proliferation and glycolytic activity in LLCs after Sema3A knockdown, whereas mTORC1 inhibition by rapamycin completely counteracted this effect. These results demonstrate that Sema3A signaling exerts its oncogenic effect by promoting an mTORC1-mediated metabolic shift from oxidative phosphorylation to aerobic glycolysis. Topics: Animals; Apoptosis; Carcinogenesis; Carcinoma, Lewis Lung; Cell Line, Tumor; Cell Proliferation; Gene Knockdown Techniques; Glucose; Glycolysis; Mechanistic Target of Rapamycin Complex 1; Mice; Multiprotein Complexes; Oxidative Phosphorylation; Semaphorin-3A; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2016 |
Growth factor progranulin promotes tumorigenesis of cervical cancer via PI3K/Akt/mTOR signaling pathway.
Progranulin (PGRN) is an autocrine growth factor with tumorigenic roles in various tumors including cervical cancer. In this study, we investigated mammalian target of rapamycin (mTOR) signaling in response to PGRN induction and the contribution of the PGRN-stimulated PI3K/Akt/mTOR signaling pathway in the transformation and progression of cervical cancer. Here we identified a strong linkage between PGRN and phosphorylated-mTOR in cervical cancer tissues. PGRN promoted the phosphorylation of mTOR and activated mTOR signaling in human cervical mucosa epithelial cells and cervical cancer cells, and TNFR2 was needed for PGRN-stimulated mTOR signaling. Inhibition of mTOR signaling with rapamycin decreased PGRN-stimulated protein synthesis, transformation and proliferation of cervical cells in vitro, and tumor formation and growth in vivo. Thus, our findings update the signal transduction pathways of PGRN by suggesting that mTOR signaling contributes to PGRN-stimulated carcinogenesis of cervical cancer. Inhibition of PGRN/PI3K/Akt/mTOR signaling may be targeted in treatment of cervical cancer. Topics: Animals; Anoikis; Carcinogenesis; Cell Movement; Cell Proliferation; Cervix Uteri; Female; HeLa Cells; Humans; Intercellular Signaling Peptides and Proteins; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Phosphatidylinositol 3-Kinases; Phosphorylation; Progranulins; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Uterine Cervical Neoplasms | 2016 |
Prevention of carcinogen and inflammation-induced dermal cancer by oral rapamycin includes reducing genetic damage.
Cancer prevention is a cost-effective alternative to treatment. In mice, the mTOR inhibitor rapamycin prevents distinct spontaneous, noninflammatory cancers, making it a candidate broad-spectrum cancer prevention agent. We now show that oral microencapsulated rapamycin (eRapa) prevents skin cancer in dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) carcinogen-induced, inflammation-driven carcinogenesis. eRapa given before DMBA/TPA exposure significantly increased tumor latency, reduced papilloma prevalence and numbers, and completely inhibited malignant degeneration into squamous cell carcinoma. Rapamycin is primarily an mTORC1-specific inhibitor, but eRapa did not reduce mTORC1 signaling in skin or papillomas, and did not reduce important proinflammatory factors in this model, including p-Stat3, IL17A, IL23, IL12, IL1β, IL6, or TNFα. In support of lack of mTORC1 inhibition, eRapa did not reduce numbers or proliferation of CD45(-)CD34(+)CD49f(mid) skin cancer initiating stem cells in vivo and marginally reduced epidermal hyperplasia. Interestingly, eRapa reduced DMBA/TPA-induced skin DNA damage and the hras codon 61 mutation that specifically drives carcinogenesis in this model, suggesting reduction of DNA damage as a cancer prevention mechanism. In support, cancer prevention and DNA damage reduction effects were lost when eRapa was given after DMBA-induced DNA damage in vivo. eRapa afforded picomolar concentrations of rapamycin in skin of DMBA/TPA-exposed mice, concentrations that also reduced DMBA-induced DNA damage in mouse and human fibroblasts in vitro. Thus, we have identified DNA damage reduction as a novel mechanism by which rapamycin can prevent cancer, which could lay the foundation for its use as a cancer prevention agent in selected human populations. Topics: 3T3 Cells; 9,10-Dimethyl-1,2-benzanthracene; Administration, Oral; Animals; Carcinogenesis; Carcinogens; Cells, Cultured; Chemoprevention; DNA Damage; Down-Regulation; Humans; Inflammation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Sirolimus; Skin Neoplasms | 2015 |
Disruption of tubular Flcn expression as a mouse model for renal tumor induction.
The study of kidney cancer pathogenesis and its treatment has been limited by the scarcity of genetically defined animal models. The FLCN gene that codes for the protein folliculin, mutated in Birt-Hogg-Dubé syndrome, presents a new target for mouse modeling of kidney cancer. Here we developed a kidney-specific knockout model by disrupting the mouse Flcn in the proximal tubules, thus avoiding homozygous embryonic lethality or neonatal mortality, and eliminating the requirement of loss of heterozygosity for tumorigenesis. This knockout develops renal cysts and early onset (6 months) of multiple histological subtypes of renal neoplasms featuring high tumor penetrance. Although the majority of the tumors were chromophobe renal cell carcinomas in affected mice under 1 year of age, papillary renal cell carcinomas predominated in the kidneys of older knockout mice. This renal neoplasia from cystic hyperplasia at 4 months to high-grade renal tumors by 16 months represented the progression of tumorigenesis. The mTOR and TGF-β signalings were upregulated in Flcn-deficient tumors, and these two activated pathways may synergetically cause renal tumorigenesis. Treatment of knockout mice with the mTOR inhibitor rapamycin for 10 months led to the suppression of tumor growth. Thus, our model recapitulates human Birt-Hogg-Dubé kidney tumorigenesis, provides a valuable tool for further study of Flcn-deficient renal tumorigenesis, and tests new drugs/approaches to their treatment. Topics: Animals; Antibiotics, Antineoplastic; Carcinogenesis; Carcinoma, Renal Cell; Cysts; Disease Models, Animal; Hyperplasia; Kidney Neoplasms; Kidney Tubules, Proximal; Mice; Mice, Knockout; Proto-Oncogene Proteins; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Tumor Suppressor Proteins | 2015 |
Metformin inhibits skin tumor promotion in overweight and obese mice.
In the present study, the ability of metformin to inhibit skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) was analyzed in mice maintained on either an overweight control diet or an obesity-inducing diet. Rapamycin was included for comparison, and a combination of metformin and rapamycin was also evaluated. Metformin (given in the drinking water) and rapamycin (given topically) inhibited development of both papillomas and squamous cell carcinomas in overweight and obese mice in a dose-dependent manner. A low-dose combination of these two compounds displayed an additive inhibitory effect on tumor development. Metformin treatment also reduced the size of papillomas. Interestingly, all treatments seemed to be at least as effective for inhibiting tumor formation in obese mice, and both metformin and rapamycin were more effective at reducing tumor size in obese mice compared with overweight control mice. The effect of metformin on skin tumor development was associated with a significant reduction in TPA-induced epidermal hyperproliferation. Furthermore, treatment with metformin led to activation of epidermal AMP-activated protein kinase (AMPK) and attenuated signaling through mTOR complex (mTORC)-1 and p70S6K. Combinations of metformin and rapamycin were more effective at blocking epidermal mTORC1 signaling induced by TPA consistent with the greater inhibitory effect on skin tumor promotion. Collectively, the current data demonstrate that metformin given in the drinking water effectively inhibited skin tumor promotion in both overweight and obese mice and that the mechanism involves activation of epidermal AMPK and attenuated signaling downstream of mTORC1. Topics: Adenylate Kinase; Adiponectin; Animals; Body Weight; Carcinogenesis; Carcinoma, Squamous Cell; Diet; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Insulin; Insulin-Like Growth Factor I; Leptin; Mechanistic Target of Rapamycin Complex 1; Metformin; Mice; Mice, Obese; Multiprotein Complexes; Neoplasms, Experimental; Obesity; Overweight; Papilloma; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Skin Neoplasms; Tetradecanoylphorbol Acetate; TOR Serine-Threonine Kinases | 2014 |
A zebrafish model of chordoma initiated by notochord-driven expression of HRASV12.
Chordoma is a malignant tumor thought to arise from remnants of the embryonic notochord, with its origin in the bones of the axial skeleton. Surgical resection is the standard treatment, usually in combination with radiation therapy, but neither chemotherapeutic nor targeted therapeutic approaches have demonstrated success. No animal model and only few chordoma cell lines are available for preclinical drug testing, and, although no druggable genetic drivers have been identified, activation of EGFR and downstream AKT-PI3K pathways have been described. Here, we report a zebrafish model of chordoma, based on stable transgene-driven expression of HRASV12 in notochord cells during development. Extensive intra-notochordal tumor formation is evident within days of transgene expression, ultimately leading to larval death. The zebrafish tumors share characteristics of human chordoma as demonstrated by immunohistochemistry and electron microscopy. The mTORC1 inhibitor rapamycin, which has some demonstrated activity in a chordoma cell line, delays the onset of tumor formation in our zebrafish model, and improves survival of tumor-bearing fish. Consequently, the HRASV12-driven zebrafish model of chordoma could enable high-throughput screening of potential therapeutic agents for the treatment of this refractory cancer. Topics: Animals; Animals, Genetically Modified; Carcinogenesis; Cell Line, Tumor; Chordoma; Disease Models, Animal; Disease Progression; Humans; Immunohistochemistry; Mutation; Notochord; Organ Specificity; Proto-Oncogene Proteins p21(ras); Sirolimus; Survival Analysis; Zebrafish | 2014 |
Loss of Tsc1 accelerates malignant gliomagenesis when combined with oncogenic signals.
Glioblastomas frequently harbour genetic lesions that stimulate the activity of mammalian target of rapamycin complex 1 (mTORC1). Loss of heterozygosity of tuberous sclerosis complex 1 (TSC1) or TSC2, which together form a critical negative regulator of mTORC1, is also seen in glioblastoma; however, it is not known how loss of the TSC complex affects the development of malignant gliomas. Here we investigated the role of Tsc1 in gliomagenesis in mice. Tsc1 deficiency up-regulated mTORC1 activity and suppressed the proliferation of neural stem/progenitor cells (NSPCs) in a serial neurosphere-forming assay, suggesting that Tsc1-deficient NSPCs have defective self-renewal activity. The neurosphere-forming capacity of Tsc1-deficient NSPCs was restored by p16(Ink4a)p19(Arf) deficiency. Combined Tsc1 and p16(Ink4a)p19(Arf) deficiency in NSPCs did not cause gliomagenesis in vivo. However, in a glioma model driven by an active mutant of epidermal growth factor receptor (EGFR), EGFRvIII, loss of Tsc1 resulted in an earlier onset of glioma development. The mTORC1 hyperactivation by Tsc1 deletion accelerated malignant phenotypes, including increased tumour mass and enhanced microvascular formation, leading to intracranial haemorrhage. These data demonstrate that, although mTORC1 hyperactivation itself may not be sufficient for gliomagenesis, it is a potent modifier of glioma development when combined with oncogenic signals. Topics: Animals; Carcinogenesis; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p19; ErbB Receptors; Glioma; Hemorrhage; Humans; Male; Mechanistic Target of Rapamycin Complex 1; Mice; Multiprotein Complexes; Neural Stem Cells; Phenotype; Signal Transduction; Sirolimus; Spheroids, Cellular; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 1 Protein; Tumor Suppressor Proteins | 2014 |
Lifespan extension and cancer prevention in HER-2/neu transgenic mice treated with low intermittent doses of rapamycin.
Target of Rapamycin (TOR) is involved in cellular and organismal aging. Rapamycin extends lifespan and delays cancer in mice. It is important to determine the minimum effective dose and frequency of its administration that still extends lifespan and prevents cancer. Previously we tested 1.5 mg/kg of rapamycin given subcutaneously 6 times per two weeks followed by a two-week break (1.5 × 6/bi-weekly schedule: total of 6 injections during a 4-week period). This intermittent treatment prolonged lifespan and delayed cancer in cancer-prone female FVB/N HER-2/neu mice. Here, the dose was decreased from 1.5 mg/kg to 0.45 mg/kg per injection. This treatment was started at the age of 2 months (group Rap-2), 4 months (Rap-4), and 5 months (Rap-5). Three control groups received the solvent from the same ages. Rapamycin significantly delayed cancer and decreased tumor burden in Rap-2 and Rap-5 groups, increased mean lifespan in Rap-4 and Rap-5 groups, and increased maximal lifespan in Rap-2 and Rap-5 groups. In Rap-4 group, mean lifespan extension was achieved without significant cancer prevention. The complex relationship between life-extension and cancer-prevention depends on both the direct effect of rapamycin on cancer cells and its anti-aging effect on the organism, which in turn prevents cancer indirectly. We conclude that total doses of rapamycin that are an order of magnitude lower than standard total doses can detectably extend life span in cancer-prone mice. Topics: Animals; Anticarcinogenic Agents; Carcinogenesis; Female; Longevity; Mammary Neoplasms, Animal; Mice; Mice, Transgenic; Receptor, ErbB-2; Sirolimus | 2014 |
Androgen deprivation induces phenotypic plasticity and promotes resistance to molecular targeted therapy in a PTEN-deficient mouse model of prostate cancer.
Castration-resistant prostate cancer is an incurable heterogeneous disease that is characterized by a complex multistep process involving different cellular and biochemical changes brought on by genetic and epigenetic alterations. These changes lead to the activation or overexpression of key survival pathways that also serve as potential therapeutic targets. Despite promising preclinical results, molecular targeted therapies aimed at such signaling pathways have so far been dismal. In the present study, we used a PTEN-deficient mouse model of prostate cancer to show that plasticity in castration-resistant tumors promotes therapeutic escape. Unlike castration-naïve tumors which depend on androgen receptor and PI3K/AKT signal activation for growth and survival, castration-resistant tumors undergo phenotypic plasticity leading to increased intratumoral heterogeneity. These tumors attain highly heterogeneous phenotypes that are characterized by cancer cells relying on alternate signal transduction pathways for growth and survival, such as mitogen-activated protein kinase and janus kinase/signal transducer and activator of transcription, and losing their dependence on PI3K signaling. These features thus enabled castration-resistant tumors to become insensitive to the therapeutic effects of PI3K/AKT targeted therapy. Overall, our findings provide evidence that androgen deprivation drives phenotypic plasticity in prostate cancer cells and implicate it as a crucial contributor to therapeutic resistance in castration-resistant prostate cancer. Therefore, incorporating intratumoral heterogeneity in a dynamic tumor model as a part of preclinical efficacy determination could improve prediction for response and provide better rationale for the development of more effective therapies. Topics: Adenocarcinoma; Animals; Antineoplastic Combined Chemotherapy Protocols; Butadienes; Carcinogenesis; Cell Proliferation; Combined Modality Therapy; Disease Models, Animal; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Drug Synergism; Everolimus; Humans; Male; Mice; Mice, Transgenic; Molecular Targeted Therapy; Nitriles; Orchiectomy; Phenotype; Prostate; Prostatic Neoplasms, Castration-Resistant; PTEN Phosphohydrolase; Receptors, Androgen; Sirolimus | 2014 |
Hcrcn81 is upregulated by rapamycin treatment in human colorectal adenocarcinoma cells.
The aim of the present study was to determine the role of hcrcn81 in the regulation of the mammalian target of rapamycin (mTOR) pathway in human colorectal adenocarcinoma cells. The effect of rapamycin treatment on hcrcn81 expression was evaluated by examining the mRNA and protein expression of hcrcn81 in rapamycin‑treated human colon carcinoma cell lines, SW480 and LoVo, using real‑time PCR and western blot analysis, respectively. The results demonstrated that mRNA and protein levels of hcrcn81 were elevated following rapamycin treatment in these cell lines, indicating that hcrcn81 expression is upregulated by rapamycin treatment in human colorectal adenocarcinoma cells. Observations of the current study indicate that hcrcn81 may play a role in tumorigenesis by regulating the mTOR signaling pathway. Topics: Adenocarcinoma; Carcinogenesis; Cell Line, Tumor; Colorectal Neoplasms; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Proteins; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2013 |