sirolimus has been researched along with Brain-Neoplasms* in 133 studies
18 review(s) available for sirolimus and Brain-Neoplasms
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Discrete signaling mechanisms of mTORC1 and mTORC2: Connected yet apart in cellular and molecular aspects.
Activation of PI3K/Akt/mTOR (mechanistic target of rapamycin) signaling cascade has been shown in tumorigenesis of numerous malignancies including glioblastoma (GB). This signaling cascade is frequently upregulated due to loss of the tumor suppressor PTEN, a phosphatase that functions antagonistically to PI3K. mTOR regulates cell growth, motility, and metabolism by forming two multiprotein complexes, mTORC1 and mTORC2, which are composed of special binding partners. These complexes are sensitive to distinct stimuli. mTORC1 is sensitive to nutrients and mTORC2 is regulated via PI3K and growth factor signaling. mTORC1 regulates protein synthesis and cell growth through downstream molecules: 4E-BP1 (also called EIF4E-BP1) and S6K. Also, mTORC2 is responsive to growth factor signaling by phosphorylating the C-terminal hydrophobic motif of some AGC kinases like Akt and SGK. mTORC2 plays a crucial role in maintenance of normal and cancer cells through its association with ribosomes, and is involved in cellular metabolic regulation. Both complexes control each other as Akt regulates PRAS40 phosphorylation, which disinhibits mTORC1 activity, while S6K regulates Sin1 to modulate mTORC2 activity. Another significant component of mTORC2 is Sin1, which is crucial for mTORC2 complex formation and function. Allosteric inhibitors of mTOR, rapamycin and rapalogs, have essentially been ineffective in clinical trials of patients with GB due to their incomplete inhibition of mTORC1 or unexpected activation of mTOR via the loss of negative feedback loops. Novel ATP binding inhibitors of mTORC1 and mTORC2 suppress mTORC1 activity completely by total dephosphorylation of its downstream substrate pS6K Topics: Antineoplastic Agents; Brain Neoplasms; Cell Movement; Cell Proliferation; Clinical Trials as Topic; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Indoles; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Neoplastic Stem Cells; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Purines; Signal Transduction; Sirolimus | 2017 |
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 | 2016 |
Targeting autophagy to sensitive glioma to temozolomide treatment.
Temozolomide (TMZ), an alkylating agent, is widely used for treating primary and recurrent high-grade gliomas. However, the efficacy of TMZ is often limited by the development of resistance. Recently, studies have found that TMZ treatment could induce autophagy, which contributes to therapy resistance in glioma. To enhance the benefit of TMZ in the treatment of glioblastomas, effective combination strategies are needed to sensitize glioblastoma cells to TMZ. In this regard, as autophagy could promote cell survival or autophagic cell death, modulating autophagy using a pharmacological inhibitor, such as chloroquine, or an inducer, such as rapamycin, has received considerably more attention. To understand the effectiveness of regulating autophagy in glioblastoma treatment, this review summarizes reports on glioblastoma treatments with TMZ and autophagic modulators from in vitro and in vivo studies, as well as clinical trials. Additionally, we discuss the possibility of using autophagy regulatory compounds that can sensitive TMZ treatment as a chemotherapy for glioma treatment. Topics: Antineoplastic Combined Chemotherapy Protocols; Autophagy; Brain Neoplasms; Cell Line, Tumor; Cell Survival; Chloroquine; Clinical Trials as Topic; Dacarbazine; Drug Resistance, Neoplasm; Drug Synergism; Glioblastoma; Humans; Sirolimus; Temozolomide | 2016 |
Rapamycin and rapalogs for tuberous sclerosis complex.
Previous studies have shown potential benefits of rapamycin or rapalogs for treating people with tuberous sclerosis complex. Although everolimus (a rapalog) is currently approved by the FDA (U.S. Food and Drug Administration) and the EMA (European Medicines Agency) for tuberous sclerosis complex-associated renal angiomyolipoma and subependymal giant cell astrocytoma, applications for other manifestations of tuberous sclerosis complex have not yet been established. A systematic review is necessary to establish the clinical value of rapamycin or rapalogs for various manifestations in tuberous sclerosis complex.. To determine the effectiveness of rapamycin or rapalogs in people with tuberous sclerosis complex for decreasing tumour size and other manifestations and to assess the safety of rapamycin or rapalogs in relation to their adverse effects.. Relevant studies were identified by authors from the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, and clinicaltrials.gov. Relevant resources were also searched by the authors, such as conference proceedings and abstract books of conferences, from e.g. the Tuberous Sclerosis Complex International Research Conferences, other tuberous sclerosis complex-related conferences and the Human Genome Meeting. We did not restrict the searches by language as long as English translations were available for non-English reports.Date of the last searches: 14 March 2016.. Randomized or quasi-randomized studies of rapamycin or rapalogs in people with tuberous sclerosis complex.. Data were independently extracted by two authors using standard acquisition forms. The data collection was verified by one author. The risk of bias of each study was independently assessed by two authors and verified by one author.. Three placebo-controlled studies with a total of 263 participants (age range 0.8 to 61 years old, 122 males and 141 females, with variable lengths of study duration) were included in the review. We found high-quality evidence except for response to skin lesions which was judged to be low quality due to the risk of attrition bias. Overall, there are 175 participants in the treatment arm (rapamycin or everolimus) and 88 in the placebo arm. Participants all had tuberous sclerosis complex as proven by consensus diagnostic criteria as a minimum. The quality in the description of the study methods was mixed, although we assessed most domains as having a low risk of bias. Blinding of treatment arms was successfully carried out in all of the studies. However, two studies did not report allocation concealment. Two of the included studies were funded by Novartis Pharmaceuticals.Two studies (235 participants) used oral (systemic) administration of everolimus (rapalog). These studies reported response to tumour size in terms of the number of individuals with a reduction in the total volume of tumours to 50% or more relative to baseline. Significantly more participants in the treatment arm (two studies, 162 participants, high quality evidence) achieved a 50% reduction in renal angiomyolipoma size, risk ratio 24.69 (95% confidence interval 3.51 to 173.41) (P = 0.001). For the sub-ependymal giant cell astrocytoma, our analysis of one study (117 participants, high quality evidence) showed significantly more participants in the treatment arm achieved a 50% reduction in tumour size, risk ratio 27.85 (95% confidence interval 1.74 to 444.82) (P = 0.02). The proportion of participants who showed a skin response from the two included studies analysed was significantly increased in the treatment arms, risk ratio 5.78 (95% confidence interval 2.30 to 14.52) (P = 0.0002) (two studies, 224 participants, high quality evidence). In one study (117 participants), the median change of seizure frequency was -2.9 in 24 hours (95% confidence interval -4.0 to -1.0) in the treatment group versus -4.1 in 24 hour (95% confidence interval -10.9 to 5.8) in the placebo group. In one study, one out of 79 participants in the treatment group versus three of 39 in placebo group had increased blood creatinine levels, while the median percentage change of forced expiratory volume at one second in the treatment arm was -1% compared to -4% in the placebo arm. In one study (117 participants, high quality. We found evidence that oral everolimus significantly increased the proportion of people who achieved a 50% reduction in the size of sub-ependymal giant cell astrocytoma and renal angiomyolipoma. Although we were unable to ascertain the relationship between the reported adverse events and the treatment, participants who received treatment had a similar risk of experiencing adverse events as compared to those who did not receive treatment. Nevertheless, the treatment itself significantly increased the risk of having dose reduction, interruption or withdrawal. This supports ongoing clinical applications of oral everolimus for renal angiomyolipoma and subependymal giant cell astrocytoma. Although oral everolimus showed beneficial effect on skin lesions, topical rapamycin only showed a non-significant tendency of improvement. Efficacy on skin lesions should be further established in future research. The beneficial effects of rapamycin or rapalogs on tuberous sclerosis complex should be further studied on other manifestations of the condition. Topics: Administration, Oral; Administration, Topical; Angiolipoma; Astrocytoma; Brain Neoplasms; Everolimus; Female; Humans; Immunosuppressive Agents; Kidney Neoplasms; Male; Randomized Controlled Trials as Topic; Seizures; Sirolimus; Skin Diseases; Tuberous Sclerosis; Tumor Burden | 2016 |
Differentiating the mTOR inhibitors everolimus and sirolimus in the treatment of tuberous sclerosis complex.
Tuberous sclerosis complex (TSC) is a genetic autosomal dominant disorder characterized by benign tumor-like lesions, called hamartomas, in multiple organ systems, including the brain, skin, heart, kidneys, and lung. These hamartomas cause a diverse set of clinical problems based on their location and often result in epilepsy, learning difficulties, and behavioral problems. TSC is caused by mutations within the TSC1 or TSC2 genes that inactivate the genes' tumor-suppressive function and drive hamartomatous cell growth. In normal cells, TSC1 and TSC2 integrate growth signals and nutrient inputs to downregulate signaling to mammalian target of rapamycin (mTOR), an evolutionarily conserved serine-threonine kinase that controls cell growth and cell survival. The molecular connection between TSC and mTOR led to the clinical use of allosteric mTOR inhibitors (sirolimus and everolimus) for the treatment of TSC. Everolimus is approved for subependymal giant cell astrocytomas and renal angiomyolipomas in patients with TSC. Sirolimus, though not approved for TSC, has undergone considerable investigation to treat various aspects of the disease. Everolimus and sirolimus selectively inhibit mTOR signaling with similar molecular mechanisms, but with distinct clinical profiles. This review differentiates mTOR inhibitors in TSC while describing the molecular mechanisms, pathogenic mutations, and clinical trial outcomes for managing TSC. Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Brain Neoplasms; Clinical Trials as Topic; Everolimus; Female; Glioma, Subependymal; Humans; Male; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins | 2015 |
[Therapeutic update in tuberous sclerosis complex: the role of mTOR pathway inhibitors].
Tuberous sclerosis complex is an autosomal dominant disease, with variable expressivity and multisystemic involvement, which is characterised by the growth of benign tumours called hamartomas. The organs that are most commonly affected are the brain, skin, kidneys, eyes, heart and lungs. Of all the children with this disease, 85% present neurological manifestations that, due to their severity, are the main cause of morbidity and mortality. The most significant neurological manifestations are epilepsy, autism spectrum disorders and mental retardation. It has been shown that in tuberous sclerosis complex the genes TSC1 and TSC2 alter the mTOR enzyme cascade, which sets off inhibition of this pathway. The possibility of resorting to treatments applied at the origin, thus inhibiting this pathway, is currently being evaluated. Topics: Anticonvulsants; Astrocytoma; Autistic Disorder; Brain Diseases; Brain Neoplasms; Drug Design; Epilepsy; Everolimus; Glioma, Subependymal; Hamartoma; Humans; Intellectual Disability; Learning Disabilities; Molecular Targeted Therapy; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins | 2012 |
[Renal carcinoma: point on treatment of brain metastasis].
Prognosis of patients with renal carcinoma has improved since the advent of targeted therapies. These last years, due to the improvement of patients overall survival, the incidence of brain metastasis among renal carcinoma patients has increased. This worsens the prognosis of patients. The present revue aims to do a point on treatment of brain metastasis from renal carcinoma. It will address both locoregional (surgery, radiotherapy and stereotactic radiosurgery) and systemic (targeted therapies) treatments. Topics: Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Bevacizumab; Brain Neoplasms; Carcinoma, Renal Cell; Everolimus; Humans; Kidney Neoplasms; Molecular Targeted Therapy; Prognosis; Radiosurgery; Receptor Protein-Tyrosine Kinases; Sirolimus | 2012 |
Tuberous sclerosis complex: tumors and tumorigenesis.
Tuberous sclerosis complex (TSC) is an inherited disorder characterized by hamartomas in different body organs, mainly in the brain, skin, kidney, liver, lung, and heart. The clinical manifestations of TSC are the result of a mutation of one of two tumor suppressor genes, TSC1 and TSC2. Cutaneous findings in TSC should be regarded as cutaneous signs of a pivotal systemic disease. The authors elucidate the variety of neoplasms seen in TSC patients, along with their clinical significance, and suggest suitable evaluation and management strategies. Topics: Angiomyolipoma; Antineoplastic Agents; Brain Neoplasms; Carcinoma, Renal Cell; Cell Transformation, Neoplastic; Female; Heart Neoplasms; Humans; Kidney Neoplasms; Lung Neoplasms; Lymphangioleiomyomatosis; Male; Mutation; Radiography; Rhabdomyoma; Sirolimus; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins | 2011 |
The management of subependymal giant cell tumors in tuberous sclerosis: a clinician's perspective.
Tuberous sclerosis (TSC) is a genetic multisystem disorder associated with hamartomas in several organs including subependymal giant cell tumors (SGCT). SGCT have the potential to grow and therefore to become symptomatic and are one of the main causes of death in TSC individuals. Surgical resection is the procedure of choice for SGCT. However, the discovery of mTOR pathway upregulation in TSC-associated tumors and recent evidence that mTOR inhibitors may induce regression of SGCT open up new treatment strategies. Based on a review of the currently available literature and on personal experience, current options for the management of TSC patients and appropriate indications, taking into account benefits and risks of surgery and pharmacotherapy, are discussed.. An earlier diagnosis of SGCT in neurologically asymptomatic children may allow a precocious surgical removal of the tumor, thus minimizing surgery-related morbidity and mortality. Biologically targeted pharmacotherapy with mTOR inhibitors such as sirolimus and everolimus provides a safe and efficacious treatment option for patients with SGCT and has the potential to change the clinical management of these tumors. However, whether pharmacotherapy is sufficient to control growth or if it only delays the need for surgical removal of symptomatic SGCT remains unclear. Further studies are needed to determine the optimal levels of mTOR inhibitors that preserve maximal anti-tumor efficacy while minimizing side effects. Topics: Animals; Astrocytoma; Brain Neoplasms; Everolimus; Humans; Immunosuppressive Agents; Neurosurgical Procedures; Sirolimus; Tuberous Sclerosis | 2011 |
mTOR inhibitors in the treatment of subependymal giant-cell astrocytomas associated with tuberous sclerosis.
Topics: Animals; Astrocytoma; Brain Neoplasms; Everolimus; Humans; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Tuberous Sclerosis | 2011 |
Everolimus tablets for patients with subependymal giant cell astrocytoma.
Better understanding of aberrantly active molecular pathways in tumors offers potential to develop more specific and less toxic therapies. Abnormal mammalian target of rapamycin (mTOR) complex signaling and defects in TSC1 and TSC2 have been associated with the development of subependymal giant cell astrocytomas (SEGAs) in tuberous sclerosis complex (TSC) patients. Recently, mTOR inhibitors such as everolimus have shown encouraging benefit for patients with SEGAs.. The authors discuss a molecular genetic pathway linked with TSC, specifically the role of two proteins whose functional absence is responsible for most SEGA tumors that arise in TSC patients. The authors also examine the rationale for targeted agents against this pathway therapeutically and describe the clinical evidence underlying the FDA approval of everolimus for patients with inoperable SEGAs.. Everolimus (Afinitor) selectively targets a molecular defect of SEGAs in TSC patients. Although surgery is effective, most SEGAs recur. An agent that inhibits an underlying molecular abnormality represents a particularly attractive therapeutic option for patients with inoperable or recurrent tumors. Studies are also underway to assess everolimus in treating other sequelae of TSC, and other gliomas. Finally, additional research aimed at better understanding aberrant cell signaling pathways may lead to the development of more effective therapeutics. Topics: Antineoplastic Agents; Astrocytoma; Brain Neoplasms; Everolimus; Humans; Mechanistic Target of Rapamycin Complex 1; Multiprotein Complexes; Proteins; Sirolimus; Tablets; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins | 2011 |
[Recent advance in tuberous sclerosis-related genes and their expression].
Topics: Adenocarcinoma; Angiomyolipoma; Antibiotics, Antineoplastic; Astrocytoma; Brain Neoplasms; Breast Neoplasms; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Kidney Neoplasms; Lung Neoplasms; Mutation; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins | 2010 |
Incorporating molecular tools into early-stage clinical trials.
Topics: Animals; Antineoplastic Agents; Brain Neoplasms; Clinical Trials as Topic; Combined Modality Therapy; Drug Delivery Systems; Drug Evaluation, Preclinical; ErbB Receptors; Glioblastoma; Humans; Neoplasm Proteins; Neoplasm Recurrence, Local; Protein Kinase Inhibitors; Protein Kinases; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2008 |
Mammalian target of rapamycin: master regulator of cell growth in the nervous system.
The mammalian target of rapamycin (mTOR) is a highly conserved serine/threonine protein kinase that regulates a number of diverse biologic processes important for cell growth and proliferation, including ribosomal biogenesis and protein translation. In this regard, hyperactivation of the mTOR signaling pathway has been demonstrated in numerous human cancers, including a number of inherited cancer syndromes in which individuals have an increased risk of developing benign and malignant tumors. Three of these inherited cancer syndromes (Lhermitte-Duclos disease, neurofibromatosis type 1, and tuberous sclerosis complex) are characterized by significant central nervous system dysfunction and brain tumor formation. Each of these disorders is caused by a genetic mutation that disrupts the expression of proteins which negatively regulate mTOR signaling, indicating that the mTOR signaling pathway is critical for appropriate brain development and function. In this review, we discuss our current understanding of the mTOR signaling pathway and its role in promoting ribosome biogenesis and cell growth. We suggest that studies of this pathway may prove useful in identifying molecular targets for biologically-based therapies of brain tumors associated with these inherited cancer syndromes as well as sporadic central nervous system tumors. Topics: Animals; Antibiotics, Antineoplastic; Brain Neoplasms; Cell Proliferation; Central Nervous System; Humans; Mutation; Protein Kinase Inhibitors; Protein Kinases; Ribosomes; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2007 |
Small-molecule and antibody approaches to molecular chemotherapy of primary brain tumors.
High-grade primary brain tumors remain refractory to conventional treatment approaches, including radiotherapy and cytotoxic chemotherapy. Molecular neuro-oncology has now begun to clarify the transformed phenotype of these malignant tumors and identify oncogenic pathways that might be amenable to small-molecule and antibody 'targeted' therapy. Growth factor signaling pathways are often upregulated in these tumors and contribute to oncogenesis through autocrine and paracrine mechanisms. Excessive growth factor receptor stimulation can also lead to overactivity of the downstream Ras signaling pathway. Other internal signal transduction pathways that may become dysregulated during transformation include Raf, MEK, PI3K, Akt (protein kinase B), and mTOR (mammalian target of rapamycin). In addition, overactivity of VEGF and other effectors leads to neoplastic angiogenesis. 'Targeted' therapy against the growth factor signaling and Ras pathways include tyrosine kinase inhibitors (eg, imatinib and erlotinib) and farnesyltransferase inhibitors (eg, tipifarnib). Molecular therapeutic small molecules specific to Raf, PI3K, and mTOR include sorafenib, LY-294002, and temsirolimus, respectively. 'Targeted' anti-angiogenesis approaches include mAbs to VEGF (eg, bevacizumab) and VEGF receptor tyrosine kinase inhibitors (eg, vatalanib and sunitinib). Further development of 'targeted' therapies designed to modulate the activity of these pathways, and evaluation of these new agents in clinical trials, will be needed to improve survival and quality-of-life for patients with malignant brain tumors. Topics: Angiogenesis Inhibitors; Antibodies, Monoclonal; Antineoplastic Agents; Brain Neoplasms; Clinical Trials as Topic; Enzyme Inhibitors; ErbB Receptors; Forecasting; Genes, ras; Humans; Intercellular Signaling Peptides and Proteins; Molecular Structure; Neovascularization, Pathologic; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Signal Transduction; Sirolimus; Treatment Outcome | 2007 |
Current status of clinical trials for glioblastoma.
Glioblastoma, the most highly aggressive and lethal form of brain cancer, has been a particular challenge to treat in terms of improving a patient's quality of life and outcome. Each of the current treatment options is limited due to factors intrinsic to the tumor's biology and the special microenvironment of its location within the brain. Surgical resection is limited by the non-circumscribed borders that can be detected. Radiation therapy has to contend with neurotoxicity to adjacent normal tissues. Chemotherapy is constrained by the blood-brain barrier, which is a very real constraint of systemic therapy -- producing minimal benefit with substantial toxicity in order to administer therapeutic dosages. In part, such hurdles explain the reasons why survival has changed little over many decades of research in this field. The newest generation of treatments includes more effective cytotoxic agents, so-called targeted compounds, and biologics/immunotherapeutics. This article summarizes the preclinical proof-of-concept research and human studies involving some of the agents creating the most positive buzz in the medical community. The advantages and limitations of each are described. Topics: Antineoplastic Agents; Antineoplastic Agents, Alkylating; Benzamides; Biocompatible Materials; Brain Neoplasms; Cancer Vaccines; Clinical Trials as Topic; Combined Modality Therapy; Dacarbazine; Decanoic Acids; ErbB Receptors; Erlotinib Hydrochloride; Farnesyltranstransferase; Gefitinib; Glioblastoma; Humans; Imatinib Mesylate; Immunotoxins; Mechanistic Target of Rapamycin Complex 1; Multiprotein Complexes; Piperazines; Polyesters; Protein Kinase Inhibitors; Proteins; Pyrimidines; Quinazolines; Sirolimus; Temozolomide; TOR Serine-Threonine Kinases; Transcription Factors | 2006 |
[Molecular targeted therapy for malignant brain tumors].
Topics: Antineoplastic Agents; Benzamides; Brain Neoplasms; Drug Delivery Systems; Drug Design; Drug Resistance, Neoplasm; Drug Therapy, Combination; ErbB Receptors; Erlotinib Hydrochloride; Gefitinib; Glioma; Humans; Imatinib Mesylate; Intracellular Signaling Peptides and Proteins; Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Piperazines; Piperidines; Protein Kinases; Protein-Tyrosine Kinases; Pyridines; Pyrimidines; Quinazolines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2005 |
Mitogenic signaling by substance P and bombesin-like neuropeptide receptors in astrocytic/glial brain tumor-derived cell lines.
Neuropeptides such as substance P (SP) and bombesin regulate many biological processes through binding to and activating their respective cell surface receptors. Recently, we reported that many astrocytic/glial-derived brain tumor cell lines express functional SP and bombesin receptors (43% and 85%, respectively). Activation of these neuropeptide receptors stimulates several signaling pathways that regulate transcription and translation leading to the induction of mitogenesis in several cell types including astrocytic brain tumor-derived cell lines. We have also shown that a number of signaling pathways are induced by SP and/or bombesin receptors in astrocytic/glial-derived brain tumor cell lines and demonstrated that inhibiting these path-ways by selective compounds such as PD 098059, tamoxifen, CGP 41251, and rapamycin blocks cell growth. In summary, mitogenic signaling by neuropeptides may play a role in brain tumor growth and/or tumor progression, and selective compounds capable of blocking mitogenic signaling have potential to be useful in the treatment of brain tumors. Topics: Adult; Astrocytoma; Bombesin; Brain Neoplasms; Cell Division; Child; Humans; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Mitogens; Receptors, Neuropeptide; Signal Transduction; Sirolimus; Substance P; Tamoxifen; Tumor Cells, Cultured | 1998 |
27 trial(s) available for sirolimus and Brain-Neoplasms
Article | Year |
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A phase I study of sirolimus in combination with metronomic therapy (CHOAnome) in children with recurrent or refractory solid and brain tumors.
To determine the maximum tolerated dose, toxicities, and response of sirolimus combined with oral metronomic therapy in pediatric patients with recurrent and refractory solid and brain tumors.. Patients younger than 30 years of age with recurrent, refractory, or high-risk solid and brain tumors were eligible. Patients received six-week cycles of sirolimus with twice daily celecoxib, and alternating etoposide and cyclophosphamide every three weeks, with Bayesian dose escalation over four dose levels (NCT01331135).. Eighteen patients were enrolled: four on dose level (DL) 1, four on DL2, eight on DL3, and two on DL4. Diagnoses included solid tumors (Ewing sarcoma, osteosarcoma, malignant peripheral nerve sheath tumor, rhabdoid tumor, retinoblastoma) and brain tumors (glioblastoma multiforme [GBM], diffuse intrinsic pontine glioma, high-grade glioma [HGG], medulloblastoma, ependymoma, anaplastic astrocytoma, low-grade infiltrative astrocytoma, primitive neuroectodermal tumor, nongerminomatous germ cell tumor]. One dose-limiting toxicity (DLT; grade 4 neutropenia) was observed on DL2, two DLTs (grade 3 abdominal pain and grade 3 mucositis) on DL3, and two DLTs (grade 3 dehydration and grade 3 mucositis) on DL4. The recommended phase II dose of sirolimus was 2 mg/m. The combination of sirolimus with metronomic chemotherapy is well tolerated in children. A phase II trial of this combination is ongoing. Topics: Administration, Metronomic; Adolescent; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Celecoxib; Child; Child, Preschool; Cyclophosphamide; Dose-Response Relationship, Drug; Etoposide; Female; Humans; Male; Maximum Tolerated Dose; Neoplasms; Sirolimus; Young Adult | 2020 |
Phase I clinical trial of temsirolimus and perifosine for recurrent glioblastoma.
Malignant glioma (MG) is the most deadly primary brain cancer. Signaling though the PI3K/AKT/mTOR axis is activated in most MGs and therefore a potential therapeutic target. The mTOR inhibitor temsirolimus and the AKT inhibitor perifosine are each well-tolerated as single agents but with limited activity reclinical data demonstrate synergistic anti-tumor effects from combined treatment. Therefore, we initiated a phase I trial of combined therapy in recurrent MGs to determine safety and a recommended phase II dose.. Adults with recurrent MG, Karnofsky Performance Status ≥ 60 were enrolled, with no limit on the number of prior therapies. Temsirolimus dose was escalated using standard 3 + 3 design from 15 mg to 170 mg administered once weekly. Perifosine was fixed as a 600 mg load on day 1 followed by 100 mg nightly (single agent MTD) until dose level 7 when the load increased to 900 mg.. We treated 35 patients with with glioblastoma (17) or other MGs (18; including nine anaplastic astrocytoma, nine anaplastic oligodendroglioma, one anaplastic oligoastrocytoma, and two low grade astrocytomas with radiographic transformation to MG). We observed five dose-limiting toxicities (DLTs): one at dose level 3 (50mg temsirolimus), then two at dose level 7 expansion (170 mg temsirolimus), and then two more at dose level 6 expansion (170 mg temsirolimus). DLTs included thrombocytopenia (n = 3), intracerebral hemorrhage (n = 1) and lung infection (n = 1).. Combining the mTOR inhibitor temsirolimus dosed at 115 mg weekly and the AKT inhibitor perifosine dosed at 100 mg daily (following 600 mg load) is tolerable in heavily pretreated adults with recurrent MGs. Topics: Adult; Aged; Antineoplastic Agents; Brain Neoplasms; Drug Therapy, Combination; Female; Glioblastoma; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Phosphorylcholine; Prospective Studies; Proto-Oncogene Proteins c-akt; Sirolimus; TOR Serine-Threonine Kinases; Young Adult | 2020 |
Phase 1/2 trial of temsirolimus and sorafenib in the treatment of patients with recurrent glioblastoma: North Central Cancer Treatment Group Study/Alliance N0572.
Mitogen-activated protein kinase (MAPK) activation and mammalian target of rapamycin (mTOR)-dependent signaling are hallmarks of glioblastoma. In the current study, the authors conducted a phase 1/2 study of sorafenib (an inhibitor of Raf kinase and vascular endothelial growth factor receptor 2 [VEGFR-2]) and the mTOR inhibitor temsirolimus in patients with recurrent glioblastoma.. Patients with recurrent glioblastoma who developed disease progression after surgery or radiotherapy plus temozolomide and with ≤2 prior chemotherapy regimens were eligible. The phase 1 endpoint was the maximum tolerated dose (MTD), using a cohorts-of-3 design. The 2-stage phase 2 study included separate arms for VEGF inhibitor (VEGFi)-naive patients and patients who progressed after prior VEGFi.. The MTD was sorafenib at a dose of 200 mg twice daily and temsirolimus at a dose of 20 mg weekly. In the first 41 evaluable patients who were treated at the phase 2 dose, there were 7 who were free of disease progression at 6 months (progression-free survival at 6 months [PFS6]) in the VEGFi-naive group (17.1%); this finding met the prestudy threshold of success. In the prior VEGFi group, only 4 of the first 41 evaluable patients treated at the phase 2 dose achieved PFS6 (9.8%), and this did not meet the prestudy threshold for success. The median PFS for the 2 groups was 2.6 months and 1.9 months, respectively. The median overall survival for the 2 groups was 6.3 months and 3.9 months, respectively. At least 1 adverse event of grade ≥3 was observed in 75.5% of the VEGFi-naive patients and in 73.9% of the prior VEGFi patients.. The limited activity of sorafenib and temsirolimus at the dose and schedule used in the current study was observed with considerable toxicity of grade ≥3. Significant dose reductions that were required in this treatment combination compared with tolerated single-agent doses may have contributed to the lack of efficacy. Cancer 2018;124:1455-63. © 2018 American Cancer Society. Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Female; Follow-Up Studies; Glioblastoma; Humans; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Recurrence, Local; Prognosis; Sirolimus; Sorafenib; Survival Rate | 2018 |
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; 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YAP-Signaling Proteins; Yogurt; Young Adult; Zebrafish; Zebrafish Proteins; Ziziphus | 2016 |
Phase II Study of Radiotherapy and Temsirolimus versus Radiochemotherapy with Temozolomide in Patients with Newly Diagnosed Glioblastoma without MGMT Promoter Hypermethylation (EORTC 26082).
EORTC 26082 assessed the activity of temsirolimus in patients with newly diagnosed glioblastoma harboring an unmethylated O6 methylguanine-DNA-methyltransferase (MGMT) promoter.. Patients (n = 257) fulfilling eligibility criteria underwent central MGMT testing. Patients with MGMT unmethylated glioblastoma (n = 111) were randomized 1:1 between standard chemo-radiotherapy with temozolomide or radiotherapy plus weekly temsirolimus (25 mg). Primary endpoint was overall survival at 12 months (OS12). A positive signal was considered >38 patients alive at 12 months in the per protocol population. A noncomparative reference arm of 54 patients evaluated the assumptions on OS12 in a standard-treated cohort of patients. Prespecified post hoc analyses of markers reflecting target activation were performed.. Both therapies were administered per protocol with a median of 13 cycles of maintenance temsirolimus. Median age was 55 and 58 years in the temsirolimus and standard arms, the WHO performance status 0 or 1 for most patients (95.5%). In the per protocol population, 38 of 54 patients treated with temsirolimus reached OS12. The actuarial 1-year survival was 72.2% [95% confidence interval (CI), 58.2-82.2] in the temozolomide arm and 69.6% (95% CI, 55.8-79.9) in the temsirolimus arm [hazard ratio (HR) 1.16; 95% CI, 0.77-1.76; P = 0.47]. In multivariable prognostic analyses of clinical and molecular factors, phosphorylation of mTORSer2448 in tumor tissue (HR 0.13; 95% CI, 0.04-0.47; P = 0.002), detected in 37.6%, was associated with benefit from temsirolimus.. Temsirolimus was not superior to temozolomide in patients with an unmethylated MGMT promoter. Phosphorylation of mTORSer2448 in the pretreatment tumor tissue may define a subgroup benefitting from mTOR inhibition. Clin Cancer Res; 22(19); 4797-806. ©2016 AACR. Topics: Adult; Aged; Brain Neoplasms; Chemoradiotherapy; Dacarbazine; DNA Methylation; DNA Modification Methylases; DNA Repair Enzymes; Female; Glioblastoma; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Promoter Regions, Genetic; Proportional Hazards Models; Sirolimus; Temozolomide; Tumor Suppressor Proteins; Young Adult | 2016 |
Vandetanib plus sirolimus in adults with recurrent glioblastoma: results of a phase I and dose expansion cohort study.
Targeting specific molecular alterations in glioblastoma (GBM) might more effectively kill tumor cells and increase survival. Vandetanib inhibits epidermal growth factor receptor and vascular endothelial growth factor receptor 2. Sirolimus inhibits mammalian target of rapamycin (mTOR), a member the phosphoinositide 3-Kinase signaling pathway. We sought to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of vandetanib combined with sirolimus. Twenty-two patients (14 men; 8 women) with recurrent GBM enrolled. Median age and KPS were 52.5 years and 90 %, respectively. Patients were naive to anti-VEGF and anti-EGF therapy and mTOR inhibitors, and not on CYP3A4-inducing drugs. Vandetanib and sirolimus were orally administered on a continuous daily dosing schedule in escalating dose cohorts. Ten patients enrolled in the dose escalation phase. Twelve more enrolled at the MTD to explore progression-free survival at 6 months (PFS6) in a single arm, single stage phase II-type design. In total, 19 patients received at least one dose at the MTD, and 15 completed at least 1 cycle at MTD. MTD was 200 mg vandetanib plus 2 mg sirolimus. The DLT was elevated AST/SGOT. The most common toxicities were lymphopenia, fatigue, rash, and hypophosphatemia. For 19 patients who received at least one dose at the MTD, including seven from the phase I group, two had a partial response [10.5 %; 95 % CI (1, 33 %)] and PFS6 was 15.8 % [95 % CI (3.9, 34.9 %)]. Vandetanib and sirolimus can be safely co-administered on a continuous, daily dosing schedule. Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Cohort Studies; Disease-Free Survival; Female; Glioblastoma; Humans; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Recurrence, Local; Piperidines; Quinazolines; Sirolimus | 2015 |
Phase I/II study of erlotinib and temsirolimus for patients with recurrent malignant gliomas: North American Brain Tumor Consortium trial 04-02.
Inhibition of epidermal growth factor receptor (EGFR) and the mechanistic target of rapamycin (mTOR) may have synergistic antitumor effects in high-grade glioma patients.. We conducted a phase I/II study of the EGFR inhibitor erlotinib (150 mg/day) and the mTOR inhibitor temsirolimus. Patients initially received temsirolimus 50 mg weekly, and the dose adjusted based on toxicities. In the phase II component, the primary endpoint was 6-month progression-free survival (PFS6) among glioblastoma patients.. Twenty-two patients enrolled in phase I, 47 in phase II. Twelve phase I patients treated at the maximum tolerated dosage were included in the phase II cohort for analysis. The maximum tolerated dosage was 15 mg temsirolimus weekly with erlotinib 150 mg daily. Dose-limiting toxicities were rash and mucositis. Among 42 evaluable glioblastoma patients, 12 (29%) achieved stable disease, but there were no responses, and PFS6 was 13%. Among 16 anaplastic glioma patients, 1 (6%) achieved complete response, 1 (6%) partial response, and 2 (12.5%) stable disease, with PFS6 of 8%. Tumor levels of both drugs were low, and posttreatment tissue in 3 patients showed no reduction in the mTOR target phosphorylated (phospho-)S6(S235/236) but possible compensatory increase in phospho-Akt(S473). Presence of EGFR variant III, phospho-EGFR, and EGFR amplification did not correlate with survival, but patients with elevated phospho-extracellular signal-regulated kinase or reduced phosphatase and tensin homolog protein expression had decreased progression-free survival at 4 months.. Because of increased toxicity, the maximum tolerated dosage of temsirolimus in combination with erlotinib proved lower than expected. Insufficient tumor drug levels and redundant signaling pathways may partly explain the minimal antitumor activity noted. Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Erlotinib Hydrochloride; Female; Follow-Up Studies; Glioma; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Neoplasm Staging; Prognosis; Quinazolines; Sirolimus; Survival Rate; Tissue Distribution; Young Adult | 2014 |
Pediatric patients with refractory central nervous system tumors: experiences of a clinical trial combining bevacizumab and temsirolimus.
Pre-clinical findings suggest that combination treatment with bevacizumab and temsirolimus could be effective against malignant pediatric central nervous system (CNS) tumors.. Six pediatric patients were treated as part of a phase I trial with intravenous temsirolimus 25 mg on days 1, 8, 15, and bevacizumab at 5, 10, or 15 mg/kg on day 1 of each 21-day cycle until disease progression or patient withdrawal.. The median patient age was six years (range=3-14 years). The primary diagnoses were glioblastoma multiforme (n=2), medullobalstoma (n=2), pontine glioma (n=1) and ependymoma (n=1). All patients had disease refractory to standard-of-care (2-3 prior systemic therapies). Grade 3 toxicities possibly related to drugs used occurred in two patients: anorexia, nausea, and weight loss in one, and thrombocytopenia and alanine aminotransferase elevation in another. One patient with glioblastoma multiforme achieved a partial response (51% regression) and two patients (with medulloblastoma and pontine glioma) had stable disease for four months or more (20 and 47 weeks, respectively). One other patient (with glioblastoma multiforme) showed 18% tumor regression (duration=12 weeks).. The combination of bevacizumab with temsirolimus was well-tolerated and resulted in stable disease of at least four months/partial response in three out of six pediatric patients with chemorefractory CNS tumors. Topics: Adolescent; Angiogenesis Inhibitors; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Brain Neoplasms; Central Nervous System Neoplasms; Child; Child, Preschool; Humans; Magnetic Resonance Imaging; Protein Kinase Inhibitors; Sirolimus; Treatment Outcome | 2014 |
[Response to everolimus in patients with giant cell astrocytoma associated to tuberous sclerosis complex].
Subependymal giant cell astrocytomas (SEGA) appear in 5-20% of patients with tuberous sclerosis complex (TSC) and are the most common brain tumours in TSC. They are benign tumours, of a glioneural stock, that develop mainly in the first two decades of life, generally close to the foramen of Monro, and can trigger hydrocephalus and intracranial hypertension. It is one of the leading causes of death in TSC. Recently mTOR inhibitors have proved to be a therapeutic alternative to surgical excision. AIM. To describe our experience of using everolimus to treat patients with SEGA and TSC.. We conducted a prospective study of the responses of patients with TSC and at least one SEGA undergoing growth.. Three females and three males with a mean age of 12.3 years received treatment. One patient had previously undergone surgery due to SEGA with hydrocephalus. The maximum mean diameter of the SEGA on beginning treatment was 15.3 mm (range: 11.3-24.8 mm). Treatment was established with everolimus, 2.5 mg/day administered orally in patients with a body surface area < 1.2 m2, and 5 mg/day in patients with a body surface area > 1.2 m2. Two patients presented hypertriglyceridemia; one, anorexia; another, a mouth ulcer; and one, amenorrhoea. The mean reduction in the volume of the SEGA at three months of treatment was 46%, and the reduction remained steady in later control examinations (6-25 months).. Treatment with everolimus reduces the size of SEGA associated with TSC with an adequate safety profile, and constitutes an alternative to surgery in certain cases.. Respuesta a everolimus en pacientes con astrocitoma de celulas gigantes asociado al complejo esclerosis tuberosa.. Introduccion. Los astrocitomas subependimarios de celulas gigantes (SEGA) se presentan en el 5-20% de los pacientes con complejo esclerosis tuberosa (CET) y son los tumores cerebrales mas comunes en el CET. Son tumores benignos, de estirpe glioneural, que se desarrollan fundamentalmente en las primeras dos decadas de la vida, en general cercanos al foramen de Monro, y pueden ocasionar hidrocefalia e hipertension intracraneal. Constituyen la principal causa de muerte en el CET. Recientemente, los inhibidores mTOR han demostrado ser una alternativa terapeutica a la reseccion quirurgica. Objetivo. Describir nuestra experiencia con everolimus para el tratamiento de pacientes con SEGA y CET. Pacientes y metodos. Estudio prospectivo de la respuesta de los pacientes con CET y al menos un SEGA en crecimiento. Resultados. Recibieron tratamiento tres mujeres y tres varones con una edad media de 12,3 años. Un paciente habia sido previamente intervenido quirurgicamente por SEGA con hidrocefalia. El diametro maximo medio del SEGA al inicio del tratamiento era de 15,3 mm (rango: 11,3-24,8 mm). Se inicio tratamiento con everolimus, 2,5 mg/dia por via oral en pacientes con superficie corporal < 1,2 m2 y 5 mg/dia en pacientes con superficie corporal > 1,2 m2. Dos pacientes presentaron hipertrigliceridemia; uno, anorexia; otro, un afta; y una paciente, amenorrea. La reduccion media del volumen del SEGA a los tres meses de tratamiento fue del 46%, y la reduccion se mantuvo estable en controles posteriores (6-25 meses). Conclusiones. El tratamiento con everolimus disminuye el tamaño de los SEGA asociados a CET con un perfil de seguridad adecuado, y constituye una alternativa a la cirugia en casos seleccionados. Topics: Administration, Oral; Adolescent; Amenorrhea; Anorexia; Astrocytoma; Brain Neoplasms; Child; Everolimus; Female; Giant Cells; Humans; Hypertriglyceridemia; Male; Neoplasm Proteins; Prospective Studies; Sirolimus; Stomatitis, Aphthous; TOR Serine-Threonine Kinases; Treatment Outcome; Tuberous Sclerosis; Tuberous Sclerosis Complex 2 Protein; Tumor Burden; Tumor Suppressor Proteins | 2014 |
Phase II study of bevacizumab and temsirolimus combination therapy for recurrent glioblastoma multiforme.
Bevacizumab combined with chemotherapy has recently shown promising efficacy in recurrent high-grade glioma. Phosphatase and tensin homolog (PTEN) mutation in glioblastoma multiforme (GBM) patients causes abnormally high activity of the pathways of Phosphatidylinositide 3-kinases (PI3K), Protein Kinase B (AKT), and the mammalian target of rapamycin (mTOR) and is associated with unfavorable prognosis. Temsirolimus, an mTOR inhibitor, has been well-tolerated in monotherapy, but with limited effects. The combination of temsirolimus and antibodies to vascular endothelial factor (VEGF) has not yet been investigated, but with the hypothesis that temsirolimus might provide complimentary therapeutic benefit in combination with bevacizumab, we included patients with progressive GBM after bevacizumab in an open phase II study.. Adult patients with GBM recurrence after standard temozolomide chemoradiotherapy and bevacizumab-containing second-line therapy, received temsirolimus (25 mg i.v.) on days 1 and 8 and bevacizumab (10 mg/kg) on day 8, every two weeks. Assessments were performed every eight weeks. Blood samples for biomarkers were collected weekly for the first eight weeks and at progression. The primary end-point was median progression-free survival (PFS) and secondary end-points were radiographic response, overall survival (OS), and safety of the bevacizumab-temsirolimus combination.. Thirteen patients were included, whereof three went off-study during the first four weeks and were replaced. The trial was terminated at 13 patients, according to the planned two-stage design, because 0/10 patients obtained partial remission (PR). Two out of 10 patients obtained radiological stable disease (SD). The median PFS survival was eight weeks, and OS was 15 weeks. One patient had an serious adverse event (SAE) with a hypersensitive reaction to temsirolimus; overall, side-effects were mild, and the most common grade III side-effect was hypercholesterolaemia (4/10). Other grade III side-effects included hypertriglyceridaemia (1/10), thrombocytopenia (1/10), infection (1/10), hypertension (1/10), and hyperglycemia (1/10).. Temsirolimus can be safely administered in combination with bevacizumab. This study failed to detect activity of such a combination in patients with progressive GBM beyond bevacizumab therapy. Topics: Adult; Aged; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Brain Neoplasms; Female; Follow-Up Studies; Glioblastoma; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Neoplasm Staging; Prognosis; Sirolimus; Survival Rate; Young Adult | 2013 |
RTOG 0913: a phase 1 study of daily everolimus (RAD001) in combination with radiation therapy and temozolomide in patients with newly diagnosed glioblastoma.
To determine the safety of the mammalian target of rapamycin inhibitor everolimus (RAD001) administered daily with concurrent radiation and temozolomide in newly diagnosed glioblastoma patients.. Everolimus was administered daily with concurrent radiation (60 Gy in 30 fractions) and temozolomide (75 mg/m(2) per day). Everolimus was escalated from 2.5 mg/d (dose level 1) to 5 mg/d (dose level 2) to 10 mg/d (dose level 3). Adjuvant temozolomide was delivered at 150 to 200 mg/m(2) on days 1 to 5, every 28 days, for up to 12 cycles, with concurrent everolimus at the previously established daily dose of 10 mg/d. Dose escalation continued if a dose level produced dose-limiting toxicities (DLTs) in fewer than 3 of the first 6 evaluable patients.. Between October 28, 2010, and July 2, 2012, the Radiation Therapy Oncology Group 0913 protocol initially registered a total of 35 patients, with 25 patients successfully meeting enrollment criteria receiving the drug and evaluable for toxicity. Everolimus was successfully escalated to the predetermined maximum tolerated dose of 10 mg/d. Two of the first 6 eligible patients had a DLT at each dose level. DLTs included gait disturbance, febrile neutropenia, rash, fatigue, thrombocytopenia, hypoxia, ear pain, headache, and mucositis. Other common toxicities were grade 1 or 2 hypercholesterolemia and hypertriglyceridemia. At the time of analysis, there was 1 death reported, which was attributed to tumor progression.. Daily oral everolimus (10 mg) combined with both concurrent radiation and temozolomide followed by adjuvant temozolomide is well tolerated, with an acceptable toxicity profile. A randomized phase 2 clinical trial with mandatory correlative biomarker analysis is currently under way, designed to both determine the efficacy of this regimen and identify molecular determinants of response. Topics: Administration, Oral; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Chemotherapy, Adjuvant; Dacarbazine; Dose Fractionation, Radiation; Everolimus; Female; Glioblastoma; Humans; Male; Maximum Tolerated Dose; Middle Aged; Sirolimus; Temozolomide | 2013 |
A feasibility and efficacy study of rapamycin and erlotinib for recurrent pediatric low-grade glioma (LGG).
To determine the toxicity and efficacy of rapamycin and erlotinib for the treatment of recurrent pediatric low-grade gliomas (LGGs).. Patients <21 years of age with recurrent LGGs who had failed conventional treatment were eligible, including those with NF1. The treatment consisted of two phases, a feasibility portion which assessed the toxicity of erlotinib at 65 mg/m(2) /day once daily and rapamycin at 0.8 mg/m(2) /dose twice daily for 28 consecutive days.. Nineteen (19) patients, median age of 8 years, with recurrent LGGs received the two-drug regimen. Eight (8) of the patients had NF1. The combination of erlotinib and rapamycin was well tolerated and no patient was removed from study due to toxicity. All 19 patients were evaluable for response and one child, with NF1, had a partial response to treatment. Six (6) patients received the planned 12 courses of treatment. The reasons for stoppage of therapy before 1 year of treatment were poor compliance (1), parental desire for withdrawal (1), persistent vomiting which pre-dated initiation of therapy (1), and radiographic progression (10). In those patients with stabilization of disease for 12 months or greater, 3 stayed on therapy and ultimately developed progressive disease, and one patient stopped therapy at 12 months and progressed. Two (2) patients, both with NF1, have had >1 year disease control.. The combination of rapamycin and erlotinib is well tolerated in children with LGGs. Objective responses were infrequent, although there was prolonged disease stabilization in some patients with LGGs, especially in two children with NF1. Topics: Adolescent; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Child; Child, Preschool; ErbB Receptors; Erlotinib Hydrochloride; Feasibility Studies; Female; Glioma; Humans; Male; Neoplasm Recurrence, Local; Quinazolines; Sirolimus; TOR Serine-Threonine Kinases | 2013 |
Phase II trial of temsirolimus in children with high-grade glioma, neuroblastoma and rhabdomyosarcoma.
A phase II study of temsirolimus was conducted in children and adolescents with high-grade glioma, neuroblastoma or rhabdomyosarcoma.. Temsirolimus 75 mg/m(2) was administered once weekly until disease progression or intolerance. Using the Simon 2-stage design, further enrolment in each disease cohort required ≥ 2 objective responses within the first 12 weeks for the first 12 evaluable patients (those who received ≥ 3 temsirolimus doses).. Fifty-two heavily pretreated patients with relapsed (12%) or refractory (88%) disease, median age 8 years (range 1-21 years), were enroled and treated. One patient with neuroblastoma achieved confirmed partial response within the first 12 weeks; thus, none of the 3 cohorts met the criterion for continued enrolment. Disease stabilisation at week 12 was observed in 7 of 17 patients (41%) with high-grade glioma (5 diffuse pontine gliomas, 1 glioblastoma multiforme and 1 anaplastic astrocytoma), 6 of 19 (32%) with neuroblastoma and 1 of 16 (6%) with rhabdomyosarcoma (partial response confirmed at week 18). In the three cohorts, median duration of stable disease or better was 128, 663 and 75 d, respectively. The most common treatment-related adverse events were thrombocytopaenia, hyperlipidaemia and aesthenia. Pharmacokinetic findings were similar to those observed in adults.. Temsirolimus administered weekly at the dose of 75 mg/m(2) did not meet the primary objective efficacy threshold in children with high-grade glioma, neuroblastoma or rhabdomyosarcoma; however, meaningful prolonged stable disease merits further evaluation in combination therapy. Topics: Adolescent; Adult; Antineoplastic Agents; Brain Neoplasms; Child; Child, Preschool; Cohort Studies; Disease Progression; Female; Glioma; Humans; Infusions, Intravenous; Male; Neuroblastoma; Rhabdomyosarcoma; Sirolimus | 2012 |
A phase I study of temozolomide and everolimus (RAD001) in patients with newly diagnosed and progressive glioblastoma either receiving or not receiving enzyme-inducing anticonvulsants: an NCIC CTG study.
This phase I trial was designed to determine the recommended phase II dose(s) of everolimus (RAD001) with temozolomide (TMZ) in patients with glioblastoma (GBM). Patients receiving enzyme-inducing antiepileptic drugs (EIAEDs) and those not receiving EIAEDs (NEIAEDs) were studied separately.. Enrollment was restricted to patients with proven GBM, either newly diagnosed or at first progression. Temozolomide was administered at a starting dose of 150 mg/m(2)/day for 5 days every 28 days, and everolimus was administered continuously at a starting dose of 2.5 mg orally on a daily schedule starting on day 2 of cycle 1 in 28-day cycles.. Thirteen patients receiving EIAEDs and 19 not receiving EIAEDs were enrolled and received 83 and 116 cycles respectively. Everolimus 10 mg daily plus TMZ 150 mg/m(2)/day for 5 days was declared the recommended phase II dose for the NEIAEDs cohort. In the EIAEDs group, doses were well tolerated without DLTs, and pharmacokinetic parameters indicated decreased everolimus exposure. Temozolomide pharmacokinetic parameters were unaffected by EIAEDs or everolimus. In the subset of 28 patients with measurable disease, 3 had partial responses (all NEIAEDs) and 16 had stable disease.. A dosage of 10 mg everolimus daily with TMZ 150 mg/m(2)/day for five consecutive days every 28 days in patients is the recommended dose for this regimen. Everolimus clearance is increased by EIAEDs, and patients receiving EIAEDs should be switched to NEIAEDs before starting this regimen. Topics: Adult; Aged; Anticonvulsants; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Dacarbazine; Drug Combinations; Everolimus; Female; Glioblastoma; Humans; Immunosuppressive Agents; Male; Middle Aged; PTEN Phosphohydrolase; Sirolimus; Temozolomide; Young Adult | 2012 |
Preliminary experience with personalized and targeted therapy for pediatric brain tumors.
A new generation of anticancer drugs has reached clinical care in common diseases, but their use in rare diseases such as pediatric brain tumors lags behind since conventional clinical trial design requires larger patient numbers.. We designed individualized treatment protocols for pediatric patients with relapsed brain tumors, based upon the patient's treatment history. In addition, each tumor was analyzed with morphoproteomics using a panel of markers to show treatment targets, resulting in a list of potential novel drugs to be added to chemotherapy. Here, we present the concept and report the experiences of the first patients enrolled in the program.. Eleven treatment protocols were designed using morphoproteomic information and given to eight patients. The histological diagnoses included: medulloblastoma (n = 3), glioblastoma multiforme (n = 2), atypical teratoid rhabdoid tumor (n = 1), choroid plexus carcinoma (n = 1), and primitive neuroectodermal tumors (n = 1). Tumor markers included p-ERK, Topoisomerase IIa, Bcl-2, VEGF-A, p-STAT3, ER-beta, p-mTOR, and p-NF-kappaBp65. The novel agents included sorafenib, bevacizumab, fulvestrant, rapamycin, bortezomib, and curcumin. The response to the first protocol was complete response: 1, partial response: 1, stable disease: 0, progressive disease: 4, and continuous complete remission: 2. The median Event-Free Survival was 0.32 year ± 0.4. For the comparison with the institutional control group, the individual response probability was calculated. The observed response was superior to the historical controls (P = 0.006 Whitman U-test).. This approach warrants further, systematic evaluation as proof of concept and then expansion to drug-specific hypotheses. Topics: Adolescent; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Benzenesulfonates; Bevacizumab; Biomarkers, Tumor; Boronic Acids; Bortezomib; Brain Neoplasms; Child; Child, Preschool; Curcumin; Disease-Free Survival; Estradiol; Female; Follow-Up Studies; Fulvestrant; Humans; Infant; Male; Niacinamide; Phenylurea Compounds; Pyrazines; Pyridines; Sirolimus; Sorafenib; Survival Rate | 2012 |
Phase II study of concurrent radiation therapy, temozolomide, and bevacizumab followed by bevacizumab/everolimus as first-line treatment for patients with glioblastoma.
To evaluate the efficacy of adding bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor, and everolimus, a mammalian target of rapamycin (mTOR inhibitor), to standard radiation therapy/temozolomide in the first-line treatment of patients with glioblastoma.. Following surgical resection or biopsy, patients with newly diagnosed glioblastoma received standard radiation therapy/temozolomide plus bevacizumab 10 mg/kg intravenously (IV) every 2 weeks. Four weeks after the completion of radiation therapy, patients began oral everolimus 10 mg daily, and continued bevacizumab every 2 weeks; therapy continued until tumor progression or unacceptable toxicity.. Sixty-eight patients were treated, 82% of whom had previously undergone partial or complete surgical resection. Sixty-four patients completed combined modality therapy, and 57 patients began maintenance therapy with bevacizumab/everolimus. Thirty-one of 51 patients (61%) with measurable tumor had objective responses. After a median follow-up of 17 months, the median progression-free survival (PFS) was 11.3 months (95% confidence interval [CI], 9.3-13.1 months); median overall survival was 13.9 months. Toxicity was consistent with the known toxicity profile of bevacizumab; grade 3/4 toxicities during maintenance therapy related to everolimus included fatigue (27%), pneumonitis (7%), and stomatitis (5%).. The use of bevacizumab and everolimus as part of first-line combined modality therapy for glioblastoma was feasible and efficacious. The PFS compared favorably to previous reports with standard radiation therapy/temozolomide therapy, and is similar to results achieved in other phase II trials in which bevacizumab was added to fist-line treatment. Ongoing randomized phase III trials will clarify the role of bevacizumab in this setting. Topics: Adult; Aged; Aged, 80 and over; Angiogenesis Inhibitors; Antibodies, Monoclonal, Humanized; Antineoplastic Agents, Alkylating; Bevacizumab; Brain Neoplasms; Combined Modality Therapy; Dacarbazine; Disease-Free Survival; Everolimus; Female; Glioblastoma; Humans; Immunosuppressive Agents; Male; Middle Aged; Sirolimus; Temozolomide; Young Adult | 2012 |
A dose escalation trial for the combination of erlotinib and sirolimus for recurrent malignant gliomas.
In order to achieve higher dosages than previously used in clinical trials, we conducted a phase I trial to determine the maximum tolerated dose (MTD) for the combination of erlotinib and sirolimus for the treatments of recurrent malignant gliomas. Patients with pathologically proven World Health Organization (WHO) grade III glioma and grade IV glioblastoma and radiographically proven tumor recurrence were eligible for this study. Treatments included once daily erlotinib, which was given alone for the first 7 days of treatments, then in combination with once daily sirolimus. Sirolimus was given with a loading dose on day 8 followed by a maintenance dose starting on day 9. Dose-limiting toxicity (DLT) was determined over the first 28 days of treatments, and the MTD was determined in a 3 + 3 classic study design. 19 patients were enrolled, and 13 patients were eligible for MTD determination. The MTD was determined to be 150 mg daily for erlotinib and 5 mg daily (after a 15 mg loading dose) for sirolimus. The DLTs included rash and mucositis (despite maximal medical managements), hypophosphatemia, altered mental status, and neutropenia. The combination of erlotinib and sirolimus is difficult to tolerate at dosages higher than previously reported in phase II trials. Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Dose-Response Relationship, Drug; Erlotinib Hydrochloride; Feasibility Studies; Female; Glioma; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Prognosis; Quinazolines; Retrospective Studies; Sirolimus; Survival Rate; Tissue Distribution | 2012 |
Phase I/II study of sorafenib in combination with temsirolimus for recurrent glioblastoma or gliosarcoma: North American Brain Tumor Consortium study 05-02.
The activity of single-agent targeted molecular therapies in glioblastoma has been limited to date. The North American Brain Tumor Consortium examined the safety, pharmacokinetics, and efficacy of combination therapy with sorafenib, a small molecule inhibitor of Raf, vascular endothelial growth factor receptor 2, and platelet-derived growth factor receptor-β, and temsirolimus (CCI-779), an inhibitor of mammalian target of rapamycin. This was a phase I/II study. The phase I component used a standard 3 × 3 dose escalation scheme to determine the safety and tolerability of this combination therapy. The phase II component used a 2-stage design; the primary endpoint was 6-month progression-free survival (PFS6) rate. Thirteen patients enrolled in the phase I component. The maximum tolerated dosage (MTD) for combination therapy was sorafenib 800 mg daily and temsirolimus 25 mg once weekly. At the MTD, grade 3 thrombocytopenia was the dose-limiting toxicity. Eighteen patients were treated in the phase II component. At interim analysis, the study was terminated and did not proceed to the second stage. No patients remained progression free at 6 months. Median PFS was 8 weeks. The toxicity of this combination therapy resulted in a maximum tolerated dose of temsirolimus that was only one-tenth of the single-agent dose. Minimal activity in recurrent glioblastoma multiforme was seen at the MTD of the 2 combined agents. Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Disease-Free Survival; Female; Glioblastoma; Humans; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Recurrence, Local; Niacinamide; Phenylurea Compounds; Sirolimus; Sorafenib; Young Adult | 2012 |
North Central Cancer Treatment Group Phase I trial N057K of everolimus (RAD001) and temozolomide in combination with radiation therapy in patients with newly diagnosed glioblastoma multiforme.
The mammalian target of rapamycin (mTOR) functions within the PI3K/Akt signaling pathway as a critical modulator of cell survival. On the basis of promising preclinical data, the safety and tolerability of therapy with the mTOR inhibitor RAD001 in combination with radiation (RT) and temozolomide (TMZ) was evaluated in this Phase I study.. All patients received weekly oral RAD001 in combination with standard chemoradiotherapy, followed by RAD001 in combination with standard adjuvant temozolomide. RAD001 was dose escalated in cohorts of 6 patients. Dose-limiting toxicities were defined during RAD001 combination therapy with TMZ/RT.. Eighteen patients were enrolled, with a median follow-up of 8.4 months. Combined therapy was well tolerated at all dose levels, with 1 patient on each dose level experiencing a dose-limiting toxicity: Grade 3 fatigue, Grade 4 hematologic toxicity, and Grade 4 liver dysfunction. Throughout therapy, there were no Grade 5 events, 3 patients experienced Grade 4 toxicities, and 6 patients had Grade 3 toxicities attributable to treatment. On the basis of these results, the recommended Phase II dosage currently being tested is RAD001 70 mg/week in combination with standard chemoradiotherapy. Fluorodeoxyglucose (FDG) positron emission tomography scans also were obtained at baseline and after the second RAD001 dose before the initiation of TMZ/RT; the change in FDG uptake between scans was calculated for each patient. Fourteen patients had stable metabolic disease, and 4 patients had a partial metabolic response.. RAD001 in combination with RT/TMZ and adjuvant TMZ was reasonably well tolerated. Changes in tumor metabolism can be detected by FDG positron emission tomography in a subset of patients within days of initiating RAD001 therapy. Topics: Administration, Oral; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Combined Modality Therapy; Dacarbazine; Everolimus; Female; Fluorodeoxyglucose F18; Follow-Up Studies; Glioblastoma; Humans; Male; Middle Aged; Positron-Emission Tomography; Radiopharmaceuticals; Sirolimus; Temozolomide | 2011 |
Combination of temsirolimus (CCI-779) with chemoradiation in newly diagnosed glioblastoma multiforme (GBM) (NCCTG trial N027D) is associated with increased infectious risks.
The mammalian target of rapamycin (mTOR) functions within the phosphoinositide 3-kinase/Akt signaling pathway as a critical modulator of cell survival.. The mTOR inhibitor temsirolimus (CCI-779) was combined with chemoradiotherapy in glioblastoma multiforme (GBM) patients in a dose-escalation phase I trial. The first 12 patients were treated with CCI-779 combined with radiation/temozolomide and adjuvant temozolomide. A second cohort of 13 patients was treated with concurrent CCI-779/radiation/temozolomide followed by adjuvant temozolomide monotherapy.. Concomitant and adjuvant CCI-779 was associated with a high rate (3 of 12 patients) of grade 4/5 infections. By limiting CCI-779 treatment to the radiation/temozolomide phase and using antibiotic prophylaxis, the rate of infections was reduced, although 2 of 13 patients developed exacerbation of pre-existing fungal or viral infections. Dose-limiting toxicities were observed in 2 of 13 patients with this modified schedule. Weekly CCI-779 (50 mg/week) combined with radiation/temozolomide is the recommended phase II dose and schedule. The immune profile of patients in the second cohort was assessed before, during, and after CCI-779 therapy. There was robust suppression of helper and cytotoxic T cells, B cells, natural killer, cells and elevation of regulatory T cells during CCI-779/radiation/temozolomide therapy with recovery to baseline levels during adjuvant temozolomide of cytotoxic T cells, natural killer cells, and regulatory T cells.. The increased infection rate observed with CCI-779 combined with chemoradiotherapy in GBM was reduced with antibiotic prophylaxis and by limiting the duration of CCI-779 therapy. The combined suppressive effects of CCI-779 and temozolomide therapy on discrete immune compartments likely contributed to the increased infectious risks observed. Topics: Aged; Antineoplastic Agents; Brain Neoplasms; Combined Modality Therapy; Dose-Response Relationship, Drug; Female; Glioblastoma; Humans; Male; Maximum Tolerated Dose; Middle Aged; Protein Kinase Inhibitors; Risk Factors; Sirolimus; Treatment Outcome | 2010 |
Everolimus for subependymal giant-cell astrocytomas in tuberous sclerosis.
Neurosurgical resection is the standard treatment for subependymal giant-cell astrocytomas in patients with the tuberous sclerosis complex. An alternative may be the use of everolimus, which inhibits the mammalian target of rapamycin, a protein regulated by gene products involved in the tuberous sclerosis complex.. Patients 3 years of age or older with serial growth of subependymal giant-cell astrocytomas were eligible for this open-label study. The primary efficacy end point was the change in volume of subependymal giant-cell astrocytomas between baseline and 6 months. We gave everolimus orally, at a dose of 3.0 mg per square meter of body-surface area, to achieve a trough concentration of 5 to 15 ng per milliliter.. We enrolled 28 patients. Everolimus therapy was associated with a clinically meaningful reduction in volume of the primary subependymal giant-cell astrocytoma, as assessed on independent central review (P<0.001 for baseline vs. 6 months), with a reduction of at least 30% in 21 patients (75%) and at least 50% in 9 patients (32%). Marked reductions were seen within 3 months and were sustained. There were no new lesions, worsening hydrocephalus, evidence of increased intracranial pressure, or necessity for surgical resection or other therapy for subependymal giant-cell astrocytoma. Of the 16 patients for whom 24-hour video electroencephalography data were available, seizure frequency for the 6-month study period (vs. the previous 6-month period) decreased in 9, did not change in 6, and increased in 1 (median change, -1 seizure; P=0.02). The mean (±SD) score on the validated Quality-of-Life in Childhood Epilepsy questionnaire (on which scores can range from 0 to 100, with higher scores indicating a better quality of life) was improved at 3 months (63.4±12.4) and 6 months (62.1±14.2) over the baseline score (57.8±14.0). Single cases of grade 3 treatment-related sinusitis, pneumonia, viral bronchitis, tooth infection, stomatitis, and leukopenia were reported.. Everolimus therapy was associated with marked reduction in the volume of subependymal giant-cell astrocytomas and seizure frequency and may be a potential alternative to neurosurgical resection in some cases, though long-term studies are needed. (Funded by Novartis; ClinicalTrials.gov number, NCT00411619.). Topics: Administration, Oral; Adolescent; Adult; Angiofibroma; Anticonvulsants; Astrocytoma; Brain Neoplasms; Child; Child, Preschool; Cognition; Drug Therapy, Combination; Everolimus; Facial Neoplasms; Female; Humans; Intracellular Signaling Peptides and Proteins; Male; Prospective Studies; Protein Serine-Threonine Kinases; Quality of Life; Seizures; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Young Adult | 2010 |
A pilot study of everolimus and gefitinib in the treatment of recurrent glioblastoma (GBM).
Twenty-two patients with recurrent glioblastoma (GBM) were prospectively treated with everolimus and gefitinib, designed to test the combined inhibition of mammalian target of rapamycin (mTOR) and epidermal growth factor receptor (EGFR) as part of a larger clinical trial. The primary endpoint was radiographic response rate. Secondary endpoints included progression-free survival and correlation of molecular profiles with treatment response. 36% of patients had stable disease and 14% a partial response; however, responses were not durable and only one patient was progression-free at six months. Radiographic changes were not well characterized by conventional response criteria, and implied differential effects of therapy within the tumor and/or antiangiogenic effects. EGFR and PTEN status did not clearly predict response to treatment. Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Disease-Free Survival; ErbB Receptors; Everolimus; Female; Gefitinib; Glioblastoma; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Neoplasm Recurrence, Local; Pilot Projects; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Quinazolines; Sirolimus | 2009 |
Antitumor activity of rapamycin in a Phase I trial for patients with recurrent PTEN-deficient glioblastoma.
There is much discussion in the cancer drug development community about how to incorporate molecular tools into early-stage clinical trials to assess target modulation, measure anti-tumor activity, and enrich the clinical trial population for patients who are more likely to benefit. Small, molecularly focused clinical studies offer the promise of the early definition of optimal biologic dose and patient population.. Based on preclinical evidence that phosphatase and tensin homolog deleted on Chromosome 10 (PTEN) loss sensitizes tumors to the inhibition of mammalian target of rapamycin (mTOR), we conducted a proof-of-concept Phase I neoadjuvant trial of rapamycin in patients with recurrent glioblastoma, whose tumors lacked expression of the tumor suppressor PTEN. We aimed to assess the safety profile of daily rapamycin in patients with glioma, define the dose of rapamycin required for mTOR inhibition in tumor tissue, and evaluate the antiproliferative activity of rapamycin in PTEN-deficient glioblastoma. Although intratumoral rapamycin concentrations that were sufficient to inhibit mTOR in vitro were achieved in all patients, the magnitude of mTOR inhibition in tumor cells (measured by reduced ribosomal S6 protein phosphorylation) varied substantially. Tumor cell proliferation (measured by Ki-67 staining) was dramatically reduced in seven of 14 patients after 1 wk of rapamycin treatment and was associated with the magnitude of mTOR inhibition (p = 0.0047, Fisher exact test) but not the intratumoral rapamycin concentration. Tumor cells harvested from the Ki-67 nonresponders retained sensitivity to rapamycin ex vivo, indicating that clinical resistance to biochemical mTOR inhibition was not cell-intrinsic. Rapamycin treatment led to Akt activation in seven patients, presumably due to loss of negative feedback, and this activation was associated with shorter time-to-progression during post-surgical maintenance rapamycin therapy (p < 0.05, Logrank test).. Rapamycin has anticancer activity in PTEN-deficient glioblastoma and warrants further clinical study alone or in combination with PI3K pathway inhibitors. The short-term treatment endpoints used in this neoadjuvant trial design identified the importance of monitoring target inhibition and negative feedback to guide future clinical development.. http://www.ClinicalTrials.gov (#NCT00047073). Topics: Adult; Aged; Antineoplastic Agents; Brain Neoplasms; Cell Division; Combined Modality Therapy; Disease Progression; Feedback, Physiological; Female; Glioblastoma; Humans; Male; Middle Aged; Neoadjuvant Therapy; Neoplasm Proteins; Neoplasm Recurrence, Local; Protein Kinase Inhibitors; Protein Kinases; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Ribosomal Protein S6; Salvage Therapy; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2008 |
Pharmacokinetic and tumor distribution characteristics of temsirolimus in patients with recurrent malignant glioma.
To characterize the pharmacokinetics of temsirolimus and its major metabolite, sirolimus, in patients receiving enzyme-inducing antiepileptic drugs (EIAED) compared with patients receiving non-EIAEDs. An additional objective was to determine whether concentrations of temsirolimus or sirolimus were achieved in brain tumor tissue.. Patients with recurrent malignant gliomas not receiving EIAEDs initially received temsirolimus weekly at a dose of 250 mg i.v. The dose was subsequently reduced to 170 mg due to intolerable side effects. For patients taking EIAEDs, the starting dose of temsirolimus was 250 mg with standard dose escalation until the maximal tolerated dose was established. Ten whole blood samples were obtained over a period of 24 h after administration of temsirolimus for pharmacokinetic assessments. Patients eligible for cytoreductive surgery received temsirolimus before tumor resection. Whole blood and tumor tissue were obtained for analysis.. Significant differences in the pharmacokinetic variables for temsirolimus and sirolimus were observed between the two patient groups at a comparable dose level of 250 mg. For patients receiving EIAEDs, the systemic exposure to temsirolimus was lower by 1.5-fold. Likewise, peak concentrations and exposure to sirolimus were lower by 2-fold. Measurable concentrations of temsirolimus and sirolimus were observed in brain tumor specimens. The average tissue to whole blood ratio for temsirolimus was 1.43 and 0.84 for sirolimus.. Drugs that induce cytochrome P450 3A4, such as EIAEDs, significantly affect the pharmacokinetics of temsirolimus and its active metabolite, sirolimus. Total exposure to temsirolimus and sirolimus was lower in the EIAED group at the maximum tolerated dose of 250 mg compared with the non-EIAED group at the maximum tolerated dose of 170 mg. However, brain tumor tissue concentrations of temsirolimus and sirolimus were relatively comparable in both groups of patients at their respective dose levels. Correlative analyses of the tissue for the inhibition of the key regulators (p70S6 kinase and 4E-binding protein 1) of mammalian target of rapamycin are necessary to define the therapeutic significance of the altered exposure to temsirolimus. Topics: Anticonvulsants; Antineoplastic Agents; Area Under Curve; Brain Neoplasms; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Drug Interactions; Glioma; Humans; Maximum Tolerated Dose; Metabolic Clearance Rate; Neoplasm Recurrence, Local; Sirolimus | 2007 |
Phase II trial of temsirolimus (CCI-779) in recurrent glioblastoma multiforme: a North Central Cancer Treatment Group Study.
Temsirolimus (CCI-779) is a small-molecule inhibitor of the mammalian target of rapamycin (mTOR) and represents a rational therapeutic target against glioblastoma multiforme (GBM).. Recurrent GBM patients with < or = 1 chemotherapy regimen for progressive disease were eligible. Temsirolimus was administered in a 250-mg intravenous dose weekly.. Sixty-five patients were treated. The incidence of grade 3 or higher nonhematologic toxicity was 51%, and consisted mostly of hypercholesterolemia (11%), hypertriglyceridemia (8%), and hyperglycemia (8%). Grade 3 hematologic toxicity was observed in 11% of patients. Temsirolimus peak concentration (Cmax), and sirolimus Cmax and area under the concentration-time curve were decreased in patients receiving p450 enzyme-inducing anticonvulsants (EIACs) by 73%, 47%, and 50%, respectively, but were still within the therapeutic range of preclinical models. Twenty patients (36%) had evidence of improvement in neuroimaging, consisting of decrease in T2 signal abnormality +/- decrease in T1 gadolinium enhancement, on stable or reduced steroid doses. Progression-free survival at 6 months was 7.8% and median overall survival was 4.4 months. Median time to progression (TTP) for all patients was 2.3 months and was significantly longer for responders (5.4 months) versus nonresponders (1.9 months). Development of grade 2 or higher hyperlipidemia in the first two treatment cycles was associated with a higher percentage of radiographic response (71% v 31%; P = .04). Significant correlation was observed between radiographic improvement and high levels of phosphorylated p70s6 kinase in baseline tumor samples (P = .04).. Temsirolimus is well tolerated in recurrent GBM patients. Despite the effect of EIACs on temsirolimus metabolism, therapeutic levels were achieved. Radiographic improvement was observed in 36% of temsirolimus-treated patients, and was associated with significantly longer TTP. High levels of phosphorylated p70s6 kinase in baseline tumor samples appear to predict a patient population more likely to derive benefit from treatment. These findings should be validated in other studies of mTOR inhibitors. Topics: Adult; Aged; Antineoplastic Agents, Alkylating; Brain Neoplasms; Disease-Free Survival; Female; Genes, erbB-1; Glioblastoma; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Phosphoric Monoester Hydrolases; Prognosis; Protein Kinase Inhibitors; Protein Kinases; PTEN Phosphohydrolase; Salvage Therapy; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Tumor Suppressor Proteins | 2005 |
Phase II study of CCI-779 in patients with recurrent glioblastoma multiforme.
Loss of PTEN, which is common in glioblastoma multiforme (GBM), results in activation of the mammalian target of rapapmycin (mTOR), thereby increasing mRNA translation of a number of key proteins required for cell-cycle progression. CCI-779 is an inhibitor of mTOR. The primary objectives of this study were to determine the efficacy of CCI-779 in patients with recurrent GBM and to further assess the toxicity of the drug.. CCI-779 was administered weekly at a dose of 250 mg intravenously for patients on enzyme-inducing anti-epileptic drugs (EIAEDs). Patients not on EIAEDs were initially treated at 250 mg; however, the dose was reduced to 170 mg because of intolerable side effects. Treatment was continued until unacceptable toxicity, tumor progression, or patient withdrawal. The primary endpoint was 6-month progression-free survival.. Forty-three patients were enrolled; 29 were not on EIAEDs. The expected toxicity profile of increased lipids, lymphopenia, and stomatitis was seen. There were no grade IV hematological toxicities and no toxic deaths. One patient was progression free at 6 months. Of the patients assessable for response, there were 2 partial responses and 20 with stabilization of disease. The median time to progression was 9 weeks.. CCI-779 was well tolerated at this dose schedule; however, there was no evidence of efficacy in patients with recurrent GBM. Despite initial disease stabilization in approximately 50% of patients, the durability of response was short. Because of the low toxicity profile, CCI-779 may merit exploration in combination with other modalities. Topics: Adult; Aged; Anemia; Anticonvulsants; Antineoplastic Agents; Brain Neoplasms; Disease-Free Survival; Drug Interactions; Female; Glioblastoma; Humans; Hypercholesterolemia; Infusions, Intravenous; Lymphopenia; Male; Middle Aged; Neoplasm Recurrence, Local; Sirolimus | 2005 |
Phase I/pharmacokinetic study of CCI-779 in patients with recurrent malignant glioma on enzyme-inducing antiepileptic drugs.
CCI-779 is an ester of the immunosuppressive agent sirolimus (rapamycin) that causes cell-cycle arrest at G1 via inhibition of key signaling pathways resulting in inhibition of RNA translation. Antitumor activity has been demonstrated using cell lines and animal models of malignant glioma. Patients receiving enzyme-inducing anti-epileptic drugs (EIAEDs) can have altered metabolism of drugs like CCI-779 that are metabolized through the hepatic cytochrome P450 enzyme system. The objectives of this study were to determine the pharmacokinetic profile and the maximum tolerated dose of CCI-779 in patients with recurrent malignant gliioma taking EIAEDs.. The starting dose of CCI-779 was 250 mg intravenously (IV) administered weekly on a continuous basis. Standard dose escalation was performed until the maximum tolerated dose was established. Toxicity was assessed using the National Cancer Institute common toxicity criteria.. Two of 6 patients treated at the second dose level of 330 mg sustained a dose-limiting toxicity: grade III stomatitis, grade 3 hypercholesterolemia, or grade 4 hypertriglyceridemia. The maximum tolerated dose was reached at 250 mg IV. Pharmacokinetic profiles were similar to those previously described, but the area under the whole blood concentration-time curve of rapamycin was 1.6 fold lower for patients on EIAEDs.. The recommended phase II dose of CCI 779 for patients on enzyme-inducing antiepileptic drugs is 250 mg IV weekly. A phase II study is ongoing to determine the efficacy of this agent. Topics: Adult; Anticonvulsants; Antineoplastic Agents; Brain Neoplasms; Cohort Studies; Cytochrome P-450 Enzyme System; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Interactions; Enzyme Induction; Female; Glioma; Humans; Infusions, Intravenous; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Recurrence, Local; Sirolimus; Treatment Outcome | 2004 |
89 other study(ies) available for sirolimus and Brain-Neoplasms
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Regulation of TORC1 by MAPK Signaling Determines Sensitivity and Acquired Resistance to Trametinib in Pediatric BRAFV600E Brain Tumor Models.
We investigated why three patient-derived xenograft (PDX) childhood BRAFV600E-mutant brain tumor models are highly sensitive to trametinib. Mechanisms of acquired resistance selected in situ, and approaches to prevent resistance were also examined, which may translate to both low-grade glioma (LGG) molecular subtypes.. Sensitivity to trametinib [MEK inhibitor (MEKi)] alone or in combination with rapamycin (TORC1 inhibitor), was evaluated in pediatric PDX models. The effect of combined treatment of trametinib with rapamycin on development of trametinib resistance in vivo was examined. PDX tissue and tumor cells from trametinib-resistant xenografts were characterized.. In pediatric models TORC1 is activated through ERK-mediated inactivation of the tuberous sclerosis complex (TSC): consequently inhibition of MEK also suppressed TORC1 signaling. Trametinib-induced tumor regression correlated with dual inhibition of MAPK/TORC1 signaling, and decoupling TORC1 regulation from BRAF/MAPK control conferred trametinib resistance. In mice, acquired resistance to trametinib developed within three cycles of therapy in all three PDX models. Resistance to trametinib developed in situ is tumor-cell-intrinsic and the mechanism was tumor line specific. Rapamycin retarded or blocked development of resistance.. In these three pediatric BRAF-mutant brain tumors, TORC1 signaling is controlled by the MAPK cascade. Trametinib suppressed both MAPK/TORC1 pathways leading to tumor regression. While low-dose intermittent rapamycin to enhance inhibition of TORC1 only modestly enhanced the antitumor activity of trametinib, it prevented or retarded development of trametinib resistance, suggesting future therapeutic approaches using rapamycin analogs in combination with MEKis that may be therapeutically beneficial in both KIAA1549::BRAF- and BRAFV600E-driven gliomas. Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Disease Models, Animal; Glioma; Humans; Mechanistic Target of Rapamycin Complex 1; Mice; Mitogen-Activated Protein Kinase Kinases; Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Sirolimus | 2022 |
Systemic chemotherapy of pediatric recurrent ependymomas: results from the German HIT-REZ studies.
Survival in recurrent ependymoma (EPN) depends mainly on the extent of resection achieved. When complete resection is not feasible, chemotherapy is often used to extend progression-free and overall survival. However, no consistent effect of chemotherapy on survival has been found in patients with recurrent EPN.. Systemic chemotherapeutic treatment of 138 patients enrolled in the German HIT-REZ-studies was analyzed. Survival depending on the use of chemotherapy, disease-stabilization rates (RR), duration of response (DOR) and time to progression (TTP) were estimated.. Median age at first recurrence was 7.6 years (IQR: 4.0-13.6). At first recurrence, median PFS and OS were 15.3 (CI 13.3-20.0) and 36.9 months (CI 29.7-53.4), respectively. The Hazard Ratio for the use of chemotherapy in local recurrences in a time-dependent Cox-regression analysis was 0.99 (CI 0.74-1.33). Evaluable responses for 140 applied chemotherapies were analyzed, of which sirolimus showed the best RR (50%) and longest median TTP [11.51 (CI 3.98; 14.0) months] in nine patients, with the strongest impact found when sirolimus was used as a monotherapy. Seven patients with progression-free survival > 12 months after subtotal/no-resection facilitated by chemotherapy were found. No definitive survival advantage for any drug in a specific molecularly defined EPN type was found.. No survival advantage for the general use of chemotherapy in recurrent EPN was found. In cases with incomplete resection, chemotherapy was able to extend survival in individual cases. Sirolimus showed the best RR, DOR and TTP out of all drugs analyzed and may warrant further investigation. Topics: Adolescent; Brain Neoplasms; Child; Child, Preschool; Ependymoma; Germany; Humans; Neoplasm Recurrence, Local; Sirolimus; Treatment Outcome | 2021 |
Neurobehavioral effects in rats with experimentally induced glioblastoma after treatment with the mTOR-inhibitor rapamycin.
Psychiatric symptoms as seen in affective and anxiety disorders frequently appear during glioblastoma (GBM) treatment and disease progression, additionally deteriorate patient's daily life routine. These central comorbidities are difficult to recognize and the causes for these effects are unknown. Since overactivation of mechanistic target of rapamycin (mTOR)- signaling is one key driver in GBM growth, the present study aimed at examining in rats with experimentally induced GBM, neurobehavioral consequences during disease progression and therapy. Male Fisher 344 rats were implanted with syngeneic RG2 tumor cells in the right striatum and treated with the mTOR inhibitor rapamycin (3 mg/kg; once daily, for eight days) before behavioral performance, brain protein expression, and blood samples were analyzed. We could show that treatment with rapamycin diminished GBM tumor growth, confirming mTOR-signaling as one key driver for tumor growth. Importantly, in GBM animals' anxiety-like behavior was observed but only after treatment with rapamycin. These behavioral alterations were moreover accompanied by aberrant glucocorticoid receptor, phosphorylated p70 ribosomal S6 kinase alpha (p-p70s6k), and brain derived neurotrophic factor protein expression in the hippocampus and amygdala in the non-tumor-infiltrated hemisphere of the brain. Despite the beneficial effects on GBM tumor growth, our findings indicate that therapy with rapamycin impaired neurobehavioral functioning. This experimental approach has a high translational value. For one, it emphasizes aberrant mTOR functioning as a central feature mechanistically linking complex brain diseases and behavioral disturbances. For another, it highlights the importance of elaborating the cause of unwanted central effects of immunosuppressive and antiproliferative drugs used in transplantation medicine, immunotherapy, and oncology. Topics: Animals; Antibiotics, Antineoplastic; Brain Neoplasms; Cell Line, Tumor; Dose-Response Relationship, Drug; Glioblastoma; Male; Maze Learning; Rats; Rats, Inbred F344; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Tumor Burden | 2021 |
A Young Woman with a Toxic Sirolimus Concentration?
Topics: Adult; Angiofibroma; Astrocytoma; Biological Availability; Brain Neoplasms; Drug Administration Routes; Drug Monitoring; Everolimus; Female; Humans; Immunosuppressive Agents; Medication Therapy Management; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis | 2020 |
An inducible system for in vitro and in vivo Fas activation using FKBP-FRB-rapamycin complex.
The inducible activation system is valuable for investigating spatiotemporal roles of molecules. A chemically inducible activation system for Fas (CD95/APO-1), which works efficiently to induce apoptosis and leads non-apoptotic pathways, has not yet been developed. Here, we engineered a rapamycin-induced dimerization system of Fas consisting of FKBP and FRB proteins. Treatment of rapamycin specifically induces cellular apoptosis. In neurons and cells with high c-FLIP expression, rapamycin-induced Fas activation triggered the activation of the non-apoptotic pathway components instead of cell death. Intracranial delivery of the system could be utilized to induce apoptosis of tumor cells upon rapamycin treatment. Our results demonstrate a novel inducible Fas activation system which operates with high efficiency and temporal precision in vitro and in vivo promising a potential therapeutic strategy. Topics: Animals; Apoptosis; Brain Neoplasms; Cells, Cultured; fas Receptor; Female; Green Fluorescent Proteins; HeLa Cells; Humans; Mice, Inbred C57BL; Neurons; Pregnancy; Protein Engineering; Rats, Sprague-Dawley; Sirolimus; Tacrolimus Binding Protein 1A; Tacrolimus Binding Proteins; Xenograft Model Antitumor Assays | 2020 |
Synergistic Combination of Oncolytic Virotherapy and Immunotherapy for Glioma.
We hypothesized that the combination of a local stimulus for activating tumor-specific T cells and an anti-immunosuppressant would improve treatment of gliomas. Virally encoded IL15Rα-IL15 as the T-cell activating stimulus and a prostaglandin synthesis inhibitor as the anti-immunosuppressant were combined with adoptive transfer of tumor-specific T cells.. vvDD-IL15Rα-YFP and vMyx-IL15Rα-tdTr each infected and killed GL261 cells. IL15Rα-IL15-armed oncolytic poxviruses provide potent antitumor effects against brain tumors when combined with adoptive T-cell therapy, rapamycin, and celecoxib. Topics: Animals; Brain Neoplasms; Celecoxib; Cell Line, Tumor; Combined Modality Therapy; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Drug Synergism; Female; Glioma; Immunosuppressive Agents; Immunotherapy; Immunotherapy, Adoptive; Interleukin-15; Male; Mice, Inbred C57BL; Myxoma virus; Oncolytic Virotherapy; Receptors, Interleukin-15; Sirolimus; Vaccinia virus | 2020 |
Rapamycin and hydroxychloroquine combination alters macrophage polarization and sensitizes glioblastoma to immune checkpoint inhibitors.
The failure of immune checkpoint inhibitor (ICPi) on glioblastoma (GBM) treatment underscores the need for improving therapeutic strategy. We aimed to change tumor associated macrophage (TAM) from M2 type (anti-inflammatory) to M1 (pro-inflammatory) type to increase the therapeutic response of ICPi. We proposed that combined rapamycin (R) and hydroxychloroquine (Q) preferentially induce M2 cells death, as fatty acid oxidation was their major source of energy.. Macrophage polarization was characterized on mice and human macrophage cell lines by specific cytokines stimulation with or without RQ treatment under single culture or co-culture with GBM cell lines. Tumor sizes were evaluated on subcutaneous and intracranial GL261 mice models with or without RQ, anti-PD1 mAb treatment. Tumor volumes assessed by MRI scan and proportions of tumor infiltrating immune cells analyzed by flow cytometry were compared.. In vitro RQ treatment decreased the macrophages polarization of M2, increased the phagocytic ability, and increased the lipid droplets accumulation. RQ treatment decreased the expression levels of CD47 and SIRPα on tumor cells and macrophage cells in co-culture experiments. The combination of RQ and anti-PD1 treatment was synergistic in action. Enhanced the intra-tumoral M1/M2 ratio, the CD8/CD4 ratio in the intracranial GL261 tumor model after RQ treatment were evident.. We provide a rationale for manipulating the macrophage phenotype and increased the therapeutic effect of ICPi. To re-educate and re-empower the TAM/microglia opens an interesting avenue for GBM treatment. Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Cell Polarity; Cells, Cultured; Female; Glioblastoma; Humans; Hydroxychloroquine; Macrophages; Mice; Mice, Inbred C57BL; Programmed Cell Death 1 Receptor; Sirolimus | 2020 |
Tuberous sclerosis with two unusual findings: cutaneous rhabdomyoma and chronic myelogenous leukaemia.
Topics: Angiomyolipoma; Brain; Brain Neoplasms; Female; Humans; Immunosuppressive Agents; Kidney Neoplasms; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Magnetic Resonance Imaging; Multiple Pulmonary Nodules; Neoplasms, Multiple Primary; Rhabdomyoma; Sirolimus; Skin Neoplasms; Tomography, X-Ray Computed; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Young Adult | 2020 |
Wild‑type IDH1 affects cell migration by modulating the PI3K/AKT/mTOR pathway in primary glioblastoma cells.
Glioblastoma (GBM) is the most common type of brain cancer and has the highest mortality. Dysregulated expression of wild‑type isocitrate dehydrogenase 1 (IDH1) has been demonstrated to promote the progression of primary GBM without accumulating D‑2‑hydroxyglutarate, which differs from IDH1 mutation‑related mechanisms of tumorigenesis. Previous studies have revealed several roles of wild‑type IDH1 in primary GBM, involving proliferation and apoptosis. However, the function of IDH1 in cell migration has not been investigated. In the current study, the results of bioinformatics analysis revealed that IDH1 expression was significantly upregulated in patients with primary GBM. Wound healing and Transwell assays demonstrated that IDH1 overexpression promoted cell migration in primary GBM cells and that IDH1 knockdown hindered this process. Furthermore, α‑ketoglutarate (α‑KG), which is the main product of IDH1‑catalyzed reactions, was significantly decreased by IDH1 knockdown and upregulated by IDH1 overexpression. α‑KG treatment significantly increased the migration of primary GBM cells. Additionally, RNA sequence analysis of patients with primary GBM reported significant alterations in the expression of phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway‑regulated genes, including Myc, Snail family transcriptional repressor 2 and Twist‑related protein 1, which are primarily cell migration regulatory factors. Western blotting revealed that the overexpression or knockdown of IDH1 promoted or inhibited the PI3K/AKT/mTOR pathway, respectively. α‑KG treatment of primary GBM cells also promoted the PI3K/AKT/mTOR pathway. Furthermore, IDH1‑overexpressing and α‑KG‑treated U87 cells were incubated with rapamycin, an mTOR‑specific inhibitor, and the results revealed that rapamycin treatment reversed the increased cell migration caused by IDH1 overexpression and α‑KG treatment. The results indicated that IDH1 regulated the migration of primary GBM cells by altering α‑KG levels and that the function of the IDH1/α‑KG axis may rely on PI3K/AKT/mTOR pathway regulation. Topics: Brain Neoplasms; Cell Line, Tumor; Cell Movement; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Glioblastoma; Humans; Isocitrate Dehydrogenase; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Sequence Analysis, RNA; Sirolimus; TOR Serine-Threonine Kinases; Up-Regulation | 2020 |
Dendrimer-Mediated Targeted Delivery of Rapamycin to Tumor-Associated Macrophages Improves Systemic Treatment of Glioblastoma.
Glioblastoma exhibits high mortality rates due to challenges with drug delivery to the brain and into solid tumors. This two-pronged barrier necessitates high doses of systemic therapies, resulting in significant off-target toxicities. Recently, dendrimer-nanomedicines (without ligands) have shown promise for targeting specific cells in brain tumors from systemic circulation, for improved efficacy and amelioration of systemic toxicities. A dendrimer-rapamycin conjugate (D-Rapa) is presented here that specifically targets tumor-associated macrophages (TAMs) in glioblastoma from systemic administration. D-Rapa improves suppression of pro-tumor expression in activated TAMs and antiproliferative properties of rapamycin in glioma cells Topics: Brain Neoplasms; Dendrimers; Drug Delivery Systems; Glioblastoma; Humans; Sirolimus; Tumor Microenvironment; Tumor-Associated Macrophages | 2020 |
Mitochondrial dysfunction contributes to Rapamycin-induced apoptosis of Human Glioblastoma Cells - A synergistic effect with Temozolomide.
Mammalian target of rapamycin (mTOR) is upregulated in a high percentage of glioblastomas. While a well-known mTOR inhibitor, rapamycin, has been shown to reduce glioblastoma survival, the role of mitochondria in achieving this therapeutic effect is less well known. Here, we examined mitochondrial dysfunction mechanisms that occur with the suppression of mTOR signaling. We found that, along with increased apoptosis, and a reduction in transformative potential, rapamycin treatment significantly affected mitochondrial health. Specifically, increased production of reactive oxygen species (ROS), depolarization of the mitochondrial membrane potential (MMP), and altered mitochondrial dynamics were observed. Furthermore, we verified the therapeutic potential of rapamycin-induced mitochondrial dysfunction through co-treatment with temzolomide (TMZ), the current standard of care for glioblastoma. Together these results demonstrate that the mitochondria remain a promising target for therapeutic intervention against human glioblastoma and that TMZ and rapamycin have a synergistic effect in suppressing glioblastoma viability, enhancing ROS production, and depolarizing MMP. Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Brain Neoplasms; Cell Line, Tumor; Cell Survival; Drug Synergism; Glioblastoma; Humans; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Dynamics; Reactive Oxygen Species; Signal Transduction; Sirolimus; Temozolomide; TOR Serine-Threonine Kinases | 2020 |
Malignant gliomas can be converted to non‑proliferating glial cells by treatment with a combination of small molecules.
Gliomas, the most highly malignant central nervous system tumors, are associated with an extremely poor patient survival rate. Given that gliomas are derived from mutations in glial precursor cells, a considerable number of them strongly react with glial precursor cell‑specific markers. Thus, we investigated whether malignant gliomas can be converted to glial cells through the regulation of endogenous gene expression implicated in glial precursor cells. In the present study, we used three small‑molecule compounds, [cyclic adenosine monophosphate (cAMP) enhancer, a mammalian target of rapamycin (mTOR) inhibitor, and a bromodomain and extra‑terminal motif (BET) inhibitor] for glial reprogramming. Small‑molecule‑induced gliomas (SMiGs) were not only transformed into exhibiting a glial‑specific morphology, but also showed positive reactions with glial‑specific markers such as glial fibrillary acidic protein (GFAP), 2',3'‑cyclic nucleotide 3'‑phosphohydrolase (CNP) and anti‑oligodendrocyte (RIP). A microarray analysis indicated that SMiGs exhibited a marked increase in specific gene levels, whereas that of a malignant cancer‑specific gene was greatly decreased. Moreover, proliferation of the cells was markedly suppressed after the conversion of malignant glioma cells into glial cells. Our findings confirmed that malignant gliomas can be reprogrammed to non‑proliferating glial cells, using a combination of small molecules, and their proliferation can be regulated by their differentiation. We suggest that our small‑molecule combination (with forskolin, rapamycin and I‑BET151) may be the next generation of anticancer agents that act by reprogramming malignant gliomas to differentiate into glial cells. Topics: 2',3'-Cyclic Nucleotide 3'-Phosphodiesterase; Animals; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cellular Reprogramming; Colforsin; Drug Therapy, Combination; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Glial Fibrillary Acidic Protein; Glioma; Heterocyclic Compounds, 4 or More Rings; Humans; Neuroglia; Oligonucleotide Array Sequence Analysis; Rats; Sirolimus; Small Molecule Libraries | 2019 |
The effect of the mTOR inhibitor rapamycin on glucoCEST signal in a preclinical model of glioblastoma.
The mammalian target of rapamycin is an enzyme that regulates cell metabolism and proliferation. It is up-regulated in aggressive tumors, such as glioblastoma, leading to increased glucose uptake and consumption. It has been suggested that glucose CEST signals reflect the delivery and tumor uptake of glucose. The inhibitor rapamycin (sirolimus) has been applied as a glucose deprivation treatment; thus, glucose CEST MRI could potentially be useful for monitoring the tumor responses to inhibitor treatment.. A human U87-EGFRvIII xenograft model in mice was studied. The mice were treated with a mammalian target of Rapamycin inhibitor, rapamycin. The effect of the treatment was evaluated in vivo with dynamic glucose CEST MRI.. Rapamycin treatment led to significant increases (P < 0.001) in dynamic glucose-enhanced signal in both the tumor and contralateral brain as compared to the no-treatment group, namely a maximum enhancement of 3.7% ± 2.3% (tumor, treatment) versus 1.9% ± 0.4% (tumor, no-treatment), 1.7% ± 1.1% (contralateral, treatment), and 1.0% ± 0.4% (contralateral, no treatment). Dynamic glucose-enhanced contrast remained consistently higher in treatment versus no-treatment groups for the duration of the experiment (17 min). This was confirmed with area-under-curve analysis.. Increased glucose CEST signal was found after mammalian target of Rapamycin inhibition treatment, indicating potential for dynamic glucose-enhanced MRI to study tumor response to glucose deprivation treatment. Topics: Animals; Antibiotics, Antineoplastic; Brain; Brain Chemistry; Brain Neoplasms; Cell Line, Tumor; Female; Glioblastoma; Humans; Magnetic Resonance Imaging; Mice; Mice, SCID; Sirolimus; Xenograft Model Antitumor Assays | 2019 |
Carnosine inhibits glioblastoma growth independent from PI3K/Akt/mTOR signaling.
Glioblastoma is a high-grade glioma with poor prognosis even after surgery and standard therapy. Here, we asked whether carnosine (β-alanyl-L-histidine), a naturally occurring dipeptide, exert its anti-neoplastic effect on glioblastoma cells via PI3K/Akt/mTOR signaling. Therefore, glioblastoma cells from the lines U87 and T98G were exposed to carnosine, to the mTOR inhibitor rapamycin and to the PI3K inhibitor Ly-294,002. Pyruvate dehydrogenase kinase (PDK4) expression, known to be a target of PI3K/Akt/mTOR, and which is also affected by carnosine, was analyzed by RT-qPCR, and reporter gene assays with the human PDK4 promoter were performed. Cell viability was assessed by cell-based assays and mTOR and Akt phosphorylation by Western blotting. Rapamycin and Ly-294,002 increased PDK4 mRNA expression in both cell lines but significance was only reached in U87. Carnosine significantly increased expression in both lines. A significant combinatorial effect of carnosine was only detected in U87 when the dipeptide was combined with Ly-294,002. Reporter gene assays revealed no specific effect of carnosine on the human PDK4 promoter, whereas both inhibitors increased reporter gene expression. Rapamycin reduced phosphorylation of mTOR, and Ly-294,002 that of Akt. A significant reduction of Akt phosphorylation was observed in the presence of carnosine in U87 but not in T98G, and carnosine had no effect on mTOR phosphorylation. Cell viability as determined by ATP in cell lysates was reduced only in the presence of carnosine. We conclude that carnosine's anti-neoplastic effect is independent from PI3K/Akt/mTOR signaling. As the dipeptide reduced viability in tumor cells that do not respond to PI3K or mTOR inhibitors, it appears to be worth to further investigate the mechanisms by which carnosine exerts its anti-tumor effect and to consider it for therapy, especially as it is a naturally occurring compound that has already been used for the treatment of other diseases without indication of side-effects. Topics: Brain Neoplasms; Carnosine; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chromones; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Morpholines; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Pyruvate Dehydrogenase Acetyl-Transferring Kinase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2019 |
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 |
Autophagy-induced KDR/VEGFR-2 activation promotes the formation of vasculogenic mimicry by glioma stem cells.
Antiangiogenesis with bevacizumab, an antibody against vascular endothelial growth factor (VEGF), has been used for devascularization to limit the growth of malignant glioma. However, the benefits are transient due to elusive mechanisms underlying resistance to the antiangiogenic therapy. Glioma stem cells (GSCs) are capable of forming vasculogenic mimicry (VM), an alternative microvascular circulation independent of VEGF-driven angiogenesis. Herein, we report that the formation of VM was promoted by bevacizumab-induced macroautophagy/autophagy in GSCs, which was associated with tumor resistance to antiangiogenic therapy. We established a 3-dimensional collagen scaffold to examine the formation of VM and autophagy by GSCs, and found that rapamycin increased the number of VM and enhanced KDR/VEGFR-2 phosphorylation. Treatment with chloroquine, or knockdown of the autophagy gene ATG5, inhibited the formation of VM and KDR phosphorylation in GSCs. Notably, neutralization of GSCs-produced VEGF with bevacizumab failed to recapitulate the effect of chloroquine treatment and ATG5 knockdown, suggesting that autophagy-promoted formation of VM was independent of tumor cell-derived VEGF. ROS was elevated when autophagy was induced in GSCs and activated KDR phosphorylation through the phosphoinositide 3-kinase (PI3K)-AKT pathway. A ROS inhibitor, N-acetylcysteine, abolished KDR phosphorylation and the formation of VM by GSCs. By examination of the specimens from 95 patients with glioblastoma, we found that ATG5 and p-KDR expression was strongly associated with the density of VM in tumors and poor clinical outcome. Our results thus demonstrate a crucial role of autophagy in the formation of VM by GSCs, which may serve as a therapeutic target in drug-resistant glioma. Topics: Animals; Autophagy; Autophagy-Related Protein 5; Bevacizumab; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Chloroquine; Female; Gene Knockdown Techniques; Glioma; Humans; Mice; Mice, SCID; Models, Biological; Neoplastic Stem Cells; Neovascularization, Pathologic; Phosphorylation; Reactive Oxygen Species; Sirolimus; Survival Analysis; Tissue Scaffolds; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2 | 2017 |
Presurgical Administration of mTOR Inhibitors in Patients with Large Subependymal Giant Cell Astrocytoma Associated with Tuberous Sclerosis Complex.
Direct surgical resection remains the standard treatment for patients with tuberous sclerosis complex (TSC) with a large subependymal giant cell astrocytoma (SEGA). Rapamycin or everolimus is seldom used in these patients because of the risk of increased intracranial pressure and possibility of sudden death.. Three patients with TSC and a large intracranial SEGA received oral rapamycin (0.5 mg/day) or everolimus (2.5 mg/day) before surgery for tumor resection. After mTOR inhibitor therapy, computed tomography scans and magnetic resonance imaging revealed tumor reduction. Tumor bleeding was easy to control during surgery, and the border between tumor and surrounding brain tissue was clearly differentiated. Analysis of postsurgical tumor specimens showed low blood density and focal necrosis.. Preoperative mTOR inhibitors could be a potentially novel treatment modality in large TSC-SEGA with hydrocephalus. In this series, mTOR inhibitors were not only safe and well tolerated, but also beneficial for tumor resection. Topics: Astrocytoma; Brain Neoplasms; Child; Child, Preschool; Everolimus; Female; Humans; Male; Preoperative Care; Protein Kinase Inhibitors; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis | 2017 |
Cobalt chloride treatment induces autophagic apoptosis in human glioma cells via a p53-dependent pathway.
Malignant glioma is the most aggressive brain tumor. Hypoxic condition has been explored for killing cancer stem cells or drug-resistant tumor cells. This study investigated the effects of hypoxia on autophagic death and the possible mechanisms. Exposure of human malignant glioma U87-MG cells to cobalt chloride (CoCl2) increased cellular hypoxia-inducible factor-1α levels and concurrently decreased cell viability concentration- and time-dependently. In parallel, treatment with CoCl2 suppressed proliferation of human U87-MG cells. Autophagic cells and levels of LC3-II were concentration- and time-dependently induced in human U87-MG cells after exposure to CoCl2. However, pretreatment with 3-mehyladenine (3-MA) and chloroquine, inhibitors of cell autophagy, caused significant alleviations in CoCl2-induced cell autophagy. In contrast, exposure to rapamycin, an inducer of cell autophagy, synergistically induced hypoxia-induced autophagy of U87-MG cells. Administration of human U87-MG cells with CoCl2 triggered caspase-3 activation and cell apoptosis. Interestingly, pretreatment with 3-MA and chloroquine remarkably suppressed CoCl2-induced caspase-3 activation and cell apoptosis. Application of p53 small interference (si)RNA into human U87-MG cells downregulated levels of this protein and simultaneously lowered hypoxia- and 3-MA-induced alterations in cell autophagy, apoptosis, and death. The hypoxia-induced autophagy and apoptosis of DBTRG-05MG cells were significantly lowered by 3-MA pretreatment and p53 knockdown. Therefore, the present study shows that CoCl2 treatment can induce autophagy of human glioma cells and subsequent autophagic apoptosis via a p53-dependent pathway. Hypoxia-induced autophagic apoptosis may be applied as a therapeutic strategy for treatment of glioma patients. Topics: Adenine; Antimutagenic Agents; Apoptosis; Autophagy; Brain Neoplasms; Caspase 3; Cell Hypoxia; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chloroquine; Cobalt; Glioma; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Microtubule-Associated Proteins; Reactive Oxygen Species; RNA Interference; RNA, Small Interfering; Sirolimus; Tumor Suppressor Protein p53 | 2017 |
A Kinase Inhibitor Targeted to mTORC1 Drives Regression in Glioblastoma.
Although signaling from phosphatidylinositol 3-kinase (PI3K) and AKT to mechanistic target of rapamycin (mTOR) is prominently dysregulated in high-grade glial brain tumors, blockade of PI3K or AKT minimally affects downstream mTOR activity in glioma. Allosteric mTOR inhibitors, such as rapamycin, incompletely block mTORC1 compared with mTOR kinase inhibitors (TORKi). Here, we compared RapaLink-1, a TORKi linked to rapamycin, with earlier-generation mTOR inhibitors. Compared with rapamycin and Rapalink-1, TORKi showed poor durability. RapaLink-1 associated with FKBP12, an abundant mTOR-interacting protein, enabling accumulation of RapaLink-1. RapaLink-1 showed better efficacy than rapamycin or TORKi, potently blocking cancer-derived, activating mutants of mTOR. Our study re-establishes mTOR as a central target in glioma and traces the failure of existing drugs to incomplete/nondurable inhibition of mTORC1. Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Female; Glioblastoma; Humans; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred BALB C; Multiprotein Complexes; Protein Kinase Inhibitors; Sirolimus; Tacrolimus Binding Protein 1A; TOR Serine-Threonine Kinases | 2017 |
Anti-tumor activities of luteolin and silibinin in glioblastoma cells: overexpression of miR-7-1-3p augmented luteolin and silibinin to inhibit autophagy and induce apoptosis in glioblastoma in vivo.
Glioblastoma is the deadliest brain tumor in humans. High systemic toxicity of conventional chemotherapies prompted the search for natural compounds for controlling glioblastoma. The natural flavonoids luteolin (LUT) and silibinin (SIL) have anti-tumor activities. LUT inhibits autophagy, cell proliferation, metastasis, and angiogenesis and induces apoptosis; while SIL activates caspase-8 cascades to induce apoptosis. However, synergistic anti-tumor effects of LUT and SIL in glioblastoma remain unknown. Overexpression of tumor suppressor microRNA (miR) could enhance the anti-tumor effects of LUT and SIL. Here, we showed that 20 µM LUT and 50 µM SIL worked synergistically for inhibiting growth of two different human glioblastoma U87MG (wild-type p53) and T98G (mutant p53) cell lines and natural combination therapy was more effective than conventional chemotherapy (10 µM BCNU or 100 µM TMZ). Combination of LUT and SIL caused inhibition of growth of glioblastoma cells due to induction of significant amounts of apoptosis and complete inhibition of invasion and migration. Further, combination of LUT and SIL inhibited rapamycin (RAPA)-induced autophagy, a survival mechanism, with suppression of PKCα and promotion of apoptosis through down regulation of iNOS and significant increase in expression of the tumor suppressor miR-7-1-3p in glioblastoma cells. Our in vivo studies confirmed that overexpression of miR-7-1-3p augmented anti-tumor activities of LUT and SIL in RAPA pre-treated both U87MG and T98G tumors. In conclusion, our results clearly demonstrated that overexpression of miR-7-1-3p augmented the anti-tumor activities of LUT and SIL to inhibit autophagy and induce apoptosis for controlling growth of different human glioblastomas in vivo. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Brain Neoplasms; Carmustine; Caspase 8; Cell Line, Tumor; Cell Movement; Cell Proliferation; Dacarbazine; Female; Glioblastoma; Humans; Luteolin; Mice; Mice, Nude; MicroRNAs; Signal Transduction; Silybin; Silymarin; Sirolimus; Temozolomide; Xenograft Model Antitumor Assays | 2016 |
ATP-site binding inhibitor effectively targets mTORC1 and mTORC2 complexes in glioblastoma.
The PI3K-AKT-mTOR signaling axis is central to the transformed phenotype of glioblastoma (GBM) cells, due to frequent loss of tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10). The mechanistic target of rapamycin (mTOR) kinase is present in two cellular multi-protein complexes, mTORC1 and mTORC2, which have distinct subunit composition, substrates and mechanisms of action. Targeting the mTOR protein is a promising strategy for GBM therapy. However, neither of these complexes is fully inhibited by the allosteric inhibitor of mTOR, rapamycin or its analogs. Herein, we provide evidence that the combined inhibition of mTORC1/2, using the ATP-competitive binding inhibitor PP242, would effectively suppress GBM growth and dissemination as compared to an allosteric binding inhibitor of mTOR. GBM cells treated with PP242 demonstrated significantly decreased activation of mTORC1 and mTORC2, as shown by reduced phosphorylation of their substrate levels, p70 S6K(Thr389) and AKT(Ser473), respectively, in a dose-dependent manner. Furthermore, insulin induced activation of these kinases was abrogated by pretreatment with PP242 as compared with rapamycin. Unlike rapamycin, PP242 modestly activates extracellular regulated kinase (ERK1/2), as shown by expression of pERK(Thr202/Tyr204). Cell proliferation and S-phase entry of GBM cells was significantly suppressed by PP242, which was more pronounced compared to rapamycin treatment. Lastly, PP242 significantly suppressed the migration of GBM cells, which was associated with a change in cellular behavior rather than cytoskeleton loss. In conclusion, these results underscore the potential therapeutic use of the PP242, a novel ATP-competitive binding inhibitor of mTORC1/2 kinase, in suppression of GBM growth and dissemination. Topics: Adenosine Triphosphate; Binding, Competitive; Brain Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Chemotaxis; Extracellular Signal-Regulated MAP Kinases; Glioblastoma; Humans; Indoles; Insulin; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Multiprotein Complexes; Phenotype; Phosphorylation; Protein Binding; Purines; S Phase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2016 |
mTOR inhibition decreases SOX2-SOX9 mediated glioma stem cell activity and temozolomide resistance.
SOX2 and SOX9 are commonly overexpressed in glioblastoma, and regulate the activity of glioma stem cells (GSCs). Their specific and overlapping roles in GSCs and glioma treatment remain unclear.. SOX2 and SOX9 levels were examined in human biopsies. Gain and loss of function determined the impact of altering SOX2 and SOX9 on cell proliferation, senescence, stem cell activity, tumorigenesis and chemoresistance.. SOX2 and SOX9 expression correlates positively in glioma cells and glioblastoma biopsies. High levels of SOX2 bypass cellular senescence and promote resistance to temozolomide. Mechanistic investigations revealed that SOX2 acts upstream of SOX9. mTOR genetic and pharmacologic (rapamycin) inhibition decreased SOX2 and SOX9 expression, and reversed chemoresistance.. Our findings reveal SOX2-SOX9 as an oncogenic axis that regulates stem cell properties and chemoresistance. We identify that rapamycin abrogate SOX protein expression and provide evidence that a combination of rapamycin and temozolomide inhibits tumor growth in cells with high SOX2/SOX9. Topics: Adult; Animals; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Cell Line, Tumor; Dacarbazine; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Glioblastoma; Glioma; Humans; Mice; Mice, Inbred NOD; Mice, Nude; Mice, SCID; Sirolimus; SOX9 Transcription Factor; SOXB1 Transcription Factors; Temozolomide; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays | 2016 |
Suppression of the invasive potential of Glioblastoma cells by mTOR inhibitors involves modulation of NFκB and PKC-α signaling.
Glioblastoma (GBM) is the most aggressive type of brain tumors in adults with survival period <1.5 years of patients. The role of mTOR pathway is documented in invasion and migration, the features associated with aggressive phenotype in human GBM. However, most of the preclinical and clinical studies with mTOR inhibitors are focused on antiproliferative and cytotoxic activity in GBM. In this study, we demonstrate that mTOR inhibitors-rapamycin (RAP), temisirolimus (TEM), torin-1 (TOR) and PP242 suppress invasion and migration induced by Tumor Necrosis Factor-α (TNFα) and tumor promoter, Phorbol 12-myristate 13-acetate (PMA) and also reduce the expression of the TNFα and IL1β suggesting their potential to regulate factors in microenvironment that support tumor progression. The mTOR inhibitors significantly decreased MMP-2 and MMP-9 mRNA, protein and activity that was enhanced by TNFα and PMA. The effect was mediated through reduction of Protein kinase C alpha (PKC-α) activity and downregulation of NFκB. TNFα- induced transcripts of NFκB targets -VEGF, pentraxin-3, cathepsin-B and paxillin, crucial in invasion were restored to basal level by these inhibitors. With limited therapeutic interventions currently available for GBM, our findings are significant and suggest that mTOR inhibitors may be explored as anti-invasive drugs for GBM treatment. Topics: Antineoplastic Agents; Brain Neoplasms; Cell Line, Tumor; Cell Movement; Glioblastoma; Humans; Indoles; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Naphthyridines; Neoplasm Invasiveness; NF-kappa B; Phenylacetates; Protein Kinase C-alpha; Purines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tumor Microenvironment; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A | 2016 |
Combination of an anti-EGFRvIII antibody CH12 with Rapamycin synergistically inhibits the growth of EGFRvIII+PTEN-glioblastoma in vivo.
There are still unmet medical needs for the treatment of glioblastoma (GBM), the most frequent and aggressive brain tumor worldwide. EGFRvIII, overexpressed in approximately 30% of GBM, has been regarded as a potential therapeutic target. In this study, we demonstrated that CH12, an anti-EGFRvIII monoclonal antibody, could significantly suppress the growth of EGFRvIII+ GBM in vivo; however, PTEN deficiency in GBM reduced the efficacy of CH12 by attenuating its effect on PI3K/AKT/mTOR pathway. To overcome this problem, CH12 was combined with the mTOR inhibitor rapamycin, leading to a synergistic inhibitory effect on EGFRvIII+PTEN- GBM in vivo. Mechanistically, the synergistic antitumor effect was achieved via attenuating EGFR and PI3K/AKT/mTOR pathway more effectively and reversing the STAT5 activation caused by rapamycin treatment. Moreover, the combination therapy suppressed angiogenesis and induced cancer cell apoptosis more efficiently. Together, these results indicated that CH12 and rapamycin could synergistically suppress the growth of EGFRvIII+PTEN- GBM, which might have a potential clinical application in the future. Topics: Animals; Anti-Bacterial Agents; Antibodies, Monoclonal; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Cell Line, Tumor; Drug Synergism; ErbB Receptors; Glioblastoma; Humans; Mice; PTEN Phosphohydrolase; Sirolimus; Xenograft Model Antitumor Assays | 2016 |
Variability of Dose and Level of Sirolimus in a Patient With Tuberous Sclerosis Complex and Subependymal Giant Cell Astrocytoma.
Topics: Astrocytoma; Brain Neoplasms; Humans; Sirolimus; Tuberous Sclerosis | 2016 |
Post-transcriptional regulation of 5'-untranslated regions of human Transient Receptor Potential Vanilloid type-1 (TRPV-1) channels: role in the survival of glioma patients.
The Transient Receptor Potential Vanilloid type-1 (TRPV1) channel is a non-selective cation channel belonging to the Transient Receptor Potential family; variation of its expression has been correlated to glioma progression. In human, TRPV1 transcripts display a remarkable homogeneity differing only for the 5'-untranslated region (5'UTR) sequence that generates four variants encoding the same protein. Herein, we investigated the role of the 5'UTR sequences in TRPV1 transcripts stability, regulation of translation, expression in glioma cells and tissues. In addition, the expression of 5'UTR TRPV1 variants as prognostic factor in the survival of glioblastoma patients was evaluated. The expression level for each 5'UTR and their stability was evaluated by RT-PCR analysis. The effect of rapamycin and interferon-gamma in 5'UTR-regulating TRPV1 translation was determined by western blot analysis in glioma cell lines. We demonstrated that the 5'UTR influences the stability and translation efficacy of TRPV1 transcripts, and that TRPV1 variant three (TRPV1v3) was the most stable and the only variant expressed in GBM samples and in glioma stem-like cells. Furthermore, we found that TRPV1v3 expression levels correlate with patient's survival, suggesting that it may represent a potential prognostic marker for patients with glioma. Topics: 5' Untranslated Regions; Brain Neoplasms; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Glioma; Half-Life; Humans; Interferon-gamma; Kaplan-Meier Estimate; Neoplastic Stem Cells; Nucleic Acid Conformation; Proportional Hazards Models; RNA Processing, Post-Transcriptional; RNA Stability; RNA, Messenger; Sirolimus; Time Factors; Transfection; TRPV Cation Channels | 2016 |
RIST: a potent new combination therapy for glioblastoma.
Glioblastoma is a highly aggressive, common brain tumor with poor prognosis. Therefore, this study examines a new therapeutic approach targeting oncogenic and survival pathways combined with common chemotherapeutics. The RIST (rapamycin, irinotecan, sunitinib, temozolomide) and the variant aRIST (alternative to rapamycin, GDC-0941) therapy delineate growth inhibiting effects in established glioblastoma cell lines and primary cultured patient material. These combinations significantly decreased cell numbers and viability compared to inhibitors and chemotherapeutics alone with aRIST being superior to RIST. Notably, RIST/aRIST appeared to be apoptogenic evoked by reduction of anti-apoptotic protein levels of XIAP and BCL-2, with concomitant up-regulation of pro-apoptotic protein levels of p53 and BAX. The treatment success of RIST therapy was confirmed in an orthotopic mouse model. This combination treatment revealed significantly prolonged survival time and drastically reduced the tumor burden by acting anti-proliferative and pro-apoptotic. Surprisingly, in vivo, aRIST only marginally extended survival time with tumor volumes comparable to controls. We found that aRIST down-regulates the microvessel density suggesting an insufficient distribution of chemotherapy. Further, alterations in different molecular modes of action in vivo than in vitro suggest, that in vivo RIST therapy may mimic the superior aRIST protocol's pro-apoptotic inhibition of pAKT in vitro. Of note, all substances were administered in therapeutically relevant low doses with no adverse side effects observed. We also provide evidence of the potential benefits of the RIST therapy in a clinical setting. Our data indicates RIST therapy as a novel treatment strategy for glioblastoma achieving significant anti-tumorigenic activity avoiding high-dose chemotherapy. Topics: Adolescent; Animals; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Camptothecin; Cell Line, Tumor; Child; Dacarbazine; Female; Glioblastoma; Humans; Indoles; Irinotecan; Male; Membrane Potential, Mitochondrial; Mice, Inbred NOD; Molecular Targeted Therapy; Pyrroles; Sirolimus; Sunitinib; Temozolomide; Xenograft Model Antitumor Assays | 2015 |
Combination of the mTOR inhibitor RAD001 with temozolomide and radiation effectively inhibits the growth of glioblastoma cells in culture.
The present in vitro study aimed to assess the effects of combining the mTOR inhibitor RAD001 and temozolomide (TMZ) together with irradiation by either low-linear energy transfer (LET) radiation (γ-rays) or high-LET radiation (fast neutrons) on the growth and cell survival of the human glioblastoma cell line U-87. We observed a strong decrease in cell proliferation along with a concomitant increase in cell death as a function of the radiation dose. As expected, high-LET radiation was more effective and induced more sustained damage to DNA than low-LET radiation. While RAD001 in association with TMZ induced autophagic cell death, additional combination with either type of radiation did not further increase its occurrence. On the contrary, apoptosis remained at a low level in all experimental groups. Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Brain Neoplasms; Cell Proliferation; Cell Survival; Dacarbazine; DNA Damage; Dose-Response Relationship, Radiation; Everolimus; Gamma Rays; Glioblastoma; Histones; Humans; Linear Energy Transfer; Sirolimus; Temozolomide; TOR Serine-Threonine Kinases | 2015 |
Combination Therapy of Intraperitoneal Rapamycin and Convection- Enhanced Delivery of Nanoliposomal CPT-11 in Rodent Orthotopic Brain Tumor Xenografts.
Glioblastoma multiforme (GBM) is the most malignant histological type of glioma. It exhibits an extremely aggressive action including invasion of large zones of brain parenchyma. Even after the application of surgery, radio and chemotherapy, the effect and survival for patients with GBM continue to be very poor. The PI3K/AKT/mTOR is a key pathway in the regulation of the proliferation of cancer cells. This is the reason to consider the mTOR inhibitors such as rapamycin analogs as an encouraging therapy for malignant glioma, but current investigations suggest that single inhibition of mTOR may be insufficient. For this reason, there is a need for the use of more than one agent rationally combined.. In this study, we have evaluated the therapeutic potential of the combination of two different drugs: intraperitoneal rapamycin and convection enhanced delivery of nanoliposomes containing the topoisomerase I inhibitor CPT-11. The effect was analyzed by flow cytometry, cell growth, immunocytochemistry and immunohistochemistry, and rodent orthotopic xenograft survival analysis.. The combination presented remarkable efficacy in a survival study. We present an increase in survival of 6-fold in xenotransplanted animals without rise in toxicity.. In summary, we propose a very powerful new combination therapy for glioma. Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Camptothecin; Cell Line, Tumor; Drug Monitoring; Glioblastoma; Humans; Infusions, Parenteral; Irinotecan; Liposomes; Rats; Sirolimus; Topoisomerase I Inhibitors; TOR Serine-Threonine Kinases; Treatment Outcome; Xenograft Model Antitumor Assays | 2015 |
Combined treatment of Nimotuzumab and rapamycin is effective against temozolomide-resistant human gliomas regardless of the EGFR mutation status.
The treatment of glioblastoma multiforme (GBM) is an unmet clinical need. The 5-year survival rate of patients with GBM is less than 3%. Temozolomide (TMZ) remains the standard first-line treatment regimen for gliomas despite the fact that more than 90% of recurrent gliomas do not respond to TMZ after repeated exposure. We have also independently shown that many of the Asian-derived glioma cell lines and primary cells derived from Singaporean high-grade glioma patients are indeed resistant to TMZ. This issue highlights the need to develop new effective anti-cancer treatment strategies. In a recent study, wild-type epidermal growth factor receptor (wtEGFR) has been shown to phosphorylate a truncated EGFR (known as EGFRvIII), leading to the phosphorylation of STAT proteins and progression in gliomagenesis. Despite the fact that combination of EGFR targeting drugs and rapamycin has been used before, the effect of mono-treatment of Nimotuzumab, rapamycin and combination therapy in human glioma expressing different types of EGFR is not well-studied. Herein, we evaluated the efficacy of dual blockage using monoclonal antibody against EGFR (Nimotuzumab) and an mTOR inhibitor (rapamycin) in Caucasian patient-derived human glioma cell lines, Asian patient-derived human glioma cell lines, primary glioma cells derived from the Mayo GBM xenografts, and primary short-term glioma culture derived from high-grade glioma patients.. The combination effect of Nimotuzumab and rapamycin was examined in a series of primary human glioma cell lines and glioma cell lines. The cell viability was compared to TMZ treatment alone. Endogenous expressions of EGFR in various GBM cells were determined by western blotting.. The results showed that combination of Nimotuzumab with rapamycin significantly enhanced the therapeutic efficacy of human glioma cells compared to single treatment. More importantly, many of the Asian patient-derived glioma cell lines and primary cells derived from Singaporean high-grade gliomas, which showed resistance to TMZ, were susceptible to the combined treatments.. In conclusion, our results strongly suggest that combination usage of Nimotuzumab and rapamycin exert higher cytotoxic activities than TMZ. Our data suggest that this combination may provide an alternative treatment for TMZ-resistant gliomas regardless of the EGFR status. Topics: Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dacarbazine; Drug Resistance, Neoplasm; ErbB Receptors; Glioblastoma; Humans; Mutation; Sirolimus; Temozolomide | 2015 |
Response of subependymal giant cell astrocytoma with spinal cord metastasis to everolimus.
Brain subependymal giant cell astrocytomas (SEGAs) in patients with tuberous sclerosis have been reported to respond to everolimus.. A 15-year-old male patient with intractable seizures and multiple SEGAs of the brain developed leptomeningeal enhancement and multiple metastatic, histologically confirmed SEGAs of the spinal cord. He received daily everolimus at a dose of 3 mg/m for 6 weeks, which was then increased to 6 mg/m.. Magnetic resonance image of the brain and spine showed significant reduction in the size of SEGAs after 6 weeks of treatment. The patient has remained free of progression for 24 months. Additional benefits included: excellent seizure control, decrease in the size of cardiac rhabdomyomas, and improved quality of life.. We describe a rare case of metastatic SEGA, which was successfully treated with everolimus. Topics: Adolescent; Antineoplastic Agents; Astrocytoma; Brain Neoplasms; Everolimus; Humans; Male; Sirolimus; Spinal Cord Neoplasms; Treatment Outcome; Tuberous Sclerosis | 2014 |
MNK1 pathway activity maintains protein synthesis in rapalog-treated gliomas.
High levels of mammalian target of rapamycin complex 1 (mTORC1) activity in malignant gliomas promote tumor progression, suggesting that targeting mTORC1 has potential as a therapeutic strategy. Remarkably, clinical trials in patients with glioma revealed that rapamycin analogs (rapalogs) have limited efficacy, indicating activation of resistance mechanisms. Targeted depletion of MAPK-interacting Ser/Thr kinase 1 (MNK1) sensitizes glioma cells to the mTORC1 inhibitor rapamycin through an indistinct mechanism. Here, we analyzed how MNK1 and mTORC1 signaling pathways regulate the assembly of translation initiation complexes, using the cap analog m7GTP to enrich for initiation complexes in glioma cells followed by mass spectrometry-based quantitative proteomics. Association of eukaryotic translation initiation factor 4E (eIF4E) with eIF4E-binding protein 1 (4EBP1) was regulated by the mTORC1 pathway, whereas pharmacological blocking of MNK activity by CGP57380 or MNK1 knockdown, along with mTORC1 inhibition by RAD001, increased 4EBP1 binding to eIF4E. Furthermore, combined MNK1 and mTORC1 inhibition profoundly inhibited 4EBP1 phosphorylation at Ser65, protein synthesis and proliferation in glioma cells, and reduced tumor growth in an orthotopic glioblastoma (GBM) mouse model. Immunohistochemical analysis of GBM samples revealed increased 4EBP1 phosphorylation. Taken together, our data indicate that rapalog-activated MNK1 signaling promotes glioma growth through regulation of 4EBP1 and indicate a molecular cross-talk between the mTORC1 and MNK1 pathways that has potential to be exploited therapeutically. Topics: Aniline Compounds; Animals; Brain Neoplasms; Cell Line, Tumor; Eukaryotic Initiation Factor-4E; Female; Gene Expression Regulation, Neoplastic; Glioma; Humans; Immunohistochemistry; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Knockout; Mice, Nude; Multiprotein Complexes; Neoplasm Transplantation; Phosphorylation; Protein Binding; Protein Biosynthesis; Protein Serine-Threonine Kinases; Purines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2014 |
Combined EGFR and autophagy modulation impairs cell migration and enhances radiosensitivity in human glioblastoma cells.
Glioblastoma (GBM) remains the most aggressive and lethal brain tumor due to its molecular heterogeneity and high motility and invasion capabilities of its cells, resulting in high resistance to current standard treatments (surgery, followed by ionizing radiation combined with Temozolomide chemotherapy administration). Locus amplification, gene overexpression, and genetic mutations of epidermal growth factor receptor (EGFR) are hallmarks of GBM that can ectopically activate downstream signaling oncogenic cascades such as PI3K/Akt/mTOR pathway. Importantly, alteration of this pathway, involved also in the regulation of autophagy process, can improve radioresistance in GBM cells, thus promoting the aggressive phenotype of this tumor. In this work, the endogenous EGFR expression profile and autophagy were modulated to increase radiosensitivity behavior of human T98G and U373MG GBM cells. Our results primarily indicated that EGFR interfering induced radiosensitivity according to a decrease of the clonogenic capability of the investigated cells, and an effective reduction of the in vitro migratory features. Moreover, EGFR interfering resulted in an increase of Temozolomide (TMZ) cytotoxicity in T98G TMZ-resistant cells. In order to elucidate the involvement of the autophagy process as pro-death or pro-survival role in cells subjected to EGFR interfering, the key autophagic gene ATG7 was silenced, thereby producing a transient block of the autophagy process. This autophagy inhibition rescued clonogenic capability of irradiated and EGFR-silenced T98G cells, suggesting a pro-death autophagy contribution. To further confirm the functional interplay between EGFR and autophagy pathways, Rapamycin-mediated autophagy induction during EGFR modulation promoted further impairment of irradiated cells, in terms of clonogenic and migration capabilities. Taken together, these results might suggest a novel combined EGFR-autophagy modulation strategy, to overcome intrinsic GBM radioresistance, thus improving the efficacy of standard treatments. J. Cell. Physiol. 229: 1863-1873, 2014. © 2014 Wiley Periodicals, Inc. Topics: Autophagy; Autophagy-Related Protein 7; Brain Neoplasms; Cell Line, Tumor; Cell Movement; Clone Cells; Dacarbazine; Drug Resistance, Neoplasm; ErbB Receptors; Gene Silencing; Glioblastoma; Humans; Radiation Tolerance; Radiation, Ionizing; RNA, Small Interfering; Sirolimus; Temozolomide; Transfection; Ubiquitin-Activating Enzymes | 2014 |
P-glycoprotein, CYP3A, and plasma carboxylesterase determine brain and blood disposition of the mTOR Inhibitor everolimus (Afinitor) in mice.
To clarify the role of ABCB1, ABCG2, and CYP3A in blood and brain exposure of everolimus using knockout mouse models.. We used wild-type, Abcb1a/1b(-/-), Abcg2(-/-), Abcb1a/1b;Abcg2(-/-), and Cyp3a(-/-) mice to study everolimus oral bioavailability and brain accumulation.. Following everolimus administration, brain concentrations and brain-to-liver ratios were substantially increased in Abcb1a/1b(-/-)and Abcb1a/1b;Abcg2(-/-), but not Abcg2(-/-)mice. The fraction of everolimus located in the plasma compartment was highly increased in all knockout strains. In vitro, everolimus was rapidly degraded in wild-type but not knockout plasma. Carboxylesterase 1c (Ces1c), a plasma carboxylesterase gene, was highly upregulated (∼80-fold) in the liver of knockout mice relative to wild-type mice, and plasma Ces1c likely protected everolimus from degradation by binding and stabilizing it. This binding was prevented by preincubation with the carboxylesterase inhibitor BNPP. In vivo knockdown experiments confirmed the involvement of Ces1c in everolimus stabilization. Everolimus also markedly inhibited the hydrolysis of irinotecan and p-nitrophenyl acetate by mouse plasma carboxylesterase and recombinant human CES2, respectively. After correcting for carboxylesterase binding, Cyp3a(-/-), but not Abcb1a/1b(-/-), Abcg2(-/-), or Abcb1a/1b;Abcg2(-/-)mice, displayed highly (>5-fold) increased oral availability of everolimus.. Brain accumulation of everolimus was restricted by Abcb1, but not Abcg2, suggesting the use of coadministered ABCB1 inhibitors to improve brain tumor treatment. Cyp3a, but not Abcb1a/1b, restricted everolimus oral availability, underscoring drug-drug interaction risks via CYP3A. Upregulated Ces1c likely mediated the tight binding and stabilization of everolimus, causing higher plasma retention in knockout strains. This Ces upregulation might confound other pharmacologic studies. Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Biological Availability; Biological Transport; Brain Neoplasms; Carboxylic Ester Hydrolases; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Everolimus; Humans; Immunosuppressive Agents; Mice; Mice, Knockout; Sirolimus; Tissue Distribution | 2014 |
In vitro treatment of melanoma brain metastasis by simultaneously targeting the MAPK and PI3K signaling pathways.
Malignant melanoma is the most lethal form of skin cancer, with a high propensity to metastasize to the brain. More than 60% of melanomas have the BRAFV600E mutation, which activates the mitogen-activated protein kinase (MAPK) pathway [1]. In addition, increased PI3K (phosphoinositide 3-kinase) pathway activity has been demonstrated, through the loss of activity of the tumor suppressor gene, PTEN [2]. Here, we treated two melanoma brain metastasis cell lines, H1_DL2, harboring a BRAFV600E mutation and PTEN loss, and H3, harboring WT (wild-type) BRAF and PTEN loss, with the MAPK (BRAF) inhibitor vemurafenib and the PI3K pathway associated mTOR inhibitor temsirolimus. Combined use of the drugs inhibited tumor cell growth and proliferation in vitro in H1_DL2 cells, compared to single drug treatment. Treatment was less effective in the H3 cells. Furthermore, a strong inhibitory effect on the viability of H1_DL2 cells, when grown as 3D multicellular spheroids, was seen. The treatment inhibited the expression of pERK1/2 and reduced the expression of pAKT and p-mTOR in H1_DL2 cells, confirming that the MAPK and PI3K pathways were inhibited after drug treatment. Microarray experiments followed by principal component analysis (PCA) mapping showed distinct gene clustering after treatment, and cell cycle checkpoint regulators were affected. Global gene analysis indicated that functions related to cell survival and invasion were influenced by combined treatment. In conclusion, we demonstrate for the first time that combined therapy with vemurafenib and temsirolimus is effective on melanoma brain metastasis cells in vitro. The presented results highlight the potential of combined treatment to overcome treatment resistance that may develop after vemurafenib treatment of melanomas. Topics: Antineoplastic Agents; Brain Neoplasms; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Humans; Indoles; Melanoma; Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; Skin Neoplasms; Sulfonamides; TOR Serine-Threonine Kinases; Vemurafenib | 2014 |
[Therapeutic possibilities in refractory epilepsy in tuberous sclerosis complex].
Tuberous sclerosis complex (TSC) is frequently accompanied by difficult-to-treat epilepsy, which conditions these patients' quality of life and cognitive level. AIM. To describe the epidemiological and clinical characteristics, as well as the treatment of patients affected by TSC with epilepsy.. A retrospective review was carried out of the medical records of 30 patients aged under 18 registered in our database, who had been diagnosed with TSC and epilepsy.. The age at onset of epilepsy in the patients with TSC in our series ranged from one month to four years. All of them began with partial crises. Two presented West's syndrome and four others had infantile spasms without hypsarrhythmia. In 19 of the patients, the epilepsy was medication resistant. As regards treatment with antiepileptic drugs, 11 are in monotherapy, 10 in bitherapy, seven in tritherapy and one with four drugs. Two were given ACTH, two carry an implanted vagal nerve stimulator, four receive treatment with everolimus and eight have undergone surgery.. Epilepsy is a very common problem and begins in the early years of life in TSC. There are currently a large number of therapeutic options available, although 63.3% of patients have non-controlled epilepsy and most of them present crises on a daily basis. Poor control of their crises is correlated with mental retardation and autism spectrum disorder. The positive response obtained with other therapeutic possibilities, such as mTOR pathway inhibitors, surgery and vagal nerve stimulator, should be noted.. Posibilidades terapeuticas en la epilepsia refractaria en el complejo esclerosis tuberosa.. Introduccion. El complejo esclerosis tuberosa (CET) cursa frecuentemente con epilepsia de dificil control, lo que condiciona la calidad de vida y el nivel cognitivo de estos pacientes. Objetivo. Describir las caracteristicas epidemiologicas, clinicas y el tratamiento de los pacientes afectos de CET con epilepsia. Pacientes y metodos. Se han revisado retrospectivamente las historias clinicas de 30 pacientes menores de 18 años, diagnosticados de CET y epilepsia registrados en nuestra base de datos. Resultados. La edad de inicio de la epilepsia en los pacientes con CET en nuestra serie esta comprendida entre el primer mes de vida y los 4 años. Todos comenzaron con crisis parciales. Dos presentaron sindrome de West y cuatro, espasmos infantiles sin hipsarritmia. En 19 de los pacientes, la epilepsia se comporto como farmacorresistente. Respecto al tratamiento con farmacos antiepilepticos, 11 estan en monoterapia, 10 en biterapia, siete en triterapia y uno con cuatro farmacos. Dos recibieron ACTH, dos tienen implantado un estimulador del nervio vago, cuatro reciben tratamiento con everolimus y ocho han sido sometidos a cirugia. Conclusiones. La epilepsia es un problema muy frecuente y de inicio en los primeros años de vida en el CET. Las opciones terapeuticas actuales son muchas, sin embargo el 63,3% de los pacientes tiene una epilepsia no controlada y la mayoria de ellos presenta crisis diarias. El mal control de las crisis se correlaciona con retraso mental y trastorno del espectro autista. Señalar la respuesta positiva obtenida con otras posibilidades terapeuticas: inhibidores de la via mTOR, cirugia y el estimulador del nervio vago. Topics: Adrenocorticotropic Hormone; Age of Onset; Anticonvulsants; Astrocytoma; Brain Neoplasms; Child; Child Development Disorders, Pervasive; Child, Preschool; Combined Modality Therapy; Drug Resistance; Drug Therapy, Combination; Epilepsies, Partial; Everolimus; Female; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Retrospective Studies; Sirolimus; Spasms, Infantile; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Vagus Nerve Stimulation | 2014 |
Transformation of quiescent adult oligodendrocyte precursor cells into malignant glioma through a multistep reactivation process.
How malignant gliomas arise in a mature brain remains a mystery, hindering the development of preventive and therapeutic interventions. We previously showed that oligodendrocyte precursor cells (OPCs) can be transformed into glioma when mutations are introduced perinatally. However, adult OPCs rarely proliferate compared with their perinatal counterparts. Whether these relatively quiescent cells have the potential to transform is unknown, which is a critical question considering the late onset of human glioma. Additionally, the premalignant events taking place between initial mutation and a fully developed tumor mass are particularly poorly understood in glioma. Here we used a temporally controllable Cre transgene to delete p53 and NF1 specifically in adult OPCs and demonstrated that these cells consistently give rise to malignant gliomas. To investigate the transforming process of quiescent adult OPCs, we then tracked these cells throughout the premalignant phase, which revealed a dynamic multistep transformation, starting with rapid but transient hyperproliferative reactivation, followed by a long period of dormancy, and then final malignant transformation. Using pharmacological approaches, we discovered that mammalian target of rapamycin signaling is critical for both the initial OPC reactivation step and late-stage tumor cell proliferation and thus might be a potential target for both glioma prevention and treatment. In summary, our results firmly establish the transforming potential of adult OPCs and reveal an actionable multiphasic reactivation process that turns slowly dividing OPCs into malignant gliomas. Topics: Animals; Antineoplastic Agents; Blotting, Western; Brain Neoplasms; Cell Cycle; Cell Differentiation; Cell Proliferation; Cell Transformation, Neoplastic; Gene Expression Profiling; Glioma; Immunohistochemistry; Mice, Inbred NOD; Mice, Knockout; Mice, SCID; Mice, Transgenic; Neural Stem Cells; Neurofibromin 1; Oligodendroglia; Oligonucleotide Array Sequence Analysis; Sirolimus; Tamoxifen; Tumor Cells, Cultured; Tumor Suppressor Protein p53 | 2014 |
Cellular factors promoting resistance to effective treatment of glioma with oncolytic myxoma virus.
Oncolytic virus therapy is being evaluated in clinical trials for human glioma. While it is widely assumed that the immune response of the patient to the virus infection limits the utility of the therapy, investigations into the specific cell type(s) involved in this response have been performed using nonspecific pharmacologic inhibitors or allogeneic models with compromised immunity. To identify the immune cells that participate in clearing an oncolytic infection in glioma, we used flow cytometry and immunohistochemistry to immunophenotype an orthotopic glioma model in immunocompetent mice after Myxoma virus (MYXV) administration. These studies revealed a large resident microglia and macrophage population in untreated tumors, and robust monocyte, T-, and NK cell infiltration 3 days after MYXV infection. To determine the role on the clinical utility of MYXV therapy for glioma, we used a combination of knockout mouse strains and specific immunocyte ablation techniques. Collectively, our experiments identify an important role for tumor-resident myeloid cells and overlapping roles for recruited NK and T cells in the clearance and efficacy of oncolytic MYXV from gliomas. Using a cyclophosphamide regimen to achieve lymphoablation prior and during MYXV treatment, we prevented treatment-induced peripheral immunocyte recruitment and, surprisingly, largely ablated the tumor-resident macrophage population. Virotherapy of cyclophosphamide-treated animals resulted in sustained viral infection within the glioma as well as a substantial survival advantage. This study demonstrates that resistance to MYXV virotherapy in syngeneic glioma models involves a multifaceted cellular immune response that can be overcome with cyclophosphamide-mediated lymphoablation. Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Cyclophosphamide; Flow Cytometry; Glioma; Humans; Immunity, Cellular; Killer Cells, Natural; Mice; Myxoma virus; Oncolytic Virotherapy; Oncolytic Viruses; Sirolimus; Xenograft Model Antitumor Assays | 2014 |
FDA approves first drug formulated for children with rare brain tumor.
Topics: Administration, Oral; Antineoplastic Agents; Astrocytoma; Brain Neoplasms; Child; Everolimus; Humans; Sirolimus | 2013 |
Treating brain tumor-initiating cells using a combination of myxoma virus and rapamycin.
Intratumoral heterogeneity in glioblastoma multiforme (GBM) poses a significant barrier to therapy in certain subpopulation such as the tumor-initiating cell population, being shown to be refractory to conventional therapies. Oncolytic virotherapy has the potential to target multiple compartments within the tumor and thus circumvent some of the barriers facing conventional therapies. In this study, we investigate the oncolytic potential of myxoma virus (MYXV) alone and in combination with rapamycin in vitro and in vivo using human brain tumor-initiating cells (BTICs).. We cultured fresh GBM specimens as neurospheres and assayed their growth characteristics in vivo. We then tested the susceptibility of BTICs to MYXV infection with or without rapamycin in vitro and assessed viral biodistribution/survival in vivo in orthotopic xenografts.. The cultured neurospheres were found to retain stem cell markers in vivo, and they closely resembled human infiltrative GBM. In this study we determined that (i) all patient-derived BTICs tested, including those resistant to temozolomide, were susceptible to MYXV replication and killing in vitro; (ii) MYXV replicated within BTICs in vivo, and intratumoral administration of MYXV significantly prolonged survival of BTIC-bearing mice; (iii) combination therapy with MYXV and rapamycin improved antitumor activity, even in mice bearing "advanced" BTIC tumors; (iv) MYXV treatment decreased expression of stem cell markers in vitro and in vivo.. Our study suggests that MYXV in combination with rapamycin infects and kills both the BTICs and the differentiated compartments of GBM and may be an effective treatment even in TMZ-resistant patients. Topics: Animals; Antibiotics, Antineoplastic; Apoptosis; Blotting, Western; Brain Neoplasms; Cell Proliferation; Combined Modality Therapy; Female; Flow Cytometry; Fluorescent Antibody Technique; Glioblastoma; Green Fluorescent Proteins; Humans; Immunoenzyme Techniques; Luciferases; Mice; Mice, SCID; Myxoma virus; Neoplastic Stem Cells; Oncolytic Virotherapy; Poxviridae Infections; Sirolimus; Tumor Cells, Cultured; Tumor Virus Infections; Virus Replication; Xenograft Model Antitumor Assays | 2013 |
Arsenic reverses glioblastoma resistance to mTOR-targeted therapies.
Topics: Antineoplastic Agents; Arsenic Trioxide; Arsenicals; Brain Neoplasms; Drug Resistance, Neoplasm; ErbB Receptors; Erlotinib Hydrochloride; Glioblastoma; Humans; Leukemia, Promyelocytic, Acute; Oxides; Quinazolines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2013 |
The mTOR inhibitor RAD001 potentiates autophagic cell death induced by temozolomide in a glioblastoma cell line.
We have studied the consequences of the combination of the mammalian target of rapamycin (mTOR) inhibitor RAD001 and temozolomide on the growth and cell death of the glioblastoma cell line U-87 in vitro. A progressive decrease of cell proliferation was recorded with increasing concentrations of temozolomide, which was markedly reinforced and prolonged by the addition of RAD001. While this combination treatment resulted in only a low level of apoptosis, it led to a pronounced enhancement of autophagic cell death. When combined with γ-ray irradiation, a significant reinforcement of the overall cytotoxicity was obtained, suggesting the efficacy of such a multipronged approach for the treatment of glioblastoma. RAD001 strongly contributes to the reinforcement of temozolomide-induced autophagy, which appears to represent a major form of cell death in glioblastoma. The association of such combined chemotherapies with radiotherapy could be useful for the management of these hard-to-treat malignancies. Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Blotting, Western; Brain Neoplasms; Cell Proliferation; Cesium Radioisotopes; Dacarbazine; Drug Synergism; Everolimus; Flow Cytometry; Gamma Rays; Glioblastoma; Humans; Sirolimus; Temozolomide; TOR Serine-Threonine Kinases; Tumor Cells, Cultured | 2013 |
Prognostic factors of survival for patients with metastatic renal cell carcinoma with brain metastases treated with targeted therapy: results from the international metastatic renal cell carcinoma database consortium.
The outcomes and prognosis of patients with brain metastases from advanced renal cell carcinoma (RCC) are not well characterized in the targeted-therapy era.. Data from patients with metastatic RCC (mRCC) and brain metastases treated with targeted therapy were collected through the International Metastatic Renal Cell Carcinoma Database Consortium from 7 cancer centers.. Overall, 106 (15%) of 705 patients with mRCC had brain metastases. Forty-seven patients had brain metastases at the start of first-line anti-vascular endothelial growth factor therapy, and the rest developed metastases during follow-up. Of the patients with brain metastases, 12%, 42% and 29% were in the favorable, intermediate, and poor prognosis groups, respectively, per the Heng criteria. Ninety percent had cerebral metastases, 17% had cerebellar metastases, 37% had a Karnofsky performance status (KPS) <80%, and 80% had neurologic symptoms at presentation. The median largest size and number of brain metastases was 1.8 cm (range, 0.2-6.6 cm) and one (range, 1 to innumerable), respectively. The patients were treated with sunitinib (n = 77), sorafenib (n = 23), bevacizumab (n = 5), and temsirolimus (n = 1). Local disease treatment included whole brain radiotherapy (81%), stereotactic radiosurgery (25%), and neurosurgery (25%). On multivariable analysis, KPS < 80%, diagnosis to treatment with targeted therapy <1 year, and a higher number of brain metastases (>4) was associated with worse survival from the time of diagnosis with brain metastases.. Patients with brain metastases from RCC are unlikely to be in the favorable risk group. KPS at the start of therapy, diagnosis to treatment time, and the number of brain metastases are prognostic factors for overall survival. Topics: Angiogenesis Inhibitors; Antibodies, Monoclonal, Humanized; Bevacizumab; Brain Neoplasms; Carcinoma, Renal Cell; Databases, Factual; Humans; Indoles; Kidney Neoplasms; Molecular Targeted Therapy; Niacinamide; Phenylurea Compounds; Protein Kinase Inhibitors; Pyrroles; Sirolimus; Sorafenib; Sunitinib; Survival; Treatment Outcome | 2013 |
Successful everolimus therapy for SEGA in pediatric patients with tuberous sclerosis complex.
Tuberous sclerosis complex (TSC) is associated with hamartomatous growths including subependymal giant cell astrocytomas (SEGAs). Although, SEGAs are slow-growing glioneuronal tumors, they represent a significant cause of morbidity and mortality due to the risk of sudden death from acute hydrocephalus. Neurosurgical resection has been the mainstay of therapy, since radiotherapy and chemotherapy were proved inefficient in those tumors. Recent studies support the use of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis and suggest it might represent a disease-modifying treatment for other aspects of tuberous sclerosis.. We describe the clinical and radiological progression of three pediatric patients with definitive diagnosis of TSC and SEGA, which have been treated with everolimus.. Up to 34 % sustained SEGA decrease was observed in the three cases. All three patients have experienced seizure control and two of them have showed cognitive and behavioral improvement. Everolimus has been well tolerated by all. No severe adverse events have been observed to date.. Everolimus offers significant promise in treating SEGAs. Studies are required to explore optimal therapy duration and management upon discontinuing therapy. Topics: Adolescent; Antineoplastic Agents; Astrocytoma; Brain Neoplasms; Child, Preschool; Everolimus; Female; Humans; Male; Sirolimus; Tuberous Sclerosis | 2013 |
Targeting cancer stem cells in glioblastoma multiforme using mTOR inhibitors and the differentiating agent all-trans retinoic acid.
Glioblastoma multiforme (GBM), the most aggressive primary brain tumor, portends a poor prognosis despite current treatment modalities. Recurrence of tumor growth is attributed to the presence of treatment-resistant cancer stem cells (CSCs). The targeting of these CSCs is therefore essential in the treatment of this disease. Mechanistic target of rapamycin (mTOR) forms two multiprotein complexes, mTORC1 and mTORC2, which regulate proliferation and migration, respectively. Aberrant function of mTOR has been shown to be present in GBM CSCs. All-trans retinoic acid (ATRA), a derivative of retinol, causes differentiation of CSCs as well as normal neural progenitor cells. The purpose of this investigation was to delineate the role of mTOR in CSC maintenance, and to establish the mechanism of targeting GBM CSCs using differentiating agents along with inhibitors of the mTOR pathways. The results demonstrated that ATRA caused differentiation of CSCs, as demonstrated by the loss of the stem cell marker Nestin. These observations were confirmed by western blotting, which demonstrated a time-dependent decrease in Nestin expression following ATRA treatment. This effect occurred despite combination with mTOR (rapamycin), PI3K (LY294002) and MEK1/2 (U0126) inhibitors. Expression of activated extracellular signal-regulated kinase 1/2 (pERK1/2) was enhanced following treatment with ATRA, independent of mTOR pathway inhibitors. Proliferation of CSCs, determined by neurosphere diameter, was decreased following treatment with ATRA alone and in combination with rapamycin. The motility of GBM cells was mitigated by treatment with ATRA, rapamycin and LY29002 alone. However, combination treatment augmented the inhibitory effect on migration suggesting synergism. These findings indicate that ATRA-induced differentiation is mediated via the ERK1/2 pathway, and underscores the significance of including differentiating agents along with inhibitors of mTOR pathways in the treatment of GBM. Topics: Antibiotics, Antineoplastic; Brain Neoplasms; Butadienes; Cell Differentiation; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chromones; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Glioblastoma; Humans; MAP Kinase Kinase 1; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Morpholines; Multiprotein Complexes; Neoplastic Stem Cells; Nestin; Nitriles; Phosphoinositide-3 Kinase Inhibitors; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tretinoin | 2013 |
[Is the same tyrosine kinase inhibitor still effective after development of brain metastases? A Case report].
There is a new era of treatment options since introduction of new biological targeted therapies (tyrosine kinase inhibitors (TKIs) and mammalian target of rapamycin (mTOR) inhibitors) in renal cell cancer. However, in patients who developed brain metastases, there is still treatment dilemma about an optimal therapeutic scenario, particularly in the subgroup of patients with-out disease progression outside the central nervous system. The objective of this case report is to present that it is possible to continue the same targeted therapy after development of brain metastasis after application of local whole brain irradiation with meaningful overall survival. Topics: Aged; Antineoplastic Agents; Brain Neoplasms; Carcinoma, Renal Cell; Disease Progression; Enzyme Inhibitors; Humans; Indoles; Kidney Neoplasms; Male; Protein-Tyrosine Kinases; Pyrroles; Sirolimus; Sunitinib; TOR Serine-Threonine Kinases; Treatment Outcome | 2013 |
Subependymal giant cell astrocytoma: diagnosis, screening, and treatment. Recommendations from the International Tuberous Sclerosis Complex Consensus Conference 2012.
Tuberous sclerosis complex is an autosomal dominant disorder predisposing to the development of benign lesions in different body organs, mainly in the brain, kidney, liver, skin, heart, and lung. Subependymal giant cell astrocytomas are characteristic brain tumors that occur in 10% to 20% of tuberous sclerosis complex patients and are almost exclusively related to tuberous sclerosis complex. Subependymal giant cell astrocytomas usually grow slowly, but their progression ultimately leads to the occlusion of the foramen of Monro, with subsequent increased intracranial pressure and hydrocephalus, thus necessitating intervention. During recent years, secondary to improved understanding in the biological and genetic basis of tuberous sclerosis complex, mammalian target of rapamycin inhibitors have been shown to be effective in the treatment of subependymal giant cell astrocytomas, becoming an alternative therapeutic option to surgery.. In June 2012, an International Tuberous Sclerosis Complex Consensus Conference was convened, during which an expert panel revised the diagnostic criteria and considered treatment options for subependymal giant cell astrocytomas. This article summarizes the subpanel's recommendations regarding subependymal giant cell astrocytomas.. Mammalian target of rapamycin inhibitors have been shown to be an effective treatment of various aspects of tuberous sclerosis complex, including subependymal giant cell astrocytomas. Both mammalian target of rapamycin inhibitors and surgery have a role in the treatment of subependymal giant cell astrocytomas. Various subependymal giant cell astrocytoma-related conditions favor a certain treatment. Topics: Adolescent; Adult; Astrocytoma; Brain Neoplasms; Child; Congresses as Topic; Female; Guidelines as Topic; Humans; Immunosuppressive Agents; Magnetic Resonance Imaging; Male; Sirolimus; Tuberous Sclerosis; Young Adult | 2013 |
Rapamycin inhibits the growth of glioblastoma.
The molecular target of rapamycin (mTOR) is up-regulated in glioblastoma (GBM) and this is associated with the rate of cell growth, stem cell proliferation and disease relapse. Rapamycin is a powerful mTOR inhibitor and strong autophagy inducer. Previous studies analyzed the effects of rapamycin in GBM cell lines. However, to our knowledge, no experiment was carried out to evaluate the effects of rapamycin neither in primary cells derived from GBM patients nor in vivo in brain GBM xenograft. These data are critical to get a deeper insight into the effects of such adjuvant therapy in GBM patients. In the present study, various doses of rapamycin were tested in primary cell cultures from GBM patients. These effects were compared with that obtained by the same doses of rapamycin in GBM cell lines (U87Mg). The effects of rapamycin were also evaluated in vivo, in brain tumors developed from mouse xenografts. Rapamycin, starting at the dose of 10nm inhibited cell growth both in U87Mg cell line and primary cell cultures derived from various GBM patients. When administered in vivo to brain xenografts in nude mice rapamycin almost doubled the survival time of mice and inhibited by more than 95% of tumor volume. Topics: Animals; Antibiotics, Antineoplastic; Blotting, Western; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Flow Cytometry; Glioblastoma; Humans; Mice; Mice, Nude; Microscopy, Electron, Transmission; Sirolimus; Xenograft Model Antitumor Assays | 2013 |
EGF signalling and rapamycin-mediated mTOR inhibition in glioblastoma multiforme evaluated by phospho-specific flow cytometry.
Development of novel patient stratification tools for cancer is a challenge that require advanced molecular screening and a detailed understanding of tumour signalling networks. Here, we apply phospho-specific flow cytometry for signal profiling of primary glioblastoma tumours after preservation of single-cell phosphorylation status as a strategy for evaluation of tumour signalling potential and assessment of rapamycin-mediated mTOR inhibition. The method has already enhanced insight into cancers and disorders of the immune system, and our study demonstrate a great potential to improve the understanding of aberrant signalling in glioblastoma and other solid tumours. Topics: Antibiotics, Antineoplastic; Base Sequence; Brain Neoplasms; Cell Proliferation; Epidermal Growth Factor; Flow Cytometry; Gene Expression Regulation, Neoplastic; Gene Library; Glioblastoma; Humans; Phosphorylation; Signal Transduction; Sirolimus; Time Factors; TOR Serine-Threonine Kinases; Tumor Cells, Cultured | 2013 |
The effect of mTOR inhibition alone or combined with MEK inhibitors on brain metastasis: an in vivo analysis in triple-negative breast cancer models.
mTOR inhibitor rapamycin and its analogs are lipophilic, demonstrate blood-brain barrier penetration, and have shown promising antitumor effects in several types of refractory tumors. We thus try to explore the therapeutic effects of mTOR inhibitors on brain metastasis models. We examined the effects of different dose of mTOR inhibitors (rapamycin, Temsirolimus-CCI-779) on cell invasion in two brain metastatic breast cancer cell lines (MDA-MB231-BR and CN34-BrM2). Antibody microarray and immunoblotting were applied to detect signaling pathways underlying the dose differential drug effects. The in vivo effects of single drug (CCI-779), and drug combination of CCI-779 with SL327 (a brain penetrant MEK inhibitor) to eliminate the unfavorable activation of MAPK pathway were evaluated in MDA-MB231-BR brain metastases xenograft mice. The two mTOR inhibitors, rapamycin and CCI-779, inhibited the invasion of brain metastatic cells only at a moderate concentration level, which was lost at higher concentrations secondary to activation of the MAPK signaling pathway. Pharmacological inhibition of ERK1/2 by PD98059 and SL327 restored the anti-invasion effects of mTOR inhibition in vitro. In vivo, a significant decrease was noted in the average number of micro and large metastatic lesions as well as the whole brain GFP expression in the CCI-779 1 mg/kg/day treated group compared with that in the vehicle group (P < 0.05). However, 10 mg/kg CCI-779 treatment did not show significant anti-metastasis effect on the animal model. High-dose CCI-779 eliciting the ERK MAPK activation in the brain metastatic lesion was corroborated. Combined with the brain penetrant MEK inhibitor SL327, high-dose CCI-779 significantly reduces the brain metastasis, and the combination treatment prohibited perivascular invasion of tumor cells and inhibits tumor angiogenesis in vivo. This study provides evidence on the potential value of CCI-779 as well as CCI-779 + SL327 in prohibiting breast cancer brain metastasis. Topics: Aminoacetonitrile; Animals; Antineoplastic Agents; Brain Neoplasms; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Female; Humans; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Mice, Nude; Mitogen-Activated Protein Kinase Kinases; Neoplasm Invasiveness; Neovascularization, Pathologic; Protein Kinase Inhibitors; Sirolimus; TOR Serine-Threonine Kinases | 2012 |
Hyperpolarized 13C MR spectroscopic imaging can be used to monitor Everolimus treatment in vivo in an orthotopic rodent model of glioblastoma.
Glioblastoma (GBM) is the most common and lethal primary malignant brain tumor in humans. Because the phosphatidylinositol-3-kinase (PI3K) signaling pathway is activated in more than 88% of GBM, new drugs which target this pathway, such as the mTOR inhibitor Everolimus, are currently in clinical trials. Early tumor response to molecularly targeted treatments remains challenging to assess non-invasively, because it is often associated with tumor stasis or slower tumor growth. Innovative neuroimaging methods are therefore critically needed to provide metabolic or functional information that is indicative of targeted therapeutic action at early time points during the course of treatment. In this study, we demonstrated for the first time that hyperpolarized (HP) 13C magnetic resonance spectroscopic imaging (MRSI) can be used on a clinical MR system to monitor early metabolic response of orthotopic GBM tumors to Everolimus treatment through measurement of the HP lactate-to-pyruvate ratios. The study was performed on a highly invasive non-enhancing orthotopic GBM tumor model in rats (GS-2 tumors), which replicates many fundamental features of human GBM tumors. Seven days after initiation of treatment there was a significant drop in the HP lactate-to-pyruvate ratio from the tumor tissue in treated animals relative to day 0 (67%±27% decrease). In the control group, no significant changes in the HP lactate-to-pyruvate ratios were observed. Importantly, at the 7 day time point, conventional MR imaging (MRI) was unable to detect a significant difference in tumor size between control and treated groups. Inhibition of tumor growth by conventional MRI was observed from day 15 of treatment. This implies that the decrease in the HP lactate-to-pyruvate ratio could be detected before any treatment-induced inhibition of tumor growth. Using immunohistochemical staining to further examine tumor response to treatment, we found that the decrease in the HP lactate-to-pyruvate ratio was associated with a drop in expression of lactate dehydrogenase, the enzyme that catalyzes pyruvate to lactate conversion. Also evident was decreased staining for carbonic anhydrase IX (CA-IX), an indicator of hypoxia-inducible factor 1α (HIF-1α) activity, which, in turn, regulates expression of lactate dehydrogenase. To our knowledge, this study is the first report of the use of HP 13C MRSI at a clinical field strength to monitor GBM response to molecularly targeted treatments. It highlights the po Topics: Animals; Antineoplastic Agents; Brain Neoplasms; Carbon Radioisotopes; Disease Models, Animal; Everolimus; Glioblastoma; Humans; Magnetic Resonance Spectroscopy; Male; Neuroimaging; Rats; Rats, Nude; Sirolimus; Xenograft Model Antitumor Assays | 2012 |
Different involvement of autophagy in human malignant glioma cell lines undergoing irradiation and temozolomide combined treatments.
Glioblastoma (GB) has a poor prognosis, despite current multimodality treatment. Beside surgical resection, adjuvant ionizing radiation (IR) combined with Temozolomide (TMZ) drug administration is the standard therapy for GB. This currently combined radio-chemotherapy treatment resulted in glial tumor cell death induction, whose main molecular death pathways are still not completely deciphered. In this study, the autophagy process was investigated, and in vitro modulated, in two different GB cell lines, T98G and U373MG (known to differ in their radiosensitivity), after IR or combined IR/TMZ treatments. T98G cells showed a high radiosensitivity (especially at low and intermediate doses), associated with autophagy activation, assessed by Beclin-1 and Atg-5 expression increase, LC3-I to LC3-II conversion and LC3B-GFP accumulation in autophagosomes of irradiated cells; differently, U373MG cells resulted less radiosensitive. Autophagy inhibition, using siRNA against BECN1 or ATG-7 genes, totally prevented decrease in viability after both IR and IR/TMZ treatments in the radiosensitive T98G cells, confirming the autophagy involvement in the cytotoxicity of these cells after the current GB treatment, contrary to U373MG cells. However, rapamycin-mediated autophagy, that further radiosensitized T98G, was able to promote radiosensitivty also in U373MG cells, suggesting a role of autophagy process in enhancing radiosensitivity. Taken together, these results might enforce the concept that autophagy-associated cell death might constitute a possible adjuvant therapeutic strategy to enhance the conventional GB treatment. Topics: Apoptosis Regulatory Proteins; Autophagy; Autophagy-Related Protein 5; Beclin-1; Brain Neoplasms; Cell Line, Tumor; Cell Survival; Combined Modality Therapy; Dacarbazine; Glioblastoma; Humans; Membrane Proteins; Microtubule-Associated Proteins; Radiation-Sensitizing Agents; RNA Interference; RNA, Small Interfering; Sirolimus; Temozolomide | 2012 |
Systemic rapamycin alone may not be a treatment option for malignant glioma: evidence from an in vivo study.
The mammalian target of rapamycin (mTOR) plays a central role in regulating the proliferation of cancer cells, and mTOR-specific inhibitors such as rapamycin analogs are considered as a promising therapy for malignant glioma. In this study, we investigated the possibility of using mTOR inhibitors to treat gliomas. We used a molecular marker, phosphorylation of S6 protein, to monitor biological effects of mTOR inhibitors within xenografts. Phosphorylation was decreased more in U87MG glioma after treatment with high doses of rapamycin or its analog, torisel (10 mg/kg or 25 mg/kg), but only slightly after a low dose of rapamycin (3 mg/kg). This effect correlated with enhanced survival of rats after weekly peritoneal injections of both drugs at the highest two doses but not at the low dose. High doses of both drugs caused weight loss in rats. Clinical trial data indicates that low doses of Torisel (<3 mg/kg) were not efficacious in recurrent GBM. It is concluded that systemic administration of rapamycin analogues may not be a treatment option for patients with malignant glioma due to the intolerability of high doses that might otherwise be effective. The present study underscores the need for better pre-clinical evaluation of drugs with respect to therapeutic window. Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Glioma; Humans; Immunosuppressive Agents; Male; Neoplasm Transplantation; Phosphorylation; Protein Kinases; Rats; Rats, Nude; Sirolimus; Time Factors; Xenograft Model Antitumor Assays | 2012 |
Brain metastasis in a patient with a sarcomatoid variant RCC with well-controlled extracerebral metastases by temsirolimus.
The sarcomatoid variant of metastatic renal cell carcinoma (RCC) has often an aggressive course and a poor prognosis, particularly when accompanied with brain metastasis.. We describe the case of a patient with sarcomatoid variant RCC in whom brain metastasis was observed as a new lesion during treatment with temsirolimus, despite other extracerebral metastatic lesions being well-controlled and progression-free.. This discrepancy between the effectiveness of temsirolimus for extracerebral metastases and the simultaneous progression of brain metastases of RCC raises a concern that while vascular endothelial growth factor (VEGF)-targeted therapy may have clinical efficacy, it may also carry a risk for new brain metastases due to weakening of the structure of the blood brain barrier.. This case indicates that computed tomography monitoring of the brain should be regularly performed during VEGF-targeted therapy in patients with sarcomatoid variant RCC, even if brain metastases are absent and extracerebral metastatic lesions are well controlled. Topics: Antineoplastic Agents; Brain Neoplasms; Carcinoma, Renal Cell; Humans; Kidney Neoplasms; Neoplasm Metastasis; Sirolimus | 2012 |
Do anti-angiogenic therapies prevent brain metastases in advanced renal cell carcinoma?
We analyzed renal cell carcinoma (RCC) brain metastasis (BM) risk factors and compared BM occurrence in metastatic RCC (mRCC) treated with or without anti-angiogenic agents (AA).. Data from all consecutive metastatic RCC patients (patients) treated in a french cancer center between 1995 and 2008 were reviewed. Patients had histologically confirmed advanced RCC without synchronous BM at the time of metastasis diagnosis. AA were sorafenib, sunitinib and bevacizumab. We also included patients treated with mTor inhibitors, temsirolimus and everolimus, as they also demonstrated anti-angiogenic activities. Characteristics of the two groups treated with or without AA were compared with a Fisher exact test. Impact of AA on overall survival (OS) and cumulative rate of brain metastasis (CRBM) was explored by Kaplan-Meier method.. One hundred and ninety-nine patients with advanced RCC were identified, 51 treated with AA and 148 without AA. The median follow-up duration was 40 months. BM occurred in 35 patients. Characteristics between AA treated and non-AA treated groups were unbalanced and favoring better prognostic factors in AA treated group. Median OS was 24 months. AA treatment was not associated with a lower CRBM (HR = 0.58 [0.26-1.30], P = 0.187). Median survival free of BM was 11.8 months, CI95% (4.95-18.65) in the group without AA treatment and 28.9 months in the AA group, CI95% (18.64-39.16). Alkaline phosphatase (AP) was an independent prognostic factor for BM (P = 0.05). In multivariate Cox model, after adjustment to AP, AA did not improve the CRBM (aHR = 0.53 [0.22-1.32]).. In this retrospective study, AA did not decrease significantly the CRBM. Elevated AP was a predictive factor for BM in mRCC. Topics: Adult; Aged; Aged, 80 and over; Alkaline Phosphatase; Angiogenesis Inhibitors; Antibodies, Monoclonal, Humanized; Benzenesulfonates; Bevacizumab; Brain Neoplasms; Cancer Care Facilities; Carcinoma, Renal Cell; Everolimus; Female; France; Humans; Indoles; Kidney Neoplasms; Male; Middle Aged; Niacinamide; Phenylurea Compounds; Proportional Hazards Models; Pyridines; Pyrroles; Retrospective Studies; Risk Factors; Sirolimus; Sorafenib; Sunitinib; Treatment Outcome | 2012 |
Prolonged natural progression from localized to symptomatic renal cell carcinoma.
Surgical excision is the gold standard therapy for clinically localized renal masses. Nevertheless, prognostication of the natural history of untreated renal cell carcinoma (RCC) remains a clinical challenge. While active surveillance (AS) has emerged as a viable treatment option in select patients with localized tumors and significant competing mortality risks, long term follow up data to assess the risk of disease progression are limited. We present a case of a localized, clinical stage T2 renal mass progressing to regional and systemic disease over 6 years, demonstrating that kinetics of disease progression may be prolonged and are yet to be fully understood. Topics: Aged; Biopsy, Needle; Brain Neoplasms; Carcinoma, Renal Cell; Disease Progression; Drug Delivery Systems; Follow-Up Studies; Humans; Immunohistochemistry; Kidney Neoplasms; Lymph Node Excision; Lymph Nodes; Male; Neoplasm Staging; Nephrectomy; Risk Assessment; Sirolimus; Time Factors; Tomography, X-Ray Computed | 2012 |
mTORC1 activation in childhood ependymoma and response to sirolimus.
Recurrent ependymomas are considered rarely responsive to chemotherapy and often have a dismal prognosis after tumor progression. Below is a brief report of a 6 year old child with a multiply progressive ependymoma whose tumor had a near complete response to sirolimus that was durable for 18 months. Immunohistochemistry for phosphorylated S6, which has been reported to be associated with tumor sensitivity to mTORC1 inhibitors, was positive in this patient's tumor. Topics: Brain Neoplasms; Child, Preschool; Ependymoma; Humans; Immunosuppressive Agents; Magnetic Resonance Imaging; Male; Ribosomal Protein S6; Serine; Sirolimus; TOR Serine-Threonine Kinases | 2011 |
Everolimus and giant-cell astrocytomas in tuberous sclerosis.
Topics: Astrocytoma; Brain Neoplasms; Everolimus; Humans; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis | 2011 |
Everolimus and giant-cell astrocytomas in tuberous sclerosis.
Topics: Amino Acid Transport System y+L; Antibiotic Prophylaxis; Astrocytoma; Brain Neoplasms; Everolimus; Humans; Leukocyte Count; Opportunistic Infections; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis | 2011 |
Induction of autophagy promotes differentiation of glioma-initiating cells and their radiosensitivity.
Glioblastoma (GBM) is a highly aggressive brain tumor characterized by increased proliferation and resistance to chemotherapy and radiotherapy. Recently, the identification of tumor-initiating cells with stem-like properties in diverse human cancers including GBM represents an important conceptual advance in cancer biology with therapeutic implications. However, the factors determining the differential development and radiosensitization of glioma-initiating cells (GICs) remain poorly defined. Here, we report that rapamycin induced differentiation of GICs and increased their sensitivity to radiation by activating autophagy. Transient in vitro exposure to rapamycin and radiation abolished the capacity of transplanted GICs to establish intracerebral GBMs. Most importantly, in vivo combination of rapamycin and radiation effectively blocked the tumor growth and associated mortality that occurs in mice after intracerebral grafting of human GICs. We demonstrate that rapamycin activated their autophagy and triggers the differentiation cascade in GICs isolated from human GBMs. This was followed by a reduction in proliferation, cell viability, clonogenic ability and increased expression of neural differentiation markers after radiation. Our results suggest that autophagy plays an essential role in the regulation of self-renewal, differentiation, tumorigenic potential and radiosensitization of GICs, suggesting autophagy could be a promising therapeutic target in a subset of GBMs. We propose that autophagy defect in GICs contributes to radioresistance of GICs by desensitizing GICs to normal differentiation cues. Activating autophagy may abrogate the resistance of GICs to radiation and could lead to the development of novel therapeutic approaches for the treatment of GBMs. Topics: Animals; Antibiotics, Antineoplastic; Autophagy; Blotting, Western; Brain Neoplasms; Cell Differentiation; Cell Proliferation; Glioblastoma; Humans; Mice; Neoplastic Stem Cells; Radiation Tolerance; Sirolimus; Tumor Cells, Cultured; Tumor Stem Cell Assay; X-Rays | 2011 |
Potential of mTOR inhibitors for the treatment of subependymal giant cell astrocytomas in tuberous sclerosis complex.
Rapamycin inhibits the mTOR (target of rapamycin) pathway and extends lifespan in multiple species. The tuberous sclerosis complex (TSC) protein is a negative regulator of mTOR. In humans, loss of the TSC protein results in a disorder characterized clinically by the growth of benign tumors in multiple organs, due to overactivation of mTOR inhibition. Subependymal giant cell astrocytomas (SEGAs) are benign brain tumors associated with TSC that have traditionally been treated by surgery, but for which mTOR inhibitors have recently been suggested as potential alternative treatments. The duration of mTOR treatment for SEGAs might have to be prolonged, probably lifelong, because SEGAs usually grow back after treatment is stopped. This cohort of patients who will experience prolonged exposure to mTOR inhibitors should be carefully followed longitudinally to better document long term side effects, but also to compare their longevity with the one of similar patients with TSC. These patients represent a unique opportunity to study the potential anti-aging properties of mTOR inhibitors in humans. Topics: Aging; Astrocytoma; Brain Neoplasms; Everolimus; Humans; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis | 2011 |
Myxoma virus combined with rapamycin treatment enhances adoptive T cell therapy for murine melanoma brain tumors.
Adoptive transfer of tumor-specific T cells has shown some success for treating metastatic melanoma. We evaluated a novel strategy to improve adoptive therapy by administering both T cells and oncolytic myxoma virus to mice with syngeneic B16.SIY melanoma brain tumors. Adoptive transfer of activated CD8(+) 2C T cells that recognize SIY peptide doubled survival time, but SIY-negative tumors recurred. Myxoma virus killed B16.SIY cells in vitro, and intratumoral injection of virus led to selective and transient infection of the tumor. Virus treatment recruited innate immune cells to the tumor and induced IFNβ production in the brain, resulting in limited oncolytic effects in vivo. To counter this, we evaluated the safety and efficacy of co-administering 2C T cells, myxoma virus, and either rapamycin or neutralizing antibodies against IFNβ. Mice that received either triple combination therapy survived significantly longer with no apparent side effects, but eventually relapsed. Importantly, rapamycin treatment did not impair T cell-mediated tumor destruction, supporting the feasibility of combining adoptive immunotherapy and rapamycin-enhanced virotherapy. Myxoma virus may be a useful vector for transient delivery of therapeutic genes to a tumor to enhance T cell responses. Topics: Animals; Antineoplastic Agents; Brain Neoplasms; CD8-Positive T-Lymphocytes; Immunotherapy, Adoptive; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Mice, Knockout; Myxoma virus; Oncolytic Virotherapy; Sirolimus | 2011 |
Local delivery of rapamycin: a toxicity and efficacy study in an experimental malignant glioma model in rats.
Rapamycin, an anti-proliferative agent, is effective in the treatment of renal cell carcinoma and recurrent breast cancers. We proposed that this potent mammalian target of rapamycin inhibitor may be useful for the treatment of gliomas as well. We examined the cytotoxicity of rapamycin against a rodent glioma cell line, determined the toxicity of rapamycin when delivered intracranially, and investigated the efficacy of local delivery of rapamycin for the treatment of experimental malignant glioma in vivo. We also examined the dose-dependent efficacy of rapamycin and the effect when locally delivered rapamycin was combined with radiation therapy. Rapamycin was cytotoxic to 9L cells, causing 34% growth inhibition at a concentration of 0.01 µg/mL. No in vivo toxicity was observed when rapamycin was incorporated into biodegradable caprolactone-glycolide (35:65) polymer beads at 0.3%, 3%, and 30% loading doses and implanted intracranially. Three separate efficacy studies were performed to test the reproducibility of the effect of the rapamycin beads as well as the validity of this treatment approach. Animals treated with the highest dose of rapamycin beads tested (30%) consistently demonstrated significantly longer survival durations than the control and placebo groups. All dose-escalating rapamycin bead treatment groups (0.3%, 3% and 30%), treated both concurrently with tumor and in a delayed manner after tumor placement, experienced a significant increase in survival, compared with controls. Radiation therapy in addition to the simultaneous treatment with 30% rapamycin beads led to significantly longer survival duration than either therapy alone. These results suggest that the local delivery of rapamycin for the treatment of gliomas should be further investigated. Topics: Animals; Antibiotics, Antineoplastic; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Combined Modality Therapy; Glioma; Humans; Neoplasms, Experimental; Polymers; Radiotherapy; Rats; Rats, Inbred F344; Sirolimus; Survival Rate | 2011 |
Rapamycin induces differentiation of glioma stem/progenitor cells by activating autophagy.
Glioma stem/progenitor cells (GSPCs) are considered to be responsible for the initiation, propagation, and recurrence of gliomas. The factors determining their differentiation remain poorly defined. Accumulating evidences indicate that alterations in autophagy may influence cell fate during mammalian development and differentiation. Here, we investigated the role of autophagy in GSPC differentiation. SU-2 cells were treated with rapamycin, 3-methyladenine (3-MA) plus rapamycin, E64d plus rapamycin, or untreated as control. SU-2 cell xenografts in nude mice were treated with rapamycin or 3-MA plus rapamycin, or untreated as control. Western blotting and immunocytochemistry showed up-regulation of microtubule-associated protein light chain-3 (LC3)-II in rapamycin-treated cells. The neurosphere formation rate and the number of cells in each neurosphere were significantly lower in the rapamycin treatment group than in other groups. Real-time PCR and immunocytochemistry showed down-regulation of stem/progenitor cell markers and up-regulation of differentiation markers in rapamycin-treated cells. Transmission electron microscopy revealed autophagy activation in rapamycin-treated tumor cells in mice. Immunohistochemistry revealed decreased Nestin-positive cells and increased GFAP-positive cells in rapamycin-treated tumor sections. These results indicate that rapamycin induces differentiation of GSPCs by activating autophagy. Topics: Adenine; Animals; Antibiotics, Antineoplastic; Autophagy; Brain Neoplasms; Cell Differentiation; Cell Line, Tumor; Female; Glial Fibrillary Acidic Protein; Glioma; Humans; Leucine; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Microtubule-Associated Proteins; Neoplastic Stem Cells; RNA, Messenger; Sirolimus; Xenograft Model Antitumor Assays | 2011 |
Myxoma virus virotherapy for glioma in immunocompetent animal models: optimizing administration routes and synergy with rapamycin.
Oncolytic myxoma virus (MYXV) is being developed as a novel virotherapeutic against human brain cancer and has promising activity against human brain tumor models in immunocompromised hosts. Because an intact immune system could reduce its efficacy, the purpose of this study was to evaluate the oncolytic potential of MYXV in immunocompetent racine glioma models. Here, we report that MYXV infects and kills all racine cell glioma lines and that its effects are enhanced by rapamycin. Intratumoral administration of MYXV with rapamycin improved viral replication in the tumor and significantly prolonged host survival. Similarly, coadministration via a method of convection-enhanced delivery (CED) enhanced viral replication and efficacy in vivo. Mechanisms by which rapamycin improved MYXV oncolysis included an inhibition of type I IFN production in vitro and a reduction of intratumoral infiltration of CD68(+) microglia/macrophages and CD163(+) macrophages in vivo. Our findings define a method to improve MYXV efficacy against gliomas by rapamycin coadministration, which acts to promote immune responses engaged by viral delivery. Topics: Animals; Antibiotics, Antineoplastic; Brain Neoplasms; Cell Line, Tumor; Drug Synergism; Glioma; Immunocompetence; Mice; Myxoma virus; NIH 3T3 Cells; Oncolytic Virotherapy; Rats; Rats, Inbred F344; Sirolimus; Virus Replication | 2010 |
[Advanced renal carcinomas with special situations. How to treat them?].
Advanced or metastatic renal carcinoma represents a frequent disease in oncologic practice. Few years ago, in immunotherapy era, treatments had quickly reached deadlock. New therapies targeting vascular endothelial growth factors and their receptors (VEGF-R), sorafenib, sunitinib and bevacizumab, and the mammalian target of rapamycin (mTOR), temsirolimus and everolimus, have modified these patients prognosis and their quality of life in a few years. Nevertheless, patients included in randomized trials presented severe inclusion criteria. Then in the daily practice, patients have distinctive characteristics which were not evaluated in large pivotal studies: poor performance status, older patients, renal dysfunction, cerebral metastases or non clear cell renal cancer. In published trials, a few data concerning these situations are reported, and these studies have often included small samples, were retrospective or not randomised. However compared to global population, tolerance have not been very different in geriatric patients, or patients with poor performance status, or with central neurological metastases, or with papillary and chromophobe sub-types. On the contrary progression free or overall survivals increases are more difficult to confirm. Also before starting treatment, ratio between potential benefit and possible toxicities have to be evaluated. In patients with renal insufficiency, VEGF receptor inhibitors seem to be cautiously initiated at reduced doses, and to be increased according to tolerance. Due to these poor proof levels, clinical trials are needed for these specific populations. Topics: Aged; Angiogenesis Inhibitors; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Benzenesulfonates; Bevacizumab; Brain Neoplasms; Carcinoma, Renal Cell; Everolimus; Humans; Indoles; Intracellular Signaling Peptides and Proteins; Kidney Neoplasms; Niacinamide; Phenylurea Compounds; Protein Serine-Threonine Kinases; Pyridines; Pyrroles; Receptors, Vascular Endothelial Growth Factor; Sirolimus; Sorafenib; Sunitinib; TOR Serine-Threonine Kinases; Vascular Endothelial Growth Factor A | 2010 |
Optic nerve tumor in tuberous sclerosis complex is not responsive to sirolimus.
A 12-year-old girl with clinically established tuberous sclerosis complex, and without signs of neurofibromatosis type 1, developed a right retro-ocular optic nerve tumor. After rapid growth for 1 year after its discovery, the optic nerve tumor demonstrated modest progression. The patient received the mammalian target of rapamycin inhibitor, sirolimus, for recurrent subependymal giant cell brain tumors. Although her left ventricular subependymal giant cell tumor demonstrated a 49% reduction in volume, the optic nerve tumor did not respond, and even underwent slight (6%) growth during the 16-month treatment. The quality of this child's vision has remained normal in both eyes, and she is otherwise asymptomatic with regard to the optic nerve tumor. Topics: Antibiotics, Antineoplastic; Astrocytoma; Brain Neoplasms; Child; Female; Humans; Neoplasm Recurrence, Local; Optic Nerve Neoplasms; Sirolimus; Treatment Outcome; Tuberous Sclerosis | 2010 |
Efficacy and safety/toxicity study of recombinant vaccinia virus JX-594 in two immunocompetent animal models of glioma.
The purpose of this study was to investigate the oncolytic potential of the recombinant, granulocyte macrophage colony-stimulating factor (GM-CSF)-expressing vaccinia virus (VV) JX-594 in experimental malignant glioma (MGs) in vitro and in immunocompetent rodent models. We have found that JX-594 killed all MG cell lines tested in vitro. Intratumoral (i.t.) administration of JX-594 significantly inhibited tumor growth and prolonged survival in rats-bearing RG2 intracranial (i.c.) tumors and mice-bearing GL261 brain tumors. Combination therapy with JX-594 and rapamycin significantly increased viral replication and further prolonged survival in both immunocompetent i.c. MG models with several animals considered "cured" (three out of seven rats >120 days, terminated experiment). JX-594 infected and killed brain tumor-initiating cells (BTICs) from patient samples grown ex vivo, and did so more efficiently than other oncolytic viruses MYXV, Reovirus type-3, and VSV(ΔM51). Additional safety/toxicity studies in nontumor-bearing rodents treated with a supratherapeutic dose of JX-594 demonstrated GM-CSF-dependent inflammation and necrosis. These results suggest that i.c. administered JX-594 triggers a predictable GM-CSF-mediated inflammation in murine models. Before proceeding to clinical trials, JX-594 should be evaluated in the brains of nonhuman primates and optimized for the viral doses, delivery routes as well as the combination agents (e.g., mTOR inhibitors). Topics: Animals; Antibiotics, Antineoplastic; Brain Neoplasms; Combined Modality Therapy; Disease Models, Animal; Female; Genetic Vectors; Glioma; Granulocyte-Macrophage Colony-Stimulating Factor; Immunoenzyme Techniques; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Oncolytic Virotherapy; Rats; Rats, Inbred F344; Sirolimus; Survival Rate; Transgenes; Tumor Cells, Cultured; Vaccines, Synthetic; Vaccinia virus; Virus Replication | 2010 |
Rapamycin as an alternative to surgical treatment of subependymal giant cell astrocytomas in a patient with tuberous sclerosis complex.
Tuberous sclerosis complex (TSC) is associated with the potential development of benign hamartomas, including subependymal giant cell astrocytomas (SEGAs). Intracranial hypertension can be caused by SEGAs due to their propensity to block the foramen of Monro. The traditional management approach is to monitor SEGAs with periodic neuroimaging and to resect those that exhibit serial growth and/or cause clinical signs of intracranial hypertension. Recent observations suggest that rapamycin therapy may induce partial regression of SEGAs, therefore providing a potential alternative to resection. The authors present the case of an 8-year-old girl with bilateral SEGAs that led to progressive hydrocephaly and incipient signs of papilledema. Three months after initiating rapamycin therapy, the SEGAs exhibited significant reduction in size (82.6% on the left and 46.7% on the right), and the lesions remained stable 5 months later. Compared with previous case reports, similar or even greater antitumor efficacy was achieved with much lower trough levels of rapamycin (10–15 compared with 3.3–4.5 ng/ml, respectively). The authors discuss various aspects of rapamycin therapy and address unresolved issues that highlight the need for further prospective clinical trials. Topics: Antibiotics, Antineoplastic; Astrocytoma; Brain Neoplasms; Child; Female; Humans; Magnetic Resonance Imaging; Neurosurgical Procedures; Sirolimus; Tuberous Sclerosis | 2010 |
Rapamycin therapy for renal, brain, and skin lesions in a tuberous sclerosis patient.
Tuberous sclerosis complex (TSC) is an inherited multisystem disorder; it may involve kidney, brain, skin, lungs, and liver. We report a 37-year-old female TSC patient presenting with skin lesions (angiofibromas, molluscum pendulum). Radiologic examination revealed additional brain and renal lesions consisting of tumors, cysts, and angiomyolipomas. Treatment with rapamycin disclosed improvement in skin lesions. The number and volume of angiofibromas and molluscum pendulum reduced progressively in 6 months. During the ninth month of treatment, magnetic resonance imaging was repeated for renal and brain lesions. Imaging results showed reduction in tumor and angiomyolipoma volumes. Oral rapamycin therapy can improve renal, brain, and skin lesions in TSC disease. Therefore, it may be an alternative therapy for TSC patients. Topics: Adult; Angiofibroma; Brain Neoplasms; Facial Neoplasms; Female; Humans; Immunosuppressive Agents; Kidney Neoplasms; Magnetic Resonance Imaging; Sirolimus; Skin Neoplasms; Tuberous Sclerosis | 2010 |
Methods for analysis of brain tumor stem cell and neural stem cell self-renewal.
Neural stem cells (NSC) self-renew and are multipotent, producing neurons and glia. Recent studies have shown that brain tumors (BT) contain cells that, like NSC, self-renew and are multipotent, producing the different types of cells found within the brain tumors. These brain tumor stem cells are a kind of cancer stem cell, competent to form tumors that mimic the parent tumor in experimental animals. Studies from our laboratory and others have demonstrated that brain tumor stem cells and NSC share similar mechanisms and pathways for proliferation. For example, we have identified that one of the AMPK/snf1 kinases, maternal embryonic leucine zipper kinase (MELK), is highly expressed in NSC and malignant brain tumors, as well as in brain tumor stem cell-enriched cell cultures. Analysis of transgenic MELK-reporter mice indicated that MELK is expressed in NSC in vivo, and our in vitro studies demonstrated that MELK is required for NSC self-renewal. We have also found that MELK is required for proliferation of putative BT stem cells. Utilizing our studies with MELK as an example, this chapter describes methods to culture NSC and BT stem cells, and to analyze the pathways, which regulate self-renewal of those cells. Topics: Animals; Astrocytes; Biological Assay; Brain Neoplasms; Cell Culture Techniques; Cell Cycle; Cell Death; Cell Proliferation; Flow Cytometry; Glial Fibrillary Acidic Protein; Green Fluorescent Proteins; Humans; Mice; Mice, Transgenic; Models, Animal; Neoplastic Stem Cells; Neurons; Phenotype; Protein Serine-Threonine Kinases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Sirolimus; Transfection | 2009 |
EGFR signaling through an Akt-SREBP-1-dependent, rapamycin-resistant pathway sensitizes glioblastomas to antilipogenic therapy.
Glioblastoma, the most common malignant brain tumor, is among the most lethal and difficult cancers to treat. Although epidermal growth factor receptor (EGFR) mutations are frequent in glioblastoma, their clinical relevance is poorly understood. Studies of tumors from patients treated with the EGFR inhibitor lapatinib revealed that EGFR induces the cleavage and nuclear translocation of the master transcriptional regulator of fatty acid synthesis, sterol regulatory element-binding protein 1 (SREBP-1). This response was mediated by Akt; however, clinical data from rapamycin-treated patients showed that SREBP-1 activation was independent of the mammalian target of rapamycin complex 1, possibly explaining rapamycin's poor efficacy in the treatment of such tumors. Glioblastomas without constitutively active EGFR signaling were resistant to inhibition of fatty acid synthesis, whereas introduction of a constitutively active mutant form of EGFR, EGFRvIII, sensitized tumor xenografts in mice to cell death, which was augmented by the hydroxymethylglutaryl coenzyme A reductase inhibitor atorvastatin. These results identify a previously undescribed EGFR-mediated prosurvival metabolic pathway and suggest new therapeutic approaches to treating EGFR-activated glioblastomas. Topics: Antineoplastic Agents; Brain Neoplasms; ErbB Receptors; Fatty Acids; Gene Knockdown Techniques; Glioblastoma; Humans; Hydrolysis; Lapatinib; Lipogenesis; Phosphatidylinositol 3-Kinases; Protein Transport; Proto-Oncogene Proteins c-akt; Quinazolines; Signal Transduction; Sirolimus; Sterol Regulatory Element Binding Protein 1 | 2009 |
PTEN loss does not predict for response to RAD001 (Everolimus) in a glioblastoma orthotopic xenograft test panel.
Hyperactivation of the phosphatidylinositol 3-kinase/Akt signaling through disruption of PTEN function is common in glioblastoma multiforme, and these genetic changes are predicted to enhance sensitivity to mammalian target of rapamycin (mTOR) inhibitors such as RAD001 (everolimus).. To test whether PTEN loss could be used as a predictive marker for mTOR inhibitor sensitivity, the response of 17 serially transplantable glioblastoma multiforme xenografts was evaluated in an orthotopic therapy evaluation model. Of these 17 xenograft lines, 7 have either genomic deletion or mutation of PTEN.. Consistent with activation of Akt signaling, there was a good correlation between loss of PTEN function and elevated levels of Akt phosphorylation. However, of the 7 lines with disrupted PTEN function, only 1 tumor line (GBM10) was significantly sensitive to RAD001 therapy (25% prolongation in median survival), whereas 1 of 10 xenograft lines with wild-type PTEN was significantly sensitive to RAD001 (GS22; 34% prolongation in survival). Relative to placebo, 5 days of RAD001 treatment was associated with a marked 66% reduction in the MIB1 proliferation index in the sensitive GBM10 line (deleted PTEN) compared with a 25% and 7% reduction in MIB1 labeling index in the insensitive GBM14 (mutant PTEN) and GBM15 (wild-type PTEN) lines, respectively. Consistent with a cytostatic antitumor effect, bioluminescent imaging of luciferase-transduced intracranial GBM10 xenografts showed slowed tumor growth without significant tumor regression during RAD001 therapy.. These data suggest that loss of PTEN function is insufficient to adequately predict responsiveness to mTOR inhibitors in glioblastoma multiforme. Topics: Animals; Antineoplastic Agents; Apoptosis; Brain Neoplasms; Cell Proliferation; ErbB Receptors; Everolimus; Glioblastoma; Humans; Mice; Mice, Nude; Neovascularization, Pathologic; Prognosis; Protein Kinases; PTEN Phosphohydrolase; Sirolimus; TOR Serine-Threonine Kinases; Transplantation, Heterotopic; Xenograft Model Antitumor Assays | 2008 |
Autophagy-inducing agents augment the antitumor effect of telerase-selve oncolytic adenovirus OBP-405 on glioblastoma cells.
Oncolytic adenoviruses are a promising tool in cancer therapy. In this study, we characterized the role of autophagy in oncolytic adenovirus-induced therapeutic effects. OBP-405, an oncolytic adenovirus regulated by the human telomerase reverse transcriptase promoter (hTERT-Ad, OBP-301) with a tropism modification (RGD) exhibited a strong antitumor effect on glioblastoma cells. When autophagy was inhibited pharmacologically, the cytotoxicity of OBP-405 was attenuated. In addition, autophagy-deficient Atg5(-/-) mouse embryonic fibroblasts (MEFs) were less sensitive than wild-type MEFs to OBP-405. These findings indicate that OBP-405-induced autophagy is a cell killing effect. Moreover, autophagy-inducing therapies (temozolomide and rapamycin) synergistically sensitized tumor cells to OBP-405 by stimulating the autophagic pathway without altering OBP-405 replication. Mice harboring intracranial tumors treated with OBP-405 and temozolomide survived significantly longer than those treated with temozolomide alone, and mice treated with OBP-405 and the rapamycin analog RAD001 survived significantly longer than those treated with RAD001 alone. The observation that autophagy inducers increase OBP-405 antitumor activity suggests a novel strategy for treating patients with glioblastoma. Topics: Adenoviridae; Animals; Autophagy; Brain Neoplasms; Cell Line, Tumor; Dacarbazine; Genetic Therapy; Glioblastoma; Mice; Oncolytic Virotherapy; Oncolytic Viruses; Sirolimus; Temozolomide | 2008 |
Regression of subependymal giant cell astrocytoma with rapamycin in tuberous sclerosis complex.
The authors present a 21-year-old woman who has been receiving rapamycin for 5 months for bilateral subependymal giant cell astrocytomas. The patient was started at a dose of 0.2 mg/kg/day. Levels were maintained between 11 and 13 ng/mL. Magnetic resonance imaging of the brain 2(1/2) months after initiating rapamycin demonstrated a decrease in size of both astrocytomas (11 to 7.5 mm on the right and 8 to 5 mm on the left). Further studies are needed with prolonged observation to confirm these findings, determine the length of necessary treatment, and evaluate recurrence risk after discontinuation of rapamycin. Topics: Antibiotics, Antineoplastic; Brain; Brain Neoplasms; Dose-Response Relationship, Drug; Female; Glioma, Subependymal; Humans; Magnetic Resonance Imaging; Sirolimus; Treatment Outcome; Tuberous Sclerosis; Young Adult | 2008 |
FK506 binding protein mediates glioma cell growth and sensitivity to rapamycin treatment by regulating NF-kappaB signaling pathway.
FK506 binding protein 5 (FKBP5) belongs to a family of immunophilins named for their ability to bind immunosuppressive drugs, also known as peptidyl-prolyl cis-trans isomerases, and also with chaperones to help protein folding. Using glioma cDNA microarray analysis, we found that FKBP5 was overexpressed in glioma tumors. This finding was further validated by real-time reverse transcription-polymerase chain reaction and Western blot analysis. The roles of FKBP5 in glioma cells were then examined. We found that cell growth was suppressed after FKBP5 expression was inhibited by short interfering RNA transfection and enhanced by FKBP5 overexpression. Electrophoretic mobility shift assay showed that nuclear factor-kappa B (NF-kappaB) and DNA binding was enhanced by FKBP5 overexpression. The expression level of I-kappa B alpha and phosphorylated NF-kappaB was regulated by the expression of FKBP5. These data suggest that FKBP5 is involved in NF-kappaB pathway activation in glioma cells. In addition, FKBP5 overexpression in rapamycin-sensitive U87 cells blocked the cells' response to rapamycin treatment, whereas rapamycin-resistant glioma cells, both PTEN-positive and -negative, were synergistically sensitive to rapamycin after FKBP5 was knocked down, suggesting that the FKBP5 regulates glioma cell response to rapamycin treatment. In conclusion, our study demonstrates that FKBP5 plays an important role in glioma growth and chemoresistance through regulating signal transduction of the NF-kappaB pathway. Topics: Antibiotics, Antineoplastic; Apoptosis; Brain Neoplasms; Cell Line, Tumor; Drug Resistance, Neoplasm; Glioma; Humans; NF-kappa B; Oligonucleotide Array Sequence Analysis; Signal Transduction; Sirolimus; Tacrolimus Binding Proteins | 2008 |
Silencing mammalian target of rapamycin signaling by small interfering RNA enhances rapamycin-induced autophagy in malignant glioma cells.
The mammalian target of rapamycin (mTOR) plays a central role in regulating the proliferation of malignant glioma cells, and mTOR-specific inhibitors such as rapamycin analogs are considered as promising therapy for malignant gliomas. However, the efficacy of mTOR inhibitors alone in the treatment of patients with malignant gliomas is only modest, potentially because these agents rather than acting as mTOR kinase inhibitors instead interfere with the function of only mTOR/raptor (regulatory-associated protein of mTOR) complex and thus do not perturb all mTOR functions. The purpose of this study was to determine whether global inhibition of the mTOR molecule enhances the antitumor effect of rapamycin on malignant glioma cells. We showed that rapamycin induced autophagy and that inhibition of autophagy by small interfering RNA (siRNA) directed against autophagy-related gene Beclin 1 attenuated the cytotoxicity of rapamycin in rapamycin-sensitive tumor cells, indicating that the autophagy was a primary mediator of rapamycin's antitumor effect rather than a protective response. Exogenous expression of an mTOR mutant interfering with its kinase activity markedly enhanced the incidence of rapamycin-induced autophagy. Moreover, silencing of mTOR with siRNA augmented the inhibitory effect of rapamycin on tumor cell viability by stimulating autophagy. Importantly, not only rapamycin-sensitive malignant glioma cells with PTEN mutations but also rapamycin-resistant malignant glioma cells with wild-type PTEN were sensitized to rapamycin by mTOR siRNA. These results indicate that rapamycin-induced autophagy is one of the agent's antitumor effects and that silencing or inhibiting mTOR kinase activity could enhance the effectiveness of rapamycin. Topics: Autophagy; Base Sequence; Brain Neoplasms; Catalysis; Cell Line, Tumor; Gene Silencing; Glioma; Humans; Microscopy, Electron; Protein Kinases; PTEN Phosphohydrolase; RNA, Small Interfering; Sirolimus; TOR Serine-Threonine Kinases | 2007 |
Telomere 3' overhang-specific DNA oligonucleotides induce autophagy in malignant glioma cells.
Telomere 3' overhang-specific DNA oligonucleotides (T-oligos) induce cell death in cancer cells, presumably by mimicking telomere loop disruption. Therefore, T-oligos are considered an exciting new therapeutic strategy. The purpose of this study was to elucidate how T-oligos exert antitumor effects on human malignant glioma cells in vitro and in vivo. We demonstrated that T-oligos inhibited the proliferation of malignant glioma cells through induction of nonapoptotic cell death and mitochondria hyperpolarization, whereas normal astrocytes were resistant to T-oligos. Tumor cells treated with T-oligos developed features compatible with autophagy, with development of autophagic vacuoles and conversion of an autophagy-related protein, microtubule-associated protein 1 light chain 3 from type I (cytoplasmic form) to type II (membrane form of autophagic vacuoles). A reverse-phase protein microarray analysis and Western blotting revealed that treatment with T-oligos inhibited the mammalian target of the rapamycin (mTOR) and the signal transducer and activator of transcription 3 (STAT3). Moreover, pretreatment with T-oligos significantly prolonged the survival time of mice inoculated intracranially with malignant glioma cells compared with that of untreated mice and those treated with control oligonucleotides (P=0.0065 and P=0.043, respectively). These results indicate that T-oligos stimulate the induction of nonapoptotic autophagic also known as type II programmed cell death and are thus promising in the treatment of malignant glioma. Topics: Animals; Apoptosis; Astrocytes; Autophagy; Blotting, Western; Brain Neoplasms; Cell Survival; Cells, Cultured; DNA; Female; Flow Cytometry; Glioma; Humans; Membrane Potential, Mitochondrial; Mice; Mice, Nude; Microtubule-Associated Proteins; Mitochondria; Oligonucleotides; Protein Array Analysis; Protein Kinases; Sirolimus; STAT3 Transcription Factor; Survival Rate; Telomerase; Telomere; TOR Serine-Threonine Kinases | 2007 |
[Glioblastomas are resistant to apoptosis but less resistant to the autophagic process].
Malignant gliomas of which glioblastomas represent the ultimate grade of malignancy are characterized by dismal prognoses because malignant glioma cells present both important proliferation and neoangiogenesis processes and can actively migrate through the narrow extra-cellular spaces in the brain, often travelling relatively long distances, making them elusive targets for effective surgical management. Invasive malignant glioma cells show a decrease in their proliferation rates and a relative resistance to apoptosis (type I programmed cell death) but seem less resistant to autophagic cell death (type II programmed cell death). Autophagic cell death represents an alternative mechanism to overcome, at least partly, the dramatic resistance of glioblastomas to pro-apoptotic-related therapies. Another way to potentially overcome apoptosis resistance is to decrease the migration of malignant glioma cells in the brain, which then should restore a level of sensitivity to pro-apoptotic drugs. We conclude this work with an algorithm showing the optimal current treatment for glioblastoma with the potent future innovations. Topics: Algorithms; Antibiotics, Antineoplastic; Antineoplastic Agents, Alkylating; Apoptosis; Autophagy; Brain Neoplasms; Cell Movement; Clinical Trials as Topic; Dacarbazine; Forecasting; Glioblastoma; Humans; Prognosis; Sirolimus; Temozolomide; Transcription Factors | 2007 |
Rapamycin causes regression of astrocytomas in tuberous sclerosis complex.
Tuberous sclerosis complex (TSC) is a genetic disorder characterized by the formation of hamartomas in multiple organs. Five to 15% of affected individuals display subependymal giant cell astrocytomas, which can lead to substantial neurological and postoperative morbidity due to the production of hydrocephalus, mass effect, and their typical location adjacent to the foramen of Monro. We sought to see whether therapy with oral rapamycin could affect growth or induce regression in astrocytomas associated with TSC.. Five subjects with clinically definite TSC and either subependymal giant cell astrocytomas (n = 4) or a pilocytic astrocytoma (n = 1) were treated with oral rapamycin at standard immunosuppressive doses (serum levels 5-15 ng/ml) from 2.5 to 20 months. All lesions demonstrated growth on serial neuroimaging studies. Magnetic resonance imaging scans were performed before and at regular intervals following initiation of therapy.. All lesions exhibited regression and, in one case, necrosis. Interruption of therapy resulted in regrowth of subependymal giant cell astrocytomas in one patient. Resumption of therapy resulted in further regression. Treatment was well tolerated.. Oral rapamycin therapy can induce regression of astrocytomas associated with TSC and may offer an alternative to operative therapy of these lesions. Topics: Adolescent; Adult; Astrocytoma; Brain Neoplasms; Child; Child, Preschool; Dose-Response Relationship, Drug; Female; Humans; Immunosuppressive Agents; Magnetic Resonance Imaging; Male; Models, Biological; Regression, Psychology; Sirolimus; Tuberous Sclerosis | 2006 |
The immunosuppressant rapamycin exacerbates neurotoxicity of Abeta peptide.
Alzheimer's disease (AD) is a neurodegenerative disease of the central nervous system characterized by two major lesions: extracellular senile plaques and intraneuronal neurofibrillary tangles. beta-Amyloid (Abeta) is known to play a major role in the pathogenesis of AD. Protein synthesis and especially translation initiation are modulated by different factors, including the PKR/eIF2 and the mTOR/p70S6K pathways. mRNA translation is altered in the brain of AD patients. Very little is known about the translation control mediated by mTOR in AD, although mTOR is a central regulator of translation initiation and also ribosome biogenesis and cell growth and proliferation. In this study, by using Western blotting, we show that mTOR pathway is down-regulated by Abeta treatment in human neuroblastoma cells, and the underlying mechanism explaining a transient activation of p70S6K is linked to cross-talk between mTOR and ERK1/2 at this kinase level. This phenomenon is associated with caspase-3 activation, and inhibition of mTOR by the inhibitor rapamycin enhances Abeta-induced cell death. Moreover, in our cell model, insulin-like growth factor-1 is able to increase markedly the p70S6K phosphorylation controlled by mTOR and reduces the caspase-3 activity, but its protective effect on Abeta cell death is mediated via an mTOR-independent pathway. These results demonstrate that mTOR plays an important role as a cellular survival pathway in Abeta toxicity and could represent a possible target for modulating Abeta toxicity. Topics: Amyloid beta-Peptides; Blotting, Western; Brain Neoplasms; Caspase 3; Cell Line, Tumor; Drug Synergism; Extracellular Signal-Regulated MAP Kinases; Fluorescent Dyes; Humans; Immunosuppressive Agents; Indoles; Insulin-Like Growth Factor I; Neuroblastoma; Neurotoxins; Peptide Fragments; Protein Kinases; Receptor Cross-Talk; Ribosomal Protein S6 Kinases, 70-kDa; Sirolimus; TOR Serine-Threonine Kinases | 2006 |
PKB/Akt mediates radiosensitization by the signaling inhibitor LY294002 in human malignant gliomas.
The phosphoinositide 3-kinase (PI3-kinase) signaling pathway is frequently aberrantly activated in glioblastoma multiforme (GM) by mutation or loss of the 3' phospholipid phosphatase PTEN. PTEN abnormalities result in inappropriate signaling to downstream molecules including protein kinase B (PKB/Akt), and mammalian target of rapamycin (mTOR). PI3-kinase activation increases resistance to radiation-induced cell death; conversely, PI3-kinase inhibition enhances the sensitivity of tumors to radiation. The effects of LY294002, a biochemical inhibitor of PI3-kinase, on the response to radiation were examined in the PTEN mutant glioma cell line U251 MG. Low doses of LY294002 sensitized U251 MG to clinically relevant doses of radiation. In contrast to LY294002, rapamycin, an inhibitor of mTOR, did not result in radiosensitization. We demonstrate that among multiple known targets of LY294002, PI3-kinase is the most likely molecule responsible for LY294002-induced radiosensitization. Furthermore, using a myristoylated PKB/Akt construct, we identified PKB/Akt as the downstream molecule that mediates the synergistic cytotoxicity between LY294002 and radiation. Thus PI3-kinase dysregulation may contribute to the notable radioresistance of GM tumors and inhibition of PKB/Akt offers an excellent target to enhance radiosensitivity. Topics: Agammaglobulinaemia Tyrosine Kinase; Analysis of Variance; Antibiotics, Antineoplastic; Brain Neoplasms; Cell Line, Tumor; Chromones; Down-Regulation; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Morpholines; Mutation; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphoric Monoester Hydrolases; Protein Kinases; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Radiation-Sensitizing Agents; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tumor Suppressor Proteins | 2005 |
Proteomic analysis reveals hyperactivation of the mammalian target of rapamycin pathway in neurofibromatosis 1-associated human and mouse brain tumors.
Individuals with the tumor predisposition syndrome, neurofibromatosis 1 (NF1), are prone to development of nervous system tumors, including neurofibromas and pilocytic astrocytomas. Based on the ability of the NF1 gene product (neurofibromin) to function as a GTPase activating protein for RAS, initial biologically based therapies for NF1-associated tumors focused on the use of RAS inhibitors, but with limited clinical success. In an effort to identify additional targets for therapeutic drug design in NF1, we used an unbiased proteomic approach to uncover unanticipated intracellular signaling pathways dysregulated in Nf1-deficient astrocytes. We found that the expression of proteins involved in promoting ribosome biogenesis was increased in the absence of neurofibromin. In addition, Nf1-deficient astrocytes exhibit high levels of mammalian target of rapamycin (mTOR) pathway activation, which was inhibited by blocking K-RAS or phosphatidylinositol 3-kinase activation. This mTOR pathway hyperactivation was reflected by high levels of ribosomal S6 activation in both Nf1 mutant mouse optic nerve gliomas and in human NF1-associated pilocytic astrocytoma tumors. Moreover, inhibition of mTOR signaling in Nf1-/- astrocytes abrogated their growth advantage in culture, restoring normal proliferative rates. These results suggest that mTOR pathway inhibition may represent a logical and tractable biologically based therapy for brain tumors in NF1. Topics: Animals; Astrocytes; Brain Neoplasms; Genes, Neurofibromatosis 1; Glioma; Humans; Mice; Mice, Transgenic; Neurofibromatosis 1; Neurofibromin 1; Phosphatidylinositol 3-Kinases; Protein Kinases; Proteomics; Ribosomal Protein S6 Kinases, 90-kDa; RNA, Messenger; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases | 2005 |
mTOR promotes survival and astrocytic characteristics induced by Pten/AKT signaling in glioblastoma.
Combined activation of Ras and AKT leads to the formation of astrocytic glioblastoma multiforme (GBM) in mice. In human GBMs, AKT is not mutated but is activated in approximately 70% of these tumors, in association with loss of PTEN and/or activation of receptor tyrosine kinases. Mechanistic justification for the therapeutic blockade of targets downstream of AKT, such as mTOR, in these cancers requires demonstration that the oncogenic effect of PTEN loss is through elevated AKT activity. We demonstrate here that loss of Pten is similar to AKT activation in the context of glioma formation in mice. We further delineate the role of mTOR activity downstream of AKT in the maintenance of AKT+KRas-induced GBMs. Blockade of mTOR results in regional apoptosis in these tumors and conversion in the character of surviving tumor cells from astrocytoma to oligodendroglioma. These data suggest that mTOR activity is required for the survival of some cells within these GBMs, and mTOR appears required for the maintenance of astrocytic character in the surviving cells. Furthermore, our study provides the first example of conversion between two distinct tumor types usually thought of as belonging to specific lineages, and provides evidence for signal transduction-mediated transdifferentiation between glioma subtypes. Topics: Animals; Apoptosis; Blotting, Western; Brain; Brain Neoplasms; Cell Differentiation; Cell Line, Tumor; Cell Survival; Cells, Cultured; Enzyme Activation; Exons; Glioblastoma; Green Fluorescent Proteins; Immunohistochemistry; In Situ Nick-End Labeling; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Mice, Transgenic; Models, Genetic; Mutation; Neurons; Phosphatidylinositol 3-Kinases; Phosphoric Monoester Hydrolases; Plasmids; Polymerase Chain Reaction; Protein Kinases; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; Stem Cells; TOR Serine-Threonine Kinases; Tumor Suppressor Proteins | 2005 |
PKC-eta mediates glioblastoma cell proliferation through the Akt and mTOR signaling pathways.
We previously demonstrated that protein kinase C-eta (PKC-eta) mediates a phorbol 12-myristate-13-acetate (PMA)-induced proliferative response in human glioblastoma (GBM) cells. In this report, we show that PMA-stimulated activation of PKC-eta in U-251 GBM cells resulted in activation of both Akt and the mammalian target of rapamycin (mTOR) signaling pathways and an increase in cell proliferation. Expression of a kinase dead PKC-eta (PKC-etaKR) construct reduced the basal and PMA-evoked proliferation of PKC-eta-expressing U-251 GBM cells, as well as abrogated the PMA-induced activation of Akt, mTOR, and the mTOR targets 4E-BP1 and STAT-3. Treatment of cells with the PI-3 kinase inhibitor LY294002 (10 muM) or the mTOR inhibitor rapamycin (10 nM) also reduced PMA-induced proliferation and cell-cycle progression. Expression of a constitutively active PKC-eta (PKC-etaDeltaNPS) construct in a GBM cell line with no endogenous PKC-eta (U-1242) also provided evidence that PKC-eta targets the Akt and mTOR signaling pathways. Moreover, activation of 4E-BP1 and STAT-3 in both PMA-treated U-251 and PKC-etaDeltaNPS-expressing U-1242 GBM cells was inhibited by rapamycin. However, activation of Akt, but not mTOR was inhibited by the PI-3 kinase inhibitor LY294002. This study identifies Akt and mTOR as downstream targets of PKC-eta that are involved in GBM cell proliferation. Topics: Brain Neoplasms; Cell Cycle; Chromones; Enzyme Inhibitors; Glioblastoma; Humans; Morpholines; Protein Kinase C; Protein Kinases; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Signal Transduction; Sirolimus; Tetradecanoylphorbol Acetate; TOR Serine-Threonine Kinases | 2004 |
Mitogenic effect of glial cell line-derived neurotrophic factor is dependent on the activation of p70S6 kinase, but independent of the activation of ERK and up-regulation of Ret in SH-SY5Y cells.
Glial cell line-derived neurotrophic factor (GDNF) activates c-Ret tyrosine kinase and several downstream intracellular pathways; the biological effects caused by the activation of each of these pathways, however, remain to be elucidated. Here we report the ability of GDNF to induce proliferation, rather than differentiation, of neuroblastoma cells (SH-SY5Y) by targeting the signaling pathway responsible for mediating this proliferative effect. GDNF induces the phosphorylation of Akt and p70S6 kinase (p70S6K) in SH-SY5Y cells in which Ret protein expression is relatively low. Interestingly, treating SH-SY5Y cells with retinoic acid greatly increases Ret protein levels and GDNF-induced Ret tyrosine phosphorylation, but does not affect the mitogenic action of GDNF and the activation of the Akt/p70S6K pathway. In contrast, the activation of the ERK pathway and the resulting induction of immediate-early genes parallel the increases in Ret protein levels. Rapamycin, a specific inhibitor of p70S6K activation by the mammalian target of rapamycin, completely prevents GDNF-induced proliferation and activation of p70S6K. These results suggest that GDNF promotes cell proliferation via the activation of p70S6K, independent of the ERK signaling pathway, and that GDNF activates the Akt/p70S6K pathway more efficiently than the ERK pathway in the cells in which Ret expression is low. Topics: Blotting, Western; Brain Neoplasms; Cell Division; Cell Line; Enzyme Activation; Glial Cell Line-Derived Neurotrophic Factor; Humans; Immunosuppressive Agents; Mitogen-Activated Protein Kinases; Mitogens; Nerve Growth Factors; Neuroblastoma; Precipitin Tests; Reverse Transcriptase Polymerase Chain Reaction; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Tumor Cells, Cultured; Up-Regulation | 2003 |
Goosebumps.
Topics: Astrocytoma; Brain Neoplasms; Carmustine; Dexamethasone; Diagnosis, Differential; Frontal Lobe; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Phenytoin; Piloerection; Seizures; Sirolimus; Taste Disorders; Temporal Lobe | 2002 |
Antitumor activity of the rapamycin analog CCI-779 in human primitive neuroectodermal tumor/medulloblastoma models as single agent and in combination chemotherapy.
We examined the cytotoxicity of the immunosuppressant agent rapamycin and its analogue CCI-779 in human brain tumor cell lines in vitro and in vivo as single agents and in combination with standard chemotherapeutic drugs. In the rapamycin-sensitive PNET/MB cell line DAOY, rapamycin exhibited additive cytotoxicity with cisplatin and with camptothecin. In vivo, CCI-779 delayed DAOY xenograft growth by 160% after 1 week and 240% after 2 weeks of systemic treatment, compared with controls. Single high-dose treatment induced 37% regression of tumor solume. Growth inhibition of DAOY xenografts was 1.3 times greater after simultaneous treatment with CCI-779 and cisplatin than after cisplatin alone. Interestingly, CCI-779 also produced growth inhibition of xenografts derived from U251 malignant glioma cells, a human cell line resistant to rapamycin in vitro. These studies suggest that the rapamycin analogue CCI-779 is an important new agent to investigate in the treatment of human brain tumors, particularly PNET/MB. Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Camptothecin; Cell Division; Cisplatin; Drug Synergism; Female; Glioma; Growth Inhibitors; Humans; Medulloblastoma; Mice; Mice, Nude; Neuroectodermal Tumors, Primitive; Sirolimus; Tumor Cells, Cultured; Xenograft Model Antitumor Assays | 2001 |
Human brain tumor xenografts in nude mice as a chemotherapy model.
Two human brain tumors which were previously established in nude mice were used to determine antitumor efficacy of various therapeutic agents. These tumors were a medulloblastoma (TE-671) and a glioma (U-251) with mass doubling times of 3.5 and 5.5 days respectively as subcutaneous implants in nude mice. Intracranial (i.c.) tumor challenge was accomplished by inoculating tissue culture-grown cells of either tumor into the right cerebral hemisphere to a depth of 3 mm. Median survival time (MST) in untreated mice with 10(5) i.c. injected TE-671 cells was approximately 30 days and 53 days in the U-251 tumor. With 2 X 10(5) U-251 tumor cells the MST was 27-31 days. Groups of mice which had been inoculated with tumor were treated with various doses and schedules of antineoplastic compounds by the i.p. route. The TE-671 tumor responded to AZQ treatment with an increase in life span (ILS) of 37% compared to untreated controls and an ILS of 30% with CCNU treatment. BCNU and PCNU were ineffective. With the U-251 tumor BCNU produced an ILS of greater than 60%, with 75% cures, greater than 112% ILS with PCNU and 49% ILS with CCNU. Neither tumor responded to procarbazine, PALA, dianhydrogalactitol, D-O-norleucine or dibromodulcitol. The U-251 tumor was treated on various schedules and doses with BCNU and found to respond well on late as well as early treatment. A new drug (rapamycin) being investigated by the NCI was found to be very effective against the U-251 tumor. This model system should prove valuable in assessing the effects of various chemotherapeutic modalities against brain tumors. Topics: Animals; Antineoplastic Agents; Brain Neoplasms; Carmustine; Disease Models, Animal; Glioma; Humans; Medulloblastoma; Mice; Mice, Nude; Neoplasm Transplantation; Neoplasms, Experimental; Polyenes; Sirolimus; Transplantation, Heterologous | 1983 |