leptin has been researched along with Neoplasms* in 129 studies
69 review(s) available for leptin and Neoplasms
Article | Year |
---|---|
Obesity and cancer: focus on leptin.
Over the past decades, obesity has grown to epidemic proportions worldwide. It has been associated with an increased risk for different types of cancer. In addition, obesity has been associated with a poor prognosis, an increased risk of metastasis and mortality, and resistance to anti-cancer therapies. The pathophysiological mechanisms underlying the obesity-cancer connection have not yet been fully elucidated. However, this connection could result, at least in part, from the action of adipokines, whose levels are increased in obesity. Among these adipokines, evidence suggests leptin's critical role in linking obesity to cancer. In this review, we first summarize the current state of the literature regarding the implication of leptin in tumorigenic processes. Next, we focus on the effects of leptin on the anti-tumor immune response. Then, we discuss the influence of leptin on the efficiency of antineoplastic treatments and the development of tumor resistance. Finally, we highlight the use of leptin as a potential target for the prevention and treatment of cancer. Topics: Adipokines; Antineoplastic Agents; Humans; Leptin; Neoplasms; Obesity | 2023 |
Leptin: A Heavyweight Player in Obesity-Related Cancers.
Obesity, defined as the abnormal or excessive expansion of white adipose tissue, has reached pandemic proportions and is recognized as an important health concern since it is a common root for several comorbidities, including malignancies. Indeed, the current knowledge of the white adipose tissue, which shifts its role from an energy storage tissue to an important endocrine and metabolic organ, has opened up new avenues for the discovery of obesity's effects on tumor biology. In this review, we will report the epidemiological studies concerning the strong impact of obesity in several types of cancer and describe the mechanisms underlying the heterotypic signals between cancer cell lines and adipocytes, with particular emphasis on inflammation, the insulin/IGF-1 axis, and adipokines. Among the adipokines, we will further describe the in vitro, in vivo, and clinical data concerning the role of leptin, recognized as one of the most important mediators of obesity-associated cancers. In fact, leptin physiologically regulates energy metabolism, appetite, and reproduction, and several studies have also described the role of leptin in affecting cancer development and progression. Finally, we will summarize the newest pharmacological strategies aimed at mitigating the protumorigenic effects of leptin, underlining their mechanisms of action. Topics: Adipokines; Adipose Tissue; Humans; Leptin; Neoplasms; Obesity | 2023 |
Psychological distress among health care professionals of the three COVID-19 most affected Regions in Cameroon: Prevalence and associated factors.
The present study aimed to assess the prevalence of symptoms of anxiety and depression among health professionals in the three most affected regions in Cameroon.. The study was a descriptive cross-sectional type. Participants were health care professionals working in the three chosen regions of Cameroon. The non_probability convinient sample technique and that of the snowball were valued via a web questionnaire. The non-exhaustive sample size was 292. The diagnosis of anxiety and depression was made by the HAD (Hospital Anxiety and Depression scale).. Les auteurs rapportent que le secteur médical est classé à un plus grand risque de contracter le COVID-19 et de le propager potentiellement à d’autres. Le nombre sans cesse croissant de cas confirmés et suspects, la pression dans les soins, l’épuisement des équipements de protection individuelle et le manque de médicaments spécifiques peuvent contribuer à un vécu anxio-dépressif significatif. La présente étude s’est donnée pour ambition d’évaluer la prévalence des symptômes de l’anxiété et de la dépression chez les professionnels de santé dans les trois Régions les plus concernées au Cameroun.. Le choix des trois Régions du Cameroun se justifie non seulement par le fait qu’elles totalisent 95,8 % des cas de coronavirus au pays depuis le début de la pandémie, mais aussi parce qu’elles disposent de plus de la moitié des personnels de santé (56 %). Il s’agit d’une étude transversale, descriptive et analytique. Les participants sont des professionnels de la santé en service dans les Régions du Centre, Littoral et de l’Ouest du Cameroun. La méthode d’échantillonnage non probabiliste de convenance couplée à celle de boule de neige via un web questionnaire a été adoptée. La collecte des données a duré du 5 au 19 avril 2020, intervalle de temps après lequel on n’avait plus eu de répondants. À la fin de cette période, la taille de l’échantillon non exhaustive était de 292 professionnels. Le diagnostic de l’état anxio-dépressive était posé via l’échelle de HAD (Hospital Anxiety and Depression scale). Dans le HAD, chaque réponse cotée évalue de manière semi-quantitative l’intensité du symptôme au cours de la semaine écoulée. Un score total est obtenu ainsi que des scores aux deux sous-échelles : le score maximal est de 42 pour l’échelle globale et de 21 pour chacune des sous-échelles. Le coefficient alpha de Cronbach est de 0,70 pour la dépression et de 0,74 pour l’anxiété. Certains auteurs après plusieurs travaux ont proposé qu’une note inférieure ou égale à 7 indique une absence d’anxiété ou de dépression ; celle comprise entre 8 et 10 suggère une anxiété ou une dépression faible à bénigne ; entre 11 et 14, pour une anxiété ou une dépression modérée ; enfin, une note comprise entre 15 et 21 est révélatrice d’une anxiété sévère. Le logiciel Excel 2013 et Epi Info version 7.2.2.6 ont été utilisés pour les traitements statistiques. Les liens entre les variables ont été considérées significatifs pour une valeur de. L’amélioration des conditions de travail et notamment la fourniture d’équipement de protection, la mise en place des cellules spéciales d’écoute pour le personnel de santé pourraient être proposées.. Taken together with satisfactory selectivity index (SI) values, the acetone and methanol extracts of. During a mean follow-up period of 25.6 ± 13.9 months, 38 (18.4%) VAs and 78 (37.7%) end-stage events occurred. Big ET-1 was positively correlated with NYHA class (. In primary prevention ICD indication patients, plasma big ET-1 levels can predict VAs and end-stage events and may facilitate ICD-implantation risk stratification.. Beyond age, cognitive impairment was associated with prior MI/stroke, higher hsCRP, statin use, less education, lower eGFR, BMI and LVEF.. These data demonstrate that even a short period of detraining is harmful for elderly women who regularly participate in a program of strength training, since it impairs physical performance, insulin sensitivity and cholesterol metabolism.. Exposure to PM. Respiratory sinus arrhythmia is reduced after PVI in patients with paroxysmal AF. Our findings suggest that this is related to a decrease in cardiac vagal tone. Whether and how this affects the clinical outcome including exercise capacity need to be determined.. BDNF and leptin were not associated with weight. We found that miR-214-5p exerted a protective role in I/R injured cardiac cells by direct targeting FASLG. The results indicated that the MGO injection reduced all CCl. The hepatoprotective effects of MGO might be due to histopathological suppression and inflammation inhibition in the liver.. OVEO showed moderate antifungal activity, whereas its main components carvacrol and thymol have great application potential as natural fungicides or lead compounds for commercial fungicides in preventing and controlling plant diseases caused by. PF trajectories were mainly related to income, pregestational BMI, birth weight, hospitalisation due to respiratory diseases in childhood, participant's BMI, report of wheezing, medical diagnosis and family history of asthma, gestational exposure to tobacco and current smoking status in adolescence and young adult age.. In chronic pain patients on opioids, administration of certain benzodiazepine sedatives induced a mild respiratory depression but paradoxically reduced sleep apnoea risk and severity by increasing the respiratory arousal threshold.. Quantitative measurements of sensory disturbances using the PainVision. The serum level of 20S-proteasome may be a useful marker for disease activity in AAV.. The electrophysiological data and MD simulations collectively suggest a crucial role of the interactions between the HA helix and S4-S5 linker in the apparent Ca. Invited for the cover of this issue are Vanesa Fernández-Moreira, Nils Metzler-Nolte, M. Concepción Gimeno and co-workers at Universidad de Zaragoza and Ruhr-Universität Bochum. The image depicts the reported bimetallic bioconjugates as planes directing the gold fragment towards the target (lysosomes). Read the full text of the article at 10.1002/chem.202002067.. The optimal CRT pacing configuration changes during dobutamine infusion while LV and RV activation timing does not. Further studies investigating the usefulness of automated dynamic changes to CRT pacing configuration according to physiologic condition may be warranted. Topics: 3' Untranslated Regions; 5'-Nucleotidase; A549 Cells; Accidental Falls; Acetylcholinesterase; Acrylic Resins; Actinobacillus; Acute Disease; Acute Kidney Injury; Adaptor Proteins, Signal Transducing; Adenosine; Adenosine Triphosphate; Administration, Inhalation; Administration, Oral; Adolescent; Adult; Advance Care Planning; Africa, Northern; Age Factors; Aged; Aged, 80 and over; Air Pollutants; Air Pollution; Air Pollution, Indoor; Albendazole; Aluminum Oxide; Anastomosis, Surgical; Ancylostoma; Ancylostomiasis; Androstadienes; Angiogenesis Inhibitors; Angiotensin II; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Antibodies, Bispecific; Antibodies, Viral; Anticoagulants; Antihypertensive Agents; Antinematodal Agents; Antineoplastic Agents; Antineoplastic Agents, Immunological; Antineoplastic Combined Chemotherapy Protocols; Antioxidants; Antiporters; Antiviral Agents; Apoptosis; Aptamers, Nucleotide; Aromatase Inhibitors; Asian People; Astrocytes; Atrial Fibrillation; Auditory Threshold; Aurora Kinase B; Australia; Autophagy; Autophagy-Related Protein 5; Autotrophic Processes; Bacillus cereus; Bacillus thuringiensis; Bacterial Proteins; Beclin-1; Belgium; Benzene; Benzene Derivatives; Benzhydryl Compounds; beta Catenin; beta-Arrestin 2; Biliary Tract Diseases; Biofilms; Biofuels; Biomarkers; Biomarkers, Tumor; Biomass; Biomechanical Phenomena; Bioreactors; Biosensing Techniques; Biosynthetic Pathways; Bismuth; Blood Platelets; Bone and Bones; Bone Regeneration; Bortezomib; Botulinum Toxins, Type A; Brain; Brain Injuries; Brain Ischemia; Brain Neoplasms; Breast Neoplasms; Breath Tests; Bronchodilator Agents; Calcium Phosphates; Cannabis; Carbon Dioxide; Carbon Isotopes; Carcinogenesis; Carcinoma, Hepatocellular; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cardiac Resynchronization Therapy; Cardiac Resynchronization Therapy Devices; Cardiomyopathies; Cardiovascular Diseases; Cariostatic Agents; Case Managers; Case-Control Studies; Catalysis; Cation Transport Proteins; CD8-Positive T-Lymphocytes; Cecropia Plant; Cell Adhesion; Cell Count; Cell Differentiation; Cell Division; Cell Line; Cell Line, Tumor; Cell Membrane; Cell Movement; Cell Proliferation; Cell Self Renewal; Cell Survival; Cells, Cultured; Cellular Reprogramming; Cellulose; Charcoal; Chemical and Drug Induced Liver Injury; Chemical Phenomena; Chemokines; Chemoradiotherapy; Chemoreceptor Cells; Child; Child Abuse; Child, Preschool; China; Chlorogenic Acid; Chloroquine; Chromatography, Gas; Chronic Disease; Clinical Competence; Coated Materials, Biocompatible; Cochlea; Cohort Studies; Color; Comorbidity; Computer Simulation; Computer-Aided Design; Contraception; Contraceptive Agents, Female; Contrast Media; COP-Coated Vesicles; Coronavirus Infections; Cost of Illness; Coturnix; COVID-19; Creatinine; Cross-Over Studies; Cross-Sectional Studies; Culex; Curriculum; Cyclic N-Oxides; Cytokines; Cytoplasm; Cytotoxicity, Immunologic; Cytotoxins; Databases, Factual; Deep Learning; Delivery, Obstetric; Denitrification; Dental Caries; Denture, Complete; Dexamethasone; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dielectric Spectroscopy; Diet, High-Fat; Dietary Fiber; Disease Models, Animal; Disease Progression; DNA; DNA Copy Number Variations; DNA, Mitochondrial; Dog Diseases; Dogs; Dopaminergic Neurons; Double-Blind Method; Down-Regulation; Doxorubicin; Drug Carriers; Drug Design; Drug Interactions; Drug Resistance, Bacterial; Drug Resistance, Neoplasm; Drug-Related Side Effects and Adverse Reactions; Drugs, Chinese Herbal; Dry Powder Inhalers; Dust; E2F1 Transcription Factor; Ecosystem; Education, Nursing; Education, Nursing, Baccalaureate; Electric Impedance; Electricity; Electrocardiography; Electrochemical Techniques; Electrochemistry; Electrodes; Electrophoresis, Polyacrylamide Gel; Endoplasmic Reticulum; Endothelial Cells; Environmental Monitoring; Enzyme Inhibitors; Epithelial Cells; Epithelial-Mesenchymal Transition; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Estrogen Receptor Modulators; Europe; Evoked Potentials, Auditory, Brain Stem; Exosomes; Feasibility Studies; Female; Ferricyanides; Ferrocyanides; Fibrinogen; Finite Element Analysis; Fistula; Fluorescent Dyes; Fluorides, Topical; Fluorodeoxyglucose F18; Fluticasone; Follow-Up Studies; Food Contamination; Food Microbiology; Foods, Specialized; Forensic Medicine; Frail Elderly; France; Free Radicals; Fresh Water; Fungi; Fungicides, Industrial; Galactosamine; Gastrointestinal Neoplasms; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Frequency; Genetic Predisposition to Disease; Genotype; Gingival Hemorrhage; Glioblastoma; Glioma; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Glucose; Glucose Transport Proteins, Facilitative; Glucosides; Glutamine; Glycolysis; Gold; GPI-Linked Proteins; Gram-Negative Bacteria; Gram-Positive Bacteria; Graphite; Haplotypes; HCT116 Cells; Healthy Volunteers; Hearing Loss; Heart Failure; Hedgehog Proteins; HEK293 Cells; HeLa Cells; Hemodynamics; Hemorrhage; Hepatocytes; Hippo Signaling Pathway; Histone Deacetylases; Homeostasis; Hospital Mortality; Hospitalization; Humans; Hydantoins; Hydrazines; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; Hydroxylamines; Hypoglycemic Agents; Immunity, Innate; Immunoglobulin G; Immunohistochemistry; Immunologic Factors; Immunomodulation; Immunophenotyping; Immunotherapy; Incidence; Indazoles; Indonesia; Infant; Infant, Newborn; Infarction, Middle Cerebral Artery; Inflammation; Injections, Intramuscular; Insecticides; Insulin-Like Growth Factor I; Insurance, Health; Intention to Treat Analysis; Interleukin-1 Receptor-Associated Kinases; Interleukin-6; Intrauterine Devices; Intrauterine Devices, Copper; Iron; Ischemia; Jordan; Keratinocytes; Kidney; Kidney Diseases; Kir5.1 Channel; Klebsiella Infections; Klebsiella pneumoniae; Lab-On-A-Chip Devices; Laparoscopy; Lasers; Lasers, Semiconductor; Lenalidomide; Leptin; Lethal Dose 50; Levonorgestrel; Limit of Detection; Lipid Metabolism; Lipid Metabolism Disorders; Lipogenesis; Lipopolysaccharides; Liquid Biopsy; Liver; Liver Abscess, Pyogenic; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Longevity; Lung Neoplasms; Luteolin; Lymph Nodes; Lymphocyte Activation; Macaca fascicularis; Macrophages; Mad2 Proteins; Magnetic Resonance Imaging; Male; Mammary Glands, Human; Manganese; Manganese Compounds; MAP Kinase Signaling System; Materials Testing; Maternal Health Services; MCF-7 Cells; Medicaid; Medicine, Chinese Traditional; Melanoma; Membrane Proteins; Mental Health; Mercury; Metal Nanoparticles; Metals, Heavy; Metformin; Methionine Adenosyltransferase; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Knockout; Mice, Nude; Microalgae; Microbial Sensitivity Tests; Microglia; MicroRNAs; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Middle Aged; Mitochondria; Mitochondrial Proteins; Mitral Valve; Mitral Valve Insufficiency; Models, Anatomic; Molecular Structure; Molybdenum; Monocarboxylic Acid Transporters; Moths; MPTP Poisoning; Multigene Family; Multiparametric Magnetic Resonance Imaging; Multiple Myeloma; Muscle, Skeletal; Mutagens; Mutation; Myeloid Cells; Nanocomposites; Nanofibers; Nanomedicine; Nanoparticles; Nanowires; Neoadjuvant Therapy; Neomycin; Neoplasm Grading; Neoplasm Recurrence, Local; Neoplasms; Neoplastic Stem Cells; Neostriatum; Neovascularization, Pathologic; Netherlands; Neuromuscular Agents; Neurons; NF-E2-Related Factor 2; NF-kappa B; Nickel; Nitrogen Oxides; Non-alcoholic Fatty Liver Disease; Nucleosides; Nucleotidyltransferases; Nutritional Status; Obesity, Morbid; Ofloxacin; Oils, Volatile; Oligopeptides; Oncogene Protein v-akt; Optical Imaging; Organic Cation Transport Proteins; Organophosphonates; Osteoarthritis; Osteoarthritis, Hip; Osteoarthritis, Knee; Osteoblasts; Osteogenesis; Oxidation-Reduction; Oxidative Stress; Oxides; Oxygen Isotopes; Pancreas; Pancreaticoduodenectomy; Pandemics; Particle Size; Particulate Matter; Patient Acceptance of Health Care; Patient Compliance; PC-3 Cells; Peptide Fragments; Peptides; Periodontal Attachment Loss; Periodontal Index; Periodontal Pocket; Periodontitis; Peroxides; Peru; Pest Control, Biological; Phosphatidylinositol 3-Kinase; Phosphatidylinositol 3-Kinases; Phylogeny; Pilot Projects; Piperidines; Plant Bark; Plant Extracts; Plant Leaves; Plasmids; Platelet Function Tests; Pneumonia, Viral; Podocytes; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Polyethylene Terephthalates; Polymers; Polymorphism, Single Nucleotide; Porosity; Portugal; Positron-Emission Tomography; Postoperative Complications; Postural Balance; Potassium Channels, Inwardly Rectifying; Povidone; Powders; Precancerous Conditions; Precision Medicine; Predictive Value of Tests; Pregnancy; Prenatal Care; Prognosis; Promoter Regions, Genetic; Prospective Studies; Prostatectomy; Prostatic Neoplasms; Proteasome Inhibitors; Protective Agents; Protein Binding; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Protein Transport; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-akt; Psychiatric Nursing; PTEN Phosphohydrolase; Pulmonary Embolism; Pyrimethamine; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Rats, Wistar; Reactive Oxygen Species; Receptor, ErbB-2; Receptor, IGF Type 1; Receptors, Estrogen; Receptors, G-Protein-Coupled; Recombinational DNA Repair; Recovery of Function; Regional Blood Flow; Renal Dialysis; Renin; Renin-Angiotensin System; Reperfusion Injury; Reproducibility of Results; Republic of Korea; Respiratory Distress Syndrome; Retrospective Studies; Rhodamines; Risk Assessment; Risk Factors; RNA, Long Noncoding; RNA, Messenger; Running; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Salinity; Salmeterol Xinafoate; Sarcoma; Seasons; Shoulder Injuries; Signal Transduction; Silicon Dioxide; Silver; Sirtuin 1; Sirtuins; Skull Fractures; Social Determinants of Health; Sodium; Sodium Fluoride; Sodium Potassium Chloride Symporter Inhibitors; Sodium-Glucose Transporter 2 Inhibitors; Soil; Soil Pollutants; Spain; Spectrophotometry; Spectroscopy, Fourier Transform Infrared; Staphylococcal Protein A; Staphylococcus aureus; Stem Cells; Stereoisomerism; Stomach Neoplasms; Streptomyces; Strontium; Structure-Activity Relationship; Students, Nursing; Substance-Related Disorders; Succinic Acid; Sulfur; Surface Properties; Survival Rate; Survivin; Symporters; T-Lymphocytes; Temozolomide; Tensile Strength; Thiazoles; Thiobacillus; Thiohydantoins; Thiourea; Thrombectomy; Time Factors; Titanium; Tobacco Mosaic Virus; Tobacco Use Disorder; Toll-Like Receptor 4; Toluene; Tomography, X-Ray Computed; TOR Serine-Threonine Kinases; Toxicity Tests, Acute; Toxicity Tests, Subacute; Transcriptional Activation; Treatment Outcome; Troponin I; Tumor Cells, Cultured; Tumor Escape; Tumor Hypoxia; Tumor Microenvironment; Tumor Necrosis Factor Inhibitors; Tumor Necrosis Factor-alpha; Tyrosine; Ubiquitin-Protein Ligases; Ubiquitination; Ultrasonic Waves; United Kingdom; United States; United States Department of Veterans Affairs; Up-Regulation; Urea; Uric Acid; Urinary Bladder Neoplasms; Urinary Bladder, Neurogenic; Urine; Urodynamics; User-Computer Interface; Vemurafenib; Verbenaceae; Veterans; Veterans Health; Viral Load; Virtual Reality; Vitiligo; Water Pollutants, Chemical; Wildfires; Wnt Signaling Pathway; Wound Healing; X-Ray Diffraction; Xenograft Model Antitumor Assays; Xylenes; Young Adult; Zinc; Zinc Oxide; Zinc Sulfate; Zoonoses | 2021 |
Nutritional modulation of leptin expression and leptin action in obesity and obesity-associated complications.
In obesity, an elevated accumulation and dysregulation of adipose tissue, due to an imbalance between energy intake and energy expenditure, usually coexists with the loss of responsiveness to leptin in central nervous system, and subsequently with hyperleptinemia. Leptin, a peptide hormone mainly produced by white adipose tissue, regulates energy homeostasis by stimulating energy expenditure and inhibiting food intake. Human obesity is characterized by increased plasma leptin levels, which have been related with different obesity-associated complications, such as chronic inflammatory state (risk factor for diabetes, cardiovascular and autoimmune diseases), as well as infertility and different types of cancer. Besides, leptin is also produced by placenta, and high leptin levels during pregnancy may be related with some pathological conditions such as gestational diabetes. This review focuses on the current insights and emerging concepts on potentially valuable nutrients and food components that may modulate leptin metabolism. Notably, several dietary food components, such as phenols, peptides, and vitamins, are able to decrease inflammation and improve leptin sensitivity by up- or down-regulation of leptin signaling molecules. On the other hand, some food components, such as saturated fatty acids may worsen chronic inflammation increasing the risk for pathological complications. Future research into nutritional mechanisms that restore leptin metabolism and signals of energy homeostasis may inspire new treatment options for obesity-related disorders. Topics: Adipose Tissue; Adipose Tissue, White; Animals; Autoimmune Diseases; Diabetes Mellitus; Energy Intake; Energy Metabolism; Fatty Acids; Female; Humans; Infertility; Inflammation; Leptin; Male; Neoplasms; Nutritional Physiological Phenomena; Obesity | 2021 |
Contribution of RAGE axis activation to the association between metabolic syndrome and cancer.
Far beyond the compelling proofs supporting that the metabolic syndrome represents a risk factor for diabetes and cardiovascular diseases, a growing body of evidence suggests that it is also a risk factor for different types of cancer. However, the involved molecular mechanisms underlying this association are not fully understood, and they have been mainly focused on the individual contributions of each component of the metabolic syndrome such as obesity, hyperglycemia, and high blood pressure to the development of cancer. The Receptor for Advanced Glycation End-products (RAGE) axis activation has emerged as an important contributor to the pathophysiology of many clinical entities, by fueling a chronic inflammatory milieu, and thus supporting an optimal microenvironment to promote tumor growth and progression. In the present review, we intend to highlight that RAGE axis activation is a crosswise element on the potential mechanistic contributions of some relevant components of metabolic syndrome into the association with cancer. Topics: Adiponectin; Adipose Tissue; Animals; Disease Progression; Gene Expression Regulation; Humans; Hyperglycemia; Hypertension; Inflammation; Insulin-Like Growth Factor I; Leptin; Ligands; Metabolic Syndrome; Mice; Neoplasms; Obesity; Peroxisome Proliferator-Activated Receptors; Rats; Receptor for Advanced Glycation End Products; Signal Transduction; Vascular Endothelial Growth Factor A; Wnt Proteins | 2021 |
Tumor Metabolic Reprogramming by Adipokines as a Critical Driver of Obesity-Associated Cancer Progression.
Adiposity is associated with an increased risk of various types of carcinoma. One of the plausible mechanisms underlying the tumor-promoting role of obesity is an aberrant secretion of adipokines, a group of hormones secreted from adipose tissue, which have exhibited both oncogenic and tumor-suppressing properties in an adipokine type- and context-dependent manner. Increasing evidence has indicated that these adipose tissue-derived hormones differentially modulate cancer cell-specific metabolism. Some adipokines, such as leptin, resistin, and visfatin, which are overproduced in obesity and widely implicated in different stages of cancer, promote cellular glucose and lipid metabolism. Conversely, adiponectin, an adipokine possessing potent anti-tumor activities, is linked to a more favorable metabolic phenotype. Adipokines may also play a pivotal role under the reciprocal regulation of metabolic rewiring of cancer cells in tumor microenvironment. Given the fact that metabolic reprogramming is one of the major hallmarks of cancer, understanding the modulatory effects of adipokines on alterations in cancer cell metabolism would provide insight into the crosstalk between obesity, adipokines, and tumorigenesis. In this review, we summarize recent insights into putative roles of adipokines as mediators of cellular metabolic rewiring in obesity-associated tumors, which plays a crucial role in determining the fate of tumor cells. Topics: Adipokines; Adipose Tissue; Adiposity; Animals; Disease Progression; Glucose; Glycolysis; Humans; Inflammation; Leptin; Lipid Metabolism; Mice; Mitochondria; Neoplasms; Nicotinamide Phosphoribosyltransferase; Obesity; Oxidation-Reduction; Phenotype; Reactive Oxygen Species; Resistin; Tumor Microenvironment | 2021 |
Obesity-Associated Myeloid Immunosuppressive Cells, Key Players in Cancer Risk and Response to Immunotherapy.
Obesity is a risk factor for developing several cancers. The dysfunctional metabolism and chronic activation of inflammatory pathways in obesity create a milieu that supports tumor initiation, progression, and metastasis. Obesity-associated metabolic, endocrine, and inflammatory mediators, besides interacting with cells leading to a malignant transformation, also modify the intrinsic metabolic and functional characteristics of immune myeloid cells. Here, the evidence supporting the hypothesis that obesity metabolically primes and promotes the expansion of myeloid cells with immunosuppressive and pro-oncogenic properties is discussed. In consequence, the accumulation of these cells, such as myeloid-derived suppressor cells and some subtypes of adipose-tissue macrophages, creates a microenvironment conducive to tumor development. In this review, the role of lipids, insulin, and leptin, which are dysregulated in obesity, is emphasized, as well as dietary nutrients in metabolic reprogramming of these myeloid cells. Moreover, emerging evidence indicating that obesity enhances immunotherapy response and hypothesized mechanisms are summarized. Priorities in deeper exploration involving the mechanisms of cross talk between metabolic disorders and myeloid cells related to cancer risk in patients with obesity are highlighted. Topics: Adipose Tissue; Animals; Carcinogenesis; Humans; Immunotherapy; Inflammation Mediators; Leptin; Macrophages; Myeloid-Derived Suppressor Cells; Neoplasm Metastasis; Neoplasms; Obesity; Risk Factors; Tumor Microenvironment | 2021 |
Leptin and Cancer: Updated Functional Roles in Carcinogenesis, Therapeutic Niches, and Developments.
Leptin is an obesity-associated adipokine that is known to regulate energy metabolism and reproduction and to control appetite via the leptin receptor. Recent work has identified specific cell types other than adipocytes that harbor leptin and leptin receptor expression, particularly in cancers and tumor microenvironments, and characterized the role of this signaling axis in cancer progression. Furthermore, the prognostic significance of leptin in various types of cancer and the ability to noninvasively detect leptin levels in serum samples have attracted attention for potential clinical applications. Emerging findings have demonstrated the direct and indirect biological effects of leptin in regulating cancer proliferation, metastasis, angiogenesis and chemoresistance, warranting the exploration of the underlying molecular mechanisms to develop a novel therapeutic strategy. In this review article, we summarize and integrate transcriptome and clinical data from cancer patients together with the recent findings related to the leptin signaling axis in the aforementioned malignant phenotypes. In addition, a comprehensive analysis of leptin and leptin receptor distribution in a pancancer panel and in individual cell types of specific organs at the single-cell level is presented, identifying those sites that are prone to leptin-mediated tumorigenesis. Our results shed light on the role of leptin in cancer and provide guidance and potential directions for further research for scientists in this field. Topics: Adipocytes; Animals; Carcinogenesis; Humans; Leptin; Neoplasms; Obesity; Receptors, Leptin; Signal Transduction; Tumor Microenvironment | 2021 |
The pleiotropic roles of leptin in metabolism, immunity, and cancer.
The discovery of the archetypal adipocytokine leptin and how it regulates energy homeostasis have represented breakthroughs in our understanding of the endocrine function of the adipose tissue and the biological determinants of human obesity. Investigations on leptin have also been instrumental in identifying physio-pathological connections between metabolic regulation and multiple immunological functions. For example, the description of the promoting activities of leptin on inflammation and cell proliferation have recognized the detrimental effects of leptin in connecting dysmetabolic conditions with cancer and with onset and/or progression of autoimmune disease. Here we review the multiple biological functions and complex framework of operations of leptin, discussing why and how the pleiotropic activities of this adipocytokine still pose major hurdles in the development of effective leptin-based therapeutic opportunities for different clinical conditions. Topics: Animals; Energy Metabolism; Gene Expression Regulation; Homeostasis; Humans; Inflammation; Leptin; Mutation; Neoplasms; Obesity | 2021 |
Advances in Understanding of the Role of Lipid Metabolism in Aging.
During aging, body adiposity increases with changes in the metabolism of lipids and their metabolite levels. Considering lipid metabolism, excess adiposity with increased lipotoxicity leads to various age-related diseases, including cardiovascular disease, cancer, arthritis, type 2 diabetes, and Alzheimer's disease. However, the multifaceted nature and complexities of lipid metabolism make it difficult to delineate its exact mechanism and role during aging. With advances in genetic engineering techniques, recent studies have demonstrated that changes in lipid metabolism are associated with aging and age-related diseases. Lipid accumulation and impaired fatty acid utilization in organs are associated with pathophysiological phenotypes of aging. Changes in adipokine levels contribute to aging by modulating changes in systemic metabolism and inflammation. Advances in lipidomic techniques have identified changes in lipid profiles that are associated with aging. Although it remains unclear how lipid metabolism is regulated during aging, or how lipid metabolites impact aging, evidence suggests a dynamic role for lipid metabolism and its metabolites as active participants of signaling pathways and regulators of gene expression. This review describes recent advances in our understanding of lipid metabolism in aging, including established findings and recent approaches. Topics: Adiponectin; Adipose Tissue; Adiposity; Aging; Alzheimer Disease; Arthritis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Fatty Acids; Gene Expression Regulation; Humans; Leptin; Lipid Metabolism; Lipidomics; Neoplasms; Obesity; Signal Transduction | 2021 |
Leptin, Both Bad and Good Actor in Cancer.
Leptin is an important regulator of basal metabolism and food intake, with a pivotal role in obesity. Leptin exerts many different actions on various tissues and systems, including cancer, and is considered as a linkage between metabolism and the immune system. During the last decades, obesity and leptin have been associated with the initiation, proliferation and progression of many types of cancer. Obesity is also linked with complications and mortality, irrespective of the therapy used, affecting clinical outcomes. However, some evidence has suggested its beneficial role, called the "obesity paradox", and the possible antitumoral role of leptin. Recent data regarding the immunotherapy of cancer have revealed that overweight leads to a more effective response and leptin may probably be involved in this beneficial process. Since leptin is a positive modulator of both the innate and the adaptive immune system, it may contribute to the increased immune response stimulated by immunotherapy in cancer patients and may be proposed as a good actor in cancer. Our purpose is to review this dual role of leptin in cancer, as well as trying to clarify the future perspectives of this adipokine, which further highlights its importance as a cornerstone of the immunometabolism in oncology. Topics: Adaptive Immunity; Animals; Humans; Immunotherapy; Leptin; Neoplasm Proteins; Neoplasms; Obesity | 2021 |
Leptin in Tumor Microenvironment.
Leptin is a hormone that plays a major role as mediator of long-term regulation of energy balance, suppressing food intake, and stimulating weight loss. More recently, important physiological roles other than controlling appetite and energy expenditure have been suggested for leptin, including neuroendocrine, reparative, reproductive, and immune functions. These emerging peripheral roles let hypothesize that leptin can modulate also cancer progression. Indeed, many studies have demonstrated that elevated chronic serum concentrations of leptin, frequently seen in obese subjects, represent a stimulatory signal for tumor growth. Current knowledge indicates that also different non-tumoral cells resident in tumor microenvironment may respond to leptin creating a favorable soil for cancer cells. In addition, leptin is produced also within the tumor microenvironment creating the possibility for paracrine and autocrine action. In this review, we describe the main mechanisms that regulate peripheral leptin availability and how leptin can shape tumor microenvironment. Topics: Animals; Energy Metabolism; Humans; Leptin; Neoplasms; Obesity; Tumor Microenvironment | 2020 |
New Actors Driving the Epithelial-Mesenchymal Transition in Cancer: The Role of Leptin.
Leptin is a hormone secreted mainly by adipocytes; physiologically, it participates in the control of appetite and energy expenditure. However, it has also been linked to tumor progression in different epithelial cancers. In this review, we describe the effect of leptin on epithelial-mesenchymal transition (EMT) markers in different study models, including in vitro, in vivo, and patient studies and in various types of cancer, including breast, prostate, lung, and ovarian cancer. The different studies report that leptin promotes the expression of mesenchymal markers and a decrease in epithelial markers, in addition to promoting EMT-related processes such as cell migration and invasion and poor prognosis in patients with cancer. Finally, we report that leptin has the greatest biological relevance in EMT and tumor progression in breast, lung, prostate, esophageal, and ovarian cancer. This relationship could be due to the key role played by the enriched tumor microenvironment in adipose tissue. Together, these findings demonstrate that leptin is a key biomolecule that drives EMT and metastasis in cancer. Topics: Animals; Biomarkers, Tumor; Epithelial-Mesenchymal Transition; Humans; Leptin; Models, Biological; Neoplasms; Signal Transduction | 2020 |
Protein Tyrosine Phosphatase (PTP1B): A promising Drug Target Against Life-threatening Ailments.
Protein tyrosine phosphatases are enzymes which help in the signal transduction in diabetes, obesity, cancer, liver diseases and neurodegenerative diseases. PTP1B is the main member of this enzyme from the protein extract of human placenta. In phosphate inhibitors development, significant progress has been made over the last 10 years. In early-stage clinical trials, few compounds have reached whereas in the later stage trials or registration, yet none have progressed. Many researchers investigate different ways to improve the pharmacological properties of PTP1B inhibitors.. In the present review, authors have summarized various aspects related to the involvement of PTP1B in various types of signal transduction mechanisms and its prominent role in various diseases like cancer, liver diseases and diabetes mellitus.. There are still certain challenges for the selection of PTP1B as a drug target. Therefore, continuous future efforts are required to explore this target for the development of PTP inhibitors to treat the prevailing diseases associated with it. Topics: Animals; Antineoplastic Agents; Diabetes Mellitus; Drug Design; Drug Evaluation, Preclinical; Enzyme Inhibitors; Female; Forecasting; Humans; Hypoglycemic Agents; Insulin; Leptin; Mice; Models, Molecular; Molecular Targeted Therapy; Neoplasm Proteins; Neoplasms; Neurodegenerative Diseases; Neuroprotective Agents; Placenta; Pregnancy; Protein Conformation; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Signal Transduction | 2020 |
Leptin-induced signaling pathways in cancer cell migration and invasion.
Increasing evidence indicates that obesity is associated with tumor development and progression. Leptin is an adipocyte-related hormone with a key role in energy metabolism and whose circulating levels are elevated in obesity. The effect of leptin on cancer progression and metastasis and its underlying mechanisms are still unclear. Leptin can impact various steps in tumor metastasis, including epithelial-mesenchymal transition, cell adhesion to the extracellular matrix (ECM), and proteolysis of ECM components. To do so, leptin binds to its receptor (OB-Rb) to activate signaling pathways and downstream effectors that participate in tumor cell invasion as well as distant metastasis.. In this review, we describe metastasis steps in detail and characterize metastasis-related molecules activated by leptin, which may help to develop a roadmap that guides future work. In addition, we conclude that a profound understanding of the fundamental molecular processes that contribute to leptin-induced metastasis may pave the way for the development of new prognostic molecules and appropriate approaches to the treatment of obesity-related cancers. Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; HT29 Cells; Humans; Leptin; MCF-7 Cells; Neoplasm Invasiveness; Neoplasms; Signal Transduction | 2019 |
Adipokines Regulate the Expression of Tumor-Relevant MicroRNAs.
Increasing prevalence of obesity requires the investigation of respective comorbidities, including tumor diseases like colorectal, renal, post-menopausal breast, prostate cancer, and leukemia. To date, molecular mechanisms of the malignant transformation of these peripheral tissues induced by obesity remain unclear. Adipose tissue secretes factors with hormone-like functions, the adipokines, and is therefore categorized as an endocrine organ. Current research demonstrates the ability of adipose tissue to alter DNA methylation and gene expression in peripheral tissues, probably affecting microRNA (miR) expression.. Literature was analyzed for adipokine-regulated miRs. Many of these adipokine upregulated or downregulated miRs exert either oncogenic or anti-tumoral potential.. The three selected and analyzed adipokines, adiponectin, leptin, and resistin, induce more strongly oncogenic miRs and simultaneously reduce anti-tumoral miRs than vice versa. This effect is not only true for the pure number of regulated miRs, it is also the case by consideration of the abundance of the respective miR expression based on actual data sets derived from next-generation sequencing.. The link of obesity and cancer is analyzed under the aspect of adipokine-regulated miRs. At the same time the impact of miR abundance is considered as a regulatory variable. This context offers new strategies for tumor therapy and diagnostics. Topics: Adipokines; Adipose Tissue; Female; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Leptin; Male; MicroRNAs; Neoplasms; Obesity; Oncogenes | 2019 |
Disease prevention and delayed aging by dietary sulfur amino acid restriction: translational implications.
Sulfur amino acids (SAAs) play numerous critical roles in metabolism and overall health maintenance. Preclinical studies have demonstrated that SAA-restricted diets have many beneficial effects, including extending life span and preventing the development of a variety of diseases. Dietary sulfur amino acid restriction (SAAR) is characterized by chronic restrictions of methionine and cysteine but not calories and is associated with reductions in body weight, adiposity and oxidative stress, and metabolic changes in adipose tissue and liver resulting in enhanced insulin sensitivity and energy expenditure. SAAR-induced changes in blood biomarkers include reductions in insulin, insulin-like growth factor-1, glucose, and leptin and increases in adiponectin and fibroblast growth factor 21. On the basis of these preclinical data, SAAR may also have similar benefits in humans. While little is known of the translational significance of SAAR, its potential feasibility in humans is supported by findings of its effectiveness in rodents, even when initiated in adult animals. To date, there have been no controlled feeding studies of SAAR in humans; however, there have been numerous relevant epidemiologic and disease-based clinical investigations reported. Here, we summarize observations from these clinical investigations to provide insight into the potential effectiveness of SAAR for humans. Topics: Adiponectin; Adipose Tissue; Amino Acids, Sulfur; Animals; Biomarkers; Blood Glucose; Cardiovascular Diseases; Diet; Energy Metabolism; Fibroblast Growth Factors; Humans; Insulin; Insulin Resistance; Insulin-Like Growth Factor I; Leptin; Liver; Models, Animal; Neoplasms | 2018 |
The role of pregnancy, perinatal factors and hormones in maternal cancer risk: a review of the evidence.
An understanding of the origin of cancer is critical for cancer prevention and treatment. Complex biological mechanisms promote carcinogenesis, and there is increasing evidence that pregnancy-related exposures influence foetal growth cell division and organ functioning and may have a long-lasting impact on health and disease susceptibility in the mothers and offspring. Nulliparity is an established risk factor for breast, ovarian, endometrial and possibly pancreatic cancer, whilst the risk of kidney cancer is elevated in parous compared with nulliparous women. For breast, endometrial and ovarian cancer, each pregnancy provides an additional risk reduction. The associations of parity with thyroid and colorectal cancers are uncertain. The timing of reproductive events is also recognized to be important. Older age at first birth is associated with an increased risk of breast cancer, and older age at last birth is associated with a reduced risk of endometrial cancer. The risks of breast and endometrial cancers increase with younger age at menarche and older age at menopause. The mechanisms, and hormone profiles, that underlie alterations in maternal cancer risk are not fully understood and may differ by malignancy. Linking health registries and pooling of data in the Nordic countries have provided opportunities to conduct epidemiologic research of pregnancy exposures and subsequent cancer. We review the maternal risk of several malignancies, including those with a well-known hormonal aetiology and those with less established relationships. The tendency for women to have fewer pregnancies and at later ages, together with the age-dependent increase in the incidence of most malignancies, is expected to affect the incidence of pregnancy-associated cancer. Topics: Age Factors; Chorionic Gonadotropin; Epigenesis, Genetic; Estrogen Replacement Therapy; Estrogens; Female; Humans; Leptin; Menarche; Menopause; Neoplasms; Parity; Pre-Eclampsia; Pregnancy; Progesterone; Risk Assessment; Somatomedins | 2018 |
Myeloid derived-suppressor cells: their role in cancer and obesity.
Myeloid-derived suppressor cells (MDSC) are present in most individuals with cancer where they inhibit adaptive and innate antitumor immunity and are an obstacle to cancer immunotherapies. Chronic inflammation is characteristic of adipose tissue and is a risk factor for the onset and progression of cancer in obese individuals. Because MDSC accumulate in response to inflammation, it has been hypothesized that one of the mechanisms by which obesity promotes malignancy is through the induction of MDSC. This article reviews the data supporting this hypothesis, the role of leptin and fatty acid metabolism in the induction of MDSC, and the surprising finding that although MDSC promote tumor progression, they are protective against some of the metabolic dysfunction associated with obesity. Topics: Adipokines; Adipose Tissue; Animals; Cell Communication; Cellular Microenvironment; Chronic Disease; Disease Progression; Disease Susceptibility; Fatty Acids; Humans; Immune System; Immunomodulation; Inflammation; Leptin; Myeloid-Derived Suppressor Cells; Neoplasms; Obesity | 2018 |
Appetite hormones in children and adolescents with cancer: a systematic review of observational studies.
Malnutrition in children with cancer is a significant risk factor for negative outcomes, but in the clinical practice setting, it is difficult to pinpoint which factors operate to cause substantial weight loss and malnutrition in a given patient. Appetite-related hormones like ghrelin and leptin are among possible mediators. However, only few studies have examined the role of these hormones in pediatric patients with cancer to date. Thus, the purpose of this study was to systematically review possible changes in the levels of appetite hormones, specially leptin and ghrelin, in pediatric patients with cancer.. We systematically reviewed the literature using PubMed, Lilacs and Scielo, as well as manual bibliographical reference search of the studies. According to the Medical Subject Headings of the National Library of Medicine (MeSH), "childhood cancer", "ghrelin" and "leptin" were used as descriptors.. Fifteen studies were included in this systematic review published in English, from 2000 to 2015. A total of 863 patients were evaluated, ages ranging from 0 to 21 years, and most of the studies reported on children and adolescents with acute lymphoblastic leukemia (ALL) survivors. Most studies analyzed leptin levels; only two studies evaluated levels of ghrelin.. This review confirms that changes in the responses of the ghrelin and leptin hormones in children and adolescents with cancer are quite diverse, probably due to the different types of cancer observed, different treatments performed and biological characteristics of this age group. Topics: Adolescent; Appetite Regulation; Child; Ghrelin; Hormones; Humans; Leptin; Neoplasms; Observational Studies as Topic | 2018 |
Energy imbalance and cancer: Cause or consequence?
Obesity has been an epidemic worldwide over the past decades and significantly increases the risk of developing a variety of deadly diseases including type 2 diabetes, cardiovascular diseases and many cancers. The relationship between obesity and type 2 diabetes and cardiovascular disease has been well documented. The drastically increased frequency of a number of cancers in obesity has attracted growing interest. On one hand, how increased adiposity promotes cancer development remains poorly understood, despite the fact that considerable epidemiological evidence has suggested links between them. On the other hand, however, numerous studies have shown that tumorigenesis leads to substantial weight loss in a large portion of cancer patients. Here, we summarize the recent advances on our understanding of the link between obesity and cancer development with a focus on the molecular mechanisms accounting for the rising cancer incidence in the context of obesity. In addition, we also discuss how cancer-associated anorexia and cachexia causes weight loss. © 2017 IUBMB Life, 69(10):776-784, 2017. Topics: Anorexia; Body Mass Index; Cachexia; Cytokines; Energy Metabolism; Gene Expression Regulation, Neoplastic; Humans; Insulin Resistance; Leptin; Neoplasms; NF-kappa B; Obesity; Receptors, Leptin; Risk Factors; Signal Transduction; STAT3 Transcription Factor | 2017 |
The potential role of leptin in tumor invasion and metastasis.
The adipocyte-released hormone-like cytokine/adipokine leptin behaves differently in obesity compared to its functions in the normal healthy state. In obese individuals, elevated leptin levels act as a pro-inflammatory adipokine and are associated with certain types of cancers. Further, a growing body of evidence suggests that higher circulating leptin concentrations and/or elevated expression of leptin receptors (Ob-R) in tumors may be poor prognostic factors. Although the underlying pathological mechanisms of leptin's association with poor prognosis are not clear, leptin can impact the tumor microenvironment in several ways. For example, leptin is associated with a number of biological components that could lead to tumor cell invasion and distant metastasis. This includes interactions with carcinoma-associated fibroblasts, tumor promoting effects of infiltrating macrophages, activation of matrix metalloproteinases, transforming growth factor-β signaling, etc. Recent studies also have shown that leptin plays a role in the epithelial-mesenchymal transition, an important phenomenon for cancer cell migration and/or metastasis. Furthermore, leptin's potentiating effects on insulin-like growth factor-I, epidermal growth factor receptor and HER2/neu have been reported. Regarding unfavorable prognosis, leptin has been shown to influence both adenocarcinomas and squamous cell carcinomas. Features of poor prognosis such as tumor invasion, lymph node involvement and distant metastasis have been recorded in several cancer types with higher levels of leptin and/or Ob-R. This review will describe the current scenario in a precise manner. In general, obesity indicates poor prognosis in cancer patients. Topics: Animals; Cell Movement; Humans; Leptin; Neoplasm Metastasis; Neoplasms; Obesity; Signal Transduction | 2017 |
The Inverse Relationship Between Cancer and Alzheimer's Disease: A Possible Mechanism.
Cancer and Alzheimer's disease (AD) are both associated with aging, but do not often occur together. Obesity is a shared risk factor for both diseases and may be involved in this curious clinical observation. Fat cells produce many active substances, including leptin and adiponectin; leptin has cancer stimulating and AD inhibiting properties, while adiponectin can inhibit cancer but stimulate AD.. To describe the opposing effects of leptin and adiponectin on cancer and AD, to outline signaling pathways involved in these effects and to suggest new research on effective control strategies for both diseases.. A review was conducted to document the inverse cancer/AD relationship and the role of excess body fat as a common risk factor. Previous studies have suggested the involvement of p53, Wnt and other cell signaling pathways in this inverse relationship. The opposing effects of leptin and adiponectin on these signaling pathways in cancer and AD were evaluated.. The inverse cancer/AD relationship is well documented, as is the role of excess body fat, especially central obesity, in increasing risk for both diseases. Leptin and adiponectin have opposing effects in cancer and AD mediated by signaling factors that influence apoptosis, angiogenesis, and other cell growth controls. Wnt and p53 are prominent among these signaling factors.. Opposing effects of leptin and adiponectin, mediated by specific cell signaling pathways, are involved in the inverse cancer/Ad relationship. Future research aimed at modifying the leptin/adiponectin ratio may lead to important treatment and control approaches in both cancer and AD. Topics: Adiponectin; Alzheimer Disease; Animals; Humans; Leptin; Neoplasms; Risk Factors; Signal Transduction; Tumor Suppressor Protein p53 | 2017 |
Targeting obesity-related adipose tissue dysfunction to prevent cancer development and progression.
The incidence of obesity, a leading modifiable risk factor for common solid tumors, is increasing. Effective interventions are needed to minimize the public health implications of obesity. Although the mechanisms linking increased adiposity to malignancy are incompletely understood, growing evidence points to complex interactions among multiple systemic and tissue-specific pathways including inflamed white adipose tissue. The metabolic and inflammatory consequences of white adipose tissue dysfunction collectively provide a plausible explanation for the link between overweight/obesity and carcinogenesis. Gaining a better understanding of these underlying molecular pathways and developing risk assessment tools that identify at-risk populations will be critical in implementing effective and novel cancer prevention and management strategies. Topics: Adiponectin; Adipose Tissue, White; Androgens; Estrogens; Humans; Inflammation; Insulin Resistance; Leptin; Lipid Metabolism; Neoplasms; Obesity | 2016 |
Tumour biology of obesity-related cancers: understanding the molecular concept for better diagnosis and treatment.
Obesity continues to be a major global problem. Various cancers are related to obesity and proper understanding of their aetiology, especially their molecular tumour biology is important for early diagnosis and better treatment. Genes play an important role in the development of obesity. Few genes such as leptin, leptin receptor encoded by the db (diabetes), pro-opiomelanocortin, AgRP and NPY and melanocortin-4 receptors and insulin-induced gene 2 were linked to obesity. MicroRNAs control gene expression via mRNA degradation and protein translation inhibition and influence cell differentiation, cell growth and cell death. Overexpression of miR-143 inhibits tumour growth by suppressing B cell lymphoma 2, extracellular signal-regulated kinase-5 activities and KRAS oncogene. Cancers of the breast, uterus, renal, thyroid and liver are also related to obesity. Any disturbance in the production of sex hormones and insulin, leads to distortion in the balance between cell proliferation, differentiation and apoptosis. The possible mechanism linking obesity to cancer involves alteration in the level of adipokines and sex hormones. These mediators act as biomarkers for cancer progression and act as targets for cancer therapy and prevention. Interestingly, many anti-cancerous drugs are also beneficial in treating obesity and vice versa. We also reviewed the possible link in the mechanism of few drugs which act both on cancer and obesity. The present review may be important for molecular biologists, oncologists and clinicians treating cancers and also pave the way for better therapeutic options. Topics: Adipokines; Agouti-Related Protein; Animals; Brain-Derived Neurotrophic Factor; Extracellular Signal-Regulated MAP Kinases; Female; Gonadal Steroid Hormones; Humans; Intracellular Signaling Peptides and Proteins; Leptin; Male; Membrane Proteins; Mice; MicroRNAs; Neoplasms; Neuropeptide Y; Obesity; Pro-Opiomelanocortin; Receptor, Melanocortin, Type 4; Receptors, Leptin | 2016 |
Obesity, adipokines and cancer: an update.
Obesity causes dysfunction of adipose tissue, with resultant chronic inflammation and adverse interplay of various adipokines, sex steroids and endocrine hormones. All these drive tumourigenesis and explain the epidemiological link between obesity and cancer. Over the past decade, the associations among obesity, adipokines and cancer have been increasingly recognized. Adipokines and their respective signalling pathways have drawn much research attention in the field of oncology and cancer therapeutics. This review will discuss the recent advances in the understanding of the association of several adipokines with common obesity-related cancers and the clinical therapeutic implications. Topics: Adipokines; Adiponectin; Adipose Tissue; Animals; Female; Hormones; Humans; Inflammation; Interleukin-6; Leptin; Male; Neoplasms; Obesity; Signal Transduction; Tumor Necrosis Factor-alpha | 2015 |
Molecular targeting of obesity pathways in cancer.
Obesity is a significant risk factor for the development of different cancer types and has been associated with poorer response to oncotherapies and linked to earlier recurrence of the neoplastic disease. While molecular mechanisms of these associations are still under investigation, functional dysregulation of two major fat tissue-derived adipokines, leptin and adiponectin, appears to play an important role. Leptin is known to activate carcinogenic pathways, while adiponectin appears to exert antineoplastic activities and interfere with leptin-induced processes. Because excess body fat is associated with increased leptin expression and adiponectin downregulation, therapeutic rebalancing of these pathways may benefit cancer patients, especially the obese subpopulations. This review focuses on our novel leptin receptor antagonists and adiponectin receptor agonists designed for therapeutic modulation of obesity-associated pathways in cancer. Topics: Adiponectin; Animals; Antineoplastic Agents; Biomimetics; Humans; Leptin; Metabolic Networks and Pathways; Molecular Targeted Therapy; Neoplasm Recurrence, Local; Neoplasms; Obesity; Peptides; Receptors, Adiponectin; Receptors, Leptin | 2015 |
Cancer as a Proinflammatory Environment: Metastasis and Cachexia.
The development of the syndrome of cancer cachexia and that of metastasis are related with a poor prognostic for cancer patients. They are considered multifactorial processes associated with a proinflammatory environment, to which tumour microenvironment and other tissues from the tumour bearing individuals contribute. The aim of the present review is to address the role of ghrelin, myostatin, leptin, HIF, IL-6, TNF-α, and ANGPTL-4 in the regulation of energy balance, tumour development, and tumoural cell invasion. Hypoxia induced factor plays a prominent role in tumour macro- and microenvironment, by modulating the release of proinflammatory cytokines. Topics: Angiopoietin-Like Protein 4; Angiopoietins; Animals; Cachexia; Cytokines; Ghrelin; Humans; Hypoxia; Hypoxia-Inducible Factor 1; Inflammation; Interleukin-6; Leptin; Myostatin; Neoplasm Metastasis; Neoplasms; Prognosis; Syndrome; Tumor Microenvironment; Tumor Necrosis Factor-alpha | 2015 |
Potential Biomarkers of Fat Loss as a Feature of Cancer Cachexia.
Fat loss is associated with shorter survival and reduced quality of life in cancer patients. Effective intervention for fat loss in cachexia requires identification of the condition using prognostic biomarkers for early detection and prevention of further depletion. No biomarkers of fat mass alterations have been defined for application to the neoplastic state. Several inflammatory cytokines have been implicated in mediating fat loss associated with cachexia; however, plasma levels may not relate to adipose atrophy. Zinc-α2-glycoprotein may be a local catabolic mediator within adipose tissue rather than serving as a plasma biomarker of fat loss. Plasma glycerol and leptin associate with adipose tissue atrophy and mass, respectively; however, no study has evaluated their potential as a prognostic biomarker of cachexia-associated fat loss. This review confirms the need for further studies to identify valid prognostic biomarkers to identify loss of fat based on changes in plasma levels of biomarkers. Topics: Adipokines; Adipose Tissue; Biomarkers; Cachexia; Carrier Proteins; Cytokines; Glycerol; Glycoproteins; Humans; Inflammation; Leptin; Lipid Metabolism; Lipolysis; Neoplasms; Prognosis; Weight Loss | 2015 |
[Obesity as a risk factor in the development of cancer].
According to the World Health Organization, every year about 3.4 million adults die of consequences related to overweight or obesity. People with a Body Mass Index above 30 are more likely to express certain diseases, including some types of cancer. In this narrative review, we assess the role of adipose tissue as a modulator of the endocrine system and facilitator of chronic subclinical inflammation. We discuss how obesity can induce a suitable micro environment for the development of tumors, mainly by enhancing the levels of oxidative stress and the concentrations of hormones such as leptin, insulin and prolactin. We conclude that all together, these factors increase the probability of cancer development. Topics: Adipose Tissue; Humans; Leptin; Neoplasms; Obesity; Risk Factors | 2015 |
Oxime ligation: a chemoselective click-type reaction for accessing multifunctional biomolecular constructs.
There is a growing need for biocompatible click reactions in order to prepare multifunctional conjugates, which are valuable molecules for innovative biomedical applications. In this context, we review the recent advances in the implementation of oxime ligation for the synthesis of multivalent or multicomponent systems. The value of these products is emphasized by their use in cell targeting, imaging, synthetic vaccines, and surface modifications. Topics: Animals; Click Chemistry; Leptin; Nanoparticles; Neoplasms; Neovascularization, Pathologic; Oxidation-Reduction; Oximes; Surface Properties; Vaccines, Synthetic | 2014 |
Association of LEP A19G polymorphism with cancer risk: a systematic review and pooled analysis.
The results from the published studies on the association between leptin (LEP) genetic polymorphism and cancer risk are conflicting. The common A19G (rs2167270) genetic polymorphism has been reported to be functional and may contribute to genetic susceptibility to cancers. However, the association between LEP A19G (rs2167270) genetic polymorphism and cancer risk remains inconclusive. To better understand the role of LEP A19G (rs2167270) genetic polymorphism in global cancer, we conducted this comprehensive meta-analysis encompassing 5,679 cases and 7,443 controls. Overall, the LEP A19G (rs2167270) genetic polymorphism was associated with lower cancer risk. In the stratified analysis, significant associations were found between the LEP A19G (rs2167270) genetic polymorphism and colorectal cancer and non-Hodgkin's lymphoma. For colorectal cancer, there was no significant association of LEP A19G (rs2167270) variant with this disease under heterozygous codominant model [odds ratio (OR) = 1.11 (0.97-1.27)], dominant genetic model [OR = 1.03 (0.91-1.17)], and additive genetic model [OR = 0.94 (0.86-1.03)]; however, there was a marginal association under homozygous codominant model [OR = 0.80 (0.66-0.97)] and recessive genetic model [OR = 0.75 (0.63-0.90)]. For non-Hodgkin's lymphoma, there was a significant association of LEP A19G (rs2167270) variant with the disease under homozygous codominant model [OR = 0.74 (0.59-0.94)], recessive genetic model [OR = 0.76 (0.61-0.94)], and additive genetic model [OR = 0.89 (0.80-0.99)], but not under heterozygous codominant model [OR = 0.95 (0.82-1.10)] and dominant genetic model [OR = 0.91 (0.79-1.04)]. Moreover, a significantly decreased cancer risk was found in recessive genetic model among Latin American population. When stratified by study design, significantly elevated susceptibility to cancer was not found among any studies. No significantly differences in genotype method and sample size in cases were found among genotypes. These findings suggest that the LEP A19G (rs2167270) genetic polymorphism may decrease the susceptibility to cancers in colorectal cancer and non-Hodgkin's lymphoma, when assuming a homozygote codominant model and a recessive genetic model among Latin American population. The phenomenon also indicates that the SNP functions as a recessive mutation, which needs to be verified or linked with functional studies. Topics: Genetic Predisposition to Disease; Genotype; Humans; Leptin; Neoplasms; Polymorphism, Genetic; Publication Bias; Risk | 2014 |
Weight control, endocrine hormones and cancer prevention.
The prevalence of obesity is increasing which becomes worrisome due to its association with several diseases and certain types of cancers. While weight control through dietary caloric restriction and/or physical activity protects against cancer in animal models, the underlying mechanisms are not fully defined. Weight loss due to negative energy balance is associated with alterations of multiple growth factors and endocrine hormones. The altered hormones and hormone-related functions appear to be responsible for anti-cancer mechanisms. In this review, we summarize the recent studies related to weight loss and the altered endocrine hormones, focusing on the reduced levels of the mitogenic insulin-like growth factor 1 (IGF-1) and adipokine leptin as well as the raised levels of adiponectin and glucocorticoids. The potential molecular targets of these hormone-dependent signalling pathways are also discussed. Considering the increasing trends of obesity throughout the world, a better understanding of the underlying mechanisms between body weight, endocrine hormones and cancer risk may lead to novel approaches to cancer prevention and treatment. Topics: Adiponectin; Animals; Caloric Restriction; Glucocorticoids; Humans; Insulin-Like Growth Factor I; Leptin; Neoplasms; Obesity; Prevalence; Weight Loss | 2013 |
Association of LEP G2548A and LEPR Q223R polymorphisms with cancer susceptibility: evidence from a meta-analysis.
Numerous epidemiological studies have examined associations of genetic variations in LEP (G2548A, -2548 nucleotide upstream of the ATG start site) and LEPR (Q223R, nonsynonymous SNP in exon 6) with cancer susceptibility; however, the findings are inconsistent. Therefore, we performed a meta-analysis to comprehensively evaluate such associations.. We searched published literature from MEDLINE, EMBASE, Web of Science and CBM for eligible publications. We also assessed genotype-based mRNA expression data from HapMap for rs7799039 (G2548A) and rs1137101 (Q223R) in normal cell lines derived from 270 subjects with different ethnicities.. The final analysis included 16 published studies of 6569 cases and 8405 controls for the LEP G2548A and 19 studies of 7504 cases and 9581 controls for the LEPR Q223R. Overall, LEP G2548A was statistically significantly associated with an increased risk of overall cancer (AA vs. GG: OR=1.27, 95% CI=1.05-1.54; recessive model: OR=1.19, 95% CI=1.00-1.41). Further stratifications by cancer type showed an increased risk for prostate cancer (recessive model: OR=1.26, 95% CI=1.05-1.51) but not for other cancers. For LEPR Q223R, no statistical evidence for an association with risk of cancer was found for all; however, further stratification by ethnicity showed an increased risk for Africans but not for other ethnicities. No significantly differences in LEP and LEPR mRNA expression were found among genotypes or by ethnicity.. Despite some limitations, this meta-analysis found some statistical evidence for an association between the LEP 2548AA genotype and overall risk of cancer, particularly for prostate cancer, but given this variant did not have an effect on mRNA expression, this association warrants additional validation in large and well-designed studies. Topics: Case-Control Studies; Databases, Bibliographic; Genetic Predisposition to Disease; HapMap Project; Humans; Leptin; Male; Models, Genetic; Neoplasms; Polymorphism, Single Nucleotide; Prostatic Neoplasms; Racial Groups; Receptors, Leptin; RNA, Messenger | 2013 |
Molecular pathways: adiponectin and leptin signaling in cancer.
The increasing percentage of obese individuals in the population and its independent association of increased risk for the development of cancer have heightened the necessity to understand the molecular mechanisms that underlie this connection. The deregulation of adipokines in the setting of obesity and their impact on cancer progression and metastasis is one such area of research. Adipokines are bioactive proteins that mediate metabolism, inflammation, angiogenesis, and proliferation. Altered levels of adipokines or their cognate receptors in cancers can ultimately lead to an imbalance in downstream molecular pathways. Discovery of adipokine receptors in various cancers has highlighted the potential for novel therapeutic targets. Leptin and adiponectin represent two adipokines that elicit generally opposing molecular effects. Epidemiologic studies have highlighted associations between increased serum leptin levels and increased tumor growth, whereas adiponectin exhibits an inverse correlation with cancer development. This review addresses the current level of understanding of molecular pathways activated by adiponectin and leptin to identify the areas of intervention and facilitate advancement in the field. Topics: Adiponectin; Humans; Leptin; Models, Biological; Neoplasms; Receptors, Adiponectin; Receptors, Leptin; Signal Transduction | 2013 |
[Chronobiological aspects of obesity and metabolic syndrome].
Circadian rhythms (approximately 24h) are widely characterized at molecular level and their generation is acknowledged to originate from oscillations in expression of several clock genes and from regulation of their protein products. While general entrainment of organisms to environmental light-dark cycles is mainly achieved through the master clock of the suprachiasmatic nucleus in mammals, this molecular clockwork is functional in several organs and tissues. Some studies have suggested that disruption of the circadian system (chronodisruption (CD)) may be causal for manifestations of the metabolic syndrome. This review summarizes (1) how molecular clocks coordinate metabolism and their specific role in the adipocyte; (2) the genetic aspects of and scientific evidence for obesity as a chronobiological illness; and (3) CD and its causes and pathological consequences. Finally, ideas about use of chronobiology for the treatment of obesity are discussed. Topics: Adiponectin; Adipose Tissue; Animals; ARNTL Transcription Factors; Cardiovascular Diseases; Chronotherapy; Circadian Rhythm; Cryptochromes; Female; Gene Expression Regulation; Humans; Jet Lag Syndrome; Leptin; Male; Mammals; Metabolic Syndrome; Neoplasms; Obesity; Period Circadian Proteins; PPAR gamma; Receptors, Adiponectin; Receptors, Leptin | 2012 |
What is the brain-cancer connection?
A focus of much cancer research is at the molecular and cellular levels. In contrast, the effects of social interactions and psychological state are less investigated, and considered by many a "soft" science. Yet several highly rigorous studies have begun to tease out biochemical pathways by which the brain can influence the development and growth of cancer. Previous reviews have discussed the concept of stress and cancer. Here, we discuss recent work showing environments that are more complex and challenging, but not stressful per se, and that have robust effects on peripheral cancer by activating a specific neuroendocrine brain-adipocyte axis. These enriched environments lead to activation of the sympathetic innervation of fat tissue, suppression of leptin, and a reduction in cancer proliferation by inducing hypothalamic BDNF expression. We summarize this work and discuss how these data integrate into the body of literature regarding stress, the environment, and cancer. Topics: Adipocytes; Animals; Brain; Brain-Derived Neurotrophic Factor; Environment; Humans; Hypothalamus; Leptin; Loneliness; Models, Biological; Neoplasms; Obesity; Signal Transduction; Social Support; Stress, Psychological; Sympathetic Nervous System | 2012 |
Growth signals, inflammation, and vascular perturbations: mechanistic links between obesity, metabolic syndrome, and cancer.
Nearly 35% of adults and 20% of children in the United States are obese, defined as a body mass index ≥ 30 kg/m(2). Obesity, which is accompanied by metabolic dysregulation often manifesting in the metabolic syndrome, is an established risk factor for many cancers. Within the growth-promoting, proinflammatory environment of the obese state, cross talk between macrophages, adipocytes, and epithelial cells occurs via obesity-associated hormones, cytokines, and other mediators that may enhance cancer risk and progression. This review synthesizes the evidence on key biological mechanisms underlying the obesity-cancer link, with particular emphasis on obesity-associated enhancements in growth factor signaling, inflammation, and vascular integrity processes. These interrelated pathways represent possible mechanistic targets for disrupting the obesity-cancer link. Topics: Adiponectin; Cell Communication; Humans; Inflammation; Insulin; Insulin-Like Growth Factor I; Intercellular Signaling Peptides and Proteins; Leptin; Metabolic Syndrome; Neoplasms; Obesity; Receptor, IGF Type 1; Receptor, Insulin; Signal Transduction; Vascular Endothelial Growth Factor A | 2012 |
Associations between adipokines and obesity-related cancer.
There is increasing evidence that obesity may have pathophysiological effects that extend beyond its well-known co-morbidities; in particular its role in cancer has received considerable epidemiological support. As adipose tissue becomes strongly established as an endocrine organ, two of its most abundant and most investigated adipokines, leptin and adiponectin, are also taken beyond their traditional roles in energy homeostasis, and are implicated as mediators of the effects of obesity on cancer development. This review examines these adipokines in relation to the prostate, breast, colorectal, thyroid, renal, pancreatic, endometrial and oesophageal cancers, and how they may orchestrate the influence of obesity on the development of these malignancies. Topics: Adiponectin; Body Mass Index; Breast Neoplasms; Colorectal Neoplasms; Endometrial Neoplasms; Esophageal Neoplasms; Female; Humans; Kidney Neoplasms; Leptin; Male; Neoplasms; Obesity; Pancreatic Neoplasms; Prostatic Neoplasms; Thyroid Neoplasms | 2011 |
Functional consequences of mTOR inhibition.
TOR (target of rapamycin) is a serine-threonine protein kinase that is conserved across a diverse range of species from fungi to mammals. The signaling pathway that is anchored by TOR is also conserved across species. In mammals, mTOR integrates growth factor, amino acid, nutrient and energy sensing signals, and thus plays a major role in cell growth and proliferation, protein synthesis and autophagy. As a result of the pivotal role of mTOR in signaling, the aberrant regulation of mTOR has been implicated in several disease processes, including cancer, diabetes, ocular diseases and neurodegenerative disorders, as well as in lifespan extension. More recently, rapamycin (sirolimus) analogs that antagonize the mTOR signaling pathway have been approved for the treatment of several cancers. This review describes some recent advances in the understanding of mTOR signaling, with an emphasis on the functional consequences of mTOR inhibition and therapeutic intervention strategies. Topics: Animals; Diabetes Mellitus; Disease Models, Animal; Enzyme Inhibitors; Eye Diseases; Humans; Intracellular Signaling Peptides and Proteins; Leptin; Longevity; Neoplasms; Neurodegenerative Diseases; Protein Serine-Threonine Kinases; Signal Transduction; TOR Serine-Threonine Kinases | 2010 |
Energy balance, host-related factors, and cancer progression.
Obesity is associated with an increased risk and worsened prognosis for many types of cancer, but the mechanisms underlying the obesity-cancer progression link are poorly understood. Several energy balance-related host factors are known to influence tumor progression and/or treatment responsiveness after cancer develops, and these have been implicated as key contributors to the complex effects of obesity on cancer outcome. These host factors include leptin, adiponectin, steroid hormones, reactive oxygen species associated with inflammation, insulin, insulin-like growth factor-1, and sirtuins. Each of these host factors is considered in this article in the context of energy balance and cancer progression. In addition, future research directions in this field are discussed, including the importance of study designs addressing energy balance across the life course, the development and application of highly relevant animal models, potential roles of cancer stem cells in the response to energy balance modulation, and emerging pharmacologic approaches that target energy balance-related pathways. Topics: Adiponectin; Adrenal Cortex Hormones; Disease Progression; Energy Metabolism; Gonadal Steroid Hormones; Humans; Inflammation; Insulin; Insulin-Like Growth Factor I; Leptin; Metabolic Syndrome; Neoplasms; Oxidative Stress; Sirtuin 1 | 2010 |
Obesity modulation - the role in carcinogenesis.
Obesity has been recognized as an important risk factor for many serious medical conditions. The association of obesity with an increased risk of many cancers is of enormous economic importance to the health industry.The metabolic syndrome and visceral obesity have an increasing prevelance and incidence in the general population.The actual prevelance of the metabolic syndrome is 24% in US population and between 24,6% and 30.9% in Europe. Recent evidence from epidemiologic and basic research studies, as well as clinical and intervention studies, supports the emerging hypothesis that metabolic syndrome may be an important etiologic factor for the onset of cancer. In addition, increased body weight has recently been shown to be associated with an increased risk of cancers at multiple specific sites. The close interaction between cancer cells and adipocytes is an intriguing issue in tumor biology. In nowdays, several metabolic markers are implicated in the development and progression of several malignancies. This review describes the emerging data concerning the role of metabolic markes in tumor cell growth and relates them to their future clinical prospects. Topics: Adiponectin; Animals; Fatty Acids, Nonesterified; Ghrelin; Humans; Insulin Resistance; Leptin; Metabolic Syndrome; Neoplasms; Obesity | 2010 |
[Pleiotropic effects of leptin].
Leptin, also called the satiation hormone plays a key role in regulating body weight, energy intake, and expenditure. Leptin interacts with its receptors, mainly located in the hypothalamus. Moreover, there has been an increasing evidence that leptin exerts pleiotropic effects. Multiple peripheral effects of leptin have been recently described including synthesis of the various hormones, e.g., sexual hormones, thyroid hormones, and growth hormone, as well as regulation of blood pressure, reproduction, osteogenesis, hematopoesis, angiogenesis. Leptin also plays a regulatory function in immunity.and in the process of tumorigenesis. Despite intensive investigations since leptin discovery in 1994 we have much to learn about the leptin mechanism of actions and effects. Topics: Animals; Body Weight; Cell Transformation, Neoplastic; Energy Metabolism; Hematopoiesis; Hormones; Humans; Leptin; Neoplasms; Neovascularization, Physiologic; Receptors, Leptin | 2009 |
Comorbidities of obesity.
Obesity, especially visceral adiposity, is associated with morbidity and mortality through endocrine and mechanical processes. Clinical manifestations due to effects of obesity on the cardiovascular, respiratory, gastrointestinal, musculoskeletal, immune, and integumentary systems have been described. Further studies are needed to understand the pathologic processes underlying these clinical manifestations to improve disease prevention. Topics: Adipocytes; Adiponectin; Adiposity; Cardiovascular Diseases; Energy Metabolism; Exercise; Gastrointestinal Diseases; Humans; Insulin Resistance; Intra-Abdominal Fat; Leptin; Musculoskeletal Diseases; Neoplasms; Obesity; Respiratory Tract Diseases | 2009 |
Leptin as clinical target.
PLeptin is an adipocyte-derived hormone with pleiotropic effects on energy homeostasis, endocrine and reproductive functions, and immune responses. The multiple actions of leptin have led to the design and development of several leptin-based approaches to modulate the metabolic and endocrine status, to reduce inflammation, and to improve immune responses. Here, we review the current patents on leptin in different clinic applications. Topics: Animals; Biomimetics; Genetic Therapy; Humans; Immune System Diseases; Immunization; Infertility; Leptin; Metabolic Diseases; Neoplasms; Patents as Topic | 2009 |
Obesity and cancer.
Epidemiological studies have suggested that obesity is associated with increased risk of several cancer types including colon, esophagus, breast (in postmenopausal women), endometrium, kidney, liver, gallbladder and pancreas. Suggested mechanisms include increased intake of potentially carcinogenic food ingredients along with excessive amount of calories, loss of cancer protective effects due to reduced physical activity, carcinogenic factors released from increased adipose tissue mass and "secondary" associations via "precursor" condition such as gallstones. The increased cancer risk in patients with obesity is a neglected topic which deserves more scientific attention. Because of its extreme chronicity and co-association with numerous other conditions true causality and underlying mechanisms are difficult to study. Nevertheless, a large body of literature is already available which provides concepts for future research. Topics: Adiposity; Comorbidity; Energy Intake; Humans; Inflammation; Insulin; Leptin; Neoplasms; Obesity; Risk Factors | 2009 |
Reducing the weight of cancer: mechanistic targets for breaking the obesity-carcinogenesis link.
The prevalence of obesity, an established epidemiologic risk factor for many cancers, has risen steadily for the past several decades in the US. The increasing rates of obesity among children are especially alarming and suggest continuing increases in the rates of obesity-related cancers for many years to come. Unfortunately, the mechanisms underlying the association between obesity and cancer are not well understood. In particular, the effects on the carcinogenesis process and mechanistic targets of interventions that modulate energy balance, such as reduced-calorie diets and physical activity, have not been well characterized. The purpose of this review is to provide a strong foundation for the translation of mechanism-based research in this area by describing key animal and human studies of energy balance modulations involving diet or physical activity and by focusing on the interrelated pathways affected by alterations in energy balance. Particular attention is placed on signaling through the insulin and insulin-like growth factor-1 receptors, including components of the Akt and mammalian target of rapamycin (mTOR) signaling pathways downstream of these growth factor receptors. These pathways have emerged as potential targets for disrupting the obesity-cancer link. The ultimate goal of this work is to provide the missing mechanistic information necessary to identify targets for the prevention and control of cancers related to or caused by excess body weight. Topics: Adiponectin; Animals; Energy Metabolism; Humans; Insulin; Insulin-Like Growth Factor I; Leptin; Neoplasms; Obesity; Oxidative Stress | 2008 |
[The metabolic syndrome and type-2 diabetes mellitus as conditions predisposing for malignant tumors].
Recently more and more evidences have emerged about the oncogenic effect of type 2 diabetes and metabolic syndrome. Among these evidences epidemiological data are in first line. There is a causal relationship according to gender, ethnicity and geographic situation between different tumors and type 2 diabetes/metabolic syndrome as well. Supposed pathomechanisms are obesity, cytokines, secreted excessively in adipose tissue, permanent and postprandial hyperglycemia, hyperinsulinism and insulin resistance, other growth factors, like proinsulin, insulin like growth factor-1, reactive oxygen species, angiogenesis, inflammation, and the multiple effects of inflammatory cytokines. It proved to be evident that both peroxisome-proliferator-activated receptors and the regulatory ubiquitin proteasome system have significant role in insulin sensitivity and in co-ordinating cell proliferation and angiogenesis. These mechanisms in metabolic syndrome are risk factors towards atherosclerosis and cancer diseases as well. This newly emerged knowledge may open new pathways in treating and preventing the above-mentioned pathologic processes. Topics: Adiponectin; Adipose Tissue; Animals; Cell Proliferation; Cytokines; Diabetes Mellitus, Type 2; Humans; Hyperglycemia; Hyperinsulinism; Inflammation; Insulin Resistance; Insulin-Like Growth Factor I; Leptin; Metabolic Syndrome; Neoplasms; Neovascularization, Pathologic; Obesity; Peroxisome Proliferator-Activated Receptors; Reactive Oxygen Species; Risk Factors; Ubiquitins; Vascular Endothelial Growth Factor A | 2008 |
Promising new causal explanations for obesity and obesity-related diseases.
Current explanations for obesity center around a predisposition in genotype and phenotype, possibly triggered by an inflammatory process or event, and exacerbated by environmental and psychological factors. It is likely that a variety of physiologic factors may act in combination to produce clinical obesity. Leptin resistance may be an important neurochemical cause of obesity; elevated leptin levels have been correlated with weight gain over extended time periods. Genetic studies support the postulate that a gene originating with our cave-dwelling ancestors, critical to survival when food was scare, has evolved into a trigger for obesity and related diseases. A variety of biochemical markers are prevalent in obesity and obesity-linked disease states. C-reactive protein, interleukin-6, and others are elevated in obesity, supporting the hypothesis that inflammation plays a role in the condition. Tumor necrosis factor-alpha is overexpressed in obesity and diabetes, suggesting that it may be part of the link between the 2 conditions. Topics: Appetite; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Causality; Cost of Illness; Diabetes Mellitus, Type 2; Dietary Fats; Genetic Predisposition to Disease; Genotype; Humans; Inflammation; Interleukin-6; Leptin; Life Style; Neoplasms; Obesity; Phenotype; Tumor Necrosis Factor-alpha; United States | 2007 |
Neuroendocrine factors in the initiation of puberty: the emergent role of kisspeptin.
Puberty is the end-point of a complex series of developmental events, defined by the dynamic interaction between genetic factors and environmental cues, ultimately leading to the attainment of reproductive capacity. The neuroendocrine basis of puberty has been the subject of extensive investigation in the last decades, and identification of the trigger(s) of puberty onset has drawn considerable attention. In this context, recognition of the fundamental role of kisspeptin (encoded by the KiSS-1 gene) and its receptor GPR54 as major gatekeepers of gonadotropic function in general, and puberty onset in particular, has been a major breakthrough in contemporary Neuroendocrinology. Indeed, during the last 3 years, the so-called KiSS-1/GPR54 system has been substantiated as pivotal regulator of puberty in mammals; the lack of GPR54 signaling being coupled to sexual immaturity (impuberism) in mice and humans. In this review, we will summarize the most salient experimental data (mostly obtained in laboratory animals) demonstrating the key roles of hypothalamic KiSS-1 neurons in the activation of the reproductive axis at puberty, and its regulation by metabolic and, eventually, environmental factors. Whether the KiSS-1 system is the trigger for puberty onset and/or it operates as integrator and effector of up-stream regulatory factors warrants further investigation. Topics: Animals; Environment; Humans; Kisspeptins; Leptin; Neoplasms; Neurosecretory Systems; Puberty; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1; Reproduction; Rodentia; Sexual Maturation; Tumor Suppressor Proteins | 2007 |
Leptin and cancer.
The prevalence of obesity has markedly increased over the past two decades, especially in the industrialized countries. While the impact of excess body weight on the development of cardiac disease and diabetes has been well documented, the link between obesity and carcinogenesis is just being recognized. This review will focus on the link between leptin, a cytokine that is elevated in obese individuals, and cancer development. First, we briefly discuss the biological functions of leptin and its signaling pathways. Then, we summarize the effects of leptin on different cancer types in experimental cellular and animal models. Next, we analyze epidemiological data on the relationship between obesity and the presence of cancer or cancer risk in patients. Finally, leptin as a target for cancer treatment and prevention will be discussed. Topics: Animals; Cell Proliferation; Humans; Leptin; Metabolism; Neoplasms; Obesity; Risk Factors; Signal Transduction | 2006 |
Adipocytokines and cancer.
Adipose tissue-produced hormones significantly affect the metabolism of lipids and carbohydrates as well as numerous other processes in human body. It is generally accepted that endocrine dysfunction of adipose tissue may represent one of the causal links between obesity and insulin resistance/diabetes. Epidemiological studies underlined that obesity represents a significant risk factor for the development of cancer, although the exact mechanism of this relationship remains to be determined. Multiple recent studies have indicated that some of adipose tissue-derived hormones may significantly influence the growth and proliferation of tumorous stroma and malignant cells within. Here we review current knowledge about possible relationship of leptin and adiponectin to the etiopathogenesis of different malignant tumors. Most of the studies indicated that while leptin may potentiate the growth of cancer cells in vitro, adiponectin appears to have an opposite effect. Further studies are necessary to decide whether obesity-induced endocrine dysfunction of adipose tissue can directly influence carcinogenesis in different tissues and organs. Topics: Adiponectin; Adipose Tissue; Breast Neoplasms; Female; Humans; Leptin; Male; Neoplasms; Prostatic Neoplasms | 2006 |
Role of insulin, adipocyte hormones, and nutrient-sensing pathways in regulating fuel metabolism and energy homeostasis: a nutritional perspective of diabetes, obesity, and cancer.
Traditionally, nutrients such as glucose and amino acids have been viewed as substrates for the generation of high-energy molecules and as precursors for the biosynthesis of macromolecules. However, it is now apparent that nutrients also function as signaling molecules in functionally diverse signal transduction pathways. Glucose and amino acids trigger signaling cascades that regulate various aspects of fuel and energy metabolism and control the growth, proliferation, and survival of cells. Here, we provide a functional and regulatory overview of three well-established nutrient signaling pathways-the hexosamine signaling pathway, the mTOR (mammalian target of rapamycin) signaling pathway, and the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. Nutrient signaling pathways are interconnected, coupled to insulin signaling, and linked to the release of metabolic hormones from adipose tissue. Thus, nutrient signaling pathways do not function in isolation. Rather, they appear to serve as components of a larger "metabolic regulatory network" that controls fuel and energy metabolism (at the cell, tissue, and whole-body levels) and links nutrient availability with cell growth and proliferation. Understanding the diverse roles of nutrients and delineating nutrient signaling pathways should facilitate drug discovery research and the search for novel therapeutic compounds to prevent and treat various human diseases such as diabetes, obesity, and cancer. Topics: Adiponectin; Amino Acids; AMP-Activated Protein Kinase Kinases; Diabetes Mellitus, Type 2; Energy Metabolism; Glucose; Hexosamines; Homeostasis; Humans; Insulin; Leptin; Metabolism; Neoplasms; Obesity; Protein Kinases; Signal Transduction; TOR Serine-Threonine Kinases | 2006 |
Leptin, estrogens and cancer.
Obesity is a state of leptin resistance in which the membrane leptin receptor and the JAK-STAT pathway are blocked. This leads to increased intracellular concentrations of lipid metabolites, increased non-oxidative metabolism by adipocytes, and stimulation of the cell estrogen cycle. These factors are potentially oncogenic via the shared mitogen-activated protein kinase (MAPK), mitogen/extracellular signal-regulated kinase (MEK) and extracellular signal-regulated kinase (ERK) cellular pathways. Topics: Adipocytes; Animals; Enzyme Inhibitors; Estrogens; Extracellular Signal-Regulated MAP Kinases; Humans; Leptin; Lipids; MAP Kinase Kinase Kinases; Mitogen-Activated Protein Kinase Kinases; Neoplasms; Obesity; Protein-Tyrosine Kinases; Receptors, Cell Surface; Receptors, Estrogen; Receptors, Leptin; STAT Transcription Factors | 2006 |
[Feeding-related disorders in medicine, with special reference to cancer anorexia-cachexia syndrome].
Cachexia is among the most debilitating and life-threatening aspects of cancer. Associated with anorexia, fat and muscle tissue wasting, psychological distress, and a lower quality of life, cachexia arises from a complex interaction between the cancer and the host. This process results from a failure of the adaptive feeding response seen in simple starvation and includes cytokine production, release of lipid-mobilizing and proteolysis-inducing factors, and alterations in intermediary metabolism. Cytokines play a pivotal role in long-term inhibition of feeding by mimicking the hypothalamic effect of excessive negative feedback signaling from leptin, a hormone secreted by adipose tissue, which is an integral component of the homeostatic loop of body weight regulation. The two major options for pharmacological therapy have been either progestational agents or corticosteroids. However, knowledge of the mechanisms of cancer anorexia-cachexia syndrome continues to lead to effective therapeutic interventions for several aspects of the syndrome. These include antiserotonergic drugs, gastroprokinetic agents, branched-chain amino acids, eicosapentanoic acid, cannabinoids, melatonin, and thalidomide, all of which act on the feeding-regulatory circuitry to increase appetite and inhibit tumor-derived catabolic factors to antagonize tissue wasting and/or host cytokine release. The outcomes of drug studies in cancer cachexia should focus on the symptomatic and quality-of-life advantages rather than simply on nutritional end points, since the survival of cachexia cancer patients may be limited to weeks or months due to the incurable nature of the underlying malignancy. As weight loss shortens the survival time of cancer patients and decreases their performance status, effective therapy would extend patient survival and improve quality of life. Topics: Adipose Tissue; Agouti Signaling Protein; Anorexia; Anti-Anxiety Agents; Anti-Inflammatory Agents, Non-Steroidal; Antidepressive Agents; Appetite Stimulants; Cachexia; Cytokines; Energy Metabolism; Gastrointestinal Agents; Glucocorticoids; Humans; Intercellular Signaling Peptides and Proteins; Leptin; Neoplasms; Neuropeptide Y; Patient Care Team; Progesterone; Signal Transduction; Starvation; Syndrome | 2006 |
[Recent development in research and management of cancer anorexia-cachexia syndrome].
Cachexia is among the most debilitating and life-threatening aspects of cancer, and is more common in children and elderly patients. Associated with anorexia, fat and muscle tissue wasting, psychological distress, and a lower quality of life, cachexia arises from a complex interaction between the cancer and the host. This process results from a failure of the adaptive feeding response seen in simple starvation and includes cytokine production, release of lipid-mobilizing and proteolysis-inducing factors, and alterations in intermediary metabolism. Cytokines play a pivotal role in long-term inhibition of feeding by mimicking the hypothalamic effect of excessive negative feedback signaling from leptin, a hormone secreted by adipose tissue, which is an integral component of the homeostatic loop of body weight regulation. This could be done by persistent inhibition of feeding-stimulatory circuitry including neuropeptide Y. Cachexia should be suspected in patients with cancer if an involuntary weight loss of greater than five percent of premorbid weight occurs within a 3-6-month period. The two major options for pharmacological therapy have been either progestational agents or corticosteroids. However, knowledge of the mechanisms of cancer anorexia-cachexia syndrome has led to, and continues to lead to, effective therapeutic interventions for several aspects of the syndrome. These include antiserotonergic drugs, gastroprokinetic agents, branched-chain amino acids, eicosapentanoic acid, cannabinoids, melatonin, and thalidomide-all of which act on the feeding-regulatory circuitry to increase appetite and inhibit tumor-derived catabolic factors to antagonize tissue wasting and/or host cytokine release. The outcomes of drug studies in cancer cachexia should focus on the symptomatic and quality-of-life advantages rather than simply on nutritional end points, since the survival of cachexia cancer patients may be limited to weeks or months due to the incurable nature of the underlying malignancy. Communication among physicians and other health care professionals provides the patient with a multidisciplinary approach to care. The patient record will be an excellent resource to document a plan of care and patient responses to treatment. Psychological distress and psychiatric disorders are common among cancer patients. These problems are also as common among the family members of people with cancer. The use of psychological and behavioral interventions in cancer is incr Topics: Animals; Anorexia; Appetite; Body Weight; Cachexia; Energy Intake; Energy Metabolism; Humans; Leptin; Neoplasms; Quality of Life; Research | 2005 |
[Hormones of adipose tissue (adipocytokines): ontogenetic and oncologic aspects].
Being an important component of body composition, adipose tissue accepts a lot of hormonal signals and, besides, is able to produce hormone-like peptides, named adipokines or adipocytokines, and participate in the metabolism of steroid hormones. Endocrine properties of adipose tissue are dependent of its volume, morphology (size and number of adipocytes), fat topography (visceral and subcutaneous fat), characteristics of distinct fat depot (including mammary fat), some features of genome, etc. Certain characteristics of the adipose organ are formed and then realized in pre- and postnatal life (pregnancy and fetal programming), in duration of puberty, after menopause and with aging. Adipocyte and non-adipocyte compartments of adipose tissue are involved into reactions of immunity/inflammation and into development of glucose intolerance and insulin resistance. The latter are peculiar for obesity and lipodystrophy, which in their turn are associated with a number of main chronic non-communicable diseases limiting the human life span. The balance among adipocytokines (adipocytokine net or lattice) with distinct properties (TNF-alpha, leptin and adiponectin as an examples) and between adipocytokines and steroid-producing capacity of adipose tissue is an important variable representing a basis for the modification of cardiovascular and oncological morbidity risk as well as a target for geroprotection and cancer prevention. Topics: Adiponectin; Adipose Tissue; Animals; Cytokines; Humans; Intercellular Signaling Peptides and Proteins; Leptin; Neoplasms; Obesity; Peptide Hormones; Risk Factors; Steroids; Tumor Necrosis Factor-alpha | 2005 |
Clinical impact of cachexia on survival and outcome of cancer patients.
Approximately one half of all cancer patients experience a complex metabolic status involving progressive exhaustion of adipose and skeletal muscle tissue. This condition, known as cachexia, is responsible for more than 20% of the overall deaths in cancer patients. Although its main mechanisms remain unknown, several hypotheses have been proposed. One of the pathogenic mechanisms involves leptin and hypothalamic neuropeptide-containing pathways. Orexigenic and anorexigenic neuropeptides are down-regulated respectively upregulated as a result of cancer. Other pathogenic theories consider tumour derived factors, such as LMF (Lipid Mobilising Factor) and PIF (Proteolysis-inducing Factor), to be responsible for the weight losing pattern of cancer patients via activation of various catabolic pathways (e.g. ubiquitin-proteasome proteolytic-pathway, etc.). Despite the controversial discussion of cachexia-inducing mechanisms it is clear that proinflammatory cytokines, such as TNFalpha, IFNgamma, IL-1, IL-6 and IL-8, are linked to all pathways that induce cachexia. Although only limited treatment exists for patients with cancer cachexia, recent studies with eicosapaentanoic acid showed promising effects in reversing weight losing pattern of cachectic patients. Cytokine targeted monoclonal antibodies, cytokine traps and genetic therapies are also evaluated for future therapeutic strategies. Topics: Cachexia; Cytokines; Genetic Therapy; Humans; Leptin; Neoplasms; Neuropeptides; Prognosis | 2005 |
Leptin is a growth factor in cancer.
Topics: Adipocytes; Animals; Anorexia; Breast Neoplasms; Cell Differentiation; Female; Gastrointestinal Neoplasms; Genital Neoplasms, Female; Growth Substances; Humans; Leptin; Leukemia; Male; Neoplasms; Prostatic Neoplasms | 2004 |
Cancer anorexia-cachexia syndrome: cytokines and neuropeptides.
Cancer anorexia-cachexia syndrome is observed in 80% of patients in the advanced stages of cancer and is a strong independent risk factor for mortality. Numerous cytokines produced by tumor and immune cells, interacting with the neuropeptidergic system, mediate the cachectic effect of cancer. Since there is currently no effective pharmacological treatment and the anorexia-cachexia syndrome continues to be defined biochemically, we review the role of cytokines and neuropeptides in this process.. Currently data suggest that cancer anorexia-cachexia syndrome results from a multifactorial process involving many mediators, including hormones (e.g. leptin), neuropeptides (e.g. neuropeptide Y, melanocortin, melanin-concentrating hormone and orexin) and cytokines (e.g. interleukin 1, interleukin 6, tumor necrosis factor alpha and interferon gamma). It is likely that close interrelation among these mediators exists in the hypothalamus, decreasing food intake and leading to cachexia.. In the pathogenesis of cancer anorexia, cytokines play a pivotal role influencing the imbalance of orexigenic and anorexigenic circuits that regulate the homeostatic loop of body-weight regulation, leading to cachexia. Interfering pharmacologically with cytokine expression or neural transduction of cytokine signals can be an effective therapeutic strategy in anorectic patients before they develop cancer anorexia-cachexia syndrome. Topics: Animals; Anorexia; Cachexia; Cytokines; Ghrelin; Humans; Leptin; Neoplasms; Neuropeptides; Peptide Hormones; Syndrome | 2004 |
Symposium introduction: nutrition and gene regulation.
Topics: Animals; Carrier Proteins; Energy Metabolism; Fatty Acid-Binding Proteins; Feedback, Physiological; Food; Gene Expression Regulation; Homeostasis; Humans; Leptin; Neoplasms; Nutritional Status | 2004 |
[Pathogenesis and treatment of cancer anorexia-cachexia, with special emphasis on aged patients].
Cachexia is among the most debilitating and life-threatening aspects of cancer and is more common in children and elderly patients. Associated with anorexia, fat and muscle tissue wasting, psychological distress, and a lower quality of life, cachexia arises from a complex interaction between the cancer and the host. This process results from a failure of the adaptive feeding response seen in simple starvation and includes cytokine production, release of lipid-mobilizing and proteolysis-inducing factors, and alterations in intermediary metabolism. Cytokines play a pivotal role in long-term inhibition of feeding by mimicking the hypothalamic effect of excessive negative feedback signaling from leptin, a hormone secreted by adipose tissue, which is an integral component of the homeostatic loop of body weight regulation. This could be caused by persistent inhibition of the feeding-stimulatory circuitry including neuropeptide Y. Cachexia should be suspected in patients with cancer if an involuntary weight loss of greater than five percent of premorbid weight occurs within a 3-6-month period. The two major options for pharmacological therapy have been either progestational agents or corticosteroids. However, knowledge of the mechanisms of cancer anorexia-cachexia syndrome has led to, and continues to lead to, effective therapeutic interventions for several aspects of the syndrome. These include antiserotonergic drugs, gastroprokinetic agents, branched-chain amino acids, eicosapentanoic acid, cannabinoids, melatonin, and thalidomide all of which act on the feeding-regulatory circuitry to increase appetite and inhibit tumor-derived catabolic factors to antagonize tissue wasting and/or host cytokine release. Because weight loss shortens the survival time of cancer patients and decreases performance status, effective therapy would extend patient survival and improve quality of life. Topics: Aged; Aging; Anorexia; Appetite; Cachexia; Humans; Leptin; Neoplasms; Nutritional Support; Quality of Life | 2004 |
Protein tyrosine phosphatases as drug targets: PTP1B and beyond.
Protein tyrosine phosphatases (PTPs) control signal transduction pathways and have recently emerged as potential drug targets. Inhibition of individual PTPs can result in the activation of therapeutically relevant kinase cascades. This is particularly useful in cases where disease is associated with hormonal resistance, such as insensitivity to insulin or leptin. Currently, PTP1B is being investigated by a number of companies as a promising target for leptin/insulin mimetics and in the treatment of diabetes and obesity. Since all 90-100 PTPs have been identified in the human genome, the challenge now is to identify the function of these enzymes and the therapeutic indications that may exist for specific PTP inhibitors. Topics: Capillary Permeability; Cyclin-Dependent Kinases; Diabetes Mellitus; Drug Design; Drug Evaluation, Preclinical; Genes, Tumor Suppressor; Humans; Immune System; Infections; Insulin; Leptin; Multigene Family; Neoplasm Proteins; Neoplasms; Obesity; Osteoporosis; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatases; Receptors, Antigen; Signal Transduction; src-Family Kinases | 2002 |
[The importance of leptin in oncology--hypothesis or facts?].
Leptin was described as a protein produced mostly by adipocytes which participates in regulation of caloric intake. This protein has further many physiological regulatory functions especially in hematopoesis and reproduction. The role of leptin in diseases is also considered. Maybe leptin is a part of the pathogenic mechanism or its metabolism can be influenced secondary to disease. Malignant tumours are the important area where leptin can acts. This imagination is supported by recent in vitro studies and some clinical observations. It is consider that some parameters of leptin metabolism can serve as usable marker for diagnosis and monitoring of some malignant tumours--especially breast cancer or some types of leukemia. The authors give a review of actual information of leptin metabolism changes in oncological diseases. Topics: Animals; Hematopoiesis; Humans; Immunity; Leptin; Neoplasms; Obesity | 2001 |
IL-6-like cytokines and cancer cachexia: consequences of chronic inflammation.
An estimated 30% of cancer deaths are attributed to cachexia and its consequences. Cachexia (wasting syndrome) is the hypercatabolism of the body's carbon sources, proteins and lipids, for conversion into energy. It is induced by a variety of pathological conditions, including cancer. Among the inflammatory responses to cancer is the synthesis of cytokines, including IL-6 and related cytokines. These cytokines have been found to induce cachexia by altering metabolism of lipids and proteins. IL-6-like cytokines have been found to inhibit lipid biosynthesis by adipocytes, which increased the rate of lipid catabolism. Others have described the atrophy and increased catabolism of muscle protein due to IL-6. A cytokine closely-related to IL-6 is leptin, which plays a major role in lipid metabolism under normal conditions. The role of leptin in pathological conditions such as cancer cachexia has not yet been fully elucidated. Detailed mechanistic information about the induction of cancer cachexia by IL-6-like cytokines requires more research. Topics: Animals; Cachexia; Humans; Inflammation; Interleukin-6; Leptin; Lipid Metabolism; Lipids; Mice; Muscle Proteins; Neoplasms | 2001 |
Diet and cancer prevention studies in p53-deficient mice.
Progress in mechanism-based cancer prevention research may be facilitated by the use of animal models displaying specific genetic susceptibilities for cancer such as mice deficient in the p53 tumor suppressor gene, the most frequently altered gene in human cancer. We observed in p53-knockout (p53-/-) mice that calorie restriction (CR; 60% of the control group's intake of carbohydrate energy) increased the latency of spontaneous tumor development (mostly lymphomas) approximately 75%, decreased serum insulin-like growth factor (IGF)-1 and leptin levels, significantly slowed thymocyte cell cycle traverse and induced apoptosis in immature thymocytes. In heterozygous p53-deficient (p53+/-) mice, CR and 1 d/wk of food deprivation each significantly delayed spontaneous tumor development (a mix of lymphomas, sarcomas and epithelial tumors) and decreased serum IGF-1 and leptin levels even when begun late in life. We have also developed a rapid and relevant p53+/- mouse mammary tumor model by crossing p53-deficient mice with MMTV-Wnt-1 transgenic mice, and found that CR and 1 d/wk food deprivation significantly increased mammary tumor latency (greater than twofold) and reduced the mean serum IGF-1 and leptin levels to <50% of that of control mice (P < 0.0001). In addition, fluasterone, fenretinide and soy each delayed tumor development but had little effect on IGF-1 or leptin levels. We have capitalized on the susceptibility of p53+/- mice to chronic, low dose, aromatic amine-induced bladder carcinogenesis to develop a useful model for evaluating bladder cancer prevention approaches such as cyclooxygenase-2 inhibition. As demonstrated by these examples, mice with specific (and human-like) genetic susceptibilities for cancer provide powerful new tools for testing and characterizing interventions that may inhibit the process of carcinogenesis in humans. Topics: Animals; Crosses, Genetic; Diet; Diet, Reducing; Disease Models, Animal; Humans; Insulin-Like Growth Factor I; Leptin; Mammary Neoplasms, Experimental; Mice; Mice, Knockout; Mice, Transgenic; Neoplasms; Neoplasms, Experimental; Tumor Suppressor Protein p53; Urinary Bladder Neoplasms | 2001 |
Overnutrition and undernutrition as modifiers of metabolic processes in disease states.
Both overnutrition and undernutrition affect energy metabolism, with overnutrition raising energy expenditure and undernutrition lowering it. Fever is a powerful stimulator of thermogenesis. In diseases such as cancer, AIDS, diabetes mellitus, and rheumatoid arthritis, whether energy expenditure is increased or decreased often depends on how advanced the disorder is. Early on, when the greater protein turnover characteristic of these conditions is paramount, energy expenditure is increased. In addition, in diseases such as cancer, AIDS, and rheumatoid arthritis in which cytokines are released, the cytokines' thermogenic effect initially increases the metabolic rate. However, as the disease becomes more advanced and leads to cachexia, energy expenditure drops below normal. Acute conditions such as burns and trauma significantly raise energy expenditure, primarily by increasing sympathetic response and the release of catecholamines, which are powerful stimulators of energy expenditure. Topics: Acquired Immunodeficiency Syndrome; Adult; Age Factors; Aged; Arthritis, Rheumatoid; Basal Metabolism; Burns; Diabetes Mellitus; Eating; Energy Metabolism; Female; Humans; Leptin; Male; Middle Aged; Neoplasms; Obesity; Wounds and Injuries | 2000 |
Cancer anorexia-cachexia syndrome: are neuropeptides the key?
Progressive wasting is common in many types of cancer and is one of the most important factors leading to early death in cancer patients. Weight loss is a potent stimulus to food intake in normal humans and animals. The persistence of anorexia in cancer patients, therefore, implies a failure of this adaptive feeding response, although the weight loss in the patients differs from that found in simple starvation. Tremendous progress has been made in the last 5 years with regard to the regulation of feeding and body weight. It has been demonstrated that leptin, a hormone secreted by adipose tissue, is an integral component of the homeostatic loop of body weight regulation. Leptin acts to control food intake and energy expenditure via neuropeptidergic effector molecules within the hypothalamus. Complex interactions among the nervous, endocrine, and immune systems affect the loop and induce behavioral and metabolic responses. A number of cytokines, including tumor necrosis factor-alpha, interleukins 1 and 6, IFN-gamma, leukemia inhibitory factor, and ciliary neurotrophic factor have been proposed as mediators of the cachectic process. Cytokines may play a pivotal role in long-term inhibition of feeding by mimicking the hypothalamic effect of excessive negative feedback signaling from leptin. This could be done by persistent stimulation of anorexigenic neuropeptides such as corticotropin-releasing factor, as well as by inhibition of the neuropeptide Y orexigenic network that consists of opioid peptides and galanin, in addition to the newly identified melanin-concentrating hormone, orexin, and agouti-related peptide. Information is being gathered, although it is still insufficient, on such abnormalities in the hypothalamic neuropeptide circuitry in tumor-bearing animals that coincide with the development of anorexia and cachexia. Characterization of the feeding-associated gene products have revealed new biochemical pathways and molecular targets for pharmacological intervention that will likely lead to new treatments. Although therapeutic intervention using neuropeptide agonists/antagonists is now directed at obesity treatment, it may also have an effect on treating cancer anorexia-cachexia, especially when combined with other agents that have effects on muscle and protein breakdown. Topics: Animals; Anorexia; Body Weight; Cachexia; Humans; Leptin; Neoplasms; Neuropeptides; Proteins; Syndrome | 1999 |
Obesity in female life--from molecular to clinical aspects.
Obesity gains increasing prevalence world-wide. Multifactorially caused it presents itself in numerous heterogeneous phenotypes with a wide spectrum of clinical symptoms. The full-blown female obesity syndrome is initiated already in childhood, associated with ovarian hyperandrogenaemia (polycystic ovary syndrome) in the reproductive phase, and characterised by increasing co-morbidity (cancer; metabolic syndrome; arteriosclerosis) in the postmenopausal state leading to shortened longevity. Due to the complexity of psychic, somatic and endocrine-metabolic disturbances a causal break-through in the treatment of the disease could not be achieved yet, but the enhanced basal understanding and recently investigated pharmaceutical principles might enable to improve the therapeutical approaches. Topics: Adolescent; Adult; Aged; Arteriosclerosis; Child; Combined Modality Therapy; Female; Gene Expression; Humans; Insulin Resistance; Leptin; Middle Aged; Neoplasms; Obesity; Polycystic Ovary Syndrome; Pregnancy; Proteins; Risk Factors | 1998 |
5 trial(s) available for leptin and Neoplasms
Article | Year |
---|---|
Psychological distress among health care professionals of the three COVID-19 most affected Regions in Cameroon: Prevalence and associated factors.
The present study aimed to assess the prevalence of symptoms of anxiety and depression among health professionals in the three most affected regions in Cameroon.. The study was a descriptive cross-sectional type. Participants were health care professionals working in the three chosen regions of Cameroon. The non_probability convinient sample technique and that of the snowball were valued via a web questionnaire. The non-exhaustive sample size was 292. The diagnosis of anxiety and depression was made by the HAD (Hospital Anxiety and Depression scale).. Les auteurs rapportent que le secteur médical est classé à un plus grand risque de contracter le COVID-19 et de le propager potentiellement à d’autres. Le nombre sans cesse croissant de cas confirmés et suspects, la pression dans les soins, l’épuisement des équipements de protection individuelle et le manque de médicaments spécifiques peuvent contribuer à un vécu anxio-dépressif significatif. La présente étude s’est donnée pour ambition d’évaluer la prévalence des symptômes de l’anxiété et de la dépression chez les professionnels de santé dans les trois Régions les plus concernées au Cameroun.. Le choix des trois Régions du Cameroun se justifie non seulement par le fait qu’elles totalisent 95,8 % des cas de coronavirus au pays depuis le début de la pandémie, mais aussi parce qu’elles disposent de plus de la moitié des personnels de santé (56 %). Il s’agit d’une étude transversale, descriptive et analytique. Les participants sont des professionnels de la santé en service dans les Régions du Centre, Littoral et de l’Ouest du Cameroun. La méthode d’échantillonnage non probabiliste de convenance couplée à celle de boule de neige via un web questionnaire a été adoptée. La collecte des données a duré du 5 au 19 avril 2020, intervalle de temps après lequel on n’avait plus eu de répondants. À la fin de cette période, la taille de l’échantillon non exhaustive était de 292 professionnels. Le diagnostic de l’état anxio-dépressive était posé via l’échelle de HAD (Hospital Anxiety and Depression scale). Dans le HAD, chaque réponse cotée évalue de manière semi-quantitative l’intensité du symptôme au cours de la semaine écoulée. Un score total est obtenu ainsi que des scores aux deux sous-échelles : le score maximal est de 42 pour l’échelle globale et de 21 pour chacune des sous-échelles. Le coefficient alpha de Cronbach est de 0,70 pour la dépression et de 0,74 pour l’anxiété. Certains auteurs après plusieurs travaux ont proposé qu’une note inférieure ou égale à 7 indique une absence d’anxiété ou de dépression ; celle comprise entre 8 et 10 suggère une anxiété ou une dépression faible à bénigne ; entre 11 et 14, pour une anxiété ou une dépression modérée ; enfin, une note comprise entre 15 et 21 est révélatrice d’une anxiété sévère. Le logiciel Excel 2013 et Epi Info version 7.2.2.6 ont été utilisés pour les traitements statistiques. Les liens entre les variables ont été considérées significatifs pour une valeur de. L’amélioration des conditions de travail et notamment la fourniture d’équipement de protection, la mise en place des cellules spéciales d’écoute pour le personnel de santé pourraient être proposées.. Taken together with satisfactory selectivity index (SI) values, the acetone and methanol extracts of. During a mean follow-up period of 25.6 ± 13.9 months, 38 (18.4%) VAs and 78 (37.7%) end-stage events occurred. Big ET-1 was positively correlated with NYHA class (. In primary prevention ICD indication patients, plasma big ET-1 levels can predict VAs and end-stage events and may facilitate ICD-implantation risk stratification.. Beyond age, cognitive impairment was associated with prior MI/stroke, higher hsCRP, statin use, less education, lower eGFR, BMI and LVEF.. These data demonstrate that even a short period of detraining is harmful for elderly women who regularly participate in a program of strength training, since it impairs physical performance, insulin sensitivity and cholesterol metabolism.. Exposure to PM. Respiratory sinus arrhythmia is reduced after PVI in patients with paroxysmal AF. Our findings suggest that this is related to a decrease in cardiac vagal tone. Whether and how this affects the clinical outcome including exercise capacity need to be determined.. BDNF and leptin were not associated with weight. We found that miR-214-5p exerted a protective role in I/R injured cardiac cells by direct targeting FASLG. The results indicated that the MGO injection reduced all CCl. The hepatoprotective effects of MGO might be due to histopathological suppression and inflammation inhibition in the liver.. OVEO showed moderate antifungal activity, whereas its main components carvacrol and thymol have great application potential as natural fungicides or lead compounds for commercial fungicides in preventing and controlling plant diseases caused by. PF trajectories were mainly related to income, pregestational BMI, birth weight, hospitalisation due to respiratory diseases in childhood, participant's BMI, report of wheezing, medical diagnosis and family history of asthma, gestational exposure to tobacco and current smoking status in adolescence and young adult age.. In chronic pain patients on opioids, administration of certain benzodiazepine sedatives induced a mild respiratory depression but paradoxically reduced sleep apnoea risk and severity by increasing the respiratory arousal threshold.. Quantitative measurements of sensory disturbances using the PainVision. The serum level of 20S-proteasome may be a useful marker for disease activity in AAV.. The electrophysiological data and MD simulations collectively suggest a crucial role of the interactions between the HA helix and S4-S5 linker in the apparent Ca. Invited for the cover of this issue are Vanesa Fernández-Moreira, Nils Metzler-Nolte, M. Concepción Gimeno and co-workers at Universidad de Zaragoza and Ruhr-Universität Bochum. The image depicts the reported bimetallic bioconjugates as planes directing the gold fragment towards the target (lysosomes). Read the full text of the article at 10.1002/chem.202002067.. The optimal CRT pacing configuration changes during dobutamine infusion while LV and RV activation timing does not. Further studies investigating the usefulness of automated dynamic changes to CRT pacing configuration according to physiologic condition may be warranted. Topics: 3' Untranslated Regions; 5'-Nucleotidase; A549 Cells; Accidental Falls; Acetylcholinesterase; Acrylic Resins; Actinobacillus; Acute Disease; Acute Kidney Injury; Adaptor Proteins, Signal Transducing; Adenosine; Adenosine Triphosphate; Administration, Inhalation; Administration, Oral; Adolescent; Adult; Advance Care Planning; Africa, Northern; Age Factors; Aged; Aged, 80 and over; Air Pollutants; Air Pollution; Air Pollution, Indoor; Albendazole; Aluminum Oxide; Anastomosis, Surgical; Ancylostoma; Ancylostomiasis; Androstadienes; Angiogenesis Inhibitors; Angiotensin II; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Antibodies, Bispecific; Antibodies, Viral; Anticoagulants; Antihypertensive Agents; Antinematodal Agents; Antineoplastic Agents; Antineoplastic Agents, Immunological; Antineoplastic Combined Chemotherapy Protocols; Antioxidants; Antiporters; Antiviral Agents; Apoptosis; Aptamers, Nucleotide; Aromatase Inhibitors; Asian People; Astrocytes; Atrial Fibrillation; Auditory Threshold; Aurora Kinase B; Australia; Autophagy; Autophagy-Related Protein 5; Autotrophic Processes; Bacillus cereus; Bacillus thuringiensis; Bacterial Proteins; Beclin-1; Belgium; Benzene; Benzene Derivatives; Benzhydryl Compounds; beta Catenin; beta-Arrestin 2; Biliary Tract Diseases; Biofilms; Biofuels; Biomarkers; Biomarkers, Tumor; Biomass; Biomechanical Phenomena; Bioreactors; Biosensing Techniques; Biosynthetic Pathways; Bismuth; Blood Platelets; Bone and Bones; Bone Regeneration; Bortezomib; Botulinum Toxins, Type A; Brain; Brain Injuries; Brain Ischemia; Brain Neoplasms; Breast Neoplasms; Breath Tests; Bronchodilator Agents; Calcium Phosphates; Cannabis; Carbon Dioxide; Carbon Isotopes; Carcinogenesis; Carcinoma, Hepatocellular; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cardiac Resynchronization Therapy; Cardiac Resynchronization Therapy Devices; Cardiomyopathies; Cardiovascular Diseases; Cariostatic Agents; Case Managers; Case-Control Studies; Catalysis; Cation Transport Proteins; CD8-Positive T-Lymphocytes; Cecropia Plant; Cell Adhesion; Cell Count; Cell Differentiation; Cell Division; Cell Line; Cell Line, Tumor; Cell Membrane; Cell Movement; Cell Proliferation; Cell Self Renewal; Cell Survival; Cells, Cultured; Cellular Reprogramming; Cellulose; Charcoal; Chemical and Drug Induced Liver Injury; Chemical Phenomena; Chemokines; Chemoradiotherapy; Chemoreceptor Cells; Child; Child Abuse; Child, Preschool; China; Chlorogenic Acid; Chloroquine; Chromatography, Gas; Chronic Disease; Clinical Competence; Coated Materials, Biocompatible; Cochlea; Cohort Studies; Color; Comorbidity; Computer Simulation; Computer-Aided Design; Contraception; Contraceptive Agents, Female; Contrast Media; COP-Coated Vesicles; Coronavirus Infections; Cost of Illness; Coturnix; COVID-19; Creatinine; Cross-Over Studies; Cross-Sectional Studies; Culex; Curriculum; Cyclic N-Oxides; Cytokines; Cytoplasm; Cytotoxicity, Immunologic; Cytotoxins; Databases, Factual; Deep Learning; Delivery, Obstetric; Denitrification; Dental Caries; Denture, Complete; Dexamethasone; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dielectric Spectroscopy; Diet, High-Fat; Dietary Fiber; Disease Models, Animal; Disease Progression; DNA; DNA Copy Number Variations; DNA, Mitochondrial; Dog Diseases; Dogs; Dopaminergic Neurons; Double-Blind Method; Down-Regulation; Doxorubicin; Drug Carriers; Drug Design; Drug Interactions; Drug Resistance, Bacterial; Drug Resistance, Neoplasm; Drug-Related Side Effects and Adverse Reactions; Drugs, Chinese Herbal; Dry Powder Inhalers; Dust; E2F1 Transcription Factor; Ecosystem; Education, Nursing; Education, Nursing, Baccalaureate; Electric Impedance; Electricity; Electrocardiography; Electrochemical Techniques; Electrochemistry; Electrodes; Electrophoresis, Polyacrylamide Gel; Endoplasmic Reticulum; Endothelial Cells; Environmental Monitoring; Enzyme Inhibitors; Epithelial Cells; Epithelial-Mesenchymal Transition; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Estrogen Receptor Modulators; Europe; Evoked Potentials, Auditory, Brain Stem; Exosomes; Feasibility Studies; Female; Ferricyanides; Ferrocyanides; Fibrinogen; Finite Element Analysis; Fistula; Fluorescent Dyes; Fluorides, Topical; Fluorodeoxyglucose F18; Fluticasone; Follow-Up Studies; Food Contamination; Food Microbiology; Foods, Specialized; Forensic Medicine; Frail Elderly; France; Free Radicals; Fresh Water; Fungi; Fungicides, Industrial; Galactosamine; Gastrointestinal Neoplasms; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Frequency; Genetic Predisposition to Disease; Genotype; Gingival Hemorrhage; Glioblastoma; Glioma; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Glucose; Glucose Transport Proteins, Facilitative; Glucosides; Glutamine; Glycolysis; Gold; GPI-Linked Proteins; Gram-Negative Bacteria; Gram-Positive Bacteria; Graphite; Haplotypes; HCT116 Cells; Healthy Volunteers; Hearing Loss; Heart Failure; Hedgehog Proteins; HEK293 Cells; HeLa Cells; Hemodynamics; Hemorrhage; Hepatocytes; Hippo Signaling Pathway; Histone Deacetylases; Homeostasis; Hospital Mortality; Hospitalization; Humans; Hydantoins; Hydrazines; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; Hydroxylamines; Hypoglycemic Agents; Immunity, Innate; Immunoglobulin G; Immunohistochemistry; Immunologic Factors; Immunomodulation; Immunophenotyping; Immunotherapy; Incidence; Indazoles; Indonesia; Infant; Infant, Newborn; Infarction, Middle Cerebral Artery; Inflammation; Injections, Intramuscular; Insecticides; Insulin-Like Growth Factor I; Insurance, Health; Intention to Treat Analysis; Interleukin-1 Receptor-Associated Kinases; Interleukin-6; Intrauterine Devices; Intrauterine Devices, Copper; Iron; Ischemia; Jordan; Keratinocytes; Kidney; Kidney Diseases; Kir5.1 Channel; Klebsiella Infections; Klebsiella pneumoniae; Lab-On-A-Chip Devices; Laparoscopy; Lasers; Lasers, Semiconductor; Lenalidomide; Leptin; Lethal Dose 50; Levonorgestrel; Limit of Detection; Lipid Metabolism; Lipid Metabolism Disorders; Lipogenesis; Lipopolysaccharides; Liquid Biopsy; Liver; Liver Abscess, Pyogenic; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Longevity; Lung Neoplasms; Luteolin; Lymph Nodes; Lymphocyte Activation; Macaca fascicularis; Macrophages; Mad2 Proteins; Magnetic Resonance Imaging; Male; Mammary Glands, Human; Manganese; Manganese Compounds; MAP Kinase Signaling System; Materials Testing; Maternal Health Services; MCF-7 Cells; Medicaid; Medicine, Chinese Traditional; Melanoma; Membrane Proteins; Mental Health; Mercury; Metal Nanoparticles; Metals, Heavy; Metformin; Methionine Adenosyltransferase; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Knockout; Mice, Nude; Microalgae; Microbial Sensitivity Tests; Microglia; MicroRNAs; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Middle Aged; Mitochondria; Mitochondrial Proteins; Mitral Valve; Mitral Valve Insufficiency; Models, Anatomic; Molecular Structure; Molybdenum; Monocarboxylic Acid Transporters; Moths; MPTP Poisoning; Multigene Family; Multiparametric Magnetic Resonance Imaging; Multiple Myeloma; Muscle, Skeletal; Mutagens; Mutation; Myeloid Cells; Nanocomposites; Nanofibers; Nanomedicine; Nanoparticles; Nanowires; Neoadjuvant Therapy; Neomycin; Neoplasm Grading; Neoplasm Recurrence, Local; Neoplasms; Neoplastic Stem Cells; Neostriatum; Neovascularization, Pathologic; Netherlands; Neuromuscular Agents; Neurons; NF-E2-Related Factor 2; NF-kappa B; Nickel; Nitrogen Oxides; Non-alcoholic Fatty Liver Disease; Nucleosides; Nucleotidyltransferases; Nutritional Status; Obesity, Morbid; Ofloxacin; Oils, Volatile; Oligopeptides; Oncogene Protein v-akt; Optical Imaging; Organic Cation Transport Proteins; Organophosphonates; Osteoarthritis; Osteoarthritis, Hip; Osteoarthritis, Knee; Osteoblasts; Osteogenesis; Oxidation-Reduction; Oxidative Stress; Oxides; Oxygen Isotopes; Pancreas; Pancreaticoduodenectomy; Pandemics; Particle Size; Particulate Matter; Patient Acceptance of Health Care; Patient Compliance; PC-3 Cells; Peptide Fragments; Peptides; Periodontal Attachment Loss; Periodontal Index; Periodontal Pocket; Periodontitis; Peroxides; Peru; Pest Control, Biological; Phosphatidylinositol 3-Kinase; Phosphatidylinositol 3-Kinases; Phylogeny; Pilot Projects; Piperidines; Plant Bark; Plant Extracts; Plant Leaves; Plasmids; Platelet Function Tests; Pneumonia, Viral; Podocytes; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Polyethylene Terephthalates; Polymers; Polymorphism, Single Nucleotide; Porosity; Portugal; Positron-Emission Tomography; Postoperative Complications; Postural Balance; Potassium Channels, Inwardly Rectifying; Povidone; Powders; Precancerous Conditions; Precision Medicine; Predictive Value of Tests; Pregnancy; Prenatal Care; Prognosis; Promoter Regions, Genetic; Prospective Studies; Prostatectomy; Prostatic Neoplasms; Proteasome Inhibitors; Protective Agents; Protein Binding; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Protein Transport; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-akt; Psychiatric Nursing; PTEN Phosphohydrolase; Pulmonary Embolism; Pyrimethamine; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Rats, Wistar; Reactive Oxygen Species; Receptor, ErbB-2; Receptor, IGF Type 1; Receptors, Estrogen; Receptors, G-Protein-Coupled; Recombinational DNA Repair; Recovery of Function; Regional Blood Flow; Renal Dialysis; Renin; Renin-Angiotensin System; Reperfusion Injury; Reproducibility of Results; Republic of Korea; Respiratory Distress Syndrome; Retrospective Studies; Rhodamines; Risk Assessment; Risk Factors; RNA, Long Noncoding; RNA, Messenger; Running; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Salinity; Salmeterol Xinafoate; Sarcoma; Seasons; Shoulder Injuries; Signal Transduction; Silicon Dioxide; Silver; Sirtuin 1; Sirtuins; Skull Fractures; Social Determinants of Health; Sodium; Sodium Fluoride; Sodium Potassium Chloride Symporter Inhibitors; Sodium-Glucose Transporter 2 Inhibitors; Soil; Soil Pollutants; Spain; Spectrophotometry; Spectroscopy, Fourier Transform Infrared; Staphylococcal Protein A; Staphylococcus aureus; Stem Cells; Stereoisomerism; Stomach Neoplasms; Streptomyces; Strontium; Structure-Activity Relationship; Students, Nursing; Substance-Related Disorders; Succinic Acid; Sulfur; Surface Properties; Survival Rate; Survivin; Symporters; T-Lymphocytes; Temozolomide; Tensile Strength; Thiazoles; Thiobacillus; Thiohydantoins; Thiourea; Thrombectomy; Time Factors; Titanium; Tobacco Mosaic Virus; Tobacco Use Disorder; Toll-Like Receptor 4; Toluene; Tomography, X-Ray Computed; TOR Serine-Threonine Kinases; Toxicity Tests, Acute; Toxicity Tests, Subacute; Transcriptional Activation; Treatment Outcome; Troponin I; Tumor Cells, Cultured; Tumor Escape; Tumor Hypoxia; Tumor Microenvironment; Tumor Necrosis Factor Inhibitors; Tumor Necrosis Factor-alpha; Tyrosine; Ubiquitin-Protein Ligases; Ubiquitination; Ultrasonic Waves; United Kingdom; United States; United States Department of Veterans Affairs; Up-Regulation; Urea; Uric Acid; Urinary Bladder Neoplasms; Urinary Bladder, Neurogenic; Urine; Urodynamics; User-Computer Interface; Vemurafenib; Verbenaceae; Veterans; Veterans Health; Viral Load; Virtual Reality; Vitiligo; Water Pollutants, Chemical; Wildfires; Wnt Signaling Pathway; Wound Healing; X-Ray Diffraction; Xenograft Model Antitumor Assays; Xylenes; Young Adult; Zinc; Zinc Oxide; Zinc Sulfate; Zoonoses | 2021 |
Leptin and adiponectin as new markers of undernutrition in cancer.
To evaluate leptin and adiponectin as markers of undernutrition in cancer patients, and compare their performances with those of other biomarkers.. This was a prospective and observational study of 132 patients with various types of cancer. Following the recommended professional criteria, we diagnosed undernutrition at the time of blood sampling for the biological analysis of leptin, adiponectin, paraoxonase (hydrolysis rate of three substrates: paraoxon (PON), phenylacetate (ARE) and thiolactone (LAC)), and the calculation of the Prognostic Inflammatory and Nutritional Index (PINI). Patients were monitored for one year to establish the mortality rate of the group. Relationships between biological variables and undernutrition were evaluated using univariate and multivariate logistic regression models. The Kaplan Meier method was used to analyse survival curves. Hazard ratios for death were calculated according to the quartiles of each biological variable.. In the case of undernutrition, a decrease was observed in levels of leptin and in the lactonase activity (LAC) of paraoxonase, while adiponectin levels increased. Besides PINI, leptin was the only parameter that was independently related to undernutrition. While no relation was found between survival and leptin or adiponectin levels, evidence was found that PINI, LAC and ARE were associated with survival, even in multivariate analysis.. Leptin and PINI are good markers of installed undernutrition, and PINI and ARE or LAC are reliable markers of the risk of death in patients suffering from cancer. Topics: Adiponectin; Aged; Biomarkers, Tumor; Disease-Free Survival; Female; Humans; Leptin; Male; Malnutrition; Middle Aged; Neoplasms; Nutritional Status; Prospective Studies; Survival Rate | 2017 |
Olanzapine for cachexia in patients with advanced cancer: an exploratory study of effects on weight and metabolic cytokines.
Olanzapine is used for treatment of psychiatric conditions but causes substantial weight gain. This study assessed safety, efficacy, and changes in metabolic cytokines associated with olanzapine administration in patients with cachexia due to advanced cancer.. Patients with cancer-related cachexia were treated with olanzapine (doses ranging from 2.5 to 20 mg daily by mouth). Patients also received anti-neoplastic treatments. Serum samples were collected at baseline and after weeks 1, 2, 4, and 8 for analysis of levels of leptin, growth hormone, ghrelin, and interleukin-6 (IL-6).. Of the 39 participants, 31 were evaluable for weight change (N = 6 excluded for new ascites; N = 2, incomplete body weight of data). Toxicities related to olanzapine were somnolence (n = 1), pancreatitis (n = 1), extrapyramidal symptoms (n = 1), and nausea/vomiting (n = 1) (all grade 2). The recommended dose of Olanzapine is 20 mg PO daily for cancer patients (same as FDA approved dose for psychiatric conditions). Samples from 29 patients were eligible for analysis of serum cytokine levels. Mean values of leptin, ghrelin, and growth hormone did not change on treatment, though IL-6 levels increased, perhaps due to tumor progression. There was no association between changes in cytokines and weight. The mean change in slope of weight loss before versus after therapy was 0.24 (95 % CI, -0.08, 0.56; p = 0.13) indicating a trend, albeit not reaching statistical significance, toward attenuation of weight loss.. Changes in metabolic cytokines and body weight did not correlate. Treatment with olanzapine had only a modest effect in altering the trajectory of weight loss. Topics: Adult; Aged; Benzodiazepines; Body Weight; Cachexia; Cytokines; Dose-Response Relationship, Drug; Female; Ghrelin; Humans; Interleukin-6; Leptin; Male; Middle Aged; Neoplasms; Olanzapine; Weight Gain; Weight Loss | 2015 |
Relationship between serum leptin levels and alcohol consumption in a controlled feeding and alcohol ingestion study.
We examined serum leptin levels in a controlled feeding and alcohol ingestion study to elucidate potential mechanisms by which alcohol may affect cancer and immunologically related health risks. A total of 53 healthy, nonsmoking postmenopausal women completed a random-order, three-period crossover design study in which each woman received zero (0 g of alcohol), one (15 g of alcohol), or two (30 g alcohol) drinks per day. After accounting for differences in body mass index, women who consumed 15 or 30 g of alcohol per day had 7.3% (95% confidence interval [CI] = 3.0% to 15.1%) and 8.9% (95% CI = 1.6% to 16.7%) higher serum leptin levels, respectively (P(trend) =.018), than women who consumed 0 g of alcohol per day. Younger women (i.e., 49-54 years) demonstrated a statistically significantly larger association of alcohol consumption level with the increase in serum leptin levels than older women (i.e., 55-79 years) (24.4%, 95% CI = 9.3% to 42.0% versus 3.7%, 95% CI = -4.1% to 12.1% increase in serum leptin levels for 30 g of alcohol per day relative to 0 g of alcohol per day for the lowest age quartile compared with the three highest age quartiles combined; P =.022). These results indicate that moderate alcohol consumption (15-30 g of alcohol per day) increases serum leptin levels in postmenopausal women and may predispose moderate drinkers to the morbidities associated with chronic elevations of this hormone including cancer. Topics: Age Factors; Aged; Alcohol Drinking; Autoimmune Diseases; Cross-Over Studies; Female; Humans; Insulin; Leptin; Middle Aged; Neoplasms; Postmenopause; Risk Factors | 2003 |
Tumor necrosis factor increases serum leptin levels in humans.
Leptin is a pleiotropic hormone believed to regulate body weight. Its function in wasting during inflammatory disease in humans is unknown. We studied the effect of repeated tumor necrosis factor (TNF) infusion on serum leptin levels in six patients with solid tumors. TNF infusion on day 1 resulted in an increase in serum leptin levels from 3.1 (SEM +/- 0.28) ng/mL to 5.2 (SEM +/- 0.6) ng/mL after 12 h (P < 0.001). The serum levels returned to baseline within 24 h. Similar results were obtained when TNF was infused on subsequent days. The study shows that leptin serum levels are under control of TNF. Topics: Aged; Female; Humans; Leptin; Male; Middle Aged; Neoplasms; Osmolar Concentration; Proteins; Recombinant Proteins; Time Factors; Tumor Necrosis Factor-alpha | 1997 |
56 other study(ies) available for leptin and Neoplasms
Article | Year |
---|---|
Increased Expression of Hepatic Stearoyl-CoA Desaturase (SCD)-1 and Depletion of Eicosapentaenoic Acid (EPA) Content following Cytotoxic Cancer Therapy Are Reversed by Dietary Fish Oil.
Cancer treatment evokes impediments to liver metabolism that culminate in fatty liver. This study determined hepatic fatty acid composition and expression of genes and mediators involved in lipid metabolism following chemotherapy treatment. Female rats bearing the Ward colon tumor were administered Irinotecan (CPT-11) +5-fluorouracil (5-FU) and maintained on a control diet or a diet containing eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) (2.3 g/100 g fish oil). Healthy animals provided with a control diet served as a reference group. Livers were collected one week after chemotherapy. Triacylglycerol (TG), phospholipid (PL), ten lipid metabolism genes, leptin, and IL-4 were measured. Chemotherapy increased TG content and reduced EPA content in the liver. Expression of SCD1 was upregulated by chemotherapy, while dietary fish oil downregulated its expression. Dietary fish oil down-regulated expression of the fatty acid synthesis gene FASN, while restoring the long chain fatty acid converting genes FADS2 and ELOVL2, and genes involved in mitochondrial β-oxidation (CPT1α) and lipid transport (MTTP1), to values similar to reference animals. Neither leptin nor IL-4 were affected by chemotherapy or diet. Depletion of EPA is associated with pathways evoking enhanced TG accumulation in the liver. Restoring EPA through diet may pose a dietary strategy to attenuate chemotherapy-associated impediments in liver fatty acid metabolism. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids; Fatty Liver; Female; Fish Oils; Fluorouracil; Interleukin-4; Irinotecan; Leptin; Liver; Neoplasms; Rats; Stearoyl-CoA Desaturase; Triglycerides | 2023 |
Breast cancer cell-derived exosome-delivered microRNA-155 targets UBQLN1 in adipocytes and facilitates cancer cachexia-related fat loss.
Cachexia occurrence and development are associated with loss of white adipose tissues, which may be involved with cancer-derived exosomes. This study attempted to characterize the functional mechanisms of breast cancer (BC) cell-derived exosome-loaded microRNA (miR)-155 in cancer cachexia-related fat loss. Exosomes were incubated with preadipocytes and cellular lipid droplet accumulation was observed using Oil Red O staining. Western blotting evaluated the cellular levels of lipogenesis marker peroxisome proliferator activated receptor gamma (PPARγ) and adiponectin, C1Q and collagen domain containing (AdipoQ). Differentiated adipocytes were incubated with exosomes, and phosphate hormone sensitive lipase (P-HSL), adipose triglyceride lipase (ATGL) and glycerol were detected in adipocytes, in addition to uncoupling protein 1 (UCP1) and leptin levels. A mouse model of cancer cachexia was established where cancer exosomes were injected intravenously. The changes in body weight and tumor-free body weights were recorded and serum glycerol levels and lipid accumulation in adipose tissues were determined. Also, the relationship between miR-155 and UBQLN1 was predicted and verified. BC exosome treatment reduced PPARγ and AdipoQ protein levels, promoted the levels of P-HSL and ATGL proteins, facilitated glycerol release, increased UCP1 expression and lowered leptin expression in adipocytes. Exosomal miR-155 inhibited lipogenesis in preadipocytes and boosted the browning of white adipose tissues. miR-155 downregulation alleviated cancer exosome-induced browning of white adipose tissues and fat loss. Mechanistically, miR-155 targeted UBQLN1, and UBQLN1 upregulation reversed the impacts of cancer exosomes. miR-155 loaded by BC cell-derived exosomes significantly affects white adipose browning and inhibition of cancer-derived exosomes. Topics: Adaptor Proteins, Signal Transducing; Adipocytes; Animals; Autophagy-Related Proteins; Cachexia; Exosomes; Glycerol; Leptin; Mice; MicroRNAs; Neoplasms; PPAR gamma; Sterol Esterase | 2023 |
Associations between dietary inflammatory scores and biomarkers of inflammation in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.
Since the first version of the dietary inflammatory index (DII®) developed in the past decade, several other versions have been developed. However, to date no study has attempted to compare these versions with respect to their associations with biomarkers of inflammation.. We aimed to investigate the relationship between four dietary inflammatory scores [DII, two energy-adjusted derivatives (E-DII and E-DII. This study included 17 637 participants from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort with at least one marker of inflammation measured in blood. Associations between the four scores and C-reactive protein (CRP), interleukin (IL)6, IL10, IL1RA, tumor necrosis factor-α (TNFα), soluble tumor necrosis factor receptor-1 (sTNFR1), sTNFR2, leptin, soluble leptin receptor (sLeptin R), adiponectin, and High Molecular Weight (HMW) adiponectin were evaluated using multivariable linear regressions adjusted for potential confounders.. Positive associations were observed between the four dietary inflammatory scores and levels of CRP, IL6, sTNFR1, sTNFR2 and leptin. However, only the DII and the ISD were positively associated with IL1RA levels and only the DII and the E-DII. Our results suggest that the four dietary inflammatory scores were associated with some biomarkers of inflammation and could be used to assess the inflammatory potential of diet in European adults but are not sufficient to capture the inflammatory status of an individual. These findings can help to better understand the inflammatory potential of diet, but they need to be replicated in studies with repeated dietary measurements. Topics: Adiponectin; Adult; Biomarkers; C-Reactive Protein; Diet; Humans; Inflammation; Leptin; Neoplasms; Prospective Studies; Tumor Necrosis Factor-alpha | 2023 |
Cancer-cell-secreted miR-204-5p induces leptin signalling pathway in white adipose tissue to promote cancer-associated cachexia.
Cancer-associated cachexia is a multi-organ weight loss syndrome, especially with a wasting disorder of adipose tissue and skeletal muscle. Small extracellular vesicles (sEVs) serve as emerging messengers to connect primary tumour and metabolic organs to exert systemic regulation. However, whether and how tumour-derived sEVs regulate white adipose tissue (WAT) browning and fat loss is poorly defined. Here, we report breast cancer cell-secreted exosomal miR-204-5p induces hypoxia-inducible factor 1A (HIF1A) in WAT by targeting von Hippel-Lindau (VHL) gene. Elevated HIF1A protein induces the leptin signalling pathway and thereby enhances lipolysis in WAT. Additionally, exogenous VHL expression blocks the effect of exosomal miR-204-5p on WAT browning. Reduced plasma phosphatidyl ethanolamine level is detected in mice lack of cancer-derived miR-204-5p secretion in vivo. Collectively, our study reveals circulating miR-204-5p induces hypoxia-mediated leptin signalling pathway to promote lipolysis and WAT browning, shedding light on both preventive screenings and early intervention for cancer-associated cachexia. Topics: Adipose Tissue, White; Animals; Cachexia; Hypoxia; Leptin; Mice; MicroRNAs; Neoplasms | 2023 |
Dietary fructose-mediated adipocyte metabolism drives antitumor CD8
Fructose consumption is associated with tumor growth and metastasis in mice, yet its impact on antitumor immune responses remains unclear. Here, we show that dietary fructose modulates adipocyte metabolism to enhance antitumor CD8 Topics: Animals; CD8-Positive T-Lymphocytes; Humans; Immunotherapy; Leptin; Lymphocyte Activation; Mice; Neoplasms | 2023 |
Leptin and Beyond: Actors in Cancer.
Leptin is a 16-kDa multifunctional, neuroendocrine peptide hormone secreted by adipocytes in proportion to total adipose tissue mass, known to control food intake, energy homeostasis, immune response, and reproductive processes [...]. Topics: Gene Expression Regulation, Neoplastic; Humans; Leptin; Neoplasms | 2021 |
Analysis of inflammatory markers and hormones in old cancer patients: A descriptive study.
Advanced cancers are associated with a chronic inflammation, especially high interleukin-6 (IL-6) and with various levels of adipokines (leptin and adiponectin), while ghrelin counteracts the anorexigenic effect of leptin in cancer-induced anorexia-cachexia syndrome. We aimed to understand how IL-6, adipokines and ghrelin plasma levels could be influenced by cancer on the one hand, and by age, frailty, and nutritional status in old cancer patients on the other hand. Ninety-nine patients aged 79[76-83] years old were included. Sixty-six percent had advanced stages of cancer, and 34% had cachexia. Fifty percent were at risk of malnutrition, and 10% had overt malnutrition. None of the variables studied was significantly correlated with the advanced stage, or cachexia. In multiple regression, the only parameter significantly and positively associated with age was adiponectin (p = 0.008). Despite a high prevalence of frailty in our study, we did not find any independent association of frailty (assessed by G8) with IL-6, leptin, adiponectin, or ghrelin in multivariate analysis. We observed that a low albumin level was independently associated with a higher level of IL-6 (p < 0.0001), but not with the MNA score. However, leptin showed a positive correlation with BMI (p < 0.0001), confirming the persistence of a relationship between leptin and adiposity, even in older cancer patients. Finally, high IL-6 level was associated with a higher mortality rate (p = 0.027). In conclusion, IL-6, leptin, adiponectin, and ghrelin are not associated with advanced stages of cancer or cancer-induced cachexia in older subjects with cancer, but they are significantly correlated with anthropometric factors and body composition. Topics: Adipokines; Adiponectin; Adiposity; Aged; Aged, 80 and over; Biomarkers; Body Mass Index; Cachexia; Female; Frailty; Ghrelin; Humans; Inflammation; Interleukin-6; Leptin; Male; Malnutrition; Neoplasms; Nutritional Status; Tumor Necrosis Factor-alpha | 2020 |
Leptin boosts T cell function in tumours.
Topics: Humans; Leptin; Neoplasms; Oncolytic Viruses; T-Lymphocytes | 2019 |
Leptin-Producing Oncolytic Virus Makes Tumor-Infiltrating T Cells Fit, Not Fat.
Effective anticancer immunosurveillance after oncolytic viral infection is often hindered by the defective metabolic function of tumor-infiltrating lymphocytes (TILs). A recent paper by Rivadeneira et al. demonstrates that intratumoral delivery of leptin by a recombinant oncolytic vaccinia virus can metabolically enhance TIL effector and memory functions through improved mitochondrial oxidative phosphorylation, thereby enhancing therapeutic efficacy. Topics: Humans; Leptin; Lymphocytes, Tumor-Infiltrating; Neoplasms; Oncolytic Viruses; T-Lymphocytes | 2019 |
Altered expression of inflammation-associated genes in the hypothalamus of obesity mouse models.
Metabolic inflammation is a distinct feature of obesity. Increased inflammation in the adipose tissue and the liver has been so far implicated to affect metabolic homeostasis, mainly insulin resistance. In addition to the peripherals, the inflammation in the hypothalamus which governs systemic metabolism by linking neuronal and endocrine signals has been suggested to be linked to the metabolic disease. However, the underlying molecular mechanisms are poorly understood. We hypothesized that a high-fat diet (HFD) led to central metabolic inflammation via transcriptional changes in the hypothalamus. To address the hypothesis, we characterized obesity-related hypothalamic, transcriptional alterations, and their effects on functional networks. Male C57BL/6J mice were fed with either a control diet (CD) or an HFD for 20 weeks. Microarray and gene ontology analyses of the hypothalamus demonstrated that immune-related pathways, including inflammatory and cytokine signaling, were overrepresented in the hypothalamus of HFD-fed mice compared to that of CD mice. In addition, through secondary analysis of leptin-deficient obese (ob/ob) mouse hypothalamus, we found that enriched gene sets for tumor necrosis factor-α signaling pathways and cancer pathways were common in both the obese mouse models. The results suggest that inflammatory pathway is transcriptionally enriched in the hypothalamus in obesity models and is related with hyperadiposity rather than the primary causes of obesity including the dietary fat and the genetic mutation. Topics: Adipose Tissue; Adiposity; Animals; Diet, High-Fat; Dietary Fats; Disease Models, Animal; Hypothalamus; Inflammation; Insulin Resistance; Leptin; Liver; Male; Metabolic Diseases; Mice, Inbred C57BL; Mice, Obese; Neoplasms; Obesity; Transcription, Genetic; Tumor Necrosis Factor-alpha | 2019 |
Paradoxical effects of obesity on T cell function during tumor progression and PD-1 checkpoint blockade.
The recent successes of immunotherapy have shifted the paradigm in cancer treatment, but because only a percentage of patients are responsive to immunotherapy, it is imperative to identify factors impacting outcome. Obesity is reaching pandemic proportions and is a major risk factor for certain malignancies, but the impact of obesity on immune responses, in general and in cancer immunotherapy, is poorly understood. Here, we demonstrate, across multiple species and tumor models, that obesity results in increased immune aging, tumor progression and PD-1-mediated T cell dysfunction which is driven, at least in part, by leptin. However, obesity is also associated with increased efficacy of PD-1/PD-L1 blockade in both tumor-bearing mice and clinical cancer patients. These findings advance our understanding of obesity-induced immune dysfunction and its consequences in cancer and highlight obesity as a biomarker for some cancer immunotherapies. These data indicate a paradoxical impact of obesity on cancer. There is heightened immune dysfunction and tumor progression but also greater anti-tumor efficacy and survival after checkpoint blockade which directly targets some of the pathways activated in obesity. Topics: Adult; Animals; Body Weight; Cell Line, Tumor; Cell Proliferation; Diet; Disease Progression; Female; Humans; Immunotherapy; Leptin; Male; Mice, Inbred C57BL; Mice, Obese; Middle Aged; Neoplasms; Obesity; Programmed Cell Death 1 Receptor; Signal Transduction; Species Specificity; T-Lymphocytes; Tumor Burden | 2019 |
Leptin promotes fatty acid oxidation and OXPHOS via the c-Myc/PGC-1 pathway in cancer cells.
Alteration in cellular energy metabolism plays a critical role in the development and progression of cancer. Leptin is a hormone secreted by adipose tissue. Recent reports have shown that leptin can induce cancer cell proliferation and regulate cell energy metabolism, but the regulatory mechanism is still unclear. Here, we showed that leptin could promote cell proliferation and maintain high adenosine triphosphate levels in HCT116 and MCF-7 cells. The expression levels of carnitine palmitoyl transferase 1A (CPT1A), pyruvate dehydrogenase, succinate dehydrogenase subunit A and mitochondrial respiratory chain-associated proteins NADH dehydrogenase 1 (ND1), NADH:ubiquinone oxidoreductase subunit B8, and mitochondrial transcription factor A (TFAM) were distinctly increased in leptin-treated HCT116 and MCF-7 cells, while fatty acid synthase and lactate dehydrogenase expression were downregulated. Simultaneously, we found that c-Myc and peroxisome proliferator-activated receptor gamma co-activator 1 (PGC-1) protein expression levels were significantly increased. These results indicated that leptin boosted fatty acid β-oxidation and the tricarboxylic acid cycle, enhanced oxidative phosphorylation (OXPHOS) activity, and inhibited fatty acid synthesis and glycolysis in tumor cells. Gene transfection experiments revealed that leptin could induce the expression of c-Myc. Moreover, the expressions of PGC-1, CPT1A, and TFAM proteins were downregulated in HCT116 cells with low expression of c-Myc, and the expression levels of these proteins were increased in HCT116 cells overexpressing c-Myc. These findings suggest that leptin plays an important role in the regulation of energy metabolism in tumor cells. It may regulate fatty acid oxidation and OXPHOS of tumor cells by regulating the c-Myc/PGC-1 pathway. Targeting metabolic pathways for cancer treatment has been investigated as potential preventive or therapeutic methods. This study has important implications for the clinical therapy of tumor cell metabolism through hormone regulation. Topics: Carnitine O-Palmitoyltransferase; Cell Line, Tumor; Fatty Acid Synthase, Type I; Fatty Acids; Gene Expression Regulation, Neoplastic; HCT116 Cells; HEK293 Cells; Humans; Leptin; MCF-7 Cells; Metabolic Networks and Pathways; Neoplasms; Oxidation-Reduction; Oxidative Phosphorylation; Proto-Oncogene Proteins c-myc; Transcription Factors | 2019 |
Editorial: Two MDSC faces in obesity: Correcting metabolic dysfunctions but promoting tumor development.
Topics: Diet, High-Fat; Humans; Leptin; Myeloid-Derived Suppressor Cells; Neoplasms; Obesity | 2018 |
Neuroendocrine and immune disequilibrium as a probable link between metabolic syndrome and carcinogenesis.
Numerous investigations prove a higher incidence of carcinogenesis in metabolic syndrome (MetS). They indicate the important role of obesity, elevated inflammatory biomarkers, hyperinsulinemia, hyperglycemia, and dyslipidemia as well. Elevated plasma insulin and free insulin-like growth factor-1 (IGF-1) levels stimulate cell proliferation. The present publication considers the role of neuroendocrine and immune disequilibrium in MetS as a reason for transition to carcinogenesis. It emphasizes the role of hormonal disbalance, i.e. hyperleptinemia, hyperinsulinemia, hypercortisolemia, hypercatecholaminemia, hyperestrogenemia and hyperandrogenemia in MetS. It is presumed that these important components modify cellular microenvironment towards carcinogenesis. The interactions between neurotrophins, leptin, and mast cells and the alterations in the hypothalamo-hypophyseal-adrenal axis in MetS are discussed. It is assumed that they are the consequence of inflammatory distress followed by hormonal and immune disbalance at a central level as well as of enlarged adipose tissue and changed adipocyte microenvironment leading, finally, to carcinogenesis. Topics: Adiponectin; Adipose Tissue; Carcinogenesis; Catecholamines; Cell Proliferation; Estrogens; Homeostasis; Humans; Hydrocortisone; Immune System; Insulin; Insulin-Like Growth Factor I; Leptin; Mast Cells; Metabolic Syndrome; Models, Theoretical; Mutation; Neoplasms; Nerve Growth Factors; Neurosecretory Systems; Obesity | 2018 |
Cachexia-associated adipose loss induced by tumor-secreted leukemia inhibitory factor is counterbalanced by decreased leptin.
Cachexia syndrome consists of adipose and muscle loss, often despite normal food intake. We hypothesized that cachexia-associated adipose wasting is driven in part by tumor humoral factors that induce adipocyte lipolysis. We developed an assay to purify secreted factors from a cachexia-inducing colon cancer line that increases lipolysis in adipocytes and identified leukemia inhibitory factor (LIF) by mass spectrometry. Recombinant LIF induced lipolysis in vitro. Peripheral LIF administered to mice caused >50% loss of adipose tissue and >10% reduction in body weight despite only transient hypophagia due to decreasing leptin. LIF-injected mice lacking leptin (ob/ob) resulted in persistent hypophagia and loss of adipose tissue and body weight. LIF's peripheral role of initiating lipolysis in adipose loss was confirmed in pair-fed ob/ob mouse studies. Our studies demonstrate that (a) LIF is a tumor-secreted factor that promotes cachexia-like adipose loss when administered peripherally, (b) LIF directly induces adipocyte lipolysis, (c) LIF has the ability to sustain adipose and body weight loss through an equal combination of peripheral and central contributions, and (d) LIF's central effect is counterbalanced by decreased leptin signaling, providing insight into cachexia's wasting, despite normophagia. Topics: Adipocytes; Adipose Tissue; Animals; Body Weight; Cachexia; Cell Line; Cytokine Receptor gp130; Cytokines; Disease Models, Animal; Leptin; Leukemia Inhibitory Factor; Lipase; Lipolysis; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neoplasms; Recombinant Proteins; STAT Transcription Factors | 2018 |
Obesity gives unexpected boost to anticancer drugs.
Topics: Animals; Antineoplastic Agents; Humans; Immune System; Leptin; Mice; Neoplasms; Obesity; Programmed Cell Death 1 Receptor; T-Lymphocytes | 2018 |
Enriching the Housing Environment for Mice Enhances Their NK Cell Antitumor Immunity via Sympathetic Nerve-Dependent Regulation of NKG2D and CCR5.
Mice housed in an enriched environment display a tumor-resistant phenotype due to eustress stimulation. However, the mechanisms underlying enriched environment-induced protection against cancers remain largely unexplained. In this study, we observed a significant antitumor effect induced by enriched environment in murine pancreatic cancer and lung cancer models. This effect remained intact in T/B lymphocyte-deficient Rag1 Topics: Animals; Cell Line, Tumor; Cytotoxicity, Immunologic; Environment; Housing, Animal; Killer Cells, Natural; Leptin; Male; Mice; Mice, Inbred C57BL; Neoplasms; NK Cell Lectin-Like Receptor Subfamily K; Receptors, CCR5; Sympathetic Nervous System | 2017 |
Serum leptin, C-reactive protein, and cancer mortality in the NHANES III.
Adipokines, such as leptin, may affect cancer through its link with inflammation and obesity. We investigated the association between leptin, C-reactive protein, and risk of cancer death while accounting general and abdominal obesity. From the Third National Health and Examination Survey (NHANES III), we selected 5957 adult men and women with baseline measurements of serum leptin and CRP. Multivariable Cox regression was used to assess leptin and CRP levels (low, moderate, high) in relation to risk of cancer death. Stratification analyses were performed for obesity as defined by body mass index (BMI) and waist circumference. Fine and Gray regression was performed to account for death from cardiovascular disease and other causes as competing events. A total of 385 participants died of cancer during a mean follow-up of 18 years. After adjusting for BMI and waist circumference, an inverse association with log-transformed leptin was found for women, with a hazard ratio (HR) of 0.81 (95% confidence interval [CI]: 0.51-1.30) and 0.40 (95% CI: 0.24-0.68) for moderate and high compared to low levels of leptin, respectively; P(trend) = 0.0007). No association for leptin was observed in men, but higher CRP corresponded to increased risk of dying from cancer (HR: 2.98; 95% CI: 1.57-5.64 for the highest vs. lowest categories of CRP). Similar associations were observed with competing risk analysis also adjusted for BMI and waist circumference. Contrasting associations of serum leptin and CRP with cancer mortality may indicate sex-specific biological or environmental pathways linking obesity and cancer in men and women which warrant mechanistic investigations. Topics: C-Reactive Protein; Female; History, 20th Century; Humans; Leptin; Male; Neoplasms; Population Surveillance; Proportional Hazards Models; Risk Factors; United States | 2016 |
Voluntary physical activity abolishes the proliferative tumor growth microenvironment created by adipose tissue in animals fed a high fat diet.
The molecular mechanisms behind the obesity-breast cancer association may be regulated via adipokine secretion by white adipose tissue. Specifically, adiponectin and leptin are altered with adiposity and exert antagonistic effects on cancer cell proliferation. We set out to determine whether altering adiposity in vivo via high fat diet (HFD) feeding changed the tumor growth supporting nature of adipose tissue and whether voluntary physical activity (PA) could ameliorate these HFD-dependent effects. We show that conditioned media (CM) created from the adipose tissue of HFD fed animals caused an increase in the proliferation of MCF7 cells compared with cells exposed to CM prepared from the adipose of lean chow diet fed counterparts. This increased proliferation was driven within the MCF7 cells by an HFD-dependent antagonism between AMP-activated protein kinase (AMPK) and protein kinase B (Akt) signaling pathways, decreasing p27 protein levels via reduced phosphorylation at T198 and downregulation of adiponectin receptor 1 (AdipoR1). PA can ameliorate these proliferative effects of HFD-CM on MCF7 cells, increasing p27(T198) by AMPK, reducing pAkt(T308), and increasing AdipoR1, resulting in cell cycle withdrawal in a manner that depends on the PA intensity. High physical activity (>3 km/day) completely abolished the effects of HFD feeding. In addition, AdipoR1 overexpression mimics the effects of exercise, abolishing the proliferative effects of the HFD-CM on MCF7 cells and further enhancing the antiproliferative effects of PA on the HFD-CM. Thus voluntary PA represents a means to counteract the proliferative effects of adipose tissue on breast cancers in obese patients. Topics: Adipokines; Adiponectin; Adipose Tissue; Adiposity; AMP-Activated Protein Kinases; Animals; Body Weight; Cell Proliferation; Culture Media, Conditioned; Diet, High-Fat; Humans; Leptin; Male; MCF-7 Cells; Neoplasms; Obesity; Physical Conditioning, Animal; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Signal Transduction; Tumor Microenvironment | 2016 |
Plasma Leptin Levels and Risk of Incident Cancer: Results from the Dallas Heart Study.
Leptin dysregulation has been postulated to affect cancer risk through its effects on obesity and inflammation. Epidemiological data evaluating this relationship are conflicting and studies in non-white cohorts is lacking. Therefore, we examined the association of leptin with the risk of incident cancer in the multiethnic Dallas Heart Study (DHS).. Participants enrolled in the DHS without prevalent cancer and with baseline leptin measurements were included. Incident cancer cases were identified through a systematic linkage of the DHS and the Texas Cancer Registry. Leptin was evaluated both as a continuous variable and in sex-specific quartiles. Multivariable Cox proportional hazards modeling was performed to examine the association between leptin levels with incident cancer after adjusting for age, sex, race, smoking status, alcohol use, family history of malignancy, body mass index (BMI), diabetes mellitus and C-reactive protein.. Among 2,919 participants (median age 44 years; 54% women; 70% nonwhite; median BMI 29.4 kg/m2), 190 (6.5%) developed cancer after median follow- up of 12 years. Median leptin levels were 12.9 (interquartile range [IQR] 5.8-29.5) ng/ml in the incident cancer group vs. 12.3 (IQR 5.4-26.4) ng/ml those without an incident cancer (p = 0.34). Leptin was not associated with cancer incidence in multivariable analysis (unit standard deviation increase in log-transformed leptin, hazard ratio 0.95; 95% confidence interval, 0.77-1.16; p = 0.60). No association was observed in analyses stratified by sex, race/ethnicity, diabetes, or obesity status.. In this study of a predominantly minority population, no association between premorbid leptin levels and cancer incidence was demonstrated. Despite preclinical rationale and positive findings in other studies, this association may not replicate across all racial/ethnic populations. Topics: Adult; Biomarkers, Tumor; Female; Humans; Leptin; Male; Middle Aged; Neoplasms; Risk Factors; Texas | 2016 |
Autophagy induction by leptin contributes to suppression of apoptosis in cancer cells and xenograft model: involvement of p53/FoxO3A axis.
Leptin, a hormone mainly produced from adipose tissue, has been shown to induce proliferation of cancer cells. However, the molecular mechanisms underlying leptin-induced tumor progression have not been clearly elucidated. In the present study, we investigated the role of autophagy in leptin-induced cancer cell proliferation using human hepatoma (HepG2) and breast cancer cells (MCF-7), and tumor growth in a xenograft model. Herein, we showed that leptin treatment caused autophagy induction as assessed by increase in expression of autophagy-related genes, including beclin-1, Atg5 and LC3 II, further induction of autophagosome formation and autophagic flux. Interestingly, inhibition of autophagic process by treatment with inhibitors and LC3B gene silencing blocked leptin-induced increase in cell number and suppression of apoptosis, indicating a crucial role of autophagy in leptin-induced tumor progression. Moreover, gene silencing of p53 or FoxO3A prevented leptin-induced LC3 II protein expression, suggesting an involvement of p53/FoxO3A axis in leptin-induced autophagy activation. Leptin administration also accelerated tumor growth in BALB/c nude mice, which was found to be autophagy dependent. Taken together, our results demonstrate that leptin-induced tumor growth is mediated by autophagy induction and autophagic process would be a promising target to regulate development of cancer caused by leptin production. Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Autophagy; Autophagy-Related Protein 5; bcl-2-Associated X Protein; Beclin-1; Disease Progression; Forkhead Box Protein O3; Forkhead Transcription Factors; Gene Silencing; Genes, p53; Hep G2 Cells; Humans; Leptin; Male; MCF-7 Cells; Membrane Proteins; Mice; Mice, Inbred BALB C; Mice, Nude; Microtubule-Associated Proteins; Neoplasm Transplantation; Neoplasms; Tumor Suppressor Protein p53 | 2015 |
Effect of Sipjeondaebo-tang on cancer-induced anorexia and cachexia in CT-26 tumor-bearing mice.
Cancer-associated anorexia and cachexia are a multifactorial condition described by a loss of body weight and muscle with anorexia, asthenia, and anemia. Moreover, they correlate with a high mortality rate, poor response to chemotherapy, poor performance status, and poor quality of life. Cancer cachexia is regulated by proinflammatory cytokines such as interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor- α (TNF- α). In addition, glucagon like peptide-1 (GIP-1), peptide YY (PYY), ghrelin, and leptin plays a crucial role in food intake. In this study, we investigated the therapeutic effects of one of the traditional herbal medicines, Sipjeondaebo-tang (Juzen-taiho-to in Japanese; SJDBT), on cancer anorexia and cachexia in a fundamental mouse cancer anorexia/cachexia model, CT-26 tumor-bearing mice. SJDBT was more significantly effective in a treatment model where it was treated after anorexia and cachexia than in a prevention model where it was treated before anorexia and cachexia on the basis of parameters such as weights of muscles and whole body and food intakes. Moreover, SJDBT inhibited a production of IL-6, MCP-1, PYY, and GLP-1 and ameliorated cancer-induced anemia. Therefore, our in vivo studies provide evidence on the role of SJDBT in cancer-associated anorexia and cachexia, thereby suggesting that SJDBT may be useful for treating cancer-associated anorexia and cachexia. Topics: Animals; Anorexia; Body Weight; Cachexia; Cell Line, Tumor; Chemokine CCL2; Drugs, Chinese Herbal; Ghrelin; Glucagon-Like Peptide 1; Inflammation; Interleukin-6; Intestinal Mucosa; Leptin; Male; Mice; Mice, Inbred BALB C; Muscles; Neoplasm Transplantation; Neoplasms; Peptide YY; Plant Preparations; Tumor Necrosis Factor-alpha | 2014 |
Associations between time spent sitting and cancer-related biomarkers in postmenopausal women: an exploration of effect modifiers.
Despite evidence that prolonged periods of sitting may influence biological mediators of cancer development, few studies have considered these relationships in a cancer-specific context.. This cross-sectional study included 755 postmenopausal women enrolled in an ancillary study of the Women's Health Initiative. Plasma levels of Insulin-like growth factor-I (IGF-I), IGF-binding protein-3, leptin, insulin, C-peptide, C-reactive protein (CRP), and Interleukin (IL)-6 were measured. The time spent sitting per day was categorized as quartiles (Qs). The relationships between sedentary time and biomarkers were modified by race, physical activity, and exogenous estrogen use.. IGF-I levels among African American (AA) women were higher than those of white women across the Qs of sedentary time. Likewise, IL-6 levels in AA women were higher than those in white women at Q3 and Q4 of sedentary time. IGFBP-3 levels were higher and insulin levels were lower across the Qs of sedentary time among women meeting guidelines for physical activity than women who were not. Additionally, CRP levels were higher among estrogen users than nonusers at Q1, Q2, and Q4 of sedentary time.. These results suggest that relationship between time spent sitting and cancer-related biomarkers may not be simply linear, but differ in the context of effect modifiers. Topics: Aged; Biomarkers, Tumor; Black or African American; C-Peptide; C-Reactive Protein; Cross-Sectional Studies; Estrogen Replacement Therapy; Female; Humans; Insulin; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor I; Interleukin-6; Leptin; Middle Aged; Neoplasms; Postmenopause; Sedentary Behavior; United States; White People; Women's Health | 2014 |
Emerging markers of cachexia predict survival in cancer patients.
Cachexia may occur in 40% of cancer patients, representing the major cause of death in more than 20% of them. The aim of this study was to investigate the role of leptin, ghrelin and obestatin as diagnostic and predictive markers of cachexia in oncologic patients. Their impact on patient survival was also evaluated.. 140 adults with different cancer diagnoses were recruited. Thirty healthy volunteers served as control. Serum ghrelin, obestatin and leptin were tested at baseline and after a follow-up period of 18 months.. Ghrelin levels were significantly higher in cancer patients than in healthy subjects (573.31 ± 130 vs 320.20 ± 66.48 ng/ml, p < 0.0001), while obestatin (17.42 ± 7.12 vs 24.89 ± 5.54 ng/ml, p < 0.0001) and leptin (38.4 ± 21.2 vs 76.28 ± 17.48 ng/ml, p < 0.0001) values were lower. At ROC analyses the diagnostic profile of ghrelin (AUC 0.962; sensitivity 83%; specificity 98%), obestatin (AUC 0.798; sensitivity 74.5%; specificity 81.5%) and leptin (AUC 0.828; sensitivity 79%; specificity 73%) was superior to that of albumin (AUC 0.547; sensitivity 63%, specificity 69.4%) for detecting cachexia among cancer patients. On Cox multivariate analyses ghrelin (HR 1.02; 95% CI 1.01 - 1.03; p < 0.0001) and leptin (HR 0.94; 95% CI 0.92 - 0.96; p < 0.0001) were significant predictors of death even after correction for other known risk factors such as presence of metastasis and chronic kidney disease.. Ghrelin and leptin are promising biomarkers to diagnose cachexia and to predict survival in cancer patients. Topics: Aged; Area Under Curve; Biomarkers; Cachexia; Case-Control Studies; Cholesterol; Diabetes Mellitus; Female; Follow-Up Studies; Ghrelin; Heart Failure; Humans; Kaplan-Meier Estimate; Leptin; Male; Middle Aged; Neoplasm Metastasis; Neoplasms; Predictive Value of Tests; Proportional Hazards Models; ROC Curve; Serum Albumin; Survival Rate | 2014 |
Adipose tissue-derived factors as potential biomarkers in cachectic cancer patients.
Cachexia, a paraneoplastic syndrome markedly associated with worsened prognosis in cancer patients, provokes profound wasting of both lean and adipose mass in an association with a state of metabolic "chaos". The white adipose tissue responds to cachexia with marked local inflammation and may be thus a relevant contributor to systemic inflammation. To address this hypothesis we examined the correlation between tissue expression of adipokines and plasma concentration in cachectic and stable weight patients with or without cancer. Adiponectin and liver-derived CRP concentration were significantly higher in the cachectic groups when compared with stable weight patients (P<0.01). The concentration of plasma IL-6 was higher (11.4-fold) in the cancer cachectic group when compared with weight-stable controls, and presented a significant correlation with the presence of cancer (P<0.001). A marked increase (5-fold) in IL-6 as a result of the interaction between the presence of cachexia and the presence of tumour was observed in the subcutaneous tissue of the patients, yet not in the visceral depot. Plasma adiponectin levels were higher in cachectic cancer patients, compared with stable weight cancer patients individually matched by age, sex, and BMI, and the subcutaneous depot was found to be the main contributing tissue, rather than the visceral pad. Based on the results we concluded that the subcutaneous adipose tissue is associated with plasma changes that may function as markers of cachexia. Topics: Adiponectin; Adipose Tissue; Aged; Biomarkers, Tumor; Cachexia; Female; Gene Expression Regulation; Humans; Inflammation Mediators; Interleukin-10; Interleukin-6; Leptin; Male; Middle Aged; Neoplasm Staging; Neoplasms; RNA, Messenger; Tumor Necrosis Factor-alpha | 2013 |
Short-term and long-term leptin exposure differentially affect human natural killer cell immune functions.
Epidemiological studies have indicated that obesity is associated with a higher risk for certain cancers caused by elevated levels of adipocyte-derived hormones. Leptin, one such hormone produced by adipocytes, is a major regulator of metabolism and has also been shown to modulate immunity. However, its role in regulating human natural killer (NK) cell functions is largely unknown. Here, we show that the leptin receptor (Ob-R) is expressed on 5% of NK cells isolated from blood donors, as measured with flow cytometry, and expression of the signal-transducing long form of the leptin receptor Ob-Rb was confirmed with quantitative PCR. The Ob-R+ subpopulation displayed a lower expression of CD16, a cell surface receptor mediating antibody-dependent activation. Short-term stimulation with leptin increased IFNγ secretion, CD69 activation marker expression, and cytotoxic lysis of tumor cells; this was mediated by an improved conjugate forming between NK cells and tumor cells as well as higher expression of tumor necrosis factor-related apoptosis-inducing ligand. On the contrary, long-term incubation with leptin significantly impaired these NK cell immune functions and decreased cell proliferation. In addition, phosphorylation of Jak-2 after leptin stimulation was reduced in peripheral mononuclear blood cells from obese humans compared with normal-weight controls. NK cells represent an immune cell population that is crucial for an effective antitumor response. Here, we show that long-term exposure to leptin, similarly to the situation in obese individuals with elevated serum leptin levels, significantly impairs integral parts of NK cell immune functions, possibly linking leptin to increased cancer susceptibility in obesity. Topics: 3T3-L1 Cells; Adipocytes; Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cells, Cultured; Cytophagocytosis; Gene Expression Regulation; Humans; Interferon-gamma; Killer Cells, Natural; Leptin; Mice; Neoplasms; Obesity; Protein Isoforms; Receptors, IgG; Receptors, Leptin; Recombinant Proteins; RNA, Messenger; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand | 2012 |
Can having fun protect you from obesity and its cancer risk?
Topics: Adipocytes; Adipose Tissue; Animals; Exercise; Humans; Intercellular Signaling Peptides and Proteins; Leptin; Melanoma; Mice; Neoplasms; Obesity; Phenotype; Physical Conditioning, Animal; Skin Neoplasms | 2012 |
PTEN mutations as a cause of constitutive insulin sensitivity and obesity.
Epidemiologic and genetic evidence links type 2 diabetes, obesity, and cancer. The tumor-suppressor phosphatase and tensin homologue (PTEN) has roles in both cellular growth and metabolic signaling. Germline PTEN mutations cause a cancer-predisposition syndrome, providing an opportunity to study the effect of PTEN haploinsufficiency in humans.. We measured insulin sensitivity and beta-cell function in 15 PTEN mutation carriers and 15 matched controls. Insulin signaling was measured in muscle and adipose-tissue biopsy specimens from 5 mutation carriers and 5 well-matched controls. We also assessed the effect of PTEN haploinsufficiency on obesity by comparing anthropometric indexes between the 15 patients and 2097 controls from a population-based study of healthy adults. Body composition was evaluated by means of dual-emission x-ray absorptiometry and skinfold thickness.. Measures of insulin resistance were lower in the patients with a PTEN mutation than in controls (e.g., mean fasting plasma insulin level, 29 pmol per liter [range, 9 to 99] vs. 74 pmol per liter [range, 22 to 185]; P=0.001). This finding was confirmed with the use of hyperinsulinemic euglycemic clamping, showing a glucose infusion rate among carriers 2 times that among controls (P=0.009). The patients' insulin sensitivity could be explained by the presence of enhanced insulin signaling through the PI3K-AKT pathway, as evidenced by increased AKT phosphorylation. The PTEN mutation carriers were obese as compared with population-based controls (mean body-mass index [the weight in kilograms divided by the square of the height in meters], 32 [range, 23 to 42] vs. 26 [range, 15 to 48]; P<0.001). This increased body mass in the patients was due to augmented adiposity without corresponding changes in fat distribution.. PTEN haploinsufficiency is a monogenic cause of profound constitutive insulin sensitization that is apparently obesogenic. We demonstrate an apparently divergent effect of PTEN mutations: increased risks of obesity and cancer but a decreased risk of type 2 diabetes owing to enhanced insulin sensitivity. (Funded by the Wellcome Trust and others.). Topics: Adiponectin; Adipose Tissue; Adult; Aged; Body Mass Index; Diabetes Mellitus, Type 2; Female; Glucose Tolerance Test; Haploinsufficiency; Humans; Insulin Resistance; Leptin; Male; Middle Aged; Neoplasms; Obesity; PTEN Phosphohydrolase | 2012 |
Peptide-based leptin receptor antagonists for cancer treatment and appetite regulation.
Leptin, a multifunctional hormone, controls various processes in both the central nervous system and in peripheral tissues. Because of the presence of multiple leptin/receptor (ObR) interaction sites and diverse leptin activities, the literature lacks truly monofunctional leptin protein derivatives or fragments. To date, selective ObR antagonists have not been reported. We developed short, pharmacologically advantageous peptide analogs of ObR-binding site III of leptin that acted as selective ObR inhibitors without any partial agonistic activity. These reduced leptin-dependent growth and signaling in cancer cell lines at picomolar and low nanomolar concentrations. In immunocompromised mice the peptides suppressed the growth of rapidly proliferating orthotopic human breast cancer xenografts by 50% when administered either intraperitoneally (i.p.) or subcutaneously (s.c.) for 38 days at a 0.1 mg/kg/day dose. The peptides were distributed to the brain, and when added to growing C57BL/6 normal mice i.p., s.c., or orally, the lead antagonist accelerated normal weight increase without producing any toxic effects. Weight gain increases could not be observed after 10-12 days of treatment indicating that the mice became resistant to the central nervous system activity of leptin antagonists. However, in normal growing rats the intranasal administration at 0.1 mg/kg/day for 20 days resulted in a 2% net total body weight gain without signs of resistance induction. In addition to the potential of these peptides in drug development against primary and metastatic tumors and cachexia, our data confirm that resistance to leptin resides at the blood-brain barrier. Topics: Animals; Antineoplastic Agents; Appetite; Appetite Stimulants; Binding Sites; Cell Line; Female; Humans; Leptin; Male; Mice; Neoplasms; Oligopeptides; Peptides; Rats; Rats, Inbred F344; Receptors, Leptin | 2011 |
The Endocrine Society 2011 Laureate Awards.
Topics: Animals; Awards and Prizes; Circadian Rhythm; Diabetes Mellitus, Type 2; Endocrinology; Endoplasmic Reticulum Stress; History, 20th Century; History, 21st Century; Humans; Insulin-Like Growth Factor I; Leptin; Neoplasms; Pediatrics; Retinoid X Receptors; Societies, Medical; Stress, Physiological; Unfolded Protein Response | 2011 |
Adipokines in patients with cancer anorexia and cachexia.
Anorexia, cachexia, and insulin resistance are commonly seen in patients with cancer. Adipocyte-derived hormones or adipokines play a role in the regulation of appetite, body weight, and insulin sensitivity. However, their role in cancer-induced cachexia has not been well-established. The objective of this study was to determine the levels of adipokines and their relation to appetite, weight loss, insulin resistance, and other hormones in cancer cachexia.. We measured adiponectin, resistin, and leptin plasma levels in 21 men with cancer cachexia, 24 noncachectic cancer subjects, and 25 noncancer controls matched by age, sex, and pre-illness body weight. Body weight change, appetite scores, insulin resistance assessed by homeostasis model assessment, and other cytokines and hormones were also measured. Differences between groups were measured by analysis of covariance. Relations between variables were examined by linear regression analyses.. Adiponectin levels were similarly elevated in cachectic and noncachectic cancer patients compared with noncancer controls. Leptin levels were significantly decreased in cancer cachexia and were directly associated with appetite and insulin resistance, explaining 37% and 19% of the variance seen in cancer patients, respectively. Resistin levels were not different between groups.. Leptin may play a role in the increased insulin resistance seen in cancer patients. However, these patients are resistant to the orexigenic effects of hypoleptinemia. Other mechanisms besides weight loss are responsible for the increased adiponectin level seen in cancer patients. It is unlikely that resistin plays a major metabolic role in this setting. Topics: Adipokines; Adiponectin; Adolescent; Adult; Aged; Anorexia; Appetite; Body Weight; Cachexia; Humans; Insulin Resistance; Leptin; Linear Models; Male; Multivariate Analysis; Neoplasms; Resistin; Weight Loss | 2010 |
Environmental enrichment: a cure for cancer? It's all in the mind.
Environmental enrichment is used to enhance mental stimulation and physical activity and has been shown to delay onset and progression of a range of brain disorders. Now, Cao et al. (2010) report in Cell that this paradigm also exerts strong influences beyond the brain and is capable of suppressing tumor growth in mice. Topics: Animals; Brain; Brain-Derived Neurotrophic Factor; Disease Progression; Environment; Leptin; Mice; Neoplasms | 2010 |
Leptin receptor signaling supports cancer cell metabolism through suppression of mitochondrial respiration in vivo.
Obesity represents a risk factor for certain types of cancer. Leptin, a hormone predominantly produced by adipocytes, is elevated in the obese state. In the context of breast cancer, leptin derived from local adipocytes is present at high concentrations within the mammary gland. A direct physiological role of peripheral leptin action in the tumor microenvironment in vivo has not yet been examined. Here, we report that mice deficient in the peripheral leptin receptor, while harboring an intact central leptin signaling pathway, develop a fully mature ductal epithelium, a phenomenon not observed in db/db mice to date. In the context of the MMTV-PyMT mammary tumor model, the lack of peripheral leptin receptors attenuated tumor progression and metastasis through a reduction of the ERK1/2 and Jak2/STAT3 pathways. These are tumor cell-autonomous properties, independent of the metabolic state of the host. In the absence of leptin receptor signaling, the metabolic phenotype is less reliant on aerobic glycolysis and displays an enhanced capacity for β-oxidation, in contrast to nontransformed cells. Leptin receptor-free tumor cells display reduced STAT3 tyrosine phosphorylation on residue Y705 but have increased serine phosphorylation on residue S727, consistent with preserved mitochondrial function in the absence of the leptin receptor. Therefore, local leptin action within the mammary gland is a critical mediator, linking obesity and dysfunctional adipose tissue with aggressive tumor growth. Topics: Animals; Cell Proliferation; Cell Respiration; Down-Regulation; Female; Leptin; Male; Mammary Neoplasms, Experimental; Mice; Mice, Mutant Strains; Mice, Transgenic; Mitochondria; Neoplasm Invasiveness; Neoplasms; Receptors, Leptin; Signal Transduction; Tumor Cells, Cultured | 2010 |
C/EBPbeta regulates body composition, energy balance-related hormones and tumor growth.
The prevalence of obesity, an established epidemiologic risk factor for many chronic diseases including cancer, has been steadily increasing in the US over several decades. The mechanisms used to regulate energy balance and adiposity and the relationship of these factors to cancer are not completely understood. Here we have used knockout mice to examine the roles of the transcription factors CCAAT/enhancer-binding protein (C/EBP) beta and C/EBPdelta in regulating body composition and systemic levels of hormones such as insulin-like growth factor-1 (IGF-1), leptin and insulin that mediate energy balance. Dual-energy X-ray absorptiometry showed that C/EBPbeta, either directly or indirectly, modulated body weight, fat content and bone density in both males and females, while the effect of C/EBPdelta was minor and only affected adiposity and body weight in female animals. Levels of IGF-1, leptin and insulin in the serum were decreased in both male and female C/EBPbeta(-/-) mice, and C/EBPbeta was associated with their promoters in vivo. Moreover, colon adenocarcinoma cells displayed reduced tumorigenic potential when transplanted into C/EBPbeta-deficient animals, especially males. Thus, C/EBPbeta contributes to endocrine expression of IGF-1, leptin and insulin, which modulate energy balance and can contribute to cancer progression by creating a favorable environment for tumor cell proliferation and survival. Topics: Adenocarcinoma; Adipose Tissue; Animals; Body Composition; Body Weight; Bone Density; CCAAT-Enhancer-Binding Protein-beta; CCAAT-Enhancer-Binding Protein-delta; Cell Division; Colonic Neoplasms; Female; Insulin; Insulin-Like Growth Factor I; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Neoplasms; Obesity | 2009 |
Obesity, insulin resistance, and cancer prognosis: implications for practice for providing care among cancer survivors.
Topics: Adipokines; Adiponectin; Cytokines; Dietetics; Disease Progression; Health Behavior; Humans; Inflammation; Insulin Resistance; Leptin; Life Style; Neoplasms; Obesity; Prevalence; Prognosis; Risk Factors; Survival Rate; United States | 2009 |
Fat may fuel breast cancer growth.
Topics: Adipose Tissue; Biomarkers, Tumor; Body Mass Index; Body Weight; Breast Neoplasms; Disease-Free Survival; Estrogens; Exercise; Female; Humans; Inflammation; Insulin; Insulin-Like Growth Factor I; Leptin; Neoplasms; Obesity; Overweight; Recurrence; Risk Assessment; Risk Factors; United Kingdom; Weight Gain | 2008 |
Statins, leptin and regulatory T cells.
Topics: Animals; Atorvastatin; Heptanoic Acids; Humans; Leptin; Lymphocyte Activation; Neoplasms; Obesity; Pyrroles; Risk Factors; T-Lymphocytes, Regulatory; Thinness | 2008 |
Lifestyle and dietary correlates of plasma insulin-like growth factor binding protein-1 (IGFBP-1), leptin, and C-peptide: the Multiethnic Cohort.
Circulating insulin-like growth factor binding protein 1 (IGFBP-1), leptin, and insulin are 3 proteins modified by obesity and have been associated with cancer at several sites in past studies. We conducted a cross-sectional study to describe the correlation of these proteins with gender, race/ethnicity, anthropometric indexes, and dietary and lifestyle factors. We measured fasting plasma levels of IGFBP-1, leptin, and C-peptide, used here as a stable measure of insulin secretion, in a random sample of 450 male and 352 postmenopausal female Hawaii and Los Angeles Multiethnic Cohort Study (MEC) participants (age range 47-82 yr at blood draw). Through a series of multiple linear regressions, we found that the most parsimonious model for plasma IGFBP-1 included inverse associations with age, body mass index (BMI), and regular soda intake. A term for interaction between age and BMI was positively associated with plasma IGFBP-1. Adjusted mean plasma leptins were highest among Whites and African Americans and lowest among Hawaiians and Japanese Leptin was also inversely associated with age and positively associated with the interaction between age and race/ethnicity, female gender, and BMI. A model with only race/ethnicity and BMI (positive association) was best for plasma C-peptide. Adjusted means for C-peptide were highest for Japanese and Whites and lowest for African Americans. The overall percent of variance in protein levels explained by these models was low for IGFBP-1(R2=0.17) and C-peptide (R(3)=0.11) and higher for leptin (R(2)=0.57). We saw no clear correlation between racial/ethnic trends in protein levels with those of colorectal, breast, or prostate cancer incidence rates in the MEC. Research to clarify factors associated with determination of these proteins and their relationship with cancer etiology is warranted. Topics: Age Factors; Aged; Aged, 80 and over; Asian; Black or African American; Body Mass Index; C-Peptide; Carbonated Beverages; Cohort Studies; Cross-Sectional Studies; Diet; Ethnicity; Female; Humans; Insulin; Insulin Secretion; Insulin-Like Growth Factor Binding Protein 1; Leptin; Life Style; Male; Middle Aged; Neoplasms; Obesity; White People | 2007 |
Increased expression of leptin and the leptin receptor as a marker of breast cancer progression: possible role of obesity-related stimuli.
Recent in vitro studies suggested that the autocrine leptin loop might contribute to breast cancer development by enhancing cell growth and survival. To evaluate whether the leptin system could become a target in breast cancer therapy, we examined the expression of leptin and its receptor (ObR) in primary and metastatic breast cancer and noncancer mammary epithelium. We also studied whether the expression of leptin/ObR in breast cancer can be induced by obesity-related stimuli, such as elevated levels of insulin, insulin-like growth factor-I (IGF-I), estradiol, or hypoxic conditions.. The expression of leptin and ObR was examined by immunohistochemistry in 148 primary breast cancers and 66 breast cancer metastases as well as in 90 benign mammary lesions. The effects of insulin, IGF-I, estradiol, and hypoxia on leptin and ObR mRNA expression were assessed by reverse transcription-PCR in MCF-7 and MDA-MB-231 breast cancer cell lines.. Leptin and ObR were significantly overexpressed in primary and metastatic breast cancer relative to noncancer tissues. In primary tumors, leptin positively correlated with ObR, and both biomarkers were most abundant in G3 tumors. The expression of leptin mRNA was enhanced by insulin and hypoxia in MCF-7 and MDA-MB-231 cells, whereas IGF-I and estradiol stimulated leptin mRNA only in MCF-7 cells. ObR mRNA was induced by insulin, IGF-I, and estradiol in MCF-7 cells and by insulin and hypoxia in MDA-MB-231 cells.. Leptin and ObR are overexpressed in breast cancer, possibly due to hypoxia and/or overexposure of cells to insulin, IGF-I, and/or estradiol. Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Breast; Breast Neoplasms; Carcinoma, Ductal, Breast; Case-Control Studies; Cell Hypoxia; Disease Progression; Estradiol; Female; Humans; Insulin; Insulin-Like Growth Factor I; Leptin; Middle Aged; Neoplasms; Obesity; Receptors, Cell Surface; Receptors, Leptin; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured | 2006 |
Critical role for the p110alpha phosphoinositide-3-OH kinase in growth and metabolic regulation.
The eight catalytic subunits of the mammalian phosphoinositide-3-OH kinase (PI(3)K) family form the backbone of an evolutionarily conserved signalling pathway; however, the roles of most PI(3)K isoforms in organismal physiology and disease are unknown. To delineate the role of p110alpha, a ubiquitously expressed PI(3)K involved in tyrosine kinase and Ras signalling, here we generated mice carrying a knockin mutation (D933A) that abrogates p110alpha kinase activity. Homozygosity for this kinase-dead p110alpha led to embryonic lethality. Mice heterozygous for this mutation were viable and fertile, but displayed severely blunted signalling via insulin-receptor substrate (IRS) proteins, key mediators of insulin, insulin-like growth factor-1 and leptin action. Defective responsiveness to these hormones led to reduced somatic growth, hyperinsulinaemia, glucose intolerance, hyperphagia and increased adiposity in mice heterozygous for the D933A mutation. This signalling function of p110alpha derives from its highly selective recruitment and activation to IRS signalling complexes compared to p110beta, the other broadly expressed PI(3)K isoform, which did not contribute to IRS-associated PI(3)K activity. p110alpha was the principal IRS-associated PI(3)K in cancer cell lines. These findings demonstrate a critical role for p110alpha in growth factor and metabolic signalling and also suggest an explanation for selective mutation or overexpression of p110alpha in a variety of cancers. Topics: Adiposity; Animals; Body Weight; Catalytic Domain; Cell Line, Tumor; Class I Phosphatidylinositol 3-Kinases; Eating; Embryo Loss; Enzyme Activation; Glucose; Growth; Heterozygote; Homozygote; Hyperinsulinism; Insulin; Insulin Receptor Substrate Proteins; Leptin; Mice; Mutation; Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoproteins; Receptor, Insulin; Signal Transduction | 2006 |
Susceptibility to induced and spontaneous carcinogenesis is increased in fatless A-ZIP/F-1 but not in obese ob/ob mice.
Obesity is typically associated with increased tumor susceptibility, whereas caloric restriction, a regimen resulting in leanness, inhibits carcinogenesis. The link between adiposity and malignancies suggests that adipose tissue may influence carcinogenesis. An adipose tissue hormone, leptin, could be procarcinogenic because it stimulates proliferation in various tissues and tumor cell lines. Leptin may contribute to the correlation between adiposity and malignancies as its levels are usually increased in obese subjects and reduced by caloric restriction. We hypothesized that leptin deficiency, despite obesity, would inhibit carcinogenesis in leptin-null ob/ob mice and tested this hypothesis in two models: (a) two-stage skin carcinogenesis initiated by 7,12-dimethylbenz(a)anthracene and promoted by phorbol 12-myristate 13-acetate (PMA) and (b) p53 deficiency. Contrary to a typical association between obesity and enhanced carcinogenesis, obese ob/ob mice developed induced skin papillomas and spontaneous p53-deficient malignancies, mostly lymphomas, similarly to their lean littermates. Surprisingly, lipodystrophic (ZIP) mice that had very little both adipose tissue and leptin were highly susceptible to carcinogenesis. Hyperphagia, hyperinsulinemia, and hyperglycemia are unlikely to have contributed significantly to the enhancement of carcinogenesis in ZIP mice because similarly hyperphagic, hyperinsulinemic, and hyperglycemic ob/ob mice had normal susceptibility to carcinogenesis. Our data suggest that, in contrast to a well-known correlation between obesity and cancer, the direct effect of adipose tissue may rather be protective. Topics: Animals; Genetic Predisposition to Disease; Humans; Leptin; Mice; Mice, Obese; Neoplasms; Obesity; Thinness | 2006 |
Body composition and time course changes in regional distribution of fat and lean tissue in unselected cancer patients on palliative care--correlations with food intake, metabolism, exercise capacity, and hormones.
Several investigations that yielded different results in terms of net changes in body composition of weight-losing cancer patients have been reported that employed a variety of methods based on fundamentally different technology. Most of those reports were cross-sectional, whereas to the authors' knowledge there is sparse information available on longitudinal follow-up measurements in relation to other independent methods for the assessment of metabolism and performance.. For the current report, the authors evaluated time course changes in body composition (dual-energy X-ray absorptiometry) with measurements of whole body and regional distribution of fat and lean tissue in relation to food and dietary intake, host metabolism (indirect calorimetry), maximum exercise capacity (walking test), and circulating hormones in cancer patients who were receiving palliative care during 4-62 months of follow-up. The entire cohort comprised 311 patients, ages 68 years +/- 3 years who were diagnosed with solid gastrointestinal tumors (84 colorectal tumors, 74 pancreatic tumors, 73 upper gastrointestinal tumors, 51 liver-biliary tumors, 3 breast tumors, 5 melanomas, and 21 other tumor types).. Decreased body weight was explained by loss of body fat, preferentially from the trunk, followed by leg tissue and arm tissue, respectively. Lean tissue (fat-free mass) was lost from arm tissue, whereas trunk and leg tissue compartments increased, all concomitant with declines in serum albumin, increased systemic inflammation (C-reactive protein, erythrocyte sedimentation rate), increased serum insulin, and elevated daily caloric intake; whereas serum insulin-like growth factor 1 (IGF-1), resting energy expenditure, and maximum exercise capacity remained unchanged in the same patients. Serum albumin levels (P < 0.001), whole body fat (P < 0.02), and caloric intake (P < 0.001) predicted survival, whereas lean tissue mass did not. Daily intake of fat and carbohydrate was more important for predicting survival than protein intake. Survival also was predicted by serum IGF-1, insulin, leptin, and ghrelin levels (P < 0.02 - P < 0.001). Serum insulin, leptin, and ghrelin (total) levels predicted body fat (P < 0.001), whereas IGF-1 and thyroid hormone levels (T3, free T3) predicted lean tissue mass (P < 0.01). Systemic inflammation primarily explained variation in lean tissue and secondarily explained loss in body fat. Depletion of lean arm tissue was related most to short survival compared with the depletion of lean leg and trunk tissue.. The current results demonstrated that body fat was lost more rapidly than lean tissue in progressive cancer cachexia, a phenomenon that was related highly to alterations in the levels of circulating classic hormones and food intake, including both caloric amount and diet composition. The results showed importance in the planning of efficient palliative treatment for cancer patients. Topics: Adipose Tissue; Aged; Blood Sedimentation; Body Composition; C-Reactive Protein; Cohort Studies; Dietary Carbohydrates; Dietary Fats; Eating; Energy Intake; Energy Metabolism; Exercise Tolerance; Follow-Up Studies; Ghrelin; Hormones; Humans; Insulin; Insulin-Like Growth Factor I; Leptin; Longitudinal Studies; Muscle, Skeletal; Neoplasms; Palliative Care; Peptide Hormones; Serum Albumin; Survival Rate; Weight Loss | 2005 |
Application of pregnancy-related proteins in prenatal and tumor diagnostics--a workshop report.
Topics: Biomarkers; Biomarkers, Tumor; Chorionic Gonadotropin; Female; Fetal Growth Retardation; Humans; Infant, Newborn; Inflammation; Interleukin-10; Killer Cells, Natural; Leptin; Luteinizing Hormone; Neoplasms; Pre-Eclampsia; Pregnancy; Pregnancy Proteins | 2005 |
Leptin and neuropeptide Y plasma levels in children with cancer.
This study investigated leptin and neuropeptide Y levels in children with cancer, the relationship of those levels to cachexia, and their usefulness as prognostic indicators. Twenty-three newly diagnosed children with cancer were included in the study. The median age at diagnosis was 8 years (range 1.5-14), and the male to female ratio was 13:10. Body mass index, serum leptin and neuropeptide Y levels were measured at diagnosis and at each cycle of chemotherapy. The mean neuropeptide Y level was 211.1 pmol/l at diagnosis and decreased to 92.8 pmol/l at the fifth cycle of chemotherapy. In contrast, the mean leptin level was 3.9 ng/ml at diagnosis and increased to 13.0 ng/ml at the fifth cycle of chemotherapy. Thus, levels of these factors are influenced by treatment status and disease progression. The mean neuropeptide Y level at diagnosis was 82.32 pmol/l in children with complete remission and 430.16 pmol/l in those who died with disease during the follow-up period. The mean leptin level at diagnosis was 6.60 ng/ml in children with complete remission and 0.192 ng/ml in patients who died with disease during the follow-up period. The neuropeptide Y and leptin levels seem to be related to prognosis and could be used as prognostic indicators in the follow-up of children with cancer. Topics: Adolescent; Anorexia; Biomarkers; Cachexia; Child; Child, Preschool; Female; Follow-Up Studies; Humans; Leptin; Male; Neoplasms; Neuropeptide Y; Prognosis; Weight Loss | 2005 |
Association of serum IL-6 levels with comprehensive geriatric assessment variables in a population of elderly cancer patients.
The primary aim of this study was to find whether any association exists between serum levels of proinflammatory cytokines, mainly IL-6, and the most important comprehensive geriatric assessment (CGA) variables such as functional status, cognitive functions and nutrition in a population of elderly cancer patients. The secondary aims were to find whether any difference existed between: i) age groups, ii) performance status scores, iii) patients who had lost weight versus those who had not. Eighty-four elderly patients with advanced cancer were included in the study (stage III 15.4%, and stage IV 72.6%). Serum levels of IL-6 and CRP were significantly higher in elderly than in the other adult cancer patients. Among the CGA variables investigated, the most affected were functional status assessed by IADL, cognitive functions by MMSE and nutrition. The ECOG PS was shown to be significantly associated with all the dimensions of CGA investigated: poor PS (>/=2) corresponded to severe disabilities. As for the relationship of serum IL-6 with CGA variables, the strongest correlations were between IL-6 and functional status assessed by both Katz ADL (p=0.0003), IADL (p=0.0070) and nutrition (p=0.0013). Moreover, we observed an association, although not statistically significant, between functional disability (ADL and IADL) and high IL-6 levels in individuals with weight loss. IL-6 levels seem to be independently associated with all CGA variables investigated in the present study in a population of elderly cancer patients. Because the most important CGA variables, in particular functional status, have been observed to be strongly associated with survival, the present study, confirming our previously reported ones, suggests that IL-6 may be a reliable marker of disease outcome and supports the feasibility of using IL-6 as a sensitive outcome marker in studies based on novel approaches aiming at modifying age- and cancer-related biologic mechanisms. Topics: Age Factors; Aged; Aged, 80 and over; C-Reactive Protein; Female; Geriatric Assessment; Humans; Interleukin-6; Leptin; Male; Neoplasm Staging; Neoplasms; Tumor Necrosis Factor-alpha; Weight Loss | 2004 |
Anti-cachectic effect of ghrelin in nude mice bearing human melanoma cells.
Ghrelin is a novel brain-gut peptide that stimulates food intake and body weight gain. We studied the anabolic effect of ghrelin in a cancer cachexia mouse model. SEKI, a human melanoma cell line, was inoculated into nude mice to examine the effects of ghrelin on food intake and body weight. The intraperitoneal administration of ghrelin twice a day (6 nmol/mice/day) for 6 days suppressed weight loss in SEKI-inoculated mice and increased the rate of weight gain in vehicle-treated nude mice. Ghrelin administration also increased food intake in both SEKI- and vehicle-treated mice. Both the weight of white adipose tissue and the plasma leptin concentration were reduced in tumor-inoculated mice compared with vehicle-treated mice; these factors increased following ghrelin administration. The levels of both ghrelin peptide and mRNA in the stomach were upregulated in tumor-inoculated mice. The anabolic effect of ghrelin efficiently reverses the cachexia in mice bearing SEKI human melanoma. Ghrelin therefore may have a therapeutic ability to ameliorate cancer cachexia. Topics: Animals; Body Weight; Cachexia; Cell Transplantation; Female; Gastric Mucosa; Ghrelin; Growth Inhibitors; Humans; Injections, Intraperitoneal; Interleukin-6; Leptin; Leukemia Inhibitory Factor; Lymphokines; Melanoma; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Peptide Hormones; Tumor Cells, Cultured | 2003 |
The changes of serum leptin and soluble leptin receptor levels in patients undergoing mobilization of peripheral blood stem cells before autologous stem cells transplantation.
Leptin was demonstrated to stimulate the proliferation of hematopoietic stem cells in vitro, but there is scarce information concerning serum leptin levels in patients with hematological diseases. The aim of our study was to measure serum leptin levels in patients undergoing mobilization of peripheral blood stem cells (PBSC) before autologous stem cell transplantation (ASCT).. Eighteen patients indicated for ASCT were included in the study. The blood samples were obtained before the initiation of mobilization chemotherapy, at the phase of maximal leukopenia and on the second day of stem cell harvest. Serum leptin levels, soluble leptin receptor, cortisol, insulin, tumor necrosis factor alpha (TNFalpha), and interleukin-1 receptor antagonist (IL-1ra) levels were measured in the withdrawn samples.. The basal values of parameters measured except for higher levels of IL-1ra in mobilized group did not differ significantly from those of a control group of healthy subjects. Serum leptin levels decreased significantly at the leukopenia phase and remained suppressed in the stem cell harvest phase (means +/- standard error means (SEM): 12.2 +/- 2.4 vs. 7.7 +/- 1.5 vs. 9.3 +/- 1.9 ng mL(-1)). No significant changes were found in soluble leptin receptor, insulin, cortisol, and TNFalpha levels throughout three measurements, while IL-1ra levels increased significantly in the SC harvest phase compared to the previous two measurements.. As no metabolic variations explaining suppressed leptin levels were found, this suppression could be the result either of G-CSF administration or increased leptin consumption by activated stem cells. Topics: Adult; Aged; Body Mass Index; Female; Hematopoietic Stem Cell Mobilization; Humans; Leptin; Male; Middle Aged; Neoplasms; Receptors, Cell Surface; Receptors, Leptin; Solubility; Stem Cell Transplantation; Transplantation, Autologous | 2002 |
The effect of leptin on engraftment in patients undergoing peripheral blood stem cell transplantation.
To evaluate the alterations of serum leptin levels during stem cell transplantation and its possible role in engraftment. Thirty-two patients (19 male, 13 female) with various hematological and solid tumors and 28 healthy subjects (15 male, 13 female) as a control group were enrolled in the study.. Serum leptin levels were measured on the day before administering G-CSF, at the time of leukapheresis harvest, on day +1st and +7th after transplantation and on the day of leukocyte engraftment.. There was no significant difference in serum leptin levels between patients (mean +/- SEM, 11.62 +/- 2.75 ng/ml) before transplantation and control groups (9.79 +/- 1.73 ng/ml). Pre-G-CSF (baseline) level of serum leptin (11.62 +/- 2.75 ng/ml) was significantly decreased to 7.73 +/- 2.02 ng/ml at the time of apheresis harvest (P = 0.0029). Later, serum leptin levels increased to 16.75 +/- 3.26 ng/ml on day +1 after transplantation (P < 0.0001). Subsequently serum leptin levels both on day +7th posttransplant (12.11 +/- 2.17 ng/ml) and leukocyte engraftment day (9.26 +/- 1.50 ng/ml) were gradually decreased. There was no correlation between the serum leptin levels and the leukocyte or platelet engraftment.. The present study concludes that serum leptin level does not change remarkably during peripheral blood stem cell transplantation and no association exists between circulating leptin levels and the onset of engraftment suggesting that circulating serum leptin does not have a significant direct influence on engraftment. Topics: Adolescent; Adult; Antineoplastic Agents; Case-Control Studies; Female; Graft Survival; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Leptin; Male; Middle Aged; Neoplasms; Peripheral Blood Stem Cell Transplantation; Recombinant Proteins; Transplantation, Autologous | 2002 |
Quantitative evaluation of oxidative stress, chronic inflammatory indices and leptin in cancer patients: correlation with stage and performance status.
In advanced cancer patients, the oxidative stress could take place either at the onset of disease or as a function of disease progression. To test this hypothesis, the following parameters were investigated: the erythrocyte activity of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), the serum activity of glutathione reductase (GR) and the serum total antioxidant status (TAS). The total antioxidant capacity of plasma LMWA was evaluated by the cyclic voltammetry methodology. We further determined the serum levels of proinflammatory cytokines (IL-6 and TNFalpha), IL-2, leptin and C-reactive protein (CRP). All of these parameters have been correlated with the most important clinical indices of patients such as Stage of disease, ECOG PS and clinical response. Eighty-two advanced stage cancer patients and 36 healthy individuals used as controls were included in the study. Our findings show that SOD activity was significantly higher in cancer patients than in controls and GPx activity was significantly lower in cancer patients than in controls. Serum values of IL-6, TNFalpha and CRP were significantly higher in patients than in controls. Serum leptin values of cancer patients were significantly lower than controls. SOD activity increased significantly from Stage II/ECOG 0-1 to Stage IV/ECOG 0-1, whereas it decreased significantly in Stage IV/ECOG 3. GPx activity decreased significantly in Stage IV/ECOG 2-3. An inverse correlation between ECOG PS and serum leptin levels was found. Serum levels of IL-2 decreased from Stage II/ECOG 0-1 to Stage IV/ECOG 2-3. A direct correlation between Stage/ECOG PS and serum levels of both IL-6 and CRP was observed. Cisplatin administration induced a significant increase of GPx after 24 hr. In conclusion, this is the first study that shows that several "biological" parameters of cancer patients such as antioxidant enzyme activity, cytokines, leptin and CRP strictly correlate with the most important clinical parameters of disease such as Stage and ECOG PS. Topics: Adult; Aged; Aged, 80 and over; C-Reactive Protein; Cisplatin; Female; Glutathione Peroxidase; Humans; Interleukin-2; Interleukin-6; Leptin; Male; Middle Aged; Neoplasm Staging; Neoplasms; Oxidative Stress; Superoxide Dismutase | 2002 |
Serum values of proinflammatory cytokines are inversely correlated with serum leptin levels in patients with advanced stage cancer at different sites.
Leptin is a recently identified hormone produced by the adipocyte ob gene which acts as a negative feedback signal critical to the normal control of food intake and body weight. A number of proinflammatory cytokines, such as interleukin 6, tumor necrosis factor alpha, and interferon gamma, have been proposed as mediators of cancer cachexia; these data suggest that abnormalities in leptin production/release or in its feedback mechanism play a role in cancer patients. We therefore studied the relationship between serum leptin and serum cytokines interleukin 6 and tumor necrosis factor alpha levels in advanced-stage cancer patients. Twenty-nine advanced stage cancer patients (all but one stage IV) with tumors at various sites were included in the study. A direct correlation between body mass index and serum leptin levels was found both in cancer patients and in healthy individuals. The serum levels of interleukin 6 were significantly higher in cancer patients than in healthy individuals. In cancer patients an inverse correlation was found between serum levels of leptin and proinflammatory cytokines. There was an inverse correlation between the Eastern Cooperative Oncology Group performance status scale and serum levels of leptin. Regarding survival, patients with very high serum levels of proinflammatory cytokines and very low levels of leptin had very short survival. Although obtained in a cancer patient population not overtly cachectic, our results provide further evidence that a simple dysregulation of leptin production and/or release cannot be involved in cancer-associated pathophysiological changes leading to cachexia. Topics: Adult; Aged; Aged, 80 and over; Body Mass Index; Cachexia; Female; Humans; Interleukin-6; Leptin; Male; Middle Aged; Neoplasm Staging; Neoplasms; Statistics as Topic; Survival; Tumor Necrosis Factor-alpha | 2001 |
Neuropeptide Y, leptin, and cholecystokinin 8 in patients with advanced cancer and anorexia: a North Central Cancer Treatment Group exploratory investigation.
Anorexia is a noxious symptom, and over half of patients with advanced cancer experience it. Neuropeptide Y (NPY), leptin, and cholecystokinin 8 (CCK8) have been implicated.. This exploratory study 1) compared circulating concentrations of NPY and leptin between anorectic cancer patients and historic controls and 2) explored whether NPY, leptin, or CCK8 may serve as correlates of anorexia severity. Cancer patients met predefined eligibility criteria: 1) weight loss > or = 2.3 kg over the preceding 2 months and/or a physician-estimated caloric intake of < 20 calories per kilogram of body weight per day and 2) patient acknowledgment that appetite or weight loss was an ongoing problem.. Seventy-three cancer patients were studied, and > 90% reported a > or = 50% decline in appetite from baseline in the preceding 2 months. NPY levels were lower than control values: mean +/- standard deviation, 466 pg/mL +/- 161 pg/mL versus 560 pg/mL +/- 151 pg/mL, respectively (P = 0.004). Because a few (but not all) earlier studies suggested an age-related decline in NPY levels, a subgroup analysis was performed and found no age-adjusted difference in NPY levels between groups. Similarly, leptin concentrations were not different between groups. Significant correlations were not observed between anorexia severity and NPY, leptin, or CCK8 levels.. There were no differences in leptin and CCK8 levels between anorectic cancer patients and historic controls. Circulating concentrations of NPY, leptin, and CCK8 did not correlate with anorexia severity. However, the current results suggest a need for further examination of NPY in cancer-associated anorexia. Topics: Adult; Aged; Aged, 80 and over; Anorexia; Cholecystokinin; Female; Humans; Leptin; Male; Middle Aged; Neoplasms; Neuropeptide Y; Peptide Fragments | 2001 |
A breakthrough in the study of cancer anorexia.
Topics: alpha-MSH; Animals; Anorexia; Brain; Cytokines; Humans; Leptin; Neoplasms; Neuropeptides; Signal Transduction | 2001 |
GH deficiency caused by cranial irradiation during childhood: factors and markers in young adults.
Cranial irradiation alters hypothalamic-pituitary function. We reevaluated 90 patients with GH deficiency caused by fractionated cranial irradiation performed at age 4.9 +/- 0.4 (SE) yr when they were 15.7 +/- 0.2 yr old. Group 1 received 18 Grays (Gy) (7 cases) or 24 Gy (21 cases) for acute lymphoblastic leukemia; group 2, 30-40 Gy for medulloblastoma (22 cases); group 3, 45-60 Gy for optic glioma and various tumors (30 cases); and group 4, 40-50 Gy for retinoblastoma (10 cases). The mean GH peaks after an arginine insulin test in group 3 (1.9 +/- 0.4 microg/liter) was lower than in groups 1 (4.8 +/- 0.5 microg/liter, P < 0.001) and 2 (3.4 +/- 0.5 microg/liter, P < 0.03). The mean plasma IGF-I concentrations in group 3 [-3.8 +/- 0.2 z score (zs)] was lower than in groups 1 (-2.4 +/- 0.3 zs, P < 0.001) and 2 (-3.1 +/- 0.2 zs, P < 0.02), as was the mean in group 4 (-3.9 +/- 0.3 zs, P < 0.01 compared with group 1 and P < 0.05 compared with group 2). GH peaks and IGF-I were correlated positively (P = 0.0001) and negatively with dose (P < 0.001 for GH and P = 0.0001 for IGF-I), but not with age at irradiation. Among the 43 patients with GH peaks below 3 microg/liter, 41 (95%) had plasma IGF-I less than -2 zs. The body mass index (BMI), plasma insulin, and leptin were similar in the four groups. They were positively correlated with each other (P < 0.001 for BMI compared with insulin and with leptin, respectively, and P < 0.01 for insulin compared with leptin), but not with age or dose of irradiation, or with markers of GH secretion. In conclusion, in patients with GH deficiency caused by cranial irradiation, the residual GH secretion and plasma IGF-I depend on the dose. Almost all the patients with severe GH deficiency had low plasma IGF-I. BMI, leptin, and insulin seem to be independent of GH status. Topics: Adolescent; Adult; Biomarkers; Body Mass Index; Child; Child, Preschool; Female; Head; Human Growth Hormone; Humans; Hypothalamo-Hypophyseal System; Infant; Insulin; Insulin-Like Growth Factor I; Leptin; Male; Neoplasms; Radiotherapy | 2001 |
Obesity not only holds cardiovascular diseases, it also hold tumors.
Topics: Cardiovascular Diseases; Humans; Leptin; Neoplasms; Obesity | 2000 |
Serum levels of leptin and proinflammatory cytokines in patients with advanced-stage cancer at different sites.
Leptin is a recently identified hormone produced by the adipocyte ob gene which acts as a negative feedback signal critical to the normal control of food intake and body weight. A number of proinflammatory cytokines, such as interleukin (IL) 1alpha, IL-6, tumor necrosis factor (TNF) alpha and interferon (IFN) gamma, have been proposed as mediators of cancer cachexia. These data suggest that abnormalities in leptin production/release or in its feedback mechanism play a role in cancer patients. To elucidate this we studied the relationship between total serum leptin and serum cytokines IL-1alpha, IL-6, TNFalpha as well as the production of leptin and cytokines by peripheral blood mononuclear cells (PBMC) isolated from cancer patients. Sixteen advanced cancer patients (mainly stage IV) with tumors at different sites were included in the study. The serum levels of leptin in cancer patients were significantly lower than those of healthy individuals at all times (7 a.m., noon, 3 p.m.). No significant differences were found in circadian rhythm between patients and controls. Serum levels of IL-1alpha, IL-6, and TNFalpha were significantly higher in cancer patients than in healthy individuals. An inverse correlation between serum levels of leptin and IL-6 was found in cancer patients. The production in culture of leptin by unstimulated PBMCs and those stimulated by phytohemagglutinin M or by phorbol myristate acetate isolated from cancer patients was very low; no differences were observed in comparison with leptin production by PBMCs from healthy individuals. Topics: Adult; Aged; Anorexia; Body Mass Index; Cachexia; Cytokines; Female; Humans; Leptin; Leukocytes, Mononuclear; Lymphocyte Activation; Male; Matched-Pair Analysis; Middle Aged; Neoplasms; Syndrome | 2000 |
Leptin sparks blood vessel growth.
Topics: Animals; Carrier Proteins; Cell Aggregation; Endothelium, Vascular; Female; Leptin; Neoplasms; Neovascularization, Physiologic; Ovarian Follicle; Ovum; Protein Biosynthesis; Proteins; Receptors, Cell Surface; Receptors, Leptin; Wound Healing | 1998 |