RESUMO
Diffuse infiltration of glioma cells into normal brain tissue is considered to be a main reason for the unfavorable outcomes of patients with malignant gliomas. Invasion of glioma cells into the brain parenchyma is facilitated by metalloprotease-mediated degradation of the extracellular matrix. Metalloproteases are released as inactive pro-forms and get activated upon cleavage by membrane bound metalloproteases. Here, we show that membrane type 1 metalloprotease (MT1-MMP) is up-regulated in glioma-associated microglia, but not in the glioma cells. Overexpression of MT1-MMP is even lethal for glioma cells. Glioma-released factors trigger the expression and activity of MT1-MMP via microglial toll-like receptors and the p38 MAPK pathway, as deletion of the toll-like receptor adapter protein MyD88 or p38 inhibition prevented MT1-MMP expression and activity in cultured microglial cells. Microglial MT1-MMP in turn activates glioma-derived pro-MMP-2 and promotes glioma expansion, as shown in an ex vivo model using MT1-MMP-deficient brain tissue and a microglia depletion paradigm. Finally, MyD88 deficiency or microglia depletion largely attenuated glioma expansion in 2 independent in vivo models.
Assuntos
Glioma/patologia , Metaloproteinase 14 da Matriz/metabolismo , Microglia/patologia , Animais , Western Blotting , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Precursores Enzimáticos/metabolismo , Feminino , Gelatinases/metabolismo , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Metaloproteinase 14 da Matriz/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Receptores Toll-Like/metabolismo , Carga Tumoral , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Glioma cells release soluble factors, which induce the expression of membrane type 1 matrix metalloprotease (MT1-MMP) in tumor associated microglia and then exploit MT1-MMP mediated matrix degradation for invasion. Here, we show that minocycline blocked the increase in MT1-MMP expression and activity in cultivated microglia stimulated with glioma conditioned medium. Glioma growth within an organotypic brain slice preparation was reduced by minocycline and this reduction depended on the presence of microglia. Glioma growth in an experimental mouse model was strongly reduced by the addition of minocycline to drinking water, compared to untreated controls. Coherently, we observed in our orthotopic glioma implantation model, that MT1-MMP was abundantly expressed in glioma associated microglia in controls, but was strongly attenuated in tumors of minocycline treated animals. Overall, our study indicates that the clinically approved antibiotic minocycline is a promising new candidate for adjuvant therapy against malignant gliomas.
Assuntos
Antibióticos Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Metaloproteinase 14 da Matriz/metabolismo , Microglia/efeitos dos fármacos , Minociclina/farmacologia , Animais , Neoplasias Encefálicas/enzimologia , Células Cultivadas , Quimioterapia Adjuvante , Meios de Cultivo Condicionados , Glioma/enzimologia , Camundongos , Microglia/citologia , Microglia/enzimologia , Invasividade Neoplásica/prevenção & controle , Neoplasias Experimentais , Técnicas de Cultura de ÓrgãosRESUMO
SUMMARY: The Biochemical Simulation Environment (BISEN) is a suite of tools for generating equations and associated computer programs for simulating biochemical systems in the MATLAB computing environment. This is the first package that can generate appropriate systems of differential equations for user-specified multi-compartment systems of enzymes and transporters accounting for detailed biochemical thermodynamics, rapid equilibria of multiple biochemical species and dynamic proton and metal ion buffering. AVAILABILITY: The software and a user manual (including several tutorial examples) are available at bbc.mcw.edu/BISEN.
Assuntos
Fenômenos Bioquímicos , Biologia Computacional/métodos , Software , AlgoritmosRESUMO
Malnutrition is a frequent manifestation in patients with head-and-neck cancer undergoing radiation therapy and a major contributor to morbidity and mortality. Thus, body composition is an important component of an overall evaluation of nutrition in cancer patients. Malnutrition is characterized by weight loss, loss of muscle mass, changes in cell membrane integrity, and alterations in fluid balance. Bioelectrical impedance analysis is a method to analyze body composition and includes parameters such as intracellular water content, extracellular water content, and cell membrane integrity in the form of a phase angle (Φ). Bioelectrical impedance analysis has consistently been shown to have prognostic value with respect to mortality and morbidity in patients undergoing chemotherapy. The goal of the present study was to evaluate the relationship between Φ, time, intracellular water content, and weight for head-and-neck cancer patients undergoing radiotherapy. The results demonstrate that Φ decreases with time and increases with intracellular water content and weight.
Assuntos
Impedância Elétrica/uso terapêutico , Neoplasias de Cabeça e Pescoço/radioterapia , Desnutrição/etiologia , Adulto , Idoso , Peso Corporal , Humanos , Masculino , Desnutrição/patologia , Pessoa de Meia-Idade , Avaliação Nutricional , PrognósticoRESUMO
Analysis of biochemical systems requires reliable and self-consistent databases of thermodynamic properties for biochemical reactions. Here a database of thermodynamic properties for the reactions of glycolysis and the tricarboxylic acid cycle is developed from measured equilibrium data. Species-level free energies of formation are estimated on the basis of comparing thermodynamic model predictions for reaction-level equilibrium constants to previously reported data obtained under different experimental conditions. Matching model predictions to the data involves applying state corrections for ionic strength, pH, and metal ion binding for each input experimental biochemical measurement. By archiving all of the raw data, documenting all model assumptions and calculations, and making the computer package and data available, this work provides a framework for extension and refinement by adding to the underlying raw experimental data in the database and/or refining the underlying model assumptions. Thus the resulting database is a refinement of preexisting databases of thermodynamics in terms of reliability, self-consistency, transparency, and extensibility.