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2.
Nat Commun ; 14(1): 6951, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37907500

RESUMO

Identifying oncological applications for drugs that are already approved for other medical indications is considered a possible solution for the increasing costs of cancer treatment. Under the hypothesis that nutritional stress through fasting might enhance the antitumour properties of at least some non-oncological agents, by screening drug libraries, we find that cholesterol biosynthesis inhibitors (CBIs), including simvastatin, have increased activity against cancers of different histology under fasting conditions. We show fasting's ability to increase CBIs' antitumour effects to depend on the reduction in circulating insulin, insulin-like growth factor-1 and leptin, which blunts the expression of enzymes from the cholesterol biosynthesis pathway and enhances cholesterol efflux from cancer cells. Ultimately, low cholesterol levels through combined fasting and CBIs reduce AKT and STAT3 activity, oxidative phosphorylation and energy stores in the tumour. Our results support further studies of CBIs in combination with fasting-based dietary regimens in cancer treatment and highlight the value of fasting for drug repurposing in oncology.


Assuntos
Jejum , Sinvastatina , Sinvastatina/farmacologia , Sinvastatina/uso terapêutico , Dieta , Insulina , Colesterol
3.
Neuropediatrics ; 54(6): 426-429, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37257496

RESUMO

Emery-Dreifuss muscular dystrophy (EDMD) is a rare disease characterized by early contractures, progressive muscle weakness, and cardiac abnormalities. Different subtypes of EDMD have been described, with the two most common forms represented by the X-linked EDMD1, caused by mutations in the EMD gene encoding emerin, and the autosomal EDMD2, due to mutations in the LMNA gene encoding lamin A/C. A clear definition of the magnetic resonance imaging (MRI) pattern in the two forms, and especially in the rarer EDMD1, is still lacking, although a preferential involvement of the medial head of the gastrocnemius has been suggested in EDMD2. We report a 13-year-old boy with mild limb girdle muscle weakness, elbow and ankle contractures, with absence of emerin at muscle biopsy, carrying a hemizygous frameshift mutation on the EMD gene (c.153dupC/p.Ser52Glufs*9) of maternal inheritance. Minor cardiac rhythm abnormalities were detected at 24-hour Holter electrocardiogram and required ß-blocker therapy. MRI scan of the thighs showed a mild diffuse involvement, while tibialis anterior, extensor digitorum longus, peroneus longus, and medial gastrocnemius were the most affected muscles in the leg. We also provide a review of the muscular MRI data in EDMD patients and highlight the relative heterogeneity of the MRI patterns found in EDMDs, suggesting that muscle MRI should be studied in larger EDMD cohorts to better define disease patterns and to cover the wide disease spectrum.


Assuntos
Contratura , Distrofia Muscular de Emery-Dreifuss , Distrofia Muscular de Emery-Dreifuss Ligada ao Cromossomo X , Masculino , Humanos , Criança , Adolescente , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/patologia , Distrofia Muscular de Emery-Dreifuss/diagnóstico por imagem , Distrofia Muscular de Emery-Dreifuss/genética , Distrofia Muscular de Emery-Dreifuss/patologia , Mutação , Debilidade Muscular , Imageamento por Ressonância Magnética
4.
Lab Invest ; 103(3): 100037, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36925196

RESUMO

Sarcoglycanopathies, limb-girdle muscular dystrophies (LGMD) caused by genetic loss-of-function of the membrane proteins sarcoglycans (SGs), are characterized by progressive degeneration of skeletal muscle. In these disorders, muscle necrosis is associated with immune-mediated damage, whose triggering and perpetuating molecular mechanisms are not fully elucidated yet. Extracellular adenosine triphosphate (eATP) seems to represent a crucial factor, with eATP activating purinergic receptors. Indeed, in vivo blockade of the eATP/P2X7 purinergic pathway ameliorated muscle disease progression. P2X7 inhibition improved the dystrophic process by restraining the activity of P2X7 receptors on immune cells. Whether P2X7 blockade can display a direct action on muscle cells is not known yet. In this study, we investigated eATP effects in primary cultures of myoblasts isolated from patients with LGMDR3 (α-sarcoglycanopathy) and in immortalized cells isolated from a patient with LGMDR5 (γ-sarcoglycanopathy). Our results demonstrated that, owing to a reduced ecto-ATPase activity and/or an enhanced release of ATP, patient cells are exposed to increased juxtamembrane concentrations of eATP and display a higher susceptivity to eATP signals. The purinoceptor P2Y2, which proved to be overexpressed in patient cells, was identified as a pivotal receptor responsible for the enhanced ATP-induced or UTP-induced Ca2+ increase in affected myoblasts. Moreover, P2Y2 stimulation in LDMDR3 muscle cells induced chemotaxis of immune cells and release of interleukin-8. In conclusion, a higher eATP concentration and sensitivity in primary human muscle cells carrying different α-SG or γ-SG loss-of-function mutations indicate that eATP/P2Y2 is an enhanced signaling axis in cells from patients with α-/γ-sarcoglycanopathy. Understanding the basis of the innate immune-mediated damage associated with the dystrophic process may be critical in overcoming the immunologic hurdles associated with emerging gene therapies for these disorders.


Assuntos
Trifosfato de Adenosina , Sarcoglicanopatias , Humanos , Trifosfato de Adenosina/metabolismo , Músculo Esquelético/metabolismo , Sarcoglicanopatias/metabolismo , Transdução de Sinais , Receptores Purinérgicos P2Y2
5.
Cancers (Basel) ; 14(7)2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35406574

RESUMO

RNF5, an endoplasmic reticulum (ER) E3 ubiquitin ligase, participates to the ER-associated protein degradation guaranteeing the protein homeostasis. Depending on tumor model tested, RNF5 exerts pro- or anti-tumor activity. The aim of this study was to elucidate the controversial role of RNF5 in neuroblastoma and melanoma, two neuroectodermal tumors of infancy and adulthood, respectively. RNF5 gene levels are evaluated in publicly available datasets reporting the gene expression profile of melanoma and neuroblastoma primary tumors at diagnosis. The therapeutic effect of Analog-1, an RNF5 pharmacological activator, was investigated on in vitro and in vivo neuroblastoma and melanoma models. In both neuroblastoma and melanoma patients the high expression of RNF5 correlated with a better prognostic outcome. Treatment of neuroblastoma and melanoma cell lines with Analog-1 reduced cell viability by impairing the glutamine availability and energy metabolism through inhibition of F1Fo ATP-synthase activity. This latter event led to a marked increase in oxidative stress, which, in turn, caused cell death. Similarly, neuroblastoma- and melanoma-bearing mice treated with Analog-1 showed a significant delay of tumor growth in comparison to those treated with vehicle only. These findings validate RNF5 as an innovative drug target and support the development of Analog-1 in early phase clinical trials for neuroblastoma and melanoma patients.

6.
Clin Neuropathol ; 40(6): 310-318, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281632

RESUMO

AIM: Since the immune system plays a role in the pathogenesis of several muscular dystrophies, we aim to characterize several muscular inflammatory features in α- (LGMD R3) and γ-sarcoglycanopathies (LGMD R5). MATERIALS AND METHODS: We explored the expression of major histocompatibility complex class I molecules (MHCI), and we analyzed the composition of the immune infiltrates in muscle biopsies from 10 patients with LGMD R3 and 8 patients with LGMD R5, comparing the results to Duchenne muscular dystrophy patients (DMD). RESULTS: A consistent involvement of the immune response was observed in sarcoglycanopathies, although it was less evident than in DMD. LGMD R3-R5 and DMD shared an abnormal expression of MHCI, and the composition of the muscular immune cell infiltrate was comparable. CONCLUSION: These findings might serve as a rationale to fine-tune a disease-specific immunomodulatory regimen, particularly relevant in view of the rapid development of gene therapy for sarcoglycanopathies.


Assuntos
Distrofias Musculares , Miosite , Sarcoglicanopatias , Biópsia , Humanos , Músculo Esquelético , Sarcoglicanopatias/genética
7.
Sci Transl Med ; 13(596)2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078746

RESUMO

Muscular dystrophies (MDs) are a group of genetic diseases characterized by progressive muscle wasting associated to oxidative stress and persistent inflammation. It is essential to deepen our knowledge on the mechanism connecting these two processes because current treatments for MDs have limited efficacy and/or are associated with side effects. Here, we identified the alarmin high-mobility group box 1 (HMGB1) as a functional link between oxidative stress and inflammation in MDs. The oxidation of HMGB1 cysteines switches its extracellular activities from the orchestration of tissue regeneration to the exacerbation of inflammation. Extracellular HMGB1 is present at high amount and undergoes oxidation in patients with MDs and in mouse models of Duchenne muscular dystrophy (DMD) and limb-girdle muscular dystrophy 3 (LGMDR3) compared to controls. Genetic ablation of HMGB1 in muscles of DMD mice leads to an amelioration of the dystrophic phenotype as evidenced by the reduced inflammation and muscle degeneration, indicating that HMGB1 oxidation is a detrimental process in MDs. Pharmacological treatment with an engineered nonoxidizable variant of HMGB1, called 3S, improves functional performance, muscle regeneration, and satellite cell engraftment in dystrophic mice while reducing inflammation and fibrosis. Overall, our data demonstrate that the balance between HMGB1 redox isoforms dictates whether skeletal muscle is in an inflamed or regenerating state, and that the nonoxidizable form of HMGB1 is a possible therapeutic approach to counteract the progression of the dystrophic phenotype. Rebalancing the HMGB1 redox isoforms may also be a therapeutic strategy for other disorders characterized by chronic oxidative stress and inflammation.


Assuntos
Proteína HMGB1 , Distrofia Muscular de Duchenne , Animais , Proteína HMGB1/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos mdx , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Oxirredução , Isoformas de Proteínas/metabolismo
8.
Int J Mol Sci ; 21(17)2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32825102

RESUMO

In muscle ATP is primarily known for its function as an energy source and as a mediator of the "excitation-transcription" process, which guarantees muscle plasticity in response to environmental stimuli. When quickly released in massive concentrations in the extracellular space as in presence of muscle membrane damage, ATP acts as a damage-associated molecular pattern molecule (DAMP). In experimental murine models of muscular dystrophies characterized by membrane instability, blockade of eATP/P2X7 receptor (R) purinergic signaling delayed the progression of the dystrophic phenotype dampening the local inflammatory response and inducing Foxp3+ T Regulatory lymphocytes. These discoveries highlighted the relevance of ATP as a harbinger of immune-tissue damage in muscular genetic diseases. Given the interactions between the immune system and muscle regeneration, the comprehension of ATP/purinerigic pathway articulated organization in muscle cells has become of extreme interest. This review explores ATP release, metabolism, feedback control and cross-talk with members of muscle inflammasome in the context of muscular dystrophies.


Assuntos
Trifosfato de Adenosina/metabolismo , Inflamassomos/metabolismo , Distrofias Musculares/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Animais , Humanos , Músculo Esquelético/metabolismo , Transdução de Sinais
9.
Curr Opin Pharmacol ; 47: 82-89, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30959357

RESUMO

Myeloid derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells expanded and recruited from the bone marrow to the periphery or to a specific site of inflammation/infection. MDSC have been described in different pathological conditions including cancer, infections, autoimmunity and obesity. The main function of MDSC is immunosuppression occurring through different mechanisms such as induction of immunosuppressive cells, impairment of lymphocyte homing, free radical production, depletion of amino acids critical for T cell functions, upregulation of ectoenzymes involved in adenosine production and activation of immune regulatory molecules responsible of T cell anergy. A novel immunosuppressive mechanism MDSC-mediated involves the ATP/P2X7 receptor axis that induces the release of immunosuppressive chemokines/cytokines upon triggering with ATP.


Assuntos
Células Supressoras Mieloides/imunologia , Receptores Purinérgicos P2X7/imunologia , Animais , Humanos , Tolerância Imunológica , Fenótipo
10.
Am J Pathol ; 189(2): 354-369, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30448410

RESUMO

In muscular dystrophies, muscle membrane fragility results in a tissue-specific increase of danger-associated molecular pattern molecules (DAMPs) and infiltration of inflammatory cells. The DAMP extracellular ATP (eATP) released by dying myofibers steadily activates muscle and immune purinergic receptors exerting dual negative effects: a direct damage linked to altered intracellular calcium homeostasis in muscle cells and an indirect toxicity through the triggering of the immune response and inhibition of regulatory T cells. Accordingly, pharmacologic and genetic inhibition of eATP signaling improves the phenotype in models of chronic inflammatory diseases. In α-sarcoglycanopathy, eATP effects may be further amplified because α-sarcoglycan extracellular domain binds eATP and displays an ecto-ATPase activity, thus controlling eATP concentration at the cell surface and attenuating the magnitude and/or the duration of eATP-induced signals. Herein, we show that in vivo blockade of the eATP/P2X purinergic pathway by a broad-spectrum P2X receptor-antagonist delayed the progression of the dystrophic phenotype in α-sarcoglycan-null mice. eATP blockade dampened the muscular inflammatory response and enhanced the recruitment of forkhead box protein P3-positive immunosuppressive regulatory CD4+ T cells. The improvement of the inflammatory features was associated with increased strength, reduced necrosis, and limited expression of profibrotic factors, suggesting that pharmacologic purinergic antagonism, altering the innate and adaptive immune component in muscle infiltrates, might provide a therapeutic approach to slow disease progression in α-sarcoglycanopathy.


Assuntos
Trifosfato de Adenosina/imunologia , Distrofia Muscular Animal , Miofibrilas , Sarcoglicanas/deficiência , Linfócitos T Reguladores , Trifosfato de Adenosina/genética , Animais , Cálcio/imunologia , Doença Crônica , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Camundongos , Camundongos Knockout , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/imunologia , Distrofia Muscular Animal/patologia , Miofibrilas/imunologia , Miofibrilas/patologia , Receptores Purinérgicos P2X/genética , Receptores Purinérgicos P2X/imunologia , Sarcoglicanas/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia
11.
Carcinogenesis ; 39(9): 1141-1150, 2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-29860383

RESUMO

Curcumin has been reported to inhibit inflammation, tumor growth, angiogenesis and metastasis by decreasing cell growth and by inducing apoptosis mainly through the inhibition of nuclear factor kappa-B (NFκB), a master regulator of inflammation. Recent reports also indicate potential metabolic effects of the polyphenol, therefore we analyzed whether and how it affects the energy metabolism of tumor cells. We show that curcumin (10 µM) inhibits the activity of ATP synthase in isolated mitochondrial membranes leading to a dramatic drop of ATP and a reduction of oxygen consumption in in vitro and in vivo tumor models. The effects of curcumin on ATP synthase are independent of the inhibition of NFκB since the IκB Kinase inhibitor, SC-514, does not affect ATP synthase. The activities of the glycolytic enzymes hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase are only slightly affected in a cell type-specific manner. The energy impairment translates into decreased tumor cell viability. Moreover, curcumin induces apoptosis by promoting the generation of reactive oxygen species (ROS) and malondialdehyde (MDA), a marker of lipid oxidation, and autophagy, at least in part due to the activation of the AMP-activated protein kinase (AMPK). According to the in vitro anti-tumor effect, curcumin (30 mg/kg body weight) significantly delayed in vivo cancer growth likely due to an energy impairment but also through the reduction of tumor angiogenesis. These results establish the ATP synthase, a central enzyme of the cellular energy metabolism, as a target of the antitumoral polyphenol leading to inhibition of cancer cell growth and a general reprogramming of tumor metabolism.


Assuntos
Antineoplásicos/uso terapêutico , Curcumina/uso terapêutico , Metabolismo Energético/efeitos dos fármacos , ATPases Mitocondriais Próton-Translocadoras/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Consumo de Oxigênio/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Hexoquinase/metabolismo , Quinase I-kappa B/antagonistas & inibidores , L-Lactato Desidrogenase/metabolismo , Malondialdeído/metabolismo , Camundongos , Camundongos Nus , Neovascularização Patológica/tratamento farmacológico , Fosfofrutoquinases/metabolismo , Piruvato Quinase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tiofenos/farmacologia
12.
Oncotarget ; 8(42): 72133-72146, 2017 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-29069774

RESUMO

The pathogenic role of the PHOX2B gene in neuroblastoma is indicated by heterozygous mutations in neuroblastoma patients and by gene overexpression in both neuroblastoma cell lines and tumor samples. PHOX2B encodes a transcription factor which is crucial for the correct development and differentiation of sympathetic neurons. PHOX2B overexpression is considered a prognostic marker for neuroblastoma and it is also used by clinicians to monitor minimal residual disease. Furthermore, it has been observed that neuronal differentiation in neuroblastoma is dependent on down-regulation of PHOX2B expression, which confirms that PHOX2B expression may be considered a target in neuroblastoma. Here, PHOX2B promoter or 3' untranslated region were used as molecular targets in an in vitro high-throughput approach that led to the identification of molecules able to decrease PHOX2B expression at transcriptional and likely even at post-transcriptional levels. Further functional investigations carried out on PHOX2B mRNA levels and biological consequences, such as neuroblastoma cell apoptosis and growth, showed that chloroquine and mycophenolate mofetil are most promising agents for neuroblastoma therapy based on down-regulation of PHOX2B expression. Finally, a strong correlation between the effect of drugs in terms of down-regulation of PHOX2B expression and of biological consequences in neuroblastoma cells confirms the role of PHOX2B as a potential molecular target in neuroblastoma.

13.
Nat Protoc ; 12(8): 1542-1562, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28683062

RESUMO

ATP, the energy exchange factor that connects anabolism and catabolism, is required for major reactions and processes that occur in living cells, such as muscle contraction, phosphorylation and active transport. ATP is also the key molecule in extracellular purinergic signaling mechanisms, with an established crucial role in inflammation and several additional disease conditions. Here, we describe detailed protocols to measure the ATP concentration in isolated living cells and animals using luminescence techniques based on targeted luciferase probes. In the presence of magnesium, oxygen and ATP, the protein luciferase catalyzes oxidation of the substrate luciferin, which is associated with light emission. Recombinantly expressed wild-type luciferase is exclusively cytosolic; however, adding specific targeting sequences can modify its cellular localization. Using this strategy, we have constructed luciferase chimeras targeted to the mitochondrial matrix and the outer surface of the plasma membrane. Here, we describe optimized protocols for monitoring ATP concentrations in the cytosol, mitochondrial matrix and pericellular space in living cells via an overall procedure that requires an average of 3 d. In addition, we present a detailed protocol for the in vivo detection of extracellular ATP in mice using luciferase-transfected reporter cells. This latter procedure may require up to 25 d to complete.


Assuntos
Trifosfato de Adenosina/análise , Técnicas Biossensoriais/métodos , Luciferases/metabolismo , Substâncias Luminescentes/metabolismo , Coloração e Rotulagem/métodos , Animais , Linhagem Celular , Técnicas Citológicas/métodos , Humanos , Camundongos
14.
Int Immunol ; 29(2): 49-58, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28338763

RESUMO

Mesenchymal stromal cells (MSCs) are committed progenitors of mesodermal origin that are found virtually in every organ and exhibit multilineage differentiation into osteocytes, adipocytes and chondrocytes. MSCs also mediate a wide spectrum of immunoregulatory activities that usually dampen innate and adaptive immune responses. These features have attracted interest in the perspective of developing novel cell therapies for autoimmune disease. However, depending on the microenvironmental conditions, MSCs may show a plastic behavior and switch to an immunostimulatory phenotype. After thorough characterization of the effects of MSCs on the immune system, MSC cell therapy has been tested in animal models of autoimmunity using different cell sources, protocols of in vitro expansion and routes and schedules of administration. The pre-clinical results have been encouraging in some models [e.g. Crohn's disease (CD), multiple sclerosis] and heterogeneous in others (e.g. graft-versus-host disease, systemic lupus erythematosus, rheumatoid arthritis). Clinical trials have been carried out and many are ongoing. As discussed, the results obtained are too preliminary to draw any conclusion, with the only exception of topical administration of MSCs in CD that has proven efficacious. The mechanism of action of infused MSCs is still under investigation, but the apparent paradox of a therapeutic effect achieved in spite of the very low number of cells reaching the target organ has been solved by the finding that MSC-derived extracellular vesicles (EVs) closely mimic the therapeutic activity of MSCs in pre-clinical models. These issues are critically discussed in view of the potential clinical use of MSC-derived EVs.


Assuntos
Doenças Autoimunes/terapia , Autoimunidade , Micropartículas Derivadas de Células/imunologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/fisiologia , Animais , Doenças Autoimunes/imunologia , Diferenciação Celular , Microambiente Celular , Ensaios Clínicos como Assunto , Humanos
15.
Oncoimmunology ; 7(1): e1378843, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29296542

RESUMO

GD2-redirected chimeric antigen receptor (CAR) T lymphocytes represent a promising therapeutic option for immunotherapy of neuroblastoma (NB). However, despite the encouraging therapeutic effects observed in some hematological malignancies, clinical results of CAR T cell immunotherapy in solid tumors are still modest. Tumor driven neo-angiogenesis supports an immunosuppressive microenvironment that influences treatment responses and is amenable to targeting with antiangiogenic drugs. The latter agents promote lymphocyte tumor infiltration by transiently reprogramming tumor vasculature, and may represent a valid combinatorial approach with CAR T cell immunotherapy. In light of these considerations, we investigated the anti-NB activity of GD2-CAR T cells combined with bevacizumab (BEV) in an orthotopic xenograft model of human NB. Two weeks after tumor implantation, mice received BEV or GD2-CAR T cells or both by single intravenous administration. GD2-CAR T cells exerted a significant anti-NB activity only in combination with BEV, even at the lowest concentration tested, which per se did not inhibit tumor growth. When combined with BEV, GD2-CAR T cells massively infiltrated tumor mass where they produced interferon-γ (IFN-γ), which, in turn, induced expression of CXCL10 by NB cells. IFN-γ, and possibly other cytokines, upregulated NB cell expression of PD-L1, while tumor infiltrating GD2-CAR T cells expressed PD-1. Thus, the PD-1/PD-L1 axis can limit the anti-tumor efficacy of the GD2-CAR T cell/BEV association. This study provides a strong rationale for testing the combination of GD2-CAR T cells with BEV in a clinical trial enrolling NB patients. PD-L1 silencing or blocking strategies may further enhance the efficacy of such combination.

16.
Sci Rep ; 6: 25092, 2016 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-27121192

RESUMO

Cancer metabolism is characterized by an accelerated glycolytic rate facing reduced activity of oxidative phosphorylation. This "Warburg effect" represents a standard to diagnose and monitor tumor aggressiveness with (18)F-fluorodeoxyglucose whose uptake is currently regarded as an accurate index of total glucose consumption. Studying cancer metabolic response to respiratory chain inhibition by metformin, we repeatedly observed a reduction of tracer uptake facing a marked increase in glucose consumption. This puzzling discordance brought us to discover that (18)F-fluorodeoxyglucose preferentially accumulates within endoplasmic reticulum by exploiting the catalytic function of hexose-6-phosphate-dehydrogenase. Silencing enzyme expression and activity decreased both tracer uptake and glucose consumption, caused severe energy depletion and decreased NADPH content without altering mitochondrial function. These data document the existence of an unknown glucose metabolism triggered by hexose-6-phosphate-dehydrogenase within endoplasmic reticulum of cancer cells. Besides its basic relevance, this finding can improve clinical cancer diagnosis and might represent potential target for therapy.


Assuntos
Retículo Endoplasmático/metabolismo , Glucose/metabolismo , Glicólise , Neoplasias/fisiopatologia , Via de Pentose Fosfato , Animais , Desidrogenases de Carboidrato/metabolismo , Linhagem Celular Tumoral , Humanos , Camundongos
17.
World J Gastroenterol ; 22(12): 3496-501, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-27022231

RESUMO

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma that can undergo local progression with possible systemic dissemination. We report a case of a patient affected by MF with a pancreatic mass that was a diagnostic challenge between primitive tumor and pancreatic metastasis from MF. Clinical setting findings and imaging studies raised the suspicion of a pancreatic primary neoplasm. A diagnostic clue was provided by the combined histomorphologic/immunohistochemical study of pancreatic and cutaneous biopsies, which revealed a pancreatic localization of MF. Considering the rarity of metastatic localization of MF to the pancreas, we next investigated whether chemokine-chemokine receptor interactions could be involved in the phenomenon to provide new insight into the possible mechanisms underlying metastatic localization of MF to the pancreas. Histological analyses of archival pancreatic tissue demonstrated that glucagon-secreting cells of the pancreatic islets expressed the CCL27 chemokine, which may have attracted in our case metastatic MF cells expressing the complementary receptor CCR10.


Assuntos
Micose Fungoide/patologia , Neoplasias Pancreáticas/secundário , Neoplasias Cutâneas/patologia , Biomarcadores Tumorais/análise , Biópsia , Diagnóstico Diferencial , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Micose Fungoide/química , Micose Fungoide/diagnóstico por imagem , Micose Fungoide/terapia , Neoplasias Pancreáticas/química , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/terapia , Valor Preditivo dos Testes , Neoplasias Cutâneas/química , Neoplasias Cutâneas/terapia , Tomografia Computadorizada por Raios X
18.
Sci Rep ; 6: 19569, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26794854

RESUMO

Emerging evidence demonstrates that targeting energy metabolism is a promising strategy to fight cancer. Here we show that combining metformin and short-term starvation markedly impairs metabolism and growth of colon and breast cancer. The impairment in glycolytic flux caused by starvation is enhanced by metformin through its interference with hexokinase II activity, as documented by measurement of 18F-fluorodeoxyglycose uptake. Oxidative phosphorylation is additively compromised by combined treatment: metformin virtually abolishes Complex I function; starvation determines an uncoupled status of OXPHOS and amplifies the activity of respiratory Complexes II and IV thus combining a massive ATP depletion with a significant increase in reactive oxygen species. More importantly, the combined treatment profoundly impairs cancer glucose metabolism and virtually abolishes lesion growth in experimental models of breast and colon carcinoma. Our results strongly suggest that energy metabolism is a promising target to reduce cancer progression.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias do Colo/metabolismo , Glicólise/efeitos dos fármacos , Metformina/farmacologia , Fosforilação Oxidativa/efeitos dos fármacos , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/patologia , Metabolismo Energético/efeitos dos fármacos , Feminino , Imunofluorescência , Glucose/metabolismo , Humanos , Camundongos Endogâmicos BALB C , Modelos Biológicos , Espécies Reativas de Oxigênio/metabolismo , Estaurosporina/farmacologia
19.
Oncotarget ; 7(3): 2968-84, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26658104

RESUMO

Nicotinamide phosphoribosyltransferase (NAMPT) is a crucial enzyme in the biosynthesis of intracellular NAD+. NAMPT inhibitors have potent anticancer activity in several preclinical models by depleting NAD+ and ATP levels. Recently, we demonstrated that CD73 enables the utilization of extracellular NAD+/nicotinamide mononucleotide (NMN) by converting them to Nicotinamide riboside (NR), which can cross the plasmamembrane and fuel intracellular NAD+ biosynthesis in human cells. These processes are herein confirmed to also occur in a human ovarian carcinoma cell line (OVCAR-3), by means of CD73 or NRK1 specific silencing. Next, we investigated the anti-tumor activity of the simultaneous inhibition of NAMPT (with FK866) and CD73 (with α, ß-methylene adenosine 5'-diphosphate, APCP), in an in vivo human ovarian carcinoma model. Interestingly, the combined therapy was found to significantly decrease intratumor NAD+, NMN and ATP levels, compared with single treatments. In addition, the concentration of these nucleotides in ascitic exudates was more remarkably reduced in animals treated with both FK866 and APCP compared with single treatments. Importantly, tumors treated with FK866 in combination with APCP contained a statistically significant lower proportion of Ki67 positive proliferating cells and a higher percentage of necrotic area. Finally, a slight but significant increase in animal survival in response to the combined therapy, compared to the single agents, could be demonstrated. Our results indicate that the pharmacological inhibition of CD73 enzymatic activity could be considered as a means to potentiate the anti-cancer effects of NAMPT inhibitors.


Assuntos
5'-Nucleotidase/antagonistas & inibidores , Acrilamidas/farmacologia , Trifosfato de Adenosina/análogos & derivados , Citocinas/antagonistas & inibidores , Mononucleotídeo de Nicotinamida/metabolismo , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Neoplasias Ovarianas/terapia , Piperidinas/farmacologia , 5'-Nucleotidase/genética , Trifosfato de Adenosina/farmacologia , Animais , Linhagem Celular Tumoral , Feminino , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/genética , Humanos , Camundongos , Camundongos Nus , NAD/metabolismo , Niacinamida/análogos & derivados , Niacinamida/biossíntese , Compostos de Piridínio , Interferência de RNA , RNA Interferente Pequeno/genética
20.
Semin Cancer Biol ; 35 Suppl: S129-S150, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26454069

RESUMO

Cancer is a disease characterized by unrestrained cellular proliferation. In order to sustain growth, cancer cells undergo a complex metabolic rearrangement characterized by changes in metabolic pathways involved in energy production and biosynthetic processes. The relevance of the metabolic transformation of cancer cells has been recently included in the updated version of the review "Hallmarks of Cancer", where dysregulation of cellular metabolism was included as an emerging hallmark. While several lines of evidence suggest that metabolic rewiring is orchestrated by the concerted action of oncogenes and tumor suppressor genes, in some circumstances altered metabolism can play a primary role in oncogenesis. Recently, mutations of cytosolic and mitochondrial enzymes involved in key metabolic pathways have been associated with hereditary and sporadic forms of cancer. Together, these results demonstrate that aberrant metabolism, once seen just as an epiphenomenon of oncogenic reprogramming, plays a key role in oncogenesis with the power to control both genetic and epigenetic events in cells. In this review, we discuss the relationship between metabolism and cancer, as part of a larger effort to identify a broad-spectrum of therapeutic approaches. We focus on major alterations in nutrient metabolism and the emerging link between metabolism and epigenetics. Finally, we discuss potential strategies to manipulate metabolism in cancer and tradeoffs that should be considered. More research on the suite of metabolic alterations in cancer holds the potential to discover novel approaches to treat it.


Assuntos
Carcinogênese/metabolismo , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Carcinogênese/genética , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Metabolismo Energético/genética , Epigênese Genética , Humanos , Redes e Vias Metabólicas/genética , Mitocôndrias/genética , Mitocôndrias/patologia , Neoplasias/genética , Neoplasias/patologia
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