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1.
Cell Death Dis ; 14(5): 314, 2023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-37160873

RESUMEN

Melanomas are characterised by accelerated cell proliferation and metabolic reprogramming resulting from the contemporary dysregulation of the MAPK pathway, glycolysis and the tricarboxylic acid (TCA) cycle. Here, we suggest that the oncogenic transcription factor EB (TFEB), a key regulator of lysosomal biogenesis and function, controls melanoma tumour growth through a transcriptional programme targeting ERK1/2 activity and glucose, glutamine and cholesterol metabolism. Mechanistically, TFEB binds and negatively regulates the promoter of DUSP-1, which dephosphorylates ERK1/2. In melanoma cells, TFEB silencing correlates with ERK1/2 dephosphorylation at the activation-related p-Thr185 and p-Tyr187 residues. The decreased ERK1/2 activity synergises with TFEB control of CDK4 expression, resulting in cell proliferation blockade. Simultaneously, TFEB rewires metabolism, influencing glycolysis, glucose and glutamine uptake, and cholesterol synthesis. In TFEB-silenced melanoma cells, cholesterol synthesis is impaired, and the uptake of glucose and glutamine is inhibited, leading to a reduction in glycolysis, glutaminolysis and oxidative phosphorylation. Moreover, the reduction in TFEB level induces reverses TCA cycle, leading to fatty acid production. A syngeneic BRAFV600E melanoma model recapitulated the in vitro study results, showing that TFEB silencing sustains the reduction in tumour growth, increase in DUSP-1 level and inhibition of ERK1/2 action, suggesting a pivotal role for TFEB in maintaining proliferative melanoma cell behaviour and the operational metabolic pathways necessary for meeting the high energy demands of melanoma cells.


Asunto(s)
Glutamina , Melanoma , Humanos , División Celular , Ciclo Celular , Melanoma/genética , Colesterol , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética
2.
Int J Pharm ; 625: 122102, 2022 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-35961419

RESUMEN

Pentamidine (PTM) is an aromatic diamidine approved for the treatment of parasitic infections that has been recently proposed for possible repositioning as an anticancer drug. To this aim, efforts have been made to improve its therapeutic efficacy and reduce associated adverse effects through both covalent derivatization and association with nanocarriers. To efficiently encapsulate PTM into biocompatible nanoparticles and to enhance its selectivity toward cancer cells, a squalene (SQ) derivative (1,1',2-tris-norsqualenoic acid, SQ-COOH) was selected to prepare PTM-loaded nanocarriers. Indeed, SQ and its derivatives self-assemble into nanoparticles in aqueous media. Furthermore, SQ-bioconjugates strongly interact with low-density lipoproteins (LDL), thus favoring preferential accumulation in cells overexpressing the LDL receptor (LDLR). We report here the preparation of nanocarriers by ion-pairing between the negatively charged SQ-COOH and the positively charged PTM free base (PTM-B), which allowed the covalent grafting of SQ to PTM to be avoided. The nanoparticles were characterized (mean size < 200 nm and zeta potential < -20 mV for SQ-COOH/PTM-B 3:1 molar ratio) and molecular modelling studies of the SQ-COOH/PTM-B interaction confirmed the nanocarrier stability. Finally, the ability to indirectly target LDLR-overexpressing cancer cells was evaluated by in vitro cell viability assays and confirmed by LDLR silencing, serum privation and simvastatin treatment.


Asunto(s)
Antineoplásicos , Nanopartículas , Neoplasias , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Supervivencia Celular , Portadores de Fármacos/farmacología , Neoplasias/tratamiento farmacológico , Pentamidina/farmacología , Escualeno/farmacología
3.
Talanta ; 222: 121441, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33167197

RESUMEN

Interest in impedance-based cellular assays is rising due to their remarkable advantages, including label-free, low cost, non-invasive, non-destructive, quantitative and real-time monitoring. In order to test their potential in cancer treatment decision and early detection of chemoresistance, we devised a new custom-made impedance measuring system based on electric cell-substrate impedance sensing (ECIS), optimized for long term impedance measurements. This device was employed in a proof of concept cell culture impedance analysis for the characterization of chemo-resistant colon cancer cells. Doxorubicin-resistant HT-29 cells were used for this purpose and monitored for 140 h. Analysis of impedance-based curves reveal different trends from chemo-sensitive and chemo-resistant cells. An impedance-based cytoxicity assay with different concentrations of doxorubicin was also performed using ECIS. The obtained results confirm the feasibility of ECIS in the study of drug resistance and show promises for studies of time-dependent factors related to physiological and behavioral changes in cells during resistance acquisition. The methodology presented herein, allows the continuous monitoring of cells under normal culture conditions as well as upon drug exposure. The ECIS device used, sets the basis for high-throughput early detection of resistance to drugs, administered in the clinical practice to cancer patients, and for the screening of new drugs in vitro, on patient-derived cells.


Asunto(s)
Técnicas Biosensibles , Neoplasias del Colon , Preparaciones Farmacéuticas , Técnicas de Cultivo de Célula , Neoplasias del Colon/tratamiento farmacológico , Resistencia a Medicamentos , Impedancia Eléctrica , Humanos
4.
Oncogene ; 37(6): 697-709, 2018 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-29059164

RESUMEN

Mitochondrial dysregulation plays a central role in cancers and drives reactive oxygen species (ROS)-dependent tumor progression. We investigated the pro-tumoral roles of mitochondrial dynamics and altered intracellular ROS levels in pancreatic ductal adenocarcinoma (PDAC). We identified 'family with sequence similarity 49 member B' (FAM49B) as a mitochondria-localized protein that regulates mitochondrial fission and cancer progression. Silencing FAM49B in PDAC cells resulted in increased fission and mitochondrial ROS generation, which enhanced PDAC cell proliferation and invasion. Notably, FAM49B expression levels in PDAC cells were downregulated by the tumor microenvironment. Overall, the results of this study show that FAM49B acts as a suppressor of cancer cell proliferation and invasion in PDAC by regulating tumor mitochondrial redox reactions and metabolism.


Asunto(s)
Adenocarcinoma/secundario , Biomarcadores de Tumor/metabolismo , Carcinoma Ductal Pancreático/secundario , Regulación Neoplásica de la Expresión Génica , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Mitocondrias/patología , Proteínas Mitocondriales/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/patología , Especies Reactivas de Oxígeno/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Animales , Apoptosis , Biomarcadores de Tumor/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Movimiento Celular , Proliferación Celular , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Ratones , Ratones Endogámicos NOD , Ratones SCID , Mitocondrias/metabolismo , Proteínas Mitocondriales/genética , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Pronóstico , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto , Neoplasias Pancreáticas
5.
Diabetologia ; 56(1): 173-84, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23064289

RESUMEN

AIMS/HYPOTHESIS: Successful outcomes have been obtained by exploiting adipose-derived stem cells (ASCs) in regenerative medicine. NADPH oxidase (NOX)-generated reactive oxygen species (ROS) are known to control stem cell self-renewal. Several high glucose (HG)-mediated effects depend on NOX-generated ROS. In this study, we investigated whether, and how mechanistically, HG concentrations control ASC fate in patients with diabetes. METHODS: ASCs from the visceral adipose tissue of non-diabetic (N-ASCs) and diabetic participants (D-ASCs), identified by surface markers, were counted and evaluated for ROS generation and stem cell properties. Their ability to release soluble factors was assessed by BioPlex analysis. To reproduce an in vitro diabetic glucose milieu, N-ASCs were cultured in HG (25 mmol/l) or normal glucose (NG) concentration (5 mmol/l), as control. ASC pluripotency was assessed by in vitro study. The p47(phox) NOX subunit, AKT and octamer-binding transcription factor 4 (OCT4; also known as POU5F1) were knocked down by small-interfering RNA technology. Stem-cell features were evaluated by sphere cluster formation. RESULTS: The ASC number was higher in diabetic patients than in non-diabetic controls. Production of OCT4 and NANOG, stem-cell-specific transcription factors, was upregulated in D-ASCs compared with N-ASCs. Moreover, we found that ROS production and AKT activation drove D-ASC, but not N-ASC, secretion. When N-ASCs were cultured in vitro in the presence of HG, they also expressed OCT4/NANOG and formed spheres. By knock-down of the p47(phox) NOX subunit, AKT and OCT4 we demonstrated that NOX-generated ROS and their downstream signals are crucial for HG-mediated ASC de-differentiation and proinflammatory cytokine production. CONCLUSIONS/INTERPRETATION: We herein provide a rationale for exploiting D-ASCs in regenerative medicine and/or exploiting HG preconditioning to increase ASCs ex vivo.


Asunto(s)
Células Madre Adultas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Proteínas de Homeodominio/biosíntesis , Hiperglucemia/etiología , Grasa Intraabdominal/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/biosíntesis , Regulación hacia Arriba , Células Madre Adultas/patología , Biomarcadores/metabolismo , Recuento de Células , Desdiferenciación Celular , Células Cultivadas , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/patología , Silenciador del Gen , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Separación Inmunomagnética , Grasa Intraabdominal/patología , NADPH Oxidasas/antagonistas & inhibidores , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , Proteína Homeótica Nanog , Factor 3 de Transcripción de Unión a Octámeros/antagonistas & inhibidores , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Células Madre Pluripotentes/metabolismo , Células Madre Pluripotentes/patología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Mensajero/metabolismo , ARN Interferente Pequeño , Especies Reactivas de Oxígeno/metabolismo
6.
Br J Pharmacol ; 167(7): 1431-47, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22788770

RESUMEN

BACKGROUND AND PURPOSE: The passage of drugs across the blood-brain barrier (BBB) limits the efficacy of chemotherapy in brain tumours. For instance, the anticancer drug doxorubicin, which is effective against glioblastoma in vitro, has poor efficacy in vivo, because it is extruded by P-glycoprotein (Pgp/ABCB1), multidrug resistance-related proteins and breast cancer resistance protein (BCRP/ABCG2) in BBB cells. The aim of this study was to convert poorly permeant drugs like doxorubicin into drugs able to cross the BBB. EXPERIMENTAL APPROACH: Experiments were performed on primary human cerebral microvascular endothelial hCMEC/D3 cells, alone and co-cultured with human brain and epithelial tumour cells. KEY RESULTS: Statins reduced the efflux activity of Pgp/ABCB1 and BCRP/ABCG2 in hCMEC/D3 cells by increasing the synthesis of NO, which elicits the nitration of critical tyrosine residues on these transporters. Statins also increased the number of low-density lipoprotein (LDL) receptors exposed on the surface of BBB cells, as well as on tumour cells like human glioblastoma. We showed that the association of statins plus drug-loaded nanoparticles engineered as LDLs was effective as a vehicle for non-permeant drugs like doxorubicin to cross the BBB, allowing its delivery into primary and metastatic brain tumour cells and to achieve significant anti-tumour cytotoxicity. CONCLUSIONS AND IMPLICATIONS: We suggest that our 'Trojan horse' approach, based on the administration of statins plus a LDL receptor-targeted liposomal drug, might have potential applications in the pharmacological therapy of different brain diseases for which the BBB represents an obstacle.


Asunto(s)
Barrera Hematoencefálica/metabolismo , Doxorrubicina/administración & dosificación , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Lovastatina/análogos & derivados , Receptores de LDL/metabolismo , Simvastatina/administración & dosificación , Transportadoras de Casetes de Unión a ATP/metabolismo , Línea Celular , Línea Celular Tumoral , Humanos , Liposomas , Lovastatina/administración & dosificación , FN-kappa B/metabolismo , Óxido Nítrico Sintasa/metabolismo , Nitritos/metabolismo , Quinasas Asociadas a rho/metabolismo , Proteína de Unión al GTP rhoA/metabolismo
7.
Leukemia ; 25(5): 828-37, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21372840

RESUMEN

Tumor cells in chronic lymphocytic leukemia (CLL) are more prone to apoptosis when cultured ex vivo, because they lack prosurvival signals furnished in vivo via B-cell receptor (BCR)-dependent and -independent pathways. This study compared the susceptibility of unmutated (UM) and mutated (M) CLL B cells to spontaneous apoptosis and prosurvival signals. UM CLL B cells showed a significantly higher rate of spontaneous apoptosis than M CLL B cells. Nuclear factor-kB (NF-kB) was rapidly inactivated, and B-cell leukemia/lymphoma 2 (Bcl-2) expression progressively down-regulated in the UM CLL B cells. CD40-Ligand, interleukin-4 and stromal cells significantly improved their viability and partially recovered Bcl-2, but not NF-kB expression. Peripheral blood mononuclear cells also offered protection of UM CLL B cells, and recovered both NF-kB and Bcl-2 expression. T cells, rather than nurse-like cells, were responsible for protecting UM CLL B cells by means of cell-to-cell contact and soluble factors. Despite their more aggressive features, UM CLL B cells are more susceptible to spontaneous apoptosis and depend from environmental prosurvival signals. This vulnerability of UM CLL B cells can be exploited as a selective target of therapeutic interventions.


Asunto(s)
Apoptosis , Linfocitos B/patología , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Mutación/genética , Adulto , Anciano , Anciano de 80 o más Años , Linfocitos B/metabolismo , Western Blotting , Ligando de CD40/metabolismo , Ensayo de Cambio de Movilidad Electroforética , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/inmunología , Masculino , Persona de Mediana Edad , FN-kappa B/genética , FN-kappa B/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal , Células Tumorales Cultivadas
8.
Curr Med Chem ; 18(6): 872-85, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21182478

RESUMEN

Cardioactive glycosides, like digoxin, ouabain and related compounds, are drugs that inhibit Na(+)/K(+)-ATPase and have a strong inotropic effect on heart: they cause the Na(+)/Ca(2+) exchanger to extrude Na+ in exchange with Ca(2+) and therefore increase the [Ca(2+)](i) concentration. For this reason, some of these drugs are currently used in the treatment of congestive heart failure and cardiac arrhythmias. Recently it has been discovered that cardiac glycosides exert pleiotropic effects on many aspects of cell metabolism. Na(+)/K(+)-ATPase is not the exclusive target, as they affect the cell response to hypoxia, modulate several signaling pathways involved in cell death and proliferation, regulate the transcription of different genes and modify the pharmacokinetics of other drugs, by altering the expression and activity of drug-metabolizing enzymes. Some of these effects are related to the steroid structure of glycosides, a property which also makes them fine modulators of the synthesis of cholesterol and steroid hormones. Moreover, new endogenously synthesized glycosides have been discovered in the last years: these molecules are involved in the balance of salt and in the control of blood pressure. This review will focus on the recent studies which have demonstrated that exogenous and endogenous glycosides, besides playing a role as inotropic agents, are also important in the pathogenesis and therapy of different human diseases, such as stroke, diabetes, neurological diseases and cancer.


Asunto(s)
Glicósidos/farmacología , Corazón/efectos de los fármacos , Animales , Enfermedades Cardiovasculares/tratamiento farmacológico , Glicósidos/metabolismo , Glicósidos/farmacocinética , Glicósidos/uso terapéutico , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Transducción de Señal/efectos de los fármacos , Esteroides/metabolismo
9.
Curr Med Chem ; 17(22): 2431-41, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20491635

RESUMEN

The behavior of fluoride ions in the human organism is a classic example of double-edged sword. On the one hand the daily supplementation with fluoride is undoubtedly an important preventing factor in protecting teeth from caries, and, as an important mitogenic stimulus for osteoblasts, it may enhance mineral deposition in bone, but on the other hand fluoride, above a threshold concentration, has been demonstrated to be toxic. We present here a brief review of fluoride metabolism and exposure, its use in caries prevention and its effects on bone, followed by an updating about the main hypotheses concerning its mechanism of action and toxicity. The effects of fluoride have been related mainly to its ability to evoke the activation of G proteins and the inhibition of phosphotyrosine phosphatases, leading to an intracellular increase of tyrosine phosphorylation and activation of the mitogen-activated protein kinase pathway, and its capacity to cause generation of reactive oxygen species. We present also a unifying hypothesis accounting for these apparently different effects, although the available experimental models and conditions are highly variable in the literature. A lot of experiments still need to be performed to clarify the positive and negative effects of fluoride. Finding the mechanisms accounting for fluoride toxicity is an important point: indeed, the use of fluoride has been proposed in the preparation of new biomaterials to be inserted in the bone, in order to improve their stable and safe integration.


Asunto(s)
Fluoruros/farmacología , Fluoruros/farmacocinética , Animales , Caries Dental/prevención & control , Relación Dosis-Respuesta a Droga , Fluoruros/efectos adversos , Fluoruros/metabolismo , Humanos
10.
Br J Pharmacol ; 158(7): 1777-86, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19888963

RESUMEN

BACKGROUND AND PURPOSE: Statins, inhibitors of hydroxymethylglutaryl-CoA reductase, reduce the intracellular synthesis of cholesterol and prevent the onset of atherosclerosis. They also decrease the synthesis of isoprenoid molecules, such as the side chain of ubiquinone and geranylgeranyl pyrophosphate. As a consequence, statins impair mitochondrial metabolism and the activation of small monomeric GTPases (such as Rho and Ras), causing toxic effects. To date, a successful strategy to prevent statin toxicity is lacking. EXPERIMENTAL APPROACH: In human monocytic THP-1 cells, we measured the synthesis of cholesterol and isoprenoids, mitochondrial electron flow, the activity of RhoA and Rac, cell death and proliferation. KEY RESULTS: Mevastatin reduced the synthesis of cholesterol, geranylgeranyl pyrophosphate and ubiquinone, mitochondrial electron transport, activity of RhoA and Rac, and cell proliferation, accompanied by increased cell death. Geranylgeraniol, a cell-permeable analogue of geranylgeranyl pyrophosphate, reversed all these effects of mevastatin, without affecting its ability to reduce cholesterol synthesis. Notably, geranylgeraniol was more effective than the addition of exogenous ubiquinone, which rescued mitochondrial respiratory activity and reversed mevastatin cytotoxicity, but did not alter the decrease in cell proliferation. The same results were obtained in human liver HepG2 cells. CONCLUSIONS AND IMPLICATIONS: Geranylgeraniol had a broader protective effect against the cytotoxicity of statins than exogenous ubiquinone. Therefore, geranylgeraniol may be a more useful and practical means of limiting the toxicities of statins, without reducing their efficacy as cholesterol lowering agents.


Asunto(s)
Colesterol/biosíntesis , Diterpenos/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/toxicidad , Lovastatina/análogos & derivados , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Transporte de Electrón/efectos de los fármacos , Células Hep G2 , Humanos , Lovastatina/toxicidad , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Terpenos/metabolismo , Ubiquinona/farmacología
11.
Cell Mol Life Sci ; 66(9): 1580-94, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19288057

RESUMEN

Digoxin and ouabain are steroid drugs that inhibit the Na(+)/K(+)-ATPase, and are widely used in the treatment of heart diseases. They may also have additional effects, such as on metabolism of steroid hormones, although until now no evidence has been provided about the effects of these cardioactive glycosides on the synthesis of cholesterol. Here we report that digoxin and ouabain increased the synthesis of cholesterol in human liver HepG2 cells, enhancing the activity and the expression of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the rate-limiting enzyme of the cholesterol synthesis. This effect was mediated by the binding of the sterol regulatory element binding protein-2 (SREBP-2) to the HMGCR promoter, and was lost in cells silenced for SREBP-2 or loaded with increasing amounts of cholesterol. Digoxin and ouabain competed with cholesterol for binding to the SREBP-cleavage-activating protein, and are critical regulators of cholesterol synthesis in human liver cells.


Asunto(s)
Cardiotónicos/farmacología , Colesterol/biosíntesis , Digoxina/farmacología , Inhibidores Enzimáticos/farmacología , Hepatocitos/efectos de los fármacos , Ouabaína/farmacología , Humanos , Hidroximetilglutaril-CoA Reductasas/metabolismo , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Lovastatina/análogos & derivados , Lovastatina/farmacología , Proteína 2 de Unión a Elementos Reguladores de Esteroles/genética , Proteína 2 de Unión a Elementos Reguladores de Esteroles/metabolismo , Ubiquinona/metabolismo
12.
Br J Pharmacol ; 156(7): 1054-66, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19298255

RESUMEN

BACKGROUND AND PURPOSE: Artemisinin is an antimalarial drug exerting pleiotropic effects, such as the inhibition of the transcription factor nuclear factor-kappa B and of the sarcoplasmic/endoplasmic reticulum Ca(++)-ATPase (SERCA) of P. falciparum. As the sesquiterpene lactone thapsigargin, a known inhibitor of mammalian SERCA, enhances the expression of P-glycoprotein (Pgp) by increasing the intracellular Ca(++) ([Ca(++)](i)) level, we investigated whether artemisinin and its structural homologue parthenolide could inhibit SERCA in human colon carcinoma HT29 cells and induce a resistance to doxorubicin. EXPERIMENTAL APPROACH: HT29 cells were incubated with artemisinin or parthenolide and assessed for SERCA activity, [Ca(++)](i) levels, Pgp expression, doxorubicin accumulation and toxicity, and translocation of the hypoxia-inducible factor, HIF-1alpha. KEY RESULTS: Artemisinin and parthenolide, like the specific SERCA inhibitors thapsigargin and cyclopiazonic acid, reduced the activity of SERCA. They also increased intracellular calcium concentration ([Ca(++)](i)) and Pgp expression and decreased doxorubicin accumulation and cytotoxicity. The intracellular Ca(++) chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, and the inhibitor of calmodulin-dependent kinase II (CaMKII) KN93 prevented these effects. CaMKII is known to promote the phosphorylation and the activation of HIF-1alpha, which may induce Pgp. In HT29 cells, artemisinin and parthenolide induced the phosphorylation of HIF-1alpha, which was inhibited by KN93. CONCLUSIONS AND IMPLICATIONS: Our results suggest that artemisinin and parthenolide may act as SERCA inhibitors and, like other SERCA inhibitors, induce resistance to doxorubicin in human colon cancer cells, via the CaMKII-dependent activation of HIF-1alpha and the induction of Pgp.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/biosíntesis , Antimaláricos/efectos adversos , Antimetabolitos Antineoplásicos/farmacología , Artemisininas/efectos adversos , Calcio/fisiología , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/antagonistas & inhibidores , Línea Celular Tumoral , Neoplasias del Colon , Humanos , Fosforilación , Transporte de Proteínas , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/antagonistas & inhibidores , Sesquiterpenos/efectos adversos
13.
Eur Respir J ; 32(2): 443-51, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18385176

RESUMEN

Human malignant mesothelioma (HMM), which is strongly related to asbestos exposure, exhibits high resistance to many anticancer drugs. Asbestos fibre deposition in the lung may cause hypoxia and iron chelation at the fibre surface. Hypoxia-inducible factor (HIF)-1alpha, which is upregulated by a decreased availability of oxygen and iron, controls the expression of membrane transporters, such as P-glycoprotein (Pgp), which actively extrude the anticancer drugs. The present study aimed to assess whether asbestos may play a role in the induction of doxorubicin resistance in HMM cells through the activation of HIF-1alpha and an increased expression of Pgp. After 24-h incubation with crocidolite asbestos or with the iron chelator dexrazoxane, or under hypoxia, HMM cells were tested for HIF-1alpha activation, Pgp expression, accumulation of doxorubicin and sensitivity to its toxic effect. Crocidolite, dexrazoxane and hypoxia caused HIF-1alpha activation, Pgp overexpression and increased resistance to doxorubicin accumulation and toxicity. These effects were prevented by the co-incubation with the cell-permeating iron salt ferric nitrilotriacetate, which caused an increase of intracellular iron bioavailability, measured as increased activity of the iron regulatory protein-1. Crocidolite, dexrazoxane and hypoxia induce doxorubicin resistance in human malignant mesothelioma cells by increasing hypoxia-inducible factor-1alpha activity, through an iron-sensitive mechanism.


Asunto(s)
Amianto/toxicidad , Resistencia a Antineoplásicos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Mesotelioma/tratamiento farmacológico , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antineoplásicos/farmacología , Asbesto Crocidolita/farmacología , Línea Celular Tumoral , Doxorrubicina/farmacología , Humanos , Hipoxia , Hierro/metabolismo , Pulmón/patología , Razoxano/farmacología
14.
Diabetologia ; 49(5): 1049-63, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16506055

RESUMEN

AIMS/HYPOTHESIS: We previously demonstrated that insulin stimulates vascular endothelial growth factor (VEGF) synthesis and secretion via phosphatidylinositol-3 kinase (PI3-K) and mitogen-activated protein kinase (MAPK) pathways in vascular smooth muscle cells (VSMC) from humans and from insulin-sensitive lean Zucker fa/+ rats. We also showed that this effect is attenuated in VSMC from insulin-resistant obese Zucker fa/fa rats. As it is not known whether the effects of insulin on VEGF involve activation of hypoxia-inducible factor-1 (HIF-1), we aimed to evaluate: (1) whether insulin modulates HIF-1alpha protein synthesis and activity; (2) the insulin signalling pathways involved; and (3) the role of insulin resistance. METHODS: Using aortic VSMC taken from humans and Zucker rats and cultured in normoxia, the following were evaluated: (1) dose-dependent (0.5, 1, 2 nmol/l) and time-dependent (2, 4, 6 h) effects exerted by insulin on HIF-1alpha content in both nucleus and cytosol, measured by Western blots; (2) insulin effects on HIF-1 DNA-binding activity on the VEGF gene, measured by electrophoretic mobility shift assay; and (3) involvement of the insulin signalling molecules in these insulin actions, by using the following inhibitors: LY294002 (PI3-K), PD98059 (extracellular signal regulated kinase [ERK]), SP600125 (Jun N terminal kinase [JNK]), SB203580 (p38 mitogen-activated protein kinase) and rapamycin (mammalian target of rapamycin), and by detecting the insulin signalling molecules by Western blots. RESULTS: In aortic VSMC from humans and Zucker fa/+ rats cultured in normoxia insulin increases the HIF-1alpha content in cytosol and nucleus via dose- and time-dependent mechanisms, and HIF-1 DNA-binding activity on the VEGF gene. The insulin-induced increase of HIF-1alpha is blunted by the translation inhibitor cycloheximide, LY294002, PD98059, SP600125 and rapamycin, but not by SB203580. It is also reduced in Zucker fa/fa rats, which present an impaired ability of insulin to induce Akt, ERK-1/2 and JNK-1/2 phosphorylation. CONCLUSIONS/INTERPRETATION: These results provide a biological mechanism for the impaired collateral vessel formation in obesity.


Asunto(s)
Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Resistencia a la Insulina/fisiología , Insulina/farmacología , Insulina/fisiología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Músculo Liso Vascular/fisiología , Fosfatidilinositol 3-Quinasas/metabolismo , Animales , Inhibidores Enzimáticos/farmacología , Humanos , Imidazoles/farmacología , Cinética , Músculo Liso Vascular/efectos de los fármacos , Piridinas/farmacología , Ratas , Ratas Zucker , Transducción de Señal/fisiología
15.
Arterioscler Thromb Vasc Biol ; 23(12): 2215-21, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14615391

RESUMEN

OBJECTIVE: In cultured human vascular smooth muscle cells, insulin increases cyclic GMP production by inducing nitric oxide (NO) synthesis. The aim of the present study was to determine whether in these cells the insulin-stimulated NO/cyclic GMP pathway plays a role in the regulation of glucose uptake. METHODS AND RESULTS: Glucose transport in human vascular smooth muscle cells was measured as uptake of 2-deoxy-d-[3H]glucose, cyclic GMP synthesis was checked by radioimmunoassay, and GLUT4 recruitment into the plasma membrane was determined by immunofluorescence. Insulin-stimulated glucose transport and GLUT4 recruitment were blocked by an inhibitor of NO synthesis and mimicked by NO-releasing drugs. Insulin- and NO-elicited glucose uptake were blocked by inhibitors of soluble guanylate cyclase and cyclic GMP-dependent protein kinase; furthermore, glucose transport was stimulated by an analog of cyclic GMP. CONCLUSIONS: Our results suggest that insulin-elicited glucose transport (and the corresponding GLUT4 recruitment into the plasma membrane) in human vascular smooth muscle cells is mediated by an increased synthesis of NO, which stimulates the production of cyclic GMP and the subsequent activation of a cyclic GMP-dependent protein kinase.


Asunto(s)
GMP Cíclico/metabolismo , Glucosa/metabolismo , Insulina/fisiología , Proteínas Musculares , Músculo Liso Vascular/fisiología , Óxido Nítrico/fisiología , Transducción de Señal/fisiología , Transporte Biológico , Membrana Celular/química , Membrana Celular/enzimología , Membrana Celular/metabolismo , Células Cultivadas , Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Técnica del Anticuerpo Fluorescente , Transportador de Glucosa de Tipo 4 , Guanilato Ciclasa/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Proteínas de Transporte de Monosacáridos/inmunología , Proteínas de Transporte de Monosacáridos/metabolismo , Proteínas de Transporte de Monosacáridos/fisiología , Músculo Liso Vascular/química , Músculo Liso Vascular/citología , Músculo Liso Vascular/enzimología , Óxido Nítrico/biosíntesis
16.
Ann Ig ; 15(4): 383-91, 2003.
Artículo en Italiano | MEDLINE | ID: mdl-14552204

RESUMEN

"Federico II" University of Naples Hospital Management's Staff considered 47 informed consent forms in order to evaluate quality and quantity of the information transmitted to patients. Every form, distinguished by procedure (surgical, pharmacological, anesthesiologic or related to blood transfusions) was evaluated for the accuracy and validity of information related to: diagnosis, prognosis, diagnostic and therapeutic opportunities, expected benefits, adverse-side effects, iatrogenic risks, privacy policy on personal data. The forms were judged by information completeness criteria "conformed" or "not conformed" with standards. Our analysis demonstrate that physicians often are unaware of legal and ethical topics related to constructing informed consent forms. They usually omit crucial information or would use strict technical language. So far, we conclude Hospital Management's Staff definitively has a role in improving informed consent forms by establishing guidelines and promoting ethical issues. Final result could be to deserve stronger patient confidence in medical institutions.


Asunto(s)
Formularios de Consentimiento , Consentimiento Informado , Médicos/psicología , Adulto , Formularios de Consentimiento/legislación & jurisprudencia , Formularios de Consentimiento/normas , Formularios de Consentimiento/estadística & datos numéricos , Control de Formularios y Registros/legislación & jurisprudencia , Adhesión a Directriz/estadística & datos numéricos , Guías como Asunto , Conocimientos, Actitudes y Práctica en Salud , Hospitales Universitarios/organización & administración , Hospitales Universitarios/estadística & datos numéricos , Humanos , Consentimiento Informado/legislación & jurisprudencia , Consentimiento Informado/normas , Italia , Registros Médicos/normas , Registros Médicos/estadística & datos numéricos
17.
Acta bioquím. clín. latinoam ; Acta bioquím. clín. latinoam;31(4): 407-13, dic. 1997. ilus
Artículo en Español | LILACS | ID: lil-217044

RESUMEN

El propósito de este trabajo fue determinar la utilidad de la heptoglobina (HP), a1-antitripsina (a1-AT), transferrina (TRF) y pre-albúmina (PA) en el SIDA pediátrico como marcadores de progresión de enfermedad. En este estudio, se utilizó la clasificación del Centro de Control y Prevención de Enfermedades (CDC), 1994. Para evaluar el comportamiento de estas proteínas en relación a los principales parámetros usados en esta clasificación, es decir la sintomatología clínica y el grado de compromiso inmunológico, los pacientes se reagruparon de acuerdo a estos parámetros en dos categorías: considerando la sintomatología clínica (N-A-B-C), y de acuerdo al grado de compromiso inmunológico (EI 1- EI 2- EI 3). Hp, a1-AT, TRF y PA son proteínas sintetizadas en el hígado. La HP y la a1-AT, pertenecientes a las proteínas reactantes de fase aguda, aumentan significativamente sus niveles plasmáticos en la inflamación e infección mientras que la TRF y la PA, proteínas de vida media corta, disminuyen sus niveles en diversas enfermedades hepáticas. Se estudiaron 53 niños infectados por el virus HIV, 27 niños y 26 niñas con edades comprendidas entre 2 meses y 10 años y 30 niños sanos como controles (Co). Dentro de la categoría clínica, los niveles de todas las proteínas estudiadas fueron similares (p > 0,05) entre los distintos grupos de pacientes HIV y los controles. Sin embargo, de acuerdo al grado de compromiso inmunológico, se observó una disminución significativa (p < 0,05) en los niveles plasmáticos de HP en pacientes HIV con evidencias de inmunosupresión severa (EI 3) con respecto a pacientes HIV con evidencia de inmunosupresión moderada (EI 2) y a los controles (EI 3: n = 8 x ñ ES = 77 ñ 25; EI 2: n = 23, x ñ ES = 193 ñ 19; Co: n = 30, x ñ ES = 193 ñ 90 mg por ciento). Por otro lado, se observó un aumento significativo (p < 0,05) en los niveles de a1-AT en EI 2 con respecto a los pacientes HIV- sin compromiso inmunológico (EI 1) y a los controles, manteniéndose dichos niveles en EI 3 (EI 3: n = 8, x ñ ES = 404 + 34; EI 2: n = 23, x ñ ES = 353 ñ 24; EI 1: n = 22, x ñ ES = 277 ñ 33; Co: n = 30, x ñ ES = 260 ñ 80 mg por ciento). Contrariamente, los niveles plasmáticos de TRF y PA fueron similares entre los distintos grupos de la categoría inmunológica...


Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , alfa 1-Antitripsina , Haptoglobinas , Prealbúmina , Progresión de la Enfermedad , Síndrome de Inmunodeficiencia Adquirida/diagnóstico , Transferrina , Biomarcadores/sangre , Síndrome de Inmunodeficiencia Adquirida/clasificación
18.
Int J Pediatr Otorhinolaryngol ; 39(2): 103-10, 1997 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-9104618

RESUMEN

Children, 36, predisposed to frequent upper respiratory infections were treated with endonasal administration of an IgA enriched preparation or placebo in a randomized double blind trial. We found a reduction in the number of infectious episodes and in the number of enlarged regional lymph nodes. Also, an increase of IgA levels in saliva in the treated group was observed, probably not only due to the effect of IgA supplementation, but also to an immunoregulatory effect on the mucosa caused by the preparation administered. We found this therapy very useful in the prophylaxis of upper respiratory infections, being the nasal administration very convenient to be used in children.


Asunto(s)
Inmunoglobulina A/uso terapéutico , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/prevención & control , Niño , Preescolar , Método Doble Ciego , Femenino , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina A/sangre , Inmunoglobulina A/farmacología , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Ganglios Linfáticos/efectos de los fármacos , Masculino , Mucosa Nasal/efectos de los fármacos , Saliva/química
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