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1.
Mol Ther ; 31(3): 686-700, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36641624

RESUMEN

Several studies have shown the influence of commensal microbes on T cell function, specifically in the setting of checkpoint immunotherapy for cancer. In this study, we investigated how vancomycin-induced gut microbiota dysbiosis affects chimeric antigen receptor (CAR) T immunotherapy using multiple preclinical models as well as clinical correlates. In two murine tumor models, hematopoietic CD19+-A20 lymphoma and CD19+-B16 melanoma, mice receiving vancomycin in combination with CD19-directed CAR T cell (CART-19) therapy displayed increased tumor control and tumor-associated antigens (TAAs) cross-presentation compared with CART-19 alone. Fecal microbiota transplant from human healthy donors to pre-conditioned mice recapitulated the results obtained in naive gut microbiota mice. Last, B cell acute lymphoblastic leukemia patients treated with CART-19 and exposed to oral vancomycin showed higher CART-19 peak expansion compared with unexposed patients. These results substantiate the role of the gut microbiota on CAR T cell therapy and suggest that modulation of the gut microbiota using vancomycin may improve outcomes after CAR T cell therapy across tumor types.


Asunto(s)
Microbioma Gastrointestinal , Receptores Quiméricos de Antígenos , Humanos , Ratones , Animales , Receptores de Antígenos de Linfocitos T/genética , Reactividad Cruzada , Vancomicina/farmacología , Inmunoterapia , Linfocitos T , Inmunoterapia Adoptiva/métodos , Receptores Quiméricos de Antígenos/genética , Antígenos CD19
2.
Chaos ; 33(3): 033108, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37003820

RESUMEN

A deterministic excitation (DE) paradigm is formulated, according to which the abrupt late Pleistocene glacial terminations correspond to the excitation, by the orbital forcing, of nonlinear relaxation oscillations (ROs) internal to the climate system in the absence of any stochastic parameterization. Specific rules are derived from the DE paradigm: they parameterize internal climate feedbacks, which, when activated by the crossing of certain tipping points, excite a RO. Such rules are then applied to the output of an energy-balance model simulating the fluctuations induced by realistic orbital forcing on the glacial state. The timing of the glacial terminations, thus, obtained in a reference simulation is found to be in good agreement with proxy records. A sensitivity analysis insures the robustness of the timing. The potential irrelevance of noise allowing DE to hold is discussed, and a possible explanation of the 100-kyr cycle problem based on DE is outlined. In conclusion, the DE paradigm provides the simplest possible dynamical systems characterization of the link between orbital forcing and glacial terminations implied by the Milankovitch hypothesis.

3.
J Immunol ; 195(8): 4020-7, 2015 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-26378078

RESUMEN

Mitochondria provide energy for cells via oxidative phosphorylation. Reactive oxygen species, a byproduct of this mitochondrial respiration, can damage mitochondrial DNA (mtDNA), and somatic mtDNA mutations have been found in all colorectal, ovarian, breast, urinary bladder, kidney, lung, and pancreatic tumors studied. The resulting altered mitochondrial proteins or tumor-associated mitochondrial Ags (TAMAs) are potentially immunogenic, suggesting that they may be targetable Ags for cancer immunotherapy. In this article, we show that the RENCA tumor cell line harbors TAMAs that can drive an antitumor immune response. We generated a cellular tumor vaccine by pulsing dendritic cells with enriched mitochondrial proteins from RENCA cells. Our dendritic cell-based RENCA mitochondrial lysate vaccine elicited a cytotoxic T cell response in vivo and conferred durable protection against challenge with RENCA cells when used in a prophylactic or therapeutic setting. By sequencing mtDNA from RENCA cells, we identified two mutated molecules: COX1 and ND5. Peptide vaccines generated from mitochondrial-encoded COX1 but not from ND5 had therapeutic properties similar to RENCA mitochondrial protein preparation. Thus, TAMAs can elicit effective antitumor immune responses, potentially providing a new immunotherapeutic strategy to treat cancer.


Asunto(s)
Antígenos de Neoplasias/inmunología , Vacunas contra el Cáncer/inmunología , Carcinoma de Células Renales/prevención & control , Ciclooxigenasa 1/inmunología , Neoplasias Renales/prevención & control , Proteínas de la Membrana/inmunología , Proteínas Mitocondriales/inmunología , NADH Deshidrogenasa/inmunología , Neoplasias Experimentales/prevención & control , Animales , Antígenos de Neoplasias/farmacología , Vacunas contra el Cáncer/farmacología , Carcinoma de Células Renales/inmunología , Ciclooxigenasa 1/farmacología , Neoplasias Renales/inmunología , Proteínas de la Membrana/farmacología , Ratones , Ratones Endogámicos BALB C , Proteínas Mitocondriales/farmacología , NADH Deshidrogenasa/farmacología , Neoplasias Experimentales/inmunología
4.
Mar Pollut Bull ; 193: 115259, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37423084

RESUMEN

The high-resolution Campania Regional Ocean Model (CROM), coupled with an online Lagrangian particle tracking algorithm, is used to investigate the horizontal and vertical behavior of different (in terms of size and density) plastic polymer types during February and August 2016 in the Gulf of Naples. The transport of passive particles is evaluated based on the three-dimensional Eulerian velocity fields provided by the ocean model. The virtual particles are released in several hot spot areas in the Gulf of Naples where most of the marine debris is supposed to come from. A sensitivity analysis on the vertical sinking for negatively buoyant particles is carried out. The sinking behavior is determined by the settling velocity, which depends on the physical properties of the individual litter item as well as on the hydrodynamical features of the marine environment. Different numerical experiments are carried out to evaluate the effect of marine dynamics on three-dimensional transport.


Asunto(s)
Monitoreo del Ambiente , Plásticos , Monitoreo del Ambiente/métodos , Fenómenos Físicos
5.
Materials (Basel) ; 16(6)2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36984214

RESUMEN

Nanocrystals' (NCs) band gap can be easily tuned over the infrared range, making them appealing for the design of cost-effective sensors. Though their growth has reached a high level of maturity, their doping remains a poorly controlled parameter, raising the need for post-synthesis tuning strategies. As a result, phototransistor device geometry offers an interesting alternative to photoconductors, allowing carrier density control. Phototransistors based on NCs that target integrated infrared sensing have to (i) be compatible with low-temperature operation, (ii) avoid liquid handling, and (iii) enable large carrier density tuning. These constraints drive the search for innovative gate technologies beyond traditional dielectric or conventional liquid and ion gel electrolytes. Here, we explore lithium-ion glass gating and apply it to channels made of HgTe narrow band gap NCs. We demonstrate that this all-solid gate strategy is compatible with large capacitance up to 2 µF·cm-2 and can be operated over a broad range of temperatures (130-300 K). Finally, we tackle an issue often faced by NC-based phototransistors:their low absorption; from a metallic grating structure, we combined two resonances and achieved high responsivity (10 A·W-1 or an external quantum efficiency of 500%) over a broadband spectral range.

6.
Cancer Res ; 83(21): 3562-3576, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37578274

RESUMEN

Parkin is an E3 ubiquitin ligase, which plays a key role in the development of Parkinson disease. Parkin defects also occur in numerous cancers, and a growing body of evidence indicates that Parkin functions as a tumor suppressor that impedes a number of cellular processes involved in tumorigenesis. Here, we generated murine and human models that closely mimic the advanced-stage tumors where Parkin deficiencies are found to provide deeper insights into the tumor suppressive functions of Parkin. Loss of Parkin expression led to aggressive tumor growth, which was associated with poor tumor antigen presentation and limited antitumor CD8+ T-cell infiltration and activation. The effect of Parkin deficiency on tumor growth was lost following depletion of CD8+ T cells. In line with previous findings, Parkin deficiency was linked with mitochondria-associated metabolic stress, PTEN degradation, and enhanced Akt activation. Increased Akt signaling led to dysregulation of antigen presentation, and treatment with the Akt inhibitor MK2206-2HCl restored antigen presentation in Parkin-deficient tumors. Analysis of data from patients with clear cell renal cell carcinoma indicated that Parkin expression was downregulated in tumors and that low expression correlated with reduced overall survival. Furthermore, low Parkin expression correlated with reduced patient response to immunotherapy. Overall, these results identify a role for Parkin deficiency in promoting tumor immune evasion that may explain the poor prognosis associated with loss of Parkin across multiple types of cancer. SIGNIFICANCE: Parkin prevents immune evasion by regulating tumor antigen processing and presentation through the PTEN/Akt network, which has important implications for immunotherapy treatments in patients with Parkin-deficient tumors.


Asunto(s)
Presentación de Antígeno , Neoplasias , Animales , Humanos , Ratones , Inmunoterapia , Neoplasias/genética , Neoplasias/terapia , Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-akt , Escape del Tumor , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo
7.
Sci Rep ; 12(1): 1375, 2022 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-35082317

RESUMEN

Several ocean Western Boundary Currents (WBCs) encounter a lateral gap along their path. Examples are the Kuroshio Current penetrating into the South China Sea through the Luzon Strait and the Gulf of Mexico Loop Current leaping from the Yucatan peninsula to Florida as part of the Gulf Stream system. Here, we present results on WBC relevant flows, generated in the world's largest rotating platform, where the Earth's sphericity necessary to support WBCs is realized by an equivalent topographic effect. The fluid is put in motion by a pump system, which produces a current that is stationary far from the gap. When the jet reaches the gap entrance, time-dependent patterns with complex spatial structures appear, with the jet leaking, leaping or looping through the gap. The occurrence of these intrinsic self-sustained periodic or aperiodic oscillations depending on current intensity is well known in nonlinear dynamical systems theory and occurs in many real systems. It has been observed here for the first time in real rotating fluid flows and is thought to be highly relevant to explain low-frequency variability in ocean WBCs.

8.
J Phys Chem Lett ; 13(30): 6919-6926, 2022 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-35867700

RESUMEN

While HgTe nanocrystals (NCs) in the mid-infrared region have reached a high level of maturity, their far-infrared counterparts remain far less studied, raising the need for an in-depth investigation of the material before efficient device integration can be considered. Here, we explore the effect of temperature and pressure on the structural, spectroscopic, and transport properties of HgTe NCs displaying an intraband absorption at 10 THz. The temperature leads to a very weak modulation of the spectrum as opposed to what was observed for strongly confined HgTe NCs. HgTe NC films present ambipolar conduction with a clear prevalence of electron conduction as confirmed by transistor and thermoelectric measurements. Under the application of pressure, the material undergoes phase transitions from the zinc blende to cinnabar phase and later to the rock salt phase which we reveal using joint X-ray diffraction and infrared spectroscopy measurements. We discuss how the pressure existence domain of each phase is affected by the particle size.

9.
Sci Rep ; 11(1): 11126, 2021 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-34045519

RESUMEN

Numerous systems in the climate sciences and elsewhere are excitable, exhibiting coexistence of and transitions between a basic and an excited state. We examine the role of tipping between two such states in an excitable low-order ocean model. Ensemble simulations are used to obtain the model's pullback attractor (PBA) and its properties, as a function of a forcing parameter [Formula: see text] and of the steepness [Formula: see text] of a climatological drift in the forcing. The tipping time [Formula: see text] is defined as the time at which the transition to relaxation oscillations (ROs) arises: at constant forcing this occurs at [Formula: see text]. As the steepness [Formula: see text] decreases, [Formula: see text] is delayed and the corresponding forcing amplitude decreases, while remaining always above [Formula: see text]. With periodic perturbations, that amplitude depends solely on [Formula: see text] over a significant range of parameters: this provides an example of rate-induced tipping in an excitable system. Nonlinear resonance occurs for periods comparable to the RO time scale. Coexisting PBAs and total independence from initial states are found for subsets of parameter space. In the broader context of climate dynamics, the parameter drift herein stands for the role of anthropogenic forcing.

10.
J Immunother Cancer ; 9(2)2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33563772

RESUMEN

BACKGROUND: Tumor endothelial marker 1 (TEM1) is a protein expressed in the tumor-associated endothelium and/or stroma of various types of cancer. We previously demonstrated that immunization with a plasmid-DNA vaccine targeting TEM1 reduced tumor progression in three murine cancer models. Radiation therapy (RT) is an established cancer modality used in more than 50% of patients with solid tumors. RT can induce tumor-associated vasculature injury, triggering immunogenic cell death and inhibition of the irradiated tumor and distant non-irradiated tumor growth (abscopal effect). Combination treatment of RT with TEM1 immunotherapy may complement and augment established immune checkpoint blockade. METHODS: Mice bearing bilateral subcutaneous CT26 colorectal or TC1 lung tumors were treated with a novel heterologous TEM1-based vaccine, in combination with RT, and anti-programmed death-ligand 1 (PD-L1) antibody or combinations of these therapies, tumor growth of irradiated and abscopal tumors was subsequently assessed. Analysis of tumor blood perfusion was evaluated by CD31 staining and Doppler ultrasound imaging. Immunophenotyping of peripheral and tumor-infiltrating immune cells as well as functional analysis was analyzed by flow cytometry, ELISpot assay and adoptive cell transfer (ACT) experiments. RESULTS: We demonstrate that addition of RT to heterologous TEM1 vaccination reduces progression of CT26 and TC1 irradiated and abscopal distant tumors as compared with either single treatment. Mechanistically, RT increased major histocompatibility complex class I molecule (MHCI) expression on endothelial cells and improved immune recognition of the endothelium by anti-TEM1 T cells with subsequent severe vascular damage as measured by reduced microvascular density and tumor blood perfusion. Heterologous TEM1 vaccine and RT combination therapy boosted tumor-associated antigen (TAA) cross-priming (ie, anti-gp70) and augmented programmed cell death protein 1 (PD-1)/PD-L1 signaling within CT26 tumor. Blocking the PD-1/PD-L1 axis in combination with dual therapy further increased the antitumor effect and gp70-specific immune responses. ACT experiments show that anti-gp70 T cells are required for the antitumor effects of the combination therapy. CONCLUSION: Our findings describe novel cooperative mechanisms between heterologous TEM1 vaccination and RT, highlighting the pivotal role that TAA cross-priming plays for an effective antitumor strategy. Furthermore, we provide rationale for using heterologous TEM1 vaccination and RT as an add-on to immune checkpoint blockade as triple combination therapy into early-phase clinical trials.


Asunto(s)
Antígenos CD/metabolismo , Neoplasias Colorrectales/terapia , Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Neoplasias Pulmonares/terapia , Proteínas de Neoplasias/metabolismo , Vacunas de ADN/administración & dosificación , Adenoviridae/genética , Animales , Vacunas contra el Cáncer/administración & dosificación , Vacunas contra el Cáncer/farmacología , Línea Celular Tumoral , Neoplasias Colorrectales/diagnóstico por imagen , Terapia Combinada , Inhibidores de Puntos de Control Inmunológico/farmacología , Neoplasias Pulmonares/diagnóstico por imagen , Ratones , Hipofraccionamiento de la Dosis de Radiación , Resultado del Tratamiento , Ultrasonografía Doppler , Vacunas de ADN/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
11.
JCI Insight ; 5(16)2020 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-32814714

RESUMEN

Granulosa cell tumors (GCT) are rare ovarian malignancies. Due to the lack of effective treatment in late relapse, there is a clear unmet need for novel therapies. Forkhead Box L2 (FOXL2) is a protein mainly expressed in granulosa cells (GC) and therefore is a rational therapeutic target. Since we identified tumor infiltrating lymphocytes (TILs) as the main immune population within GCT, TILs from 11 GCT patients were expanded, and their phenotypes were interrogated to determine that T cells acquired late antigen-experienced phenotypes and lower levels of PD1 expression. Importantly, TILs maintained their functionality after ex vivo expansion as they vigorously reacted against autologous tumors (100% of patients) and against FOXL2 peptides (57.1% of patients). To validate the relevance of FOXL2 as a target for immune therapy, we developed a plasmid DNA vaccine (FoxL2-tetanus toxin; FoxL2-TT) by fusing Foxl2 cDNA with the immune-enhancing domain of TT. Mice immunization with FoxL2-TT controlled growth of FOXL2-expressing ovarian (BR5) and breast (4T1) cancers in a T cell-mediated manner. Combination of anti-PD-L1 with FoxL2-TT vaccination further reduced tumor progression and improved mouse survival without affecting the female reproductive system and pregnancy. Together, our results suggest that FOXL2 immune targeting can produce substantial long-term clinical benefits. Our study can serve as a foundation for trials testing immunotherapeutic approaches in patients with ovarian GCT.


Asunto(s)
Vacunas contra el Cáncer/farmacología , Proteína Forkhead Box L2/inmunología , Tumor de Células de la Granulosa/inmunología , Linfocitos Infiltrantes de Tumor/patología , Adulto , Animales , Vacunas contra el Cáncer/inmunología , Línea Celular Tumoral , Epítopos , Femenino , Proteína Forkhead Box L2/genética , Proteína Forkhead Box L2/metabolismo , Tumor de Células de la Granulosa/patología , Tumor de Células de la Granulosa/terapia , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Tolerancia Inmunológica/efectos de los fármacos , Linfocitos Infiltrantes de Tumor/inmunología , Ratones Endogámicos , Persona de Mediana Edad , Embarazo , Receptor de Muerte Celular Programada 1/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Microambiente Tumoral , Vacunas de ADN/inmunología , Vacunas de ADN/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
12.
J Clin Invest ; 130(1): 466-479, 2020 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-31815742

RESUMEN

Alterations in gut microbiota impact the pathophysiology of several diseases, including cancer. Radiotherapy (RT), an established curative and palliative cancer treatment, exerts potent immune modulatory effects, inducing tumor-associated antigen (TAA) cross-priming with antitumor CD8+ T cell elicitation and abscopal effects. We tested whether the gut microbiota modulates antitumor immune response following RT distal to the gut. Vancomycin, an antibiotic that acts mainly on gram-positive bacteria and is restricted to the gut, potentiated the RT-induced antitumor immune response and tumor growth inhibition. This synergy was dependent on TAA cross presentation to cytolytic CD8+ T cells and on IFN-γ. Notably, butyrate, a metabolite produced by the vancomycin-depleted gut bacteria, abrogated the vancomycin effect. In conclusion, depletion of vancomycin-sensitive bacteria enhances the antitumor activity of RT, which has important clinical ramifications.


Asunto(s)
Presentación de Antígeno/efectos de la radiación , Antígenos de Neoplasias/inmunología , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/inmunología , Microbioma Gastrointestinal , Neoplasias Experimentales , Animales , Presentación de Antígeno/genética , Antígenos de Neoplasias/genética , Butiratos/inmunología , Linfocitos T CD8-positivos/patología , Células Dendríticas/patología , Femenino , Microbioma Gastrointestinal/inmunología , Microbioma Gastrointestinal/efectos de la radiación , Ratones , Ratones Noqueados , Neoplasias Experimentales/genética , Neoplasias Experimentales/inmunología , Neoplasias Experimentales/patología , Neoplasias Experimentales/radioterapia
13.
JCI Insight ; 3(4)2018 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-29467322

RESUMEN

Adoptive T cell therapy (ACT) is a promising new modality for malignancies. Here, we report that adoptive T cell efficacy in tumor-bearing mice is significantly affected by differences in the native composition of the gut microbiome or treatment with antibiotics, or by heterologous fecal transfer. Depletion of bacteria with vancomycin decreased the rate of tumor growth in mice from The Jackson Laboratory receiving ACT, whereas treatment with neomycin and metronidazole had no effect, indicating the role of specific bacteria in host response. Vancomycin treatment induced an increase in systemic CD8α+ DCs, which sustained systemic adoptively transferred antitumor T cells in an IL-12-dependent manner. In subjects undergoing allogeneic hematopoietic cell transplantation, we found that oral vancomycin also increased IL-12 levels. Collectively, our findings demonstrate an important role played by the gut microbiota in the antitumor effectiveness of ACT and suggest potentially new avenues to improve response to ACT by altering the gut microbiota.


Asunto(s)
Células Dendríticas/inmunología , Microbioma Gastrointestinal/inmunología , Trasplante de Células Madre Hematopoyéticas , Interacciones Microbiota-Huesped/inmunología , Inmunoterapia Adoptiva/métodos , Interleucina-12/inmunología , Neoplasias/terapia , Adulto , Anciano , Animales , Bacterias/efectos de los fármacos , Bacterias/genética , Bacterias/inmunología , Bacterias/aislamiento & purificación , Antígenos CD8/inmunología , Antígenos CD8/metabolismo , Línea Celular Tumoral/trasplante , Estudios de Cohortes , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Trasplante de Microbiota Fecal , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/genética , Interacciones Microbiota-Huesped/efectos de los fármacos , Humanos , Interleucina-12/antagonistas & inhibidores , Interleucina-12/genética , Interleucina-12/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Neomicina/administración & dosificación , Neoplasias/inmunología , Neoplasias/microbiología , Linfocitos T/inmunología , Linfocitos T/trasplante , Resultado del Tratamiento , Vancomicina/administración & dosificación
15.
Oncoimmunology ; 6(12): e1398878, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29209575

RESUMEN

DNA-based vaccination is a promising approach to cancer immunotherapy. DNA-based vaccines specific for tumor-associated antigens (TAAs) are indeed relatively simple to produce, cost-efficient and well tolerated. However, the clinical efficacy of DNA-based vaccines for cancer therapy is considerably limited by central and peripheral tolerance. During the past decade, considerable efforts have been devoted to the development and characterization of novel DNA-based vaccines that would circumvent this obstacle. In this setting, particular attention has been dedicated to the route of administration, expression of modified TAAs, co-expression of immunostimulatory molecules, and co-delivery of immune checkpoint blockers. Here, we review preclinical and clinical progress on DNA-based vaccines for cancer therapy.

16.
Oncoimmunology ; 6(9): e1326442, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28932632

RESUMEN

Cancer immunotherapy relies upon the ability of T cells to infiltrate tumors. The endothelium constitutes a barrier between the tumor and effector T cells, and the ability to manipulate local vascular permeability could be translated into effective immunotherapy. Here, we show that in the context of adoptive T cell therapy, antitumor T cells, delivered at high enough doses, can overcome the endothelial barrier and infiltrate tumors, a process that requires local production of C3, complement activation on tumor endothelium and release of C5a. C5a, in turn, acts on endothelial cells promoting the upregulation of adhesion molecules and T-cell homing. Genetic deletion of C3 or the C5a receptor 1 (C5aR1), and pharmacological blockade of C5aR1, impaired the ability of T cells to overcome the endothelial barrier, infiltrate tumors, and control tumor progression in vivo, while genetic chimera mice demonstrated that C3 and C5aR1 expression by tumor stroma, and not leukocytes, governs T cell homing, acting on the local endothelium. In vitro, endothelial C3 and C5a expressions were required for endothelial activation by type 1 cytokines. Our data indicate that effective immunotherapy is a consequence of successful homing of T cells in response to local complement activation, which disrupts the tumor endothelial barrier.

17.
Head Neck ; 36(8): 1103-8, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23804521

RESUMEN

BACKGROUND: Laryngeal squamous cell carcinoma (laryngeal SCC) is a frequently occurring cancer of the head and neck area. Epigenetic changes of tumor-related genes contribute to its genesis and progression. METHODS: We assessed promoter methylation status of the selected genes (CDKN2A, MGMT, MLH1, and DAPK) using methylation-sensitive high resolution melting (MS-HRM) in 100 patients with laryngeal SCC and studied the correlations with clinical characteristics. RESULTS: The prevalence of promoter methylation in MGMT, CDKN2A, MLH1, and DAPK was 59 of 97 (60.8%), 46 of 97 (47.4%), 45 of 97 (46.4%), and 41 of 97 patients (42.3%), respectively. Significantly increased methylation of CDKN2A was observed in heavy smokers. Epigenetic inactivation of CDKN2A and MLH1 were found to be associated with lymph node involvement. An inverse correlation was present between MLH1 methylation and alcohol consumption. CONCLUSION: Our results strongly suggest that deregulation of p16-associated, and MLH1-associated pathways, because of promoter hypermethylation, is associated with increased cancer cell migration, tumor invasiveness, and, thus, aggressive phenotype.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Carcinoma de Células Escamosas/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Metilación de ADN , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Proteínas Quinasas Asociadas a Muerte Celular/genética , Neoplasias Laríngeas/genética , Proteínas Nucleares/genética , Proteínas Supresoras de Tumor/genética , Adulto , Anciano , Bulgaria , Carcinoma de Células Escamosas/patología , Femenino , Humanos , Neoplasias Laríngeas/patología , Masculino , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL , Prevalencia , Regiones Promotoras Genéticas
18.
Phys Rev E Stat Nonlin Soft Matter Phys ; 85(2 Pt 2): 027101, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22463358

RESUMEN

A crucial question recently raised in climate dynamics concerns abrupt climate transitions: Are they due to a tipping point (TP) being exceeded, or is fast noisy dynamics the cause of their excitation? In this respect, a case study based on a low-order ocean model is developed to show that in an excitable dynamical system perturbed by noise (a possible climate condition) the TPs may have limited physical meaning, with the coherence resonance mechanism being predominant. The analysis is based on an operational definition of stochastic TP, which accounts for the effect of noise and reconciles formally the TP and coherence resonance views.

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