Modulation of TGF-beta signaling by proinflammatory cytokines in articular chondrocytes.

OBJECTIVE: The normal structure and function of articular cartilage are the result of a precisely balanced interaction between anabolic and catabolic processes. The transforming growth factor-beta (TGF-beta) family of growth factors generally exerts an anabolic or repair response; in contrast, proinflammatory cytokines such as interleukin 1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) exert a strong catabolic effect. Recent evidence has shown that IL-1beta, and TNF-alpha, and the TGF-beta signaling pathways share an antagonistic relationship. The aim of this study was to determine whether the modulation of the response of articular chondrocytes to TGF-beta by IL-1beta or TNF-alpha signaling pathways occurs through regulation of activity and availability of mothers against DPP (Drosophila) human homologue (Smad) proteins. METHODS: Human articular chondrocytes isolated from knee joints from patients with osteoarthritis (OA) or normal bovine chondrocytes were cultured in suspension in poly-(2-hydroxyethyl methacrylate)-coated dishes with either 10% fetal bovine serum media or serum-deprived media 6h before treatment with IL-1beta alone, TNF-alpha alone or IL-1beta followed by TGF-beta. Nuclear extracts were examined by electrophoretic mobility-shift assays (EMSA) for nuclear factor-kappa B (NF-kappaB) and Smad3/4 deoxyribonucleic acid (DNA) binding. Nuclear extracts were also subjected to the TranSignal Protein/DNA array (Panomics, Redwood City, CA) enabling the simultaneous semiquantitative assessment of DNA-binding activity of 54 different transcription factors. Nuclear phospho-Smad2/3 and total Smad7 protein expression in whole cell lysates were studied by Western blot. Cytoplasmic Smad7, type II collagen alpha 1 (COL2A1), aggrecan and SRY-related high mobility group-Box gene 9 (SOX-9) mRNA expression were measured by real-time polymerase chain reaction (PCR). RESULTS: The DNA-binding activity of Smad3/4 in the TranSignal Protein/DNA array was downregulated by TNF-alpha (46%) or IL-1beta treatment (42%). EMSA analysis showed a consistent reduction in Smad3/4 DNA-binding activity in human articular chondrocytes treated with IL-1beta or TNF-alpha. TGF-beta-induced Smad3/4 DNA-binding activity and Smad2/3 phosphorylation were also reduced following pretreatment with IL-1beta in human OA and bovine chondrocytes. Real-time PCR and Western blot analysis showed that IL-1beta partially reversed the TGF-beta stimulation of Smad7 mRNA and protein levels in TGF-beta-treated human OA cells. In contrast, TGF-beta-stimulated COL2A1, aggrecan, and SOX-9 mRNA levels were abrogated by IL-1beta. CONCLUSIONS: IL-1beta or TNF-alpha exerted a suppressive effect on Smad3/4 DNA-binding activity in human articular chondrocytes, as well as on TGF-beta-induced stimulation of Smad3/4 DNA-binding activity and Smad2/3 phosphorylation in human OA and bovine articular chondrocytes. IL-1beta partially reversed the increase in TGF-beta-stimulated Smad7 mRNA or protein levels suggesting that Smad7 may not be involved in the suppression of TGF-beta signaling induced by IL-1beta or TNF-alpha in articular chondrocytes. The balance between the IL-1beta or TNF-alpha and the TGF-beta signaling pathways is crucial for maintenance of articular cartilage homeostasis and its disruption likely plays a substantial role in the pathogenesis of OA

Kinetics of photo-oxidation of nanostructured porous silicon

Durante la recombinación bimolecular de portadores fotogenerados en silicio poroso nanoestructurado, la energía puede relajar en forma no radiativa a través de fluctuaciones de alta energía y corta vida (SLEFs) que provocan movimiento de átomos de hidrógeno presentes en la superficie de los poros, pudiendo incluso exodifundir. Durante estas fluctuaciones se producen además enlaces colgantes que generan estados de defecto, atenuando la luminiscencia del material. La creación de enlaces olgantes, el decaimiento de la fotoluminiscencia y catodoluminiscencia, y la exodifusión de hidrógeno responden a la misma cinética determinada por la existencia de SLEFs. Se muestra que la cinética de foto-oxidación del silicio poroso preparado bajo condiciones de iluminación intensa puede explicarse con un modelo que contempla como factor limitante al cubrimiento superficial con hidrógeno, controlado por SLEFsDuring bimolecular recombination of photogenerated chariers, non radiative energy relaxation can occur in nanostructured porous silicon, through short lived-high energy fluctuations (SLEFs). During these fluctuations, hydrogen atoms present in the pore walls are moved, and hydrogen exodiffusion can also occur. Dangling bonds are also created producing defect states in the gap, which attenuates the porous silicon luminescence. The dangling bond creation, photoluminescence and cathodoluminescence dacay and hdrogen exodifussion show the same kinetics, which is determined by SLEFs existence. In this work we show that the kinetics of photo-oxidationof porous silicon prepared under high illumination conditions can be explained with a model which consider, as the limiting factor, the surface coverage with hydrogen, which is ruled by SLEFsFil: Jimenez, A.. Universidad Autónoma de Puebla. Centro de Investigación en Dispositivos Semiconductores; MéxicoFil: Ruano Sandoval, Gustavo Daniel. Comisión Nacional de Energía Atómica. Gerencia del Area Investigación y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Balseiro). División Colisiones Atómicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Acquaroli, Leandro Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Física del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García Salgado, G.. Universidad Autónoma de Puebla. Centro de Investigación en Dispositivos Semiconductores; MéxicoFil: Ferron, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Física del Litoral; Argentina. Universidad Nacional del Litoral. Facultad de Ingenieria Quimica. Departamento de Materiales; ArgentinaFil: Arce, Roberto Delio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Física del Litoral; Argentina. Universidad Nacional del Litoral. Facultad de Ingenieria Quimica. Departamento de Materiales; ArgentinaFil: Koropecki, Roberto Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Física del Litoral; Argentina. Universidad Nacional del Litoral. Facultad de Ingenieria Quimica. Departamento de Materiales; Argentin

Overview of the predictive value of quantitative 18 FDG PET in head and neck cancer treated with chemoradiotherapy.

18 F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) allows to quantify the metabolic activity of a tumor (glycolysis) and has become a reference tool in oncology for the staging, restaging, radiotherapy planning and monitoring response in many cancers. Quantitative analyses have been introduced in order to overcome some of the limits of the visual methods, allowing an easier and more objective comparison of the inter- and intra-patients variations. The aims of this review were to report available evidences on the clinical value of quantitative PET/CT parameters in HNC. Forty-five studies, for a total of 2928 patients, were analyzed. Most of the data available dealt with the intensity of the metabolism, calculated from the Standard Uptake Value (SUV). Metabolic Tumor Volume (MTV) was well correlated with overall survival and disease free survival, with a higher predictive value than the maximum SUV. Spatial distribution of metabolism and textural analyses seems promising

Transcriptional silencing of the Dickkopfs-3 (Dkk-3) gene by CpG hypermethylation in acute lymphoblastic leukaemia

Dkk-3 is a newly characterised mortalisation-related gene and an antagonist of the Wnt oncogenic signalling pathway whose expression is decreased in a variety of cancer cell lines, suggesting that the Dkk-3 gene, located at chromosome 11p15.1, functions as a tumour suppressor gene. Although 11p15 is a ‘hot spot’ for methylation in acute lymphoblastic leukaemia (ALL), the role of Dkk-3 abnormalities has never been evaluated in this disease. We analysed CpG island methylation of the Dkk-3 promoter in six ALL cell lines and 183 ALL patients. We observed Dkk-3 hypermethylation in all cell lines and in cells from 33% (60/183) of ALL patients. Moreover, Dkk-3 methylation was associated with decreased Dkk-3 mRNA expression and this expression was restored after exposure to the demethylating agent 5-AzaC. Clinical features did not differ between hypermethylated and unmethylated patients. Estimated disease-free survival (DFS) and overall survival at 10 and 11 years, respectively, were 49.8 and 45.6% for normal patients and 10.5 and 15.1% for hypermethylated patients (P¼0.001 and 0.09). Multivariate analysis demonstrated that Dkk-3 methylation was an independent prognostic factor predicting DFS (P¼0.0009). Our data suggest that Dkk-3 methylation occurs at an early stage in ALL pathogenesis and probably influences the clinical behaviour of the disease

Promoter hypermethylation of cancer-related genes: a strong independent prognostic factor in acute lymphoblastic leukemia

Promoter hypermethylation plays an important role in the inactivation of cancerrelated genes. This abnormality occurs early in leukemogenesis and seems to be associated with poor prognosis in acute lymphoblastic leukemia (ALL). To determine the extent of hypermethylation in ALL, we analyzed the methylation status of the CDH1, p73, p16, p15, p57, NES-1, DKK-3, CDH13, p14, TMS-1, APAF-1, DAPK, PARKIN, LATS-1, and PTEN genes in 251 consecutive ALL patients.Atotal of 77.3% of samples had at least 1 gene methylated, whereas 35.9% of cases had 4 or more genes methylated. Clinical features and complete remission rate did not differ among patients without methylated genes, patients with 1 to 3 methylated genes (methylated group A), or patients with more than 3 methylated genes (methylated group B). Estimated disease-free survival (DFS) and overall survival (OS) at 11 years were 75.5% and 66.1%, respectively, for the nonmethylated group; 37.2% and 45.5% for methylated group A; and 9.4% and 7.8% for methylated group B (P < .0001 and P .0004, respectively). Multivariate analysis demonstrated that the methylation profile was an independent prognostic factor in predicting DFS (P < .0001) and OS (P .003). Our results suggest that the methylation profile may be a potential new biomarker of risk prediction in AL

Epigenetic regulation of human cancer/testis antigen gene, HAGE, in chronic myeloid leukemia

Cancer testis antigens (CTA) provide attractive targets for cancer-specific immunotherapy. Although CTA genes are expressed in some normal tissues, such as the testis, this immunologically protected site lacks MHC I expression and as such, does not present self antigens to T cells. To date, CTA genes have been shown to be expressed in a range of solid tumors via demethylation of their promoter CpG islands, but rarely in chronic myeloid leukemia (CML) or other hematologic malignancies

Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia

Aberrant genome-wide hypomethylation is thought to be related to tumorigenesis by promoting genomic instability. Since DNA methylation is considered an important mechanism for the silencingof retroelements, hypomethylation in human tumors may lead to their reactivation. However, the role of DNA hypomethylation in chronic myeloid leukemia (CML) remains to be elucidated. In this study, the methylation status of the LINE-1 (L1) retrotransposon promoter was analysed in CML samples from the chronicphase (CP, n¼140) and the blast crisis (BC, n¼47). L1 hypomethylation was significantly more frequent in BC (74.5%) than in CP (38%) (Po0.0001). Furthermore, L1 hypomethylation led to activation of both ORF1 sense transcription (Po0.0001) and c-MET gene antisense transcription (Po0.0001), and was significantly associated with high levels of BCR–ABL (P¼0.02) and DNMT3b4 (P¼0.001) transcripts. Interestingly, in CP-CML, extensive L1 hypomethylation was associated with poorer prognosis in terms of cytogenetic response to interferon (P¼0.004) or imatinib (P¼0.034) and progression-free survival (P¼0.005). The above results strongly suggest that activation of both sense and antisense transcriptions by aberrant promoter hypomethylation of the L1 elements plays a role in the progression and clinical behavior of the CML

J-PLUS: Detecting and studying extragalactic globular clusters -- the case of NGC 1023

Extragalactic globular clusters (GCs) are key objects for studying the formation and evolution of galaxies. The arrival of wide-field surveys such as the Javalambre Photometric Local Universe Survey (J-PLUS) offers new possibilities for the study of GCs. Nevertheless, GCs are not detected a priori by the data reduction pipeline of J-PLUS and, due to its pixel scale, the standard techniques of GCs detection are challenged. To fill this gap, we develop a semi-automatic pipeline to detect GCs in J-PLUS that can also be adapted to similar surveys. As a case study, we use data from the S0 galaxy NGC 1023 and we also study the stellar population content of GC candidates in the galaxy. To detect GCs, our methodology is based on Source Extractor and does not require a previous filtering or modelling of the host galaxy. We study colors and perform spectral energy distribution (SED) analysis on our final GC candidate catalog to obtain stellar population parameters. In NGC 1023, GCFinder identifies 523 GC candidates. We observe evidence of color bimodality in a few broad-band colors but not on narrow-band colors. The SED analysis reveals a clear metallicity bimodality and we observe that narrow-band filters are very useful to constrain metallicities. We also identified a broad age-metallicity relation as well as a wide metallicity distribution that are evidence that NGC 1023 experienced accretion events in the past. It is the first time this kind of study is performed with J-PLUS data. By detecting GC candidates in wide-field images without modeling the light of the galaxy, GCFinder becomes considerably faster, at a marginal loss of centrally-located GC candidates of about 7 percent. As GCFinder is entirely based on Source Extractor, it could be easily incorporated into automated software handling wide-field surveys.Comment: 21 pages, 19 figures, submitted to A&