173 research outputs found

    Posttranslational modification and microtubule stability.

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    Actin and microtubules drive differential aspects of planar cell polarity in multiciliated cells

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    Actin dynamics are required for proper cilia spacing, global coordination of cilia polarity, and coordination of metachronic cilia beating, whereas cytoplasmic microtubule dynamics are required for local coordination of polarity between neighboring cilia

    Methylation screening of the TGFBI promoter in human lung and prostate cancer by methylation-specific PCR

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    <p>Abstract</p> <p>Background</p> <p>Hypermethylation of the <it>TGFBI </it>promoter has been shown to correlate with decreased expression of this gene in human tumor cell lines. In this study, we optimized a methylation-specific polymerase chain reaction (MSP) method and investigated the methylation status of the <it>TGFBI </it>promoter in human lung and prostate cancer specimens.</p> <p>Methods</p> <p>Methylation-specific primers were designed based on the methylation profiles of the <it>TGFBI </it>promoter in human tumor cell lines, and MSP conditions were optimized for accurate and efficient amplification. Genomic DNA was isolated from lung tumors and prostatectomy tissues of prostate cancer patients, bisulfite-converted, and analyzed by MSP.</p> <p>Results</p> <p>Among 50 lung cancer samples, 44.0% (22/50) harbored methylated CpG sites in the <it>TGFBI </it>promoter. An analysis correlating gene methylation status with clinicopathological cancer features revealed that dense methylation of the <it>TGFBI </it>promoter was associated with a metastatic phenotype, with 42.9% (6/14) of metastatic lung cancer samples demonstrating dense methylation vs. only 5.6% (2/36) of primary lung cancer samples (<it>p </it>< 0.05). Similar to these lung cancer results, 82.0% (41/50) of prostate cancer samples harbored methylated CpG sites in the <it>TGFBI </it>promoter, and dense methylation of the promoter was present in 38.9% (7/18) of prostate cancer samples with the feature of locoregional invasiveness vs. only 19.4% (6/31) of prostate cancer samples without locoregional invasiveness (<it>p </it>< 0.05). Furthermore, promoter hypermethylation correlated with highly reduced expression of the <it>TGFBI </it>gene in human lung and prostate tumor cell lines.</p> <p>Conclusion</p> <p>We successfully optimized a MSP method for the precise and efficient screening of <it>TGFBI </it>promoter methylation status. Dense methylation of the <it>TGFBI </it>promoter correlated with the extent of <it>TGFBI </it>gene silencing in tumor cell lines and was related to invasiveness of prostate tumors and metastatic status of lung cancer tumors. Thus, <it>TGFBI </it>promoter methylation can be used as a potential prognostic marker for invasiveness and metastasis in prostate and lung cancer patients, respectively.</p

    FACT - Time-resolved blazar SEDs

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    Blazars are highly variable objects and their spectral energy distribution (SED) features two peaks. The emission at low energies is understood, however, the origin of the emission at TeV energies is strongly debated. While snapshots of SEDs usually can be explained with simple models, the evolution of SEDs challenges many models and allows for conclusions on the emission mechanisms. Leptonic models expect a correlation between the two peaks, while hadronic models can accommodate more complex correlations. To study time-resolved SEDs, we set up a target-of-opportunity program triggering high-resolution X-ray observations based on the monitoring at TeV energies by the First G-APD Cherenkov Telescope (FACT). To search for time lags and identify orphan flares, this is accompanied by X-ray monitoring with the Swift satellite. These observations provide an excellent multi-wavelength (MWL) data sample showing the temporal behaviour of the blazar emission along the electromagnetic spectrum. To constrain the origin of the TeV emission, we extract the temporal evolution of the low energy peak from Swift data and calculate the expected flux at TeV energies using a theoretical model. Comparing this to the flux measured by FACT, we want to conclude on the underlying physics. Results from more than five years of monitoring will be discussed.D. Dorner, J. Adam, M.L. Ahnen, D. Baack, M. Balbo, A. Biland, M. Blank, T. Bretz, a, K. Bruegge, M. Bulinski, J. Buss, A. Dmytriiev, S. Einecke, D. Elsaesser, C. Hempfling, T. Herbst, D. Hildebrand, L. Kortmann, L. Linhoff, M. Mahlke, a, K. Mannheim, S.A. Mueller, D. Neise, A. Neronov, M. Noethe, J. Oberkirch, A. Paravac, F. Pauss, W. Rhode, B. Schleicher, F. Schulz, A. Shukla, V. Sliusar, F. Temme, J. Thaele, R. Walter, FACT Collaboration, A. Kreikenbohm, K. Leite
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