525 research outputs found

    GNAS1 T393C polymorphism and disease progression in patients with malignant melanoma

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    <p>Abstract</p> <p>Background</p> <p>Once metastasized, despite a variety of therapeutic options, the prognosis of patients with malignant melanoma (MM) is still poor. Therefore, the search for reliable markers to identify patients with high risk of disease progression is of high clinical importance. We have recently shown that TT genotypes of the single-nucleotide polymorphism (SNP) T393C in the gene <it>GNAS1 </it>are significantly associated with better outcome in a variety of carcinomas.</p> <p>Patients</p> <p>In the present study we assessed whether the T393C SNP is also related to the clinical course in MM. 328 patients with MM were retrospectively genotyped and genotypes were correlated with clinical outcome.</p> <p>Results</p> <p>While the allele frequency in the MM group (fC 0.52) did not significantly differ from that of healthy blood donors, the T393C SNP was associated with tumor progression of MM. Carriers of the C-allele showed a significantly more severe tumor progression as estimated from the time period to develop metastasis (HR 2.2, 95% CI 1.1-3.2, p = 0.017). Proportions of 5-year metastasis-free intervals were 87.1% for TT genotypes and 66.0% for C-allele carriers. Moreover, multivariable Cox regression analysis including tumor stage and melanoma subtype proved the T393C polymorphism to be an independent factor for metastasis (p = 0.012).</p> <p>Conclusions</p> <p>In summary, the <it>GNAS1 </it>T393C SNP represents a genetic host factor for predicting tumor progression also in patients with MM; genotyping of this SNP may contribute to better define patients who could benefit from an early individualized therapy.</p

    RNA:protein ratio of the unicellular organism as a characteristic of phosphorous and nitrogen stoichiometry and of the cellular requirement of ribosomes for protein synthesis

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    Background Mean phosphorous:nitrogen (P:N) ratios and relationships of P:N ratios with the growth rate of organisms indicate a surprising similarity among and within microbial species, plants, and insect herbivores. To reveal the cellular mechanisms underling this similarity, the macromolecular composition of seven microorganisms and the effect of specific growth rate (SGR) on RNA:protein ratio, the number of ribosomes, and peptide elongation rate (PER) were analyzed under different conditions of exponential growth. Results It was found that P:N ratios calculated from RNA and protein contents in these particular organisms were in the same range as the mean ratios reported for diverse organisms and had similar positive relationships with growth rate, consistent with the growth-rate hypothesis. The efficiency of protein synthesis in microorganisms is estimated as the number of active ribosomes required for the incorporation of one amino acid into the synthesized protein. This parameter is calculated as the SGR:PER ratio. Experimental and theoretical evidence indicated that the requirement of ribosomes for protein synthesis is proportional to the RNA:protein ratio. The constant of proportionality had the same values for all organisms, and was derived mechanistically from the characteristics of the protein-synthesis machinery of the cell (the number of nucleotides per ribosome, the average masses of nucleotides and amino acids, the fraction of ribosomal RNA in the total RNA, and the fraction of active ribosomes). Impairment of the growth conditions decreased the RNA:protein ratio and increased the overall efficiency of protein synthesis in the microorganisms. Conclusion Our results suggest that the decrease in RNA:protein and estimated P:N ratios with decrease in the growth rate of the microorganism is a consequence of an increased overall efficiency of protein synthesis in the cell resulting from activation of the general stress response and increased transcription of cellular maintenance genes at the expense of growth related genes. The strong link between P:N stoichiometry, RNA:protein ratio, ribosomal requirement for protein synthesis, and growth rate of microorganisms indicated by the study could be used to characterize the N and P economy of complex ecosystems such as soils and the oceans

    Pediatric Differentiated Thyroid Carcinoma in The Netherlands: A Nationwide Follow-Up Study

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    Introduction: Treatment for differentiated thyroid carcinoma (DTC) in pediatric patients is based mainly on evidence from adult series due to lack of data from pediatric cohorts. Our objective was to evaluate presentation, treatment-related complications, and long-term outcome in patients with pediatric DTC in the Netherlands. Patients and methods: In this nationwide study, presentation, complications and outcome of patients with pediatric DTC (age at diagnosis ≤18 years) treated in the Netherlands between 1970 and 2013 were assessed using medical records. Results: We identified 170 patients. Overall survival was 99.4% after median follow-up of 13.5 (range 0.3–44.7) years. Extensive follow-up data were available for 105 patients (83.8% women), treated in 39 hospitals. Median age at diagnosis was 15.6 (range 5.8–18.9) years. At initial diagnosis, 43.8% of the patients had cervical lymph node metastases; 13.3% had distant metastases. All patients underwent total thyroidectomy. Radioiodine was administered to 97.1%, with a median cumulative activity of 5.66 (range 0.74–35.15) GBq. Lifelong postoperative complications (permanent hypoparathyroidism and/or recurrent laryngeal nerve injury) were present in 32.4% of the patients. At last known follow-up, 8.6% of the patients had persistent disease and 7.6% experienced a recurrence. TSH suppression was not associated with recurrences (OR 2.00, 95% CI 0.78 to 5.17, P = 0.152). Conclusions: Survival of pediatric DTC is excellent. Therefore, minimizing treatment-related morbidity takes major priority. Our study shows a frequent occurrence of lifelong postoperative complications. Adverse effects may be reduced by centralization of care, which is crucial for children with DTC

    QPRT: a potential marker for follicular thyroid carcinoma including minimal invasive variant; a gene expression, RNA and immunohistochemical study

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    Background The differential diagnosis between follicular thyroid adenoma and minimal invasive follicular thyroid carcinoma is often difficult for several reasons. One major aspect is the lack of typical cytological criteria in well differentiated specimens. New marker molecules, shown by poly- or monoclonal antibodies proved helpful. Methods We performed global gene expression analysis of 12 follicular thyroid tumours (4 follicular adenomas, 4 minimal invasive follicular carcinomas and 4 widely invasive follicular carcinomas), followed by immunohistochemical staining of 149 cases. The specificity of the antibody was validated by western blot analysis Results In gene expression analysis QPRT was detected as differently expressed between follicular thyroid adenoma and follicular thyroid carcinoma. QPRT protein could be detected by immunohistochemistry in 65% of follicular thyroid carcinomas including minimal invasive variant and only 22% of follicular adenomas. Conclusion Consequently, QPRT is a potential new marker for the immunohistochemical screening of follicular thyroid nodules

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

    Fission of Tubular Endosomes Triggers Endosomal Acidification and Movement

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    The early endosome acts as a sorting station for internalized molecules destined for recycling or degradation. While recycled molecules are sorted and delivered to tubular endosomes, residual compartments containing molecules to be degraded undergo “maturation” before final degradation in the lysosome. This maturation involves acidification, microtubule-dependent motility, and perinuclear localization. It is currently unknown how sorting and the processes of maturation cooperate with each other. Here, we show that fission of a tubular endosome triggers the maturation of the residual endosome, leading to degradation. Use of the dynamin inhibitor dynasore to block tubular endosome fission inhibited acidification, endosomal motility along microtubules, perinuclear localization, and degradation. However, tubular endosome fission was not affected by inhibiting endosomal acidification or by depolymerizing the microtubules. These results demonstrate that the fission of recycling tubules is the first important step in endosomal maturation and degradation in the lysosome. We believe this to be the first evidence of a cascade from sorting to degradation

    Quantification of SLIT-ROBO transcripts in hepatocellular carcinoma reveals two groups of genes with coordinate expression

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    <p>Abstract</p> <p>Background</p> <p>SLIT-ROBO families of proteins mediate axon pathfinding and their expression is not solely confined to nervous system. Aberrant expression of <it>SLIT-ROBO </it>genes was repeatedly shown in a wide variety of cancers, yet data about their collective behavior in hepatocellular carcinoma (HCC) is missing. Hence, we quantified <it>SLIT-ROBO </it>transcripts in HCC cell lines, and in normal and tumor tissues from liver.</p> <p>Methods</p> <p>Expression of <it>SLIT-ROBO </it>family members was quantified by real-time qRT-PCR in 14 HCC cell lines, 8 normal and 35 tumor tissues from the liver. ANOVA and Pearson's correlation analyses were performed in R environment, and different clinicopathological subgroups were pairwise compared in Minitab. Gene expression matrices of cell lines and tissues were analyzed by Mantel's association test.</p> <p>Results</p> <p>Genewise hierarchical clustering revealed two subgroups with coordinate expression pattern in both the HCC cell lines and tissues: <it>ROBO1</it>, <it>ROBO2</it>, <it>SLIT1 </it>in one cluster, and <it>ROBO4</it>, <it>SLIT2</it>, <it>SLIT3 </it>in the other, respectively. Moreover, <it>SLIT-ROBO </it>expression predicted <it>AFP</it>-dependent subgrouping of HCC cell lines, but not that of liver tissues. <it>ROBO1 </it>and <it>ROBO2 </it>were significantly up-regulated, whereas <it>SLIT3 </it>was significantly down-regulated in cell lines with high-<it>AFP </it>background. When compared to normal liver tissue, <it>ROBO1 </it>was found to be significantly overexpressed, while <it>ROBO4 </it>was down-regulated in HCC. We also observed that <it>ROBO1 </it>and <it>SLIT2 </it>differentiated histopathological subgroups of liver tissues depending on both tumor staging and differentiation status. However, <it>ROBO4 </it>could discriminate poorly differentiated HCC from other subgroups.</p> <p>Conclusion</p> <p>The present study is the first in comprehensive and quantitative evaluation of <it>SLIT-ROBO </it>family gene expression in HCC, and suggests that the expression of <it>SLIT-ROBO </it>genes is regulated in hepatocarcinogenesis. Our results implicate that <it>SLIT-ROBO </it>transcription profile is bi-modular in nature, and that each module shows intrinsic variability. We also provide quantitative evidence for potential use of <it>ROBO1</it>, <it>ROBO4 </it>and <it>SLIT2 </it>for prediction of tumor stage and differentiation status.</p

    Stage-Specific Effects of Candidate Heterochronic Genes on Variation in Developmental Time along an Altitudinal Cline of Drosophila melanogaster

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    Background: Previously, we have shown there is clinal variation for egg-to-adult developmental time along geographic gradients in Drosophila melanogaster. Further, we also have identified mutations in genes involved in metabolic and neurogenic pathways that affect development time (heterochronic genes). However, we do not know whether these loci affect variation in developmental time in natural populations. Methodology/Principal Findings: Here, we constructed second chromosome substitution lines from natural populations of Drosophila melanogaster from an altitudinal cline, and measured egg-adult development time for each line. We found not only a large amount of genetic variation for developmental time, but also positive associations of the development time with thermal amplitude and altitude. We performed genetic complementation tests using substitution lines with the longest and shortest developmental times and heterochronic mutations. We identified segregating variation for neurogenic and metabolic genes that largely affected the duration of the larval stages but had no impact on the timing of metamorphosis. Conclusions/Significance: Altitudinal clinal variation in developmental time for natural chromosome substitution lines provides a unique opportunity to dissect the response of heterochronic genes to environmental gradients. Ontogenetic stage-specific variation in invected, mastermind, cricklet and CG14591 may affect natural variation in development time an

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Novel germline variants identified in the inner mitochondrial membrane transporter TIMM44 and their role in predisposition to oncocytic thyroid carcinomas

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    Familial Non-Medullary Thyroid Carcinoma (fNMTC) represents 3–7% of all thyroid tumours and is associated with some of the highest familial risks among all cancers, with an inheritance pattern compatible with an autosomal dominant model with reduced penetrance. We previously mapped a predisposing locus, TCO (Thyroid tumour with Cell Oxyphilia) on chromosome 19p13.2, for a particular form of thyroid tumour characterised by cells with an abnormal proliferation of mitochondria (oxyphilic or oncocytic cells). In the present work, we report the systematic screening of 14 candidate genes mapping to the region of linkage in affected TCO members, that led us to identify two novel variants respectively in exon 9 and exon 13 of TIMM44, a mitochondrial inner membrane translocase for the import in the mitochondria of nuclear-encoded proteins. These variants were co-segregating with the TCO phenotype, were not present in a large group of controls and were predicted to negatively affect the protein (exon 9 change) or the transcript (exon 13 change). Functional analysis was performed in vitro for both changes and although no dramatic loss of function effects were identified for the mutant alleles, subtler effects might still be present that could alter Timm44 function and thus promote oncocytic tumour development. Thus we suggest that TIMM44 should be considered for further studies in independent samples of affected individuals with TCO
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