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Hutzinger R.,Innsbruck Medical University | Mrazek J.,Innsbruck Medical University | Mrazek J.,University of California at Los Angeles | Vorwerk S.,Febit Biomedical GmbH | Huttenhofer A.,Innsbruck Medical University
RNA Biology | Year: 2010

Epstein-Barr virus (EBV) infection of human B cells requires the presence of non-coding RNAs (ncRNAs), which regulate expression of viral and host genes. To identify differentially expressed regulatory ncRNAs involved in EBV infection, a specialized cDNA library, enriched for ncRNAs derived from EBV-infected cells, was subjected to deep-sequencing. From the deep-sequencing analysis, we generated a custom-designed ncRNA-microchip to investigate differential expression of ncRNA candidates. By this approach, we identified 25 differentially expressed novel host-encoded ncRNA candidates in EBV-infected cells, comprised of six non-repeat-derived and 19 repeat-derived ncRNAs. Upon EBV infection of B cells, we also observed increased expression levels of oncogenic miRNAs mir-221 and mir-222, which might contribute to EBV-related tumorigenesis, as well as decreased expression levels of RNase P RNA, a ribozyme involved in tRNA maturation. Thus, in this study we demonstrate that our ncRNA-microchip approach serves as a powerful tool to identify novel differentially expressed ncRNAs acting as potential regulators of gene expression during EBV infection. © 2010 Landes Bioscience. Source

Patenge N.,University of Rostock | Billion A.,Justus Liebig University | Raasch P.,University of Rostock | Normann J.,University of Rostock | And 6 more authors.
BMC Genomics | Year: 2012

Background+: Small non-coding RNAs (sRNAs) have attracted attention as a new class of gene regulators in both eukaryotes and bacteria. Genome-wide screening methods have been successfully applied in Gram-negative bacteria to identify sRNA regulators. Many sRNAs are well characterized, including their target mRNAs and mode of action. In comparison, little is known about sRNAs in Gram-positive pathogens. In this study, we identified novel sRNAs in the exclusively human pathogen Streptococcus pyogenes M49 (Group A Streptococcus, GAS M49), employing a whole genome intergenic tiling array approach. GAS is an important pathogen that causes diseases ranging from mild superficial infections of the skin and mucous membranes of the naso-pharynx, to severe toxic and invasive diseases.Results: We identified 55 putative sRNAs in GAS M49 that were expressed during growth. Of these, 42 were novel. Some of the newly-identified sRNAs belonged to one of the common non-coding RNA families described in the Rfam database. Comparison of the results of our screen with the outcome of two recently published bioinformatics tools showed a low level of overlap between putative sRNA genes. Previously, 40 potential sRNAs have been reported to be expressed in a GAS M1T1 serotype, as detected by a whole genome intergenic tiling array approach. Our screen detected 12 putative sRNA genes that were expressed in both strains. Twenty sRNA candidates appeared to be regulated in a medium-dependent fashion, while eight sRNA genes were regulated throughout growth in chemically defined medium. Expression of candidate genes was verified by reverse transcriptase-qPCR. For a subset of sRNAs, the transcriptional start was determined by 5' rapid amplification of cDNA ends-PCR (RACE-PCR) analysis.Conclusions: In accord with the results of previous studies, we found little overlap between different screening methods, which underlines the fact that a comprehensive analysis of sRNAs expressed by a given organism requires the complementary use of different methods and the investigation of several environmental conditions. Despite a high conservation of sRNA genes within streptococci, the expression of sRNAs appears to be strain specific. © 2012 Patenge et al.; licensee BioMed Central Ltd. Source

Meder B.,University of Heidelberg | Haas J.,University of Heidelberg | Keller A.,Biomarker Discovery Center | Heid C.,University of Heidelberg | And 13 more authors.
Circulation: Cardiovascular Genetics | Year: 2011

Background: Today, mutations in more than 30 different genes have been found to cause inherited cardiomyopathies, some associated with very poor prognosis. However, because of the genetic heterogeneity and limitations in throughput and scalability of current diagnostic tools up until now, it is hardly possible to genetically characterize patients with cardiomyopathy in a fast, comprehensive, and cost-efficient manner. Methods and Results: We established an array-based subgenomic enrichment followed by next-generation sequencing to detect mutations in patients with hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). With this approach, we show that the genomic region of interest can be enriched by a mean factor of 2169 compared with the coverage of the whole genome, resulting in high sequence coverage of selected disease genes and allowing us to define the genetic pathogenesis of cardiomyopathies in a single sequencing run. In 6 patients, we detected disease-causing mutations, 2 microdeletions, and 4 point mutations. Furthermore, we identified several novel nonsynonymous variants, which are predicted to be harmful, and hence, might be potential disease mutations or modifiers for DCM or HCM. Conclusions: The approach presented here allows for the first time a comprehensive genetic screening in patients with hereditary DCM or HCM in a fast and cost-efficient manner. © 2011 American Heart Association, Inc. Source

Keller A.,Biomarker Discovery Center | Keller A.,Febit Biomedical GmbH | Leidinger P.,Saarland University | Gislefoss R.,Cancer Registry of Norway | And 5 more authors.
RNA Biology | Year: 2011

Circulating microRNAs in human serum have increasingly been recognized as stable markers for cancer detection. However, there is still a lack of miRNome wide studies over a long period of time with respect to pathogenic processes. We obtained serum samples from the janus serum bank collected prior and after diagnosis of lung cancer. We analyzed the abundance of 904 miRNAs in serum from eight cancer patients at three time points and from six healthy control individuals. Based on the identified miRNA signatures, hierarchical clustering and a self-organizing map identified three major clusters including one cluster containing most of the of the pre-diagnostic samples, a second cluster with mainly post-diagnostic samples, and a third cluster with mainly control samples. Correlation analyses showed that although the profiles were generally stable over several years, most obvious changes of the miRNA pattern seem to occur at a time close to diagnosis. Our findings support the idea that a developing lung cancer might be detectable years prior to diagnosis through a specific miRNA signature and that this signature changes during tumor development. © 2011 Landes Bioscience. Source

Summerer D.,Febit Biomedical GmbH | Schracke N.,Febit Biomedical GmbH | Wu H.,Febit Inc. | Cheng Y.,Febit Biomedical GmbH | And 4 more authors.
Genomics | Year: 2010

Sequence capture methods for targeted next generation sequencing promise to massively reduce cost of genomics projects compared to untargeted sequencing. However, evaluated capture methods specifically dedicated to biologically relevant genomic regions are rare. Whole exome capture has been shown to be a powerful tool to discover the genetic origin of disease and provides a reduction in target size and thus calculative sequencing capacity of > 90-fold compared to untargeted whole genome sequencing. For further cost reduction, a valuable complementing approach is the analysis of smaller, relevant gene subsets but involving large cohorts of samples. However, effective adjustment of target sizes and sample numbers is hampered by the limited scalability of enrichment systems. We report a highly scalable and automated method to capture a 480 Kb exome subset of 115 cancer-related genes using microfluidic DNA arrays. The arrays are adaptable from 125 Kb to 1. Mb target size and/or one to eight samples without barcoding strategies, representing a further 26 - 270-fold reduction of calculative sequencing capacity compared to whole exome sequencing. Illumina GAII analysis of a HapMap genome enriched for this exome subset revealed a completeness of > 96%. Uniformity was such that > 68% of exons had at least half the median depth of coverage. An analysis of reference SNPs revealed a sensitivity of up to 93% and a specificity of 98.2% or higher. © 2010 Elsevier Inc. Source

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