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  • 1. Abrahamsson, T. R.
    et al.
    Jakobsson, H. E.
    Andersson, Anders F.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Björkstén, B.
    Engstrand, Lars
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Jenmalm, M. C.
    Low gut microbiota diversity in early infancy precedes asthma at school age2014In: Clinical and Experimental Allergy, ISSN 0954-7894, E-ISSN 1365-2222, Vol. 44, no 6, p. 842-850Article in journal (Refereed)
    Abstract [en]

    Background Low total diversity of the gut microbiota during the first year of life is associated with allergic diseases in infancy, but little is known how early microbial diversity is related to allergic disease later in school age. Objective To assess microbial diversity and characterize the dominant bacteria in stool during the first year of life in relation to the prevalence of different allergic diseases in school age, such as asthma, allergic rhinoconjunctivitis (ARC) and eczema. Methods The microbial diversity and composition was analysed with barcoded 16S rDNA 454 pyrosequencing in stool samples at 1week, 1month and 12months of age in 47 infants which were subsequently assessed for allergic disease and skin prick test reactivity at 7years of age (ClinicalTrials.gov ID NCT01285830). Results Children developing asthma (n=8) had a lower diversity of the total microbiota than non-asthmatic children at 1week (P=0.04) and 1month (P=0.003) of age, whereas allergic rhinoconjunctivitis (n=13), eczema (n=12) and positive skin prick reactivity (n=14) at 7years of age did not associate with the gut microbiota diversity. Neither was asthma associated with the microbiota composition later in infancy (at 12months). Children having IgE-associated eczema in infancy and subsequently developing asthma had lower microbial diversity than those that did not. There were no significant differences, however, in relative abundance of bacterial phyla and genera between children with or without allergic disease. Conclusion and Clinical Relevance Low total diversity of the gut microbiota during the first month of life was associated with asthma but not ARC in children at 7years of age. Measures affecting microbial colonization of the infant during the first month of life may impact asthma development in childhood.

  • 2. Abrahamsson, Thomas R.
    et al.
    Jakobsson, Hedvig E.
    Andersson, Anders F.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Björksten, Bengt
    Engstrand, Lars
    KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Jenmalm, Maria C.
    Gut microbiota diversity and atopic disease: Does breast-feeding play a role? Reply2013In: Journal of Allergy and Clinical Immunology, ISSN 0091-6749, E-ISSN 1097-6825, Vol. 131, no 1, p. 248-249Article in journal (Other academic)
  • 3. Abrahamsson, Thomas R.
    et al.
    Jakobsson, Hedvig E.
    Andersson, Anders F.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Björkstén, Bengt
    Engstrand, Lars
    Jenmalm, Maria C.
    Low diversity of the gut microbiota in infants with atopic eczema2012In: Journal of Allergy and Clinical Immunology, ISSN 0091-6749, E-ISSN 1097-6825, Vol. 129, no 2, p. 434-U244Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: It is debated whether a low total diversity of the gut microbiota in early childhood is more important than an altered prevalence of particular bacterial species for the increasing incidence of allergic disease. The advent of powerful, cultivation-free molecular methods makes it possible to characterize the total microbiome down to the genus level in large cohorts. OBJECTIVE: We sought to assess microbial diversity and characterize the dominant bacteria in stool during the first year of life in relation to atopic eczema development. METHODS: Microbial diversity and composition were analyzed with barcoded 16S rDNA 454-pyrosequencing in stool samples at 1 week, 1 month, and 12 months of age in 20 infants with IgE-associated eczema and 20 infants without any allergic manifestation until 2 years of age (ClinicalTrials.gov ID NCT01285830). RESULTS: Infants with IgE-associated eczema had a lower diversity of the total microbiota at 1 month (P= .004) and a lower diversity of the bacterial phylum Bacteroidetes and the genus Bacteroides at 1 month (P= .02 and P= .01) and the phylum Proteobacteria at 12 months of age (P= .02). The microbiota was less uniform at 1 month than at 12 months of age, with a high interindividual variability. At 12 months, when the microbiota had stabilized, Proteobacteria, comprising gram-negative organisms, were more abundant in infants without allergic manifestation (Empirical Analysis of Digital Gene Expression in R edgeR test: P= .008, q= 0.02). CONCLUSION: Low intestinal microbial diversity during the first month of life was associated with subsequent atopic eczema.

  • 4. Acero Sanchez, Josep Ll.
    et al.
    Joda, Hamdi
    Henry, Olivier Y. F.
    Solnestam, Beata W.
    Kvastad, Linda
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Sahlén, Pelin
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Laddach, Nadja
    Ramakrishnan, Dheeraj
    Riley, Ian
    Schwind, Carmen
    Latta, Daniel
    O'Sullivan, Ciara K.
    Electrochemical Genetic Profiling of Single Cancer Cells2017In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 89, no 6, p. 3378-3385Article in journal (Refereed)
    Abstract [en]

    Recent understandings in the development and spread of cancer have led to the realization of novel single cell analysis platforms focused on circulating tumor cells (CTCs). A simple, rapid, and inexpensive analytical platform capable of providing genetic information on these rare cells is highly desirable to support clinicians and researchers alike to either support the selection or adjustment of therapy or provide fundamental insights into cell function and cancer progression mechanisms. We report on the genetic profiling of single cancer cells, exploiting a combination of multiplex ligation-dependent probe amplification (MLPA) and electrochemical detection. Cells were isolated using laser capture and lysed, and the mRNA was extracted and transcribed into DNA. Seven markers were amplified by MLPA, which allows for the simultaneous amplification of multiple targets with a single primer pair, using MLPA probes containing unique barcode sequences. Capture probes complementary to each of these barcode sequences were immobilized on a printed circuit board (PCB) manufactured electrode array and exposed to single-stranded MLPA products and subsequently to a single stranded DNA reporter probe bearing a HRP molecule, followed by substrate addition and fast electrochemical pulse amperometric detection. We present asimple, rapid, flexible, and inexpensive approach for the simultaneous quantification of multiple breast cancer related mRNA markers, with single tumor cell sensitivity.

  • 5.
    Afkham, Heydar Maboudi
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Ek, Carl Henrik
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Carlsson, Stefan
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    A topological framework for training latent variable models2014In: Proceedings - International Conference on Pattern Recognition, 2014, p. 2471-2476Conference paper (Refereed)
    Abstract [en]

    We discuss the properties of a class of latent variable models that assumes each labeled sample is associated with a set of different features, with no prior knowledge of which feature is the most relevant feature to be used. Deformable-Part Models (DPM) can be seen as good examples of such models. These models are usually considered to be expensive to train and very sensitive to the initialization. In this paper, we focus on the learning of such models by introducing a topological framework and show how it is possible to both reduce the learning complexity and produce more robust decision boundaries. We will also argue how our framework can be used for producing robust decision boundaries without exploiting the dataset bias or relying on accurate annotations. To experimentally evaluate our method and compare with previously published frameworks, we focus on the problem of image classification with object localization. In this problem, the correct location of the objects is unknown, during both training and testing stages, and is considered as a latent variable. ©

  • 6.
    Afkham, Heydar Maboudi
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Ek, Carl Henrik
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Carlsson, Stefan
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Gradual improvement of image descriptor quality2014In: ICPRAM 2014 - Proceedings of the 3rd International Conference on Pattern Recognition Applications and Methods, 2014, p. 233-238Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose a framework for gradually improving the quality of an already existing image descriptor. The descriptor used in this paper (Afkham et al., 2013) uses the response of a series of discriminative components for summarizing each image. As we will show, this descriptor has an ideal form in which all categories become linearly separable. While, reaching this form is not feasible, we will argue how by replacing a small fraction of these components, it is possible to obtain a descriptor which is, on average, closer to this ideal form. To do so, we initially identify which components do not contribute to the quality of the descriptor and replace them with more robust components. Here, a joint feature selection method is used to find improved components. As our experiments show, this change directly reflects in the capability of the resulting descriptor in discriminating between different categories.

  • 7.
    Afkham, Heydar Maboudi
    et al.
    KTH, School of Computer Science and Communication (CSC).
    Qiu, Xuanbin
    KTH, School of Computer Science and Communication (CSC).
    The, Matthew
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Käll, Lukas
    KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Uncertainty estimation of predictions of peptides' chromatographic retention times in shotgun proteomics2017In: Bioinformatics, ISSN 1367-4803, E-ISSN 1367-4811, Vol. 33, no 4, p. 508-513Article in journal (Refereed)
    Abstract [en]

    Motivation: Liquid chromatography is frequently used as a means to reduce the complexity of peptide-mixtures in shotgun proteomics. For such systems, the time when a peptide is released from a chromatography column and registered in the mass spectrometer is referred to as the peptide's retention time. Using heuristics or machine learning techniques, previous studies have demonstrated that it is possible to predict the retention time of a peptide from its amino acid sequence. In this paper, we are applying Gaussian Process Regression to the feature representation of a previously described predictor ELUDE. Using this framework, we demonstrate that it is possible to estimate the uncertainty of the prediction made by the model. Here we show how this uncertainty relates to the actual error of the prediction. Results: In our experiments, we observe a strong correlation between the estimated uncertainty provided by Gaussian Process Regression and the actual prediction error. This relation provides us with new means for assessment of the predictions. We demonstrate how a subset of the peptides can be selected with lower prediction error compared to the whole set. We also demonstrate how such predicted standard deviations can be used for designing adaptive windowing strategies.

  • 8.
    Ahmadian, Afshin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    AnderssonSvahn, Helene
    KTH, School of Biotechnology (BIO), Nano Biotechnology (closed 20130101). KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Massively parallel sequencing platforms using lab on a chip technologies2011In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 11, no 16, p. 2653-2655Article in journal (Refereed)
  • 9.
    Ahmadian, Afshin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Ehn, M.
    Hober, Sophia
    KTH, School of Biotechnology (BIO), Proteomics.
    Pyrosequencing: History, biochemistry and future2006In: Clinica Chimica Acta, ISSN 0009-8981, E-ISSN 1873-3492, Vol. 363, no 02-jan, p. 83-94Article, review/survey (Refereed)
    Abstract [en]

    Background: Pyrosequencing is a DNA sequencing technology based on the sequencing-by-synthesis principle. Methods: The technique is built on a 4-enzyme real-time monitoring of DNA synthesis by bioluminescence using a cascade that upon nucleotide incorporation ends in a detectable light signal (bioluminescence). The detection system is based on the pyrophosphate released when a nucleotide is introduced in the DNA-strand. Thereby, the signal can be quantitatively connected to the number of bases added. Currently, the technique is limited to analysis of short DNA sequences exemplified by single-nucleotide polymorphism analysis and genotyping. Mutation detection and single-nucleotide polymorphisin genotyping require screening of large samples of materials and therefore the importance of high-throughput DNA analysis techniques is significant. In order to expand the field for pyrosequencing, the read length needs to be improved. Conclusions: Th pyrosequencing system is based on an enzymatic system. There are different current and future applications of this technique.

  • 10. Ahmadian, Afshin
    et al.
    Pettersson, Erik
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Method for amplification2005Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The invention refers to a method for multiplex amplification of at least one specific nucleic acid locus, comprising the steps of: providing at least one oligonucleotide probe pair that is designed so that the first and second probe of the pair anneal to a specific nucleic acid locus on a target molecule, in which pair the first probe has an extendable 3'-end, and a second probe has a 5'-end that is directly or indirectly labelled with a phosphate group; providing a target molecule comprising at least one specific nucleic acid locus; allowing the probe pair to anneal to the target molecule; allowing the 3'-end of the first probe to extend by influence of polymerase by adding a set of three different dNTPs; ligating the 3'-end of the extended first probe to the 5'-end of the second probe. Hereby, a method is provided which allows a high specificity for simultaneous amplification of several loci. Further, the invention involves a kit for use in the method of the invention.

  • 11.
    Ahmadian, Afshin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Ren, Z P
    Williams, Cecilia
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Pontén, F
    Odeberg, Jacob
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Pontén, J
    Uhlén, Mathias
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Genetic instability in the 9q22.3 region is a late event in the development of squamous cell carcinoma.1998In: Oncogene, ISSN 0950-9232, E-ISSN 1476-5594, Vol. 17, no 14Article in journal (Refereed)
    Abstract [en]

    Squamous cell carcinoma (SCC) of the skin represents a group of neoplasms which is associated with exposure to UV light. Recently, we obtained data suggesting that invasive skin cancer and its precursors derive from one original neoplastic clone. Here, the analysis were extended by loss of heterozygosity (LOH) analysis in the chromosome 9q22.3 region. A total of 85 samples, taken from twenty-two sections of sun-exposed sites, corresponding to normal epidermis, morphological normal cells with positive immuno-staining for the p53 protein (p53 patches), dysplasias, cancer in situ (CIS) and squamous cell carcinomas (SCC) of the skin were analysed. Overall, about 70% of p53 patches had mutations in the p53 gene but not LOH in the p53 gene or 9q22.3 region. Approximately 70% of the dysplasias showed p53 mutations of which about 40% had LOH in the p53 region but not in the 9q22.3 region. In contrast, about 65% of SCC and CIS displayed LOH in the 9q22.3 region, as well as frequent (80%) mutations and/or LOH in the p53 gene. These findings strongly suggest that alterations in the p53 gene is an early event in the progression towards SCC, whereas malignant development involves LOH and alterations in at least one (or several) tumor suppressor genes located in chromosome 9q22.3.

  • 12. Ahmed, Engy
    et al.
    Hugerth, Luisa W.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Logue, Jürg Brendan
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Bruchert, Volker
    Andersson, Anders F.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Holmström, Sara J. M.
    Mineral Type Structures Soil Microbial Communities2017In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 34, no 6, p. 538-545Article in journal (Refereed)
    Abstract [en]

    Soil microorganisms living in close contact with minerals play key roles in the biogeochemical cycling of elements, soil formation, and plant nutrition. Yet, the composition of microbial communities inhabiting the mineralosphere (i.e., the soil surrounding minerals) is poorly understood. Here, we explored the composition of soil microbial communities associated with different types of minerals in various soil horizons. To this effect, a field experiment was set up in which mineral specimens of apatite, biotite, and oligoclase were buried in the organic, eluvial, and upper illuvial horizons of a podzol soil. After an incubation period of two years, the soil attached to the mineral surfaces was collected, and microbial communities were analyzed by means of Illumina MiSeq sequencing of the 16S (prokaryotic) and 18S (eukaryotic) ribosomal RNA genes. We found that both composition and diversity of bacterial, archaeal, and fungal communities varied across the different mineral surfaces, and that mineral type had a greater influence on structuring microbial assemblages than soil horizon. Thus, our findings emphasize the importance of mineral surfaces as ecological niches in soils.

  • 13.
    Akan, Pelin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Alexeyenko, Andrey
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Costea, Paul Igor
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Hedberg, Lilia
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Werne Solnestam, Beata
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lundin, Sverker
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Hallman, Jimmie
    Lundberg, Emma
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Uhlén, Mathias
    KTH, School of Biotechnology (BIO), Proteomics (closed 20130101). KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Comprehensive analysis of the genome transcriptome and proteome landscapes of three tumor cell lines2012In: Genome Medicine, ISSN 1756-994X, E-ISSN 1756-994X, Vol. 4, p. 86-Article in journal (Refereed)
    Abstract [en]

    We here present a comparative genome, transcriptome and functional network analysis of three human cancer cell lines (A431, U251MG and U2OS), and investigate their relation to protein expression. Gene copy numbers significantly influenced corresponding transcript levels; their effect on protein levels was less pronounced. We focused on genes with altered mRNA and/or protein levels to identify those active in tumor maintenance. We provide comprehensive information for the three genomes and demonstrate the advantage of integrative analysis for identifying tumor-related genes amidst numerous background mutations by relating genomic variation to expression/protein abundance data and use gene networks to reveal implicated pathways.

  • 14.
    Alexeyenko, Andrey
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lee, Woojoo
    Pernemalm, Maria
    Guegan, Justin
    Dessen, Philippe
    Lazar, Vladimir
    Lehtio, Janne
    Pawitan, Yudi
    Network enrichment analysis: extension of gene-set enrichment analysis to gene networks2012In: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 13, p. 226-Article in journal (Refereed)
    Abstract [en]

    Background: Gene-set enrichment analyses (GEA or GSEA) are commonly used for biological characterization of an experimental gene-set. This is done by finding known functional categories, such as pathways or Gene Ontology terms, that are over-represented in the experimental set; the assessment is based on an overlap statistic. Rich biological information in terms of gene interaction network is now widely available, but this topological information is not used by GEA, so there is a need for methods that exploit this type of information in high-throughput data analysis. Results: We developed a method of network enrichment analysis (NEA) that extends the overlap statistic in GEA to network links between genes in the experimental set and those in the functional categories. For the crucial step in statistical inference, we developed a fast network randomization algorithm in order to obtain the distribution of any network statistic under the null hypothesis of no association between an experimental gene-set and a functional category. We illustrate the NEA method using gene and protein expression data from a lung cancer study. Conclusions: The results indicate that the NEA method is more powerful than the traditional GEA, primarily because the relationships between gene sets were more strongly captured by network connectivity rather than by simple overlaps.

  • 15.
    Alexeyenko, Andrey
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Nystedt, Björn
    Vezzi, Francesco
    Sherwood, Ellen
    Ye, Rosa
    Knudsen, Bjarne
    Simonsen, Martin
    Turner, Benjamin
    de Jong, Pieter
    Wu, Cheng-Cang
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Efficient de novo assembly of large and complex genomes by massively parallel sequencing of Fosmid pools2014In: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 15, no 1, p. 439-Article in journal (Refereed)
    Abstract [en]

    Background: Sampling genomes with Fosmid vectors and sequencing of pooled Fosmid libraries on the Illumina platform for massive parallel sequencing is a novel and promising approach to optimizing the trade-off between sequencing costs and assembly quality. Results: In order to sequence the genome of Norway spruce, which is of great size and complexity, we developed and applied a new technology based on the massive production, sequencing, and assembly of Fosmid pools (FP). The spruce chromosomes were sampled with similar to 40,000 bp Fosmid inserts to obtain around two-fold genome coverage, in parallel with traditional whole genome shotgun sequencing (WGS) of haploid and diploid genomes. Compared to the WGS results, the contiguity and quality of the FP assemblies were high, and they allowed us to fill WGS gaps resulting from repeats, low coverage, and allelic differences. The FP contig sets were further merged with WGS data using a novel software package GAM-NGS. Conclusions: By exploiting FP technology, the first published assembly of a conifer genome was sequenced entirely with massively parallel sequencing. Here we provide a comprehensive report on the different features of the approach and the optimization of the process. We have made public the input data (FASTQ format) for the set of pools used in this study: ftp://congenie.org/congenie/Nystedt_2013/Assembly/ProcessedData/FosmidPools/.(alternatively accessible via http://congenie.org/downloads).The software used for running the assembly process is available at http://research.scilifelab.se/andrej_alexeyenko/downloads/fpools/.

  • 16.
    Alexeyenko, Andrey
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Schmitt, Thomas
    Tjärnberg, Andreas
    Stockholm University, Science for Life Laboratory.
    Guala, Dmitri
    Stockholm University, Science for Life Laboratory.
    Frings, Oliver
    Stockholm University, Science for Life Laboratory.
    Sonnhammer, Erik L. L.
    Stockholm University, Science for Life Laboratory.
    Comparative interactomics with Funcoup 2.02012In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 40, no D1, p. D821-D828Article in journal (Refereed)
    Abstract [en]

    FunCoup (http://FunCoup.sbc.su.se) is a database that maintains and visualizes global gene/protein networks of functional coupling that have been constructed by Bayesian integration of diverse high-throughput data. FunCoup achieves high coverage by orthology-based integration of data sources from different model organisms and from different platforms. We here present release 2.0 in which the data sources have been updated and the methodology has been refined. It contains a new data type Genetic Interaction, and three new species: chicken, dog and zebra fish. As FunCoup extensively transfers functional coupling information between species, the new input datasets have considerably improved both coverage and quality of the networks. The number of high-confidence network links has increased dramatically. For instance, the human network has more than eight times as many links above confidence 0.5 as the previous release. FunCoup provides facilities for analysing the conservation of subnetworks in multiple species. We here explain how to do comparative interactomics on the FunCoup website.

  • 17.
    Alneberg, Johannes
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Bjarnason, Brynjar Smári
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    de Bruijn, Ino
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab. Bioinformatics Infrastructure for Life Sciences (BILS), Sweden.
    Schirmer, Melanie
    Quick, Joshua
    Ijaz, Umer Z.
    Lahti, Leo
    Loman, Nicholas J.
    Andersson, Anders F.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Quince, Christopher
    Binning metagenomic contigs by coverage and composition2014In: Nature Methods, ISSN 1548-7091, E-ISSN 1548-7105, Vol. 11, no 11, p. 1144-1146Article in journal (Refereed)
    Abstract [en]

    Shotgun sequencing enables the reconstruction of genomes from complex microbial communities, but because assembly does not reconstruct entire genomes, it is necessary to bin genome fragments. Here we present CONCOCT, a new algorithm that combines sequence composition and coverage across multiple samples, to automatically cluster contigs into genomes. We demonstrate high recall and precision on artificial as well as real human gut metagenome data sets.

  • 18. Ameur, Adam
    et al.
    Dahlberg, Johan
    Olason, Pall
    Vezzi, Francesco
    Karlsson, Robert
    Martin, Marcel
    Viklund, Johan
    Kahari, Andreas Kusalananda
    Lundin, Par
    Che, Huiwen
    Thutkawkorapin, Jessada
    Eisfeldt, Jesper
    Lampa, Samuel
    Dahlberg, Mats
    Hagberg, Jonas
    Jareborg, Niclas
    Liljedahl, Ulrika
    Jonasson, Inger
    Johansson, Asa
    Feuk, Lars
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Syvanen, Ann-Christine
    Lundin, Sverker
    Nilsson, Daniel
    Nystedt, Bjorn
    Magnusson, Patrik K. E.
    Gyllensten, Ulf
    SweGen: a whole-genome data resource of genetic variability in a cross-section of the Swedish population2017In: European Journal of Human Genetics, ISSN 1018-4813, E-ISSN 1476-5438, Vol. 25, no 11, p. 1253-1260Article in journal (Refereed)
    Abstract [en]

    Here we describe the SweGen data set, a comprehensive map of genetic variation in the Swedish population. These data represent a basic resource for clinical genetics laboratories as well as for sequencing-based association studies by providing information on genetic variant frequencies in a cohort that is well matched to national patient cohorts. To select samples for this study, we first examined the genetic structure of the Swedish population using high-density SNP-array data from a nation-wide cohort of over 10 000 Swedish-born individuals included in the Swedish Twin Registry. A total of 1000 individuals, reflecting a cross-section of the population and capturing the main genetic structure, were selected for whole-genome sequencing. Analysis pipelines were developed for automated alignment, variant calling and quality control of the sequencing data. This resulted in a genome-wide collection of aggregated variant frequencies in the Swedish population that we have made available to the scientific community through the website https://swefreq.nbis.se. A total of 29.2 million single-nucleotide variants and 3.8 million indels were detected in the 1000 samples, with 9.9 million of these variants not present in current databases. Each sample contributed with an average of 7199 individual-specific variants. In addition, an average of 8645 larger structural variants (SVs) were detected per individual, and we demonstrate that the population frequencies of these SVs can be used for efficient filtering analyses. Finally, our results show that the genetic diversity within Sweden is substantial compared with the diversity among continental European populations, underscoring the relevance of establishing a local reference data set.

  • 19.
    Andersen, Malin
    KTH, School of Biotechnology (BIO), Gene Technology.
    Computational and experimental approaches to regulatory genetic variation2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Genetic variation is a strong risk factor for many human diseases, including diabetes, cancer, cardiovascular disease, depression, autoimmunity and asthma. Most of the disease genes identified so far alter the amino acid sequences of encoded proteins. However, a significant number of genetic variants affecting complex diseases may alter the regulation of gene transcription. The map of the regulatory elements in the human genome is still to a large extent unknown, and it remains a challenge to separate the functional regulatory genetic variations from linked neutral variations.

    The objective of this thesis was to develop methods for the identification of genetic variation with a potential to affect the transcriptional regulation of human genes, and to analyze potential regulatory polymorphisms in the CD36 glycoprotein, a candidate gene for cardiovascular disease.

    An in silico tool for the prediction of regulatory polymorphisms in human genes was implemented and is available at www.cisreg.ca/RAVEN. The tool was evaluated using experimentally verified regulatory single nucleotide polymorphisms (SNPs) collected from the scientific literature, and tested in combination with experimental detection of allele specific expression of target genes (allelic imbalance). Regulatory SNPs were shown to be located in evolutionary conserved regions more often than background SNPs, but predicted transcription factor binding sites were unable to enrich for regulatory SNPs unless additional information linking transcription factors with the target genes were available.

    The in silico tool was applied to the CD36 glycoprotein, a candidate gene for cardiovascular disease. Potential regulatory SNPs in the alternative promoters of this gene were identified and evaluated in vitro and in vivo using a clinical study for coronary artery disease. We observed association to the plasma concentrations of inflammation markers (serum amyloid A protein and C-reactive protein) in myocardial infarction patients, which highlights the need for further analyses of potential regulatory polymorphisms in this gene.

    Taken together, this thesis describes an in silico approach to identify putative regulatory polymorphisms which can be useful for directing limited laboratory resources to the polymorphisms most likely to have a phenotypic effect.

  • 20.
    Andersen, Malin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Engström, Pär
    Lithwick, Stuart
    Arenillas, David
    Eriksson, Per
    Lenhard, Boris
    Wasserman, Wyeth
    Odeberg, Jacob
    KTH, School of Biotechnology (BIO), Gene Technology.
    In silico detection of sequence variations modifying transcriptional regulation2008In: PloS Computational Biology, ISSN 1553-734X, E-ISSN 1553-7358, Vol. 4, no 1, p. e5-Article in journal (Refereed)
    Abstract [en]

    Identification of functional genetic variation associated with increased susceptibility to complex diseases can elucidate genes and underlying biochemical mechanisms linked to disease onset and progression. For genes linked to genetic diseases, most identified causal mutations alter an encoded protein sequence. Technological advances for measuring RNA abundance suggest that a significant number of undiscovered causal mutations may alter the regulation of gene transcription. However, it remains a challenge to separate causal genetic variations from linked neutral variations. Here we present an in silico driven approach to identify possible genetic variation in regulatory sequences. The approach combines phylogenetic footprinting and transcription factor binding site prediction to identify variation in candidate cis-regulatory elements. The bioinformatics approach has been tested on a set of SNPs that are reported to have a regulatory function, as well as background SNPs. In the absence of additional information about an analyzed gene, the poor specificity of binding site prediction is prohibitive to its application. However, when additional data is available that can give guidance on which transcription factor is involved in the regulation of the gene, the in silico binding site prediction improves the selection of candidate regulatory polymorphisms for further analyses. The bioinformatics software generated for the analysis has been implemented as a Web-based application system entitled RAVEN ( regulatory analysis of variation in enhancers). The RAVEN system is available at http://www.cisreg.ca for all researchers interested in the detection and characterization of regulatory sequence variation.

  • 21.
    Andersen, Malin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Fisher, Rachel
    Holmberg, Kristina
    KTH, School of Biotechnology (BIO), Gene Technology.
    Samnegård, Ann
    Hamsten, Anders
    Eriksson, Per
    Odeberg, Jacob
    KTH, School of Biotechnology (BIO), Gene Technology.
    In silico prediction of regulatory SNPs in the CD36 gene and evaluation of their effect in a clinical study for coronary artery diseaseManuscript (Other academic)
  • 22.
    Andersen, Malin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Lenhard, Boris
    Whatling, Carl
    Eriksson, Per
    Odeberg, Jacob
    KTH, School of Biotechnology (BIO), Gene Technology.
    Alternative promoter usage of the membrane glycoprotein CD362006In: BMC Molecular Biology, ISSN 1471-2199, E-ISSN 1471-2199, Vol. 7, p. 8-Article in journal (Refereed)
    Abstract [en]

    Background: CD36 is a membrane glycoprotein involved in a variety of cellular processes such as lipid transport, immune regulation, hemostasis, adhesion, angiogenesis and atherosclerosis. It is expressed in many tissues and cell types, with a tissue specific expression pattern that is a result of a complex regulation for which the molecular mechanisms are not yet fully understood. There are several alternative mRNA isoforms described for the gene. We have investigated the expression patterns of five alternative first exons of the CD36 gene in several human tissues and cell types, to better understand the molecular details behind its regulation.

    Results: We have identified one novel alternative first exon of the CD36 gene, and confirmed the expression of four previously known alternative first exons of the gene. The alternative transcripts are all expressed in more than one human tissue and their expression patterns vary highly in skeletal muscle, heart, liver, adipose tissue, placenta, spinal cord, cerebrum and monocytes. All alternative first exons are upregulated in THP-1 macrophages in response to oxidized low density lipoproteins. The alternative promoters lack TATA-boxes and CpG islands. The upstream region of exon 1b contains several features common for house keeping gene and monocyte specific gene promoters.

    Conclusion: Tissue-specific expression patterns of the alternative first exons of CD36 suggest that the alternative first exons of the gene are regulated individually and tissue specifically. At the same time, the fact that all first exons are upregulated in THP-1 macrophages in response to oxidized low density lipoproteins may suggest that the alternative first exons are coregulated in this cell type and environmental condition. The molecular mechanisms regulating CD36 thus appear to be unusually complex, which might reflect the multifunctional role of the gene in different tissues and cellular conditions.

  • 23.
    Andersson, Anders
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Lundgren, Magnus
    Department of Molecular Evolution, Evolutionary Biology Center, Uppsala University.
    Eriksson, Stefan
    Department of Molecular Evolution, Evolutionary Biology Center, Uppsala University.
    Rosenlund, Magnus
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
    Bernander, Rolf
    Department of Molecular Evolution, Evolutionary Biology Center, Uppsala University.
    Nilsson, Peter
    KTH, School of Biotechnology (BIO), Gene Technology.
    Global analysis of mRNA stability in the archaeon Sulfolobus2006In: Genome Biology, ISSN 1465-6906, E-ISSN 1474-760X, Vol. 7, no 10, p. R99-Article in journal (Refereed)
    Abstract [en]

    Background: Transcript half-lives differ between organisms, and between groups of genes within the same organism. The mechanisms underlying these differences are not clear, nor are the biochemical properties that determine the stability of a transcript. To address these issues, genome-wide mRNA decay studies have been conducted in eukaryotes and bacteria. In contrast, relatively little is known about RNA stability in the third domain of life, Archaea. Here, we present a microarray-based analysis of mRNA half-lives in the hyperthermophilic crenarchaea Sulfolobus solfataricus and Sulfolobus acidocaldarius, constituting the first genome-wide study of RNA decay in archaea. Results: The two transcriptomes displayed similar half-life distributions, with medians of about five minutes. Growth-related genes, such as those involved in transcription, translation and energy production, were over-represented among unstable transcripts, whereas uncharacterized genes were over-represented among the most stable. Half-life was negatively correlated with transcript abundance and, unlike the situation in other organisms, also negatively correlated with transcript length. Conclusion: The mRNA half-life distribution of Sulfolobus species is similar to those of much faster growing bacteria, contrasting with the earlier observation that median mRNA half-life is proportional to the minimal length of the cell cycle. Instead, short half-lives may be a general feature of prokaryotic transcriptomes, possibly related to the absence of a nucleus and/or more limited post-transcriptional regulatory mechanisms. The pattern of growth-related transcripts being among the least stable in Sulfolobus may also indicate that the short half-lives reflect a necessity to rapidly reprogram gene expression upon sudden changes in environmental conditions.

  • 24.
    Andersson, Anders
    et al.
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Biotechnology (BIO), Gene Technology.
    Pelve, Erik A.
    Lindeberg, Stefan
    Lundgren, Magnus
    Nilsson, Peter
    KTH, School of Biotechnology (BIO), Proteomics (closed 20130101).
    Bernander, Rolf
    Replication-biased genome organisation in the crenarchaeon Sulfolobus2010In: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 11, p. 454-Article in journal (Refereed)
    Abstract [en]

    Background: Species of the crenarchaeon Sulfolobus harbour three replication origins in their single circular chromosome that are synchronously initiated during replication. Results: We demonstrate that global gene expression in two Sulfolobus species is highly biased, such that early replicating genome regions are more highly expressed at all three origins. The bias by far exceeds what would be anticipated by gene dosage effects alone. In addition, early replicating regions are denser in archaeal core genes (enriched in essential functions), display lower intergenic distances, and are devoid of mobile genetic elements. Conclusion: The strong replication-biased structuring of the Sulfolobus chromosome implies that the multiple replication origins serve purposes other than simply shortening the time required for replication. The higher-level chromosomal organisation could be of importance for minimizing the impact of DNA damage, and may also be linked to transcriptional regulation.

  • 25.
    Andrade, Jorge
    KTH, School of Biotechnology (BIO), Gene Technology.
    Grid and High-Performance Computing for Applied Bioinformatics2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The beginning of the twenty-first century has been characterized by an explosion of biological information. The avalanche of data grows daily and arises as a consequence of advances in the fields of molecular biology and genomics and proteomics. The challenge for nowadays biologist lies in the de-codification of this huge and complex data, in order to achieve a better understanding of how our genes shape who we are, how our genome evolved, and how we function.

    Without the annotation and data mining, the information provided by for example high throughput genomic sequencing projects is not very useful. Bioinformatics is the application of computer science and technology to the management and analysis of biological data, in an effort to address biological questions. The work presented in this thesis has focused on the use of Grid and High Performance Computing for solving computationally expensive bioinformatics tasks, where, due to the very large amount of available data and the complexity of the tasks, new solutions are required for efficient data analysis and interpretation.

    Three major research topics are addressed; First, the use of grids for distributing the execution of sequence based proteomic analysis, its application in optimal epitope selection and in a proteome-wide effort to map the linear epitopes in the human proteome. Second, the application of grid technology in genetic association studies, which enabled the analysis of thousand of simulated genotypes, and finally the development and application of a economic based model for grid-job scheduling and resource administration.

    The applications of the grid based technology developed in the present investigation, results in successfully tagging and linking chromosomes regions in Alzheimer disease, proteome-wide mapping of the linear epitopes, and the development of a Market-Based Resource Allocation in Grid for Scientific Applications.

  • 26.
    Andrade, Jorge
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Andersen, Malin
    KTH, School of Biotechnology (BIO), Gene Technology.
    Berglund, Lisa
    KTH, School of Biotechnology (BIO), Proteomics.
    Odeberg, Jacob
    KTH, School of Biotechnology (BIO), Gene Technology.
    Applications of grid computing in genetics and proteomics2007In: Applied Parallel Computing: State Of The Art In Scientific Computing / [ed] Kagstrom, B; Elmroth, E; Dongarra, J; Wasniewski, J, 2007, Vol. 4699, p. 791-798Conference paper (Refereed)
    Abstract [en]

    The potential for Grid technologies in applied bioinformatics is largely unexplored. We have developed a model for solving computationally demanding bioinformatics tasks in distributed Grid environments, designed to ease the usability for scientists unfamiliar with Grid computing. With a script-based implementation that uses a strategy of temporary installations of databases and existing executables on remote nodes at submission, we propose a generic solution that do not rely on predefined Grid runtime environments and that can easily be adapted to other bioinformatics tasks suitable for parallelization. This implementation has been successfully applied to whole proteome sequence similarity analyses and to genome-wide genotype simulations, where computation time was reduced from years to weeks. We conclude that computational Grid technology is a useful resource for solving high compute tasks in genetics and proteomics using existing algorithms.

  • 27.
    Andrade, Jorge
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Andersen, Malin
    KTH, School of Biotechnology (BIO), Gene Technology.
    Sillén, Anna
    Graff, Caroline
    Odeberg, Jacob
    KTH, School of Biotechnology (BIO), Gene Technology.
    The use of grid computing to drive data-intensive genetic research2007In: European Journal of Human Genetics, ISSN 1018-4813, E-ISSN 1476-5438, Vol. 15, no 6, p. 694-702Article in journal (Refereed)
    Abstract [en]

    In genetics, with increasing data sizes and more advanced algorithms for mining complex data, a point is reached where increased computational capacity or alternative solutions becomes unavoidable. Most contemporary methods for linkage analysis are based on the Lander-Green hidden Markov model (HMM), which scales exponentially with the number of pedigree members. In whole genome linkage analysis, genotype simulations become prohibitively time consuming to perform on single computers. We have developed 'Grid-Allegro', a Grid aware implementation of the Allegro software, by which several thousands of genotype simulations can be performed in parallel in short time. With temporary installations of the Allegro executable and datasets on remote nodes at submission, the need of predefined Grid run-time environments is circumvented. We evaluated the performance, efficiency and scalability of this implementation in a genome scan on Swedish multiplex Alzheimer's disease families. We demonstrate that 'Grid-Allegro' allows for the full exploitation of the features available in Allegro for genome-wide linkage. The implementation of existing bioinformatics applications on Grids (Distributed Computing) represent a cost-effective alternative for addressing highly resource-demanding and data-intensive bioinformatics task, compared to acquiring and setting up clusters of computational hardware in house (Parallel Computing), a resource not available to most geneticists today.

  • 28.
    Andrade, Jorge
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Berglund, Lisa
    KTH, School of Biotechnology (BIO), Gene Technology.
    Uhlén, Mathias
    KTH, School of Biotechnology (BIO), Gene Technology.
    Odeberg, Jacob
    KTH, School of Biotechnology (BIO), Gene Technology.
    Using Grid Technology for Computationally Intensive Applied Bioinformatics Analyses2006In: In Silico Biology, ISSN 1386-6338, Vol. 6, no 6, p. 495-504Article in journal (Refereed)
    Abstract [en]

    For several applications and algorithms used in applied bioinformatics, a bottle neck in terms of computational time may arise when scaled up to facilitate analyses of large datasets and databases. Re-codification, algorithm modification or sacrifices in sensitivity and accuracy may be necessary to accommodate for limited computational capacity of single work stations. Grid computing offers an alternative model for solving massive computational problems by parallel execution of existing algorithms and software implementations. We present the implementation of a Grid-aware model for solving computationally intensive bioinformatic analyses exemplified by a blastp sliding window algorithm for whole proteome sequence similarity analysis, and evaluate the performance in comparison with a local cluster and a single workstation. Our strategy involves temporary installations of the BLAST executable and databases on remote nodes at submission, accommodating for dynamic Grid environments as it avoids the need of predefined runtime environments (preinstalled software and databases at specific Grid-nodes). Importantly, the implementation is generic where the BLAST executable can be replaced by other software tools to facilitate analyses suitable for parallelisation. This model should be of general interest in applied bioinformatics. Scripts and procedures are freely available from the authors.

  • 29.
    Angleby, Helen
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Oskarsson, Mattias
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Pang, Junfeng
    Zhang, Ya-ping
    Leitner, Thomas
    Braham, Caitlyn
    Arvestad, Lars
    KTH, School of Computer Science and Communication (CSC), Computational Biology, CB. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Webb, Kristen M.
    Savolainen, Peter
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Forensic Informativity of similar to 3000bp of Coding Sequence of Domestic Dog mtDNA2014In: Journal of Forensic Sciences, ISSN 0022-1198, E-ISSN 1556-4029, Vol. 59, no 4, p. 898-908Article in journal (Refereed)
    Abstract [en]

    The discriminatory power of the noncoding control region (CR) of domestic dog mitochondrial DNA alone is relatively low. The extent to which the discriminatory power could be increased by analyzing additional highly variable coding regions of the mitochondrial genome (mtGenome) was therefore investigated. Genetic variability across the mtGenome was evaluated by phylogenetic analysis, and the three most variable similar to 1kb coding regions identified. We then sampled 100 Swedish dogs to represent breeds in accordance with their frequency in the Swedish population. A previously published dataset of 59 dog mtGenomes collected in the United States was also analyzed. Inclusion of the three coding regions increased the exclusion capacity considerably for the Swedish sample, from 0.920 for the CR alone to 0.964 for all four regions. The number of mtDNA types among all 159 dogs increased from 41 to 72, the four most frequent CR haplotypes being resolved into 22 different haplotypes.

  • 30.
    Angleby, Helen
    et al.
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Savolainen, Peter
    KTH, School of Biotechnology (BIO), Gene Technology.
    Forensic informativity of domestic dog mtDNA control region sequences2005In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 154, no 03-feb, p. 99-110Article in journal (Refereed)
    Abstract [en]

    We have analysed the genetic information to be obtained from analysis of mitochondrial DNA (mtDNA) in domestic dogs studying the exclusion capacity in different populations and the correlation between mtDNA types and breeds or types of dogs. The exclusion capacities for a 573 bp sequence of the mitochondrial control region was between 0.86 and 0.95 for dogs in Sweden, the UK, Germany, Japan and China. The direct correlation between mtDNA type and breed, type of dog, and geographical origin of breed was generally low, but in some cases certain mtDNA types were overrepresented in one breed, and for wider groupings such as morphologically similar breeds, some mtDNA types were in many cases found in a distinct group of breeds, often originating from the same geographic region. This type of information may be used as an indication of the breed and, with some degree of probability, to include or exclude certain breeds from being the source of evidence materials.

  • 31. Apellaniz-Ruiz, Maria
    et al.
    Sanchez-Barroso, Lara
    Gutierrez-Gutierrez, Gerardo
    Sereno, Maria
    Garcia-Donas, Jesus
    Avall-Lundqvist, Elisabeth
    Green, Henrik
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Brosen, Kim
    Bergmann, Troels K.
    Rodriguez-Antona, Cristina
    Replication of Genetic Polymorphisms Reported to Be Associated with Taxane-Related Sensory Neuropathy in Patients with Early Breast Cancer Treated with Paclitaxel-Letter2015In: Clinical Cancer Research, ISSN 1078-0432, E-ISSN 1557-3265, Vol. 21, no 13, p. 3092-3093Article in journal (Refereed)
  • 32. Apostolova, Galina
    et al.
    Dorn, Roland
    Ka, Sojeong
    Hallbook, Finn
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Liser, Keren
    Hakim, Vicky
    Brodski, Claude
    Michaelidis, Theologos M.
    Dechant, Georg
    Neurotransmitter phenotype-specific expression changes in developing sympathetic neurons2007In: Molecular and Cellular Neuroscience, ISSN 1044-7431, E-ISSN 1095-9327, Vol. 35, no 3, p. 397-408Article in journal (Refereed)
    Abstract [en]

    During late developmental phases individual sympathetic neurons undergo a switch from noradrenergic to cholinergic neurotransmission. This phenomenon of plasticity depends on target-derived signals in vivo and is triggered by neurotrophic factors in neuronal cultures. To analyze genome-wide expression differences between the two transmitter phenotypes we employed DNA microarrays. RNA expression profiles were obtained from chick paravertebral sympathetic ganglia, treated with neurotrophin 3, glial cell line-derived neurotrophic factor or ciliary neurotrophic factor, all of which stimulate cholinergic differentiation. Results were compared with the effect of nerve growth factor, which functions as a pro-noradrenergic stimulus. The gene set common to all three comparisons defined the noradrenergic and cholinergic synexpression groups. Several functional categories, such as signal transduction, G-protein-coupled signaling, cation transport, neurogenesis and synaptic transmission, were enriched in these groups. Experiments based on the prediction that some of the identified genes play a role in the neurotransmitter switch identified bone morphogenetic protein signaling as an inhibitor of cholinergic differentiation.

  • 33.
    Araújo, Ana Catarina
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Song, Yajing
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Ståhl, Patrik L.
    Brumer, Harry, III
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Activated Paper Surfaces for the Rapid Hybridization of DNA through Capillary Transport2012In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 84, no 7, p. 3311-3317Article in journal (Refereed)
    Abstract [en]

    The development of low-cost, accurate, and equipment-free diagnostic tests is crucial to many clinical, laboratory, and field applications, including forensics and medical diagnostics. Cellulose fiber-based paper is an inexpensive, biodegradable, and renewable resource, the use of which as a biomolecule detection matrix and support confers several advantages compared to traditional materials such as glass. In this context, a new, facile method for the preparation of surface functionalized papers bearing single-stranded probe DNA (ssDNA) for rapid target hybridization via capillary transport is presented. Optimized reaction conditions were developed that allowed the direct, one-step activation of standard laboratory filters by the inexpensive and readily available bifunctional linking reagent, 1,4-phenylenediisothiocyanate. Such papers were thus amenable to subsequent coupling of amine-labeled ssDNA under standard conditions widely used for glass-based supports. The intrinsic wicking ability of the paper matrix facilitated rapid sample elution through arrays of probe DNA, leading to significant, detectable hybridization in the time required for the sample liquid to transit the vertical length of the strip (less than 2 min). The broad applicability of these paper test strips as rapid and specific diagnostics in "real-life" situations was exemplified by the discrimination of amplicons generated from canine and human mitochondrial and genomic DNA in mock forensic samples.

  • 34.
    Ardalan, Arman
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Molecular Profiling of the Population Dynamics: Foundation and Expansion of an Archaic Domesticate2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    "An ‘exponential growth of science’ throughout modern history has been frequently boasted by numerous narcissistic accounts of ‘modern humanity.’ Nonetheless, ‘modern science’ seems to have overwhelmingly compromised on its original promises by fitting into an ‘industrial scheme.’ With this concern, ‘molecular phylogeographics with conservational ambitions’ would look an intact ground for research efforts in a ‘school of biotechnology.’ The dog (Canis familiaris) as an earliest domestic animal has a history of conflicts over its origins and dispersal. Having those disputes addressed, valuable knowledge could be acquired on the nature and dynamics of domestication, and of human societies particularly of pre-agricultural ages. We employed two most widely-used genealogical markers, the mitochondrial DNA (mtDNA) and the non-recombining portion of the Y-chromosome (NRY), to address dog demography. Through 582 bps of mtDNA Control Region, complemented with whole mitochondrial genomes, it was established that almost all maternal lineages of the domestic dog worldwide coalesce to a population of at least 51 and perhaps many more female wolves in Asia South of Yangtze River (ASY) approximately 16,000 years before present (BP). This was based on the presence of a maximal diversity in this area, a descending gradient of diversity outward it, and a ubiquitous population structure everywhere in the world. A closer examination of this portrait in Southwest Asia (SwAsia) and the Fertile Crescent (FC), a region which has supplied persuasive evidence on early presence of the domestic dog, retrieved the same information, with implications for backbreeding with the local wolf population. Meanwhile, analyses of mtDNA dispersal showed that dogs took the long way via land to Madagascar Island, and not together with humans via sea. By the other approach, the NRY data in 14,437 bps length supplemented the mtDNA in reporting the height of diversity from ASY with a founding population of at least 13 male wolves, but expectably produced lower inter-regional differentiation by diversity. Screening of NRY by a SNP assay in the dingoes of Australia Island as a population of feral dogs revealed restricted and similar dispersal patterns for sires and dams. Prospects of ancient, multilocus and whole genome assays with the emerging high-throughput technologies has still more to promise on finer elaborations of these issues."

  • 35.
    Ardalan, Arman
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Kluetsch, Cornelya F. C.
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Biotechnology (BIO), Gene Technology.
    Zhang, Ai-bing
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Erdogan, Metin
    Uhlén, Mathias
    KTH, School of Biotechnology (BIO), Proteomics (closed 20130101).
    Houshmand, Massoud
    Tepeli, Cafer
    Ashtiani, Seyed Reza Miraei
    Savolainen, Peter
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Comprehensive study of mtDNA among Southwest Asian dogs contradicts independent domestication of wolf, but implies dog–wolf hybridization2011In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 1, no 3, p. 373-385Article in journal (Refereed)
    Abstract [en]

    Studies of mitochondrial DNA (mtDNA) diversity indicate explicitly that dogs were domesticated, probably exclusively, in southern East Asia. However, Southwest Asia (SwAsia) has had poor representation and geographical coverage in these studies. Other studies based on archaeological and genome-wide SNP data have suggested an origin of dogs in SwAsia. Hence, it has been suspected that mtDNA evidence for this scenario may have remained undetected. In the first comprehensive investigation of genetic diversity among SwAsian dogs, we analyzed 582 bp of mtDNA for 345 indigenous dogs from across SwAsia, and compared with 1556 dogs across the Old World. We show that 97.4% of SwAsian dogs carry haplotypes belonging to a universal mtDNA gene pool, but that only a subset of this pool, five of the 10 principal haplogroups, is represented in SwAsia. A high frequency of haplogroup B, potentially signifying a local origin, was not paralleled with the high genetic diversity expected for a center of origin. Meanwhile, 2.6% of the SwAsian dogs carried the rare non-universal haplogroup d2. Thus, mtDNA data give no indication that dogs originated in SwAsia through independent domestication of wolf, but dog–wolf hybridization may have formed the local haplogroup d2 within this region. Southern East Asia remains the only region with virtually full extent of genetic variation, strongly indicating it to be the primary and probably sole center of wolf domestication. An origin of dogs in southern East Asia may have been overlooked by other studies due to a substantial lack of samples from this region.

  • 36.
    Ardalan, Arman
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. Division of Animal Biotechnology and Genomics, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran 14965/161, Iran.
    Oskarsson, Mattias C. R.
    KTH, School of Biotechnology (BIO), Gene Technology.
    van Asch, Barbara
    Rabakonandriania, Elisabeth
    Savolainen, Peter
    KTH, School of Biotechnology (BIO), Gene Technology.
    African origin for Madagascan dogs revealed by mtDNA analysis2015In: Royal Society Open Science, E-ISSN 2054-5703Article in journal (Refereed)
    Abstract [en]

    Madagascar was one of the last major land masses to be inhabited by humans. It was initially colonized by Austronesian speaking Indonesians 1500–2000 years ago, but subsequent migration from Africa has resulted in approximately equal genetic contributions from Indonesia and Africa, and the material culture has mainly African influences. The dog, along with the pig and the chicken, was part of the Austronesian Neolithic culture, and was furthermore the only domestic animal to accompany humans to every continent in ancient times. To illuminate Madagascan cultural origins and track the initial worldwide dispersal of dogs, we here investigated the ancestry of Madagascan dogs. We analysed mtDNA control region sequences in dogs from Madagascar (n=145) and compared it with that from potential ancestral populations in Island Southeast Asia (n=219) and sub-Saharan Africa (n=493). We found that 90% of the Madagascan dogs carried a haplotype that was also present in sub-Saharan Africa and that the remaining lineages could all be attributed to a likely origin in Africa. By contrast, only 26% of Madagascan dogs shared haplotypes with Indonesian dogs, and one haplotype typical for Austronesian dogs, carried by more than 40% of Indonesian and Polynesian dogs, was absent among the Madagascan dogs. Thus, in contrast to the human population, Madagascan dogs seem to trace their origin entirely from Africa. These results suggest that dogs were not brought to Madagascar by the initial Austronesian speaking colonizers on their transoceanic voyage, but were introduced at a later stage, together with human migration and cultural influence from Africa.

  • 37.
    Ardalan, Arman
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Oskarsson, Mattias
    KTH, School of Biotechnology (BIO), Gene Technology.
    Natanaelsson, Christian
    KTH, School of Biotechnology (BIO), Gene Technology.
    Wilton, Alan N.
    Ahmadian, Afshin
    KTH, School of Biotechnology (BIO), Gene Technology.
    Savolainen, Peter
    KTH, School of Biotechnology (BIO), Gene Technology.
    Narrow genetic basis for the Australian dingo confirmed through analysis of paternal ancestry2012In: Genetica, ISSN 0016-6707, E-ISSN 1573-6857, Vol. 140, no 1-3, p. 65-73Article in journal (Refereed)
    Abstract [en]

    The dingo (Canis lupus dingo) is an iconic animal in the native culture of Australia, but archaeological and molecular records indicate a relatively recent history on the continent. Studies of mitochondrial DNA (mtDNA) imply that the current dingo population was founded by a small population of already tamed dogs from Southeast Asia. However, the maternal genetic data might give a unilateral picture, and the gene pool has yet to be screened for paternal ancestry. We sequenced 14,437 bp of the Y-chromosome (Y-chr) from two dingoes and one New Guinea Singing Dog (NGSD). This positioned dingo and NGSD within the domestic dog Y-chr phylogeny, and produced one haplotype not detected before. With this data, we characterized 47 male dingoes in 30 Y-chr single-nucleotide polymorphism sites using protease-mediated allele-specific extension technology. Only two haplotypes, H3 and H60, were found among the dingoes, at frequencies of 68.1 and 31.9 %, respectively, compared to 27 haplotypes previously established in the domestic dog. While H3 is common among Southeast Asian dogs, H60 was specifically found in dingoes and the NGSD, but was related to Southeast Asian dog Y-chr haplotypes. H3 and H60 were observed exclusively in the western and eastern parts of Australia, respectively, but had a common range in Southeast. Thus, the Y-chr diversity was very low, similar to previous observations for d-loop mtDNA. Overall genetic evidence suggests a very restricted introduction of the first dingoes into Australia, possibly from New Guinea. This study further confirms the dingo as an isolated feral dog.

  • 38. Arendt, M.
    et al.
    Cairns, K. M.
    Ballard, J. W. O.
    Savolainen, Peter
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Axelsson, E.
    Diet adaptation in dog reflects spread of prehistoric agriculture2016In: Heredity, ISSN 0018-067X, E-ISSN 1365-2540, Vol. 117, no 5, p. 301-306Article in journal (Refereed)
    Abstract [en]

    Adaptations allowing dogs to thrive on a diet rich in starch, including a significant AMY2B copy number gain, constituted a crucial step in the evolution of the dog from the wolf. It is however not clear whether this change was associated with the initial domestication, or represents a secondary shift related to the subsequent development of agriculture. Previous efforts to study this process were based on geographically limited data sets and low-resolution methods, and it is therefore not known to what extent the diet adaptations are universal among dogs and whether there are regional differences associated with alternative human subsistence strategies. Here we use droplet PCR to investigate worldwide AMY2B copy number diversity among indigenous as well as breed dogs and wolves to elucidate how a change in dog diet was associated with the domestication process and subsequent shifts in human subsistence. We find that AMY2B copy numbers are bimodally distributed with high copy numbers (median 2n AMY2B =11) in a majority of dogs but no, or few, duplications (median 2n AMY2B =3) in a small group of dogs originating mostly in Australia and the Arctic. We show that this pattern correlates geographically to the spread of prehistoric agriculture and conclude that the diet change may not have been associated with initial domestication but rather the subsequent development and spread of agriculture to most, but not all regions of the globe.

  • 39.
    Arvestad, Lars
    et al.
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Visa, N.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Wieslander, L.
    Savolainen, Peter
    KTH, School of Biotechnology (BIO), Gene Technology.
    Expressed sequence tags from the midgut and an epithelial cell line of Chironomus tentans: annotation, bioinformatic classification of unknown transcripts and analysis of expression levels2005In: Insect molecular biology (Print), ISSN 0962-1075, E-ISSN 1365-2583, Vol. 14, no 6, p. 689-695Article in journal (Refereed)
    Abstract [en]

    Expressed sequence tags (ESTs) were generated from two Chironomus tentans cDNA libraries, constructed from an embryo epithelial cell line and from larva midgut tissue. 8584 5'-end ESTs were generated and assembled into 3110 tentative unique transcripts, providing the largest contribution of C. tentans sequences to public databases to date. Annotation using BLAST gave 1975 (63.5%) transcripts with a significant match in the major gene/protein databases, 1170 with a best match to Anopheles gambiae and 480 to Drosophila melanogaster. 1091 transcripts (35.1%) had no match to any database. Studies of open reading frames suggest that at least 323 of these contain a coding sequence, indicating that a large proportion of the genes in C. tentans belong to previously unknown gene families.

  • 40.
    Asp, Michaela
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology.
    Salmen, Fredrik
    KTH, School of Biotechnology (BIO), Gene Technology.
    Stahl, Patrik L.
    Vickovic, Sanja
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Felldin, Ulrika
    Lofling, Marie
    Navarro, Jose Fernandez
    Maaskola, Jonas
    Eriksson, Maria J.
    Persson, Bengt
    Corbascio, Matthias
    Persson, Hans
    Linde, Cecilia
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Spatial detection of fetal marker genes expressed at low level in adult human heart tissue2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 12941Article in journal (Refereed)
    Abstract [en]

    Heart failure is a major health problem linked to poor quality of life and high mortality rates. Hence, novel biomarkers, such as fetal marker genes with low expression levels, could potentially differentiate disease states in order to improve therapy. In many studies on heart failure, cardiac biopsies have been analyzed as uniform pieces of tissue with bulk techniques, but this homogenization approach can mask medically relevant phenotypes occurring only in isolated parts of the tissue. This study examines such spatial variations within and between regions of cardiac biopsies. In contrast to standard RNA sequencing, this approach provides a spatially resolved transcriptome- and tissue-wide perspective of the adult human heart, and enables detection of fetal marker genes expressed by minor subpopulations of cells within the tissue. Analysis of patients with heart failure, with preserved ejection fraction, demonstrated spatially divergent expression of fetal genes in cardiac biopsies.

  • 41. Asplund, A.
    et al.
    Bjorklund, M. Gry
    Sundquist, C.
    Stromberg, S.
    Edlund, K.
    Oestman, A.
    Nilsson, Peter
    KTH, School of Biotechnology (BIO), Proteomics.
    Ponten, F.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Expression profiling of microdissected cell populations selected from basal cells in normal epidermis and basal cell carcinoma2008In: British Journal of Dermatology, ISSN 0007-0963, E-ISSN 1365-2133, Vol. 158, no 3, p. 527-538Article in journal (Refereed)
    Abstract [en]

    Background Basal cell carcinomas (BCCs) are prevalent tumours with uniform histology that develop without any known precursor lesion. Alterations in the sonic hedgehog-patched1 signalling pathway are accepted as necessary events for tumorigenesis, and mutations in the patched1 gene are frequently present in tumours. Objectives To analyse transcript profiles in BCC. Methods We used laser-assisted microdissection to isolate and collect cell populations defined under the microscope. Peripheral cells from nests of BCC were selected to represent tumour cells, and normal keratinocytes from epidermis basal layer were used as control. Extracted RNA was amplified and hybridized on to a cDNA microarray. Results Our results show that BCC cells express a transcript signature that is significantly different from that of normal keratinocytes, and over 350 genes with various functions were identified as differentially expressed. The compiled data suggest an upregulation of the Wnt signalling pathway as a major event in BCC cells. Furthermore, tumour cells appear to have an increased sensitivity to oxygen radicals and dysregulated genes involved in antigen presentation. Results were validated at both the transcriptional level using real-time polymerase chain reaction and at the protein level using immunohistochemistry. Conclusions We show that microdissection in combination with robust strategies for RNA extraction, amplification and cDNA microarray analysis allow for reliable transcript profiling and that antibody-based proteomics provides an advantageous strategy for the analysis of corresponding differentially expressed proteins. We found that expression patterns were significantly altered in BCC cells compared with basal keratinocytes and that the Wnt signalling pathway was upregulated in tumour cells.

  • 42. Asplund, A.
    et al.
    Gustafsson, A. C.
    Wikonkal, N. M.
    Sela, A.
    Leffell, D. J.
    Kidd, K.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Brash, D. E.
    Ponten, F.
    PTCH codon 1315 polymorphism and risk for nonmelanoma skin cancer2005In: British Journal of Dermatology, ISSN 0007-0963, E-ISSN 1365-2133, Vol. 152, no 5, p. 868-873Article in journal (Refereed)
    Abstract [en]

    Background The PTCH tumour suppressor gene is involved in the development of nearly all basal cell carcinomas (BCCs) of the skin and a fraction of squamous cell carcinomas (SCCs). A nonconservative Pro/Leu nucleotide polymorphism within PTCH exon 23 at codon 1315 was recently reported to be potentially important for the development of breast epithelial cell cancers. Objectives Accordingly, the status of PTCH codon 1315 was analysed for a possible association with the development of nonmelanoma skin cancers (NMSCs) in a pilot study. Because skin cancer risk is affected by specific population-dependent phenotypes such as skin and hair colour, codon 1315 was also analysed for normal allele frequency variation in human populations having differing extents of eumelanin vs. phaeomelanin. Methods The single nucleotide polymorphism in codon 1315 of the human PTCH gene was analysed in genomic DNA from six different populations comprising 472 blood samples and from 170 patients in four different categories with NMSC. Polymerase chain reaction and pyrosequencing were used to determine the allele frequencies. Allelic loss was furthermore determined in tumours following microdissection. Results The Pro/Pro genotype frequency ranged from 30% to 65% between populations, with a significant trend for a reduced frequency of the Pro/Pro genotype in populations having lighter pigmentation (P = 0.020). Pro/Pro frequency showed an increasing trend with increasing tumour case severity (P = 0.027). In 260 samples from 180 Swedish patients with NMSC and a control group of 96 healthy ethnically matched volunteers, no statistically significant pairwise differences between groups were detected in the PTCH codon 1315 allelic distribution, neither was a difference seen for multiple or early onset cases of BCC in the Swedish population. In Swedish patients with single tumours, allelic loss (loss of heterozygosity) was observed in 20 of 30 (67%) patients with BCC and four of 22 (18%) patients with SCC, with no preference in the allele lost. In contrast, the Pro/Pro genotype was frequent in seven U.S. patients having multiple independent BCCs. One of these patients was heterozygous, enabling allelic loss studies. Of 20 independent tumours, 11 had lost an allele; 10 of the 11 had lost Leu, suggesting nonrandom loss that favoured retention of Pro (P = 0.0059). Conclusions Our results indicate an association between the eumelanin-to-phaeomelanin shift and a shift from the Pro/Pro genotype to Leu-containing genotypes. Failure to lose Pro during the shift to phaeomelanin may be associated with an increased population risk for BCC and increased individual risk for multiple BCC. During development of a tumour, the effect of Pro may be magnified by loss of the Leu allele.

  • 43. Asplund, A.
    et al.
    Sivertsson, A.
    Backvall, H.
    Ahmadian, Afshin
    KTH, School of Biotechnology (BIO), Gene Technology.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Ponten, F.
    Genetic mosaicism in basal cell carcinoma2005In: Experimental dermatology, ISSN 0906-6705, E-ISSN 1600-0625, Vol. 14, no 8, p. 593-600Article in journal (Refereed)
    Abstract [en]

    Human basal cell cancer (BCC) shows unique growth characteristics, including a virtual inability to metastasize, absence of a precursor stage and lack of tumour progression. The clonal nature of BCC has long been a subject for debate because of the tumour growth pattern. Despite a morphologically multifocal appearance, genetic analysis and three-dimensional reconstructions of tumours have favoured a unicellular origin. We have utilized the X-chromosome inactivation assay in order to examine clonality in 13 cases of BCC. Four parts of each individual tumour plus isolated samples of stroma were analysed following laser-assisted microdissection. In 12/13 tumours, the epithelial component of the tumour showed a monoclonal pattern suggesting a unicellular origin. Surprisingly, one tumour showed evidence of being composed of at least two non-related monoclonal clones. This finding was supported by the analysis of the ptch and p53 gene. Clonality analysis of tumour stroma showed both mono- and polyclonal patterns. A prerequisite for this assay is that the extent of skewing is determined and compensated for in each case. Owing to the mosaic pattern of normal human epidermis, accurate coefficients are difficult to obtain; we, therefore, performed all analyses both with and without considering skewing. This study concludes that BCC are monoclonal neoplastic growths of epithelial cells, embedded in a connective tissue stroma at least in part of polyclonal origin. The study results show that what appears to be one tumour may occasionally constitute two or more independent tumours intermingled or adjacent to each other, possibly reflecting a local predisposition to malignant transformation.

  • 44. Backvall, H.
    et al.
    Asplund, A.
    Gustafsson, A.
    Sivertsson, A.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Ponten, F.
    Genetic tumor archeology: microdissection and genetic heterogeneity in squamous and basal cell carcinoma2005In: Mutation research, ISSN 0027-5107, E-ISSN 1873-135X, Vol. 571, no 02-jan, p. 65-79Article, review/survey (Refereed)
    Abstract [en]

    Carcinogenesis is a multi-step series of somatic genetic events. The complexity of this multi-hit process makes it difficult to determine each single event and the definitive outcome of such events. To investigate the genetic alterations in cancer-related genes, sensitive and reliable detection methods are of major importance for generating relevant results. Another critical issue is the quality of starting material which largely affects the outcome of the analysis. Microdissection of cells defined under the microscope ensures a selection of representative material for subsequent genetic analysis. Skin cancer provides an advantageous model for studying the development of cancer. Detectable lesions occur early during tumor progression, facilitating molecular analysis of the cell populations from both preneoplastic and neoplastic lesions. Alterations of the p53 tumor suppressor gene are very common in non-melanoma skin cancer, and dysregulation of p53 pathways appear to be an early event in the tumor development. A high frequency of epidermal p53 clones has been detected in chronically sun-exposed skin. The abundance of clones containing p53 mutated keratinocytes adjacent to basal cell (BCC) and squamous cell carcinoma (SCC) suggests a role in human skin carcinogenesis. Studies using p53 mutations as a clonality marker have suggested a direct link between actinic keratosis, SCC in situ and invasive SCC. Microdissection-based studies have also shown that different parts of individual BCC tumors can share a common p53 mutation yet differ with respect to additional alterations within the p53 gene, consistent with subclonal development within tumors. Here, we present examples of using well-defined cell populations, including single cells, from complex tissue in combination with molecular tools to reveal features involved in skin carcinogenesis.

  • 45. Bagnoud, Alexandre
    et al.
    de Bruijn, Ino
    Andersson, Anders F.
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Biotechnology (BIO), Gene Technology.
    Diomidis, Nikitas
    Leupin, Olivier X.
    Schwyn, Bernhard
    Bernier-Latmani, Rizlan
    A minimalistic microbial food web in an excavated deep subsurface clay rock2016In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 92, no 1, article id UNSP fiv138Article in journal (Refereed)
    Abstract [en]

    Clay rocks are being considered for radioactive waste disposal, but relatively little is known about the impact of microbes on the long-term safety of geological repositories. Thus, a more complete understanding of microbial community structure and function in these environments would provide further detail for the evaluation of the safety of geological disposal of radioactive waste in clay rocks. It would also provide a unique glimpse into a poorly studied deep subsurface microbial ecosystem. Previous studies concluded that microorganisms were present in pristine Opalinus Clay, but inactive. In this work, we describe the microbial community and assess the metabolic activities taking place within borehole water. Metagenomic sequencing and genome-binning of a porewater sample containing suspended clay particles revealed a remarkably simple heterotrophic microbial community, fueled by sedimentary organic carbon, mainly composed of two organisms: a Pseudomonas sp. fermenting bacterium growing on organic macromolecules and releasing organic acids and H-2, and a sulfate-reducing Peptococcaceae able to oxidize organic molecules to CO2. In Opalinus Clay, this microbial system likely thrives where pore space allows it. In a repository, this may occur where the clay rock has been locally damaged by excavation or in engineered backfills.

  • 46. Bendz, Maria
    et al.
    Skwark, Marcin
    Nilsson, Daniel
    Granholm, Viktor
    Cristobal, Susana
    Käll, Lukas
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Elofsson, Arne
    Membrane protein shaving with thermolysin can be used to evaluate topology predictors2013In: Proteomics, ISSN 1615-9853, E-ISSN 1615-9861, Vol. 13, no 9, p. 1467-1480Article in journal (Refereed)
    Abstract [en]

    Topology analysis of membrane proteins can be obtained by enzymatic shaving in combination with MS identification of peptides. Ideally, such analysis could provide quite detailed information about the membrane spanning regions. Here, we examine the ability of some shaving enzymes to provide large-scale analysis of membrane proteome topologies. To compare different shaving enzymes, we first analyzed the detected peptides from two over-expressed proteins. Second, we analyzed the peptides from non-over-expressed Escherichia coli membrane proteins with known structure to evaluate the shaving methods. Finally, the identified peptides were used to test the accuracy of a number of topology predictors. At the end we suggest that the usage of thermolysin, an enzyme working at the natural pH of the cell for membrane shaving, is superior because: (i) we detect a similar number of peptides and proteins using thermolysin and trypsin; (ii) thermolysin shaving can be run at a natural pH and (iii) the incubation time is quite short. (iv) Fewer detected peptides from thermolysin shaving originate from the transmembrane regions. Using thermolysin shaving we can also provide a clear separation between the best and the less accurate topology predictors, indicating that using data from shaving can provide valuable information when developing new topology predictors.

  • 47. Bergmann, Troels K.
    et al.
    Brasch-Andersen, Charlotte
    Gréen, Henrik
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Mirza, Mansoor R.
    Skougaard, Kristin
    Wihl, Jessica
    Keldsen, Nina
    Damkier, Per
    Peterson, Curt
    Vach, Werner
    Brosen, Kim
    Impact of ABCB1 Variants on Neutrophil Depression: A Pharmacogenomic Study of Paclitaxel in 92 Women with Ovarian Cancer2012In: Basic & Clinical Pharmacology & Toxicology, ISSN 1742-7835, E-ISSN 1742-7843, Vol. 110, no 2, p. 199-204Article in journal (Refereed)
    Abstract [en]

    The standard treatment for ovarian cancer in advanced stages is post-surgery treatment with taxane-platin chemotherapy. Despite an initial high response rate, most patients eventually relapse. The dose-limiting toxicities of paclitaxel are neutropenia and neuropathy, but the inter-individual variability is large. The aim of this prospective study was to investigate the impact of genetic variants in key drug metabolizing/transporter genes on toxicity and compliance. CYP2C8*3 and three ABCB1 polymorphisms were chosen for primary analysis, and a host of other candidate genes was explored in 92 prospectively recruited Scandinavian Caucasian women with primary ovarian cancer who were treated with paclitaxel and carboplatin. A single investigator assessed the clinical toxicity in 97% of the patients. Patients carrying variant alleles of ABCB1 C3435T experienced more pronounced neutrophil decrease (63%, 72% and 80% for 3435CC, CT and TT, respectively; p-value 0.03). A similar association was found for G2677T /A, p-value 0.02. For C1236T, there was a trend with p-value 0.06. No statistically significant correlations were found for paclitaxel compliance and sensory neuropathy in the primary analysis. Variants in the drug transporter ABCB1 gene are possibly associated with the neutrophil suppressing effect of paclitaxel in patients with ovarian cancer. This finding has implications for the understanding of bone marrow suppression and future tailored chemotherapy.

  • 48. Bergmann, Troels K.
    et al.
    Vach, Werner
    Feddersen, Soren
    Eckhoff, Lise
    Gréen, Henrik
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Herrstedt, Jörn
    Brosen, Kim
    GWAS-based association between RWDD3 and TECTA variants and paclitaxel induced neuropathy could not be confirmed in Scandinavian ovarian cancer patients2013In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 52, no 4, p. 871-873Article in journal (Refereed)
  • 49. Bjorklund, Marcus Gry
    et al.
    Natanaelsson, Christian
    Eriksson Karlström, Amelie
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Hao, Yong
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Microarray analysis using disiloxyl 70mer oligonucleotides2008In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 36, no 4, p. 1334-1342Article in journal (Refereed)
    Abstract [en]

    DNA microarray technology has evolved dramatically in recent years, and is now a common tool in researchers portfolios. The scope of the technique has expanded from small-scale studies to extensive studies such as classification of disease states. Technical knowledge regarding solid phase microarrays has also increased, and the results acquired today are more reliable than those obtained just a few years ago. Nevertheless, there are various aspects of microarray analysis that could be improved. In this article we show that the proportions of full-length probes used significantly affects the results of global analyses of transcriptomes. In particular, measurements of transcripts in low abundance are more sensitive to truncated probes, which generally increase the degree of cross hybridization and loss of specific signals. In order to improve microarray analysis, we here introduce a disiloxyl purification step, which ensures that all the probes on the microarray are at full length. We demonstrate that when the features on microarrays consist of full-length probes the signal intensity is significantly increased. The overall increase in intensity enables the hybridization stringency to be increased, and thus enhance the robustness of the results.

  • 50. Bjursell, Magnus K.
    et al.
    Blom, Henk J.
    Cayuela, Jordi Asin
    Engvall, Martin L.
    Lesko, Nicole
    Balasubramaniam, Shanti
    Brandberg, Goran
    Halldin, Maria
    Falkenberg, Maria
    Jakobs, Cornelis
    Smith, Desiree
    Struys, Eduard
    von Dobeln, Ulrika
    Gustafsson, Claes M.
    Lundeberg, Joakim
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Biotechnology (BIO), Gene Technology.
    Wedell, Anna
    Adenosine Kinase Deficiency Disrupts the Methionine Cycle and Causes Hypermethioninemia, Encephalopathy, and Abnormal Liver Function2011In: American Journal of Human Genetics, ISSN 0002-9297, E-ISSN 1537-6605, Vol. 89, no 4, p. 507-515Article in journal (Refereed)
    Abstract [en]

    Four inborn errors of metabolism (IEMs) are known to cause hypermethioninemia by directly interfering with the methionine cycle. Hypermethioninemia is occasionally discovered incidentally, but it is often disregarded as an unspecific finding, particularly if liver disease is involved. In many individuals the hypermethioninemia resolves without further deterioration, but it can also represent an early sign of a severe, progressive neurodevelopmental disorder. Further investigation of unclear hypermethioninemia is therefore important. We studied two siblings affected by severe developmental delay and liver dysfunction. Biochemical analysis revealed increased plasma levels of methionine, S-adenosylmethionine (Ado Met), and S-adenosylhomocysteine (AdoHcy) but normal or mildly elevated homocysteine (Hcy) levels, indicating a block in the methionine cycle. We excluded S-adenosylhomocysteine hydrolase (SAHH) deficiency, which causes a similar biochemical phenotype, by using genetic and biochemical techniques and hypothesized that there was a functional block in the SAHH enzyme as a result of a recessive mutation in a different gene. Using exome sequencing, we identified a homozygous c.902C>A (p.Ala301Glu) missense mutation in the adenosine kinase gene (ADK), the function of which fits perfectly with this hypothesis. Increased urinary adenosine excretion confirmed ADK deficiency in the siblings. Four additional individuals from two unrelated families with a similar presentation were identified and shown to have a homozygous c.653A>C (p.Asp218Ala) and c.38G>A (p.Gly13Glu) mutation, respectively, in the same gene. All three missense mutations were deleterious, as shown by activity measurements on recombinant enzymes. ADK deficiency is a previously undescribed, severe IEM shedding light on a functional link between the methionine cycle and adenosine metabolism.

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