12 results on '"Björn Viklund"'
Search Results
2. Scattered genomic amplification in dedifferentiated liposarcoma
- Author
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Nils Mandahl, Linda Magnusson, Jenny Nilsson, Björn Viklund, Elsa Arbajian, Fredrik Vult von Steyern, Anders Isaksson, and Fredrik Mertens
- Subjects
Liposarcoma ,Chromosomes ,Amplification ,5p ,12q ,Gene expression ,Genetics ,QH426-470 - Abstract
Abstract Background Atypical lipomatous tumor (ALT), well differentiated liposarcoma (WDLS) and dedifferentiated liposarcoma (DDLS) are cytogenetically characterized by near-diploid karyotypes with no or few other aberrations than supernumerary ring or giant marker chromosomes, although DDLS tend to have somewhat more complex rearrangements. In contrast, pleomorphic liposarcomas (PLS) have highly aberrant and heterogeneous karyotypes. The ring and giant marker chromosomes contain discontinuous amplicons, in particular including multiple copies of the target genes CDK4, HMGA2 and MDM2 from 12q, but often also sequences from other chromosomes. Results The present study presents a DDLS with an atypical hypertriploid karyotype without any ring or giant marker chromosomes. SNP array analyses revealed amplification of almost the entire 5p and discontinuous amplicons of 12q including the classical target genes, in particular CDK4. In addition, amplicons from 1q, 3q, 7p, 9p, 11q and 20q, covering from 2 to 14 Mb, were present. FISH analyses showed that sequences from 5p and 12q were scattered, separately or together, over more than 10 chromosomes of varying size. At RNA sequencing, significantly elevated expression, compared to myxoid liposarcomas, was seen for TRIO and AMACR in 5p and of CDK4, HMGA2 and MDM2 in 12q. Conclusions The observed pattern of scattered amplification does not show the characteristics of chromothripsis, but is novel and differs from the well known cytogenetic manifestations of amplification, i.e., double minutes, homogeneously staining regions and ring chromosomes. Possible explanations for this unusual distribution of amplified sequences might be the mechanism of alternative lengthening of telomeres that is frequently active in DDLS and events associated with telomere crisis.
- Published
- 2017
- Full Text
- View/download PDF
3. Figure S1 from Integrated Molecular Analysis of Undifferentiated Uterine Sarcomas Reveals Clinically Relevant Molecular Subtypes
- Author
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Joseph W. Carlson, Anders Isaksson, Kaisa Lehti, Ben Davidson, Gunnar B. Kristensen, Anna Måsbäck, John K. Schoolmeester, Debra A. Bell, Lidia Moyano-Galceran, Jordi Gonzalez-Molina, Pádraic Corcoran, Nina Hollfelder, Cheng-Han Lee, Marisa R. Nucci, Tjalling Bosse, Mehran Ghaderi, Björn Viklund, Elin Hardell, and Amrei Binzer-Panchal
- Abstract
Supplemental Figure 1
- Published
- 2023
- Full Text
- View/download PDF
4. Table S2 from Integrated Molecular Analysis of Undifferentiated Uterine Sarcomas Reveals Clinically Relevant Molecular Subtypes
- Author
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Joseph W. Carlson, Anders Isaksson, Kaisa Lehti, Ben Davidson, Gunnar B. Kristensen, Anna Måsbäck, John K. Schoolmeester, Debra A. Bell, Lidia Moyano-Galceran, Jordi Gonzalez-Molina, Pádraic Corcoran, Nina Hollfelder, Cheng-Han Lee, Marisa R. Nucci, Tjalling Bosse, Mehran Ghaderi, Björn Viklund, Elin Hardell, and Amrei Binzer-Panchal
- Abstract
Table S2
- Published
- 2023
- Full Text
- View/download PDF
5. Data from Integrated Molecular Analysis of Undifferentiated Uterine Sarcomas Reveals Clinically Relevant Molecular Subtypes
- Author
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Joseph W. Carlson, Anders Isaksson, Kaisa Lehti, Ben Davidson, Gunnar B. Kristensen, Anna Måsbäck, John K. Schoolmeester, Debra A. Bell, Lidia Moyano-Galceran, Jordi Gonzalez-Molina, Pádraic Corcoran, Nina Hollfelder, Cheng-Han Lee, Marisa R. Nucci, Tjalling Bosse, Mehran Ghaderi, Björn Viklund, Elin Hardell, and Amrei Binzer-Panchal
- Abstract
Purpose:Undifferentiated uterine sarcomas (UUS) are rare, extremely deadly, sarcomas with no effective treatment. The goal of this study was to identify novel intrinsic molecular UUS subtypes using integrated clinical, histopathologic, and molecular evaluation of a large, fully annotated, patient cohort.Experimental Design:Fifty cases of UUS with full clinicopathologic annotation were analyzed for gene expression (n = 50), copy-number variation (CNV, n = 40), cell morphometry (n = 39), and protein expression (n = 22). Gene ontology and network enrichment analysis were used to relate over- and underexpressed genes to pathways and further to clinicopathologic and phenotypic findings.Results:Gene expression identified four distinct groups of tumors, which varied in their clinicopathologic parameters. Gene ontology analysis revealed differential activation of pathways related to genital tract development, extracellular matrix (ECM), muscle function, and proliferation. A multivariable, adjusted Cox proportional hazard model demonstrated that RNA group, mitotic index, and hormone receptor expression influence patient overall survival (OS). CNV arrays revealed characteristic chromosomal changes for each group. Morphometry demonstrated that the ECM group, the most aggressive, exhibited a decreased cell density and increased nuclear area. A cell density cutoff of 4,300 tumor cells per mm2 could separate ECM tumors from the remaining cases with a sensitivity of 83% and a specificity of 94%. IHC staining of MMP-14, Collagens 1 and 6, and Fibronectin proteins revealed differential expression of these ECM-related proteins, identifying potential new biomarkers for this aggressive sarcoma subgroup.Conclusions:Molecular evaluation of UUS provides novel insights into the biology, prognosis, phenotype, and possible treatment of these tumors.
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- 2023
- Full Text
- View/download PDF
6. Integrated Molecular Analysis of Undifferentiated Uterine Sarcomas Reveals Clinically Relevant Molecular Subtypes
- Author
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Joseph W. Carlson, Debra A. Bell, Tjalling Bosse, Gunnar B. Kristensen, Cheng-Han Lee, Marisa R. Nucci, Jordi Gonzalez-Molina, Pádraic Corcoran, Anders Isaksson, Björn Viklund, Lidia Moyano-Galceran, Amrei Binzer-Panchal, John K. Schoolmeester, Kaisa Lehti, Elin Hardell, Ben Davidson, Anna Måsbäck, Mehran Ghaderi, and Nina Hollfelder
- Subjects
Proteomics ,0301 basic medicine ,Cancer Research ,Mitotic index ,DNA Copy Number Variations ,Kaplan-Meier Estimate ,Biology ,Extracellular matrix ,03 medical and health sciences ,0302 clinical medicine ,Gene expression ,Biomarkers, Tumor ,Image Processing, Computer-Assisted ,medicine ,Humans ,Gene ,Proportional Hazards Models ,Chromosome Aberrations ,Gene Expression Profiling ,Computational Biology ,Sarcoma ,Prognosis ,medicine.disease ,Immunohistochemistry ,Phenotype ,3. Good health ,Gene expression profiling ,Gene Ontology ,030104 developmental biology ,Molecular Diagnostic Techniques ,Oncology ,030220 oncology & carcinogenesis ,Uterine Neoplasms ,Cancer research ,Female ,Neoplasm Grading - Abstract
Purpose: Undifferentiated uterine sarcomas (UUS) are rare, extremely deadly, sarcomas with no effective treatment. The goal of this study was to identify novel intrinsic molecular UUS subtypes using integrated clinical, histopathologic, and molecular evaluation of a large, fully annotated, patient cohort. Experimental Design: Fifty cases of UUS with full clinicopathologic annotation were analyzed for gene expression (n = 50), copy-number variation (CNV, n = 40), cell morphometry (n = 39), and protein expression (n = 22). Gene ontology and network enrichment analysis were used to relate over- and underexpressed genes to pathways and further to clinicopathologic and phenotypic findings. Results: Gene expression identified four distinct groups of tumors, which varied in their clinicopathologic parameters. Gene ontology analysis revealed differential activation of pathways related to genital tract development, extracellular matrix (ECM), muscle function, and proliferation. A multivariable, adjusted Cox proportional hazard model demonstrated that RNA group, mitotic index, and hormone receptor expression influence patient overall survival (OS). CNV arrays revealed characteristic chromosomal changes for each group. Morphometry demonstrated that the ECM group, the most aggressive, exhibited a decreased cell density and increased nuclear area. A cell density cutoff of 4,300 tumor cells per mm2 could separate ECM tumors from the remaining cases with a sensitivity of 83% and a specificity of 94%. IHC staining of MMP-14, Collagens 1 and 6, and Fibronectin proteins revealed differential expression of these ECM-related proteins, identifying potential new biomarkers for this aggressive sarcoma subgroup. Conclusions: Molecular evaluation of UUS provides novel insights into the biology, prognosis, phenotype, and possible treatment of these tumors.
- Published
- 2019
- Full Text
- View/download PDF
7. Different patterns of clonal evolution among different sarcoma subtypes followed for up to 25 years
- Author
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Otte Brosjö, Björn Viklund, Nils Mandahl, Jakob Hofvander, Pehr Rissler, Fredrik Vult von Steyern, Anders Isaksson, and Fredrik Mertens
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Oncogene Proteins, Fusion ,Science ,General Physics and Astronomy ,Liposarcoma ,Biology ,medicine.disease_cause ,Somatic evolution in cancer ,Polymorphism, Single Nucleotide ,General Biochemistry, Genetics and Molecular Biology ,Article ,Chromosomes ,Clonal Evolution ,03 medical and health sciences ,medicine ,Humans ,lcsh:Science ,Chromosome 12 ,Medicinsk genetik ,Genetics ,Chromosome Aberrations ,Myxoid liposarcoma ,Mutation ,Multidisciplinary ,Nucleotides ,Cytogenetics ,Karyotype ,Sarcoma ,General Chemistry ,Sequence Analysis, DNA ,medicine.disease ,Liposarcoma, Myxoid ,Chromosome Banding ,030104 developmental biology ,lcsh:Q ,Gene Fusion ,Neoplasm Recurrence, Local ,Medical Genetics ,Transcription Factor CHOP ,Follow-Up Studies - Abstract
To compare clonal evolution in tumors arising through different mechanisms, we selected three types of sarcoma—amplicon-driven well-differentiated liposarcoma (WDLS), gene fusion-driven myxoid liposarcoma (MLS), and sarcomas with complex genomes (CXS)—and assessed the dynamics of chromosome and nucleotide level mutations by cytogenetics, SNP array analysis and whole-exome sequencing. Here we show that the extensive single-cell variation in WDLS has minor impact on clonal key amplicons in chromosome 12. In addition, only a few of the single nucleotide variants in WDLS were present in more than one lesion, suggesting that such mutations are of little significance in tumor development. MLS displays few mutations other than the FUS-DDIT3 fusion, and the primary tumor is genetically sometimes much more complex than its relapses, whereas CXS in general shows a gradual increase of both nucleotide- and chromosome–level mutations, similar to what has been described in carcinomas., Hofvander and colleagues compare the patterns of clonal evolution in different pathogenetic subgroups of sarcoma. They show that sarcomas driven by gene fusion or amplification display few additional changes over time, whereas sarcomas with complex karyotypes show a gradual increase of nucleotide- and chromosome-level mutations.
- Published
- 2018
8. Genomic and transcriptomic features of dermatofibrosarcoma protuberans : Unusual chromosomal origin of the COL1A1-PDGFB fusion gene and synergistic effects of amplified regions in tumor development
- Author
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Felix Haglund, Fredrik Mertens, Linda Magnusson, Jan Köster, Nils Mandahl, Björn Viklund, Anders Isaksson, Jakob Hofvander, Henrik C. F. Bauer, and Elsa Arbajian
- Subjects
Adult ,G2 Phase ,Male ,Cancer Research ,Skin Neoplasms ,Adolescent ,Oncogene Proteins, Fusion ,Chromosomes, Human, Pair 22 ,Ring chromosome ,Chromosomal translocation ,Biology ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Translocation mechanisms ,Genetics ,Dermatofibrosarcoma protuberans ,medicine ,Humans ,Child ,Fusion ,Molecular Biology ,Aged ,Skin ,Medicinsk genetik ,Cancer och onkologi ,medicine.diagnostic_test ,Gene Expression Profiling ,Dermatofibrosarcoma ,Infant ,Chromosome ,Karyotype ,Genomics ,Middle Aged ,medicine.disease ,Gene Expression Regulation, Neoplastic ,SNP-array ,Child, Preschool ,030220 oncology & carcinogenesis ,Cancer and Oncology ,COL1A1/PDGFB Fusion Gene ,Female ,RNA-seq ,Medical Genetics ,Chromosomes, Human, Pair 17 ,SNP array ,Fluorescence in situ hybridization - Abstract
The dermatofibrosarcoma protuberans family of tumors (DPFT) comprises cutaneous soft tissue neoplasms associated with aberrant PDGFBR signaling, typically through a COL1A1-PDGFB fusion. The aim of the present study was to obtain a better understanding of the chromosomal origin of this fusion and to assess the spectrum of secondary mutations at the chromosome and nucleotide levels. We thus investigated 42 tumor samples from 35 patients using chromosome banding, fluorescence in situ hybridization, single nucleotide polymorphism arrays, and/or massively parallel sequencing (gene panel, whole exome and transcriptome sequencing) methods. We confirmed the age-associated differences in the origin of the COL1A1-PDGFB fusion and could show that it in most cases must arise after DNA synthesis, i.e., in the S or G2 phase of the cell cycle. Whereas there was a non-random pattern of secondary chromosomal rearrangements, single nucleotide variants seem to have little impact on tumor progression. No clear genomic differences between low-grade and high-grade DPFT were found, but the number of chromosomes and chromosomal imbalances as well as the frequency of 9p deletions all tended to be greater among the latter. Gene expression profiling of tumors with COL1A1-PDGFB fusions associated with unbalanced translocations or ring chromosomes identified several transcriptionally up-regulated genes in the amplified regions of chromosomes 17 and 22, including TBX2, PRKCA, MSI2, SOX9, SOX10, and PRAME.
- Published
- 2020
9. Gains of Chromosome 1p and 15q are Associated with Poor Survival After Cytoreductive Surgery and HIPEC for Treating Colorectal Peritoneal Metastases
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Malin Enblad, Wilhelm Graf, Anders Isaksson, Helgi Birgisson, Alexei Terman, Pascal Pucholt, and Björn Viklund
- Subjects
Oncology ,Male ,medicine.medical_specialty ,Aneuploidy ,Molecular Inversion Probe ,03 medical and health sciences ,0302 clinical medicine ,Surgical oncology ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,Translational Research and Biomarkers ,Peritoneal Neoplasms ,030304 developmental biology ,Aged ,Chromosome Aberrations ,Cancer och onkologi ,0303 health sciences ,Chromosomes, Human, Pair 15 ,business.industry ,Kirurgi ,Hazard ratio ,Chromosome ,Cytoreduction Surgical Procedures ,Hyperthermia, Induced ,Middle Aged ,medicine.disease ,Prognosis ,Confidence interval ,Survival Rate ,Chemotherapy, Adjuvant ,Chromosomes, Human, Pair 1 ,Cancer and Oncology ,030220 oncology & carcinogenesis ,Peritoneal Cancer Index ,Surgery ,Hyperthermic intraperitoneal chemotherapy ,Female ,business ,Colorectal Neoplasms ,Follow-Up Studies - Abstract
Purpose Genetic alterations in colorectal peritoneal metastases (PM) are largely unknown. This study was designed to analyze whole-genome copy number alterations (CNA) in colorectal PM and to identify alterations associated with prognosis after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Methods All patients with PM, originating from a colorectal adenocarcinoma, who were treated with CRS and HIPEC in Uppsala Sweden, between 2004 and 2015, were included (n = 114). DNA derived from formalin-fixed paraffin-embedded (FFPE) specimens were analyzed for CNA using molecular inversion probe arrays. Results There were extensive but varying degrees of CNA, ranging from minimal CNA to total aneuploidy. In particular, gain of parts of chromosome 1p and major parts of 15q were associated with poor survival. A combination of gains of 1p and 15q was associated with poor survival, also after adjustment for differences in peritoneal cancer index and completeness of cytoreduction score [hazard ratio (HR) 5.96; 95% confidence interval (CI) 2.19–16.18]. These patients had a mean copy number (CN) of 3.19 compared with 2.24 in patients without gains. Complete CN analysis was performed in 53 patients. Analysis was unsuccessful for the remaining patients due to insufficient amounts of DNA and signals caused by interstitial components and normal cells. There was no difference in survival between patients with successful and unsuccessful CN analysis. Conclusions This study shows that gains of parts of chromosome 1p and of major parts of chromosome 15q were significantly associated with poor survival after CRS and HIPEC, which could represent future prognostic biomarkers.
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- 2019
10. Four evolutionary trajectories underlie genetic intratumoral variation in childhood cancer
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Louise Cornmark, Noémie Braekeveldt, Jenny Karlsson, Torbjörn Backman, Anna Börjesson, Ingrid Øra, Johan Staaf, Sofia Bredin, Linda Holmquist Mengelbier, Barbara Gürtl Lackner, Bengt Sandstedt, Niklas Pal, Daniel Bexell, Anders Isaksson, Anders Valind, Björn Viklund, Tord Jonson, Caroline Jansson, Amina Wali, and David Gisselsson
- Subjects
0301 basic medicine ,Gene Rearrangement ,medicine.medical_specialty ,Single tumor ,Childhood cancer ,Clone (cell biology) ,Chromosome ,Disease ,Biology ,Chromosomes ,Evolution, Molecular ,03 medical and health sciences ,030104 developmental biology ,Variation (linguistics) ,Evolutionary biology ,Neoplasms ,Cancer cell ,Mutation ,Genetics ,medicine ,Medical genetics ,Humans ,Tumor Suppressor Protein p53 ,Child - Abstract
A major challenge to personalized oncology is that driver mutations vary among cancer cells inhabiting the same tumor. Whether this reflects principally disparate patterns of Darwinian evolution in different tumor regions has remained unexplored1–5. We mapped the prevalence of genetically distinct clones over 250 regions in 54 childhood cancers. This showed that primary tumors can simultaneously follow up to four evolutionary trajectories over different anatomic areas. The most common pattern consists of subclones with very few mutations confined to a single tumor region. The second most common is a stable coexistence, over vast areas, of clones characterized by changes in chromosome numbers. This is contrasted by a third, less frequent, pattern where a clone with driver mutations or structural chromosome rearrangements emerges through a clonal sweep to dominate an anatomical region. The fourth and rarest pattern is the local emergence of a myriad of clones with TP53 inactivation. Death from disease was limited to tumors exhibiting the two last, most dynamic patterns.
- Published
- 2017
11. Scattered genomic amplification in dedifferentiated liposarcoma
- Author
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Anders Isaksson, Linda Magnusson, Fredrik Mertens, Elsa Arbajian, Jenny Nilsson, Nils Mandahl, Björn Viklund, and Fredrik Vult von Steyern
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Pathology ,Dedifferentiated liposarcoma ,lcsh:QH426-470 ,Medicinska och farmaceutiska grundvetenskaper ,Amplification ,Biology ,Liposarcoma ,Biochemistry ,Chromosomes ,Atypical Lipomatous Tumor ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,medicine ,neoplasms ,Molecular Biology ,Genetics (clinical) ,5p ,12q ,Well Differentiated Liposarcoma ,Research ,Biochemistry (medical) ,Cytogenetics ,Karyotype ,Anatomy ,Basic Medicine ,medicine.disease ,body regions ,lcsh:Genetics ,030104 developmental biology ,030220 oncology & carcinogenesis ,Molecular Medicine ,Gene expression - Abstract
Background Atypical lipomatous tumor (ALT), well differentiated liposarcoma (WDLS) and dedifferentiated liposarcoma (DDLS) are cytogenetically characterized by near-diploid karyotypes with no or few other aberrations than supernumerary ring or giant marker chromosomes, although DDLS tend to have somewhat more complex rearrangements. In contrast, pleomorphic liposarcomas (PLS) have highly aberrant and heterogeneous karyotypes. The ring and giant marker chromosomes contain discontinuous amplicons, in particular including multiple copies of the target genes CDK4, HMGA2 and MDM2 from 12q, but often also sequences from other chromosomes. Results The present study presents a DDLS with an atypical hypertriploid karyotype without any ring or giant marker chromosomes. SNP array analyses revealed amplification of almost the entire 5p and discontinuous amplicons of 12q including the classical target genes, in particular CDK4. In addition, amplicons from 1q, 3q, 7p, 9p, 11q and 20q, covering from 2 to 14 Mb, were present. FISH analyses showed that sequences from 5p and 12q were scattered, separately or together, over more than 10 chromosomes of varying size. At RNA sequencing, significantly elevated expression, compared to myxoid liposarcomas, was seen for TRIO and AMACR in 5p and of CDK4, HMGA2 and MDM2 in 12q. Conclusions The observed pattern of scattered amplification does not show the characteristics of chromothripsis, but is novel and differs from the well known cytogenetic manifestations of amplification, i.e., double minutes, homogeneously staining regions and ring chromosomes. Possible explanations for this unusual distribution of amplified sequences might be the mechanism of alternative lengthening of telomeres that is frequently active in DDLS and events associated with telomere crisis. Electronic supplementary material The online version of this article (doi:10.1186/s13039-017-0325-5) contains supplementary material, which is available to authorized users.
- Published
- 2017
12. Rawcopy: Improved copy number analysis with Affymetrix arrays
- Author
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Björn Viklund, Anders Isaksson, and Markus Mayrhofer
- Subjects
0301 basic medicine ,Multidisciplinary ,Microarray ,business.industry ,Microarray analysis techniques ,Computer science ,Copy number analysis ,Pattern recognition ,Computational biology ,computer.software_genre ,Noise (electronics) ,Article ,Loss of heterozygosity ,03 medical and health sciences ,030104 developmental biology ,Biomedicinsk laboratorievetenskap/teknologi ,Biomedical Laboratory Science/Technology ,Artificial intelligence ,Data mining ,business ,computer - Abstract
Microarray data is subject to noise and systematic variation that negatively affects the resolution of copy number analysis. We describe Rawcopy, an R package for processing of Affymetrix CytoScan HD, CytoScan 750k and SNP 6.0 microarray raw intensities (CEL files). Noise characteristics of a large number of reference samples are used to estimate log ratio and B-allele frequency for total and allele-specific copy number analysis. Rawcopy achieves better signal-to-noise ratio and higher proportion of validated alterations than commonly used free and proprietary alternatives. In addition, Rawcopy visualizes each microarray sample for assessment of technical quality, patient identity and genome-wide absolute copy number states. Software and instructions are available at http://rawcopy.org.
- Published
- 2015
- Full Text
- View/download PDF
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