| 1. |
- Johansson, Henrik, et al.
(författare)
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Targeted resequencing of candidate genes using Selector Probes
- 2011
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Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 39:2, s. e8-
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Tidskriftsartikel (refereegranskat)abstract
- Targeted genome enrichment is a powerful tool for making use of the massive throughput of novel DNA-sequencing instruments. We herein present a simple and scalable protocol for multiplex amplification of target regions based on the Selector technique. The updated version exhibits improved coverage and compatibility with next-generation-sequencing (NGS) library-construction procedures for shotgun sequencing with NGS platforms. To demonstrate the performance of the technique, all 501 exons from 28 genes frequently involved in cancer were enriched for and sequenced in specimens derived from cell lines and tumor biopsies. DNA from both fresh frozen and formalin-fixed paraffin-embedded biopsies were analyzed and 94 specificity and 98 coverage of the targeted region was achieved. Reproducibility between replicates was high (R 2=0, 98) and readily enabled detection of copy-number variations. The procedure can be carried out in <24 h and does not require any dedicated instrumentation.
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| 2. |
- Karlsson, Anna K, et al.
(författare)
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Genomic and transcriptional alterations in lung adenocarcinoma in relation to smoking history.
- 2014
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 20:18, s. 4912-4924
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Cigarette smoking is the major pathogenic factor for lung cancer. The precise mechanisms of tobacco-related carcinogenesis, and its effect on the genomic and transcriptional landscape in lung cancer are not fully understood. Experimental Design 1398 (277 never-smokers, 1121 smokers) genomic and 1449 (370 never-smokers, 1079 smokers) transcriptional profiles were assembled from public lung adenocarcinoma cohorts, including matched next-generation DNA-sequencing data (n=423). Unsupervised and supervised methods were used to identify smoking-related copy number alterations (CNAs), predictors of smoking status, and molecular subgroups. Results Genomic meta-analyses showed that never-smokers and smokers harbored a similar frequency of total CNAs, although, specific regions (5q, 8q, 16p, 19p, and 22q) displayed a 20-30% frequency difference between the two groups. Importantly, supervised classification analyses based on CNAs or gene expression could not accurately predict smoking status (balanced accuracies ~60-80%). However, unsupervised multicohort transcriptional profiling stratified adenocarcinomas into distinct molecular subgroups with specific patterns of CNAs, oncogenic mutations, and mutation transversion frequencies that were independent of the smoking status. One subgroup included ~55-90% of never-smokers and ~20-40% of smokers (both current and former) with molecular and clinical features of a less aggressive and smoking-unrelated disease. Given the considerable intra-group heterogeneity in smoking-defined subgroups, especially among former-smokers, our results emphasize the clinical importance of accurate molecular characterization of lung adenocarcinoma. Conclusions The landscape of smoking-related CNAs and transcriptional alterations in adenocarcinomas is complex, heterogeneous, and with moderate differences. Our results support a molecularly distinct less aggressive adenocarcinoma entity, arising in never-smokers and a subset of smokers.
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| 3. |
- Leuchowius, Karl-Johan, et al.
(författare)
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Parallel Visualization of Multiple Protein Complexes in Individual Cells in Tumor Tissue
- 2013
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 12:6, s. 1563-1571
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Tidskriftsartikel (refereegranskat)abstract
- Cellular functions are regulated and executed by complex protein interaction networks. Accordingly, it is essential to understand the interplay between proteins in determining the activity status of signaling cascades. New methods are therefore required to provide information on different protein interaction events at the single cell level in heterogeneous cell populations such as in tissue sections. Here, we describe a multiplex proximity ligation assay for simultaneous visualization of multiple protein complexes in situ. The assay is an enhancement of the original proximity ligation assay, and it is based on using proximity probes labeled with unique tag sequences that can be used to read out which probes, from a pool of probes, have bound a certain protein complex. Using this approach, it is possible to gain information on the constituents of different protein complexes, the subcellular location of the complexes, and how the balance between different complex constituents can change between normal and malignant cells, for example. As a proof of concept, we used the assay to simultaneously visualize multiple protein complexes involving EGFR, HER2, and HER3 homo- and heterodimers on a single-cell level in breast cancer tissue sections. The ability to study several protein complex formations concurrently at single cell resolution could be of great potential for a systems understanding, paving the way for improved disease diagnostics and possibilities for drug development.
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| 4. |
- Planck, Maria, et al.
(författare)
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Genomic and Transcriptional Alterations in Lung Adenocarcinoma in Relation to EGFR and KRAS Mutation Status
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:10, s. e78614-
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In lung adenocarcinoma, the mutational spectrum is dominated by EGFR and KRAS mutations. Improved knowledge about genomic and transcriptional alterations in and between mutation-defined subgroups may identify genes involved in disease development or progression. Methods: Genomic profiles from 457 adenocarcinomas, including 113 EGFR-mutated, 134 KRAS-mutated and 210 EGFR and KRAS-wild type tumors (EGFRwt/KRASwt), and gene expression profiles from 914 adenocarcinomas, including 309 EGFR-mutated, 192 KRAS-mutated, and 413 EGFRwt/KRASwt tumors, were assembled from different repositories. Genomic and transcriptional differences between the three mutational groups were analyzed by both supervised and unsupervised methods. Results: EGFR-mutated adenocarcinomas displayed a larger number of copy number alterations and recurrent amplifications, a higher fraction of total loss-of-heterozygosity, higher genomic complexity, and a more distinct expression pattern than EGFR-wild type adenocarcinomas. Several of these differences were also consistent when the three mutational groups were stratified by stage, gender and smoking status. Specific copy number alterations were associated with mutation status, predominantly including regions of gain with the highest frequency in EGFR-mutated tumors. Differential regions included both large and small regions of gain on 1p, 5q34-q35.3, 7p, 7q11.21, 12p12.1, 16p, and 21q, and losses on 6q16.3-q21, 8p, and 9p, with 20-40% frequency differences between the mutational groups. Supervised gene expression analyses identified 96 consistently differentially expressed genes between the mutational groups, and together with unsupervised analyses these analyses highlighted the difficulty in broadly resolving the three mutational groups into distinct transcriptional entities. Conclusions: We provide a comprehensive overview of the genomic and transcriptional landscape in lung adenocarcinoma stratified by EGFR and KRAS mutations. Our analyses suggest that the overall genomic and transcriptional landscape of lung adenocarcinoma is affected, but only to a minor extent, by EGFR and KRAS mutation status.
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| 5. |
- Staaf, Johan, et al.
(författare)
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Landscape of somatic allelic imbalances and copy number alterations in human lung carcinoma
- 2013
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 132:9, s. 2020-2031
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Tidskriftsartikel (refereegranskat)abstract
- Lung cancer is the worldwide leading cause of death from cancer and has been shown to be a heterogeneous disease at the genomic level. To delineate the genomic landscape of copy number alterations, amplifications, loss-of-heterozygosity (LOH), tumor ploidy and copy-neutral allelic imbalance in lung cancer, microarray-based genomic profiles from 2,141 tumors and cell lines including adenocarcinomas (AC, n = 1,206), squamous cell carcinomas (SqCC, n = 467), large cell carcinomas (n = 37) and small cell lung carcinomas (SCLC, n = 88) were assembled from different repositories. Copy number alteration differences between lung cancer histologies were confirmed in 285 unrelated tumors analyzed by BAC array comparative genomic hybridization. Tumor ploidy patterns were validated by DNA flow cytometry analysis of 129 unrelated cases. Eighty-nine recurrent copy number alterations (55 gains, 34 losses) were identified harboring genes with gene expression putatively driven by gene dosage through integration with gene expression data for 496 cases. Thirteen and 26 of identified regions discriminated AC/SqCC and AC/SqCC/SCLC, respectively, while 48 regions harbored recurrent (n > 15) high-level amplifications comprising established and putative oncogenes, differing in frequency and coamplification patterns between histologies. Lung cancer histologies displayed differences in patterns/frequency of copy number alterations, genomic architecture, LOH, copy-neutral allelic imbalance and tumor ploidy, with AC generally displaying less copy number alterations and allelic imbalance. Moreover, a strong association was demonstrated between different types of copy number alterations and allelic imbalances with tumor aneuploidy. In summary, these analyses provide a comprehensive overview of the landscape of genomic alterations in lung cancer, highlighting differences but also similarities between subgroups of the disease.
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| 6. |
- Botling, Johan, et al.
(författare)
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Biobanking of fresh frozen tissue from clinical surgical specimens : transport logistics, sample selection, and histologic characterization.
- 2011
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Ingår i: Methods in Molecular Biology. - Totowa, NJ : Humana Press. - 1064-3745 .- 1940-6029. ; 675, s. 299-306
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Tidskriftsartikel (refereegranskat)abstract
- Access to high-quality fresh frozen tissue is critical for translational cancer research and molecular -diagnostics. Here we describe a workflow for the collection of frozen solid tissue samples derived from fresh human patient specimens after surgery. The routines have been in operation at Uppsala University Hospital since 2001. We have integrated cryosection and histopathologic examination of each biobank sample into the biobank manual. In this way, even small, macroscopically ill-defined lesions can be -procured without a diagnostic hazard due to the removal of uncharacterized tissue from a clinical -specimen. Also, knowledge of the histomorphology of the frozen tissue sample - tumor cell content, stromal components, and presence of necrosis - is pivotal before entering a biobank case into costly molecular profiling studies.
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| 7. |
- Botling, Johan, et al.
(författare)
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Biomarker Discovery in Non-Small Cell Lung Cancer : Integrating Gene Expression Profiling, Meta-analysis, and Tissue Microarray Validation
- 2013
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 19:1, s. 194-204
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Global gene expression profiling has been widely used in lung cancer research to identify clinically relevant molecular subtypes as well as to predict prognosis and therapy response. So far, the value of these multigene signatures in clinical practice is unclear, and the biologic importance of individual genes is difficult to assess, as the published signatures virtually do not overlap.Experimental Design: Here, we describe a novel single institute cohort, including 196 non-small lung cancers (NSCLC) with clinical information and long-term follow-up. Gene expression array data were used as a training set to screen for single genes with prognostic impact. The top 450 probe sets identified using a univariate Cox regression model (significance level P < 0.01) were tested in a meta-analysis including five publicly available independent lung cancer cohorts (n = 860).Results: The meta-analysis revealed 14 genes that were significantly associated with survival (P < 0.001) with a false discovery rate < 1%. The prognostic impact of one of these genes, the cell adhesion molecule 1 (CADM1), was confirmed by use of immunohistochemistry on tissue microarrays from 2 independent NSCLC cohorts, altogether including 617 NSCLC samples. Low CADM1 protein expression was significantly associated with shorter survival, with particular influence in the adenocarcinoma patient subgroup.Conclusions: Using a novel NSCLC cohort together with a meta-analysis validation approach, we have identified a set of single genes with independent prognostic impact. One of these genes, CADM1, was further established as an immunohistochemical marker with a potential application in clinical diagnostics. Clin Cancer Res; 19(1); 194-204. (c) 2012 AACR.
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| 8. |
- Botling, Johan, et al.
(författare)
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Fresh frozen tissue : RNA extraction and quality control
- 2011
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Ingår i: Methods in Molecular Biology. - Totowa, NJ : Humana Press. - 1064-3745 .- 1940-6029. ; 675, s. 405-413
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Tidskriftsartikel (refereegranskat)abstract
- Since RNA is believed to be the most vulnerable molecular component of unfixed tissue, preserved RNA integrity can be used as a general quality indicator in fresh frozen tissue biobanks. As the size of samples and biopsies often is small, in the range of millimeters or milligrams, it is important to implement quality control procedures adapted to minute the amounts of tissue. To this end, we here describe RNA extraction from one or a few frozen tissue sections and subsequent analysis of structural RNA integrity by microcapillary gel electrophoresis.
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