| 1. |
- Charitou, Theodosia, et al.
(författare)
-
Transcriptional and metabolic rewiring of colorectal cancer cells expressing the oncogenic KRAS(G13D) mutation
- 2019
-
Ingår i: British Journal of Cancer. - : NATURE PUBLISHING GROUP. - 0007-0920 .- 1532-1827. ; 121:1, s. 37-50
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Activating mutations in KRAS frequently occur in colorectal cancer (CRC) patients, leading to resistance to EGFRtargeted therapies. METHODS: To better understand the cellular reprogramming which occurs in mutant KRAS cells, we have undertaken a systems-level analysis of four CRC cell lines which express either wild type (wt) KRAS or the oncogenic KRAS(G13D) allele (mtKRAS). RESULTS: RNAseq revealed that genes involved in ribosome biogenesis, mRNA translation and metabolism were significantly upregulated in mtKRAS cells. Consistent with the transcriptional data, protein synthesis and cell proliferation were significantly higher in the mtKRAS cells. Targeted metabolomics analysis also confirmed the metabolic reprogramming in mtKRAS cells. Interestingly, mtKRAS cells were highly transcriptionally responsive to EGFR activation by TGF alpha stimulation, which was associated with an unexpected downregulation of genes involved in a range of anabolic processes. While TGF alpha treatment strongly activated protein synthesis in wtKRAS cells, protein synthesis was not activated above basal levels in the TGF alpha-treated mtKRAS cells. This was likely due to the defective activation of the mTORC1 and other pathways by TGF alpha in mtKRAS cells, which was associated with impaired activation of PKB signalling and a transient induction of AMPK signalling. CONCLUSIONS: We have found that mtKRAS cells are substantially rewired at the transcriptional, translational and metabolic levels and that this rewiring may reveal new vulnerabilities in oncogenic KRAS CRC cells that could be exploited in future.
|
|
| 2. |
- Fasterius, Erik, 1987-, et al.
(författare)
-
Analysis of public RNA-sequencing data reveals biological consequences of genetic heterogeneity in cell line populations
- 2018
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Meta-analysis of datasets available in public repositories are used to gather and summarise experiments performed across laboratories, as well as to explore consistency of scientific findings. As data quality and biological equivalency across samples may obscure such analyses and consequently their conclusions, we investigated the comparability of 85 public RNA-seq cell line datasets. Thousands of pairwise comparisons of single nucleotide variants in 139 samples revealed variable genetic heterogeneity of the eight cell line populations analysed as well as variable data quality. The H9 and HCT116 cell lines were found to be remarkably stable across laboratories (with median concordances of 99.2% and 98.5%, respectively), in contrast to the highly variable HeLa cells (89.3%). We show that the genetic heterogeneity encountered greatly affects gene expression between same-cell comparisons, highlighting the importance of interrogating the biological equivalency of samples when comparing experimental datasets. Both the number of differentially expressed genes and the expression levels negatively correlate with the genetic heterogeneity. Finally, we demonstrate how comparing genetically heterogeneous datasets affect gene expression analyses and that high dissimilarity between same-cell datasets alters the expression of more than 300 cancer-related genes, which are often the focus of studies using cell lines.
|
|
| 3. |
- Fasterius, Erik, 1987-, et al.
(författare)
-
SeqCAT : A bioconductor R-package for variant analysis of high throughput sequencing data [version 1; peer review: 1 approved with reservations, 1 not approved]
- 2018
-
Ingår i: F1000 Research. - : F1000 Research Ltd. - 2046-1402. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- High throughput sequencing technologies are flourishing in the biological sciences, enabling unprecedented insights into e.g. genetic variation, but require extensive bioinformatic expertise for the analysis. There is thus a need for simple yet effective software that can analyse both existing and novel data, providing interpretable biological results with little bioinformatic prowess. We present seqCAT, a Bioconductor toolkit for analysing genetic variation in high throughput sequencing data. It is a highly accessible, easy-to-use and well-documented R-package that enables a wide range of researchers to analyse their own and publicly available data, providing biologically relevant conclusions and publication-ready figures. SeqCAT can provide information regarding genetic similarities between an arbitrary number of samples, validate specific variants as well as define functionally similar variant groups for further downstream analyses. Its ease of use, installation, complete data-to-conclusions functionality and the inherent flexibility of the R programming language make seqCAT a powerful tool for variant analyses compared to already existing solutions. A publicly available dataset of liver cancer-derived organoids is analysed herein using the seqCAT package, demonstrating that the organoids are genetically stable. A previously known liver cancer-related mutation is additionally shown to be present in a sample though it was not listed in the original publication. Differences between DNA- and RNA-based variant calls in this dataset are also analysed revealing a high median concordance of 97.5%.
|
|
| 4. |
- Fasterius, Erik, 1987-, et al.
(författare)
-
Single-cell RNA-seq variant analysis for exploration of genetic heterogeneity in cancer
- 2019
-
Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Inter-and intra-tumour heterogeneity is caused by genetic and non-genetic factors, leading to severe clinical implications. High-throughput sequencing technologies provide unprecedented tools to analyse DNA and RNA in single cells and explore both genetic heterogeneity and phenotypic variation between cells in tissues and tumours. Simultaneous analysis of both DNA and RNA in the same cell is, however, still in its infancy. We have thus developed a method to extract and analyse information regarding genetic heterogeneity that affects cellular biology from single-cell RNA-seq data. The method enables both comparisons and clustering of cells based on genetic variation in single nucleotide variants, revealing cellular subpopulations corroborated by gene expression-based methods. Furthermore, the results show that lymph node metastases have lower levels of genetic heterogeneity compared to their original tumours with respect to variants affecting protein function. The analysis also revealed three previously unknown variants common across cancer cells in glioblastoma patients. These results demonstrate the power and versatility of scRNA-seq variant analysis and highlight it as a useful complement to already existing methods, enabling simultaneous investigations of both gene expression and genetic variation.
|
|
| 5. |
- Kennedy, S. A., et al.
(författare)
-
Extensive rewiring of the EGFR network in colorectal cancer cells expressing transforming levels of KRASG13D
- 2020
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Protein-protein-interaction networks (PPINs) organize fundamental biological processes, but how oncogenic mutations impact these interactions and their functions at a network-level scale is poorly understood. Here, we analyze how a common oncogenic KRAS mutation (KRASG13D) affects PPIN structure and function of the Epidermal Growth Factor Receptor (EGFR) network in colorectal cancer (CRC) cells. Mapping >6000 PPIs shows that this network is extensively rewired in cells expressing transforming levels of KRASG13D (mtKRAS). The factors driving PPIN rewiring are multifactorial including changes in protein expression and phosphorylation. Mathematical modelling also suggests that the binding dynamics of low and high affinity KRAS interactors contribute to rewiring. PPIN rewiring substantially alters the composition of protein complexes, signal flow, transcriptional regulation, and cellular phenotype. These changes are validated by targeted and global experimental analysis. Importantly, genetic alterations in the most extensively rewired PPIN nodes occur frequently in CRC and are prognostic of poor patient outcomes.
|
|
| 6. |
- Selvin, Tove, et al.
(författare)
-
Single-cell transcriptional pharmacodynamics of trifluridine in a tumor-immune model
- 2022
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the immunological effects of chemotherapy is of great importance, especially now that we have entered an era where ever-increasing pre-clinical and clinical efforts are put into combining chemotherapy and immunotherapy to combat cancer. Single-cell RNA sequencing (scRNA-seq) has proved to be a powerful technique with a broad range of applications, studies evaluating drug effects in co-cultures of tumor and immune cells are however scarce. We treated a co-culture comprised of human colorectal cancer (CRC) cells and peripheral blood mononuclear cells (PBMCs) with the nucleoside analogue trifluridine (FTD) and used scRNA-seq to analyze posttreatment gene expression profiles in thousands of individual cancer and immune cells concurrently. ScRNA-seq recapitulated major mechanisms of action previously described for FTD and provided new insight into possible treatment-induced effects on T-cell mediated antitumor responses.
|
|
| 7. |
- Strandberg, Kristin, et al.
(författare)
-
Blood-derived biomarkers correlate with clinical progression in Duchenne muscular dystrophy
- 2020
-
Ingår i: Journal of Neuromuscular Diseases. - : IOS Press. - 2214-3599 .- 2214-3602. ; 7:3, s. 231-246
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Duchenne Muscular Dystrophy is a severe, incurable disorder caused by mutations in the dystrophin gene. The disease is characterized by decreased muscle function, impaired muscle regeneration and increased inflammation. In a clinical context, muscle deterioration, is evaluated using physical tests and analysis of muscle biopsies, which fail to accurately monitor the disease progression. Objectives: This study aims to confirm and asses the value of blood protein biomarkers as disease progression markers using one of the largest longitudinal collection of samples. Methods: A total of 560 samples, both serum and plasma, collected at three clinical sites are analyzed using a suspension bead array platform to assess 118 proteins targeted by 250 antibodies in microliter amount of samples. Results: Nine proteins are confirmed as disease progression biomarkers in both plasma and serum. Abundance of these biomarkers decreases as the disease progresses but follows different trajectories. While carbonic anhydrase 3, microtubule associated protein 4 and collagen type I alpha 1 chain decline rather constantly over time, myosin light chain 3, electron transfer flavoprotein A, troponin T, malate dehydrogenase 2, lactate dehydrogenase B and nestin plateaus in early teens. Electron transfer flavoprotein A, correlates with the outcome of 6-minutes-walking-test whereas malate dehydrogenase 2 together with myosin light chain 3, carbonic anhydrase 3 and nestin correlate with respiratory capacity. Conclusions: Nine biomarkers have been identified that correlate with disease milestones, functional tests and respiratory capacity. Together these biomarkers recapitulate different stages of the disorder that, if validated can improve disease progression monitoring.
|
|
| 8. |
- Söderhäll, Irene, et al.
(författare)
-
Characterization of hemocytes and hematopoietic cells of a freshwater crayfish based on single-cell transcriptome analysis
- 2022
-
Ingår i: iScience. - : Cell Press. - 2589-0042. ; 25:8
-
Tidskriftsartikel (refereegranskat)abstract
- Crustaceans constitute a species-rich and ecologically important animal group, and their circulating blood cells (hemocytes) are of critical importance in immunity as key players in pathogen recognition, phagocytosis, melanization, and antimicrobial defense. To gain a better understanding of the immune responses to different pathogens, it is crucial that we identify different hemocyte subpopulations with different functions and gain a better understanding of how these cells are formed. Here, we performed single-cell RNA sequencing of isolated hematopoietic tissue (HPT) cells and hemocytes from the crayfish Pacifastacus leniusculus to identify hitherto undescribed hemocyte types in the circulation and show that the circulating cells are more diversified than previously recognized. In addition, we discovered cell populations in the HPT with clear precursor characteristics as well as cells involved in iron homeostasis, representing a previously undiscovered cell type. These findings may improve our understanding of hematopoietic stem cell regulation in crustaceans and other animals.
|
|
