| 1. |
- Vicari, Marco, et al.
(författare)
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Spatial multimodal analysis of transcriptomes and metabolomes in tissues
- 2023
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Ingår i: Nature Biotechnology. - 1087-0156 .- 1546-1696.
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Tidskriftsartikel (refereegranskat)abstract
- We present a spatial omics approach that combines histology, mass spectrometry imaging and spatial transcriptomics to facilitate precise measurements of mRNA transcripts and low-molecular-weight metabolites across tissue regions. The workflow is compatible with commercially available Visium glass slides. We demonstrate the potential of our method using mouse and human brain samples in the context of dopamine and Parkinson’s disease.
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| 2. |
- Bergenstråhle, Ludvig, et al.
(författare)
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Super-resolved spatial transcriptomics by deep data fusion
- 2022
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Ingår i: Nature Biotechnology. - : Nature Research. - 1087-0156 .- 1546-1696. ; 40:4, s. 476-479
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Tidskriftsartikel (refereegranskat)abstract
- Current methods for spatial transcriptomics are limited by low spatial resolution. Here we introduce a method that integrates spatial gene expression data with histological image data from the same tissue section to infer higher-resolution expression maps. Using a deep generative model, our method characterizes the transcriptome of micrometer-scale anatomical features and can predict spatial gene expression from histology images alone.
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| 3. |
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| 4. |
- Erickson, A, et al.
(författare)
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Spatially resolved clonal copy number alterations in benign and malignant tissue
- 2022
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 608:7922, s. 360-
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Tidskriftsartikel (refereegranskat)abstract
- Defining the transition from benign to malignant tissue is fundamental to improving early diagnosis of cancer1. Here we use a systematic approach to study spatial genome integrity in situ and describe previously unidentified clonal relationships. We used spatially resolved transcriptomics2 to infer spatial copy number variations in >120,000 regions across multiple organs, in benign and malignant tissues. We demonstrate that genome-wide copy number variation reveals distinct clonal patterns within tumours and in nearby benign tissue using an organ-wide approach focused on the prostate. Our results suggest a model for how genomic instability arises in histologically benign tissue that may represent early events in cancer evolution. We highlight the power of capturing the molecular and spatial continuums in a tissue context and challenge the rationale for treatment paradigms, including focal therapy.
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| 5. |
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| 6. |
- Erickson, Andrew, et al.
(författare)
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The spatial landscape of clonal somatic mutations in benign and malignant tissue
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Defining the transition from benign to malignant tissue is fundamental to improve early diagnosis of cancer. Here, we provide an unsupervised approach to study spatial genome integrity in situ to gain molecular insight into clonal relationships. We employed spatially resolved transcriptomics to infer spatial copy number variations in >120 000 regions across multiple organs, in benign and malignant tissues. We demonstrate that genome-wide copy number variation reveals distinct clonal patterns within tumours and in nearby benign tissue. Our results suggest a model for how genomic instability arises in histologically benign tissue that may represent early events in cancer evolution. We highlight the power of an unsupervised approach to capture the molecular and spatial continuums in a tissue context and challenge the rationale for treatment paradigms, including focal therapy.
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| 7. |
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| 8. |
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| 9. |
- Kvastad, Linda, et al.
(författare)
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The spatial landscape of transcriptomes and genomes in pediatric brain tumors
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Treatment of pediatric brain tumors is continually being improved; still, there is a great need for new treatment options. Here we explore the spatial transcriptomic and genomic landscape in a cohort of pediatric brain tumors using a new generation of unbiased methodologies. We demonstrate the gene expression patterns of the essential cancer-related gene programs of epithelial-to-mesenchymal transition (EMT), the reverse process mesenchymal-to-epithelial transition (MET), and tumor microenvironment (TME) observations through microglia. Furthermore, we identify the gene expression of SPP1 by microglia in the TME as a potential prognostic mRNA marker - in pediatric brain tumor relapse patients.
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| 10. |
- Mirzazadeh, Reza
(författare)
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Novel methods to study genomic fragility and structural variation
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- DNA double-strand breaks (DSBs) are major DNA lesions that when repaired unfaithfully can give rise to loss of genetic information, chromosomal rearrangements such as insertions/deletions (indels) and copy number alterations (CNAs), which in turn lead to genomic instability that is characteristic of almost all cancer types. In this context, it is thought that genomic instability has critical roles in cancer initiation, progression and intra-tumor heterogeneity (ITH). DSBs have also been exploited for genome-editing purposes where using different CRISPR (clustered regularly interspaced short palindromic repeats) systems, one can create DSBs in the target DNA to alter sequences and modify gene function. However, this approach is not without drawbacks, as DSBs can be created at sites other than the intended target (known as off-target effects), which can potentially be mutagenic. Therefore, given the importance of DSBs in genomic instability, their role in generation of CNAs and genome-editing technologies, it is of great interest to determine genomic locations of DSBs and their frequency along the genome, together with DNA copy number profiling. Thus, the focus of this thesis was to develop molecular tools for detection and quantification of DSBs with single-nucleotide resolution in different model systems, in combination with the development of technologies for DNA copy number profiling, by which we can collectively understand the biology behind DSBs, their links to CNAs in the context of cancer and assess the safety profile of CRISPR systems for therapeutic applications. In Paper I, we developed BLISS (Breaks Labeling In Situ and Sequencing) as a quantitative method enabling genome-wide DSB profiling. We showed that BLISS accurately identified both endogenous and drug-induced DSBs genome-wide, even in samples of a few thousand cells and in single tissue sections. Additionally, we demonstrated that BLISS is a powerful tool to measure the off-target activities of Cas9 and Cpf1 CRISPR systems, and indeed we found that Cpf1 was more specific than Cas9. In Paper II, using BLISS-generated DSB data from cell lines, we modeled the contribution of genetic and epigenetic features in shaping the cancer fragility, and made predictions of the frequency of expected breaks across the human genome. We constructed random forest regression models from four DSB datasets and found that the most influential feature in DSB frequency prediction is replication timing across all models. In addition, we noticed that open chromatin at transcriptionally active genes and associated regulatory factors have the largest influence on the frequency of DSBs than transcription per se. In Paper III, we developed CUTseq, which builds on the design of BLISS from Paper I, and can be used for gDNA barcoding and amplification to generate multiplexed DNA sequencing libraries for performing reduced representation sequencing of DNA samples extracted from cell lines, FFPE tissue sections or small sub-regions thereof. We demonstrated the applicability of CUTseq for CNA profiling, and showed that CUTseq can reproducibly detect a considerable fraction of high-confidence single nucleotide variants (SNVs) that were also detected by a standard exome capture method. Finally, we demonstrated that CUTseq can be applied for multi-region tumor sequencing to assess ITH of CNA profiles of multiple-small regions of a single FFPE tissue sections of primary and metastatic breast cancer lesions.
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| 11. |
- Mirzazadeh, Reza, et al.
(författare)
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Spatially resolved transcriptomic profiling of degraded and challenging fresh frozen samples
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Spatially resolved transcriptomics has enabled precise genome-wide mRNA expression profiling within tissue sections. The performance of methods targeting the polyA tails of mRNA relies on the availability of specimens with high RNA quality. Moreover, the high cost of currently available spatial resolved transcriptomics assays requires a careful sample screening process to increase the chance of obtaining high-quality data. Indeed, the upfront analysis of RNA quality can show considerable variability due to sample handling, storage, and/or intrinsic factors. We present RNA-Rescue Spatial Transcriptomics (RRST), a workflow designed to improve mRNA recovery from fresh frozen specimens with moderate to low RNA quality. First, we provide a benchmark of RRST against the standard Visium spatial gene expression protocol on high RNA quality samples represented by mouse brain and prostate cancer samples. Then, we test the RRST protocol on tissue sections collected from five challenging tissue types, including human lung, colon, small intestine, pediatric brain tumor, and mouse bone/cartilage. In total, we analyze 52 tissue sections and demonstrate that RRST is a versatile, powerful, and reproducible protocol for fresh frozen specimens of different qualities and origins.
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| 12. |
- Sountoulidis, Alexandros, et al.
(författare)
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A topographic atlas defines developmental origins of cell heterogeneity in the human embryonic lung
- 2023
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Ingår i: Nature Cell Biology. - : Springer Nature. - 1465-7392 .- 1476-4679.
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Tidskriftsartikel (refereegranskat)abstract
- Sountoulidis et al. provide a spatial gene expression atlas of human embryonic lung during the first trimester of gestation and identify 83 cell identities corresponding to stable cell types or transitional states. The lung contains numerous specialized cell types with distinct roles in tissue function and integrity. To clarify the origins and mechanisms generating cell heterogeneity, we created a comprehensive topographic atlas of early human lung development. Here we report 83 cell states and several spatially resolved developmental trajectories and predict cell interactions within defined tissue niches. We integrated single-cell RNA sequencing and spatially resolved transcriptomics into a web-based, open platform for interactive exploration. We show distinct gene expression programmes, accompanying sequential events of cell differentiation and maturation of the secretory and neuroendocrine cell types in proximal epithelium. We define the origin of airway fibroblasts associated with airway smooth muscle in bronchovascular bundles and describe a trajectory of Schwann cell progenitors to intrinsic parasympathetic neurons controlling bronchoconstriction. Our atlas provides a rich resource for further research and a reference for defining deviations from homeostatic and repair mechanisms leading to pulmonary diseases.
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| 13. |
- Thrane, Kim, et al.
(författare)
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Single-Cell and Spatial Transcriptomic Analysis of Human Skin Delineates Intercellular Communication and Pathogenic Cells
- 2023
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Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 143:11, s. 13-2177
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Tidskriftsartikel (refereegranskat)abstract
- Epidermal homeostasis is governed by a balance between keratinocyte proliferation and differentiation with contributions from cell–cell interactions, but conserved or divergent mechanisms governing this equilibrium across species and how an imbalance contributes to skin disease are largely undefined. To address these questions, human skin single-cell RNA sequencing and spatial transcriptomics data were integrated and compared with mouse skin data. Human skin cell–type annotation was improved using matched spatial transcriptomics data, highlighting the importance of spatial context in cell-type identity, and spatial transcriptomics refined cellular communication inference. In cross-species analyses, we identified a human spinous keratinocyte subpopulation that exhibited proliferative capacity and a heavy metal processing signature, which was absent in mouse and may account for species differences in epidermal thickness. This human subpopulation was expanded in psoriasis and zinc-deficiency dermatitis, attesting to disease relevance and suggesting a paradigm of subpopulation dysfunction as a hallmark of the disease. To assess additional potential subpopulation drivers of skin diseases, we performed cell-of-origin enrichment analysis within genodermatoses, nominating pathogenic cell subpopulations and their communication pathways, which highlighted multiple potential therapeutic targets. This integrated dataset is encompassed in a publicly available web resource to aid mechanistic and translational studies of normal and diseased skin.
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| 14. |
- Villacampa, Eva Gracia, et al.
(författare)
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Genome-wide Spatial Expression Profiling in Formalin-fixed Tissues
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Formalin-fixed paraffin embedding (FFPE) is the most widespread long-term tissue preservation approach. Here we present a procedure to perform genome-wide spatial analysis of mRNA in FFPE fixed tissue sections. The procedure takes advantage of well-established, commercially available methods for imaging and spatial barcoding using slides spotted with barcoded oligo(dT) probes to capture the 3’ end of mRNA molecules in tissue sections. First, we conducted expression profiling and cell type mapping in coronal sections from the mouse brain to demonstrate the method’s capability to delineate anatomical regions from a molecular perspective. Second, we explored the spatial composition of transcriptomic signatures in ovarian carcinosarcoma samples using data-driven analysis methods, exemplifying the method’s potential to elucidate molecular mechanisms in heterogeneous clinical samples. Finally, we demonstrate the applicability of the assay to characterize organoids and a human lung biopsy specimen infected with SARS-CoV-2.
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| 15. |
- Villacampa, Eva Gracia, et al.
(författare)
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Genome-wide spatial expression profiling in formalin-fixed tissues
- 2021
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Ingår i: Cell Genomics. - : Elsevier BV. - 2666-979X. ; 1:3
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Tidskriftsartikel (refereegranskat)abstract
- Formalin-fixed paraffin embedding (FFPE) is the most widespread long-term tissue preservation approach. Here, we report a procedure to perform genome-wide spatial analysis of mRNA in FFPE-fixed tissue sections, using well-established, commercially available methods for imaging and spatial barcoding using slides spotted with barcoded oligo(dT) probes to capture the 3′ end of mRNA molecules in tissue sections. We applied this method for expression profiling and cell type mapping in coronal sections from the mouse brain to demonstrate the method's capability to delineate anatomical regions from a molecular perspective. We also profiled the spatial composition of transcriptomic signatures in two ovarian carcinosarcoma samples, exemplifying the method's potential to elucidate molecular mechanisms in heterogeneous clinical samples. Finally, we demonstrate the applicability of the assay to characterize human lung and kidney organoids and a human lung biopsy specimen infected with SARS-CoV-2. We anticipate that genome-wide spatial gene expression profiling in FFPE biospecimens will be used for retrospective analysis of biobank samples, which will facilitate longitudinal studies of biological processes and biomarker discovery.
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| 16. |
- Wu, Chi-Chih, et al.
(författare)
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In situ quantification of individual mRNA transcripts in melanocytes discloses gene regulation of relevance to speciation
- 2019
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Ingår i: Journal of Experimental Biology. - : COMPANY BIOLOGISTS LTD. - 0022-0949 .- 1477-9145. ; 222:5
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Tidskriftsartikel (refereegranskat)abstract
- Functional validation of candidate genes involved in adaptation and speciation remains challenging. Here, we exemplify the utility of a method quantifying individual mRNA transcripts in revealing the molecular basis of divergence in feather pigment synthesis during early-stage speciation in crows. Using a padlock probe assay combined with rolling circle amplification, we quantified cell-typespecific gene expression in the histological context of growing feather follicles. Expression of Tyrosinase Related Protein 1 (TYRP1), Solute Carrier Family 45 member 2 (SLC45A2) and Hematopoietic Prostaglandin D Synthase (HPGDS) was melanocyte-limited and significantly reduced in follicles from hooded crow, explaining the substantially lower eumelanin content in grey versus black feathers. The central upstream Melanocyte Inducing Transcription Factor (MITF) only showed differential expression specific to melanocytes - a feature not captured by bulk RNA-seq. Overall, this study provides insight into the molecular basis of an evolutionary young transition in pigment synthesis, and demonstrates the power of histologically explicit, statistically substantiated single-cell gene expression quantification for functional genetic inference in natural populations.
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| 17. |
- Wu, Chenglin, et al.
(författare)
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RollFISH achieves robust quantification of single-molecule RNA biomarkers in paraffin-embedded tumor tissue samples
- 2018
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Ingår i: Communications biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- Single-molecule RNA fluorescence in situ hybridization (smFISH) represents a promising approach to quantify the expression of clinically useful biomarkers in tumor samples. However, routine application of smFISH to formalin-fixed, paraffin-embedded (FFPE) samples is challenging due to the low signal intensity and high background noise. Here we present RollFISH, a method combining the specificity of smFISH with the signal boosting of rolling circle amplification. We apply RollFISH to quantify widely used breast cancer biomarkers in cell lines and FFPE samples. Thanks to the high signal-to-noise ratio, we can visualize selected biomarkers at low magnification (20 x) across entire tissue sections, and thus assess their spatial heterogeneity. Lastly, we apply RollFISH to quantify HER2 mRNA in 150 samples on a single tissue microarray, achieving a sensitivity and specificity of detection of HER2-positive samples of similar to 90%. RollFISH is a robust method for quantifying the expression and intratumor heterogeneity of biomarkers in FFPE tissues.
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