Project description:Characterizing the complex composition of solid tumors is fundamental for understanding tumor initiation, progression and metastasis. While patient-derived samples provide valuable insight, they are heterogeneous on multiple molecular levels, and often originate from advanced tumor stages. Here, we use single-cell transcriptome and epitope profiling together with pathway and lineage analyses to study tumorigenesis from a developmental perspective in a mouse model of salivary gland squamous cell carcinoma. We provide a comprehensive cell atlas and characterise tumor-specific cells. We find that these cells are connected along a reproducible developmental trajectory: initiated in basal cells exhibiting an epithelial-to-mesenchymal transition signature, tumorigenesis proceeds through Wnt-differential cancer stem cell-like subpopulations before differentiating into luminal-like cells. Our work provides unbiased insights into tumor-specific cellular identities in a whole tissue environment and emphasizes the power of using defined genetic model systems.
Project description:Characterizing the complex composition of solid tumors is fundamental for understanding tumor initiation, progression and metastasis. While patient-derived samples provide valuable insight, they are heterogeneous on multiple molecular levels, and often originate from advanced tumor stages. Here, we use single-cell transcriptome and epitope profiling together with pathway and lineage analyses to study tumorigenesis from a developmental perspective in a mouse model of salivary gland squamous cell carcinoma. We provide a comprehensive cell atlas and characterize tumor-specific cells. We find that these cells are connected along a reproducible developmental trajectory: initiated in basal cells exhibiting an epithelial-to-mesenchymal transition signature, tumorigenesis proceeds through Wnt-differential cancer stem cell-like subpopulations before differentiating into luminal-like cells. Our work provides unbiased insights into tumor-specific cellular identities in a whole tissue environment, and emphasizes the power of using defined genetic model systems.
Project description:In vivo lineage tracing holds great potential to reveal fundamental principles of tissue development and homeostasis. However, lineage tracing in humans relies on DNA mutations that are extremely rare. In mice, the improved genetic labeling approach has low resolution over cell division histories. Here, we demonstrated for the first time that frequent epimutations on DNA methylation can be exploited to infer lineage histories in normal cells, enabled by our newly developed computational method MethyTree. Using both in-house and public sparse single-cell DNA methylation datasets with known lineage labels, MethyTree reconstructed lineage histories at high resolution and accuracy across different cell types, stages, and species. Applying MethyTree, we identified the first fate decision in human embryo development and pinpointed in total ~230 clones of hematopoietic stem cells in mice. Our study opens the door for high-resolution, noninvasive lineage tracing in mice, humans and beyond.
Project description:In vivo lineage tracing holds great potential to reveal fundamental principles of tissue development and homeostasis. However, lineage tracing in humans relies on DNA mutations that are extremely rare. In mice, the improved genetic labeling approach has low resolution over cell division histories. Here, we demonstrated for the first time that frequent epimutations on DNA methylation can be exploited to infer lineage histories in normal cells, enabled by our newly developed computational method MethyTree. Using both in-house and public sparse single-cell DNA methylation datasets with known lineage labels, MethyTree reconstructed lineage histories at high resolution and accuracy across different cell types, stages, and species. Applying MethyTree, we identified the first fate decision in human embryo development and pinpointed in total ~230 clones of hematopoietic stem cells in mice. Our study opens the door for high-resolution, noninvasive lineage tracing in mice, humans and beyond.
Project description:In vivo lineage tracing holds great potential to reveal fundamental principles of tissue development and homeostasis. However, lineage tracing in humans relies on DNA mutations that are extremely rare. In mice, the improved genetic labeling approach has low resolution over cell division histories. Here, we demonstrated for the first time that frequent epimutations on DNA methylation can be exploited to infer lineage histories in normal cells, enabled by our newly developed computational method MethyTree. Using both in-house and public sparse single-cell DNA methylation datasets with known lineage labels, MethyTree reconstructed lineage histories at high resolution and accuracy across different cell types, stages, and species. Applying MethyTree, we identified the first fate decision in human embryo development and pinpointed in total ~230 clones of hematopoietic stem cells in mice. Our study opens the door for high-resolution, noninvasive lineage tracing in mice, humans and beyond.
Project description:In vivo lineage tracing holds great potential to reveal fundamental principles of tissue development and homeostasis. However, lineage tracing in humans relies on DNA mutations that are extremely rare. In mice, the improved genetic labeling approach has low resolution over cell division histories. Here, we demonstrated for the first time that frequent epimutations on DNA methylation can be exploited to infer lineage histories in normal cells, enabled by our newly developed computational method MethyTree. Using both in-house and public sparse single-cell DNA methylation datasets with known lineage labels, MethyTree reconstructed lineage histories at high resolution and accuracy across different cell types, stages, and species. Applying MethyTree, we identified the first fate decision in human embryo development and pinpointed in total ~230 clones of hematopoietic stem cells in mice. Our study opens the door for high-resolution, noninvasive lineage tracing in mice, humans and beyond.
Project description:In vivo lineage tracing holds great potential to reveal fundamental principles of tissue development and homeostasis. However, lineage tracing in humans relies on DNA mutations that are extremely rare. In mice, the improved genetic labeling approach has low resolution over cell division histories. Here, we demonstrated for the first time that frequent epimutations on DNA methylation can be exploited to infer lineage histories in normal cells, enabled by our newly developed computational method MethyTree. Using both in-house and public sparse single-cell DNA methylation datasets with known lineage labels, MethyTree reconstructed lineage histories at high resolution and accuracy across different cell types, stages, and species. Applying MethyTree, we identified the first fate decision in human embryo development and pinpointed in total ~230 clones of hematopoietic stem cells in mice. Our study opens the door for high-resolution, noninvasive lineage tracing in mice, humans and beyond.
Project description:In the current study, we combined a multi-fluorescent reporter mouse model with a conditional knockout mouse model, in which the tumor suppressor genes Pten and p27 were deleted in GCs, to perform cell lineage tracing of mutant GCs. We found that only 30% of ovaries with substantial mutant GCs developed into GCTs that derived from a single mutant GC. In-depth molecular analysis of the process of tumorigenesis demonstrated that up-regulation of immune evasion genes Cd24a and Cd47 led, in part, to the transition of mutant GCs to GCTs. Therefore, treatment with the Cd47 inhibitor RRX-001 was tested and found to efficiently suppress the growth of GCTs in vivo.
Project description:Cardiac fibroblasts convert to myofibroblasts with injury to mediate healing after acute myocardial infarction and to mediate long-standing fibrosis with chronic disease. Myofibroblasts remain a poorly defined cell-type in terms of their origins and functional effects in vivo. Methods: Here we generate Postn (periostin) gene-targeted mice containing a tamoxifen inducible Cre for cellular lineage tracing analysis. This Postn allele identifies essentially all myofibroblasts within the heart and multiple other tissues. Results: Lineage tracing with 4 additional Cre-expressing mouse lines shows that periostin-expressing myofibroblasts in the heart derive from tissue-resident fibroblasts of the Tcf21 lineage, but not endothelial, immune/myeloid or smooth muscle cells. Deletion of periostin+ myofibroblasts reduces collagen production and scar formation after myocardial infarction. Periostin-traced myofibroblasts also revert back to a less activated state upon injury resolution. Conclusions: Our results define the myofibroblast as a periostin-expressing cell-type necessary for adaptive healing and fibrosis in the heart, which arises from Tcf21+ tissue-resident fibroblasts. Fluidigm C1 whole genome transcriptome analysis of lineage mapped cardiac myofibroblasts