Project description:We investigated changes to murine pancreatic fibroblast gene expression in response to co-culture with 8 murine pancreatic tumour cell sub-populations. Tumours are complex ecosystems where phenotypically diverse tumour cells are embedded in a heterocellular environment. Using an in vitro model of intra-tumoral heterogeneity, we show that clonal tumour cell populations establish distinct interactions with stromal fibroblasts to expand phenotypic diversity across tumour and stromal cell populations. Heterocellular interactions drive differential engagement of tumour cell reciprocal signalling pathways, resulting in normalisation of cell-autonomous differences in MAPK signalling but diversification of AKT signalling. Consequently, tumour cell clones display differential cell-autonomous and non-cell autonomous dependencies. These results demonstrate that tumour-stroma interactions amplify tumour cell autonomous diversity and that our existing perspective on tumour cell heterogeneity underestimates functional diversity.
Project description:We investigated changes to gene expression in 8 murine pancreatic tumour sub-clones response to co-culture with fibroblasts. Tumours are complex ecosystems where phenotypically diverse tumour cells are embedded in a heterocellular environment. Using an in vitro model of intra-tumoral heterogeneity, we show that clonal tumour cell populations establish distinct interactions with stromal fibroblasts to expand phenotypic diversity across tumour and stromal cell populations. Heterocellular interactions drive differential engagement of tumour cell reciprocal signalling pathways, resulting in normalisation of cell-autonomous differences in MAPK signalling but diversification of AKT signalling. Consequently, tumour cell clones display differential cell-autonomous and non-cell autonomous dependencies. These results demonstrate that tumour-stroma interactions amplify tumour cell autonomous diversity and that our existing perspective on tumour cell heterogeneity underestimates functional diversity.
Project description:Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy characterised by a pathological fibroinflammatory microenvironment. Dichotomous tumour-promoting and -restrictive roles have been ascribed to the tumour microenvironment, however the effects of individual stromal subsets remains incompletely characterised. Here, we describe how heterocellular OSM-OSMR signalling instructs fibroblast reprogramming, tumour growth and metastasis. Macrophage-secreted OSM stimulates inflammatory gene expression in cancer-associated fibroblasts (CAFs), which in turn induce a pro-tumorigenic environment and engage tumour cell survival and migratory signalling pathways. Tumour cells implanted in Osm-deficient (Osm-/-) mice display an epithelial-dominated morphology, reduced tumour growth and did not metastasise. Moreover, the tumour microenvironment of Osm-/- animals exhibit increased abundance of αSMApos myofibroblasts and a shift in myeloid and T cell phenotypes, consistent with a more immunogenic environment. Taken together, these data demonstrate how OSM-OSMR signalling coordinates heterocellular interactions to drive a pro-tumorigenic environment in PDA.
Project description:Fibroblasts are functionally heterogeneous cells, capable of promoting and suppressing tumour progression. Across cancer types, the extent and cause of this phenotypic diversity remains unknown. We used single-cell RNA sequencing and multiplexed immunohistochemistry to examine fibroblast heterogeneity in human lung and non-small cell lung cancer (NSCLC) samples. This identified seven fibroblast subpopulations: including inflammatory fibroblasts and myofibroblasts (representing terminal differentiation states), quiescent fibroblasts, proto-myofibroblasts (x2) and proto-inflammatory fibroblasts (x2). Fibroblast subpopulations were variably distributed throughout tissues but accumulated at discrete niches associated with differentiation status. Bioinformatics analyses suggested TGF-β1 and IL-1 as key regulators of myofibroblastic and inflammatory differentiation respectively. However, in vitro analyses showed that whilst TGF-β1 stimulation in combination with increased tissue tension could induce myofibroblast marker expression, it failed to fully re-capitulate ex-vivo phenotypes. Similarly, IL-1β treatment only induced upregulation of a subset of inflammatory fibroblast marker genes. In silico modelling of ligand-receptor signalling identified additional pathways and cell interactions likely to be involved in fibroblast activation, This highlighted a potential role for IL-11 and IL-6 (among other ligands) in myofibroblast and inflammatory fibroblast activation respectively. This analysis provides valuable insight into fibroblast subtypes and differentiation mechanisms in NSCLC.
Project description:Fibroblasts are functionally heterogeneous cells, capable of promoting and suppressing tumour progression. Across cancer types, the extent and cause of this phenotypic diversity remains unknown. We used single-cell RNA sequencing and multiplexed immunohistochemistry to examine fibroblast heterogeneity in human lung and non-small cell lung cancer (NSCLC) samples. This identified seven fibroblast subpopulations: including inflammatory fibroblasts and myofibroblasts (representing terminal differentiation states), quiescent fibroblasts, proto-myofibroblasts (x2) and proto-inflammatory fibroblasts (x2). Fibroblast subpopulations were variably distributed throughout tissues but accumulated at discrete niches associated with differentiation status. Bioinformatics analyses suggested TGF-β1 and IL-1 as key regulators of myofibroblastic and inflammatory differentiation respectively. However, in vitro analyses showed that whilst TGF-β1 stimulation in combination with increased tissue tension could induce myofibroblast marker expression, it failed to fully re-capitulate ex-vivo phenotypes. Similarly, IL-1β treatment only induced upregulation of a subset of inflammatory fibroblast marker genes. In silico modelling of ligand-receptor signalling identified additional pathways and cell interactions likely to be involved in fibroblast activation, This highlighted a potential role for IL-11 and IL-6 (among other ligands) in myofibroblast and inflammatory fibroblast activation respectively. This analysis provides valuable insight into fibroblast subtypes and differentiation mechanisms in NSCLC.
Project description:Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy characterised by a pathologicalfibroinflammatorymicroenvironment. Dichotomous tumour-promoting and -restrictive roles have been ascribed to the tumour microenvironment, however thedisparate effect of individual stromal subsets remains incompletely characterised. Here, we describe how heterocellular OSM-OSMR signalling instructsfibroblast reprogramming,tumourgrowth and metastasis.Macrophage-secreted OSM stimulatesinflammatory gene expression in cancer-associated fibroblasts (CAFs), which in turn induce a pro-tumorigenic environment and engage tumour cellsurvival and migratory signalling pathways. Tumour cells implanted in Osm-deficient (Osm-/-) mice display an epithelial-dominated morphology, reduced tumour growth and did notmetastasise. Moreover, the tumour microenvironment of Osm-/-animals exhibit increased abundance of αSMAposmyofibroblasts and a shift in myeloid and T cell phenotypes, consistent with a more immunogenic environment. Taken together, these data demonstrate how OSM-OSMR signalling coordinates heterocellular interactions to drive a pro-tumorigenic environment in PDA.
Project description:The EGFR/Ras/ERK signalling pathway is a primary driver of cancer cell proliferation and metastasis in tumours that exhibit high cell-to-cell heterogeneity. While the signalling activity of this pathway is frequently amplified in tumours, it is not understood how the kinetic aspects of its activation in tumours differ from normal cellular signalling. We explored these single-cell kinetic differences using live-cell reporters of ERK signalling in the breast cancer progression series HMT-3522 and found that ERK activity in invasive cells is similar in amplitude to non-malignant cells but is highly dynamic and more disordered, leading to more heterogeneous expression of ERK target genes. We traced this variability to a high degree of amphiregulin-mediated autocrine signalling by invasive cells. Dynamic ERK activity could be transferred from invasive to pre-malignant cells through paracrine signalling in co-culture, and could drive temporal variation in the expression of genes including Fra-1, c-Myc, and Egr1 at the single-cell level. Our findings establish a mechanism for the generation of tumour cell plasticity, in which paracrine signalling in the microenvironment is translated into continually shifting diversity in gene expression profiles, helping drive the phenotypic heterogeneity of tumour cells.