Interactions in CSF1-driven Tenosynovial Giant Cell Tumors
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ABSTRACT: A major component of cells in Tenosynovial Giant Cell Tumor (TGCT) consists of bystander macrophages responding to CSF1 that is overproduced by a small number of neoplastic cells with a chromosomal translocation involving the CSF1 gene. An autocrine loop was postulated where the neoplastic cells are stimulated through CSF1R expressed on their surface. Here we use single cell RNA sequencing to investigate cellular interactions in TGCT.
Project description:Tenosynovial giant-cell tumor (TGCT) and pigmented villonodular synovitis (PVNS) are related conditions with features of both reactive inflammatory disorders and clonal neoplastic proliferations. Chromosomal translocations involving chromosome 1p13 have been reported in both TGCT and PVNS. We confirm that translocations involving 1p13 are present in a majority of cases of TGCT and PVNS and show that CSF1 is the gene at the chromosome 1p13 breakpoint. In some cases of both TGCT and PVNS, CSF1 is fused to COL6A3 (2q35). The CSF1 translocations result in overexpression of CSF1. In cases of TGCT and PVNS carrying this translocation, it is present in a minority of the intratumoral cells, leading to CSF1 expression only in these cells, whereas the majority of cells express CSF1R but not CSF1, suggesting a tumor-landscaping effect with aberrant CSF1 expression in the neoplastic cells, leading to the abnormal accumulation of nonneoplastic cells that form a tumorous mass. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
Project description:Tenosynovial giant-cell tumor (TGCT) and pigmented villonodular synovitis (PVNS) are related conditions with features of both reactive inflammatory disorders and clonal neoplastic proliferations. Chromosomal translocations involving chromosome 1p13 have been reported in both TGCT and PVNS. We confirm that translocations involving 1p13 are present in a majority of cases of TGCT and PVNS and show that CSF1 is the gene at the chromosome 1p13 breakpoint. In some cases of both TGCT and PVNS, CSF1 is fused to COL6A3 (2q35). The CSF1 translocations result in overexpression of CSF1. In cases of TGCT and PVNS carrying this translocation, it is present in a minority of the intratumoral cells, leading to CSF1 expression only in these cells, whereas the majority of cells express CSF1R but not CSF1, suggesting a tumor-landscaping effect with aberrant CSF1 expression in the neoplastic cells, leading to the abnormal accumulation of nonneoplastic cells that form a tumorous mass.
Project description:Tenosynovial giant-cell tumor (TGCT) and pigmented villonodular synovitis (PVNS) are related conditions with features of both reactive inflammatory disorders and clonal neoplastic proliferations. Chromosomal translocations involving chromosome 1p13 have been reported in both TGCT and PVNS. We confirm that translocations involving 1p13 are present in a majority of cases of TGCT and PVNS and show that CSF1 is the gene at the chromosome 1p13 breakpoint. In some cases of both TGCT and PVNS, CSF1 is fused to COL6A3 (2q35). The CSF1 translocations result in overexpression of CSF1. In cases of TGCT and PVNS carrying this translocation, it is present in a minority of the intratumoral cells, leading to CSF1 expression only in these cells, whereas the majority of cells express CSF1R but not CSF1, suggesting a tumor-landscaping effect with aberrant CSF1 expression in the neoplastic cells, leading to the abnormal accumulation of nonneoplastic cells that form a tumorous mass. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
Project description:Signalling via the colony stimulating factor 1 receptor (CSF1R) controls the survival, differentiation and proliferation of macrophages which are a source of the somatic growth factor insulin growth factor 1 (IGF1). Treatment of newborn mice with CSF1 has previously been shown to produce an increase in somatic growth rate and we hypothesised that treatment of neonatal low birth weight (LBW) rats with CSF1 would do the same. Growth rates were not affected, yet CSF1 treatment caused an unexpectedly large, but reversible increase in liver size and hepatic fat deposition in both normal and LBW rats. By transcriptional profiling, we have highlighted numerous CSF1-regulated genes known to be involved in lipid droplet formation in the liver and novel candidate genes for further investigation. In contrast to mice and weaner pigs, CSF1 treatment did not increase hepatocyte proliferation in neonatal rats, rather the data were consistent with increased macrophage proliferation instead. This suggests that Kupffer cells promote lipid accumulation in neonates and treatment to ablate CSF1R signalling may reverse lipid accumulation in the liver. Conclusion: Treatment of neonatal rats with CSF1 caused an increase in liver size and hepatic lipid accumulation, due to Kupffer cell expansion and/or activation rather than hepatocyte proliferation Livers were harvested from neonatal rats on Day 6, following 5 days treatment with 1 ug/g porcine CSF1-Fc or PBS by subcutaneous injection. Bone marrow derived macrophages were generated in vitro by culture in CSF1.
Project description:Caspases, which are key effectors of apoptosis, have demonstrated non-apoptotic functions. One of these functions is the differentiation into macrophages of peripheral blood monocytes exposed to Colony-Stimulating Factor-1 (CSF1). Macrophage polarization plays an important role in the pathogenesis of diverse human diseases as cancer, leading us to explore if caspase inhibition would affect macrophage polarization. To explore the role of caspases in CSF1 differentiation, we used human monocytes sorted from buffy coats treated by cytokines. We reported that caspase inhibition delays the ex vivo differentiation of peripheral blood monocytes exposed to CSF1 and modifies the phenotype of generated macrophages, e.g. cell shape, surface markers. Moreover, by RNAseq, we observed that the macrophages generated in presence of CSF1 and QVD are different from CSF1-treated monocytes. This study confirms the importance of caspase activation in CSF1 differentiation.
Project description:CSF1 expression in the central nervous system (CNS) increases in response to a variety of stimuli, and CSF1 is overexpressed in many CNS diseases. In young adult mice we previously showed that CSF1 overexpression in the CNS caused proliferation of IBA1+ microglia without promoting expression of M2 polarization markers. Here we further examine the impacts of increased CSF1 levels in the brain. As CSF1 over-expressing mice age, IBA1+ cell numbers are constrained by a decline in proliferation rate. Compared to controls, there were no differences in expression of the M2 markers ARG1 and MRC1 (CD206) in CSF1 overexpressing mice of any age, indicating that even prolonged exposure to increased CSF1 is not sufficient to promote M2 polarization in vivo. Moreover, RNA-sequencing (RNA-seq) confirmed the lack of increased expression of markers of M2 polarization in microglia exposed to CSF1 over-expression, but did reveal changes in expression of other immune related genes. Although treatment with inhibitors of the CSF1 receptor, CSF1R, has been shown to impact other glia, no increased expression of astrocyte or oligodendrocyte lineage markers was observed in CSF1 OE mice. Our data indicate that CSF1 overexpression as an isolated stimulus has limited impacts in the CNS, and that microglia ultimately adapt to the presence of the CSF1 mitogenic signal.
Project description:Caspases, which are key effectors of apoptosis, have demonstrated non-apoptotic functions. One of these functions is the differentiation into macrophages of peripheral blood monocytes exposed to Colony-Stimulating Factor-1 (CSF1). Conversely, GM-CSF induces the differentiation of monocytes into macrophages in a caspase-independent manner. Macrophages generated by CSF1 and GM-CSF have distinct polarity. Macrophage polarization plays an important role in the pathogenesis of diverse human diseases as cancer, leading us to explore if caspase inhibition would affect macrophage polarization. To explore the role of caspases in CSF1 differentiation, we used human monocytes sorted from buffy coats treated by cytokines. We reported that caspase inhibition delays the ex vivo differentiation of peripheral blood monocytes exposed to CSF1 and modifies the phenotype of generated macrophages, e.g. cell shape, surface markers. Moreover, by RNAseq, we observed that the macrophages generated in presence of CSF1 and QVD are different from CSF1-treated monocytes and from GM-CSF-treated monocytes. Cell cycle and focal adhesion-related pathway genes were selectively down-regulated. This study confirms the importance of caspase activation in CSF1 differentiation.