Vemurafenib acts as molecular switch in Langerhans Cell Histiocytosis
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PROVIDER: PRJNA732460 | ENA |
REPOSITORIES: ENA
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Project description:Langerhans cell histiocytosis (LCH) is a neoplasm marked by the accumulation of CD1a+CD207+ cells. It is most commonly driven by a somatic activating mutation in the BRAF kinase (BRAFV600E). Multisystem disease with risk-organ involvement requires intensive chemotherapy, making BRAF-inhibitors an attractive option. Here, we present a comprehensive analysis of the course of an LCH patient treated with the combination of vemurafenib with salvage chemotherapy who achieved complete clinical and molecular remission. We conclusively show that there is no relationship between blood-BRAF levels and clinical presentation during treatment with vemurafenib, but that vemurafenib leads to a fast, efficient, but reversible inhibition of clinical manifestations of high-risk LCH such as cytopenia, fever, and hypoproteinemia. In line, serum levels of inflammatory cytokines exactly mirror vemurafenib administration. Genotyping for the BRAFV600E mutation shows its presence in multiple hematopoietic cell types, including NK cells and granulocytes. Single-cell transcriptome analysis of peripheral blood and bone marrow cells at time of diagnosis and during treatment indicate that RAF-inhibition abrogates the expression of inflammatory cytokines previously implicated in LCH. Together, our data suggest that while the CD1a+CD207+ histiocytes are the hallmark of LCH, other BRAF-mutated cells themselves contribute significantly to morbidity in patients with multisystem LCH.
2021-09-23 | GSE175480 | GEO
Project description:Langerhans cell histiocytosis (LCH) is a disease characterized by the accumulation of eponymous CD1a+ Langerin+ Langerhans-cell (LC)-like dendritic cells (DC) of largely unknown origin. Here we have performed comparative transcriptome analysis of highly purified CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations and disease courses and three major human dendritic cell lineages: epidermal Langerhans cells, myeloid dendritic cells (mDC1) and plasmacytoid dendritic cells (pDC) in order to investigate the relationship between LCH cells and naturally occurring dendritic cells. Data obtained indicate that LCH cells form a distinct DC entity. Furthermore, we have identified transcripts that are uniquely expressed by LCH cells in comparison to LC, mDC1, and pDC, and induce LCH-specific features in human DC. Primary cells were isolated from peripheral blood (mDC1 and pDC), skin (epidermal Langerhans cells) and CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations. RNA was isolated from these cells ex vivo.
2012-10-24 | E-GEOD-35340 | biostudies-arrayexpress
Project description:This study aims to identify the cell of origin of Langerhans Cell Histiocytosis and the molecular mechanisms of its pathogenesis.
2018-07-29 | GSE114181 | GEO
Project description:Langerhans cell histiocytosis (LCH) is a neoplasm marked by the accumulation of CD1A+CD207+ cells. It is most commonly driven by a somatic, activating mutation in the BRAF serine-threonine kinase (BRAFV600E). Multisystem disease with risk-organ involvement requires myelotoxic chemotherapy, making BRAF-inhibitors an attractive treatment option. Here, we present a comprehensive analysis of the course of an LCH patient treated with the combination of vemurafenib and salvage chemotherapy who achieved sustained clinical and molecular remission. We show that there is no relationship between peripheral blood BRAFV600E levels and clinical presentation during treatment with vemurafenib, but that vemurafenib leads to a fast, efficient, but reversible inhibition of clinical manifestations of systemic inflammation. In line, serum levels of inflammatory cytokines exactly mirror vemurafenib administration. Genotyping analysis identified the BRAFV600E mutation in multiple hematopoietic cell types, including NK cells and granulocytes. Single-cell transcriptome analyses of peripheral blood and bone marrow cells at time of diagnosis and during treatment indicate that RAF-inhibition abrogates the expression of inflammatory cytokines previously implicated in LCH such as IL1B and CXCL8. Together, our data suggest that while the CD1A+CD207+ histiocytes are the hallmark of LCH, other BRAF-mutated cell populations may contribute significantly to morbidity in patients with multisystem LCH.
| S-EPMC8945316 | biostudies-literature
Project description:Langerhans cell histiocytosis (LCH) is a disease characterized by the accumulation of eponymous CD1a+ Langerin+ Langerhans-cell (LC)-like dendritic cells (DC) of largely unknown origin. Here we have performed comparative transcriptome analysis of highly purified CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations and disease courses and three major human dendritic cell lineages: epidermal Langerhans cells, myeloid dendritic cells (mDC1) and plasmacytoid dendritic cells (pDC) in order to investigate the relationship between LCH cells and naturally occurring dendritic cells. Data obtained indicate that LCH cells form a distinct DC entity. Furthermore, we have identified transcripts that are uniquely expressed by LCH cells in comparison to LC, mDC1, and pDC, and induce LCH-specific features in human DC.
2012-10-24 | GSE35340 | GEO
Project description:Langerhans-cell histiocytosis (LCH) is characterized by heterogeneous lesions containing CD207+ Langerhans cells (LCs) and lymphocytes. In this study, we isolated CD207+ cells and CD3+ T cells from LCH lesions to determine cell-specific gene expression. Compared to control epidermal CD207+ cells, the LCH CD207+ cells yielded 2113 differentially-expressed genes (FDR<0.01). Surprisingly, expression of many genes previously associated with LCH, including cell-cycle regulators, pro-inflammatory cytokines and chemokines were not significantly different from control LCs in our study. However, several novel genes whose products activate and recruit T cells to sites of inflammation, including SPP1 (osteopontin), were highly over-expressed in LCH CD207+ cells. Furthermore, several genes associated with immature myeloid dendritic cells were over-expressed in LCH CD207+ cells. Compared to the peripheral CD3+ cells from LCH patients, the LCH lesion CD3+ cells yielded only 162 differentially-regulated genes (FDR<0.01), and the expression profile of the LCH lesion CD3+ cells was consistent with an activated regulatory T cell phenotype with increased expression of FOXP3, CTLA4 as well as SPP1. Based on these results, we propose a new model of LCH pathogenesis in which lesions do not arise from epidermal Langerhans cells, but from accumulation of bone-marrow derived immature myeloid dendritic cells that recruit activated lymphocytes.
2010-03-15 | GSE16395 | GEO
Project description:Langerhans-cell histiocytosis (LCH) is characterized by heterogeneous lesions containing CD207+ Langerhans cells (LCs) and lymphocytes. In this study, we isolated CD207+ cells and CD3+ T cells from LCH lesions to determine cell-specific gene expression. Compared to control epidermal CD207+ cells, the LCH CD207+ cells yielded 2113 differentially-expressed genes (FDR<0.01). Surprisingly, expression of many genes previously associated with LCH, including cell-cycle regulators, pro-inflammatory cytokines and chemokines were not significantly different from control LCs in our study. However, several novel genes whose products activate and recruit T cells to sites of inflammation, including SPP1 (osteopontin), were highly over-expressed in LCH CD207+ cells. Furthermore, several genes associated with immature myeloid dendritic cells were over-expressed in LCH CD207+ cells. Compared to the peripheral CD3+ cells from LCH patients, the LCH lesion CD3+ cells yielded only 162 differentially-regulated genes (FDR<0.01), and the expression profile of the LCH lesion CD3+ cells was consistent with an activated regulatory T cell phenotype with increased expression of FOXP3, CTLA4 as well as SPP1. Based on these results, we propose a new model of LCH pathogenesis in which lesions do not arise from epidermal Langerhans cells, but from accumulation of bone-marrow derived immature myeloid dendritic cells that recruit activated lymphocytes. Cell-specific gene expression from LCH biopsy specimens was evaluated by comparing hybridization signal from amplified cDNA on Affymetrix gene chips (U133A Plus 2.0) (Table1). Three sets of comparisons were performed: 1) Thirteen LCH CD207+ samples were compared to 12 control skin LCH CD207+ samples. 2) Seven LCH lesion CD3+ samples were compared to 7 peripheral blood CD3+ samples from the same patients. 3) Twelve LCH lesion CD3+ samples were compared to 4 pooled control tonsil CD3+ samples (5 individual tonsil CD3+ samples/pool).
2010-03-23 | E-GEOD-16395 | biostudies-arrayexpress
Project description:Langerhans cell histiocytosis (LCH) is a rare neoplasm predominantly affecting children. It occupies a characteristic hybrid position between cancers and inflammatory diseases, which makes it an attractive model for studying cancer development. To explore the molecular mechanisms underlying the pathophysiology of LCH and its characteristic clinical heterogeneity, we investigated the transcriptomic and epigenomic diversity in primary LCH lesions. Using single-cell RNA sequencing, we identified multiple recurrent types of LCH cells within these biopsies, including putative LCH progenitor cells and several subsets of differentiated LCH cells. We confirmed the presence of proliferative LCH cells in all analysed biopsies using immunohistochemistry, and we defined the epigenomic and gene-regulatory basis of the different LCH cell subsets using chromatin profiling. In summary, our single-cell analysis of LCH uncovered an unexpected degree of cellular, transcriptomic, and epigenomic heterogeneity among LCH cells, reflecting complex developmental hierarchies in LCH lesions.
2019-07-30 | GSE133704 | GEO
Project description:Langerhans cell histiocytosis (LCH) is a potentially fatal myeloid neoplasia, stemming from the mononuclear phagocyte (MNP) system. Discrimination of neoplastic cells that share features with normal MNPs is essential for mapping disease origin and pathogenesis. Here, we performed a deep profiling of LCH cells combining single cell RNA-seq and protein analysis enabling us to assess their heterogeneity and compare to their normal counterparts within the tumor microenvironment. Downstream analysis revealed LCH signatures pointing to senescence and tumor immune surveillance escape mechanisms. Developmentally, two major LCH arms, phenotypically resembling DC2 and monocyte/DC3 lineages, were identified and validated in situ across different pathological tissue sites using high-throughput microscopy. The present results support a dual origin model of LCH with an underlying neoplastic hit prior to the fate commitment to DC2 and monocyte/DC3 lineages, and provides basis for development of future targets in LCH and other histiocytic disorders.
2022-12-09 | GSE173923 | GEO
Project description:Langerhans cell histiocytosis (LCH) is a rare neoplasm predominantly affecting children. It occupies a characteristic hybrid position between cancers and inflammatory diseases, which makes it an attractive model for studying cancer development. To explore the molecular mecha-nisms underlying the pathophysiology of LCH and its characteristic clinical heterogeneity, we investi-gated the transcriptomic and epigenomic diversity in primary LCH lesions. Using single-cell RNA se-quencing, we identified multiple recurrent types of LCH cells within these biopsies, including putative LCH progenitor cells and several subsets of differentiated LCH cells. We confirmed the presence of pro-liferative LCH cells in all analysed biopsies using immunohistochemistry, and we defined the epigenomic and gene-regulatory basis of the different LCH cell subsets using chromatin profiling. In summary, our single-cell analysis of LCH uncovered an unexpected degree of cellular, transcriptomic, and epigenomic heterogeneity among LCH cells, reflecting complex developmental hierarchies in LCH lesions.
2019-07-30 | GSE133785 | GEO