Whole genome transcriptional analysis of monocytes/macrophages purified from bone marrow of xeno-transplanted mice
Ontology highlight
ABSTRACT: The development and progression of CLL are dependent upon a complex microenvironmental network of cellular and molecular signals. As an example the in vitro survival of CLL cells is supported by nurse-like cells, which have been identified as a CLL-specific tumor-associated macrophage (TAM) population. However little is known regarding the role of TAMs in CLL development and progression. In the CLL xenograft model based on the engraftment of MEC1 human CLL cell line into Rag2-/-γc-/-, we analyzed the whole-genome transcriptome of TAMs isolated from the bone marrow. We found an enrichment of genes involved in inflammation and interaction between TAMs and leukemic cells. Rag2-/-γc-/- were injected intravenously with MEC1 cells and sacrificed at early stage of leukemia with age-matched wt Rag2-/-γc-/- mice (n=3/group). RNA was isolated from bone marrow murine monocytes/macrophages purified by magnetic separation and processed for illumina whole-genome gene expression direct-hybridization assay.
Project description:The development and progression of CLL are dependent upon a complex microenvironmental network of cellular and molecular signals. As an example the in vitro survival of CLL cells is supported by nurse-like cells, which have been identified as a CLL-specific tumor-associated macrophage (TAM) population. However little is known regarding the role of TAMs in CLL development and progression. In the CLL xenograft model based on the engraftment of MEC1 human CLL cell line into Rag2-/-γc-/-, we analyzed the whole-genome transcriptome of leukemic B cells, exposed in vivo to TAMs, isolated from the bone marrow. We found an enrichment of genes involved in inflammation and interaction between TAMs and leukemic cells. Rag2-/-γc-/- were injected intravenously with MEC1 cells and sacrificed at early stage of leukemia (n=3). RNA was isolated from: i) in vitro pre-injected human CD19+ MEC1 cells and ii) human CD19+ MEC1 cells purified from murine bone marrow by magnetic separation and processed for illumina whole-genome gene expression direct-hybridization assay
Project description:The development and progression of CLL are dependent upon a complex microenvironmental network of cellular and molecular signals. As an example the in vitro survival of CLL cells is supported by nurse-like cells, which have been identified as a CLL-specific tumor-associated macrophage (TAM) population. However little is known regarding the role of TAMs in CLL development and progression. In the CLL xenograft model based on the engraftment of MEC1 human CLL cell line into Rag2-/-γc-/-, we analyzed the whole-genome transcriptome of TAMs isolated from the bone marrow. We found an enrichment of genes involved in inflammation and interaction between TAMs and leukemic cells.
Project description:The development and progression of CLL are dependent upon a complex microenvironmental network of cellular and molecular signals. As an example the in vitro survival of CLL cells is supported by nurse-like cells, which have been identified as a CLL-specific tumor-associated macrophage (TAM) population. However little is known regarding the role of TAMs in CLL development and progression. In the CLL xenograft model based on the engraftment of MEC1 human CLL cell line into Rag2-/-γc-/-, we analyzed the whole-genome transcriptome of leukemic B cells, exposed in vivo to TAMs, isolated from the bone marrow. We found an enrichment of genes involved in inflammation and interaction between TAMs and leukemic cells.
Project description:Immune cells of the myeloid lineage and CLL cells support each other during leukemia progression and dissemination. We have investigated the molecular interactions supporting this cell-cell interdependence with a special focus on ncRNAs and microRNAs, whose role in nonmalignant monocytes and macrophages is largely unknown. In the CLL xenograft model based on the engraftment of MEC1 human CLL cell line into Rag2-/-γc-/-, we analyzed the transcriptome of monocytes/macrophages isolated from the bone marrow during leukemia progression. We found a significant enrichment of both upregulated and downregulated ncRNAs including miRNAs and long ncRNAs. These findings corroborate the hypothesis that ncRNA have a role in the protumor function of nonmalignant immune cells during leukemia progression.
Project description:Siglec-6 is a glycoprotein overexpressed on chronic lymphocytic leukemia (CLL) cell. We have shown that Siglec-6 promotes migration and adhesion of CLL cells towards CLL bone marrow stromal cells. To elucidate the mechanistic pathway involved in Siglec-6 dependent migration, we performed mass spectrometry proteomics analysis on MEC1-002 CLL cell line pulled down with a Siglec-6 targeted antibody, which revealed that Siglec-6 interacts with DOCK8, a guanine nucleotide exchange factor. Interaction of Siglec-6 with its ligand promotes DOCK8 dependent Cdc42 activation, WASP protein recruitment and F-actin polymerization. Therapeutically, Siglec-6 leukemic cells can be eliminated with a Siglec-6 targeted bispecific antibody in vitro and in vivo.
Project description:We used a RAG2-GFP reporter mouse to show that RAG+ B lineage cells can be found in the small intestinal lamina proria in normally-housed mice at weaning age. We used microarry expression analysis to compare the RAG2+ population in the gut to the RAG2+ B lineage population in the bone marrow. Microarray was used to compare RAG2+ lamina propria B cells to RAG2+ bone marrow B cells.
Project description:Chronic lymphocytic leukemia (CLL) B-cells receive signals from the lymph node and bone marrow (BM) microenvironments that regulate their survival and proliferation. These signals and the pathways that propagate them to the interior of the cell represent potential targets for therapeutic intervention. To characterize the pathways that are activated by the BM microenvironment in CLL cells in vivo, we performed gene expression profiling of tumor cells purified from BM and peripheral blood. Functional classification analysis revealed that the most frequently upregulated genes in BM-CLL cells are genes involved in cell cycle and mitosis. Among the most significantly overexpressed were the Aurora A and B kinases. To investigate whether these kinases could represent potential therapeutic targets in CLL, we performed RNA interference experiments in the CLL cell lines MEC1 and EHEB. Downregulation of Aurora A and B inhibited the proliferation and induced apoptosis in these cells. Similar effects were observed with the pan-Aurora kinase inhibitor VX-680 in primary CLL cells induced to proliferate by CpG-ODN and IL-2. VX-680 also inhibited leukemia growth in vivo in a mouse model of CLL. These data suggest that inhibition of Aurora kinases could represent a potential strategy to selectively target the proliferating compartment in CLL. To identify gene expression related to microenvironmental stimuli in B-cell Chronic Lymphocytic Leukemia (CLL) cells in vivo, expression profiles of CLL cells purified (>95%) from bone marrow (BM) and peripheral blood (PB) were compared. Paired BM and PB samples from 6 individuals were used for this analysis.
Project description:We used a RAG2-GFP reporter mouse to show that RAG+ B lineage cells can be found in the small intestinal lamina proria in normally-housed mice at weaning age. We used microarry expression analysis to compare the RAG2+ population in the gut to the RAG2+ B lineage population in the bone marrow. Microarray was used to compare RAG2+ lamina propria B cells to RAG2+ bone marrow B cells. For each experiment, RAG2-GFP+ cells from 8-12 post-natal day 17-25 RAG2-GFP reporter mice were sorted from small intestinal lamina propria lymphocyte preparations and bone marrow. RNA extracted from trizol was used for the analysis. 3 independent replicates were performed.
Project description:Expression profiling of Rag2-deficient Ets1++ and Rag2-deficient Ets1-- mature NK cells and WT bone marrow progenitors, WT T cells, and WT Pro B cells
Project description:Chronic lymphocytic leukemia (CLL) B-cells receive signals from the lymph node and bone marrow (BM) microenvironments that regulate their survival and proliferation. These signals and the pathways that propagate them to the interior of the cell represent potential targets for therapeutic intervention. To characterize the pathways that are activated by the BM microenvironment in CLL cells in vivo, we performed gene expression profiling of tumor cells purified from BM and peripheral blood. Functional classification analysis revealed that the most frequently upregulated genes in BM-CLL cells are genes involved in cell cycle and mitosis. Among the most significantly overexpressed were the Aurora A and B kinases. To investigate whether these kinases could represent potential therapeutic targets in CLL, we performed RNA interference experiments in the CLL cell lines MEC1 and EHEB. Downregulation of Aurora A and B inhibited the proliferation and induced apoptosis in these cells. Similar effects were observed with the pan-Aurora kinase inhibitor VX-680 in primary CLL cells induced to proliferate by CpG-ODN and IL-2. VX-680 also inhibited leukemia growth in vivo in a mouse model of CLL. These data suggest that inhibition of Aurora kinases could represent a potential strategy to selectively target the proliferating compartment in CLL.