ABSTRACT
The t(4;14) translocation occurs frequently in multiple myeloma (MM) and results in the simultaneous dysregulated expression of 2 potential oncogenes, FGFR3 (fibroblast growth factor receptor 3) from der(14) and multiple myeloma SET domain protein/Wolf-Hirschhorn syndrome candidate gene 1 from der(4). It is now shown that myeloma cells carrying a t(4;14) translocation express a functional FGFR3 that in some cases is constitutively activated by the same mutations that cause thanatophoric dysplasia. As with activating mutations of K-ras and N-ras, which are reported in approximately 40% of patients with MM, activating mutations of FGFR3 occur during tumor progression. However, the constitutive activation of ras and FGFR3 does not occur in the same myeloma cells. Thus the activated forms of these proteins appear to share an overlapping role in tumor progression, suggesting that they also share the signaling cascade. Consistent with this prediction, it is shown that activated FGFR3-when expressed at levels similar to those seen in t(4;14) myeloma-is an oncogene that acts through the MAP kinase pathway to transform NIH 3T3 cells, which can then generate tumors in nude mice. Thus, FGFR3, when overexpressed in MM, may be not only oncogenic when stimulated by FGF ligands in the bone marrow microenvironment, but is also a target for activating mutations that enable FGFR3 to play a ras-like role in tumor progression.
Subject(s)
Multiple Myeloma/genetics , Protein-Tyrosine Kinases , Receptors, Fibroblast Growth Factor/genetics , 3T3 Cells , Animals , Cell Transformation, Neoplastic , Disease Progression , Gene Expression , Genes, ras , Humans , MAP Kinase Signaling System , Mice , Mice, Nude , Models, Genetic , Multiple Myeloma/metabolism , Multiple Myeloma/pathology , Mutation , Oncogene Proteins/genetics , Oncogene Proteins/metabolism , Receptor, Fibroblast Growth Factor, Type 3 , Receptors, Fibroblast Growth Factor/metabolism , Transfection , Translocation, Genetic , Tumor Cells, CulturedABSTRACT
Adaptive immune responses begin after antigen-bearing dendritic cells (DCs) traffic from peripheral tissues to lymph nodes. Here, we show that DC migration from skin to lymph nodes utilizes the leukotriene C(4) (LTC(4)) transporter multidrug resistance-associated protein 1 (MRP1). DC mobilization from the epidermis and trafficking into lymphatic vessels was greatly reduced in MRP1(-/-) mice, but migration was restored by exogenous cysteinyl leukotrienes LTC(4) or LTD(4). In vitro, these cysteinyl leukotrienes promoted optimal chemotaxis to the chemokine CCL19, but not to other related chemokines. Antagonism of CCL19 in vivo prevented DC migration out of the epidermis. Thus, MRP-1 regulates DC migration to lymph nodes, apparently by transporting LTC(4), which in turn promotes chemotaxis to CCL19 and mobilization of DCs from the epidermis.
Subject(s)
ATP-Binding Cassette Transporters/metabolism , Chemokines, CC/metabolism , Dendritic Cells/metabolism , Leukotriene C4/metabolism , Lymph Nodes/metabolism , ATP-Binding Cassette Transporters/physiology , Animals , Blotting, Western , Cell Movement , Cells, Cultured , Chemokine CCL19 , Chemokines, CC/antagonists & inhibitors , Chemotaxis , Dose-Response Relationship, Drug , Flow Cytometry , Fluorescein-5-isothiocyanate/pharmacology , Humans , Immunoblotting , Leukotriene Antagonists/pharmacology , Leukotriene D4/metabolism , Ligands , Mice , Mice, Knockout , Multidrug Resistance-Associated Proteins , Propionates/pharmacology , Quinolines/pharmacology , Receptors, CCR7 , Receptors, Chemokine/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Skin/metabolismABSTRACT
Chemokines are thought to be important for the recruitment of granulocytes and mononuclear cells and thus for the maintenance of inflammation in ulcerative colitis (UC). We have studied the expression of interferon-gamma inducible protein-10 (IP-10), interleukin-8 (IL-8), monocyte chemoattractant protein (MCP)-1, MCP-3, and macrophage inflammatory protein (MIP)-1alpha in UC patients and control individuals to assess the role of these chemokines in disease progression. Colonic biopsies were taken endoscopically from patients and controls, frozen immediately and subsequently stained for IP-10, IL-8, MCP-1, MCP-3, and MIP-1alpha in serial sections. Cells infiltrating the lamina propria but not epithelial cells express the analyzed chemokines. They were differentiated and counted, and chemokine-expressing cells were quantified by image analysis. The percentage of cells expressing IP-10, IL-8, MCP-1, and MCP-3 was significantly enhanced in all UC samples as compared to controls. Expression in the controls was borderline, except for IP-10. No expression of MIP-1alpha was found in controls and UC. IP-10 was also markedly expressed in the mucosa of control biopsies and therefore could have a role in activated T lymphocytes' recruitment into the healthy mucosa.
Subject(s)
Chemokine CCL2/metabolism , Chemokine CXCL10/metabolism , Colitis, Ulcerative/metabolism , Cytokines , Interleukin-8/metabolism , Monocyte Chemoattractant Proteins/metabolism , Adult , Chemokine CCL3 , Chemokine CCL4 , Chemokine CCL7 , Colon/anatomy & histology , Female , Gene Expression , Humans , Immunohistochemistry , Macrophage Inflammatory Proteins/metabolism , Male , Middle Aged , Up-RegulationABSTRACT
We investigated the differentiation and trafficking of inflammatory monocytes that phagocytosed subcutaneously injected fluorescent microspheres. As expected, most of the monocytes became microsphere+ macrophages, which remained in subcutaneous tissue. However, about 25% of latex+ cells migrated to the T cell area of draining lymph nodes, where they expressed dendritic cell (DC)-restricted markers and high levels of costimulatory molecules. Microsphere-transporting cells were distinct from resident skin DCs, and this transport was reduced by more than 85% in monocyte-deficient osteopetrotic mice. Thus, a substantial minority of inflammatory monocytes carry phagocytosed particles to lymph nodes and differentiate into DCs.
