scholarly journals Critical Prosurvival Roles for C/EBPβ and Insulin-Like Growth Factor I in Macrophage Tumor Cells

2004 ◽  
Vol 24 (8) ◽  
pp. 3238-3250 ◽  
Author(s):  
Jennifer Wessells ◽  
Shoshana Yakar ◽  
Peter F. Johnson

ABSTRACT One of the hallmarks of leukemic cells is their ability to proliferate and survive in the absence of exogenous growth factors (GFs). However, the molecular mechanisms used by myeloid tumor cells to escape apoptosis are not fully understood. Here we report that Myc/Raf-transformed macrophages require the transcription factor C/EBPβ to prevent cell death. In contrast to wild-type cells, C/EBPβ−/− macrophages were completely dependent on macrophage colony-stimulating factor or granulocyte-macrophage colony-stimulating factor for survival and displayed impaired tumorigenicity in vivo. Microarray analysis revealed that C/EBPβ-deficient cells expressed significantly reduced levels of the prosurvival factor insulin-like growth factor I (IGF-I). Overexpression of C/EBPβ stimulated transcription from the IGF-I promoter, indicating that IGF-I is a direct transcriptional target of C/EBPβ. Serological neutralization of IGF-I in C/EBPβ+/+ tumor cell cultures induced apoptosis, showing that IGF-I functions as an autocrine survival factor in these cells. Macrophage tumor cells derived from IGF-I−/− mice were GF dependent, similar to C/EBPβ-deficient cells. Forced expression of either C/EBPβ or IGF-I in C/EBPβ−/− bone marrow cells restored Myc/Raf-induced transformation and permitted neoplastic growth without exogenous GFs. Thus, our findings demonstrate that C/EBPβ is essential for oncogenic transformation of macrophages and functions at least in part by regulating expression of the survival factor IGF-I.

2003 ◽  
Vol 21 (17) ◽  
pp. 3343-3350 ◽  
Author(s):  
Robert Soiffer ◽  
F. Stephen Hodi ◽  
Frank Haluska ◽  
Ken Jung ◽  
Silke Gillessen ◽  
...  

Purpose: Vaccination with irradiated, autologous melanoma cells engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) by retroviral-mediated gene transfer generates potent antitumor immunity in patients with metastatic melanoma. Further clinical development of this immunization scheme requires simplification of vaccine manufacture. We conducted a phase I clinical trial testing the biologic activity of vaccination with irradiated, autologous melanoma cells engineered to secrete GM-CSF by adenoviral-mediated gene transfer.Patients and Methods: Excised metastases were processed to single cells, transduced with a replication-defective adenoviral vector encoding GM-CSF, irradiated, and cryopreserved. Individual vaccines were composed of 1 × 106, 4 × 106, or 1 × 107tumor cells, depending on overall yield, and were injected intradermally and subcutaneously at weekly and biweekly intervals.Results: Vaccines were successfully manufactured for 34 (97%) of 35 patients. The average GM-CSF secretion was 745 ng/106cells/24 hours. Toxicities were restricted to grade 1 to 2 local skin reactions. Eight patients were withdrawn early because of rapid disease progression. Vaccination elicited dense dendritic cell, macrophage, granulocyte, and lymphocyte infiltrates at injection sites in 19 of 26 assessable patients. Immunization stimulated the development of delayed-type hypersensitivity reactions to irradiated, dissociated, autologous, nontransduced tumor cells in 17 of 25 patients. Metastatic lesions that were resected after vaccination showed brisk or focal T-lymphocyte and plasma cell infiltrates with tumor necrosis in 10 of 16 patients. One complete, one partial, and one mixed response were noted. Ten patients (29%) are alive, with a minimum follow-up of 36 months; four of these patients have no evidence of disease.Conclusion: Vaccination with irradiated, autologous melanoma cells engineered to secrete GM-CSF by adenoviral-mediated gene transfer augments antitumor immunity in patients with metastatic melanoma.


1992 ◽  
Vol 262 (4) ◽  
pp. C876-C881 ◽  
Author(s):  
M. Pinzani ◽  
H. E. Abboud ◽  
L. Gesualdo ◽  
S. L. Abboud

Macrophage colony-stimulating factor (M-CSF) selectively promotes mononuclear phagocyte survival, proliferation, and differentiation. The production of this factor within the liver may be necessary to support the relatively long-term survival of circulating monocytes as they migrate into tissues and differentiate into macrophages. We studied the constitutive expression and the effects of platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), and epidermal growth factor (EGF) on M-CSF mRNA levels and secretion of M-CSF in murine liver fat-storing cells (FSC), vascular pericytes likely involved in the development of liver fibrosis. By Northern analysis, using a murine M-CSF cDNA, FSC constitutively express two major transcripts of 4.4 and 2.2 kb, similar to those detected in mouse L cells, used as a control. Exposure to 10 ng/ml PDGF or bFGF increased M-CSF mRNA levels. Peak effects were observed at 3 and 6 h for PDGF and bFGF, respectively, returning to baseline levels by 12 h. Under basal conditions, detectable amounts of M-CSF, measured by radioimmunoassay, were found in cell supernatants conditioned for 8 and 24 h. PDGF and bFGF markedly stimulated the release of M-CSF as early as 8 h, an effect persisting for at least 24 h. These findings suggest that liver FSC release M-CSF upon stimulation by PDGF and bFGF and may contribute to the activation of resident or infiltrating cells in inflammatory liver diseases.


2014 ◽  
Vol 34 (4) ◽  
pp. 877-886 ◽  
Author(s):  
Allison Ostriker ◽  
Henrick N. Horita ◽  
Joanna Poczobutt ◽  
Mary C.M. Weiser-Evans ◽  
Raphael A. Nemenoff

Objective— To define the contribution of vascular smooth muscle cell (SMC)–derived factors to macrophage phenotypic modulation in the setting of vascular injury. Approach and Results— By flow cytometry, macrophages (M4) were the predominant myeloid cell type recruited to wire-injured femoral arteries, in mouse, compared with neutrophils or eosinophils. Recruited macrophages from injured vessels exhibited a distinct expression profile relative to circulating mononuclear cells (peripheral blood monocytes; increased: interleukin-6, interleukin-10, interleukin-12b, CC chemokine receptor [CCR]3, CCR7, tumor necrosis factor-α, inducible nitric oxide synthase, arginase 1; decreased: interleukin-12a, matrix metalloproteinase [MMP]9). This phenotype was recapitulated in vitro by maturing rat bone marrow cells in the presence of macrophage-colony stimulating factor and 20% conditioned media from cultured rat SMC (sMφ) compared with maturation in macrophage-colony stimulating factor alone (M0). Recombinant transforming growth factor (TGF)-β1 recapitulated the effect of SMC conditioned media. Macrophage maturation studies performed in the presence of a pan-TGF-β neutralizing antibody, a TGF-β receptor inhibitor, or conditioned media from TGF-β–depleted SMCs confirmed that the SMC-derived factor responsible for macrophage activation was TGF-β. Finally, the effect of SMC-mediated macrophage activation on SMC biology was assessed. SMCs cocultured with sMφ exhibited increased rates of proliferation relative to SMCs cultured alone or with M0 macrophages. Conclusions— SMC-derived TGF-β modulates the phenotype of maturing macrophages in vitro, recapitulating the phenotype found in vascular lesions in vivo. SMC-modulated macrophages induce SMC activation to a greater extent than control macrophages.


Blood ◽  
1991 ◽  
Vol 77 (5) ◽  
pp. 971-979 ◽  
Author(s):  
T Tsuda ◽  
D Wong ◽  
J Dolovich ◽  
J Bienenstock ◽  
J Marshall ◽  
...  

Abstract We have recently shown that nerve growth factor (NGF) promotes human granulopoiesis, specifically augmenting basophilic cell differentiation observed in methylcellulose hematopoietic colony assays of human peripheral blood. Because the NGF effect was seen in the presence of conditioned medium derived from a human T-cell line (Mo-CM) containing granulocyte-macrophage colony-stimulating factor (GM-CSF), we examined interactions of purified NGF and recombinant human GM-CSF (rhGM-CSF) on granulocyte growth and differentiation. rhGM-CSF stimulated a dose- dependent increase in methylcellulose colony growth at concentrations between 0.1 U/mL and 10 U/mL, and in the presence of NGF at 500 ng/mL this effect was enhanced. The number of basophilic cell colony-forming units (CFU-Baso) and histamine-positive colonies increased synergistically when NGF was added to rhGM-CSF. Furthermore, because Mo- CM acts with sodium butyrate to promote basophilic differentiation of alkaline-passaged myeloid leukemia cells, HL-60, we also examined the interaction of NGF and Mo-CM or rhGM-CSF using this assay. In the presence of NGF, Mo-CM at concentrations of 0.5% to 20% vol/vol, and rhGM-CSF at concentrations of 0.1 U/mL to 100 U/mL synergistically increased histamine production by butyrate-induced, alkaline-passaged HL-60 cells; this was associated with the appearance of metachromatic, tryptase-negative, IgE receptor-positive cells. The effects of rhGM-CSF or Mo-CM were completely abrogated by a specific anti-rhGM-CSF neutralizing antibody in methylcellulose, with or without NGF; the NGF synergy with rhGM-CSF in the HL-60 assay was also inhibited by either anti-rhGM-CSF or anti-NGF antibody. These studies support the notion that differentiation in the basophilic lineage may be enhanced by NGF acting to increase the number of GM-CSF-responsive basophilic cell progenitors.


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