Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human stem cell factor (SCF) acts in the presence of other growth factors to stimulate the growth of primitive hematopoietic progenitor cells. These effects are performed by activation of the SCF receptor, c-kit. Because of the potential use of SCF in patients undergoing chemotherapy and bone marrow transplantation, the effect of SCF on nonhematopoietic tumors requires investigation. To determine whether human tumor cell lines display c-kit receptors, we performed binding experiments with 125I-SCF on a breast carcinoma cell line (Du4475), a gastric carcinoma cell line (KATO III), a melanoma cell line (HTT144), as well as two small cell lung carcinoma cell lines (H69 and H128). The biologic effect of SCF on tumor cell lines was assessed by its ability to stimulate tritiated thymidine uptake and to enhance colony growth in methylcellulose. The breast carcinoma cell line, Du4475, as well as two small cell lung carcinoma cell lines, H69 and H128, exhibit high-affinity c-kit receptors with approximate binding affinities of 40, 100, and 90 pmol/L, respectively. The number of high-affinity receptors per cell ranged from 700 to 9,500. The gastric carcinoma cell line, as well as the melanoma cell line, showed trace binding of 125I-SCF. In the presence of SCF alone, or in combination with granulocyte-macrophage colony-stimulating factor or interleukin-3, there was less than a 17% increase in the colony growth of Du4475, H69, or H128 cell lines. Postulating that the lack of growth response could be secondary to endogenous SCF production by the tumor cell lines, we used an RNAse protection assay to determine whether the tumor cell lines contain SCF messenger RNA (mRNA). In addition, we tested tumor cell line supernatants for the presence of secreted SCF protein by enzyme immunoassay, and analyzed the tumor cell lines for membrane-bound SCF by indirect immunofluorescence. Our results show that the Du4475, H69, and H128 cell lines, as well as a melanoma cell line (HTT144), have multiple copies of SCF mRNA. Soluble SCF protein was detected in the cell supernatants in the Du4475 and H69 cell lines and SCF was found on the surface of all four cell lines. These data show that some human solid tumor cell lines display high-affinity c-kit receptors and produce SCF, which can be detected on the cell surface. These results suggest the possibility that autocrine production of SCF by c-kit receptor-bearing tumor cells may enhance cell growth in tumor cell lines.
 ...
PMID:Nonhematopoietic tumor cell lines express stem cell factor and display c-kit receptors. 137 16

Hematopoietic growth factor receptors are present on cells of normal nonhematopoietic tissues such as endothelium and placenta. We previously demonstrated functional human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptors on small cell carcinoma of the lung cell lines, and others have reported that certain solid tumor cell lines respond to GM-CSF in clonogenic assays. In the current study, we examine human melanoma cell lines and fresh specimens of melanoma to determine whether they have functional GM-CSF receptors. Scatchard analyses of 125I-GM-CSF equilibrium binding to melanoma cell lines showed a mean of 542 +/- 67 sites per cell with a kd of 0.72 +/- 0.14 nmol/L. Cross-linking studies in the melanoma cell line, M14, showed a major GM-CSF receptor species of 84,000 daltons. Under the conditions tested, the M14 cells did not have a proliferative response to GM-CSF in vitro, nor was any induction of primary response genes detected by Northern analysis in response to GM-CSF. Studies to determine internal translocation of the receptor-ligand complex indicated less than 10% of the 125I-GM-CSF internalized was specifically bound to receptors. Primary melanoma cells from five surgical specimens had GM-CSF receptors; Scatchard analysis was performed on one sample, showing 555 sites/cell with a kd of 0.23 nmol/L. These results indicate that human tumor cells may express a low-affinity GM-CSF receptor protein that localizes to the cell surface and binds ligand, but lacks functional components or accessory factors needed to transduce a signal.
 ...
PMID:Identification and characterization of a low-affinity granulocyte-macrophage colony-stimulating factor receptor on primary and cultured human melanoma cells. 183 Apr 97

The possibility that production of some cytokines in the carcinoma microenvironment is associated with the presence and differentiation of cells belonging to the dendritic cell (DC)/Langerhans' cell (LC) lineage was investigated. Immunohistochemical examination showed the presence of intraepithelial LCs (CD1a- and S100-positive cells) in 6 of 10 squamous cell carcinomas and in 8 of 10 adenocarcinomas. Langerhans' cells were mainly located close to lymphoid aggregates. In situ hybridization performed in four cases (three LC positive and one LC negative) of squamous cell carcinoma and in five cases (four LC positive and one LC negative) of adenocarcinoma showed that some mononuclear cells in the interstitium displayed hybridization with granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF alpha), and interleukin 1-beta (IL1 beta) cDNA probes. Only in LC-positive carcinomas did epithelial cells close to lymphoid aggregates display small amounts of GM-CSF and TNF alpha mRNA expression. Immunohistochemical analysis performed in the 20 cases of lung carcinoma showed that epithelial cells in tumors with lymphoid aggregates and LCs were immunoreactive with antihuman GM-CSF monoclonal antibody. Specimens negative for GM-CSF contained very few LCs. Northern blot analysis was used to investigate GM-CSF, TNF alpha, IL1 alpha, and IL1 beta mRNA expression in six human lung carcinoma cell lines. A constitutive expression of TNF alpha mRNA was found in all of them, whereas only three showed a low constitutive expression of GM-CSF mRNA. In the latter three cell lines treatment with phytohemagglutinin (PHA)-stimulated peripheral blood lymphocyte (PBL) supernatant (PHA-SUP) upregulated GM-CSF mRNA expression and induced that of IL1 alpha mRNA. Carcinomatous epithelial cells producing small amounts of cytokines could promote the recruitment of cells of DC/LC lineage. Subcellular factors produced by reactive lymphocytes and/or macrophages may influence the production of GM-CSF and IL1 alpha by various epithelia. Up-regulation of this production could favor the arrival and differentiation of DCs and activate LC functions.
 ...
PMID:Role of cytokines in distribution and differentiation of dendritic cell/Langerhans' cell lineage in human primary carcinomas of the lung. 763 48

Production of granulocyte-macrophage colony-stimulating factor (GM-CSF) by metastatic Lewis lung carcinoma tumors (LLC-LN7) has been shown to increase their migration and invasion in vitro, and metastasis in vivo. The present studies showed that treatment of the LLC-LN7 cells by 2 days culture with 1 alpha, 25-dihydroxyvitamin D3 [1,25(OH)2D3] inhibited their production of GM-CSF. The 1,25(OH)2D3-treated cells also became less migratory and invasive. This inhibitory effect on tumor motility could not be readily reversed upon removal of 1,25(OH)2D3. The mechanism by which 1,25(OH)2D3 reduced tumor motility was attributed to the inhibition of tumor GM-CSF production since the capacity to migrate and invade could be restored by supplementing the medium with recombinant GM-CSF. In vivo studies showed that treatment of LLC-LN7-bearing mice with 1,25(OH)2D3 had no effect on growth of s.c. primary tumors, but reduced the formation of tumor metastases. These results show that 1,25(OH)2D3 can interrupt the autocrine motility-stimulation cascade by reducing tumor production of GM-CSF, thus reducing the expression of properties that are characteristic of metastatic tumor cells.
 ...
PMID:Inhibition of tumor production of granulocyte-macrophage colony-stimulating factor by 1 alpha, 25-dihydroxyvitamin D3 reduces tumor motility and metastasis. 803 38

Metastatic Lewis lung carcinoma (LLC-LN7) cells have previously been shown to produce granulocyte-macrophage colony-stimulating factor (GM-CSF) which induces the appearance of immunosuppressive granulocytic-macrophage progenitor cells (GM-suppressor cells). The present in vitro studies showed that treatment of LLC-LN7 tumor cells with 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] plus low dose gamma-interferon (IFN-gamma) resulted in a synergistic reduction in tumor GM-CSF secretion and a blockage in the capacity of the tumor cells to induce GM-suppressor cells. The production of GM-CSF by bulk cultures of enzymatically dissociated LLC-LN7 tumors that had been excised as s.c. tumors from mice was also blocked when the dissociated tumor was cultured with 1,25(OH)2D3 plus IFN-gamma. Our previous and present studies showed that GM-suppressor cells persist in bulk cultures of dissociated LLC-LN7 tumors after a 1-week period of culture. Addition of either 1,25(OH)2D3 or IFN-gamma did not diminish the persistence of GM-suppressor cells. However, when tumor production of GM-CSF was inhibited by culture with both 1,25(OH)2D3 and IFN-gamma, the ability of the dissociated tumor culture to sustain the presence of GM-suppressor cells was blocked. This elimination of GM-suppressor cells by treatment of the dissociated tumor with 1,25(OH)2D3 and IFN-gamma coincided with increased expansion of CD8+ tumor-infiltrating leukocytes and increased cytotoxic T-lymphocytes activity of tumor-infiltrating lymphocytes. These results suggest that blocking tumor production of GM-CSF can interrupt the suppressor-inducing cascade of the tumor and enhance expansion and anti-tumor cytolytic reactivity of tumor-infiltrating leukocytes.
 ...
PMID:1 alpha,25-dihydroxyvitamin D3 plus gamma-interferon blocks lung tumor production of granulocyte-macrophage colony-stimulating factor and induction of immunosuppressor cells. 826 14

The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on murine antitumour responses was examined. Sixty mice received Lewis lung carcinoma implants and were then randomized to receive GM-CSF 1 microgram/day, GM-CSF 0.5 microgram/day or saline for 10 days and studied with regard to tumour volume, carcass weight and food intake. Macrophage antitumour mechanisms including oxygen free radical production and nitric oxide release were studied in peritoneal macrophages after co-culture with GM-CSF in vitro and in vivo. GM-CSF 1 microgram/day decreased tumour growth after 5 days (mean(s.e.m.) 0.62(0.14) versus 1.24(0.19) cm3, P = 0.017). GM-CSF upregulated macrophage antitumour mechanisms by enhancing the in vivo production of superoxide radicals (mean(s.e.m.) 0.69(0.06) versus 0.45(0.10) nmol, P < 0.05) and nitric oxide (mean(s.e.m.) 48(3) versus 24(4) mumol, P < 0.01). GM-CSF functions through the enhancement of macrophage tumoricidal activity, suggesting a therapeutic potential for this cytokine in the tumour-bearing host.
 ...
PMID:Granulocyte-macrophage colony-stimulating factor inhibits tumour growth. 829 20

Granulocyte-macrophage colony-stimulating factor (GM-CSF) that is produced by metastatic Lewis lung carcinoma (LLC-LN7) cells functions as an autocrine stimulator of tumor-cell motility through protein kinase A (PKA) signal transduction. This GM-CSF-mediated enhancement of LLC-LN7 cell motility coincides with a reduction in the level of polymerized F-actin. In contrast, non-metastatic LLC-C8 tumor cells, which have a diminished level of PKA signaling, do not produce GM-CSF and do not respond to exogenous GM-CSF, since they remain non-motile and retain a high content of filamentous actin. The capacity of PKA to regulate the cytoskeletal organization of tumor cells was further studied with the use of LLC variants that had been stably transfected to over-express the C alpha subunit of PKA (CEV cells) or to express a mutant cAMP-resistant PKA RI alpha subunit resulting in a defective PKA (REV cells). When compared with wild-type metastatic LLC-LN7 cells, in which the F-actin staining was too diffuse to be clearly visualized microscopically, the PKA-defective REV-LN7 transfectants had an increased level of F-actin. In comparison with the wild-type non-metastatic LLC-C8 cells, which had a high content of F-actin, the CEV-C8 transfectants that over-expressed PKA activity had a reduced level of F-actin. The reduced polymerization of actin in these CEV-C8 transfectants was accompanied by reduced levels of the intermediate filament protein vimentin and a shift in the distribution both of F-actin and of vimentin to the periphery of the cells. These results show reduced cytoskeletal organization in metastatic LLC-LN7 cells as compared with that of non-metastatic LLC-C8 cells, and indicate that elevation of PKA activity, either by autologous GM-CSF or by genetic manipulation, diminishes cytoskeletal organization.
 ...
PMID:Activation of the protein kinase a signal transduction pathway by granulocyte-macrophage colony-stimulating factor or by genetic manipulation reduces cytoskeletal organization in Lewis lung carcinoma variants. 831 33

Expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) by metastatic Lewis lung carcinoma cells (LLC-LN7) was previously shown to contribute to the maintenance of phenotypic characteristics associated with an increased capacity to metastasize. In the present study, pre-incubation of LLC-LN7 cells with neutralizing anti-GM-CSF antibodies diminished the capacity of the tumor cells to form experimental metastases after i.v. inoculation, while pre-incubation with recombinant GM-CSF (rGM-CSF) increased formation of metastases. In the presence of rGM-CSF, the LLC-LN7 cells exhibited an increased capacity to migrate, invade through a reconstituted basement membrane, and adhere to lung tissue. Studies to identify the signal transduction pathway through which GM-CSF enhanced the in vitro metastatic properties of the LLC-LN7 tumor cells implicated protein kinase A (PKA). Signaling through PKA was suggested by the demonstration that the stimulation of tumor-cell motility by GM-CSF was blocked in the presence of the adenylate cyclase inhibitor nicotinic acid, or the PKA inhibitors A3 or KT5720. In addition, the role of PKA as a signaling mechanism for GM-CSF was assessed by using REV-LN7 cells, which are LLC-LN7 cells that have been stably transfected with an expression vector encoding a mutant PKA RI alpha subunit and which, in turn, express a cAMP-resistant PKA. Adherence and invasion by the PKA-defective REV-LN7 cells were not stimulated by rGM-CSF, contrasting with the stimulation observed for wild-type LLC-LN7 cells. These data suggest that rGM-CSF can further enhance the in vitro metastatic characteristics of LLC-LN7 tumor cells and that this is dependent on signal transduction through PKA.
 ...
PMID:Granulocyte-macrophage colony-stimulating factor stimulates the metastatic properties of Lewis lung carcinoma cells through a protein kinase A signal-transduction pathway. 843 41

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has not been found to exert any influence on the proliferation of Lewis lung carcinoma (LLC) cells in vitro. Nevertheless, when administered intraperitoneally, GM-CSF accelerated the growth of subcutaneously growing LLC in mice.
 ...
PMID:Granulocyte-macrophage colony-stimulating factor accelerates growth of Lewis lung carcinoma in mice. 862 Apr 69

By secreting granulocyte-macrophage colony-stimulating factor (GM-CSF), Lewis lung carcinoma tumors induce immune suppressive granulocyte-macrophage progenitor cells. Treating mice having established tumors and high levels of suppressor activity with vitamin D3 eliminated suppressor activity, increased anti-tumor immunity, induced an immune stimulatory cell population, and reduced tumor growth. When instead, the vitamin D3 treatment was initiated earlier, when implanted tumors first became detectable and when natural suppressor activity was less prominent, the treatment had no effect. Thus, vitamin D3 treatment can stimulate the immune competence of tumor bearers when treatment is targeted to coincide with a heightened presence of GM-CSF-induced suppressor cells.
 ...
PMID:Vitamin D3 treatment of tumor bearers can stimulate immune competence and reduce tumor growth when treatment coincides with a heightened presence of natural suppressor cells. 866 83


1 2 3 Next >>