Effects of granulocyte-macrophage colony-stimulating factor on in vitro growth of human solid tumors.

1989 ◽  
Vol 7 (9) ◽  
pp. 1346-1350 ◽  
Author(s):  
S E Salmon ◽  
R Liu

Solid tumor biopsies from 33 patients were tested in vitro to evaluate the growth modulatory effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF). In 29 of 33 studies (88%), addition of GM-CSF either had no effect on in vitro growth, or induced growth inhibition. While significant growth inhibition was observed in 10 studies, marked inhibition was only observed in three studies. However, all dose-response curves were usually flat, suggesting indirect effects. Moderate growth stimulation was observed in four instances, which may have been due to residual granulocyte-macrophage progenitors within the biopsies. We conclude that GM-CSF has little or no growth-modulatory effect on most nonhematopoietic neoplasms. The primary role of GM-CSF in patients with solid tumors appears to be in prevention or reversal of myelosuppression associated with therapy. Thus, while GM-CSF seems unlikely to have a role in monotherapy of cancer, it is also unlikely to have its utility compromised by enhancement of tumor growth.

1987 ◽  
Vol 166 (1) ◽  
pp. 129-141 ◽  
Author(s):  
W F Owen ◽  
M E Rothenberg ◽  
D S Silberstein ◽  
J C Gasson ◽  
R L Stevens ◽  
...  

Normodense human peripheral blood eosinophils were isolated under sterile conditions from the 22/23 and 23/24% interfaces and the cell pellet of metrizamide gradients. After culture for 7 d in RPMI media in the presence of 50 pM biosynthetic (recombinant) human granulocyte/macrophage colony-stimulating factor (rH GM-CSF), 43 +/- 7% (mean +/- SEM, n = 8) of the cells were viable; in the absence of rH GM-CSF, no eosinophils survived. The rH GM-CSF-mediated viability was concentration dependent; increased survival began at a concentration of 1 pM, a 50% maximal response was attained at approximately 3 pM, and a maximal effect was reached at concentrations of greater than or equal to 10 pM rH GM-CSF. In the presence of rH GM-CSF and mouse 3T3 fibroblasts, 67 +/- 6% (mean +/- SEM, n = 8) of the eosinophils survived for 7 d. In a comparative analysis, there was no difference in eosinophil viability after 7 and 14 d (n = 3) in the presence of 50 pM GM-CSF and fibroblasts. Culture with fibroblasts alone did not support eosinophil survival. The addition of fibroblast-conditioned media to rH GM-CSF did not further improve eosinophil viability, indicating a primary role for GM-CSF in supporting these eosinophil cell suspensions ex vivo and a supplementary role for 3T3 fibroblasts. Eosinophils cultured for 7 d localized on density gradient sedimentation at the medium/18, 18/20, and 20/21 interfaces of metrizamide gradients, indicating a change to the hypodense phenotype from their original normodense condition. In addition, the cultured eosinophils generated approximately 2.5-fold more LTC4 than freshly isolated cells when stimulated with the calcium ionophore A23187 and manifested sevenfold greater antibody-dependent killing of S. mansoni larvae than the freshly isolated, normodense cells from the same donor. Thus we demonstrate the rH GM-CSF dependent conversion in vitro of normodense human eosinophils to hypodense cells possessing the augmented biochemical and biological properties characteristic of the hypodense eosinophils associated with a variety of hypereosinophilic syndromes. In addition, these studies provide a culture model of at least 14 d suitable for the further characterization of hypodense eosinophils.


Blood ◽  
1988 ◽  
Vol 72 (4) ◽  
pp. 1329-1332 ◽  
Author(s):  
DC Kaufman ◽  
MR Baer ◽  
XZ Gao ◽  
ZQ Wang ◽  
HD Preisler

Expression of the granulocyte-macrophage colony-stimulating factor (GM- CSF) gene in acute myelocytic leukemia (AML) was assayed by Northern blot analysis. GM-CSF messenger RNA (mRNA) was detected in the freshly obtained mononuclear cells of only one of 48 cases of AML, in contrast with recent reports that GM-CSF mRNA might be detected in half of the cases of AML when RNA is prepared from T-cell- and monocyte-depleted leukemic cells. We did find, however, that expression of the GM-CSF gene was detectable in five of ten cases after in vitro T-cell and monocyte depletion steps. Additional studies suggest that expression of GM-CSF in the bone marrow of the one positive case, rather than being autonomous, was under exogenous control, possibly by a paracrine factor secreted by marrow stromal cells. These studies emphasize the potential for altering in vivo patterns of gene expression by in vitro cell manipulation.


Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 1912-1918 ◽  
Author(s):  
A Tobler ◽  
HP Marti ◽  
C Gimmi ◽  
AB Cachelin ◽  
S Saurer ◽  
...  

Abstract Tumor necrosis factor alpha (TNF alpha) stimulates granulocyte- macrophage colony-stimulating factor (GM-CSF) production in human fibroblasts and other mesenchymal cells. However, relatively little is known about agents that downregulate cytokine production in these cells. In the present report we show that dexamethasone (Dexa), a synthetic glucocorticoid, markedly reduced GM-CSF production in TNF alpha-stimulated fibroblasts at both the protein and the RNA levels. CSF activity, GM-CSF protein, and RNA levels, determined by an in vitro colony-forming assay in normal human bone marrow cells, by an enzyme immunoassay, and by Northern blotting assay, were reduced to greater than 90% of control values by Dexa (1 mumol/L). Similarly, 1,25- dihydroxyvitamin D3 [1,25(OH)2D3], a hormone with possible physiologic immunoregulatory significance, reduced GM-CSF expression in a concentration- and time-dependent manner. However, this repression was less pronounced than that of Dexa, and in part due to a decreased proliferative activity. In contrast, cyclosporine A (CsA), another immunosuppressive agent, did not alter GM-CSF expression in TNF alpha- stimulated fibroblasts. Our in vitro studies suggest that by inhibiting GM-CSF production in fibroblasts, glucocorticoids and possibly 1,25(OH)2D3, but not CsA, may attenuate TNF alpha-mediated inflammatory processes and influence the regulation of hematopoiesis.


1987 ◽  
Vol 166 (5) ◽  
pp. 1436-1446 ◽  
Author(s):  
W Y Weiser ◽  
A Van Niel ◽  
S C Clark ◽  
J R David ◽  
H G Remold

Recombinant granulocyte/macrophage colony-stimulating factor (rGM-CSF) obtained from cloned complementary Mo cell DNA and expressed in COS-1 cells activates cultured peripheral blood monocyte-derived macrophages in vitro to become cytotoxic for intracellular L. donovani. The antileishmanial effect of rGM-CSF, which can be completely neutralized by anti-rGM-CSF antiserum, is maximal after 36 h preincubation with the cultured macrophages, compared with that of rIFN-gamma, which reaches its maximum at 72 h of preincubation. The antileishmanial effect of GM-CSF as well as IFN-gamma is independent of detectable amounts of LPS and is not augmented by the addition of 10 or 50 ng/ml of LPS. Simultaneous administration of suboptimal doses of rGM-CSF and rIFN-gamma to monocyte-derived macrophages results in greater antileishmanial activity by these cells than administration of either lymphokine alone, although no enhancement of antileishmanial activity is observed when optimal doses of these two lymphokines are applied together.


1987 ◽  
Vol 166 (6) ◽  
pp. 1851-1860 ◽  
Author(s):  
D Caracciolo ◽  
N Shirsat ◽  
G G Wong ◽  
B Lange ◽  
S Clark ◽  
...  

Human macrophage colony-stimulating factor (M-CSF or CSF-1), either in purified or in recombinant form, is able to generate macrophagic colonies in a murine bone marrow colony assay, but only stimulates small macrophagic colonies of 40-50 cells in a human bone marrow colony assay. We report here that recombinant human granulocytic/macrophage colony stimulating factor (rhGM-CSF) at concentrations in the range of picograms enhances the responsiveness of bone marrow progenitors to M-CSF activity, resulting in an increased number of macrophagic colonies of up to 300 cells. Polyclonal antiserum against M-CSF did not alter colony formation of bone marrow progenitors incubated with GM-CSF at optimal concentration (1-10 ng/ml) for these in vitro assays. Thus, GM-CSF at higher concentrations (nanogram range) can by itself, elicit macrophagic colonies, and at lower concentrations (picogram range) acts to enhance the responsiveness of these progenitors to M-CSF.


Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1433-1438
Author(s):  
T Ishibashi ◽  
H Kimura ◽  
Y Shikama ◽  
T Uchida ◽  
S Kariyone ◽  
...  

To investigate the effect of recombinant granulocyte-macrophage colony- stimulating factor (rGM-CSF) on murine megakaryocytopoiesis in vitro, the factor was added to both serum-free colony assays and liquid marrow cultures. GM-CSF had a significant megakaryocytic colony-stimulating activity. After 2 hours of preincubation with and without 10 ng/mL rGM- CSF, the percentage of megakaryocyte colony-forming cell (CFU-MK) in DNA synthesis was determined by tritiated-thymidine suicide using colony growth. The reduction of CFU-MK colony numbers in marrow culture was 47.5% +/- 9.9%, 20.9% +/- 5.2% (control), respectively, indicating that the factor affected cell cycle at CFU-MK levels. When acetylcholinesterase (AchE) production was measured fluorometrically after 4 days of liquid culture, rGM-CSF elicited an increase in AchE activity in a dose-dependent fashion. To determine if the hematopoietin acts directly on megakaryocytic differentiation, 2 ng/mL rGM-CSF was added to serum-free cultures of 295 single megakaryocytes isolated from CFU-MK colonies. An increase in size was observed in 65% of cells initially 10 to 20 microns in diameter, 71% of cells 20 to 30 microns, and 40% of cells greater than 30 microns. Conversely, in absence of GM- CSF, 17%, 31%, and 10% of cells in each group increased in diameter. These data suggest that rGM-CSF promotes murine megakaryocytopoiesis in vitro and that the response to the factor is direct. To determine if the factor influences megakaryocytic/thrombocytic lineage in vivo, 1 and 5 micrograms of rGM-CSF were administered intraperitoneally every 12 hours for 6 consecutive days. Although a two- to three-fold increase in peripheral granulocytes was observed, neither megakaryocytic progenitor cells or platelets changed. Histologic analysis of bone marrow megakaryocytes showed no increase in size and number. The in vivo studies demonstrated no effect of GM-CSF on thrombocytopoiesis. The discrepancies between the in vitro and in vivo effects of GM-CSF require additional investigations.


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