Indomethacin enhanced macrophage cytostasis against MOPC-315 tumor cells in vitro. The effect of indomethacin was inhibited by prostaglandin E2 and by the lipoxygenase inhibitor nordihydroguaiaretic acid. Prostaglandin E2 and nordihydroguaiaretic acid also inhibited indomethacin stimulation of macrophage thymidine incorporation. Indomethacin inhibited macrophage prostaglandin E2 formation and stimulated leukotriene B4 synthesis. Nordihydroguaiaretic acid inhibited leukotriene B4 production. Our data indicate that eicosanoids play a role in regulating macrophage cytostasis.
The response of human acute myeloid leukemia (AML) cells to the distinct hematopoietic growth factors (HGFs), ie, recombinant interleukin-3 (IL-3), granulocyte-macrophage-CSF (GM-CSF), granulocyte- CSF (G-CSF), macrophage-CSF (M-CSF), and erythropoietin (Epo) was investigated under well-defined serum-free conditions. Proliferative responses to these factors, when added separately as well as in combinations, were analyzed in 25 cases of human AML using 3H-thymidine incorporation and colony assays. The 3H-thymidine uptake data revealed that IL-3, GM-CSF, G-CSF, and M-CSF were stimulators of AML proliferation in 19, 15, 13, and 4 cases, respectively. Epo only stimulated DNA synthesis in the cells of the single erythroleukemia case. GM-CSF stimulation was seen only in IL-3 reactive cases and GM- CSF, when combined with IL-3, could not further elevate the DNA synthesis evoked by IL-3 alone. On the other hand, in six cases, G-CSF enhanced the IL-3- or GM-CSF-stimulated thymidine uptake. These results suggest that subpopulations of AML cells that are activated by distinct CSFs (eg, IL-3/GM-CSF-responsive cells and G-CSF-responsive cells) coexist. The 3H-thymidine incorporation assay was more sensitive for measuring CSF responses than methylcellulose colony cultures, since activation of DNA synthesis was more frequently seen than induction of colony formation. DNA synthesis experiments revealed eight different CSF response patterns among these 25 cases. CSF phenotyping may be a useful addition to the morphologic classification of AML, since these patterns directly reflect the ability of the proliferating subsets of AML cells to respond to the CSFs.
The response of human acute myeloid leukemia (AML) cells to the distinct hematopoietic growth factors (HGFs), ie, recombinant interleukin-3 (IL-3), granulocyte-macrophage-CSF (GM-CSF), granulocyte- CSF (G-CSF), macrophage-CSF (M-CSF), and erythropoietin (Epo) was investigated under well-defined serum-free conditions. Proliferative responses to these factors, when added separately as well as in combinations, were analyzed in 25 cases of human AML using 3H-thymidine incorporation and colony assays. The 3H-thymidine uptake data revealed that IL-3, GM-CSF, G-CSF, and M-CSF were stimulators of AML proliferation in 19, 15, 13, and 4 cases, respectively. Epo only stimulated DNA synthesis in the cells of the single erythroleukemia case. GM-CSF stimulation was seen only in IL-3 reactive cases and GM- CSF, when combined with IL-3, could not further elevate the DNA synthesis evoked by IL-3 alone. On the other hand, in six cases, G-CSF enhanced the IL-3- or GM-CSF-stimulated thymidine uptake. These results suggest that subpopulations of AML cells that are activated by distinct CSFs (eg, IL-3/GM-CSF-responsive cells and G-CSF-responsive cells) coexist. The 3H-thymidine incorporation assay was more sensitive for measuring CSF responses than methylcellulose colony cultures, since activation of DNA synthesis was more frequently seen than induction of colony formation. DNA synthesis experiments revealed eight different CSF response patterns among these 25 cases. CSF phenotyping may be a useful addition to the morphologic classification of AML, since these patterns directly reflect the ability of the proliferating subsets of AML cells to respond to the CSFs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.