: Incubation of quiescent tumor cells with fetal calf serum induced ornithine decarboxylase (ODCase) activity concomitantly with mitogenic stimulation. Pretreatment of cells with highly purified natural or recombinant murine interferon-gamma (MuIFN-gamma) for 5 h caused a dose-dependent increase of ODCase activity induced by fetal calf serum (FCS). Pretreatment of target cells with IFN-gamma for 5 h in absence of FCS stimulation did not induce ODCase activity. When pretreatment of cells with natural or recombinant MuIFN-gamma was prolonged for 18 h both ODCase activity and DNA synthesis induced by FCS were suppressed. By contrast when a mixture of MuIFN-alpha and -beta was used, ODCase activity was significantly suppressed after 5 h pretreatment compared to untreated controls. These results suggest that IFN-gamma exerts a differential effect on mitogen-stimulated events depending on the dose and the time of addition.
Time-dependent differential effects of natural and recombinant murine interferon-gamma on ornithine decarboxylase activity of tumor cells
Ghezzi, P;
1987
Abstract
: Incubation of quiescent tumor cells with fetal calf serum induced ornithine decarboxylase (ODCase) activity concomitantly with mitogenic stimulation. Pretreatment of cells with highly purified natural or recombinant murine interferon-gamma (MuIFN-gamma) for 5 h caused a dose-dependent increase of ODCase activity induced by fetal calf serum (FCS). Pretreatment of target cells with IFN-gamma for 5 h in absence of FCS stimulation did not induce ODCase activity. When pretreatment of cells with natural or recombinant MuIFN-gamma was prolonged for 18 h both ODCase activity and DNA synthesis induced by FCS were suppressed. By contrast when a mixture of MuIFN-alpha and -beta was used, ODCase activity was significantly suppressed after 5 h pretreatment compared to untreated controls. These results suggest that IFN-gamma exerts a differential effect on mitogen-stimulated events depending on the dose and the time of addition.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
