Involvement of polyamines in the action of transforming growth factor beta and interleukin-1 on cultured chick embryo fibroblasts

In this study we have examined the relationship between growth factor-induced proliferation and ODC/polyamine levels. TGFβ promotes cell growth and enhances [3H]-thymidine incorporation in chick embryo fibroblasts maintained in a serum-depleted medium. The action on DNA synthesis declines in the second day of treatment. IL-1 does not affect proliferation or [3H]-thymidine incorporation either when it is added alone or in combination with TGFβ. The response of the cells to TGFβ is associated with a significant stimulation of ODC activity and Put, Spd levels together with an enhancement of the Spd/polyamines ratio. IL-1, which does not act on cell proliferation, fails to activate ODC and to increase polyamine levels, thus indicating that the ODC/polyamine system is most likely to be an important link in the chain of events that leads to growth factor-induced proliferation.