1992 Volume 17 Issue 5 Pages 257-261
It is well known that interferons inhibit cell growth. However, we found that human interferon-γ (HuIFN-γ) enhanced the growth of human osteosarcoma cells, HOS-Y1 cells, in a dose-dependent manner. This enhancing effect was found only under the following conditions: when the cells were precultured for 2 or 3 days and then treated with HuIFN-γ for 2, 3, or 4 days, and when the cells were seeded at a density of 1, 000 or 2, 000 cells/well. The degree of enhancement of cell growth was maximum when the cells were precultured at a density of 1, 000 cells/well for 3 days and then treated with HuIFN-γ for 2 days. The enhancing effect of HuIFN-γ disappeared in the presence of anti-HuIFN-γ antibody. In addition, it was found that the conditioned medium from HOS-Y1cells enhanced the growth of HOS-Y1 cells, and that the conditioned medium from HOS-Y 1cells cultured with HuIFN-γ enhanced the cell growth more than that from cells cultured without HuIFN-γ. Epidermal growth factor (EGF), acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF), and transforming growth factor-β1(TGF-β1) did not enhance the growth of HOS-Y1 cells. These results suggest that HuIFN-γ enhanced the cell growth by augmenting the production of unknown growth factor(s) in HOS-Y1cells via an autocrine mechanism.
