EFFECTS OF INTERFERON BETA-SER AND TRANSFORMING GROWTH-FACTOR-BETA ON PROSTATIC CELL-LINES

The effect of interferon-beta-ser (IFN-beta-ser) on the growth of three prostatic cancer cell lines DU-145, PC-3 and LNCaP was studied. IFN-beta-ser inhibited growth of anchorage dependent semiconfluent monolayers and anchorage dependent colony formation of both DU-145 and PC-3 in a dose dependent manner but had no effect on LNCaP. Transforming growth factor beta (TGF-beta-1) inhibited proliferation of DU-145 and PC-3 cells in 1% but not 8% fetal calf serum. The combination of TGF-beta-1 and IFN-beta-ser was additive in its effects on growth. Neither epidermal growth factor (EGF) nor transforming growth factor alpha (TGF-alpha) reduced the antiproliferative effect of IFN-beta-ser on these cells. These antiproliferative effects were reproduced in studies on primary epithelial cell cultures derived from prostate specimens with various pathologies. The potential use of IFN-beta-ser in combination with hormonal therapy to delay the development of hormone refractory tumors is discussed.