Macrophage-colony stimulating factor inhibits the growth of human ovarian cancer cells in vitro

The effect of macrophage-colony stimulating factor (M-CSF), which regulates the growth and differentiation of haematopoietic progenitor cells on the g rowth of ovarian cancer cells was investigated in three ovarian cancer cell lines in vitro. The spontaneous growth of these cells was significantly in hibited by the addition of M-CSF in a concentration-dependent manner over 9 6 h of culturing. The maximum response was obtained with 10 ng/ml (3857 U/m l) of M-CSF by counting the viable cell number using the trypan blue exclus ion assay. [H-3]-thymidine incorporation by these cells was also suppressed following a 96-h incubation with M-CSF. The inhibitory effect of M-CSF was reversed by the addition of anti-M-CSF monoclonal antibody. Flow cytometri c analysis revealed that the treated ovarian cancer cells arrested at the G 0/G1 phase of the cell cycle. These cells expressed M-CSF receptors on thei r surface as detected by Scatchard plot analysis using I-125-labelled M-CSF . These results indicate that M-CSF has an antitumour activity for ovarian cancer cells and suggest that it can be applied for the treatment of this d isease. (C) 2000 Elsevier Science Ltd. All rights reserved.