Expression of transcripts for CSF-1 and for the "macrophage" and "epithelial" isoforms of the CSF-1R transcripts in human ovarian carcinomas.

Levels of CSF-1 and CSF-1 receptor (CSF-1R) (fms) transcripts were quantified by Northern and dot blotting in total RNA extracts from 68 human ovarian carcinomas and positive and negative controls. Overall, very high levels of CSF-1 and CSF-1R transcripts were found in 11 and 21% of ovarian carcinoma specimens, respectively. When probes specific for CSF-1R exon1 were employed, which hybridize with the "epithelial" but not with the "hematopoietic" isoforms of the CSF-1R transcripts, the results suggested that both isoforms of the CSF-1R transcript were present in the tumor specimens. When levels of CSF-1 and CSF-1R were compared, a positive correlation was observed. Taken together, these results confirm prior observations of high levels of CSF-1 and CSF-1R in ovarian carcinoma specimens and that the latter include both "epithelial" and "macrophage" CSF-1R transcript isoforms, as might be expected for specimens composed of malignant epithelial cells and stromal macrophages.