Coexpression of granulocyte colony stimulating factor and its receptor in primary ovarian carcinomas

Immunohistochemistry was used to determine the expression of granulocyte co lony-stimulating factor (G-CSF) and its receptor (G-CSFR) in primary ovaria n carcinomas. The expression of G-CSFR was observed in the malignant cells of each of the 46 primary carcinomas examined; G-CSF was coexpressed in bot h the malignant epithelial cells and the stroma of 56.5% of the specimens. Thus the majority of ovarian carcinomas harbor both potential autocrine and paracrine G-CSF axes. In 37% of the samples, G-CSF was expressed only with in stromal cells, suggesting that only a potential paracrine system is in p lace. In a preliminary, retrospective, evaluation, the survival of patients whose tumors expressed only the apparent paracrine loop was significantly worse than patients whose tumors expressed both potential autocrine and par acrine G-CSF-based regulatory loops (14.5 vs. 42.5 months, respectively). S tudies on the potential function of G-CSF were performed using the G-CSFR-e xpressing OVCAR-3 ovarian carcinoma line. As a single agent, rhG-CSF failed to stimulate [H-3]-thymidine incorporation in these cells, but enhanced th e mitogenic action of epidermal growth factor (EGF) in a dose-dependent man ner. Thus, potential autocrine and/or paracrine loops involving G-CSF and i ts receptor occur in over 90% of primary ovarian carcinomas, and may act to modulate the action of growth factors. (C) 2001 Elsevier Science Ireland L td. All rights reserved.