Elevated expression of the oncogene c-fms and its ligand, the macrophage colony-stimulating factor-1, in cervical cancer and the role of transforming growth factor-beta1 in inducing c-fms expression.

Cervical cancer is the third most common gynecologic cancer in the United States. The presence and possible involvement of several cytokines have been studied in cervical cancer; however, very little data, if any, are available on whether cervical tumors are responsive to stimulation by the macrophage colony-stimulating factor-1 (CSF-1). Given the involvement of c-fms and its ligand CSF-1 in gynecologic cancers, such as that of the uterus and the ovaries, we have examined the expression of c-fms and CSF-1 in cervical tumor (n = 17) and normal cervix (n = 8) samples. The data show that c-fms and its ligand are significantly higher in cervical carcinomas compared with normal samples. Immunohistochemistry not only showed that tumor cells expressed significantly higher levels of c-fms but also c-fms levels were markedly higher in tumor cells than tumor-associated stromal cells. Blocking c-fms activity in cervical cancer cells, which express CSF-1 and c-fms, resulted in increased apoptosis and decreased motility compared with control, suggesting that CSF-1/c-fms signaling may be involved in enhanced survival and possibly invasion by cervical cancer cells via an autocrine mechanism. Combined, the data show for the first time the induction of CSF-1 and c-fms in cervical carcinomas and suggest that c-fms activation may play a role in cervical carcinogenesis. Additionally, our data suggest that transforming growth factor-beta1 may be a factor in inducing the expression of c-fms in cervical cancer cells. The data suggest that c-fms may be a valuable therapeutic target in cervical cancer.