Cultured mammary carcinoma cells contain gonadotropin-releasing hormone-like immunoreactivity, GnRH binding sites and chorionic gonadotropin.

Immunoperoxidase staining and radioimmunoassay were used to identify gonadotropin-releasing hormone (GnRH) and chorionic gonadotropin (hCG) in 4 mammary carcinoma cell lines. GnRH-like immunoreactivity was found in all cell lines; 2 lines also contained hCG. Binding of a GnRH agonist was demonstrated by radioreceptor assay in cultured mammary carcinoma cells. In cell column perfusion of the same cells, exogenous GnRH did not stimulate release of hCG.