Steroid-growth factor interaction in human prostate cancer. 1. Short-term effects of transforming growth factors on growth of human prostate cancer cells

In order to betweer define potential mechanisms of growth regulation in human prostate cancer cells, we have compared biological responses (such as short-term response to both transforming growth factor α and β; TFGα and TFGβ) in relation to hormone sensitivity of LNCaP, DU145, and PC3 cells. Androgen receptor (AR) and epidermal growth factor receptor (EGF-R) content of each cell line was also investigated. In addition, expression of EGF, TGFα, and TGFβ was evaluated through immunofluorescent staining. Growth of androgen non-responsive PC3 cells was stimulated by TGFα (about 35%) and inhibited by TGFβ more than 50%), with respect to controls, after 48h exposure. Conversely, AR-positive, hormone-responsive LNCaP cells proved to be poorly sensitive, at least short-term, to either growth factor. Furthermore, high levels of both EGF-R and TGFα, and a fairly high amount of EGF, were found in DU145 cells and, to a lesser extent, in LNCaP cells; in contrast, PC3 cells exhibited low expression levels of both receptors (EGF-R) and ligands (EGF, TGFα), but displayed remarkable TGFβ binding and relatively high levels of endogenous TGFβ. Overall, these results suggest a differential sensitivity to TGFα and TGFβ by prostate cancer cells; TGFα response seems not to be proportional to the EGF-R content of individual cell lines. (Steroids 59: 412–420, 1994)