The role of transforming growth factor-β and its receptors in human prostate smooth muscle cell fibronectin production

Abstract

In the present study, the role of transforming growth factor-β (TGFβ) on the production of the extracellular matrix component, fibronectin, in the prostate has been studied. The mRNA levels of fibronectin, TGFβ and the two TGFβ receptors, ALK5 (activin like kinase) and type II, were measured using reverse-transcription polymerase chain reaction (RT-PCR). TGFβ increased fibronectin mRNA and protein (7-fold) in a concentration-dependent fashion. An interesting relationship between the two TGFβ receptors was found in that TGFβ caused an upregulation of its type I receptor mRNA (5–6-fold) and a downregulation of the type II receptor mRNA (5-fold). Time-course experiments revealed that the change in expression of the TGFβ receptors reached maximum at 24 h with an early increase at 4–5 h, whereas the fibronectin gene expression was not significantly stimulated until about 24 h. These data provide evidence that TGFβ stimulates extracellular matrix production in prostate cells.