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

In the present study, the role of transforming growth factor-beta (TGF beta ) on the production of the extracellular matrix component, fibronectin, in the prostate has been studied. The mRNA levels of fibronectin, TGF beta and the two TGF beta receptors, ALK5 (activin like kinase) and type II, were m easured using reverse-transcription polymerase chain reaction (RT-PCR). TGF beta increased fibronectin mRNA and protein (7-fold) in a concentration-de pendent fashion. An interesting relationship between the two TGF beta recep tors was found in that TGF beta caused an upregulation of its type I recept or mRNA (5-6-fold) and a downregulation of the type II receptor mRNA (5-fol d). Time-course experiments revealed that the change in expression of the T GF beta receptors reached maximum at 24 h with an early increase at 4-5 h, whereas the fibronectin gene expression was not significantly stimulated un til about 24 h. These data provide evidence that TGF beta stimulates extrac ellular matrix production in prostate cells. (C) 2001 Published by Elsevier Science B.V.