Immunohistochemical localization of transforming growth factor-alpha and transforming growth factor-beta during early human fetal prostate development.

Abstract

We investigated the role of peptide growth factors and androgens in the developing human prostate. We performed immunohistochemical staining of prostate tissue sections from human fetuses 9.5, 11.5, 13, 16.5, 18 and 20 weeks in gestation. The temporal and spatial expression of these growth factors was related to the gestational androgen surge. Before the androgen surge (9.5 to 11.5 weeks) transforming growth factor (TGF)-alpha, TGF-beta1 and TGF-beta3 but not TGF-beta2 were present in the mesenchyme. The epithelium exhibited no detectable staining for any of the growth factors. During the androgen peak (13 to 16.5 weeks) TGF-beta1 decreased and TGF-beta2 increased in the mesenchyme, and TGF-alpha, TGF-beta1 and TGF-beta3 increased in the epithelium. With declining androgen levels TGF-alpha, TGF-beta2 and TGF-beta3 remained unchanged but TGF-beta1 increased in the mesenchyme with no change in the tested peptide growth factor levels in the epithelium. These data suggest that androgens regulate the differential expression of TGF-alpha and TGF-beta, and support a role for peptide growth factors as the direct mediators of androgen action on the mesenchymal and epithelial interactions responsible for prostate development.