RESUMEN
<p><b>OBJECTIVE</b>To investigate whether the sonic hedgehog signaling pathway is involved in the development of human fetal prostate, and to evaluate the changing staining patterns of its molecules, sonic hedgehog (SHH), patchedl (PTC1), smoothened (SMO), and GLI1, in the human fetal prostate at various gestation stages.</p><p><b>METHODS</b>Fifteen human fetal prostate specimens at various developmental stages (10 - 39 weeks) were included in this study. SHH, PTC1, SMO and GLI1 were detected in all the specimens by immunohistochemical technique. All the slides were observed and assessed under the light microscope.</p><p><b>RESULTS</b>SHH, PTC1, SMO and GLI1 could be detected in human fetal prostate tissues, and their expression formed two surges, the former at week 16, and the latter at week 28. The staining of SHH and SMO was distributed only in the ductal epithelium but not in the stroma. The expression of PTC1 and GLI1 could be found mainly in the epithelium, with minimal staining in the stroma.</p><p><b>CONCLUSION</b>The sonic hedgehog signaling pathway is involved in the development of the human fetal prostate. The high expression of its molecules at early gestation stages might be associated with the induction of prostatic buds, while their abundant expression at later gestation stages might be related to the prostate ductal branching, growth, differentiation and morphogenesis.</p>