Localization of protein gene product 9.5 immunoreactivity in derivatives of the human Wolffian duct and in prostate cancer

BACKGROUND. Protein gene product 9.5 (PGP 9.5) has been considered to be a neuronal marker, but it is also present in extraneuronal tissues, e.g., the human mammary gland and rat epididymis. Its presence and distribution in t he developing and adult male human genital tract have been unknown. METHODS. Immunohistochemical reactions were performed on human embryonic an d postnatal specimens of the male genital tract, using commercial monoclona l and polyclonal antibodies. RESULTS. PGP 9.5 immunoreactivity was found in the Wolffian duct of human e mbryos (55-85 mm crown-rump length). Strong reactivity was observed in meso nephric tubular cells and at the apical rim of Wolffian duct cells. Owing t o their PGP 9.5 immunoreactivity, these cells could also be identified on t he surface of the embryonic verumontanum, extending from the orifices of th e Wolffian duct to a small stretch of the urogenital sinus. There they cont rasted sharply against non-Wolffian cells. Ln the adult human genital tract , PGP 9.5 immunoreactive material was present in the supranuclear portion o f some epithelial cells of the epididymal efferent ductules, in isolated ce lls of the ejaculatory ducts, and in prostate cancer specimens. In the ejac ulatory ducts, the PGP 9.5-immunoreactive cells were free of immunoreactivi ty for semenogelin, the major secretory product of the ejaculatory-vesicula r-ampullary complex, and they also lacked chromogranin A-immunoreactivity. In prostate cancer specimens, PGP 9.5 immunoreactivity was never observed i n secretory cells (immunoreactive for prostate-specific antigen), but was r estricted to neuroendocrine cells, where it occurred either alone or coexpr essed with chromogranin A-immunoreactivity. CONCLUSIONS. PGP 9.5-immunoreactivity is prenatally distributed in the Wolf fian duct and its derivations; postnatally, it is restricted to a few cells derived from the initial and terminal segment of the Wolffian duct, and to neuroendocrine cells in prostate cancer specimens. (C) 1999 Wiley-Liss, In c.