Branching activity in the human prostate: A closer look at the structure of small glandular buds

Objective: Knowledge regarding cell biologic characteristics of small solid glandular buds in the prostate and their relationship with branching activ ity in the human prostate is still fragmentary. Our object was to demonstra te, on the basis of immunophenotype, loci that harbor the potential for bra nching activity within the adult human prostate. Materials and Methods: Semiserial sectioning was performed on 13 adult pros tates in an effort to identify structures in the prostate that could be con sidered foci of growth. Selected slides were stained with biomarkers for ba sal/luminal cells (keratins), proliferation (MIB-1), apoptosis inhibitor (b cl-2), intercellular adhesion (E-cadherin), and stromal-epithelial interact ions (tenascin-C). Results were compared with fetal and prepubertal human p rostates and microdissected rat prostates. Results: Five histologic epithelial structures were identified in 19 paraff in blocks, which on serial sectioning showed morphologic transitions with a common pattern, consisting of reduction in number and caliber of acini unt il small solid buds of epithelial cells were reached. Immunophenotypically, the small solid glandular buds had a basal-cell kertatin phenotype, expres sion of bcl-2 in virtually all cells, high proliferative activity, prominen t intracellular localization of E-cadherin, and enhanced periglandular tena scin-C immunoreactivity. The budding tips in fetal and prepubertal prostate s revealed an immunostaining pattern identical to the small solid glandular buds in the adult, but different to the rat prostate. Conclusions: Our data suggest that dispersed small solid glandular buds hav e a capacity for growth, and as such may be considered foci of resumed reaw akening branching activity with in the adult human prostate. Copyright (C) 2001 S. Karger AG, Basel.