To better understand the underlying mechanism behind the recurrence of end-stage, androgen depletion independent prostate cancer (ADI), we have successfully characterized primary human prostate tumor cells in vitro. This thesis presents a reliable culture system that consistently propagates and maintains epithelial cultures taken directly from early-stage prostate adenocarcinomas. As a result of our methodology, we were able to put 70 prostate radical resection tissue samples into culture: 42 adenocarcinomas and 28 benign hyperplasias. All 42 early-stage cancers produced few (3-5) to many (400+) single epithelial colonies and expressed putative stem/progenitor cell markers CD44, integrin-á2â1, High MW CK 5/14, and CD133 along with embryonic transcription factors Oct4, Sox-2, and immortalization gene Bmi-1. Every proliferating colony possessed a naturally formed prostate stem cell niche, which supplied the highly epithelial prostate progenitors. These presumed stem cell niches, we termed “Stem Cell Centers” (SCC), stained positive for stem cell marker CD133. Senescence was observed in all cultures in later passages due to the loss of the necessary SCC. Our methodology is optimal for reliably growing out early-stage prostate tumor stem/progenitor cells - which is essential in the understanding of lethal ADI progression - and allows for the development of better therapies and treatments for this metastatic disease.