Identification of a stem cell candidate in the normal human prostate gland

• DOI: 10.1016/j.ejcb.2004.12.019
• Publication Date: 2005-08-18T11:36:46Z
• Authors: Monika Schmelz; Roland Moll; Ulrike Hesse; Anil R. Prasad; Jay A. Gandolfi; Shirin R. Hasan; Marty Bartholdi; Anne E. Cress
• Keywords: Male; 0303 health sciences; Stem Cells; Prostate; Antibodies, Monoclonal; Cell Differentiation; Epithelium; 03 medical and health sciences; Fetus; Humans; Keratins; Biomarkers; Cell Proliferation

Stem cells of the human prostate gland have not yet been identified utilizing a structural biomarker. We have discovered a new prostatic epithelial cell phenotype-expressing cytokeratin 6a (Ck6a+ cells). The Ck6a+ cells are present within a specialized niche in the basal cell compartment in fetal, juvenile and adult prostate tissue, and within the stem cell-enriched urogenital sinus. In adult normal prostate tissue, the average abundance of Ck6a+ cells was 4.9%. With proliferative stimuli in the prostate organ culture model, in which the epithelial-stromal interaction was maintained, a remarkable increase of Ck6a expression was noticed to up to 64.9%. The difference in cytokeratin 6a expression between the normal adult prostate and the prostate organ culture model was statistically significant (p<0.0001). Within the prostate organ culture model the increase of cytokeratin 6a-expressing cells significantly correlated with increased proliferation index (r = 0.7616, p = 0.0467). The Ck6a+ cells were capable of differentiation as indicated by their expression of luminal cell markers such as ZO-1 and prostate specific antigen (PSA). Our data indicate that Ck6a+ cells represent a prostatic epithelial stem cell candidate possessing high potential for proliferation and differentiation. Since the development of benign prostatic hyperplasia and prostate carcinogenesis are disorders of proliferation and differentiation, the Ck6a+ cells may represent a major element in the development of these diseases.