Intermediate basal cells of the prostate: in vitro and in vivo characterization

Prostate. 2003 May 15;55(3):206-18. doi: 10.1002/pros.10244.


Background: Progenitor cells within the prostate basal layer may play important roles in differentiation and carcinogenesis; however, prostate stem cell populations remain uncharacterized.

Methods: Immunohistochemical and immunoblot analyses were used to characterize prostate epithelial cells (PrEC), a commercially available prostate basal cell isolate.

Results: Proliferating PrECs exhibited immunophenotypic characteristics most consistent with basal cells, but during senescence PrECs up-regulated androgen receptor (AR) mRNA, p27, and low-molecular-weight cytokeratin (LMWCK) expression, suggestive of partial differentiation. PrECs also stained strongly for involucrin, which marked a subset of intermediate prostate basal cells in vivo. Basal hyperplasia consisting of involucrin-positive cells was prevalent in prostate tissue from androgen-ablated patients, and formed epithelial clusters flanked by involucrin-negative basal and luminal monolayers. Cultivation of PrECs on matrigel together with androgen-treated stromal conditioned media resulted in dense aggregates, with a peripheral rim of basal-like cells expressing p63 and basal cytokeratins.

Conclusions: PrEC represents an epithelial population whose basal characteristics are modified in response to matrigel, stromal factors, and senescence, consistent with a transient amplifying population. These cells may derive from a previously unrecognized, involucrin-positive subset present in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Blotting, Western
  • Cell Differentiation
  • Cellular Senescence / physiology
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism
  • Humans
  • Immunohistochemistry
  • Keratins / metabolism
  • Male
  • Prostate / cytology*
  • Prostate / metabolism
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology
  • Protein Precursors / metabolism
  • RNA / chemistry
  • RNA / genetics
  • Receptors, Androgen / genetics
  • Receptors, Androgen / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stem Cells / cytology
  • Stem Cells / metabolism


  • Protein Precursors
  • Receptors, Androgen
  • involucrin
  • RNA
  • Keratins