Early human prostate adenocarcinomas harbor androgen-independent cancer cells

PLoS One. 2013 Sep 25;8(9):e74438. doi: 10.1371/journal.pone.0074438. eCollection 2013.

Abstract

Although blockade of androgen receptor (AR) signaling represents the main treatment for advanced prostate cancer (PrCa), many patients progress to a lethal phenotype of "Castration-Resistant" prostate cancer (CR-PrCa). With the hypothesis that early PrCa may harbor a population of androgen-unresponsive cancer cells as precursors to CR-recurrent disease, we undertook the propagation of androgen-independent cells from PrCa-prostatectomy samples of early, localized (Stage-I) cases. A collection of 120 surgical specimens from prostatectomy cases was established, among which 54 were adenocarcinomas. Hormone-free cell culture conditions were developed allowing routine propagation of cells expressing prostate basal cell markers and stem/progenitor cell markers, and which proliferated as spheres/spheroids in suspension cultures. Colonies of androgen-independent epithelial cells grew out from 30/43 (70%) of the adenocarcinoma cases studied in detail. Fluorescence microscopy and flow cytometry showed that CR-PrCa cells were positive for CD44, CD133, CK5/14, c-kit, integrin α2β1, SSEA4, E-Cadherin and Aldehyde Dehydrogenase (ALDH). All 30 CR-PrCa cell cultures were also TERT-positive, but negative for TMPRSS2-ERG. Additionally, a subset of 22 of these CR-PrCa cell cultures was examined by orthotopic xenografting in intact and castrated SCID mice, generating histologically typical locally-invasive human PrCa or undifferentiated cancers, respectively, in 6-8 weeks. Cultured PrCa cells and orthotopically-induced in vivo cancers lacked PSA expression. We report here the propagation of Cancer Initiating Cells (CIC) directly from Stage I human PrCa tissue without selection or genetic manipulation. The propagation of stem/progenitor-like CR-PrCa cells derived from early human prostate carcinomas suggests the existence of a subpopulation of cells resistant to androgen-deprivation therapy and which may drive the subsequent emergence of disseminated CR-PrCa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / enzymology
  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology*
  • Aldehyde Dehydrogenase / metabolism
  • Androgens / metabolism*
  • Animals
  • Biomarkers, Tumor / metabolism
  • Castration
  • Cell Count
  • Cell Proliferation
  • Cell Shape
  • Collagen
  • Drug Combinations
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Laminin
  • Male
  • Mice
  • Neoplasm Staging
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology*
  • Oncogene Proteins, Fusion / genetics
  • Oncogene Proteins, Fusion / metabolism
  • Prostatic Neoplasms / enzymology
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / pathology*
  • Proteoglycans
  • Spheroids, Cellular / metabolism
  • Spheroids, Cellular / pathology
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • Androgens
  • Biomarkers, Tumor
  • Drug Combinations
  • Laminin
  • Oncogene Proteins, Fusion
  • Proteoglycans
  • TMPRSS2-ERG fusion protein, human
  • matrigel
  • Collagen
  • Aldehyde Dehydrogenase

Grants and funding

All funds were generously provided through the UC San Diego Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.