Receptor protein tyrosine phosphatase alpha signaling is involved in androgen depletion-induced neuroendocrine differentiation of androgen-sensitive LNCaP human prostate cancer cells

Oncogene. 2003 Oct 2;22(43):6704-16. doi: 10.1038/sj.onc.1206764.

Abstract

The neuroendocrine (NE) cells represent the third cell population in the normal prostate. Results of several clinical studies strongly indicate that the NE cell population is greatly increased in prostate carcinomas during androgen ablation therapy that correlates with hormone-refractory growth and poor prognosis. However, the mechanism of NE cell enrichment in prostate carcinoma remains an enigma. We investigated the molecular mechanism by which androgen-sensitive C-33 LNCaP human prostate cancer cells become NE-like cells in an androgen-reduced environment, mimicking clinical phenomenon. In the androgen-depleted condition, androgen-sensitive C-33 LNCaP cells gradually acquired the NE-like morphology and expressed an increased level of neuron-specific enolase (NSE), a classical marker of neuronal cells. Several NE-like subclone cells were established. Biochemical characterizations of these subclone cells showed that receptor-type protein-tyrosine phosphatase alpha (RPTPalpha) is elevated and ERK is constitutively activated, several folds higher than that in parental cells. In androgen-depleted condition, PD98059, an MEK inhibitor, could efficiently block not only the activation of ERK, but also the acquisition of the NE-like morphology and the elevation of NSE in C-33 LNCaP cells. In RPTPalpha cDNA-transfected C-33 LNCaP cells, ERK was activated and NSE was elevated. In those cells in the presence of PD98059, the ERK activation and NSE elevation were abolished, following a dose-response fashion. Additionally, in constitutively active MEK mutant cDNA-transfected C-33 LNCaP cells, ERK was activated and NSE level was elevated, and cells obtained the NE-like phenotype. Our data collectively indicated that RPTPalpha signaling via ERK is involved in the NE transdifferentiation of androgen-sensitive C-33 LNCaP human prostate cancer cells in the androgen-depleted condition.

Publication types

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

MeSH terms

  • Androgens / metabolism*
  • Blotting, Western
  • Cell Differentiation
  • Cell Division
  • DNA, Complementary / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Flavonoids / pharmacology
  • Green Fluorescent Proteins
  • Humans
  • Luminescent Proteins / metabolism
  • Male
  • Microscopy, Fluorescence
  • Mitogen-Activated Protein Kinases / metabolism
  • Models, Biological
  • Phosphopyruvate Hydratase / biosynthesis
  • Prostatic Neoplasms / metabolism*
  • Protein Tyrosine Phosphatases / metabolism*
  • Receptor-Like Protein Tyrosine Phosphatases, Class 4
  • Receptors, Cell Surface*
  • Signal Transduction*
  • Time Factors
  • Transfection
  • Tumor Cells, Cultured

Substances

  • Androgens
  • DNA, Complementary
  • Enzyme Inhibitors
  • Flavonoids
  • Luminescent Proteins
  • Receptors, Cell Surface
  • Green Fluorescent Proteins
  • Mitogen-Activated Protein Kinases
  • PTPRA protein, human
  • Protein Tyrosine Phosphatases
  • Receptor-Like Protein Tyrosine Phosphatases, Class 4
  • Phosphopyruvate Hydratase
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one