Peroxisome proliferator-activated receptor-gamma suppresses cyclooxygenase-2 expression in human prostate cells

Cancer Epidemiol Biomarkers Prev. 2004 Nov;13(11 Pt 1):1704-9.


Recent studies have found that cyclooxygenase-2 (COX-2) protein expression was low and inducible with cytokines in prostate cancer cells (in the absence of serum) and that, in contrast, COX-2 expression was high in normal prostate epithelial cells (EC). Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) was expressed at high levels in the prostate cancer cell line PC-3 but not in ECs. In contrast to previous findings by others, PPAR-gamma ligands did not induce PPAR-gamma expression in EC or PC-3. The present study examined the relationship between PPAR-gamma and COX-2 expression patterns in EC and PC-3 in the presence and absence of serum and/or the PPAR-gamma agonist 15-deoxy-Delta12,14-prostaglandin J(2) (15d-PGJ(2)). We also evaluated the effects that the forced expression of PPAR-gamma1 and PPAR-gamma2 had on COX-2 in ECs. We found that expression of PPAR-gamma and COX-2 protein was inversely correlated in ECs and PC-3. Low COX-2 expression in PC-3 was up-regulated by serum, and 15d-PGJ(2) blocked serum-induced COX-2 expression and activity in a dose-dependent manner. 15d-PGJ(2) had no effect on COX-2 expression in ECs or PPAR-gamma expression in either cell type. However, forced expression of PPAR-gamma1 or PPAR-gamma2 in ECs suppressed the high level of endogenous COX-2. This effect was not isoform specific and was augmented by 15d-PGJ(2). The present study showed that PPAR-gamma activation can be an important regulator of COX-2 in prostate cells and may be an important target for prostate cancer chemoprevention.

Publication types

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

MeSH terms

  • Cells, Cultured
  • Cyclooxygenase 2
  • Down-Regulation / drug effects
  • Endothelium / drug effects
  • Endothelium / enzymology
  • Humans
  • Isoenzymes / drug effects
  • Isoenzymes / metabolism*
  • Isoenzymes / physiology
  • Male
  • Membrane Proteins
  • PPAR gamma / agonists
  • PPAR gamma / pharmacology
  • PPAR gamma / physiology*
  • Prostaglandin D2 / analogs & derivatives*
  • Prostaglandin D2 / pharmacology*
  • Prostaglandin-Endoperoxide Synthases / drug effects
  • Prostaglandin-Endoperoxide Synthases / metabolism*
  • Prostaglandin-Endoperoxide Synthases / physiology
  • Prostate / drug effects
  • Prostate / enzymology*
  • Transfection


  • 15-deoxyprostaglandin J2
  • Isoenzymes
  • Membrane Proteins
  • PPAR gamma
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases
  • Prostaglandin D2