Prostaglandin E2 modulates components of the Wnt signaling system in bone and prostate cancer cells.
Both Wnt signaling and prostaglandin E(2) (PGE(2)) play pivotal roles in bone development, remodeling, osteoporosis and prostate cancer (PCa) bone metastases. We investigated the effects of PGE(2) on Wnt signaling in osteoblast-lineage cells and Wnt-inhibitor expression in PCa cells. We demonstrate that low dose PGE(2) (0.1 microM) promotes Wnt signaling while higher doses of PGE(2) (1.0-10 microM) inhibit these same parameters in osteoblast-lineage cells. The differential effects of low vs high-dose PGE(2) on pre-osteoblasts may be attributed to dose-dependent modulation of prostaglandin receptor (EP) subtype expression; with lower doses increasing the expression the cAMP-stimulatory EP4 receptor subtype and higher doses increasing the expression of the cAMP-inhibitory EP3 receptor subtype. Moreover, we demonstrate that high expression levels of COX-2 and PGE(2) promote the secretion of Wnt inhibitors from prostate cancer cells. These data demonstrate that there are dose-dependent effects of PGE(2) on Wnt activation in osteoblast-lineage cells and Wnt-inhibitor expression in PCa cells which may have clinical implications in the management.
Liu
Xin-Hua
XH
Department of Medicine, Division of Endocrinology and Metabolism, Mount Sinai School of Medicine, New York, NY 10029, USA.
Kirschenbaum
Alexander
A
Weinstein
Barrie M
BM
Zaidi
Mone
M
Yao
Shen
S
Levine
Alice C
AC
D001859:Bone Neoplasms / Q000378:metabolism* / Q000556:secondary; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000494:pharmacology / Q000502:physiology*; D006801:Humans; D008297:Male; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D018078:Receptors, Prostaglandin E / Q000378:metabolism; D015398:Signal Transduction; D051153:Wnt Proteins / Q000378:metabolism*
D018078:Receptors, Prostaglandin E; D051153:Wnt Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D015232:Dinoprostone