TY - JOUR
T1 - Regulation of bombesin-stimulated cyclooxygenase-2 expression in prostate cancer cells
AU - Wen, Xiaodong
AU - Chao, Celia
AU - Ives, Kirk
AU - Hellmich, Mark R.
N1 - Funding Information:
We thank Eileen Figueroa and Steve Schuenke for their assistance in the preparation of this manuscript. This work is supported by grants from the National Institutes of Health (5P01 DK035608 and 5R01 DK048345, and 5K08 CA125209-02).
PY - 2011/7/11
Y1 - 2011/7/11
N2 - Background: Cyclooxygenase-2 (COX-2) and the bombesin (BBS)-like peptide, gastrin-releasing peptide (GRP), have been implicated in the progression of hormone-refractory prostate cancer; however, a mechanistic link between the bioactive peptide and COX-2 expression in prostate cells has not been made.Results: We report that BBS stimulates COX-2 mRNA and protein expression, and the release of prostaglandin E2 from the GRP receptor (GRPR)-positive, androgen-insensitive prostate cancer cell line, PC-3. BBS-stimulated COX-2 expression is mediated, in part, by p38MAPK and PI3 kinase (PI3K)/Akt pathways, and blocked by a GRPR antagonist. The PI3K/Akt pathway couples GRPR to the transcription factor, activator protein-1 (AP-1), and enhanced COX-2 promoter activity. Although BBS stimulates nuclear factor-kappaB (NF-κB) in PC-3, NF-κB does not regulate GRPR-mediated COX-2 expression. The p38MAPK pathway increases BBS-stimulated COX-2 expression by slowing the degradation of COX-2 mRNA. Expression of recombinant GRPR in the androgen-sensitive cell line LNCaP is sufficient to confer BBS-stimulated COX-2 expression via the p38MAPK and PI3K/Akt pathways.Conclusions: Our study establishes a mechanistic link between GRPR activation and enhanced COX-2 expression in prostate cancer cell lines, and suggests that inhibiting GRPR may, in the future, provide an effective therapeutic alternative to non-steroidal anti-inflammatory drugs for inhibiting COX-2 in patients with recurrent prostate cancer.
AB - Background: Cyclooxygenase-2 (COX-2) and the bombesin (BBS)-like peptide, gastrin-releasing peptide (GRP), have been implicated in the progression of hormone-refractory prostate cancer; however, a mechanistic link between the bioactive peptide and COX-2 expression in prostate cells has not been made.Results: We report that BBS stimulates COX-2 mRNA and protein expression, and the release of prostaglandin E2 from the GRP receptor (GRPR)-positive, androgen-insensitive prostate cancer cell line, PC-3. BBS-stimulated COX-2 expression is mediated, in part, by p38MAPK and PI3 kinase (PI3K)/Akt pathways, and blocked by a GRPR antagonist. The PI3K/Akt pathway couples GRPR to the transcription factor, activator protein-1 (AP-1), and enhanced COX-2 promoter activity. Although BBS stimulates nuclear factor-kappaB (NF-κB) in PC-3, NF-κB does not regulate GRPR-mediated COX-2 expression. The p38MAPK pathway increases BBS-stimulated COX-2 expression by slowing the degradation of COX-2 mRNA. Expression of recombinant GRPR in the androgen-sensitive cell line LNCaP is sufficient to confer BBS-stimulated COX-2 expression via the p38MAPK and PI3K/Akt pathways.Conclusions: Our study establishes a mechanistic link between GRPR activation and enhanced COX-2 expression in prostate cancer cell lines, and suggests that inhibiting GRPR may, in the future, provide an effective therapeutic alternative to non-steroidal anti-inflammatory drugs for inhibiting COX-2 in patients with recurrent prostate cancer.
KW - Gastrin-releasing peptide receptor
KW - Hormone-refractory
KW - Neuroendocrine differentiation
KW - Prostate cancer
KW - Signal transduction
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U2 - 10.1186/1471-2199-12-29
DO - 10.1186/1471-2199-12-29
M3 - Article
C2 - 21745389
AN - SCOPUS:79960063902
VL - 12
JO - BMC Molecular Biology
JF - BMC Molecular Biology
SN - 1471-2199
M1 - 29
ER -