Journal Article

The resistance to the tumor suppressive effects of COX inhibitors and COX-2 gene disruption in TRAMP mice is associated with the loss of COX expression in prostate tissue

Xingya Wang, Jennifer K.L. Colby, Peiying Yang, Susan M. Fischer, Robert A. Newman and Russell D. Klein

in Carcinogenesis

Volume 29, issue 1, pages 120-128
Published in print January 2008 | ISSN: 0143-3334
Published online October 2007 | e-ISSN: 1460-2180 | DOI: http://dx.doi.org/10.1093/carcin/bgm226
The resistance to the tumor suppressive effects of COX inhibitors and COX-2 gene disruption in TRAMP mice is associated with the loss of COX expression in prostate tissue

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics

GO

Show Summary Details

Preview

Over-expression of cyclooxygenase-2 (COX-2) and prostaglandin E2 has been demonstrated to play a significant role in the tumorigenesis of colon, lung, breast, bladder and skin. However, inconsistent and controversial reports on the expression and activity of COX-2 in prostate cancer raised the question of whether COX-2 plays a pivotal role in prostate carcinogenesis. To address this question, we examined the effects of COX-2 inhibition on prostate tumorigenesis in the transgenic adenocarcinoma mouse prostate (TRAMP) model. Three-week-old TRAMP mice were fed control, celecoxib- or indomethacin-supplemented diets for 27 weeks. A TRAMP/COX-2 knockout mouse model was also generated to determine the effects of the loss of the COX-2 gene on prostate tumorigenesis in TRAMP mice. These studies demonstrated that neither non-steroidal anti-inflammatory drugs (NSAIDs) nor genetic disruption of COX-2 was inhibitory in terms of tumor and metastases incidence, lobe weight or types of pathological lesions. A careful analysis of wild-type and TRAMP tissues was undertaken for the expression of cyclooxygenase-1 (COX-1) and COX-2 using immunoblotting, quantitative real time polymerase chain reaction (qRT-PCR) and immunohistochemistry approaches in TRAMP dorsal prostate tissue from 10- and 16-week-old, as well as tumor from 30-week-old mice. We found that the expression of COX-1 and COX-2 dramatically decreased during TRAMP carcinogenesis. Using the probasin promoter, a COX-2 over-expressing mouse model was also generated but failed to show any pathology in any of the prostate lobes. Collectively, our results suggest that COX-2 may not play a tumorigenic role during prostate carcinogenesis in the TRAMP model.

Journal Article.  6521 words.  Illustrated.

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.