PEA3 is up-regulated in response to Wnt1 and activates the expression of cyclooxygenase-2.
The inducible prostaglandin synthase cyclooxygenase-2 (COX-2) is aberrantly expressed in intestinal tumors resulting from APC mutation, and is also transcriptionally up-regulated in mouse mammary epithelial cells in response to Wnt1 expression. beta-Catenin stabilization is a consequence of both APC mutation and Wnt signaling. We have previously observed coordinate regulation of the matrilysin promoter by beta-catenin and Ets family transcription factors of the PEA3 subfamily. Here we show that while beta-catenin only weakly activates the COX-2 promoter, PEA3 family transcription factors are potent activators of COX-2 transcription. Consistent with this, PEA3 is up-regulated in Wnt1-expressing mouse mammary epithelial cells, and PEA3 factors are highly expressed in tumors from Wnt1 transgenic mice, in which Cox-2 is also up-regulated. Promoter mapping experiments suggest that the NF-IL6 site in the COX-2 promoter is important for mediating PEA3 responsiveness. The NF-IL6 site is also important for COX-2 transcription in some colorectal cancer lines (Shao, J., Sheng, H., Inoue, H., Morrow, J. D., and DuBois, R. N. (2000) J. Biol. Chem. 275, 33951-33956), and PEA3 factors are highly expressed in colorectal cancer cell lines. Therefore, we speculate that PEA3 factors may contribute to the up-regulation of COX-2 expression resulting from both APC mutation and Wnt1 expression.
Howe
L R
LR
Department of Cell Biology and Anatomy, Weill Medical College of Cornell University, New York, New York 10021, USA.
Crawford
H C
HC
Subbaramaiah
K
K
Hassell
J A
JA
Dannenberg
A J
AJ
Brown
A M
AM
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D051546:Cyclooxygenase 2; D004247:DNA; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015854:Up-Regulation; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins
D007527:Isoenzymes; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; C495247:WNT1 protein, human; D051153:Wnt Proteins; D051155:Wnt1 Protein; C495246:Wnt1 protein, mouse; D029961:Zebrafish Proteins; C065788:transcription factor PEA3; D004247:DNA; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases