First Author | Hasselblatt P | Year | 2008 |
Journal | Oncogene | Volume | 27 |
Issue | 47 | Pages | 6102-9 |
PubMed ID | 18679426 | Mgi Jnum | J:140139 |
Mgi Id | MGI:3811979 | Doi | 10.1038/onc.2008.211 |
Citation | Hasselblatt P, et al. (2008) The role of the transcription factor AP-1 in colitis-associated and beta-catenin-dependent intestinal tumorigenesis in mice. Oncogene 27(47):6102-9 |
abstractText | Chronic inflammation is an important cancer risk factor but the molecular pathways linking inflammation and cancer are incompletely understood. The transcription factor c-Jun/AP-1 (activator protein 1) is involved in inflammatory responses and tumorigenesis and has been proposed as an essential mediator of oncogenic beta-catenin signaling in the intestine. Here, we examined the functions of c-Jun in two distinct mouse models of conditional and intestine-specific activation of beta-catenin. c-Jun is strongly expressed in the small intestine of mutant mice. However, beta-catenin-dependent cell proliferation is surprisingly not affected in mice lacking c-jun in intestinal epithelium, suggesting that c-Jun is not an essential immediate target of beta-catenin signaling in the small intestine. To examine the functions of Jun and Fos proteins during inflammation and cancer in the colon, colitis-associated tumors were induced chemically in the respective knockout mice. Tumors were characterized by activated beta-catenin and strongly expressed c-Jun and JunB. However, tumorigenesis was not affected by inactivation of c-Jun in either intestinal epithelium or myeloid cells. Moreover, tumorigenesis was not altered in mice lacking junB, junD, c-fos, fra-1 or fra-2, suggesting that inhibition of c-Jun or other single AP-1 proteins is not a determining factor in colitis-associated cancer in mice. |