| First Author | Bakker ER | Year | 2013 |
| Journal | Oncogene | Volume | 32 |
| Issue | 38 | Pages | 4579-85 |
| PubMed ID | 23045279 | Mgi Jnum | J:203241 |
| Mgi Id | MGI:5525223 | Doi | 10.1038/onc.2012.449 |
| Citation | Bakker ER, et al. (2013) beta-Catenin signaling dosage dictates tissue-specific tumor predisposition in Apc-driven cancer. Oncogene 32(38):4579-85 |
| abstractText | Apc-driven tumor formation in patients and Apc-mutant mouse models is generally attributed to increased levels of beta-catenin signaling. We and others have proposed that a specific level of beta-catenin signaling is required to successfully initiate tumor formation, and that each tissue prefers different dosages of signaling. This is illustrated by APC genotype-tumor phenotype correlations in cancer patients, and by the different tumor phenotypes displayed by different Apc-mutant mouse models. Apc1638N mice, associated with intermediate beta-catenin signaling, characteristically develop intestinal tumors (<10) and extra-intestinal tumors, including cysts and desmoids. Apc1572T mice associated with lower levels of beta-catenin signaling are free of intestinal tumors, but instead develop mammary tumors. Although the concept of beta-catenin signaling dosage and its impact on tumor growth among tissues is gaining acceptance, it has not been formally proven. Additionally, alternative explanations for Apc-driven tumor formation have been proposed. To obtain direct evidence for the dominant role of beta-catenin dosage in tumor formation and tissue-specific tumor predisposition, we crossed Apc1638N mice with heterozygous beta-catenin knockout mice, thereby reducing beta-catenin levels. Whereas all the Apc1638N;Ctnnb1(+/+) mice developed gastrointestinal tumors, none were present in the Apc1638N;Ctnnb1(-/+) mice. Incidence of other Apc1638N-associated lesions, including desmoids and cysts, was strongly reduced as well. Interestingly, Apc1638N;Ctnnb1(-/+) females showed an increased incidence of mammary tumors, which are normally rarely observed in Apc1638N mice, and the histological composition of the tumors resembled that of Apc1572T-related tumors. Hereby, we provide in vivo genetic evidence confirming the dominant role of beta-catenin dosage in tumor formation and in dictating tumor predisposition among tissues in Apc-driven cancer. |
