Open AccessB-catenin deficiency, but not Myc deletion, suppresses the immediate phenotypes of APC loss in the liver
Author(s) -
Karen Ruth Reed,
Dimitris Athineos,
Valérie S. Méniel,
Julie Wilkins,
Rachel A. Ridgway,
Zoë D. Burke,
Vanesa Muncan,
Alan R. Clarke,
Owen J. Sansom
Publication year - 2008
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0805778105
Subject(s) - wnt signaling pathway , phenotype , biology , context (archaeology) , catenin , cancer research , effector , beta catenin , signal transduction , gene , microbiology and biotechnology , genetics , paleontology
Dysregulated Wnt signaling is seen in approximately 30% of hepatocellular carcinomas; thus, finding pathways downstream of the activation of Wnt signaling is key. Here, using cre-lox technology, we deleted the Apc gene in the adult mouse liver and observed a rapid increase in nuclear beta-catenin and c-Myc, which is associated with an induction of proliferation that led to hepatomegaly within 4 days of gene deletion. To investigate the downstream pathways responsible for these phenotypes, we analyzed the impact of inactivating APC in the context of deficiency of the potentially key effectors beta-catenin and c-Myc. beta-catenin loss rescues both the proliferation and hepatomegaly phenotypes after APC loss. However, c-Myc deletion, which rescues the phenotypes of APC loss in the intestine, had no effect on the phenotypes of APC loss in the liver. The consequences of the deregulation of the Wnt pathway within the liver are therefore strikingly different from those observed within the intestine, with the vast majority of Wnt targets being beta-catenin-dependent but c-Myc-independent in the liver.