Crypt-restricted proliferation and commitment to the Paneth cell lineage following Apc loss in the mouse intestine

Loss of Apc appears to be one of the major events initiating colorectal cancer. However, the first events responsible for this initiation process are not well defined and the ways in which different epithelial cell types respond to Apc loss are unknown. We used a conditional gene-ablation approach in transgenic mice expressing tamoxifen-dependent Cre recombinase all along the crypt-villus axis to analyze the immediate effects of Apc loss in the small intestinal epithelium, both in the stem-cell compartment and in postmitotic epithelial cells. Within 4 days, Apc loss induced a dramatic enlargement of the crypt compartment associated with intense cell proliferation, apoptosis and impairment of cell migration. This result confirms the gatekeeper role of Apc in the intestinal epithelium in vivo. Although Apc deletion activatedβ -catenin signaling in the villi, we observed neither proliferation nor morphological change in this compartment. This highlights the dramatic difference in the responses of immature and differentiated epithelial cells to aberrant β-catenin signaling. These distinct biological responses were confirmed by molecular analyses, revealing that Myc and cyclin D1, two canonical β-catenin target genes, were induced in distinct compartments. We also showed that Apc is a crucial determinant of cell fate in the murine intestinal epithelium. Apc loss perturbs differentiation along the enterocyte, goblet and enteroendocrine lineages, and promotes commitment to the Paneth cell lineage through β-catenin/Tcf4-mediated transcriptional control of specific markers of Paneth cells, the cryptdin/defensin genes.

[1]  Takuji Tanaka,et al.  Microadenomatous lesions involving loss of Apc heterozygosity in the colon of adult Apc(Min/+) mice. , 2002, Cancer research.

[2]  R. Fodde,et al.  Apc modulates embryonic stem-cell differentiation by controlling the dosage of β-catenin signaling , 2002, Nature Genetics.

[3]  M. Giovannini,et al.  Liver-targeted disruption of Apc in mice activates beta-catenin signaling and leads to hepatocellular carcinomas. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[4]  Kazuo Suzuki,et al.  Identification of the leukocyte cell‐derived chemotaxin 2 as a direct target gene of β‐catenin in the liver , 2004, Hepatology.

[5]  B. Hogan,et al.  Hyperactive Wnt signaling changes the developmental potential of embryonic lung endoderm , 2004, Journal of biology.

[6]  G. Niedobitek,et al.  The invasion front of human colorectal adenocarcinomas shows co-localization of nuclear beta-catenin, cyclin D1, and p16INK4A and is a region of low proliferation. , 2001, The American journal of pathology.

[7]  F. McCormick,et al.  Beta-catenin regulates expression of cyclin D1 in colon carcinoma cells. , 1999, Nature.

[8]  Pauline Chu,et al.  Essential requirement for Wnt signaling in proliferation of adult small intestine and colon revealed by adenoviral expression of Dickkopf-1 , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[9]  Daniel Metzger,et al.  Tissue‐specific and inducible Cre‐mediated recombination in the gut epithelium , 2004, Genesis.

[10]  J. Papkoff,et al.  Regulation of epithelial cell migration and tumor formation by beta-catenin signaling. , 2002, Experimental cell research.

[11]  J. Gordon,et al.  Notes from some crypt watchers: regulation of renewal in the mouse intestinal epithelium. , 1998, Current opinion in cell biology.

[12]  T. Ganz,et al.  The multifaceted Paneth cell , 2002, Cellular and Molecular Life Sciences CMLS.

[13]  Hans Clevers,et al.  The beta-catenin/TCF-4 complex imposes a crypt progenitor phenotype on colorectal cancer cells. , 2002, Cell.

[14]  H. Clevers,et al.  Live and let die in the intestinal epithelium. , 2004, Current opinion in cell biology.

[15]  Hans Clevers,et al.  Caught up in a Wnt storm: Wnt signaling in cancer. , 2003, Biochimica et biophysica acta.

[16]  H. Clevers,et al.  APC, Signal transduction and genetic instability in colorectal cancer , 2001, Nature Reviews Cancer.

[17]  J. Gordon,et al.  Paneth cell differentiation in the developing intestine of normal and transgenic mice. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[18]  Tony Pawson,et al.  β-Catenin and TCF Mediate Cell Positioning in the Intestinal Epithelium by Controlling the Expression of EphB/EphrinB , 2002, Cell.

[19]  M. Taketo,et al.  Intestinal polyposis in mice with a dominant stable mutation of the β‐catenin gene , 1999, The EMBO journal.

[20]  P. Polakis The adenomatous polyposis coli (APC) tumor suppressor. , 1997, Biochimica et biophysica acta.

[21]  Hans Clevers,et al.  Depletion of epithelial stem-cell compartments in the small intestine of mice lacking Tcf-4 , 1998, Nature Genetics.

[22]  K. Kinzler,et al.  Top-down morphogenesis of colorectal tumors , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[23]  A. Sparks,et al.  Identification of c-MYC as a target of the APC pathway. , 1998, Science.

[24]  M. Bienz Faculty Opinions recommendation of Beta-catenin and TCF mediate cell positioning in the intestinal epithelium by controlling the expression of EphB/ephrinB. , 2002 .

[25]  H. Clevers,et al.  Linking Colorectal Cancer to Wnt Signaling , 2000, Cell.

[26]  Paul Polakis,et al.  The metalloproteinase matrilysin is a target of β-catenin transactivation in intestinal tumors , 1999, Oncogene.

[27]  M. Giovannini,et al.  Colorectal cancers in a new mouse model of familial adenomatous polyposis: influence of genetic and environmental modifiers , 2004, Laboratory Investigation.

[28]  W. Fu,et al.  The presence of FGF2 signaling determines whether beta-catenin exerts effects on proliferation or neuronal differentiation of neural stem cells. , 2004, Developmental biology.

[29]  W. Bodmer,et al.  Bottom-up histogenesis of colorectal adenomas: origin in the monocryptal adenoma and initial expansion by crypt fission. , 2003, Cancer research.

[30]  Ian P Newton,et al.  Loss of Apc in vivo immediately perturbs Wnt signaling, differentiation, and migration. , 2004, Genes & development.

[31]  K. Kinzler,et al.  Lessons from Hereditary Colorectal Cancer , 1996, Cell.

[32]  J. Hendry,et al.  Radiation and gut , 1995 .

[33]  E. Fuchs,et al.  Lymphoid enhancer factor 1 directs hair follicle patterning and epithelial cell fate. , 1995, Genes & development.

[34]  Hans Clevers,et al.  Canonical Wnt signals are essential for homeostasis of the intestinal epithelium. , 2003, Genes & development.