The Myc 3′ Wnt-Responsive Element Regulates Homeostasis and Regeneration in the Mouse Intestinal Tract

ABSTRACT The Wnt/β-catenin signaling pathway controls cellular proliferation in the intestines. In response to Wnt, β-catenin transits into the nucleus and associates with members of the T-cell factor (TCF) family of transcription factors. β-Catenin/TCF complexes bind Wnt responsive DNA elements (WREs) to activate target gene expression. The c-MYC proto-oncogene (MYC) is a direct target of β-catenin/TCF complexes. We recently identified the MYC 3′ WRE, which maps 1.4-kb downstream from the MYC transcription stop site. To investigate the role of the Myc 3′ WRE in the intestines, we generated a mouse model with a germ line deletion of this element. The intestinal architecture was largely preserved in knockout mice; however, removal of the Myc 3′ WRE compromised the crypt microenvironment. In comparison to wild-type intestines, knockout intestines contained an increased number of proliferative cells and a reduced number of differentiated cells comprising both absorptive and secretory lineages. Using a model of colitis, we found that knockout colons repaired more rapidly during the recovery period of the protocol. These results indicate that regulation of MYC expression through the Myc 3′ WRE contributes to intestinal homeostasis. Furthermore, our study implicates MYC as an important regulator of intestinal regeneration following injury.

[1]  Yutao Yan,et al.  Dextran Sodium Sulfate (DSS) Induces Colitis in Mice by Forming Nano-Lipocomplexes with Medium-Chain-Length Fatty Acids in the Colon , 2012, PloS one.

[2]  T. Denning,et al.  The Wnt antagonist Dkk1 regulates intestinal epithelial homeostasis and wound repair. , 2011, Gastroenterology.

[3]  Calvin J. Kuo,et al.  Regulation of self-renewal and differentiation by the intestinal stem cell niche , 2011, Cellular and Molecular Life Sciences.

[4]  G. Yochum.  Multiple Wnt/ß-Catenin Responsive Enhancers Align with the MYC Promoter through Long-Range Chromatin Loops , 2011, PloS one.

[5]  Julie A. Wilkins,et al.  Focal adhesion kinase is required for intestinal regeneration and tumorigenesis downstream of Wnt/c-Myc signaling. , 2010, Developmental cell.

[6]  Daniel Bottomly,et al.  Identification of β-catenin binding regions in colon cancer cells using ChIP-Seq , 2010, Nucleic acids research.

[7]  G. Coetzee,et al.  8q24 prostate, breast, and colon cancer risk loci show tissue-specific long-range interaction with MYC , 2010, Proceedings of the National Academy of Sciences.

[8]  O. Sansom,et al.  Myc heterozygosity attenuates the phenotypes of APC deficiency in the small intestine , 2010, Oncogene.

[9]  Hongling Liao,et al.  Long-range enhancers on 8q24 regulate c-Myc , 2010, Proceedings of the National Academy of Sciences.

[10]  Michael D. Cole,et al.  Upregulation of c-MYC in cis through a Large Chromatin Loop Linked to a Cancer Risk-Associated Single-Nucleotide Polymorphism in Colorectal Cancer Cells , 2010, Molecular and Cellular Biology.

[11]  R. Goodman,et al.  A β-catenin/TCF-coordinated chromatin loop at MYC integrates 5′ and 3′ Wnt responsive enhancers , 2009, Proceedings of the National Academy of Sciences.

[12]  D. Reich,et al.  Functional Enhancers at the Gene-Poor 8q24 Cancer-Linked Locus , 2009, PLoS genetics.

[13]  Esko Ukkonen,et al.  The common colorectal cancer predisposition SNP rs6983267 at chromosome 8q24 confers potential to enhanced Wnt signaling , 2009, Nature Genetics.

[14]  G. Evan,et al.  Acute Overexpression of Myc in Intestinal Epithelium Recapitulates Some but Not All the Changes Elicited by Wnt/β-Catenin Pathway Activation , 2009, Molecular and Cellular Biology.

[15]  Xi He,et al.  Wnt/beta-catenin signaling: components, mechanisms, and diseases. , 2009, Developmental cell.

[16]  K. Basler,et al.  β-Catenin hits chromatin: regulation of Wnt target gene activation , 2009, Nature Reviews Molecular Cell Biology.

[17]  H. Clevers,et al.  Stem cells, self-renewal, and differentiation in the intestinal epithelium. , 2009, Annual review of physiology.

[18]  Hans Clevers,et al.  Crypt stem cells as the cells-of-origin of intestinal cancer , 2009, Nature.

[19]  G. Evan,et al.  Distinct thresholds govern Myc's biological output in vivo. , 2008, Cancer cell.

[20]  R. Eisenman,et al.  Myc's broad reach. , 2008, Genes & development.

[21]  R. Goodman,et al.  A Genome-Wide Screen for β-Catenin Binding Sites Identifies a Downstream Enhancer Element That Controls c-Myc Gene Expression , 2008, Molecular and Cellular Biology.

[22]  Fiona G. G. Nielsen,et al.  Genome-Wide Pattern of TCF7L2/TCF4 Chromatin Occupancy in Colorectal Cancer Cells , 2008, Molecular and Cellular Biology.

[23]  T. Baudino,et al.  Inhibition of Intestinal Polyposis with Reduced Angiogenesis in ApcMin/+ Mice Due to Decreases in c-Myc Expression , 2007, Molecular Cancer Research.

[24]  Julie A. Wilkins,et al.  Myc deletion rescues Apc deficiency in the small intestine , 2007, Nature.

[25]  Stefan Wirtz,et al.  Chemically induced mouse models of intestinal inflammation , 2007, Nature Protocols.

[26]  S. McWeeney,et al.  Serial analysis of chromatin occupancy identifies β-catenin target genes in colorectal carcinoma cells , 2007, Proceedings of the National Academy of Sciences.

[27]  S. McWeeney,et al.  An Antisense Transcript Induced by Wnt/β-Catenin Signaling Decreases E2F4* , 2007, Journal of Biological Chemistry.

[28]  D. Besselsen,et al.  Role of c-Myc in intestinal tumorigenesis of the Apc min/+ mouse1 , 2006, Cancer biology & therapy.

[29]  H. Clevers,et al.  Rapid Loss of Intestinal Crypts upon Conditional Deletion of the Wnt/Tcf-4 Target Gene c-Myc , 2006, Molecular and Cellular Biology.

[30]  Kathryn A. O’Donnell,et al.  The c-Myc target gene network. , 2006, Seminars in cancer biology.

[31]  K. Jones,et al.  The APC tumor suppressor counteracts beta-catenin activation and H3K4 methylation at Wnt target genes. , 2006, Genes & development.

[32]  Andreas Trumpp,et al.  c-Myc Is Required for the Formation of Intestinal Crypts but Dispensable for Homeostasis of the Adult Intestinal Epithelium , 2005, Molecular and Cellular Biology.

[33]  Hans Clevers,et al.  Signaling pathways in intestinal development and cancer. , 2004, Annual review of cell and developmental biology.

[34]  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.

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

[36]  John L Cleveland,et al.  c-Myc is essential for vasculogenesis and angiogenesis during development and tumor progression. , 2002, Genes & development.

[37]  Yaping Chen,et al.  Insights from mouse models of colitis , 2000, Journal of leukocyte biology.

[38]  E. Prochownik,et al.  MYC oncogenes and human neoplastic disease , 1999, Oncogene.

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

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

[41]  A. Bradley,et al.  A null c-myc mutation causes lethality before 10.5 days of gestation in homozygotes and reduced fertility in heterozygous female mice. , 1993, Genes & development.

[42]  A. Malcolm,et al.  Increased expression of c-myc proto-oncogene in biopsies of ulcerative colitis and Crohn's colitis. , 1992, Gut.

[43]  S. McWeeney,et al.  An antisense transcript induced by Wnt/beta-catenin signaling decreases E2F4. , 2007, The Journal of biological chemistry.

[44]  H. Clevers.  Wnt/beta-catenin signaling in development and disease. , 2006, Cell.