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. 2011 Mar 22;108(12):4914-9.
doi: 10.1073/pnas.1102300108. Epub 2011 Mar 7.

T-cell factor 4 functions as a tumor suppressor whose disruption modulates colon cell proliferation and tumorigenesis

Melinda L Angus-Hill  1 , Kathryn M Elbert, Julio Hidalgo, Mario R Capecchi
Affiliations

T-cell factor 4 functions as a tumor suppressor whose disruption modulates colon cell proliferation and tumorigenesis

Melinda L Angus-Hill et al. Proc Natl Acad Sci U S A. .

Abstract

The Wnt/β-catenin pathway plays multiple and diverse roles in development by regulating gene expression via T-cell factor/Lymphoid enhancer-binding factor (Tcf/Lef) DNA binding factors. Misregulation of this pathway is thought to initiate colon adenoma formation. It is controversial whether Tcf4 (Tcf7L2) functions as an oncogene or tumor suppressor gene in colon carcinogenesis. We show here that Tcf4 haploinsufficiency results in colon tumor formation in a mouse tumor model that normally only develops small intestinal tumors. Further, we show that loss of Tcf4 early in development and in adult colon results in increased cell proliferation. These findings strongly suggest that Tcf4 normally modulates proliferation of the colonic epithelium and that disruption of Tcf4 activity increases proliferation, leading to colon tumorigenesis. Taken together, our in vivo studies favor a tumor suppressor function for Tcf4.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Model of the role of Tcf4 during intestinal development and in tumor formation (in the text).
Fig. 2.
Fig. 2.
Newborn Tcf4Null mice are not viable and show necrotic death of proliferative progenitors and differentiated epithelial cell types in the colon. (A) Newborn Tcf4Null mice die within 24 h of birth and lack a milk spot (white arrows). (B) Intestines isolated from Tcf4Null mice have a distended duodenum (red arrows) and diffuse meconium (black arrows) compared with the intestines of Tcf4Het newborn mice. The effects of loss of Tcf4 during intestinal development were analyzed in both Tcf4Het and Tcf4Null mice. (C and D) Tcf4 lineage marks the membranes of epithelial cells in cryosections of newborn colon. Red arrow denotes large masses of fluorescent dead cells in the lumen and yellow arrows mark the loss of Tcf4 lineage and crypt structure in mutant crypts (crypts outlined in blue). Loss of Tcf4 impairs enteroendocrine and goblet cell differentiation throughout the gut. Staining of newborn colons with anti-chromogranin A (E and F; enteroendocrine; white arrows) and UEA-1 (G and H; goblet cells; yellow arrows). (I and J) Ki-67 staining marks proliferative cells in the colon of newborn mice. Yellow arrows mark crypts and red arrows mark background peroxidase staining of necrotic cells (scale bar, 10 μm).
Fig. 3.
Fig. 3.
Loss of Tcf4 causes increased proliferation in the intestinal epithelium of Tcf4Null E13.5 embryos. (A) Membrane bound GFP marks Tcf4 lineage and reveals increased proportion of Tcf4 lineage in the epithelium of Tcf4Null E13.5 embryos. Yellow arrows mark red cells that have never expressed Cre and blue dotted line marks the endoderm/epithelium (B). Phh3 staining (blue) reveals increased numbers of mitotic cells in Tcf4Null E13.5 embryos. (C) BrdU staining (red) reveals increased numbers of cells in S phase of the cell cycle in Tcf4Null E13.5 embryos. Unequal variance two-tailed t test. Horizontal line, mean (scale bar, 50 μm).
Fig. 4.
Fig. 4.
Loss of Tcf4 results in hyperplasia without neoplasia. (A) Loss of Tcf4 in the colon Tcf4CreNeo/lox (Tcf4NeoNull) mice is not sufficient for tumor formation. mGFP marks crypts that are Tcf4Null; mTom marks crypts that are Tcf4Het. (A) Mice were collected between 4 mo and 1 y and did not develop colon tumors. (B) Tcf4NeoNull lineage-positive intact crypts are enlarged and maintain proliferative capacity as demonstrated by EdU labeling of crypts (yellow arrows). Dotted white lines encircle Tcf4Null crypts and dotted yellow lines encircle Tcf4Het crypts. P2-values calculated using paired two-sample t test for means (scale bar, 50 μm).
Fig. 5.
Fig. 5.
Tcf4 is a tumor suppressor in normal colonic epithelium. (A and B) Heterozygous loss of Tcf4 causes increased colon tumor formation in Tcf4Het ApcMin mice compared with Tcf4WTApcMin control mice. (C) Hematoxylin and eosin staining of colonic adenoma isolated from Tcf4Het ApcMin mice. (D) Tcf4 lineage analysis in cryosections of colon and adenoma tissue. (E) In colon tumors, Tcf4 antibody staining of tissue shows Tcf4 protein, Apc antibody staining demonstrates loss of heterozygosity of Apc and nuclear β-catenin antibody staining shows β-Catenin activation in colon tumors. (F) Tcf4 antibody staining of paraffin embedded grossly uninvolved human colon and human colon cancer tissue. (G) Heterozygous Tcf4 nonsense Exon 1 truncations have been found in genome-wide sequencing analysis of primary human CRC (12). These mutations are very similar to those created in targeted mTcf4Cre and mTcf4Lox alleles. (H) Tcf4 is not essential for tumorigenesis. Whole mount (wm) and sections of normal colonic epithelium and colon adenomas demonstrate Tcf4 lineage in the absence of Tcf4 in Tcf4NeoNull ApcMin mice. Dotted white lines encircle Tcf4Null tumor cells and dotted yellow lines encircle Tcf4Het tumor cells of a colon adenoma (scale bar, 50 μm).
Fig. 6.
Fig. 6.
Lef1 and Tcf1 (Tcf7) are up-regulated in colon tumors. (A) Expression microarray and QPCR analysis of RNA isolated from the colons of Tcf4WTApcMin and Tcf4Het ApcMin littermates reveals misregulation of Wnt signaling components and downstream targets.
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References

    1. Goss KH, Groden J. Biology of the adenomatous polyposis coli tumor suppressor. J Clin Oncol. 2000;18:1967–1979. - PubMed
    1. Bienz M, Clevers H. Linking colorectal cancer to Wnt signaling. Cell. 2000;103:311–320. - PubMed
    1. Morin PJ. beta-Catenin signaling and cancer. Bioessays. 1999;21:1021–1030. - PubMed
    1. Moser AR, Pitot HC, Dove WF. A dominant mutation that predisposes to multiple intestinal neoplasia in the mouse. Science. 1990;247:322–324. - PubMed
    1. Su LK, et al. Multiple intestinal neoplasia caused by a mutation in the murine homolog of the APC gene. Science. 1992;256:668–670. - PubMed

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