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GEO help: Mouse over screen elements for information. |
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| Status |
Public on Apr 20, 2010 |
| Title |
The Leukemia-associated Mllt10/Af10- Dot1l, dedicated b-catenin coactivators essential for intestinal homeostasis |
| Organism |
Homo sapiens |
| Experiment type |
Expression profiling by array
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| Summary |
Background: Wnt signaling maintains the undifferentiated state of intestinal crypt progenitor cells by inducing the formation of nuclear TCF4/beta-catenin complexes. In colorectal cancer, activating mutations in Wnt pathway components cause inappropriate activation of TCF4/beta-catenin-driven transcription. Despite the passage of a decade after the discovery of TCF4 and beta-catenin as the molecular effectors of the Wnt signal, few transcriptional activators essential and unique to the regulation of this transcription program have been found.
Methodology/Principal Findings: Using proteomics, we identified the leukemia-associated Mllt10/Af10 and the methyltransferase Dot1l, as Tcf4/beta-catenin interactors in mouse small intestinal crypts. Mllt10/Af10-Dot1l, essential for transcription elongation, are recruited to Wnt target genes in a beta-catenin -dependent manner, resulting in H3K79 methylation over their coding regions in vivo in proliferative crypts of mouse small intestine, in colorectal cancer and Wnt-inducible HEK293T cells. Depletion of MLLT10/AF10 in colorectal cancer and Wnt-inducible HEK293T cells followed by expression array analysis identifies MLLT10/AF10 and DOT1L as essential activators dedicated to Wnt target gene regulation. In contrast, previously published b-catenin coactivators p300 and beta-catenin displayed a more pleiotropic target gene expression profile controlling Wnt and other pathways. tcf4, mllt10/af10 and dot1l are co-expressed in Wnt-driven tissues in zebrafish and essential for Wnt-reporter activity. Intestinal differentiation defects in apc-mutant zebrafish can be rescued by depletion of Mllt10 and Dot1l, establishing these genes as activators downstream of Apc in Wnt target gene activation in vivo. Morpholino-depletion of mllt10/af10-dot1l in zebrafish results in defects in intestinal homeostasis and a significant reduction in the in vivo expression of direct Wnt target genes and in the number of proliferative intestinal epithelial cells.
Conclusions/Significance: We conclude that Mllt10/Af10-Dot1l are essential, dedicated activators of Wnt-dependent transcription, critical for maintenance of intestinal proliferation and homeostasis. The methyltransferase Dot1l may present an attractive candidate for drug targeting in colorectal cancer.
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| Overall design |
6 samples for Ls174T cells: si-b-catenin against si-control and dyeswap of it, si-control, si-MLLT10, si-BRG1 and si-P300 are hybridized against common reference RNA; 6 samples of HEK293T cells: Wnt3A or control medium (CM) induction for 9 hours, si-MLLT10, si-DOT1L, si-BRG1 and si-P300 upon 9 hour Wnt3A induction are all hybridized against common reference RNA
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| Contributor(s) |
Mahmoudi T, Boj SF, Hatzis P, Li VS, Taouatas N, Vries RG, Teunissen H, Begthel H, Korving J, Mohammed S, Heck AJ, Clevers H |
| Citation(s) |
21103407 |
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| Submission date |
Apr 16, 2010 |
| Last update date |
Mar 18, 2020 |
| Contact name |
Vivian Li |
| E-mail(s) |
vivian.li@crick.ac.uk
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| Organization name |
The Francis Crick Institute
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| Lab |
Stem Cell and Cancer Biology
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| Street address |
1 Midland Road
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| City |
London |
| ZIP/Postal code |
NW1 1AT |
| Country |
United Kingdom |
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| Platforms (1) |
| GPL4133 |
Agilent-014850 Whole Human Genome Microarray 4x44K G4112F (Feature Number version) |
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| Samples (12)
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| Relations |
| BioProject |
PRJNA126101 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE21367_RAW.tar |
59.4 Mb |
(http)(custom) |
TAR (of TXT) |
| Processed data included within Sample table |
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