Chromosomal instability by beta-catenin/TCF transcription in APC or beta-catenin mutant cells.
Oncogene
; 26(24): 3511-20, 2007 May 24.
Article
in En
| MEDLINE
| ID: mdl-17160019
ABSTRACT
Adenomatous polyposis coli (APC/Apc) gene encodes a key tumor suppressor whose mutations activate beta-catenin/T-cell factor (TCF)-mediated transcription (canonical Wnt signaling). Here, we show that Wnt signaling can cause chromosomal instability (CIN). As an indicator of CIN, we scored anaphase bridge index (ABI) in mouse polyps and ES cells where Wnt signaling was activated by Apc or beta-catenin mutations. We found three to nine times higher ABI than in wild-type controls. Furthermore, karyotype analysis confirmed that the Wnt signal-activated ES cells produced new chromosomal aberrations at higher rates; hence CIN. Consistently, expression of dominant-negative TCFs in these cells reduced their ABI. We also found that Wnt signal activation increased phosphorylation of Cdc2 (Cdk1) that inhibited its activity, and suppressed apoptosis upon exposure of the cells to nocodazole or colcemid. The data suggest that Wnt signaling stimulates the cells to escape from mitotic arrest and apoptosis, resulting in CIN. In human gastric cancer tissues with nuclear beta-catenin, ABI was significantly higher than in those without. These results collectively indicate that beta-catenin/TCF-mediated transcription itself increases CIN through dysregulation of G2/M progression.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Adenomatous Polyposis Coli Protein
/
Chromosomal Instability
/
Beta Catenin
/
TCF Transcription Factors
/
Mutation
Limits:
Animals
/
Humans
Language:
En
Journal:
Oncogene
Journal subject:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Year:
2007
Document type:
Article
Affiliation country:
Japan