TRIB2 acts downstream of Wnt/TCF in liver cancer cells to regulate YAP and C/EBPα function.

Abstract

Dysregulation of Wnt signaling is closely associated with human liver tumorigenesis. However, liver cancer-specific Wnt transcriptional programs and downstream effectors remain poorly understood. Here, we identify tribbles homolog 2 (TRIB2) as a direct target of Wnt/TCF in liver cancer and demonstrate that transcription of Wnt target genes, including TRIB2, is coordinated by the TCF and FoxA transcription factors in liver cancer cells. We show that Wnt-TRIB2 activation is critical for cancer cell survival and transformation. Mechanistically, TRIB2 promotes protein stabilization of the YAP transcription coactivator through interaction with the βTrCP ubiquitin ligase. Furthermore, we find that TRIB2 relieves the liver tumor suppressor protein C/EBPα-mediated inhibition of YAP/TEAD transcriptional activation in liver cancer cells. Altogether, our study uncovers a regulatory mechanism underlying liver cancer-specific Wnt transcriptional output, and suggests that TRIB2 functions as a signaling nexus to integrate the Wnt/β-catenin, Hippo/YAP, and C/EBPα pathways in cancer cells.

• Authors: Jiayi Wang, Joo-Seop Park, Yingying Wei, Mihir Rajurkar, Jennifer L Cotton, Qishi Fan, Brian C Lewis, Hongkai Ji, Junhao Mao
• Journal: Molecular cell (Mol Cell) Vol. 51 Issue 2 Pg. 211-25 (Jul 25 2013) ISSN: 1097-4164 [Electronic] United States
• PMID: 23769673 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Elsevier Inc. All rights reserved.

Chemical References

• Biomarkers, Tumor
• CCAAT-Enhancer-Binding Protein-alpha
• Cell Cycle Proteins
• Intracellular Signaling Peptides and Proteins
• Nuclear Proteins
• RNA, Messenger
• T Cell Transcription Factor 1
• TCF7 protein, human
• Transcription Factors
• Wnt Proteins
• YY1AP1 protein, human
• beta Catenin
• Calcium-Calmodulin-Dependent Protein Kinases
• TRIB2 protein, human

Topics

• Biomarkers, Tumor (genetics, metabolism)
• Blotting, Western
• CCAAT-Enhancer-Binding Protein-alpha (genetics, metabolism)
• Calcium-Calmodulin-Dependent Protein Kinases
• Carcinoma, Hepatocellular (genetics, metabolism, pathology)
• Cell Cycle Proteins
• Cell Differentiation
• Cell Proliferation
• Fluorescent Antibody Technique
• Gene Expression Profiling
• Humans
• Immunoenzyme Techniques
• Immunoprecipitation
• Intracellular Signaling Peptides and Proteins (genetics, metabolism)
• Liver Neoplasms (genetics, metabolism, pathology)
• Nuclear Proteins (genetics, metabolism)
• Oligonucleotide Array Sequence Analysis
• RNA, Messenger (genetics)
• Real-Time Polymerase Chain Reaction
• Reverse Transcriptase Polymerase Chain Reaction
• T Cell Transcription Factor 1 (genetics, metabolism)
• Transcription Factors (genetics, metabolism)
• Wnt Proteins (genetics, metabolism)
• beta Catenin (genetics, metabolism)