Related Experiment Video
Updated: Jun 14, 2026

The Soft Agar Colony Formation Assay
Published on: October 27, 2014
Repression of beta-catenin signaling by PPAR gamma ligands
1University of California San Diego (UCSD) Moores Cancer Center, La Jolla, CA 92093, USA. delu@ucsd.edu
Abstract:
Aberrant activation of the Wnt/beta-catenin signaling pathway plays a crucial role in oncogenesis of various human malignancies. It has been demonstrated that there is a direct interaction between beta-catenin and PPAR gamma. Here we examined the effects of fifteen reported PPAR ligands in a reporter gene assay that is dependent on beta-catenin activation of TCF/LEF transcription factors; only the thiazolidinedione PPAR gamma agonists troglitazone, rosiglitazone and pioglitazone, and a non-thiazolidinedione PPAR gamma activator GW1929 inhibited beta-catenin-induced transcription in a PPAR gamma dependent fashion. The results from mammalian one-hybrid experiments showed that functional PPAR gamma was necessary for ligand-dependent inhibition of beta-catenin transactivation. However, a PPAR gamma activator Fmoc-Leu could not repress beta-catenin-mediated signaling and its transactivation activity. These results indicate that activation of PPAR gamma is necessary, but not sufficient, for the beta-catenin antagonistic activity of a PPAR gamma agonist, and that the inhibitory compounds interfere directly with beta-catenin transactivation activity.
Related Concept Videos
TGF - β Signaling Pathway
Catenins
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...
GPCRs Regulate Adenylyl Cylase Activity
Two...
Cell Specific Gene Expression
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
GPCR Desensitization
