Some cancer cells exhibit elevated levels of free fatty acids (FAs) as well as high levels of β-catenin, a transcriptional co-activator that promotes their growth. Here, we link these two phenomena by showing that unsaturated FAs inhibit degradation of β-catenin. Unsaturated FAs bind to the UAS domain of Fas-associated factor 1 (FAF1), a protein known to bind β-catenin, accelerating its degradation. FA binding disrupts the FAF1/β-catenin complex, preventing proteasomal degradation of ubiquitinated β-catenin. This mechanism for stabilization of β-catenin differs from that of Wnt signaling, which blocks ubiquitination of β-catenin. In clear cell renal cell carcinoma (ccRCC) cells, unsaturated FAs stimulated cell proliferation through stabilization of β-catenin. In tissues from biopsies of human ccRCC, elevated levels of unsaturated FAs correlated with increased levels of β-catenin. Thus, targeting FAF1 may be an effective approach to treat cancers that exhibit elevated FAs and β-catenin. Kim et al. demonstrate that excess unsaturated fatty acids produced in cancer cells stabilize β-catenin. This mechanism, which is independent of Wnt-mediated stabilization of β-catenin, requires direct interaction of the fatty acids with FAF1, a protein facilitating degradation of β-catenin. This interaction inactivates FAF1, thereby stabilizing β-catenin.

Original languageEnglish (US)
Article number2062
Pages (from-to)495-503
Number of pages9
JournalCell Reports
Issue number3
StatePublished - Oct 20 2015

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology


Dive into the research topics of 'Unsaturated Fatty Acids Stimulate Tumor Growth through Stabilization of β-Catenin'. Together they form a unique fingerprint.

Cite this