Targeting peroxisome proliferator-activated receptor-β/δ in colon cancer: How to aim?

Peroxisome proliferator-activated receptor-beta/delta (PPAR delta) is a ubiquitously expressed, ligand-activated transcriptional factor that performs diverse critical functions in normal cells (e.g., fatty acid metabolism, obesity, apoptosis, and inflammation). Various studies in humans have found that PPAR delta is upregulated in primary colorectal cancers; however, these findings have been challenged by those of other reports. Similarly, various in vitro and in vivo mechanistic pre-clinical models have yielded data demonstrating that PPAR delta promotes colonic tumorigenesis, but other models have yielded data that contradicts this notion. Definitive studies are therefore needed to establish the exact role of PPAR delta in human colorectal tumorigenesis and to provide a theoretical basis for PPAR delta therapeutic targeting. (C) 2012 Elsevier Inc. All rights reserved.