The Role of PPARs in Cancer

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that belong to the nuclear hormone receptor superfamily. PPAR alpha is mainly expressed in the liver, where it activates fatty acid catabolism. PPAR alpha activators have been used to treat dyslipidemia, causing a reduction in plasma triglyceride and elevation of high-density lipoprotein cholesterol. PPAR delta is expressed ubiquitously and is implicated in fatty acid oxidation and keratinocyte differentiation. PPAR delta activators have been proposed for the treatment of metabolic disease. PPAR gamma 2 is expressed exclusively in adipose tissue and plays a pivotal role in adipocyte differentiation. PPAR gamma is involved in glucose metabolism through the improvement of insulin sensitivity and represents a potential therapeutic target of type 2 diabetes. Thus PPARs are molecular targets for the development of drugs treating metabolic syndrome. However, PPARs also play a role in the regulation of cancer cell growth. Here, we review the function of PPARs in tumor growth. Copyright (C) 2008 Keisuke Tachibana et al.