PPARgamma and Apoptosis in Cancer

Peroxisome proliferator-activated receptors (PPARs) are ligand binding transcription factors which function in many physiological roles including lipid metabolism, cell growth, differentiation, and apoptosis. PPARs and their ligands have been shown to play a role in cancer. In particular, PPARgamma ligands including endogenous prostaglandins and the synthetic thiazolidinediones (TZDs) can induce apoptosis of cancer cells with antitumor activity. Thus, PPARgamma ligands have a potential in both chemoprevention and therapy of several types of cancer either as single agents or in combination with other antitumor agents. Accordingly, the involvement of PPARgamma and its ligands in regulation of apoptosis of cancer cells have been extensively studied. Depending on cell types or ligands, induction of apoptosis in cancer cells by PPARgamma ligands can be either PPARgamma-dependent or -independent. Through increasing our understanding of the mechanisms of PPARgamma ligand-induced apoptosis, we can develop better strategies which may include combining other antitumor agents for PPARgamma-targeted cancer chemoprevention and therapy. This review will highlight recent research advances on PPARgamma and apoptosis in cancer.