To Live or to Die: Prosurvival Activity of PPARγin Cancers

Abstract

The role of PPARγin tumorigenesis is controversial. In this article, we review and analyze literature from the past decade that highlights the potential proneoplastic activity of PPARγ. We discuss the following five aspects of the nuclear hormone receptor and its agonists: (1) relative expression of PPARγin human tumorversusnormal tissues; (2) receptor-dependent proneoplastic effects; (3) impact of PPARγand its agonists on tumors in animal models; (4) clinical trials of thiazolidinediones (TZDs) in human malignancies; (5) TZDs as chemopreventive agents in epidemiology studies. The focus is placed on the most relevantin vivoanimal models and human data.In vitrocell line studies are included only when the effects are shown to be dependent on the PPARγreceptor.