Anti- and Protumorigenic Effects of PPARγin Lung Cancer Progression: A Double-Edged Sword
Peroxisome proliferator-activated receptor-γ(PPARγ) is a member of the nuclear receptor superfamily of ligand-activated transcription factors that plays an important role in the control of gene expression linked to a variety of physiological processes, including cancer. Ligands for PPARγinclude naturally occurring fatty acids and the thiazolidinedione class of antidiabetic drugs. Activation of PPARγin a variety of cancer cells leads to inhibition of growth, decreased invasiveness, reduced production of proinflammatory cytokines, and promotion of a more differentiated phenotype. However, systemic activation of PPARγhas been reported to be protumorigenic in somein vitrosystems andin vivomodels. Here, we review the available data that implicate PPARγin lung carcinogenesis and highlight the challenges of targeting PPARγin lung cancer treatments.