PPAR, PTEN, and the Fight against Cancer
Peroxisome proliferator-activated receptor gamma (PPAR) is a ligand-activated transcription factor, which belongs to the family of nuclear hormone receptors. Recent in vitro studies have shown that PPAR can regulate the transcription ofphosphatase and tensin homolog on chromosometen(PTEN), a known tumor suppressor.PTENis a susceptibility gene for a number of disorders, including breast and thyroid cancer. Activation of PPAR through agonists increases functional PTEN protein levels that subsequently induces apoptosis and inhibits cellular growth, which suggests that PPAR may be a tumor suppressor. Indeed, several in vivo studies have demonstrated that genetic alterations of PPAR can promote tumor progression. These results are supported by observations of the beneficial effects of PPAR agonists in the in vivo cancer setting. These studies signify the importance of PPAR andPTEN's interaction in cancer prevention.