Translational Regulation of TRAIL Sensitivity

Abstract
TNF-related apoptosis-inducing ligand (TRAIL) is a peptide that induces apoptosis to varying degrees in tumor cells, but not in normal cells. While TRAIL sensitivity in tumors has been linked to c-myc- and MEK/Erk-induced enhancement of caspase activation, our recent study identified a third input controlling TRAIL sensitivity, namely the Akt-mTOR pathway. We showed that instead of enhancing TRAIL sensitivity, Akt expression, acting through mTOR and the mTOR targets S6 kinase and eIF-4E, selectively enhances translation of the anti-apoptotic protein FLIPs and confers TRAIL resistance. In this perspective article we will discuss the linkage of the AktmTOR pathway to other regulators of TRAIL sensitivity, its importance in controlling a broader range of apoptotic events, its utility in predicting TRAIL responsiveness, and its potential manipulation for therapeutic benefit.