Enhancement of tumor-TRAIL susceptibility by modulation of autophagy

Autophagy has recently been recognized as an important cellular response to stress. However, the prospect of manipulating the autophagic process for the enhancement of cancer therapy remains unresolved. This lack of resolution stems from the current controversy regarding the fundamental function of autophagy in tumor stress response: Does it have a positive or negative impact on tumor survival capability? Our studies were designed to investigate the role of autophagy in the response to TRAIL of tumor cells with various apoptotic defects. Based on our findings, we propose that divergent mechanisms of resistance to TRAIL can be reversed by a common approach of targeting specific components of the autophagic process for inhibition. This concept may have significant implications for the development of new strategies to circumvent TRAIL resistance in tumors.Addendum to: Han J, Hou W, Goldstein LA, Lu C, Stolz DB, Yin XM, Rabinowich H. Involvement of protective autophagy in TRAIL resistance of apoptosis-defective tumor cells. J Biol Chem 2008; 283:19665-77.