Autophagy and tumorigenesis.

Autophagy, or cellular self-digestion, is activated in cancer cells in response to multiple stresses and has been demonstrated to promote tumor cell survival and drug resistance. Nonetheless, genetic evidence supports that autophagy functions as a tumor suppressor mechanism. Hence, the precise role of autophagy during cancer progression and treatment is both tissue and context dependent. Here, we discuss our current understanding of the biological functions of autophagy during cancer development, overview how autophagy is regulated by cancer-associated signaling pathways, and review how autophagy inhibition is being exploited to improve clinical outcomes. Copyright 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.