Autophagy and Tumor Cell Metabolism

Macroautophagy is a lysosomal degradative process for cellular components that is regulated by oncogenes and tumor suppressors. Macroautophagy plays a major role in cell homeostasis and in response to stress, where it acts as a cell survival mechanism. Indeed, during periods of starvation, stimulation of the autophagic pathway fuels cells with nutrients via lysosomal recycling to maintain metabolic activity and to respond to the demand for energy. The role of macroautophagy in cancer is complex and context dependent. Defective macroautophagy favors DNA damage and genomic instability, whereas normal macroautophagy protects cancer cells against metabolic stress by providing what is required to maintain metabolism in cancer cells. This chapter will describe the interplay between macroautophagy and metabolism and its regulation by metabolites, including those that control the posttranslational acetylation potential of proteins. The last part of the chapter will concern the role of autophagy in the maintenance and self-renewal of cancer stem cells.