Autophagy is required for PTEN-loss driven prostate cancer

Protein catabolic pathways are of critical importance to cellular physiology. The breakdown of proteins and organelles serves not only as a form of protein and organelle quality control, but also to generate amino acids and free fatty acids for reuse by the cell. Macroautophagy (hereafter referred to as autophagy) is a major pathway of protein degradation in eukaryotic cells that has been preserved through evolution. There has been much interest in the role of autophagy and cancer because mutations in autophagy genes have been observed in human cancers, autophagic activity is altered in cancer cells, and suppression of autophagy could be utilized as a cancer therapy (1,2). A recent report by the DiPaola group (3) demonstrated for the first time that autophagy is essential for the development of prostate cancer driven by PTEN-loss in a mouse model.