Autophagy and cancer

Autophagy is an evolutionary conserved intracellular degradation and stress response mechanism that is mainly responsible for the breakdown and recycling of cytoplasmic materials, including long-lived proteins, protein aggregates, and damaged organelles. In this way, autophagy provides the cell with building blocks and allows the maintenance of homeostasis under stress conditions such as growth factor deficiency, nutrient deprivation, hypoxia, and toxins. Consequently, abnormalities of autophagy contribute to a number of pathologies ranging from neurodegenerative diseases to cancer. Autophagy was reported to have a dual role in cancer. Depending on cancer stage, autophagy seems to act as tumor suppressor or as a mechanism supporting tumor growth and spread. In this review, we provide a summary of the relevant literature and discuss the role of autophagy in cancer formation and chemotherapy responses.