Regulatory Roles of Autophagy in Cancer

Autophagy is an intracellular degradation and recycling system that aids in maintaining the cellular metabolism and homeostasis. Various cellular stresses, including organelle damage, deprivation of nutrients, and accumulation of damaged proteins lead to autophagy that can be associated with cell survival or cell death. Autophagy is initiated with the formation of autophagosome which is a double membrane vesicle. Autophagosome fuses with the lysosome to form autolysosome and deliver cytoplasmic contents that can be degraded or recycled to adapt cellular stressful conditions. Autophagy acts in playing dual roles in tumor suppression and tumor promotion. In addition, autophagy is involved in the maintenance of stemness and homeostasis in cancer stem cells, cancer metastases, and development of resistance to anti-cancer reagents by regulating the expression of many autophagy associated genes. Autophagy modulators such as chloroquine, rapamycin, and their derivatives are used against many cancers, and are in clinical trials. The complete understanding of mechanisms that link autophagy with cancer growth and suppression may aid in the development of promising therapeutics against cancer.