*6.8.1 Autophagy*

Autophagy ("self- eating") is the process in which lysosomal enzymes digest the own components of the cell during stress. It is a survival mechanism that occurs during a state of severe nutrient deficiency. By this mechanism, the starved cell can live by eating its own contents (e.g., organelles, proteins, and membranes) and by recycling these contents to provide nutrients and energy.

If this adaptive mechanism fails, the cells die.

Autophagy in cancer: Role of autophagy in the development and progression of cancer is complex and represents a double-edged sword. Several autophagy genes (e.g., Beclin-1 and some Atg genes) that promote autophagy, act as tumor suppressors and are deleted or mutated in many cancers. Tumor cells may accumulate mutations that deranges the pathways that induce autophagy and allows the cancer cells to grow without triggering autophagy. Tumor cells may corrupt the autophagy process to provide nutrients for continued growth and survival. On the other hand, autophagy can protect cancer cells if they are deprived of nutrients or oxygen because of therapy or insufficient blood supply [18, 19].
