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. | Turkish Journal of Biology Review Article Turk J Biol (2014) 38: 720-739 © TÜBİTAK doi: Autophagy and cancer Hacer Ezgi KARAKAŞ, Devrim GÖZÜAÇIK* Molecular Biology, Genetics, and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabancı University, İstanbul, Turkey Received: Accepted: Published Online: Printed: Abstract: 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. Key words: Autophagy, stress, cancer, tumor, oncogenes, tumor suppressors, metastasis, cell death, chemotherapy 1. Introduction Autophagy is a basic cellular event conserved in all eukaryotes from yeast to man. It serves as an intracellular quality-control mechanism recycling long-lived or misfolded/aggregate-prone proteins and damaged organelles, such as mitochondria. Moreover, under stress conditions, autophagy is upregulated in order to generate building blocks that are necessary for cellular survival (Kuma and Mizushima, 2010; Rabinowitz and White, 2010). Therefore, autophagy mainly serves as a stress-adaptation and .
