Survival or death: disequilibrating the oncogenic and tumor suppressive autophagy in cancer

Autophagy (macroautophagy) is an evolutionarily conserved lysosomal degradation process, in which a cell degrades long-lived proteins and damaged organelles. Recently, accumulating evidence has revealed the core molecular machinery of autophagy in carcinogenesis; however, the intricate relationship between autophagy and cancer continue to remain an enigma. Why does autophagy have either pro-survival (oncogenic) or pro-death (tumor suppressive) role at different cancer stages, including cancer stem cell, initiation and progression, invasion and metastasis, as well as dormancy? How does autophagy modulate a series of oncogenic and/or tumor suppressive pathways, implicated in microRNA (miRNA) involvement? Whether would targeting the oncogenic and tumor suppressive autophagic network be a novel strategy for drug discovery? To address these problems, we focus on summarizing the dynamic oncogenic and tumor suppressive roles of autophagy and their relevant small-molecule drugs, which would provide a new clue to elucidate the oncosuppressive (survival or death) autophagic network as a potential therapeutic target.