[Autophagy: a new concept in cancer research]

Macroautophagy is a lysosomal catabolic process involved in recycling cell components and maintaining cellular homeostasis. Identifying some of the molecules involved in the control and execution steps of autophagy has shed light on the close link between autophagy and tumour progression. Several tumour-suppressor proteins -including Beclin 1, a protein involved in autophagosome formation- positively regulate autophagy. Conversely, some oncogenic proteins display inhibitory effects on autophagy. The antitumoral role of autophagy is supported by its involvement in reducing chromosome instability, proliferation and inflammation of tumour cells. However, autophagy can also be a protumoral mechanism which helps tumour cells to adapt to changes in their microenvironment (hypoxia, starvation...). Moreover, autophagy is induced in response to several anticancer treatments. This response can either be a mechanism allowing cell survival or a mechanism promoting cell death. The aim of this article is to summarize recent progress focusing on the dual role of autophagy in cancer.