Figure 1

From: Autophagy in cancer metastasis

Figure 1

Schematic illustrating roles of autophagy in the metastatic cascade. Autophagy increases as tumor cells progress to invasiveness and this in turn is linked to increased cell motility, EMT, a stem cell phenotype, secretion of pro-migratory factors, release of MMPs, drug resistance and escape from immune surveillance at the primary site in some tumors. Many aspects of these autophagy-dependent changes during acquisition of invasiveness also likely contribute to the ability of disseminating tumor cells to intravasate, survive and migrate in the circulation before extravasating at secondary site. At the secondary site, autophagy is required to maintain tumor cells in a dormant state, possibly through its ability to promote quiescence and a stem cell phenotype, that in turn is linked to tumor cell survival and drug resistance. Emerging functions for autophagy in metastasis include a role in establishing the pre-metastatic niche as well as promoting tumor cell survival, escape from immune surveillance and other aspects required to ultimately grow out an overt metastasis.