FIG. 6.

Schematic of tumor development. As incipient tumors (or micrometastases) grow beyond the homeostatic limit (∼150 μM), they often experience insufficient supplies of oxygen and nutrients. Tumor cells must overcome this stress before replenishment arrives by way of neoangiogenesis. Our data show that ST antigen-mediated induction of autophagy can be one such mechanism that provides an alternate source of energy for tumor growth and the establishment of metastases. Thus, pathways activating autophagy can be targeted for cancer therapy.