Fig. 2.

Regulators of OXPHOS and FAO. In response to energy stress, cancer cells activate PGC-1α and AMPK signaling, which are mediated by the tumor suppressor genes PML, p53, and LKB1. Both signaling pathways in turn augment mitochondrial biogenesis, which mainly determines the activity of mitochondrial respiration. PPARα, activated by PGC-1α, and AMPK enhance CPT1, the rate-limiting enzyme of FAO. The oncogene MYC also induces FAO through an as-yet-unknown mechanism. Through these mechanisms, increased OXPHOS and FAO produce sufficient ATP for cancer progression