Figure 1.

AMPK regulates metabolic and energy homeostasis in cancer cells. Under nutrient-abundant condition, AMPK is suppressed and mTOR is activated, which promotes generation of biomass that leads to cell growth and proliferation. While under glucose-limiting condition, AMPK, by activating p38 and by inhibiting mTOR, regulates expression of PGC1-α, which controls mitochondrial biogenesis in cancer cells, thereby allowing oxidative metabolism of non-glucose carbon sources, such as glutamine, lactate and fatty acids, to generate ATP. Simultaneously, AMPK can elevate the rate of glycolysis by activating PFK2 and glucose utilization to maintain metabolic homeostasis. (Thick lines represent activated state and dotted lines represent inactivated state.) F-6-P, fructose 6-phosphate; F-1,6-BP, fructose 1,6-bisphosphate; G6P, glucose 6-phosphate