AMP-Activated Protein Kinase Contributes to Apoptosis Induced by the Bcl-2 Inhibitor Venetoclax in Acute Myeloid Leukemia

SIMPLE SUMMARY: The Bcl2 inhibitor venetoclax is a breakthrough therapy in acute myeloid leukemia (AML). We show that venetoclax induces caspase-dependent degradation of AMPK, a central regulator of cellular energy metabolism, with implications in the anti-Leukemic activity of venetoclax in AML. ABSTRACT: The treatment of acute myeloid leukemia (AML) remains a challenge especially among the elderly. The Bcl-2 inhibitor venetoclax recently showed significant survival benefits in AML patients when combined to low-dose cytarabine or azacitidine. Bcl-2 inhibition initiate mitochondrial apoptosis, but also respiration and cellular ATP production in AML. AMP-Activated Protein Kinase (AMPK) is a central energy sensor activated by increased AMP:ATP ratio to restore the cellular energy balance. Unexpectedly, we observed that venetoclax inhibited AMPK activity through caspase-dependent degradation of AMPK subunits in AML cells. On the other hand, genetic models of AMPK invalidation and re-expression suggested that AMPK participated to the early stages of apoptotic response through a negative regulation of multi-domain anti-apoptotic effectors such as Mcl-1 or Bcl-xL. Together our results suggested a new link between AMPK and Bcl-2-dependent mitochondrial apoptosis that participated to the anti-leukemic activity of venetoclax in AML.