The PIP4K2 inhibitor THZ-P1-2 exhibits antileukemia activity by disruption of mitochondrial homeostasis and autophagy

Abstract: Treatment of acute leukemia is challenging due to genetic heterogeneity between and even within patients. Leukemic stem cells (LSCs) are relatively drug-resistant and frequently lead to relapse. Their plasticity and capacity to adapt to extracellular stress, in which mitochondrial metabolism and autophagy play important roles, further complicates treatment. Genetic models of phosphatidylinositol-5-phosphate 4-kinase type 2 proteins (PIP4K2s) inhibition demonstrated the relevance of these enzymes in mitochondrial homeostasis and autophagic flux. Here, we uncover the cellular and molecular effects of THZ-P1-2, a pan-inhibitor of PIP4K2s, in acute leukemia cells. THZ-P1-2 reduced cell viability and induced DNA damage, apoptosis, loss of mitochondrial membrane potential, and accumulation of acidic vesicular organelles. Protein expression analysis revealed that THZ-P1-2 impaired autophagy flux. In addition, THZ-P1-2 induced cell differentiation and showed synergistic effects with venetoclax in resistant leukemic models. In primary leukemia cells, LC-MS/MS-based proteome analysis revealed that sensitivity to THZ-P1-2 was associated with mitochondrial metabolism, cell cycle, cell-of-origin, and the TP53 pathway. Minimal effects of THZ-P1-2 observed in healthy CD34+ cells suggested a favorable therapeutic window. Our study provides insight into pharmacological inhibition of PIP4Ks targeting mitochondrial homeostasis and autophagy shedding light on a new class of drugs for acute leukemias.