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.

Identification of ARUK2002821 as an isoform-selective PI5P4Kα inhibitor

“…17 Various PI5P4K inhibitors have been reported to have a therapeutic effect in oncology settings. 18,19 Covalent pan-PI5P4K inhibitor THZ-P1-2 (1) was shown to have antiproliferative activity in acute myeloid and lymphoblastic leukaemias (AML/ALL) [19][20][21][22] and the small molecule A131 (2), which was shown to target mitotic pathways and PI5P4Ks, was effective in cancer cell-specific lethality 18 (Fig. 1).…”

The rational design of ARUK2007145, a dual inhibitor of the α and γ isoforms of the lipid kinase phosphatidylinositol 5-phosphate 4-kinase (PI5P4K)

“…Both PI5P4Kα and PI5P4Kβ are involved in p53-deficient breast cancer and soft tissue sarcomas 22,23 and high expression of both PI5P4Kα and PI5P4Kγ associate with unfavourable clinical outcome in AML. 24 Several recent reports detail inhibitors for PI5P4Ks, not only pan-specific [25][26][27][28][29] but also isoform specific. [30][31][32][33][34] Emerging tools are also being developed for dual-specific inhibitors for PI5P4Kα and PI5P4Kβ 22,35 and methods have also been reported for removing protein completely in cells using PROTAC systems, such as JWZ-1-80 for PI5P4Kγ, 36 which will be useful to interrogate non-catalytic roles.…”