Downregulation of Polo-like kinase 4 induces cell apoptosis and G2/M arrest in acute myeloid leukemia

Endoplasmic Reticulum Stress in Acute Myeloid Leukemia: Pathogenesis, Prognostic Implications, and Therapeutic Strategies

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy that poses a significant therapeutic challenge due to its high recurrence rate and demanding treatment regimens. Increasing evidence suggests that endoplasmic reticulum (ER) stress and downstream activation of the unfolded protein response (UPR) pathway play a key role in the pathogenesis of AML. ER stress is triggered by the accumulation of misfolded or unfolded proteins within the ER. This causes activation of the UPR to restore cellular homeostasis. However, the UPR can shift from promoting survival to inducing apoptosis under prolonged or excessive stress conditions. AML cells can manipulate the UPR pathway to evade apoptosis, promoting tumor progression and resistance against various therapeutic strategies. This review provides the current knowledge on ER stress in AML and its prognostic and therapeutic implications.

Computer-Aided Identification and Design of Ligands for Multi-Targeting Inhibition of a Molecular Acute Myeloid Leukemia Network

BACKGROUND/OBJECTIVES

Acute myeloid leukemia (AML) is characterized by therapeutic failure and long-term risk for disease relapses. As several therapeutic targets participate in networks, they can rewire to eventually evade single-target drugs. Hence, multi-targeting approaches are considered on the expectation that interference with many different components could synergistically hinder activation of alternative pathways and demolish the network one-off, leading to complete disease remission.

METHODS

Herein, we established a network-based, computer-aided approach for the rational design of drug combinations and de novo agents that interact with many AML network components simultaneously.

RESULTS

A reconstructed AML network guided the selection of suitable protein hubs and corresponding multi-targeting strategies. For proteins responsive to existing drugs, a greedy algorithm identified the minimum amount of compounds targeting the maximum number of hubs. We predicted permissible combinations of amiodarone, artenimol, fostamatinib, ponatinib, procaine, and vismodegib that interfere with 3-8 hubs, and we elucidated the pharmacological mode of action of procaine on DNMT3A. For proteins that do not respond to any approved drugs, namely cyclins A1, D2, and E1, we used structure-based de novo drug design to generate a novel triple-targeting compound of the chemical formula C15H15NO5, with favorable pharmacological and drug-like properties.

CONCLUSIONS

Overall, by integrating network and structural pharmacology with molecular modeling, we determined two complementary strategies with the potential to annihilate the AML network, one in the form of repurposable drug combinations and the other as a de novo synthesized triple-targeting agent. These target-drug interactions could be prioritized for preclinical and clinical testing toward precision medicine for AML.

Synthesis of 2-phenylnaphthalenoid amide derivatives and their topoisomerase IIα inhibitory and antiproliferative activities

Topoisomerases are highly associated with cell proliferation, becoming an important target for the development of antitumor drugs. 2-Phenylnaphthalenoids (2PNs) have been identified as human DNA topoisomerase IIα (TopoIIα) inhibitors. In this study, based on the 2PN scaffold, 20 amide derivatives (J1-J10, K1-K10) were synthesized. Among them, K10 showed high TopoIIα inhibitory activity and stronger antiproliferation activity against HepG-2 and MDA-MB-231 cells (IC50 0.33 and 0.63 μM, respectively) than the positive control VP-16 (IC50 9.19 and 10.86 μM) and the lead F2 (IC50 0.64 and 1.51 μM). Meanwhile, K10 could also inhibit migration and promote apoptosis of HepG-2 and MDA-MB-231 cells. Therefore, K10 can be developed into a potent TopoIIα inhibitor as an antitumor agent. The structure-activity relationship was also discussed.

Preclinical characterization and clinical trial of CFI-400945, a polo-like kinase 4 inhibitor, in patients with relapsed/refractory acute myeloid leukemia and higher-risk myelodysplastic neoplasms

CFI-400945 is a selective oral polo-like kinase 4 (PLK4) inhibitor that regulates centriole duplication. PLK4 is aberrantly expressed in patients with acute myeloid leukemia (AML). Preclinical studies indicate that CFI-400945 has potent in vivo efficacy in hematological malignancies and xenograft models, with activity in cells harboring TP53 mutations. In this phase 1 study in very high-risk patients with relapsed/refractory AML and myelodysplastic syndrome (MDS) (NCT03187288), 13 patients were treated with CFI-400945 continuously in dose escalation from 64 mg/day to 128 mg/day. Three of the 9 efficacy evaluable AML patients achieved complete remission (CR). Two of 4 AML patients (50%) with TP53 mutations and complex monosomal karyotype achieved a CR with 1 patient proceeding to allogenic stem cell transplant. A third patient with TP53 mutated AML had a significant reduction in marrow blasts by > 50% with an improvement in neutrophil and platelet counts. Responses were observed after 1 cycle of therapy. Dose-limiting toxicity was enteritis/colitis. A monotherapy and combination therapy study with a newer crystal form of CFI-400945 in patients with AML, MDS and chronic myelomonocytic leukemia (CMML) is ongoing (NCT04730258).