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Disruption of dNTP homeostasis by ribonucleotide reductase hyperactivation overcomes AML differentiation blockade
Journal article   Open access   Peer reviewed

Disruption of dNTP homeostasis by ribonucleotide reductase hyperactivation overcomes AML differentiation blockade

Hanying Wang, Xin He, Lei Zhang, Haojie Dong, Feiteng Huang, Jie Xian, Min Li, Wei Chen, Xiyuan Lu, Khyatiben Pathak, …
Blood, Vol.139(26), pp.3752-3770
06/30/2022
DOI: 10.1182/blood.2021015108
PMCID: PMC9247363
PMID: 35439288
url
https://doi.org/10.1182/blood.2021015108View
Published (Version of record) Open Access

Abstract

Differentiation blockade is a hallmark of acute myeloid leukemia (AML). A strategy to overcome such a blockade is a promising approach against the disease. The lack of understanding of the underlying mechanisms hampers development of such strategies. Dysregulated ribonucleotide reductase (RNR) is considered a druggable target in proliferative cancers susceptible to deoxynucleoside triphosphate (dNTP) depletion. Herein, we report an unanticipated discovery that hyperactivating RNR enables differentiation and decreases leukemia cell growth. We integrate pharmacogenomics and metabolomics analyses to identify that pharmacologically (eg, nelarabine) or genetically upregulating RNR subunit M2 (RRM2) creates a dNTP pool imbalance and overcomes differentiation arrest. Moreover, R-loop-mediated DNA replication stress signaling is responsible for RRM2 activation by nelarabine treatment. Further aggravating dNTP imbalance by depleting the dNTP hydrolase SAM domain and HD domain-containing protein 1 (SAMHD1) enhances ablation of leukemia stem cells by RRM2 hyperactivation. Mechanistically, excessive activation of extracellular signal-regulated kinase (ERIC) signaling downstream of the imbalance contributes to cellular outcomes of RNR hyperactivation. A CRISPR screen identifies a synthetic lethal interaction between loss of DUSP6, an ERK-negative regulator, and nelarabine treatment. These data demonstrate that dNTP homeostasis governs leukemia maintenance, and a combination of DUSP inhibition and nelarabine represents a therapeutic strategy.
Hematology Life Sciences & Biomedicine Science & Technology

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