Abstract 7058: NSD2 overexpression drives multiple myeloma dependence on adenylate kinase 2 by diverting one-carbon metabolism to the epigenome

Abstract

Abstract Chromosomal translocation (4;14), an adverse prognostic factor in multiple myeloma (MM), drives overexpression of the oncogenic histone methyltransferase NSD2. Genome-wide CRISPR screens in isogenic MM cells with high and low NSD2 expression identified adenylate kinase 2 (AK2), an enzyme critical for transport of ATP from the mitochondria, as an NSD2-driven vulnerability. AK2 suppression in t(4;14) MM cells decreased NADP(H) critical for conversion of ribonucleotides to deoxyribonucleosides by the enzyme ribonucleotide reductase (RNR). Consequently, metabolomic studies revealed depletion of deoxynucleotide triphosphates (dNTPs) in AK2-deficient t(4;14) MM cells, which resulted in replication stress, DNA damage and apoptosis. Exogenous supplementation with deoxynucleosides rescued AK2 depleted MM cells confirming the role of AK2 in dNTP homeostasis. In addition, NSD2 overexpression drives a large genome-wide increase in chromatin methylation, which depletes the methyl donor S-adenosylmethionine (SAM). Accordingly, we found that high NSD2 expression in MM cells disrupts creatine biosynthesis, a process dependent on SAM. The creatine/phosphocreatine system represents an alternative means of transporting high energy phosphate from the mitochondria. Hence, creatine supplementation restored NADP(H) levels and rescued AK2-deficient t(4;14) MM cells indicating that the hypersensitivity of these cells to AK2 depletion is driven by creatine deficiency due to NSD2 overexpression. Furthermore, AK2 inhibition impaired ATP-dependent protein folding increasing sensitivity of t(4;14) MM cells to proteasome inhibition. These findings delineate a novel mechanism in which aberrant transfer of carbon to the epigenome creates a metabolic vulnerability, with direct therapeutic implications for t(4;14) MM. Citation Format: Amin Sobh, Elena Encinas, Alisha Patel, Greeshma Surapaneni, Charlotte Kaestner, Janai Poullard, Monica Clerio, Karthik Vasan, Tzipporah Freeman, Dongwen Lv, Daphne Dupere-Richer, Alberto Riva, Benjamin Barwick, Daohong Zhou, Lawrence Boise, Constantine Mitsiades, Baek Kim, Richard Bennett, Navdeep Chandel, Jonathan Licht. NSD2 overexpression drives multiple myeloma dependence on adenylate kinase 2 by diverting one-carbon metabolism to the epigenome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7058.