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1273 DNA Polymerase Theta Protects Leukemia Cells from Metabolic-Induced DNA Damage

Program: Oral and Poster Abstracts
Session: 602. Myeloid Oncogenesis: Basic: Poster I
Hematology Disease Topics & Pathways:
Lymphoid Leukemias, Acute Myeloid Malignancies, AML, Research, MPN, Translational Research, CML, Chronic Myeloid Malignancies, Diseases, Myeloid Malignancies
Saturday, December 10, 2022, 5:30 PM-7:30 PM

Umeshkumar M Vekariya, PhD1*, Katherine Sullivan-Reed, PhD1*, Monika Toma, PhD1*, Margaret Nieborowska-Skorska, MD, PhD1*, Bac Viet Le, PhD1*, Marie-Christine Caron, PhD2*, Anna-Mariya Kukuyan, PhD1*, Paulina Podszywalow-Bartnicka, PhD3*, Kumaraswamy Chitrala, PhD1*, Jessica Atkins, BSc4*, Malgorzata Drzewiecka, PhD1,5*, Wanjuan Feng, PhD6*, Joe Chan, PhD1*, Konstantin Golovine, PhD1*, Jaroslav Jelinek, MD, PhD7*, Tomasz Sliwinski, PhD5*, Jayashri Ghosh, PhD1*, Ksenia Maslawska-Wasowska, PhD8*, Reza Nejati, MD9*, Mariusz A Wasik, MD9*, Stephen M. Sykes, PhD10, Katarzyna Piwocka, PhD3*, Emir Hadzijusufovic, DVM11,12,13*, Peter Valent, MD12, Richard Pomerantz, PhD14*, George Morton, PhD15*, Wayne Childers, PhD15*, Huaqing Zhao, MS, PhD16*, Elisabeth Paietta, PhD17, Ross L. Levine, MD18, Martin S. Tallman, MD19, Hugo F Fernandez, MD20*, Mark R. Litzow, MD21, Gaorav P Gupta, PhD6*, Jean-Yves Masson, PhD2* and Tomasz Skorski, MD, PhD4

1Fels Cancer institute For Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA
2CHU de Québec Research Centre (Oncology Division), Laval University Cancer Research Center, Québec City, QC, Canada
3Nencki Institute of Experimental Biology, Warsaw, Poland
4Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA
5Laboratory of Medical Genetics, University of Lodz, Lodz, Poland
6Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
7Coriell Institute for Medical Research, Coriell University, Camden, NJ
8Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL
9Department of Pathology, Fox Chase Cancer Center, Philadelphia, PA
10Department of Pediatrics, Washington University, Saint Louis, MO
11Department for Companion Animals and Horses, University Clinic for Small Animals, Internal Medicine Small Animals, University of Veterinary Medicine Vienna, Vienna, Austria
12Ludwig Boltzmann Institute for Hematology and Oncology, Medical University of Vienna, Vienna, Austria
13Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria
14Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA
15Moulder Center for Drug Discovery, School of Pharmacy, Temple University, Philadelphia, PA
16Lewis Katz School of Medicine at Temple University, Philadelphia, PA
17Cancer Center, Montefiore Medical Center, Bronx, NY
18Department of Medicine and Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY
19Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY
20Moffitt Malignant Hematology & Cellular Therapy at Memorial Healthcare System, Pembroke Pines
21Division of Hematology, Mayo Clinic, Rochester, MN

Leukemia cells accumulate DNA damage but altered DNA repair mechanisms protect them from apoptosis. We showed here that formaldehyde generated by serine/one-carbon cycle metabolism contributed to accumulation of toxic DNA-protein crosslinks (DPCs) in leukemia cells, especially in driver clones harboring oncogenic tyrosine kinases [OTKs: FLT3(ITD), JAK2(V617F), BCR/ABL1]. To counteract this effect, OTKs enhanced the expression of DNA polymerase theta (POLθ) by ERK1/2 serine/threonine kinase-dependent inhibition of c-CBL E3 ligase-mediated ubiquitination of POLθ and its proteasomal degradation. Overexpression of POLθ in OTK-positive cells resulted in efficient repair of DPC-containing DNA double-strand breaks (DSBs) by POLθ-mediated end-joining (TMEJ). Transforming activity of OTKs and other leukemia-inducing oncogenes, especially of those causing inhibition of BRCA1/2 -mediated homologous recombination (HR) with and without concomitant inhibition of DNA-PK -dependent non-homologous end-joining (D-NHEJ), was abrogated in Polq-/- murine bone marrow cells. Genetic and pharmacological targeting of POLθ polymerase and helicase activities revealed that both activities are promising targets in leukemia cells. Moreover, OTK inhibitor or DPC-inducing drug etoposide enhanced anti-leukemia effect of POLθ inhibitor (POLθi) in vitro and in vivo. POLθ can interplay with PARP1 (alternative NHEJ) and RAD52 (alternative HR) to repair DSBs. Remarkably, transformation potential of the oncogenes inducing HR and NHEJ deficiencies (BCR-ABL1 and AML1-ETO) was severely limited in Polq-/-;Parp1-/- and Polq-/-;Rad52-/- cells when compared to single knockouts. Moreover, simultaneous targeting of POLθ and PARP1 or RAD52 exerted dual synthetic lethality against HR deficient leukemias. In conclusion, we demonstrated that POLθ plays an essential role in protecting leukemia cells from metabolically induced toxic DNA lesions and it can be targeted to achieve therapeutic effect.

Figure 1. POLθ is required to resolve DPCs caused by formaldehyde generated by serine/1C cycle metabolism in OTKs-positive hematological malignancies. A scheme illustrating functional pathway where OTKs - reprogrammed serine/1C cycle – produced formaldehyde induces DPCs which are likely repaired by POLθ-mediated end-joining (TMEJ). OTKs also enhance the expression of POLθ by stimulating ERK1/2 serine/threonine kinases, which inhibit c-CBL E3 ligase-dependent ubiquitination of POLθ and its proteasomal degradation.

Disclosures: Valent: Blueprint Medicines: Honoraria; Celgene: Honoraria, Research Funding; Novartis: Consultancy, Honoraria; Incyte: Honoraria. Pomerantz: Recombination Therapeutics LLC: Current Employment, Research Funding. Levine: Syndax, Incyte, Janssen, Astellas, Morphosys and Novartis: Consultancy; Astra Zeneca and Kura: Other: honoraria for invited lectures ; Imago, Mission Bio, Bakx, Zentalis, Ajax, Auron, Prelude, C4 Therapeutics and Isoplexis: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Gilead and Novartis: Other: Grant reviews; Ajax, Abbvie, Constellation, Zenalis, Celgene, Roche, and Prelude: Other: research support; Qiagen: Other: supervisory board member. Tallman: Novartis: Membership on an entity's Board of Directors or advisory committees; Biosight: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Oncolyze: Membership on an entity's Board of Directors or advisory committees; KAHR-Adv Bd: Membership on an entity's Board of Directors or advisory committees; Orsenix: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Rafael Pharmaceuticals: Research Funding; Glycomimetics: Research Funding; Biosight: Research Funding; Orsenix: Research Funding; Abbvie: Research Funding; Innate Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Kura: Membership on an entity's Board of Directors or advisory committees; UpToDate: Patents & Royalties: Royalties; Ipsen Biopharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Syros Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Fernandez: Incyte: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Litzow: Amgen: Research Funding; Astellas: Research Funding; Novartis: Research Funding; Syndax: Research Funding; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Actinium: Research Funding; Pluristem: Research Funding; Biosight: Consultancy, Other: Data Monitoring Board; Abbvie: Research Funding.

*signifies non-member of ASH