Folkerts Melissa L, Hom Cameron, Nguyen Angie, Shen Kaiyuan V, Rangel Valeria, Ortega Pedro, Buisson Rémi, Masri Selma, Adachi Noritaka, Meek Katheryn, Pannunzio Nicholas R
Divison of Hematology/Oncology, Department of Medicine, University of California, Irvine, Irvine, CA, USA.
Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA.
Res Sq. 2025 Jun 19:rs.3.rs-6317145. doi: 10.21203/rs.3.rs-6317145/v1.
Topoisomerase 2 (Top2) poisons are widely used in cancer therapy but are associated with toxicity and secondary malignancies. Removing Top2 adducts requires endonuclease activity and repair by non-homologous end joining (NHEJ). We show that the NHEJ enzyme Artemis is a promising target for co-treatment with Top2 poisons. Inhibition of the Artemis activator, DNA-PKcs, with peposertib (M3814) sensitizes B cells to Top2 poisons while ATM or ATR inhibition does not. Interestingly, while M3814 treatment blocks Artemis endonuclease activity, Artemis phosphorylation is still detectible and is only affected upon inhibiting ATM, suggestive of an additional role for Artemis in DNA damage response signaling. Additionally, Artemis loss results in a significant accumulation of Top2 DNA adducts following treatment, indicating Artemis may act outside its canonical role in NHEJ to reduce adduct burden. Clinical data demonstrates that high Artemis expression correlates with poor survival in several cancers, and we demonstrate that Artemis function is critical for survival following combination drug treatment. These insights can be leveraged to unlock new avenues for the treatment of aggressive cancers by enhancing the cytotoxicity of agents through blockade of DNA break repair.
拓扑异构酶2（Top2）抑制剂在癌症治疗中被广泛应用，但与毒性和继发性恶性肿瘤相关。去除Top2加合物需要核酸内切酶活性并通过非同源末端连接（NHEJ）进行修复。我们发现NHEJ酶Artemis是与Top2抑制剂联合治疗的一个有前景的靶点。用peposertib（M3814）抑制Artemis激活剂DNA-PKcs会使B细胞对Top2抑制剂敏感，而抑制ATM或ATR则不会。有趣的是，虽然M3814处理会阻断Artemis核酸内切酶活性，但仍可检测到Artemis磷酸化，且只有在抑制ATM时才会受到影响，这表明Artemis在DNA损伤反应信号传导中还有其他作用。此外，Artemis缺失会导致处理后Top2 DNA加合物显著积累，表明Artemis可能在其NHEJ的经典作用之外发挥作用以减轻加合物负担。临床数据表明，Artemis高表达与几种癌症的不良生存相关，并且我们证明Artemis功能对于联合药物治疗后的生存至关重要。这些见解可用于通过阻断DNA断裂修复增强药物的细胞毒性来开辟侵袭性癌症治疗的新途径。
