Isoquinoline-1,3-diones as Selective Inhibitors of Tyrosyl DNA Phosphodiesterase II (TDP2)

• Published in: Journal of medicinal chemistry Vol. 59; no. 6; pp. 2734 - 2746
• Main Authors: Kankanala, Jayakanth, Marchand, Christophe, Abdelmalak, Monica, Aihara, Hideki, Pommier, Yves, Wang, Zhengqiang
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 24-03-2016
• Subjects: Animals; Antineoplastic Agents - pharmacology; DNA Damage; DNA-Binding Proteins; Drug Design; High-Throughput Screening Assays; Isoquinolines - chemical synthesis; Isoquinolines - pharmacology; Mice; Models, Molecular; Phosphoric Diester Hydrolases; Recombinant Proteins; Structure-Activity Relationship; Substrate Specificity; Topoisomerase II Inhibitors - pharmacology; Tumor Necrosis Factor Receptor-Associated Peptides and Proteins - antagonists & inhibitors
• ISSN: 0022-2623; 1520-4804
• DOI: 10.1021/acs.jmedchem.5b01973

Tyrosyl DNA phosphodiesterase II (TDP2) is a recently discovered enzyme that specifically repairs DNA damages induced by topoisomerase II (Top2) poisons and causes resistance to these drugs. Inhibiting TDP2 is expected to enhance the efficacy of clinically important Top2-targeting anticancer drugs. However, TDP2 as a therapeutic target remains poorly understood. We report herein the discovery of isoquinoline-1,3-dione as a viable chemotype for selectively inhibiting TDP2. The initial hit compound 43 was identified by screening our in-house collection of synthetic compounds. Further structure–activity relationship (SAR) studies identified numerous analogues inhibiting TDP2 in low micromolar range without appreciable inhibition against the homologous TDP1 at the highest testing concentration (111 μM). The best compound 64 inhibited recombinant TDP2 with an IC50 of 1.9 μM. The discovery of this chemotype may provide a platform toward understanding TDP2 as a drug target.