A novel triazolonaphthalimide induces apoptosis and inhibits tumor growth by targeting DNA and DNA-associated processes

// Liyan Ji 1, 2, * , Simin Yang 1, * , Shasha Li 1 , Shan Liu 1 , Shunan Tang 1 , Zhongqiu Liu 2 , Xiangbao Meng 1 , Siwang Yu 1 1 Department of Chemical Biology, Peking University School of Pharmaceutical Sciences, Beijing 100191, China 2 International Institute for Translational Chinese Medicine, Guangzhou Traditional Chinese Medicine University, Guangzhou 510006, China * These authors contributed equally to this work Correspondence to: Siwang Yu, email: swang_yu@bjmu.edu.cn Xiangbao Meng, email: xbmeng@bjmu.edu.cn Keywords: triazolonaphthalimide, DNA binding, topoisomerase 2, DNA replication, cell cycle arrest Received: June 29, 2016      Accepted: March 27, 2017      Published: April 08, 2017 ABSTRACT DNA and DNA-associated processes have been classes of the most important targets of chemotherapeutic drugs. As classic DNA intercalators and topoisomerase inhibitors, naphthalimides have been extensively investigated as potential anti-cancer drugs. We recently synthesized a novel series of triazolonaphthalimides with excellent anti-cancer activities. In the present study, one of the most potent triazolonaphthalimides, LSS-11, was investigated. LSS-11 bound to DNA in vitro and in cell mainly by minor groove binding and significantly increased the stability of DNA, which could be fundamental for the biological activities of LSS-11. In addition to inhibiting DNA topoisomerase II-catalyzed decatenation of knotted circulated DNA, LSS-11 dramatically inhibited DNA replication mediated by polymerase chain reaction and isothermal helicase-dependent amplification, as well as the expression of luciferase driven by a minimal TA promoter in cell . Furthermore, LSS-11 exhibited strong cytotoxicity in selected human colon cancer cell lines by inducing cell cycle arrest and apoptosis, which was accompanied by DNA damage response. Finally, LSS-11 potently inhibited the growth of S180 murine sarcoma and SW480 human colorectal cancer xenografts in vivo without significant major toxicities. These results suggest that LSS-11 deserves further research and development as a novel anti-cancer agent, and provided new understandings of mechanisms by which LSS-11 inhibited multiple DNA-associated processes and tumor growth.