Dual targeting of microtubule and topoisomerase II by α-carboline derivative YCH337 for tumor proliferation and growth inhibition

// Jun-Mei Yi 1, * , Xiao-Fei Zhang 2, * , Xia-Juan Huan 1 , Shan-Shan Song 1 , Wei Wang 1 , Qian-Ting Tian 1 , Yi-Ming Sun 1 , Yi Chen 1 , Jian Ding 1 , Ying-Qing Wang 1 , Chun-Hao Yang 2 , Ze-Hong Miao 1 1 Division of Antitumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica , Chinese Academy of Sciences, Shanghai 201203, People’s Republic of China 2 Division of Medicinal Chemistry, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica , Chinese Academy of Sciences, Shanghai 201203, People’s Republic of China * These authors have contributed equally to this work Correspondence to: Ze-Hong Miao, e-mail: zhmiao@simm.ac.cn Chun-Hao Yang, e-mail: chyang@simm.ac.cn Ying-Qing Wang, e-mail: yqwang@simm.ac.cn Keywords: YCH337, α-carboline derivative, microtubule, topoisomerase II, antitumor activity Received: January 01, 2015      Accepted: January 31, 2015      Published: March 27, 2015 ABSTRACT Both microtubule and topoisomerase II (Top2) are important anticancer targets and their respective inhibitors are widely used in combination for cancer therapy. However, some combinations could be mutually antagonistic and drug resistance further limits their therapeutic efficacy. Here we report YCH337, a novel α-carboline derivative that targets both microtubule and Top2, eliciting tumor proliferation and growth inhibition and overcoming drug resistance. YCH337 inhibited microtubule polymerization by binding to the colchicine site and subsequently led to mitotic arrest. It also suppressed Top2 and caused DNA double-strand breaks. It disrupted microtubule more potently than Top2. YCH337 induced reversible mitotic arrest at low concentrations but persistent DNA damage. YCH337 caused intrinsic and extrinsic apoptosis and decreased MCL-1, cIAP1 and XIAP proteins. In this aspect, YCH337 behaved differently from the combination of vincristine and etoposide. YCH337 inhibited proliferation of tumor cells with an averaged IC 50 of 0.3 μM. It significantly suppressed the growth of HT-29 xenografts in nude mice too. Importantly, YCH337 nearly equally killed different-mechanism-mediated resistant tumor cells and corresponding parent cells. Together with the novelty of its chemical structure, YCH337 could serve as a promising lead for drug development and a prototype for a dual microtubule/Top2 targeting strategy for cancer therapy.