Both topoisomerase II (Topo II) and histone deacetylase (HDAC) are important therapeutic targets for cancer. In this study, two series of novel compounds containing pyrimido[5,4-b]indole and pyrazolo[3,4-d]pyrimidine motifs were designed and synthesized as dual Topo II/HDAC inhibitors. MTT assay indicated that all the compounds displayed potential antiproliferative activity against three cancer cell lines (MGC-803, MCF-7 and U937) and low cytotoxicity on normal cell line (3T3). In the enzyme activity inhibition experiments, compounds 7d and 8d exhibited excellent dual inhibitory activities against Topo II and HDAC. Cleavage reaction assay showed that 7d was a Topo II poison, which was consistent with the docking results. Further experimental results revealed that compounds 7d and 8d could promote apoptosis and significantly inhibit the migration in MCF-7 cells. Molecular docking showed that compounds 7d and 8d bind Topo II and HDAC at the active sites. Molecular dynamics simulation showed that 7d can stably bind to Topo II and HDAC.

拓扑异构酶 II (Topo II) 和组蛋白脱乙酰酶 (HDAC) 都是重要的癌症治疗靶点。在这项研究中，设计并合成了两个系列的含有嘧啶并[5,4- b ]吲哚和吡唑并[3,4- d ]嘧啶基序的新型化合物作为双重 Topo II/HDAC 抑制剂。MTT 测定表明，所有化合物均对三种癌细胞系（MGC-803、MCF-7 和 U937）显示出潜在的抗增殖活性，对正常细胞系（3T3）具有低细胞毒性。在酶活性抑制实验中，化合物7d和8d对Topo II和HDAC表现出优异的双重抑制活性。裂解反应测定显示7d是 Topo II 毒物，与对接结果一致。进一步的实验结果表明，化合物7d和8d在MCF-7细胞中可促进细胞凋亡并显着抑制迁移。分子对接显示化合物7d和8d在活性位点结合 Topo II 和 HDAC。分子动力学模拟表明7d可以稳定地结合Topo II和HDAC。