Design and Synthesis of New Benzimidazole-Carbazole Conjugates for the Stabilization of Human Telomeric DNA, Telomerase Inhibition, and Their Selective Action on Cancer Cells
Design and Synthesis of New Benzimidazole-Carbazole Conjugates for the Stabilization of Human Telomeric DNA, Telomerase Inhibition, and Their Selective Action on Cancer Cells
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DOI：
10.1021/jm500427n
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发表时间：
2014-08-28
影响因子：
7.3
通讯作者：
Bhattacharya, Santanu
中科院分区：
文献类型：
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作者：
Maji, Basudeb;Kumar, Krishan;Bhattacharya, Santanu
增强G-四链体（G4）DNA结构稳定性的细胞可渗透小分子是目前最受关注的抑制端粒酶活性的配体之一。本文报道了四种新型苯并咪唑咔唑偶联物的设计和合成，并证明了它们对G4 DNA的高结合亲和力。Si核酸酶分析证实了配体介导的G-四链体DNA保护作用。来自端粒重复序列扩增方案（TRAP-LIG）测定的额外证据证明配体的有效端粒酶抑制活性。两个配体在TRAP-LIG测定中显示出亚微摩尔范围内的IC 50值，这是迄今为止报道的苯并咪唑衍生物中最好的。配体还表现出癌细胞选择性核内化，核浓缩，片段化，并最终在长期细胞活力测定中的抗增殖活性。Annexin V-FITC/PI染色分析证实配体诱导的细胞死亡遵循凋亡途径。从分子动力学模拟中获得了对配体结合模式的洞察。
Cell-permeable small molecules that enhance the stability of the G-quadruplex (G4) DNA structures are currently among the most intensively pursued ligands for inhibition of the telomerase activity. Herein we report the design and syntheses of four novel benzimidazole carbazole conjugates and demonstrate their high binding affinity to G4 DNA. Si nuclease assay confirmed the ligand mediated G-quadruplex DNA protection. Additional evidence from Telomeric Repeat Amplification Protocol (TRAP-LIG) assay demonstrated efficient telomerase inhibition activity by the ligands. Two of the ligands showed IC50 values in the sub-micromolar range in the TRAP-LIG assay, which are the best among the benzimidazole derivatives reported so far. The ligands also exhibited cancer cell selective nuclear internalization, nuclear condensation, fragmentation, and eventually antiproliferative activity in long-term cell viability assays. Annexin V-FITC/PI staining assays confirm that the cell death induced by the ligands follows an apoptotic pathway. An insight into the mode of ligand binding was obtained from the molecular dynamics simulations.