Introduction: Topoisomerase II alpha (Topo IIα) has become one of the extensively exploited targets in chemotherapy due to its role in regulating the topological constraints of DNA during replication and transcription. Small molecules targeting Topo IIα’s activity such as etoposide (VP-16) and doxorubicin are extensively used in the treatment of many different types of cancer.

Objective: Here, the effects of three small molecules, named as azacyanines, on Topo IIα have been assessed.

Methods: In-vitro Topoisomerase IIα drug screening kit and agarose gel imaging were used for the assessment of Topo IIα’s activity.

Results: Our results revealed that all the azacyanines investigated decreased the catalytic activity of Topo IIα dramatically. More importantly, the decrease in the catalytic activity of Topo IIα in the presence of azacyanines was higher than the presence of VP-16, which is a commercially available chemotherapy drug. Upon further investigation, it has been observed that Azamethyl’s catalytic inhibition of Topo IIα was concentration dependent and the catalytic activity of Topo IIα was almost completely abolished in the presence of 100.0 μM of Azamethyl.

Conclusion: These findings reveal the potential of azacyanines as effective Topo IIα inhibitors and chemotherapeutic agents.

简介：拓扑异构酶IIα（TopoIIα）由于其在复制和转录过程中调节DNA拓扑约束的作用而已成为化学疗法中广泛使用的靶标之一。靶向TopoIIα活性的小分子，例如依托泊苷（VP-16）和阿霉素，被广泛用于治疗许多不同类型的癌症。

目的：在这里，已经评估了三个名为氮杂花青素的小分子对TopoIIα的作用。

方法：采用体外拓扑异构酶IIα药物筛选试剂盒和琼脂糖凝胶成像法评估拓扑oIIα的活性。

结果：我们的结果表明，所有研究的氮杂花青素均显着降低了TopoIIα的催化活性。更重要的是，在存在花青素的情况下，TopoIIα的催化活性的降低高于在市场上可买到的化疗药物VP-16的存在。进一步研究发现，在100.0μM的氮杂甲基存在下，氮杂甲基对TopoIIα的催化抑制作用是浓度依赖性的，并且几乎完全废除了TopoIIα的催化活性。

结论：这些发现揭示了花青素作为有效的TopoIIα抑制剂和化学治疗剂的潜力。