Telomeric DNA are TTAGGG tandem repeats, which are susceptible for oxidative DNA damage and hotspot regions for formation of DNA secondary structures such as t-loop, D-loop, G-quadruplexes (G4), and R-loop. In the past two decades, unique DNA or RNA secondary structures at telomeres or some specific regions of genome have become promising therapeutic targets. G-quadruplex and R-loops at telomeres or transcribed regions of genome have been considered as the potential targets for cancer therapy. Here we discuss the potentials to target the secondary structures (G4s and R-loops) in genome as therapy approaches.

中文翻译：

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端粒的DNA二级结构和基因组不稳定

端粒DNA是TTAGGG串联重复序列，易受氧化DNA损伤和热点区域的影响，形成DNA二级结构，例如t环，D环，G四联体（G4）和R环。在过去的二十年中，端粒或基因组某些特定区域的独特DNA或RNA二级结构已成为有希望的治疗靶标。基因组的端粒或转录区的G-四链体和R环被认为是癌症治疗的潜在靶标。在这里，我们讨论了靶向基因组中二级结构（G4和R环）作为治疗方法的潜力。