BACKGROUND G-quadruplex oligonucleotides (GQs) exhibit specific anti-survival activity in human cancer cell lines; they can selectively inhibit the viability/proliferation. The most studied, AS1411, had been in clinical trials. This anti-proliferative ability of GQs could be translated into glioma, which currently has poor prognosis and low-efficiency therapeutic treatments for glioblastoma multiform (GBM). Set of GQs have been designed, synthesized, and tested: they have different amount of Q-quartets, they have dimers of different GQ modules: either covalent dimers or non-covalent ones; all of them could be coined as ‘twins’. MATERIAL AND METHODS Folding of synthetic DNA oligonucleotides into GQs and thermal stability have been studied by circular dichroism, melting with unfolding-folding regimes, oligomerization was followed by original SE-HPLC. Conventional human cell lines U87 and fibroblasts from human embryo (HEF) were provided from the collection of the Centre of Neurosurgery (Moscow, Russia). GBM primary cell cultures N1, G11, Sus/fP2, G22, G23, and G01 were developed in Burdenko National Medical Research Centre of Neurosurgery (NMRCN) from the surgery samples of patients (PCC_SSP). All samples had WT IDH1. This study was approved by the Ethics Committee of Burdenko NMRCN, Russian Academy of Medical Sciences (№_12/2020, 15.12.2020). All subjects gave written informed consent in accordance with the guidelines of Declaration of Helsinki. Cell viability was tested by conventional MTT-test. RESULTS Novel bi-modular GQ, bi-(AID-1-T), twin of three-quartet AID-1-T, was designed by covalent conjugation of two AID-1-Ts via three thymidine link, TTT; and linking did not interfere with its GQ structure. Comparison of bi-(AID-1-T) with mono-modular AID-1-T, mono-modular two-quartet HD1, bi-modular bi-HD1, and two-quartet AS1411, was made. Among five GQs, bi-(AID-1-T) had the highest anti-survival activity for U87, while not affecting the control, HEF. GQs, for the first time, were tested on several PCC_SSP. Sensitivity of PCC_SSP toward GQs varied, with apparent IC50 of less than 1 μM for bi-(AID-1-T) toward the most sensitive G11 (glioma, Grade III). CONCLUSION GQs as anti-proliferative crypto-aptamers with moderate activity due to restricted functioning of apparent GQ-binding proteins could be applied toward real glioma PCC_SSP. Variety of effects reflects glioma inter-tumor heterogeneity.Research was funded by Ministry of Education and Science of Russia, grant number № 075-15-2020-809 (13.1902.21.0030) and by Russian Foundation for Basic Research, grants number №18-29-01047

中文翻译：

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P13.19 双模块 G-四链体 DNA-密码适体降低患者胶质瘤原代细胞培养物的活力

背景 G-四链体寡核苷酸 (GQ) 在人类癌细胞系中表现出特异性的抗存活活性。它们可以选择性地抑制活力/增殖。研究最多的 AS1411 一直在临床试验中。GQs 的这种抗增殖能力可以转化为胶质瘤，其目前对多形性胶质母细胞瘤 (GBM) 的预后不良和低效治疗。已经设计、合成和测试了一组 GQ：它们具有不同数量的 Q-四重体，它们具有不同 GQ 模块的二聚体：共价二聚体或非共价二聚体；他们都可以被称为“双胞胎”。材料和方法合成DNA寡核苷酸折叠成GQs和热稳定性已经通过圆二色性研究，以展开折叠方案熔化，寡聚化之后是原始的SE-HPLC。常规人类细胞系 U87 和来自人类胚胎 (HEF) 的成纤维细胞由神经外科中心 (莫斯科，俄罗斯) 提供。GBM 原代细胞培养 N1、G11、Sus/fP2、G22、G23 和 G01 是在 Burdenko 国家神经外科医学研究中心 (NMRCN) 从患者的手术样本 (PCC_SSP) 中开发的。所有样品都有 WT IDH1。本研究得到俄罗斯医学科学院 Burdenko NMRCN 伦理委员会的批准（№_12/2020, 15.12.2020）。所有受试者均按照赫尔辛基宣言的指导方针签署了书面知情同意书。细胞活力通过常规 MTT 测试进行测试。结果 新型双模块 GQ，bi-(AID-1-T)，三四重 AID-1-T 的双胞胎，是由两个 AID-1-T 通过三个胸苷连接 TTT 共价共轭设计的；并且链接不会干扰其 GQ 结构。对双 (AID-1-T) 与单模 AID-1-T、单模双四重奏 HD1、双模双 HD1 和双四重奏 AS1411 进行了比较。在五个 GQ 中，bi-(AID-1-T) 对 U87 的抗存活活性最高，而对对照 HEF 没有影响。GQ 首次在多个 PCC_SSP 上进行了测试。PCC_SSP 对 GQ 的敏感性各不相同，bi-(AID-1-T) 对最敏感的 G11（胶质瘤，III 级）的表观 IC50 小于 1 μM。结论 GQs 作为具有中等活性的抗增殖隐适体，由于明显的 GQ 结合蛋白功能受限，可应用于真正的胶质瘤 PCC_SSP。各种影响反映了胶质瘤间肿瘤异质性。研究由俄罗斯教育和科学部资助，资助号 № 075-15-2020-809 (13.