Brylev Vladimir A, Ryabukhina Ekaterina V, Nazarova Ekaterina V, Samoylenkova Nadezhda S, Gulyak Evgeny L, Sapozhnikova Ksenia A, Dzarieva Fatima M, Ustinov Alexey V, Pronin Igor N, Usachev Dmitry Y, Kopylov Alexey M, Golovin Andrey V, Pavlova Galina V, Ryazantsev Dmitry Yu, Korshun Vladimir A
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia.
Burdenko National Medical Research Center of Neurosurgery, 4th Tverskaya-Yamskaya 16, 125047 Moscow, Russia.
Pharmaceutics. 2024 Nov 11;16(11):1434. doi: 10.3390/pharmaceutics16111434.
Targeted delivery of chemotherapeutic agents is a well-established approach to cancer therapy. Antibody-drug conjugates (ADCs) typically carry toxic payloads attached to a tumor-associated antigen-targeting IgG antibody via an enzyme-cleavable linker that releases the drug inside the cell. Aptamers are a promising alternative to antibodies in terms of antigen targeting; however, their polynucleotide nature and smaller size result in a completely different PK/PD profile compared to an IgG. This may prove advantageous: owing to their lower molecular weight, aptamer-drug conjugates may achieve better penetration of solid tumors compared to ADCs. On the way to therapeutic aptamer-drug conjugates, we aimed to develop a versatile and modular approach for the assembly of aptamer-enzymatically cleavable payload conjugates of various drug-aptamer ratios. We chose the epidermal growth factor receptor (EGFR), a transmembrane protein often overexpressed in brain tumors, as the target antigen. We used the 46 mer EGFR-targeting DNA sequence GR-20, monomethylauristatin E (MMAE) on the cathepsin-cleavable ValCit--aminobenzylcarbamate linker as the payload, and pentaerythritol-based tetraazide as the branching point for the straightforward synthesis of aptamer-drug conjugates by means of a stepwise Cu-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction. Branched aptamer conjugates of 1:3, 2:2, and 3:1 stoichiometry were synthesized and showed higher cytotoxic activity compared to a 1:1 conjugate, particularly on several glioma cell lines. This approach is convenient and potentially applicable to any aptamer sequence, as well as other payloads and cleavable linkers, thus paving the way for future development of aptamer-drug therapeutics by easily providing a range of branched conjugates for in vitro and in vivo testing.
化疗药物的靶向递送是一种成熟的癌症治疗方法。抗体药物偶联物（ADC）通常携带通过酶可裂解连接子连接到肿瘤相关抗原靶向IgG抗体上的有毒载荷，该连接子在细胞内释放药物。就抗原靶向而言，适体是抗体的一种有前景的替代物；然而，它们的多核苷酸性质和较小的尺寸导致其与IgG相比具有完全不同的药代动力学/药效学特征。这可能证明是有利的：由于其较低的分子量，适体药物偶联物与ADC相比可能在实体瘤中实现更好的渗透。在开发治疗性适体药物偶联物的过程中，我们旨在开发一种通用且模块化的方法，用于组装各种药物 - 适体比例的适体 - 酶可裂解载荷偶联物。我们选择表皮生长因子受体（EGFR）作为靶抗原，EGFR是一种在脑肿瘤中经常过度表达的跨膜蛋白。我们使用46聚体的靶向EGFR的DNA序列GR - 20、组织蛋白酶可裂解的缬氨酸 - 瓜氨酸 - 氨基苄基氨基甲酸酯连接子上的单甲基澳瑞他汀E（MMAE）作为载荷，以及基于季戊四醇的四叠氮化物作为分支点，通过逐步铜催化的叠氮化物 - 炔烃环加成（CuAAC）点击反应直接合成适体药物偶联物。合成了化学计量比为1:3、2:2和3:1的分支适体偶联物，并且与1:1偶联物相比显示出更高的细胞毒性活性，特别是在几种胶质瘤细胞系上。这种方法方便且可能适用于任何适体序列，以及其他载荷和可裂解连接子，从而通过轻松提供一系列用于体外和体内测试的分支偶联物，为适体药物治疗的未来发展铺平了道路。
