Synthetic Polyglutamylation of Dual-Functional MTX Ligands for Enhanced Combined Cytotoxicity of Poly(I:C) Nanoplexes
Synthetic Polyglutamylation of Dual-Functional MTX Ligands for Enhanced Combined Cytotoxicity of Poly(I:C) Nanoplexes
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DOI：
10.1021/mp500017u
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发表时间：
2014-08-01
影响因子：
4.9
通讯作者：
Wagner, Ernst
中科院分区：
文献类型：
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作者：
Laechelt, Ulrich;Wittmann, Valentin;Wagner, Ernst
抗叶酸药物甲氨蝶呤(MTX)可以作为抗肿瘤药物传递的双功能配体，诱导叶酸受体介导的细胞摄取和细胞内的细胞毒作用。然而，MTX的生物活性通过结合而改变；细胞内转化为更有效的聚谷氨酰胺衍生物的过程受阻，可能会影响MTX的活性。因此，在肿瘤联合治疗方法中，为了实现细胞mdc dsRNA多肌苷多胞苷多胞苷多聚(LC)的共传递，合成了一系列分子精确的低聚(乙氨基)酰胺类化合物，包括聚乙二醇偶联型MTX配体。这些结合物在附加谷氨酸残基的数量上不同，以研究不同程度的合成的先验的多谷氨酰化的影响。研究了这些化合物的生物活性，包括二氢叶酸还原酶(DHFR)抑制、细胞毒性、核酸结合能力、细胞对聚(LC)复合体的摄取以及抗叶酸/聚(LC)的联合毒性。合成的多谷氨酰化对多聚(LC)高效传递的几个阶段以及MTX的联合细胞毒性具有至关重要的影响。随着聚谷氨酸链长的增加，对DHFR的抑制作用明显增强。在直接比较中，谷氨酰化度最高的文库成员的表现甚至优于游离MTX。在KB细胞中的研究表明，多聚谷氨酰化可以相应地增强细胞毒性。此外，谷氨酸化的MTX突变体的聚(LC)复合体在叶酸受体阳性细胞系中显示出更高的细胞摄取率。最后，在转染的KB细胞中观察到多谷氨酰化的MTX配体和络合的聚(LC)货物的协同联合细胞毒作用。目前基于MTX的配体的构效关系研究表明，合成聚谷氨酰化是优化抗叶酸结合物生物活性的一种很有前途的方法，也可以被认为是一种有用的工具，也可以用于其他药物传递系统。
The antifolate drug methotrexate (MTX) can serve as a dual-functional ligand in antitumoral drug delivery, inducing both a folate receptor mediated cellular uptake and an intracellular cytotoxic action. Bioactivity of MTX however changes by conjugation; the activity can be affected by the hampered intracellular conversion to more potent poly-yglutamyl derivatives. Therefore, in a cancer combination therapy approach for the codelivery of cytotmdc dsRNA polyinosinic polycytidylic acid poly(LC), a set of molecularly precise oligo(ethanamino)amides were synthesized comprising poly(ethylene glycol) conjugated MTX ligands. The conjugates differed in the number of additional glutamic acid residues to investigate the effect of different degrees of synthetic "a priori" polyglutamylation. The bioactivity of these compounds concerning dihydrofolate reductase (DHFR) inhibition, cytotoxicity, nucleic acid binding potency, cellular uptake of poly(LC) polyplexes, and combined antifolate/poly(LC) toxicity was investigated. Synthetic polyglutamylation had a crucial impact on several stages of efficient poly(LC) delivery and combined MTX cytotoxicity. DHFR inhibition of the conjugates significantly increased with increasing polyglutamate chain length. The library member with highest glutamylation degree even outperformed free MTX in direct comparison. Studies in KB cells showed the corresponding enhanced cytotoidcity by polyglutamylation. Also poly(LC) polyplexes of the glutamylated MTX variants exhibited higher cellular uptake in the folate receptor positive cell line. Finally, a synergistic combined cytotoxicity of polyglutamylated MTX ligands and complexed poly(LC) cargo was observed in transfected KB cells. The present structure activity relationship study of MTX-based ligands pinpoints the concept of synthetic polyglutamylation as a promising approach for optimizing bioactivity of antifolate conjugates, which might be considered as a useful tool also in context of other drug delivery systems.